SANTA MONICA, Calif. - Miriam Cardenas was puzzled when she first saw the strange reading in the water-quality report she got back from the laboratory. As chief water chemist for the city of Santa Monica, it was her job to see that the tap water in this sun-drenched beach community is safe to drink.
The annual test Cardenas had run for potentially harmful contaminants in the city's water came back in the fall of 1995 with the usual negative results --- except for finding traces of a new chemical, methyl tertiary butyl ether, or MTBE. Cardenas had never heard of it.
"What is this?" she recalled wondering. "Why is it there?" She quickly found out what most of the rest of the country has since learned as well. MTBE is a gasoline additive that has proven incredibly adept at contaminating groundwater, and is maddeningly difficult to get out once it's there.
As residents living near Fallston in Maryland wrestle with the recent discovery of an MTBE plume contaminating the wells of 84 homes around an Exxon service station there, they can consider what happened in Santa Monica.
This upscale, slightly offbeat city just west of Los Angeles - where homeless men lounge next to parked Mercedes-Benz autos - was one of the first communities in the country to discover the gasoline byproduct in its water supply, and one of the worst hit.
Eight years ago, after MTBE began showing up in one municipal well after another, city officials shut down seven of them, eliminating roughly half of the community's water supply.
To this day, those wells remain dormant, as Santa Monica has been forced to import replacement water from Northern California and from the Colorado River, hundreds of miles away.
The cost, about $3 million a year, is borne by a group of oil companies that had gas stations around the city's well field. Until those companies were forced to step forward, though, Santa Monica had to increase its water rates by 25 percent.
Now, after eight years of litigation and negotiations, the city has reached an out-of-court settlement with the oil companies to pay $100 million in damages and to clean up the MTBE-tainted aquifer.
Once studies under way determine the best approach, the companies have agreed to underwrite construction of a treatment plant - which officials project could cost $50 million to $100 million to build, plus millions more annually to operate.
It may be another five years, at the earliest, city officials predict, before they can begin pumping water again from the city's largest well field.
"It just boggles the mind how much money this has cost and will cost," says Craig Perkins, Santa Monica's director of environment and public works. "The irony, I guess, is that the cheapest thing for the oil companies would be just to pay for our replacement water in perpetuity, but that's not acceptable to us, or, fortunately, to the regulatory authorities."
MTBE was supposed to help clean up the environment, not contaminate it.
Made from wood alcohol and a byproduct of petroleum refining, MTBE had been added to gasoline on a limited basis since the late 1970s to enhance octane and reduce engine knock.
Beginning in the 1980s, though, it began to be put in gas to combat harmful air pollutants like carbon monoxide and ozone, the chief ingredient in summertime smog. Its use really took off, though, after 1990, when Congress ordered the sale of clean-burning "reformulated gas" in the 10 metropolitan areas with the worst smog levels. Los Angeles was at the top of the list, and Baltimore wasn't far behind.
But the same chemical properties that made MTBE useful as an "oxygenate" in cleaner-burning fuel also made it prone to contaminate groundwater. It dissolves easily, much more so than the other ingredients of gasoline.
With many service stations' underground fuel tanks corroding and springing leaks by the early 1980s, it didn't take long for the chemical to start showing up in people's wells - in Rockaway, N.J., and locally, in Jacksonville in rural Baltimore County.
Despite such warnings, no one was looking for MTBE when Santa Monica officials learned they had it in their wells. There were no federal or state guidelines then on how much was safe in drinking water, and precious little information on its health effects.
When the additive showed up in the city's Charnock well field, recalls Cardenas, she initially thought it was a lab error.
Even after follow-up samples confirmed the finding early in 1996, city officials at first figured they could keep the contaminant at minimal levels by mixing the water from the one tainted well with clean water from the other four.
But, within a few weeks, MTBE levels soared in the first well to 610 parts per billion, prompting officials to shut it down - only to watch with alarm as the contaminant began popping up in the remaining wells in its Charnock well field.
