Vacaville sued over ‘Erin Brockovich’ contaminant in water supply

Environmental activist Erin Brockovich speaks with the media before leading a community meeting addressing groundwater contamination in the village and wells in the Town of Hoosick on Saturday, Jan. 30, 2016, at Bennington College in Bennington, Vt. less Environmental activist Erin Brockovich speaks with the media before leading a community meeting addressing groundwater contamination in the village and wells in the Town of Hoosick on Saturday, Jan. 30, 2016, ... more Photo: Cindy Schultz, Albany Times Union Buy photo Photo: Cindy Schultz, Albany Times Union Image 1 of / 1 Caption Close Vacaville sued over ‘Erin Brockovich’ contaminant in water supply 1 / 1 Back to Gallery

The city of Vacaville is facing pressure to clean up its water supplies after an environmental group sued this week over the amount of chromium-6 in groundwater.

In a federal lawsuit filed Monday at the U.S. District Court in Sacramento, California River Watch is demanding that the Solano County city purge its water of chromium-6, the naturally occurring carcinogen that famously sickened Southern California residents as depicted in the movie “Erin Brockovich.”

The environmental advocacy group also wants Vacaville leaders to give residents more notice of potential health problems associated with the contaminant as well as provide bottled water or another clean source to seniors and children.

“Their job is to keep their citizens safe and inform them of the risk,” said David Weinsoff, the attorney managing the case for the Sebastopol-based River Watch. “When you don’t do that, you’ve failed at your responsibility.”

The legal challenge comes as Vacaville is already taking steps to bring its drinking water into compliance with California health regulations.

City spokesman Mark Mazzaferro declined to comment on pending litigation, but he said the water department is working with the state Division of Drinking Water to get the level of chromium-6, also called hexavalent chromium, below the legal limit by 2020.

“Adding hexavalent chromium removal treatment systems to the wells will take considerable time and money,” Mazzaferro wrote in an email. But “the affected wells will eventually have equipment installed.”

Five of the city’s 11 groundwater wells contain chromium-6 at levels above the state standard, according to recent testing. While the amount is far below what was found in the Mojave Desert town of Hinkley, which inspired the 2000 Oscar-winning film that documented a fight to clean up water supplies, state officials cite an increased risk of cancer for those consuming water above the threshold.

Although Vacaville leaders have plans to spend millions to clean up their water, Weinsoff said the city’s timetable comes up short.

“Tomorrow is unacceptable. Yesterday is unacceptable,” he said. “It should have never happened in the first place, and it’s been happening 15 years.”

Because state law gives the city until 2020 to come into compliance, River Watch’s lawsuit cites federal hazardous waste law. Under the Resource Conservation and Recovery Act, the city is illegally transporting chromium-6, according to the suit. The complaint also accuses the city of understating the threat of the contaminant in notices provided to the public.

Chromium-6 is found in deposits deep in the ground. It can also be produced through industrial processes, such as steel production and metal finishing, and has been used as an additive to prevent corrosion, as was the case in Hinkley.

Vacaville is among several California cities that have been wrestling with the carcinogen since 2014, when the state adopted the nation’s first chromium-6 rules.

The new law requires drinking water to contain no more than 10 parts per billion of the contaminant, the equivalent of about 10 drops of water in an Olympic-size swimming pool. State health officials recommend that supplies contain even less — no more than 0.02 parts per billion.

Vacaville’s groundwater has tested up to 24 parts per billion. The well water makes up about 37 percent of the city’s supply. The rest is imported surface water.

Before the California standard took effect, state water suppliers were required to meet only a threshold for all forms of chromium of 50 parts per billion. Besides chromium-6, the mineral chromium is found in other forms and in combination with other elements.

The national standard for total chromium is 100 parts per billion.

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander