States › Michigan › Cass County

Cass County, MI Water Quality

Water quality data for 10 public water systems serving Cass County, Michigan — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 10 water systems · 15 cities
✅
Excellent — All Systems Performing Well

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

A

Cass County Earns a A

Cass County: 15 communities across 10 water systems. 93.3% have no open violations.

  • Median lead where detected: 3.70 ppb
  • 10 communities with a lead detection, 4 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 1 with significant inspection deficiencies
  • 93.3% of communities have no open violations
3.7 ppb
Median Lead Level
County-wide, 90th percentile
10
Water Systems
Active CWS & NTNCWS
93%
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
  • Calvin
    Not detected
    No federal limits exceeded on record
    B
  • LaGrange
    Not reported
    No federal limits exceeded on record
    B
  • Howard
    2.00 ppb
    No federal limits exceeded on record
    A
  • Penn
    Not detected
    No federal limits exceeded on record
    B
  • Mason
    Not detected
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Ontwa
    3.40 ppb
    1 violation currently open
    C
  • Marcellus
    3.90 ppb
    Copper above the 1,300 ppb action level
    B
  • Porter
    1.51 ppb
    1 significant inspection deficiency
    B
  • Dowagiac
    12.00 ppb
    Lead at 12.00 ppb, above a third of the action level
    A
  • Wayne
    12.00 ppb
    Lead at 12.00 ppb, above a third of the action level
    A
County Lead Level — Median 3.7 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 3.7 ppb — 24.7% of the federal action level
Systems by Lead Level
Under 5 ppb
6
10 – 15 ppb
4
No Data
5

All Cities in Cass County

Dowagiac 12.00 ppb A
Ontwa 3.40 ppb C
Marcellus 3.90 ppb B
LaGrange Not reported B
Howard 2.00 ppb A
Wayne 12.00 ppb A
Pokagon 12.00 ppb A
Penn Not detected B
Porter 1.51 ppb B
Mason Not detected B
Silver Creek 12.00 ppb A
Jefferson 3.50 ppb B
Milton 2.00 ppb A
Newberg Not detected B
Calvin Not detected B
Showing 15 cities
No active violations Active violations

About Cass County Drinking Water

Cass County is served by 10 water systems covering 15 communities. 93% have no open violations.

Of the communities reporting lead results, 10 recorded a detection, with a median of 3.70 ppb — 25% of the federal action level. 4 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 1 of them.

Frequently Asked Questions

Is Cass County tap water safe to drink?▼
93% of communities have no open violation. No community has PFAS above the federal limit on record.
What is the lead level in Cass County?▼
Among communities with a detection the median is 3.70 ppb, 25% of the 15 ppb action level. 4 reported none detected and 1 reported no result.
How many water systems serve Cass County?▼
10 community water systems serve 15 communities here.
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