Development of Biochar Specification Criteria as Soil Amendment for Slopes, Conveyances and Stormwater Treatment Systems (Phase 1)

Abstract

The objective of this project is to develop knowledge, tools, and protocols to inform best practice standards for effective implementation of biochar in bioretention systems (BRSs) for treating roadway runoff. This project will be performed in two phases, with the first phase (this report) focusing on biochar production, characterization, and contaminant sorption performance. Results from the first phase will inform decisions for the second phase which will look at vegetation growth studies and soil hydrology evaluations. We anticipate the primary project output (following completion of Phase 2) to be a tool or protocol (e.g., a decision-making matrix) to provide standardized guidance for best practices regarding the practical implementation of biochar in BRSs treating roadway runoff. The work plan for Phase 1 is presented herein, which will result in following outputs: 1) Recommendations for locally available, suitable biomass feedstocks and feedstock-specific pyrolysis conditions which can be reproduced at scale. 2) Biochar physical property specification criteria associated with contaminant-removal targets which can be assessed at reasonable costs. 3) Protocols for screening-level contaminant-removal performance tests based on broadly accessible materials and methods. 4) Plans for further evaluations to verify treatment performance and evaluate hydraulic and soil health effects, to be proposed as a part of Phase 2 investigations.