ENVIRONMENTAL PROTECTION AGENCY

	40 CFR Part 450

	[EPA-HQ-OW-2008-0465; FRL-XXXX-X]

	RIN 2040-AE91

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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 up to $1.9 billion dollars per year and
reduce discharges of sediment by up to 27 billion pounds annually. This
proposed rule requests comment and information on the proposed
regulation and a variation of the proposed option with a different
numeric limit, as well as specific aspects of the proposal such as
technologies, costs, and affordability.

DATES: Comments must be received on or before [INSERT DATE 90 DAYS AFTER
DATE OF PUBLICATION IN THE FEDERAL REGISTER].

ADDRESSES: Submit your comments, identified by Docket ID No.
EPA-HQ-OW-2008-0465, by one of the following methods:

  HYPERLINK "http://www.regulations.gov"  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.

	(	Email: 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  
HYPERLINK "http://www.regulations.gov"  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 www.regulations.gov or e-mail. The   HYPERLINK
"http://www.regulations.gov"  www.regulations.gov  website 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 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   HYPERLINK
"http://www.regulations.gov"  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   HYPERLINK
"http://www.regulations.gov"  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 website; 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 (  HYPERLINK "mailto:doley.todd@epa.gov" 
doley.todd@epa.gov ).

SUPPLEMENTARY INFORMATION:

Regulated Entities

	Entities potentially regulated by this action include:

Category	Examples of Regulated Entities	North American Industry
Classification System (NAICS) Code

Industry	Construction activities required to obtain NPDES permit
coverage and performing the following activities:

	Construction of buildings, including building, developing and general
contracting	236

	Heavy and civil engineering construction, including land subdivision
237



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 § 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
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 regulations:

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 website 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  TC \l1 "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  TC \l1 "II. Purpose &
Summary of 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
principle remaining water quality problems throughout the United States.
Sediment is the primary pollutant that causes 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. The sediment
entrained in stormwater discharges from construction activity
contributes to harm in aquatic ecosystems, increases drinking water
treatment costs, and degrades 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 establishes 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, 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 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. Permittees have the
flexibility to select management practices that are best suited to
site-specific conditions present on each individual C&D site.

 

III. Background on Existing Regulatory Program  TC \l1 "III. Background 

A. Clean Water Act  TC \l2 "A. Clean Water Act 

	Congress passed the Federal Water Pollution Control Act of 1972 (Public
Law 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 (Public Law 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  TC \l2 "B. NPDES Storm Water 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;.

EPA defines these as “large” construction sites as stormwater
discharges 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  TC \l3 "1. Storm Water
Permits for Construction: General and Individual 

	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  TC \l4 "a. General 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  TC \l4 "b. EPA Construction General
Permit 

	Since 1992, EPA has issued a series of “national” Construction
General Permits 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 website 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  TC \l4 "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).

	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
constructions 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  TC \l4 "d. Individual 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  TC \l4 "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 is (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  TC \l4 "b. EPA Guidance to
Municipalities 

	EPA developed several guidance documents for municipalities to
implement the NPDES Phase II rule.

•	National Menu of BMPs (  HYPERLINK
http://www.epa.gov/npdes/menuofbmps/menu.htm
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 (  HYPERLINK
http://www.epa.gov/npdes/stormwater/measurablegoals
http://www.epa.gov/npdes/storm water/measurablegoals ). This document
assists small MS4s in defining performance targets and 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,   HYPERLINK
http://cfpub.epa.gov/npdes/stormwater/smms4.cfm?program_id=6
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  TC \l2 "C. Other State
and Local Storm Water 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  TC
\l2 "D. Effluent Guidelines and Standards Program 

	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)  TC \l3
"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 does
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)  TC \l3 "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 Cir1988). 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, 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)  TC \l3 "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)  TC \l3 "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  TC \l3 "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 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 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  TC \l1 "IV. Scope of 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 up to $1.9 billion dollars per year and reduce discharges of
sediment by up to 27 billion pounds annually. 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, 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 at 50 NTUs 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 size, rainfall, or soil type thresholds for
determining which sites would be required to comply with a turbidity
limit on the sediment basin effluent. 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).

