Estimating Pollutant Load Reduction for Individual BMPs
The NPS/TMDL Section and the U.S. EPA require all Section 319(h) grant projects that install BMPs to provide an estimate of pollutant load reductions achieved with each BMP. To facilitate this process, the NPS/TMDL Section developed a spreadsheet application based on the Michigan Department of Environmental Quality's (MDEQ) "Pollutants Controlled Calculation and Documentation for Section 319 Watersheds Training Manual." This spreadsheet application was then further modified by incorporating the Illinois Environmental Protection Agency's (IEPA) calculations for urban settings. The joint effort between the NPS/TMDL Section, MDEQ, and IEPA ultimately produced the Microsoft Excel interactive file called the Pollutant Load Reduction Model. This was then adopted by the U.S. EPA Region 5 office for all states to use.
Because the (customized for Indiana) IDEM/U.S. EPA Region 5 Pollutant Load Reduction Model is not a special software program, it can be easily used and transferred between users. In addition, every effort was made to ensure the application was easy to understand and use.
The IDEM/U.S. EPA Region 5 Pollutant Load Reduction Model is based on very simple and sound principles. Please keep in mind that this application does not estimate the load reduction for dissolved pollutants, should only be used to estimate load reductions for individual BMPs, and does not apply to every BMP (i.e. nutrient management). Please consult with your Section 319 Project Manager regarding the applicability of the IDEM/U.S. EPA Region 5 Pollutant Load Reduction Model to your project. The Watershed Management Section encourages Section 319 grant projects to utilize more rigorous methods to estimate pollutant load reductions when possible.