#H2S

Blog Against Smog

Nov 29, 2021

2 More H2S Exceedances for Mon Valley, Still No Word from ACHD on What’s Being Done to Stem Issue

That makes 48 days so far this year that H2S levels exceeded the air quality standard at the Liberty monitor. There have been 17 other such exceedances at ACHD’s air quality monitor in North Braddock Borough. Despite the rising number of H2S exceedances, ACHD has provided the public with no update on what’s causing the issue and what is being done to address it. While the department issued an enforcement order in April against U.S. Steel for H2S violations at its Clairton Cok

Nov 22, 2021

Weekend Sees Yet Another H2S Exceedance for Mon Valley

Concentrations of the air pollutant known by its rotten-egg odor were high enough to exceed Pennsylvania’s 24-hour average of 0.005 ppm, ending the day at 0.008 ppm. This marks the 46th day of 2021 when H2S exceeded that standard at the Liberty monitor. There were 17 other such exceedances at ACHD’s air quality monitor in North Braddock Borough. “The Mon Valley remains on pace to hit at least 50 H2S exceedances by the end of the year. For those who might not know, that would

Nov 18, 2021

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

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

Nov 8, 2021

<UPDATED> Abysmal Air Quality Continues in the Mon Valley

For the third day in a row, hydrogen sulfide (H2S) levels were so high Tuesday that an exceedance of Pennsylvania’s 24-hour average was guaranteed by 10 a.m. at Allegheny County Health Department’s air quality monitor in Liberty Borough. Tuesday’s exceedance will mark the 43rd of the year at the Liberty monitor. There have been 16 such exceedances at ACHD’s air quality monitor in North Braddock, the most recent of which occurred Monday. Unfortunately, the Mon Valley grappled

Nov 7, 2021

Allegheny Co. Health Dept. Issues Mon Valley Air Pollution Warning as PM2.5 Concentrations Spike

Photo by GASP Board Member Roger Day Editor’s Note: This blog was updated at 4:20 p.m. Nov. 7 to include additional information from the state Department of Environmental Protection. Allegheny County Health Department (ACHD) Sunday morning issued a Mon Valley Air Pollution Warning, with preliminary data showing levels of fine particulate matter exceeded federal health-based air quality standards at its Liberty monitor. According to airnow.gov, the NowCast Air Quality Index (A

Nov 5, 2021

Mon Valley Sees 55th H2S Exceedance, Liberty-Clairton Air Quality Again Worst in Nation Friday

For a time this morning, AirNow.gov showed the Liberty-Clairton area as having the worst NowCast Air Quality Index (AQI) in the nation when it soared to 156. According to the EPA, air quality in the affected area was “unhealthy,” meaning that people with heart or lung disease, older adults, children, and teens should have avoided strenuous outdoor activities, kept outdoor activities short, and considered moving physical activities indoors or rescheduling them to reduce exposu

Nov 3, 2021

GASP to Health Officials: You Have a Responsibility to Residents to Do More About Mon Valley Stench,

GASP attended the Allegheny County Board of Health meeting Wednesday to once again request that officials provide an update to the public about ongoing exceedances of the state hydrogen sulfide standard in the Mon Valley and what’s being done to stave off the associated rotten-egg stench. Here are the full comments presented by GASP Executive Director Patrick Campbell: Dear Allegheny County Board of Health: Good afternoon. My name is Patrick Campbell, I am the new Executive D

Oct 27, 2021

Liberty Air Quality Monitor Experiences Malfunction; GASP, ACHD Provide Answers

At GASP we review air quality data the Allegheny County Health Department (ACHD) publishes on a regular basis. Today we noticed previously published data disappear from ACHD’s Daily Summary report. This is an issue that happens from time to time and wanted to take time to explain if you’ve ever noticed a similar phenomenon. This particular case started Tuesday morning when GASP staff reviewed the hourly air quality data ACHD publishes on its website here. The report page show

Oct 25, 2021

UPDATED: Mon Valley Experiences Another Air Quality Exceedance, GASP Asks Allegheny Co. Health Dept.

By 9 a.m. Monday, concentrations of hydrogen sulfide (H2S) were so high at Allegheny County Health Department’s air quality monitor in North Braddock Borough that an exceedance of Pennsylvania’s 24-hour average was already guaranteed. That makes 15 exceedances of the state standard so far this year at that site for H2S, which has a tell-tale rotten egg odor those in the Mon Valley (and folks downwind of it) endure all too often. For those keeping track, there have also been 3

Oct 20, 2021

UPDATED: Rotten Egg Stench Persists in Mon Valley as Liberty Experiences More Air Quality Exceedance

Editor’s Note: This story was updated at 11:05 a.m. on 10/20 to include information on today’s H2S exceedances and again at 11:35 a.m. 10/21 with an updated data chart. Sorry, Mon Valley friends, but you won’t get a reprieve today from the tell-tale rotten egg stench associated with hydrogen sulfide: Concentrations of the stinky air pollutant have been so high at Allegheny County Health Department’s air quality monitors in Liberty and Braddock boroughs that exceedances of the

Oct 19, 2021

More Rotten Egg Stench in Mon Valley as Braddock Monitor Experiences 13th Hydrogen Sulfide Exceedanc

