DATE: UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION III 1650 Arch Street Philadelphia, Pennsylvania 19103

SUBJECT: Technical SupportDocument: Pennsylvania: North Reading; Control Strategies, Reasonable Further Progress, and Contingency Measures FROM: Ellen Schmitt, Life Scientist Office ofAir Program Planning TO:
THRU: · CristinaFemandez, Associate Director Office ofAir Program Planning

A. INTRODUCTION

This document provides a technical review ofthe control strategies, reasonable further progress (RFP), and contingency measures used inthe attainmentplan for the 2008 lead North Reading nonattainment area. This document is to support the Environmental Protection Agency's (EPA's) proposed approval ofthe attainment plan for the North Reading nonattainment area.
B. BACKGROUND

OnNovember 12, 2008 (73 FR66964), EPA established a 2008 primary and secondary lead NAAQS at 0.15 micrograms per cubic meter (11g/m3) based on a maximum arithmetic 3-month mean concentration for a 3-yearperiod. See 40 CFR 50.16. OnNovember 22,2010 (75 FR 71033), EPA published its initial air quality designations and classifications for the 2008 lead NAAQS based upon air quality monitoring data for calendar years 2007-2009. The November 22, 2010 Federal Registerpublication included the nonattainment designation ofan area located within Berks County, Pennsylvania (including Laurendale Borough, Muhlenberg Township and Alsace Township) and which will hereby be referred to as "NorthReading Area" or "Area." See 40 CFR 81.339. The initial2008 lead NAAQS designations, including the NorthReading Area nonattainment designation, became effective on December 31, 2010. 1

1 EPA completed a second and fmal round ofdesignations for the 2008 leadNAAQS onNovember 22, 2011. See

76 FR72097. No additional areas in Pennsylvania were designated as nonattainment for the 2008 lead NAAQS**Sta~es** with nonattainment areas, such as Pennsylvania, are required by section 172 ofthe Clean Air Act (CAA) to submit a plan that demonstrates attainment ofthe applicable ambient air quality standard as expeditiously as practicable, but no laterthan the specified attainment date. Specifically, section 172(c) ofthe CAA indicates that these attainment SIPs must, among other things, include an RFP plan, contain contingency measures, and include provisions, such as emissions limitations and control measures that are necessary to provide for the attainment ofthe nonattainment area. In addition to the requirements set forth in section 172 ofthe CAA, specific attainmentplanrequirements for lead nonattainment areas are outlined in40 CFR 51.117.



### C. CAA ATTAINMENT DEMONSTRATION REQUIREMENTS 1. Control Strategies Section 172(c)(1) ofthe CAA indicates that attainment plans must provide "for the implementation ofall reasonably available control measures as expeditiously as practicable (including suchreductions in emissions from existing sources inthe area as may be obtained through the adoption, at a minimum, ofreasonably available control technology) and shall provide for the attainment ofthe national primary ambient air quality standards." EPA believes that in determining appropriate emission control levels, the state should consider the collective publichealth benefits that can be realized in the area due to projected improvements in air quality.
In accordance with section 172(c)(l), lead nonattainment area SIPs must containreasonably available control measures (RACM), including reasonably available control techniques (RACT), that address existing sources ofambient air lead concentrations. EPA defines RACM as measures that a state finds to be reasonably available and to contribute to attainment as expeditiously as practicable in its nonattainment area. RACT applies to the "existing sources" oflead in an area including stack emissions, industrial process fugitive emissions, and industrial fugitive dust emissions (e.g., on-site haul roads, unpaved staging areas at the facility). EPA'sprevious guidance for implementing the pre-existing lead NAAQS recommends that stationary sources which emit a total offive (5) tons peryear (tpy) oflead or lead compounds, measured as elemental lead, be the minimum starting point for RACT analysis. See 58 FR 67750 (December 22, 1993). Further, EPA's existing guidance recommends that available control technology be applied to those existing sources inthe nonattainment area that are reasonable to control in light ofthe attainment needs of the area and the feasibility ofsuch controls. Thus, a state's control technology analysis may need to include sources which actually emit less than five (5) tpy oflead in the area, or other sources in the areathat are reasonable to control,'in light ofthe attainment needs and feasibility ofcontrol for the area. In its 2008 final rule, EPA recommended a threshold for RACT analysis such that at least all stationary sources emitting 0.5 tpy or more should undergo a RACTreview. However, EPA believes that a state's control technology analysis should potentially include sources which emit less than the threshold level of0.5 tpy oflead inthe area, or other sources in the area during this second round ofdesignations.



