Wellhead Protection Areas

Wellhead Protection Area (WHPA) is the Minnesota Department of Health (MDH) approved surface and subsurface area surrounding a public water supply well or well field that supplies a public water system, through which contaminants are likely to move toward and reach the well or well field.

Drinking water supply management area (DWSMA) is the Minnesota Department of Health (MDH) approved surface and subsurface area surrounding a public water supply well that completely contains the scientifically calculated wellhead protection area and is managed by the entity identified in a wellhead protection plan. The boundaries of the drinking water supply management area are delineated by identifiable physical features, landmarks or political and administrative boundaries.

Drinking water supply management area (DWSMA) vulnerability is an assessment of the likelihood for a potential contaminant source within the drinking water supply management area to contaminate a public water supply well based on the aquifer’s inherent geologic sensitivity; and the chemical and isotopic composition of the groundwater.

Source water assessment area (SWA) is the Minnesota Department of Health (MDH) interim surface and subsurface area surrounding a public water supply well that completely contains the scientifically calculated time-of-travel (TOT) area. The primary purpose of the SWA is to give the public water supplier an idea of the potential size of the final Wellhead Protection Area (WHPA). The TOT for a non-vulnerable SWA is 3 years and for a vulnerable SWA is 10 years. Ultimately the SWA will be replaced by a WHPA and a corresponding Drinking Water Supply Management Area (DWSMA).

https://www.mda.state.mn.us/protecting/waterprotection/drinkingwater.aspx

**Some towns may have completed their WHPA and the GIS data may not have been updated.  When it becomes available our maps will also be updated.