CITY REPORT IL

Oswego, IL: 2 Violations — 64/100 (2026)

1 ZIP code · 8 water systems · Updated 2026-06-03

Unlike higher-rated cities in IL, Oswego carries a fair number of documented violations — the pattern of compliance gaps keeps the city in the middle tier of EPA safety rankings.

How Oswego Compares

Oswego64/100
Illinois avg61/100
National avg67/100

Data: EPA SDWIS Last verified: 2026-06-03

1
ZIP Codes
8
Water Systems
1
ZIPs with Violations
C · 64
Avg Safety Score
Zone 1
Radon Risk (High)
$319K
Median Home Value
$2,400
Est. Remediation (0.8% of home value)

What You Should Know About Oswego Water

  • Your city's water systems recorded 2 violations in the past 5 years.
  • Average lead level: 0.0013 mg/L.
  • Homes built before 1986: 24% — older plumbing may contain lead solder.
  • Estimated remediation: $2,400 per household.
  • CDC health risk index: 11.2.

Who Supplies Your Water in Oswego

3 independent water providers serve Oswego, IL — 8 systems appear in federal records.

Aurora
Serves ~183,000 people · 2 violations
64
/100
Joliet
Serves ~160,000 people · 2 violations
64
/100
Plainfield
Serves ~50,000 people · 2 violations
64
/100

Overview

We track water quality and home safety data for 1 ZIP code in Oswego, Illinois (population ~41,723), covering 8 community water systems serving approximately 483,291 people region-wide.

1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.

Home Safety Score

Average Home Safety Score for Oswego: C (64/100)

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

Oswego water systems draw from: Groundwater.

Lead & Copper

  • Average lead level (90th percentile): 0.0013 mg/L (EPA action level: 0.015 mg/L)
  • 0 ZIP codes exceed the EPA lead action level

Radon Risk

Dominant radon zone: Zone 1 (High Risk)

The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.

Top Contaminants

Contaminant Category Violations ZIPs Affected
Surface Water Treatment Rule Treatment Technique 2 1
Revised Total Coliform Rule Microbiological 2 1

Areas with Most Violations

ZIP Code Safety Score Violations Health-Based System
60543 C 2 0 Oswego

All ZIP Codes in Oswego

  • 60543 [C] — 2 violations

Data Sources

Updated daily.

Health Outcomes in Oswego

9.5%
Asthma (US: 9.8%)
9.4%
Diabetes (US: 10.4%)
15.4%
Poor Mental Health (US: 14.8%)

Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.

Compared to National Average

Asthma 9.5% ↓
Diabetes 9.4% ↓
Mental Health 15.4% ↑

Vertical line = national average. Above national · Below national

Top Contaminants in Oswego Water

Surface Water Treatment Rule 2 violations
Treatment Technique
Pathogens may not be adequately removed
Revised Total Coliform Rule 2 violations
Microbiological
Indicates possible bacterial contamination

Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.

Housing & Infrastructure in Oswego

1992
Median Build Year
24%
Built Before 1986
7%
Built Before 1970
Copper
Likely Pipe Material

Housing age data helps assess potential lead pipe and infrastructure risks. Newer housing stock generally means lower plumbing-related contamination risk.

Source: U.S. Census Bureau American Community Survey (ACS).

Housing Age Profile

Compared to many older metro areas, Oswego carries a relatively newer housing profile — the median build year of 1992 places most of the stock in the post-1986 era when lead solder was federally banned from new plumbing. That shift meaningfully reduces the baseline likelihood of lead leaching from copper joint solder. Homes from before 1986 do still exist in the mix, however, and individual testing remains the only way to confirm what a specific tap actually delivers.

1992
Median Year Built
24%
Pre-1986 (Lead Paint Risk)
7%
Pre-1970 (Lead Pipes Risk)
Pre-1970 (7%) 1970–1986 (17%) Post-1986 (76%)

Most homes in Oswego were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.

Source: U.S. Census Bureau ACS B25034.

Cost Context: What Remediation Means for Oswego Homeowners

What does remediation cost in financial context for Oswego 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.

Median Home Value
$319,300
Est. Remediation
$2,400
Remediation as % of home value 0.8%

Remediation costs in Oswego are relatively low compared to home values. The $1,600–$3,300 estimated range is a small fraction of median property value. Home values are 74% above the Illinois average.

Lead Exposure Risk for Children in Oswego

24%
Homes Built Before 1986
0.0013
mg/L Avg Lead (Limit: 0.015)

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.

Although citywide aggregate readings pass cleanly and just 24% of Oswego housing comes from the pre-rule era, the difference between what utilities sample and what arrives at one specific faucet remains a structural feature of how monitoring works. Households with kids in the home can find a certified lead-removal filter and a draw-test kit through retailer-verified channels. That step is independent of system-level data.

Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.

Flood & Climate Risk in Oswego

The National Flood Insurance Program captures decades of claims at the local level, building a record of cumulative community flood exposure. For Oswego, that record documents 23 claims and 100% 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.

23
Total FEMA Flood Claims
$10,426
Avg Claim Payout
100%
ZIPs in FEMA Flood Zones
~1
Est. Claims/Year

Oswego has a moderate flood history with 23 FEMA claims averaging $10,426 per payout. 100% 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>$2,400</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 Oswego

  1. Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
  2. Install a certified water filter. Filters rated for Surface Water Treatment Rule can reduce the most common contaminant found in Oswego's water.
  3. Check your home's plumbing. Homes built before 1986 may have lead solder in pipes. A licensed plumber can assess your risk.

Frequently Asked Questions

Is the water safe to drink in Oswego, IL?
Oswego has an average water safety score of 64/100 (Grade C). 2 EPA violations have been recorded. Check individual ZIP code reports for details specific to your neighborhood.
How many water violations does Oswego have?
Oswego water systems have a total of 2 EPA violations. Violations are tracked across 1 ZIP code.
Does Oswego water have lead?
The average 90th-percentile lead level in Oswego is 0.0013 mg/L. This is below the EPA action level of 0.015 mg/L. Lead levels can vary by home — testing is recommended especially in older properties.
How does Oswego compare to Illinois average?
Oswego has an average water safety score of 64/100, which is above the Illinois state average of 61/100.
How many water systems serve Oswego?
Oswego is served by 8 public water systems across 1 ZIP code, serving approximately 41,723 people.
How much does it cost to fix water issues in Oswego?
Estimated remediation costs in Oswego average $2,400 per household, ranging from $1,600 to $3,300. Costs include filtration, pipe replacement, radon mitigation, and flood protection.
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