### 2that are reasonable to control, depending uponthe attainment needs and feasibility of controls in the nonattainment area.2
EPA has historically defined RACT as the lowest emission limitation that a particular source is capable ofmeeting by the application ofcontrol technology that is reasonably available considering technological and economic feasibility. EPA suggests that the first step in addressing RACM/RACT for lead is identifying the potential measures for controlling lead emissions from sources oflead in the nonattainment area, and evaluating eachmeasures for reasonableness, considering their technological and economic feasibility in the nonattainment area.3 According to sections 172(c)(6) and 110(a)(2)(A) ofthe CAA, once the process of determining RACM/RACT for an area is completed, the individual measures should then be converted into a legally enforceable vehicle such as a regulation orpermit. The regulations or other measures submitted should meet EPA's criteriaregarding the enforceability ofSIPs and SIP revisions.4



### 2. Reasonable Further Progress Section 172(c)(2) ofthe CAA provides that SIP provisions in nonattainment areas must require reasonable further progress. Historically, for some pollutants, RFP has been metby showing annual incremental emissionreductions generally sufficient to maintain linear progress toward attainmentby the applicable attainment date. SIPs for lead nonattainment areas should provide for the implementation ofcontrol measures for point and area sources oflead emissions which demonstrate attainment ofthe lead NAAQS as expeditiously as practicable, but no later than the applicable statutory attainment date for the area. Ifa state adopts less than all available measures in an area but demonstrates, adequately, that RFP, and ·attainment ofthe leadNAAQS are assured, and the application ofall such available measures would notresult in attainment any faster, then a plan which

.requires implementation ofless than all technologically and economically available measures may be approved. See 44 FR20375 (April4, 1979) and 56 FR5460 (February 11, 1991). EPA believes that it wouldbe unreasonable to require that aplan which demonstrates attainment include all technologically and economically available control measures eventhough such measures would not expedite attainment.5 Thus, for some sources in areas which demonstrate attainment, it is possible that some available control measures may not be reasonably available becausetheir implementation would not expedite attainment ofthe affected area.

2 Final rule for the 2008 leadNAAQS. 73 FR66964 (November 12, 2008). Located in EPA's SIP Toolkit at

www3.epa.gov/airquality/lead/pdfs/2012ImplementationGuide.pdf 3 "Implementation ofthe 2008 Lead National Ambient Air Quality Standards Guide to Developing Reasonably

Available Control Measures (RACM) for Controlling Lead Emissions" March 2012, which is included in EPA's SIP Toolkit located at www3.epa

.gov/airquality /lead/pdf s/20 121mplementationGuide

.pdf 4 An explanation ofthe enforceability ofSIPs can be found in a September 23, 1987 memorandum (with

attachments) entitled "Review ofState Implementation Plans and Revisions ofEnforceability and Legal Sufficiency" from J. Craig Potter, Assistant Administrator for Air and Radiation, et a!. 5 73 FR66964 (November 12, 2008).

33. Contingency Measures Section 172(c)(9) ofthe CAA**provid~s** that SIPs in nonattainment areas "shall provide for the implementation ofspecific measures to be undertaken ifthe area fails to make reasonable further progress, or to attainthe [NAAQS] by the attainment date applicable under this part. Such measures shall be included in the planrevision as contingency measures to take effect in any such case without further action by the State or [EPA]." Contingency measures are implemented ifRFP targets are not achieved, or ifattainment is not realized by the attainment date. The key requirements associated with contingency measures are: (1) Contingency measures mustbe fully adopted rules or control measures that are ready to be implemented as expeditiously as practicable upon a determination by EPA that the areahas failed to achieve, ormaintain RFP, or attain the lead NAAQS bythe applicable statutory attainment date; (2) The SIP should contain trigger mechanisms for the contingency measures and specify a schedule for implementation; and (3) The SIP must indicate that the measures will be implemented without further action (or only minimal action) by the state or by EPA Administrator. The contingency measures should also consist ofcontrol measures for the area that are not already included in the control strategy for the attainment demonstration of the SIP.
As mentioned above, section 172(c)(9) ofthe CAAprovides that contingency measures should be included in the state SIP for a lead nonattainment area and shall take effect without further action by the state or the Administrator. EPA interprets this requirement to meanthat no further rulemaking actions by the state, or EPA, would be neededto implement the contingency measures. EPA recognizes that certain actions, such as the notification ofsources, modification ofpermits, etc., may be needed before a measure could be implemented. However, states must showthat their contingency measures canbe implemented with only minimal further action on theirpart and with no additional rulemaking actions such as public hearings or legislative review. The state should ensure that the measures are fully implemented as expeditiously as practicable after the requirement takes effect.

