The 1,4 dioxane plume emanating from the old Gelman Sciences Facility on Wagner Road in Scio Township has caused environmental damage and remains a threat to public health. In this week's "Issues of the Environment," WEMU's David Fair has a conversation with Roger Rayle, who is both chair of the Coalition for Action on Remediation of Dioxane (CARD) and Scio Residents for Safe Water (SRSW), about the ongoing efforts to remediate the dioxane plume.
- A public meeting was held in October 2019 to explain a new 3-D model created by a consultant to the city of Ann Arbor to better model where the Gelman dioxane plume is actively monitored, how that relates to concentration, and extrapolate where more monitoring ought to occur. A CTN recording of the entire meeting can be viewed here.
- The work is done in six phases:
- Data collection (July) - collation of dioxane monitoring wells data from existing contamination data, including well logs and dioxane test results from the Michigan Department of Environment, Great Lakes, and Energy, Washtenaw County Health Department, Coalition for Action on Remediation of Dioxane and polluter Gelman Sciences)
- 3-D monitoring (August) - a 3-dimensional model of the underground topography, monitoring well sites, and concentration/migration of dioxane integrated the data
- Independent review (September) - results and model were reviewed by Central Michigan University Professor Larry Lemke, who has spent over 20 years studying and modeling the plume. (Based on CARD’s knowledge of Lemke’s work, once dioxane crosses the M-14 boundary it is expected to progress rapidly toward Barton Pond.)
- Sample collection (July-September) - unfortunately, “the responsible party” would not allow the further well monitoring/sampling that would strengthen the accuracy of the model. Gelman would not allow testing to occur at a detection level below what they are required to test for (1 ppb). It would have been helpful to have data below this level (0.07ppb) to show where areas that currently are non-detect, might be seeing very low levels thus far, showing where water is flowing directionally and the rate of flow. (This testing would better show how fast concentrations go from minimal to concerning in different types of topography.)
- Well location (December) - water heads to the north and turns to the east underground, there is a lot of missing data to the north and few monitoring wells in this region. More wells would help delineate where water flows and turns. For now, it appears that more wells might be warranted in the northern section of the plume, toward the Maple/Miller region.
- Public engagement (July - December)
New monitoring wells informed by the model data would be expected to installed in 2021-2022. The estimated cost is $400,000.
Gelman currently is required to pump and treat dioxane to levels consistent with legal limits, but they are not required to remove it entirely. Just a few parts per billion in drinking water, with long-term exposure, poses a 1 in 100,000 cancer risk, according to the EPA. According to the Washtenaw County Public Health Department, water with levels below 7.2 ppb are considered safe to consume and use daily activities. Dioxane is classified by the EPA as likely to be carcinogenic to humans by all routes of exposure. It also can cause kidney and liver damage, and respiratory problems.
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