Primary and secondary pollutant removal mechanisms

This table shows a list of BMPs and associated pollutant removal mechanisms. Primary (removal) means the BMP was designed for this specific mechanism. Secondary (removal) means the BMP provides additional removal of pollutants for this mechanism even though the BMP was not designed for that purpose. An empty cell means the BMP provides limited or no removal for that mechanism.
Link to this table.

BMP group	Pollutant removal mechanisms
	Water quality
	Filtration	Infiltration	Settling	Biological uptake	Temperature control	Soil adsorption
Pollution prevention	Not applicable - pollutants not exposed to stormwater
Better Site Design/low impact development	primary	secondary	secondary	secondary	secondary	secondary
Runoff volume minimization		secondary			secondary
Temporary construction sediment control			primary
Bioretention	primary	secondary	secondary	secondary	secondary	secondary
Filtration	primary	secondary		secondary		secondary
Infiltration	secondary	primary		secondary	primary	secondary
Stormwater ponds		secondary	primary	secondary
Stormwater wetlands	secondary	secondary	primary	primary		secondary
Supplemental treatment	Each supplemental and proprietary device should be carefully studied to learn the primary and secondary removal functions