Infiltration Testing Background

  • Infiltration tests estimate the rate at which runoff will infiltrate into the subgrade of stormwater facilities installed in undisturbed, native soil.
  • Infiltration tests should be performed across the proposed development area prior to the development of the site grading plan. This provides the opportunity to install LID (Low Impact Development) facilities on optimal soils and geology. If buildings are proposed on slower infiltrating soils and stormwater facilities sited in faster infiltrating soils, builders can plan their sites to improve stormwater management, prevent flooding, address water-quality issues and decrease the cost of the on-site stormwater management facilities.
  • The information obtained from the infiltration test studies can be used to answer three important questions. Is the site suitable for an infiltration facility? Can the site be developed to meet water quality standards? What size of low-impact development (LID) facility should be installed?