
[Federal Register: November 28, 2008 (Volume 73, Number 230)]
[Proposed Rules]               
[Page 72561-72614]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr28no08-29]                         


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Part II





Environmental Protection Agency





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40 CFR Part 450



Effluent Limitations Guidelines and Standards for the Construction and 
Development Point Source Category; Proposed Rule


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 450

[EPA-HQ-OW-2008-0465; FRL-8744-1]
RIN 2040-AE91

 
Effluent Limitations Guidelines and Standards for the 
Construction and Development Point Source Category

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency is proposing a regulation 
that would strengthen the existing regulatory program for discharges 
from construction sites by establishing technology-based Effluent 
Limitations Guidelines and New Source Performance Standards for the 
Construction and Development (C&D) point source category. This 
proposal, if implemented, would significantly reduce the amount of 
sediment and other pollutants discharged from construction sites. EPA 
estimates that this proposed rule would cost $1.9 billion dollars per 
year with annual monetized benefits of $332.9 million. This proposed 
rule requests comment and information on the proposed regulation and an 
alternate option with a different numeric limit based on different 
technologies, as well as specific aspects of the proposal such as 
technologies, costs, loading reductions, and economic achievability.

DATES: Comments must be received on or before February 26, 2009.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2008-0465, by one of the following methods:
     http://www.regulations.gov: This is EPA's preferred 
approach, although you may use the alternatives presented below. Follow 
the on-line instructions for submitting comments.
     E-mail: OW-Docket@epa.gov.
     Mail: USEPA Docket Center, Environmental Protection 
Agency, Docket Number EPA-HQ-OW-2008-0465, Mailcode 2822T, 1200 
Pennsylvania Ave., NW., Washington, DC 20460.
     Hand Delivery: USEPA Docket Center, Public Reading Room, 
1301 Constitution Ave., NW., Room 3334, EPA West Building, Washington 
DC 20004. Such deliveries are only accepted during the Docket's normal 
hours of operation, and special arrangements should be made for 
deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OW-2008-
0465. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through http://
www.regulations.gov or e-mail. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through http://www.regulations.gov, your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/
epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the USEPA Docket 
Center, Public Reading Room, Room 3334, EPA West Building, 1301 
Constitution Ave., NW., Washington DC. The Public Reading Room is open 
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The telephone number for the Public Reading Room is (202) 
566-1744, and the telephone number for the EPA Docket Center is (202) 
566-2426. Please note that several of the support documents are 
available at no charge on EPA's Web site; see Supporting Documentation 
below.

FOR FURTHER INFORMATION CONTACT: For technical information concerning 
today's proposed rule, contact Mr. Jesse W. Pritts at 202-566-1038 
(pritts.jesse@epa.gov). For economic information contact Mr. Todd Doley 
at 202-566-1160 (doley.todd@epa.gov).

SUPPLEMENTARY INFORMATION:

Regulated Entities

    Entities potentially regulated by this action include:

------------------------------------------------------------------------
                                                         North American
                                                            Industry
          Category             Examples of regulated     Classification
                                      entities           System (NAICS)
                                                              code
------------------------------------------------------------------------
Industry                      Construction activities required to obtain
                                NPDES permit coverage and performing the
                                         following activities:
                             -------------------------------------------
                                Construction of                      236
                                 buildings, including
                                 building, developing
                                 and general
                                 contracting.
                                Heavy and civil                      237
                                 engineering
                                 construction,
                                 including land
                                 subdivision.
------------------------------------------------------------------------

    EPA does not intend the preceding table to be exhaustive, but 
provides it as a guide for readers regarding entities likely to be 
regulated by this action. This table lists the types of entities that 
EPA is now aware could potentially be regulated by this action. Other 
types of entities not listed in the table could also be regulated. To 
determine whether your facility is regulated by this action, you should 
carefully examine the applicability criteria in Sec.  450.10 of today's 
proposed rule and the definition of ``construction activity'' and 
``small construction activity'' in existing EPA regulations at 40 CFR 
122.26(b)(14)(x) and 122.26(b)(15), respectively. If you have questions 
regarding the

[[Page 72563]]

applicability of this action to a particular entity, consult one of the 
persons listed for technical information in the preceding FOR FURTHER 
INFORMATION CONTACT section.

Supporting Documentation

    Several key documents support the proposed regulation:
    1. ``Development Document for Proposed Effluent Guidelines and 
Standards for the Construction and Development Category,'' EPA-821-R-
08-007. (``Development Document'') This document presents EPA's 
methodology and technical conclusions concerning the C&D category.
    2. ``Economic Analysis for Proposed Effluent Guidelines and 
Standards for the Construction and Development Category,'' EPA-821-R-
08-008. (``Economic Analysis'') This document presents the methodology 
employed to assess economic impacts of the proposed rule and the 
results of the analysis.
    3. ``Environmental Impact and Benefits Assessment for Proposed 
Effluent Guidelines and Standards for the Construction and Development 
Category,'' EPA-821-R-08-009 (``Environmental Assessment''). This 
document presents the methodology to assess environmental impacts and 
benefits of the proposed rule and the results of the analysis.
    Major supporting documents are available in hard copy from the 
National Service Center for Environmental Publications (NSCEP), U.S. 
EPA/NSCEP, P.O. Box 42419, Cincinnati, Ohio, USA 45242-2419, telephone 
800-490-9198, http://www.epa.gov/ncepihom/. You can obtain electronic 
copies of this preamble and proposed rule as well as the technical and 
economic support documents for today's proposal at EPA's Web site for 
the C&D rule, http://www.epa.gov/waterscience/guide/construction.

Overview

    This preamble describes the terms, acronyms, and abbreviations used 
in this document; the background documents that support these proposed 
regulations; the legal authority of this proposed rule; a summary of 
the proposal; background information; and the technical and economic 
methodologies used by the Agency to develop this proposed regulation. 
While EPA solicits comments on this entire proposal, EPA emphasizes 
specific areas of interest where we would particularly like comments, 
information and data.

Table of Contents

I. Legal Authority
II. Purpose & Summary of the Proposed Rule
III. Background on Existing Regulatory Program
    A. Clean Water Act
    B. NPDES Stormwater Permit Program
    C. Other State and Local Stormwater Requirements
    D. Technology-Based Effluent Limitations Guidelines and 
Standards
IV. Scope of the Proposal
V. Overview of the Construction and Development Industry and 
Construction Activities
VI. Summary of Data Collection Activities
    A. State Data
    B. National Land Cover Dataset (NLCD)
    C. Enhanced River Reach File 1.2 (ERF1)
    D. NPDES Notice of Intent (NOI) Data
    E. Soils Data
    F. NOAA Rainfall Data
    G. Parameter Elevation Regressions on Independent Slopes Model 
(PRISM)
    H. Revised Universal Soil Loss Equation (RUSLE) R Factors
    I. Economic Data
VII. Characteristics of Discharges From Construction Activity
VIII. Description of Available Technologies
    A. Introduction
    B. Erosion Control Measures
    C. Sediment Control Measures
    D. Other Construction and Development Site Management Practices
IX. Development of Effluent Limitations Guidelines and Standards
    A. Description of the Regulatory Options Considered
    B. Effluent Limitations Included in All Regulatory Options
    C. Options for BPT, BCT, BAT and NSPS
    D. Option Selection Rationale for BPT
    E. Option Selection Rationale for BAT and NSPS
    F. Option Selection Rationale for BCT
X. Methodology for Estimating Costs to the Construction and 
Development Industry
XI. Economic Impact and Social Cost Analysis
    A. Introduction
    B. Description of Economic Activity
    C. Method for Estimating Economic Impacts
    D. Results
XII. Cost-Effectiveness Analysis
XIII. Non Water-Quality Environmental Impacts
    A. Air Pollution
    B. Solid Waste Generation
    C. Energy Usage
XIV. Environmental Assessment
    A. Introduction
    B. Methodology for Estimating Environmental Impacts and 
Pollutant Reductions
XV. Benefit Analysis
    A. Benefits Categories Estimated
    B. Quantification of Benefits
XVI. Monetized Benefit-Cost Comparison
XVII. Approach to Determining Long-Term Averages, Variability 
Factors, and Effluent Limitations and Standards
    A. Definitions
    B. Data Selection
    C. Statistical Percentile Basis for Limitations
    D. Daily Maximum Limitations
    E. Engineering Review of Limitations
    F. Monthly Average Limitations
XVIII. Regulatory Implementation
    A. Relationship of Effluent Guidelines to NPDES Permits and ELG 
Compliance Dates
    B. Upset and Bypass Provisions
    C. Variances and Waivers
    D. Other Clean Water Act Requirements
XIX. Related Acts of Congress, Executive Orders, and Agency 
Initiatives
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175 (Consultation and Coordination With 
Indian Tribal Governments)
    G. Executive Order 13045: Protection of Children from 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211 (Energy Effects)
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations.
XX. Solicitation of Data and Comments
    A. General Solicitation of Comment
    B. Specific Solicitation of Comments and Data
    C. Guidelines for Submission of Analytical Data

I. Legal Authority

    EPA is proposing this regulation under the authorities of sections 
301, 304, 306, 308, 402, 501 and 510 of the Clean Water Act (CWA), 33 
U.S.C. 1311, 1314, 1316, 1318, 1342, 1361 and 1370 and pursuant to the 
Pollution Prevention Act of 1990, 42 U.S.C. 13101 et seq.

II. Purpose & Summary of the Proposed Rule

    Despite substantial improvements in the nation's water quality 
since the inception of the Clean Water Act, 45 percent of assessed 
river and stream miles, 47 percent of assessed lake acres, and 32 
percent of assessed square miles of estuaries show impairments from a 
wide range of sources. Improper control of stormwater discharges from 
construction activity is among the many contributors of sediment which 
is one of the major remaining water quality problems throughout the 
United States. Sediment is the leading cause of water quality 
impairment for streams and rivers. It is also one of the leading causes 
of lake and reservoir water quality impairment and wetland degradation. 
Turbidity and suspended solids are also major sources of water quality 
impairment nationwide. Turbidity or suspended solids impair 695,133 
miles of streams nationwide. In

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addition, 376,832 acres of lakes and reservoirs have been documented as 
impaired by turbidity or suspended solids nationwide. The sediment and 
turbidity entrained in stormwater discharges from construction activity 
contributes to harm in aquatic ecosystems, increases drinking water 
treatment costs, and contributes to impairment to recreational uses of 
impacted waters. Sediment can also accumulate in rivers, lakes, and 
reservoirs, leading to the need for dredging or other mitigation.
    Construction activity typically involves site selection and 
planning, and land-disturbing tasks such as clearing, excavating and 
grading. Disturbed soil, if not managed properly, can be easily washed 
off-site during storm events. Stormwater discharges generated during 
construction activities can cause an array of physical, chemical and 
biological impacts. Sediment discharges can cause an array of physical 
and biological impacts on receiving waters. In addition to sediment, a 
number of other pollutants (e.g., metals and nutrients) are 
preferentially absorbed or adsorbed onto mineral or organic particles 
found in fine sediment. These pollutants can cause an array of chemical 
and biological water quality impairments. The interconnected processes 
of erosion (i.e., detachment of soil particles by water), sediment 
transport, and delivery to receiving waters are the primary pathways 
for the addition of pollutants from construction and development (C&D) 
sites into aquatic systems.
    A primary concern at most C&D sites is the erosion and transport 
process related to fine sediment because rain splash, rills (small 
channels typically less than one foot deep) and sheetwash (thin sheets 
of water flowing across a surface) encourage the detachment and 
transport of sediment to water bodies. Although streams and rivers 
naturally carry sediment loads, discharges from construction activity 
can elevate these loads to levels above those in undisturbed 
watersheds.
    Existing national stormwater regulations at 40 CFR 122.26 require 
permittees to implement control measures to manage discharges 
associated with construction activity. Today's proposal would establish 
a technology-based ``floor'' or minimum requirements on a national 
basis. This rule would constitute the nationally applicable, 
technology-based effluent limitations guidelines (ELGs) and new source 
performance standards (NSPS) (referred to collectively in this notice 
as ``ELGs'' or ``effluent limitations guidelines,'' unless specifically 
referencing NSPS), applicable to all dischargers currently required to 
obtain a National Pollutant Discharge Elimination System (NPDES) permit 
pursuant to 40 CFR 122.26(b)(14)(x) and 122.26(b)(15). The proposed 
ELGs would require stormwater discharges from certain C&D sites to meet 
effluent limitations designed to reduce the amount of sediment, 
turbidity, Total Suspended Solids (TSS) and other pollutants in 
stormwater discharges from the site. EPA acknowledges that many state 
and local governments have existing effluent limitations and standards 
for controlling stormwater and wastewater discharges from construction 
sites. Today's proposed ELGs are intended to work in concert with these 
existing state and local programs. Today's proposed regulation would 
establish a numeric effluent limit for turbidity in discharges from 
some C&D sites. EPA envisions these turbidity effluent limits as 
requiring an additional layer of management practices and/or treatment 
above what most state and local programs are currently requiring. 
Permitting authorities would be required to incorporate these turbidity 
limitations into their permits and permittees would be required to 
implement control measures to meet a numeric turbidity limit in 
discharges of stormwater from their C&D sites. EPA is not dictating 
that a specific technology be used to meet the numeric limit, but is 
specifying the maximum turbidity level that can be present in 
discharges from C&D sites. However, EPA's proposed limits are based on 
its assessment of what specific technologies can reliably achieve. 
Permittees would have the flexibility to select management practices 
that are best suited to site-specific conditions present on each 
individual C&D site if they are able to consistently meet the limits.

III. Background on Existing Regulatory Program

A. Clean Water Act

    Congress passed the Federal Water Pollution Control Act of 1972 
(Pub. L. 92-500, October 18, 1972) (hereinafter the Clean Water Act or 
CWA), 33 U.S.C. 1251 et seq., with the stated objectives to ``restore 
and maintain the chemical, physical, and biological integrity of the 
Nation's waters.'' Section 101(a), 33 U.S.C. 1251(a). To achieve this 
goal, the CWA provides that ``the discharge of any pollutant by any 
person shall be unlawful'' except in compliance with other provisions 
of the statute. CWA section 301(a). U.S.C. 1311. The CWA defines 
``discharge of a pollutant'' broadly to include ``any addition of any 
pollutant to navigable waters from any point source.'' CWA section 
502(12). 33 U.S.C. 1362(12). EPA is authorized under CWA section 402(a) 
to issue a National Pollutant Discharge Elimination System (NPDES) 
permit for the discharge of any pollutant from a point source 
notwithstanding Section 301(a). These NPDES permits are issued by EPA 
regional offices or NPDES authorized state or tribal agencies. Since 
1972, EPA and the states have issued NPDES permits to thousands of 
dischargers, both industrial (e.g., manufacturing, energy and mining 
facilities) and municipal (e.g., sewage treatment plants). As required 
under Title III of the CWA, EPA has promulgated ELGs and standards for 
many industrial point source categories, and these requirements are 
incorporated into the permits.
    The Water Quality Act of 1987 (Pub. L. 100-4, February 4, 1987) 
amended the CWA, adding CWA section 402(p) to require implementation of 
a comprehensive program for addressing stormwater discharges. 33 U.S.C. 
1342(p). The NPDES program was expanded by requiring EPA or NPDES 
authorized states or tribes to issue NPDES permits for stormwater 
discharges listed under Section 402(p)(2), which include municipal and 
industrial stormwater discharges. Industrial stormwater dischargers, 
municipal separate storm sewer systems and other stormwater dischargers 
designated by EPA must obtain NPDES permits pursuant to CWA section 
402(p). Stormwater discharges associated with industrial activity must 
meet all applicable provisions of CWA sections 301 and 402, including 
meeting technology-based effluent limitations.

B. NPDES Stormwater Permit Program

    EPA's Phase I stormwater regulations promulgated in 1990 identified 
stormwater discharges associated with construction activity as one of 
several types of industrial activity requiring an NPDES permit. 
Dischargers must apply for and obtain authorization to discharge (or 
``permit coverage'') (40 CFR 122.26(b)(14)(x) and (c)(1)). As described 
in the Phase I regulations, a permit is required for discharges 
associated with construction activity, including clearing, grading, and 
excavation, if the construction activity:
     Will disturb five acres or greater; or
     Will disturb less than five acres but is part of a larger 
common plan of development or sale whose total land disturbing 
activities total five acres or greater.


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EPA defines these ``large'' construction sites as one of the eleven 
categories of stormwater dischargers associated with industrial 
activity. (See 40 CFR 122.26(b)(14)).
    The Phase II stormwater regulations, promulgated in 1999, extended 
permit coverage to construction activity that results in land 
disturbance of one acre or greater (40 CFR 122.26(b)(15)), including 
sites less than one acre that are part of a larger common plan of 
development or sale whose total land disturbing activities total more 
than an acre. EPA's NPDES regulations define these sites, i.e., sites 
disturbing between one and five acres, as ``small'' construction sites.
    In addition to requiring permits for discharges associated with 
construction activity, the NPDES regulations require permits for 
certain municipal separate storm sewer systems (MS4s). Operators of 
these MS4s, typically local governments, must develop and implement a 
stormwater management program, including a requirement to address 
stormwater discharges from construction activity. More details on the 
requirements of MS4 programs are described in section III.B.2.
1. Stormwater Permits for Construction Activity
    The NPDES regulations provide two options for obtaining 
authorization to discharge or ``permit coverage'': General permits and 
individual permits. A brief description of these types of permits as 
they apply to construction sites follows.
a. General NPDES Permits
    The vast majority of discharges from construction activity are 
covered under NPDES general permits. EPA, states and tribes use general 
permits to cover a group of similar dischargers under one permit. See 
40 CFR 122.28. General permits simplify the process for dischargers to 
obtain authorization to discharge, provide permit requirements for any 
discharger that files a notice of intent to be covered, and reduce the 
administrative workload for NPDES permitting authorities. General 
permits, including a fact sheet describing the rationale for permit 
conditions, are issued by NPDES permitting authorities through public 
notice. Typically, to obtain authorization to discharge under a 
construction general permit, a discharger (typically, a developer, 
builder, or contractor) submits to the permitting authority a Notice of 
Intent (NOI) to be covered under the general permit. By submitting the 
NOI, the discharger acknowledges that it is eligible for coverage under 
the general permit and agrees to the conditions in the published 
general permit. Discharges from the construction activity are 
authorized consistent with the terms and conditions established in the 
general permit.
    EPA regulations allow NPDES permitting authorities to regulate 
discharges from small C&D sites under a general permit without the 
discharger submitting an NOI if the permitting authority determines an 
NOI is inappropriate and the general permit includes language 
acknowledging that an NOI is unnecessary (40 CFR 122.28(b)(2)(v)). To 
implement such a requirement, the permitting authority must specify in 
the public notice of the general permit any reasons why an NOI is not 
required. In these instances, any stormwater discharges associated with 
small construction activity are automatically covered under an 
applicable general permit and the discharger is required to comply with 
the terms, conditions and effluent limitations of such permit.
    Similarly, EPA, states and tribes have the authority to notify a 
C&D site operator that it is covered by a general permit, even if that 
operator has not submitted an NOI (40 CFR 122.28(b)(2)(vi)). In these 
instances, the operator is given the opportunity to request coverage 
under an individual permit. Individual permits are discussed in section 
III.B.1.d.
b. EPA Construction General Permit
    Since 1992, EPA has issued a series of ``national'' Construction 
General Permits (CGP) that cover areas where EPA is the NPDES 
permitting authority. At present, EPA is the permitting authority in 
five states (Alaska, Idaho, Massachusetts, New Hampshire, and New 
Mexico), the District of Columbia, Puerto Rico, all other U.S. 
territories with the exception of the Virgin Islands, federal 
facilities in four states (Colorado, Delaware, Vermont, and 
Washington), most Indian lands and a couple of other specifically 
designated activities in specific states (e.g., oil and gas activities 
in Texas and Oklahoma). EPA issued a final ``national'' CGP on July 1, 
2003 (63 FR 7898), modified on November 22, 2004 (changes effective 
January 21, 2005). EPA's current CGP became effective on June 30, 2008 
(see 74 FR 40338). Following promulgation of the effluent limitations 
guidelines, EPA will issue a revised CGP incorporating the new ELGs.
    The key component of EPA's CGP is the requirement to minimize 
discharges of pollutants in stormwater discharges using control 
measures that reflect best engineering practices. Dischargers must 
minimize their discharge of pollutants in stormwater using appropriate 
erosion and sediment control ``best management practices'' (BMPs) and 
control measures for other pollutants such as litter, construction 
debris, and construction chemicals that could be exposed to stormwater 
and other wastewater. The 2008 CGP requires dischargers to develop and 
implement a stormwater pollution prevention plan (SWPPP) to document 
the steps they will take to comply with the terms, conditions and 
effluent limitations of the permit. EPA's guidance manual, ``Developing 
Your Stormwater Pollution Prevention Plan: A Guide for Construction 
Sites,'' (EPA 833/R-060-04, May 2007; available on EPA's Web site at 
http://www.epa.gov/npdes/stormwater) describes the SWPPP process in 
detail. As detailed in EPA's CGP, the SWPPP must include a description 
of the C&D site with maps showing drainage patterns, discharge points, 
and locations of runoff controls; a description of the control measures 
used; and inspection procedures. A copy of the SWPPP must be kept on 
the construction site from the date of project initiation to the date 
of final stabilization. The CGP does not require permittees to submit a 
SWPPP to the permitting authority; however a copy must be readily 
available to authorized inspectors during normal business hours.
    Other requirements in the CGP include conducting regular 
inspections and reporting releases of reportable quantities of 
hazardous substances.
    To discontinue permit coverage, a discharger must either complete 
final stabilization of the site, transfer responsibility to another 
party (e.g., a developer transferring land to a home builder), or for a 
residential property, complete temporary stabilization and transfer the 
property to the homeowner. The permittee submits a Notice of 
Termination (NOT) Form to the permitting authority upon satisfying the 
appropriate permit termination conditions described in the CGP.
c. State Construction General Permits
    Whether EPA, a state or a tribe issues the general permit, the CWA 
requires that NPDES permits must include technology-based effluent 
limitations. In addition, where technology-based effluent limitations 
are insufficient for the discharge to meet applicable water quality 
standards, the permit must contain water quality-based effluent 
limitations as necessary to meet those standards. See sections 301, 
304, 303, 306, and 402 of the CWA. PUD No. 1 of Jefferson County v. 
Washington Department of Ecology, 511 U.S. 700, 704-705 (1994).

[[Page 72566]]

    For the most part, state-issued general permits for stormwater 
discharges from construction activity have followed EPA's CGP format 
and content, starting with EPA's first CGP issued in 1992 (57 FR 41176; 
September 9, 1992). Over time, some states have changed components of 
their permits to better address the specific conditions encountered at 
construction sites within their jurisdiction (e.g., soil types, 
topographic or climatic characteristics, or other relevant factors). 
For example, Washington, Oregon and Vermont's CGPs include turbidity 
action levels and discharge monitoring requirements for C&D sites 
applicable to all or a subset of construction sites.
d. Individual NPDES Permits
    A permitting authority may require any C&D site to apply for an 
individual permit rather than using the general permit. Likewise, any 
discharger may request to be covered under an individual permit rather 
than seek coverage under an otherwise applicable general permit (40 CFR 
122.28(b)(3)). Unlike a general permit, an individual permit is 
intended to be issued to one permittee, or a few co-permittees. 
Individual permits for stormwater discharges from construction sites 
are rarely used, but when done so, are most often used for very large 
projects or projects located in sensitive watersheds. EPA estimates 
that fewer than one half of one percent (< 0.5%) of all construction 
sites are covered under individual permits.
2. Municipal Stormwater Permits and Local Government Regulation of 
Stormwater Discharges Associated With Construction Activity
    Many local governments, as MS4 permittees, have a role to play in 
the regulation of construction activities. This section provides an 
overview of MS4 responsibilities associated with controlling stormwater 
discharges from construction activity.
a. NPDES Requirements
    A municipal separate storm sewer system (MS4) is a conveyance or 
system of conveyances designed or used for collecting or conveying 
stormwater. These systems are not combined sewers and not part of a 
Publicly Owned Treatment Works (POTW). See 40 CFR 122.26(b)(8). A 
municipal separate storm sewer system (MS4) is all large, medium, and 
small municipal storm sewers or those designated as such under the 
regulations. See 40 CFR 122.26(b)) (18). The NPDES stormwater 
regulations require many MS4s to apply for permits. In general, the 
1990 Phase I rule requires MS4s serving populations of 100,000 or more 
to obtain coverage under an MS4 individual permit. See 40 CFR 
122.26(a)(3). The 1999 Phase II rule requires most small MS4s located 
in urbanized areas also to obtain coverage. See 40 CFR 122.33. The 
Phase II regulations also provide permitting authorities with the 
authority to designate any additional MS4s located outside of urbanized 
areas for permit coverage where the permitting authority determines 
that storm water controls are needed for the discharge based on 
wasteload allocations that are part of total maximum daily loads that 
address pollutants of concern or the permitting authority or the EPA 
Regional Administrator determines that the discharge, or category of 
discharges within a geographic area, contributes to a violation of a 
water quality standard or is a significant contributor of pollutants to 
waters of the United States. 40 CFR 122.26(9)(i)(C) and (D). Regardless 
of the type of permit, MS4s are required to develop stormwater 
management programs that detail the procedures they will use to control 
discharges of pollutants in stormwater from the MS4.
    Both the Phase I and II rules require regulated municipalities to 
develop comprehensive stormwater management programs which include, 
among other elements, the regulation of discharges from construction 
sites. The Phase I regulations require medium and large MS4s to 
implement and maintain a program to reduce pollutants in stormwater 
runoff from construction sites, including procedures for site planning, 
requirements for structural and non-structural BMPs, procedures for 
identifying priorities for inspecting sites and enforcing control 
measures, and development and dissemination of appropriate educational 
and training materials. In general, the Phase II regulations require 
small MS4s to develop, implement, and enforce a program to control 
pollutants in stormwater runoff from construction activities which 
includes developing an ordinance to require implementation of erosion 
and sediment control practices, to control waste and to have procedures 
for site plan review and site inspections. Thus, as described above, 
both the Phase I and Phase II regulations specifically anticipate a 
local program for regulating stormwater discharges from construction 
activity. See 40 CFR 122.26(d)(2)(iv)(D) for Phase I MS4s and 40 CFR 
122.34(b)(4) for Phase II MS4s. EPA has provided many guidance 
materials to the NPDES permitting authorities and MS4s that recommend 
components and activities for a well-operated local stormwater 
management program.
    EPA promulgated two provisions intended to minimize potential 
duplication of requirements or inconsistencies between requirements. 
First, 40 CFR 122.35 provides that a small MS4 is allowed to rely on 
another entity to satisfy its NPDES permit obligations, including 
construction site control, provided the other entity implements a 
program that is at least as stringent as the corresponding NPDES permit 
requirements and the other entity agrees to implement the control 
measures on the small MS4's behalf. Thus, for example, where a county 
implements a construction site stormwater control program already, and 
that program is at least as stringent as the controls required by a 
small MS4's NPDES permit, the MS4 may reference that program in the 
Notice of Intent to be covered by a general permit, or in its permit 
application, rather than developing and implementing a new program to 
require control of construction site stormwater within its 
jurisdiction.
    Similarly, EPA or the state permitting authority may substitute 
certain aspects of the requirements of the EPA or state permit by 
incorporating by reference the requirements of a ``qualifying local 
program'' in the EPA or state CGP. A ``qualifying local program'' is an 
existing sediment and erosion control program that meets the minimum 
requirements as established in 40 CFR 122.44(s). By incorporating a 
qualifying local, state or tribal program into the EPA or state CGP, 
construction sites covered by the qualifying program in that 
jurisdiction would simply follow the incorporated local requirements in 
order to meet the corresponding requirements of the EPA or state CGP.
b. EPA Guidance to Municipalities
    EPA developed several guidance documents for municipalities to 
implement the NPDES Phase II rule.
     National Menu of BMPs (http://www.epa.gov/npdes/
menuofbmps/menu.htm). This document provides guidance to regulated MS4s 
as to the types of practices they could use to develop and implement 
their stormwater management programs. The menu includes descriptions of 
practices that local programs can implement to reduce impacts of 
stormwater discharges from construction activities.
     Measurable Goals Guidance for Phase II MS4s (http://
www.epa.gov/npdes/stormwater/measurablegoals). This document assists 
small MS4s in defining performance targets and

[[Page 72567]]

includes examples of goals for practices to control stormwater 
discharges from construction activities.
     Storm Water Phase II Compliance Assistance Guide (EPA 833-
R-00-002, March 2000, http://cfpub.epa.gov/npdes/stormwater/
smms4.cfm?program_id=6). The guide provides an overview of compliance 
responsibilities for MS4s, small construction sites, and certain other 
industrial stormwater discharges affected by the Phase II rule.
     Fact Sheets on various stormwater control technologies, 
including hydrodynamic separators (EPA 832-F-99-017), infiltrative 
practices (EPA 832-F-99-018 and EPA 832-F-99-019), modular treatment 
systems (EPA 832-F-99-044), porous pavement (EPA 832-F-99-023), sand 
filters (EPA 832-F-99-007), turf reinforcement mats (EPA 832-F-99-002), 
vegetative covers (EPA 832-F-99-027), swales (EPA 832-F-99-006) and wet 
detention ponds (EPA 832-F-99-048). (Available at http://www.epa.gov/
npdes/stormwater/; click on ``Publications.'')

C. Other State and Local Stormwater Requirements

    States and municipalities may have other requirements for flood 
control, erosion and sediment control, and in many cases, stormwater 
management. Many of these provisions were enacted before the 
promulgation of the EPA Phase I stormwater rule although many have been 
updated since. An EPA analysis found that all states have laws for 
erosion and sediment control measures, with these laws implemented by 
state, county, or local governments. A summary of existing state 
requirements is provided in the Development Document.

D. Technology-Based Effluent Limitations Guidelines and Standards

    Effluent limitation guidelines and new source performance standards 
are technology-based effluent limitations required by CWA sections 301 
and 306 for categories or subcategories of point source dischargers. 
These limitations, which can be either numeric or non-numeric, along 
with water quality-based effluent limitations, if necessary, are 
incorporated into NPDES permits. ELGs and NSPS are based on the degree 
of control that can be achieved using various levels of pollutant 
control technology, as defined in Title III of the CWA and outlined 
below.
1. Best Practicable Control Technology Currently Available (BPT)
    In establishing effluent guidelines for a point source category, 
the CWA requires EPA to specify BPT effluent limits for conventional, 
toxic, and nonconventional pollutants. In doing so, EPA is required to 
determine what level of control is technologically available and 
economically practicable. CWA section 301(b)(1)(A). In specifying BPT, 
the CWA requires EPA to look at a number of factors. EPA considers the 
cost of achieving effluent reductions in relation to the effluent 
reduction benefits. The Agency also considers the age of the equipment 
and facilities, the processes employed and any required process 
changes, engineering aspects of the control technologies, non-water 
quality environmental impacts (including energy requirements), and such 
other factors as the Administrator deems appropriate. CWA section 
304(b)(1)(B). Traditionally, EPA establishes BPT effluent limitations 
based on the average of the best performance of facilities within the 
category of various ages, sizes, processes or other common 
characteristics. Where existing performance is uniformly inadequate, 
EPA may require higher levels of control than currently in place in a 
category if the Agency determines that the technology can be 
practicably applied. See e.g., American Frozen Foods Inst. v. Train, 
539 F.2d 107, 117 (D.C. Cir. 1976).
    EPA assesses cost-reasonableness of BPT limitations by considering 
the cost of treatment technologies in relation to the effluent 
reduction benefits achieved. This inquiry does not limit EPA's broad 
discretion to adopt BPT limitations that are achievable with available 
technology unless the required additional reductions are ``wholly out 
of proportion to the costs of achieving such marginal level of 
reduction.'' Moreover, the inquiry does not require the Agency to 
quantify benefits in monetary terms. See, e.g., American Iron and Steel 
Institute v. EPA, 526 F. 2d 1027, 1051 (3rd Cir. 1975).
    In balancing costs against the effluent reduction, EPA considers 
the volume and nature of expected discharges after application of BPT, 
the general environmental effects of pollutants, and the cost and 
economic impacts of the required level of pollution control. In past 
effluent limitation guidelines, BPT cost-reasonableness comparisons 
ranged from $0.26 to $41.44 per pound removed in year 2008 dollars. 
This range is not inclusive of all categories regulated by BPT, but 
nonetheless represents a very broad range of cost-reasonableness 
values. About half of the cost-reasonableness values represented by 
this range are less than $2.50 per pound (in 2001 dollars). In 
developing guidelines, the Act does not require consideration of water 
quality problems attributable to particular point sources, nor does it 
require consideration of water quality improvements in particular 
bodies of water. See American Frozen Foods Inst. v. Train, 539 F.2d 
107, 117 (D.C. Cir. 1976); Weyerhaeuser Company v. Costle, 590 F. 2d 
1011, 1036, 1041-44 (D.C. Cir. 1978).
2. Best Available Technology Economically Achievable (BAT)
    BAT effluent guidelines are applicable to toxic (priority) and 
nonconventional pollutants. EPA has identified 65 pollutants and 
classes of pollutants as toxic pollutants, of which 126 specific 
substances have been designated priority toxic pollutants. 40 CFR 
401.15 and 40 CFR part 423, Appendix A. In general, BAT represents the 
best available performance of direct discharging facilities in the 
subcategory or category. CWA section 304(b)(2)(A). The factors 
considered in assessing BAT include the cost of achieving BAT effluent 
reductions, the age of equipment and facilities involved, the processes 
employed, engineering aspects of the control technology, potential 
process changes, non-water quality environmental impacts (including 
energy requirements), and such factors as the Administrator deems 
appropriate. CWA section 304(b)(2). The Agency retains considerable 
discretion in assigning the weight to be accorded to these factors. 
Natural Resources Defense Council v. EPA, 863 F.2d 1420, 1426 (9th Cir. 
1988). An additional statutory factor considered in setting BAT is 
``economic achievability.'' EPA may determine the economic 
achievability of an option on the basis of the total cost to the 
subcategory and the overall effect of the rule on the industry's 
financial health. The Agency may base BAT limitations upon effluent 
reductions attainable through changes in a facility's processes and 
operations. See Texas Oil & Gas Ass'n v. EPA, 161 F.3d 923, 928 (5th 
Cir. 1998) (citing ``process changes'' as one factor EPA must consider 
in determining BAT); see also, American Meat Institute v. EPA, 526 F.2d 
442, 464 (7th Cir. 1975). As with BPT, where existing performance is 
uniformly inadequate, EPA may base BAT upon technology transferred from 
a different subcategory or from another category. See CPC International 
Inc. v. Train, 515 F.2d 1032, 1048 (8th Cir. 1975) (established 
criteria EPA must consider in determining whether technology from one 
industry can be applied to another); see also, Tanners' Council of 
America, Inc. v. Train, 540 F.2d 1188 (4th Cir. 1976). In addition,

[[Page 72568]]

the Agency may base BAT upon manufacturing process changes or internal 
controls, even when these technologies are not common industry 
practice. See American Frozen Foods Inst. v. Train, 539 F.2d 107, 132 
(D.C. Cir. 1976).
3. Best Conventional Pollutant Control Technology (BCT)
    The 1977 amendments to the CWA required EPA to identify effluent 
reduction levels for conventional pollutants associated with BCT 
technology for discharges from existing point sources. BCT is not an 
additional limitation, but replaces Best Available Technology (BAT) for 
control of conventional pollutants. In addition to other factors 
specified in CWA section 304(b)(4)(B), the Act requires that EPA 
establish BCT limitations after consideration of a two-part ``cost-
reasonableness'' test. EPA explained its methodology for the 
development of BCT limitations in July 1986 (51 FR 24974).
    Section 304(a)(4) designates the following as conventional 
pollutants: Biochemical oxygen demand (BOD5), total suspended solids 
(TSS), fecal coliform, pH, and any additional pollutants defined by the 
Administrator as conventional. 40 CFR 401.16. The Administrator 
designated oil and grease as an additional conventional pollutant on 
July 30, 1979 (44 FR 44501).
4. New Source Performance Standards (NSPS)
    NSPS reflect effluent reductions that are achievable based on the 
best available demonstrated control technology. New sources, as defined 
in CWA section 306, have the opportunity to install the best and most 
efficient production processes and wastewater treatment technologies. 
As a result, NSPS should represent the greatest degree of effluent 
reduction attainable through the application of the best available 
demonstrated control technology for all pollutants (i.e., conventional, 
nonconventional, and priority pollutants). In establishing NSPS, CWA 
section 306 directs EPA to take into consideration the cost of 
achieving the effluent reduction and any non-water quality 
environmental impacts and energy requirements.
5. Pretreatment Standards
    The CWA also defines standards for indirect discharges, i.e., 
discharges into publicly owned treatment works (POTWs). These standards 
are known as Pretreatment Standards for Existing Sources (PSES) and 
Pretreatment Standards for New Sources (PSNS), and are promulgated 
under CWA section 307(b). EPA has no data indicating that construction 
sites typically discharge directly to POTWs. Therefore, EPA is not 
proposing PSES or PSNS for the C&D category. EPA determined that the 
majority of construction sites discharge either directly to waters of 
the U.S. or through MS4s. In some urban areas, construction sites may 
discharge to combined sewer systems (i.e., sewers carrying both 
stormwater and domestic sewage through a single pipe) which lead to 
POTWs. Sediment and turbidity, which are the primary pollutants 
associated with construction site discharges, are susceptible to 
treatment in POTWs, using technologies commonly employed such as 
primary clarification. EPA has no evidence that construction site 
discharges to POTWs would cause interference, pollutant pass-through or 
sludge contamination.
6. EPA Authority to Promulgate Non-Numeric Effluent Limitations
    The regulatory options proposed today include non-numeric effluent 
limitations that will control the discharge of pollutants from C&D 
sites. It is well established that EPA has the authority to promulgate 
non-numeric effluent limitations in addition to or in lieu of numeric 
limits. The CWA does not mandate the use of numeric limitations only 
and EPA's position finds support in the language of the CWA. The 
definition of ``effluent limitation'' means ``any restriction * * * on 
quantities, rates, and concentrations of chemical, physical, 
biological, and other constituents * * *'' CWA section 502(11).
    Federal courts have recognized the CWA does not mandate that EPA 
use numeric effluent limitations. In Citizens Coal Council v. U.S. EPA, 
447 F3d 879, 895-96 (6th Cir. 2006), the Sixth Circuit, in upholding 
EPA's use of non-numeric effluent limitations, agreed with EPA that it 
derives authority under CWA sections 402(a), 304(b) and 502(11) to 
incorporate non-numeric effluent limitations for conventional and non-
conventional pollutants. The Sixth Circuit further held as reasonable 
the Agency position that CWA sections 304(b), 304(e) and 502(11), read 
together, allow non-numeric effluent limitations to supplement CWA 
section 304(b), or can stand as effluent limitations themselves. See 
also, Waterkeeper Alliance, Inc. v. U.S. EPA, 399 F.3d 486, 496-97, 502 
(2d Cir. 2005) (EPA use of non-numerical effluent limitations in the 
form of best management practices are effluent limitations under the 
CWA); Natural Res. Def. Council, Inc. v. EPA, 673 F.2d 400, 403 (D.C. 
Cir. 1982) (``section 502(11) [of the CWA] defines 'effluent 
limitation' as 'any restriction' on the amounts of pollutants 
discharged, not just a numerical restriction.''); Natural Res. Def. 
Council, Inc. v. Costle, 568 F.2d 1369 (D.C. Cir. 1977) (in determining 
EPA did not have the authority to exclude a particular point source 
from the NPDES program, the Court held ``when numerical effluent 
limitations are infeasible, EPA may issue permits with conditions 
designed to reduce the level of effluent discharges to acceptable 
levels. This may well mean opting for a gross reduction in pollutant 
discharge rather than fine-tuning suggested by numerical 
limitations.'')
    EPA's NPDES regulations reflect EPA's long standing interpretation, 
as supported by federal court decisions, that the CWA allows for non-
numeric effluent limitations. 40 CFR 122.44(k).
7. 2002 Construction and Development Proposal and Subsequent Litigation
    EPA identified the C&D industry in its CWA section 304(m) plan in 
2000 as an industrial point source category for which EPA intended to 
conduct rulemaking. 65 FR at 53,008 and 53,011 (August 31, 2000). On 
June 24, 2002, EPA published a proposed rule that contained several 
options for the control of stormwater discharges from construction 
sites, including ELGs and NSPS. (67 FR 42644; June 24, 2002).
    On April 26, 2004, EPA determined that national effluent 
limitations guidelines would not be the most effective way to control 
discharges from construction sites, and instead chose to rely on the 
range of existing programs, regulations, and initiatives that already 
existed at the federal, state and local level. (69 FR 22472; April 26, 
2004).
    On October 6, 2004, the Natural Resources Defense Council, Inc. and 
additional plaintiffs filed a complaint in district court alleging that 
EPA's decision not to promulgate ELGs and NSPSs for the C&D industry 
violated a mandatory duty under the CWA. The district court, in NRDC v. 
EPA, 437 F.Supp.2d 1137, 1139 (C.D. Cal. 2006), held that CWA section 
304(m) imposes on EPA a mandatory duty to promulgate ELGs and NSPSs for 
new industrial point source categories named in a CWA section 304(m) 
plan. The district court enjoined EPA to propose ELGs and NSPSs for the 
C&D industry by December 1, 2008 and to promulgate ELGs and NSPSs as 
soon as practicable, but in no event later than December 1, 2009. On 
appeal, the Ninth Circuit in NRDC v. EPA, 2008 WL 4253944 (9th Cir. 
2008) affirmed the district court's

[[Page 72569]]

decision holding that ``* * * the CWA is unambiguous that the EPA must 
promulgate ELGs and NSPSs for the point-source categories listed in a 
plan pursuant to [section] 304(m) * * *'' The deadline to seek re-
hearing in the Ninth Circuit was November 3, 2008. The Agency requested 
a 30-day extension of the re-hearing deadline, which was granted, thus 
the new deadline for EPA to seek re-hearing is December 3, 2008.

