States › Oklahoma › Logan County

Logan County, OK Water Quality

Water quality data for 8 public water systems serving Logan County, Oklahoma — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 8 water systems · 12 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

Logan County Earns a B

Logan County: 12 communities across 8 water systems. 100.0% have no open violations.

  • Median lead where detected: 4.05 ppb
  • 4 communities with a lead detection, 8 reporting none detected
  • 0 communities with PFAS above the federal limit
  • 4 with significant inspection deficiencies
  • 100.0% of communities have no open violations
4.05 ppb
Median Lead Level
County-wide, 90th percentile
8
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
  • Coyle
    2.80 ppb
    2 health-based violations since 2015
    B
  • Seward
    Not detected
    1 health-based violation since 2015
    A
  • Marshall
    Not detected
    Copper above the 1,300 ppb action level
    B
  • Crescent Springs
    Not detected
    Copper above the 1,300 ppb action level
    B
  • Cimarron City
    Not detected
    Copper above the 1,300 ppb action level
    B
⚠ Needs Attention
  • Crescent
    3.50 ppb
    Copper above the 1,300 ppb action level
    C
  • Guthrie
    4.60 ppb
    2 significant inspection deficiencies
    C
  • Langston
    Not detected
    2 significant inspection deficiencies
    C
  • Cedar Valley
    4.60 ppb
    2 significant inspection deficiencies
    C
  • Mulhall
    Not detected
    Copper above the 1,300 ppb action level
    C
County Lead Level — Median 4.05 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 4.05 ppb — 27% of the federal action level
Systems by Lead Level
Under 5 ppb
4
No Data
8

All Cities in Logan County

Guthrie 4.60 ppb C
Crescent 3.50 ppb C
Langston Not detected C
Coyle 2.80 ppb B
Cedar Valley 4.60 ppb C
Mulhall Not detected C
Marshall Not detected B
Crescent Springs Not detected B
Cimarron City Not detected B
Orlando Not detected C
Lovell Not detected C
Seward Not detected A
Showing 12 cities
No active violations Active violations

About Logan County Drinking Water

Logan County is served by 8 water systems covering 12 communities. No community here has an open violation on record.

Of the communities reporting lead results, 4 recorded a detection, with a median of 4.05 ppb — 27% of the federal action level. 8 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 4 of them.

Frequently Asked Questions

Is Logan County tap water safe to drink?▼
No community in Logan County has an open violation on record. No community has PFAS above the federal limit on record.
What is the lead level in Logan County?▼
Among communities with a detection the median is 4.05 ppb, 27% of the 15 ppb action level. 8 reported none detected and 0 reported no result.
How many water systems serve Logan County?▼
8 community water systems serve 12 communities here.
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