In fact, concentrations of H2S were so high Tuesday that by 8 a.m. it was mathematically impossible for them *not* to exceed Pennsylvania’s air quality standard at the Braddock monitor. It marks the 13th such exceedance at the Braddock air quality monitor so far this year. But those aren’t the only H2S exceedances of concern locally: There have also been 37 days so far in 2021 at the nearby air quality monitor in Liberty Borough where hydrogen sulfide levels exceeded the stat

Oct 14, 2021

Mon Valley Experiences More Malodors, Liberty Monitor Again Exceeds PA Air Quality Standard

So, did you smell it yesterday – that all-too-familiar stench of rotten eggs? Because Wednesday marked the 37th day in 2021 that hydrogen sulfide (H2S) levels exceeded the state air quality standard at Allegheny County Health Department’s air quality monitor in Liberty Borough. Little background: Hydrogen sulfide is a colorless gas that’s recognizable by its rotten-egg odor. It’s a stench our friends in the Mon Valley (and those downwind of it) endure way too often. The 24-ho

Oct 4, 2021

Mon Valley Stench Returns, GASP Again Calls on ACHD for Public Update

CreateLab’s SmellPGH app received a smattering of odor reports Saturday from local residents, one of whom said the outside air smelled like “someone mixed rotten eggs with manure and set it on fire.” If you were among those who asked yourself and others, “What. Is. That. STENCH?” or made complaints about an industrial, sulfur-like odor this past weekend, you might be interested to know that Saturday marked the 36th day in 2021 that hydrogen sulfide (H2S) levels exceeded the s

Aug 23, 2021

Smoke & Flames at Edgar Thomson Plant, More H2S Exceedances Punctuate Need for Public Update

GASP’s resident smoke reader and longtime project manager Sue Seppi snapped into action, reviewing Breathe Cam footage of the facility, noting that thick black smoke and flames were visible around 10:15 a.m. that Thursday, Aug. 19. Then on Saturday and Tuesday, the Mon Valley experienced two more exceedances of Pennsylvania’s 24-hour standard of 0.005 ppm for hydrogen sulfide (AKA H2S, also known by its pungent rotten-egg odor). That makes 35 such exceedance at the Liberty mo

Aug 5, 2021

Public Comment Period for Allegheny County Health Department’s Annual Air Monitoring Plan Closes Mon

Time is running out to submit public comments on Allegheny County Health Department’s 2022 air monitoring network plan, an annual report that provides a detailed description of how and where air pollution is monitored in the county. A little background: To ensure that all areas of the country meet federally established ambient air quality standards (NAAQS), the U.S. Environmental Protection Agency (EPA) requires submission of Air Monitoring Network Plans from each state and l

Jul 27, 2021

The Mon Valley Stinks (Literally): Sky-High H2S Concentrations Cause Air Quality Exceedances

Editor’s Note: This story was updated at 9:25 a.m. on Thursday, July 29 to include additional information about an air quality exceedance that occurred on Wednesday, July 28. The associated chart was also updated to reflect the new data. Hydrogen sulfide concentrations at Allegheny County Health Department’s air quality monitors in Liberty and North Braddock boroughs were sky-high Tuesday morning – so high that by 10 a.m. exceedances of the state’s 24-hour average standard we

Jul 6, 2021

County Sees More Air Quality Exceedances Monday, Tuesday Designated as Code Orange Air Quality Actio

Air quality stayed mostly in the unhealthy range Monday, with concentrations of fine particle pollution exceeding the federal health-based standard at all three of Allegheny County Health Department’s operating PM2.5 monitors. The 24-hour average PM2.5 National Ambient Air Quality Standard is 35 micrograms per cubic meter. Yesterday the 24-hour average at the Lawrenceville Monitor was 36.6 ug/m3, 44.5 ug/m3 at Liberty, and 59.1 ug/m3 at Parkway East. ACHD’s Avalon monitor, wh

Jun 29, 2021

More Air Quality Exceedances for Mon Valley, Allegheny County on Pace to Exceed 2017 H2S Numbers

That makes 29 exceedances of the H2S standard in the past six months at Allegheny County Health Department’s air quality monitor in Liberty borough. Hydrogen sulfide is a colorless gas recognizable by its rotten egg odor. To put those numbers into perspective: There were just 25 exceedances in all of 2020 and 36 in 2019. “We are now on pace for 59 exceedances this year, which would equal 2017’s total,” GASP staff attorney Ned Mulcahy explained. “It’s difficult to understate h

Jun 21, 2021

Air Quality Exceedances Mounting, GASP Again Calls on ACHD to Update Public on Mon Valley Pollution

UPDATE: There was another hydrogen sulfide exceedance at Allegheny County Health Department’s air quality monitor in Liberty Borough Monday – making 27 so far this year. Allegheny County experienced its 26th hydrogen sulfide exceedance of the year Friday when concentrations of the colorless gas recognizable by its rotten-egg odor surpassed the state’s 24-hour-average standard at the Liberty monitor in the Mon Valley. That makes 26 such exceedances so far in 2021. That means:

Jun 7, 2021

More Unhealthy Air Quality, Exceedances Pervade Mon Valley – Update on H2S Problem Needed

The colorless gas is most commonly recognized by its “rotten egg” odor and concentrations exceeded the Pennsylvania 24-hour average standard of 0.005 ppm on both Saturday (0.007 ppm) and Sunday (0.009 ppm) at Allegheny County Health Department’s air quality monitor in Liberty borough. “There have been 24 H2S exceedances so far this year at Liberty. That’s only one less than in all of 2020, but it’s also worth noting that the first exceedance in 2021 at that monitor didn’t occ

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