In early March 2018, Tyco submitted a Site Investigation Work Plan to the DNR which provided detailed plans for additional investigation of groundwater, soil, ditches and surface water. Tyco also submitted a Long-Term Potable Well Sampling Plan with a schedule for additional sampling of drinking water wells. The DNR provided comments on those plans, and updated documents were prepared in response to those comments. The DNR recently approved the updated documents. These documents, along with additional information regarding use of PFAS at the Site, have been posted on the DNR BRRTS on the Web website which can be found at http://dnr.wi.gov/botw under activity number 0238580694.
Tyco is also evaluating long-term options to address PFOA and PFOS in drinking water wells.
Tyco has started preparations for implementing the activities under the Site Investigation Work Plan, and will conduct the next phase of investigation and monitoring work beginning in Spring 2018. As new data is obtained, it will be used to determine if additional investigation work is necessary. This is consistent with the data-driven, step-wise approach Tyco has been taking to develop the most appropriate measures to address PFAS in the environment.
As part of the activities under the Long-Term Potable Well Sampling Plan, drinking water wells where PFOA and/or PFOS were detected will be sampled quarterly to understand seasonal variations in groundwater. In late March 2018, Tyco again contacted all of the drinking water well owners/users within the sampling area to collect additional Spring 2018 samples from each well and that sampling is underway.
For wells that were sampled previously, and where PFOA and PFOS were not detected, an additional sample will be collected in Spring 2018 to confirm the absence of PFOA and PFOS. The potential need for additional sampling of drinking water wells with non-detect results will be assessed after review of the Spring 2018 sampling results.