Denison, IA: High Radon Risk — 60/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Drilling into federal monitoring figures for Denison in IA, the pattern is middle-of-the-road — some utilities have documented MCL exceedances or treatment technique violations in recent years, while others have operated without a single flag, making the city's grade a genuine average rather than a rounded-down high.
How Denison Compares
Data: EPA SDWIS Last verified: 2026-06-03
Denison Water: The Quick Version
- Average lead level: 0.0012 mg/L.
- Homes built before 1986: 82% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 14.62 — above typical levels.
Water Systems Serving Denison
Residential water service in Denison, IA is divided among 2 separate utilities, drawn from 2 systems on file with federal regulators.
Overview
We track water quality and home safety data for 1 ZIP code in Denison, Iowa, covering 2 community water systems serving approximately 9,586 people.
No EPA violations recorded across any ZIP codes in Denison — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Denison: C (60/100)
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
Denison water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0012 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 |
|---|---|---|---|
| 51442 | C | Denison Water Supply | 9,381 |
All ZIP Codes in Denison
- 51442 [C]
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 Denison
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
How Old Is Denison's Housing Stock?
With 82% 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 lead that enters tap water in older homes often comes not from the municipal supply but from the home's own plumbing — from solder used in copper joints before the 1986 federal ban, or from lead pipes installed before 1970. In Denison, where the median build year is 1978, these older materials are widespread. More than half the residential stock predates the 1986 solder ban, and a significant fraction predates 1970 as well. For residents in those homes, the city-wide water quality picture is a less relevant frame than the specific materials inside their own walls and under their own street.
Over half of homes in Denison 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.
Denison: Remediation Cost in Perspective
Looking at how documented remediation costs fit within Denison's property market, the equity share lands in the elevated tier — a result that positions the household financial perspective as one requiring structured preparation, where mapping costs against household budget, documenting scope early, and sequencing by urgency are the practical tools that distinguish manageable outcomes from financially disruptive ones.
At 2.1% of home value, remediation costs in Denison represent a significant financial burden. For homes valued near the median, fixing water and safety issues could cost $2,000–$4,000. Home values here are 11% below the Iowa average.
Protecting Children from Lead in Denison
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.
Households with kids in the home — for whom CDC guidance places particular weight on minimizing exposure — face a specific local picture in Denison. 82% of homes here come from the pre-rule era, and aggregate utility samples either approach or cross 0.015 mg/L. A baseline draw-test kit and certified lead-removal filtration are available via retailer networks for households confirming conditions at a specific tap.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Denison
A moderate NFIP record for Denison — 82 insurance claims paired with 100% of ZIP codes in FEMA flood zones — points to a flood history where water-quality pathways have likely been periodically relevant.
Denison has a moderate flood history with 82 FEMA claims averaging $20,690 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>$3,000</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 Denison
- 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 82% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Denison, IA