Comment and Response Document For the Lower Beaver Nonattainment Area 2008 Lead National Ambient Air Quality Standards Attainment Demonstration

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1 Comment and Response Document For the Lower Beaver Nonattainment Area 2008 Lead National Ambient Air Quality Standards Attainment Demonstration On July 26, 2014, the Pennsylvania Department of Environmental Protection (Department or DEP) requested written comments and provided notice of a public hearing on September 3, 2014, on the proposed Attainment Demonstration for the Lower Beaver Lead Nonattainment Area. One person provided testimony during the public hearing held at DEP s Southwest Regional Office (400 Waterfront Drive, Pittsburgh, PA 15222) on September 3, The public comment period closed on September 5, Comments received during the hearing and public comment period are addressed in this document. Two commentators provided written comments on the proposed State Implementation Plan (SIP) revision. 1. Dr. Peter W. Deutsch Associate Professor of Physics, Emeritus Penn State University 100 University Drive Monaca, PA Cristina Fernandez Associate Director, Office of Air Program Planning Air Protection Division US Environmental Protection Agency, Region III 1650 Arch Street Philadelphia, PA COMMENTS AND RESPONSES. The identity of each commentator making the comment is indicated by the assigned number in parentheses after each comment. 1. Comment: The implementation of the monitoring appears to my unpracticed eye, professional, thoughtful, and well-traveled. But I am concerned that it may be limited in scope because it is focused on point and area sources. It may not be structured to model significant if possibly temporary inputs of lead in the recent past, currently, and possibly in the future. (1) Response: It is unclear whether the commentator is discussing air quality monitoring or the dispersion modeling contained in the SIP revision. Therefore, both have been addressed. The air quality lead monitoring conducted in the area meets the requirements of federal regulations codified in 40 CFR Part 58. Possible temporary inputs of lead from unknown sources were not considered, and were not required to be considered, when siting the lead monitors

2 Possible temporary inputs of lead from unknown sources were also not required to be considered in the modeling conducted for the future year, The SIP revision also contains revised contingency measures to address any potential violation of the lead NAAQS. 2. Comment: These time dependent surface impacts may include dust, likely containing lead, which may be distributed into the air as the Horsehead zinc production plant site in Potter Township is reclaimed by teams evaluating or remediating the site for possible Shell Corporation exploration or use. There is concern among us as to whether the ground is being dampened to keep lead bearing dust from rising into the air and being distributed in the Lower Beaver Valley or nearby. They may increase the impact of lead on peoples health in and near the Lower Beaver Valley. This concern is not addressed directly in the document. There is indirect mention of lead propagation in the shut down and clean up on P 42, but it doesn t look specific enough or energetic enough to protect the public in a timely fashion. (1) Response: The commentator s concerns about dust during evaluation or remediation at the site have been addressed by enhancing the description of dust control in the contingency measure section of the SIP revision. Pennsylvania has SIP-approved regulations contained in 25 Pa. Code Chapter 123 restricting particulate emissions from stationary sources and restricting fugitive dust emissions. These regulations assist in reducing potential impacts on lead concentrations and are discussed in the contingency measure section of the SIP revision. As per 25 Pa. Code 123.2, a person may not permit fugitive particulate matter to be emitted into the outdoor atmosphere from a source specified in 123.1(a)(1)-(9) (construction and demolition of buildings; grading, paving and maintenance of roads and streets; use of roads and streets; cleaning of land; stockpiling of materials and open burning operations) if the emissions are visible at the point the emissions pass outside the person s property. Furthermore, 123.1(c) provides that a person responsible for any source specified in subsections (a)(1)-(7) or (9) shall take all reasonable actions to prevent particulate matter from becoming airborne. It gives specific measures that can be used, such as using water or chemicals to control dust, and paving and maintenance of roadways, for example. The DEP has been on the Horsehead site numerous times during the demolition activities of recent months for asbestos inspections in accordance with 40 CFR Part 61, Subpart M (relating to national emission standard for asbestos). Measures to prevent airborne asbestos are similar to measures required to prevent lead bearing dust from affecting ambient air. (Note that the EPA defines ambient air in 40 CFR 50.1(e) as that portion of the atmosphere, external to buildings, to which the general public has access.) The Department has found no evidence of fugitive particulate emission violations during these routine inspections. The DEP s Southwest Regional Office (SWRO) did receive a complaint regarding dust on September 25, In response to this complaint, the DEP asked the demolition contractor to monitor for dust more frequently and to modify its - 2 -

