KATHIE MARCHLEWSKI, MIDLAND DAILY NEWS, OCTOBER 24, 2006
With permission from property owners, The Dow Chemical Co. Monday began testing Midland soils for dioxin levels. And Midland City Council on Monday gave the go-ahead to have city-owned parcels added to the list of to-be-tested properties.
As part of Dow’s agreement with the state that it would find the nature and extent of contamination in Midland, the company requested that 14 city properties be included. The areas are on Orchard Drive, Grove Street, Carpenter Street, Lyon Road, Nelson Street, East Patrick Road, West St. Andrews Road, Iowa Street, Kent Court, Cronkright Street and State Street.
City Utilities Director Noel Bush said parcels and their owners — 571 including the City of Midland have been contacted — were randomly chosen. Dow and the Michigan Department of Environmental Quality mapped out the city and chose the areas that might be contaminated, based in part on wind direction from the plant. Testing generally will take place to the north and northeast of the Dow plant, out as far as Wheeler Road.
The city and participating residents have been assured that results of specific properties will be kept confidential unless levels exceed 1,000 parts per trillion of dioxin, the federal action level.
“I’m not believing that’s going to happen,” Bush said.
Midland’s historical dioxin contamination is the result of airborne particles that settled into the top layer of soil. Unlike the higher levels found in the Tittabawassee River flood plain and Saginaw River — there levels measure into the thousands and in some cases tens of thousands of parts per trillion — levels in Midland are much lower, most hovering around the 90 ppt level the state considers acceptable for residential contact.
To achieve confidentiality, several properties are being grouped into blocks and samples are not being linked to those properties. Results will come from one block of several parcels, but not from any one specific parcel.
“You won’t be able to get each property’s results, only the station’s results,” Bush said.
Soil will be collected by hand from several locations on each parcel with little disruption to the yard and within about an hour.
The goal is to collect soil that will be used in a bioavailability study. Dow plans to conduct the study in order to determine, based on the variety of soil types, how much dioxin is absorbed into the body when soil is ingested. Dow also plans to analyze samples for other potential contaminants. The plan is a multiphase one and a requirement of Dow’s state-issued operating license.
In the past, the City of Midland expressed concern on behalf of its residents that soil sampling could have a negative impact on property values and sales. To protect targeted properties from negative stigma, the City had argued that testing should not be done until the state and Dow agreed on a level at which cleanup or other remedial action would be taken.
To come up with that level, however, Dow officials say it is important to conduct the bioavailability study. The state cleanup level for dioxin in residential areas is 90 parts per trillion. Some areas of Midland are not much higher, averaging 150 to 200 parts per trillion. If the bioavailability study shows that dioxin is not absorbed into the body at as high a rate the state assumes in setting the 90 ppt standard, that standard could be edged up, removing portions of Midland from the list of potential areas of concern.