Decatur, IL: 12 Violations — 55/100 (2026)
6 ZIP codes · 6 water systems · Updated 2026-06-03
Decatur shows moderate tap water quality for IL — some areas carry documented EPA violations while others meet standards without issues.
How Decatur Compares
Data: EPA SDWIS Last verified: 2026-06-03
Water Quality Map: Decatur, IL
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Score Distribution
How ZIP codes in Decatur score across all safety grades.
What You Should Know About Decatur Water
- Your city's water systems recorded 12 violations in the past 5 years.
- Average lead level: 0.0077 mg/L.
- Homes built before 1986: 85% — older plumbing may contain lead solder.
- Estimated remediation: $2,083 per household.
- CDC health risk index: 14.56 — above typical levels.
Who Supplies Your Water in Decatur
Structurally, Decatur, IL's water supply is divided. Federal data identifies 6 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 6 ZIP codes in Decatur, Illinois, covering 6 community water systems serving approximately 79,432 people.
6 of 6 ZIP codes (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Decatur: C (55/100)
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
Decatur water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0077 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)
- Zone 1 (High): 6 ZIP codes
- Zone 2 (Moderate): 0 ZIP codes
- Zone 3 (Low): 0 ZIP codes
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Contaminant 1009 | Other | 7 | 6 |
| Surface Water Treatment Rule | Treatment Technique | 7 | 6 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 62521 | C | 2 | 0 | Decatur |
| 62522 | D | 2 | 0 | Decatur |
| 62523 | C | 2 | 0 | Decatur |
| 62524 | C | 2 | 0 | Decatur |
| 62525 | C | 2 | 0 | Decatur |
| 62526 | D | 2 | 0 | Decatur |
All ZIP Codes in Decatur
- 62521 [C] — 2 violations
- 62522 [D] — 2 violations
- 62523 [C] — 2 violations
- 62524 [C] — 2 violations
- 62525 [C] — 2 violations
- 62526 [D] — 2 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.
Health Outcomes in Decatur
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
Top Contaminants in Decatur Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Decatur
With 85% 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
When more than half a city's housing predates the 1986 federal ban on lead solder, plumbing-era lead risk becomes a citywide concern rather than an exception. Decatur's median build year of 1956 places it squarely in that category.
Over half of homes in Decatur 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.
Cost Context: What Remediation Means for Decatur Homeowners
Middle of the range — Decatur homeowners face a remediation share that calls for real financial attention without reaching crisis territory.
Remediation costs are moderate relative to home values in Decatur. The estimated $1,383–$2,833 range is manageable for most homeowners but still worth budgeting for. Home values are 41% below the Illinois average.
Lead Exposure Risk for Children in Decatur
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 85% pre-rule share in Decatur 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.
Flood & Climate Risk in Decatur
Over the multi-decade window covered by the National Flood Insurance Program, Decatur has accumulated 181 claims — a total that suggests more than isolated flood exposure. With 67% 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.
Decatur has a moderate flood history with 181 FEMA claims averaging $5,993 per payout. 67% 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>$2,083</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 Decatur
- 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 Contaminant 1009 can reduce the most common contaminant found in Decatur's water.
- Check your home's plumbing. With 85% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Decatur, IL