The Heart of the Valley Metropolitan Sewerage District’s Waters Quality Trading Plan has received conditional approval from the Wisconsin Department of Natural Resources (WDNR).
Heart of the Valley (HOV) will utilize water quality trading to comply with the effluent limitations for total suspended solids (TSS) for their discharge to the Lower Fox River.
After learning Water Quality Trading could decrease compliance costs and have a positive benefit to the Fox River, HOV decided to choose Water Quality Trading as their compliance option for TSS. The Water Quality Trading Plan prepared for HOV by the Fox-Wolf Watershed Alliance (FWWA) details how the installation of one sediment basin collecting drainage from a total of 20.7 acres and the installation of permanent vegetative cover on 3.6 acres will generate between 1,517 – 3,157 pounds of total suspended solids credit per year for the next five (5) years. HOV anticipates needing to use less than 500 credits per year but feels good about the level of insurance this trade provides.
HOV contracted with Outagamie County in 2016 to design and install the credit generating practices. The practices, while generating between 1,517 – 3,157 credits annually, actually capture between 2,296 and 17,191 pounds of TSS from entering the water! The amount of credits generated is calculated based on modeled pounds reduced by the practice, applying the trade ratio and a TSS delivery factor. Following the water quality trading guidance from WDNR, credits are only calculated for the practices in years when the TSS reductions allow for the TMDL credit generating threshold to be met.
What happens next?
- WDNR will further review the information provided by HOV to assess whether any additional modifications in the WQT Plan are required prior to the reissuance of HOV’s WPDES permit.
- HOV will conduct monthly inspections to ensure practices are functioning as intended. HOV will hire an independent certifier annual to inspect the practices.
- HOV will analyze the practices installed for their potential to generate phosphorus credits.
- HOV will update the WQT Plan to include phosphorus credits that can be used to meet future phosphorus requirements and update the plan to include any long term TSS credits generated by the installed practices prior to permit expiration.
More information about Heart of the Valley Metropolitan Sewerage District’s treatment facility and their decision to use Water Quality Trading as their compliance option to meet an increased TSS requirement as well as an overview of Water Quality Trading in a TMDL watershed can be found in a presentation Brian and Jessica gave at the 2018 Fox-Wolf Watershed Alliance’s Watershed Conference in March.
Questions about this article or Water Quality Trading can be directed to Jessica Schultz, jessica@fwwa.org