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 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  TC \l1 "V. 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. 

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 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 Aeronautical
Administration (NOAA) aeronautical charts having a scale of 1:500,000.
ERF1 contains 67,171 watersheds with a minimum size of 247 acres (1 km2)
and an average size of 30,182 acres (122 km2). 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 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 (  HYPERLINK "http://www.soilinfo.psu.edu/" 
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.
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 cut-offs. 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 MSA-level data are available from the Census). 

VII. Characteristics of Discharges from Construction Activity  TC \l1
"VII. Storm Water Discharge Characteristics 

	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 other pollutants in the water body, most notably
turbidity, suspended solids, total suspended solids (TSS), suspended
sediment concentration (SSC), or settleable solids. CWA section 304(a)
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 401.16; 43
FR 32857, 32858 (July 28, 1978). Turbidity and settleable solids are
non-conventional pollutants. See 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, as
reflected by turbidity levels that 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 turbidity, 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  TC \l2 "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   TC \l2 "B. Erosion and Sediment Controls
and Other Site Management Practices 

	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.

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
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 would typically 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. 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 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. 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 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   TC \l3
"4. Control of Other Pollutants 

	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  TC \l1
"IX.  Development of Effluent Limitation Guidelines and Standards 

A.   TC \l2 "B. Regulatory Options Considered 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

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 plain 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 until final stabilization of the
disturbed area. Where no such engineering calculation had been
performed, a sediment basin providing a water storage volume of 3,600
cubic feet per acre drained 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 quality
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 XXXXX). 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 about 670 million pounds annually.

	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-yr, 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
XXXXX) contains an example of designing a sediment basin to remove a
specified particle size standard based on wet sieve analysis or the 10
micron particle for a 10-year, 6-hour storm event. EPA estimates, using
this approach, sediment basins required to remove particles greater than
10 microns nationwide would cost approximately $1.6 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 disturbed area, 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 10 or more acres of
disturbed land that are not required to meet the turbidity requirement
because 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 high clay content, the
proposed rule would achieve significant reductions of the
slowly-settling or non-settleable particles 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 sites 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 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 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. 

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 up to$1.9 billion per year (2008 $), not
including costs for Alaska, Hawaii and the U.S. territories, and reduce
discharges of pollutants by up to 27 billion pounds 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 up to $3.8 billion per year (2008 $), not
including costs for Alaska, Hawaii and the U.S. territories, and reduce
discharges of pollutants by up to 50 billion pounds annually.

D. Option Selection Rationale for Best BPT 

	EPA proposes to select Option 1 as the basis for establishing BPT
effluent limitations. The requirements established by Option 1 are
well-established by construction activities in all parts of the country
and are consistent with the control measures currently in place under
EPA’s Construction General Permit and many 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 (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 consistent with the
EPA CGP, reducing pollutant discharges by approximately 670 million
pounds per year. 

	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 has selected 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, is a nonconventional pollutant
because it is not identified as either a toxic or conventional pollutant
under the CWA. See CWA section 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
controls 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. 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 criteria, dischargers have used the active
treatment systems described previously – electrocoagulation, polymer
clarification, and chitosan-enhanced sand filtration. 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.

	The selection of Option 2 is consistent with 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 site, 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 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.”

	Although the NRC report reports recommended turbidity limits of 25 and
75 NTUs, which are higher than the proposed limit of 13 NTUs in
today’s proposal, EPA’s analysis of ATS effluent data from more than
6,000 data points indicates that a limit of 13 NTUs is attainable.

	California assembled a blue ribbon panel to evaluate, among other
things, the feasibility of establishing numeric effluent limits from
construction sites (see DCN XXX). 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.

	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’s analyses show 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.

	Under Option 2, an estimated 1,032 firms (1.3 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
the firms' ability to pass some of their compliance costs along to
customers is accounted for (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 costs exceeding 3 percent of revenue. 

