WaterVerge

Is Maricopa, AZ Tap Water Safe to Drink?

Graded D — but Strontium and Chlorate were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓

91K residents served 10 water systems PWSID: AZ0411131
Overall Score
45.6 / 100
Violations
162 active
Last Updated
May 2026
Source
Groundwater
#240 of 292 in Arizona Top 90% nationally
Private
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
DGRADE
Water Quality Grade
45.6/100
waterverge.com
D 45.6/100

Maricopa, AZ — Water Quality Report

Maricopa's drinking water received a grade of D (45.6 out of 100), indicating poor water quality. The city's 10 water systems serve approximately 90,552 residents using groundwater.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.

The system has 1389 violations on record, including 228 health-based violations. 162 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Maricopa's water

Maricopa ranks #240 out of 292 cities in Arizona for water quality, placing it among the lowest-rated in the state.

Maricopa relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.

PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.

Hexavalent chromium (chromium-6) was detected at 7.00 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.

The system has seen 161 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
45.6 out of 100 Grade D
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
0/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
12.6/20
C
1 PFAS compound detected.
Compliance
8/10
B
Monitoring and reporting compliance with EPA regulations.
Source Risk
5/5
A
Water source: Groundwater.
Water Safety

Is Maricopa, AZ water safe to drink?

Concerns Identified

Maricopa's drinking water has significant quality concerns based on EPA testing data. With a grade of D (45.6/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 10 water systems serve approximately 90,552 residents using groundwater (wells).

162
Active Violations
0.0 ppb
Lead (90th %ile)
1 compound
PFAS Detected
7 events
Disaster History

Recent water quality updates for Maricopa

A timeline of significant water quality events, violations, and data updates.

PFAS
1 PFAS "forever chemical" compound detected

Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Maricopa's water quality assessment. Grade: D (45.6/100).

Violation
2 drinking water violations recorded

Contaminants: Revised Total Coliform Rule, Chlorine.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Nitrate.

Violation
1 drinking water violation recorded

1 health-based. Contaminants: Revised Total Coliform Rule.

Disaster
HURRICANE KATRINA EVACUATION

Federal disaster declaration (FEMA DR-3241). Hurricane event — may have impacted local water infrastructure.

Key contaminant findings

Based on the most recent EPA sampling data for Maricopa's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

PFAS (1 compound) Elevated
Detected: Highest: lithium at 263.0000 µg/L Limit: 0.004 µg/L (EPA MCL)

Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.

Chromium-6 (Hexavalent Chromium) Elevated
Detected: 7.00 µg/L Limit: 10 µg/L (California MCL — no federal limit)

The "Erin Brockovich" chemical. There is no federal MCL, but California has set a limit of 10 µg/L. Reverse osmosis filtration is effective at removing hexavalent chromium.

Violation history

Maricopa's water system has 1,389 total violations on record, including 228 health-based violations. 162 remain unresolved. 161 violations were issued in the last 5 years.

MONMRMCLOtherRPTTT
Most recent violations:
Nov 2025 Revised Total Coliform Rule Resolved
Nov 2025 Chlorine Resolved
Oct 2025 Nitrate Resolved
Aug 2025 Revised Total Coliform Rule Resolved
Jul 2025 Public Notice Open

Flood & environmental risk

Pinal County has experienced 7 federally declared disasters since 1966. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Gila River.

HURRICANE KATRINA EVACUATION
Hurricane FEMA DR-3241
SEVERE STORMS, TORNADOES & FLOODING
Flood FEMA DR-977
SEVERE STORMS & FLOODING
Flood FEMA DR-884

Where does Maricopa's water come from?

Maricopa's drinking water comes from groundwater (wells), supplied by 10 water systems serving approximately 90,552 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Gila River (river).

What Maricopa residents can do

Install a water filter

Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Maricopa's water.

Request your utility's CCR

Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.

Monitor alerts during storms

Maricopa's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.

Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
lithium
PFAS / Forever Chemical
Near MCL
263.0000 µg/L
EPA MCL: 0.004 µg/L · +20% over limit
Detected
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
2.9 µg/L
EPA MCL: 60 µg/L · 5% of limit
Within LimitUCMR 4 DataHAA6Br: 4.2 µg/LHAA9: 4.4 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Elevated
7.00 µg/L
CA MCL (no federal MCL): 10 µg/L · 70% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Over HRL
2500.0 µg/L
EPA Health Ref Level: 1,500 µg/L · +20% over limit
Over HRLUCMR 3 Data
Manganese
Inorganic
Detected
1.9 µg/L
EPA Secondary MCL: 50 µg/L · 4% of limit
DetectedUCMR 4 Data
Vanadium
Inorganic
Detected
7.20 µg/L
EPA Short-term HA: 21 µg/L · 34% of limit
DetectedUCMR 3 Data
Chlorate
Disinfection Byproduct
Over HA
280.0 µg/L
EPA Lifetime HA: 210 µg/L · +20% over limit
Over Health AdvisoryUCMR 3 Data
Molybdenum
Inorganic
Detected
4.30 µg/L
EPA Lifetime HA: 40 µg/L · 11% of limit
DetectedUCMR 3 Data
Lithium
Inorganic
Above state screening
263.0 µg/L
State screening level: 60 µg/L · +20% over limit
DetectedNo federal MCLUCMR 5 Data (2023–2025)
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
1
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

1389
Total violations
228
Health-based
162
Active / unresolved
Nov 2025
Most recent violation
Compliance Record

Violations & advisories

1389 Total
162 Active
228 Health-based
1227 Resolved
14 SNC
Violations by category
Nitrate Rule
252
Stage 1 Disinfectants and Disinfection Byproducts Rule
230
Total Coliform Rule
225
Volatile Organic Chemicals
218
Arsenic Rule
107
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Apr 2025 Active
Public Notice
Other Violation 0
Jan 2025 Active
Public Notice
Other Violation 0
Jan 2025 Active
Public Notice
Other Violation 0
Dec 2024 Active
Public Notice
Other Violation 0
Dec 2024 Active
Public Notice
Other Violation 0
Dec 2024 Active
Public Notice
Other Violation 0
Dec 2024 Active
Public Notice
Other Violation 0
Nov 2024 Active
Groundwater Rule
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Reporting
Reporting 0
Oct 2024 Active
LEAD AND COPPER RULE REVISIONS
Treatment Technique
Health-Based Health 0
Showing 20 of 1389 violations
Environmental Risk

Drought conditions

D2 — severe drought

Pinal County is currently in D2 (severe drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.

4
Weeks at D2+ (current streak)
44.8%
Months in D2+ (last 30y)
4
Weeks at D2+ (last 5y)

Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.

Environmental Risk

Flood & disaster history

7
Declared disasters
Sep 2005
Most recent
Flood
Most common type

Pinal County has experienced 7 federally declared disasters since 1966. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2005
HURRICANE KATRINA EVACUATION
Hurricane FEMA #3241
Jan 1993
SEVERE STORMS, TORNADOES & FLOODING
Flood FEMA #977
Dec 1990
SEVERE STORMS & FLOODING
Flood FEMA #884
Oct 1983
SEVERE STORMS & FLOODING
Flood FEMA #691
Nov 1977
SEVERE STORMS & FLOODING
Flood FEMA #540
Jul 1972
SEVERE STORMS & FLOODING
Flood FEMA #343

Recommended water filters

Based on contaminants detected in Maricopa's water supply, we recommend the following filter types.

