Thomson, IL: 3 Violations — 67/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Compared to top-scoring cities in IL, Thomson lands in the middle tier — some water systems meet standards cleanly, others carry documented violations, and performance can vary significantly across service areas.
How Thomson Compares
Data: EPA SDWIS Last verified: 2026-06-03
Thomson Water: The Quick Version
- Your city's water systems recorded 3 violations in the past 5 years.
- Average lead level: 0.0006 mg/L.
- Homes built before 1986: 62% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 14.57 — above typical levels.
Water Systems Serving Thomson
Structurally, Thomson, IL's water supply is divided. Federal data identifies 3 water systems in the area, with 3 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 Thomson, Illinois (population ~2,687), covering 3 community water systems serving approximately 5,766 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 Thomson: C (67/100)
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
Thomson water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0006 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 |
|---|---|---|---|
| Gross Beta | Radionuclides | 4 | 1 |
| Stage 2 DBP Rule | Treatment Technique | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 61285 | C | 3 | 0 | Savanna |
All ZIP Codes in Thomson
- 61285 [C] — 3 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.
CDC Health Data for Thomson
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
Key Contaminants Detected in Thomson
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Thomson's Housing Stock?
With 62% 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
Lead solder was standard in copper plumbing until federally banned in 1986; lead pipes were common in service lines pre-1970. Thomson's median build year of 1974 reflects a housing stock where these older materials are a pervasive feature — not a rare legacy — of the residential plumbing landscape.
Over half of homes in Thomson 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.
Thomson: Remediation Cost in Perspective
Remediation costs in Thomson represent a moderate share of typical home values — worth budgeting for carefully, though within reach for most homeowners who plan ahead.
Remediation costs are moderate relative to home values in Thomson. The estimated $2,000–$4,000 range is manageable for most homeowners but still worth budgeting for. Home values are 10% below the Illinois average.
Protecting Children from Lead in Thomson
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.
Even where utility-side monitoring meets Lead and Copper Rule requirements, the 62% pre-rule share in Thomson keeps interior-plumbing variation as a household-level question that aggregate data cannot resolve.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Thomson
Over the multi-decade window covered by the National Flood Insurance Program, Thomson has accumulated 4 claims — a total that suggests more than isolated flood exposure. With 100% of ZIP codes in designated flood zones, the water-quality implications of flooding move from hypothetical to periodically relevant: treatment intake can be compromised, wells can be infiltrated, and distribution backflow can occur.
Thomson has a moderate flood history with 4 FEMA claims averaging $27,442 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 Thomson
- 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 Gross Beta can reduce the most common contaminant found in Thomson's water.
- Check your home's plumbing. With 62% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Thomson, IL