Pollutant removal characteristics

Hydrodynamic separation devices - pollutant removal characteristics
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Proprietary devices Primary mechanism Secondary mechanism Other mechanism Pollutants removed
Vortechs TM by Contech1 Hydrodynamic separation Settling Buoyancy/Skimming Sediment, particulates > 50 microns, floatables
Continuous Deflective Separation (CDS) R by Contech1 Hydrodynamic separation Settling/straining Buoyancy/Skimming Sediment, trash, floatables
Downstream Defender TM H.I.L. Technology1 Hydrodynamic separation Settling Buoyancy/Skimming Particles >150 microns, floatables, oil and grease
First Defense R by Hydro International2 Hydrodynamic separation Settling Buoyancy/Skimming Total suspended solids, sediment, trash, hydrocarbons, oil and grease
Stormceptor R by Imbrium or Rinker Materials3 Hydrodynamic separation Settling Buoyancy/Skimming Sediment, oil and grease
Barracuda by BaySaver4 Hydrodynamic separation Settling Total suspended solids
Dual Vortex Separator by OldCastle5 Hydrodynamic separation Settling Total suspended solids, gross solids, trash, debris, oil and grease
SciClone TM by BioClean6 Hydrodynamic separation Buoyancy/skimming Total suspended solids, trash, oil and grease

Reference links: 1; 2; 3; 4; 5; 6


System design information

Hydrodynamic separation devices - system design information
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Device Drainage area Entrance velocity Dimensions Layout Recommendations (physical location, off-line placement)
Vortechs TM by Contech <10 acres, recommended <5 acres with <1-acre impervious cover1, 2 1.6-25 cfs3 9 standard sizes: 9 ft x 3 ft to 18 ft x 12 ft3 Small footprints of predesigned models are suitable for urban areas and as a retrofit to existing networks. Can be online or off-line.3, 4
Continuous Deflective Separation (CDS) R by Contech <10 acres, recommended <5 acres with <1-acre impervious cover5, 6 Inline up to 6 cfs, offline precast modules 3-62 cfs, offline cast in place up to 300 cfs7, 8 16 models: 3-10 ft diameter8 Small footprints of predesigned models are suitable for urban areas and as a retrofit to existing networks9
Downstream Defender TM H.I.L. Technology <10 acres, recommended <5 acres with <1-acre impervious cover10, 11 1.6-24 cfs for 50% removal of 100-micron particles, peak flow rate 3-38 cfs12 Predesigned manhole sizes: 4-12 ft in diameter, custom: up to 40 ft in diameter; Depth: 3.33 - 9.42 ft13, 14 Small footprints of predesigned models are suitable for urban areas and as a retrofit to existing networks15
First Defense R by Hydro International 0.85-6.0 cfs for 50% TSS Removal16 Six models: Diameter= 3-8 ft, Depth = 3.75-8 ft16 At point of entry into drainage line, sites constrained by space, topography, or drainage profiles, and retrofit installations16
Stormceptor R by Imbrium or Rinker Materials Varies from 1 acre to 150 acres depending on model, common in-line models can treat 0.55-6.7 acres impervious cover17, 18 8 prefabricated in-line models, 1 48-in diameter inlet model, large-scale MAX model18 Small footprints of predesigned models are suitable for urban areas and as a retrofit to existing networks. Extended Oil Storage and Oil and Sand Removal Systems available for hot spot areas. Can be inlet or in-line, single or in series19, 20
Barracuda by BaySaver Recommended <5 acres with <1-acre impervious cover21 50% TSS removal: 1.25 cfs, Maximum: 6.25 cfs22 6 manhole models: 36-120 in diameters22 Small footprints of predesigned models are suitable for urban areas and as a retrofit to existing networks
Dual Vortex Separator by OldCastle 0.56 – 9 cfs23 Multiple sizes for both square manhole and square grated inlet models: 36 in to 144 in diameter24 Small footprints of predesigned models are suitable for urban areas and as a retrofit to existing networks. Can be online or offline24
SciClone TM by BioClean WQ flow rate = 0.7-6.3 cfs25 Twelve models: 3-14 ft diameter, storage capacity 11-231 cu ft26 Small footprints of predesigned models are suitable for urban areas and as a retrofit to existing networks27