3 water application methods in order to meet the federal asbestos remediation requirements in 40 CFR Part 61, Subpart M (relating to national emission standard for asbestos). 3. Comment: What happens as Shell works to reconfigure the highway system near the Horse Head facility? What happens when Shell moves the highway a few hundred yards inland and up the hill away from the Ohio River in its work to evaluate the Horsehead site? This will take considerable if ultimately limited time. It will necessarily alter significantly a hill side which stunted trees of a former grove or forest are inhabiting now. What happens to lead that may be in the hills as the Frankford road (Route 18) highway is significantly if locally altered into a six lane highway potentially to serve a cracker plant? This concern is not addressed directly in the document. (1) Response: The DEP understands that Shell is working closely with the U.S. Army Corps of Engineers, Pennsylvania Department of Transportation (PennDOT), the Federal Highway Administration, DEP Southwest Regional Office and the Southwest Pennsylvania Commission to obtain the necessary permits for the proposed changes to Route 18 and I-376 in Beaver County. The permit applicant is required to consider all potential pollutants, including possibly contaminated soils, in the waterways permit application(s) associated with the project. While this SIP revision for the Lower Beaver Valley Lead Nonattainment Area does not include a specific plan for the road construction projects under consideration in the area, the DEP will continue to enforce the fugitive emissions regulations found in 25 Pa. Code Sections and (See also response to comment #2.) The contingency measures section of the SIP revision for the area has been modified to provide additional information regarding enforcement activities if necessary for any violation of the requirements for fugitive emissions. 4. Comment: Anecdotes have generated speculation that certain health symptoms at locations downwind from the Horsehead site are triggered by lead laden dust and debris being moved around and transported through the air as the Horsehead site is reconditioned two miles or so away. I have heard that people in the Lower Beaver Valley area have flu-like symptoms. I have also heard that such symptoms are associated with lead exposure. In addition, I have heard that there is high lead pollution in vegetable gardens both in Van Port and in Center Township especially in gardens behind the shopping center containing a Lowes hardware store. I have heard that the garden lead pollution concerns are recent. People have been urged not to eat their tomatoes perhaps by the local Agricultural Extension. DEP should investigate these anecdotes. (1) Response: The DEP has investigated the anecdotes as requested. These garden lead pollution anecdotal reports seem to be in reference to a large soil and water sampling effort throughout Beaver County in 1984, which involved a Penn State study of metal levels in gardens and their recommendation for using raised bed gardens. The DEP found results of some soil testing in the area taken in 1984 and 1985, which reported some lead in the soil. Using a report from the Penn State Extension titled: Lead in Residential Soils: Sources, Testing and Reducing Exposure to interpret the data, it - 3 -

4 appears that the lead levels at that time were mostly none to very low (less than 150 mg/km) or some low ( mg/km) with only a couple of samples in the medium (400-1,000 mg/km) range. The report recommends for soil at the medium level, that leafy vegetables should be grown in raised beds filled with non-contaminated soil. Therefore, this was a conservative suggestion at that time to protect public health. We are unaware of any newly issued reports or suggestions. The anecdotes and speculation that certain health symptoms are triggered by lead laden dust are beyond the scope of the SIP revision and expertise of DEP staff. 5. Comment: I am more concerned about the general impact of lead on people and especially on children as laid out in the preface to the Hearing Document. A significant portion of Beaver County interacting with the rest of the world occurs very near or in the lead problematic Lower Beaver Valley. The nonattainment area is a fairly small portion of Beaver County, but there is a lot of transient activity, people arriving and leaving this region within two to four miles of the Horsehead facility and nearby hills and tree groves. This area may be contaminated by lead as well as by other heavy metals and or asbestos: A lot of interchange with the rest of the Beaver County and the world occurs very close to the Lower Beaver Valley. The commentator also describes the shopping centers, hotels, colleges, and churches that are near, though not necessarily in the Lower Beaver Valley nonattainment area. (1) Response: The DEP understands the commentator s concerns about potential pollution from the Horsehead site affecting portions of Beaver County outside the nonattainment area. The SIP revision has been expanded to include additional discussion about how the DEP will work to prevent such adverse effects. The owners of the Horsehead property, PennDOT and other DEP programs including the Environmental Cleanup and Brownfields, Waste and Water Programs must work together to mitigate potential impacts to the public from lead contamination of the site, public roadways and waterways during the decommissioning and any future construction. Please also see response to comment #2, which discusses the prevention of lead bearing dust from entering ambient air during reconditioning activities and #3, which identifies PennDOT procedures for environmental assessments for road construction. Lead is naturally occurring in soils at concentrations that range from 10 to 50 mg/kg (milligrams of lead per kilogram of soil) or 10 to 50 ppm (parts of lead per million parts of soil) according to the Penn State Extension document referenced above and 50 to 400 parts per million according to the U.S. Environmental Protection Agency (EPA) website. The EPA has an entire webpage devoted to lead information and how to protect yourself from lead in homes and in the outdoor environment ( Because of the large molecular weight of lead, it settles out of the air quickly and stays close to the source. Therefore, lead emitting sources have a very localized area surrounding them for nonattainment compared to many other pollutants. This is why the EPA designated a nonattainment area specific to the localized impact from the smelter operations at the Horsehead plant

