Castle Rock, MN: High Radon Risk — 40/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
A meaningful share of water systems in Castle Rock have recorded health-based violations in recent MN monitoring periods — placing the city in the lower tier for tap water safety.
How Castle Rock Compares
Data: EPA SDWIS Last verified: 2026-06-03
Castle Rock Water: The Quick Version
- Estimated remediation: $1,200 per household.
- CDC health risk index: 11.2.
Water Systems Serving Castle Rock
A single utility carries the primary residential water load in Castle Rock, MN — the dominant provider across 1 federally tracked system.
Overview
We track water quality and home safety data for 1 ZIP code in Castle Rock, Minnesota, covering 1 community water system serving approximately 20,790 people.
No EPA violations recorded across any ZIP codes in Castle Rock — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Castle Rock: D (40/100)
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
Castle Rock water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Castle Rock
- 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 |
|---|---|---|---|
| 55010 | D | Northfield | 20,790 |
All ZIP Codes in Castle Rock
- 55010 [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.
CDC Health Data for Castle Rock
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
What You Can Do in Castle Rock
- 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. Homes built before 1986 may have lead solder in pipes. A licensed plumber can assess your risk.
- 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 Castle Rock, MN