D. PENNSYLVNIA SUBMITTAL 1. Control Strategies Exide Plan Approval No. 06-050331 Federal regulations establishing performance or emission standards under section 112 ofthe CAA at 40 CFRpart 63 are incorporated byreference into PADEP's air quality permitting program under section 6.6 ofPennsylvania's Air Pollution Control Act, 35 P.S. §4006;6,

4' !



## ·I 

# i and under Pennsylvania's air quality permitting regulations at 25 

### Pa. Code§127.35(b) (1997). One such federal regulation is the National Emission Standards for Hazardous Air Pollutants for Secondary Lead Smelting sources (Secondary Lead SmeltingNESHAP) (40 CFRpart 63, subpartX), which EPApromulgated revised requirements for on January 5, 2012. 6
Afterthe effective date ofaperformance or emission standard, such as the Secondary Lead SmeltingNESHAP, the owners and operators ofnew, reconstructed, modified and existing sources must comply with the performance or emission standards pursuant to the compliance schedule established under section 112 ofthe CAA and the regulations thereunder.
As a secondary lead smelter facility, Exide is

-subject to the NESHAP and therequirements are incorporated into PlanApproval No. 06-050661, a pre-constructionpermit, which was issued by PADEP onAugust 31,2012. Plan Approval No. 06-050661 authorizes modifications to the existing configuration.ofthe Exide facility in order to achieve compliance with the revised Secondary Lead SmeltingNESHAP. Once implemented, Plan Approval No. 06-050661 measures would totally enclose existing buildings, add new control equipment, redirect emissions from existing named sources to new or differently named control devices, eliminate some existing control devices and modify the refining kettles.
See table 9 in the Pennsylvania attainment plan submittal for a list control measures that Plan Approval No. 06-050661 authorizes Exide to implementbefore the facility canresume its secondary lead smelting operations.7 Also included in PADEP'stable 9 are the RACM/RACT measures that each Plan Approval No. 06-050661 control measure is associated with.
As the NESHAP requirements are incorporated by reference into Pennsylvaniaregulations, they are state and federally enforceable.8 Additionally, a consent order and agreement (COA) betweenExide and PADEP requires Exide to be in compliance with PlanApproval No. 06-050661 andNESHAP requirements in order to restart the facility's lead smelting operations. Exide COA Exide entered into a COA with PADEP on June 15,2015, which included the following legally-binding orders: a) Exide shall notresume operation ofany portion ofits facility until it has completed all the Exide facility modification workproposed inExide PlanApproval I.

6 77 FR 556 (January 5, 2012). 7 The Exide facility has been in an idling state, with no active lead smelting operations, since February 2013

. 8 Pennsylvania's plan approvals are federally enforceable under40 CFR section 52.2062(a).



### 5b) Exide shall comply with all emission, testing, monitoring, recordkeeping, reporting, workpractice, and additional requirements inExide Plan Approval I. c) IfExide elects to implement the Exide Facility modificationwork proposed in Exide PlanApproval I, in preparation for resuming operation ofthe Exide Facility, Exide shall nevertheless only proceed with the work at suchtimes as the Exide Plan Approval I, or an extension thereof, remains valid, or at suchtimes as the PlanApproval Work is authorized by some other quality plan approval. d) Exide shall submit an application to extend PlanApproval I by no laterthan June 30, 2015.9 e) Exide shall not permit exceedances ofthe following stack emission limits for lead:

Stack

S55 S62 Sl3 S63 S19 S23A

S64 S47 S70 Emissions Limitfor lead

- grams per second (gls) 0.00502732 0.00226500 0.000398590 0.00604100 0.00191900 0.00108700 0.00604100 0.00185900 0.000158760
For any Exide sources affected by the emission limits above, which would not otherwise be scheduled to be stacktested as part ofthe Exide PlanApproval I requirements, Exide shall, unless otherwise approved in writing by PADEP, perform stack testing ofsuch sources within 180 days ofstartup ofsuch sources, to demonstrate compliance with the emission limitations found above. Additionally, for all affected sources, Exide shall comply with all the provisions of 40 CFRpart 63, subpart X, including, but not limited to testing, monitoring, recordkeeping and reporting provisions. f) By no later than August 24, 2015, Exide shall ensure that a fence limiting public access to the Exide Facility is installed and/or maintained as perthe diagram in Attachment A inthe COA. 10
Yuasa COA Yuasaentered into a COA with PADEP on June 12,2015, which included the following

9 On January 31, 2014, the Department extended Plan ApprovalNo. 06-050661 to remain effective until July 31,

2015. Following this, PADEP approved another extension request from Exide which made Plan Approval 06- 050661 effective until January 31, 2017. 10 The fence was installed on August 21, 2015.

6legally-binding orders:

. a) By no later than December 31, 2015, Yuasa shall complete any facility modifications projectedto be necessary inorderto meetthe following lead stack emission limits:

Stack 

### SOl S03 S06 S07 S15 S20 Emissions Limit for lead

- grams per second (g/s) 0.000687948 0.000459000 0.000352794 0.000352794 0.000174986 0.000252000
Yuasa shall comply with those limits at all times after December 31,2015, and shall demonstrate compliance withthose limits by reference method stack testing by no later than June 30, 2016

. Additionally, unless otherwise approved inwriting by PADEP, Yuasa shall conduct stacktesting on all the stacks listed above in 2020, and thereafter in any year that is divisible, withremainder, by five.
For all affected sources atthe Yuasa facility, Yuasa shall comply with all the applicable provisions of40 CFRpart 63, subpart PPPPPP, including, but not limited to applicable monitoring, recordkeeping, and reporting provisions. b) By no later than August 24, 2015, Yuasa shall ensure that a fence limiting public access to the Yuasa Facility is installed and/or maintained withrespectto the property owned by Yuasa as perthe diagram in Attachment A ofthe COA. 11
2. Reasonable Further Progress In their August 12, 2015 attainment plan SIP submittal for the NorthReading Area, PADEP provided the following measures, which are part ofthe control strategy for meeting attainment ofthe 2008 leadNAAQS, and which the Commonwealth asserts sufficiently demonstrate progress towards reducing lead emissions and attainment in the Area. 

### T bl 1 RFP M'l t (! h N th R d' A

a e 0 1es ones or t e or ea mg rea Action Facility Implementation Date Updated fugitive dust control Exide PADEP approved measure on operating procedures March 30,2011 Installation and maintenance of Exide No later than August 24, 2015 fence line Installation and maintenance of Yuasa No later than August 24, 2015 fence line Stack emission limitations Yuasa No laterthan December 31 , 2015

11 Fence installmentwas completed byJuly 24, 2015

.

7

### 3. Contingency Measures In the North Reading Area attainmentplan submittal, the Commonwealth clarified that the lead emissionreductions from theirproposed contingency measures are surplus to those included and calculated in the attainment demonstration. In its August 2015 submittal, PADEP indicated that Exide and/or Yuasa will be required to implement at least one contingency measure ifPADEP determines in writing: (1) That the facility's ongoing emissions caused or significantly contributed to an exceedance ofthe 2008leadNAAQS at a PADEP monitor, and (2) That specific contingency measures are necessary and appropriate to abate the emissions which PADEP determined are causing or significantly contributing to the 2008 leadNAAQS exceedance.
PADEP will notify Exide and Yuasawhen a monitored violation ofthe 2008 lead NAAQS occurs at a PADEP monitor. In the notification, PADEP will identify the necessary and appropriate contingency measure(s) to be implemented. 