5 6. Comment: The present study should be expanded to address explicitly these areas (reclamation of Horsehead site and the transportation project discussed in comment 3) to satisfy a lay audience as well as a technical one. The commentator stated that it is difficult to access all the DEP documents available on an issue and to translate and document the procedures and also write reports like this in a timely fashion. The commentator is concerned that lead transport into the air during shut down and recondition is being addressed. Not after the fact but in a timely fashion. The commentator stated that he had difficulty in gaining information about the public hearing on the SIP revision. The commentator stated that continuing lack of awareness will likely remain the case for others in the future even if [the commentator tries] to educate them. He noted that the people of the Beaver Valley need to keep DEP hearings in mind as the Horsehead facility is reclaimed and Shell follows with its plan and that broader publicity is needed. (1) Response: The DEP s SIP revision, which is an attainment demonstration for the Lower Beaver Valley Nonattainment Area for the 2008 lead NAAQS, has been modified to include specifics on enforcement in the case that fugitive lead emissions affect the ambient air or should actions at the site violate Pennsylvania fugitive emission regulations. During the public participation process for the proposed SIP revision, the DEP followed the public notice procedures required by the federal Clean Air Act and the Pennsylvania Air Pollution Control Act, including Act 27 of These public notice procedures included publication in a newspaper in the area affected by the SIP revision, publication in the Pennsylvania Bulletin, notification of legislative committees and posting on the DEP s website. Furthermore, as the commentator discovered, regional DEP staff are available to assist the public in accessing materials proposed for comment. In accordance with Act 27 of 2012, proposed and final SIP revisions are posted on the DEP elibrary under Publications, Air Quality and then under State Implementation Plan SIP - Revisions ( In addition, the DEP offers services by which the public can access information about enforcement results (efacts) and by which the public can be notified of permit applications and progress (enotice). Both services can be found on the DEP website under Tools ( In regard to the construction of new sources at the Horsehead site, Section 172(c)(5) of the Clean Air Act and Section 6.1 of the Air Pollution Control Act require permits for the construction and operation of new or modified major stationary sources in the nonattainment area. Pennsylvania administers a New Source Review (NSR) permitting program under 25 Pa. Code Chapter 127 (relating to construction, modification, reactivation and operation of sources) for new and modified major sources of lead and other pollutants. As part of the Pennsylvania SIP, the NSR Program is also enforceable by EPA. Among other requirements, permits issued in Pennsylvania require a demonstration that emissions from the new or modified source will not cause or contribute to a NAAQS violation. The emissions from all new sources must be reduced to the maximum extent under Pennsylvania s Best Available Technology Program. The program also requires a public notice and comment process

6 7. Comment: I cannot decouple concerns about other substances as they are coupled with the lead both in space and time. Correlation is a hallmark of the physical world as more than one thing happens at once. Correlation say between lead and or other heavy metals or asbestos can tell us about cause and effect. It can help us elucidate what is actually happening with the lead. Further, perception by the public of enhanced risk makes assessing the real risk that much more difficult or problematic. (1) Response: As discussed in the response to comment #5, lead and other heavy metals from the reclamation activities are prohibited from entering the ambient air by Pennsylvania regulations relating to fugitive and visible emissions. Asbestos remediation activities must be conducted in compliance with federal regulations (40 CFR Part 61, Subpart M, specifically relating to the standard for demolition and renovation). Compliance with these rules, which also can help in controlling lead-bearing dust, is enforced by the DEP and the EPA. A discussion of public risk perception is beyond the scope of the SIP revision. 8. Comment: The document is not clear on what exactly is a design value. (1) Response: The final SIP revision has been modified to describe design value as a statistic that describes the air quality status of a given location relative to the level of a specific NAAQS. For the 2008 lead NAAQS, it is calculated by assessing the rolling 3-month averages over 36 consecutive valid periods, specifically for a three calendar year period and the two previous months. (See Appendix R to Part 50 Interpretation of the National Ambient Air Quality Standards for Lead, Section 4.) 9. Comment: I am puzzled by a statement that the Ohio River flows from the lower Beaver valley toward Pittsburgh or words to that effect. See (which runs from the Ohio/Pennsylvania border eastward and then southward toward Pittsburgh). That s on page 10 of the Lower Beaver Valley State Implementation Plan (SIP). Much water in the Ohio River ends up in the Mississippi, not in the opposite direction where the Allegheny and Monongahela (sic) Rivers merge to form the Ohio River. I ll refresh my memory when I can by looking at the Ohio River flow at a convenient spot familiar to me. Which way does the gradient run as in Elevation ranges from 660 to 1380 feet.? I think from hill or plateau top to River. I ll bet the River is lower in western Beaver County than in south eastern Beaver County. (1) Response: The final SIP revision has been revised to address the flow of the Ohio River. The directions that the gradients run vary throughout the county. The elevation of the river throughout the county is irrelevant for attainment demonstration purposes. 10. Comment: Also I am distracted by flow rates and possibly other quantities being reported in with many figures. See for example Table 4. Can they really measure flow rates per second to eight or nine significant figures? Or did they divide standard values such as a ton or weight or mass by the number of seconds say in a year? Is that really high precision? Or is it something else? (1) - 6 -

