Filtration Summary Table

Stormwater filtration BMPs summary table
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Stormwater BMP	Illustration	Pollutant Removal Mechanism	Location in Treatment Train	Pollutant Removal 1	Potential Application	Cost	Maintenance Requirements 3	Space needed	Pretreatment 4	Habitat Quality 5
Dry swale or step pool		Sedimentation / Infiltration	Throughout	TSS: Medium TN: Low TP: Medium Chloride: Low Metals: Medium Oils and Grease: Low Pathogens: Low	Residential Commercial Industrial Highway/Road Recreational	Low to medium (depends on components)	Simple‐Intensive	Small	Oil/Water Separator Sediment Basin (depending on watershed soil types, contributing drainage area, and potential for system fouling/plugging)	Low
Wet swale		Sedimentation / Transpiration	Throughout	TSS: Medium TN: Low TP: Low Chloride: Low Metals: Low Oils and Grease: Low Pathogens: Low	Residential Commercial Industrial Highway/Road Recreation	Low	Simple	Small	Oil/Water Separator	Low
Biofiltration Basin		Sedimentation / Filtration	Beginning	TSS: High TN: Low/Medium TP: Medium/High2 Chloride: Low Metals: High Oils and Grease: High	Residential Commercial Retrofit	Low $0.5‐$1.3 CF	Simple‐Intensive	Small to medium	Needed Oil/Water Separator, Vegetated Filter, Sediment Basin, Water Quality Inlets	Medium‐High
Permeable pavement with underdrain		Filtration	Beginning	TSS: High TN: Medium/High TP: Medium/High Chloride: Low Metals: High Oils and Grease: High	Residential Commercial Ultra Urban Retrofit	Medium 3‐10 CF	Medium	Small to medium	No Pretreatment Required	None
Tree Trench/Tree Box (with underdrain)		Filtration, Transpiration	Throughout	TSS: High TN: Medium/High TP: Medium/High Chloride: Low Metals: High Oils and Grease: High Pathogens: High	Commercial Ultra Urban Retrofit	High $1.80 ‐ $12.70 CF based on recommended soil volume of 1,414 CF per tree	Intensive	Small to large	Needed Oil/Water Separator, Water Quality Inlets	Medium
Media filter (sand filter)		Filtration	Throughout	TSS: High TN: Medium TP: Medium/High Chloride: Low Metals: Medium/High Oils and Grease: High Pathogens: High	Residential Commercial Industrial Recreation	Low	Simple-moderate	Small	Needed Oil/Water Separator, Vegetated Filter, Sediment Basin	Low
Green roof		Filtration	Throughout	TSS: High TN: Low TP: Low Chloride: Low Metals: High Oils and Grease: High Pathogens: High	Residential Commercial Ultra Urban Industrial Retrofit	High	Moderate-intensive	Small	Low	Medium

¹² Low = < 30%; Medium = 30‐65%; High = 65‐100%
²Some media mixes can leach phosphorus.