States › Arizona › Cochise County

Cochise County, AZ Water Quality

Water quality data for 19 public water systems serving Cochise County, Arizona — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 19 water systems · 20 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

Cochise County Earns a B

Cochise County: 20 communities across 19 water systems. 85.0% have no open violations.

  • Median lead where detected: 2.20 ppb
  • 6 communities with a lead detection, 14 reporting none detected
  • 1 communities with PFAS above the federal limit
  • 4 with significant inspection deficiencies
  • 85.0% of communities have no open violations
2.2 ppb
Median Lead Level
County-wide, 90th percentile
19
Water Systems
Active CWS & NTNCWS
85%
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
  • Sierra Vista
    1.00 ppb
    No federal limits exceeded on record
    A
  • Benson
    Not detected
    No federal limits exceeded on record
    A
  • Willcox
    Not detected
    No federal limits exceeded on record
    A
  • Sierra Vista Southeast
    1.40 ppb
    No federal limits exceeded on record
    B
  • Whetstone
    0.69 ppb
    No federal limits exceeded on record
    B
⚠ Needs Attention
  • Elfrida
    7.00 ppb
    1 violation currently open
    F
  • Bisbee
    Not detected
    PFAS above the limit at 1 of 1 sampling points
    D
  • Naco
    Not detected
    1 violation currently open
    C
  • Mescal
    Not detected
    1 significant inspection deficiency
    B
  • Sunsites
    Not detected
    1 significant inspection deficiency
    B
County Lead Level — Median 2.2 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.2 ppb — 14.7% of the federal action level
Systems by Lead Level
Under 5 ppb
5
5 – 10 ppb
1
No Data
14

All Cities in Cochise County

Sierra Vista 1.00 ppb A
Douglas Not detected A
Benson Not detected A
Bisbee Not detected D
Willcox Not detected A
Sierra Vista Southeast 1.40 ppb B
Huachuca City Not detected B
St. David Not detected B
Mescal Not detected B
Tombstone Not detected B
Whetstone 0.69 ppb B
Naco Not detected C
Sunsites Not detected B
Elfrida 7.00 ppb F
Bowie 3.00 ppb B
San Simon Not detected B
Dragoon Not detected B
McNeal 4.10 ppb B
Palominas Not detected B
Pirtleville Not detected A
Showing 20 cities
No active violations Active violations

About Cochise County Drinking Water

Cochise County is served by 19 water systems covering 20 communities. 85% have no open violations.

Of the communities reporting lead results, 6 recorded a detection, with a median of 2.20 ppb — 15% of the federal action level. 14 reported none detected, which means below the laboratory limit rather than an absence of lead.

1 of 20 communities have PFAS above the limits EPA set in 2024, measured as a running annual average at each sampling point. State inspectors recorded significant deficiencies at 4 of them.

Frequently Asked Questions

Is Cochise County tap water safe to drink?▼
85% of communities have no open violation. 1 of 20 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Cochise County?▼
Among communities with a detection the median is 2.20 ppb, 15% of the 15 ppb action level. 14 reported none detected and 0 reported no result.
How many water systems serve Cochise County?▼
19 community water systems serve 20 communities here.
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