Difference between revisions of "Decision process for selecting liners"
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| − | <td><span title="Filtration Best Management Practices (BMPs) treat urban stormwater runoff as it flows through a filtering medium, such as sand or an organic material. They are generally used on small drainage areas (5 acres or less) and are primarily designed for pollutant removal. They are effective at removing total suspended solids (TSS), particulate phosphorus, metals, and most organics. They are less effective for soluble pollutants such as dissolved phosphorus, chloride, and nitrate."> [https://stormwater.pca.state.mn.us/index.php?title= | + | <td><span title="Filtration Best Management Practices (BMPs) treat urban stormwater runoff as it flows through a filtering medium, such as sand or an organic material. They are generally used on small drainage areas (5 acres or less) and are primarily designed for pollutant removal. They are effective at removing total suspended solids (TSS), particulate phosphorus, metals, and most organics. They are less effective for soluble pollutants such as dissolved phosphorus, chloride, and nitrate."> [https://stormwater.pca.state.mn.us/index.php?title=Stormwater_filtration_Best_Management_Practices '''Filtration practices''']</span> with less than 3 feet of separation to seasonal saturated soil or bedrock</td> |
<td>1</td> | <td>1</td> | ||
<td>Required under the [https://stormwater.pca.state.mn.us/index.php?title=Construction_stormwater_program Construction Stormwater permit]</td> | <td>Required under the [https://stormwater.pca.state.mn.us/index.php?title=Construction_stormwater_program Construction Stormwater permit]</td> | ||
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| − | <td>Constructed wet ponds underlain by soils with an infiltration rate of 0.3 inches per hour or greater (HSG A or B soils | + | <td>[https://stormwater.pca.state.mn.us/index.php?title=Stormwater_ponds Constructed wet ponds] underlain by soils with an infiltration rate of 0.3 inches per hour or greater (HSG A or B soils)</td> |
<td>1</td> | <td>1</td> | ||
<td>To maintain a permanent pool</td> | <td>To maintain a permanent pool</td> | ||
Latest revision as of 19:53, 25 October 2022
Design process for selecting the appropriate liner level.
Link to this table
| Condition | Design level | Note |
|---|---|---|
| Filtration practices with less than 3 feet of separation to seasonal saturated soil or bedrock | 1 | Required under the Construction Stormwater permit |
| BMP in confirmed potential stormwater hotspot with high or very high groundwater pollution potential or areas where infiltrating water will mobilize contaminants in soil or groundwater | 1 | Applies to all post-construction BMPs. See section on Potential stormwater hotspots for more information |
| Constructed ponds with less than 3 feet separation from seasonally high water table in a potential hotspot | 1 | |
| Constructed wet ponds underlain by soils with an infiltration rate of 0.3 inches per hour or greater (HSG A or B soils) | 1 | To maintain a permanent pool |
| Karst terrain with high or very high groundwater pollution potential1 | 1 | See section on karst for more information |
| Prevent groundwater intrusion into a BMP requiring aerobic conditions, such as iron-enhanced media | 1 | |
| Maintain permanent pool in constructed ponds or constructed wetlands in areas underlain by geologic material that is fractured or has a high infiltration rate | 2 | |
| Separation distance from a BMP cannot be achieved | 2 | |
| Separate tree BMP from road, parking lot, sidewalk or adjacent walls or building foundation | 2 | To prevent tree root intrusion. See link |
1 Groundwater pollution potential is determined based on hydrogeologic conditions, which are used to estimate the time of travel for water and conservative chemicals to pass through the soil and vadose zone and into groundwater.
This page was last edited on 25 October 2022, at 19:53.