Groundwater Protection

Groundwater is an important resource in Minnesota. Groundwater accounts for 75% of reported water use in most years, both for drinking water and agricultural irrigation. Groundwater has a greater risk to contamination in areas of high pollution sensitivity, such as coarse-textured soils or karst topography. Such areas allow the rapid downward movement of water into surficial sands (water table) aquifers, increasing the risk for groundwater contamination from surface pollutants.

Understanding pollution sensitivity is a key consideration to prevent groundwater pollution. Many land-use activities (including row crop agriculture, stormwater, septic systems, and tanks/landfills) within a watershed could contaminate groundwater if pollutants are not carefully managed, especially in areas of high pollution sensitivity.

Activities on the land surface can also affect groundwater levels by reducing infiltration (groundwater recharge); these activities include tiling, changes in vegetation, increased areas of impervious surface, and changing surface water or stormwater flow.

Steps for Protecting Groundwater in Your Area

Review groundwater information for your area

In order to better understand the groundwater protection and restoration needs of your area, review existing data that impacts the resource. Groundwater Restoration and Protection Strategies (GRAPS) reports have been developed for a number of watersheds in Minnesota. GRAPS reports, coordinated by the Minnesota Department of Health, contain maps and data describing groundwater conditions in the watershed, identify local groundwater concerns, and outline strategies and programs to address them.

If a GRAPS does not yet exist for your area, other sources are available. Land use, geology, hydrogeology, pollution sensitivity, and groundwater withdrawals can affect groundwater quality and quantity. The susceptibility of groundwater to contamination depends on multiple factors, including properties of soils and geologic materials, land use practices, and climate factors such as the amount and intensity of precipitation. Available resources include: 

• County Geologic and Groundwater Atlases provide county by county geologic and groundwater information. Geologic studies include surficial deposits and bedrock. Groundwater studies include flow systems, aquifers, groundwater chemistry, and sensitivity to pollution. Atlases include downloadable GIS files.

• The Minnesota Geospatial Commons website provides downloadable GIS files on many topics, including land use, cropping patterns, pollution sensitivity of bedrock and near-surface materials, and potentially contaminated sites.

• Water use permits are managed by the Minnesota DNR and detailed in a publicly accessible database and downloadable GIS files.

• Township testing for nitrate concentrations in private wells is being conducted by the Minnesota Department of Agriculture and initial and final results are posted statewide and by county.

• MDH source water protection website: https://www.health.state.mn.us/communities/environment/water/swp/mapviewer.html

• Drinking Water Supply Management Area and Wellhead Protection Area vulnerability information can be found at:  https://www.mda.state.mn.us/protecting/waterprotection/waterprotectionmapping

• DWSMAs that are mitigation level 1 or higher as identified in the Minnesota Groundwater Protection Rule (MR 1573):  https://www.mda.state.mn.us/mitigation-level-determination

• DNR pollution sensitivity: https://www.dnr.state.mn.us/waters/programs/gw_section/mapping/platesum/mha_ps-ns.html

• MDA vulnerable area:  https://mnag.maps.arcgis.com/apps/webappviewer/index.html?id=47a342afe6654640b935c8e76023da92

• For Public Water Supplies, identify if the project is in a Drinking Water Supply Management Area (DWSMA) (https://mdh.maps.arcgis.com/apps/View/index.html?appid=5051b7d910234421b0728c40a1433baa).

• For private wells, identify the assigned vulnerability to groundwater contamination for the project area (https://www.dnr.state.mn.us/whaf/about/scores/geomorphology/g_i_psnsm.html).

• Groundwater Restoration and Protection Strategy Reports https://www.health.state.mn.us/communities/environment/water/cwf/localimplem.html).

• EPA’s National Primary Drinking Water Standards: https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations

• MDH Human Health Based Water Guidance Table: https://www.health.state.mn.us/communities/environment/risk/guidance/gw/table.html

Identify and prioritize groundwater concerns, sources and target areas

Using the information you gathered, identify groundwater concerns for your area. Determine the location of the sources of the identified concerns.

In most cases, you will need to prioritize your response by focusing on specific target areas in order to be the most effective. For additional guidance on prioritizing resources and issues, see the One Watershed, One Plan Guidebook.

Set goals and actions

Determine your baseline, then develop groundwater protection goals you want to achieve.

A logic model can help you organize your strategy, actions and goals into a story about your project or program. See page 19 of the One Watershed, One Plan Guidebook for a logic model template.

Funding

Available Funding for Groundwater Projects (pdf)

BWSR Wellhead Protection Partner Grant

BWSR Projects and Practices Drinking Water Sub-Grant

BWSR Watershed-Based Implementation Funding

Training

BWSR Online Learning Library

Groundwater Education Module One: Groundwater 101 

Examples

• City of Adrian buys parcels
• East Otter Tail SWCD irrigation management
• St. Louis County septic solutions
• Crow Wing County well sealing funding
• City of St. James uses RIM to protect drinking water