#H2S

Blog Against Smog

May 24, 2021

Watchdog Report: Another Weekend, Another Pair of Air Quality Exceedances for Mon Valley

Allegheny County also tallied two more air quality exceedances over the weekend, when concentrations of hydrogen sulfide exceeded Pennsylvania’s 24-hour average standard of 0.005 ppm at the Liberty monitor Friday (0.007 ppm) and Saturday (0.012 ppm). The latest bout of poor air quality pushed exceedances at the Liberty monitor to 22 so far this year. By contrast, there were 25 such exceedances at the Liberty monitor in ALL of 2020. Hydrogen sulfide is a colorless gas most com

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 24, 2021

Allegheny Co. Health Dept. Issues Mon Valley Air Pollution Warning; Yet Another H2 Exceedance Noted

Editor’s Note: This story was updated at 12:53 p.m. Saturday to include information about an H2S exceedance. Allegheny County Health Department on Saturday morning issued a Mon Valley Air Pollution Warning through its Allegheny Alerts system. The message read: An Air Pollution Warning has been issued for the Mon Valley. The 24-hour PM2.5 standard for the Mon Valley has been exceeded at an official monitoring station in the Mon Valley and is likely to continue. Young children,

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 7, 2021

UPDATED: Yet Another H2S Exceedance & More Unhealthy Air for Mon Valley, ACHD Responds

This story was updated at 10:32 a.m. Wednesday to include a statement issued by the Allegheny County Health Department. Another day, another air quality exceedance for the Mon Valley. For the second straight day, concentrations of hydrogen-sulfide (H2S) at Allegheny County Health Department’s air quality monitor in Liberty exceeded the state 24-hour average standard of 0.005 ppm on Tuesday. The average concentration there was 0.007 ppm. Hydrogen sulfide is a colorless gas mos

Apr 5, 2021

UPDATED: Several More H2S Exceedances for Mon Valley as Poor Air Quality Lingers

Editor’s Note: This story was updated at 3:51 p.m. Monday to include today’s exceedances at the Liberty and North Braddock air quality monitors. High concentrations of hydrogen sulfide (H2S) in the Mon Valley led to exceedances of the state standard on Saturday and Monday at the Allegheny County Health Department’s air quality monitoring sites in Liberty and North Braddock. For the uninitiated: Hydrogen sulfide is a colorless gas most commonly recognized by its “rotten egg” 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 12, 2021

Thursday Marked Fourth Straight Day of Hydrogen Sulfide Exceedances in the Mon Valley

The values in red denote exceedances of PA’s 24-hour H2S standard of 0.005 ppm. Thursday marked the fourth straight day of air quality exceedances in the Mon Valley, with hydrogen sulfide (H2S) concentrations again exceeding the Pennsylvania standard at Allegheny County Health Department’s Liberty monitor – the 24-hour average H2S concentration was 0.009 ppm at the Liberty monitor. The PA standard is 0.005 ppm. That means there were H2S exceedances at the Liberty air quality

Mar 11, 2021

UPDATED: Mon Valley Experiences 2 More Air Quality Exceedances Wednesday – First of 2021 For PM2.5

The values in red are indicative of exceedances of the state H2S standard of 0.005 ppm. Editor’s Note: This story was updated at 1:46 p.m. Thursday, March 11 to include information from a press release issued by residents of the Mon Valley and Clean Water Action. It probably won’t come as a surprise to our friends in the Mon Valley who suffered through what was at one point the worst air quality in the nation yesterday: Allegheny County experienced more air quality exceedance

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

Dec 28, 2020

Allegheny County Tallied Two More Air Quality Exceedances Last Week

Allegheny County experienced two more air quality exceedances last week when the midnight-to-midnight 24-hour average concentration of hydrogen sulfide (H2S) exceeded Pennsylvania’s air quality standard of 0.005 ppm. Those exceedances occurred at Allegheny County Health Department’s (ACHD’s) North Braddock air quality monitor on both Dec. 23 and Dec. 24, with 24-hour concentrations of 0.007 ppm and 0.008 ppm, respectively. For those keeping track: The latest H2S exceedances b

Nov 18, 2020

About That Rotten Egg Odor Plaguing Your Neighborhood, What Causes It & How U.S. Steel Can Help

Editor’s Note: This blog was updated at 6:47 p.m. Nov. 19 to clarify the health impacts related to hydrogen sulfide. For many in the Mon Valley, the first week of November was punctuated by the persisting odor of rotten eggs – an odor pungent enough to force local residents to shutter their windows and doors despite unseasonably warm and sunny weather. The culprit, of course, was hydrogen sulfide (H2S for short) – a colorless, flammable, gas that’s long been an issue for comm

Nov 11, 2020

Watchdog Report: Tuesday Marked Seventh Day in a Row for Hydrogen Sulfide Exceedances in Allegheny C

For the seventh straight day, Allegheny County on Tuesday tallied another air quality exceedance – the 24-hour concentration of hydrogen sulfide (H2S) at the health department’s Liberty monitor exceeded Pennsylvania’s air quality standard of .005 ppm with an average concentration of .006 ppm, according to preliminary data from the Allegheny County Health Department (ACHD). But that’s not all: Allegheny County also experienced three straight days where concentrations of fine p

Nov 10, 2020

Allegheny County Health Department Responds to Extended Bout of Bad Air Quality, Again Blames the We

Here at GASP, we’re all about giving credit where credit is due. To that end, we thank the Allegheny County Health Department (ACHD) for finally issuing a public update regarding the recent bout of horrific air quality exacerbated by nearly a week of stagnant weather conditions. Yes, the department provided the public with a statement that indicated that air quality was expected to improve as weather conditions more conducive to clean air were rolling in. Yes, the department

Nov 10, 2020

Steps You Can Take to Minimize Impacts of Poor Air Quality as We Wait for ACHD, Industry Action

In air quality warnings issued by the state Department of Environmental Protection (DEP) and Allegheny County Health Department (ACHD) over the past few days, you might have noticed both agencies predicted air quality would improve in the afternoons. GASP is pointing this out because it could provide citizens with one small step toward minimizing their exposure to harmful air pollution. We graphed ACHD’s monitor data for fine particulate matter (PM2.5) and hydrogen sulfide (H

Group Against Smog & Pollution

Blog Against Smog

Navigate

Contact Us

Get Involved