Water Quality in Northbrook, IL: 8 Violations — Grade D
Grade D · Score 43/100 · 5 water systems · Updated 2026-05-03
Northbrook's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Drinking water compliance data for Northbrook, IL reflects 8 EPA violations — details in the grid below.
Water Quality by ZIP Code in Northbrook
Water quality varies across Northbrook's 2 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 60062 | D | 42 | 4 | 0 | View report → |
| 60065 | D | 44 | 4 | 0 | View report → |
Water Quality Overview
Northbrook, Illinois receives a water quality grade of D with an overall score of 43 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Northbrook have accumulated 8 EPA violations (all monitoring/reporting type). These violations are tracked across 2 ZIP codes serving approximately 42,671 people.
What Grade D Means
A grade of D indicates significant compliance issues. Northbrook's water systems have accumulated violations that suggest ongoing water quality challenges. Residents should check their specific ZIP code report and consider water testing or filtration.
Lead Levels
The average 90th percentile lead level across Northbrook water systems is 0.0160 mg/L — this exceeds the EPA action level of 0.015 mg/L. 2 ZIP codes exceed the EPA lead action level.
With 67% of homes built before 1986, Northbrook has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Northbrook is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Northbrook
Northbrook is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 42,671 people across 2 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 20 enforcement actions against water systems serving Northbrook. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Northbrook
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Northbrook Water Systems
The following contaminants have been detected or caused violations across Northbrook's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 4 | 2 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 4 | 2 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 6 enforcement actions against water systems serving Northbrook. Recent actions:
| Date | Action Type |
|---|---|
| 2025-08-12 | State Informal Action |
| 2025-07-03 | State Informal Action |
| 2025-07-03 | State Informal Enforcement |
| 2025-07-02 | State Informal Action |
| 2025-07-02 | State Informal Enforcement |
| 2024-05-13 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-08-12.
Northbrook vs. Nearby Illinois Cities
How Northbrook's water quality compares to similar cities in Illinois:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Northbrook | D | 8 | 5 | 42,671 |
| Buffalo Grove | B | 2 | 1 | 43,212 |
| East Saint Louis | D | 0 | 4 | 43,673 |
| Bartlett | C | 0 | 1 | 41,500 |
Common Questions About Northbrook Water
These are the most common questions residents search for about water quality in Northbrook, Illinois:
Is Northbrook water hard or soft? Water hardness varies by source. Northbrook's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Northbrook tap water? Northbrook's water receives a grade of D (43/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Northbrook? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Northbrook vs. Illinois Average
Understanding how Northbrook compares to the broader Illinois average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Northbrook.
ZIP Codes in Northbrook
Northbrook spans 2 ZIP codes. The ZIP with the lowest water quality score is 60062. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
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
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.