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Abysmal Air Quality Returns to Mon Valley as Three More H2S Exceedances Noted

Updated: Apr 16



Stench returned to the Mon Valley. The likely culprit? Another day with sky-high concentrations of hydrogen sulfide (called H2S for short, an air pollutant known by its telltale rotten-egg odor) at the Allegheny County Health Department’s air quality monitors in both Liberty and North Braddock boroughs.


Adding to the discomfort, levels of fine particulate pollution were elevated throughout the day, with AirNow.gov showing NowCast AQI values for the Liberty-Clairton as high as 152 – which the EPA classifies as unhealthy.


While particulate pollution levels ended the day within federal guidelines, H2S levels at the North Braddock and Liberty monitors Wednesday exceeded Pennsylvania’s 24-hour average standard. By 9 a.m. today, another such exceedance was guaranteed at Liberty.


That means there have been 45 such exceedances at the Liberty monitor and 17 more at North Braddock.


“We’re still on pace to hit 50 exceedances by year’s end, which would double the total from 2020,” GASP Executive Director Patrick Campbell said. “GASP continues to be concerned not only with the number of exceedances that the Mon Valley has experienced, but also the physical impact air quality is having on residents.”


He continued:


“It’s well past time for the Allegheny County Health Department to provide the public with an update on what it is doing to get to the root of this problem. An enforcement action was levied against U.S. Steel back in April for violating the state’s H2S standard and since then there have been myriad exceedances but not one word from ACHD.”


GASP is again – still – calling on ACHD to do right by the residents who deal with malodors all too often and to provide a public update on what’s causing the exceedances and what they are doing to stem them.


“The total silence from ACHD speaks volumes to the people who bear the brunt of this pollution,” Campbell said. “Residents deserve better from the people charged with protecting our public health.”


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