ARSENIC OPTIONS SOUGHT LANCASTER-AREA WELLS EXCEED LIMITS FOR 2006.

Byline: Charles F. Bostwick Staff Writer

LANCASTER - Facing new federal restrictions on a naturally occurring toxin, Los Angeles County officials are trying to figure out what to do about arsenic contamination in Lancaster-area wells.

Eleven of 28 wells used by Los Angeles County to supply homes and businesses around Lancaster tested at arsenic levels higher than allowed under stiffer federal regulations that take effect in 2006.

Drilling new wells and blending well water with arsenic-free California Aqueduct water appears to be the cheapest option, though still costly, officials say.

``The estimated cost for such a program ranges from $5 million to $7 million, not including land acquisition or environmental studies,'' a county Public Works Department report to supervisors says. ``If treatment is necessary, this cost may multiply.''

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.

Arsenic in Antelope Valley wells - and in most other places in the United States, especially the West - doesn't 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 is 10 parts per billion, or about 10 drops in 13,000 gallons of water. The present standard, in place for 49 years, is 50 parts per billion, or 50 drops per 13,000 gallons of water.

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, the EPA estimates.

In the Los Angeles County waterworks wells, the highest concentrations of arsenic are around Lancaster.

One Lancaster well tested in a 2000 study at 47.1 parts per billion, though that well has since been shut off.

Three other Lancaster-area wells have also been shut off because of elevated arsenic levels, officials said.

The average concentration for Lancaster-area wells is 4 parts per billion.

No waterworks wells outside Lancaster have arsenic higher than 5.5 parts per billion, county records show.

Wells deeper than 500 or 600 feet tend to have higher levels of arsenic than shallower wells, said Manuel DelReal, a principal engineer with the waterworks district.

``The ones that are deep are the ones that produce the most water,'' he added.

Wells provide about 40 percent of the water supplied by the waterworks district, which covers most of Lancaster. The rest of the water comes from the California Aqueduct, which has no detectable levels of arsenic.

Because well water is blending with aqueduct water in pipelines, people who live near wells with relatively high levels of arsenic aren't necessarily getting more arsenic than people across town, waterworks officials say.

The EPA said it plans to provide $20 million over the next two years for research into cheaper treatment technologies.

Los Angeles County officials are seeking $250,000 from a state well- water program to share in a U.S. Geological Survey study of ways to reduce arsenic in Antelope Valley water.

The study would chemically evaluate the type of arsenic in Antelope Valley water and look at the possibility of sealing off well shafts in the segments where arsenic concentrations are highest, officials said.