D
54

Poor Water Quality

Joliet, IL 60436

Will County · Population served: 162,012 · Data updated March 2026

Water Systems Serving This Area

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JOLIET
Groundwater · Pop. 160,000
PWSID: IL1970450
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ROCKDALE
Groundwater · Pop. 2,012
PWSID: IL1970850

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
13.0
15 ppb 1 ppb Warning
Copper
1360.0
1300 ppb 300 ppb Exceeded

Violation History (Last 5 Years)

36Total (5yr)
1Health-Based
23Major

Water Quality Summary

Understanding Your Water in Joliet

Tap water quality in Joliet, Illinois (60436) receives an overall grade of D (Poor) with a score of 54 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 20 points below the Illinois state average of 74. Compared to the national average (75), this area scores significantly lower. The area is served by 2 water systems providing water to approximately 162,012 people, using groundwater sources. Testing has found elevated levels of Lead, Copper that warrant attention. Over the past 5 years, water systems here have accumulated 36 violations, including 1 health-based violations.

Your Score 54/100 D
vs State 20 pts below Illinois avg (74)
vs National 21 pts below national avg (75)

What a Grade D Means

A score of 54/100 signals poor water quality in Joliet, IL. Significant issues have been identified, which may include multiple violations, contaminant levels near or above regulatory limits, or PFAS contamination. We recommend reviewing the detailed contaminant data below, considering a certified water filter, and checking your utility's Consumer Confidence Report for the latest information.

Groundwater: drawn from underground aquifers via wells

Health Information

What These Contaminants Mean for You

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Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

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Copper in Your Water

Copper can leach into water from copper plumbing, especially in newer homes or when water is acidic.

Health Effects

Short-term exposure above 1,300 ppb can cause gastrointestinal distress. Long-term exposure may cause liver or kidney damage. People with Wilson's disease are especially vulnerable.

Common Sources

Copper pipes, fittings, and faucets are the most common source. Corrosive (low-pH) water accelerates copper leaching.

What You Can Do

If copper levels are elevated, flush pipes by running water for 15–30 seconds before use. Reverse osmosis and distillation systems effectively remove copper.

Common Questions

Frequently Asked Questions

Tap water in Joliet, Illinois receives a grade of D (Poor) with a score of 54/100. This indicates significant water quality concerns based on violation history, contaminant levels, or enforcement actions. We recommend reviewing the specific contaminants detected below and considering a certified water filter.

ZIP code 60436 is served by 2 water systems using groundwater sources, providing water to approximately 162,012 people. Groundwater is naturally filtered through rock and soil, often requiring less treatment. However, it can be vulnerable to contamination from underground sources like naturally occurring arsenic, nitrates from agriculture, or PFAS from industrial sites.

Lead was detected at 13.0 ppb in Joliet, Illinois. While this is below the EPA action level of 15 ppb, it exceeds the health guideline of 1 ppb recommended by health organizations. Consider a certified lead filter, especially if you have young children.

No PFAS ("forever chemicals") were detected in water systems serving Joliet, Illinois during the most recent EPA monitoring period (UCMR5). However, not all water systems have been tested for all PFAS compounds, and new contamination can occur over time.

Water systems serving Joliet, Illinois have received 36 violations in the last 5 years, including 1 health-based violation. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (lead, copper), residents in Joliet, Illinois should consider: NSF/ANSI 53 certified filter — specifically rated for lead reduction. Pitcher filters (like Brita Longlast or PUR) and under-sink systems both work. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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