STUDY ON DRINKING WATER CONTAMINANTS IN COUNTY WELLS AT ISSUE.

Byline: Charles F. Bostwick Staff Writer

LANCASTER - Los Angeles County officials plan to spend $282,000 in a joint study with the federal government to investigate how to meet impending new drinking-water standards for two underground contaminants.

The study with the U.S. Geological Survey will analyze concentrations of arsenic and chromium 6 in county wells in the Antelope Valley and identify ways to reduce the levels to meet new standards from the state and federal governments.

``You either shut down wells or blend the water in with other sources,'' said Ken Pellman, a spokesman for Los Angeles County Department of Public Works. ``Tap water is kept to a very high standard.''

County water is safe to drink, he said.

Los Angeles County supervisors are scheduled to vote today on the agreement with the Geological Survey. If the study is funded, a final report is due in January 2005, with interim reports to county public works officials along the way, Pellman said.

Supervisor Mike Antonovich, who represents the Antelope Valley, supports the effort to reduce contaminants, a spokesman said.

``Supervisor Antonovich is committed to ensuring our groundwater and our drinking water are pure and safe and free from contaminants and pollutants,'' spokesman Tony Bell said.

By January 2006, the federal government will bar public water suppliers from delivering water with more than 10 parts per billion of arsenic, down from a 50-year-old standard of 50 parts per billion.

A deadly poison at higher concentrations, arsenic at low levels in drinking water has been linked to cancer of the bladder, lungs, skin, kidney, nasal passages, liver and prostate, experts say.

In January 2004, the state government is expected to set a new drinking-water standard for chromium 6. At present there is no drinking water regulation setting a maximum level for chromium 6, other than the overall chromium limit of 50 parts per billion set by the state government and 100 parts per billion set by the federal government.

Experts say chromium 6 is more dangerous than other forms of chromium. More properly called hexavalent chromium, chromium 6 was the chemical villain in an Oscar-winning movie, ``Erin Brockovich.'' The substance has been shown to cause cancer when it is inhaled, though experts disagree on the level of danger when swallowed.

The county revealed last year that 11 of 28 wells used by Los Angeles County to supply homes and businesses around Lancaster tested at arsenic levels higher than the impending federal level. But the average in drinking water supplied to homes remained lower than the new standard, at 8.88 parts per billion, county records show.

Arsenic in Antelope Valley wells - and in most other places in the United States, especially the West - does not come from industrial pollution but occurs naturally in the rock and soils, officials say.

The EPA estimates that about 4,000 water systems - most serving fewer than 10,000 people and most in the western United States - have water contaminated by arsenic at concentrations higher than the 2006 federal standard.

The amounts of arsenic involved are minuscule: The new federal standard of 10 parts per billion is equivalent to about 10 drops in 13,000 gallons of water. The present standard of 50 parts per billion has been in place for 49 years.

The EPA estimated that reducing arsenic from 50 parts per billion to 10 parts per billion will prevent 20 or 30 deaths a year nationwide from lung and bladder cancer.

Deeper wells tend to have the higher levels of arsenic in the Antelope Valley, county officials said, but they also produce more water than shallower wells.

Wells provide about 40 percent of the water supplied by the county waterworks district, which covers most of Lancaster and other areas around the Antelope Valley.

The rest of the water comes from the California Aqueduct, which has no detectable levels of arsenic.

Average chromium 6 levels in county waterworks supplies in the Antelope Valley range from zero to 13.3 parts per billion.

State health officials at one point suggested the maximum allowable level should be 0.2 parts per billion, but they later withdrew the recommendation on the basis their initial risk assessment was flawed.