7 Response: The values the commentator identified were calculated, not measured. Explanatory text and equations have been added to the final SIP revision, specifically in Section III - Emission Inventory to explain how these rates, as well as additional rates for AES Beaver Valley, were calculated. Additional tables have been included in the final SIP which caused the numbering scheme to change. Table 4, which was referenced in the comment, has been reformatted and the information is now contained in Table Comment: In the Pennsylvania Department of Environmental Protection s (PADEP) proposed attainment plan, the emissions inventory for the nonpoint sources is based on EPA s 2008 National Emissions Inventory (NEI) data (page 17), while the emissions inventory for point sources is based on 2010 actual emissions data reported by stationary sources to PADEP (page 14). For the 2008 lead standard, EPA recommends that states use the year of designation (2010 or 2011) as the base year. States may use a year other than the nonattainment area s year of designation if they can show that the proposed year is more appropriate. Additionally, PADEP should rely on the same year for all of the source categories included in this inventory. If 2010 actual data is not available for nonpoint sources, then PADEP needs to provide a justification for selecting 2008 for the actual emissions estimates of this source type as an appropriate year. (2) Response: There is no 2010 actual emissions inventory data available for nonpoint sources. Nonpoint emissions inventory data is only available every three years (for 2008 and 2011) under the Air Emission Report Requirements. The DEP has revised the SIP revision following the EPA s recommendation to use the EPA s 2011 NEI data because it is the most recent data available. This data availability justification and the EPA s recommendation for the selection of the emissions year for the nonpoint source inventory has been added to the SIP revision. 12. Comment: Table 4 (page 16) of the proposed attainment plan includes actual emissions for 2010 in tons per year (tpy) and maximum allowable emissions rates in grams per second. EPA would like to clarify that the Agency requires actual emissions for the base year inventory. EPA will not consider the 2010 maximum allowable emissions rates when evaluating approvability of the 2010 base year inventory to satisfy the requirements of section 172(c)(3) of the Clean Air Act (CAA). EPA will only consider the 2010 maximum allowable emissions rates as additional information. (2) Response: The DEP has provided actual emissions for the base year inventory as required. The stationary source emissions are those reported by facilities as required by 25 Pa. Code Section 135, as verified by the DEP; the nonpoint source emissions are from the EPA s National Emissions Inventory. The DEP agrees that the maximum allowable emission rates column of proposed Table 4 is not relevant for purposes of CAA Section 172(c)(3) and has removed the column. However, the information is still available in the (renumbered) tables of the modeling section. See also response to comment #

8 13. Comment: Section III B - On page 8 of the proposed attainment plan, PADEP provides a discussion of the methodology used in estimating their 2010 allowable maximum emissions rates. The methodology used is inadequate. Annual potential emissions should be based on allowable (permitted) emissions rates of the source, an emissions factor, and the maximum allowed hours of operating the source. In addition, supporting information should be documented as part of the plan. (2) Response: The DEP disagrees that the methodology used in estimating emission rates for the 2010 inventory is inadequate. After the DEP had further discussion with the EPA about this methodology, the EPA staff accepted that the methodology in the proposed SIP revision is reasonable if additional supporting information is provided in the SIP revision. The supporting information including additional equations, tables and text explanations of calculations have been added to the SIP revision. The EPA commented in comment #12 that the 2010 potential emissions rates are only additional information and not required for attainment demonstrations. The DEP is including them so that results of the modeling for the base year (also not required), and therefore the changes leading to a modeled demonstration of attainment, can be put in context. 14. Comment: Section III-C, Table 7 - On page 20 of PADEP s proposed attainment plan, the 2015 projected lead emissions presented are based on actual emissions. However, the projected inventory should be provided as allowable emissions, reflecting applicable federally-enforceable control measures. Further, PADEP should provide the basis for the 2015 maximum allowable emissions rates to support that these rates are based on permanent and federally-enforceable control measures. As emissions units at Horsehead are limited to control emissions of particulate matter and not directly lead, PADEP should specify the emissions factors used in estimating lead-specific emissions. (2) Response: After further consultation with and concurrence of EPA Region 3 staff, the DEP has further differentiated between the 2015 inventory which is based on actual emissions, and the 2015 modeled emissions which are based on federally enforceable emission limits. The final SIP revision includes an explanation of how the values were derived using the COA for Horsehead and maximum potential emissions calculated from maximum boiler heat ratings and AP-42 factors for AES Beaver Valley. Chapter III, Section C, Summary of Methodologies for 2015 Projected Inventories, includes new Tables 9 and 10 and an updated explanation of the values used for the attainment demonstration. See also response to comment # Comment: Section III -C-l - On page 20 of the proposed attainment plan, PADEP states that the 2015 projected emissions take activity and emissions growth and/or controls into account, but then in section III-C-2 states that (t)he estimate for 2015 anticipates zero growth for emissions changes between 2010 and The second statement is consistent with the projected emissions included in the proposed plan. Please, revise the first statement for an accurate description of the inventory. (2) - 8 -

