States › Arizona › Maricopa County

Maricopa County, AZ Water Quality

Water quality data for 34 public water systems serving Maricopa County, Arizona — based on EPA SDWIS enforcement records, lead testing results, and health-based violation history.

📅 2026 Report 🔄 Data updated 2026 Q2 📍 34 water systems · 40 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

Maricopa County Earns a B

Maricopa County: 40 communities across 34 water systems. 85.0% have no open violations.

  • Median lead where detected: 2.30 ppb
  • 13 communities with a lead detection, 27 reporting none detected
  • 6 communities with PFAS above the federal limit
  • 10 with significant inspection deficiencies
  • 85.0% of communities have no open violations
2.3 ppb
Median Lead Level
County-wide, 90th percentile
34
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
  • Glendale
    1.55 ppb
    No federal limits exceeded on record
    A
  • Scottsdale
    2.30 ppb
    No federal limits exceeded on record
    A
  • Queen Creek
    Not detected
    No federal limits exceeded on record
    A
  • Sun City West
    Not detected
    No federal limits exceeded on record
    A
  • Tolleson
    0.66 ppb
    No federal limits exceeded on record
    A
⚠ Needs Attention
  • St. Johns
    0.60 ppb
    1 violation currently open
    F
  • Gila Crossing
    0.60 ppb
    1 violation currently open
    F
  • Komatke
    0.60 ppb
    1 violation currently open
    F
  • Surprise
    Not detected
    1 violation currently open
    D
  • Citrus Park
    Not detected
    1 violation currently open
    D
County Lead Level — Median 2.3 ppb
Based on most recent 90th percentile lead tests across all reporting systems
0 ppb5 ppb10 ppb15 ppb
County median: 2.3 ppb — 15.3% of the federal action level
Systems by Lead Level
Under 5 ppb
11
5 – 10 ppb
1
10 – 15 ppb
1
No Data
27

All Cities in Maricopa County

Phoenix 2.74 ppb A
Mesa 5.01 ppb A
Chandler 1.40 ppb A
Gilbert Not detected C
Glendale 1.55 ppb A
Scottsdale 2.30 ppb A
Tempe 4.40 ppb C
Peoria Not detected A
Avondale Not detected C
Surprise Not detected D
Queen Creek Not detected A
Goodyear Not detected B
Sun City Not detected A
El Mirage Not detected A
Sun City West Not detected A
Fountain Hills Not detected A
Buckeye Not detected B
Anthem Not detected A
Sun Lakes 10.00 ppb B
Tolleson 0.66 ppb A
Youngtown Not detected A
Litchfield Park Not detected C
Wickenburg Not detected A
Paradise Valley Not detected A
Guadalupe 4.40 ppb C
Citrus Park Not detected D
New River Not detected A
Cave Creek Not detected C
Carefree Not detected A
Rio Verde Not detected A
Gila Bend Not detected B
Wittmann Not detected B
St. Johns 0.60 ppb F
Gila Crossing 0.60 ppb F
Komatke 0.60 ppb F
Aguila Not detected C
Circle City Not detected B
Theba Not detected B
Morristown Not detected B
Maricopa Colony 2.74 ppb A
Showing 40 cities
No active violations Active violations

About Maricopa County Drinking Water

Maricopa County is served by 34 water systems covering 40 communities. 85% have no open violations.

Of the communities reporting lead results, 13 recorded a detection, with a median of 2.30 ppb — 15% of the federal action level. 27 reported none detected, which means below the laboratory limit rather than an absence of lead.

6 of 40 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 10 of them.

Frequently Asked Questions

Is Maricopa County tap water safe to drink?▼
85% of communities have no open violation. 6 of 40 have PFAS above the federal limit, which is the main open concern.
What is the lead level in Maricopa County?▼
Among communities with a detection the median is 2.30 ppb, 15% of the 15 ppb action level. 27 reported none detected and 0 reported no result.
How many water systems serve Maricopa County?▼
34 community water systems serve 40 communities here.
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