### Exide ContingencyMeasures The following are contingency measures that PADEP, in consultationwith Exide, developed in the case thatthe facility's ongoing emissions are determined to have caused or significantly contributed to an exceedance ofthe 2008 leadNAAQS at a PADEP monitor and for which PADEP has determined as necessary or appropriate to abate such emissions. Upgrade Existing Fugitive Dust Control Devices Within 60 days after written a notice from PADEP, Exide shall submit to PADEP for approval, a planregarding the installation ofhigh-efficiency particulate air (HEPA) filters on any or all ofthe following baghouses located withinthe facility: C19, C23A and C47. Upon PADEP approval, Exide shall install and begin operating the HEPA filters within 180 days, unless otherwise proposed in the investigative study detailed below. After implementing this measure Exide or PADEP shall collect and review air quality data for lead in order to determine ifattainment ofthe 2008 lead NAAQS has beenrestored.
Increase ExistingLeadEmission StackHeights If, following implementation ofthe Exide contingency measure listed above fails to restore attainment ofthe 2008 leadNAAQS, Exide shall, within 60 days after the: receipt ofwrittennotice from PADEP, submit to PADEP a request orplan application for an increase in the stack height for any or all ofthe following stacks within the facility: S13, S23A and S70. Exide shall complete construction ofthehigher stacks within 180 days ofPADEP approval, unless otherwise proposed inthe investigative study detailed below.

8IncreasedPlantRoadway Cleaning Frequency Within one (1) day afterthe receipt ofwritten PADEP notice, Exide shall increasethe in-plantroad cleaning at the Exide facility to 10 hours each working day, and shall continue in-plantroad cleaning activities at this frequency unless and until otherwise approved in writing byPADEP. Investigative Study By no later than 180 days after the receipt ofwrittenPADEP notice, Exide shall submitto PADEP an investigative study identifyingthe potential or likely source(s) ofemissions principally contributing to the exceedance so that a strategy maybe developed to eliminatethe likelihood ofanother exceedance. The study will list all bestpractices and best available technologies identified from industrial smelter ormetal manufacturing facilities with similarfugitive emissions control challenges, and, for eachtechnology orpractice, will: 1) identify those technologies and/or practices thatExide deems technically feasible and cost effective, 2) quantify associated emissions reductions expected to result from the use ofthe practices or technologies, and 3) provide a time**fram~** for implementation ofeach in a manner that allows attainment ofthe NAAQS inthe most cost-effective manner and schedule. Upon PADEP approval ormodification ofstudy aspects, the items so approved ormodified shall be deemed incorporatedby reference as Order items inthe COAbetween Exide and PADEP and shall be completed bythe approved deadlines. OtherEquivalentMeasures lfExide identifies and demonstrates to the Commonwealth's satisfaction alternative control measures(s) that would achieve equal or greater lead emission reductions than the contingency measures identified above, Exide maythe new control measure(s) for the contingency measure(s) identified above upon PADEP'sprior written approval.
Yuasa ContingencyMeasures PADEP, in consultation with Yuasa, developed the following contingencymeasure in the case thatthe facility's ongoing emissions are determined to have caused or significantly contributed to an exceedance ofthe 2008leadNAAQS at a PADEP monitor and for whichPADEP has determined as necessary or appropriate to abate such emissions. Investigative Study Byno later than 180 days after the receipt ofa written PADEP notice, Yuasa shall submitto PADEP an investigative study identifying the potential or likely source(s) ofemissions principally contributing to the exceedance so that a strategy maybe developed to eliminate the likelihood ofanother exceedance. The study will list all bestpractices and best available technologies identified from industrial smelter ormetal manufacturing facilities with similar fugitive

9emissions control challenges, and, for each technology or practice, will: 1) identify those technologies and/or practices that Yuasa deems technically feasible and cost effective, 2) quantify associated emissions reductions expected to result from the use ofthe practices ortechnologies, and 3) provide a time frame for implementation ofeach in a manner that allows attainment ofthe NAAQS in the most cost-effective manner and schedule. Upon PADEP approval ormodification ofstudy aspects, the items so approved ormodified shall be deemed incorporated byreference as Order items in the COA between Yuasa and PADEP and shall be completed by the approved deadlines. 