9 Response: The DEP agrees with the suggestion. The first statement has been revised accordingly. 16. Comment: EPA requires states to demonstrate reasonable further progress (RFP) by adherence to an ambitious compliance schedule, one which is expected to provide for periodic yields in significant emissions reductions or linear progress, when appropriate. Also, EPA recommends that states accurately indicate in their attainment plans the corresponding annual emissions reductions to be achieved. In the proposed attainment plan, PADEP predicts significant emissions reductions to be achieved by the shutdown of most Horsehead point sources by October 2014, as required by the Consent Order and Agreement between PADEP and the Horsehead Corporation (COA). To support reasonable further progress, PADEP should describe and quantify in the attainment plan any other permanent and federally-enforceable emissions reductions that were achieved in the Lower Beaver Valley nonattainment area during the attainment period ( ). (2) Response: After further consultation with the EPA Region 3 staff, the SIP revision has been clarified as follows: Because the Horsehead facility is required to shut down no later than October 2014, except for two small sources, and did shut down all leademitting sources at the end of April 2014, the reasonable further progress requirement is no longer applicable. 17. Comment: On page 16 of the proposed attainment plan, PADEP states that the dispersion modeling required to demonstrate attainment of the 2008 lead NAAQS by December 2015 uses maximum allowable emissions. Although the above statement is generally correct, EPA would like to clarify that the Agency does not require states to complete dispersion modeling for the base year as part of the attainment demonstration. Therefore, EPA will not consider the 2010 modeling results in evaluating approvability of the modeling demonstration for the Lower Beaver Valley. (2) Response: The DEP completed dispersion modeling for the base year in order to provide compelling evidence that attainment of the 2008 lead NAAQS in 2015 is due to reduction in emissions through permanent and enforceable measures. The statement cited has been clarified to remove the discussion of the modeling as a requirement. 18. Comment: The BPIP (building downwash) files used in the modeling analysis should be included as supporting documentation for the attainment demonstration. (2) Response: These files have been included in the final SIP revision submitted to the EPA as suggested by the commentator. 19. Comment: Appendix B of the proposed attainment plan describes how the Horsehead facility estimated fugitive emissions from several sources at Horsehead. The base-case run included two (building) fugitive emission sources. These fugitive sources were not carried forward into the future-case run. (2) - 9 -

10 Response: The sources at the Horsehead facility that emitted the fugitive emissions in the base case scenario discontinued operation on April 26, 2014 (thus satisfying the requirements of the COA) and were therefore no longer considered to be operating in the future case attainment demonstration. DEP has confirmed with on-site inspections that this requirement of the COA has been satisfied. That is why the emissions were not carried forward in the modeling or emission inventory for Comment: It is unclear in the proposed attainment plan if PADEP has considered if there are additional lead emissions at the Horsehead facility from product handling processes or road dust, and if these additional lead emission sources have been included in the modeling. (2) Response: The 2010 inventory and modeling include process fugitive emissions as reported by Horsehead, but non-process (road dust) emissions were not reported by the facility or included in the modeling. For the 2015 modeling, the only sources that were possible to be operational were the Refinery Feed Pot, Source ID 802, and the Larvik Furnaces, Source ID 904. For these sources, the facility emission limit of 0.1 tpy of lead was modeled. As stated in the proposed and final SIP revisions, this federally enforceable emission limit was site-wide and applies to all emissions from the site, including any fugitives, process or otherwise. The DEP recognizes that road dust could contribute to a potential future violation. The contingency measures have been revised to better address these potential emissions. 21. Comment: In regards to the evaluation of the 2015 attainment year in PADEP s proposed attainment plan, it is unclear if PADEP took into consideration what, if any, lead emissions could occur during the site decommissioning process. (2) Response: In the modeling, the DEP did not include any lead emissions that might occur during the site decommissioning process. Decommissioning at the Horsehead site is subject to 40 CFR Part 61, Subpart M (relating to national emission standard for asbestos) as well as 25 Pa. Code 123.1(c). The DEP reasonably assumed that these provisions would prevent lead emissions during decommissioning from leaving the site. The possibility that there would be an adverse effect on ambient air from any lead emissions during decommissioning or construction at the site is discussed in the contingency measure section of the final SIP revision. Specifically, the investigation and mitigation steps that will be taken if either of two types of triggers occur: ambient air quality in a single sample in the Lower Beaver Valley nonattainment area is reported to exceed 0.15 µg/m 3 ; or fugitive emission events are observed by DEP AQ staff or registered as a complaint. See also responses to comments #2 and #3, which discuss the DEP s responsibility for enforcing fugitive dust regulations, not allowing new construction to affect the NAAQS nonattainment areas and PennDOT procedures for environmental assessments. 22. Comment: PADEP should clarify the time basis for the emissions rates applied to the modeled sources. AERMOD emission rates need to be hourly rates. (2)

