WATERLOO - Underground soil contamination from the former Chamberlain Manufacturing Corp. plant is too deep and too old to clean up, environmental officials say.

The contamination has spread under surrounding homes, according to samples taken by officials from the Environmental Protection Agency.

Representatives from the EPA joined city officials for a public meeting Thursday night to discuss the contamination. Stephanie Doolan, of the EPA Region 7 office in Kansas City, Kan., said officials from the agency are still testing to see how many homes are affected and whether vapor contamination has seeped into homes near the Chamberlain site at 550 Esther St.

Previous testing revealed concentrations of heavy metals and other hazardous compounds, including the carcinogen trichloroethylene, known as TCE, on the site. TCE vapor can seep from the contaminated groundwater into homes, Doolan said.

Tests show that homes to the south and west of the site had TCE vapor in the soil beneath their basement floors. Air samples were not taken from those homes. Doolan said the EPA would like to gather air samples to see if the vapor is inside some of the homes. Doolan said the agency would like to determine if the levels drop within a block or two of the site and by how much.

Some residents at the meeting said testing for the vapor isn't enough.

"They need to clean it up and get rid of it," said Terry Stevens. "This place has been contaminating the area for a long time."

Doolan said that is one of the reasons a full clean up may not be feasible. The contaminants are heavy and likely sank to the bedrock.

"What I'm seeing is, it got flushed on through," Doolan said.

The EPA is working with Chamberlain, based in Chicago, to draft an order to assist in cleanup and pay for ventilation systems in the homes affected by the contamination. An order detailing the company's obligation will likely be drafted within about 60 days, she said.

"The responsible thing to do is to get the people who profited from it to pay for it," Doolan said.

The contamination doesn't affect the drinking water provided by the city to the homes in the affected area, Doolan added. However, the groundwater samples show the metals and TCE above EPA standards for drinking and bathing.

Doolan said the levels of the vapors under the homes are too low to pose an immediate health threat, but are above established limits.

Doolan didn't say what the EPA threshold for tolerable levels are and what level concentration was found under the homes. The information was available in documents at the meeting, but some people attending the meeting said they wanted more specifics.

"I was expecting more facts," said Doyle MacMahon. "What is acceptable, what is not."

Chris Western, Waterloo brownfield coordinator, gave an update on demolition at the site. Letting for asbestos removal needed to begin before demolition will start in the early spring, he said. About three-fourths of the facility will be demolished and a few structurally sound buildings might be salvaged by the city, Western said.

Doolan said the site would best be used as a park or outdoor space.

"There aren't going to be buildings there to trap the vapors," she said.

Chamberlain closed in 1994. It was a defense contractor which prior to its closing produced Patriot missile components during the 1991 Persian Gulf War.