Impacts of frozen soils on the performance of infiltration treatment facilities

Infiltration treatment best management practices (BMPs) mitigate stormwater runoff from impervious surfaces, taking advantage of water percolation through soil to remove pollutants and recharge groundwater. However, in cold regions, frozen soil moisture negatively impacts infiltration facility performance by reducing available pore spaces for infiltrating water, causing a significant increase in runoff volumes. To understand the impacts of frozen soils on infiltrability rates and to improve infiltration treatment BMP designs for cold climates, laboratory experiments examined two soil types (loam and sandy loam) from infiltration treatment facility sites located in the cities of Spokane and Richland, Washington. Soil infiltrability measurements for unfrozen and frozen soil columns were performed using a developed air permeameter flow test. The time allowed for soil?water redistribution prior to freezing was varied among the ?