We know the most effective stormwater runoff controls often involve redirecting surface flow into to the native soil, reducing runoff and preventing many pollutants from entering waterways.
Stormwater management structures can include bioswales, rain gardens, permeable pavements, subsurface infiltration structures, and infiltration basins, among others. To determine the feasibility of stormwater infiltration and to properly design stormwater management structures, our clients need accurate and reliable evaluation of the soil infiltration rate or permeability.
With our staff of field engineers and geologists, our array of testing equipment, and our accredited laboratories, we are capable of handling all aspects of the soil infiltration or permeability testing process and provides high-quality data so that stormwater management systems can be efficiently and effectively designed.
Infiltration rate is calculated by measuring how quickly water enters the soil over time. It is typically expressed in inches per hour and is determined by dividing the volume of water infiltrated by the surface area and time. Field testing methods, such as a double ring infiltrometer, provide accurate results.
A “good” infiltration rate depends on the application, but generally:
Acceptable rates are typically defined by local regulations and project requirements.
While both measure how water moves through soil, they serve different purposes:
Infiltration testing helps determine how stormwater will be managed on-site. It ensures that drainage systems, detention basins, and infiltration practices are designed properly to prevent flooding, erosion, and regulatory non-compliance.
A DRI test is used when accurate; site-specific infiltration data is needed for stormwater design. It is especially appropriate for:
Several site conditions can lead to poor infiltration results, including: