




                 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                            REGION IX AIR DIVISION
                                       
                                       
                                       
                                       
                                       
                          Technical Support Document
                                       
                                       
                                       
                                       
                                       
                          EPA's Proposed Rulemaking
                                       
                                    For the
                                       
                   Pinal County Air Quality Control District
                                       
Chapter 4, Article 1, West Pinal PM10 Moderate Nonattainment Area Fugitive Dust
                                       
                                       
                                       
                                       
                                       
                                       
                       Prepared by:  Christine Vineyard
                                       
                                  March 2016
                                       
                                       
                                       
                                       






RULE IDENTIFICATION 

Agency
Pinal County Air Quality Control District

Subject of this TSD
Rule:   Chapter 4, Article 1  -  West Pinal PM10 Moderate 
            Nonattainment Area Fugitive Dust
Adopted  -  October 28, 2015 
Submitted  -  December 21, 2015

Completeness Finding
March 21, 2016

RULE SUMMARY

Applicability  -  the purpose of the Article is to control fugitive dust from open areas/vacant lots, unpaved roads, unpaved lots and paved public roadways by requiring measures to prevent, reduce or mitigate fugitive dust emissions.

Exemptions 
The standards and requirements of this Article shall not apply to:
 Legitimate vehicle test and development facilities and operations conducted by or for equipment manufacturers where dust is required to test and validate the design integrity, product quality and/or commercial acceptance.
 Sudden and unforeseeable emergency response activities that may disturb the soil conducted by any utility or government agency in order to prevent public injury or to restore critical utilities to functional status.  
 Normal farm cultural practices.
 Dust generating operations subject to the standards and/or requirements described in Chapter 4, Article 3  -  Construction Sites  -  Fugitive Dust.
 The establishment of initial landscape without the use of mechanized equipment, conducting landscape maintenance without the use of mechanized equipment, and playing on or maintaining a field used for non-motorized sports; and shall not include grading, or trenching, performed to establish initial landscapes or to redesign existing landscapes.

Definitions 
Applicable definitions are included to add clarity to the rule.

Standards
General  -  the owner and/or operator of open areas/vacant lots, unpaved lots, unpaved roads and paved public roadways must implement control measures to meet the visible emissions requirements, stabilization requirements and compliance determinations for each applicable category.  Failure to implement control measures as required by this rule shall be deemed a violation of this rule.

Open Areas/Vacant Lots:
          The owner and/or operator of open areas/vacant lots shall not cause, suffer, allow, or permit fugitive dust emissions which exceed twenty percent (20%) opacity.
          Upon evidence of trespass, an owner/operator shall install and maintain no trespassing signs and physical barriers such as curbs, fences, gates, posts, shrubs, trees, or other effective control measures.
          Owners and/or operators of open areas/vacant lots 1.0 acre (43,560 ft[2]) or larger and have a cumulative of 0.5 acre (21,780 ft[2]) or more disturbed surface area in addition to the general requirements shall implement an additional control measure listed in this section.
          Open area/vacant lots 1.0 acre (43,560 ft[2]) or larger and have a cumulative of 0.5 acre (21,780 ft[2]) or more disturbed area, shall sign up to receive the Pinal County dust control forecast within 30 calendar days following the initial discovery of the disturbed surface area.  In addition, the owner and/or operator shall ensure the open area/vacant lot is stabilized the day leading up to and the day that is forecast to be high risk for dust emissions.
          No person shall use blading, disking, plowing under or any other means to remove vegetation from any open area/vacant lots without implementing all the required control measures.
          A list of stabilization requirements compliance methods are included.

Unpaved Lots
          The owner and/or operator of an unpaved lot greater than 5,000 ft[2] shall not:
               Cause or allow visible fugitive dust emissions to exceed 20% opacity;
               Allow silt loading equal to or greater than 0.33 oz./ft[2] as determined by the referenced test method.  If silt loading is equal to or greater than 0.33 oz./ft[2], the owner and/or operator shall not allow the silt content to exceed 8%;
               In addition to the opacity and silt requirements, the owner and/or operator shall pave; or apply and maintain dust suppressants to maintain a stabilized surface; or apply and maintain surface gravel uniformly; or an alternative control measure approved by the Control Officer and EPA.
          Control measures shall be considered effectively implemented when the unpaved lot meets the visible emissions and stabilization requirements.

Unpaved Roads
          The owner and/or operator of unpaved roads with average daily trips (ADT) greater than 150 shall not:
 Cause or allow visible fugitive dust emissions to exceed 20% opacity;
 Allow silt loading equal to or greater than 0.33 oz./ft[2] as determined by the referenced test method.  If silt loading is equal to or greater than 0.33 oz./ft[2], the owner and/or operator shall not allow the silt content to exceed 6%;
 In addition to the opacity and silt requirements, the owner and/or operator shall pave; or apply and maintain dust suppressants other than water; or uniformly apply and maintain surface gravel.
         
          The control measures listed in A. are considered implemented when:
             One of the control measures is annually implemented on 15 miles per year of unpaved roads having ADT of 150 or more under the listed circumstances.
             For year 2019 and beyond, control measures applied on unpaved roads with less than 150 ADT can be used for compliance with this Section through use of the equivalency conversion table included in the rule.
         