	Assuming a cost pass-through rate of 85 percent for residential sectors
and 71 percent for non-residential and non-building sectors, a total of
179 firms are estimated to incur financial stress as a result of
regulatory requirements, which represents 0.2 percent of in-scope firms,
and a total of 132 firms are estimated to experience negative business
value and be at risk of closure due to regulatory requirements, which
represents 0.2 percent of in-scope firms. These impact measures are not
necessarily additive, as they evaluate different aspects of a firm's
financial viability, and the same firm may be counted under more than
one measure. Nevertheless, given the consistently low measures of
financial impact, in terms of percentage of in-scope firms, EPA
considers the rule to be economically achievable by the construction
industry. In addition, these impacts do not take into consideration less
costly ways for industry to comply with the final rule, if it is
promulgated as proposed. One primary way a company could avoid being
subject to the turbidity limit on sites of 30 or more acres would be to
decide to only undertake projects smaller than 30 acres in the future,
thus lowering their potential compliance costs.

	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 rejected 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 found 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 a Option 2 could reasonably be afforded by the
industry. 

	EPA also rejected 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 determined 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 has
determined 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
determined that Option 3 does not represent the best available or best
demonstrated technology for the C&D point source category.

	In summary, EPA has determined that Option 2 is technologically
available, economically achievable, and has acceptable non-water quality
environmental impacts. EPA has determined 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 of 50 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 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
XXXXX) 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 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 XXXXX) 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 "DirtII"). 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 on
the site for this event. Thus, no sediment was discharged from the site
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, was estimated to cost
approximately $12,000 (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 (we plan to translate the 1999 NZ $ to 2008 U.S. $
during OMB review).

	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 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, 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 XXX) and by McLaughlin (see DCN XXX). 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 XXX). 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 XXXX) 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 (see
DCNs XXX through XXX - this is a list of 7 papers).   

	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 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 NTUs (or some
other value). EPA also solicits comment on the ability to reliably meet
a 50 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 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.

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 has selected Option 2 as the basis for the proposed BCT. As
discussed in IX.C.5 above, the requirements of Option 2 have been
demonstrated to be technologically available and EPA’s analyses show
that the requirements are economically achievable. Additionally, Option
2 passes EPA’s two-part BCT cost test. See 51 FR 24974.

	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 technologies 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 $). EPA calculated the incremental cost per
pound of conventional pollutants removed ($/lb TSS) for Option 2 to be
$0.07. Since this result is less than the POTW benchmark, Option 2
passes the first part of the two-part 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 ICR calculated ration for
Option 2 is 0.28; therefore, it passes the second part of the BCT cost
test. EPA requests comments on the Agency’s loading analysis and on
the BCT cost test calculations.

	EPA estimated loading reductions, which are used as the basis of the
BCT cost test, 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 requests comment on this approach and on the proper data
sources and concentration values to use in such a calculation.

	EPA also evaluated BCT for Option 3. In establishing BCT limitations,
any “candidate” technologies are evaluated to determine if they are
technically available and economically achievable. [See EPA’s BCT
Final Rule, 51 FR 24974, 24976 (col.1) (July 9, 1986)]. As discussed
above in the BAT options section, this option is not economically
achievable in light of the total industry cost and the appropriateness
of ELG turbidity limits in arid areas and at construction sites where
soils contain little clay. Therefore, EPA determined that Option 3 does
not represent BCT for the C&D point source category.

X. Methodology for Estimating Costs to the Construction and Development
Industry  TC \l1 "XI. Methodology for Estimating Costs 

	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 project 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 estimate for 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 five 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. 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 five model projects. EPA then estimated the costs for treating
stormwater from each model construction site within 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. EPA notes that this approach likely resulted in an overestimation
of actual treatment costs, since EPA expects that many construction
sites would not need to rely on active treatment systems in order to
reliably meet the effluent limit, and could instead meet the effluent
limit by relying on passive treatment systems or conventional stormwater
BMPs. In addition, there are other treatment technologies available that
may be cheaper than chitosan-enhanced sand filtration that permittees
could use to meet an effluent limit.

	Chapter 7 of the Development Document contains a more detailed
discussion of the EPA’s costing approach.

