States › Michigan › St. Clair County

St. Clair County, MI Water Quality

Water quality data for 20 public water systems serving St. Clair County, Michigan — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 20 water systems · 24 cities
✅
Excellent — All Systems Performing Well

Water quality across the county is outstanding with minimal violations and very low lead levels.

A

St. Clair County Earns a A

St. Clair County: 24 communities across 20 water systems. 100.0% have no open violations.

  • Median lead where detected: 2.30 ppb
  • 13 communities with a lead detection, 6 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 2 with significant inspection deficiencies
  • 100.0% of communities have no open violations
2.3 ppb
Median Lead Level
County-wide, 90th percentile
20
Water Systems
Active CWS & NTNCWS
100%
Violation-Free
No active violations on record
How we grade counties: MyWaterIQ uses EPA SDWIS enforcement data — actual MCL violations and lead test results — not the aspirational MCLG targets used by some sites. A grade reflects real compliance history, not theoretical risk. Learn more →

Cities by Water Quality

⭐ Best Performing
  • Riley
    Not reported
    No federal limits exceeded on record
    B
  • Fort Gratiot charter
    1.80 ppb
    No federal limits exceeded on record
    A
  • Clay
    3.44 ppb
    No federal limits exceeded on record
    A
  • Algonac
    1.60 ppb
    No federal limits exceeded on record
    A
  • Ira
    1.00 ppb
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Marine City
    2.30 ppb
    2 significant inspection deficiencies
    B
  • Mussey
    Not reported
    1 significant inspection deficiency
    B
  • Berlin
    5.90 ppb
    Lead at 5.90 ppb, above a third of the action level
    A
  • Port Huron
    5.10 ppb
    Lead at 5.10 ppb, above a third of the action level
    A
  • Marysville
    6.00 ppb
    Lead at 6.00 ppb, above a third of the action level
    A
County Lead Level — Median 2.3 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.3 ppb — 15.3% of the federal action level
Systems by Lead Level
Under 5 ppb
8
5 – 10 ppb
5
No Data
11

All Cities in St. Clair County

Port Huron 5.10 ppb A
Marysville 6.00 ppb A
Fort Gratiot charter 1.80 ppb A
St. Clair 2.00 ppb B
Port Huron charter 5.10 ppb A
Clay 3.44 ppb A
Algonac 1.60 ppb A
Marine City 2.30 ppb B
Ira 1.00 ppb A
St. Clair 2.00 ppb B
Mussey Not reported B
East China 8.00 ppb A
Yale Not reported B
Kimball Not detected A
Burtchville Not detected B
Cottrellville Not detected B
Clyde Not detected A
Columbus Not reported B
China 2.00 ppb B
Greenwood Not detected B
Brockway Not reported B
Casco Not detected A
Riley Not reported B
Berlin 5.90 ppb A
Showing 24 cities
No active violations Active violations

About St. Clair County Drinking Water

St. Clair County is served by 20 water systems covering 24 communities. No community here has an open violation on record.

Of the communities reporting lead results, 13 recorded a detection, with a median of 2.30 ppb — 15% of the federal action level. 6 reported none detected, which means below the laboratory limit rather than an absence of lead.

No community here has PFAS above the federal limit on record. State inspectors recorded significant deficiencies at 2 of them.

Frequently Asked Questions

Is St. Clair County tap water safe to drink?▼
No community in St. Clair County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in St. Clair County?▼
Among communities with a detection the median is 2.30 ppb, 15% of the 15 ppb action level. 6 reported none detected and 5 reported no result.
How many water systems serve St. Clair County?▼
20 community water systems serve 24 communities here.
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