State Orders Cleanup of Former Landfill : Environment: Officials say the leakage of toxic chemicals into ground water at the Simi Valley site poses no immediate risk to the public.

The state has ordered the cleanup of a former landfill site in Simi Valley after a recent inspection uncovered high levels of toxic chemicals leaking into ground water beneath the property, officials said Tuesday.

State and county officials who conducted a joint inspection of the old Tierra Rejada Landfill site last month said the leaks pose no immediate health risk to the public.

But after the inspection, the California Regional Water Quality Control Board ordered that the 65-acre site north of Lleverancho Road be cleaned up because there is a potential for health and safety problems arising from the chemical leaks and from methane gas seeping out from cracks in the soil.

And despite the reassurances that there is no imminent health hazard, Simi Valley officials said they are unconvinced and will conduct their own examination of the site, which served as a county landfill from 1962 to 1972.

“We need to know all the facts,” Simi Valley City Councilman Glen McAdoo said. “There’s a potential for a major problem. Our responsibility is to make sure that anyone who may live in the area is not in danger from this.”

The property is now owned by the Rancho Simi Recreation and Park District, whose officials said they hope to develop it into a park someday.

The area surrounding the site is not heavily populated, but a small subdivision of houses begins between 500 and 1,000 feet from the edge of the old landfill site.

In addition to the park district, three other agencies were named in the state’s order as responsible for cleaning the site: the Simi Valley-Ventura County Sanitation District, the county Department of Public Works and the Ventura County Regional Sanitation District.

The state has required the agencies to submit a cleanup plan by July 15 or pay a joint fine of up to $5,000 a day, officials said.

Terrence Gilday, a manager with the county Environmental Services Department, said it could cost from $5 million to $10 million to clean up the site.

A meeting of representatives from the four agencies to discuss which should foot the bill is scheduled for Friday, said Kay Martin, director of the county Solid Waste Management Department, which governs the two sanitation districts named in the state order.

But Martin said there is a “very strong possibility” that the issue of who pays for the cleanup will wind up in court.

Richard Harrison, director of operations and maintenance for the park district, declined to comment until after Friday’s meeting. The district develops parkland across eastern Ventura County from Simi Valley to Oak Park.

McAdoo said the county should pick up most of the cleanup cost because it operated the landfill.

“It’s clearly their responsibility,” he said.

During the inspection of the old dump site, amounts of vinyl chloride and tetrachloroethylene in excess of state water-protection standards were found in the ground water underneath the property. Vinyl chloride is a liquid coolant used in making plastics and tetrachloroethylene is used as a solvent in removing grease from metals.

Low levels of methane gas, a common product of decomposing trash, also were found seeping from small cracks in the topsoil covering the landfill.

Gilday of Environmental Services said no one living near the site is being exposed to the chemical and gas leaks. He said the ground water underneath the old dump is not used for drinking.

“There is no serious health risk at this time,” Gilday said. “If the appropriate measures are taken to secure the site, there never will be. If not, serious problems could arise.”

Gilday said there are concerns that portions of the landfill that have shifted over the years could slide into the Arroyo Simi flood control channel. He said low levels of toxic chemicals, identical to those underneath the dump site, have been discovered downstream.

“These are not hazardous concentrations,” he said.

However, Blythe Ponek-Bacharowski, a geologist with the state Water Quality Control Board, said toxic chemicals that end up in the Arroyo Simi could eventually pose a hazard to wildlife along the channel.

She said it is also possible that chemicals in the channel could seep into ground-water supplies located away from the site that people use for drinking.