11 Response: The SIP revision has been modified accordingly to explain that the AERMOD emission rates are expressed as hourly rates. 23. Comment: PADEP should provide additional documentation and/or explanation on how the facility s permitted emission limits were used to establish the AERMOD emission rates for lead used in the modeling (included in tables 9A, 9B and 10, all located on pages of the proposed attainment plan). (2) Response: The values for proposed Tables 9A, 9B and 10 (renumbered as Tables 11, 12 and 13 in the final SIP revision) were developed from permit conditions at each of the facilities and source information in the DEP Air Information Management System (AIMS) database. The values originated with the facility submissions of plan approvals or operating permits, and direct inquiries to the facilities, when necessary. The modeling parameters for the area sources were developed from correspondence from Horsehead regarding fugitive emission estimates from their facility (see Appendix B of the final SIP revision). The locations of the fugitive emissions were estimated building-wide. Due to the nature of fugitive emissions at the Horsehead facility, the DEP followed guidance outlined in the EPA s August 10, 2012, Addendum to its June 8, 2011 memorandum entitled, 2008 Lead (Pb) National Ambient Air Quality Standards (NAAQS) Implementation Questions and Answers. Based on that guidance, the DEP characterized the fugitive emissions as area sources in the modeling. In the future case modeling, four point sources for Horsehead and four point sources for AES-Beaver Valley were identified. Appendix F has been added to the final SIP revision. Appendix F provides additional documentation to show how emission sources were associated with stacks in the 2010 modeling inventory. However, DEP understands that the EPA will not consider the 2010 modeling results in evaluating approvability of the modeling demonstration for the Lower Beaver Valley. 24. Comment: EPA determines compliance of the 2008 lead standard based on a design value calculated based on air quality monitoring data and compared to the level of the standard, 0.15µg/m 3. Per 40 CFR Part 50, Appendix R, EPA defines the lead design value as the highest 3-month rolling average during a 38-month period consisting of a three consecutive calendar year period plus the two preceding months (i.e., 36 consecutive 3-month periods). Air quality dispersion modeling is used in demonstrating attainment of the 2008 lead standard by the statutory attainment date of December It is unclear if the modeled future case maximum predicted 3-month rolling average concentration (page 36) is representative of a design value. (2) Response: No, the value in the proposed SIP revision was not a design value because it did not take into account a 36 consecutive 3-month period plus the preceding 2 months. DEP assumed the modeled concentration reflects the 3-month period ending with the required attainment date. Therefore, the SIP revision has been modified to better characterize the concentration predicted by the future case modeling as the maximum

12 3-month rolling average. In its performance of the dispersion modeling, DEP followed procedures in 40 CFR Part 50, Appendix R. Furthermore, the introduction Chapter VI, Air Dispersion Modeling Analysis, of the final SIP revision explains that even though the modeling predicted that the maximum 3-month rolling average will be significantly below the NAAQS by the statutory attainment date of December 2015 with implementation of the permanent and enforceable control measures described in this SIP revision, because the area experienced violations of the standard in 2013 and 2014 before the implementation of the control measures, the design value for the three calendar years will not meet the NAAQS. The NAAQS will be attained on the basis of ambient data as a result of implementation of this SIP revision. 25. Comment: Section VI-C: Source Pathway - In table 7 of the proposed attainment plan (page 20), a significant portion of Horsehead s projected lead emissions are labeled as Other Miscellaneous or Fugitive Emissions. However, no fugitive emission sources were included in the future-case modeling analysis, as shown in table 10 (page 26). PADEP should explain this possible discrepancy. (2) Response: The DEP agrees with the comment. After further consultation with EPA Region 3 staff, the DEP has modified this table (renumbered as Table 9) in the final SIP revisions to better represent the projected lead inventory for Also, the final SIP revision includes an explanation section after the table, which explains the rationale for the modeled emissions. See also response to comment # Comment: Section VI-C: Source Pathway - The proposed attainment plan shows that most of the Horsehead lead-emitting sources will not be operating in Only four lead-emitting sources at Horsehead are projected to be operating in The modeled lead emissions from Horsehead s four sources in the future-case run (table 10, page 26) appear to decline slightly compared to the 2010 modeled emissions in the base-case run (table 9A, page 26). PADEP should explain this discrepancy and indicate if there will be additional permanent and federally-enforceable controls or operating restrictions to account for the decrease in source emissions. (2) Response: The DEP agrees with the commentator, that the four lead emitting sources (although they are actually denoted as four stacks to two sources in proposed Tables 9A and 10) have a slightly lower emission rate in the future case modeling, proposed Table 10, than the base case modeling, proposed Table 9A. This is a direct result of the permanent and federally-enforceable facility-wide emission limit of 0.1 tpy of lead, which was agreed to in the COA. No changes to Section VI were made based on this comment. However, Section III, Emission Inventory, in the final SIP revision gives a clearer explanation of the base case and future case modeling and emissions used. 27. Comment: Section VI-D: Background Air Quality Concentrations - PADEP appears to have selected a background monitoring site ( , Potter Township) that is located on the western side of the Lower Beaver Valley nonattainment area. By

