Difference between revisions of "Filtration - system design information"
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<td>Level-Spreader - Vegetative Filter Strip System (LS-VFS)</td> | <td>Level-Spreader - Vegetative Filter Strip System (LS-VFS)</td> | ||
<td>< a few acres [https://stormwater.pca.state.mn.us/index.php?title=Design,_construction,_operation_and_maintenance_specifications_for_pretreatment_vegetated_filter_strips]</td> | <td>< a few acres [https://stormwater.pca.state.mn.us/index.php?title=Design,_construction,_operation_and_maintenance_specifications_for_pretreatment_vegetated_filter_strips]</td> | ||
| − | <td><=10cfs [https:// | + | <td><=10cfs [https://files.nc.gov/ncdeq/Energy%20Mineral%20and%20Land%20Resources/Stormwater/BMP%20Manual/C-9--Level-Spreader-Filter-Strips-11-20-2020.pdf]</td> |
<td>Maximum 72 hours [https://www.stormwaterpa.org/assets/media/BMP_manual/chapter_6/Chapter_6-4-9.pdf]</td> | <td>Maximum 72 hours [https://www.stormwaterpa.org/assets/media/BMP_manual/chapter_6/Chapter_6-4-9.pdf]</td> | ||
| − | <td>LS width (parallel to sheet flow) = 10-100 ft, VFS width >= 30-50 ft [https:// | + | <td>LS width (parallel to sheet flow) = 10-100 ft, VFS width >= 30-50 ft [https://files.nc.gov/ncdeq/Energy%20Mineral%20and%20Land%20Resources/Stormwater/BMP%20Manual/C-9--Level-Spreader-Filter-Strips-11-20-2020.pdf]</td> |
| − | <td>Concrete, soil, grass [https:// | + | <td>Concrete, soil, grass [https://files.nc.gov/ncdeq/Energy%20Mineral%20and%20Land%20Resources/Stormwater/BMP%20Manual/C-9--Level-Spreader-Filter-Strips-11-20-2020.pdf]</td> |
| − | <td>Distance from surface waters: LS and VFS must be outside riparian buffer, LS must be outside stormwater setbacks [https:// | + | <td>Distance from surface waters: LS and VFS must be outside riparian buffer, LS must be outside stormwater setbacks [https://files.nc.gov/ncdeq/Energy%20Mineral%20and%20Land%20Resources/Stormwater/BMP%20Manual/C-9--Level-Spreader-Filter-Strips-11-20-2020.pdf]</td> |
| − | <td>VFS max slope = 8% [https:// | + | <td>VFS max slope = 8% [https://files.nc.gov/ncdeq/Energy%20Mineral%20and%20Land%20Resources/Stormwater/BMP%20Manual/C-9--Level-Spreader-Filter-Strips-11-20-2020.pdf]</td> |
</tr> | </tr> | ||
<tr> | <tr> | ||
Revision as of 15:56, 2 August 2022
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 |