COUNTY REPORT IL

Williamson County, Illinois

10 ZIP codes · Home Safety Score unavailable · 0 of 10 tracked ZIP records scored

Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData

Unavailable
0 of 10 tracked ZIP records scored
10
ZIP Codes
$101K
Median Home Value
$817
Avg Remediation (0.81% of home value)

ZIP Code Risk Map

Water Quality Map: Williamson County, Illinois

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 14 (asthma 10.5%, diabetes 12.4%)

Modeled additional annual cost estimate per homeowner: $1,167, largest modeled factor: Flood

50% of homes built before 1980 (lead paint was banned for residential use in 1978)

County Health Indicators vs National Average

Asthma 10.5% (national: 8.9%)
Diabetes 12.4% (national: 10.5%)
Obesity 40.1% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1978
Median Build Year
50%
Pre-1980 Housing
44/100
Infrastructure Stress Indicator
80%
ZIPs with High Infrastructure Stress
High
Lead Pipe Risk

Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINSA infrastructure needs, EPA SDWIS violations, and EPA lead indicators.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $1,167

Flood $767/yr
Energy Code Gap $432/yr
Water / Lead $306/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

28,780 housing units in Williamson County

Pre-1940 15%
1940–1959 12%
1960–1979 23%
1980–1999 25%
2000+ 25%

Source: U.S. Census Bureau ACS B25034 (Year Structure Built).

Water Safety Affordability

How much it costs to fix water issues relative to home values in Williamson County

$101K
Median Home Value
$817
Est. Remediation Cost
0.8%
of Home Value
Remediation as % of home value low burden

Modeled remediation costs in Williamson County can be compared with the median property value; actual costs vary by property.

Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.

Health Outcomes vs National Average

CDC PLACES data for Williamson County residents

Asthma 10.5% (US avg: 8.9%)
Diabetes 12.4% (US avg: 11%)
Obesity 40.1% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water systems mapped to Williamson County ZIP codes

8 community water systems mapped to Williamson County ZIP codes; EPA may list more systems serving the county.

Show all 8 water systems

14 water systems mapped to Williamson County ZIP codes in our data; EPA may list more systems serving the county.

Systems with the most violations in Williamson County

5 water systems with violations in EPA records.

All ZIP Codes in Williamson County

10 ZIP codes tracked in Williamson County.

# ZIP Code City Safety Score Grade Violations Home Value
1 62841 Freeman Spur — — 4 $64K
2 62915 Cambria — — 2 $78K
3 62918 Carterville — — 52 (10 health) $183K
4 62921 Colp — — $75K
5 62933 Energy — — 13 $139K
6 62948 Herrin — — 13 $112K
7 62949 Hurst — — 6 (1 health) $74K
8 62951 Johnston City — — 22 (2 health) $90K
9 62959 Marion — — 22 (6 health) $166K
10 62974 Pittsburg — — 3 (3 health) $162K

Recommended Buyer Guides for Williamson County

When no specific signal shows up in the records, the list falls back to general water testing and filtration guides rather than staying empty.

Overview

Williamson County in Illinois covers 10 tracked ZIP records. No Home Safety Score is published because the required model evidence is incomplete for every tracked record; missing evidence is not treated as zero.

9 of 9 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 15 health-based violations appear in the available health breakdown.

← Back to Illinois Home Safety Profile

Data Sources

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.

Frequently Asked Questions

How many water systems serve Williamson County?
We map 14 public water systems to 10 ZIP codes in our data for Williamson County. EPA may list more systems serving the county, so this is not a full count.
What is the biggest environmental risk in Williamson County?
In ZipCheckup's cost model, the factor with the largest estimated average annual cost in Williamson County is flood. Across all modeled risk factors, the estimated average additional annual cost is $1,167 per homeowner; actual costs vary by home.
How old are homes in Williamson County?
The median home build year in Williamson County is 1978. 50% of homes were built before 1980; homes built before 1978 may contain lead-based paint, and older homes may have older plumbing materials.

How to cite this page

APA ZipCheckup. (2026). Williamson County, Illinois Home Safety Profile. https://zipcheckup.com/county/illinois/williamson/
BibTeX
@misc{zipcheckup-county-illinois-williamson,
  author = {{ZipCheckup}},
  title  = {{Williamson County, Illinois Home Safety Profile}},
  year   = {2026},
  url    = {https://zipcheckup.com/county/illinois/williamson/}
}

Page version: October 2026.

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