Tests Show Rise in Toxic Levels at Old Plant Site : Ground water: Despite jump in contaminants, official says there is no threat to Thousand Oaks drinking supplies.

Eight years after waste ponds were closed, ground-water tests at the site of a former aircraft component manufacturer in Newbury Park show an increase in two toxic substances, according to a report released by state health officials.

Samples taken in November from wells on the 18-acre Talley Corp. site at 3303 Old Conejo Road show a jump in the levels of trichloroethylene (TCE) and chromium, according to the state Department of Health Services report.

The wells “have shown quantifiable increases of contaminants,” the report said.

Levels of TCE, a known cancer-causing substance used in industrial solvents, increased in 13 of 24 wells during a three-month period that ended in November. Concentrations of chromium, which is toxic but not a known carcinogen, increased in 18 wells.

One well showed TCE levels of up to 10,000 parts per billion, 2,000 times higher than allowed in drinking water. Chromium levels of up to 1,000 parts per billion were also found, about 50 times above the permitted level.

Jose Kou, a senior waste management engineer with the state Toxic Substances Control Program, said officials plan to monitor the wells to determine if the contamination continues to increase.

e contaminated ground water does not yet threaten drinking supplies in Thousand Oaks, Kou said. Surrounding wells once used for drinking have been closed, but the company “has to clean the water to a level that if someone did drink it, they wouldn’t get sick,” he said.

Located south of the Ventura Freeway, the property contains toxic wastes left by a manufacturing plant that operated for nearly four decades.

Officials with the state agency and the federal Environmental Protection Agency ordered the cleanup because of the potential hazards to nearby residences and businesses and a school bordering the property.

An official with Oxnard-based Teleflex Inc., which now owns the Talley property, said he had not seen the report and could not comment.

In the report, however, Teleflex blamed the increase on a faulty treatment system that “was not consistently operational between August and November.” The report recommended that Teleflex investigate the efficiency of the treatment plant.

Pumps at the southeast corner of the property extract water from the ground, then run it through a filter to purge toxic wastes. After it is filtered to levels considered safe for drinking, the water is discharged into storm drains.

Kou said pump failures might have caused the treatment plant to shut down temporarily, causing the waste to accumulate. The pumping equipment broke down occasionally when it was installed two years ago, he said. The treatment plant is monitored daily for breakdowns.

Henry Chui, a waste management engineer for the state overseeing the cleanup, said ground water within a half-mile of the property is contaminated. The underground waste is moving southeast, but at a slow pace.

“It’s pretty much contained,” he said. “It isn’t spreading now.”

Lack of rain during the five-year drought has helped keep toxic wastes from seeping into a wider area around the plant, Kou said. But rains might speed the movement of wastes in the ground water, he said.

In addition to concerns about the ground water, the state has been careful to remove contaminated soil, excavating about 3,200 cubic yards over the past seven years.

A large pile of dirt remains covered with plastic to keep dust from blowing onto nearby residences and businesses. There have been no reports of cancer from residents living near the site, officials said.

Talley operated the plant from 1950 until it closed in 1989. Two outdoor ponds held waste water used in metal-cleaning and plating operations.

The company stopped using the ponds after 1983, when officials with the Regional Water Quality Control Board discovered that cracks in the pond walls had allowed chemicals to seep into the ground and water.

Talley was ordered to pay $100,000 in punitive damages to regulatory agencies and to finance the costs of the cleanup.

In May, 1986, Teleflex acquired the business and property and three years later moved the facility to Oxnard. The plant manufactures civilian and military aircraft components.