Northbrook, IL: Lead Above EPA Limits — 43/100 (2026)
2 ZIP codes · 8 water systems · Updated 2026-06-03
Although conditions vary by service area, Northbrook's water systems collectively show below-average compliance within IL — health-based violations are documented throughout the city, and the overall grade reflects a pattern rather than isolated incidents.
How Northbrook Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Northbrook Residents
- Your city's water systems recorded 8 violations in the past 5 years.
- Average lead level: 0.016 mg/L — exceeds the EPA action level of 0.015 mg/L.
- Estimated remediation: $3,010 per household.
- CDC health risk index: 11.18.
Northbrook's Water Providers
Water delivery in Northbrook, IL is handled by 3 utilities rather than a single system — drawn from 8 providers in federal records, each filing its own compliance reports and setting its own rates.
Overview
We track water quality and home safety data for 2 ZIP codes in Northbrook, Illinois (population ~41,667), covering 8 community water systems serving approximately 149,448 people region-wide.
2 of 2 ZIP codes (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Northbrook: D (43/100)
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
Northbrook water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0160 mg/L (exceeds EPA action level) (EPA action level: 0.015 mg/L)
- 2 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 2 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 |
|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 6 | 2 |
| Stage 2 DBP Rule | Treatment Technique | 6 | 2 |
Areas with Most Violations
All ZIP Codes in Northbrook
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.
Northbrook 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 Northbrook's Water?
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Remediation Costs Compare in Northbrook
What does remediation cost in financial context for Northbrook homeowners? Proportionally very little — the equity share here is low, and addressing documented issues is a manageable planning question rather than a material financial burden.
Remediation costs in Northbrook are relatively low compared to home values. The $1,740–$4,380 estimated range is a small fraction of median property value. Home values are 240% above the Illinois average.
Northbrook: 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.
If you have young children or are pregnant, consider testing your home's water — especially if your home was built before 1986.
<strong>2 ZIP codes</strong> (100% of the city) exceed the EPA lead action level of 0.015 mg/L.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Northbrook: Flood History & Water Damage Risk
The National Flood Insurance Program captures decades of claims at the local level, building a record of cumulative community flood exposure. For Northbrook, that record documents 127 claims and 50% of ZIP codes inside FEMA-designated flood zones. What makes those numbers relevant to water quality is the set of mechanisms flooding activates: heavy precipitation that floods treatment intake zones can introduce contaminants upstream of normal filtration; well casings in low-lying areas can be infiltrated by floodwaters carrying bacteria, sediment, and chemical residue; and distribution system pressure changes during flooding can create backflow conditions. These effects become more probable as flood frequency and magnitude increase — and the NFIP record indicates both are meaningful factors locally.
Northbrook has a moderate flood history with 127 FEMA claims averaging $14,838 per payout. 50% 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>$3,010</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 Northbrook
- Test your water at home. City-level data shows averages — your tap may differ. Lead testing is especially recommended given the area's lead levels.
- Install a certified water filter. Filters rated for Total Trihalomethanes (TTHM) can reduce the most common contaminant found in Northbrook's water.
- Check your home's plumbing. Homes built before 1986 may have lead solder in pipes. A licensed plumber can assess your risk.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Northbrook, IL