Field evaluation of stormwater best management practices to characterize the comprehensive contaminant removal performance of biochar-augmented filter media

The primary objective of this project is to characterize the effectiveness of stormwater best management practices (BMPs) that incorporate biochar-augmented filtration media for comprehensive contaminant removal from stormwater at the catchment scale. While biochar- augmented filtration systems are an emerging technology for improved removal of bacteria and dissolved contaminants from stormwater, little is known regarding (i) the type(s) of biochars that are most effective for comprehensive contaminant removal, and (ii) how biochar maintains its contaminant removal capacity upon field deployment. 

We therefore propose to (1) conduct laboratory tests to evaluate the effectiveness of Minnesota-produced biochars for removal of a suite of contaminants from stormwater, and (2) evaluate the most promising biochar for its performance in field-scale filter media testbeds. We will install biochar-augmented filter media into an existing testbed located at the Mississippi Watershed Management Organization (MWMO) office building. This system treats the building’s roof and parking lot runoff using three filter cells in parallel, enabling comparison across three different media configurations. We propose to evaluate a broad suite of stormwater contaminants, including bacteria (i.e., E. Coli), chloride, nutrients (e.g., total nitrogen and phosphorus), heavy metals (e.g. zinc and copper), organic contaminants (e.g., pesticides).

The intended outputs of this project will be (1) a peer-reviewed publication that advances knowledge regarding the comprehensive contaminant removal performance of biochar-augmented filter media following field deployment, and (2) a written report that provides practitioners with best practice recommendations with respect to the design of BMPs that incorporate biochar-augmented filter media.

Projected outcomes

  • Improved understanding of the biochar properties and production characteristics that indicate effective stormwater contaminant removal performance.
  • Increased accessibility for practitioners to best practice recommendations regarding the design of biochar-augmented treatment systems.
  • Broader implementation of an emerging BMP that incorporates Minnesota-sourced materials.
  • Establishment of a new client base for biochar use in the Twin Cities, Duluth, and other Minnesota urban centers.
  • Broader implications that are vital to the health and well-being of urban residents, including mitigation of water pollution and jobs creation.

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