U.S. Steel ties Mon Valley pollution to vehicle traffic
U.S. Steel has said significant declines of soot in the Monongahela River Valley last spring were the result of reduced vehicle emissions during the COVID-19 stay-at-home order.
The Pittsburgh-based steelmaker also noted in a news release Tuesday that its Clairton Coke Works, which has a history of pollution violations, was fully operational during the 10 days that were the focus of the study.
The company said it found that concentrations of fine airborne particle pollution, known as “PM2.5,” declined by 40%. That came during pandemic restrictions when traffic declined by 50%.
U.S. Steel also said Trinity Consultants, an international industrial consulting firm, confirmed the study results.
The findings were based on the period of March 16-26, when coke production at the coke works had not been reduced and the pandemic stay-at-home order was in effect, said Ian Donaldson, a managing consultant with Trinity.
He said the findings show a “direct, significant correlation” between PM2.5 readings at the Allegheny County Health Department’s Liberty air quality monitor, downwind from Clairton, and state Department of Transportation traffic numbers from a 40-mile radius of the area.
“Further evaluation of this dataset, as well as traffic and
monitor concentrations from other time frames, could prove useful to more fully understand PM2.5 contributions,” Mr. Donaldson said.
“These findings shed light on the impact that mobile sources, such as vehicle emissions, have on our community, including during weather conditions such as inversions, and indicate the importance of multifaceted strategies to address the impact of inversions,” Brett Tunno, a U.S. Steel environmental engineer, said in the news release. “We look forward to exploring this further and support and encourage similar efforts by other members of our community.”
Jim Kelly, the county health department deputy director of environmental health, declined to comment on the findings but said, “The Health Department in 2020 did observe lower levels of PM2.5 and other air pollutants at its monitors across the county and is currently reviewing that data to learn more about how pandemic-related policies affected air quality in the region.”
The study was released as the health department considers more stringent coke oven gas emissions rules. The public comment period on those proposed rules ends Jan. 21.
U.S. Steel’s coking facility along the Monongahela River, 20 miles south of Pittsburgh, is the largest in the U.S. and the last such coking plant in Allegheny County. The facility, which bakes coal into coke, an ingredient of the steel-making process, has a long history of air pollution violations.
On Dec. 24, 2018, a fire destroyed the plant’s pollution control system and caused it to exceed sulfur dioxide, hydrogen sulfide and soot limits.
In 2019, a settlement of violations amassed prior to the fire required the company to spend $3 million to establish a trust fund to benefit Mon Valley communities impacted by pollution.
The proposed coking emissions rules aim to reduce concentrations of allowable hydrogen sulfide emissions and would, for the first time, include five other sulfur compounds in that measurement.