Testing Inadequate, Report Alleges : Safety: Engineering firm did not find contamination, but says monitoring of ground water near landfill is insufficient. County officials dispute the claim.

Testing is inadequate to ensure that ground drinking water supplies will not be polluted by the Puente Hills Landfill, a study commissioned by a local water agency has concluded.

The report, prepared by Stetson Engineers Inc. in West Covina for the Upper San Gabriel Valley Municipal Water District, found no evidence that the valley’s drinking water has been contaminated by the county-owned landfill.

But the engineers who prepared the report allege that ground water monitoring at the dump, and state oversight of test results, is insufficient.

County officials dispute the findings, saying they are based more on opinion than fact.

The report’s authors contend that the county is not doing enough ground water testing and that much of the testing that is done is not thorough. They also say the state Water Quality Control Board is not able to monitor the dump or even some of the county’s reports on testing because the state agency is understaffed and underfunded.

The water district is particularly concerned about testing around the site because of two instances of contamination of ground water beyond the dump’s barriers. Also, the district’s report states that there is little information available from the county on the potential for hazardous materials to seep through the bottom of the dump, which was built on fractured bedrock.

The county has been trying to prevent landfill gases from tainting nearby ground water. Over the past few years, county officials say, sampling wells placed just outside the dump’s barrier have detected unsafe levels of some cancer-causing substances in ground water. In response, the county has begun installing a system designed to capture landfill gases before they can taint nearby water wells.

Also, carcinogens have been found outside an older barrier at the dump that is suspected to have leaked. That old clay barrier is being replaced, county officials said.

Bob Berlien, general manager of the El Monte-based municipal water district, said the report was commissioned after residents expressed concern about possible ground water contamination from the landfill. He said an engineer was retained to review technical documents on the landfill that are kept by the County Sanitation Districts, which has operated the 1,365-acre landfill since 1970. The dump opened in 1957.

The water district, Berlien said, is concerned about ground water quality because the agency is charged with supplementing the San Gabriel Valley’s ground water supply with imported water from the state water project. It would be difficult, he said, for the state to provide the valley with much more imported water, so it is important to ensure the quality of the ground water supply here.

John Gulledge, assistant head of the county’s Solid Waste Management Department, said he has reviewed the district’s report and is disappointed with its findings: “We would take strong exception to everything in there.”

The county has taken adequate steps to test for ground water contamination outside the dump’s barriers, and the state Water Quality Control Board is doing a good job overseeing such testing, as well as other aspects of the landfill operation, he said.

He said the county plans to send a representative to a committee that the water district is forming to deal with concerns raised in the report.