Trading away pollution

Wastewater managers in southwest Ohio use water quality trading to reduce nutrient levels in local waterways.

A primer on the EPA's Water Quality Trading PolicyAlthough water quality trading programs have been conducted in a handful of states since the 1990s, interest spiked after the EPA released its Water Quality Trading Policy in 2003.

Intended as a guideline for states to develop voluntary trading programs, the policy sets forth recommendations for establishing a framework to facilitate the development of pollution credits and the means by which such credits can be traded among point sources, or among point sources and nonpoint sources.

The programs can involve nutrients and sediment, as well as cross-pollutant trading of oxygen-demanding pollutants. Although other pollutants may be considered for trading, they would require additional scrutiny, according to the EPA.

While trading programs can involve waterways that have been designated as 'impaired' for failing to meet water quality standards as well as waterways that meet such standards, trades must occur within the same watershed. And participating wastewater treatment plants must continue to meet existing technology-based limits specified in their discharge permits.

Seven states-Colorado, Idaho, Michigan, Ohio, Oregon, Pennsylvania, and Vermont-have established statewide trading frameworks. Three more-Florida, Maryland, and Minnesota-are in the process of implementing such frameworks. Meanwhile, Connecticut, Delaware, and Virginia have established trading programs for specific watersheds, and trading programs have been conducted in another 10 states that don't have trading frameworks.