Tests of nearly four dozen north Los Angeles County water wells has found chromium 6 at levels up to 17.6 parts per billion, about 90 times above levels recommended by a state health agency, a county study showed Thursday.
Chromium 6, a suspected carcinogen, was found in 32 of 44 wells tested. Some of the wells had chromium 6 levels nearly twice as high as found in a survey of tap water at county facilities last month.
"These are the highest levels of chromium 6 our lab has found so far and I didn’t expect it," said Wasfy Shindy, director of the county’s environmental toxicology bureau. "We ought to either clean up the wells or shut them down altogether."
All of the wells are operated by the Los Angeles County Department of Public Works, and supply drinking water to Palmdale, Lancaster, Littlerock and other communities.
The county has no immediate plans to shut the wells because they do not exceed state standards for total chromium of 50 parts per billion, public works spokesman Ken Pellman said.
"We do everything we are required to do by law," Pellman said.
California has no specific standard for chromium 6. The Office of Environmental Health Hazard Assessment, however, has called for a tougher standard of 2.5 parts per billion for total chromium, which officials say would reduce chromium 6 concentrations to 0.2 parts per billion.
Pellman said about 44,000 homes and businesses in northern L.A. County receive water from the tested wells. But he said chromium 6 levels in the tap water could be lower than the amounts found in the wells because the well water may be blended with other water sources.
State Department of Health officials declined comment on the county well tests, saying they had not reviewed the findings. But David Spath, health department drinking water chief, has previously said the concentrations of chromium 6 in tap water--up to nearly 9 ppb--did not present an immediate public health threat.
The highest levels were recorded in four wells in Lancaster: 17.6 ppb of chromium 6 in a well at 1701 W. Avenue H-8; 16.5 ppb at 44205 N. 15th St. W., and 15.8 ppb at 45548 N. Division St. and 45938 N. 15th St. W.
Chromium 6 levels of 10 ppb also were found at eight other Lancaster sites as well as Hi Vista and Lake Los Angeles.
County Supervisor Mike Antonovich said the tests point to the need for "an aggressive action plan to protect our water supply."
Antonovich said he would introduce a motion calling for county officials to report back within 30 days with a plan to remove carcinogens and other impurities from the water as well as examining the impact of limiting or closing wells.
Last month county supervisors ordered testing for chromium 6 at 200 drinking water wells countywide, with a report due to the board in three months. The motion--passed unanimously--also called for county officials to report back in six months on chromium 6 levels in tap water at all county facilities.
That came afer tap water tests at 110 county facilities last month recorded chromium 6 levels of up to 7.84 ppb. That reading was at a health clinic in Burbank.
The Board of Supervisors called for the study after The Los Angeles Times reported Aug. 20 that the state health department could take up to five years to act on the tougher standard for total chromium.
SOURCE: The Los Angeles Times