Median pollutant removal of hydrocarbons by stormwater treatment practices. Values represent percentage of incoming pollutant load that is removed. Source: Minnesota Stormwater Manual. Manual data was based on information from ASCE/EPA International Database; Winer (2000)
BMP group Hydrocarbons>
Bioretentiona 80c
Filtrationb 80
Infiltrationd 100
Stormwater ponds 80
Stormwater wetlands 85

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.