Cottage Grove
EPA ID: MN1820004 · 42,760 people served · 3 ZIP codes
ZipCheckup's reading of EPA SDWIS for Cottage Grove (MN1820004): no EPA violations recorded in the last five years. Throughout five consecutive years of federal water monitoring, Cottage Grove recorded zero violations - solid performance for a utility serving 42,760 people.
Data: EPA SDWIS
Service Area Map
Coverage area for Cottage Grove Source: EPA SDWIS service area boundaries.
Service area boundary - Grade C
Service Area Demographics
The Cottage Grove serves a community with a median household income of $102,026 and an estimated 74,973 residents across its service area. Approximately 55% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Cottage Grove's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Superfund Proximity Note: This service area ranks in the 60th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 10 detections recorded. 2 exceed federal EPA limits (4 ppt for PFOA/PFOS).
Comparable Water Systems
Similar-sized systems in Minnesota
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Cottage Grove (EPA ID: MN1820004) is a community water system in Minnesota that serves approximately 42,760 people from groundwater sources.
This system provides water to 3 ZIP codes across 3 communities.
ZIP-Area Home Safety Context: C (67/100)
This is the average Home Safety Score for 1 of 3 service-area ZIP codes with all required score domains observed. It is not a grade for the water utility.
Model 4.0.0 uses SDWIS identity plus accepted ECHO SDWA lifecycle-based water compliance, the UCMR 5 PFAS MCL screen, EPA radon zone, and annual EPA AirData AQI across three equally weighted domains. Missing required evidence suppresses the score.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.002 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by MN or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Cottage Grove (MN1820004) on EPA.gov.
Frequently Asked Questions
Is Cottage Grove water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Cottage Grove in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does Cottage Grove serve?
Cottage Grove serves approximately 42,760 people across 3 ZIP codes in Minnesota.
Where does Cottage Grove get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected below the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →
How Water Systems Appear in Rankings
Water systems are evaluated by violation history, contaminant detections, and service population. Larger systems with more service connections appear in more rankings.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Cottage Grove, MN: Serves 43K People. https://zipcheckup.com/water-system/mn1820004/
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title = {{Cottage Grove, MN: Serves 43K People}},
year = {n.d.},
url = {https://zipcheckup.com/water-system/mn1820004/}
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What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
Cottage Grove (EPA ID: MN1820004) - request the latest Consumer Confidence Report or ask about specific contaminants.