IV. Scope of the Proposal

    EPA is proposing a regulation that would strengthen the existing 
controls on discharges from construction activity by establishing 
technology-based effluent limitations guidelines and new source 
performance standards for the C&D point source category. This proposal, 
if implemented, would significantly reduce the amount of sediment, TSS, 
turbidity and other pollutants discharged from construction sites due 
to construction activities. EPA estimates that today's proposed rule 
would cost $1.9 billion dollars per year. These estimates do not 
include costs for Alaska, Hawaii and the U.S. territories because EPA 
lacked data on the amount of construction occurring in these areas. 
However, EPA does expect that some construction sites in these areas 
would incur compliance costs as a result of today's proposal. EPA 
solicits data that can be used to estimate the number of acres of 
construction activity that occurs annually in these areas.
    The proposed rule would establish a set of non-numeric effluent 
limitations requiring dischargers to provide and maintain effective 
erosion control measures, sediment control measures, and other 
pollution prevention measures to minimize and control the discharge of 
pollutants in stormwater and other wastewater from construction sites. 
The rule would specify particular minimum BMPs to meet the effluent 
limitations requiring effective erosion control and pollution 
prevention.
    In addition, reflecting current requirements in the EPA CGP, sites 
disturbing 10 or more acres at one time would be required to install a 
sediment basin to contain and settle sediment from stormwater runoff. 
The proposed rule would require minimum standards of design for 
sediment basins; however, alternatives that control sediment discharges 
in a manner equivalent to sediment basins would be authorized where 
approved by the permitting authority.
    Finally, reflecting the BAT and NSPS levels of control, for certain 
large sites located in areas of high rainfall energy and with soils 
with significant clay content, discharges of stormwater from the site 
would be required to meet a numeric effluent limit on the allowable 
level of turbidity. The numeric turbidity limit is 13 nephelometric 
turbidity units (NTUs). The turbidity limit is intended to remove fine-
grained and slowly settling or non-settleable particles contained in 
stormwater. Particles such as clays and fine silts contained in 
stormwater discharges from C&D sites typically cannot be effectively 
removed by conventional stormwater BMPs (such as sediment basins and 
sediment traps) that rely solely on settling unless sufficient 
detention time or additives are implemented. The technology basis for 
the turbidity limit is active treatment systems (ATS), which consists 
of polymer-assisted clarification followed by filtration.
    In addition to this proposed option, EPA is specifically soliciting 
comment on setting a turbidity limit in the range of 50 to 150 NTUs (or 
some other number) based on passive treatment, instead of ATS. See 
section IX.A.5.a of today's proposal for additional discussion of this 
alternative approach.
    EPA considered several other regulatory approaches while developing 
this proposed rule, such as specifying certain design criteria for 
sediment basins, or using different site size, rainfall, or soil type 
thresholds for determining which sites would be required to comply with 
a turbidity limit. EPA also considered setting BAT and NSPS equal to 
the proposed BPT level of control, based on non-numeric BMP-based 
effluent limitations, as well as an expanded version of today's 
proposed rule. EPA requests comment on these alternative regulatory 
approaches. Details of the proposed rule and alternative approaches 
considered are described in this notice, the Development Document, 
Economic Analysis, and Environmental Assessment (see the Supporting 
Documentation section of this notice) and additional documentation is 
contained in the record.

V. Overview of the Construction and Development Industry and 
Construction Activities

    The C&D point source category covers firms classified by the Census 
Bureau into two North American Industry Classification System (NAICS) 
codes.
     Construction of Buildings (NAICS 236) includes 
residential, nonresidential, industrial, commercial and institutional 
building construction.
     Heavy and Civil Engineering Construction (NAICS 237) 
includes utility systems construction (water and sewer lines, oil and 
gas pipelines, power and communication lines); land subdivision; 
highway, street, and bridge construction; and other heavy and civil 
engineering construction.

Other types of entities not included in this list could also be 
regulated.
    A single construction project may involve many firms from both 
subsectors. The number of firms involved and their financial and 
operational relationships may vary greatly from project to project. In 
typical construction projects, the firms identifying themselves as 
``operators'' under a construction general permit are usually general 
building contractors or developers. While the projects often engage the 
services of specialty contractors such as excavation companies, these 
specialty firms are typically subcontractors to the general building 
contractor and are not separately identified as operators in stormwater 
permits. Other classes of subcontractors such as carpentry, painting, 
plumbing and electrical services typically do not apply for, nor 
receive, NPDES permits. The types and numbers of firms in the 
construction industry are described in more detail in the Development 
Document and the Economic Analysis.
    Construction on any size parcel of land almost always calls for a 
remodeling of the earth. Therefore, actual site construction typically 
begins with site clearing and grading. Earthwork activities are 
important in site preparation because they ensure that a sufficient 
layer of organic material (ground cover and other vegetation, 
especially roots) is removed. The size of the site, extent of water 
present, the types of soils, topography and weather determine the types 
of equipment that will be needed during site clearing and grading. 
Material that will not be used on the site may be hauled away. Clearing 
activities involve the movement of materials from one area of the site 
to another or complete removal from the site. When grading a site, 
builders typically take measures to ensure that new grades are as close 
to the original grade as possible to reduce erosion and stormwater 
runoff. Proper grade also ensures a flat surface for development and is 
designed to attain proper drainage away from the constructed buildings. 
A wide variety of equipment is often used during excavation and 
grading. The type of equipment used generally depends on the functions 
to be performed and on specific site conditions. Shaping and compacting 
the earth is an important part of site preparation. Earthwork 
activities might require that fill material be used on the site. In 
such cases, the

[[Page 72570]]

fill must be spread in uniform, thick layers and compacted to a 
specific density. An optimum moisture content must also be reached. 
Graders and bulldozers are the most common earth-spreading machines, 
and compaction is often accomplished with various types of rollers. If 
rock is to be removed from the site, the contractor must first loosen 
and break the rock into small pieces using various types of drilling 
equipment or explosives. (Adapted from Peurifoy, Robert L. and 
Oberlender, Garold D. (1989). Estimating Construction Costs (4th ed.). 
New York: McGraw Hill Book Company.)
    Once materials have been excavated and removed and the ground has 
been cleared and graded, the site is ready for construction of 
buildings, roads, and/or other structures. During construction 
activity, the disturbed land can remain exposed without vegetative 
cover for a substantial period of time. Where the soil surface is 
unprotected, soil particles and other pollutants are particularly 
susceptible to erosion and may be easily washed away by rain or snow 
melt and discharged from the site. Permittees typically use a 
combination of erosion and sediment control measures designed to 
prevent mobilization of the soil particles and capture of those 
particles that do mobilize and become entrained in stormwater from the 
C&D site. In most cases these control measures take the form of BMPs, 
but in some cases construction sites actively treat a portion of the 
discharge using filtration or other treatment technologies. Erosion and 
sediment control measures are described further in the Development 
Document.

VI. Summary of Data Collection Activities

    In developing today's proposal, EPA gathered and evaluated 
technical and economic data from various sources. EPA also used data 
collected previously to develop the 2002 proposed C&D rule and the 2004 
withdrawal of the proposed rule.
    EPA used these data to estimate costs, pollutant loading 
reductions, environmental benefits and economic impacts of various 
regulatory options. This section summarizes EPA's data collection 
efforts.

A. State Data

    EPA compiled and evaluated existing state program information about 
the control of construction site stormwater. EPA collected data by 
reviewing state construction general permits, Web sites, summary 
references, state regulations, and erosion and sediment control design 
and guidance manuals. A summary of criteria and standards for 
construction site stormwater erosion and sediment control that are 
implemented by states are presented in Appendix A of the Development 
Document for this proposed rulemaking. EPA did not collect information 
from counties or municipalities regarding current construction site 
stormwater requirements. EPA relied on state-level requirements to 
characterize requirements in all areas of the state. So, if county or 
municipal requirements are more stringent than state-level requirements 
for control of construction site stormwater discharges, EPA's baseline 
estimates of costs and pollutant reductions would not reflect these 
more stringent requirements currently in place. Therefore, certain 
components of EPA's cost and loadings estimates for the regulatory 
options may be overestimates. In addition, EPA did not account for 
those sites that would already be required to meet a turbidity limit. 
For example, some construction sites around the country are already 
required to meet numeric effluent limits for turbidity that are 
comparable to EPA's proposed turbidity limit. EPA has not accounted for 
these sites in its analysis of costs and loading reductions, although 
the number of these sites is likely to be only a small fraction of 
construction sites nationwide.

B. National Land Cover Dataset (NLCD)

    The NLCD provides a national source of data on land cover. EPA used 
these data to estimate the amount of land across the U.S. that was 
converted to development (e.g., from forest or farmland to residential 
communities), which in turn was used to estimate the amount of acreage 
that may be subject to the requirements of the C&D rule.
    The Multi-Resolution Land Characteristics Consortium (MRLC) has 
produced the NLCD datasets that created a 30-meter resolution land 
cover data layer over the conterminous United States using remote 
sensing data. There are approximately 24 billion data points from 
remote sensing data that comprise the NLCD database. NLCD data is 
publicly available for the years 1992 and 2001.
    Due to new developments in mapping methodology, new sources of 
input data, and changes in the mapping legend for the 2001 National 
Land Cover Database (NLCD 2001), direct comparison between NLCD 2001 
and the 1992 National Land Cover Dataset (NLCD 1992) is difficult. 
Thus, MRLC prepared the NLCD 1992/2001 Land Cover Change Product (see 
http://www.mrlc.gov/change_detection.asp). The NLCD 1992/2001 Land 
Cover Change Product was developed to offer more accurate direct change 
analysis between the two products. This land cover change map and all 
documents pertaining to it are considered ``provisional'' until a 
formal accuracy assessment can be conducted. Detailed definitions and 
discussion of the NLCD 1992/2001 Land Cover Change Product is 
summarized in the Development Document.
    EPA estimated the annual number of acres of land converted to 
development in the U.S. and used that estimate as a surrogate measure 
of the acres of construction activities subject to national effluent 
guidelines regulations, since no national database of the number and 
size of construction activities exists. EPA used estimates of the 
amount of construction activity occurring in each state based on NLCD 
data as a basis for calculating state-level compliance costs. NLCD data 
was also used to estimate the amount of construction activity occurring 
in each of the watersheds in the U.S. based on the EPA Reach File 
cataloging system (discussed below). Watershed level data (along with 
other data sources) was used to estimate the quantity of construction 
activities and the associated pollutant loads occurring in each 
watershed and to link these loads to stream reaches for modeling of 
water quality improvements and benefits estimates.

C. Enhanced River Reach File 1.2 (ERF1)

    EPA used the EPA Reach File 1.2 dataset (ERF1) to summarize land 
cover change in drainage area units (or watersheds). ERF1 for the 
Conterminous United States is a vector database of approximately 
700,000 miles of streams and open waters in the conterminous United 
States. ERF1 was prepared by EPA in 1982 from National Oceanographic 
and Atmospheric Administration (NOAA) aeronautical charts having a 
scale of 1:500,000. ERF1 contains 67,171 watersheds with a minimum size 
of 247 acres (1 km\2\) and an average size of 30,182 acres (122 km\2\). 
ERF1 serves as the foundation for SPARROW (Spatially Referenced 
Regressions [of nutrient transport] on Watershed) modeling (see Section 
XIV of this proposal for a discussion of SPARROW).

D. NPDES Notice of Intent (NOI) Data

    As stated above, when a discharger wishes to be authorized to 
discharge under a general permit, it files a NOI to be covered under 
the general permit. EPA used NOI data to estimate the distribution of 
construction activity by site size and development type. Using NOI 
data, EPA broadly characterized the

[[Page 72571]]

construction industry into three land use types (residential 
construction, non-residential construction and road/highway 
construction). Differentiation of construction activities by site size 
and project type was also done for EPA's technical and economic 
analyses. EPA used NOI data from approximately 138,000 permit 
applications, containing data from 38 States for construction 
activities occurring primarily between the mid-1990s and 2006. 
Depending on the state, the number of NOI records available ranged from 
fewer than 10 to more than 10,000. The data are available either from a 
database of permits processed directly by EPA (referred to as the EPA 
NOI database) or from per-state databases obtained independently.

E. Soils Data

    EPA used the State Soil Geographic (STATSGO) data compiled by Penn 
State University (http://www.soilinfo.psu.edu/) in order to estimate 
variation in soil types nationwide. The variation in soil types found 
within the United States is a significant factor in estimating sediment 
discharges, pollutant load reductions, and stormwater pollution 
prevention costs for construction sites. EPA used the STATSGO soils 
data in support of the loadings and removal estimates for this 
proposal. EPA used the Revised Universal Soil Loss Equation (RUSLE) in 
combination with the soils data to determine soil erosion rates from 
model construction sites in different areas of the country. EPA used 
these estimates, in combination with estimates of pollutant removal 
efficiencies for the various technologies evaluated, to estimate 
sediment discharges from C&D sites under baseline conditions and under 
each regulatory option evaluated. Although EPA was not able to find a 
national database of measured sediment concentrations in treated and 
untreated construction site stormwater runoff, EPA did find monitoring 
data from several states and compared these measured concentrations to 
the estimate concentration based on RUSLE. A discussion of this 
comparison is provided below in section IX. F. Additional details on 
the soil data collected can be found in the Development Document.

F. NOAA Rainfall Data

    Variations in rainfall depth and intensity are also important 
factors in determining erosion rates, sediment discharges, pollutant 
load reductions and control technology costs for construction sites. In 
order to account for variations in rainfall patterns, EPA collected 
rainfall data for one indicator city within each of the 48 conterminous 
states. Data for each of these indicator cities were used as point 
estimates for estimating rainfall depths and intensities for 
construction activities for the entire state. A major urban area was 
chosen as the indicator city in each state; which in most cases was the 
capital city.
    For each indicator city, precipitation data was gathered and 
analyzed using the National Oceanic and Atmospheric Administration 
(NOAA) National Weather Service (NWS) Precipitation Frequency Data 
Server (PFDS), NOAA Atlas 14, a series of maps presented in older NWS 
publications, and NOAA Atlas 2 (Precipitation Frequency Atlas of the 
Western United States (1973)). Alaska and Hawaii, as well as the U.S. 
territories, were not included in this analysis because EPA lacked 
sufficient data on the annual amount of construction occurring in these 
areas. More details on EPA's analysis can be found in the Development 
Document.

G. Parameter Elevation Regressions on Independent Slopes Model (PRISM)

    PRISM is a climate mapping system that was used to estimate the 
annual acres that would be subject to the regulatory options given 
various annual rainfall cutoffs. Using PRISM GIS layers of average 
annual precipitation along with RF1-level estimates of annual acres of 
new construction, EPA was able to estimate acres that would be subject 
to various regulatory options given various average annual 
precipitation cutoffs.

H. Revised Universal Soil Loss Equation (RUSLE) R Factors

    EPA used maps of rainfall-runoff erosivity factors (or R factors) 
contained in the RUSLE documentation. These maps, in GIS form, along 
with RF1-level estimates of annual acres of new construction, were used 
to estimate acres that would be subject to regulations given various R 
factor values.

I. Economic Data

    EPA utilized various economic data sources in developing today's 
proposal. The primary data source is the 2002 Economic Census, 
conducted every five years by the U.S. Census Bureau. The U.S. Small 
Business Administration (SBA) and Census Bureau also provide important 
information in Statistics of U.S. Business (SUSB). SUSB provides firm-
level data that is particularly important for the firm and industry 
impact assessment and for the small entity analysis. An important 
source of project level data is Reed Construction, a commercial 
construction industry data service that collects and reports 
information on multifamily, commercial/institutional, and industrial 
construction projects undertaken nationally. EPA assigned baseline 
financial characteristics--balance sheet, income statement, and metrics 
of financial performance and condition--to each of the model firms as 
defined by NAICS sector and revenue size range, from financial 
statement information reported by Risk Management Association's (RMA) 
publication, Annual Statement Studies. The Census Bureau's 2006 
American Community Survey (ACS) was used to characterize new home 
prices and lot sizes (2006 was chosen because it is the most recent 
year for which the required Metropolitan Statistical Area (MSA)-level 
data are available from the Census).

VII. Characteristics of Discharges From Construction Activity

    The nature of construction activity is that it changes, often 
significantly, many elements of the natural environment. Typically, 
construction activities involve clearing the land of vegetation, 
digging, earth moving and grading, followed by the active construction 
period when the affected land is usually left denuded and the soil 
compacted, often leading to an increase in the peak discharge rate and 
the total volume of stormwater discharged and higher rates of erosion. 
During the land disturbance period, affected land is generally exposed 
after removal of grass, rocks, pavement and other protective ground 
covers. Where the soil surface is unprotected, soil and sand particles 
may be easily picked up by wind and/or washed away by rain or snow 
melt. Typically, the water carrying these particles eventually reaches 
a water body.
    Discharges from construction activity have been documented to 
increase the loadings of several pollutants in the receiving 
waterbodies. The most prominent and most widespread pollutant 
discharged from C&D sites is sediment. The level of sediment is often 
identified through the measurement of the pollutants' turbidity, 
suspended solids, total suspended solids (TSS), suspended sediment 
concentration (SSC), and/or settleable solids. CWA section 304(a)(4) 
identified suspended solids as a conventional pollutant and in 1978 EPA 
defined ``suspended solids'' as ``total suspended solids (non-
filterable) (TSS)'' and stated that TSS ``is a laboratory measure of 
the organic and inorganic particulate matter in wastewater which does 
not pass through a specified glass filter disk.'' See 40 CFR

[[Page 72572]]

401.16; 43 FR 32857, 32858 (July 28, 1978). Turbidity and settleable 
solids are non-conventional pollutants. See CWA section 301(b)(2)(F); 
304(a)(4); Rybachek v. EPA, 904 F.2d 1276, 1291-92 (9th Cir. 1990). The 
Agency defined ``turbidity'' as ``an expression of the optical property 
that causes light to be scattered and absorbed rather than transmitted 
with no change in direction of flux level through the sample * * * 
caused by suspended and colloidal matter such as clay, silt, finely 
divided organic and inorganic matter and plankton and other microscopic 
organisms.'' 40 CFR 136.3; 72 FR 11200, 11247 (March 12, 2007). (See 
Section IX for a discussion of why EPA proposes turbidity as the 
desired pollutant to control in determining the appropriate 
technology).
    Stormwater discharges can have highly variable levels of 
pollutants. Available data show that turbidity levels range from as low 
as 10-50 NTU to several thousand NTU. When the denuded and exposed 
areas contain nutrients, pathogens, metals or organic compounds, these 
other pollutants are likely to be carried at increased rates (relative 
to discharges from undisturbed areas) to surrounding waterbodies via 
stormwater and other discharges (e.g., inadequately controlled 
construction equipment wash water). Discharges of these pollutants from 
construction activities can cause changes in the physical 
characteristics of waterbodies, such as pH, water temperature, or 
stream flow velocity, as well as changes in biological characteristics 
such as aquatic species abundance and composition.
    Actions taken to stabilize disturbed areas of the C&D site can 
include seeding to restore vegetative cover. When fertilizers or 
herbicides are applied to these areas, a portion of the chemicals 
applied may become entrained in stormwater and will be discharged from 
the site. Fertilizers contribute nutrients such as nitrogen and 
phosphorus to the wastestream.
    Discharges from construction activity are expected to contain 
varying concentrations of metals, some of which may be contributed by 
equipment used onsite for grading and other construction activities. 
Metals are also naturally present in soils and, by removing vegetative 
cover and increasing erosion and sediment loss, there will likely be an 
increase in the amount of metals discharged from the C&D site. Metals 
present as a contaminant or additive in fertilizers and other soil 
amendments may serve as another source of pollutants in the stormwater 
discharge.
    Fuels and lubricants are maintained onsite to refuel and maintain 
vehicles and equipment used during construction activities. These 
products, should they come in contact with stormwater and other site 
discharges, would contribute toxic organic pollutants. Pathogenic 
pollutants can be present in stormwater that comes into contact with 
sanitary wastes where portable sanitation facilities are poorly located 
or maintained.
    The environmental impacts associated with discharges from 
construction sites are described in section XIV.

VIII. Description of Available Technologies

A. Introduction

    As described in Section VII, construction activity results in the 
discharge of pollutants to waters of the U.S. These discharges can be 
controlled by applying site design techniques that preserve or avoid 
areas prone to erosion and through the effective use of a combination 
of erosion and sediment control measures. Construction activities 
should be managed to reduce erosion and retain sediment on the C&D 
site. Erosion and sedimentation are two separate processes and the 
practices to control them differ. Erosion is the process of wearing 
away of the land surface by water, wind, ice, gravity, or other 
geologic agents. Sedimentation is the deposition of soil particles, 
both mineral and organic, which have been transported by water, wind, 
air, gravity or ice (adapted from North Carolina Erosion and Sediment 
Control Planning and Design Manual, September 1, 1988).
    Erosion control measures are intended to minimize dislodging and 
mobilizing of sediment particles. Sediment control measures are 
controls that serve to capture particles that have mobilized and are 
entrained in stormwater, with the objective of removing sediment and 
other pollutants from the stormwater discharge. An overview of 
available technologies and practices is presented below; see the 
Development Document for more complete descriptions. Many states and 
local governments and other entities have also published detailed 
manuals for erosion and sediment control measures, and other stormwater 
management practices.

B. Erosion Control Measures

    The use of erosion control measures is widely recognized as the 
most important means of limiting soil detachment and mobilization of 
sediment. The controls described in this notice are designed to reduce 
mobilization of soil particles and minimize the amount of sediment and 
other pollutants entrained in discharges from construction activity. 
Erosion can be minimized by a variety of practices. The selection of 
control measures that will be most effective for a particular site is 
dictated by site-specific conditions (e.g., topography, soil type, 
rainfall patterns). The main strategies used to reduce erosion include 
minimizing the time bare soil is exposed, preventing the detachment of 
soil and reducing the mobilization and transportation of soil particles 
off-site.
    Decreasing the amount of land disturbed can significantly reduce 
sediment detachment and mobilization, as well as overall erosion and 
sediment control costs. This can be accomplished by reducing the 
overall area of disturbed land or by phasing construction so that only 
a portion of the site is disturbed at a time. Another effective 
approach is to schedule clearing and grading events to reduce the 
probability that bare soils will be exposed to rainfall.
    Managing stormwater flows on the site can be highly effective at 
reducing erosion. Typical practices include actively managing off-site 
and on-site stormwater using diversion berms, conveyance channels and 
slope drains to avoid stormwater contact with disturbed areas. In 
addition, stormwater should be managed using energy dissipation 
approaches to prevent high runoff velocities and concentrated flows 
that are erosive. Vegetative filter strips are often considered as 
sediment controls, but they can also be quite effective at dissipating 
energy and reducing the velocity (and thus erosive power) of 
stormwater.
    After land has been disturbed and construction activity has ceased 
on any portion of the site, exposed soils should be covered and 
stabilized immediately. Vegetative stabilization using annual grasses 
is a common practice used to control erosion. Polymers, physical 
barriers such as geotextiles, straw, rolled erosion control products 
and mulch are other common methods of controlling erosion. These 
materials and methods are intended to reduce erosion where soil 
particles can be initially dislodged on a C&D site, either from 
rainfall, snow melt or up-slope runoff.
    The effectiveness of erosion control measures is dependent on 
periodic inspection and identification and correction of deficiencies 
(e.g., after each storm event). Erosion control measures alone will not 
eliminate the mobilization of soil particles and such controls must be 
used in conjunction with sediment control measures.

[[Page 72573]]

C. Sediment Control Measures

    Despite the proper use of erosion control measures, some sediment 
detachment and movement is inevitable. Sediment control measures are 
used to control and trap sediment that is entrained in stormwater 
runoff. Typical sediment controls include perimeter controls such as 
silt fences constructed with filter fabric, straw bale dikes, berms or 
swales. Trapping devices such as sediment traps and basins and inlet 
protectors are examples of in-line sediment controls. Sediment traps 
and basins are commonly used approaches for settling out sediment 
eroded from small and large disturbed areas. Their performance can be 
enhanced using baffles and skimmers and active treatment processes such 
as electrocoagulation, filtration, and chemically enhanced settling 
(e.g., polymer addition).
    Active treatment systems are typically used in conjunction with 
other sediment controls to improve pollutant removals, especially to 
improve removals of fine-grained and slowly settling or non-settleable 
particles and turbidity contained in stormwater. Unless sufficient 
detention time is provided or additives are implemented, particles such 
as clays and fine silts contained in stormwater discharges from 
construction sites typically cannot be effectively removed by 
conventional stormwater BMPs (such as sediment basins and sediment 
traps) that rely solely on gravity settling. EPA has identified several 
demonstrated technologies capable of achieving significant reductions 
of these particles. Based on the information in the record, 
electrocoagulation, polymer clarification, and chitosan-enhanced 
filtration treatment technologies are demonstrated as being capable of 
achieving low levels of turbidity in stormwater discharges.
    The active treatment systems EPA has evaluated operate by 
destabilizing the suspended particles by various mechanisms, 
aggregating them into larger particles that are easier to remove 
through settling or filtering. In addition to physical characteristics 
(e.g., particle surface area, density) that impede timely settling by 
gravity, these small particles (often clay particles) typically are 
substantially influenced by net electrical repulsive forces at particle 
surfaces that prevent the particles from joining together. Coagulation 
refers to the process whereby these repulsive electrical forces are 
reduced, allowing particles to come into contact with one another. 
Flocculation refers to the agglomeration of the destabilized particles 
by joining and bridging to form larger particles. Following 
coagulation/flocculation, the densified floc can more easily and 
effectively be removed via gravitational settling or media filtration 
(e.g., sand, gravel, bag, or cartridge filters).
    Electrocoagulation treatment uses an electrical field to disturb 
the natural electrical charges of the colloidal particles suspended in 
stormwater, enabling the particles to coagulate and flocculate, and 
facilitating gravity settling. This settling may be followed by 
filtration prior to discharge of the stormwater.
    Polymer clarification can operate as a batch process whereby a 
polymer is added to stormwater contained in a basin. The polymer causes 
clays and other fine particles to flocculate and gravity settle. Once 
the turbidity reaches the necessary value and other permit requirements 
are met, the stormwater is discharged from the basin. Polymer 
clarification can also be used in flow-through systems. In this 
application, liquid polymer is injected into the influent to the 
sediment basin or gel or solid polymer is added by placing polymer-
filled socks or ``floc logs'' in channels or pipes carrying sediment-
laded runoff into the basin. Stormwater flowing over the socks or logs 
dissolves the solid polymer, and turbulence at the basin inflow point 
facilitates mixing and aids in the coagulation/flocculation process.
    Chitosan-enhanced filtration is a process that adds a polymer (in 
this instance, a polymer produced from the chitin in crab shells) to 
the stormwater to promote flocculation. The flocculated stormwater is 
then passed through one or more filtration steps and, if permit 
conditions are met, can be discharged.
    These active treatment systems are often equipped with automated 
instrumentation to monitor stormwater quality, flow rate, and dosage 
control for both influent and effluent flows.
    It has been suggested that, while operating active treatment 
systems that use polymers to reduce the turbidity of stormwater, 
construction site dischargers may overuse polymers and, in doing so, 
introduce toxicity or cause other adverse effects. EPA believes toxic 
effects from discharges treated to meet a turbidity limit should not be 
occurring and such events would be indicative of a poorly operated 
treatment system. Polymers are widely used at a variety of wastewater 
treatment systems and facilities throughout the country, and EPA is not 
aware of any studies indicating that polymer addition to treat 
stormwater from construction sites using ATS has been found to pose a 
significant risk to water quality at those facilities. There are ample 
regulatory (i.e., enforcement actions) and financial (e.g., chemical 
costs) disincentives for dischargers to willfully overuse polymers in 
their treatment systems. In addition, vendors have indicated that 
dosages of polymers are carefully metered in ATS systems. Upon closer 
review of the matter, it appears that this concern has been raised due 
to anecdotal suggestions, rather than documented evidence of actual 
discharge events causing toxic effects. To date, EPA has not identified 
any documented cases where the use of a polymer to treat C&D stormwater 
discharges caused an adverse effect in the receiving waters. Also, 
Washington and other States have researched toxicity of some polymers 
and established a sound basis for testing and significant controls on 
dosage and usage. For example, Washington State has established 
protocols for residual chemical and toxicity testing for ATS systems 
and has required vendors to receive state approval. However, 
California, in a draft permit fact sheet describing chemical treatment, 
states the following:

    ``These systems can be very effective in reducing the sediment 
in storm water runoff, but the systems that use additives/polymers 
to enhance sedimentation also pose a potential risk to water quality 
(e.g., operational failure, equipment failure, additive/polymer 
release, etc.). We are concerned about the potential acute and 
chronic impacts that the polymers and other chemical additives may 
have on fish and aquatic organisms if released in sufficient 
quantities or concentrations. In addition to anecdotal evidence of 
polymer releases causing aquatic toxicity in California, the 
literature supports this concern. For example, cationic polymers 
have been shown to bind with the negatively charged gills of fish, 
resulting in mechanical suffocation. Due to potential toxicity 
impacts, which may be caused by the release of additives/polymers 
into receiving waters, residual polymer monitoring and toxicity 
requirements have been established in this General Permit for 
discharges from construction sites that utilize an ATS in order to 
protect receiving water quality and beneficial uses.'' (see DCN 
41137).

    Therefore, EPA recognizes the merits of ensuring that chemical 
additives are properly used. EPA solicits information and data that 
quantify the number of instances where overuse of polymers occurred, 
the circumstances resulting in such overuse, and the actual or 
potential environmental impacts associated with such events. In 
addition, EPA solicits comments on the need for approaches (either 
voluntary or regulatory) to prevent or minimize the potential for such 
instances and the need for EPA to

[[Page 72574]]

develop guidance on use of polymers at construction sites.
    More detailed descriptions of sediment and erosion control measures 
can be found in the Development Document.

D. Other Construction and Development Site Management Practices

    Construction activity generates a variety of wastes and wastewater, 
including concrete truck rinsate, municipal solid waste (MSW), trash, 
and other pollutants. Construction materials and chemicals should be 
handled, stored and disposed of properly to avoid contamination of 
runoff. Dischargers utilize various practices to manage these wastes 
and minimize discharges to surface waters, including:
     Protecting construction materials, chemicals and fuels and 
lubricants from exposure to rainfall;
     Limiting exposure of freshly placed concrete to rainfall;
     Segregating stormwater and other wastewaters from fuels, 
lubricants, sanitary wastes, and chemicals such as fertilizers, 
pesticides and herbicides;
     Neat and orderly storage of chemicals, pesticides, 
fertilizers, and fuels that are being stored on the site;
     Prompt collection and management of trash and sanitary 
waste;
     Prompt cleanup of spills of liquid or dry materials.

IX. Development of Effluent Limitations Guidelines and Standards

A. Description of the Regulatory Options Considered

    In developing today's proposal, EPA evaluated several different 
options for reducing pollutant discharges from construction activity. 
The options evaluated by EPA are intended to control the discharge of 
sediment, turbidity and other pollutants in stormwater and other 
wastewater from C&D sites. Construction activity typically involves 
clearing, grading and excavating of land areas. Prior to construction, 
these land areas may have been agricultural, forested or other 
undeveloped lands. Construction can also occur as redevelopment of 
existing rural or urban areas, or infill development on open space 
within existing developed areas. During the C&D process, vegetation or 
surface cover is typically removed and underlying soils become more 
susceptible to detachment by rainfall and erosion by stormwater runoff. 
Soil is often compacted by construction equipment, reducing the 
infiltration capacity of underlying soils and increasing stormwater 
discharge rates. Sediments and other pollutants contained in stormwater 
can and often are transported off-site and discharged from construction 
sites. Today's proposal provides regulatory tools to improve erosion 
and sediment control measures and pollution prevention measures on C&D 
sites to minimize and control stormwater and other discharges from 
construction activity.
    Certain limitations being proposed today are common to each 
regulatory option. These common requirements consist of a set of non-
numeric effluent limitations that require dischargers to provide and 
maintain effective erosion control measures, sediment control measures, 
and other pollution prevention measures to minimize the discharge of 
pollutants in stormwater and other wastewater from construction sites. 
These non-numeric effluent limitations included in each regulatory 
option are described in Section IX.B below.

