Water Quality in Joliet, IL: 306 Violations — Grade D
Grade D · Score 49/100 · 5 water systems · Updated 2026-05-03
Joliet's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Joliet, IL — 306 compliance events documented in the federal drinking water record.
Water Quality Map: Joliet, IL
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Joliet
Water quality varies across Joliet's 6 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 60432 | D | 44 | 51 | 7 | View report → |
| 60433 | D | 44 | 51 | 7 | View report → |
| 60431 | D | 49 | 51 | 7 | View report → |
| 60435 | D | 49 | 51 | 7 | View report → |
| 60436 | D | 49 | 51 | 7 | View report → |
| 60434 | C | 59 | 51 | 7 | View report → |
Violation Trend
EPA violations recorded for water systems serving Joliet.
Water Quality Overview
Joliet, Illinois receives a water quality grade of D with an overall score of 49 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Joliet have accumulated 306 EPA violations, including 42 health-based violations. These violations are tracked across 6 ZIP codes serving approximately 165,747 people.
What Grade D Means
A grade of D indicates significant compliance issues. Joliet'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 Joliet water systems is 0.0070 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 70% of homes built before 1986, Joliet 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
Joliet is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Joliet
Joliet is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 165,747 people across 6 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 60 enforcement actions against water systems serving Joliet. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Joliet
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 Joliet Water Systems
The following contaminants have been detected or caused violations across Joliet's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Stage 2 DBP Rule | Treatment Technique | N/A | 54 | 6 | Yes |
| Surface Water Treatment Rule | Treatment Technique | N/A | 48 | 6 | No |
| Revised Total Coliform Rule | Microbiological | N/A | 42 | 6 | No |
| Lead and Copper Rule | Treatment Technique | N/A | 42 | 6 | No |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 42 | 6 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 12 | 6 | Yes |
| Gross Beta | Radionuclides | 50 pCi/L | 6 | 6 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving Joliet:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2022 | 6 | 6 |
| 2023 | 6 | 6 |
| 2024 | 30 | 30 |
Violations have increased from 6 in 2022 to 30 in 2024. This trend warrants monitoring.
EPA Enforcement History
The EPA and state regulators have taken 8 enforcement actions against water systems serving Joliet. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-26 | State Order Extension |
| 2025-09-24 | State Informal Action |
| 2025-09-22 | State Informal Action |
| 2025-09-06 | State Informal Action |
| 2025-08-22 | State Informal Action |
| 2025-08-22 | State Informal Enforcement |
| 2025-08-07 | State Informal Action |
| 2025-08-05 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-26.
Joliet vs. Nearby Illinois Cities
How Joliet's water quality compares to similar cities in Illinois:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Joliet | D | 306 | 5 | 165,747 |
| Champaign | C | 12 | 3 | 163,680 |
| Naperville | B | 6 | 1 | 156,406 |
| Kankakee | D | 8 | 5 | 153,577 |
Recommended Water Filters for Joliet
Based on contaminants detected in Joliet's water supply, these filter types are recommended:
Reverse Osmosis (under-sink)
- Removes: Copper, Lead, Gross Alpha (excluding radon and uranium)
- Effectiveness: 95-99%
- Cost range: $150–$500
- Certification: NSF/ANSI 58
- Recommended products:
- Waterdrop G3P800
- Aquasana AQ-5200
- Clearly Filtered Pitcher
Ion Exchange Water Softener (POE)
- Removes: Likely Source of ContaminationCombined Radium226/228
- Effectiveness: 90-97%
- Cost range: $500–$2500
- Certification: NSF/ANSI 44
- Recommended products:
- Waterdrop G3P800
- Fleck 5600SXT Softener
Water Quality by ZIP Code in Joliet
Water quality varies across Joliet's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 60432 | 44 | D | 51 | 7 |
| 60433 | 44 | D | 51 | 7 |
| 60431 | 49 | D | 51 | 7 |
| 60435 | 49 | D | 51 | 7 |
| 60436 | 49 | D | 51 | 7 |
| 60434 | 59 | C | 51 | 7 |
Common Questions About Joliet Water
These are the most common questions residents search for about water quality in Joliet, Illinois:
Is Joliet water hard or soft? Water hardness varies by source. Joliet's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Joliet tap water? Joliet's water receives a grade of D (49/100). There are 42 health-based violations — consider filtration.
What is the best water filter for Joliet? Based on detected contaminants, a reverse osmosis (under-sink) filter is most recommended. See our Water Filter Matcher for personalized recommendations.
Joliet vs. Illinois Average
Understanding how Joliet 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 Joliet.
ZIP Codes in Joliet
Joliet spans 6 ZIP codes. The ZIP with the lowest water quality score is 60431. 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.