Substantially elevated levels of 30 to 40 times the limit of one part per million have been found in roadways and nearby yards.

The higher readings are at samples from a depth of six inches.

State Ecology and City environmental agencies say it may be necessary to remove the top 12 inches of soil from the several square block area.

"The residential standard for PCB's is one part per million," explained BJ Cummings of the Duwamish River Cleanup Coalition. "We are finding levels in the 90's. So yes, that does concern us."

South Park is not exactly a garden community. There are homes; but a half block away there's an oil recycler.

To some, Basin Oil, looked like a problem. Apparently not. The state says surveys there show no connection.

Terry Drexler of Basin Oil told KOMO 4 News, "I don't put oil on roads, haven't since the 70's."

Drexler added he wasn't in the South Park area in the 70's. In fact, the site of Basin Oil contained just a house in the 70's when the PCB problem is now believed to have developed.

At that time, the major business in the area was Duwamish Manufacturing.

"At one point they were taking thousands of gallons a month of waste oil, some of it known to contain PCB's, and using it as fuel for their boilers to keep their asphalt product heated," said Dan Cargill with the Department of Ecology.

Cargill said Ecology doesn't know if Duwamish Manufacturing was the source of the newly discovered contamination. Another possibility is road oiling which was a common practice in the area.

But, Cargill said some of the highest concentrations of PCB were found on the banks of the Duwamish on the east side of the plant. And at the street end on the west side. The actual site is a superfund clean up area, but there is no evidence linking the site to the residential contamination.

The state says it could be worse. PCB in soil is most likely to affect children who play outside.

"Only adults live in these homes and adults don't roll in dirt, play in it, or eat it," said one technician.

That's little comfort for Billy Kincaid who bought a house in the neighborhood one year ago.

"It's kind of beside the point. Adults don't roll around in dirt, well some don't," he said. "But, it's beside the point. It's in our city, it's in our yard, it's on the street."

The city agrees. It too wants the Duwamish River cleaned up.

The drainage on the streets of South Park improved.

And the homes made safe.

Work may start next week. Current plans call for removing the top 12 inches of contaminated soil.

The state has suggested residents in the area wash their hands frequently, use gloves while gardening and take off their shores before going into their homes.

Despite those warnings, health department officials say even at the worst levels of contamination found in the area it is unlikely that there would be any substantial health impact.