Reference links: 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27


System and component sizing

Hydrodynamic separation devices - system and component sizing
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Device Land use Downstream BMP (type) Mechanism enhancement Sizing calculations Inlets Outlets Openings Flow diversion structures
Vortechs TM by Contech Ultra-high density, Industrial, Commercial, "Hotspots" such as gas stations or high vehicular traffic areas1, 2 Filtration, Detention/Infiltration, Rainwater Harvesting3 Yes Each system custom sized for site one of two ways: to provide a specific removal efficiency of a predefined particle size distribution, or by the Rational Rainfall Method. In most cases, pollutant removal goals can be met with a smaller system configured with an external bypass4, 5 Perpendicular to vault to be tangential to grit chamber to induce swirling flow pattern6 Orientation determined for each system 7 Low flow control orifice sized to submerge inlet pipe when operating at 20%, High flow control weir sized to pass peak system capacity minus peak orifice flow7 Baffle wall, circular grit chamber, flow control chamber, oil chamber8
Continuous Deflective Separation (CDS) R by Contech Ultra-high density, Industrial, Commercial, "Hotspots" such as gas stations or high vehicular traffic areas8, 9 Filtration, Infiltration, Detention10 Yes Three primary methods of sizing system: the Water Quality Flow Rate Method to provide a specific removal efficiency of a predefined particle size distribution, the Rational Rainfall Method, or the Probabilistic Method when a specific removal efficiency of net annual sediment load is required11, 12 Grate inlet at street level and pipe inlet (may have multiple), inlet throat area sized to pass flow at surface elevation equal to crest of diversion weir, can be widened to increase capacity13 Diversion weir length and height dimensions determine hydraulic capacity of system13 Diversion chamber, diversion weir, separation chamber, separation screen, oil baffle13
Downstream Defender TM H.I.L. Technology Ultra-high density, Industrial, Commercial, "Hotspots" such as gas stations or high vehicular traffic areas15, 16 Filtration, Infiltration, Detention, Wetland17 Yes Q = ciA (runoff coeff. * intensity * area), then see (NJCAT) or refer to sizing calculator from manufacturer (does not require registration) or updated design tool (requires registration) Tangential to chamber18 Sloping base joined to a benching skirt at a 30-degree angle, dip plate19
First Defense R by Hydro International Ultra-high density, Industrial, Commercial, "Hotspots" such as gas stations or high vehicular traffic areas19, 20 Filtration, Infiltration, Detention21 Yes Q = ciA (runoff coeff. * intensity * area), then see Table 1 (NJCAT) or refer to updated design tool from manufacturer (requires registration) Grate inlet at street level and pipe inlet (may have multiple), max pipe diameter = 18-48 in22 Max pipe diameter = 18-48 in, Min dist from outlet invert to top of rim = 2-3.5 in to 3-6 in depending first on model then on pipe diameter Built-in bypass, inlet chute22
Stormceptor R by Imbrium or Rinker Materials Ultra-high density, Industrial, Commercial, "Hotspots" such as gas stations or high vehicular traffic areas23, 24 Filtration and Detention/Retention systems25 Yes PCSWMM for Stormceptor available from manufacturer for optimal design and sizing purposes (requires registration) Varies by model Varies by model Varies by model Insert slows water and directs it to lower chamber, non-turbulent treatment chamber with bypass insert25
Barracuda by BaySaver Ultra-high density, Industrial, Commercial, "Hotspots" such as gas stations or high vehicular traffic areas26, 27 Filtration, Infiltration, Detention28 No Volume based, treatment chamber capacity ranges from 212 gallons to 7496 gallons29 12 in diameter, variable inlet/outlet angle configurations30, 31 12 in diameter, variable inlet/outlet angle configurations32, 33 Weir prevents inflow from bypassing vortex separator, “teeth” reduce turbulence in sump area, inline may offer internal bypass34, 35
Dual Vortex Separator by OldCastle Infiltration, Detention, and Retention systems36 Yes See sizing and selection tool (does not require registration) Fits 1-3 inlets, see sizing and selection tool for max pipe sizes (does not require registration) Incoming flow directed into parallel vortex tubes, isolated storage area with baffles36
SciClone TM by BioClean Filtration, Infiltration, Detention37 Yes Single outlet Single outlet Flow splitter, sump chamber, outlet weir38

