Title
Resolution to Authorize Amendment No. 3 to the Tetra Tech Engineering Services Agreement to Sample and Test Wet Basements in High Risk Areas in Ann Arbor for 1,4 Dioxane and Appropriate Funds from the Risk Fund Fund Balance ($40,323.00) (8 Votes Required)
Memorandum
This memorandum and resolution requests authorization for Tetra Tech to conduct a sampling campaign of wet basements that are in the footprint of the Gelman dioxane plume for 1,4 dioxane (dioxane). Analysis of dioxane concentrations in groundwater in the vicinity of West Park by Tetra Tech, as well as groundwater elevation contours has identified an area where the possibility of dioxane-laden groundwater could potentially enter the basement of a home.
The city proposes to offer testing to homes within this identified boundary that have groundwater intrusion into their basements. The boundary is proposed to be the intersection of the 850' topographic contour and all properties located below this contour line and the 1 ppb dioxane plume boundary. In this area, groundwater exists 25 feet or less below the ground surface. The city will send a letter to impacted homes offering this service. Homeowners that accept this service will be asked to sign an agreement that the analytical data that is collected will be public and shared with the State of Michigan Department of Environment, Great Lakes and Energy, as well as the Washtenaw County Public Health Department. As part of this testing protocol, Tetra Tech will complete a survey of chemical products in residents' basements. This is an important part of the sampling protocol because many household products contain dioxane as a co-contaminant at high levels and it is possible that, if detected, the dioxane source may be from household products.
If dioxane is detected at an elevated level, this information would be shared with the Washtenaw County Health Department for a follow up investigation as to potential health impacts for residents at ...
Click here for full text