13 PADEP s own analysis, this monitor may be impacted by sources in the nonattainment area. This brings up the possibility that the background monitor is actually being impacted by the sources included in the modeling analysis (double counting). While EPA agrees that using the Potter Township monitor would be conservative in estimating the projected future case design value it would be more appropriate if PADEP explored whether an alternative background monitor outside the nonattainment area could be used. A map showing the locations of nearby lead monitors can be found on EPA s Air Trends website ( There appear to be lead monitors further down the Ohio River that could be considered as an alternative background monitor ( ). (2) Response: The DEP disagrees that using data from other monitors is appropriate to define background for the modeling, but has modified its approach in estimating background. The August 10, 2012 Addendum to the 2008 Lead NAAQS Implementation document ( outlines the procedure necessary for determining background. Specifically, the addendum document states Background concentrations are determined by excluding observations when the source being modeled is impacting the monitor. Since the EPA is concerned that the proposed background value the DEP utilized was too conservatively high, the DEP has removed the 24-hour lead concentration of November 10, 2010 and re-averaged the 3-month average. Removing this concentration has changed the 3-month average from 0.08 µg/m 3 to 0.05 µg/m 3, which is reflected in the final SIP revision. 28. Comment: Section VI F: Meteorology Pathway - In the proposed attainment plan, PADEP used the average surface moisture conditions for Pennsylvania Climate Region 9 in constructing the Bowen ratios for the modeling analysis, but did not include specific information on how this data was utilized in the modeling analysis. This information (for the AERSURFACE runs) should be included in section VI-F of PADEP s attainment plan. (2) Response: This information has been included in the appropriate section of the final SIP revision, and a supporting Appendix G has been added. 29. Comment: Section VI -G: Modeling Analysis Results - EPA has concern that the maximum model concentrations may occur in areas outside the Lower Beaver Valley nonattainment area. PADEP limited its model receptor grid to areas inside the Lower Beaver Valley nonattainment area. PADEP should ensure that the model receptor grid is capable of capturing the maximum modeled concentrations in accordance with section (a) of EPA s Appendix W - Guideline on Air Quality Models. (2) Response: The DEP believes that the model receptor grid has captured the maximum modeled concentrations, even though the receptor grid is limited to the boundaries of the Lower Beaver Valley nonattainment area. After further discussions with EPA staff, the EPA staff agreed. It is clear from Figure 12A in the SIP revision that the maximum modeled concentrations, which do not exceed 0.03 µg/m 3, occur closest to the Horsehead

14 facility. Extending the receptor grid beyond the nonattainment area would not have demonstrated that any area would exist with concentrations above that maximum. In addition, while Section (a) of the Guideline of Air Quality Models does require the model receptor grid to capture the maximum modeled concentration, the DEP believes this is limited to the boundary of the nonattainment area. CAA Section 107(d)(1)(A)(i) defines nonattainment as: any area that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the national primary or secondary ambient air quality standard for the pollutant. In December 2009, DEP recommended the boundaries of the Lower Beaver Valley lead nonattainment area based on analysis conducted based on the EPA s recommended criteria for designation recommendations. In November 2010, the EPA accepted those recommendations, which were subsequently modified in November 2011 by the addition of Center Township because the monitor established as a result of the new monitoring requirements of the 2008 NAAQS was located over the Potter Township boundary, not because of any additional concern about impact. Therefore, by definition, the DEP only placed modeling receptors within the nonattainment area to demonstrate attainment because the DEP had previously determined (and the EPA agreed by not expanding DEP s nonattainment area recommendations) that there are no other sources (for instance, Bruce Mansfield in Shippingport Borough) contributing to the nonattainment area or affected by the lead sources in the nonattainment area. 30. Comment: In estimating the amount of required contingency reductions, PADEP estimated annual RFP reductions by estimating the level of emissions necessary to reach the attainment lead concentration of 0.15 µg/m 3 (level of the 2008 lead standard). Although determining the exact level of emissions that would result in exactly 0.15 µg/m 3 of lead 3-month concentration would generally represent a more accurate estimate of contingency reductions than needed, PADEP did not perform modeling to accurately estimate the emissions level related to air concentrations at the level of the 2008 lead standard. Instead, PADEP has assumed a linear relationship between lead emissions and air quality and has calculated, by extrapolation, an emissions level that would achieve lead concentrations of exactly 0.15 µg/m 3 in the Lower Beaver nonattainment area. PADEP s estimation of contingency reductions is not consistent with EPA s recommendations. In the July 8, 2011 Memorandum 2008 Lead (Pb) National Ambient Air Quality Standards (NAAQS) Implementation- Questions and Answers, EPA directs states to conservatively assume that the projected attainment emissions level, as estimated for the attainment inventory, is just sufficient to achieve attainment of the standard, and that emissions reductions are achieved on a linear progress during the attainment period. Thus, the annual reductions achieved during the attainment period would represent at least the amount of reductions needed to be achieved through implementation of contingency measures. Further, EPA does not agree that PADEP s linear extrapolation is appropriate nor that the estimation of attainment emissions needed for reaching the level of the 2008 lead

