Transferability of Post-Construction Stormwater Quality BMP Effectiveness Studies

This study evaluated state practices for assessing stormwater best management practices (BMPs), reviewed BMP effectiveness data applicable to highway runoff, evaluated variables potentially affecting data transferability, and assessed the feasibility of establishing a highway BMP database. These were all accomplished to answer the following questions: (1) What BMP performance monitoring studies applicable for highways are available in data clearinghouses and as published literature? (2) What are the observed effects of geographic variables on highway BMP performance? (3) How can highway BMP performance monitoring evaluations be standardized? and (4) What recommendations can be provided for assessing the feasibility of establishing a BMP performance monitoring study central repository for transportation agencies? The review of transportation-related BMP performance studies and data clearinghouses revealed several data gaps, particularly with regard to the national distribution of studies. In some areas of the country, BMP monitoring studies are completely lacking, while other areas have limited studies for particular BMP types or monitored parameters. The International Stormwater BMP Database (BMPDB) was identified as the most comprehensive national-scale database that already contains many highway BMP studies. The literature review identified 21 additional studies for potential entry into the BMPDB. To assess the combined effect of geographic factors, hypothesis testing was conducted on a dataset of highway runoff event mean concentrations (EMCs) for different Environmental Protection Agency (EPA) rain zones. Statistically significant differences in median concentrations were identified for total suspended solids (TSS), total Kjeldahl nitrogen (TKN), nitrate+nitrite (NOx), total phosphorus (TP), total copper (TCu), total lead (TPb), and total zinc (TZn). The effects of traffic volumes and land uses were also evaluated. With the exception of chemical oxygen demand (COD) and fecal coliform (both sparse datasets), all constituents analyzed (TSS, TKN, NOx, TP, TCu, TPb, and TZn) showed statistically significant increases in median concentrations with increases in average annual daily traffic (AADT), but AADT correlations with TSS and TP were relatively weak compared to the other constituents. Comparisons of state department of transportation (DOT)-specific to non-DOT BMP performance data indicate that some non-DOT studies may be appropriate for assessing BMP performance for the highway environment and that influent concentration magnitudes are a potentially significant variable to consider when assessing performance. With regard to a central repository for highway BMP studies, it is recommended, with the Project Panel concurrence, that DOTs utilize and build upon the existing BMPDB, as opposed to creating a separate transportation BMP database. The BMPDB has a proven track record and has an organization (Water Environment Research Foundation [WERF]) committed to its long-term growth and maintenance. A targeted number of enhancements have been proposed for the BMPDB to better support DOT objectives, including the addition of a DOT-specific portal and additional database fields for storing DOT-specific information. The resources necessary to complete these enhancements have been estimated and described.

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  • Summary URL:
  • Supplemental Notes:
    • This research was sponsored by the American Association of State Highway and Transportation Officials, in cooperation with the Federal Highway Administration, and was conducted in the National Cooperative Highway Research Program, which is administered by the Transportation Research Board of the National Academies.
  • Corporate Authors:

    Geosyntec Consultants, Incorporated

    Portland, OR  United States 

    Wright Water Engineers, Incorporated

    Denver, CO  United States 

    Venner Consulting

    Lakewood, CO  United States  80232
  • Authors:
    • Leisenring, Marc
    • Pankani, Daniel
    • Strecker, Eric
    • Clary, Jane
    • Earles, Andrew
    • Jones, Jonathan
    • Venner, Marie
  • Publication Date: 2015-7


  • English

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; Glossary; References; Tables;
  • Pagination: 135p

Subject/Index Terms

Filing Info

  • Accession Number: 01672222
  • Record Type: Publication
  • Report/Paper Numbers: NCHRP Project 25-25, Task 92
  • Files: TRIS
  • Created Date: Jun 8 2018 2:35PM