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The Chesapeake Bay is arguable the United States' premier estuary, providing billions of dollars in economic benefits to the mid-Atlantic, unlimited recreational opportunities, and incalculable environmental values. But, consistent with its location, the Bay has substantial nutrient problems.

Since the 1980's, the states most affected and the District of Columbia have worked to address the excessive influx of nitrogen, phosphorous, and sediment to the Bay. Although these efforts have been successful, substantial problems remain, particularly dissolved oxygen (DO) depletion in portions of the Bay and tributaries. In 1998–99, the Environmental Protection Agency (EPA) overlisted the Virginia portions of the Bay under Clean Water Act section 303(d) for nutrient overenrichment, effectively superimposing a regulatory framework to the states' voluntary and programmatic efforts. Virginia currently schedules the completion of Total Maximum Daily Load development for the Bay for late in this decade, or the early 2010's. Because of the size of the problem (currently 285 million pounds per year total nitrogen (TN) Bay inputs, and the diverse sources of nutrients and sediment, Chesapeake Bay TMDL development and implementation will require unprecedented efforts and resources.

Accordingly, the states are utilizing all available resources to reduce Bay loadings in an ongoing, partly voluntary, TMDL-like process. The states and EPA have committed to delisting by 2010 prior to the development of a formal TMDL. Even if unsuccessful in formally delisting, the current process will make a Bay TMDL manageable in terms of size, science, policy choices, and the other challenges.

A critical part of this TMDL process is nutrient trading. We have developed on behalf of Virginia clients a point source/nonpoint source nutrient trading program to bring about timely nutrient reductions from all significant point sources in a systematic, fair, and economical manner. We proposed to the General Assembly in January a Chesapeake Bay VPDES (Virginia Pollutant Discharge Elimination System) Permit and Nutrient Credit Exchange Program involving a statewide General Permit, functioning as a nutrient “bubble” throughout the state. We envisioned the General Permit to impose for each affected municipal and industrial discharger integrated water quality-based/technologybased TN and total phosphorus (TP) wasteload allocations. But, the statewide “bubble” concept provides for both point source and nonpoint source trading to allow the affected point sources to comply in the most expeditious and cost effective manner.

Given the complexity of the Chesapeake Bay nutrients problem and the complexity of the ecosystem, trading will not be simple. Rather, the value of TN and TP reductions must be normalized to account for reductions prior to the points of impact, primarily the Bay deep channels.

The benefits of the Chesapeake Bay VPDES Permit and Nutrient Credit Exchange Program will be that dischargers will be able to optimize costs in what is expected to approach a 10 billion statewide nutrient reduction program, trading will support a more practical implementation schedule for the numerous remaining biological nutrient removal and other wastewater treatment projects, dischargers will be able to effectively bank TN and TP credits for future expansion and possible new discharges, and there will be substantial earlier results providing measurable positive effects.

Document Type: Research Article


Publication date: January 1, 2005

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