Benzene levels at the PES refinery

Air monitors that surround the PES refinery measured some of the highest benzene levels of any refinery in the country. During a two-week period in July, one monitor registered 190 micrograms per cubic meter of air (ug/m³), 21 times the U.S. Environmental Protection Agency (EPA) “action level” of 9 ug/m³.

Under EPA action level

Over EPA action level

Monitor station: ST1

190 ug/m³

A single high emission doesn't require action. But if a facility's annual average exceeds 9 ug/m³, it must investigate and make a plan to address emissions. Data PES submitted to the EPA show its air monitoring stations (STs) routinely registered high benzene readings. As of September, its annual average was 49 ug/m³, more than five times the EPA action level.

July 3–17, 2019

190 ug/m³

Benzene level

Benzene emission data submitted to the EPA by the refineries quarterly, in micrograms per cubic meter of air.

Action level

Regulations require refineries to take corrective action if average annual benzene readings top 9 ug/m³.

Monitor station

A single high emission doesn’t trigger the action, but the series of high emissions from the refinery put the facility over the edge.