#hydrogensulfide

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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 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

Aug 3, 2021

It’s Been Nearly 4 Years EPA, Public Deserves Transparency, Action Regarding Edgar Thomson Emissions

A reddish-brown plume of smoke that streamed out of U.S. Steel’s Edgar Thomson plant in June 2020 prompted air quality complaints and outcry from residents and environmental groups alike. The incident did not, however, spur a notice of violation or other enforcement action from the Allegheny County Health Department (ACHD). Or at least any that has been made public. Let us explain. While ACHD did issue an NOV to U.S. Steel regarding exceedances of emissions limits at the plan

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

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

May 19, 2021

Liberty-Clairton Area Dealt More Unhealthy Air Quality, More H2S Exceedances

AQI soared into the red, unhealthy-for-everybody range this morning, peaking at 163. An air dispersion report issued Wednesday by the Allegheny County Health Department (ACHD) noted a strong surface inversion occurred today. The forecast, sourced from the state Department of Environmental Protection (DEP) said: Fine particulate levels will be at their highest between 4 and 10 a.m. this morning, then the breaking inversion along with a southeast wind will send overall averages

May 17, 2021

Mon Valley Experiences Multi-Day Bad-Air Episode, Two More Air Quality Exceedances

It was a rough weekend of air quality for the Mon Valley, which experienced another days-long bad-air episode and two more air quality exceedances. The Liberty-Clairton air shed – Clairton, Glassport, Liberty, Lincoln, and Port Vue – was regularly at the top of AirNow.gov’s list of areas with the worst air quality in the nation over the past week, and was the subject of a state Department of Environmental Protection Agency (DEP) Code Orange Air Quality Action Day on Saturday.

May 3, 2021

April Ends With Three More Air Quality Exceedances in the Mon Valley

Hydrogen sulfide (or H2S) is a colorless gas most commonly recognized by its “rotten egg” smell. The average concentration of H2S at the Liberty monitor on both Tuesday and Wednesday was 0.007 ppm, according to preliminary health department data. The state 24-hour standard is 0.005 ppm. There was also an exceedance at the North Braddock monitor Wednesday, with a 24-hour concentration of 0.010 ppm – twice the state standard. That made nine H2S exceedances at the Liberty monito

Apr 19, 2021

Another Weekend, Another H2S Air Quality Exceedance for Mon Valley

The average concentration yesterday was 0.006 ppm, according to preliminary health department data. The state 24-hour standard is 0.005 ppm. The Sunday H2S exceedance was the sixth so far this month and the 13th so far this year at the Liberty monitor. Hydrogen sulfide is a colorless gas most commonly recognized by its “rotten egg” smell. This most recent exceedance comes in the wake of a Notice of Violation issued by ACHD to U.S. Steel on April 1 regarding H2S emissions. The

Apr 14, 2021

Mon Valley Experiences Another H2S Exceedance Tuesday at Liberty Air Quality Monitor

The average concentration yesterday was 0.006 ppm, according to preliminary health department data. The state 24-hour standard is 0.005 ppm. The Tuesday H2S exceedance was fifth so far this month at the Liberty monitor. #H2S #H2Sexceedance #hydrogensulfide #AlleghenyCountyHealthDepartment #ACHD #airquality

Apr 8, 2021

UPDATED | Watchdog Report: Two More Air Quality Exceedances for Mon Valley

This story was updated at 3:28 p.m. April 8 to include information released by the Allegheny County Health Department via the Allegheny Alerts system. Not subscribed yet? You can sign up to receive them here. Allegheny County tallied two more air quality exceedances Wednesday – one for hydrogen-sulfide (H2S) and the other for fine particulate matter (PM2.5). The 24-hour average PM2.5 concentration at Allegheny County Health Department’s air quality monitor in Liberty yesterda

Apr 1, 2021

Health Department Issues Notice Of Violation to U.S. Steel Over Hydrogen-Sulfide Exceedances

The Allegheny County Health Department on April 1 issued a Notice of Violation against U.S. Steel for hydrogen sulfide exceedances that occurred at the Liberty monitor. The NOV covers 25 exceedances, which occurred in 2020 and seven to date in 2021. The notice is the first step for any enforcement action, including civil penalties of up to $25,000 per violation per day, for sources. Hydrogen sulfide is a colorless gas most commonly recognized by its “rotten egg” smell. U.S. S

Mar 29, 2021

#ICYMI: Mon Valley Tallies Two More Air Quality Exceedances This Past Weekend

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

Mar 25, 2021

Yet Another Air Quality Exceedance in Mon Valley, as Area (Again) Experiences Worst AQI in Nation

It’s official: The Mon Valley will experience yet another air quality exceedance today according to preliminary data from the Allegheny County Health Department (ACHD). The air was so rotten Thursday that by 6 a.m. it was numerically impossible for the North Braddock and Liberty monitors *not* to exceed the state’s 24-hour hydrogen sulfide standard of 0.005 ppm – the seventh such exceedance so far this year. There was also another insane one-hour value (0.081 ppm) at North Br

Mar 4, 2021

Same Old Story: More Rotten (Egg) Air Quality, Exceedances, in the Mon Valley

Ambient air concentrations of hydrogen sulfide (H2S) exceeded Pennsylvania’s 24-hour standard in North Braddock and Liberty on Wednesday according to Allegheny County Health Department (ACHD) air quality monitoring data. Concentrations of H2S were so high in North Braddock that by 4:00 a.m. yesterday it was mathematically impossible *not* to exceed the 0.005 ppm standard, a figure that is averaged over an entire day. Although concentrations were down to 0.000 ppm for most of

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