🧪
For PFAS
Reverse Osmosis or Activated Carbon Block
1 PFAS compound detected

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 15 ppb Inorganic Safe
11Cl-PF3OUdS ND HI µg/L PFAS Not Detected
4:2 FTS ND HI µg/L PFAS Not Detected
6:2 FTS ND HI µg/L PFAS Not Detected
8:2 FTS ND HI µg/L PFAS Not Detected
9Cl-PF3ONS ND HI µg/L PFAS Not Detected
ADONA ND HI µg/L PFAS Not Detected
HFPO-DA ND 0.01 µg/L PFAS Not Detected
lithium 263.000 HI µg/L PFAS Detected
NEtFOSAA ND HI µg/L PFAS Not Detected
NFDHA ND HI µg/L PFAS Not Detected
NMeFOSAA ND HI µg/L PFAS Not Detected
PFBA ND HI µg/L PFAS Not Detected
PFBS ND HI µg/L PFAS Not Detected
PFDA ND HI µg/L PFAS Not Detected
PFDoA ND HI µg/L PFAS Not Detected
PFEESA ND HI µg/L PFAS Not Detected
PFHpA ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA ND HI µg/L PFAS Not Detected
PFPeS ND HI µg/L PFAS Not Detected
PFTA ND HI µg/L PFAS Not Detected
PFTrDA ND HI µg/L PFAS Not Detected
PFUnA ND HI µg/L PFAS Not Detected
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 1.5 ppb from 2003 (1.5 ppb) to 2025 (0.0 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Groundwater
Operator
Private
Population Served
90,552
Water Systems
10
Source breakdown
Groundwater
9
Purchased Groundwater
1
Water Source

Where Maricopa's water comes from

Groundwater

Maricopa's drinking water is drawn from underground aquifers through wells.

Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.

Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.

The system is operated by private ownership and serves approximately 90,552 people through 10 water systems.

Local Hydrology

Water bodies near Maricopa

Maricopa is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.

Gila River
river
Infrastructure

Water systems serving Maricopa

System Name PWSID Population Source
GW SANTA CRUZ WATER CO AZ0411131 84,000 GW
THUNDERBIRD FARMS DWID AZ0411100 2,231 GW
GW SANTA CRUZ WATER - MARICOPA SW AZ0411575 1,170 GW
COPPER MOUNTAIN RANCH CFD AZ0411328 1,071 GW
MARICOPA CONSOLIDATED DWID AZ0411036 928 GW
PAPAGO BUTTE DWID AZ0411097 530 GW
VALLE ESCONDIDO AZ0411409 405 GW
NEW SADDLEBACK VISTA AZ0411557 100 GW
AMERICAN REALTY MORTGAGE COMPANY AZ0411301 60 GWP
GW SANTA CRUZ WATER -TWIN HAWKS WATER AZ0411460 57 GW
Regional Comparison

How Maricopa compares

Full Arizona rankings →

Maricopa's score of 45.6/100 is on par with the average of 42/100 among major Arizona cities. It outscores 9 of 10 nearby cities.

Maricopa (this city)
45.6
Phoenix
37.5
Tucson
38.1
Mesa
40.6
Chandler
40.5
Gilbert
34.8
Arizona avg
42
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Frequently asked questions

Is Maricopa, AZ tap water safe to drink?

Maricopa's water quality earned a grade of D (45.6/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #240 out of 292 cities tested in Arizona.

What contaminants are in Maricopa's water?

Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 1389 violations are on record.

How is Maricopa's water quality grade calculated?

The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.

Do I need a water filter in Maricopa?

PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.

Where does Maricopa's water come from?

Maricopa's water is sourced from Groundwater. The city has 10 water systems serving approximately 90,552 residents.

What health violations has Maricopa's water system had?

Maricopa has 228 health-based violations on record. The most recent violation was recorded in November 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 162 violations remain unresolved.

Is Maricopa's groundwater at risk of contamination?

Maricopa uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 1389 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.

How does Maricopa's water compare to other cities?

Maricopa ranks #240 out of 292 cities in Arizona (better than 18% of state cities) and #14128 out of 15744 cities nationally (10th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.