### ContingencyMeasure Triggers The need for contingency measures will be triggered by an exceedance or violation of the 2008 lead NAAQS at a PADEP monitor, by an emissions event, or by missing an RFP milestone. Ifduring any 3-monthrolling period, two (2) samples at the same lead monitor in the North Reading Area are reported to exceed 0.15 J..lg/m3

, PADEP will double the sampling frequency atthat monitorto once every three (3) days for a period of30 days. Additionally, ifduring any 3-monthrolling period, three (3) samples at the same lead monitor inthe North Reading Area are reported to exceed 0.15 J..lg/m3

, PADEP will conduct daily sampling at that monitor for a period of30 days. Finally, ifduring any 3-month rolling period, four (4) ormore sample results at the same lead monitor in the North Reading Area are reported to exceed 0.15 J..lg/m3

, PADEP would initiate additional lead ambient air monitoring inthe area. A sampling plan would be developed within 15 days and monitors would be deployed as soon as possible. Contingency measures would also be implemented ifa violation ofthe 2008 lead NAAQS occurs. A violation ofthe 2008 lead NAAQS occurs**wh~m,** based on data collected and quality-assured by PADEP, the design value ofany rolling 3-month averaging period exceeds 0.15 J..lg/m3

. Further details regarding the contingency measures andtheirtriggers canbe found in the COAs between Exide and PADEP, and Yuasa and PADEP which were included in PADEP's August 12,2015 SIP submittal and, upon approval by EPA, will be incorporated by reference into the Pennsylvania SIP.



### E. EPA'S ANALYSIS 1. Control 

### Strategies As Exide is the only source in the North Reading Area with potential emissions greaterthan 0.5 tpy, it was the only source in the Arearesponsible for meeting the RACM/RACT requirements. Specifically, PlanApproval No. 06-05066I authorizes Exide to implement

10measures consistent withthe Secondary Lead Smelting NESHAP. As a secondary lead smelter facility, Exide is subjectto the NESHAP and the requirements are incorporated into Plan Approval No. 06-05066! which was issued by PADEP on August 31,2012. The primarypermanent and enforceable control measures that enable the North Reading Areato demonstrate attainment ofthe 2008 lead NAAQS include implementation of, and compliance with, the Secondary Lead Smelting NESHAP at the Exide facility upon reactivation ofthe currently idled lead operations. These measures include totally enclosing existing buildings, adding newcontrol equipment, redirecting emissions from existing named sources to new or differently named control devices, eliminating some existing control devices and modifying the refining kettles. Additionally, COAs betweenthe Commonwealth and Exide, and the Commonwealth and Yuasa provide additional measures for both facilities and will assistthe North Reading Area in attaining the 2008 lead NAAQS. The 2015 projected lead emissions from Exide and Yuasa were based on a combination of NESHAP and COA limits. Based onimplementation ofthese projected operations at Exide and Yuasa, the modeledprojected lead concentration is 0.129107**~-tglm .**  Adding to this, 0.012**~-tglm ,**  the representative background concentration oflead in the region, and the total projected lead concentration in the North Reading Area is 0.141107**~-tglm ,**  belowthe 2008 leadNAAQS. The emissionreductions that allowed for the projected 2015 emissions calculation are dependent upon a combination ofCOA and NESHAP limits, ofwhich many will only be in place ifExide begins its smelting operations again. However, as Exide has been idling with no lead smelting operations ongoing since February 2013, Exide's actual lead emissions have been 0.00004 tpy, muchlowerthan the projected 2015 lead emissions of0.8991 tpy which was used in modeling attainment. Therefore, the idled state ofthe Exide facility is a more conservative scenario for lead emissions inthe North Reading Areathan the NESHAP control strategy scenario, which has been modeled to show attainment.
EPAbelieves thatthe Commonwealthhas evaluated all control measures for Exide and Yuasa, the two stationary lead sources in the nonattainment area. The selected control measures were modeled and show attainment, thus no further measures need to be considered for RACM/RACT. TheNorth Reading Area shows itwill attain withthe measures that were included in the Commonwealth's August 12,2015 submittal. EPAfinds these control measures reasonable for the Area to attain based on modeling and analysis completed by Pennsylvania. Additionally, these control measures were also determined by the Commonwealthto be feasible for the two stationary lead sources to implement given that they are technically feasible and cost effective. Therefore, EPA finds that Pennsylvania adheres to existing guidance which recommends that available control technology be applied to those existing sources in the nonattainment area that are reasonable to control in light ofthe attainment needs ofthe area and the feasibility ofsuch controls.

