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Ottawa County, OH Water Quality

Water quality data for 7 public water systems serving Ottawa County, Ohio — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 7 water systems · 8 cities
✅
Generally Safe — Most Systems Performing Well

The majority of water systems have no active violations and lead levels well below the federal action level.

B

Ottawa County Earns a B

Ottawa County: 8 communities across 7 water systems. 100.0% have no open violations.

  • Median lead where detected: 1.00 ppb
  • 3 communities with a lead detection, 5 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 2 with significant inspection deficiencies
  • 100.0% of communities have no open violations
1 ppb
Median Lead Level
County-wide, 90th percentile
7
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
  • Port Clinton
    Not detected
    No federal limits exceeded on record
    A
  • Oak Harbor
    Not detected
    No federal limits exceeded on record
    A
  • Marblehead
    1.00 ppb
    1 health-based violation since 2015
    B
  • Lakeside
    1.00 ppb
    1 health-based violation since 2015
    B
  • Elmore
    Not detected
    3 significant inspection deficiencies
    B
⚠ Needs Attention
  • Put-in-Bay
    10.90 ppb
    Copper above the 1,300 ppb action level
    C
  • Genoa
    Not detected
    Copper above the 1,300 ppb action level
    C
  • Curtice
    Not detected
    Copper above the 1,300 ppb action level
    C
  • Elmore
    Not detected
    3 significant inspection deficiencies
    B
  • Marblehead
    1.00 ppb
    1 health-based violation since 2015
    B
County Lead Level — Median 1 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 1 ppb — 6.7% of the federal action level
Systems by Lead Level
Under 5 ppb
2
10 – 15 ppb
1
No Data
5

All Cities in Ottawa County

Port Clinton Not detected A
Oak Harbor Not detected A
Genoa Not detected C
Elmore Not detected B
Marblehead 1.00 ppb B
Lakeside 1.00 ppb B
Curtice Not detected C
Put-in-Bay 10.90 ppb C
Showing 8 cities
No active violations Active violations

About Ottawa County Drinking Water

Ottawa County is served by 7 water systems covering 8 communities. No community here has an open violation on record.

Of the communities reporting lead results, 3 recorded a detection, with a median of 1.00 ppb — 7% of the federal action level. 5 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 Ottawa County tap water safe to drink?▼
No community in Ottawa County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Ottawa County?▼
Among communities with a detection the median is 1.00 ppb, 7% of the 15 ppb action level. 5 reported none detected and 0 reported no result.
How many water systems serve Ottawa County?▼
7 community water systems serve 8 communities here.
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