COUNTY REPORT MO

St. Clair County, Missouri

6 ZIP codes · Avg score 73/100 · Grade B · Updated 2026-06-03

Covering 6 ZIP codes, St. Clair County earns a high grade for tap water — most systems report zero health-based violations, and the overall compliance rate comfortably exceeds federal benchmarks.

How St. Clair County Compares

St. Clair County73/100
Missouri avg69/100
National avg68/100

How St. Clair County Compares

B
County Grade
73/100
Avg Safety Score
6
ZIP Codes
7
Water Systems

St. Clair County scores 4 points above the Missouri state average (69/100) and 5 points above the national average (68/100).

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

B
County Grade
73
Avg Safety Score
6
ZIP Codes
Best ZIP: 64738 (83/100)
Lowest ZIP: 64781 (53/100)
$141K
Median Home Value
$450
Avg Remediation (32% of home value)

ZIP Code Risk Map

Water Quality Map: St. Clair County, Missouri

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: 16.9 (asthma 10.8%, diabetes 16.2%)

Estimated additional annual cost per homeowner: $385, driven primarily by water_lead

Infrastructure: 0.398% avg pipe failure probability, 40% of ZIPs at high risk

70.8% of homes built before 1978 (lead paint era)

Violation History (2024–2025)

→ Stable trend

EPA violation counts by year across St. Clair County water systems. Health-based shown in red, total in blue.

2024
1 (1 health)
2025
1 (1 health)

Peak year: 2024 with 1 violation. Past 5 years: 2 total (2 health-based).

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 10.8% (national: 8.9%)
Diabetes 16.2% (national: 10.5%)
Obesity 37.6% (national: 32.4%)

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

Infrastructure Overview

1971
Median Build Year
70.8%
Pre-1978 Housing
40%
Pipe Failure Probability
40%
ZIPs at High Infra Risk
Low
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $385

Water / Lead $250/yr
Energy Code Gap $135/yr

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

Housing Age Distribution

4,733 housing units in St. Clair County

Pre-1940 17%
1940–1959 11%
1960–1979 32%
1980–1999 25%
2000+ 15%

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 St. Clair County

$141K
Median Home Value
$450
Est. Remediation Cost
0.3%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in St. Clair County, representing a small fraction of property value.

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 St. Clair County residents

Asthma 10.8% (US avg: 8.9%)
Diabetes 16.2% (US avg: 11%)
Obesity 37.6% (US avg: 32.4%)

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

Water Systems with Most Violations

Top 5 systems in St. Clair County ranked by EPA violation count.

# Water System Population Violations
1 Harry S Truman Pwsd 2 2,700 4
2 Bates County Pwsd 6 1,613 2
3 Bates County Pwsd 7 500 2
4 Appleton City Public Water System 1,518 2
5 Lowry City Public Water System 640 2

7 total water systems serve St. Clair County.

All ZIP Codes in St. Clair County

6 ZIP codes tracked in St. Clair County.

# ZIP Code City Safety Score Grade Violations Home Value
1 64738 Collins 83 B 1 $181K
2 64724 Appleton City 82 B 2 (1 health) $108K
3 64763 Lowry City 81 B 2 $142K
4 64776 Osceola 68 C 0 $141K
5 64789 Osceola 68 C 0
6 64781 Roscoe 53 D 0 $71K

Recommended Buyer Guides for St. Clair County

Where county records show a lead exceedance or pre-1978 housing concentration, lead-specific filters and test kits move toward the top of the list.

Overview

St. Clair County in Missouri covers 6 ZIP codes with an average Home Safety Score of B (73/100).

3 of 6 ZIP codes have recorded EPA violations. 1 health-based violation have been documented.

← Back to Missouri water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in St. Clair County?
St. Clair County receives a grade of B, indicating generally safe tap water across its 6 ZIP codes.
How many water systems serve St. Clair County?
St. Clair County is served by 7 public water systems that supply drinking water to residents across 6 ZIP codes.
What is the biggest environmental risk in St. Clair County?
The primary environmental risk factor in St. Clair County is water_lead. This contributes to an estimated additional annual cost of $385 per homeowner.
How old are homes in St. Clair County?
The median home build year in St. Clair County is 1971. 70.8% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does St. Clair County compare to Missouri?
St. Clair County has an average water safety score of 73/100, which is above the Missouri state average of 69/100.

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