Pollutant Removal Credits for Buffers

Tool Resource
July 2019

Pollutant Removal Credits for Restored or Constructed Buffers in MS4 Permits: Technical Memo and Final Report

Vegetated land along the edges of waterways - also known as buffers - are widely understood to help protect water quality. However, until now there has not been a way to quantify the ability of restored or constructed buffers to reduce pollution, or for communities to receive credit for their use under regulatory permits. As a result, buffers have not been considered alongside other water quality best management practices (BMPs).

An innovative tool has been created tools to help New Hampshire communities meet water quality standards through the use of buffers. The Credit for Going Green Project engaged a panel of experts to generate science-based recommendations for calculating the pollutant removal rate of restored or constructed buffers established on shorelines with different soils and slopes.

Communities can use this information to receive pollutant removal credits under permits issued by the NPDES Stormwater Permit Program. Municipal staff and boards can promote it as a way to protect water quality, while achieving the other benefits that buffers provide, like habitat provision and flood mitigation. This approach not only has the potential to enhance green infrastructure throughout the state, it also leverages the many opportunities for buffer restoration in New Hampshire.

Project results have been summarized in several reports targeted at different audiences. The expert elicitation process has also been documented to help others apply the method to other complicated management problems, see: FAST Expert Panel Process. And the team created a variety of outreach tools to help project partners promote the work, see: Credit for Going Green Outreach Toolkit.

Tools for Developing Pollutant Removal Credits

  • Technical Memorandum: Presents performance curves, use cases, considerations for applications, and supporting decisions made by the panel. Intended for more technical audiences, e.g., consultants and municipal staff.
  • Final Panel ReportComprehensive overview of the panel’s process, decisions, and products, along with information about the local contexts that led to the project.
  • Non-Technical Summary: Two-page overview for anyone, but particularly for less technical audiences, e.g., conservation commissions and planning boards.

Primary Authors and Project Leads: 

James Houle, University of New Hampshire
Cory Riley, Great Bay National Estuarine Research Reserve 
Dolores Leonard, Roca Communications