SAN FRANCISCO, California, November 1, 2002 (ENS) - Deteriorating water works, pollution, and outdated treatment technology are combining to deliver drinking water that might pose health risks to residents in four of California's largest cities, a new report warns.

While tap water quality in Fresno, Los Angeles, San Diego and San Francisco meets most federal and state safety standards, it still contains pollutants that pose health and environmental risks, concludes the early release California edition of, "What's On Tap? Grading Drinking Water in U.S. Cities."

Drinking tap water may not be safe in four California cities. (Photo courtesy USGS)

The four city California report is part of a larger one on water supplies in 19 cities nationwide that the NRDC will publish in the next few months. The environmental group decided to release the California section early to let voters know about the problems before they vote next Tuesday on Proposition 50, a ballot initiative that would authorize $3.4 billion to protect water resources.

The NRDC report found no confirmed violations of enforceable federal tap water standards in the four cities, but concluded that infrastructure and other problems in each of the municipal water supplies might pose health risks to some residents.

Although the report does not advise residents to stop drinking tap water, it cites medical experts who suggest that pregnant women and parents of infants consult with their health care providers.

Echoing recommendations by the Centers for Disease Control and Prevention (CDC), the NRDC also urged that people who have serious immune system problems, such as those taking some cancer chemotherapy drugs or people with HIV/AIDS, consult with their health care providers regarding the safety of drinking tap water.

Fresno's water supply, which the report cites as the worst of the four, has serious problems caused by nitrates, pesticides and industrial chemicals. To address these concerns, the report recommends that Fresno improve its waterworks infrastructure and source water protection.

Perhaps acknowledging the problem, the city of Fresno this year urged that pregnant women and parents of infants consult with their health care providers about their tap water.

"Nitrates and other contaminants are a serious problem in Fresno's tap water," said Dr. Beatte Ritz of Physicians for Social Responsibility, an assistant professor of epidemiology at the University of California at Los Angeles School of Public Health. "Last year the city itself told pregnant women to avoid drinking it. That's good advice."

The Hetch Hetchy watershed, an area located in Yosemite National Park, provides drinking water for San Francisco. (Photo courtesy National Park Service)

The report recommends that San Francisco make major water treatment and infrastructure improvements to address its water quality problems. But it also notes the city's source water protection effort, which includes working with ranchers in the Alameda watershed to prevent cattle from polluting waterways.

Los Angeles also has significant levels of chlorine byproducts, as well as substantial concentrations of arsenic. Although below the new EPA standard, the arsenic levels there are high enough, according to the National Academy of Sciences, to pose a significant cancer risk.

Sections of the Los Angeles water supply have elevated levels of radioactive and cancer causing radon, and levels of the rocket fuel perchlorate - a thyroid toxin - that exceed the California health warning level and the EPA's draft safe level. The system's water also is compromised by uncovered reservoirs, and some city well water shows elevated nitrate levels.

All of these problems will require major infrastructure and treatment improvements, and stronger measures to protect Los Angeles water sources from pollution, according to the report.

San Diego's water supply has a high level of trihalomethanes - averaging slightly below the new EPA standard but still posing a risk to public health - and perchlorate in parts of the system at levels higher than the state's action level and the draft EPA safe level.

The San Diego water supply also has other contaminants that, while not at levels high enough to trigger violations, exceed EPA health standards.

The contaminants include ethylene dibromide, a carcinogen and reproductive toxin; lead; and three cancer causing radioactive elements. The report concluds that, like the other cities, San Diego needs to protect its source water from pollution and make significant investments to improve water treatment and infrastructure.

To protect drinking water sources, the report recommends that the state and cities upgrade drinking water treatment, invest in water conservation measures, and replace and update pipes and water distribution system components.

The report also recommends that state and municipal authorities purchase land or easements, and adopt standards to protect watersheds and areas above aquifers draining into California water supplies.

"The problems NRDC's report found in four major California cities are emblematic of what both large and small municipalities are facing across the state," said Marguerite Young of California Clean Water Action. "And on November 5, California voters have an opportunity to do something about it: Pass Proposition 50. Prop. 50 will provide critically needed funds to improve drinking water quality infrastructure, prevent water pollution, and promote water conservation."

Young also urged the Central Valley Regional Water Quality Control Board to approve new controls for agricultural discharges, which pollute the drinking water supply of millions of Californians.

The report reviews each of the cities' mandated right to know reports, which are designed to inform residents about water system problems. Among other things, the NRDC found that San Francisco failed to include a required warning for immune compromised people regarding the potential risks posed by pathogens in its water, San Diego failed to disclose the levels of radioactive and other contaminants in its water, and Fresno buried critical information about high nitrate levels in footnotes.

The Los Angeles right to know report received relatively high marks for revealing tap and source water problems.

"Fresno, San Diego and San Francisco don't adequately inform their residents about contamination," said NRDC's Olson. "Californians have a right to know what's in their tap water and whether it might harm them."

An executive summary of the report is available at: http://www.nrdc.org/water/drinking/uscities/execsum.asp