Thornton, CO: 8 Violations — 66/100 (2026)
1 ZIP code · 5 water systems · Updated 2026-06-03
In recent monitoring cycles, Thornton tap water shows a mixed record for CO — several systems have documented violations alongside areas with clean compliance histories.
How Thornton Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Thornton Residents
- Your city's water systems recorded 8 violations in the past 5 years.
- Average lead level: 0.0023 mg/L.
- Homes built before 1986: 18% — older plumbing may contain lead solder.
- Estimated remediation: $3,600 per household.
- CDC health risk index: 10.98.
Thornton's Water Providers
3 water utilities share the residential service territory in Thornton, CO — out of 5 total systems in federal records.
Overview
We track water quality and home safety data for 1 ZIP code in Thornton, Colorado (population ~33,393), covering 5 community water systems serving approximately 232,051 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Thornton: C (66/100)
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, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0023 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.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Fecal Coliform | Microbiological | 8 | 1 |
| Contaminant 1006 | Other | 2 | 1 |
| Gross Alpha | Radionuclides | 2 | 1 |
| Stage 1 DBP Rule | Treatment Technique | 2 | 1 |
| E. coli | Microbiological | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 80241 | C | 8 | 0 | City of Thornton |
All ZIP Codes in Thornton
- 80241 [C] — 8 violations
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
What's in Thornton's Water?
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Thornton Infrastructure Age
Housing age data helps assess potential lead pipe and infrastructure risks. Newer housing stock generally means lower plumbing-related contamination risk.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Lead exposure in tap water isn't just a function of what water utilities deliver — it's also shaped by the plumbing inside individual homes. Structures built before 1986 may contain lead-soldered copper joints, and homes built before 1970 face an additional risk from lead pipes themselves. Thornton's median build year of 1995 suggests the housing stock is broadly weighted toward the safer post-1986 era, but the age distribution shown above makes clear that the pre-1986 share of the inventory still represents a meaningful fraction worth understanding for anyone in an older home.
Most homes in Thornton were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
How Remediation Costs Compare in Thornton
In Thornton, property values comfortably outpace what documented remediation typically costs — the equity share is proportionally low.
Remediation costs in Thornton are relatively low compared to home values. The $2,400–$4,800 estimated range is a small fraction of median property value. Home values are 11% above the Colorado 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.
18% — that captures the slice of Thornton stock built before federal rules removed lead-bearing solder from new construction. Combined with system samples below the regulatory action mark, the picture points to a quiet baseline, with one-home draws as the only direct read on a specific address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Thornton: Flood History & Water Damage Risk
Although Thornton's flood history doesn't reach high-severity thresholds, NFIP data documents 1 claim and FEMA maps place 100% of ZIP codes in designated flood zones — a combined profile that makes flood-related water quality considerations a reasonable planning baseline.
Thornton has a moderate flood history with 1 FEMA claims. 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>$3,600</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 Thornton
- 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. Filters rated for Fecal Coliform can reduce the most common contaminant found in Thornton's water.
- Check your home's plumbing. Homes built before 1986 may have lead solder in pipes. A licensed plumber can assess your risk.
Deep Dive Reports
Detailed analysis for Thornton, CO