Screening and straining devices - general information

Screening and straining devices - general information
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Device Proprietary/nonproprietary Above ground or below ground Pollutants removed
Rain Guardian - Bunker Proprietary Below grade Litter and coarse debris, sediment
Rain Guardian - Turret Proprietary Below grade Litter and coarse debris, sediment
Rain Guardian - Foxhole Proprietary Below grade Litter and coarse debris, sediment
Riprap check dams Nonproprietary Above ground Sediment
Wattles Proprietary/nonproprietary Above ground Sediment, organic matter
Hydro Screen Proprietary Above ground/below ground Trash, debris, organics


Screening and straining devices - system design information

Screening and straining devices - system design information
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Device Drainage area Entrance velocity Dimensions Materials Layout Recommendations (physical location, off-line placement) Soils
Rain Guardian - Bunker Up to 6.11 cfs [1] Standard exterior dimensions = 51.25 in L x 20 in W x 15.75 in H, Designed for garden standard ponding depth of 9 in or 12 in [2] 95% recycled plastic lumber [3] Residential bioretention (rain gardens) [4]
Rain Guardian - Turret Up to 3.45 cfs [5] 46 in by 50 in base, 19.5 in total height, designed for garden standard ponding depth of 12 in [6] Reinforced concrete base, fiberglass grate [7] Parking lot rain gardens and high traffic areas [8]
Rain Guardian - Foxhole 2 ft 11 in W x 1 ft 7 in H x As Long as Needed in 3 ft increments Reinforced concrete base, fiberglass grate Under walkways, paths and roads into a rain garden [9]
Riprap check dams <10 acres [10] 4-5 ft wide at the bottom, 1.5 to 2 ft wide at the top, 1.5 to 2 ft high, side slopes no steeper than 2:1 [11] Riprap, coarse aggregate facing uphill side, mixture of rock sizes, nonwoven geotextile below [12] Small open channels (not streams or rivers) with channel slopes >10% [13] Areas conducive to erosion (sandy/silty) [14]
Wattles Not available, although perhaps similar to silt fence <0.25 acre Two sizes: 9 in diameter x 25 ft long and 12 in diameter x 20 ft long, wooden stakes through wattle into soil every 3-4 ft [15] Straw, tubular UV-stabilized black synthetic netting, 18-24 in wooden stakes [16] Newly constructed or disturbed slopes [17]
Hydro Screen Depends on model/application Outfall screen can handle up to 1,000 cfs [18] Depends on model/application Stainless steel Downspouts, detention ponds, private property/roofs, curbs, parking lots, farms [19]


Screening and straining devices - system and component sizing

Screening and straining devices - system and component sizing
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Device Land use Downstream BMP (type) Enhancement opportunity Sizing calculations Inlets Outlets Flow diversion structures
Rain Guardian - Bunker Residential (recommended) Bioretention No Inlet flush with street surface, see detailed schematic See detailed schematic
Rain Guardian - Turret Commercial and Industrial areas Bioretention Yes Inlet flush with street surface, See detailed schematic [20] See detailed schematic [21]
Rain Guardian - Foxhole Multiple/various Bioretention No See detailed schematic [22]
Riprap check dams Multiple/various No NA NA Optional shallow pool upstream of check [23]
Wattles Multiple/various No Depends on application NA NA NA
Hydro Screen (multiple model sizes) Commercial, Industrial, Residential, Agricultural [24] Yes Depends on application NA NA Depends on model, most have bypass capabilities


Screening and straining devices - installation and maintenance recommendations

Screening and straining devices - installation and maintenance recommendations
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Device Installation notes Frequency of inspections Maintenance checklist (link) Permitted on private land/ Maintenance agreement recommended Practices for minimizing sediment and trash buildup Practices for mitigating erosion Cost considerations (equipment needed and man hours)
Rain Guardian - Bunker Specifications and installation notes available here Following rain events [25] Maintenance guide Remove debris if grate is clogged, chamber is >75% full, or vertical filter wall is clogged [26] NA Simple hand tools; <5 minutes
Rain Guardian - Turret Specifications and installation notes available here Following rain events [27] Maintenance guide Remove debris if grate is clogged, chamber is >75% full, or vertical filter wall is clogged [28] NA Simple hand tools; <5 minutes
Rain Guardian - Foxhole Specifications and installation notes available here Following rain events [29] Maintenance guide Remove debris if grate is clogged, chamber is >75% full, or vertical filter wall is clogged [30] NA Simple hand tools; <5 minutes
Riprap check dams General installation guidelines available here Following each runoff event, especially after rainfall exceeding 0.5 inches [31] Maintenance guide Remove sediment adjacent to and behind check dam before it reaches halfway to the top, repair and restore dam [32] To the extent feasible, use erosion prevention practices such as stabilization rather than sediment control practices, restabilization of areas where sediment removal results in exposed soil [33]
Wattles Installation guide here Following rain events Frequent sediment removal is necessary NA
Hydro Screen No information available. Must call. No information available. Must call. No information available. Must call. No information available. Must call. No information available. Must call. No information available. Must call. No information available. Must call.