Dennison, OH: High Radon Risk — 65/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Dennison water quality is uneven — some service areas show clean compliance; others carry documented violations in OH EPA records.
How Dennison Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Dennison Residents
- Average lead level: 0.002 mg/L.
- Homes built before 1986: 76% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 15.38 — above typical levels.
Dennison's Water Providers
Structurally, Dennison, OH's water supply is divided. Federal data identifies 2 water systems in the area, with 2 providers serving the bulk of residential connections. These utilities operate independently, meaning rate-setting authority and EPA compliance accountability are distributed rather than centralized.
Overview
We track water quality and home safety data for 1 ZIP code in Dennison, Ohio (population ~4,639), covering 2 community water systems serving approximately 11,371 people region-wide.
No EPA violations recorded across any ZIP codes in Dennison — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Dennison: C (65/100)
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
Dennison water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0020 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 |
|---|---|---|---|
| 44621 | C | Twin City Water and Sewer District Public Water System | 9,224 |
All ZIP Codes in Dennison
- 44621 [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.
Dennison Community Health Snapshot
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
Dennison Infrastructure Age
With 76% 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
Because the majority of Dennison's housing predates 1986, when lead solder was banned from new plumbing, the median build year of 1966 reflects a city where lead-era plumbing materials are common rather than exceptional.
Over half of homes in Dennison 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.
How Remediation Costs Compare in Dennison
The Dennison remediation share exceeds what lower-tier markets face — the cost-to-value ratio here is elevated, and the household financial perspective reflects a commitment that most homeowners need to plan for explicitly.
At 2.0% of home value, remediation costs in Dennison represent a significant financial burden. For homes valued near the median, fixing water and safety issues could cost $1,600–$3,300. Home values here are 35% below the Ohio average.
Dennison: Lead Risk & Vulnerable Populations
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.
Routinely in Dennison, where 76% of housing predates the solder ban and aggregate utility readings hover near the federal threshold, a faucet-level draw functions as a standard household step for families with small kids.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Dennison: Flood History & Water Damage Risk
Flood risk in Dennison occupies the middle ground: 11 NFIP claims and 100% of local ZIP codes within FEMA flood zones. At that level, the risk pathways connecting flooding to water quality — treatment system stress, well infiltration, distribution backflow — become relevant considerations during significant flood events, even if day-to-day water quality is unaffected by flood history.
Dennison has a moderate flood history with 11 FEMA claims averaging $4,206 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>$2,400</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 Dennison
- 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 76% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Dennison, OH