Wide Area Tainted by Old DDT Factory

Contamination from a shuttered Harbor Gateway chemical plant that manufactured DDT for 35 years is more widespread than earlier believed and has tainted underground water basins as well as nearby homes and businesses, the U.S. Environmental Protection Agency has reported.

Recent EPA tests found the banned pesticide and another dangerous chemical--the solvent monochlorobenzene, or MCB--in the Bellflower and Gage aquifers, which run underneath the site of the Montrose Chemical Corp. but do not supply drinking water.

In both aquifers, MCB, which can cause liver and kidney damage, was much more prevalent than DDT, a suspected carcinogen. In the Bellflower aquifer, the one closest to the surface, the tests showed MCB at concentrations of 600,000 parts per billion--10,000 times the maximum standard proposed by the EPA.

Two deeper aquifers--the Lynwood and Silverado aquifers, which do feed into the drinking water supply--have not yet been tested, although tests are planned.

The lower aquifers are separated from the upper aquifers by a natural layer of clay, which water company officials say has generally protected the drinking water supply from contamination.

Assessing the Threat

Johanna Miller, who is supervising cleanup of the site for the EPA, said officials are “confident that if it has reached a drinking water aquifer, the contamination would not have yet reached an actual drinking water well.”

The closest well is 2 miles away and has turned up no evidence of contamination, according to officials at the Dominguez Water Co., which maintains it, and the Central and West Basin Water Replenishment District, which reviews tests conducted by all the water companies in the area.

John Joham, district general manager, said he is not concerned about the EPA’s findings at the former Montrose plant.

But, he said, “we want to keep our eye on it. We’re not going to go ahead and ignore it and stick it in a file someplace and let it get dusty.”

The 13-acre Montrose site, on Normandie Avenue near the intersection of the Harbor and San Diego freeways, has been targeted for placement on the EPA’s Superfund list of the worst toxic waste sites in the nation.

The Montrose Chemical Corp. manufactured DDT there from 1947 until 1982, when an EPA investigation revealed unusually high concentrations of DDT in surface water runoff and sediments leaving the property. The plant is now closed.

Tests conducted since that time continue to reveal toxic waste both on and off the site.

“Through each phase of our investigation, we have discovered that the contamination has traveled farther than we would have expected,” Miller said.

He said EPA officials were particularly surprised to find DDT in the two upper aquifers, because DDT is not generally thought to be soluble. However, it apparently mixed with the solvent MCB, which allowed it to spread.

Dust, Soil Samples

In addition to the ground water contamination, the most recent round of EPA tests revealed significant levels of DDT in dust and soil samples taken from 23 homes and businesses near the Montrose site. The EPA report said the contamination is not serious enough to produce “any immediate health effects.”

Area residents, however, are skeptical. And they are frustrated over the long-delayed cleanup of the site, which was originally scheduled for completion in 1986 but will not begin for at least another year.