Median pollutant removal of total suspended solids by stormwater treatment practices. Values represent percentage of incoming pollutant load that is removed. Source: Minnesota Stormwater Manual.
Bioretentiona 85c
Filtrationb 85
Infiltrationd 100
Stormwater ponds 80
Stormwater wetlands 75

aData based on fewer than five monitoring studies bExcludes vertical sand filters and filter strips cFiltration values used dNote that 100% is assumed for all infiltration, but only for that portion of the flow fully treated in the infiltration facility; by-passed runoff does not receive any treatment.