Site Soil Infiltration Testing

Understanding the suitability of a project site for infiltration-based LID structures is critical for facility success and aids in maximizing functionality during design. A guidance document was prepared for LIDI by Earth Systems Pacific to provide a simple and cost-effective field investigation methodology to support location and sizing of small-scale infiltration facilities. Click here to download.

Bioretention Facility Soil

Bioretention Soil Media (BSM) is a critical element of the bioretention system. The BSM has a ratio of inorganic and organic materials to allow the appropriate infiltration rates for stormwater; facilitate pollutant removal through chemical, biological and physical processes; and provide a sufficient growing medium for plants. Research is still being conducted to determine the ideal specification for BSM.

Currently, the Central Coast Water Quality Control Board allows use of two BSM specifications:

  1. The Bay Area Stormwater Management Agencies (BASMA) developed a technical report that includes a BSM specification.
    BASMA Technical Report and BSM Specification

  2. A BSM specification was developed for the San Diego Region that includes a slightly lower compost percentage.
    San Diego Region BSM Specification with accompanying Memorandum
Information on this webpage was adopted with permission from Central Coast Low Impact Development Initiative.