B. Effluent Limitations Included in All Regulatory Options

    EPA's preferred approach is twofold: First, prevent the discharges 
of sediment and other pollutants from occurring through the use of 
effective site-specific planning, erosion control measures and 
pollution prevention measures; and second, control discharges that do 
occur through the use of effective sediment control measures. Under 
each regulatory option, dischargers would be required to meet non-
numeric effluent limitations requiring them to minimize and control 
discharges from the site by providing and maintaining effective erosion 
and sediment control measures and pollution prevention measures.
    Dischargers would be required to prevent soil erosion and minimize 
the discharge of sediment from all areas of the site by providing and 
maintaining effective erosion control measures. Erosion controls are 
considered effective when bare soil is uniformly and evenly covered 
with vegetation or other suitable materials, stormwater is controlled 
so that rills and gullies are not visible, and channels and streambanks 
are not eroding. Dischargers would be required to provide and maintain 
recognized and accepted erosion control measures, including stabilizing 
disturbed soils immediately after clearing, grading, or excavating 
activities have permanently or temporarily ceased (i.e., when such 
activities have been stopped on a portion of the site and will not 
resume for a period exceeding 14 calendar days). In addition, 
dischargers would be required to minimize the amount of soil exposed 
and control stormwater within the site to prevent soil erosion by using 
effective erosion control measures. Stormwater discharges leaving the 
site would also need to be controlled to prevent channel and streambank 
erosion and erosion at outlets.
    The following list of principles and practices are generally 
recognized and accepted as effective erosion controls and would be 
provided in the rule to help guide the selection, design, and 
implementation of control measures to meet the effluent limitations on 
individual construction sites.
     Preserve topsoil and natural vegetation.
     Minimize soil compaction.
     Sequence or phase construction activities to minimize the 
areas disturbed at any one time.
     Stabilize disturbed areas using temporary or permanent 
vegetation, and controls such as mulch, geotextiles, or sod.
     Minimize the disturbance of steep slopes, and where such 
slopes are disturbed implement erosion controls designed to control 
soil erosion on slopes.
     Establish and maintain natural buffers around surface 
waters.
     Minimize the construction of stream crossings.
     Divert stormwater that may run onto the site away from any 
disturbed areas of the site.
    Dischargers would also be required to meet non-numeric effluent 
limits requiring that they provide and maintain effective sediment 
controls to minimize the discharge of sediment and other pollutants 
from C&D sites. Sediment control measures implemented at the site would 
include, at a minimum, the following:
     Establishing perimeter controls for any portion of the 
down-slope and side-slope perimeter where stormwater will be discharged 
from disturbed areas of the site.
     Establishing and using stabilized construction entrances 
and exits that control sediment discharges from the site. Ensuring that 
vehicles entering and exiting the site use such access points to 
prevent tracking of sediment onto roads or other areas that convey 
sediment to surface waters. Removing any sediment or other pollutants, 
including construction materials, from paved surfaces daily. Washing 
sediment or other pollutants off paved surfaces into storm drains would 
be prohibited.
     Establishing and using controls and practices to minimize 
the introduction of sediment and other pollutants to storm drain inlets 
that receive stormwater discharges from the site.

[[Page 72575]]

     Controlling sediment and other contaminants from 
dewatering activities. Discharges of dewatering wastes are prohibited 
unless treated in a sediment basin or similar control measure.
    Each regulatory option includes pollution prevention measures that 
would minimize or prohibit the discharge of pollutants from a variety 
of sources and activities at C&D sites. Each option would prohibit 
discharges of construction wastes, trash, sanitary wastes, and 
wastewater from washout of concrete, paint, and other such materials. 
The regulatory options would also prohibit the discharge of fuels, 
oils, and other materials used in vehicle and equipment operation and 
maintenance. The discharge of wastewater from washing vehicles and 
equipment where soaps or solvents are used would be prohibited. The 
discharge of pollutants resulting from the washing of equipment and 
vehicles using only water would also be prohibited, unless wash waters 
were treated in a sediment basin or alternative control that provides 
equivalent or better treatment. Dischargers would be required to 
implement measures to minimize the exposure of stormwater to building 
materials, landscape materials, fertilizers, pesticides, herbicides, 
detergents, and other liquid or dry products. In addition, dischargers 
would be required to implement appropriate spill prevention and 
response procedures for these materials.

C. Options for BPT, BCT, BAT and NSPS

    EPA considered the following three regulatory options for today's 
proposal.
     Option 1
    Each C&D site subject to the rule would be required to implement 
the limitations described above in Section IX.B. In addition, certain 
larger sites would be required to install and maintain sediment basins 
or equivalent sediment controls. Specifically, for portions of sites 
that drain to one location and will have 10 or more acres disturbed at 
one time, dischargers would be required to install a sediment basin to 
control and treat the stormwater discharges. The proposed rule would 
impose minimum standards of design and performance for sediment basins. 
The basin would be required to provide storage for a calculated volume 
of stormwater (called the water storage volume) from a 2-year, 24-hour 
storm from each disturbed acre drained plus a sediment storage volume 
of at least an additional 1,000 cubic feet, until final stabilization 
of the disturbed area. Alternatively, a sediment basin providing a 
water storage volume of 3,600 cubic feet per acre drained plus the 
sediment storage volume would be required. To ensure adequate retention 
time to facilitate settling of sediment particles, the proposed rule 
would require that the effective length of the basin must be at least 
four times the width of the basin and that the water storage volume be 
designed to drain over a period of at least 72 hours using a surface 
outlet (such as a skimmer), unless otherwise designated by the 
permitting authority. The size of the basin that would be required is 
based on the size of the drainage area that will have vegetation 
removed and soils disturbed (i.e., if the total drainage area is 15 
acres, but only 13 acres of this area will have vegetation removed and 
soils disturbed during the course of the project and the remaining 2 
acres will remain vegetated and stormwater is directed around both the 
disturbed area and the sediment basin, then the storage volume can be 
sized based on 13 acres).
    In addition, the design of the sediment basin would be required to 
address site-specific factors such as amount, frequency, intensity and 
duration of stormwater runoff; soil types; and other factors affecting 
pollutant removal efficacy. For example, particle settling 
characteristics, and thus pollutant removal efficacy, can be affected 
by physical parameters of the basin such as inlet and outlet 
velocities, basin surface area, and basin depth and volume necessary to 
provide sufficient storage for sediment load and stormwater runoff. 
Effective erosion and sediment controls are generally recognized as 
including actions to divert stormwater away from disturbed areas of the 
site, so that sediment erosion is reduced and sediment controls, such 
as basins, are not overwhelmed by stormwater volumes.
    To minimize carryover and discharge of suspended particles from the 
sediment basin, the basins would be required to incorporate an outlet 
device designed to remove water from the top of the water column in 
order to minimize the amount of sediment and other pollutants entrained 
in the discharge. This can be accomplished by using technologies such 
as a siphoning outlet, surface skimmer or floating weir.
    Recognizing that there may be impediments to using sediment basins 
in some instances or that alternative approaches may provide better 
controls depending on site-specific conditions, the proposed rule would 
authorize dischargers to use alternative controls equivalent to 
sediment basins where approved by the permitting authority.
    EPA encourages dischargers to use improved sediment basin designs 
that incorporate features such as baffles and to increase the length to 
width ratio of the basin to maximize detention time and settling. The 
use of these practices may significantly improve the performance of 
sediment basins in certain cases. The North Carolina Department of 
Transportation (NCDOT) has developed draft specifications for baffles 
in sediment basins (see DCN 43083). EPA solicits comments on whether 
porous baffles, as described in the draft NCDOT specifications, should 
be minimum requirements for all sediment basins nationwide. EPA also 
requests comments on the costs and effectiveness of baffles used in 
sediment basins, either alone or in combination with skimmers and 
polymer addition. EPA also solicits comments on the detention time 
requirements for sediment basins contained in today's proposal, and 
whether the proposed rule should include other specific detention time, 
overflow rate or other design or performance requirements for sediment 
basins. EPA also solicits comments on whether the regulation should 
require that sediment basins be designed to remove a specified particle 
size. EPA also requests comments on whether sediment basin designs 
should be required to address downstream channel erosion by requiring 
peak or discharge rates to match predevelopment conditions, and for 
what storm events such a standard should apply.
    Option 1 is estimated to cost approximately $132 million per year 
(2008 $), not including costs for Alaska, Hawaii and the U.S. 
territories, and reduce discharges of pollutants by 670 million pounds 
annually. Monetized benefits of Option 1 are estimated to be $18 
million per year. The cost estimates for Option 1 only include costs 
for larger sediment basins in those states whose sizing requirements 
are less stringent than those contained in the proposal. These cost 
estimates do not include any additional costs for implementing skimmers 
or the additional volume for sediment storage. EPA assumed that these 
costs would not impact sediment basin costs significantly. Skimmers can 
be purchased from commercial suppliers, or fabricated on-site. Also not 
included are costs for deep ripping and decompaction of soils, and 
several other required BMPs that are not currently part of the CGP or 
most state permits. EPA solicits comments on the cost assumptions of 
Option 1. The efficacy of Option 1 (percent of raw stormwater

[[Page 72576]]

sediment load removed) may be underestimated because only the basins 
are modeled in the loading analysis. Removals due to other on-site BMPs 
have not been modeled or included in the analysis.
    While developing and evaluating Option 1, EPA considered several 
possible variations for sediment basin requirements. One approach would 
have eliminated flexibility for dischargers to use a 3600 cf/acre basin 
in lieu of the 2-year, 24-hour basin. In effect, all sites required to 
install a sediment basin under Option 1 would have been required to 
construct a basin sized to treat runoff from the 2-year, 24-hour storm 
(or use equivalent control measures). EPA estimated that this variation 
of Option 1 would cost approximately $1.09 billion per year. EPA also 
considered an approach that, in addition to specifying a particular 
size of basin, would require that the sediment basin be sized and 
constructed to enable settling of a specified-size particle--e.g., 10-
micron particles. This approach would be a design standard rather than 
a numeric limitation on the sediment basin effluent. For example, the 
California Stormwater Quality Association Construction Handbook (see 
DCN 43017) contains an example of designing a sediment basin to remove 
a specified particle size standard based on wet sieve analysis for the 
10 micron particle for a 10-year, 6-hour storm event. EPA estimates, 
using this approach, that sediment basins required to remove particles 
greater than 10 microns nationwide would cost approximately $1.7 
billion per year. More information about these potential sediment basin 
approaches is presented in the Development Document. EPA solicits 
comment on whether Option 1 or other variations described here would be 
appropriate regulatory approaches and, if so, why, based on the 
statutory requirements of CWA section 304, they should be considered to 
represent BPT, BCT, BAT, or NSPS level of control for this industry.
     Option 2
    The requirements that would be established under Option 2 
incorporate all of the Option 1 requirements. In addition, a numeric 
limit on turbidity of stormwater discharges would apply to sites that 
meet certain criteria for size of the site, average clay content of the 
soil (with clay content being defined as soil particles less than 2 
microns in diameter), and rainfall erosivity factor (``R factor'') as 
defined by the Revised Universal Soil Loss Equation (see Predicting 
Soil Erosion by Water: A Guide to Conservation Planning With the 
Revised Universal Soil Loss Equation (RUSLE), United States Department 
of Agriculture, Agriculture Handbook Number 703, January 1997). Option 
2 would establish a numeric effluent limit on the turbidity of 
stormwater discharges for any site that meets all three of the 
following criteria: (1) Average soil clay content of more than 10 
percent; (2) annual R factor of 50 or more; and (3) has a size of 30 or 
more acres. The numeric turbidity standard would apply to discharges 
produced from rainfall events up to the local 2-year, 24-hour storm. 
Any volume in excess of the 2-year, 24-hour storm would be exempt from 
the turbidity standard. The turbidity limitation would apply to these 
sites in addition to the Option 1 requirements (i.e., such sites would 
also be required to implement the non-numeric erosion and sediment 
control measures described under Option 1). Under Option 2, dischargers 
would be required to monitor stormwater discharges for turbidity, which 
can be done either by using automated instrumentation or with a 
portable, hand-held turbidimeter or similar device. Sites with a common 
drainage location that serves an area with 10 or more acres of land 
disturbed land at one time that are not required to meet the turbidity 
requirement, either because the total size of the site is less than 30 
acres, the R factor is less than 50 or the average clay content of 
soils is less than 10 percent, would be required to install sediment 
basins as described under Option 1. Site size for sites subject to the 
proposed turbidity limit is based on the total size of the site, not 
the amount of disturbed acres or some other subset of the site. Any 
site which is 30 acres or larger regardless of how much of the site 
will be disturbed would be subject to the turbidity limit if they also 
meet the R factor and soil clay content thresholds.
    By considering the construction site's soil clay content, this 
option takes into account the pollutant reductions that are achievable 
using the erosion control measures and traditional sediment control 
measures (i.e., those other than active treatment systems) included in 
the proposed rule. These more traditional approaches to controlling 
stormwater discharges can be very effective in soils with low clay 
content where the entrained sediment is amenable to gravity settling. 
However, as the amount of clay in the soil rises, gravity settling 
processes are less effective and processes to enhance the removal of 
pollutants from stormwater are necessary. By applying the proposed 
turbidity limit in Option 2 to sites with 10% or more clay content, the 
proposed rule would achieve significant reductions of the slowly 
settling or non-settleable particles and turbidity contained in 
stormwater. In order to remove these fine-grained particles from 
stormwater discharges, active treatment technologies, such as those 
described in Section VIII, typically would need to be employed. The 
information in the record shows that these systems can achieve low 
levels of turbidity in the stormwater discharges.
    While it is impossible to predict the weather several months in 
advance of construction, for many areas of the country, there are 
definite optimal periods for conducting construction activities in 
order to limit soil erosion, such as a dry season when rain tends to 
fall less frequently and with less force. When feasible, this is the 
time to disturb the earth, so that the site is stabilized by the time 
the seasonal wet weather returns. The R factor is intended to reflect 
consideration of the amount and intensity of precipitation expected 
during the time the earth will be exposed.
    The method for determining a site's R factor is based on the 
Universal Soil Loss Equation (USLE) developed by the U.S. Department of 
Agriculture (USDA) in the 1950s to help farmers conserve topsoil. The 
USLE has been updated to the Revised USLE (RUSLE). Using a computer 
model supported by decades worth of rainfall data, USDA established 
estimates of rainfall erosivity factors (R) for locations throughout 
the country. These R factors are used as surrogate measures of the 
impact that rainfall has on erosion from a particular site. The R 
factor represents the driving force for erosion, taking into 
consideration total rainfall, intensity and seasonal distribution of 
the rain. Isoerodent maps depicting the R factor in various parts of 
the country have been created by USDA and are included in Chapter 2 of 
Agriculture Handbook Number 703.
    While developing and evaluating Option 2, EPA considered several 
possible variations for the applicability of a limitation on turbidity 
of stormwater discharges. One approach would replace the R factor 
criteria with one based on total annual rainfall for the site location. 
Under this approach, EPA preliminarily considered values of 20 inches 
and 40 inches of total annual rainfall. EPA considers the R factor 
approach better than total annual rainfall at addressing stormwater 
discharges because the R factor captures both rainfall energy (a 
function of the volume of rainfall and runoff) and intensity (which has 
direct bearing on the erosive power of a rainfall event). EPA has 
structured the regulatory

[[Page 72577]]

option accordingly. However, since R factors have not been calculated 
for all areas of Alaska and the U.S. territories, a criterion of 20-
inches total annual rainfall (30-year average using National Weather 
Service records) has been retained as a substitute for R factor for 
construction sites in those locations unless an R factor applicable to 
the construction site is calculated.
    EPA also considered approaches that would apply the turbidity 
effluent limitation to larger sites (e.g., 50 acres instead of 30 
acres) or with higher clay content of the soil (e.g., 20 percent 
instead of 10 percent clay). More information about these potential 
approaches is presented in the Development Document. EPA solicits 
comment on whether Option 2 or other combinations of rainfall, clay 
content and acreage limitations like those described above would be 
more appropriate regulatory approaches and, if so, why, based on the 
statutory requirements of CWA section 304, they should be considered to 
represent BPT, BCT, BAT, or NSPS level of control for this industry. 
Another option would be to base Option 2 on disturbed acres, instead of 
the total site size. EPA solicits comments on this approach.
    EPA evaluated the advantages and disadvantages of establishing a 
limitation on turbidity vs. total suspended solids (TSS) in stormwater 
discharges from construction sites. EPA selected turbidity for two 
reasons. First, EPA is specifically targeting fine silt, clay and 
colloidal particles in stormwater runoff. These particles have small 
diameters and frequently contain a surface charge that prevents 
agglomeration. As a result, these particles typically do not settle in 
sediment basins and are not effectively removed by conventional BMPs 
such as silt fences, which have a large pore diameter. Consequently, 
discharges from sites with appreciable clay soils may have low TSS 
concentrations but may still have high turbidity levels. Second, 
turbidity can be easily measured in the field while TSS requires 
collection of a sample and analysis in a laboratory. Since most BMPs 
and treatment systems are flow-through systems, TSS would not be a 
practical means of estimating compliance because permittees would not 
be able to verify whether or not they had met the standard before 
discharging. With turbidity, permittees can measure turbidity levels in 
discharges continuously and adjust treatment parameters accordingly or 
recycle effluent if they are in danger of exceeding the turbidity 
limit. For these reasons, EPA believes that turbidity is a more 
appropriate measure of effectiveness and can be implemented more easily 
than TSS. EPA requests comments on this approach.
    Option 2 is estimated to cost $1.9 billion per year (2008 $), not 
including costs for Alaska, Hawaii and the U.S. territories, and reduce 
discharges of pollutants by 27 billion pounds annually, with a 
sensitivity analysis estimate of 6.2 billion pounds annually. Monetized 
benefits of Option 2 are estimated to be $333 million annually.
     Option 3
    Under Option 3, all sites with common drainage locations that serve 
an area with 10 or more acres disturbed at one time would be required 
to comply with the turbidity effluent limitation (in addition to the 
non-numeric effluent limitations in Option 1). This option does not 
establish thresholds for R factor (or total annual rainfall) or soil 
type (i.e., clay content). Under this option, all other sites (i.e., 
sites with less than 10 acres disturbed at one time) would be required 
to implement the requirements described under Option 1 (for sites with 
common drainage locations that serve an area of less than 10 acres 
disturbed at one time).
    Option 3 is estimated to cost $3.8 billion per year (2008 $), not 
including costs for Alaska, Hawaii and the U.S. territories, and reduce 
discharges of pollutants by 50 billion pounds annually, with a 
sensitivity analysis estimate of 11.1 billion pounds annually. 
Monetized benefits of Option 3 are $470 million annually. EPA notes 
that its modeling of acres subject to the options evaluated is based on 
total site size instead of amount of disturbed area on a site. EPA does 
not have data that can be used to estimate the percentage of a site 
that is typically disturbed. For example, if a site is 15 acres, but 
only 7 acres were to be disturbed, then under Option 3 this site would 
not be subject to the turbidity standard. However, EPA has estimated 
costs for Option 3 for all sites that, in total, are more than 10 
acres. Therefore, to the extent that EPA has overestimated the quantity 
of acres that would be subject to Option 3, EPA's estimates of costs, 
benefits and loadings reductions for turbidity controls under Option 3 
would also be overestimated.
    With regard to Option 3, depending on the location of the 
construction site and time of year, it is possible that relatively 
little rain would be expected during construction (based on historical 
average rainfall patterns) and perhaps dischargers could opt to not 
install active treatment systems. However, such an approach would 
expose permittees to the risk of discharging stormwater that exceeds 
the turbidity limit. On the other hand, taking an overly precautionary 
approach could result in sites installing treatment equipment that sees 
little or no use. EPA seeks comment on this issue.
    Also with regard to Option 3, EPA has also considered the 
availability of treatment systems capable of achieving the turbidity 
effluent limit, as well as whether there is sufficient vendor capacity 
to meet the demand that would be presented by extending the turbidity 
effluent limit to all construction sites disturbing more that 10 acres 
at a time. Option 3 means that substantial numbers of active treatment 
systems would need to be manufactured and mobilized, along with 
sizeable levels of vendor support, in a relatively short period of time 
as NPDES permits incorporating the ELGs and NSPS are issued.
    EPA solicits comments on this issue.

D. Option Selection Rationale for BPT

    EPA proposes to select Option 1 as the basis for establishing BPT 
effluent limitations. The requirements established by Option 1 are 
well-established for construction activities in all parts of the 
country and are generally consistent with and in some cases more 
stringent than the control measures currently in place under EPA's 
Construction General Permit. Some requirements of Option 1 are more 
stringent than many state general permits, while other requirements are 
less stringent than some state general permits. EPA has determined that 
Option 1 represents a level of control that is technologically 
available and economically practicable. EPA considered the non-water 
quality environmental impacts of this option and found them to be 
minimal and thus acceptable. Selecting Option 1 as BPT for this point 
source category is consistent with the CWA and regulatory 
determinations made for other point source categories, in that the 
Option 1 requirements represent limitations based on the average of the 
best performance of facilities within the C&D industry. See Weyerhauser 
Co. v. Costle, 590 F.2d 1011, 1053-54 (D.C. Cir. 1978). As stated in 
Section III, EPA assesses cost-reasonableness of BPT effluent 
limitations by considering the cost of treatment in relation to the 
effluent reduction benefits achieved. EPA has determined that the 
pollutant reduction benefits achieved by Option 1 justify the costs. We 
have typically described this as dollars/pound and compare the results 
with other rules. The incremental costs of Option 1 are approximately 
$132 million per year

[[Page 72578]]

(2008 $). EPA anticipates that construction sites in approximately 11 
states would incur costs to comply with the proposed Option 1 BPT 
requirements requiring sediment basins generally consistent with the 
EPA CGP. As noted above, the efficacy of this option may be 
underestimated.
    EPA rejected Options 2 and 3 because EPA views BPT performance as 
the first level of technology-based control representing the average of 
the best performance. EPA's record does not indicate that meeting a 
turbidity limit, even for the subset of facilities identified in Option 
2 would represent today's average of the best performance and it would 
not represent the BPT level of control for this point source category. 
EPA requests comment on what should be considered BPT for this 
category.

E. Option Selection Rationale for BAT and NSPS

1. Selection Rationale
    EPA proposes to select Option 2 as the basis for BAT and NSPS. This 
option would require all C&D sites to implement the non-numeric 
effluent limitations described for Option 1, as well as requiring 
certain sites to meet a numeric limitation of 13 NTU (nephelometric 
turbidity units) to control turbidity for stormwater discharges. 
Turbidity is being regulated in this proposed rule as a nonconventional 
pollutant and an indicator pollutant for the control of other 
pollutants associated with sediment and materials on construction sites 
that can become entrained in stormwater discharges from construction 
sites, including metals and nutrients. Turbidity, measured as NTU, 
which in construction site runoff primarily reflects sediment, is a 
nonconventional pollutant because it is not identified as either a 
toxic or conventional pollutant under the CWA. See CWA section 
301(b)(2)(F); 304(a)(4); 40 CFR 401.16; Rybachek v. EPA, 904 F.2d 1276, 
1291-92 (9th Cir. 1990). Turbidity is ``an expression of the optical 
property that causes light to be scattered and absorbed rather than 
transmitted with no change in direction of flux level through the 
sample * * * caused by suspended and colloidal matter such as clay, 
silt, finely divided organic and inorganic matter and plankton and 
other microscopic organisms.'' 40 CFR 136.3; 72 FR 11200, 11247 (March 
12, 2007). In this rulemaking, EPA is identifying turbidity as a 
pollutant of concern in construction site discharges. By providing a 
measure of the sediment entrained in stormwater discharges, turbidity 
is an indicator of the degree to which sediment and other pollutants 
associated with sediment and found in stormwater discharges are 
reduced. Turbidity is also a more effective measure of the presence of 
fine silts, clays and colloids, which are the particles in stormwater 
discharges that EPA is specifically targeting in today's proposal.
    Metals, nutrients, and other toxic and nonconventional pollutants 
are naturally present in soils, and can also be contributed by 
equipment/materials used during construction or by activities that 
occurred at the site prior to the construction activity. Many of these 
pollutants are present as particulates and will be removed with other 
particles. Dissolved forms of pollutants are often absorbed or adsorbed 
to particulate matter and can also be removed along with the 
particulates (i.e., sediment). EPA has determined that effluent 
limitations that reduce turbidity in the stormwater discharge will also 
achieve reductions of the other pollutants of concern. Demonstrating 
compliance with a turbidity limit would be relatively easy and 
inexpensive for construction site dischargers to implement. Hand-held 
turbidity meters (turbidimeters) can be used to measure turbidity in 
discharges, or data loggers coupled with in-line turbidity meters can 
be used to automatically measure and log turbidity measurement reducing 
labor requirements associated with sampling. In addition, the use of 
turbidity meters will provide dischargers with immediate, real-time 
information on the efficacy of their treatment systems and sediment 
control measures to facilitate timely adjustments of system operation 
where necessary.
    The requirements of Option 2 have been demonstrated to be 
technologically available. Active treatment systems have been used and 
are currently being used at several hundred construction sites 
throughout the country. Construction sites where these active treatment 
systems have been used are primarily located in California, Oregon and 
Washington, with some in Florida, Maryland, Vermont and other states. 
Oregon requires sites to meet a 160 NTU benchmark if the site is 
discharging to a waterbody listed as not meeting applicable water 
quality standards under section 303(d) or a waterbody with a total 
maximum daily load (TMDL) for sediment and turbidity. Washington has 
turbidity benchmark limits that are set at values relative to the 
turbidity in the receiving steam. Benchmark requirements (e.g., in the 
context of the Oregon and Washington permits), as opposed to numeric 
effluent limits, require the facility to take some action to address 
the potential water quality issue such as additional monitoring or BMP 
review and do not result in a permit violation. Vermont requires what 
it defines as ``moderate risk'' projects to take corrective action if 
turbidity exceeds 25 NTUs. Also, several other states have turbidity 
limitations or standards that are either in draft permits (such as 
California), are set relative to background levels (Georgia), or are 
set only for specific regions or specific waterbodies within the state 
(such as the Lake Tahoe Basin of California) or for specific 
construction projects (such as construction of a new runway at the Sea-
Tac airport). To comply with these turbidity-based requirements, 
dischargers have used the active treatment systems described 
previously--electrocoagulation, polymer clarification, and chitosan-
enhanced sand filtration, as well as other approaches. The information 
in the record demonstrates the efficacy of these treatment systems, 
showing that they consistently achieve very low levels of turbidity in 
stormwater discharges. A summary of existing state requirements are 
contained in the TDD.
    EPA also considered the recommendations of the National Research 
Council (NRC). EPA commissioned the NRC to evaluate the NPDES 
stormwater program and make recommendations for improvement of the 
program. The Water Sciences and Technology Board released the report 
Urban Stormwater Management in the United States (Committee on Reducing 
Stormwater Discharge Contributions to Water Pollution, National 
Research Council, National Academies Press) in October of 2008. The 
report is the product of a 2-year process undertaken by a 15-member 
committee of national experts.
    While the report did not specifically endorse numeric effluent 
limits for construction sites, the report did contain several 
recommendations, including that ``Numeric enforcement criteria can be 
used to define what constitutes an egregious water quality violation at 
construction sites and provide a technical criterion to measure the 
effectiveness of erosion and sediment control practices.'' The study 
continues to report that ``A maximum turbidity limit would establish 
definitive criteria as to what constitutes a direct sediment control 
violation and trigger an assessment for remediation and prevention 
actions. For example, local erosion and sediment control ordinances 
could establish a numeric turbidity limit of 75 Nephelometric

[[Page 72579]]

Turbidity Units (NTU) as an instantaneous maximum for rainfall events 
less than an inch (or a 25 NTU monthly average) and would prohibit 
visible sediment in water discharged from upland construction sites. 
While the exact turbidity limit would need to be derived on a regional 
basis to reflect geology, soils, and receiving water sensitivity, 
research conducted in the Puget Sound of Washington indicates that 
turbidity limits in the 25 to 75 NTU can be consistently achieved at 
most highway construction sites using current erosion and sediment 
control technology that is properly maintained (Horner et al., 1990). 
If turbidity limits are exceeded, a detailed assessment of site 
conditions and follow-up remediation actions would be required. If 
turbidity limits continue to be exceeded, penalties and enforcement 
actions would be imposed. Enforcement of turbidity limits could be 
performed either by state, local, or third party erosion and sediment 
control inspectors, or--under appropriate protocols, training, and 
documentation--by citizens or watershed groups.''
    EPA recognizes that the turbidity limits discussed in the report 
are more like the action levels specified by Washington and other 
states, rather than binding numeric effluent limitations being proposed 
by EPA. However, EPA's analysis of ATS effluent data from more than 
6,000 data points indicates that a limit of 13 NTUs is technologically 
available.
    California assembled a blue ribbon panel to evaluate, among other 
things, the feasibility of establishing numeric effluent limits from 
construction sites (see DCN 41010). The blue ribbon panel found that 
``It is the consensus of the Panel that active treatment technologies 
make Numeric Limits technically feasible for pollutants commonly 
associated with stormwater discharges from construction sites (e.g. TSS 
and turbidity) for larger construction sites. Technical practicalities 
and cost-effectiveness may make these technologies less feasible for 
smaller sites, including small drainages within a larger site, as these 
technologies have seen limited use at small construction sites. If 
chemical addition is not permitted, then Numeric Limits are not likely 
feasible.''
    EPA's selection of Option 2, which requires a turbidity limit only 
for larger sites, is therefore consistent with the panel's conclusion. 
EPA notes that although the panel mentions that a numeric limit is not 
feasible without chemical addition (e.g., polymers) there are 
technologies available (such as electrocoagulation) that do not use 
polymers. Further, data in the literature suggests that a somewhat 
higher limt (e.g., 50-150 NTU) may be achievable using enhanced 
sediment basin design practices without relying on ATS. An option based 
on this approach is discussed in more detail below.
    The panel, in determining that numeric effluent limits are 
technically feasible, did express concerns, including cost-
effectiveness for small sites, toxicity of treatment chemicals, and the 
potential for discharges with low TSS and turbidity into receiving 
waters with high background levels (such as in some arid and semi-arid 
areas) contributing to channel erosion. EPA has determined that Option 
2 addresses these concerns, because the turbidity standard only applies 
to larger sites and does not apply in arid and semi-arid areas because 
of the R-factor applicability criteria. EPA is soliciting comment on 
the need for regulatory requirements or guidance to address the 
concerns regarding potential toxicity of treatment chemicals. EPA also 
solicits comments on whether and how toxicity concerns should factor 
into EPA's BAT determination.
    Based on the analysis conducted for this proposed rule, EPA 
believes that the requirements of Option 2 are economically achievable. 
Option 2 is projected to have a total industry compliance cost, once 
fully implemented in NPDES permits, of $1.9 billion per year (2008 $). 
Since EPA expects that the effluent guidelines requirements will be 
implemented over time as states revise their general permits, EPA 
expects full implementation within five years of the effective date of 
the final rule, currently required to be promulgated in December 2009, 
which would be 2014. EPA estimates that, once fully implemented, there 
will be nearly 82,000 firms that perform work falling within scope of 
Option 2. Average annual revenue for these in-scope firms is $544.14 
billion (2008 $). Option 2 compliance costs are 0.35 percent of in-
scope firm revenues. Of these 82,000 fims, 6,396 would incur costs 
under option 2. These firms have revenues of $409.02 billion (2008$) 
and costs are 0.46% of revenues for firms incurring costs.
    Under Option 2, an estimated 774 firms (0.9 percent of all in-scope 
firms) are estimated to incur compliance costs exceeding 1 percent of 
annual revenue, and 76 firms (0.1 percent of in-scope firms) are 
expected to incur compliance costs exceeding 3 percent of revenue. When 
using EPA's assumption that under normal business conditions firms can 
pass most of their compliance costs along to customers (85 percent of 
costs for residential construction and 71 percent for non-residential), 
there are 20 firms estimated to incur (net) costs exceeding 1 percent 
of revenue, and no firms expected to incur (net) costs exceeding 3 
percent of revenue.
    EPA has attempted to analyze the secondary impacts on home buyers 
when costs are fully passed through. As part of this analysis, EPA 
converted compliance costs into the likely dollar increase in housing 
prices. Making assumptions about likely terms of financing, this was 
converted to an increase in the monthly mortgage payment, where the 
percent increase in home price is approximately equal to the percent 
increase in mortgage payment. This analysis assumes there is no change 
in the set of households that are new home buyers because of the 
proposed regulation. EPA then used income distribution data to estimate 
the change in the number of households in the market for a new home 
that would qualify to purchase the median and lower quartile priced new 
home under the higher monthly mortgage payment. This analysis was 
performed using the median and lower quartile priced new home for each 
metropolitan statistical area (MSA). For the MSA's, the weighted 
average median priced for a home is $322,000, and the percent increase 
would be 0.65%. In this way, EPA has attempted to characterize how the 
potential increase in mortgage payment may affect housing 
affordability. EPA estimated that 2,195 of these prospective home 
purchasers would no longer qualify to purchase a median priced home 
affected by the rule, and 3,243 would no longer qualify to purchase a 
new lower quartile priced home affected by the rule. However, this 
approach only looks at two specific points along the spectrum of 
housing prices and therefore does not represent the total number of 
households potentially impacted by the rule. EPA is interested in 
developing an analysis reflective of the number of households that 
would likely be adversely affected by the proposed regulation, and 
solicits comment on appropriate methodology and any data that would be 
required to conduct such an analysis. Based on our analysis thus far 
EPA believes that the secondary impacts to new home buyers are 
affordable.
    Under normal business conditions with cost pass-through (85% 
residential and 71% non-residential) EPA estimates the number of firms 
expected to incur financial stress as a result of the regulatory 
requirements to be 147 firms which represents 0.2 percent of in-scope 
firms and 2.3 percent of firms incurring