	

XI. Economic Impact and Social Cost Analysis  TC \l1 "XII. Economic
Impact and Social Cost Analysis 

A. Introduction  TC \l2 "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 Order
12866. See section XIX of today's notice.

B. Description of Economic Activity  TC \l2 "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 near term future projections are for renewed
growth in housing starts as soon as the third quarter of 2009.
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” 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” 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 (Public Law 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

NAICS	Description	1992 (No.)	1997 (No.)	2002 (No.)	Change 92-97(%)
Change 97-02 (%)

236	Construction of Buildings, except all other Heavy Constructiona
168,407	191,101	211,629	13.50%	10.70%

237 except 2372	Heavy Construction, except Land Subdivision	37,180
42,554	49,433	14.50%	16.20%

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
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 if the estimated number of acres disturbed in a 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. For example, no adjustments have been made to account for
firms in the non-residential construction or heavy construction
industries that may disturb less than one acre of land. 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

NAICS	Industry Sector	Firms



Number	Percent of Total

2361 	 Residential Building Construction 

236115	New Single-family Housing Construction (except operative builder)
33,609	41%

236116	New Multifamily Housing Construction (except operative builder)
2,620	3%

236117	New Housing Operative Builder	17,295	21%

2362 	Nonresidential Building Construction 

236210 	Industrial Building Construction	1,610	2%

236220	Commercial and Institutional Building Construction	20,797	26%

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  TC \l2 "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 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. In addition, EPA
convened a SBAR panel in 2008 for this proposal, but did not obtain any
information during the SBREFA process that resulted in changes in
EPA’s economic analysis.

		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. Detailed
information on the data, models, methods, and results of the economic
impact analyses are available in the Economic Analysis.

1. Model Project Analysis  TC \l3 "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 frequently 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." 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 developed estimates of the project-specific costs and revenue at
each stage of project development in the baseline scenario. The result
is a cash flow analysis of the costs and revenue associated with the
project. 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).

	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. 

	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-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 cost pass-through rate of 85% for
residential sectors and 71% for non-residential and non-building
sectors. This is the expected 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.

	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 extreme 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 extreme cases also
provide an approximation of the sensitivity of impact estimates to the
partial cost pass-through assumptions used for the expected case. EPA
requests comment on the partial cost pass-through assumptions used for
the expected 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  TC \l3 "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 developed for NAICS sectors aligning with each of the
principal C&D business segments expected to be affected by the
regulation (See Table XI-2). Each model firm represents the baseline
(i.e., pre-regulation) financial performance and condition of typical
businesses in these industry segments. These model firms are used in
combination with compliance cost estimates to examine the potential for
financial stress, employment effects, and increased barriers to the
entrance of new firms to the industry. Model firms are broken out
further by revenue size ranges for each of the NAICS categories for
which data are reported by the Statistics of U.S. Business (SUSB) and
the Economic Census. 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 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. 

	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 XXXXX). 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 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. For this
analysis, EPA used both the partial and no cost pass-through, to assess
potential economic impacts on the industry under the expected and
worst-case scenarios. Full cost pass-through would have no impact at the
firm level.

3. Housing Market Impacts  TC \l3 "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 was able 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 both the partial and full cost pass-through assumptions, to
estimate both the expected and 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  TC \l3 "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 XXXXX). 

	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
estimate of the impacts on national output and employment.

D. Results  TC \l2 "D. Results 

1. Firm-Level Impacts  TC \l3 "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 actual
conditions based on EPA's review of the academic literature and its
discussions with industry officials who indicate that most, if not all
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

Option	Costs Exceeding 1% Revenue	Costs Exceeding 3% Revenue

	Number of Firms	Percent of Firms	Number of Firms	Percent of Firms

Option 1	0	0.0%	0	0.0%

Option 2	1,032	1.3%	76	0.1%

Option 3	3,638	4.5%	220	0.3%

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. 

