TESTS FIND FUEL ADDITIVE IN LAKES; OFFICIALS: CHEMICAL AT ALLOWABLE LEVELS IN CASTAIC, PYRAMID.

Byline: Teresa Jimenez Daily News Staff Writer

A gasoline additive meant to make fuel burn more cleanly has been found in Castaic and Pyramid lakes, which provide drinking water to dozens of agencies, but the levels are considered to be safe, officials said.

State officials have commissioned studies to find out the additive's health effects, which have not been determined, authorities said Wednesday.

State water officials only recently began testing reservoirs that store state water for methyl tert-butyl ether after some gas station employees and mechanics reported problems such as nose, throat and eye irritation, said Stefan Cajina, a sanitary engineer for the state Department of Health Services, which as set the safety standard.

MTBE also has been found at other locations, including Lake Tahoe, Donner Lake, Shasta Lake, Don Pedro Reservoir and Pardee Reservoir.

``In tests on rodents, (MTBE) has caused cancer. But there has been no link made to effects on humans,'' Cajina said. ``People have reported nose and throat irritation and other symptoms, but they haven't been definitively linked to MTBE. Studies have been inconclusive.''

Monitoring of Castaic and Pyramid lakes, which provide state water to the Castaic Lake Water Agency and the Metropolitan Water District, began in June for MTBE, said Dan Peterson, chief of environmental assessment for the State Water Project.

During the months of testing, MTBE was found in both recreational reservoirs, Peterson said. The additive enters the water supply through recreational vehicles such as power boats and Jet Ski-like personal watercrafts, he said.

``It's not surprising that we found levels there if you have Jet Skis and motor boats,'' Peterson said. ``We find more of it in the top three feet (of the reservoirs). There's less at deeper depths.''

The state Department of Health Services has set the MTBE ``action level,'' or safety level, at 35 micrograms per liter of water. And that level is still well-below what health officials believe to be a dangerous amount, Cajina said.

``That level is thousands less than what might be considered a risk,'' Cajina said. ``It is very, very unlikely that exposure will cause health problems.''

During testing in June and July, officials found anywhere from one to 24 micrograms per liter in Castaic Lake, Peterson said. Pyramid's levels were even lower, with the highest reading at 15 micrograms per liter, he said.

Water from Castaic Lake is split among three agencies. Three percent goes to the Castaic Lake Water Agency, 96 percent goes to the MWD and 1 percent goes to the Ventura County Flood Control Agency.

The Castaic Lake Water Agency provides state water primarily to the Valencia Water Co. and the Santa Clarita Water Co., as well as to the Newhall County Water District and Los Angeles County Water Works District 36.

The state water is usually mixed with pumped groundwater.

The MWD uses state water from Castaic Lake, Pyramid Lake, Lake Silverwood and the Colorado River Aqueduct, said MWD spokesman Rob Hallwachs.

Water from those sites are also mixed with groundwater, Hallwachs said. All 16 million of the MWD's water customers receive a mixed supply from those sources, he said.

Nearby agencies Calleguas Municipal Water District in Simi Valley and Las Virgenes Municipal Water District in Calabasas rely almost entirely on state water to supply their customers, Hallwachs said.

``I think the most significant thing is that we did find traces of it, but it is below the action level,'' Peterson said.

State Sen. Richard Mountjoy, R-Arcadia, has proposed a bill that would give the University of California system $500,000 to study the health and environmental effects of MTBE. In addition, state Sen. Tom Hayden, D-Los Angeles, and Assemblywoman Sheila Kuehl, D-Encino, have proposed bills that would require the state to adopt drinking water standards for MTBE.

The recent contamination is similar to the discovery this year of perchlorate in wells around the state. Perchlorate was found to have contaminated well water in areas where rocket fuel was manufactured and seeped into the ground.

Traces of perchlorate were found in one of Newhall County Water District's wells. After the well was flushed, the level was found to be below the state's safety level.