[[Page 72580]]

costs under Option 2. A total of 103 firms are estimated to experience 
negative business value and be at risk of closure due to regulatory 
requirements, which represents 0.1 percent of in-scope firms and 1.6 
percent of total firms incurring costs. These impact measures are not 
additive, as they evaluate different aspects of a firm's financial 
viability, and the same firm may be counted under more than one 
measure. EPA recognizes that this industry is subject to business 
cycles and performed an adverse business conditions analysis to assess 
the impacts during an economic downturn. The adverse business 
conditions case assumes no cost pass-through as well as other less 
favorable operating factors for the industry. No-cost pass through is a 
rigid assumption where all impacts are born by the permitee, and there 
are no secondary impacts on builders who buy lots or buyers of the 
finished construction. For the adverse case, the results for Option 2 
show the number of firms expected to incur financial stress as a result 
of the regulatory requirements to be 479 firms, which represents 0.6 
percent of in-scope firms and 8.3 percent of firms incurring costs 
under Option 2. A total of 662 firms are estimated to experience 
negative business value and be at risk of closure due to regulatory 
requirements, which represents 0.9 percent of in-scope firms and 11.4 
percent of firms incurring costs. Nevertheless, given the measures of 
financial impact, in terms of percentage of in-scope firms and firms 
incurring costs, EPA considers the rule to be economically achievable 
by the construction industry. EPA requests comments on its economic 
achievability analyses and on its proposed determination that Option 2 
is economically achievable.
    EPA's analysis shows that Option 2 has acceptable non-water quality 
environmental impacts. The pollution prevention, sediment and erosion 
control measures included in the proposed rule, including the 
collection and treatment of stormwater at some construction sites, will 
not result in a significant incremental increase in the energy 
consumption, air emissions, or generation of solid waste at 
construction sites.
    EPA has proposed to reject Option 1 as the basis for BAT and NSPS 
in part because it would not represent the best available or best 
demonstrated technology for controlling discharges from this industry. 
Narrative effluent limitations, such as those contained in Option 1, to 
prevent and minimize erosion and sediment dischargers have been a 
feature of NPDES permits for many years. Controls are available and 
demonstrated that provide a higher degree of pollution reduction than 
Option 1 and consistently provide low turbidity values, making a 
numeric turbidity limit feasible. In addition, in considering economic 
achievability of the option, EPA believes that the measures of 
affordability EPA has used in the past, facility closure and firm 
failure, and the firm stress metric used in Regulatory Flexibility 
Analysis also considered here (percent of revenue lost and whether that 
measure is above 1 or 3 percent) demonstrate that Option 2 can be 
reasonably borne by the industry.
    EPA has also proposed to reject Option 3 as the basis for BAT and 
NSPS, due primarily to the total industry cost (estimated at $3.8 
billion annually). Option 3, once fully implemented, would cost $1.9 
billion more annually than Option 2. EPA closely evaluated whether 
establishing a turbidity limit on all construction sites disturbing 
more than 10 acres at a time represents the BAT or NSPS level of 
control--and believes that it does not. Option 3 would require all 
construction sites, in every part of the country and at all times of 
the year, to meet a numeric effluent limitation on turbidity if the 
construction activity disturbs 10 or more acres of land at a time. 
Construction sites that have soils containing relatively little clay 
(e.g., a site in coastal Florida with sandy soils) or with low 
rainfall-runoff erosivity (such as those in certain parts of Idaho) can 
likely control the discharge of sediments and other pollutants through 
effective use of the erosion and sediment control measures included in 
the non-numeric effluent limitations being proposed today. With 
relatively little of the difficult-to-settle clay present, and with low 
rainfall energy, sediment production is expected to be low and EPA 
expects much of the sediment to be removed from stormwater through the 
use of effective sediment controls. Therefore, EPA believes that 
requiring these sites to meet a numeric turbidity limit, including the 
additional costs for monitoring that a numeric turbidity limit would 
impose, does not represent BAT for these sites. EPA solicits comments 
on this approach.
    In light of the high total cost of Option 3 and the appropriateness 
of ELG and NSPS turbidity limits in arid areas and at construction 
sites where rainfall energy is low and soils contain little clay, EPA 
believes that Option 3 does not represent the best available or best 
demonstrated technology for the C&D point source category.
    In summary, EPA believes that Option 2 is technologically 
available, economically achievable, and has acceptable non-water 
quality environmental impacts. EPA believes that establishing a numeric 
turbidity limitation on a segment of the point source category 
represents best available and best available demonstrated technology 
for the C&D industry, striking an appropriate balance that addresses 
the factors EPA is required to consider under the CWA and the nature of 
stormwater discharges from construction sites. In addition, EPA has 
determined that the non-numeric effluent limitations being proposed 
under Option 2 represent best available and best available demonstrated 
technology for all dischargers in the C&D industry.
    Although EPA has proposed Option 2 as a basis for BAT and NSPS, EPA 
is soliciting comment on the appropriateness of the numeric turbidity 
limit of 13 NTUs and the technology basis (i.e., ATS) for Option 2. EPA 
has identified information that indicates that a limit in the range of 
50-150 NTUs might be met by relying on passive, rather than active, 
treatment systems. Passive treatment systems consist of a number of 
techniques that do not rely on pumping of stormwater or mechanical 
filtration and that are not as complex, do not cost as much and do not 
utilize as much energy as ATS.
    Data in the literature indicate that passive systems may be able to 
provide a high level of turbidity reduction at a significantly lower 
cost than active treatment systems. For example, McLaughlin (see DCN 
41005) evaluated several modifications to standard sediment trap 
designs at the North Carolina State University Sediment and Erosion 
Control Research and Education Facility (SECREF). He evaluated standard 
trap designs as contained in the North Carolina Erosion and Sediment 
Control Manual utilizing a stone outlet structure as well as 
alternative designs utilizing a skimmer outlet and various types of 
porous baffles. Baffle materials tested included silt fence, jute/
coconut and tree protection fence tripled over. Tests were conducted 
using simulated storm events in which sediment was added to stormwater 
at flows of 10 to 30 liters per second. McLaughlin found that a 
standard gravel outlet did not significantly reduce turbidity values. 
Average turbidity values in the basin were 843 NTUs, while average 
turbidity in the effluent was 758 NTUs using the standard outlet. Use 
of a skimmer instead of a standard gravel outlet reduced turbidity to 
an average of 353

[[Page 72581]]

NTUs. Additional tests were conducted to evaluate the addition of 
polyacrylamide (PAM) through the use of floc logs. Floc logs are a 
solid form of PAM which are designed to be placed in flowing water. 
They are typically anchored by a rope or by placing them in a mesh bag 
or cage either in open channels or in pipes. As the water flows over 
the floc logs, the PAM dissolves somewhat proportional to flow. The 
floc logs typically have substantial amounts of non-PAM components, 
which are intended to improve PAM release, maintain the physical 
integrity of the blocks and enhance PAM performance (McLaughlin--Soil 
Facts; Chemical Treatments to Control Turbidity on Construction Sites). 
McLaughlin found that addition of PAM to sediment traps resulted in 
average effluent turbidities of 152 NTUs using a rock outlet and 162 
NTUs using a skimmer outlet. For one set of tests, use of a standard 
stone outlet along with PAM was able to attain an average effluent 
turbidity of 51 NTUs, while tests with jute/coconut mesh baffles with 
PAM were only slightly higher, at 71 NTUs.
    Warner (see DCN 43071) evaluated several innovative erosion and 
sediment controls at a full-scale demonstration site in Georgia as part 
of the Erosion and Sedimentation Control Technical Study Committee 
(known as ``Dirt II''). The Dirt II project consisted, among other 
things, of field monitoring as well as modeling of erosion and sediment 
control effectiveness at construction sites. The demonstration site was 
a 50-acre lot in a suburban area near Atlanta where a school was being 
constructed. In total, 22.5 acres of the site was disturbed. A 
comprehensive system of erosion and sediment controls were designed and 
implemented to mimic pre-developed peak flow and runoff volumes with 
respect to both quantity and duration. The system included perimeter 
controls that were designed to discharge through multiple outlets to a 
riparian buffer, elongated sediment controls (called seep berms) 
designed to contain runoff volume from 3 to 4 inch storms and slowly 
discharge to down-gradient areas, multi-chambered sediment basins 
designed with a siphon outlet that discharged to a sand filter, and 
various other controls. Extensive monitoring was conducted at the site. 
For one particularly intense storm event of 1.04 inches (0.7 inches of 
which occurred during one 27 minute period), the peak sediment 
concentration monitored prior to the basin was 160,000 mg/L while the 
peak concentration discharged from the sand filter after the basin was 
168 mg/L. Effluent turbidity values ranged from approximately 30 to 80 
NTUs. Using computer modeling, it was shown that discharge from the 
sand filter, which flowed to a riparian buffer, was completely 
infiltrated for this event. Thus, no sediment was discharged to waters 
of the state from the sand filter for this event. For another storm 
event, a 25-year rainfall event of 3.7 inches occurred over a 2 day 
period. Effluent from one sand filter during this storm was 175 mg/L 
while discharge from a second sand filter was 100 mg/L, except for the 
first-flush data point occurring at the beginning of the storm event.
    There are other references in the literature describing the various 
types of passive treatment systems and the efficacy of passive 
treatment systems. One potential application of a passive system would 
be to add liquid polymer, such as PAM, to the influent of a 
conventional sediment basin. This can be accomplished by using a small 
metering pump to introduce a pre-established dose of polymer in the 
influent pipe or channel. If the polymer is added in a channel far 
enough above the basin, then turbulent mixing in the channel can aid in 
the flocculation process. Otherwise, some sort of provision may need to 
be made to provide mixing in the basin to produce flocs. Polymers 
typically used in this particular application include PAM, chitosan, 
polyaluminum chloride (PAC), aluminum sulfate (alum) and gypsum. With 
any polymer, jar tests should be performed beforehand with soils 
present on the site in order to determine an appropriate polymer type 
and dosage.
    The Auckland (New Zealand) Regional Council conducted several 
trials to evaluate the effectiveness of chemical flocculants and 
coagulants in improving settling of suspended sediment contained in 
sediment laden runoff from earthworks sites (Auckland Regional Council. 
The Use of Flocculants and Coagulants to Aid the Settlement of 
Suspended Sediment in Earthworks Runoff--Trials, Methodology and 
Design. Technical Publication 227. June, 2004). Trials were conducted 
using both liquid and solid forms of flocculants. Trials were initially 
conducted on two projects: a highway project and residential 
development.
    The highway project (ALPURT) evaluated both a liquid polymer system 
and solid polymers. Liquid polymers evaluated were alum and PAC and 
solid polymers evaluated were all polyacrylamide products (Percol AN1, 
Percol AN2 and Percol CN1). Bench tests indicated that AN2 performed 
best among the solid polymers and that both PAC and alum were effective 
in flocculating the soils present on the site.
    Following bench testing of the polymers, liquid and solid dosing 
systems were developed. For the liquid dosing system, initial 
consideration was given to a runoff proportional dosing system which 
would include a weir or flume for flow measurement, an ultrasonic 
sensor and signal generating unit, and a battery driven dosing pump. 
These components, together with costs for necessary site preparatory 
work, chemical storage tanks and a secure housing, were estimated to 
cost approximately $12,000 (1999 NZ $) per installation. An alternative 
system was developed that provided a chemical dose proportional to 
rainfall. This rainfall driven system, which did not require either a 
runoff flow measurement system or a dosing pump, had a total cost of 
$2,400 (1999 NZ $) per installation.
    The rainfall driven system operated by collecting rainfall in a 
rainfall catchment tray. Rainfall into this tray was used to displace 
the liquid treatment chemical from a storage tank into the stormwater 
diversion channel prior to entering the sediment basin. The size of the 
catchment tray was determined based on the size of the catchment 
draining to the basin, taking into consideration the desired chemical 
dosage rate obtained from the bench tests. Accumulated rainfall from 
the catchment tray fills a displacement tank that floats in the 
chemical storage tank. As the displacement tank fills with rainfall and 
sinks, liquid chemical is displaced from the chemical storage tank and 
flows via gravity to the dosing point.
    Field trials of the liquid treatment system using alum were 
conducted at the ALPURT site. The authors report that the system 
performed ``satisfactorily in terms of reduction of suspended solids 
under a range of rainfall conditions varying from light rain to a very 
high intensity, short duration storm, where 24mm of rainfall fell over 
a period of 25 minutes.'' Suspended solids removal for the intense 
storm conditions was 92% with alum treatment. For a similar storm on 
the same catchment with the same retention pond without alum treatment, 
suspended solids removal was about 10%.
    Field trials at the ALPURT site were also conducted using PAC. In 
total, 21 systems were used with contributing catchments ranging 
between 0.5 and 15 hectares (approximately 1 to 37 acres). The overall 
treatment efficiency of the PAC treated basins in terms of suspended 
sediment reduction were

[[Page 72582]]

reported to be between 90% and 99% for ponds with good physical 
designs. The authors noted that some systems did not perform as well 
due to mechanical problems with the system or physical problems such as 
high inflow energy (which likely caused erosion or sediment 
resuspension) or poor separation of basin inlets and outlets. The 
suspended solids removal for all ponds incorporating PAC ranged from 
77% to 99.9%, while the removal in a pond not incorporating PAC ranged 
from 4% to 12%. Influent suspended solids concentrations for the 
systems incorporating PAC ranged from 128 to 28,845 mg/L while effluent 
concentrations ranged from 3 to 966 mg/L. In comparison, influent 
suspended solids concentrations for the untreated ponds were 
approximately 1,500 mg/L while effluent concentrations were 
approximately 1,400 mg/L. The authors also noted that dissolved 
aluminum concentrations in the outflow from the basins treated with 
PAC, in most cases, were actually less than the inflow concentrations, 
and were also less than the outflow concentrations from the untreated 
ponds. Outflow aluminum concentrations in the PAC treated ponds ranged 
from 0.01 to 0.072 mg/L. The ALPURT trials generally indicate that a 
relatively simple, passive treatment system using liquid polymers can 
result in significant reductions in suspended sediment concentrations, 
even with influent concentrations in excess of 25,000 mg/L. Although 
some effluent concentrations were as high as several hundred mg/L, the 
majority were below 100 mg/L. This indicates that a passive liquid 
polymer system, perhaps coupled with a gravity sand filter or 
distributed discharge to a vegetated buffer (as described by Warner, 
2001) could be used to meet a numeric effluent limit for turbidity at a 
significantly lower cost than ATS. EPA solicits comments on this issue.
    Field trials of polymer treatment using solid forms of PAM by the 
Auckland Regional Council were conducted at the ALPURT site as well as 
a residential project (Greenhithe). Trials at the ALPURT site were 
conducted by placing the floc blocks in plastic mesh bags in plywood 
flumes through which the runoff from the site was directed. Initial 
trials encountered problems due to the high bedload of granular 
material, which accumulated against and stuck to the floc logs 
inhibiting solubility of the polymer. The system was reconfigured to 
incorporate a forebay before the flumes in order to facilitate removal 
of the bedload fraction. The authors noted that while this system was 
generally effective at low flow rates, it was difficult to control 
dosage rates and sediment accumulation in the flumes continued to be a 
problem. The authors concluded that ``Floc Block treatment has a high 
potential for removal of suspended solids from stormwater with 
consistent quality, particularly for small catchments; when flow 
balancing can be achieved prior to treatment.''
    Field trials were also conducted at the Greenhithe site, which was 
a 4 hectare (approximately 10 acre) residential project. As with the 
ALPURT trial, a flume was constructed and placed in the flow path 
immediately before the sediment basin. Results of the trials were 
mixed. The authors noted several problems with the floc logs, such as 
drying and breakdown of the logs due to prolonged exposure to the air 
and softening and breakdown during periods of prolonged submergence. 
Sediment accumulation around the logs and breakdown continued to be a 
problem. Incorporating an effective sediment forebay and limiting 
bedload are suggestions for increasing performance. In addition, the 
authors recommended soaking the floc logs in water to allow hydration 
before use and periodic spraying with water as ways to limit drying of 
the floc logs. EPA notes that similar problems with floc logs have been 
noted by some construction site field inspectors (see DCN 41109) and by 
McLaughlin (see DCN 43082). EPA solicits comments on the effectiveness 
of floc logs as components of passive treatment systems. EPA also 
solicits comments on any operational or maintenance considerations that 
should accompany use of solid forms of polymers.
    Results of the PAC studies at the ALPURT sites have led the 
Auckland regional council to require chemical treatment for any site 
that produces more than 1.5 metric tons of (net) sediment as determined 
by the Universal Soil Loss Equation. Sites that exceed this threshold 
will require chemical treatment in accordance with a site chemical 
treatment plan. Exceptions include projects of less than one month 
duration and sites with granular volcanic soils and sand areas. 
Chemical treatment may also not be required if bench testing indicates 
that chemical treatment will provide no improvement in sediment removal 
efficiency (see DCN 41111). EPA solicits comments on the approach 
adopted by the Auckland Regional Council and its applicability to 
construction and development site discharges in the U.S.
    In addition to (or in place of) adding polymers to sediment basins, 
polymers can be introduced on other areas of the site as a soil 
stabilization measure or as components of other BMPs. For example, 
McLaughlin (DCN 41005) evaluated adding polymer to check dams on 
highway projects. Various other researchers evaluated PAM as a soil 
stabilization agent. There are a number of documents in the 
administrative record for this rulemaking describing the use of PAM.
    The data from these studies indicate that various types of passive 
treatment systems that utilize both solid and liquid forms of polymers 
have been reported to be effective in reducing turbidity levels in 
discharges from construction and development sites. EPA is therefore 
soliciting comments on whether a turbidity limitation of 50 to 150 NTUs 
(or some other value) based on passive treatment systems should instead 
serve as the basis for BAT limitations and NSPS. EPA solicits comments 
on the costs, pollutant removal effectiveness and effluent quality 
attainable by passive treatment systems and on the technical basis for 
establishing a particular a numeric turbidity limit of 50 to 150 NTUs 
(or some other value). EPA also solicits comment on the ability to 
reliably meet a 50 to 150 NTU limit using passive systems on different 
types of construction and development sites and in locations across the 
country and on the appropriate monitoring requirements that should 
accompany passive treatment systems. EPA also solicits comments on the 
applicability of a 50 to 150 NTU (or some other value) standard. 
Specifically, since passive systems may be less costly and require less 
expertise and operator supervision than active treatment systems, EPA 
solicits comments on whether a standard based on passive systems should 
apply more broadly and to more sites than are covered by EPA's proposed 
Option 2, or if EPA should establish a tiered set of turbidity 
limitations, reflecting variation of site parameters such as site size, 
rainfall patterns, soil types, soil erodibility, or some other 
parameter and the specific thresholds that should apply to such 
parameters. EPA also requests comment on whether it should develop an 
enhanced non-numeric limitation based on the types of passive 
technologies discussed above without establishing a specific numeric 
limit, as well as whether it should consider an ``action level'' based 
approach such as is required by Washington and several other states 
through their construction general permits. EPA further requests 
comment on the feasibility and burden

[[Page 72583]]

on permitting authorities of an ``action level'' established 
nationally.
2. Definition of ``New Source'' for the Construction and Development 
Category
    EPA interprets the definition of ``new source'' at CWA section 
306(a)(2) as not including discharges associated with construction 
activity. Section 306(a)(2) of the CWA defines ``new source'' as ``any 
source, the construction of which is commenced after publication of 
proposed regulations * * *'' The plain language of section 306 excludes 
C&D sites because a construction site cannot itself be constructed. 
Further, the term ``source'' is defined in 306(a)(3) of the CWA to mean 
``any building, structure, facility, or installation * * *'' or in-
other-words sources that are the product of the construction, not the 
construction activity itself. Additionally, there is an independent 
definition of ``construction'' in section 306(a)(5). If construction 
sites were intended to be ``new sources,'' the Agency finds it 
illogical that there would be a separate definition for 
``construction'' or that there would be a requirement in section 306 of 
the CWA that ``sources'' be ``constructed'' prior to becoming ``new 
sources.''
    Though EPA interprets the CWA not to apply NSPS under section 306 
of the CWA to the C&D point source category, the District Court order 
enjoins EPA to propose and promulgate NSPS. Therefore, EPA proposes to 
define ``new source'' for purposes of part 450 as any source of 
stormwater discharge associated with construction activity that itself 
will result in an industrial source from which there will be a 
discharge of pollutants regulated by a new source performance standard 
in subchapter N other than today's rulemaking. (All new source 
performance standards promulgated by EPA for categories of point 
sources are codified in subchapter N). The definition of new source 
proposed today for purposes of part 450 would mean that the land-
disturbing activity associated with constructing a particular facility 
would itself constitute a ``new source'' when the facility being 
constructed would be a ``new source'' regulated by new source 
performance standards under section 306 of the CWA. For example, 
construction activity that builds a new pharmaceutical plant covered by 
40 CFR 439.15 would be subject to new source performance standards 
under 40 CFR 450.24.

F. Option Selection Rationale for BCT

    EPA is proposing to establish BCT requirements equivalent to BPT. 
As discussed in IX.C above, the requirements of the proposed BPT have 
been demonstrated to be technologically available and EPA's analyses 
show that the requirements are economically achievable.
    Establishing BCT effluent limitations for a point source category 
begins by identifying technology options that provide additional 
conventional pollutant control beyond that provided by application of 
BPT effluent limitations. Conventional pollutants under the CWA are 
biochemical oxygen demand (BOD5), total suspended solids 
(TSS), fecal coliform, pH, and oil and grease. CWA section 304(a); 40 
CFR 401.16. Stormwater discharges, if not adequately controlled, can 
contain very high levels of TSS. In addition, many of the construction 
materials used at the site can contribute BOD or oil and grease. Fecal 
coliform can also be present at elevated levels, due to natural sources 
(contributed by animal wastes) or if stormwater is not segregated from 
sanitary waste facilities. See Section VII for additional discussion of 
pollutant sources.
    EPA evaluates the candidate BCT options by applying the two-part 
BCT cost test. The first part of the BCT cost test is the POTW test. To 
``pass'' the POTW test, the cost per pound of conventional pollutant 
discharges removed in upgrading from BPT to the candidate BCT must be 
less than the cost per pound of conventional pollutant removed in 
upgrading POTWs from secondary treatment to advanced secondary 
treatment. Using the RS Means Historical Cost Indices, the inflation-
adjusted POTW benchmark (originally calculated to be $0.25 in 1976 
dollars) is $0.92 (2008 $). To examine whether an option passes this 
first test, EPA calculates incremental values of the candidate option 
relative to the proposed BPT (Option 1). EPA calculated the incremental 
cost per pound of conventional pollutants removed ($/lb TSS) for Option 
2 to be $0.068. Since this result is less than the POTW benchmark, 
Option 2 passes the first part of the two-part BCT cost test. EPA also 
calculated the incremental cost per pound of conventional pollutants 
removed for Option 3, which is $0.074. Therefore, Option 3 also passes 
the first part of the BCT cost test.
    To pass the second part of the BCT cost test, the industry cost 
effectiveness test, EPA computes a ratio of two incremental costs. The 
numerator is the cost per pound of conventional pollutants removed by 
the BCT candidate technology relative to BPT. The denominator is the 
cost per pound of conventional pollutants removed by BPT relative to no 
treatment (i.e., raw wasteload). As in the POTW test, the ratio of the 
numerator divided by the denominator is compared to an industry cost 
benchmark. The industry cost benchmark is the ratio of two incremental 
costs: The cost per pound to upgrade a POTW from secondary treatment to 
advanced secondary treatment, divided by the cost per pound to 
initially achieve secondary treatment from raw wasteload. If the 
calculated ratio is lower than the industry cost benchmark of 1.29 
(i.e., the normalized cost increase must be less than 29 percent), then 
the candidate technology passes the industry cost test. The calculated 
ratio for Option 2 is 4.46; therefore, it fails the second part of the 
BCT cost test. The calculated ratio for Option 3 is 4.81; therefore, it 
also fails the second part of the BCT cost test. Therefore, EPA is 
proposing to set BCT equal to Option 1.
    EPA estimated loading reductions, which are used as the basis of 
the BCT cost test (as well as the removals, water quality impacts and 
monetized benefits analysis), by using a model site approach and 
modeling soil erosion using the Revised Universal Soil Loss Equation 
(RUSLE). An alternative approach would be to estimate removals on a 
concentration basis by comparing average effluent TSS concentrations in 
construction site discharges under baseline conditions to 
concentrations following EPA's candidate BCT technology options. EPA 
could then estimate total stormwater treatment volumes and, based on 
the change in concentrations following treatment, determine the total 
load of conventional pollutants removed.
    EPA did not use a concentration based approach because a nationally 
representative database of discharge data from construction sites does 
not exist and EPA believes that the data from several states identified 
in the literature is inadequate to use as a basis for national 
estimates. Instead, EPA used RUSLE to estimate soil erosion rates from 
construction sites. EPA chose to use RUSLE because it is a nationally-
recognized model that is based on extensive field data. RUSLE, and its 
predecessors and variants (such as the Universal Soil Loss Equation 
(USLE) and the Modified Universal Soil Loss Equation (MUSLE)), have 
been widely used to estimate erosion rates from agricultural areas. The 
Office of Surface Mining has developed guidelines (see DCN 41113) for 
using RUSLE on mine lands, construction sites and reclaimed areas and 
RUSLE has been widely used to estimate soil erosion rates from these 
areas. RUSLE estimates soil erosion

[[Page 72584]]

rates based on a number of input parameters. These input parameters are 
the rainfall-runoff erosivity factor (R), the soil erodibility factor 
(K), slope length factor (L), slope steepness factor (S), cover-
management factor (C), and practice support factor (P). In developing 
estimates of soil erosion rates, EPA used a mix of data sources as well 
as estimates based on best professional judgment (BPJ). For R, EPA used 
the RUSLE 2 database (RUSLE 2 ARS Version January 19, 2005, Program 
Database) to extract values for each of the indicator cities modeled. 
For K and S, EPA used STATSGO soil survey data for each of the 
indicator cities modeled. For S, EPA inventoried STATSGO soil survey 
data for over 20 million acres of land surrounding eleven indicator 
cities to determine area-weighted average slopes present. EPA used the 
average slope value to calculate the loadings estimates, pollutant 
loading reductions and water quality changes and associated benefits 
contained in today's proposal. EPA also calculated a low slope estimate 
and a high slope estimate in order to evaluate how variation in slope 
values would affect the results. So as not to use the lowest slope 
values reported or the highest slope values reported in the STATSGO 
data, EPA calculated a low slope value as the average of the range of 
low slope values reported and the overall average slope calculated for 
the area. Likewise, EPA calculated a high slope estimate as the average 
between the range of the highest reported slope values reported and the 
overall average slope calculated for the area. EPA estimated baseline 
loads and pollutant load reductions using the high and low slope 
estimates, but did not determine water quality improvements or benefits 
using these values. For L, EPA assumed a range of slope lengths based 
on BPJ. For C and P, EPA used BPJ to select values contained in the 
SEDCAD documentation (SEDCAD 4, Design Manual and User's Guide, Warner, 
R.C. et al. 2006). For C, EPA used a value of 1.0, which corresponds to 
bare soil. For P, EPA used a value of 0.9, which represents a ``Roughed 
and Irregularly Tracked'' soil surface.
    EPA recognizes that alternate reasonable assumptions might 
substantially lower the estimated erosion rates, however, we believe 
that our assumptions based on BPJ are reasonable. EPA notes that the 
RUSLE estimates developed in support of the BCT calculations are 
sensitive to the BPJ assumptions for P, C, and L. EPA assumed bare soil 
conditions with no soil cover for the duration of the construction 
project, which was assumed to be 9 months. EPA also assumed that 90% of 
the construction project would be disturbed. EPA has not identified a 
data source that indicates typical values on construction sites for any 
of these parameters.
    Changing C from 1 to some other value to reflect cover present on a 
portion of the site would reduce the erosion estimates for that portion 
of the site that has been covered. As an example, for subsoil on a 6% 
gradient with straw mulch at 1 ton per acre, the value of C may be 0.2. 
This would lower the erosion estimates for that portion of the site 
that has been covered by a factor of 5. EPA expects that some portion 
of the site would be bare soil for the duration of the construction 
period, while other portions of the site would have cover installed. 
EPA therefore recognizes that its estimates of sediment generation are 
tied to the BPJ assumptions associated with some of the RUSLE 
parameters and solicits data on the percentage of sites of different 
sizes that are likely to be bare soil vs. containing various types of 
cover, and the amount of time these conditions would be present.
    Changes in P would also affect erosion rates. The values selected 
for P would reflect management practices used on the site such as silt 
fences, terraces and straw bale barriers. P is best determined using 
the RUSLE program, since values vary based on location. For example, in 
Lexington, Kentucky, the P value for contour furrowing with moderate 
ridge height on a 300 foot hillslope with a 10% gradient and hydrologic 
soil group B on nearly bare soil is 0.89. This value assumes no silt 
fences, terraces, straw bale barriers or other perimeter controls. 
Because P factors are usually associated with agricultural management 
practices, it is not clear to EPA how to compute a P value that would 
reflect the use practices common on construction sites. EPA solicits 
comments on this issue. As an alternate example of how P might change, 
if 50% cover were to be applied to the above example for Lexington, 
Kentucky, then the P value would change from 0.89 to 0.58, lowering the 
estimated soil erosion rates by 35% (not accounting for any effects 
that changes in cover would have on the other parameters in the model).
    Likewise, changes in estimates for slope and slope length would 
change the erosion rate estimates. EPA notes that the United States 
Department of Transportation (USDOT) specifies maximum slope lengths 
for flows to silt fences, which range from 25 feet on a 50% slope to 
500 feet on a slope of less than 2% for a 30-inch silt fence (USDOT. 
1995. Best management practices for erosion and sediment control. 
Report No. FHWA-FLP-94-005. Eastern Federal Lands Highway Design, U.S 
Department of Transportation, Sterling, Virginia), which are generally 
consistent with the BPJ slope lengths selected by EPA, which range from 
150 to 425 feet. Maximum slope lengths can be even longer if super silt 
fence is used. Maryland Department of the Environment (MDE) specified 
maximum slope lengths for super silt fences ranging from 250 feet on a 
50% or greater slope to 1,500 feet on a slope between 10 and 20%. For 
slopes less than 10%, there are no limitations on maximum slope lengths 
when super silt fence is used (see Table 7-14 of the TDD). In contrast, 
the March 18, 2008 draft California construction general permit would 
require dischargers for Risk Level 2 and 3 sites to apply linear 
sediment controls along the toe, face and at the grade breaks of 
exposed and erodible slopes. Maximum sheet flow lengths would be 20 
feet for slopes between 0 and 25%, 15 feet for slopes between 25 to 50% 
and 10 feet for slopes over 50%. If EPA were to make different 
assumptions about slope length, or use different data to estimate 
slopes, this could significantly lower the soil erosion estimates. EPA 
solicits comments on using the USDOT, MDE, draft California, or other 
data or recommendations as appropriate bases for estimating slope 
lengths likely to be present on construction sites. EPA also solicits 
data indicating slope lengths as a function of slope present on actual 
construction sites as well as other methods to approximate slope 
lengths. It has been suggested that using the average slope value from 
STATSGO for areas surrounding EPA's indicator cities may not reflect 
the possibility that permittees may choose to select land that has 
flatter slopes than the average values calculated from the STATSGO 
data, or that permittees may quickly grade sites to be a flatter slope 
than the average values calculated from the STATSGO data before exposed 
soil is exposed to significant rainfall. EPA notes that in these cases, 
the slope length on these sites may be longer than the values estimated 
by EPA. Conversely, using the average slope value from STATSGO for 
areas surrounding EPA's indicator cities may not reflect steeper slopes 
that may be present on projects such as infill developments within 
existing urban or suburban areas. These sites may not have been 
developed earlier because flatter land was available to developers.

[[Page 72585]]

However, as development progresses outward from the urban core and land 
becomes less available, it is plausible to assume that undeveloped 
areas with steeper slopes may be developed. In these cases, slope 
lengths may be shorter than those estimated by EPA.
    While EPA chose to use the RUSLE model because a nationally 
representative database of discharge data from construction sites does 
not exist, EPA did compare available data with its RUSLE model results. 
EPA identified several sources of discharge data. Table 5-1 of the TDD 
lists eight studies from six states (Maryland, Pennsylvania, 
Washington, Georgia, Texas and Ohio) that contain TSS data from 
construction site discharges. These studies show mean inflow TSS 
concentrations ranging from 359 to 17,500 mg/L, with a mean TSS 
concentration from all studies of 3,681 mg/L. Additionally, during the 
current rulemaking, EPA collected discharge data from two vendors and 
the Oregon Department of Environmental Quality associated with ATS 
systems on 17 sites located in the states of Oregon, Washington and 
California. These data show NTU measurements in the influent to the ATS 
ranging from 0.3 to 4,816 NTUs, with most measurements in the hundreds 
of NTUs. Although relationships between TSS and turbidity are highly 
site-specific, it has been suggested that TSS concentrations are 
roughly 3 times turbidity measured in NTUs. Using this conversion for 
the ATS data, influent concentrations ranged from approximately 1 to 
14,400 mg/L, with most measurements below 2,000 mg/L. EPA also 
identified data in two studies discussed earlier in this notice. On a 
site located in Fulton County, GA, Warner found that influent to a 
basin for a 1.04 inch storm (with 0.7 inches falling in a 27 minute 
period) had a peak TSS concentration of 160,000 mg/l. For the Auckland 
monitoring studies, influent concentrations for ponds not using 
chemical treatment ranged from 680 to 1,500 mg/L. Influent 
concentrations to ponds utilizing chemical addition ranged from 128 to 
28,845 mg/L.
    In comparison, EPA's RUSLE model results for the 11 indicator 
cities ranged from a low of 5,984 mg/L in Albany, New York (using the 
low slope estimates) to a high of 283,417 mg/L in Las Vegas, Nevada 
(using the high slope estimate). For the average slope value, which is 
the basis for the load reduction, water quality improvement and 
benefits estimates contained in today's proposal, concentration values 
ranged from a low of 9,874 mg/L in Albany, New York to a high of 
190,872 mg/L in Las Vegas, Nevada, with a median of 78,516 mg/L. These 
results are presented in the record (see DCN 41138).
    Moreover, results from Seattle, WA from one of the eight studies 
mentioned above (Horner, Guerdy, and Kortenhoff, 1990, DCN 01350) can 
be compared with EPA's model results for Seattle. In Horner, the mean 
inflow TSS concentration was 17,500 mg/L. Using the RUSLE model, the 
modeled concentration was 125,593 mg/l.
    EPA also compared its estimates of effluent concentrations from a 
standard sediment basin (without ATS) to available data. Warner 
monitored sediment basins in Georgia and noted TSS concentrations in 
basin effluents ranging from 100 to 20,000 mg/L with effluent turbidity 
values ranging from 125 to 3,500 NTUs. Data from the Aukland study 
found conventional sediment basin effluent concentrations of about 
1,400 mg/L. Data from Horner, Guerdy and Kortenhoff, 1990, Schueler and 
Lugbill, 1990, and Jarrett, 1996 give mean effluent concentrations 
ranging from 63 mg/L to 876 mg/L, with a mean concentration of 365 mg/L 
(see DCN 41138). In addition, 2005 DMR data from 120 construction sites 
in King County, WA (Seattle) show a median effluent concentration of 
9.2 NTU and a mean concentration of 43.11 NTU (which corresponds to 
about 30 mg/L to 130 mg/L using the rough conversion factor referenced 
above). See DCN 41138 for these DMR data. EPA solicits comments on the 
representativeness of the Seattle data as a basis for estimating 
sediment basin effluent concentrations, since it is EPA's understanding 
that this data consists of grab samples collected within 24 hours of a 
storm event (consistent with the Washington monitoring requirements) 
rather than flow-weighted or time-weighted composite samples collected 
during the entire effluent hydrograph. Likewise, EPA solicits comments 
on the other references cited above, and whether these studies should 
be considered representative of discharges from all areas of the 
country.
    In comparison, EPA's RUSLE model and sediment basin removal 
calculation results for the 11 indicator cities ranged from a low 
effluent concentration of 2,992 mg/L in Albany, New York (using the low 
slope estimate) to a high of 79,585 mg/L in Denver, CO (using the high 
slope estimate). For average slope value, which is the basis for the 
load reduction, water quality improvement and benefits estimates 
contained in today's proposal, concentration values ranged from a low 
of 4,937 mg/L in Albany, New York to a high of 61,286 mg/L in Denver 
Colorado, with a median of 34,357mg/L. These results are presented in 
the record (see DCN 41138).
    EPA is concerned about the significant difference between its RUSLE 
modeled results and the basin influent and discharge data from vendors, 
the state of Oregon, DMR data from King County and available studies, 
and the effect this could have on EPA's estimates of loadings, 
monetized benefits, and projected water quality impacts. EPA assumes 
this difference is a reflection of both those parameters in RUSLE for 
which EPA used its professional judgment (e.g., cover, practices and 
slope length), and the possibility that the measured valued reported in 
the literature are not representative of average influent and sediment 
basin effluent concentrations for the range of storm events likely to 
occur for the duration of the construction project.
    To address this concern, EPA conducted a sensitivity analysis to 
explore the potential impacts on its loadings analysis by revising 
several of the RUSLE assumptions. EPA changed its assumptions for the C 
factor and revised the slope length estimates to be consistent with the 
USDOT reference. For C, EPA assumed that half of the site was in bare 
soil conditions (with a C of 1) while the other half of the site had a 
C of 0.12 for sites with less than 5% slope or 0.06 for sites with 
greater than 5% slope. For slope lengths, EPA fit a curve to the USDOT 
data for maximum slope lengths for 30 inch silt fence and determined 
slope lengths for each model site based on the STATSGO average slope 
present. Using these assumptions, estimated load reductions for Option 
2 were 6.2 billion pounds and estimated load reductions for Option 3 
were 11.1 billion pounds. This represents a 77% reduction for Option 2 
and a 78% reduction in estimated removals for Option 3, as compared to 
EPA's primary analysis. EPA solicits comments on this sensitivity 
analysis.
    EPA notes that this sensitivity analysis does not capture the full 
range of uncertainty in its RUSLE based analysis as compared to 
available data. For example, looking just at Seattle, WA, one of EPA's 
11 indicator cities, for which data are also available in Horner, 
Guerdy, and Kortenhoff, 1990, the measured influent value of 17,500 mg/
L is about a factor of seven lower than EPA's calculated average 
influent value of 125,593 mg/L, while for the effluent, the measured 
value is 626 mg/L, which is about a factor of 57 below EPA's calculated 
effluent value of 36,422 mg/L. During the SBREFA outreach, URS

[[Page 72586]]

(on behalf of the National Association of Homebuilders) used 
alternative values for C, P, slopes and slope length and calculated 
sediment erosion rates that were lower by a factor of about 100 than 
EPA's estimates. EPA requests comment on all aspects of its RUSLE 
analysis and the sensitivity analysis.
    EPA requests comment on all aspects of its modeling approach, 
particularly its input values. Additionally, EPA is interested in any 
other sources of sediment basin influent and effluent concentration 
data from construction sites. This data should also include information 
on the location of the site, site characteristics, weather patterns 
(specifically the volume and intensity of storms) and the timing of 
sampling with respect to storm events.

