Arsenic Levels in Water May Exceed New Limits, Study Finds

Six Ventura County agencies may have difficulty meeting tighter limits on levels of arsenic flowing in drinking water, according to a study released Thursday by a national environmental group.

Although local water supplies apparently comply with today’s standards for the toxin, there is wide agreement that the existing limit does not protect human health and must be dramatically lowered. New limits, expected to be in place next January, could render a handful of local agencies hard-pressed to comply, the study by the Natural Resources Defense Council suggests.

The six agencies supply water to about 400,000 households and businesses from Thousand Oaks to Santa Paula to tiny San Nicholas Island 60 miles offshore.

But some water officials dispute data contained in the report. They say the water they provide contains so little arsenic that they would have no trouble meeting more stringent limits.

“We don’t see any crisis brewing. We’ll be OK,” said Robert Westdyke, director of public works for the Camarillo Water Department.

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The report, which examines arsenic in 24,000 public water systems in 25 states, says high levels of arsenic have been detected in water supplies used by six local purveyors. The concentrations ranged between 8 and 43 parts of arsenic per billion parts of water, well below the current limit of 50, but above the standard of five that the U.S. Environmental Protection Agency intends to propose in April.

The six entities are Calleguas Creek Municipal Water District (14 ppb in February 1995); Camarillo Water Department (30 ppb in April 1994); Camrosa Water District (8 ppb in July 1996); Santa Paula water department (20 ppb in July 1992); Ventura water department (43 ppb in June 1994); and the Naval station on San Nicholas Island (21 ppb in August 1991).

Three of those agencies have average concentrations of arsenic in water that would exceed the new limit the EPA is preparing, according to the report. They are the Calleguas, Camarillo and Ventura water providers.

The Natural Resources Defense Council, a national environmental advocacy group, released the report to coincide with its announcement of a lawsuit to force the EPA to implement new arsenic standards promptly. The results are based on 10,000 water samples the EPA collected from local water suppliers between 1990 and 1998.

Although concentrations of arsenic reported in local water supplies are not large, it is enough to cause a hazard that the EPA has deemed an unacceptable environmental risk. The nation’s arsenic standard, unchanged since 1942, predates modern health research that shows the substance continues to be harmful in small amounts.

“Arsenic is much more of a threat than we had appreciated in the past,” said EPA drinking water toxicologist Bruce Macler. “It’s one of the top drinking water issues of concern right now for the public, so much of a threat that we need to lower the standard about tenfold.”

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Most often recognized as a poison of choice for homicide, arsenic is an element in the Earth’s crust that dissolves in water flowing through rivers or in aquifers that feed drinking-water wells. It also leaks from old mines and has been used in pesticides.

Years of exposure to low doses of arsenic can cause damage to the nervous system, heart and blood vessels, and skin lesions and cancers of the bladder, kidney, liver and lungs.

But local water suppliers say there is just not enough of the contaminant flowing through wells and pipes to pose much danger.

Steve Wilson, superintendent for the Ventura water department, said the most recent test taken in June showed the city’s water supply contained 3 parts per billion of arsenic, well within existing or envisioned limits. Like many other local water officials, he could not say whether all the arsenic tests taken during the 1990s were low enough to meet the new limits the EPA is considering.

Numerous technologies exist to treat water to remove arsenic, including use of lime in water softeners, improved filtration and reverse-osmosis units that can be installed under kitchen sinks. Estimated cost to local water agencies to meet a 5-ppb arsenic limit would be about $686 million per year.