Site considerations
Revision as of 18:56, 29 March 2019 by Tvanseters (talk | contribs)
| Installation type | Depth to high water or bedrock (m)[1] | Typical ratio of Impervious drainage area to Treatment Facility Area |
Native soil infiltration rate (mm/hr)[2] | Head (m)[3] | Space % [4] | Slope % [5] | Applicable in pollution hotspots [6] | Set backs | Water table separation[7] | Wellhead protection area[8] |
|---|---|---|---|---|---|---|---|---|---|---|
| Rain Barrel | Not applicable | 5 to 50 m2 | Not applicable | 1 | 0 | NA | Yes | None | No | None |
| Cistern | Not applicable | 1:1 | Not applicable | 0 | 0 | 0 | Yes | None | No | None |
| Roof downspout disconnection | Not applicable | 5 to 100 m2 | Amend if < 15 mm/hr | 0.5 | 5 to 20 | 1 to 5 | Yes | Building Foundation | No | None |
| Soakaway, infiltration trench or chamber | 1 | 5:1 to 20:1 | Not a constraint | 1 to 2 | 0 to 1 | <15 % | No | 4m- Building Foundation Underground Utilities, Trees, Drinking Water Wellhead Protection Areas |
Yes | 2 yr |
| Bioretention | 1 | 5:1 to 15:1 | Underdrain recommended if < 15 mm/hr |
1 to 2 | 5 to 10 | 0 to 2 | No | 4m- Building Foundation Underground Utilities, Trees, Drinking Water Wellhead Protection Areas |
Yes | 2 yr |
| Stormwater planters | Not applicable | 5:1 | Not applicable | 1 to 2 | 2 to 5 | 0 to 2 | Yes | Building Foundation, Trees | No | 2 Yr (infiltrating); None (non-infiltrating) |
| Vegetated filter strip | 1 | 5:1 | Amend if < 15 mm/hr | 0 to 1 | 15 to 20 | 1 to 5 | No | None | No | None |
| Permeable pavement | 1 | 1:1 to 1.2:1 | Underdrain recoomended if < 15 mm/hr |
0.5 to 1 | 0 | 1 to 5 | No | 4m-Underground Utilities Drinking Water Wellhead Protection Areas |
Yes | 2 Yr |
| Enhanced grass swale(has checkdams) | 1 | 5:1 to 10:1 | Not applicable | 1 to 3 | 5 to 15 | 0.5 to 6 | No | 4m- Building Foundation Underground Utilities |
Yes | None |
| Dry swale (Bioswale) | 1 | 5:1 to 15:1 | Underdrain recommended if < 15 mm/hr |
1 to 3 | 5 to 10 | 0.5 to 6 | No | 4m (3m if impermeable liner is used)Building foundation, Underground utilities, drinking water wellhead protection areas |
Yes | 2 Yr |
| Perforated pipe system | 1 | 5:1 to 10:1 | Not a constraint | 1 to 3 | 0 | < 15% | No | 4m- Building Foundation Underground Utilities, Trees, Drinking Water Wellhead Protection Areas |
Yes | 2 Yr |
- ↑ Minimum depth between the base of the facility and the elevation of the seasonally high water table or top of bedrock
- ↑ Infiltration rate estimates based on measurements of hydraulic conductivity under field saturated conditions at the proposed location and depth of the practice
- ↑ Vertical distance between the inlet and outlet of the LID practice
- ↑ Percent of open pervious land on the site that is required for the LID practice
- ↑ Slope at the LID practice location
- ↑ Suitable in pollution hot spots or runoff source areas where land uses or activities have the potential to generate highly contaminated runoff
- ↑ Must have adequate separation from the seasonally high water table or top of bedrock elevation
- ↑ |Time-of-travel within wellhead protection areas