X. Methodology for Estimating Costs to the Construction and Development 
Industry

    In developing today's proposed rule, EPA has used numeric models to 
estimate the costs of compliance with potential regulatory approaches. 
This approach was used to estimate the incremental costs associated 
with the regulatory options at the state and national level.
    In order to estimate costs to different segments of the industry, 
EPA developed nine model project types. These nine model project types 
are: Small, medium and large transportation; small, medium and large 
residential; and small, medium and large non-residential. Small 
projects are those less than 10 acres, medium projects are 10 or more 
but less than 30 acres, and large projects are 30 or more acres. Using 
the NOI data discussed in Section VI.D, EPA developed a national 
distribution of construction projects and determined the median project 
size (in acres) of each of the nine model project types. Using 
estimates of the annual quantity of acres of new developed land 
determined from the NLCD data (discussed in Section VI.B.), EPA 
determined the number of model projects in each of the nine categories 
in each state (excluding Alaska, Hawaii and U.S. territories). Detailed 
results of this analysis are discussed in the Development Document.
    For estimating baseline conditions, EPA evaluated each state's 
erosion and sediment control requirements to determine the size of 
sediment basins currently required in each state. For each of the model 
projects within each state, EPA calculated the size of the sediment 
basin that would be required. When a state's sediment basin 
requirements were based on containing runoff from a specific size of 
storm (such as runoff from the 2-year, 24-hour storm), EPA used one 
indicator city in each state and obtained rainfall data from various 
NOAA sources (see discussion on rainfall data in Section VI.F). EPA 
used the rainfall data for each indicator city for all model projects 
within a given state. To determine runoff quantities, EPA calculated a 
runoff coefficient for each state (see discussion in the Development 
Document for detailed information on these calculations). While EPA 
acknowledges that using one indicator city to represent rainfall 
conditions in an entire state is a somewhat simplified approach, it 
does capture the range of precipitation that occurs across the country 
and serves as a reasonable method of estimating the costs of the 
regulatory options.
    For each of the regulatory approaches considered, EPA determined 
the sediment basin volume (in cubic feet) that would be required for 
each of the model projects in each state. Using data on sediment basin 
costs, EPA estimated the increase in costs over baseline requirements 
for each model project in each state. Using the number of model 
projects in each state, EPA estimated the total costs due to larger 
sediment basins in each state.
    For determining costs for options that include numeric effluent 
limits, EPA obtained data from vendors of stormwater treatment systems. 
The technology EPA used as a basis for estimating costs is chitosan-
enhanced sand filtration, one type of active treatment system. 
Information in the record indicates other active treatment technologies 
have comparable costs. Using data submitted by the vendors, EPA 
determined a cost for treating stormwater for each of the model 
projects that would be expected to be subject to the turbidity limit. 
These costs include treatment chemical costs, labor costs and equipment 
rental costs, as well as sediment disposal and monitoring costs. 
However, EPA did not cost these items separately for each model project 
type. Rather, EPA concluded from examining these data that the average 
cost across all projects using chitosan-enhanced sand filtration is 
$0.02 per gallon treated. This includes all of the costs that would be 
incurred by the operator to install, operate, maintain and remove the 
treatment systems. Using NOAA data on average annual rainfall for one 
indicator city within each state, and using state-specific runoff 
coefficients, EPA determined, for each state, the volume of stormwater 
that would require treatment for each of the nine model projects. EPA 
then estimated the costs for treating stormwater from each model 
construction site within each state based on the $0.02 per gallon 
estimate. EPA also included additional costs for installing storage 
necessary to impound runoff from the 2-year, 24-hour storm event, if 
this volume was greater than the sediment basin storage volume 
currently required in each state. Using the number of model 
construction projects within each state, EPA then determined the total 
costs for treatment at the state and national level.
    Chapter 9 of the Development Document contains a more detailed 
discussion of the EPA's costing approach.

XI. Economic Impact and Social Cost Analysis

A. Introduction

    EPA's Economic Analysis (see Supporting Documentation) describes 
the impacts of today's proposed rule in terms of firm financial 
performance, firm closures, employment losses, and market changes. In 
addition, the report provides information on the impacts of the 
proposal on sales and prices for residential construction. The results 
from the small business impact screening analysis support EPA's 
implementation of the Regulatory Flexibility Act (RFA), as amended by 
the Small Business Regulatory Enforcement Fairness Act (SBREFA). The 
report also presents identified, quantified, and monetized benefits of 
the proposal as described in Executive Order 12866.
    This notice includes related sections such as the cost-
effectiveness analysis in Section XII, benefits analysis in Section XV, 
and benefit-cost analysis in Section XVI. In their entirety, these 
sections comprise the economic analysis (referred to collectively as 
the ``C&D economic analysis'') for the proposed rule. EPA's 
Environmental Assessment provides the framework for the monetized 
benefits analysis. See the complete set of supporting documents for 
additional information on the environmental impacts, social costs, 
economic impact analysis, and benefit analyses.
    The C&D economic analysis, covering subsectors that disturb land 
(NAICS 236 and 237), uses information from, and builds upon, the 2002 
proposed rule (67 FR 42644; June 24, 2002) and the 2004 withdrawal of 
the proposed rule (69 FR 22472; April 26, 2004). In addition to CWA 
requirements, EPA has followed OMB guidance on the preparation of the 
economic analyses for federal regulations to comply with Executive

[[Page 72587]]

Order 12866. See section XIX of today's notice.

B. Description of Economic Activity

    The construction sector is a major component of the United States 
economy as measured by the gross domestic product (GDP), a measure of 
the output of goods and services produced domestically in one year by 
the U.S. economy. Historically, the construction sector has directly 
contributed about five percent to the GDP. Moreover, one indicator of 
the economic performance in this industry, housing starts, is also a 
``leading economic indicator,'' one of the indicators of overall 
economic performance for the U.S. economy. Several other economic 
indicators that originate in the C&D industry include construction 
spending, new home sales, and home ownership.
    During most of the 1990s, the construction sector experienced a 
period of relative prosperity along with the overall economy. Although 
cyclical, the number of housing starts increased from about 1.2 million 
in 1990 to almost 1.6 million in 2000, with annual cycles during this 
period. (U.S. Census Bureau, ``Current Construction Reports, Series 
C20--Housing Starts,'' 2000. http://www.census.gov/const/www). At the 
beginning of the 21st century, the economy began to slow relative to 
previous highs in the 1990s. This slower economic growth had a negative 
impact on construction starts for new commercial and industrial 
projects. Driven in part by low mortgage interest rates, consumer 
spending for new homes continued to remain strong through 2005. 
However, speculative buying and relaxed lending standards helped create 
a market bubble that burst in 2006. Currently the housing market is in 
an economic downturn, yet some near term future projections are for 
renewed growth in housing starts in the third quarter of 2009. (Global 
Insight, ``U.S. Economic Service, Executive Summary'' October, 2008.) 
EPA acknowledges that future predictions can be highly uncertain and 
that other projections may be less optimistic. Nonresidential 
construction, which was weak during the first five years of the decade, 
recovered to 2000 levels by 2007. (Global Insight, ``The Nonresidential 
Picture: Will the Rescuer Need To Be Rescued?'' 2007. Global Insight, 
``U.S. Economic Service, Executive Summary'' October, 2008.) However, 
the construction industry is expected to experience declines for the 
residential, non-residential, and non-building sectors for the near 
future. The weakness in the construction industry will likely continue 
until residential markets work through the current inventory of unsold 
homes and credit markets and the general economy return to a better 
condition (Global Insight, ``U.S. Economic Service, Executive Summary'' 
October, 2008.)
    The C&D point source category is comprised of activities that 
disturb land. The category contains business establishments (the Census 
Bureau uses the term ``establishment'' to mean a place of business; 
``Employer establishment'' means an establishment with employees) that 
are involved in building construction (NAICS 236) as well as heavy and 
civil engineering construction (NAICS 237). As a starting point, Table 
XI-1 shows the number of business establishments in the C&D category in 
1992, 1997, and 2002. Only a portion of these establishments would be 
covered by the proposed regulation, because some of these 
establishments are house remodelers and others build on sites with less 
than one acre of disturbed land each year. The NAICS classification 
system changed between the issuance of the 1997 and 2002 Economic 
Census.
    Table XI-1 shows a sharp decline in the number of developers 
between 1992 and 1997. The decrease in the number of developers may 
have been a response to changes in tax laws and the Financial 
Institutions Reform, Recovery, and Enforcement Act (FIRREA) of 1989 
(Pub. L. 101-73, August 9, 1989) and the 1993 implementing regulations. 
The objective of FIRREA and the implementing regulations was to correct 
events and policies that led to a high rate of bankruptcies in the 
thrift industry in the late 1980s. The regulations changed lending 
practices by financial institutions, requiring a higher equity position 
for most projects, with lower loan-to-value ratios, and more 
documentation from developers and builders. (Kone, D. L. ``Land 
Development 9th ed.'', Home Builder Press of the National Association 
of Home Builders, Washington, DC, 2000).

          Table XI-1--Number of C&D Industry Establishments, 1992, 1997, and 2002, Economic Census Data
----------------------------------------------------------------------------------------------------------------
                                                         1992        1997        2002     Change  92- Change  97-
            NAICS                   Description          (No.)       (No.)       (No.)      97 (%)      02 (%)
----------------------------------------------------------------------------------------------------------------
236..........................  Construction of           168,407     191,101     211,629       13.50       10.70
                                Buildings, except
                                all other Heavy
                                Construction \a\.
237 except 2372..............  Heavy Construction,        37,180      42,554      49,433       14.50       16.20
                                except Land
                                Subdivision.
2372.........................  Land Subdivision.....       8,848       8,185       8,403       -7.50        2.70
                              ----------------------------------------------------------------------------------
    Total...........................................     214,435     241,840     269,465       14.10      11.30
----------------------------------------------------------------------------------------------------------------
\a\ In the 2002 NAICS classification framework, All Other Heavy Construction was assigned among NAICS 236, 237,
  and 238. To maintain relevant comparisons, 2002 All Other Heavy Construction data were reassigned back into
  NAICS 237 (Heavy Construction).
Figures do not necessarily add to totals due to rounding.
Source: U.S. Census Bureau (2005).

    Building upon Table XI-1, Table XI-2 shows the number of firms that 
are expected to be covered under the C&D proposed regulation. 
Construction establishments are relatively permanent places of business 
where the usual business conducted is construction related. 
Construction firms are an aggregation of construction establishments 
owned by a parent company that share an annual payroll. EPA estimates 
that for approximately 99 percent of construction firms there is only 
one establishment, and those that do have more than one establishment 
tend to be in the highest revenue categories.
    For Table XI-2, EPA subtracted out firms that are engaged in home 
remodeling (NAICS 236118) from the total of about 269,000 firms in 
2002, as they would not be subject to the proposed regulations. The 
elimination of remodelers is based on the fact that remodeling and 
renovation activities generally disturb less than one acre of land, if 
at all. EPA requests comment on its methodology for removing remodelers 
from the analysis. Thus, the total number of C&D firms would be 
178,835.
    EPA used data from the Economic Census and other sources to define 
an

[[Page 72588]]

average housing density for the nation as a whole (average number of 
housing units per acre), then used this figure to identify firms to be 
excluded from regulation based on their likelihood of disturbing less 
than one acre on a per project basis. EPA believes that these estimates 
(of firms unaffected by the proposed options) are conservative, meaning 
that they potentially overestimate the actual number of firms that will 
be affected. First, while the regulatory threshold applies to each 
site, EPA excluded firms only if the estimated number of acres 
disturbed in a whole year falls below the regulatory threshold. In 
addition, the analysis was not adjusted for the portion of a site that 
is potentially left undisturbed, such as open space and buffers. 
Furthermore, EPA assumes that all of the housing units built by a firm 
during a year are in a project covered by a single NPDES storm water 
permit, while in reality the firm could build on several separate 
sites. However, the Agency does not have information on the amount of 
houses that are built within subdivisions, rather than on discrete 
lots, by these firms. EPA requests comment on its methodology for 
excluding firms that do not disturb more than one acre of land from the 
analysis.
    Based upon these adjustments of the total number of firms, EPA 
believes there currently are about 81,628 firms that would be covered 
under the rule. However, the Agency has insufficient data to make any 
further adjustments to the population of developers and builders 
covered by the proposal. EPA solicits comment on the Agency's estimate 
of the number of firms that would be covered under the proposal.

          Table XI-2--Number of Firms Covered by the Construction and Development Proposed Regulations
----------------------------------------------------------------------------------------------------------------
                                                                                                    Firms
                                                                                           ---------------------
                   NAICS                                    Industry sector                             Percent
                                                                                              Number    of total
----------------------------------------------------------------------------------------------------------------
2361.......................................                   Residential Building Construction
                                            --------------------------------------------------------------------
236115.....................................  New Single-family Housing Construction            33,609         41
                                              (except operative builder).
236116.....................................  New Multifamily Housing Construction (except       2,620          3
                                              operative builder).
236117.....................................  New Housing Operative Builder................     17,295         21
                                            --------------------------------------------------------------------
2362.......................................                  Nonresidential Building Construction
                                            --------------------------------------------------------------------
236210.....................................  Industrial Building Construction.............      1,610          2
236220.....................................  Commercial and Institutional Building             20,797         26
                                              Construction.
                                            --------------------------------------------------------------------
237........................................                Heavy and Civil Engineering Construction
                                            --------------------------------------------------------------------
237310.....................................  Highway, Street, and Bridge Construction.....      5,696          7
                                            --------------------------------------------------------------------
        Total.............................................................................     81,628
----------------------------------------------------------------------------------------------------------------
Source: Economic Analysis.

C. Method for Estimating Economic Impacts

    EPA has conducted economic impact analyses to determine the 
economic achievability of each of the three ELG options presented in 
this notice. An important aspect of the economic impact analysis is an 
assessment of how incremental costs would be shared by developers and 
home builders, home buyers, and society. This method is called ``cost 
pass-through'' analysis or CPT analysis. Details of this method may be 
found in Chapter 4 of the Economic Analysis.
    The economic analysis for the C&D proposal also uses another method 
called partial equilibrium analysis that builds upon analytical models 
of the marketplace. These models are used to estimate the changes in 
market equilibrium that could occur as a result of the proposed 
regulations. In theory, incremental compliance costs would shift the 
market supply curve, lowering the supply of construction projects in 
the market place. This would increase the market price and lower the 
quantity of output, i.e., construction projects. If the demand schedule 
remains unchanged, the new market equilibrium would result in higher 
costs for housing and lower quantity of output. The market analysis is 
an important methodology for estimating the impacts of the provision 
proposed in today's notice. The economic analysis also reflects 
comments in the October 2001 final report from the Small Business 
Advocacy Review (SBAR) Panel submitted to the EPA Administrator as part 
of the requirements under SBREFA. The SBAR Panel was convened as part 
of the 2002 rulemaking effort and EPA considers the information in the 
2001 report to still be relevant to today's C&D proposal. Small Entity 
Representative (SERs) commenters questioned a number of the assumptions 
in EPA's economic and loading analysis. After considering these 
comments, EPA determined that it was appropriate to continue to rely on 
its existing analysis for this proposed rule. EPA will continue to 
consider the SER comments along with comments received on the proposed 
rule and revise its analyses for the final rule as appropriate.
    EPA estimated the incremental compliance costs for the regulatory 
options using an engineering cost model that accounts for cost factors 
such as treatment costs, labor and operation and maintenance costs. 
Because some of the erosion and sediment controls considered have 
design requirements that take into account meteorological and soil 
conditions, EPA developed compliance costs that take into account 
regional differences.
    EPA estimated both the incremental compliance costs and the 
economic impacts of each regulatory option at the project, firm, and 
industry (national) level. The economic impact analysis considered 
impacts on both the firms in the C&D industry, and on consumers who 
purchase the homes, and buy or rent industrial buildings and commercial 
and office space. In the case of public works projects, such as roads, 
schools, and libraries, the economic impacts would accrue to the final 
consumers, who, in most circumstances, are the taxpaying residents of 
the community. The sections below summarize each modeling effort.

[[Page 72589]]

Detailed information on the data, models, methods, and results of the 
economic impact analyses are available in the Economic Analysis.
1. Model Project Analysis
    EPA estimated project-level costs and impacts for a series of model 
projects. The models establish the baseline economic and financial 
conditions for model projects and assess the significance of the change 
in cash flow that results from the incremental compliance costs. EPA 
used the model project analysis to indicate whether typical projects 
affected by the proposed regulations would be vulnerable to abandonment 
or closure. The Agency developed nine model projects based on 
consideration of size and construction categories. The construction 
categories were: Residential; commercial & industrial building; and 
transportation. These three categories were broken out further into 
small (one acre or more, but less than ten acres), medium (ten acres or 
more, but less than thirty acres) and large (thirty acres or more) 
projects.
    Based on a review of NOI data, each model of the nine project types 
was assigned an average number of acres. Implicit in the model project 
analysis is the assumption that each project is undertaken in its 
entirety by a single entity acting as both developer and builder. EPA 
recognizes that in practice there may be several parties with financial 
investment, planning, and construction roles in a particular land 
development and construction project. For example, on some projects a 
developer may acquire the land, conduct the initial engineering and 
site assessments, and obtain the necessary approvals. The land may then 
be sold to another developer or builder who will undertake the actual 
construction work. Projects are also sometimes undertaken by a 
consortium of firms or individuals, through various types of limited 
liability partnerships (LLP). While it is important to acknowledge this 
variation, for modeling purposes EPA has simplified this aspect and 
assumed only a single entity is involved from beginning to end, 
referred to below as a ``developer-builder.'' This approach measures 
the direct impact of the rule on permit holders expected to incur 
compliance costs. EPA acknowledges that a portion of these costs will 
likely be passed along to small builders. The ability of permitees to 
pass costs through to other builders will vary based on market 
conditions. These effects are addressed as part of the sensitivity 
analysis in Appendix 8-1 of the RFA Chapter in the Economic Analysis. 
Some of these small builders may also be copermitees who are required 
to be in compliance with these standards. To the extent that they are 
copermittees, they are not accounted for in the firms incurring costs. 
However, all costs have been attributed to firms. Allocating costs over 
a broader number of firms may or may not increase the estimated 
impacts, but spreads the same costs over a larger number of firms. EPA 
requests comment about this economic modeling approach.
    Land development and construction typically occurs in a series of 
stages or phases. The model projects developed by EPA incorporate 
assumptions concerning the costs incurred and revenue earned at each 
stage. EPA has modeled all of the projects to reflect three principal 
development stages:
    (1) Land acquisition. The starting point is usually acquisition of 
a parcel of land deemed suitable for the nature and scale of 
development envisioned. The developer-builder puts together the 
necessary financing to purchase the parcel. When lenders are involved, 
they may require certain documentation, such as financial statements, 
tax returns, appraisals, proof of the developer's ability to obtain 
necessary zoning, evaluations of project location, assessments of the 
capacity of existing infrastructure, letters of intent from city/town 
to install infrastructure, environmental approvals, etc. To satisfy 
these needs, the developer may incur costs associated with compiling 
these data.
    (2) Land development. The developer-builder obtains all necessary 
site approvals and prepares the site for the construction phase of the 
project. Costs incurred during this stage are divided among ``soft'' 
costs for architectural and engineering services, legal work, permits, 
fees, and testing, and ``hard'' costs such as land clearing, installing 
utilities and roads, and preparing foundations or pads. The result of 
this phase is a parcel with one or more finished lots ready for 
construction.
    (3) Construction. The developer-builder undertakes the actual 
construction of the buildings. A substantial portion of this work may 
be subcontracted out to specialty subcontractors (foundation, framing, 
roofing, plumbing, electrical, painting, etc.). In the case of a 
housing subdivision, marketing often begins prior to the start of this 
phase, hence the developer-builder may also incur some marketing costs 
at this time. Housing units may come under agreement at any time prior 
to, during, or after completion of construction. Marketing costs are 
part of the baseline costs. EPA determined that no incremental 
marketing costs would be imposed by today's proposed rule.
    EPA conducted an analysis of the multiplier that determines how 
direct compliance costs translate into the change in the cost of the 
final product, or finished construction project. EPA developed 
estimates of the project-specific costs and revenue at each stage of 
project development as part of this baseline scenario. The general 
approach used in establishing the baseline scenario is to assume normal 
returns on invested capital and normal operating profit margins to 
arrive at the sales price for the final product (for example, completed 
new single-family homes in a residential development, or office space 
in a new office park). This produces a more accurate estimate of the 
costs of complying with the proposed regulation than the costs of 
installing and operating the technology alone. These are not the same 
assumptions that are used in the firm level analysis to follow, 
particularly for economic impacts.
    EPA analyzed the impact of today's proposed rule by adding in the 
regulatory costs at the appropriate stage of the project life cycle. An 
important consideration for assessing who ultimately bears the 
financial burden of a new regulation is the ability of the regulated 
entity to pass the incremental costs of the rule on to their customers. 
If the developer-builder can pass all of their costs through to the 
buyer, the impact of the rule on developer-builders is negligible and 
the buyer bears all the impact. Conversely, if they are unable to pass 
any of the cost to buyers through higher prices, then they must assume 
the entire cost. For the economic impact analysis EPA uses three pass-
through cases: Zero cost pass-through; full cost pass-through; and 
partial cost pass-through (85% for residential and 71% for non-
residential).
    Under the first case, the zero (0%) cost pass-through assumption, 
the incremental regulatory costs are assumed to accrue entirely to the 
builder-developer, and appear as a reduction in per-project profits. 
The sale price of the constructed unit and surrounding lot remains the 
same as the asking price in the baseline. Using the full (100%) cost 
pass-through assumption, all incremental regulatory costs are passed 
through to end consumers. Under this approach, the compliance costs are 
also adjusted to reflect the developer's cost of debt, equity, and 
overhead. Consumers experience the impact of the proposed regulatory 
options in the form of a higher price for each new building or housing 
unit. For the partial cost pass-

[[Page 72590]]

through case, firms are assumed to pass on part of the compliance 
outlay to other parties. For the partial cost pass-through case, EPA 
assumes a cost pass-through rate of 85% for residential sectors and 71% 
for non-residential and non-building sectors. This is the expected 
average long-term level of cost pass-through based on observed response 
of market supply and demand to changes in prices for new construction. 
For more on the method used for determining the level of cost pass-
through see Section 3.5 of the Economic Analysis, Analysis of Social 
Cost of the Economic Analysis. When a sector is stressed, cost pass-
through will tend to be below this long-term average (i.e., more costs 
being borne by builders). Conversely, when a sector is booming, most 
costs are likely to be passed through.
    Information in the record indicates that builders do pass through 
much of the regulatory costs to customers. This is supported by the 
academic literature and industry publications. However, the financial 
impact analysis also calculates results under the two bounding cases, 
no cost pass-through for firms and full cost pass-through for 
customers, to assess the ability of these groups to absorb the impact 
of the regulation under a worst case scenario. The two bounding cases 
also provide an approximation of the sensitivity of impact estimates to 
the partial cost pass-through assumptions used for the primary case. 
EPA requests comment on the partial cost pass-through assumptions used 
for the primary case.
    EPA notes that under certain conditions developers might also 
attempt to pass regulatory costs back to land sellers. For example, in 
a depressed market, builders may argue successfully that a regulatory 
cost increase would make a particular project unprofitable unless the 
land costs can be reduced. If the land seller is convinced that a 
residential subdivision project would not proceed, they may be willing 
to accept a lower price for undeveloped land. The ability of developers 
to pass such costs back would likely depend on the sophistication of 
the land owner, their experience in land development projects, 
knowledge of the local real estate market, and, in particular, their 
understanding of the regulations and their likely cost. While evidence 
of cost pass-back to land owners exists for fixed and readily 
identifiable regulatory costs such as development impact fees, it is 
unclear whether a builder's claim that costs would be higher due to 
construction site control regulations would induce land owners to make 
concessions. EPA requests comment on the likely success of developers 
attempting to pass regulatory costs for incremental storm water 
controls back to land owners.
2. Model Firm Analysis
    EPA analyzed the impacts of the regulations at the level of the 
firm by building financial models of representative construction firms. 
Model firms are broken out by revenue ranges for each of the NAICS 
sectors aligning with the principal C&D business segments expected to 
be affected by the regulation (See Table XI-2). These revenue range and 
sector breakouts are based on data reported by the Statistics of U.S. 
Business (SUSB) and the Economic Census. Within each business sector 
and revenue range model firms are further differentiated based on 
median, lower quartile, and upper quartile measures of baseline 
financial performance and condition (i.e., capital returns, profit 
margins, levels of debt and equity to capital, etc.). Firms in the 
upper quartile have better than normal financial metrics, while the 
metrics for firms in the lower quartile are worse than normal. Baseline 
financing costs (cost of debt and equity) was varied over revenue 
ranges, with firms in higher revenue ranges having access to more 
favorable terms. However, the financial data was not sufficiently 
disaggregated to allow financing terms to vary over the three 
quartiles. These model firms are used in combination with compliance 
cost estimates to examine the potential for financial stress, firm 
closures, employment effects, and increased barriers to the entrance of 
new firms to the industry. EPA did not base its analysis, as it has for 
many past ELGs, on firm-specific data because it did not have time 
under the court imposed deadline to survey the industry and gather such 
data.
    The financial statements for the model firms are constructed to 
capture two business condition cases for the firm-level analysis: 
General Business Conditions case that reflects the financial 
performance and condition of C&D industry businesses during normal 
economic conditions; and Adverse Business Conditions case that is meant 
to reflect financial performance during weak economic conditions. The 
two business condition cases are differentiated by the baseline 
operating financial circumstances of the model firms as well as other 
important factors in firm financial performance, including cost of debt 
and equity capital.
    Compliance costs for a given regulatory option are assigned to the 
model firms, by sector and revenue size category, based on an estimate 
of ``annual in-scope acreage per dollar of revenue'' for the various 
model firms. The compliance costs for a given regulatory option were 
converted to a per-acre basis based on project size, type of 
construction and other compliance cost-related characteristics such as 
state and/or climatic region, depending on the option being considered. 
Since affected acreage is the principal driver of compliance costs, the 
number of projects and in-scope project acreage associated with a given 
level of firm revenue will be the primary basis on which compliance 
costs are assigned to the model firms. The basis for estimating number 
of projects and in-scope project acreage for model firms will vary by 
sector and principal construction activity. The estimated per-acre 
compliance costs for the areas subject to the proposed turbidity limits 
range from $1,135 to $16,535, with a median value of $7,501.
    EPA assigns the per acre compliance costs to each model firm based 
on an estimate of the acreage developed per million dollars of 
construction value for the model firm. For residential construction, 
the acreage per million dollars was derived from the Census Bureau's 
Census of Housing. For nonresidential construction, information on 
project acreage and estimated project value from Reed Construction Data 
is used to derive an average number of acres developed per million 
dollars of value (Reed Construction, March 2008; see DCN 51017). Using 
each model firm's acreage to revenue relationship, costs are then 
assigned to firms based on the number of in-scope firms in each revenue 
range category. EPA requests comment on its approach for assigning 
compliance costs to model firms.
    EPA was then able to assess the impact of the annual compliance 
costs on key business ratios and other financial indicators. 
Specifically, EPA examined impacts on the following measures: (1) Costs 
to Revenue Ratio, (2) Pre-Tax Income to Total Assets Ratio, (3) 
Earnings before Interest and Taxes (EBIT) to Interest Ratio, and (4) 
change in business value. The first is a simple screening level measure 
which is important for measuring the impact on small entities. The 
second and third are financial measures reported by Risk Management 
Associates (RMA) for median, lower and upper quartiles by sector and 
business size that were used in constructing the baseline financial 
statements for the model firms. The change in business value measure is 
based on application of compliance

[[Page 72591]]

costs to the model firm financial statements, both as the estimated 
absolute dollar change in value and the fraction of firms whose net 
business value becomes negative because of compliance outlays. The 
impacts of the compliance costs were examined by calculating the values 
of each ratio with and without the compliance costs.
    In previous effluent guidelines rulemakings, EPA has sometimes 
varied levels of cost pass-through and sometimes assumed no cost pass-
through. In practice, the actual level of cost pass-through is 
difficult to estimate and changes over time. For example, when a 
particular industry faces severe economic distress, as with the current 
homebuilding industry, it is less likely that producers will be able to 
pass through as significant a portion of compliance costs. When an 
industry is healthy, higher levels of cost pass-through are likely. 
Also, the larger share of an industry subject to the regulatory 
requirements in question, the greater the ability of individual firms 
to pass through compliance costs, as they will have less competition 
from unregulated producers. For this analysis, EPA used both the 
partial and no cost pass-through scenarios, to assess potential 
economic impacts on the industry under the primary analysis and upper 
bound scenarios. Full cost pass-through would have no impact on the 
firms.
3. Housing Market Impacts
    EPA developed models to assess the potential impacts of the 
regulations on the national housing market. Buyers of new 
nonresidential properties will also be impacted as costs are passed 
through to them. However, they account for a minority of the 
construction projects considered and EPA assumes that this group of 
customers is not as vulnerable to changes in prices as are households 
in the market for new homes. Therefore, impacts to purchasers of new 
nonresidential construction sites were not highlighted as part of the 
financial impact assessment and are accounted for on a more general 
basis as part of the analysis of impacts on the national economy.
    To analyze the impacts of compliance costs on housing 
affordability, EPA estimated the level of income that would be 
necessary to purchase both the median and lower quartile priced new 
home without the proposed regulation, and the change in income needed 
to purchase the median and lower quartile priced new home under each of 
the regulatory options. The Agency then used income distribution data 
to estimate the change in the number of households that would qualify 
to purchase the median and lower quartile priced new home under each of 
the regulatory options. In this way, EPA attempted to estimate the 
number of households that may not be able to afford the exact same new 
home they could under baseline conditions. The housing market analysis 
was performed at the level of the metropolitan statistical area (MSA) 
to account for regional differences in housing prices and income. The 
housing market analysis uses the full cost pass-through assumption, to 
estimate the worst-case impacts on new single-family home buyers.
    When assessing the impact of the rule on housing affordability, EPA 
acknowledges that even those buyers who are able to afford the median 
valued single-family home at the new price may still experience an 
impact. Many households would continue to qualify to purchase (or rent) 
a housing unit of approximately the same price (or rent) as before the 
C&D regulation, but would instead experience a reduction in some 
desirable housing attributes instead. This analysis looks not only at 
the affordability effect at the median-priced housing unit but also 
considers the impact on housing affordability at lower housing prices, 
specifically the impact on households that can afford the lower 
quartile priced home. Focusing on housing prices below the median 
provides important insight into the regulation's impact on housing 
affordability accounting for the likely greater number of households at 
the income levels that just qualify to purchase/rent lower price units. 
EPA requests comment on its approach to assessing impacts of the rule 
on housing affordability.
4. Impacts on the National Economy
    The market model generates an estimate of the change in the total 
value of construction produced by the industry, i.e., industry output. 
Two effects of the regulation are acting on the market value of 
construction output. First, the cost of construction increases, leading 
to a price rise and an increase in market value of final projects. 
Second, the quantity of houses sold is reduced because of the higher 
price due to compliance costs. The net effect on market value may be 
either positive or negative, depending on whether the elasticity of 
demand for housing is less than or greater than 1. There are also 
secondary impacts in other markets, caused by the shift in consumer 
spending, necessitated by the increased housing costs, from other goods 
to housing.
    Markets vary in the level of activity, structure of the industry, 
and ultimately cost pass-through potential, from state-to-state and 
region-to-region. The modeling approach used for the national impact 
analysis captures such regional variation in the impacts of the 
proposed regulatory options by estimating partial equilibrium models at 
the state level for four major building construction sectors (single-
family, multi-family, commercial, and industrial). The analysis of 
state- and national-level economic impacts is based on estimating 
changes to economic output, employment, and welfare measures that 
result from the estimated baseline market equilibrium to the estimated 
post-compliance market equilibrium for each construction sector in each 
state.
    A partial equilibrium analysis assumes that the proposed regulation 
will only directly affect a single industry; in this case, the four 
major construction sectors considered. Holding other industries 
``constant'' in this way is generally appropriate since the compliance 
costs of the proposed regulatory options are expected to result in only 
marginal changes in prices and quantities and the rule does not 
directly affect the other industries (HUD, 2006; see DCN 52015).
    For the partial equilibrium analysis, EPA uses estimated 
elasticities of market supply and demand to calculate the impact of 
incremental costs on the supply curve and, thus, on prices and 
quantities of construction products under post-compliance conditions.
    Economic impacts in the directly affected construction industry can 
trigger further shifts in output and employment losses in the set of 
broader U.S. industrial sectors as these changes pass through the 
economy. The U.S. Department of Commerce uses input-output techniques 
to derive ``multipliers'' which indicate, for a given change in one 
industry's output, how output and employment in the whole U.S. economy 
will respond. EPA has applied the multipliers from the Regional Input-
Output Modeling System, version 2 (RIMS II) to the change in output 
estimated from the market model to estimate some of the anticipated 
impacts on national output and employment. EPA is also using the 
Regional Economic Models, Inc. (REMI) Economic Geography Forecasting 
and Policy Analysis Model to derive a more comprehensive estimate of 
the potential long-term effects on the national economy. The REMI model 
uses a similar set of industry sector multipliers, but also 
incorporates econometric and general equilibrium models to derive a 
more refined

[[Page 72592]]

estimate of the impacts on national output and employment.

D. Results

1. Firm-Level Impacts
    EPA has estimated the economic impacts of the proposed rule at the 
firm level by estimating the number of firm closures, the number of 
lost jobs, and the decrease in firms' profits. The economic impact 
analysis at the firm level looks at two cases. The first assumes that 
none of the incremental costs would be passed through to the final 
consumer, i.e., zero cost pass-through. The Agency used this assumption 
for the economic impact analysis, because it presents the worst-case 
scenario (i.e., the largest impacts to the firm). The second case 
assumes partial cost pass-through, and EPA believes this is more 
reflective of typical circumstances based on EPA's review of the 
academic literature and its discussions with industry officials who 
indicate that under normal business conditions most costs are passed 
through to the final consumer and are not absorbed by firms in the 
industry.
    EPA analyzed economic impacts at the firm level. The firm is the 
entity responsible for managing financial and economic information. 
Moreover, the firm is responsible for maintaining and monitoring 
financial accounts. For the C&D category, most of the business 
establishments, as defined by the Census Bureau, are firms. Likewise, a 
small number of establishments are entities within a larger firm. A 
small percentage of firms have multiple establishments and some firms 
are regional or national in scope.
    Table XI-3 presents one economic indicator, the relationship of 
compliance cost to firms' annual revenue. A comparison between costs 
and revenues is typically done prior to any consideration of the pass-
through of costs to buyers. Firms whose costs exceed 1% of revenue are 
only 4.5 percent of the approximately 82 thousand in-scope firms for 
the most costly option. Furthermore, firms whose costs exceed 3% of 
revenue are significantly less than 1% for all options considered for 
proposal.

                           Table XI-3--Cost to Revenue, Assuming No Cost Pass-Through
----------------------------------------------------------------------------------------------------------------
                                              Costs exceeding 1% revenue          Costs exceeding 3% revenue
                                         -----------------------------------------------------------------------
                                                                  Percent of                          Percent of
                 Option                   Number  of  Percent of     firms     Number of    Percent      firms
                                             firms     firms  in-  incurring     firms     of firms    incurring
                                                         scope       costs                 in-scope      costs
----------------------------------------------------------------------------------------------------------------
Option 1................................           0         0.0         0.0           0         0.0         0.0
Option 2................................         774         0.9        12.1          33         0.0         0.5
Option 3................................       2,475         3.0        18.0         146         0.2         1.1
----------------------------------------------------------------------------------------------------------------
Source: Economic Analysis.

    Table XI-4 presents two additional economic indicators that measure 
the potential decrease in firms' financial fitness. These indicators 
are presented using the partial cost pass-through case, which 
represents the firms' expected ability to pass costs through to buyers. 
These two indicators were also assessed using the no cost pass-through 
assumption as one of the revisions made to the adverse analysis case 
discussed below.

 Table XI-4--Firms Expected To Incur Financial Stress, Assuming Partial
                            Cost Pass-Through
------------------------------------------------------------------------
                                          Option 1   Option 2   Option 3
------------------------------------------------------------------------
     Firms Estimated To Incur Deterioration in Measures of Financial
                               Performance
------------------------------------------------------------------------
Number Incurring Effect................         17        147        445
% of All In-scope Firms................        0.0       0.18        0.5
% of Firms Incurring Cost..............        0.5        2.3        3.2
------------------------------------------------------------------------
     Firms Whose Net Business Value Becomes Negative as a Result of
                               Compliance
                          (Potential Closures)
------------------------------------------------------------------------
Number Incurring Effect................         18        103        389
% of All In-scope Firms................        0.0       0.13        0.5
% of Firms Incurring Cost..............        0.6        1.6        2.8
Number of Jobs.........................      1,087     11,359     25,266
% of In-scope Firm Employees...........        0.5        1.8        2.7
------------------------------------------------------------------------
Source: Economic Analysis.

