WaterQ
Illinois State Report All States
Official Status: March 2026

Is Oswego tap water safe to drink?

⚠ Caution Advised
D

Use extra caution — Oswego scores 42/100.

Safety Score
42
out of 100

Still not sure if you need a filter in Oswego?

Read Decision Guide →

Oswego

Illinois

View Illinois state report Data updated: Mar 2026

Is Oswego tap water safe to drink?

Use extra caution — Oswego scores 42/100. This report aggregates EPA drinking water data across 1 local system in Oswego. We found 285 total violations (34 unresolved).

Real-Time Environment

Live: 09:45 PM
0mm Precipitation

☀️ No active precipitation. Rainfall can impact surface water turbidity and pollutant runoff in Oswego.

Water Quality Impact

✅ Minimal Impact Localized weather conditions may influence test result variability.

🛡️ Home Water Treatment Needs

Should you invest in filtration or softening for your home in Oswego?

Requirement Status
Recommended
🟡
💡

Expert Advice

Given the safety margin, a Carbon Block or sediment filter is recommended to improve taste and remove trace particulates.

Buying a Filter?

Should you buy a water purifier in Oswego? See our analysis.

Baby Formula Safety

Is Oswego tap water safe for infants? Critical safety guide.

Homebuyer's Perspective

For those looking to relocate to Oswego, water quality is a key factor in long-term property maintenance. With a score of 42/100, we recommend budgeting for high-quality point-of-entry filtration systems to protect your home's value.

Property Impact: Requires Mitigation

Health & Family Safety

Residents should monitor Lead (90th percentile) levels. Pregnant women and families with young children should consult the specific EPA health goals listed below.

View Health Risk Glossary →

Compliance Record for Oswego

285
Violations (5yr)
34
Unresolved
1
Contaminants Tracked
0
Exceeding EPA Limit

Based on EPA SDWIS violation records and contaminant test results for all water systems serving Oswego.

Frequently Asked Questions

Is Oswego tap water safe to drink?

Use extra caution — Oswego scores 42/100.

How many water systems serve Oswego?

Oswego is served by 1 public water system in our latest EPA-backed dataset.

How can I check water quality for my exact address in Oswego?

Use the WaterQ search tool to look up your ZIP code and view nearby systems, contaminant levels, and recent violations for Oswego.

What is the water quality score for Oswego?

The water quality score for Oswego is 42 out of 100, based on EPA contaminant data, violation history, and testing results across the 1 system serving the city.

What are the top contaminants in Oswego?

The top contaminants detected in Oswego include Lead (90th percentile). View detailed information on our contaminants page.

Water Quality Score
42/100
Grade
F
Water Systems
1
Population
38,169

Oswego Water Quality Summary

Oswego, IL receives a water quality score of 42/100 (Grade F) based on EPA Safe Drinking Water Information System (SDWIS) compliance data for 1 public water system serving the area.

Oswego's water quality score is below the national average, indicating a history of EPA violations or elevated contaminant levels. Residents are encouraged to check their specific water system report and consider additional filtration.

Oswego's score of 42 is 24 points below the Illinois state average of 66, and below the nationwide average of roughly 78/100 across all U.S. states.

Water quality data is sourced from the U.S. EPA SDWIS database and updated quarterly. Learn about our scoring methodology → Read our Illinois water quality rankings report →

Key Contaminants

Lead (90th percentile)
0.00125 / 0.015 mg/L
0 mg/L MCL: 0.015 mg/L

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Water Systems Serving Oswego (1)

Related

Compare Oswego water quality: View all states · Contaminant library · How we score water quality