Marshall, MN: High Radon Risk — 53/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Federal monitoring data for Marshall puts the city in MN's lower safety tier — exceedances show up in multiple utility districts, several systems have met thresholds requiring public notification under the Safe Drinking Water Act, and the compliance deficit has persisted across more than one consecutive reporting cycle, with no clear reversal visible in the most recent data available.
How Marshall Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Marshall Water
- Average lead level: 0.008 mg/L.
- Homes built before 1986: 66% — older plumbing may contain lead solder.
- Estimated remediation: $2,900 per household.
- CDC health risk index: 12.73 — above typical levels.
Who Supplies Your Water in Marshall
Multiple utilities divide Marshall, MN's water service — 3 leading providers among 3 on the federal register.
Overview
We track water quality and home safety data for 1 ZIP code in Marshall, Minnesota (population ~15,843), covering 3 community water systems serving approximately 27,623 people region-wide.
No EPA violations recorded across any ZIP codes in Marshall — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Marshall: D (53/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Marshall water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0080 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 56258 | D | Marshall | 13,890 |
All ZIP Codes in Marshall
- 56258 [D]
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Marshall
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Housing & Infrastructure in Marshall
With 66% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
The character of Marshall's housing stock is one of deep historical layering — a median build year of 1975 signals a city built largely before the plumbing era changes of 1986 and 1970. Lead-soldered copper joints and, in the oldest properties, lead service lines are commonly present in this inventory. That context shapes what individual water testing may reveal, particularly in neighborhoods where the oldest housing is concentrated.
Over half of homes in Marshall were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Marshall Homeowners
Middle of the range — Marshall homeowners face a remediation share that calls for real financial attention without reaching crisis territory.
Remediation costs are moderate relative to home values in Marshall. The estimated $1,900–$4,100 range is manageable for most homeowners but still worth budgeting for. Home values are 12% below the Minnesota average.
Lead Exposure Risk for Children in Marshall
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
In recent monitoring under the Lead and Copper Rule, citywide samples for Marshall have approached or crossed the regulatory action level on multiple occasions. Combined with 66% of stock dating from the pre-rule era, the picture supports baseline single-tap reads as a standard household-level step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Marshall
52 FEMA flood insurance claims are on file for Marshall, and 100% of local ZIP codes fall within federally designated flood zones — enough to put flood exposure on the planning radar, though short of the concentrated-risk threshold where treatment-system vulnerability becomes a primary consideration.
Marshall has a moderate flood history with 52 FEMA claims averaging $2,059 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,900</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Marshall
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. With 66% of homes built before 1986, lead solder is a real possibility.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Marshall, MN