Thornton, IA: High Radon Risk — 70/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Across Thornton, EPA monitoring data shows low violation rates and healthy safety margins — a pattern that places the city well above IA's average for drinking water compliance across recent reporting cycles.
How Thornton Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Thornton Residents
- Average lead level: 0.002 mg/L.
- Homes built before 1986: 87% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 14.3 — above typical levels.
Thornton's Water Providers
A single utility carries the primary residential water load in Thornton, IA — the dominant provider across 1 federally tracked system.
Overview
We track water quality and home safety data for 1 ZIP code in Thornton, Iowa, covering 1 community water system serving approximately 783 people.
No EPA violations recorded across any ZIP codes in Thornton — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Thornton: B (70/100)
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
Thornton 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 |
|---|---|---|---|
| 50479 | B | Thornton Water Supply | 400 |
All ZIP Codes in Thornton
- 50479 [B]
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.
Thornton 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
Thornton Infrastructure Age
With 87% 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
Decades of residential development in Thornton took place before the two main regulatory milestones that reduced plumbing-era lead risk: the phase-out of lead pipes before 1970, and the federal ban on lead solder in 1986. With a median build year of 1943, the housing stock here is anchored in that earlier period. The distinction between pre-1970 and 1970-to-1986 construction matters: the oldest homes may have lead pipes in the service line and lead solder in the copper joints, while the 1970-to-1986 tier still carries the solder risk even after lead pipes became less common. Together, these two risk layers affect a majority of the residential properties in the city — a fact the aggregate water quality data doesn't directly reveal.
Over half of homes in Thornton 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 Thornton
Looking at how documented remediation costs fit within Thornton'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 Thornton 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 32% below the Iowa average.
Thornton: 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.
Households with kids in the home — for whom CDC guidance places particular weight on minimizing exposure — face a specific local picture in Thornton. 87% 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.
Thornton: Flood History & Water Damage Risk
A moderate NFIP record for Thornton — 2 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.
Thornton has a moderate flood history with 2 FEMA claims averaging $1,331 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.
Deep Dive Reports
Detailed analysis for Thornton, IA