COUNTY REPORT AZ

Maricopa County, Arizona

197 ZIP codes · Avg score 64/100 · Grade C · Updated 2026-06-03

The systems supplying Maricopa County's 197 ZIP codes vary in performance — most meet minimum standards, but violations in select areas are on record.

How Maricopa County Compares

Maricopa County64/100
Arizona avg64/100
National avg68/100

How Maricopa County Compares

C
County Grade
64/100
Avg Safety Score
197
ZIP Codes
87
Water Systems

Maricopa County scores 0 points above the Arizona state average (64/100) and 4 points below the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-03

C
County Grade
64
Avg Safety Score
197
ZIP Codes
Best ZIP: 85342 (83/100)
Lowest ZIP: 85031 (48/100)
$400K
Median Home Value
$1,972
Avg Remediation (49% of home value)

ZIP Code Risk Map

Water Quality Map: Maricopa County, Arizona

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 11.3 (asthma 10%, diabetes 10.6%)

Estimated additional annual cost per homeowner: $1,753, driven primarily by wildfire

Infrastructure: 0.314% avg pipe failure probability, 15% of ZIPs at high risk

39.2% of homes built before 1978 (lead paint era)

Violation History (2021–2025)

↑ Worsening trend

EPA violation counts by year across Maricopa County water systems. Health-based shown in red, total in blue.

2021
5 (5 health)
2022
23 (23 health)
2023
9 (9 health)
2024
255 (255 health)
2025
45 (45 health)

Peak year: 2024 with 255 violations. Past 5 years: 337 total (337 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 10% (national: 8.9%)
Diabetes 10.6% (national: 10.5%)
Obesity 30.4% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1991
Median Build Year
39.2%
Pre-1978 Housing
31%
Pipe Failure Probability
15%
ZIPs at High Infra Risk
Low
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $1,753

Wildfire $1,200/yr
Flood $432/yr
Energy Code Gap $75/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

1,812,645 housing units in Maricopa County

Pre-1940 1%
1940–1959 6%
1960–1979 23%
1980–1999 36%
2000+ 33%

Source: U.S. Census Bureau ACS B25034 (Year Structure Built).

Water Safety Affordability

How much it costs to fix water issues relative to home values in Maricopa County

$400K
Median Home Value
$1,972
Est. Remediation Cost
0.5%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Maricopa County, representing a small fraction of property value.

Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.

Health Outcomes vs National Average

CDC PLACES data for Maricopa County residents

Asthma 10% (US avg: 8.9%)
Diabetes 10.6% (US avg: 11%)
Obesity 30.4% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water Systems with Most Violations

Top 5 systems in Maricopa County ranked by EPA violation count.

# Water System Population Violations
1 City of Glendale 234,766 10686
2 City of Phoenix 1,695,000 10405
3 Pima Utilities 20,000 9968
4 Arizona Water Company - Apache Junction 62,055 9849
5 Arizona Water Company - Pinal Valley 134,432 9828

87 total water systems serve Maricopa County.

