Private Wells: A Patchwork of Protections

Tannie Eshenaur, MPH | Water Policy Center

Minnesota Department of Health

Drinking Water Protection: State Agency Collaboration

4/29/2025

BWSR

DNR

MDA

MPCA

MDH

• Water Quantity
• Ecosystem Interactions

• Water Monitoring
• Standards
• Permits
• Clean-up

• Pesticides
• Fertilizers

• Private Land Owners
• Soil Health
• Water Quality

• Groundwater Guidance
• Public Drinking Water
• Wells

Disparities in safeguards over the lifespan of a well

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What are we concerned about in private wells?

Few private well users are testing and taking necessary action

2016 survey of 798 well owners who had arsenic above 10 µg/L in their new well sample

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Arsenic exposure reductions from MCL change

2001: MCL reduced from 50 µg/L to 10 µg/L

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Nigra, et.al., 2017, Welch, et. al., 2018

How many preventable cancer cases?

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EPA directive to state agencies

Develop a coordinated and comprehensive work plan to reduce nitrate contamination of drinking water aquifers in eight southeastern Minnesota counties.

Letter, Minnesota’s response, reports: Response to Nitrate in Southeast Minnesota

Plan components: Private well focus

1. Develop coordinated communication plan
2. Identify all private wells
3. Provide education and outreach:
• Private wells owners/users 
• Community water system customers
4. Offer testing for all private wells
5. Offer remediation for wells that exceed drinking water guidance
6. Establish public access to data and records
7. Report quarterly to US EPA

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Township Testing results for 8 county area

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Workplan has three phases 

health.state.mn.us

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CWF helps fund public health intervention

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The Power of Partnerships

health.state.mn.us

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Phase II: Public Health Intervention

• Free water tests for private well households in 8-county area, prioritizing households with babies or a pregnant person ~1400+ requests
• Mitigation (RO systems) provided by MDA for households with nitrate above 10 mg/L ~160 RO systems installed
• Well inventory to locate private wells
• Outreach: support local outreach and education about well testing and mitigation; media contract
• Use a scalable approach: Design the approach so it can be used throughout MN

Leverage and elevate Tap-In �and existing efforts

Test kits requested by week

How did you hear about the free well test kit?

Early Private Well Testing Results

Out of 236 Test Kits:

• 11% nitrate >10 mg/L
• 12% bacteria present
• 1% E.coli present
• 12% arsenic present
• 45% lead present
• 5% manganese present

Data from June 3, 2024 – February 20, 2025

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Number of Test Kits Returned by County

Water Treatment System Installations

* As of 3/31/2025

12% of homes had an infant under the age of 1 or

a pregnant woman in the household

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31% of applicants have income below 300%

of the federal poverty level

Example reverse osmosis system installation

Outreach and Education

• Social Media, TV, Radio, Newspaper
• Community meetings, webinars
• Private Well Steward Network, UMN Extension
• Groundwater Awareness Week, Drinking Water Week
• MDH Website
• Realtor CEUs, Buying and Selling a Home brochures
• Well mitigation navigator with county laboratory
• Social science research with UMN

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Well Inventory

• Process aligns with MN Geologic Survey/UMN
• Identify all private wells supplying drinking water for a home (county by county)
• Provide information to update the County Well Index (which updates Minnesota Well Index)

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Where do we go from here?

• Improve test kit return rate and bacteria hold time compliance
• Expand mitigation options to maximize cost/benefit and sustainability
• Additional local champions like community health workers
• Address nitrate and other "top five" contaminants in other parts of the state

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Approaches to carry forward

health.mn.gov

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Questions?

Tannie Eshenaur

tannie.eshenaur@state.mn.us

651-201-4074