Reference links: 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38


Installation and maintenance recommendations

Hydrodynamic separation 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 buildup Removal of trash and debris Cost considerations (equipment needed and man hours)
Vortechs TM by Contech Site specific considerations and contractor notes available here1, 2 Once a month or after each heavy contaminant load for the first year, then twice per year Inspection and maintenance log Remove sediment with vacuum truck when buildup reaches within 18 inches of inlet pipe2 Remove oil immediately after spill, absorbent pads may be used. Removal of most other floating material possible through same access point as sediment, but also may require skimming of baffle chamber2 Vacuum truck or “clamshell” grab, absorbent pads2
Continuous Deflective Separation (CDS) R by Contech Site specific considerations and contractor notes available here After every runoff event for the first 30 days, then once every 30 days during wet season, screen inspection at least once per year3 Inspection and maintenance log Sump pumped out when level of sediment reaches 75% of sump height. Also clean area outside screen.4 Remove oil immediately after spill, absorbent pads may be used.4 Vacuum truck and/or absorbent material5
Downstream Defender TM H.I.L. Technology Handling and installation instructions available here Once a month during first year of operation to determine rate of accumulation, then every 6 months6 Inspection and maintenance log Removal once per year, or as needed (when sediment depth is greater than 75% of maximum cleanout depth) or following a spill in the drainage area7 During sediment clean out or immediately following spill7 Vactor truck: Manual skimming8
First Defense R by Hydro International Handling and installation instructions available here Regularly for first year, then every 6 months9 Inspection and maintenance log Sediment removal with vactor hose once per year, or as needed, or following a spill in the drainage area9 Oil and floatables removal with vactor hose once per year with sediment removal or following a spill in the drainage area9 Vactor truck: Manual skimming10
Stormceptor R by Imbrium or Rinker Materials Installation instructions available here11 Routinely for first year and after a spill, visual inspections (with dipstick) especially recommended for units that may capture petroleum-based pollutants Inspection and maintenance instructions Remove sediment with vacuum truck when unit is filled 15% of total storage capacity or at least once per year11, 12 During sediment clean out or immediately following spill Vacuum truck; Standard visit costs approximately $1000 per structure13
Barracuda by BaySaver Installation guides available here Bimonthly inspection for the first year, then annually14 Removal of sediment with vacuum truck when depth has exceeded 10 inches (typically every 12-18 months)14 Vacuum truck14
Dual Vortex Separator by OldCastle Installation instructions available here Conducted at least twice per year, but more frequently the first 2-3 years and during winter15 Maintenance manual Obtain proper traffic diversion if necessary15 Removal of sediment when depth exceeds 12 inches15 Replace sorbent pads when dirty or saturated, vacuum truck required to remove floating trash and debris cannot be retrieved with net or oil is significant16 Vacuum truck, tethered sorbent pads if applicable16
SciClone TM by BioClean Same procedure as standard manhole installation17 Multiple times during first year to assess site-specific conditions, use this to establish inspection schedule18 Maintenance manual and inspection form Removal of sediment when depth exceeds 18 inches18 Removal of trash and floatables when length and width of skimmer is fully impacted (extending down 9 inches)18 Vacuum truck

Reference links: 1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18

This page was last edited on 1 August 2022, at 21:34.