City of Gwinner
EPA ID: ND4100428 · 753 people served · 2 ZIP codes
Compared to the national average for mid-size utilities, City of Gwinner sits well above the baseline — five years of EPA monitoring show no violations, no MCL exceedances, and no enforcement actions for the full service territory of 753 people.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for City of Gwinner Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The City of Gwinner serves a community with a median household income of $66,172 and an estimated 1,185 residents across its service area. Approximately 68% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
City of Gwinner'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.
About 1% of homes in Cass County, North Dakota rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Wastewater Proximity Note: This service area ranks in the 65th percentile nationally for proximity to wastewater discharge points.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in North Dakota
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
City of Gwinner (EPA ID: ND4100428) is a community water system in North Dakota that serves approximately 753 people from groundwater sources.
This system provides water to 2 ZIP codes across 2 communities.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
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
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for City of Gwinner (ND4100428) on EPA.gov.
Frequently Asked Questions
Is City of Gwinner water safe to drink?
Based on EPA records, City of Gwinner has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does City of Gwinner serve?
City of Gwinner serves approximately 753 people across 2 ZIP codes in North Dakota.
Where does City of Gwinner get its water?
The primary water source is groundwater.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.