Kathie Marchlewski, Midland Daily News, November 11, 2006
Soil sampling to find out how much dioxin is in Midland is about half done.
Dow Chemical Co. officials said that as of Tuesday, 179 of 405 properties had been visited and their soil collected.
“This is more than enough for us to achieve the statistically valid results we hope to get,” Dow spokesman John Musser said.
The sampling is part of Dow’s efforts to resolve the local dioxin contamination problem. First on the agenda is a bioavailability study which will determine how much dioxin is absorbed into the body from soil that is ingested. Since the amount can vary based on the type of soil, Dow needs samples of the different types in Midland.
“That’s the number one reason for soil sampling in Midland,” Musser said.
The state estimates the level of dioxin absorbed. By finding real-life numbers based on real-life data, the 90 parts per trillion state standard for dioxin could potentially be readjusted for Midland. If the shift were upward because the rate of absorption was found to be lower, the dioxin problem could be resolved for large portions of Midland. Many areas have borderline dioxin levels just slightly over the 90 ppt.
The second reason for soil sampling is the testing for the levels of dioxins, furans and other chemical compounds.
Results of testing, which will be disclosed in a way that keeps individual properties from being identified and linked to their levels except in cases where the numbers exceed federal action levels, are expected after the first of the year.
Field work on the dioxin issue in the Tittabawassee River also is progressing. Crews have clocked 6,000 man hours and collected 2,600 soil samples at 600 locations along the river in the last 90 days. “That’s a task no one has completed in the history of man,” said Peter Simon of Ann Arbor-based ATS, which is conducting the study called GeoMorphing.
The goal is to first find out how the river works; what its erosion and deposition patterns are. Based on that knowledge, a plan can be developed to address the contamination without making it worse by stirring up settled but contaminated sediment.
He said that analyzing the data, a task that usually takes longer than a week, is being done in about 48 hours. “We’ve consumed most of the lab capacity on the Midwest,” Simon said.
The quick turnaround has enabled the team to move through the investigation on a near “real-time” basis, get through the field season before snow sets in, and begin developing a remedial investigation work plan for the river based on the data. That plan is expected to be submitted to the state in December.