St. Clair County, Michigan
19 ZIP codes · Avg score 78/100 · Grade B · Updated 2026-06-03
Based on current EPA data, St. Clair County's 19 ZIP codes maintain an above-average drinking water safety record.
How St. Clair County Compares
How St. Clair County Compares
St. Clair County scores 4 points above the Michigan state average (74/100) and 10 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: St. Clair County, Michigan
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.6 (asthma 11.7%, diabetes 12.5%)
Estimated additional annual cost per homeowner: $1,568, driven primarily by flood
Infrastructure: 0.364% avg pipe failure probability, 26% of ZIPs at high risk
60% of homes built before 1978 (lead paint era)
Violation History (2021–2024)
→ Stable trendEPA violation counts by year across St. Clair County water systems. Health-based shown in red, total in blue.
Peak year: 2021 with 4 violations. Past 5 years: 7 total (7 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,568
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
65,105 housing units in St. Clair County
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
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
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 | Capac, Village of | 1,775 | 6 |
| 2 | YALE, CITY OF | 1,900 | 5 |
| 3 | City of Port Huron, | 33,800 | 5 |
| 4 | Dunrentin Heights Subdivision | 81 | 5 |
| 5 | Port Huron Township | 10,654 | 4 |
17 total water systems serve St. Clair County.
All ZIP Codes in St. Clair County
19 ZIP codes tracked in St. Clair County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 48061 | Port Huron | 94 | A | 2 | — |
| 2 | 48040 | Marysville | 92 | A | 3 | $186K |
| 3 | 48097 | Yale | 91 | A | 5 (1 health) | $175K |
| 4 | 48059 | Fort Gratiot | 90 | A | 1 | $199K |
| 5 | 48060 | Port Huron | 89 | A | 2 | $152K |
| 6 | 48041 | Memphis | 88 | A | 0 | $296K |
| 7 | 48063 | Columbus | 86 | A | 2 (1 health) | $298K |
| 8 | 48014 | Capac | 84 | B | 6 | $208K |
| 9 | 48039 | Marine City | 84 | B | 2 (1 health) | $171K |
| 10 | 48001 | Algonac | 80 | B | 1 | $250K |
| 11 | 48022 | Emmett | 73 | B | 0 | $246K |
| 12 | 48032 | Jeddo | 73 | B | 0 | $240K |
| 13 | 48074 | Smiths Creek | 73 | B | 0 | $192K |
| 14 | 48002 | Allenton | 66 | C | 0 | $295K |
| 15 | 48006 | Avoca | 66 | C | 0 | $226K |
| 16 | 48049 | North Street | 66 | C | 0 | $226K |
| 17 | 48454 | Melvin | 66 | C | 0 | $178K |
| 18 | 48079 | Saint Clair | 65 | C | 0 | $277K |
| 19 | 48028 | Harsens Island | 55 | C | 0 | $339K |
Recommended Buyer Guides for St. Clair County
While many sites publish identical guide lists across every county they cover, the selection here changes by location — driven by the EPA, NSF, FEMA, and CDC datasets that describe the actual conditions documented for this jurisdiction in the federal record.
- Best Lead Paint Test Kits — 60% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for St. Clair County, Michigan
Overview
St. Clair County in Michigan covers 19 ZIP codes with an average Home Safety Score of B (78/100).
9 of 19 ZIP codes have recorded EPA violations. 3 health-based violations have been documented.
← Back to Michigan water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.