    Deterioration of firm financial performance is based on assessing 
the impact of costs on two financial measures (Pre-Tax Income/Total 
Assets and Earnings before Interest and Taxes/Interest). EPA estimated 
the fraction of firms in the various sector and revenue ranges whose 
financial indicators decline below the lower quartile for these two 
measures, as reported by Risk Management Associates (RMA). For each 
sector and revenue category, whichever of the two measures have the 
greatest decline is used to represent the impact on financial 
performance. For additional information on EPA's analysis of the change 
in financial position, see Section 3.3.4, Estimating the Change in 
Model Firm Financial Performance and Condition, from the Economic 
Analysis.
    The second economic indicator is firm closures and resulting job 
loss, by regulatory options. These numbers represent the impact on 
firms with thin profit margins who are most vulnerable to impacts from 
costs increases, and they do not represent the effects of a reduction 
in the overall quantity of

[[Page 72593]]

construction activity as a result of the C&D rule. Both phenomena can 
result in job losses, but they are two separate measures of job losses 
and are not necessarily wholly additive or overlapping. Construction is 
a highly competitive industry that is characterized by many small firms 
with a relatively high turnover and low barriers to entry. Firms 
routinely expand and contract their workforce in response to work load 
and as a result many workers laid off when a firm closes are rehired by 
new and other existing more financially healthy firms. Therefore, job 
losses due to firm closures are in many cases a temporary displacement 
of the workforce. By contrast, job losses due to market contraction 
result from an overall reduction in the volume of construction and can 
be considered a more lasting effect until market conditions change 
again. For more information on job losses due to market contraction, 
see Section 3.5 Analysis of Social Cost in the Economic Analysis.
    The C&D industry has historically been a relatively volatile 
sector, and is subject to wider swings of economic performance than the 
economy as a whole. EPA has used historical financial and census data 
for the C&D industry to discern long-term trends within the market 
fluctuations. EPA based its primary economic analysis on data that 
reflects average long-term performance rather than a temporary high or 
low. The industry is currently experiencing a period of weakness, which 
will persist until residential markets work through the current 
inventory of unsold homes, and credit markets and the general economy 
return to a better condition. There continues to be considerable 
uncertainty regarding how much the market for new construction will 
contract or how far real estate values will decline, before the 
construction industry begins to recover. EPA realizes that the rule 
will be promulgated during a low period for the industry, and there may 
be concerns that additional compliance costs, associated with the rule, 
could have a greater than normal impact on C&D firms and potentially 
slow the industry recovery. Again using historical census and financial 
data for the industry EPA identified periods of weakness for various 
industry sectors and used them to develop a secondary analysis that 
represents potential impacts of additional compliance costs during a 
period of adverse economic circumstances. Three key assumptions EPA 
used to represent adverse conditions for the industry were that there 
would be a contraction in overall market activity, firms would finance 
projects under less favorable terms and no costs incurred by the firm 
as a result of compliance would be passed through to the buyer. Table 
XI-5 below shows the results of the adverse analysis case. The number 
of firms experiencing impacts reflects the market contraction, so they 
are not directly comparable to the primary analysis case, since they 
represent differing levels of regulated activity. However, a comparison 
of the percentage of in-scope firms experiencing impacts and firms 
incurring costs that experience impacts illustrate the relative 
difference between the two cases. With regard to Option 2, the 
percentage of firms in-scope incurring financial stress in the adverse 
case is three and a half times the percentage in the primary economic 
analysis and the percentage of in-scope firms at risk of closure in the 
adverse case is seven times the percentage in the primary economic 
analysis. There are also corresponding increases in short-term 
employment losses. However, even with the greater impacts seen under 
the adverse analysis case, the percentage of total firms experiencing 
financial hardship, under any of the metrics considered, does not 
exceed one percent of total in-scope firms or 12 percent of firms 
incurring costs, for the proposed option. Another important 
consideration for the adverse analysis case is that under the no-cost 
pass through assumption, there are no secondary impacts on small 
builders or affordability effects for buyers. For additional 
information on the adverse impact analysis case, see Chapters Three and 
Five of the Economic Analysis.

               Table XI-5--Adverse Impact Analysis Results
------------------------------------------------------------------------
        Impact analysis concept           Option 1   Option 2   Option 3
------------------------------------------------------------------------
Firms with Costs Exceeding 1 Percent of
 Revenue:
    Number of Firms....................          0        698      2,233
    % of Firms In-Scope................       0.0%       0.9%       3.0%
    % of Firms Incurring Cost..........       0.0%      12.0%      17.9%
------------------------------------------------------------------------
Firms with Costs Exceeding 3 Percent of
 Revenue:
    Number of Firms....................          0         30        132
    % of Firms In-Scope................       0.0%       0.0%       0.2%
    % of Firms Incurring Cost..........       0.0%       0.5%       1.1%
------------------------------------------------------------------------
Firms Incurring Financial Stress:
    Number of Firms....................         51        479      1,534
    % of Firms In-Scope................       0.1%      0.64%       2.0%
    % of Firms Incurring Cost..........      1.75%       8.3%      12.3%
------------------------------------------------------------------------
Firms with Negative Business Value
 (Potential Closures):
    Number of Firms....................         88        662      2,164
    % of Firms In-Scope................       0.1%      0.88%       2.9%
    % of Firms Incurring Cost..........      3.03%      11.4%      17.4%
------------------------------------------------------------------------
Source: Economic Analysis.

    Since EPA expects that the effluent guidelines requirements will be 
implemented over time as states revise their general permits (EPA 
expects full implementation within five years of the effective date of 
the final rule, currently required to be promulgated in December 2009, 
which would be 2014), EPA has used macroeconomic forecasts of 
construction activity to assess when the industry is likely to return 
to its long-term trend (Global Insight, ``Housing and Construction'', 
2008) (Global Insight, ``U.S. Economic Service, Executive Summary'' 
2008). Based on these forecasts, EPA anticipates that the industry 
activity will have recovered to

[[Page 72594]]

the long-term trend during the period when the rule is being 
implemented.
2. Impacts on Governments
    EPA has analyzed the impacts of today's proposed rule on government 
entities. This analysis includes the cost to governments for compliance 
at government-owned construction project sites (construction-related). 
For construction-related costs, EPA assumed that 100 percent of the 
incremental compliance costs that contractors incur at government-owned 
construction sites are passed through to the government. EPA also 
estimated the additional administrative costs that government entities 
would incur for reviewing the additional monitoring reports associated 
with the turbidity monitoring requirements of Options 2 and 3. Table 
XI-6 shows the costs that government entities are expected to incur at 
federal, state, and local levels.

               Table XI-6--Total Costs by Government Unit
                            [Millions 2008 $]
------------------------------------------------------------------------
                                          Option 1   Option 2   Option 3
------------------------------------------------------------------------
                            Compliance Costs
------------------------------------------------------------------------
Federal................................       $2.3      $34.0      $66.5
State..................................        4.4       68.1      128.2
Local..................................       25.1      390.7      735.8
------------------------------------------------------------------------
                          Administrative Costs
------------------------------------------------------------------------
Federal................................        0.0        0.0        0.0
State..................................        0.0        0.1        0.2
Local..................................        0.0        0.6        1.0
------------------------------------------------------------------------
                               Total Costs
------------------------------------------------------------------------
Federal................................        2.3       34.0       66.5
State..................................        4.4       68.2      128.4
Local..................................       25.1      391.3      736.8
                                        --------------------------------
    Total..............................       31.8      593.5      931.7
------------------------------------------------------------------------
Source: Economic Analysis.

    These additional government costs are not expected to have a 
significant impact on state and local governments as they account for 
less than a tenth of a percent of state government revenues and less 
than a tenth of a percent of estimated local government revenues. For 
additional information on the effect of the rule on government entities 
see the UMRA analysis in Chapter 9 of the Economic Analysis.
3. Community-Level Impacts
    EPA has estimated community-level impacts based upon the 
incremental costs of the proposed rule at the household level. The 
household impacts are those that would affect local communities in 
terms of the costs of housing. EPA's analysis considers the impacts on 
the price of housing based on the increase/decrease in the median price 
per house. Table XI-7 shows the change by selected option in the price 
per house. It is important to note that these costs would not apply to 
all new houses built in the U.S., but rather only to those houses that 
are part of construction projects that are subject to the given 
regulatory option. Approximately 3 percent of total annual home sales 
are expected to be in projects subject to Option 1, 8 percent to Option 
2 and 13 percent to Option 3. When considering only newly-built homes, 
approximately 21 percent of sales are expected to be in projects 
subject to Option 1, 52 percent to Option 2 and 90 percent to Option 3. 
The table also provides estimates of the expected change in monthly 
payments under each option for the median and lower quartile priced 
home. The monthly mortgage payments were calculated using the median 
and lower quartile priced house for each Metropolitan Statistical Area 
(MSA) in the country. For the MSA's, the weighted average median price 
for a home is $322,000, the 5th percentile is $110,000, and the 95th 
percentile is $560,000. For the lower quartile priced home, the 
weighted average is $201,000, the 5th percentile is $66,000, and the 
95th percentile is $404,000. The U.S. Census does not report lot sizes 
for the upper or lower quartile. However, housing census data indicates 
that lower-priced homes have a greater likelihood of having a smaller 
lot size (U.S. Census Characteristics of New Housing, 2006). To account 
for this factor, EPA performed the affordability analysis for the 
lower-quartile price home twice, using both the median lot size for all 
single family homes and the median lot size for attached single family 
homes.

   Table XI-7--Change in Monthly Mortgage Payment for New Single-Family
                                  Home
                        [Full cost pass-through]
------------------------------------------------------------------------
                                          Option 1   Option 2   Option 3
------------------------------------------------------------------------
                  New Single-Family Median Priced Home
------------------------------------------------------------------------
Price Change New Single-Family Home on        $330     $2,100     $2,242
 Median Sized Lot......................
Baseline Mortgage Payment ($/month)....     $1,971     $1,971     $1,971
New Mortgage Payment ($/month).........     $1,972     $1,985     $1,986

[[Page 72595]]


% Change...............................      0.05%      0.70%      0.75%
------------------------------------------------------------------------

    New Single-Family Lower Quartile Priced Home on Median Sized Lot
------------------------------------------------------------------------
Price Change New Single-Family Home on        $330     $2,100     $2,242
 Median Sized Lot......................
Baseline Mortgage Payment ($/month)....     $1,358     $1,358     $1,358
New Mortgage Payment ($/month).........     $1,359     $1,372     $1,373
% Change...............................      0.04%      1.01%      1.09%
------------------------------------------------------------------------
  New Single-Family Lower Quartile Priced Home on Median Sized Lot for
                       Attached Single-Family Home
------------------------------------------------------------------------
Price Change New Single-Family Home on        $118       $738       $803
 Median Sized Attached Lot.............
Baseline Mortgage Payment ($/month)....     $1,358     $1,358     $1,358
New Mortgage Payment ($/month).........     $1,359     $1,363     $1,364
% Change...............................      0.01%      0.36%      0.39%
------------------------------------------------------------------------
Source: Economic Analysis.

    The increase in mortgage payments attributable to the proposed 
options compared to the estimated mortgage payment for the median price 
of a new house in the U.S., currently about $1,971, is a small 
percentage of the overall payment. For these costs, the average monthly 
mortgage payment would increase by $1, $14, and $15 per month for 
Options 1, 2, and 3, respectively. For the analysis, EPA assumes that 
buyers finance approximately 80% of the home purchase price using a 30-
year conventional fixed rate mortgage with an interest rate of 7.39%.
    EPA also estimated how the change in home prices would affect 
mortgage availability. EPA estimated that 2,195 prospective new home 
purchasers would no longer qualify to purchase a new median priced home 
affected by the rule, and 3,243 would no longer qualify to purchase a 
new lower quartile priced home affected by the rule. Most impacted home 
buyers, except those at the low end of the income distribution, would 
still be able to purchase newly built homes, but not as expensive a 
home as they could afford without the regulation. EPA has attempted to 
characterize how the potential increase in mortgage payment may affect 
housing affordability. However, this approach only looks at two 
specific points along the spectrum of housing prices and therefore does 
not represent the total number of households that would have to make a 
different homebuying decision as a result of the rule. EPA is 
interested in developing an analysis reflective of the number of 
households that would likely be adversely affected by the proposed 
regulation, and solicits comment on appropriate methodology and any 
data that would be required to conduct such an analysis. For more 
information on the affordability analysis see Section 3.4, Analysis of 
Regional-Level Housing Affordability Impacts, of the Economic Analysis.
4. Foreign Trade Impacts
    As part of its economic analysis, EPA has evaluated the potential 
for changes in U.S. trade (imports, exports) of C&D related goods and 
services. A significant component of the U.S. C&D category operates 
internationally, and, in addition, numerous foreign firms that 
participate in this category also operate in the U.S. EPA judged that 
the potential for U.S. C&D firms to be differentially affected by the 
proposed rule is negligible. The proposed rule will be implemented at 
the project level, not the firm level, and will affect projects within 
the U.S. only. All firms undertaking such projects, domestic or 
foreign, will be subject to the proposed rule. U.S. firms doing 
business outside the U.S. will not be differentially affected compared 
to foreign firms, nor will foreign firms doing business in the U.S.
    This proposed rule could theoretically stimulate or depress demand 
for some construction-related goods. To the extent that the proposed 
rule acts to depress the overall construction market, demand for 
conventional construction-related products may decline. This decline 
may be offset by purchase of goods and services related to erosion and 
sediment control. Overall, EPA does not anticipate that any shifts in 
demand for such goods and services resulting from the proposal would 
have a significant implication for U.S. and foreign trade.
5. Impacts on New Firms
    The construction sector is a relatively fluid industry, as 
documented in the industry profile, with low barriers to entry and 
considerable entry and exit activity from year to year. As a result, 
the potential employment losses or capital idling effects of weakness 
in a specific firm are likely to be offset by changing levels of 
activity in other existing firms or entry of new firms into the local 
market. EPA conducted an analysis to assess the impacts on new firms 
that choose to enter the C&D point source category. This analysis uses 
a method called ``barrier to entry''. EPA examined the ratio of 
compliance costs to current and total assets to determine if new market 
entrants could find it more difficult to assemble the capital 
requirements to start a project than would existing firms. The 
methodology is conservative, because it doesn't account for the fact 
that a firm would typically be expected to finance 20 percent of the 
incremental compliance costs from their own financial resource to 
obtain the loan, not the full amount as assumed here. In addition, 
existing firms would need to meet the same requirement, and therefore 
would not obtain a competitive advantage over new entrants. For more 
information on the analysis see Section 3.3.6 Assessing Potential 
Barriers to Entry of New Businesses to the C&D Industry from the 
Economic Analysis.
    For the proposed regulatory option (Option 2), the increase in 
financing requirement varies from approximately 2.7 percent to 7.7 
percent of baseline assets depending on the firms size and business 
sectors. This comparison assumes that the new firm's compliance outlay 
would be financed and recorded

[[Page 72596]]

on its balance sheet. To the extent that the compliance outlay is 
financed and recorded not on the firm's baseline sheet but as part of a 
separate project-based financing for each individual project, this 
comparison is likely to be overstated, perhaps substantially. EPA does 
not consider the increase in financing requirements to pose a 
significant barrier to entry for potential businesses and projects.
6. Social Costs
    EPA's analysis of social costs for each option contains four costs 
components: (1) Firm compliance costs; (2) incremental increase in 
government administrative costs; and (3) deadweight loss (loss of 
economic efficiency in the construction market). When summed, these 
three cost categories comprise the total social costs for each option.
    EPA has conducted a social cost analysis for each option. The 
Economic Analysis provides the complete social cost analysis for the 
proposed regulation. The firm-level estimate compliance cost, however, 
does not account for the potential affect of the proposed options on 
the quantity of construction activity/units performed in the various 
C&D markets. Compliance costs for each proposed option have the effect 
of increasing builder/developer costs, which can cause a leftward shift 
in the market's supply curve. Part of the increased costs may raise the 
price of new housing, with the balance of increased costs being 
absorbed by the builder, depending on the relative elasticities of 
supply and demand. The resulting shift in market equilibrium may also 
reduce the quantity of construction units produced in a given market.
    EPA has estimated a state-by-state linear partial equilibrium 
market model for each C&D building sector to estimate this potential 
market effect on the quantity of output. The estimated change in the 
quantity of output produced in each C&D market segment is then used to 
not only adjust the firm-level resource cost of compliance, but also to 
compute the economic value of the reduction in C&D output, and estimate 
the total loss of consumer and producer surplus, referred to as the 
deadweight loss. Table XI-8 shows the change in cost due to the 
quantity effect (i.e. reduction in market activity), the dead weight 
loss, and their combined effect on total costs.

                Table XI-8--Total Social Cost of Options
                           [Millions of $2008]
------------------------------------------------------------------------
                                          Option 1   Option 2   Option 3
------------------------------------------------------------------------
Total Costs, Unadjusted for Quantity          $132     $1,891     $3,797
 Effect................................
    Change in Costs Due to Quantity            0.1          7         17
     Effect............................
    Total Costs, Adjusted for Quantity         132      1,884      3,780
     Effect............................
Total Dead Weight Loss.................        0.0        3.5        8.4
Additional Government Administrative           0.0        0.7        1.2
 Costs.................................
Total Social Cost of the Regulation....        132      1,888     3,789
------------------------------------------------------------------------
Source: Economic Analysis.

7. Small Business Impacts
    Section XIX.C of today's document provides EPA's Regulatory 
Flexibility Analysis (RFA) analyzing the effects of the rule on small 
entities. For purposes of assessing the economic impacts of today's 
proposed rule on small entities, small entity is defined by the U.S. 
Small Business Administration (SBA) size standards for small businesses 
and RFA default definitions for small governmental jurisdictions. The 
small entities regulated by this proposed rule are small land 
developers, small residential construction firms, small commercial, 
institutional, industrial and manufacturing building firms, and small 
heavy construction firms.
    Table XI-9 shows the impacts of the proposal using the one percent 
and three percent revenue tests, a method used by EPA to estimate the 
impacts on small businesses. The table presents the results for the 
regulatory options.

     Table XI-9--Small Business Analysis for Options, 1% and 3% Revenue Tests, Assuming No Cost Pass-Through
----------------------------------------------------------------------------------------------------------------
                                                                1% Revenue test             3% Revenue test
                                                         -------------------------------------------------------
                         Option                             Number of    Percent of     Number of    Percent of
                                                           small firms   small firms   small firms   small firms
----------------------------------------------------------------------------------------------------------------
Option 1................................................             0           0.0             0           0.0
Option 2................................................           618           0.8            51           0.1
Option 3................................................         3,049           3.9           185           0.2
----------------------------------------------------------------------------------------------------------------
Source: Economic Analysis.

    Table XI-9 shows that for the preferred option (Option 2), less 
than a thousand small firms would be likely to incur direct costs 
exceeding one percent of revenue, which accounts for less than one 
percent of the approximately 78 thousand small in-scope firms. 
Therefore, EPA does not consider the preferred option to have the 
potential to cause a significant economic impact on a substantial 
number of small entities. EPA acknowledges that additional small 
builders may experience secondary impacts in the form of higher lot 
prices as larger developers attempt to pass some of their compliance 
costs through. The ability of large developers to pass-through costs to 
builders will vary based on market conditions in the same manner that 
the pass-through rate to the purchaser of the finished construction can 
vary. These effects are addressed as part of the sensitivity analysis 
in Appendix 8-1 of the RFA Chapter in the Economic Analysis. 
Additionally, as noted above, some of these small builders may also be 
copermittees who are required to be in compliance with these standards. 
To the extent they are copermittees, they are not accounted for

[[Page 72597]]

in the firms incurring costs. However, all costs have been attributed 
to firms. Allocating costs over a broader number of firms may or may 
not increase the estimated impacts, but spreads the costs over a larger 
number of firms.

XII. Cost-Effectiveness Analysis

    For many effluent guidelines, EPA performs a cost-effectiveness (C-
E) analysis using toxic-weighted pound equivalents. The C-E analysis is 
useful for describing the relative efficiency of different 
technologies. The pollutant removals estimated for today's proposed 
rule are all based on sediment. While EPA expects that today's rule 
would also result in a significant reduction of other pollutants 
associated with sediment at construction sites, such as nutrients and 
metals, and other pollutants found in urban stormwater runoff, such as 
organics, oil and grease, pesticides and herbicides, the Agency has not 
quantified these reductions. The Agency does not have a methodology for 
converting sediment, measured as TSS or turbidity, into toxic-weighted 
pound equivalents for a C-E analysis. Instead, EPA compared the cost of 
each regulatory option to the pounds of sediment removed. This 
unweighted pollutant removal analysis is meaningful because it allows 
EPA to compare the cost effectiveness of one option against another, 
and to other sediment reduction efforts. Table XII-1 shows a comparison 
of the cost-effectiveness of the options for controlling sediment 
discharges. EPA notes that the total pollutant reductions for Options 2 
and 3 are likely upper-bound estimates, because it is very difficult to 
estimate baseline sediment discharges from this industry given the 
variation in stormwater discharge rates, sediment concentrations and 
the range of conditions present on construction sites across the 
country.

               Table XII-1--Cost-Effectiveness of Options
------------------------------------------------------------------------
                                  Option 1      Option 2      Option 3
------------------------------------------------------------------------
Compliance Cost (millions             $132.2      $1,891.0      $3,796.5
 2008$).......................
Sediment Removed (million lbs/           670        26,426        50,413
 yr)..........................
Cost per Pound Removed ($/lb).         $0.20         $0.07         $0.08
------------------------------------------------------------------------
Source: Economic Analysis.

    EPA notes that changes in the loading reduction estimates, as 
discussed earlier, would affect the cost per pound estimates presented 
in Table XII-1.

XIII. Non-Water Quality Environmental Impacts

    Under sections 304(b) and 306(b) of the CWA, EPA is to consider the 
``non-water quality environmental impacts'' (NWQEI) when setting ELGs 
and NSPS. EPA used various methods to estimate the NWQEI for each of 
the options considered for today's proposed rule.

A. Air Pollution

    EPA estimates that today's proposed rule would have no significant 
effect on air pollution because none of the approaches considered would 
significantly alter the use of heavy equipment at construction sites, 
nor the manner in which construction sites are prepared. Accordingly, 
the levels of exhaust emissions from diesel-powered heavy construction 
equipment and fugitive dust emissions generated by construction 
activities would not change substantially from current conditions under 
the proposed rule. Use of active treatments systems that utilize 
diesel-powered pumps and generators would produce additional emissions, 
however, these emissions are expected to be small compared to current 
emissions for this industry. EPA estimates that fuel combustion used by 
ATS would increase industry emissions by approximately 0.3% under 
Option 2 and 0.5% under Option 3. Increased emissions for Option 1 are 
expected to be less than 0.1%.

B. Solid Waste Generation

    Generation of solid waste could be affected under Options 2 or 3 
because of the large volumes of sediment contaminated with polymers or 
other chemicals that would accumulate in sediment basins. Where 
permittees are using polymers or other chemicals to treat stormwater, 
then sediment accumulated in sediment basins or filter backwash waters 
may need to be handled as solid waste, depending on the nature of the 
chemical used. However, most dischargers using chemical additives are 
expected to select polymers that would enable the operator to apply 
solids (i.e., sediment) on-site to avoid the transportation and 
disposal costs associated with hauling off-site. For example, chitosan 
is biodegradable and discussions with vendors indicate that accumulated 
sediments containing chitosan are usually incorporated as fill 
materials on-site. If ATS systems utilize bag or cartridge particulate 
filters, then disposal of these filters would produce additional solid 
waste. EPA expects that these filters can be managed as nonhazardous 
solid waste. If states decide to regulate sediment containing polymers 
as solid waste, then generation of solid waste could be substantially 
affected.
    The Administration recently created an initiative to strengthen 
control of marine debris, which includes any man-made, solid material 
that enters the nation's waterways either directly or indirectly via 
land- and ocean-based sources. Materials from construction sites may 
become marine debris if they are improperly disposed of or maintained 
(California Coastal Commission, June 2006). However, many actions can 
be taken at construction sites to prevent materials used on-site from 
becoming marine debris. For example, permittees can schedule regular 
collection and disposal of trash before dumpsters become full, or 
ensure that adequate waste and recycling receptacles are available and 
properly covered. Today's guideline includes control measures that 
should address these issues and preventative actions. (Source: 
Eliminating Land-based Discharges of Marine Debris in California: A 
Plan of Action From the Plastic Debris Project, California Coastal 
Commission, June 2006, available on the Internet at: http://
www.plasticdebris.org/CA_Action_Plan_2006.pdf).

C. Energy Usage

    The consumption of energy as a result of today's proposed rule is 
not expected to be significant regardless of the option selected 
because the operations that currently consume energy (both direct 
fossil fuel use and electricity) will not be changing to any 
substantial degree during land disturbance. Use of active treatment 
systems that utilize diesel-powered pumps and generators would result 
in increased fuel consumption. Likewise, the installation of larger 
sediment basins would require

[[Page 72598]]

additional run-time for construction equipment. However the additional 
fuel consumption for these activities is expected to be small compared 
to current consumption for this industry. EPA estimates that gasoline 
and diesel fuel consumption due to portable generators and pumps used 
as part of an ATS would be approximately 22 million gallons per year 
under Option 2 and approximately 45 million gallons under Option 3. 
This represents an increase in fuel usage by the industry of 0.3% under 
Option 2 and 0.5% under Option 3. Increased fuel consumption under 
Option 1 is expected to be less than 0.1%. In addition, polymers such 
as polyacrylamide are produced from petroleum, so additional 
polyacrylamide usage to treat construction site stormwater runoff would 
result in increased petroleum consumption. However, usage on 
construction sites is not expected to significantly increase demand for 
acrylamide (U.S. acrylamide demand in 2001 was estimated to be 
approximately 253 million pounds, and additional usage on construction 
sites would be small). Chitosan, another polymer commonly used on 
construction sites, and the basis for EPA's BAT option, is manufactured 
from crustacean shells. Therefore, additional petroleum and energy 
consumption due to chitosan production and usage is expected to be 
small. If every site subject to the turbidity limit were to use 
chitosan, then total chitosan acetate usage (assuming a dosage of 2 mg/
L) under Option 2 would be approximately 2 million pounds per year, 
while under Option 3 would be approximately 2.3 million pounds per 
year. By comparison, the global chitin market is estimated to be 
approximately 113 million annually pounds by 2012. See section 11 of 
the TDD for additional discussion.

XIV. Environmental Assessment

A. Introduction

    In its Environmental Assessment (see ``Supporting Documentation''), 
EPA evaluated environmental impacts associated with the discharge of 
stormwater from construction activities.
    As discussed in Section VII, construction stormwater discharges 
have been documented to increase the loadings of several pollutants to 
receiving surface waters. The most prominent and widespread pollutants 
from construction sites are turbidity and TSS, which are primarily 
caused by sediment. Discharges of metals, nutrients, and polycyclic 
aromatic hydrocarbons (PAHs) have also been documented. Other possible 
construction site pollutants include materials that exert biochemical 
oxygen demand (BOD), pesticides and other toxic organic compounds.
    Pollutants other than sediment derive from construction equipment 
and materials, contaminants naturally present in a site's soils, or 
contamination by some other source prior to the start of construction 
activity at a site. Construction activities mobilize sediments and 
other pollutants by disturbing soil and altering stormwater runoff 
quantity and patterns. Construction equipment washes and irrigation of 
revegetation areas, if not properly managed, can mobilize pollutants 
during dry weather.
    Surface water effects from construction site discharges include 
physical and biological changes. Physical changes include increased 
turbidity levels, increased total suspended solids concentrations, 
increased sedimentation rates, increased levels of pollutants other 
than sediment, and modified stream flow. Biological changes include 
decreased organism abundance, modified species composition, and 
decreased species diversity.
    Sediment is the predominant pollutant from construction activity 
and is also one of the most common sources of impairment under Clean 
Water Act Section 303(d). According to the National Water Quality 
Inventory Report to Congress: 2002 Reporting Cycle (USEPA, 2007), 
sediment is the top source of impairment for streams and rivers in the 
United States. Sediment and siltation impairs 100,446 stream and river 
miles and turbidity or suspended solids impair 695,133 miles. In 
addition, 1,317,938 acres of lakes and reservoirs have been documented 
as impaired by sediment or siltation and 376,832 acres are impaired by 
turbidity or suspended solids. The report states that sediment also has 
significant impacts on wetlands. Because only a subset of all surface 
waters were assessed for water quality impairment during the 2002 
Reporting Cycle, it is likely that the quantity of surface water 
impaired by sediment is greater than the numbers above indicate.
    Construction site discharges impair or place additional stress on 
already impaired waterbodies. Twenty-four states have been able to 
identify construction activity as a cause of impairment for some 
waterbodies under their jurisdiction. Identifying the causes of a 
waterbody's impairment is often a challenging task, however, so it is 
likely that construction activity is a cause of impairment for more 
waterbodies than states have been able to identify at this time.
    Ecological impacts from sediment discharges to surface waters can 
be acute or chronic and vary in severity depending on the quantity of 
sediment discharged, the nature of the receiving waterbody and aquatic 
community, and the length of time over which discharges take place. 
Sediment can depress aquatic organism growth, reproduction, and 
survival, leading to declines in organism abundance and changes in 
community species composition and distribution. Threatened and 
Endangered (T&E) and other special status species are particularly 
susceptible to adverse habitat impacts. According to the United States 
Fish and Wildlife Service, increased sedimentation is one of the main 
contributors to the demise of some fish, plants, and invertebrates (see 
Drennen, Daniel J. United States Fish and Wildlife Service. 2003. The 
urban life of darters (excessive sedimentation endangers darter 
fishes). Endangered Species Bulletin. Also see ``Endangered Species 
Program: Species Information'' at http://www.fws.gov/endangered/
wildlife.html).
    There are numerous processes by which sediment affects aquatic 
communities. Sediment deposition on waterbody beds can bury benthic 
communities, smothering fish eggs and other immobile benthic organisms 
and severing connections to organisms in the water column. 
Sedimentation also modifies certain types of benthic habitats by 
filling crevices and burying hard substrates, making recolonization by 
previously existing organisms difficult unless the sediment is removed.
    In the water column, increased turbidity levels block light needed 
for photosynthesis by submerged aquatic vegetation (SAV), resulting in 
its reduced growth or death. Because SAV is a primary producer depended 
upon by many other aquatic organisms in ecosystems, its loss or 
reduction can create an impact cascade throughout an entire community, 
lowering the community's total health and productivity. Increased 
turbidity also impairs the ability of visual predators (e.g., many fish 
species) to forage successfully. Increased TSS concentrations in the 
water column can also impair fish gill function, reducing the ability 
of fish to breathe. These and additional processes by which sediment 
discharges impact aquatic ecosystems are discussed in more detail in 
the Environmental Assessment.
    Increased sediment and turbidity levels in surface waters can also

[[Page 72599]]

adversely affect direct human uses of water resources such as navigable 
channels, reservoirs, drinking water supplies, industrial process 
water, agricultural uses, and recreational uses, as well as property 
values.
    Sediment deposition on riverbeds can fill and impede use of 
navigable channels. Between 1995 and 2006, the U.S. Army Corps of 
Engineers (USACE) funded approximately 3,700 dredging projects at a 
cost of more than $6.3 million (2007 dollars) to remove more than 2.3 
billion cubic yards of sediment from U.S. navigable waters (United 
States Army Corps of Engineers Dredging Database. 2007).
    Reservoirs and lakes serve a variety of functions, including 
drinking water storage, hydropower supply, flood control, and 
recreation. Sediment deposition on reservoir and lake beds reduces 
their capacity to serve these functions. An increase in sedimentation 
rate reduces the useful life of these waterbodies unless measures are 
taken to reclaim their capacity. In waters serving as a drinking water 
source, increased turbidity levels and TSS concentrations degrade water 
quality unless treatment levels are increased to remove the additional 
sediment.
    Sediment can also have negative effects on industrial activities. 
Suspended sediment increases the rate at which hydraulic equipment, 
pumps, and other equipment wear out, causing accelerated depreciation 
of capital equipment. Sediment can clog cooling water systems at power 
plants and other large industrial facilities.
    Irrigation water used for agriculture that contains sediment or 
other pollutants from construction site discharges can harm crops and 
reduce agricultural productivity. Suspended sediment can form a crust 
over a field, reducing water absorption, inhibiting soil aeration, and 
preventing emergence of seedlings. Sediment can also coat plant leaves, 
inhibiting plant growth and reducing crop value and marketability. 
Other pollutants can damage soil quality (Clark, Edwin, Jennifer A. 
Haverkamp, and William Chapman. 1985. ``Eroding Soils: The Off-Farm 
Impacts.'' Washington, DC: The Conservation Foundation).
    Sediment deposition in river channels, ditches, and culverts 
reduces their capacity and can increase flood levels and frequency, 
increasing the level of adjoining property damage from flooding. 
Sediment can also lower values of property near impacted surface waters 
by degrading surface water appearance (ibid). Degraded aesthetics can 
also lower the value of surface waters for recreational activities such 
as boating, fishing, and swimming.
    Sediment is the primary source of the pollutants turbidity and TSS 
known to be associated with construction activity, but as stated 
earlier in this section, other pollutants such as nutrients, PAHs, and 
metals are also discharged from construction sites. Environmental 
impacts associated with these other pollutants are qualitatively 
discussed in the Environmental Assessment. The remaining discussion in 
this section describes EPA's quantitative analysis of the water quality 
impacts associated with sediment discharges from construction activity. 
Additional qualitative information on sediment impacts is also provided 
in the Environmental Assessment. EPA solicits submission of additional 
information on discharges from construction activity and environmental 
impacts associated with those discharges.

B. Methodology for Estimating Environmental Impacts and Pollutant 
Reductions

    This section describes the methodology EPA used to quantitatively 
assess water quality impacts from construction activity sediment 
discharges and the water quality benefits expected from today's 
proposed options. Other pollutants from construction activity, such as 
nutrients, PAHs, and metals, create water quality impacts, but the 
information available to EPA on discharges other than sediment from 
construction sites is insufficient for EPA to quantitatively analyze 
their impacts. These discharges are instead discussed qualitatively in 
the Environmental Assessment.
1. National Analysis
    EPA conducted a national quantitative analysis of water quality 
impacts associated with construction activity sediment discharges. To 
conduct this analysis, EPA used a Spatially Referenced Regressions on 
Watershed Attributes (SPARROW) model. SPARROW is a statistically-based 
modeling approach developed by the United States Geological Survey that 
relates measured levels of water quality components to the attributes 
of contributing watersheds. SPARROW has been used previously to 
estimate deliveries of nitrogen and phosphorus to surface waters from 
point, nonpoint, and atmospheric sources at both national and regional 
scales. The sediment version of SPARROW allows EPA to estimate levels 
of total suspended solids (TSS) in the larger freshwater surface waters 
(Reach File 1 level) in the contiguous 48 states (see description of 
Enhanced Reach File 1.2 (RF1) in Section VI). EPA used this analysis to 
examine expected water quality impact improvements under various 
options relative to current levels of water quality impact. To the 
extent that changes in the loadings estimates, as discussed above in 
the sensitivity analysis, may be lower, then the lower loadings 
estimates would lower the SPARROW estimates of water quality changes by 
a comparable amount. A full description of EPA's analysis is provided 
in the Environmental Assessment.
    SPARROW estimates total sediment loadings to estuaries but is 
unable to estimate sediment concentrations in estuaries. EPA instead 
used the Dissolved Concentration Potential (DCP) approach developed by 
the National Oceanic and Atmospheric Administration (NOAA) to estimate 
ambient concentrations of conserved contaminants introduced to 
estuaries that are subject to mixing and dilution. NOAA has provided 
DCP factors for most major estuaries in the contiguous 48 states. These 
factors allow estimation of estuarine TSS concentrations without 
detailed numerical simulation modeling. A full description of this 
analysis is provided in the Environmental Assessment.
    The compliance options vary in the number of RF1 river and stream 
miles they improve. Option 1 improves water quality in 175,775 RF1 
reach miles. Option 2 improves water quality in 522,120 RF1 reach 
miles. Option 3 improves water quality in 542,408 RF1 reach miles. In 
addition to improving water quality in rivers and streams, each option 
also improves water quality in other types of surface waters such as 
lakes and estuaries.
    Construction activity in the United States is unevenly distributed 
among watersheds. It is highly concentrated in some areas and very 
sparse in others. For this reason, EPA presents information on water 
quality improvements associated with the compliance options for two 
different groups of watersheds. The first group contains the 10 percent 
of RF1 watersheds in the conterminous United States with the highest 
number of construction acres during the 1992-2001 time period (``Top 
10%'') and includes 115,568 RF1 stream miles. This group represents 75 
percent of all construction activity during this time period and 
therefore reflects conditions associated with the majority of 
construction site activity. The second group encompasses all RF1 
watersheds containing construction activity during the 1992-2001 time 
period (``All'') and

[[Page 72600]]

includes 517,982 RF1 stream miles. Median TSS concentration reductions 
under the compliance options are greater for the ``Top 10%'' group 
because construction sites exert a greater influence on water quality 
in these reaches. This is because construction activities comprise a 
higher percentage of watershed area in these watersheds.
    For the group of watersheds representing 75 percent of construction 
activity during the 1992-2001 time period, Option 1 reduces sediment 
discharges by approximately 0.5 billion pounds per year. It reduces 
median TSS concentration from 248.34 mg/L to 248.05 mg/L, or 0.29 mg/L. 
Option 2 reduces sediment discharges more than 19 billion pounds per 
year. It reduces median TSS concentration from 248.34 mg/L to 239.16 
mg/L, or 9.18 mg/L. Option 3 reduces sediment discharges by more than 
37 billion pounds per year. It reduces median TSS concentration from 
248.34 mg/L to 231.65 mg/L, or 16.69 mg/L. The corresponding changes in 
the group of ``All'' RF1 reaches are shown in Table XIV-1 below.
    The median concentrations in Table XIV-1 reflect conditions over 
multi-year time periods and across a large geographic area. Most 
construction site discharges are driven by precipitation events and are 
therefore highly episodic. In-stream TSS concentrations deriving from 
construction site discharges tend to be higher during and shortly after 
precipitation events and lower during periods in between precipitation 
events. In addition, the average median concentrations in Table XIV-1 
do not describe the high level of variability seen among different 
locations affected by construction site discharges. For more 
information on these sources of variability, see the Environmental 
Assessment.