Paved Public Roadway
          The owner and/or operator of the property from which trackout or erosion-cased deposition came from upon discovery of mud/dirt that extends 50 feet or more from the nearest unpaved surface exit onto the paved public roadway shall:
 Within 24 hours of discovery, remove the mud/dirt from roadway by:
 Manually sweeping and picking up; or
 Operating a rotary brush or broom accompanied or preceded by sufficient wetting to limit opacity to 20% or less; or
 Operating a PM10 efficient street sweeper; or
 Flushing with water, if curb and gutters are not present and the use of water will not result in adverse impacts or violate of any permit programs.
 If needed, restrict vehicles from traveling over mud/dirt until the material has been removed from the travel lanes of the paved public roadway.
 Remove mud/dirt in a manner that does not cause another source of fugitive dust.
 In the event unsafe travel conditions would result from restricting traffic, and removal of such material isn't possible within 72 hours due to a weekend or holiday condition, the provisions of section A.i. above can be extended upon notification to and approval by the Control Officer.
 Requirements the owner and/or operator of any existing paved public roadway shall comply with prior to, during and after work on unpaved road shoulder:
                Apply dust suppressant to total disturbed area in sufficient quantity and frequency to maintain a stabilized surface.
                Prevent trackout by using one of the control measures in A.i. above. 
               
Recordkeeping
Any person subject to the requirements of this rule shall compile and retain records that provide evidence of control measure applications including the type of treatment or control measures, extent of coverage, and date applied.  Records and supporting documentation shall be provided within 48 hours of Control Officers verbal or written request. 

Reporting Requirements 
Any city, county, or state agency with primary responsibility for an existing paved public roadway and unpaved roads shall comply with the following:
 By January 30 of each year provide the Air District with a list of all unpaved road in its jurisdiction (i.e. length, ADT, unpaved road segments).
 By January 30 of each year submit to the Air District a list of unpaved roads which were paved the previous year including the total number of unpaved roads miles, ADTs and the respective segments.
  
Records Retention 
All required recordkeeping and reporting records shall be retained for at least 2 years.

Violations
Failure of any person to comply with the applicable requirements of this rule shall constitute a violation.

       The opacity requirements shall not apply during:
           Wind conditions that cause fugitive dust to exceed the opacity requirements if all applicable control measures are implemented, applied and maintained, and all dust contributing disturbed area are stabilized.
           Emergency maintenance of flood control channels and water retention basins if at least 1 applicable control measure is applied, and maintained.

Emission Reductions 
If the attainment controls do not produce the expected emissions reductions, the control measures in this rule will be implemented as expeditiously as practicable as a contingency to achieve the following additional reductions: 

Open Areas/Vacant Lots:  1,727.9 TPY

Unpaved Lots: 143.3 TPY

Unpaved Roads: 1142.7 TPY

Paved Public Roadway:  7.6 TPY

A detailed explanation on how these reductions will be achieved can be found in Appendix D  -  Pinal County PM10 Nonattainment Area, 2018 Attainment Demonstration and Controlled Emissions Inventories, Air Quality Division, December 21, 2015  -  Final.


RULE EVALUATION 
    Rule Stringency - CAA Sections 172(c)(1) and 189(a)(1)(C) require that moderate nonattainment area SIP revisions include emissions reductions from existing sources of PM10 emissions, as may be obtained through RACM and reasonably available control technology (RACT). RACM and RACT must be implemented as "expeditiously as practicable" and "shall provide for the attainment of the NAAQS." Additionally, if an area is classified as moderate, a State must implement RACM no later than four years after designation. However, RACM findings are generally made in context of an overall attainment demonstration.  Consequently, our stringency evaluation primarily reviews the State's comparison of these Pinal provisions with with analogous requirements in other areas. Specifically, the State provided a demonstration that the requirements in Article 1, West Pinal PM10 Moderate Nonattainment Area Fugitive Dust, are as stringent and in some areas more stringent than other Air Agency RACM measures (Appendix F  -  RACM analysis for the West Pinal County PM10 Nonattainment Area, Arizona Department of Environmental Quality, Final December 21, 2015).

    Enforceability  -  CAA §110(a)(2)(A) requires that regulations submitted to EPA for SIP approval must be clear and legally enforceable.  The rule requirements for open areas/vacant lots, unpaved lots, unpaved roads and paved public roadways to suppress fugitive dust emissions contain definitions, recordkeeping, reporting, control requirements and other provisions that are sufficiently clear and enforceable.
   
    Anti-Backsliding - We propose to determine that our approval of the submitted rule would comply with CAA §110(l) because the West Pinal PM10 Moderate Nonattainment Area does not contain any control requirements for the control of fugitive dust emissions at open areas/vacant lots, unpaved lots, unpaved roads and paved public roadways, and our approval of Rule Chapter 4, Article 1 into the SIP only adds new SIP requirements and does not interfere with the on-going process for ensuring that requirements for RFP and attainment of the NAAQS are met.  Section 193 of the Act does not apply to our proposed action because this is a new rule to the SIP and does not modify any SIP-approved control requirement in effect before November 15, 1990, in a nonattainment area.

EPA ACTION
The submitted Rule Chapter 4, Article 1, West Pinal PM10 Moderate Nonattainment Area Fugitive Dust, strengthens the SIP by restricting emissions from fugitive dust.  The rule fulfils the relevant CAA §110 and part D requirements.  Therefore, EPA staff recommends approval of Chapter 4, Article 1. 

References:

 "Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations," (a.k.a., Bluebook) EPA OAQPS, May 25, 1988 (http://www.epa.gov/ttn/naaqs/ozone/ozonetech/voc_bluebook.pdf).
 Chapter 4, Article 1, West Pinal PM10 Moderate Nonattainment Area Fugitive Dust.

