High Levels of Solvent Found in L.A. Water

Higher than advised concentrations of a suspected cancer-causing solvent are showing up in portions of Los Angeles’ water supply because of a temporary breakdown in the Owens Valley aqueduct, state and city officials cautioned Friday.

The warning was issued at the urging of state Department of Health Services officials, who complained that the city Department of Water and Power had objected to making a public announcement out of fear it might cause undue alarm.

The disclosures Friday come on top of previous DWP test findings that, during six months of the last three years, water supplied to some Los Angeles homes and businesses from wells in the San Fernando Valley has exceeded state advisory limits for trichloroethylene, or TCE.

Pumping More Water

State and local officials said the immediate TCE problem developed last week when a break in the aqueduct forced DWP to begin pumping more water from Valley wells to make up for shortages caused by the interruption in service.

About 75 DWP wells clustered between the North Hollywood area and Griffith Park provide roughly 15% of the city’s water supply. The well water rarely is piped to Valley homes and businesses but provides at least part of the supply for about 400,000 people living in East, Central and West Los Angeles, according to the DWP.

The state was informed Thursday that TCE levels now are 12 parts per billion, well above the state advisory standard of 5 ppb.

State officials, however, do not consider this level to be a danger to public health because the problem is temporary and will be solved when the aqueduct is back in service, expected by Oct. 21.

Officials cited estimates that if a person drank two quarts of water a day containing 5 ppb of TCE for 70 years, he (or she) would have only a one in a million greater chance of contracting cancer.

Still, state officials insisted that Los Angeles water customers should be notified.

“We don’t consider it a public health threat but we do believe the public has a right to know,” said Pete Rogers, chief of the sanitary engineering branch of the state department.

After the expressions of concern by state officials, city aides agreed to assist in releasing the information.

But Ali Webb, press secretary to Los Angeles Mayor Tom Bradley, released a letter from DWP General Manager Paul Lane to state Health Services Department Director Dr. Kenneth W. Kizer asserting:

“While we agree with you that the public certainly should be informed when there is a health risk associated with their water supply, we are puzzled why you are requesting such public notice since you agree with us that there presently is no health risk to any of the water customers in the city of Los Angeles.”

‘Annual Average’

The letter said that the advisory 5 ppb level is an “annual average” and that the TCE levels are not approaching the 20-ppb level that had been set as a “daily” limit.

DWP test data reviewed earlier by The Times showed that the average amount of TCE in water supplied from the Valley wells exceeded the advisory standard of 5 parts per billion during four months in 1982 and two months in 1984.

The data appears to conflict with public statements by the utility that its practice of blending or closing polluted wells has assured that water reaching customers meets the TCE limit.

No Inconsistency Seen

But a high-ranking DWP official said there is no inconsistency between the test results and statements by the utility, since the yearly average of TCE in the water has stayed below the 5-parts-per-billion advisory level.

“I don’t think the public has been misled on it,” said Laurent McReynolds, assistant chief engineer of the water system. “They’ve not been put at any greater risk.”

During the last five years, many individual wells have been found to contain TCE and a second common industrial cleanser, perchloroethylene, or PCE, at levels above state advisory limits, also known as “action levels.” In response, the DWP has stopped pumping some of the wells and has blended others with cleaner aqueduct water to dilute the contamination.

As a result of these efforts, a 1983 DWP report said, “only water in compliance with the recommended quality guidelines was delivered to the customer for consumption.”

Some Evaporated

But DWP data shows that TCE in the well water averaged 6.6 parts per billion in June, 1984; 8.3 ppb in May, 1984; 9.1 ppb in November, 1982; 7.1 ppb in October, 1982; and 8 ppb in both July and August of 1982. The DWP tests showed that monthly average concentrations of PCE have never topped the action level for that chemical since regular monitoring began more than three years ago.

The measurements were taken from a water supply conduit--not at the tap--making it likely that some of the TCE, which is highly volatile, evaporated before reaching customers, DWP officials say.

McReynolds said that, in effect, the action level, which is not a legal standard, was never violated because it is intended to limit chronic rather than temporary exposure to TCE in water. Test results show that average TCE levels have topped 4 parts per billion over 12-month periods but have never averaged 5 parts per billion during any one year period.

TCE is not a proven human carcinogen but has caused cancer in laboratory animals exposed to large doses.

DWP an Exception

The state Department of Health Services, which set the guideline, has had an informal policy of requiring utilities to notify their customers when water exceeds actions levels.

However, that policy has not been followed with the DWP, which convinced officials in the state agency’s Los Angeles office that compliance with the action level should be based on a 12-month average of TCE in the water.

McReynolds said there was no cause to notify the public during the months when the TCE limit was topped because the situation was temporary.

“Under those conditions there was no increased risk to the public,” he said. “I think it would be a disservice to the public to notify them of something that is not a risk to them and have them believe it is a risk.”

According to DWP tests, contamination generally has been spreading to more Valley wells, apparently because decreased pumping of the most polluted wells has allowed tainted ground water to move further downgrade. DWP officials say they believe that the contaminants leaked or were dumped into the ground years ago by industries.