Today, we provided WDNR sampling results that were taken downstream from both ditches, as well as results from Green Bay.
The results for Ditch A and Green Bay are well below the recommended PFOS and PFOA surface water standards for the State of Wisconsin.
Ditch A recorded 6.9ppt for PFOA and 6.2ppt for PFOS. For Green Bay, it was 13ppt for PFOA and 4.2ppt for PFOS.
The results from Ditch B were much less favorable – 1000ppt PFOA and 72ppt for PFOS.
The drinking water of nearby residents is not affected but those results are disappointing and not acceptable to us.
This year and last have been some of the wettest on record in Wisconsin. Simply put, while the Ditch B system is filtering PFOA and PFOS as designed, these extreme conditions have been wreaking havoc by producing more water than the system can handle.
We have regularly tested the water coming into and leaving the Ditch B system. The treated water leaving the Ditch B system consistently tests at a non-detect level. The new results include both water treated by that system and water that flows past it due to these historically high flow rates.
In addition to the natural weather conditions, the system has not always operated at full capacity because issues such as increased sediment in the ditch have hindered its technical performance.
We designed the treatment system based on the observed historic flow of 450 gallons of water per minute in Ditch B. The system is built to meet not only that flow rate but a surge capacity of 600 gallons of water per minute, a 33% increase over the ditch’s historic average flow rate.
At the time Ditch B was sampled on July 28, however, the flow rate was 1700 gallons per minute—nearly four times the historical average.
Given these recent results, we immediately began to enhance the Ditch B treatment system and improve its effectiveness, by addressing the sediment increases and installing an additional water pump to draw more water from Ditch B. Several of these measures are already in place, and the rest will be soon.
And we are also committed to doing more.
Most importantly, we are accelerating our evaluation of a permanent solution, including emerging technologies that will cut the PFAS off at the source before it can get to Ditch B, going directly at the groundwater itself. We are engaging several experts in this area and we are making adjustments to our overall strategy.
We have regularly provided WDNR with full data on how the system is operating, including the rate of flow into and through the system. And, of course, we informed the agency today of the latest PFOA and PFOS results.
The Ditch B results are not acceptable to us, but we are not going to let that disappointment get in the way of finding a permanent and more effective solution. As we have demonstrated with the Menominee River restoration project and the steps we have taken at our Stanton Street facility over the last three decades, we have always shown a commitment to work to do what is right for the people of Marinette and the surrounding communities.
The current situation at Ditch B is not up to our standards as an environmental leader and we will do everything we can to resolve it quickly.