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	19	179	561

% of All In-scope Firms	0.0%	0.2%	0.7%

Firms whose Net Business Value Becomes Negative as a Result of
Compliance (Potential Closures)

Number Incurring Effect	21	132	795

% of All In-scope Firms	0.0%	0.2%	1%

Number of Jobs	1,100	11,900	29,400

% of In-scope Firm Employees	0.4%	1.7%	2.7%

Source: Economic Analysis



	Both the financial performance and net business value measures show
that a very small percentage of the approximately 86 thousand in-scope
firms will experience any financial stress as a result of the proposed
options. 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 decline
that is the greatest 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 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. With
regard to Option 2, comparing the results of the primary economic
analysis, to those of the adverse case analysis shows a four fold
increase in the number of firms incurring financial stress; and a 550
percent increase in firms at risk of closure. 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, never exceeds two percent of total in-scope firms.

	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 the long-term trend during the period
when the rule is being implemented by states and will be able to absorb
the rule’s requirements without undue adverse effect.

2. Impacts on Governments  TC \l3 "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-5 shows the costs that government entities are expected to incur at
federal, state, and local levels.

Table XI-5 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  TC \l3 "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-6
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 new houses are expected to be in projects
subject to Option 1, 8 percent to Option 2 and 13 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.

Table XI-6. Change in Monthly Mortgage Payment for New Single-Family
Home (Full Cost Pass-Through)

	Option 1	Option 2	Option 3

Price Change New Single-Family Home 	$330	$2,100	$2,242

New Single-Family Median Priced Home

Baseline Mortgage Payment ($/month)	$1,971	$1,971	$1,971

New Mortgage Payment ($/month)	$1,972	$1,985	$1,986

% Change	0.05%	0.70%	0.75%

New Single-Family Lower Quartile Priced Home

Baseline Mortgage Payment ($/month)	$1,358	$1,358	$1,358

New Mortgage Payment ($/month)	$1,359	$1,363	$1,364

% Change	0.07%	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%. 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  TC \l3 "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  TC \l3 "5. Impacts on New Facilities 

	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 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. Still, EPA does not consider the increase in
financing requirements to pose a significant barrier to entry for
potential businesses and projects.

6. Social Costs  TC \l3 "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-7 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-7: Total Social Cost of Options (millions of $2008)

	Option 1	Option 2	Option 3

Total Costs, Unadjusted for Quantity Effect	$132	$1,891	$3,797

Change in Costs Due to Quantity Effect	$0.1	$7	$17

Total Costs, Adjusted for Quantity Effect	$132	$1,884	$3,780

Total Dead Weight Loss	$0.0	$3.5	$8.4

Additional Government Administrative Costs	$0.0	$0.7	$1.2

Total Social Cost of the Regulation	$132	$1,888	$3,789

Source: Economic Analysis



7. Small Business Impacts  TC \l3 "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 US 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-8 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-8. Small Business Analysis for Options, 1% and 3% Revenue
Tests, Assuming No Cost Pass-Through

Option	1% Revenue Test	3% Revenue Test

	Number of Small Firms	Percent of Small Firms	Number of Small Firms
Percent of 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-8 shows that for the preferred option (Option 2), less than a
thousand small firms would be likely to incur 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.

XII. Cost-Effectiveness Analysis  TC \l1 "XIII. 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, a conventional pollutant. 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 C&D proposed 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 2008$)	$132.2	$1,891.0	$3,796.5

Sediment Removed (million lbs/yr)	670	26,426	50,413

Cost per Pound Removed ($/lb)	$0.20 	$0.07	$0.08

Source: Economic Analysis



XIII. Non-Water Quality Environmental Impacts  TC \l1 "XIV. 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  TC \l2 "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.

B. Solid Waste Generation  TC \l2 "B. Solid Waste 

	Generation of solid waste would not be substantially affected
regardless of the option selected because the majority of solid waste
generated at construction activities derives from wastage of materials
brought onto and used at construction sites. Likewise, for redevelopment
projects, the amount of solid waste generated, while possibly greater
than the amounts generated at new developments, would not vary
regardless of the option selected. In many states, sediment accumulated
in sediment basins can typically be removed and applied on-site as fill
material, so long as the material is not contaminated with litter or
chemicals. 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. 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. 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.

