Los Banos water tests high in contaminant for state standards

The chromium-6 levels of water flowing from Los Banos residents’ faucets hasn’t changed.

But water sample results from March show that the city’s water is now non-compliant under state standards that were changed two years ago, according to a city public notice

Those new standards are far stricter than former limits and federal thresholds, according to the notice.

However, non-compliance doesn’t mean residents need to use alternative water sources, Los Banos Water Quality Specialist Randy Williamson said.

“We’re not the only town where this has happened,” Williamson said.

Chromium-6 is a naturally occurring, manufactured and “well-established carcinogen associated with lung, nasal, and sinus cancer,” according to the Centers for Disease Control and Prevention.

According to a public notice by the city, water sample results obtained in March raised the annual average chromium-6 levels in the water to between 18 parts per billion and 39 parts per billion.

“We’ve always met or exceeded state and federal standards with drinking water, until California set its limit on chromium-6 to 10 parts per billion in 2014,” Williamson said.

Prior to the change in 2014, the maximum contaminant level was 50 parts per billion. The federal level is 100 parts per billion. One part per billion is equivalent to one milligram per 1,000 liters.

The notice states that the city has been working on an action plan to lower the chromium-6 levels of the cities 13 groundwater wells.

Williamson said pilot projects have been launched to determine the cost effectiveness of three treatment methods.

“It takes years of pilot testing,” Williamson said, noting that securing funding for treatment is also an issue. “It’s going to be an extremely expensive process.”

This story was originally published April 6, 2016 at 1:00 AM with the headline "Los Banos water tests high in contaminant for state standards."