Water Quality Trading Case Studies
EPA has updated five case studies originally developed for the Water Quality Trading Toolkit for Permit Writers. Each updated case study describes background information on the drivers and approach for developing the program, key trading program elements, and benefits and challenges of implementing the program. See the updated case studies below to learn how states are implementing water quality trading approaches to reduce pollutant discharges and improve water quality.
- Rahr Malting Company Permit, Minnesota (pdf) – Describes the water quality trading program implemented through the NPDES permit for Rahr Malting Company in Shakopee, Minnesota. The permit authorizes point source—nonpoint source trades to offset pollutant loading from the company’s new wastewater treatment plant to the Minnesota River because the applicable total maximum daily load (TMDL) did not include reserve capacity for new discharges.
- Wisconsin’s Statewide Water Quality Trading Program (pdf) – Provides an overview of Wisconsin’s statewide water quality trading program. The Wisconsin state legislature established the legal framework for trading in 2011 and the Wisconsin Department of Natural Resources has issued guidance defining protocols for establishing trading provisions. Wisconsin’s program allows both point source—point source and point source—nonpoint source trading.
- Nutrient Credit Exchange Program, Chesapeake Bay, Virginia (pdf) - Summarizes water quality trading facilitated through the Virginia Nutrient Credit Trading Exchange Program. Permittees covered under Virginia’s general permit for total nitrogen and total phosphorus discharges to the Chesapeake Bay may comply with applicable effluent limits through water quality trading facilitated by the Virginia Nutrient Credit Exchange Association.
- Grassland Area Farmers Tradable Loads Program in the Lower San Joaquin River, California (pdf) - Describes a water quality trading program among seven irrigation and drainage districts in the Central Valley of California. An order from the California Regional Water Quality Control Board Central Valley Region regulates the discharge of selenium by applying individual selenium load allocations to each of the seven districts as well as a collective regional cap on selenium loads. To meet the regional cap the seven districts participate in nonpoint source-nonpoint source trading. If the regional cap is exceeded the districts must pay a tiered “incentive fee” based on the percent exceedance. Exceeding the regional cap by more than 20 percent will lead to termination of the agreement.
- Southern Minnesota Beet Sugar Cooperative Permit, Minnesota (pdf) - Describes the water quality trading program implemented through the NPDES permit for the Southern Minnesota Beet Sugar Cooperative. The permit authorizes point source—nonpoint source trades to fully offset phosphorus loading from the Cooperative’s new wastewater treatment plant to prevent further reductions in dissolved oxygen in the Minnesota River because the applicable total maximum daily load (TMDL) did not include reserve capacity for new discharges.
In addition to the case studies above, Chapter 3 of the Compendium of State and Regional NPDES Nutrient Permitting Approaches (pdf) includes information on Water Quality Trading programs across the US. These examples include information on the geographic scope, types of trades allowed, key drivers, trading ratios, pollutants being traded, and other highlights of the programs. State trading programs found in Chapter 3 of the compendium include; California, Colorado, Connecticut, Florida, Idaho, Louisiana, Maryland, Minnesota, Montana, Ohio, Oregon, Pennsylvania, Virginia, Washington, and Wisconsin.