Removal of pollutants from simulated highway runoff using a laboratory model of an exfiltration trench

This paper documents a laboratory study on the efficacy of the components of an exfiltration trench, a Best Management Practice (BMP) utilized by the Ohio Department of Transportation (ODOT), to reduce pollutants in post construction stormwater runoff. Runoff flows through media layers of the trench, consisting of pervious concrete, aggregate and sand filter media. A laboratory scale model consisting of a specimen of one of two mixes of pervious concrete was used in a falling-head permeameter with the effluent subsequently filtered through a specimen of sand or manganese greensand filter media in a constant-head permeameter. The ODOT specified media were first characterized and then pollutant removal tests were conducted. Also, an alternative pervious concrete mix (recommended by the Ohio Ready MixConcrete Association (ORMCA)) and filter media (green sand) were investigated. The ODOT pervious concrete mix removed on average 39% of TSS from the artificial runoff, while the ORMCA mix achieved an average removal of 16%. The sand and greensand achieved over 75% and 90% removals, respectively, for TSS from artificial runoff. The composite system of ODOT mix and sand averaged 84% removal of TSS and the Ohio Ready Mix and greensand combination averaged 92% removal. Computed system removals for ODOT/greensand and ORMCA/sand were about 94% and 79%, respectively. The composite system provided 63% to 98% removal for seven heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, and Zn). Greensand was superior to sand in removing metals from solution.

  • Supplemental Notes:
    • This paper was sponsored by TRB committee AFB60 Hydrology, Hydraulics and Water Quality
  • Corporate Authors:

    Transportation Research Board

    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Authors:
    • Mitchell, Gayle F
    • Sargand, Shad
    • Russ, Andrew
  • Conference:
  • Date: 2012

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 25p
  • Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

Filing Info

  • Accession Number: 01368125
  • Record Type: Publication
  • Report/Paper Numbers: 12-1803
  • Files: TRIS, TRB
  • Created Date: Apr 20 2012 12:08PM