EPA strengthens dioxin cleanup goals

As promised last summer, the U.S. Environmental Protection agency has announced new, more stringent rules for cleanup of dioxin, a highly toxic byproduct of the chemical manufacturing process that has contaminated the Saginaw River watershed.

In a New Year’s Eve announcement EPA called for public comments on a plan to change the preliminary remediation goals for dioxin in residential soil from the current federal level of 1,000 parts per trillion (ppt) to 72 ppt.

The agency also recommended that dioxin remediation goals for commercial/industrial soil will be changed from 5,000-20,000 ppt to 950 ppt.

The proposed strengthened cleanup goals could go into effect in June and are considered interim levels.

EPA has also promised to complete a long-delayed dioxin health assessment by the end of 2010. This assessment is to be the agency’s scientific foundation for future decision-making about dioxins in the environment and may result in another adjustment of allowable dioxin levels.

Dioxin has spread from Dow Chemical’s Midland plant, through the Tittabawassee and Saginaw Rivers and into Lake Huron’s Saginaw Bay, and has contaminated hundreds of residential properties in the river floodplain.

Michelle Hurd Riddick of the Lone Tree Council is a longtime advocate for cleanup of Dow’s dioxin contamination.

In a phone interview she said that the strengthened cleanup guidelines are a very welcome development.

“EPA is going to use current science,” she said. “They are going to base decisions on science and what is best for public health and divest themselves from the politics of the issue.”

According to EPA:

Dioxins may cause a large number of different health effects, like cancer and reproductive effects. Dioxins are of concern because they are the result of combustion, and are absorbed from the air into the food chain where they can stay for many years.

Dioxin levels as high as 1.6 million ppt have been measured in the Saginaw River.