11EPA proposes to approve Pennsylvania's North Reading attainment plan SIP as meeting section 172(c)(1) ofthe CAA. 

### 2. Reasonable Further Progress The North Reading Area is ontrack to meetthe 2008 leadNAAQS. Although historically, for some pollutants, RFP has been met by showing annual incremental emissionreductions generally sufficientto maintain linear progress toward attainment by the applicable attainment date, this does not always needto be the case. EPA expects that some nonattainment area designations were for the mostpart attributable to a single stationary source and that these areas would not necessarily show a linear progress towards attainment. Where one source is the major cause ofnonattainment, EPA would not expect linear progress towards attainment. Rather, there may be relatively less progress while the source adopts non-technological control measures and begins to install necessary technological controls, and then significantprogress towards attainment in a short period oftime once all the controls are operational. This is true for the North Reading Area whose major lead source has traditionally been Exide. The modeling Pennsylvania included in its attainment demonstration show thattheNorth Reading Areawill attain the 2008leadNAAQS. In its August 12,2015 submittal, Pennsylvania explained the control measures selected for both Exide and Yuasa, the two lead sources in the Area, and determined that there are no additional measures which will sufficiently advance the attainment date. Thus, the RFP plan found in Pennsylvania's Nmih Reading attainmentplan is reasonable and meets CAArequirements for RFP.
EPA proposes to approve Pennsylvania's SIP as meeting section 172(C)(2) ofthe CAA. 

### 3. Contingency Measures Contingency measures for attainment demonstrations with non-linear RFP should still include key requirements, which are, in summary: Fully adopted and ready for implementation, contain trigger mechanisms and a schedule, be implemented without further action, and consist ofcontrol measures not already in the control strategy. However, for the requirement ofone year's worth ofRFP, a more qualitative approach would be appropriate. In the scenario where there is one main source, a violation ofthe 2008 lead NAAQS could be caused by a malfunction, so a more stringent control may not even solve the problem.**Fle~ibility,** while still necessitating auto-triggermechanisms, is more appropriate for single major source scenarios with non-linear RFP.
In its submittal, PADEP provided two types oftriggers, with increased monitoring for every single sample exceeding 0.15 !lg/m 3

. The contingency measures for Exide include a variety ofmeasures for controlling area source fugitive emissions as well as process-related fugitive emissions. The SIP submittal also includes as a contingency measure, an option to complete an investigative study to identify the potential or likely source(s) ofemissions principally

12contributing to the exceedance so that a strategy may be developed to eliminate the likelihood ofanother exceedance. The contingency measures for bothExide and Yuasa are located inthe portions ofthe COAs that, upon EPA approval, will be incorporated in the Pennsylvania SIP, thereby making them federally enforceable. The contingency measures that Pennsylvaniaincluded in its August 12, 2015 SIP submittal are contained in the COAs in specific**detail~** and are measures not already in the control strategy. Additionally, the submittal indicates the trigger mechanisms for the contingency measures and the measures canbe implemented with minimal to no action by the state or EPA. EPA concludes that the measures Pennsylvaniaincluded in the attainmentplan SIP are reasonable as contingency measures to address any attainment challenges the areamay encounter. EPA is proposing to determine that the Commonwealth ofPennsylvaniahas met it obligations pursuantto 172(c)(9) ofthe CAA. 

### F. CONCLUSIONS AND RECOMMENDED AGENCY ACTIONS EPA has evaluated the control strategy, RFP, and contingency measures information provided in PADEP'sNorth Reading attainmentplan submittal and believes that the SIP submitted by the Commonwealth satisfies requirements ofsections 172(c)(1 ), (2), and (9) ofthe CAA.
EPA is proposing to approve that the North Reading Areahas metthe CAArequirements ofan attainment demonstration that pertain to adopting emissions reduction measures with schedules for implementation and meet EPA's criteriafor the enforceability.

13