Even now, the U.S. Environmental Protection Agency has yet to establish a safety threshold for MTBE in drinking water, though it does assure that the chemical poses little health risk at the low levels frequently found in household wells or public water supplies.
The EPA classifies it as a possible carcinogen, based on laboratory studies in which rats inhaled high doses of MTBE fumes. But because MTBE has a harsh, turpentine-like odor that some people can detect at minute levels, the EPA recommends keeping it below 20 to 40 parts per billion - the range at which many people can smell or taste it.
"A lot of it has to do with the faith people put in their drinking water," says Gilbert M. Borboa Jr., the city's water resources manager. "They expect it to be palatable - not only to look clean, but taste and smell clean."
So by mid-1996, Santa Monica shut down its Charnock well field, and two wells elsewhere that also showed evidence of MTBE contamination.
Meanwhile, the city had no difficulty finding out where the chemical might be coming from. A survey identified 20 to 30 service stations within a mile and a half of the well field - some with known leaks from their underground fuel tanks - as well as two gasoline pipelines running under nearby streets.
"We were sort of floored by that," Perkins says. An initial appeal to the companies to get together on a plan for cleaning up the city's water supply produced little other than denial and finger-pointing, the public works director recalls. So the city hired three teams of outside lawyers and filed suit.
As the litigation dragged on, the city did succeed in getting state and federal help, including an order requiring the oil companies to pay for the replacement water bought from the Metropolitan Water District.
In the meantime, MTBE cropped up repeatedly in other communities in California, and nationwide - basically, wherever reformulated gasoline was sold. A 1999 survey by the U.S. Geological Survey found that it had tainted groundwater in more than a quarter of the urban areas where MTBE-dosed gasoline was sold.
Ban on additive
Driven in large part by Santa Monica's plight, California officials reacted to the ever-widening problem in their state, first by setting one of the tightest drinking-water standards in the country, 13 parts per billion (Maryland's "action" level is 20 parts per billion), and in 1999 by ordering the phaseout of gasoline containing MTBE by the end of last year.
About 16 other states have likewise banned or limited MTBE.
Shell Oil spokesman Cameron Smyth said the company - with a large share of responsibility for the Santa Monica problem - opted on its own to stop selling MTBE-laced gas in California a year before the state's ban took effect.
Finally, last November, the city reached an out-of-court settlement with the eight remaining oil industry defendants.
In arid Southern California, water is a precious resource - having its own supply is what kept Santa Monica from being swallowed up by Los Angeles 80-some years ago, in the water-development scramble dramatized by the classic movie Chinatown. Santa Monica's taps did not go dry when a 1994 earthquake knocked out water to the rest of the area.
The city's well fields are actually in Los Angeles, just beyond Santa Monica's borders. They draw from an underground aquifer of maybe five or six square miles, about 250 feet beneath busy streets.
The Charnock well field, Santa Monica's largest, is tucked away in a largely residential neighborhood. The wells themselves actually border the athletic field of a private school, where teenage boys practiced lacrosse one day last week. The pumps there are silent, though, except for the hum of water coursing through one sky-blue pipe that runs here through canals from Northern California.
After 21 years in Santa Monica government, Perkins hopes to be around long enough to see the pumps running again at Charnock, with a treatment plant in place to strip MTBE from the water before it goes to residents.
It will not be easy. At the Shell station nearest the well field, a small processing plant erected by the oil company has pumped 282 million gallons out of the ground since 1999 and managed to remove about 350 gallons of MTBE, according to a Shell spokesman.
Perkins says the city's experts estimated 15,000 to 20,000 gallons of fuel leaked from that Shell station alone.
Even as the engineers work to form a cleanup plan, Santa Monica's legal struggle over MTBE is not over. The city's outside lawyers have sued the city, claiming they are due as much as $66 million for their services, and the city has countersued.
Meanwhile, Perkins says, "The hard work remains, cleaning the stuff up."