Drinking water in peril

MTBE contaminates 48 wells in public system

Jane Kay / SF Chronicle 26aug01

Leaks of the gas additive MTBE from nearly 1,200 underground tank sites threaten the drinking water supply of millions of Californians, state records show.

In the Bay Area, 251 leaking tank sites pose an MTBE contamination threat to public wells.

A Chronicle analysis of data from the State Water Resources Control Board and the state Department of Health Services reveals for the first time that the fast-moving MTBE already has reached 48 wells in public water systems serving hundreds of thousands of people, including seven wells in the Bay Area -- at San Francisco's Presidio, in Montara and in San Jose -- forcing closures or expensive treatment.

The data don't include tens of thousands of private wells in California and hundreds of thousands nationwide, which aren't regulated by public agencies and thus generally aren't tested for MTBE unless nearby leaking underground tanks cause concerns.

Although MTBE is not an immediate health threat because it's too noxious to drink -- it tastes and smells like paint thinner -- the pollutant worries officials because it is scattered throughout the environment. It's in nearly every tank that holds gasoline, and it appears to escape even the newer tanks approved by the government as leakproof.

Once it leaks into soil, then groundwater, MTBE -- or methyl tertiary butyl ether -- moves much faster than conventional petroleum products, hydrologist say.

The 1,189 underground tank sites leaking MTBE lie within 1,000 feet of public supply wells or on vulnerable drinking water aquifers, state records show. There are an additional 1,729 leaking tank sites farther away from drinking water wells that also pose a concern.

"The most important thing the state should be doing is working on prevention and prioritizing cleanup," said Anne Happel, member of the U.S. Environmental Protection Agency's blue ribbon panel on MTBE. "The regulators should use the data that's being collected to identify the sites that pose the greatest threat, those closest to drinking water wells."

More than 2,500 public drinking water systems that serve 30.5 million -- or 90 percent of the state's population of 34 million -- have been sampled for MTBE.

Of the 8,311 groundwater sources sampled, 48 contained MTBE. Of the 595 surface water sources, 26 contained MTBE.

Statewide, Los Angeles County has the most with 16, centered in Santa Monica, Glendale and Burbank, followed by eight each in San Diego County and El Dorado County with its South Tahoe problems.

In the Bay Area, Alameda County led with five contaminated sources, followed by San Francisco with four, then San Mateo and Santa Clara with two each and Sonoma and Solano with one each.

WARNING ON MTBE IN WATER

A U.S. health advisory says people shouldn't consume MTBE at greater than 35 parts per billion. California has set a maximum limit of 13 parts per billion to protect health because MTBE is a carcinogen. The state also warns that water might have taste and odor problems at 5 parts per billion.

Some examples of problems created by MTBE:

• In Los Gatos, the Loma Prieta Elementary School found three years ago that its well had been serving trace amounts of MTBE to 400 children. The Santa Clara Valley Water District, which manages the wells, found 3.6 parts per billion in one of three wells while investigating the site of an excavated 550-gallon fuel tank that had been used for school district vehicles.
• Between Rohnert Park and Santa Rosa, a fuel distributing company contaminated nine residential and business wells. Next door, Kari Solem, owner of Advanced Tech Collision, had MTBE coming out of her tap at 240 parts per billion when the county finally forced testing in December 1999. "You could actually see it in the water. It stained the sink," said Solem. The company supplied water to Solem, then put a granular carbon treatment system on her well.
• In Novato, a gas station leaked MTBE 1,000 feet away into a well serving from 30 to 42 trailers in El Novato Mobile Home Park, now called Redwood Mobile Home Park. The gas station's consultants found MTBE at 92 parts per billion, plus metal and bacterial contaminants. The park is now receiving water from North Marin Water District.
• In Vacaville, a private well at the former Sierra Children's Home has MTBE up to 2.5 parts per billion. Owner Agape Villages Foster Family Agency, which closed the home in 1999, continues to have the well tested. A now-removed underground fuel tank might have been the source of contamination.
• In San Mateo County, MTBE has hit 12 private wells in Belmont, Redwood City, Menlo Park, San Mateo and other cities. Levels are below 13 parts per billion. County officials also discovered MTBE in 1998 in two of Montara's nine public wells -- or more than a quarter of its public water supply. Citizens Utilities Co., which owns all the wells, installed a granular carbon treatment system on the two. Citizens says it has spent $250,000 testing, treating and putting the cleansed water back into the system.
• In Volcano (Amador County), Claudia and George Christiansen saw their peaceful retirement turn to a fight for a clean water supply when MTBE from a tank at a nearby minimart invaded their well. First, the business sent in replacement water, Then, it installed a treatment system.

"I tasted something different in the water in the early 1990s and was suspicious enough to call the county. There was no testing for MTBE at the time, and I wouldn't have known what it was if they told me," said Claudia Christiansen, an Antioch School District employee for 20 years.

"You can imagine how we felt when they told us what it was in 1999. You think of all the years you've been smelling it in the hot water in the shower, washing your dishes in it and wearing it on your clothes. You think what if something will happen to one or the other of us? How will we pay the nursing home bill? What do we do? Let the property go?"

The Christiansens represent the class of small well owners in California who are part of a nationwide lawsuit against 12 major oil companies. The suit representing people in 16 states was originally filed in April 2000 in Illinois.

OK'D AS ADDITIVE IN 1979

The EPA approved MTBE in 1979 as a 2 to 5 percent blend in gasoline to boost octane and make cars burn cleaner. In 1992, it was blended at 10 to 15 percent for use in the winter to reduce carbon monoxide in air. In 1996, California used it year-round at 11 percent in a new reformulated gas program.

In 1998, the Lawrence Livermore National Laboratory released a study estimating 10,000 to 19,000 storage tank sites had contaminated the state's groundwater with MTBE.

The scientists projected that one-quarter of these plumes leaking from tank sites -- if left unchecked -- could reach lengths between 1,000 to 3,000 feet by 2020.

MTBE plumes tend to grow three to four times greater in size than plumes of such conventional gas products as benzene, 80 percent of which don't reach more than 300 feet, said Brendan Dooher, an environmental scientist on leave from Lawrence Livermore.

In 1999, armed with the bitter knowledge that Santa Monica and South Lake Tahoe had lost crucial wells to MTBE, plus a major University of California at Davis study confirming the threat to the groundwater, Gov. Gray Davis issued an executive order phasing it out by 2003.

STUDY OF WELLS INTENSIFIED

With more money in the state budget, the state water board added regulators in the nine regional water boards and focused on the sites that would most likely contaminate drinking water wells.

The state initiated GeoTracker, an environmental data warehouse, where water purveyors, oil companies, regulators and public interest groups exchanged information on leaking tank sites, public drinking water wells and remedial, enforcement and compliance actions.

The public can search for the information on MTBE and other water pollutants by ZIP code, city or county at www.geotracker.swrcb.ca.gov.

Private well owners won't find their information here. There is no requirement for testing, and no list of private wells contaminated from the thousands of leaking tank sites.

"We don't know how many drinking water wells have really been impacted. There are a lot of wells that remain untested. We don't sample our private wells, and they're often the most vulnerable because they draw water from shallow aquifers," said Happel of the blue ribbon panel on MTBE.

Dave Spath, chief of the state health department's drinking water division, said, "MTBE has a potential for being a significant problem. It's only been used for a short period of time in large quantities, and maybe this is the tip of the iceberg."

On the other hand, he said, "we have a lot of monitoring and cleanup going on. It's quite possible that the mitigation measures may be such that they'll prevent widespread contamination."