Filtration - system and component sizing
Link to this table

Device Land use Downstream BMP (type) Enhancement opportunity Sizing calculations Inlets/oulets Flow diversion structures Slopes
Pretreatment vegetated filter strip (VFS) Often not suitable for in ultra-urban settings where space is limited or areas with high pollutant loading [1] Infiltration, Retention [2] No Depends on slope and imperviousness of drainage area: See MPCA table entitled “Guidelines for filter strip pre-treatment sizing” Outflow 2-3 inches above filter strip [3] May include pervious berm or check dam, which should have an outlet pipe or overflow weir [4] 2-6% depending on soil, 0% perpendicular to flow [5]
Level-Spreader - Vegetative Filter Strip System (LS-VFS) Often not suitable for in ultra-urban settings where space is limited or areas with high pollutant loading [6] Infiltration, Retention [7] No LS length: 10 ft/cfs, VFS sized for a 1 in/hr storm (larger flows bypassed) Outflow 2-3 inches above filter strip [8] May include flow bypass, forebay and/or blind swale, and underdrain Depth at inlet = 3 ft, depth before outlet = 1 ft
Up-Flo Filter Suited to industrial sites, locations contributing to wetlands/protected regions or area requiring high level of treatment Yes See manufacturer’s sizing tool (requires registration) Can accept 15 in or 24 in pipes Bypass siphon, sump, filter module, outlet module
Storm Clean Underground Injection Controls (UIC), swales, detention/ retention ponds, infiltration trenches Yes Sized to rectangular or round catch basin, adaptive design available for larger catch basins Bypass port, strainer, filter element
Gravel filtration Areas with high erosion concern such as construction sites. No Each gravel bag can be adjusted to meet specific flow, sediment, or filtration requirements
Filtration berm Residential, Commercial, Industrial, Retrofit, Highway/Road, limited Ultra-Urban [9] No 8 linear feet per 1 cfs based on 10-yr, 24-hr design storm [10] Size outlets for 24-hour drawdown time [11] Suitable for most steep surface slopes [12]
SiltSoxx R by Filtrexx Construction, Residential, Commercial No restriction Yes Flow-based, see time to overflow at different flow rates (1-7.5 gpm/linear ft) for each size in Table 1 Slope up to 1:1 grade [13]
StormExx No restriction Yes One-size fits all with modification supports [14] Treated water outlet from cartridge = 2 in diameter Bypass structure

This page was last edited on 3 August 2022, at 19:05.