	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  TC \l2 "C. Energy Usage 

	The consumption of energy as a result of today's proposed rule is not
expected to be significantly affected 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 treatments systems that utilize
diesel-powered pumps and generators would result in increased fuel
consumption. Likewise, the installation of larger sediment basins would
require 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. 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 usage in 2001 was estimated to be
approximately 200 million pounds, and additional usage on construction
sites would be minimal; see DCN XXXX). Chitosan, another polymer
commonly used on construction sites, and the basis for EPA’s BAT
option, is manufactured from crustacean shells. Therefore, additional
energy consumption due to chitosan production and usage is expected to
be minimal.

XIV. Environmental Assessment  TC \l1 "XV. 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 pollutant
from construction sites is 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 pollutants affecting waters listed as
impaired 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 other 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
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 pollutant 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 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. 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%”).
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”). 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 more construction activities are occurring 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 median concentrations in Table XIV-1 reflect average 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

	“Top 10%” RF1 Watersheds - Median TSS Concentration (mg/L)
Reduction in Median TSS Concentration (mg/L)	“All” RF1 Watersheds -
Median TSS Concentration (mg/L)	Reduction in Median TSS Concentration

(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 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 is
provided in the Environmental Assessment. The case study has not been
completed, so EPA intends to include the case study analysis in the
documentation in support of the final rule. EPA requests comments on
this approach.

XV. Benefit Analysis  TC \l1 "XVI. 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  TC \l2 "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 the 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.


Table XV-1. Summary of Benefits from Reducing Sediment Runoff from
Construction Sites

  SEQ CHAPTER \h \r 1 Activity	Environmental Service Potentially
Affected by Runoff from Construction Sites	 Benefits Category

Recreation

 - Outings

 - Boating

 - Swimming

 - Fishing 	Aesthetics, water clarity, water safety, degree of
sedimentation, weed growth, fish and shellfish populations	Non-market
direct use

Commercial Fishing and Shellfishing	Fish and shellfish populations
Markets

Property Ownership	Aesthetics, safety of property from flooding,
property value	Markets

Water Conveyance and Supply

 - Water conveyance

 - Water storage

 - Water treatment	Turbidity, degree of sedimentation	Avoided Costs

Transportation	Degree of sedimentation	Avoided Costs

Water Use

 - Industrial 

 - Municipal 

 - Agricultural 	Turbidity	Avoided Costs

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  TC \l2 "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 US 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.

Table XV-2. Annual Benefits (million 2008 $) for Options

Benefit Categories	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 Costsa	$1.8	$37.9	$70.9

Welfare Improvements	$16.6	$295.0	$398.5

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  TC \l1 "XVII. 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.

Table XVI-1. Total Annualized Benefits and Costs of Options (year 2008
$)

Option	Social Costs 

(2008 $ millions per year)	Monetized Benefits 

(2008 $ millions per 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. 

 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.

	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. 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.

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 occasionally sites may
discharge at a level that is greater than the long-term average. This
variability also means that sites may occasionally 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. That is,
targeting treatment to achieve the limitation may result in frequent
values exceeding the limitation due to routine variability in treated
effluent, and thus, EPA also 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 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. 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  TC \l1 "XVIII. Regulatory
Implementation 

A. Relationship of Effluent Guidelines to NPDES Permits and ELG
Compliance Dates  TC \l2 "B. Relationship of Effluent Guidelines to
NPDES Permits 

	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.  TC \l2 "A.
Compliance Dates  

B. Upset and Bypass Provisions  TC \l2 "C. 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.

C. Variances and Waivers  TC \l2 "D. 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 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  TC \l2 "E. 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   SEQ CHAPTER \h \r 1
(58 FR 51735, October 4, 1993), this action is an "economically
significant regulatory action”  SEQ CHAPTER \h \r 1  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.

