A Framework for Trading Phosphorus Credits in the Lake Allatoona Watershed

This project integrated research, education and extension activities to develop a framework for trading phosphorus (P) credits between point and nonpoint sources in the Lake Allatoona watershed in north Georgia.

According to the EPA Allatoona Phase 1 Clean Lakes Diagnostic Feasibility Study, unless measures were taken to control nonpoint sources of sediment and P in the watershed, Lake Allatoona would ultimately be unfit for drinking or recreational purposes.

Using the Lake Allatoona watershed as a case study, the project team worked with stakeholders to develop a management program based on the premise of trading P credits, recognizing that nonpoint source management practices that reduce P are also likely to reduce sediment and FC loads.

The overall objective was to establish a framework for trading P credits between point sources (eight wastewater treatment plants) and agricultural/forestry non-point sources in the Lake Allatoona watershed. The team:

  • Estimated the annual using load of P, sediment, and FC entering Lake Allatoona using historical stream and water quality data and data collected as part of this project.
  • Calibrated a semi-distributed watershed mode (Hydrological Simulation Program – Fortran, HSPF) using monitoring data and uses it to identify the spatial distribution of point and nonpoint sources of P, sediment, and FC entering Lake Allatoona.
  • Developed scientifically-based trading ratios using uncertainty analysis of the model for all of the best management practices that were likely to be used by agricultural and forestry nonpoint sources.
  • Performed a cost analysis to see if trading between point and nonpoint sources was likely to be feasible.
  • Investigated different frameworks for trading, ranging from unregulated trading between individual parties to a supervised fund from which trading credits could be purchased and best management practices funded.
  • Established an advisory council consisting of stakeholders and all potential trading partners within the watershed.
  • Sponsored a pollutant trading conference and workshop in the last year of the study.



Lake Allatoona