High Levels of Chromium 6 Discovered in Private Wells


Tests of 220 small private water systems across Los Angeles County have found levels of chromium 6 as high as 13.7 parts per billion, more than 65 times what one state agency says is safe, according to a study released Wednesday.

The new readings generally were lower than chromium 6 levels detected late last year at county-owned wells, but still prompted concern from officials.

“The numbers might not be as high as other tests, but these results show chromium 6 continues to be a widespread problem in Los Angeles County,” said Dr. Wasfy Shindy, director of the county’s environmental toxicology bureau.


“It also shows the owners of these wells should clean up the contamination or not use them. And they owe it to their customers to tell them what is in the water,” he said.

Los Angeles County Supervisor Michael D. Antonovich said he would call on the county to order ongoing testing of private wells, and might seek random, countywide testing of bottled water.

The highest readings of chromium 6, a suspected carcinogen, were taken in the Antelope and Santa Clarita valleys, Downey, El Monte and Malibu. But even those levels were below the 17.9 parts per billion detected in county-owned wells in the Antelope Valley, and the more than 400 ppb found at a private well in Bell Gardens.

The private water systems--which serve as many as 55,000 people--are regulated by the County Department of Health Services.

Chromium 6 was at the center of the famous pollution case in Hinkley, Calif., that formed the basis for the film “Erin Brockovich.” But concentrations in that case were 24,000 parts per billion, many times higher than even the highest reading taken in Los Angeles County.

No maximum allowable level for chromium 6 in drinking water has been established. Instead, the state limits total chromium to 50 ppb as a means of cutting levels of chromium 6, which is a chemical byproduct of the metal. The federal chromium standard is 100 ppb.


Chromium 6 is classified as a carcinogen when inhaled as particles or fumes, but its risk in water remains unknown.

The state Office of Environmental Health Hazard Assessment has called for a goal of 2.5 ppb for total chromium, which officials say would reduce chromium 6 concentrations to 0.2 ppb.

Last month, the state Department of Health Services, which sets drinking water standards, ordered more than 3,000 of the state’s water systems to test for chromium 6 and report back to the agency by 2003.

But the agency has not yet responded to public officials calling for an immediate state requirement that the public be notified when the chemical exceeds 2.5 parts per billion in drinking water.

Antonovich reiterated his call for a partnership among federal, state and local officials to deal with water quality issues. He said he had sent a letter to EPA director Christie Whitman, urging that uniform standards for chromium, arsenic and lead be adopted.


County Readings of Chromium 6Tests of 220 small private water systems across Los Angeles County have found levels of chromium 6 in drinking water wells as high as 13.7 parts per bilion, well above 0.2 ppb, which one state agency said provides optimum safety.



Source: Los Angeles County Environmental Toxicology Burea