     Table XIV-1--RF1 River and Stream Median TSS Concentration Improvements Under Three Compliance Options
----------------------------------------------------------------------------------------------------------------
                                                                                  ``All'' RF1
                                             ``Top 10%'' RF1     Reduction in     watersheds--     Reduction in
                                           watersheds--median     median TSS       median TSS       median TSS
                                            TSS concentration   concentration    concentration    concentration
                                                 (mg/L)             (mg/L)           (mg/L)           (mg/L)
----------------------------------------------------------------------------------------------------------------
Baseline.................................             266.86   ...............           287.22  ...............
Option 1.................................             266.85              0.01           287.03             0.19
Option 2.................................             257.10              9.76           282.23             4.99
Option 3.................................             250.13             16.73           279.71             7.51
----------------------------------------------------------------------------------------------------------------

    Estimates from EPA's national quantitative analysis of water 
quality impacts were used for an analysis of the potential economic 
benefits of each of today's proposed options. See Section XV for 
additional information on the economic benefits analysis.
2. Case Study Analysis
    In addition to a national analysis of water quality, EPA is 
conducting a case study analysis. SPARROW allows national examination 
of water quality at the scale of Reach File 1 surface waters, which is 
a relatively coarse scale. Reach File 1 surface waters do not include 
many smaller rivers and streams in the national surface water network. 
In order to quantitatively examine the nature of water quality impacts 
from construction activity on smaller rivers and streams, EPA is using 
the Soil and Water Assessment Tool (SWAT) in combination with the 
Agricultural Policy--Environmental Extender (APEX) model. SWAT is a 
watershed-scale simulation model and APEX is a site-scale simulation 
model. SWAT-APEX was developed by the United States Department of 
Agriculture's Agricultural Research Service (USDA-ARS). Because of 
higher computational requirements for the SWAT-APEX model relative to 
the SPARROW model, EPA has chosen to use the SWAT-APEX model for a 
single watershed in the Dallas metropolitan region that has experienced 
significant levels of construction. A description of the case study 
methodology is provided in the Environmental Assessment. The case study 
has not been completed, so EPA intends to consider the results of the 
case study and include the case study analysis in the documentation in 
support of the final rule. EPA requests comments on this modeling 
approach.

XV. Benefit Analysis

    EPA has assessed the potential benefits associated with the 
proposed rule by identifying various types of benefits that can result 
from reducing the level of sediment and turbidity being discharged from 
construction sites. Where possible, EPA has attempted to quantify and 
monetize benefits attributable to the regulatory options. Section XIV, 
Environmental Assessment, established the analytical framework for the 
benefits analysis.

A. Benefits Categories Estimated

    Discharges of sediment and other pollutants from construction 
activity can have a wide range of effects on down stream water 
resources. As discussed in Section XIV, there are numerous potential 
impacts to local aquatic environments, and there are also consequences 
for human welfare. Human activities and uses affected by construction 
discharge-related environmental changes include recreation, commercial 
fishing, public and private property ownership, navigation, and water 
supply and use. Sediments and other pollutants in discharges from C&D 
sites can also cause environmental changes that affect the non-use 
values that individuals have for the assurance that environmental 
resources are in good condition. These existence services, sometimes 
described as ``ecological benefits,'' are reflected under the Clean 
Water Act as aquatic life, wildlife, and habitat designated uses.
    Stormwater control measures reduce the amount of sediment that 
reaches waterways from C&D sites. As sediment loads are reduced, TSS 
and turbidity levels in adjacent waters decline, which in turn 
increases the production of environmental services that people and 
industry value. These environmental services valued by industry and the 
public include: recreation, public and private property ownership, 
navigation, water supply and use, and existence services. Table XV-1 
provides a summary of various water related activities and their 
associated environmental services potentially impacted by discharges of 
sediment from C&D sites.

[[Page 72601]]



              Table XV-1--Summary of Benefits From Reducing Sediment Runoff from Construction Sites
----------------------------------------------------------------------------------------------------------------
                                          Environmental service
                                         potentially affected by
              Activity                  runoff from construction                  Benefits category
                                                  sites
----------------------------------------------------------------------------------------------------------------
Recreation..........................  Aesthetics, water clarity,    Non-market direct use.
--Outings...........................   water safety, degree of
--Boating...........................   sedimentation, weed growth,
--Swimming..........................   fish and shellfish
--Fishing...........................   populations.
Commercial Fishing and Shellfishing.  Fish and shellfish            Markets.
                                       populations.
Property Ownership..................  Aesthetics, safety of         Markets.
                                       property from flooding,
                                       property value.
Water Conveyance and Supply.........  Turbidity, degree of          Avoided Costs.
--Water conveyance..................   sedimentation.
--Water storage.....................
--Water treatment...................
Transportation......................  Degree of sedimentation.....  Avoided Costs.
Water Use...........................  Turbidity...................  Avoided Costs.
--Industrial........................
--Municipal.........................
--Agricultural......................
Knowledge (No Direct Uses)..........  Environmental health........  Non-market existence value.
----------------------------------------------------------------------------------------------------------------

    However, not all of the changes in these services can be readily 
quantified as it requires a thorough understanding of the relationship 
between changes in water pollutant loads and production of 
environmental services. This problem is exacerbated by the fact that 
both the pollutant source and load reductions are relatively small, 
sporadic, numerous, and dispersed over a wide area when compared to 
more traditional sources of pollutants, such as a wastewater treatment 
plant. As a result of the difficulty in assessing changes in each 
environmental service associated with an activity listed in Table XV-1, 
EPA chose to focus on two main categories of benefits: avoided costs 
and non-market benefits. The specific categories of avoided costs 
considered were: Reservoir dredging, navigable waterway dredging, and 
drinking water treatment and sludge disposal. Non-market benefits 
considered were improvements in recreational activities and existence 
value from improvements in the health of aquatic environments.

B. Quantification of Benefits

    Reduced costs for water treatment, water storage, and navigational 
dredging are three benefit categories that EPA is using to estimate the 
benefits of the proposed rule. EPA used estimates of changes in 
sediment deposition and in-stream TSS concentrations from the SPARROW 
model runs to quantify the reduction in the amount of sediment that 
would need to be dredged from reservoirs and the reduction in the 
amount of TSS that must be removed from the source water used for the 
production of potable water. The SPARROW results provided these changes 
for each waterbody in the RF1 network (approximately 60,000 stream 
segments). This allowed EPA to associate these changes with: Data from 
the U.S. Army Corps of Engineers on navigable waterways that are 
routinely dredged; EPA data on source water for drinking water 
treatment plants; and USGS data on the location of reservoirs used for 
hydroelectric power, flood control, a source for drinking water, and 
recreation. SPARROW results also allowed for the estimated change in 
TSS concentrations in the RF1 network which were mapped to a Water 
Quality Index (WQI). The index is used to map changes in pollutant 
parameters, such as TSS, to effects on human uses and support for 
aquatic and terrestrial species habitat. Section 10.1.1 of the 
Environmental Assessment Document provides detail on the WQI index and 
its application to the benefits analysis for the C&D regulation. The 
WQI presents water quality by linking to suitability for various human 
uses, but does not in itself identify associated changes in human 
behavior. Behavioral changes and associated welfare effects are implied 
in the proposed benefit transfer approach for measuring economic 
values. For more on the benefit transfer approach see Appendix 7-1 
Meta-Analysis Results from the Economic Analysis.
    The benefits analysis results are shown in Table XV-2. To the 
extent that changes in the loadings estimates, as discussed above in 
the sensitivity analysis may lower the loadings estimates then the 
lower loadings estimates would lower the SPARROW estimates of water 
quality changes and the associated benefits presented in Table XV-2 by 
a comparable amount.

        Table XV-2--Annual Benefits (Million 2008 $) for Options
------------------------------------------------------------------------
                                                Regulatory options
                                        --------------------------------
                                          Option 1   Option 2   Option 3
------------------------------------------------------------------------
                              Avoided Costs
------------------------------------------------------------------------
Reservoir Dredging.....................       $0.6      $17.6      $30.6
Navigable Waterway Dredging............        1.0       12.9       27.2
Drinking Water Treatment...............        0.2        7.4       13.1
                                        --------------------------------
    Total Avoided Costs \a\............        1.8       37.9       70.9

Welfare Improvements...................       16.6      295.0      398.5
                                        --------------------------------

[[Page 72602]]


    Total Monetized Benefits...........       18.4      332.9      469.5
------------------------------------------------------------------------
\a\ Totals do not add due to rounding.
Source: Economic Analysis; Environmental Assessment.

XVI. Monetized Benefit-Cost Comparison

    EPA has conducted a benefit-cost analysis of the C&D effluent 
guidelines proposed in today's notice. The benefit-cost analysis may be 
found in the complete set of support documents. Sections XI, XIV, and 
XV of this notice provide additional details of the benefit-cost 
analysis.
    Table XVI-1 provides the results of the benefit-cost analysis. A 
discount rate of 3% was used to annualize costs and benefits. To the 
extent that changes in the loadings estimates, as discussed above in 
the sensitivity analysis may lower the loadings estimates, then the 
lower estimates would lower the SPARROW estimates of water quality 
changes and the associated benefits presented in Table XVI-1 by a 
comparable amount. Moreover, changes in the RUSLE parameters as 
described earlier would reduce EPA's estimates of runoff volumes 
requiring treatment, which would reduce the costs of Options 2 and 3.

       Table XVI-1--Total Annualized Benefits and Costs of Options
                              [Year 2008 $]
------------------------------------------------------------------------
                                                     Monetized benefits
           Option              Social costs  (2008  (2008 $ millions per
                              $ millions per year)          year)
------------------------------------------------------------------------
Option 1....................                  $132                   $18
Option 2....................                 1,891                   333
Option 3....................                 3,797                   470
------------------------------------------------------------------------

XVII. Approach to Determining Long-Term Averages, Variability Factors, 
and Effluent Limitations and Standards

    This section describes the statistical methodology used to develop 
long-term averages, variability factors, and limitations for BAT and 
NSPS. For simplicity, the following discussion refers only to effluent 
limitations guidelines; however, the discussion also applies to new 
source performance standards. EPA also is soliciting comments on a 
limitation on pH as described in Section XX. Such a limitation would 
not be developed using the statistical methodology described below. 
Instead, EPA typically establishes a range of acceptable values from 6 
to 9 to protect against extreme acidity or alkalinity.

A. Definitions

    The proposed limitations for turbidity, as presented in today's 
notice, are provided as the maximum daily discharge limitation. 
Definitions provided in 40 CFR 122.2 state that the ``maximum daily 
discharge limitation'' is the ``highest allowable `daily discharge.'' ' 
``Daily discharge'' is defined as the `` `discharge of a pollutant' 
measured during a calendar day or any 24-hour period that reasonably 
represents the calendar day for purposes of sampling.'' To be 
consistent with the daily discharge definition, EPA averaged all 
measurements recorded each day from each treatment system before 
calculating the proposed limitations. In complying with the final rule, 
the number of measurements required each day would be determined by the 
permit authority. EPA would, however, discourage the practice of 
allowing the number of monitoring samples to vary arbitrarily merely to 
allow a site to achieve a desired average concentration, i.e., a value 
below the limitation that day. EPA expects that enforcement authorities 
would prefer, or even require, monitoring samples at some regular, pre-
determined frequency. As explained below, if a site has difficulty 
complying with the limitation on an ongoing basis, then the site should 
improve its equipment, operations, and/or maintenance.

B. Data Selection

    The proposed limitations are based upon data from sites located in 
three western states: California, Oregon and Washington. EPA is 
soliciting data (see Section XX for a detailed request for data), in 
part, to evaluate whether the limitations are appropriate for other 
locations. Typically, EPA qualitatively reviews all the data before 
making its data selection used to calculate the limitations in final 
rules. EPA generally selects only from facilities that have the model 
technologies for the option and meet several other criteria. One 
criterion generally requires that the influents and effluents from the 
treatment components represent typical wastewater from the industry, 
with no incompatible wastewater from other sources (e.g., sanitary 
wastes). A second criterion typically ensures that the pollutants were 
present in the influent at sufficient concentrations to evaluate 
treatment effectiveness. A third criterion generally requires that the 
facility demonstrate good operation of the treatment component (e.g., 
data sets for episodes with generally high pollutant concentrations are 
often excluded). A fourth criterion typically requires that the data 
can not represent periods of treatment upsets or shut-down periods. EPA 
solicits comment on its data selection and criteria.
    EPA relied on data from two vendors and the Oregon Department of 
Environmental Quality to calculate limits. Sites were located in 
California, Oregon and Washington and employed chitosan-enhanced sand 
filtration. Data were from 19 treatment systems located at 17 different 
sites. For some of these sites, EPA has data on site locations, 
treatment systems, flowrates, operating conditions, and treatment 
volumes. For other sites, this information was not available from the 
vendors. In total, EPA

[[Page 72603]]

has 6,537 individual data points on turbidity effluent from these 
systems. The influent concentrations in these data points are generally 
substantially lower than the concentrations modeled by EPA in its RUSLE 
analysis as discussed in section IX. F, which is not consistent with 
the first criterion above. EPA will be examining this discrepancy 
between this proposed rule and the final rule and its affect on EPA's 
analysis. In its calculations of the proposed limitations, EPA applied 
its criteria and excluded data that do not appear to demonstrate 
typical performance (e.g., extremely large values for a measurement, 
daily value, and/or site) and typographical errors. EPA retained 6,003 
measurements after incorporating data exclusions. For the final rule, 
EPA intends to reevaluate its exclusions and inclusions of data, and 
seek additional information about the sites used as a basis for the 
proposed limitations. EPA also intends to evaluate, and incorporate as 
appropriate, any additional data provided by commenters and other 
sources. For example, a memorandum by GeoSyntec Consultants (see DCN 
41114) contains additional data on ATS performance that EPA has not 
considered in evaluating the limitations.

C. Statistical Percentile Basis for Limitations

    The daily maximum limitation is an estimate of the 99th percentile 
of the distribution of the daily measurements. EPA calculates the daily 
maximum limitation based upon a percentile chosen with the intention, 
on one hand, to accommodate reasonably anticipated variability within 
the control of the site and, on the other hand, to reflect a level of 
performance consistent with the Clean Water Act requirement that these 
effluent limitations be based on well operated and maintained 
facilities. The percentile for the daily maximum limitation is 
estimated using the product of the long-term average and the 
variability factor. For the proposed rule, EPA estimated the long-term 
average and variability factor using a statistical model based upon the 
lognormal distribution. The Development Document describes this model 
and others that EPA will consider in developing the final regulations.

D. Daily Maximum Limitation

    In establishing the daily maximum limitation, EPA's objective is to 
restrict the discharges on a daily basis at a level that is achievable 
for a site that targets its treatment at the long-term average. EPA 
acknowledges that variability around the long-term average results from 
normal operations. This variability means that at certain times sites 
may discharge at a level that is greater than the long-term average. 
This variability also means that sites may at other times discharge at 
a level that is considerably lower than the long-term average. To allow 
for these possibly higher daily discharges, EPA has established the 
daily maximum limitation that is based upon a long-term average and a 
variability factor.
1. Long-Term Average
    In the first of two steps in estimating the different types of 
limitations, EPA determines an average performance level (the ``long-
term average'') that a site with well-designed and operated model 
technologies (which reflect the appropriate level of control) is 
capable of achieving. This long-term average is calculated from the 
data from the sites using the model technologies for the option. EPA 
expects that all sites subject to the limitations will design and 
operate their treatment systems to achieve the long-term average 
performance level on a consistent basis because sites with well-
designed and operated model technologies have demonstrated that this 
can be done. The proposed long-term average of 2.77 NTU is the median 
value of 19 long-term averages collected from 17 construction sites 
(two sites each had two treatment systems). The long-term averages 
ranged from a minimum of 0.43 NTU to a maximum of 21.86 NTU. The median 
is the midpoint of the 19 values, and thus, nine of the system averages 
are above the proposed long-term average and nine are below.
    A site that discharges consistently at a level near the proposed 
daily maximum limitation of 13 NTU would not be operating its treatment 
to achieve the long-term average of 2.77 NTU, which is part of EPA's 
objective in establishing the daily maximum limitations. Targeting 
treatment to achieve the limitation may result in frequent values 
exceeding the limitation due to routine variability in treated 
effluent. Operators should instead target the long-term average, and if 
they do so, should be able to consistently discharge below the limit. 
To ensure that this is possible, EPA has incorporated an allowance for 
variability into the limitation.
2. Variability Factor
    In the second step of developing a limitation, EPA determines an 
allowance for the variation in pollutant concentrations when processed 
through well designed and operated treatment systems. This allowance 
for variance incorporates all components of variability including 
process and wastewater generation, sample collection, shipping, 
storage, and analytical variability. This allowance is incorporated 
into the limitations through the use of the variability factors, which 
are calculated from the data from the sites using the model 
technologies. If a site operates its treatment system to meet the 
relevant long-term average, EPA expects the site to be able to meet the 
limitations. The variability factor assures that normal fluctuations in 
a site's treatment are accounted for in the limitation. By accounting 
for these reasonable excursions above the long-term average, EPA's use 
of variability factors results in limitations that are generally well 
above the actual long-term averages. The proposed variability factor of 
4.58 is the arithmetic average of 19 variability factors collected from 
the 17 construction sites also used to calculate the proposed long-term 
average. The variability factors ranged from a minimum of 1.96 to a 
maximum of 10.85.
    In its evaluation of the proposed daily variability factor, EPA 
examined TSS limitations promulgated during the last 10 years. 
Engineering references (e.g. , American Society of Civil Engineers 
(ASCE)/American Water Works Association (AWWA), Water Treatment Plant 
Design, 4th Edition, McGraw-Hill, NYC, NY, 2005) cite conversion 
factors for turbidity to TSS values. Because of the generally accepted 
relationship between turbidity and TSS, EPA assumes that the 
variability also would be similar for turbidity and TSS. Furthermore, 
although the regulations were based upon different treatment 
technologies, wastewater professionals generally agree that TSS and 
turbidity can be adequately controlled by many different types of 
treatment systems. Furthermore, each regulation used data from well 
operated and controlled treatment processes in determining the 
variability of TSS. As shown in the TDD, the values are relatively 
close in value, ranging from 2.9 to 5.4, with an arithmetic average of 
4.1. Because the C&D technology is a relatively simple one, EPA 
concluded that the relatively large value of 4.58 for the proposed 
variability factor still ensures a level of control that EPA considers 
possible for a simple technology.

E. Engineering Review of Limitations

    In conjunction with the statistical methods, EPA performs an 
engineering review to verify that the limitations are reasonable based 
upon the design and expected operation of the control technologies and 
the facility conditions. EPA compared the value of the

[[Page 72604]]

proposed limitation to the data values used to calculate the 
limitation. Most monitoring results were substantially lower than the 
proposed turbidity limit. In most instances where the effluent 
turbidity was higher than the proposed turbidity limit, the data 
indicated sudden jumps in turbidity levels which suggested that the 
treatment system was not being operated properly.
    For the final rule, EPA will perform a more in-depth examination of 
the range of performance by the treatment systems used as the basis of 
the limitation. Data from some treatment systems demonstrate the best 
available technology. Data from other systems may demonstrate the same 
technology, but not the best demonstrated design and operating 
conditions for that technology. For these sites, EPA will evaluate the 
degree to which the site can upgrade its design, operating, and 
maintenance conditions to meet the limitations. If such upgrades are 
not possible, then EPA will modify the limitations to reflect the 
lowest levels that the technologies can reasonably be expected to 
achieve. EPA recognizes that, as a result of the proposed limitation, 
some dischargers may need to improve treatment systems, erosion and 
sediment controls, and/or treatment system operations in order to 
consistently meet the effluent limitation. EPA determined that this 
consequence is consistent with the Clean Water Act statutory framework, 
which requires that discharge limitations reflect the best available 
technology.

F. Monthly Average Limitations

    Because this industry generally does not have continuous 
discharges, EPA is proposing only a daily maximum limitation that would 
apply only on days when the site discharges. While the actual 
monitoring requirements will be determined by the permitting authority, 
the Agency has assumed that sites will monitor every day that the 
discharge occurs. In similar situations when it has assumed daily 
monitoring for other industries, EPA typically has also promulgated 
monthly average limitations with the daily maximum limitations. In 
establishing monthly average limitations, EPA's objective is to provide 
an additional restriction to help ensure that sites target their 
average discharges to achieve the long-term average. The monthly 
average limitation requires continuous dischargers to provide on-going 
control, on a monthly basis, that complements controls imposed by the 
daily maximum limitation. However, EPA expects C&D discharges to be 
intermittent (only during and after precipitation) with substantial 
variability in rainfall and site characteristics over the life of the 
project. Under these circumstances, EPA believes that it appropriate to 
rely on a daily maximum to ensure that systems are being operated 
properly. EPA solicits comment on whether monthly average limitations 
or some other approach would be appropriate to further ensure that 
sites target treatment at the long-term average.

XVIII. Regulatory Implementation

A. Relationship of Effluent Guidelines to NPDES Permits and ELG 
Compliance Dates

    Effluent guidelines act as a primary mechanism to control the 
discharge of pollutants to waters of the U.S. Once finalized, the 
proposed C&D regulations would be applied to C&D sites through 
incorporation in individual NPDES permits or a general permit issued by 
EPA or authorized states or tribes under section 402 of the Act.
    The Agency has developed the limitations for this proposed rule to 
cover the discharge of pollutants for this point source category. In 
specific cases, the NPDES permitting authority may elect to establish 
effluent limitations for pollutants not covered by this regulation. In 
addition, if state water quality standards or other provisions of state 
or federal law authorize or require limits on pollutants not covered by 
this regulation or authorize or require more stringent limits or 
standards on pollutants to achieve compliance, the permitting authority 
has authority to apply those effluent limitations or standards in their 
NPDES permits. EPA does not intend for this rule to preclude states 
from including controls in their stormwater programs that are found to 
be effective at controlling discharges of pollutants.
    Since EPA expects that the effluent guidelines requirements will be 
implemented over time as states revise their general permits, EPA 
expects full implementation within five years of the effective date of 
the final rule, currently required to be promulgated in December 2009, 
which would be 2014.

B. Upset and Bypass Provisions

    A ``bypass'' is an intentional diversion of the streams from any 
portion of a treatment facility. An ``upset'' is an exceptional 
incident in which there is unintentional and temporary noncompliance 
with technology-based permit effluent limitations because of factors 
beyond the reasonable control of the permittee. EPA's regulations 
concerning bypasses and upsets for direct dischargers are set forth at 
40 CFR 122.41(m) and (n).
    Because much of today's proposed rule includes requirements for the 
design, installation, and maintenance of erosion and sediment controls, 
EPA considered the need for a bypass-type provision in regard to large 
storm events. However, EPA did not specifically include such a 
provision in the text of the proposed regulation because the proposed 
ELGs only require dischargers to meet a numeric turbidity limit for 
discharges from storm events smaller than the 2-year, 24-hour storm. 
Because EPA is not establishing requirements for control of larger 
storm events, specific bypass provisions were not necessary. Standard 
upset and bypass provisions are generally included in all NPDES 
permits, and EPA expects this will be the case for construction 
stormwater permits issued after this rule becomes effective.

C. Variances and Waivers

    The CWA requires application of effluent limitation guidelines 
established pursuant to section 301 to all direct dischargers. However, 
the statute provides for the modification of these national 
requirements in a limited number of circumstances. Moreover, the Agency 
has established administrative mechanisms to provide an opportunity for 
relief from the application of ELGs for categories of existing sources 
for toxic, conventional, and nonconventional pollutants. ``Ability to 
Pay'' and ``water quality'' waivers do not apply to conventional or 
toxic pollutants (e.g., TSS, PCBs) and, therefore, do not apply to 
today's proposed rule. However, the variance for Fundamentally 
Different Factors (FDFs) may apply in some circumstances.
    EPA will develop effluent limitations or standards different from 
the otherwise applicable requirements if an individual discharging 
facility is fundamentally different with respect to factors considered 
in establishing the limitation of standards applicable to the 
individual facility. Such a modification is known as a ``fundamentally 
different factors'' (FDF) variance.
    Early on, EPA, by regulation provided for the FDF modifications 
from the BPT and BAT limitations for toxic and nonconventional 
pollutants and BPT limitations for conventional pollutants for direct 
dischargers. For indirect dischargers, EPA provided for modifications 
for PSES. FDF variances for toxic pollutants were challenged judicially 
and ultimately sustained by the Supreme Court. Chemical

[[Page 72605]]

Manufacturers Assn v. NRDC, 479 U.S. 116 (1985).
    Subsequently, in the Water Quality Act of 1987, Congress added new 
section 301(n) of the Act explicitly to authorize modifications of the 
otherwise applicable BAT effluent limitations or categorical 
pretreatment standards for existing sources if a facility is 
fundamentally different with respect to the factors specified in 
section 304 (other than costs) from those considered by EPA in 
establishing the effluent limitations or pretreatment standard. Section 
301(n) also defined the conditions under which EPA may establish 
alternative requirements. Under section 301(n), an application for 
approval of a FDF variance must be based solely on (1) information 
submitted during rulemaking raising the factors that are fundamentally 
different or (2) information the applicant did not have an opportunity 
to submit. The alternate limitation or standard must be no less 
stringent than justified by the difference and must not result in 
markedly more adverse non-water quality environmental impacts than the 
national limitation or standard.
    EPA regulations at 40 CFR part 125, subpart D, authorizing the 
Regional Administrators to establish alternative limitations and 
standards, further detail the substantive criteria used to evaluate FDF 
variance requests for direct dischargers. Thus, 40 CFR 125.31(d) 
identifies six factors (e.g., volume of process wastewater, age and 
size of a discharger's facility) that may be considered in determining 
if a facility is fundamentally different. The Agency must determine 
whether, on the basis of one or more of these factors, the facility in 
question is fundamentally different from the facilities and factors 
considered by EPA in developing the nationally applicable effluent 
guidelines. The regulation also lists four other factors (e.g., 
infeasibility of installation within the time allowed or a discharger's 
ability to pay) that may not provide a basis for an FDF variance. In 
addition, under 40 CFR 125.31(b)(3), a request for limitations less 
stringent than the national limitation may be approved only if 
compliance with the national limitations would result in either (a) a 
removal cost wholly out of proportion to the removal cost considered 
during development of the national limitations, or (b) a non-water 
quality environmental impact (including energy requirements) 
fundamentally more adverse than the impact considered during 
development of the national limits. EPA regulations provide for an FDF 
variance for indirect dischargers at 40 CFR 403.13. The conditions for 
approval of a request to modify applicable pretreatment standards and 
factors considered are the same as those for direct dischargers.
    The legislative history of section 301(n) underscores the necessity 
for the FDF variance applicant to establish eligibility for the 
variance. EPA's regulations at 40 CFR 125.32(b)(1) are explicit in 
imposing this burden upon the applicant. The applicant must show that 
the factors relating to the discharge controlled by the applicant's 
permit which are claimed to be fundamentally different are, in fact, 
fundamentally different from those factors considered by the EPA in 
establishing the applicable guidelines. An FDF variance is not 
available to a new source subject to NSPS.

D. Other Clean Water Act Requirements

    Compliance with the provisions of this proposed rule would not 
exempt a discharger from any other requirements of the CWA. Notable, if 
construction activity results in the ``discharge of dredged or fill 
material'' into waters of the U.S. the discharger at the C&D site must 
obtain a separate permit under section 404 of the CWA.

XIX. Related Acts of Congress, Executive Orders, and Agency Initiatives

A. Executive Order 12866: Regulatory Planning and Review

    Under section 3(f)(1) of Executive Order 12866 (58 FR 51735, 
October 4, 1993), this action is an ``economically significant 
regulatory action'' because it is likely to have an annual effect on 
the economy of $100 million or more. Accordingly, EPA submitted this 
action to the Office of Management and Budget (OMB) for review under 
Executive Order 12866 and any changes made in response to OMB 
recommendations have been documented in the docket for this action.
    In addition, EPA prepared an analysis of the potential costs and 
benefits associated with this action. This analysis is contained in 
Section 8.3, Comparison of Social Cost and Monetized Benefits in 
Chapter 8 of the Economic Analysis. A copy of the analysis is available 
in the docket for this action and the analysis is briefly summarized 
here. Table XIX-1 provides the results of the benefit-cost analysis.

   Table XIX-1--Total Annualized Benefits and Costs of the Regulatory
                                 Options
------------------------------------------------------------------------
                               Social costs  (2008   Monetized benefits
           Option                $ millions  per      (2008 $ millions
                                      year)               per year)
------------------------------------------------------------------------
Option 1....................                  $132                   $18
Option 2....................                 1,891                   333
Option 3....................                 3,797                   470
------------------------------------------------------------------------

B. Paperwork Reduction Act

    The information collection requirements in this proposed rule have 
been submitted for approval to the Office of Management and Budget 
(OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The 
Information Collection Request (ICR) document prepared by EPA has been 
assigned EPA ICR number 2336.01.
    Today's proposed option, Option 2, would require operators to 
perform turbidity monitoring that would entail measuring and recording 
the NTU level of effluent prior to discharge.
    EPA estimates that this provision would create a total annual 
burden of about 224,000 hours for the proposed rule for permittees and 
about 25,000 hours for permitting authorities. This estimate is the 
incremental burden above the currently-approved burden level for the 
EPA and State construction general permits. EPA has received OMB 
approval for the current permit requirements under control no. 2040-
0188, ``Notice of Intent for Storm Water Discharges Associated with 
Construction Activity under a NPDES General Permit.'' Burden is defined 
at 5 CFR 1320.3(b).
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9.

[[Page 72606]]

    To comment on the Agency's need for this information, the accuracy 
of the provided burden estimates, and any suggested methods for 
minimizing respondent burden, EPA has established a public docket for 
this rule, which includes this ICR, under Docket ID number [EPA-HQ-OW-
2008-0465]. Submit any comments related to the ICR to EPA and OMB. See 
ADDRESSES section at the beginning of this notice for where to submit 
comments to EPA. Send comments to OMB at the Office of Information and 
Regulatory Affairs, Office of Management and Budget, 725 17th Street, 
NW., Washington, DC 20503, Attention: Desk Office for EPA. Since OMB is 
required to make a decision concerning the ICR between 30 and 60 days 
after November 28, 2008, a comment to OMB is best assured of having its 
full effect if OMB receives it by December 29, 2008. The final rule 
will respond to any OMB or public comments on the information 
collection requirements contained in this proposal.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For the purposes of assessing the impacts of today's rule on small 
entities, small entity is defined as either a: (1) A small business as 
defined by the Small Business Administration's (SBA) regulations at 13 
CFR 121.201; (2) a small governmental jurisdiction that is a government 
of a city, county, town, school district or special district with a 
population of less than 50,000; or (3) a small organization that is any 
not-for-profit enterprise which is independently owned and operated and 
is not dominant in its field. EPA does not anticipate any impacts on 
small organizations and impacts on small governments are covered under 
the UMRA analysis section. The RFA provides that EPA generally define 
small businesses according to the size standards established by the 
Small Business Administration (SBA). The SBA established criteria for 
identifying small businesses is based on either the number of employees 
or annual revenues (13 CFR 121). These size standards vary by NAICS 
(North American Industrial Classification System) code. For the C&D 
industry NAICS categories (236 and 237) the small business annual 
revenue threshold is set at $33.5 million. The SBA sets the small 
business threshold for NAICS 2372 (Land Subdivision of NAICS 237) at $7 
million. However, for the purpose of the economic analysis, EPA 
allocated this sector amongst the four primary building construction 
sectors: Single-family housing, multifamily housing, industrial 
building, and commercial and institutional building construction.
    In order to gather more information on the potential impacts of 
today's proposal on small businesses, EPA voluntarily followed the 
provisions of section 609(b) of the Regulatory Flexibility Act (RFA) as 
amended by the Small Business Regulatory Enforcement Fairness Act of 
1996 (SBREFA). EPA voluntarily convened a panel for this rulemaking on 
September 10, 2008. EPA held an outreach meeting with SERs on September 
17, 2008. A list of SERs and the outreach materials sent to SERs are 
included in the docket (see DCN 41115-41133). Because of the voluntary 
nature under which EPA followed section 609(b), EPA does not plan to 
complete the panel process or release an Initial Regulatory Flexibility 
Analysis (IRFA). However, EPA did prepare a report that summarizes 
information obtained from the panel, which is also included in the 
docket (see DCN 41136).
    After considering the economic impacts of today's proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. Overall, EPA 
estimates that in a typical year there will be 82,000 in-scope firms, 
and of this total, approximately 78,000, or about 96 percent, are 
defined as small businesses. For this option, EPA estimates that about 
618 small businesses would experience costs exceeding 1 percent of 
revenue and 51 small businesses would incur costs exceeding 3 percent 
of revenue. Both numbers represent very small percentages of the in-
scope small firms. The 618 firms estimated to incur costs exceeding 1 
percent of revenue represent about 0.4 percent of all small C&D sector 
firms and 0.8 percent of estimated potentially in-scope small 
businesses. The 51 firms estimated to incur costs exceeding 3 percent 
of revenue are again very small percentages at less than one-tenth of a 
percent of both small business counts. Therefore, EPA does not consider 
the preferred option to have the potential to cause a significant 
economic impact on a substantial number of small entities.
    In developing the current set of proposed options, EPA considered 
potential affects on small firms, as demonstrated by the inclusion of a 
one to less than ten acre project size category for each option. The 
regulatory requirements for these small size projects are considered to 
be significantly less burdensome than those for the larger size 
projects. Although small firms do not directly equate to small 
projects, EPA's review of the construction industry suggests that 
smaller firms tend to undertake smaller projects.
    Therefore, EPA considers the inclusion of a separate small site 
size category with less burdensome requirements to be an effective way 
to address potential impacts on small firms. We continue to be 
interested in the potential impacts of the proposed rule on small 
entities and welcome comments on issues related to such impacts.

D. Unfunded Mandates Reform Act (UMRA)

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments

[[Page 72607]]

to have meaningful and timely input in the development of EPA 
regulatory proposals with significant Federal intergovernmental 
mandates, and informing, educating, and advising small governments on 
compliance with the regulatory requirements.
    EPA has determined that this rule contains a Federal mandate that 
may result in expenditures of $100 million or more for State, local, 
and tribal governments, in the aggregate, or the private sector in any 
one year. Accordingly, EPA has prepared under section 202 of the UMRA a 
written statement which is summarized below.
    Consistent with the intergovernmental consultation provisions of 
section 204 of the UMRA EPA has already initiated consultations with 
the governmental entities affected by this rule. EPA took and responded 
to comments from government entities on the earlier proposed C&D rule. 
To help characterize the potential impacts to government entities EPA 
has gathered state government data on NOI submissions, and from U.S. 
Census data and Reed Construction Data, EPA has compiled information on 
how much construction activity is undertaken by government entities. 
EPA has routinely consulted with EPA regional offices who maintain 
direct and regular contact with state entities. Finally, EPA met 
directly with and solicited data from all the state Stormwater 
Coordinators who attended EPA's Annual Stormwater Conference in 2007. 
As part of the financial impact analysis, EPA looked specifically at 
the impact on government entities resulting from both compliance with 
construction site requirements and from administering the additional 
monitoring reports submitted by in-scope firms. Table XIX-2 shows the 
results of this analysis. For more information on how this analysis was 
performed see Section 9-1 Assessing Costs to Government Entities in 
Chapter 9 of the Economic Analysis.

      Table XIX-2--Impacts of Regulatory Options on State and Local
                               Governments
                            [Million 2008 $]
------------------------------------------------------------------------
                                          Option 1   Option 2   Option 3
------------------------------------------------------------------------
                            Compliance Costs
------------------------------------------------------------------------
Federal................................       $2.3      $34.0      $66.5
State..................................        4.4       68.1      128.2
Local..................................       25.1      390.7      735.8
------------------------------------------------------------------------
                          Administrative Costs
------------------------------------------------------------------------
Federal................................        0.0        0.0        0.0
                                        --------------------------------
State..................................        0.0        0.1        0.2
Local..................................        0.0        0.6        1.0
------------------------------------------------------------------------
                               Total Costs
------------------------------------------------------------------------
Federal................................        2.3       34.0       66.5
State..................................        4.4       68.2      128.4
Local..................................       25.1      391.3      736.8
------------------------------------------------------------------------
Source: Economic Analysis.

