Louisiana state officials are investigating whether a Dow Chemical Co. vinyl chloride monomer plant in Plaquemine, La., is leaking the chemical into nearby ground-water systems at five times the level allowed by federal safe drinking water laws.
Tainted wells were found in a trailer park of about 100 homes two miles from the Dow plant, but state officials said they are not sure if the chemical came from the Dow factory. Dow and the state are drilling more wells closer to the Dow factory and testing them.
An official with the Louisiana Environmental Action Network, a coalition of environmental groups based in Baton Rouge, said evidence points to a Dow leak. The tainted wells are in a rough line pointing to Dow and the higher concentrations are found closer to the Dow plant, said Wilma Subra, president of Subra Co. in New Iberia, La., and a technical consultant to LEAN.
Bob Johannessen, spokesman for Louisiana's Department of Health and Hospitals, said, ``I don't think any of the agencies are ready to make that interpretation yet, but yes, the well that is nearest the facility had the highest level.''
State officials also are investigating why, after similar test results in 1997 and 1998, its officials apparently did not notify the community, as required, Johannessen said. The state can find no record that it told the trailer park owner or residents, he said.
Federal law allows two parts per billion of VCM, a building block of PVC, in drinking water. The tests this year showed 8-11 ppb, while 1998 results showed 11-13 ppb, and 1997 results were 4-6 ppb. The well closest to Dow had 42 ppb; it is used as the water source for a heat pump, state officials said.
Both Subra and Johannessen said they are not sure what health effects people can have from exposure at the levels in the wells. Johannessen said the health-effect studies that have been done have focused on occupational exposure at levels in the thousands of parts per billion.
Once the residents were alerted, they were connected to a local municipal water system two days later, Subra said.
The Department of Environmental Quality, which is investigating the contamination, is not sure if the Dow plant is the source because the plume of VCM runs in a different direction than the underground water typically would flow, said Tim Knight, administrator of DEQ's environmental technology division.
Dow spokeswoman Donna Carville said the company is not the source because VCM never has been detected in Dow's on-site monitoring wells. She said chlorinated solvents used in things like dry cleaning can break down into VCM.