Water contaminant level high in some Valley towns, tests find

A likely cancerous drinking water contaminant featured in the movie "Erin Brokovich" showed up in relatively high levels in hundreds of tests throughout Stanislaus County and neighboring communities.

Some public officials say the data may be unreliable and have little meaning until the government sets a new standard, a process just getting under way.

Drinking water advocates blame pressure from industrial polluters for putting the review seven years behind schedule.

Hexavalent chromium, also known as chromium 6, causes cancer in laboratory animals and was listed as a likely carcinogen by the U.S. Environmental Protection Agency in September. But federal and state regulators have not addressed meaningful limits in public tap water.

Hexavalent chromium was a common industrial chemical until about 20 years ago. It is still used in plastic and dye manufacturing. Naturally eroding soil and rock also can produce the contaminant.

Two weeks ago, a national environmental group reported finding the contaminant in 31 of 35 cities across the United States, 25 with readings higher than a benchmark that could become California's standard.

Nearly all of those readings, however, are far less than those detected in samplings from wells in Stanislaus, San Joaquin and Merced counties.

A well at Los Banos' Morning Star Packing Co., for example, produced a 2005 hexavalent chromium level 600 times higher than a statewide maximum proposed in August 2009 and 1,800 times higher than the public health goal being studied.

Hexavalent chromium levels were particularly alarming in communities on the Valley's west side and in Merced County.

But Ken August, spokesman for the California Department of Public Health, said, "The data are problematic at best." Most tests are several years old and some suggest lab error, he said.

Dr. John Walker, Stanislaus County's public health officer, said Tuesday: "To my knowledge, I am not aware that chromium 6 levels (here) are a significant human health hazard."

Hexavalent chromium rocketed to public consciousness in the 2000 film "Erin Brokovich" starring Julia Roberts. Accused of tainting groundwater near Hinkley for three decades, Pacific Gas & Electric Co. paid $333 million in damages and pledged to clean it up.

California and other states engaged in safe tap water campaigns, resulting in data compiled by the Department of Public Health and cited in this report. California legislators in 2001 demanded a new state standard for hexavalent chromium by 2004. But the effort stalled, and department officials acknowledge the testing represents "one point in time," August said Tuesday.

Clean Water Action program manager Andria Ventura blamed "unconscionable delay tactics by polluters, some water providers" and former Gov. Schwarz-enegger's administration.

The 2009 proposal -- never adopted -- of 0.06 parts per billion of hexavalent chromium was replaced last week with a more stringent 0.02 parts per billion for purposes of studying what's called a public health goal. A public comment period on that number opened this week and closes Jan. 31.

If adopted by state Environmental Protection Agency officials, the Department of Public Health would consider setting a legal standard, taking into account costs of treating water.

This story was originally published January 8, 2011 at 12:13 AM with the headline "Water contaminant level high in some Valley towns, tests find."