Minnesota Stormwater Manual test page 5
Warning: This page is an edit and testing page use by the wiki authors. It is not a content page for the Manual. Information on this page may not be accurate and should not be used as guidance in managing stormwater.
Other water supply wells (e.g. private, transient)
Adequate separation must be maintained between all water supply wells and infiltration systems. Unlike municipal public supply wells, modeling and other technical analysis is rarely done to determine appropriate separation distances for these wells. We recommend one of the following three approaches to determining a separation distance between an infiltration system and a water supply well.
- Follow Minnesota Department of Health guidelines, which specify a minimum 100 foot horizontal separation between any infiltration BMP and a sensitive water supply well, and a 50 foot minimum horizontal separation between any infiltration BMP and all other water supply wells. Sensitive water supply wells may be identified using existing reliable groundwater maps (e.g. MDH vulnerability maps, Minnesota Department of Natural Resources (MDNR) County Atlases), or by applying MDNR groundwater sensitivity criteria (see page 8)
- Applying the guidance found at this page, determine an appropriate separation distance based on a mounding analysis. We recommend adding an additional safety factor if runoff delivered to the infiltration practice is located in a stormwater hotspot or has the potential to contain mobile organic chemicals or pathogens.
- Calculate a time of travel. This can be done if there are sufficient data to apply Darcy's equation V= KI/n, where V is the groundwater velocity, K is the horizontal hydraulic conductivity, I is the horizontal hydraulic gradient, and n is the effective porosity.