Filtration - system design information

Filtration - system design information
Link to this table

Device	Drainage area	Entrance/exit velocity	Drain down/detention time	Dimensions	Materials	Layout Recommendations (physical location, off-line placement)	Soils
Pretreatment vegetated filter strip (VFS)	< a few acres, max flow path 75-150 ft depending on perviousness, slope of drainage area <5% [1]; [2]	<1 ft/s, flow should be sheet flow and unconcentrated [3]	Maximum 72 hours [4]	VFS width (parallel to sheet flow) = 25-100 ft depending on vegetation, slope and drainage area soil [5]; [6]	Soil, grass [7]	Residential lawns, parking lots, part of riparian buffer [8]	Hydrologic Soil Groups A-D permitted, table for corresponding slopes [9]
Level-Spreader - Vegetative Filter Strip System (LS-VFS)	< a few acres [10]	<=10cfs [11]	Maximum 72 hours [12]	LS width (parallel to sheet flow) = 10-100 ft, VFS width >= 30-50 ft [13]	Concrete, soil, grass [14]	Distance from surface waters: LS and VFS must be outside riparian buffer, LS must be outside stormwater setbacks [15]	VFS max slope = 8% [16]
Up-Flo Filter	0.66 acres impervious drainage area per filter module based on Nashville design storm [17]	0.056 cfs per filter module (max number of modules 6-54) [18]		Round manhole: 4 ft diameter, 7.5 ft high Rectangular vaults: 6 ft x 8 ft x 6.5 ft to 15 ft x 13 ft x 6.5 ft		Roads, carparks, commercial properties, airports, offline and online treatment of existing storm drains [19]
Storm Clean		Filtration flow rates (nominal/max)= 40/80 gpm, Strainer flow rate >= 100 gpm [20]		Filtration surface area (fabric elements) = 6.4 sq ft, Strainer surface area = 4.8 sq ft [21]	Stainless steel [22]	Can be fit into existing catch basin, curb inlet, drop inlet, or downspout [23]
Gravel filtration	Same as inlet gravel bags are placed around			Varies by need. For example, one version available comes in 11x48, 11x96, and 19x28 inch bags. [24]	Bags are high quality woven polymer material with high UV rating, gravel [25]	In front of or around existing catch basin inlets [26]
Filtration berm		1 cfs per 8 linear ft [27]		Berm height = 12-18 inches high with 3:1 side slopes, every 100-300 feet depending on slope [28]	Washed, well-graded gravel/rock ¾ to 3 inches in size with <5% fines [29]	Right-of-ways, traffic areas, construction sites [30]	No restriction
SiltSoxx R by Filtrexx	Varies by application	Varies by application		Available in 5 in to 32 in diameter depending on application, up to 200 ft in length [31]; [32]	Filtrexx Media in Filtrexx Mesh [33]	Existing inlets, site perimeters, paved surfaces, compacted soils, exposed slopes [34]	Compacted or susceptible to erosion
StormExx R by Filtrexx	Same as catch basin	15-40 gpm [35]		15-gallon storage, fits any existing storm drain [36]	Stainless steel or HDPE, EnviroSoxx filtering media cartridge [37]	Existing inlet