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Water Quality Trading

Water Quality Trading Feasibility Study

An important element of the USEPA Targeted Watersheds Grant for the Bear River Watershed was to explore the feasibility of water quality pollutant trading as a means of reducing point and non-point source pollution inputs to the watershed in the most cost effective manner. Water quality trading is an innovative approach to acheive water quality goals more efficiently. Trading is based on the fact that pollutant sources in a watershed can face very different costs to control the same pollutant. Trading programs enable sources facing higher pollution control costs to meet their regulatory obligations by purchasing environmentally equivalent (or superior) pollution reductions from another source at a lower cost, this acheiving the same water quality improvement at lower overall cost.

The water quality trading feasibility study for the Bear River focused on total phosphorus pollution in the following areas:

  • Bear River from Oneida Narrows Reservoir to Cutler Reservoir, including the Cub River
  • Little Bear River and Spring Creek
Water quality map

A Total Maximum Daily Load (TMDL) study has been completed for each of these river reaches. In addition, a draft TMDL for Cutler Reservoir has been completed. These TMDLs provided the necessary framework within which the trading study was completed.

Water quality trading is complicated because the value of phosphorus for a trade is dependent on where the phosphorus enters the river. Phosphorus particles that have washed off a field or been discharged from a pipe may still have quite a journey before they reach a compliance point. Along the way, the phosphorus may settle out of the water, be used by plants, or otherwise be trapped or transformed. Therefore, sources at different locations in a watershed with the same amount of phosphorus loading may contribute very different amounts of phosphorus to a compliance point, depending on the distance from the source to the compliance point.

Water Quality Modeling to Support Water Quality Trading

A water quality model has been developed that predicts the fate of phosphorus from any point in the Bear River water quality trading focus area, and determines how much of that phosphorus is likely to make it the compliance point. This is important because only phosphorus at the compliance point is eligible for trade. The purpose of the model is to:

  • Simulate the physical, chemical, and biological processes that affect pollutant concentrations within the watershed
  • Consider the spatial and temporal nature of pollutant loading in order to calculate delivery ratios for different areas of the watershed and different compliance points. These delivery rations are neccessary to determine the environmental equivalance of load reductions for potential trades.

Click here to learn more about the water quality model that was developed to support the water quality trading study in the Bear River.

Who to contact if you are interested in learning more:

  • Contact USU Water Quality Extension regarding pollutant trading in the Bear River watershed at (435) 797-2580 or visit
  • If you are interested in participating in an ongoing citizen/stakeholder advisory committee or in having a presentation about trading, contact USU Water Quality Extension at (435) 797-2580 or visit

Related Links

Water Quality Trading Resources and References – Find more information about water quality trading programs, rules, TMDLs, and other resources

Water Quality Trading Glossary – Find definitions of common water quality trading terminology.

Frequently Asked Questions About Water Quality Trading - Read answers to frequently asked questions about water quality trading.

Water Quality Trading Calculator - Rind more information about the water quality trading calculator developed by USU to evaluate trading in the Bear River Watershed.