By Peak Johnson
Large quantities of suspended solids and selenium, an element that is extremely toxic to wildlife, was discharged into California’s Suisun Bay and the Carquinez Strait earlier this year.
The East Bay Times reported that the element flowed into the bay after a plant employee from the Valero oil refinery disturbed industrial wastewater treatment by “allowing a feed of water treatment chemicals to remain closed after a routine check,” the San Francisco Regional Water Quality Control Board said a civil complaint.
Regulators have said that an operator appearing on the next shift saw the error and corrected it, but unfortunately by then “about 1.17 million gallons of inadequately treated industrial wastewater” had already entered the bay, which is also a nursery and migratory grounds for fish.
State water pollution regulators proposed to fine the refinery $197,500 for the accident.
State board engineers wrote in a complaint made public last month that “The Valero refinery discharged partially treated wastewater to Suisun Bay for the entire day,” in violation of its federal permit limits.
According to SFGate, late last month the Valero Refining Company agreed to pay nearly a quarter of a million dollars to settle violations of air quality regulations at its Benicia plant.
The Bay Area Air Quality Management District reported that “the Solano County refinery violated emission limits on nine occasions, reported hydrocarbon leaks from storage tanks six times, and had errors in a database that resulted in missed leak inspections for some valves.”
Ralph Borrmann, a spokesman for the air district told SFGate that in total there were 29 violations, with most of them taking place in 2013. Borrmann added that the problem has since been addressed.
The announcement of the settlement came a week after the San Francisco Bay Regional Water Quality Control Board said it would seek nearly $200,000 from the Valero refinery for a long list of violations.
Board engineers wrote that “the selenium releases exceeded the refinery’s permit, but the primary concern of that toxic element is chronic exposure over a lifetime.”
The report concluded that “this short term discharge does not likely have the potential to harm receptors such as aquatic life.”
To prevent future incidents, the refinery “installed a turbidity meter that triggers an alarm when the treatment fails to work properly.”
Image credit: "Detroit Oil Refinery, November 2007" Grangernite © 2007 used under an Attribution 2.0 Generic license:https://creativecommons.org/licenses/by/2.0/