15 standard are correct. Unless further modeling is completed to estimate the exact amount of emissions reductions needed to achieve a concentration in the nonattainment area at the level of the standard, EPA recommends that PADEP rely on EPA s methodology in estimating contingency reductions. See EPA s July 8, 2011 Memorandum 2008 Lead (Pb) National Ambient Air Quality Standards (NAAQS) Implementation- Questions and Answers for an example of calculating the amount of contingency measure emissions reductions. (2) Response: The DEP agrees that the method the proposed SIP revision used to calculate the amount of contingency emission reductions is not the same as the recommended method in EPA s July 8, 2011 memorandum. However, since the only major source of lead emissions no longer operates in the nonattainment area, the requirement to have contingency measures in the amount of one-fifth of the total reduction between 2010 and 2015 no longer applies, nor would it be physically possible to achieve for a facility that has permanently ceased operation. In accordance with further consultation with EPA Region 3 staff, the numerical calculation of contingency emission reductions has been removed from the SIP revision. 31. Comment: Under section 172(c)(9) of the CAA, EPA requires states to implement contingency measures if the nonattainment area fails to satisfy a reasonable further progress milestone or fails to attain the NAAQS by the applicable attainment date. For this reason, EPA interprets that contingency measures must be fully adopted and ready for implementation upon failure to achieve RFP or attainment of the standard. PADEP identifies two different events that would trigger implementation of contingency measures. First, PADEP identifies that contingency measures will be triggered no later than the end of the next quarter following a 3-month period in which a violation occurred, which assumes that contingency measures are implemented upon a violation. Then, PADEP identifies that the contingency measures included in the Consent Order and Agreement (COA) with Horsehead will be implemented at the facility if after the production of the zinc metal ceases, Horsehead maintains operations at the site described in the COA and that PADEP would determine in writing that Horsehead s ongoing emissions cause or significantly contribute to ongoing lead NAAQS exceedances. It is unclear if implementation of the contingency measures at Horsehead will occur upon a violation of the standard or upon PADEP s determination that Horsehead s emissions significantly contribute to a violation. Additionally, PADEP did not explain in its proposed attainment plan how PADEP will determine that Horsehead emissions are significantly contributing to lead exceedances. (2) Response: The SIP revision has been modified to clarify the triggers for implementation of contingency measures and an explanation has been added of how a significant contribution will be determined. See also response to comment #

16 32. Comment: In the proposed attainment plan for the Lower Beaver Valley nonattainment area, PADEP failed to include what contingency measures will be implemented in case that RFP fails. (2) Response: The DEP had additional consultation with EPA Region 3 staff to determine that because the only major source of lead emissions no longer operates in the area, RFP no longer applies. See response to comment # Comment: The proposed attainment plan states that if PADEP cannot determine that Horsehead s ongoing emissions cause or significantly contribute to ongoing lead NAAQS exceedances and that the measures described in the COA are necessary and appropriate to abate these emissions, the DEP will begin an investigation of other possible causes of the violation. However, a study alone will not result in any lead emissions reductions. PADEP must identify additional specific controls in the case that implementation of Horsehead measures does not result in the necessary reductions. A study could also be performed to further assist PADEP in identifying additional or more appropriate control measures to be implemented and resolve the lead problem. PADEP should include a schedule for implementation of these additional contingency measures in the proposed attainment plan. (2) Response: The final SIP revision has been substantially modified to further explain the DEP s reliance on enforcement of 25 Pa. Code Section (relating to fugitive emissions) to put in place additional appropriate controls should contingency measures be triggered. A schedule for enforcement activities has been included, and a list of potential measures that could be required by an enforcement action has also been included in the final SIP revision. Choosing the right contingency measure(s) would depend on the cause of the exceedance