On March 21, the State Water Resources Control Board announced a proposed maximum contaminant level (MCL) for hexavalent chromium, also known as Chromium 6, from 50 parts per billion (ppb) to 10 ppb.
What does this mean to the town of Winters as it delivers drinking water from five wells with a new one on the way? Possibly tens of millions of dollars to upgrade the City’s water system resulting in increased water bills to approximately 2,000 residential customers.
In 2020, the average total chromium level detected in Winters drinking water, as published in the Winters Water Quality Report, was 18 ppb.
Although yet to be published, the city has reported the total chromium average for 2021 was 10 ppb.
Chromium-6 was the subject of the 2000 academy award winning film “Erin Brockovich,” where dangerous levels of the toxin were present for decades in the drinking water of Hinkley, CA. A class action lawsuit against PG&E settled in 1996 with PG&E paying out $333 million.
Hexavalent chromium is an odorless and tasteless heavy metal that occurs naturally throughout the environment and through industrial processes that pollutes water systems. Studies have linked long-term exposure to hexavalent chromium to increased risk of cancer.
“We are working with our attorneys to submit formal written comments to the draft administrative guidelines issued by the Water Resources Board. We have not updated what potential compliance might cost the community as that is an engineering effort, and without knowing what the final threshold will be, we will wait for the approved regulations,” City Manager Kathleen Salguero Trepa told the Express,
Mayor Wade Cowan warned the State Water Board in a December 2020 letter that Winters’ water customers could see spikes in their monthly water bills of 305 to 431 percent if required to comply with a 10 ppb threshold.
According to the State Water Board, “The proposal is an administrative draft only.” Any final MCL threshold to be adopted by the Board will be made after a period of extended public comment and as recommended changes are considered.
The State Water Board has determined that attaining the 10 ppb MCL standard in two to four years should be achievable for 95 percent of the systems serving California,
“I would hope that the State would provide funding for these investments based on new mandates and the new found emphasis on investing in public infrastructure; otherwise, these costs will be borne by the rate payers. And those least able to afford higher rates will be more dramatically impacted,” Trepa said.