	  SEQ CHAPTER \h \r 1 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

Option	Social Costs 

(2008 $ millions per year)	Monetized Benefits 

(2008 $ millions per year)

Option 1	$132	$18

Option 2	$1,891	$333

Option 3	$3,797	$470



B. Paperwork Reduction Act  TC \l2 "A. 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. 

	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 [Insert date of publication in the Federal Register.], a comment
to OMB is best assured of having its full effect if OMB receives it by
[Insert date 30 days after publication in the Federal Register.]. 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 evaluate potential impacts of today’s proposal on small
businesses, EPA convened a SBREFA panel for this rulemaking on September
10, 2008. EPA held an outreach meeting with Small Entity Representatives
(SERs) on September 17, 2008. A list of SERs and the outreach materials
sent to SERs are included in the docket (see DCN XXXXX - XXXXX). EPA,
OMB and SBA prepared a panel report, which is also included in the
docket (see DCN XXXXX).

	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), P.L.
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 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 US 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 & 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 two 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 

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 Outlay	0.09%	1.37%	2.57%

Construction Outlay Only	8,529	8,529	8,529

Total Costs as % of Total Construction Outlay	0.14%	2.16%	4.06%

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 insignificant, 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, (Public Law 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 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   TC \l2 "B. 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 section at the beginning of this preamble for
technical contacts at EPA.

B. Specific Solicitation of Comments and Data  TC \l2 "A. 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   HYPERLINK
"http://cfpub.epa.gov/npdes/stormwater/lew/lewcalculator.cfm" 
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 request 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.

6. EPA solicits data on the costs and performance of stormwater
treatment systems and construction site erosion and sediment controls.
EPA specifically solicits comments on treatment systems other than
chitosan-enhanced filtration that could be used by permittees to meet
the proposed 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 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 of 50 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 as standard (i.e., should a 50 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.

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 XXXXX) 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 are 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 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 XXX) 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.

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 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. 

  TC \l1 "XX. Solicitation of Data and Comments 

List of Subjects in 40 CFR part 450

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

_____________________

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:

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: Sections 301, 304, 306, 308, 402, 501 and 510 of the Clean
Water Act, as amended; 33 U.S.C. 1311, 1314, 1316, 1318, 1342, 1361 and
1370.

Subpart A–General Provisions

§ 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). 

§ 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 prevent using available control
measures (including best management practices) that reflect 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. 

(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

§ 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
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:

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.

Control discharges from silt fences using a vegetated filter strip or
vegetated buffer at least six feet in width.

Minimize the length of slopes and install linear sediment controls along
the toe, face and at the grade breaks of exposed and erodible slopes.

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.

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.

 Establish, use and maintain controls and practices to minimize the
introduction of sediment and other pollutants to storm drain inlets.

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.

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:

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.

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.

 The effective length of the basin must be at least four times the width
of the basin.

 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.

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.

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:

Prohibit the discharge of construction wastes, trash, and sanitary waste
in stormwater;

Prohibit the discharge of wastewater from washout of concrete, stucco,
paint, and cleanout of other construction materials;

Prohibit the discharge of fuels, oils, or other pollutants used in
vehicle and equipment operation and maintenance; 

Prohibit the discharge of pollutants resulting from the washing of
equipment and vehicles where soaps or solvents are used;

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; 

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.

Prevent stormwater runoff from contacting areas with uncured concrete to
minimize changes in stormwater pH.

§ 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):

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): 

The effluent limitations specified in § 450.21 shall apply.

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:

Pollutant or pollutant property	Maximum for any time (NTU)*

Turbidity	13

* - Nephelometric turbidity units.

The requirements of paragraph (a)(2) 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.

			

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 § 450.21.

§ 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 § 450.22.

§ 450.24	New source performance
standar獤⠠华卐⸩ऍ䄉祮渠睥猠畯捲⁥畳橢捥⁴潴琠楨
⁳畳灢牡⁴畭瑳愠档敩敶渠睥猠畯捲⁥数晲牯慭据⁥瑳
湡慤摲⁳丨偓⥓›桔⁥瑳湡慤摲⁳牡⁥桴⁥慳敭愠⁳桴
⁥楬業慴楴湯⁳灳捥晩敩⁤湩꜠㐠〵㈮⸲഍഍ഃЍ഍ഃ
Ѝ഍഍഍倓䝁⁅ᔠ

