The California Department of Public Health's new cap on water contaminant chromium 6 of 10 parts per billion is set to take effect July 1 after the limit received final approval from an administrative arm of the department last week.

The Office of Administrative Law's approval follows more than three years of work by the health department to reduce the maximum contaminant level for the cancer-causing element featured in the 2000 film "Erin Brokovich." Public health officials used more than a decade of research done by the city of Glendale to craft the new cap.

Prior to the change, made official Wednesday, the state department limited total chromium, which includes the cancer-causing chromium 6 and the nutrient chromium 3, to 50 parts per billion.

One part per billion is often compared to a drop of water in an Olympic-sized swimming pool, so setting the limit at 10 parts per billion would be equivalent to 10 drops of chromium 6 in a 130,000-gallon pool.

Glendale and other cities in the San Fernando Valley have been plagued for decades by the water pollutant that leaked into groundwater after being used by the long-gone aerospace industry.

But Glendale Water & Power won’t be impacted by the recommended cap on the cancer-causing contaminant because the city’s utility currently limits chromium 6 levels to 5 parts per billion by cleaning polluted water and blending it with expensive, but clean, imported water.

Rep. Adam Schiff, who has long complained that the state department of public health was taking too long to set the new limit, called the cap an "important step forward" in a statement Monday.

“With this new rule, California will lead the way in providing quality drinking water, free of dangerous levels of this carcinogen," he said.

Still, the democrat from Burbank challenged water agencies to work to limit the carcinogen level in their drinking water even more.

“Though this is welcome news, I hope that communities will go beyond this standard and insist on even lower levels of chromium until we can completely remove it from our water supply," he said.

Health department officials have estimated that reducing the limit to 10 parts per billion will cost water agencies statewide $156 million in total.

-- Brittany Levine, brittany.levine@latimes.com

Follow on Google+ and on Twitter: @brittanylevine.

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