States › Ohio › Warren County

Warren County, OH Water Quality

Water quality data for 9 public water systems serving Warren County, Ohio — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 9 water systems · 17 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

Warren County Earns a B

Warren County: 17 communities across 9 water systems. 88.2% have no open violations.

  • Median lead where detected: 1.60 ppb
  • 17 communities with a lead detection, 0 reporting none detected
  • 5 communities with PFAS above the federal limit
  • 0 with significant inspection deficiencies
  • 88.2% of communities have no open violations
1.6 ppb
Median Lead Level
County-wide, 90th percentile
9
Water Systems
Active CWS & NTNCWS
88%
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
  • Lebanon
    1.20 ppb
    No federal limits exceeded on record
    A
  • Franklin
    2.10 ppb
    No federal limits exceeded on record
    A
  • South Lebanon
    1.00 ppb
    No federal limits exceeded on record
    A
  • Carlisle
    2.10 ppb
    No federal limits exceeded on record
    A
  • Hunter
    2.10 ppb
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • Morrow
    1.90 ppb
    Copper above the 1,300 ppb action level
    D
  • Roachester
    1.90 ppb
    Copper above the 1,300 ppb action level
    D
  • Butlerville
    1.30 ppb
    PFAS above the limit at 2 of 2 sampling points
    D
  • Pleasant Plain
    1.30 ppb
    PFAS above the limit at 2 of 2 sampling points
    D
  • Mason
    2.06 ppb
    PFAS above the limit at 1 of 2 sampling points
    C
County Lead Level — Median 1.6 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 1.6 ppb — 10.7% of the federal action level
Systems by Lead Level
Under 5 ppb
17

All Cities in Warren County

Mason 2.06 ppb C
Lebanon 1.20 ppb A
Springboro 4.40 ppb B
Franklin 2.10 ppb A
Landen 1.30 ppb A
South Lebanon 1.00 ppb A
Carlisle 2.10 ppb A
Waynesville 1.60 ppb A
Five Points 4.40 ppb B
Loveland Park 1.30 ppb A
Kings Mills 1.30 ppb A
Maineville 1.30 ppb A
Morrow 1.90 ppb D
Roachester 1.90 ppb D
Butlerville 1.30 ppb D
Pleasant Plain 1.30 ppb D
Hunter 2.10 ppb A
Showing 17 cities
No active violations Active violations

About Warren County Drinking Water

Warren County is served by 9 water systems covering 17 communities. 88% have no open violations.

Of the communities reporting lead results, 17 recorded a detection, with a median of 1.60 ppb — 11% of the federal action level. 0 reported none detected, which means below the laboratory limit rather than an absence of lead.

5 of 17 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded no significant deficiencies.

Frequently Asked Questions

Is Warren County tap water safe to drink?▼
88% of communities have no open violation. 5 of 17 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Warren County?▼
Among communities with a detection the median is 1.60 ppb, 11% of the 15 ppb action level. 0 reported none detected and 0 reported no result.
How many water systems serve Warren County?▼
9 community water systems serve 17 communities here.
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