States › Oklahoma › Delaware County

Delaware County, OK Water Quality

Water quality data for 11 public water systems serving Delaware County, Oklahoma — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 11 water systems · 23 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

Delaware County Earns a B

Delaware County: 23 communities across 11 water systems. 100.0% have no open violations.

  • Median lead where detected: 1.80 ppb
  • 10 communities with a lead detection, 13 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 5 with significant inspection deficiencies
  • 100.0% of communities have no open violations
1.8 ppb
Median Lead Level
County-wide, 90th percentile
11
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
  • Jay
    Not detected
    No federal limits exceeded on record
    B
  • Cleora
    1.50 ppb
    No federal limits exceeded on record
    A
  • New Eucha
    Not detected
    No federal limits exceeded on record
    B
  • Drowning Creek
    Not detected
    No federal limits exceeded on record
    B
  • Oak Hill-Piney
    Not detected
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Grove
    9.30 ppb
    1 significant inspection deficiency
    C
  • Cayuga
    9.30 ppb
    1 significant inspection deficiency
    C
  • Butler
    9.30 ppb
    1 significant inspection deficiency
    C
  • Dodge
    9.30 ppb
    1 significant inspection deficiency
    C
  • Dennis
    1.10 ppb
    Copper above the 1,300 ppb action level
    C
County Lead Level — Median 1.8 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 1.8 ppb — 12% of the federal action level
Systems by Lead Level
Under 5 ppb
6
5 – 10 ppb
4
No Data
13

All Cities in Delaware County

Grove 9.30 ppb C
Jay Not detected B
Cleora 1.50 ppb A
West Siloam Springs 1.40 ppb B
Colcord Not detected B
Kansas Not detected B
New Eucha Not detected B
Copeland Not detected B
Flint Creek 1.80 ppb B
Bernice Not detected B
Dennis 1.10 ppb C
Zena 1.10 ppb C
Drowning Creek Not detected B
Oak Hill-Piney Not detected B
Cayuga 9.30 ppb C
Butler 9.30 ppb C
Sycamore Not detected B
Dripping Springs 1.80 ppb B
Bull Hollow Not detected B
Dodge 9.30 ppb C
Old Eucha Not detected B
Brush Creek Not detected B
Tagg Flats Not detected B
Showing 23 cities
No active violations Active violations

About Delaware County Drinking Water

Delaware County is served by 11 water systems covering 23 communities. No community here has an open violation on record.

Of the communities reporting lead results, 10 recorded a detection, with a median of 1.80 ppb — 12% of the federal action level. 13 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 5 of them.

Frequently Asked Questions

Is Delaware County tap water safe to drink?▼
No community in Delaware County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Delaware County?▼
Among communities with a detection the median is 1.80 ppb, 12% of the 15 ppb action level. 13 reported none detected and 0 reported no result.
How many water systems serve Delaware County?▼
11 community water systems serve 23 communities here.
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