Last week we submitted to EGLE a revised Response Activity Plan seeking approval to install a substantially larger and more robust groundwater interceptor system at our former tannery property than the system that EGLE originally approved last year. This system is designed to intercept groundwater and prevent it from flowing into the Rogue River and Rum Creek. You can review our submission at this link , and we understand that EGLE will be accepting public comment in the near future.
Our revised plan submitted last week builds off the original plan that EGLE approved last year. During initial fieldwork to implement the original plan last summer, however, we found that due to previously unknown conditions the system would not likely intercept as much groundwater as intended. So, on December 1, 2022, we sought EGLE’s approval to revise the original plan and install a substantially larger, more robust groundwater interceptor system.
On March 10, 2023, EGLE denied our request to revise and expand the groundwater interceptor system. EGLE did not express concerns about our overall proposal to expand our system, but they asked us to provide more detail about it.
We began assembling that information immediately, and also reached out to EGLE to set up a series of technical meetings. We then met with EGLE many times to discuss and understand their comments, so that we could be as responsive as possible with our revised submission that we provided to EGLE last week.
The plan EGLE originally approved called for the installation of 22 extraction wells to capture groundwater migrating to surface water at the Tannery. If we receive approval for our proposed expansion, the revised and expanded system we will use both extraction wells plus 2,000 feet of trenches. That combination is roughly equivalent to installing a network of approximately 2,000 wells along the entire length of the property. These wells and trenches will capture groundwater from the property and stop it from flowing into Rum Creek or the Rogue River. We have confidence in this proposal and are not aware of any technology with a better chance of success in the circumstances.
Determining where to place the components of a system like this on the property is a complex and delicate balance. The wells and trenches must be located in such a way as to stop groundwater from flowing to surface water, but at the same time prevent too much river water from being captured and drawn into the system. To achieve that balance, the locations for the 2,000 feet of trenches were identified based on aquifer testing and modeling on the north and south sides of Rum Creek over a period of years. The trenches are intentionally and strategically located to capture groundwater without pulling excessive surface water from Rum Creek or the Rogue River.
Because the primary purpose of the system is to prevent the flow of groundwater from the property into the Rogue River and Rum Creek, we will measure and demonstrate effectiveness by measuring groundwater elevations. These readings, taken both on the property and in the surface waters, will confirm that groundwater is not entering Rum Creek or the Rogue River. If performance monitoring indicates that all or part of the system is either drawing too much water from the river or creek, or not controlling groundwater to a level below observed surface water elevations, then operational modifications will be carried out as appropriate.
Just like last year’s EGLE-approved plan, our revised and expanded plan also provides for collecting groundwater samples and analyzing them for PFAS. We will evaluate that data and propose any adjustments to the system or monitoring frequency that are warranted by the findings. But, as with last year’s EGLE-approved plan, this data will supplement the groundwater elevation readings mentioned above, and will not be how we will know the system is working.
We have already begun designing our proposed collection and temporary treatment systems, and we are ready to proceed further as soon as EGLE review, approval, and permitting allows. Under the schedule in this week’s submission on page 64 , we will begin field work within sixty days of EGLE approval and will proceed in three phases.
After completion of final design work and receipt of all necessary permits, phase one will commence with construction of the trenches, offsite disposal of excavated soil, backfill of granular material, installation of six extraction wells, placement of pumps in each trench and extraction well, and routing of electrical conduit and piping.
Phase two consists of starting the groundwater interceptor system. To allow capture of groundwater as soon as possible, phase two will use a temporary, modular treatment system while the permanent treatment system design and operation is optimized and finalized. Upon completion of phase one, phase two will begin as soon as regulatory approvals allow.
Phase three consists of design and construction of the permanent treatment system and transition from the temporary treatment system. The final schedule is dependent on regulatory approvals and contractor bids, but we currently expect permanent treatment system operation within approximately three years from EGLE approval of yesterday’s Response Activity Plan.
We will continue keeping the community informed about progress on our remediation plan and other matters through updates on this blog, www.WeAreWolverine.com, and through information posted at kiosks and in other locations accessible to the public. As always, residents with questions or feedback are encouraged to contact Wolverine Worldwide directly at HouseStreet@wwwinc.com or (616) 866-5627.