    In developing this rule, EPA consulted with small governments 
pursuant to its plan established under section 203 of the UMRA to 
address impacts of regulatory requirements in the rule that might 
significantly or uniquely affect small governments. To ensure that the 
proposed Options were not disproportionately affecting small government 
entities EPA analyzed impacts on small government entities. The 
assessment of impacts on small governmental entities involved three 
steps: (1) Identifying small government entities (i.e., those serving 
populations of less than 50,000, (5 U.S.C. 601[5])), (2) estimating the 
share of total government costs for the regulatory options incurred by 
small governments, and (3) estimating the potential impact from these 
costs based on comparison of small government outlays with small 
government revenue and outlays. For details of this analysis see 
Section 9.2 Assessing Costs and Impacts on Small Government Entities in 
Chapter 9 of the Economic Analysis. Table XIX-3 has the results of the 
small government entity impact analysis.

  Table XIX-3--Impacts of Regulatory Options on Small Government Units
                            [Million 2008 $]
------------------------------------------------------------------------
                                       Option 1    Option 2    Option 3
------------------------------------------------------------------------
                            Compliance Costs
------------------------------------------------------------------------
Small Government Entities...........       $11.8      $183.6      $345.8
------------------------------------------------------------------------
                          Administrative Costs
------------------------------------------------------------------------
Small Government Entities...........        $0.0        $0.3        $0.5
------------------------------------------------------------------------
                               Total Costs
------------------------------------------------------------------------
Small Government Entities...........       $11.8      $183.9      $346.3
------------------------------------------------------------------------

[[Page 72608]]


                Small Government Impact Analysis Concepts
------------------------------------------------------------------------
Total Revenues......................    $125,515    $125,515    $125,515
Total Costs as % of Total Revenues..       0.01%       0.15%       0.28%
Capital Outlay......................     $13,455     $13,455     $13,455
Total Costs as % of Total Capital          0.09%       1.37%       2.57%
 Outlay.............................
Construction Outlay Only............      $8,529      $8,529      $8,529
Total Costs as % of Total                  0.14%       2.16%       4.06%
 Construction Outlay................
------------------------------------------------------------------------
Source: Economic Analysis.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    This proposed rule does not have federalism implications. It will 
not have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132. The proposed rule would not 
alter the basic state-federal scheme established in the Clean Water Act 
under which EPA authorizes states to carry out the NPDES permitting 
program. EPA expects the proposed rule would have little effect on the 
relationship between, or the distribution of power and responsibilities 
among, the federal and state governments. Thus, Executive Order 13132 
does not apply to this rule.
    In the spirit of Executive Order 13132, and consistent with EPA 
policy to promote communications between EPA and State and local 
governments, EPA specifically solicits comment on this proposed rule 
from State and local officials.

F. Executive Order 13175 (Consultation and Coordination With Indian 
Tribal Governments)

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 6, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.''
    ``Policies that have Tribal implications'' is defined in the 
Executive Order to include regulations that have substantial direct 
effects on one or more Indian Tribes, on the relationship between the 
Federal government and the Indian Tribes, or on the distribution of 
power and responsibilities between the Federal government and Indian 
Tribes. This proposed rule does not have tribal implications. It will 
not have substantial direct effects on Tribal governments, on the 
relationship between the Federal government and Indian Tribes, or on 
the distribution of power and responsibilities between the Federal 
government and Indian tribes as specified in Executive Order 13175. 
Today's proposed rule contains no Federal mandates for Tribal 
governments and does not impose any enforceable duties on Tribal 
governments. Thus, Executive Order 13175 does not apply to this rule. 
In the spirit of Executive Order 13175, and consistent with EPA policy 
to promote communications between EPA and Tribal governments, EPA 
specifically solicits comment on this proposed rule from tribal 
officials.

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    Executive Order 13045, ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies 
to any rule that: (1) Is determined to be ``economically significant'' 
as defined under Executive Order 12866, and (2) concerns an 
environmental health or safety risk that EPA has reason to believe may 
have a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    This proposed rule is not subject to Executive Order 13045 because 
it does not concern an environmental health or safety risk that EPA has 
reason to believe may have a disproportionate effect on children. This 
rule is based on technology performance, not health or safety risks.

H. Executive Order 13211 (Energy Effects)

    This rule is not a ``significant energy action'' as defined in 
Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 
28355, May 22, 2001) because it is not likely to have a significant 
adverse effect on the supply, distribution, or use of energy. The 
treatment systems required by most sites affected by today's proposed 
rule rely on treatment techniques that do not utilize mechanical 
equipment. The proposed rule may require larger sediment basins in 
certain cases and some sites would need to operate treatment systems 
designed to reduce the turbidity of stormwater discharges, and 
therefore may result in the use of additional fuel for construction 
equipment conducting excavation and soil moving activities or to 
operate electrical generators to power pumps. EPA determined that the 
additional fuel usage would be small, relative to the total fuel 
consumption at construction sites and the total annual U.S. fuel 
consumption.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act (NTTAA) of 1995, (Pub. L. 104-113, section 12(d); 15 U.S.C. 272 
note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise

[[Page 72609]]

impractical. Voluntary consensus standards are technical standards 
(e.g., materials specifications, test methods, sampling procedures, and 
business practices) that are developed or adopted by voluntary 
consensus standard bodies. The NTTAA directs EPA to provide Congress, 
through OMB, explanations when the Agency decides not to use available 
and applicable voluntary consensus standards.
    The Agency is not aware of any consensus-based technical standards 
for the types of controls contained in today's proposal. EPA welcomes 
comments on this aspect of the proposed rulemaking and, specifically, 
invites the public to identify potentially-applicable voluntary 
consensus standards and to explain why such standards should be used in 
this regulation.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629 (Feb. 16, 1994)) establishes 
federal executive policy on environmental justice. Its main provision 
directs federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    EPA has determined that this proposed rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it increases the 
level of environmental protection for all affected populations without 
having any disproportionately high and adverse human health or 
environmental effects on any population, including any minority or low-
income population. The proposed rule will reduce the negative effects 
of discharges from construction sites in the nation's waters to benefit 
all of society, including minority communities.

XX. Solicitation of Data and Comments

A. General Solicitation of Comment

    EPA encourages public participation in this rulemaking. EPA asks 
that commenters address any deficiencies that they perceive in the 
record supporting this proposal and that suggested revisions or 
corrections to the rule, preamble or record be supported by data. EPA 
invites all parties to coordinate their data collection activities with 
the Agency to facilitate cost-effective data submissions. Please refer 
to the FOR FURTHER INFORMATION CONTACT section at the beginning of this 
preamble for technical contacts at EPA.

B. Specific Solicitation of Comments and Data

    EPA solicits comments on all aspects of today's proposal. In 
addition to the various topics on which EPA has solicited comments 
throughout this proposal, EPA specifically solicits comments on the 
following:
    1. EPA is proposing an effluent limit for turbidity. EPA solicits 
comments on the need to regulate additional pollutants or require 
monitoring of additional parameters, specifically pH. High pH can 
result from discharges of concrete truck washout as well as from 
stormwater that flows over recently placed concrete. EPA solicits 
comments on whether an effluent limit for pH is needed. Such a 
limitation would not be developed using the statistical methodology 
used to develop the turbidity limitation. Instead, EPA typically 
establishes a range of acceptable values from 6 to 9 to protect against 
extreme acidity or alkalinity.
    2. EPA is proposing that construction activity located in areas of 
the country that have an annual R-factor of less than 50 not be 
required to meet the turbidity standard. EPA solicits comment on the 
use of the annual R-factor as an applicability provision. EPA also 
solicits comment on incorporating a seasonal R-factor applicability 
provision, similar to the waiver provision for small construction sites 
currently in place under the Phase II regulation, into this regulation. 
(EPA's rainfall erosivity factor calculator can be found at http://
cfpub.epa.gov/npdes/stormwater/lew/lewcalculator.cfm). EPA solicits 
comment on the appropriate seasonal R-factor to consider, as well how 
it would be implemented. EPA is aware that R-factor information may not 
be widely available in Alaska, Hawaii and the U.S. territories. EPA 
solicits comment on the availability of R-factors in these areas. EPA 
also solicits comments on using annual precipitation instead of R-
factor as an applicability provision for Alaska, as well as for other 
areas where R-factor information is not readily available.
    3. EPA solicits comments on other factors related to soil type, 
climate or soil erosivity that should be considered as potential 
applicability provisions. EPA considered annual precipitation as an 
applicability provision in concert with or in place of an annual R-
factor applicability criterion. EPA solicits comments on the merits of 
an annual precipitation applicability criterion.
    4. EPA is proposing that construction activity located in areas 
with less than 10 percent soil clay content, by mass, not be required 
to meet the turbidity standard. EPA solicits comments on the 
feasibility and ease of implementation of the proposed 10 percent clay 
content applicability criteria. Specifically, EPA requests comments on 
how permittees could demonstrate that soils on their construction sites 
contain less than 10 percent clay content. EPA envisions permittees 
using available soil survey data as a way of establishing 
applicability, or permittees conducting laboratory analysis of soils 
present on-site. For example, ASTM D-422 (Standard Test Method for 
Particle-Size Analysis of Soils) could be specified. EPA requests 
comment on these two approaches. Specifically, EPA requests comments on 
the availability of soil survey data for the entire U.S. (including 
Alaska, Hawaii and the U.S. territories) and also the appropriate 
laboratory methods or standards that should be used by permittees to 
analyze soils on their sites. EPA also solicits comments on the number 
of samples that should be collected, the type and location of samples 
to be collected (i.e., should EPA consider that the applicability 
provision apply to topsoil or should EPA consider all soils expected to 
be exposed during the duration of the construction project). EPA 
solicits comments on how to aggregate or weight soil data for different 
areas of the site and for different soil horizons. EPA also solicits 
comment on whether the proposed 10 percent clay content value is an 
appropriate value to use for an applicability provision of the 
turbidity standard.
    5. EPA is proposing that C&D sites required to meet the turbidity 
limit provide storage and treatment for runoff expected from the local 
2-year, 24-hour storm. EPA solicits comments on whether this volume is 
adequate, or whether additional storage (such as runoff from the 10-
year, 24-hour storm or the 25-year, 24-hour storm) or less storage 
(such as runoff from the 1-year, 24-hour storm) should be required. EPA 
also solicits comments on whether specific analytical approaches or 
models (such as TR-55) should be used by permittees to calculate runoff 
volumes and storage requirements and whether specific assumptions in 
these models (such as specifying minimum runoff curve numbers that must 
be used) should be mandated through the regulation.

[[Page 72610]]

    6. EPA solicits data on the costs and performance of stormwater 
treatment systems and construction site erosion and sediment controls. 
EPA requests comment on the $0.02 per gallon cost for ATS EPA used as a 
basis for calculating costs for Options 2 and 3. EPA specifically 
solicits comments on treatment systems other than chitosan-enhanced 
filtration that could be used by permittees to meet the proposed or an 
alternate turbidity limit. EPA requests costs and performance data for 
these systems, as well as information on specific locations, project 
types or soil types for which these systems would be applicable. EPA 
also solicits comments on the costs to install conventional sediment 
basins.
    7. EPA has based its baseline assumptions on requirements currently 
contained in state construction general permits. EPA has not considered 
existing local or municipal requirements or regulations that may be 
more stringent than requirements contained in state general permits. 
EPA solicits comments and data on existing or proposed state, local and 
municipal requirements that are more stringent than the data used in 
EPA's analysis so that EPA may more accurately characterize the 
baseline of regulatory programs nationwide. EPA also solicits comments 
on the extent to which water quality standards or Total Maximum Daily 
Loads are requiring a higher level of control than currently required 
by state construction general permits.
    8. EPA solicits comments on the modeling approach used to estimate 
sediment generation and reductions due to the proposed option, which is 
described in the Development Document. EPA also solicits information 
and data on concentrations of pollutants, including sediment, 
turbidity, TSS, nutrients, metals, organics and other pollutants 
typically found in construction site stormwater discharges. EPA 
recognizes that currently available data generally show significantly 
lower influent and effluent sediment concentrations (for traditional 
sedimentation basins) than are reflected in EPA's modeling analysis. 
EPA solicits comment on whether and how these data should be 
incorporated into its analysis. More generally, EPA solicits comments 
on ways in which the load and pollutant removal estimates generated in 
support of this proposal can be improved, and how EPA's load estimates 
and benefits estimation methodologies can incorporate consideration of 
pollutants other that sediment.
    9. EPA has used NOI data from approximately 38 states. EPA solicits 
NOI data from other states, as well as other data that can be used to 
estimate the annual number of construction sites in the U.S. and the 
proportion of sites that would be subject to today's proposed 
regulations.
    10. EPA solicits comments on the typical duration of construction 
projects, the percent of construction projects acres that are 
disturbed, and the typical duration that soils are exposed.
    11. EPA solicits comments on the ability of dischargers to meet a 
numeric turbidity limit using passive, instead of active systems and 
the costs and performance of available technologies. EPA solicits 
comments on basing a turbidity limit on passive systems at a level in 
the range of 50-150 NTUs (or some other level) and the costs and 
pollutant load reductions that would be attributable to such a 
standard. EPA solicits comments on the applicability provisions of such 
a standard (i.e., should a 50-150 NTU (or some other level) standard 
apply to all permitted sites, only sites above 10 acres, should the 
standard include consideration of R-factor, annual precipitation or 
soil clay content, or other factors). EPA solicits information on the 
potential toxicity of polymers used in wastewater treatment, especially 
those used or marketed for use in stormwater treatment. EPA further 
solicits information on regulator and industry strategies and methods 
for avoiding any toxic effects of polymers used on construction sites. 
EPA requests comment on whether an approach based on passive controls 
could be implemented without specific numeric limits, or with action 
levels that would not themselves lead to permit violations but for 
which exceedances would result in additional controls, monitoring, 
inspection, and/or reporting requirements.
    12. EPA solicits comments on the ability of dischargers located in 
areas with R-factors less than 50 and with less than 10% soil clay 
content to meet a numeric turbidity limit and what technologies would 
be necessary to meet the proposed standard under Option 2 using 
conventional BMPs or passive treatment systems. Specifically, EPA 
requests comment on whether or not these sites, due to low rainfall, 
soil erosivity and low clay content, could meet the proposed Option 2 
turbidity standard using conventional BMPs and at a substantially lower 
costs than ATS.
    13. EPA solicits comments on whether national standards regulating 
peak flowrates from sediment basins should be included in the effluent 
guideline in order to limit channel erosion and what specific criteria 
or standards, such as matching predevelopment peak discharge rates for 
a specific design storm (such as the 1-year, 24-hour or 2-year, 24-
hour) should be included.
    14. EPA solicits comments on whether perimeter controls should be 
designed to remove a specific particle size and on any specific design 
or performance criteria that should be established for perimeter 
controls.
    15. EPA solicits comments on the costs and feasibility of requiring 
that flow from silt fences discharge through a vegetated filter strip 
or buffer before leaving the construction site.
    16. EPA solicits comments on ways in which permittees could certify 
that soils on their C&D site would not exceed the percent clay criteria 
associated with the turbidity limit.
    17. EPA solicits comments on requiring porous baffles in sediment 
basins as minimum requirements nationwide and whether the draft porous 
baffle design standards published by the North Carolina Department of 
Transportation (see DCN 43083) would be appropriate, or if other design 
standards are appropriate.
    18. EPA solicits comments on whether the detention time 
requirements proposed for sediment basins are appropriate and if other 
detention time requirements should be considered. EPA solicits comments 
on whether sediment basin requirements should address any other 
factors, such as a minimum surface area or a discharge rate per unit 
watershed area. EPA solicits data on effectiveness of any alternative 
criteria.
    19. EPA solicits comments on whether it would be feasible to 
require construction sites to maintain a minimum cover factor for soils 
based on the C-factor in RUSLE. For example, would it be feasible to 
require permittees to document in their SWPPP or erosion and 
sedimentation control plan the various phases of their project and 
calculate an area-weighted C-factor for each phase. Permittees would be 
required to meet a minimum average C-factor for the entire site during 
all phases of the project. Such a standard could vary based on the size 
of the site, with a lower average C-factor applying to larger sites. 
EPA solicits comments on the costs and feasibility of such an approach, 
and comments on what the specific C-factors should be for sites of 
various sizes (or other criteria) under such a standard. EPA solicits 
comments on the appropriate C-factors that would apply to various 
rolled erosion control products, hydromulches and other types of ground 
covers and erosion control

[[Page 72611]]

products currently in use by the industry.
    20. EPA solicits comments on whether or not the guideline should 
establish maximum slope lengths before a grade break or linear sediment 
control must be provided for steep slopes. EPA solicits comments on 
appropriate slope lengths for various slope values. EPA points readers 
to the March 18, 2008, Draft California CGP (see DCN 41137) for an 
example.
    21. Under the current permitting system, permittees (such as a 
developer) may sell or transfer control of a property to a builder or 
several builders and file for an NOT at some point during the course of 
the project, thus ending permit coverage for the developer. The builder 
or builders assuming control of the property would then be the 
permittee(s). If the project, while under control of the developer, was 
subject to the proposed turbidity limit because the project was over 40 
acres in size and met the R-factor and clay content applicability 
provisions, and the project was sold to two builders, each controlling 
20 acres, neither builder now controls more than 30 acres. As a result, 
there is some question as to whether or not the turbidity limit would 
still apply and which of the builders would be responsible for meeting 
the turbidity limit. EPA solicits comments from permitting authorities 
on if, and how, the proposed turbidity limit applicability provisions 
should be structured and the regulatory language structured so that the 
project remains subject to the turbidity limit until the entire project 
is completed.
    22. EPA solicits comments on the need for text in the rule language 
regarding proper operation and maintenance and chemical dosages of 
chemical treatment systems, or whether these requirements should be 
addressed through guidance.
    23. EPA's proposed option includes an applicability provision tied 
to the RUSLE R-factor. However, certain areas of the U.S., such as 
parts of Idaho, have a low annual R-factor but can experience high 
erosivity during certain times of the year, such as when rain occurs on 
snow or partially frozen ground. Also, for some cold mountainous 
climates, most of the erosivity is attributable to snowfall, instead of 
rainfall. EPA solicits comments on how to address applicability of the 
turbidity standard in areas such as these, and whether the rule 
language should include specific requirements regarding calculation of 
an R-factor for these areas or whether these issues should be addressed 
through guidance issued by EPA and/or left to the discretion of the 
permitting authority.
    24. EPA solicits comments on the proper techniques for turbidity 
measurement in the field to demonstrate compliance with today's 
proposal. EPA has an approved analytical method for turbidity (EPA 
Method 180.1 Rev 2.0). However, EPA is not proposing that a specific 
analytical method be used to demonstrate compliance. EPA's intent with 
today's proposal is to allow turbidity measurements to be made in the 
field using properly calibrated portable turbidity meters, or a 
properly calibrated automated turbidity meter coupled with a data 
logger, which typically is a component of ATS. EPA solicits comments on 
whether EPA Method 180.1 Rev 2.0 is appropriate in this case, or 
whether a revised method or other guidance would be needed in order to 
reduce monitoring burden and allow for the use of equipment commonly 
available and in use by ATS operators.
    25. EPA solicits comments on whether the effluent limit for 
turbidity should be a daily maximum value, as proposed today, or an 
instantaneous maximum based on continuous measurement. With a daily 
maximum, no individual measurements could be above the limit. With an 
instantaneous maximum, there could be a provision for brief exceedances 
of the limit. See 40 CFR 401.17 for an example of pH effluent 
limitations under continuous monitoring. EPA solicits comments on 
whether a similar approach should be applied for turbidity, and what 
specific excursion criteria would be appropriate.
    26. EPA solicits comments on whether any of the proposed options 
for BAT, BPT, BCT or NSPS should be based on the total size of the 
project, the disturbed area of the project, the quantity of soil 
disturbed at any one time, or the amount of disturbed area draining to 
any particular location. EPA solicits comment on the 30 acre site size 
provision for Option 2.
    27. EPA solicits comments on whether an approach based on passive 
treatment systems could be implemented as BAT, BCT, BPT or NSPS without 
specific numeric limits. EPA solicits comments on how permit 
authorities would implement and enforce such a standard. EPA 
specifically requests comment on action level or benchmark approaches, 
including what benchmark or action level should be used, and what 
measurement protocol should be used, and what measurement protocol 
should be established. EPA also solicits comment on how to account for 
soil conditions, storm events, and other variables in setting an action 
level or benchmark.
    28. EPA solicits comments on cases where discharges of stormwater 
from construction sites with low turbidity and TSS values to waters 
with high natural background concentrations of sediment may contribute 
to receiving stream channel instability and increase stream channel 
erosion. EPA solicits comments on whether the R-factor applicability 
provisions, which exempt most arid and semi-arid areas of the country, 
adequately address these concerns, or whether the guideline should 
incorporate specific provisions to allow permitting authorities 
flexibility in applying the turbidity limit to sites where receiving 
channel instability may be of concern.

C. Guidelines for Submission of Analytical Data

    EPA requests that commenters to today's proposed rule submit 
analytical and flow data to supplement data collected by the Agency 
during the regulatory development process. To ensure that commenter 
data may be effectively evaluated by the Agency, EPA has developed the 
following guidelines for submission of data.
1. Types of Data Requested
    EPA requests paired influent and effluent treatment data for 
systems capable of reducing the turbidity of stormwater runoff from 
construction sites. EPA prefers paired influent and effluent treatment 
data, but also solicits unpaired data as well.
    For the systems treating C&D stormwater, EPA requests paired 
influent and effluent treatment data from BMPs and treatment systems. 
Submission of effluent data alone is acceptable, but the commenters 
should provide evidence that the influent concentrations contain 
treatable levels of the pollutants. EPA also prefers individual 
measurements, rather than averages, to better evaluate variability, but 
will consider averages if individual measurements are unavailable. If 
commenters sample their stormwater to respond to this proposal, EPA 
encourages them to sample both the influent and effluent to BMPs and 
treatment systems and provide the individual measured values.
    EPA prefers that the data be submitted in an electronic format. In 
addition to providing the measurement of the pollutant in each sample, 
EPA requests that sites provide the detection limit (rather than 
specifying zero or ``ND'') if the pollutant is non-detected in the 
stormwater. Each measurement should be identified with a sample 
collection

[[Page 72612]]

date, the sampling point location, and the flow rate at that location. 
For each sample or pollutant, EPA requests that the chemical analytical 
method be identified.
    In support of the treatment data, commenters should submit the 
following items if they are available: A process diagram of the 
treatment system that includes the sampling point locations; treatment 
chemical addition rates; laboratory reports; influent and effluent flow 
rates for each treatment unit during the sampling period; a brief 
discussion of the treatment technology sampled; and a list of C&D 
operations contributing to the sampled wastestream. If available, 
information on capital cost, annual (operation and maintenance) cost, 
and treatment capacity should be included for each treatment unit 
within the system.
2. Analytes Requested
    EPA requests analytical data for any pollutant parameters that 
commenters believe are of concern in the C&D industry. Of particular 
interest are turbidity, TSS, and pH data. Commenters should document 
the method used for all data submissions. Submissions of analytical 
data should include any available documentation of QA/QC procedures; 
however, EPA will still consider data submitted without detailed QA/QC 
information. If commenters sample their stormwater to respond to this 
proposal, EPA encourages them to provide detailed documentation of the 
QA/QC checks for each sample.

List of Subjects in 40 CFR Part 450

    Environmental protection, Construction industry, Land development, 
Erosion, Sediment, Stormwater, Water pollution control.

    Dated: November 19, 2008.
Stephen L. Johnson,
Administrator.
    For the reasons set out in the preamble, EPA proposes to amend 
title 40, chapter I of the Code of Federal Regulations to add a new 
part 450 as follows:

PART 450--CONSTRUCTION AND DEVELOPMENT POINT SOURCE CATEGORY

Subpart A--General Provisions
Sec.
450.10 Applicability.
450.11 General definitions.
Subpart B--Construction and Development Effluent Guidelines
450.21 Effluent limitations reflecting the best practicable 
technology currently available (BPT).
450.22 Effluent limitations reflecting the best available technology 
economically achievable (BAT).
450.23 Effluent limitations reflecting the best conventional 
pollutant control technology (BCT).
450.24 New source performance standards (NSPS).

    Authority: 33 U.S.C. 1311, 1314, 1316, 1318, 1342, 1361 and 
1370.

Subpart A--General Provisions


Sec.  450.10  Applicability.

    This part applies to discharges associated with construction 
activity required to obtain NPDES permit coverage pursuant to 40 CFR 
122.26(b)(14)(x) and (b)(15).


Sec.  450.11  General definitions.

    The following definitions apply to this part:
    (a) Commencement of construction means the initial removal of 
vegetation and disturbance of soils associated with clearing, grading, 
excavating, or other construction activities.
    (b) Construction activity includes, but is not limited to, 
clearing, grading, excavation, and other site preparation work related 
to construction of residential buildings and non-residential buildings, 
and heavy construction (e.g., highways, streets, bridges, tunnels, 
pipelines, transmission lines and industrial non-building structures).
    (c) Minimize means to reduce and/or eliminate to the extent 
achievable using control measures (including best management practices) 
that are technologically available and economically practicable and 
achievable in light of best industry practices.
    (d) New Source means any source from which there will be a 
discharge associated with construction activity that will result in a 
building, structure, facility, or installation subject to new source 
performance standards elsewhere under subchapter N of this chapter.
    (e) Erosion as used in this part means the process of carrying away 
soil particles by the action of water.
    (f) Sediment basin means a structure designed to detain sediment 
laden stormwater long enough to allow sediment to settle in the basin 
and then discharge stormwater at a controlled rate through an 
engineered outlet device.

Subpart B--Construction and Development Effluent Guidelines


Sec.  450.21  Effluent limitations reflecting the best practicable 
technology currently available (BPT).

    Except as provided in 40 CFR 125.30 through 125.32, any point 
source subject to this subpart must achieve the following effluent 
limitations representing the application of the best practicable 
control technology currently available (BPT).
    (a) Erosion Controls. During all phases of construction activity, 
provide and maintain effective erosion controls in accordance with 
established industry practices on all disturbed areas of the 
construction site to minimize the discharge of sediment and other 
pollutants. Erosion controls are considered effective when bare soil is 
uniformly and evenly covered with vegetation or other suitable 
materials, stormwater is controlled so that rills and gullies are not 
visible, sediment is not visible in runoff from these areas and 
channels and streambanks are not eroding. Disturbed areas must be 
stabilized using erosion controls immediately after any clearing, 
grading, excavating or other earth disturbing activities have 
permanently or temporarily ceased. Assessment of erosion potential and 
appropriate erosion controls must take into account the rainfall, 
topography, soil types, climate, and vegetation or other cover at each 
site. Erosion controls implemented at the site must, at a minimum be 
designed and installed to achieve the following:
    (1) Stabilize disturbed soils immediately when earth disturbing 
work has temporarily or permanently ceased. Stabilization measures must 
be implemented immediately on any portion of the site whenever final 
grade is reached or when earth disturbing work has been stopped on that 
portion of the site and will not resume for a period exceeding 14 
calendar days.
    (2) Control stormwater volume and velocity within the site to 
minimize soil erosion.
    (3) Minimize the amount of soil exposed for the duration of the 
construction activity as well as at any one time during the 
construction activity.
    (4) Control stormwater discharges, including both peak flowrates 
and total stormwater volume, leaving the site to prevent channel and 
streambank erosion and erosion at outlets.
    (5) Preserve topsoil and natural vegetation.
    (6) Minimize soil compaction by construction equipment in areas 
that will not contain permanent structures or where compaction is not 
necessary for structural integrity. In disturbed areas that will not 
contain structures or where compaction is not necessary for structural 
integrity, utilize deep ripping and decompaction of soils and

[[Page 72613]]

incorporate organic matter to restore infiltrative capacity.
    (7) Provide and maintain natural buffers around surface waters.
    (8) Minimize the construction of stream crossings.
    (9) Sequence/phase construction activities to minimize the extent 
and duration of exposed soils.
    (10) Minimize disturbance of steep slopes.
    (11) Implement erosion controls specifically designed to prevent 
soil erosion on slopes.
    (12) Establish temporary or permanent vegetation, such as grass or 
sod, or use non-vegetative controls such as mulch, compost, 
geotextiles, rolled erosion control products, polymers or soil 
tackifiers to stabilize exposed soils.
    (13) Divert stormwater that runs onto the site away from disturbed 
areas of the site.
    (b) Sediment Controls. Provide and maintain effective sediment 
controls in accordance with established industry practice to minimize 
the discharge of sediment from the site. Effective sediment controls 
include a variety of practices that are designed to remove sediment 
within the range of particle sizes expected to be present on the site, 
taking into account rainfall, topography, soil types, climate and 
vegetation at each site and the proximity to storm drain inlets and 
receiving waters. Sediment controls must be installed, operated, and 
maintained in accordance with established industry practices to 
minimize the discharge of sediment and other pollutants from the site. 
Install appropriate sediment controls prior to the commencement of 
construction and maintain during all phases of construction activity. 
Effective sediment controls must include, at a minimum, the following:
    (1) Establish and maintain perimeter control measures for any 
portion of the down-slope and side-slope perimeter where stormwater 
will be discharged from disturbed areas of the site. Perimeter controls 
include, but are not limited to, BMPs such as diversion dikes, storm 
drain inlet protection, filter berms, and silt fencing. Perimeter 
control measures along the down-slope perimeter of the site must be 
installed following the contours of the land. Discharge stormwater from 
perimeter controls through vegetated areas and functioning stream 
buffers.
    (2) Control discharges from silt fences using a vegetated filter 
strip or vegetated buffer at least six feet in width.
    (3) Minimize the length of slopes and install linear sediment 
controls along the toe, face and at the grade breaks of exposed and 
erodible slopes.
    (4) Establish, use and maintain stabilized construction entrances 
and exits. Install, utilize and maintain wheel wash stations to remove 
sediment from construction equipment and vehicles leaving the site.
    (5) Remove any sediment and other pollutants, including 
construction materials, from paved surfaces daily to minimize 
discharges from the site. Washing sediment and other pollutants off 
paved surfaces into storm drains is prohibited unless those storm 
drains discharge to a sediment basin or other sediment control on the 
site.
    (6) Establish, use and maintain controls and practices to minimize 
the introduction of sediment and other pollutants to storm drain 
inlets.
    (7) Control sediment and other pollutants from dewatering 
activities and obtain and comply with any state or local discharge 
standards or permits for dewatering activities. Discharges from 
dewatering activities are prohibited unless treated to minimize the 
discharge of pollutants and sediment within the range of particle sizes 
expected to be present on the site.
    (8) For common drainage locations that serve an area with 10 or 
more acres disturbed at one time, install and maintain a sediment basin 
to control and treat the stormwater runoff. The permitting authority 
may allow alternative controls where alternative controls provide an 
equivalent or better level of pollutant reduction. The sediment basin 
must incorporate, at a minimum, the following requirements:
    (i) Provide a water storage volume for the calculated volume of 
stormwater runoff from the local 2-year, 24-hour storm for the entire 
watershed area draining to the basin until final stabilization of the 
disturbed area. Alternatively, a sediment basin providing a water 
quality storage volume of 3,600 cubic feet per acre of total watershed 
area draining to the basin must be provided until final stabilization 
of the disturbed area. If water will be flowing onto the construction 
site from up-slope and into the basin, the calculation of sediment 
basin volume must also account for this volume.
    (ii) In addition to the water storage volume, a sediment storage 
volume of at least an additional 1,000 cubic feet per acre of disturbed 
land area directed to the basin must be provided. If water will be 
flowing onto the construction site from up-slope and into the basin, 
the calculation of the sediment storage volume must also account for 
this volume.
    (iii) The effective length of the basin must be at least four times 
the width of the basin.
    (iv) Sediment basins must include and utilize an outlet device, 
such as a skimmer, designed to withdraw water from the surface of the 
water column. If a basin is to be used during freezing conditions which 
would interfere with the operation of an outlet device designed to 
withdraw water from the surface of the water column, then an 
alternative means of dewatering may be used only during periods of 
freezing conditions.
    (v) Discharges from sediment basins must be regulated in a manner 
that maximizes the residence time of the water in the basin. The 
dewatering time must consider the range of soil particle sizes and the 
settling time for soil particles expected to be present on the 
construction site. The dewatering time for the water storage volume 
must be at least 72 hours, unless otherwise specified by the permitting 
authority. However, in no case shall the dewatering time be less than 
24 hours. The design of the sediment basin must address factors such as 
the amount, frequency, intensity and duration of stormwater runoff, 
soil types, soil particle sizes, and other factors affecting pollutant 
removal performance.
    (9) Direct stormwater discharges from sediment controls to seep 
berms and level spreaders or utilize spray or drip irrigation systems 
to distribute stormwater to vegetated areas and functioning stream 
buffers to increase sediment removal and to maximize infiltration.
    (c) Pollution Prevention Measures. During all phases of 
construction activity, provide and maintain effective pollution 
prevention measures in accordance with established industry practice to 
control the discharge of pollutants from the site. Effective pollution 
prevention measures include a variety of recognized and accepted 
industry practices that minimize the discharge of pollutants from the 
site taking into account the specific circumstances at each site. 
Pollution prevention measures must be implemented to achieve, at a 
minimum, the following:
    (1) Prohibit the discharge of construction wastes, trash, and 
sanitary waste in stormwater;
    (2) Prohibit the discharge of wastewater from washout of concrete, 
stucco, paint, and cleanout of other construction materials;
    (3) Prohibit the discharge of fuels, oils, or other pollutants used 
in vehicle and equipment operation and maintenance;

[[Page 72614]]

    (4) Prohibit the discharge of pollutants resulting from the washing 
of equipment and vehicles where soaps or solvents are used;
    (5) Prohibit the discharge of pollutants resulting from the washing 
of equipment and vehicles using only water to remove sediment, unless 
wash waters, such as water from wheel wash stations, are treated in a 
sediment basin or alternative controls that provide equivalent or 
better treatment;
    (6) Implement measures to minimize the exposure of stormwater to 
building materials, landscape materials, fertilizers, pesticides, 
herbicides, detergents, and other liquid or dry products. Implement 
appropriate chemical spill prevention and response procedures. Any 
spills and leaks that do occur shall be immediately addressed in a 
manner that prevents the discharge of pollutants.
    (7) Prevent stormwater runoff from contacting areas with uncured 
concrete to minimize changes in stormwater pH.


Sec.  450.22   Effluent limitations reflecting the best available 
technology economically achievable (BAT).

    Except as provided in 40 CFR 125.30 through 125.32, any point 
source subject to this subpart must achieve the following effluent 
limitations representing the degree of effluent reduction attainable by 
the application of the best available technology economically 
achievable (BAT):
    (a) For construction activity located at a site with 10 percent or 
greater by mass of soils less than 2 microns in diameter (down to the 
graded and excavated level of the site), and that has an annual 
rainfall erosivity factor (R factor) of 50 or higher as defined by the 
Revised Universal Soil Loss Equation (for construction activity located 
in Alaska or a U.S. territory where the R factor applicable to the 
activity has not been calculated, the 30-year average total annual 
precipitation of 20 inches or more shall be used in place of the R 
factor):
    (1) The effluent limitations specified in Sec.  450.21 shall apply.
    (2) Except as provided by paragraph (a)(3) of this section, for any 
construction activity of 30 or more acres, the discharge of stormwater 
shall not exceed the value listed in the following table:

------------------------------------------------------------------------
                                                             Maximum for
              Pollutant or pollutant property                  any time
                                                              (NTU) \1\
------------------------------------------------------------------------
Turbidity..................................................          13
------------------------------------------------------------------------
\1\ Nephelometric turbidity units.

    (3) The requirements of paragraph (a)(2) of this section do not 
apply to the discharge of pollutants in the overflow from the sediment 
basin or other storage impoundment whenever rainfall events, either 
chronic or catastrophic, cause an overflow of stormwater from a 
sediment basin or other impoundment designed, constructed and operated 
to contain runoff from a 2-year, 24-hour rainfall event.
    (b) For any construction activity subject to this Subpart and not 
specified in paragraph (a) of this section, the effluent limitations 
are the same as those specified in Sec.  450.21.


Sec.  450.23  Effluent limitations reflecting the best conventional 
pollutant control technology (BCT).

    Except as provided in 40 CFR 125.30 through 125.32, any point 
source subject to this subpart must achieve the following effluent 
limitations representing the application of the best conventional 
pollutant control technology (BCT): The effluent limitations are the 
same as those specified in Sec.  450.21.


Sec.  450.24  New source performance standards (NSPS).

    Any new source subject to this subpart must achieve new source 
performance standards (NSPS): The standards are the same as the 
limitations specified in Sec.  450.22.

 [FR Doc. E8-27848 Filed 11-26-08; 8:45 am]

BILLING CODE 6560-50-P
