Earlier this month we submitted an Addendum to our Response Activity Plan (RAP) for the design and installation of a remediation system intended to prevent groundwater from impacting the Rogue River at our former Tannery property in Rockford. The Addendum proposes design and system changes to the RAP that we submitted on March 31, 2022.
In April and May, after EGLE approved the RAP, we performed extraction well performance testing at the property, also known as pump testing. Those pump tests showed that our initial system plan and design, calling for 22 extraction wells on the property, likely would not function as intended and meet the performance standards for the system.
Based on these pump test results, we determined modifications to our EGLE-approved design were needed. However, designing those modifications would take time, and installing the modified system would alter the timeline from the one we proposed in our initial RAP.
Rather than proceed with installing an approved but potentially ineffective system on schedule, we discussed the results of our pump tests with EGLE and the impact those results could have on system design and timing. On September 27, we proposed making improvements to the system and committed to submitting a revised RAP to make sure the system we install is as effective as possible given the new information available to us from the pump tests.
Our RAP Addendum proposes to revise the groundwater interceptor system by utilizing groundwater collection trenches plus extraction wells. Our proposal to install over 2,000 feet of groundwater collection trenches and paired extraction wells is a larger project than initially designed, and we believe it will provide the most effective means of preventing groundwater from reaching the Rogue River.
Designing, installing, and tuning a groundwater extraction system is an iterative, complex process. We know there will need to be further adjustments along the way, but we want to do everything we can to do it well the first time. So, we have decided to proceed in phases, first by installing the trenches and extraction wells and testing them for efficacy while using a temporary treatment system. Assuming that system works as intended, we would then construct a more permanent treatment building.
These system design and schedule impacts are included in detail in the RAP Addendum, specifically on pages 22-24. Groundwater treatment will begin upon completion of Phase One of the RAP Addendum schedule, which is projected for Spring of 2024. This 8-month difference from the projected groundwater treatment date of the March 31, 2022 RAP accounts for the significant aquifer evaluation and the major design and construction changes of the interceptor system. The extensive, 2,000 linear foot trench and capture well system will be constructed expeditiously to meet a similar construction timeframe as the extraction well network. Groundwater treatment and control of PFAS will begin as soon as construction and permits allow and will continue throughout the Performance Monitoring period while the final on-Site treatment system and building are refined and completed.
Update on House Street Work Plan
On May 26, 2022, we submitted a Work Plan for the final remedy for our House Street Property. We proposed installing three separate engineered caps that will cover approximately 27 acres of the House Street property and help prevent the infiltration of PFAS into groundwater. EGLE approved our Work Plan on October 18, 2022, and we immediately got to work.
So far, we are moving ahead of schedule. We have already applied for the permits we will need clear vegetation at the property, and we expect to begin clearing as early as January 2023. We will provide bid documents to bidders by March 2, 2023, and we still expect construction of the caps to begin by Fall 2023. A detailed construction schedule will be determined as part of the contractor bidding process, but the overall project is still expected to take at least three years to complete. We have notified neighbors near the property about the project schedule and will continue to provide regular updates as work progresses and before significant site activities.
We will continue keeping the community informed 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.