Water Quality Trading Case Studies
EPA has updated three 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.
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.