We want to provide some additional information about our plan to install a remediation system to prevent groundwater from impacting the Rogue River at our former Tannery property in Rockford. Our initial plan was approved by EGLE on March 31, 2022, but after fieldwork indicated that it would not be as effective as intended we sought approval from EGLE in December 2022 to implement a substantially larger, more robust, and more effective system. Unfortunately, EGLE denied our proposed expansion last week. We would like to provide further background on our proposal, our next steps, and the delay that will result from EGLE’s decision.
Our Remediation Plan
Our initial, EGLE-approved tannery remediation plan was submitted on March 31, 2022, and called for installing 22 extraction wells intended to capture groundwater before it migrated to surface waters. We then performed additional pump testing, which indicated that due to previously unknown underground site conditions, our initial design would not be as effective as intended and would allow some groundwater to continue impacting Rogue River.
Rather than proceed with installing an approved but potentially underperforming system, we notified EGLE and proposed expanding and improving the system to make it substantially larger, more robust, and more effective. We submitted this proposal on time on December 1, 2022, and the key features are:
- Rather than rely solely on groundwater extraction wells as in the initial plan, we proposed pairing extraction wells with over 2,000 feet of groundwater collection trenches (similar to French drains).
- There would be a sump and pump at each of the trench runs to pump groundwater from the trenches to the treatment system.
- There would also be additional extraction wells to pump deeper groundwater, and several shallow wells to contain groundwater at the south end of the property.
- The initial plan with 22 extraction wells included 100 feet-spacing between wells. The proposed expansion using extraction wells plus trenches, however, is much more effective and essentially equivalent to installing extraction wells at a spacing of 1-foot, continuously along the entire property.
- The use of wells plus trenches would achieve a much more uniform collection of groundwater, while actively inducing an inward hydraulic gradient, dictated by the control of the pump rates. As a result, our anticipated groundwater collection volumes are nearly double what was expected with the initial plan that contained extraction wells alone.
Impacts of EGLE Decision
We are disappointed that EGLE denied our proposal to install a much larger remediation system that will be more effective at preventing groundwater from impacting the Rogue River. EGLE did not express concerns about our plan to pair extraction wells and trenches to increase system performance, but asked that we submit more information and details about it.
We have already begun to assemble this information and look forward to working with EGLE to obtain quick approval of our expanded system. EGLE’s denial will unfortunately result in a delay in preventing groundwater from reaching the Rogue River, but we are committed to implementing our expanded system and are moving forward with design and permit applications so we can begin construction as soon as regulatory approvals allow.
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.