Updated: Sep 13, 2022
Another weekend, another pair of air quality exceedances for the Mon Valley – concentrations of hydrogen sulfide at Allegheny County Health Department’s Liberty and North Braddock air quality monitors exceeded the state’s 24-hour hydrogen-sulfide standard of 0.005 ppm again Saturday.
The 24-hour H2S average at the North Braddock air quality monitor Saturday was 0.008 ppm. Liberty’s was 0.010 ppm – twice the state standard.
“Air quality in the Mon Valley has been particularly bad this month. We’ve had seven days of hydrogen sulfide exceedances so far,” GASP Executive Director Rachel Filippini said. “Despite all these exceedances – and the community outcry that the foul air elicited – the health department has stayed mum, providing zero communications to the public about the exceedances or what it is doing to get to the bottom of them.”
She added that it’s not just the frequency of the exceedances, but the insanely high one-hour values experienced at the North Braddock air quality monitor in particular.
Example: There was a 0.081 ppm peak March 23 and a 0.077 ppm peak on March 3, which are the second- and fourth-highest one-hour h2s readings over the past five years. That means that two of the worst four hours over the past five years have occurred in the past three weeks in North Braddock.
GASP put out a call last week for ACHD to better communicate these exceedances to the public, and to make finding the source of these concerning H2S peaks a priority. We are renewing that call today.