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Writer's pictureGroup Against Smog & Pollution

GASP Submits Comments on ACHD Air Quality Monitoring Plan, County SIP

Updated: Dec 20, 2022

At GASP, we take a three-fold approach to improving air quality: We educate, we advocate, and we do legal watchdog work to ensure that the regulated community—and the agencies that regulate them—are complying with the law.


This week, GASP’s legal staff submitted public comments on two air quality plans of note—Allegheny County Health Department’s (ACHD) Air Monitoring Plan for 2020, as well as Allegheny County’s proposed revisions to the PM2.5 State Implementation Plan.


GASP’s Comments on ACHD Air Quality Monitoring Plan for 2020


GASP’s submitted comments on ACHD’s 2020 Air Monitoring Plan mostly centered on transparency and the need for additional air quality monitoring. We argued that ACHD must:

  1. Examine the necessity of additional, permanent sulfur dioxide monitoring in the vicinity of Clairton Coke. “Compared to other sources, US Steel’s Clairton Coke facility “contributes overwhelmingly to SO2 pollution” in Allegheny County’s Mon Valley. Accordingly, ACHD’s Liberty monitor is located to measure the maximum ground concentration. However, this monitor location is based on an annual average of atmospheric conditions. Data revealed by ACHD’s additional SO2 monitoring after the Dec. 24, 2018, fire at Clairton Coke suggests a single site might not be sufficient to monitor for maximum concentration.

  2. Not use EPA mismanagement as a valid excuse for delaying its photochemical assessment monitoring station (PAMS) implementation. “On May 31, 2019 – just one day before the deadline – EPA published notice of its intent to extend the PAMS implementation until June 1, 2021. While the EPA provided some attempt at an excuse in the aforementioned notice, gross mismanagement of the PAMS program does not excuse ACHD from fulfilling its requirement to protect the health of local citizens. Critical to understanding the potential harm this delay will cause is that the PAMS program had six objectives, some of which went beyond the science of ozone formation.”

  3. Undertake additional efforts to provide the public with air quality data and meaningful interpretations thereof. “The public still faces significant hurdles in getting timely, relevant, understandable information about air quality. While leaving the methodology wide open, the air quality monitoring regulations demand more from ACHD in this regard. There is nothing that would attract the public to black and white tables of numbers. Raw data showing hourly measurements of pollutants in micrograms per cubic meter are off-putting and tend to repulse, rather than attract, the general public; some context, analysis, and explanation is necessary.

GASP’s Comments on Allegheny County’s Revisions to its State Implementation Program (SIP)


By way of background, in 2012, the Environmental Protection Agency revised the primary National Ambient Air Quality Standard for fine particle pollution (PM2.5) In 2015, EPA designated Allegheny County as a moderate nonattainment area of the 2012 PM2.5 Standard. As such, Allegheny County must attain the 2012 PM2.5 standard by Dec. 31, 2021. The SIP outlines how the county will achieve that attainment.


GASP’s legal staff pointed out that “the Proposed SIP Revision provides no margin for error in its attainment demonstration. Despite this, no new controls or limits on emissions of PM2.5 or its precursors will be imposed in Allegheny County in connection with the SIP revision.”


We went on to say, “Because the Proposed SIP Revision predicts that PM2.5 concentrations at the Liberty monitor will only just barely attain the 2012 PM2.5 Standard by the 2021 attainment date, and because no new controls or limits will be imposed to reduce PM2.5 emissions, the contingency measures in the Proposed SIP Revision may need to be invoked. However, it does not appear that they comply with the requirements of the Clean Air Act.”


Additionally, we pointed out, the emissions inventory for the Clairton Plant used in the Proposed SIP Revision’s attainment demonstration should include excess emissions resulting from the Plant’s violations of permit limitations. It is not clear, however, that they do. Not modeling excess emissions from the Clairton Plant would tend to cause the modeled concentrations of PM2.5 at the Liberty monitor to be understated, and would thus result in a false attainment demonstration.


Editor’s Note: Check back to the GASP website for updates on both the SIP and air monitoring plans.


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