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 that property and recommendations for further action.
If Council authorizes moving forward with this project, staff will host a public meeting within 60 days of the approved resolution, to which all potentially impacted homeowners will be invited to attend. Staff will present the scope of the project, describe the waiver and release of data agreement that all participating homeowners will be asked to sign, and answer any questions that prospective participants may have.
There are approximately 85 properties located in the high-risk area and it is assumed that 50% of these properties will elect to have their basement’s tested. The total cost for the sample collection, site survey, and analytical testing is estimated to be $812.00 per property for a total estimated cost of $40,323.00. This cost includes administrative costs for the consultant to oversee the sampling effort and provide a report of results to each property tested as well as a final report for the city. The estimate also assumes that the consultant is able to sample four properties on a given day. This provides an economy of scale that reduces the cost per sample by over 50 percent.
Budget/Fiscal Impact: Funds for this project are available from the Risk Fund fund balance to be appropriated to the Water Treatment Services General Fund Budget.
Tetra Tech complies with the City’s Living Wage and Non-Discrimination Ordinances.
Staff
Prepared by: Brian Steglitz, Manager, Water Treatment Services
Reviewed by: Craig Hupy, Public Services Area Administrator
Approved by: Tom Crawford, Interim City Administrator
Sponsored by: Councilmembers Ramlawi and Smith
Body
Whereas, Tetra Tech has an existing Professional Services Agreement with the city to provide hydrogeological consulting services;
Whereas, Council has requested that staff provide an approach to test groundwater that has infiltrated basements in Ann Arbor for dioxane in areas where the dioxane plume is at a high enough elevation that it could enter building structures; and
Whereas, Tetra Tech complies with the City’s Living Wage and Non-Discrimination Ordinances;
RESOLVED, That Amendment No. 3 to the Professional Services Agreement with Tetra Tech of Michigan, PC for Engineering Services for the Water Treatment Services Unit in the amount of $40,323.00 for the 1,4 dioxane sampling program outlined in their January 15, 2020 Scope of Work is approved;
RESOLVED, That $40,323.00 be appropriated from the Risk Fund fund balance to Water Treatment Services budget within the General Fund to test groundwater infiltration in basements in the identified high risk area for dioxane;
RESOLVED, That funding be available without regard to fiscal year;
RESOLVED, That the Mayor and City Clerk are authorized and directed to execute Amendment No. 3 after approval as to substance by the City Administrator and approval as to form by the City Attorney; and
RESOLVED, That the City Administrator be authorized to take the necessary administrative actions to implement this resolution.