February 23, 2004

On Friday, February 20, the Department of Environmental Quality sent owners of residential property located within and along the Tittabawassee River floodplain the preliminary dioxin concentration results identified in soil samples collected from their property. These preliminary results are consistent with the results of prior floodplain soil samples, collected by the DEQ since December of 2000. It was found that soil located within portions of property downstream of Midland that is or has been subjected to frequent flooding by the Tittabawassee River is contaminated with elevated concentrations of dioxin.

During the spring, summer, and autum of 2003 as a part of its continuing effort to understand the extent of dioxin contamination along the Tittabawassee River floodplain the DEQ sampled residential properties located within and along the Tittabawassee River floodplain downstream of Midland. The preliminary sample results indicated the following:

• Portions of property subjected to frequent flooding by the Tittabawassee River contain elevated concentrations of dioxin. Concentrations ranging as high as 5,660 parts per trillion (ppt) of dioxin toxic equivalence (TEQ) were identified within frequently flooded portions of property. The DEQ has currently established that dioxin concentrations below 90 ppt TEQ in soil are acceptable for human direct contact for residential property.

• Portions of property located outside of the floodplain, or those portions of property located within the floodplain that are not subjected to frequent flooding because of filling activities or local topographic features, do not contain elevated dioxin concentrations.

• Portions of property that are not subject to flooding, but have received soil fill material collected from frequently flooded areas within the Tittabawassee River floodplain, contained elevated dioxin concentrations.

The DEQ is continuing with its evaluation of the data and will work to keep property owners informed of any additional findings. In addition, the DEQ is sharing this information with the Department of Community Health to assist the DCH in its ongoing efforts to evaluate human health concerns related to Tittabawassee River floodplain dioxin contamination. The residential soil data will also be placed on the DEQ webpage at www.michigan.gov/tittabawassee.

The preliminary residential soil data continues to emphasize the importance for owners of Tittabawassee River floodplain property to follow guidance previously provided by the DEQ, the DCH, and the Department of Agriculture, related to limiting contact with dioxin contaminated soil, gardening within dioxin contaminated areas, and moving or otherwise disturbing dioxin contaminated soil. These advisories continue to be available on the DEQ webpage or from the DEQ Saginaw Bay District Office, 503 N. Euclid, Bay City, Michigan; or by calling Sue Kaelber-Matlock, DEQ Remediation and Redevelopment Division, at 989-686-8025, ext. 8303.

Editor’s note: DEQ news releases are available on the department’s Internet home page at www.michigan.gov/deq.

Revised February 23, 2004 by Pat Watson