All ZIP Codes in Maricopa County

197 ZIP codes tracked in Maricopa County.

# ZIP Code City Safety Score Grade Violations Home Value
1 85342 Morristown 83 B 0 $268K
2 85377 Carefree 83 B 0 $1059K
3 85252 Scottsdale 82 B 21 (1 health)
4 85256 Scottsdale 82 B 21 (1 health) $132K
5 85259 Scottsdale 82 B 21 (1 health) $956K
6 85261 Scottsdale 82 B 21 (1 health)
7 85262 Scottsdale 82 B 21 (1 health) $1179K
8 85267 Scottsdale 82 B 21 (1 health)
9 85271 Scottsdale 82 B 21 (1 health)
10 85280 Tempe 82 B 24 (1 health)
11 85282 Tempe 82 B 24 (1 health) $370K
12 85283 Tempe 82 B 24 (1 health) $410K
13 85284 Tempe 82 B 24 (1 health) $646K
14 85285 Tempe 82 B 24 (1 health)
15 85287 Tempe 82 B 24 (1 health)
16 85289 Tempe 82 B 24 (1 health)
17 85338 Goodyear 82 B 11 (1 health) $396K
18 85340 Litchfield Park 82 B 10 (1 health) $500K
19 85354 Tonopah 82 B 3 $278K
20 85361 Wittmann 82 B 26 (1 health) $389K
21 85395 Goodyear 82 B 11 (1 health) $525K
22 85358 Wickenburg 81 B 22 (2 health)
23 85392 Avondale 81 B 4 $365K
24 85127 Chandler Heights 80 B 3
25 85227 Chandler Heights 80 B 3
26 85263 Rio Verde 80 B 3 $776K
27 85224 Chandler 78 B 20 (2 health) $391K
28 85225 Chandler 78 B 20 (2 health) $387K
29 85226 Chandler 78 B 20 (2 health) $452K
30 85236 Higley 78 B 9 (1 health)
31 85248 Chandler 78 B 20 (2 health) $489K
32 85249 Chandler 78 B 20 (2 health) $611K
33 85244 Chandler 77 B 20 (2 health)
34 85250 Scottsdale 77 B 21 (1 health) $508K
35 85254 Scottsdale 77 B 21 (1 health) $702K
36 85257 Scottsdale 77 B 21 (1 health) $453K
37 85258 Scottsdale 77 B 21 (1 health) $745K
38 85260 Scottsdale 77 B 21 (1 health) $637K
39 85266 Scottsdale 77 B 21 (1 health) $1027K
40 85281 Tempe 77 B 24 (1 health) $364K
41 85286 Chandler 77 B 20 (2 health) $549K
42 85323 Avondale 76 B 4 $335K
43 85351 Sun City 76 B 9 $250K
44 85372 Sun City 76 B 9
45 85373 Sun City 76 B 9 $317K
46 85390 Wickenburg 76 B 22 (2 health) $466K
47 85337 Gila Bend 75 B 7 $121K
48 85142 Queen Creek 74 B 35 (1 health) $521K
49 85375 Sun City West 74 B 2 $351K
50 85202 Mesa 72 B 7 $334K
51 85204 Mesa 72 B 7 $296K
52 85205 Mesa 72 B 7 $301K
53 85207 Mesa 72 B 7 $461K
54 85208 Mesa 72 B 7 $261K
55 85209 Mesa 72 B 7 $364K
56 85210 Mesa 72 B 7 $302K
57 85211 Mesa 72 B 7
58 85212 Mesa 72 B 7 $531K
59 85213 Mesa 72 B 7 $408K
60 85214 Mesa 72 B 7
61 85215 Mesa 72 B 7 $398K
62 85216 Mesa 72 B 7
63 85251 Scottsdale 72 B 21 (1 health) $501K
64 85255 Scottsdale 72 B 21 (1 health) $975K
65 85274 Mesa 72 B 7
66 85275 Mesa 72 B 7
67 85277 Mesa 72 B 7
68 85303 Glendale 72 B 68 (8 health) $287K
69 85310 Glendale 72 B 68 (8 health) $489K
70 85320 Aguila 72 B 3 $398K
71 85376 Sun City West 71 B 2
72 85233 Gilbert 70 B 51 (4 health) $469K
73 85234 Gilbert 70 B 51 (4 health) $489K
74 85295 Gilbert 70 B 51 (4 health) $527K
75 85296 Gilbert 70 B 51 (4 health) $496K
76 85297 Gilbert 70 B 51 (4 health) $559K
77 85298 Gilbert 70 B 51 (4 health) $598K
78 85305 Glendale 69 C 68 (8 health) $410K
79 85307 Glendale 69 C 68 (8 health) $369K
80 85311 Glendale 69 C 68 (8 health)
81 85312 Glendale 69 C 68 (8 health)
82 85318 Glendale 69 C 68 (8 health)
83 85327 Cave Creek 69 C 22
84 85381 Peoria 69 C 14 $408K
85 85382 Peoria 69 C 14 $408K
86 85383 Peoria 69 C 14 $608K
87 85396 Buckeye 69 C 19 $451K
88 85253 Paradise Valley 68 C 5 $2000K
89 85201 Mesa 67 C 7 $293K
90 85203 Mesa 67 C 7 $388K
91 85206 Mesa 67 C 7 $323K
92 85268 Fountain Hills 67 C 7 $577K
93 85299 Gilbert 67 C 51 (4 health)
94 85301 Glendale 67 C 68 (8 health) $218K
95 85302 Glendale 67 C 68 (8 health) $327K
96 85304 Glendale 67 C 68 (8 health) $345K
97 85306 Glendale 67 C 68 (8 health) $342K
98 85308 Glendale 67 C 68 (8 health) $420K
99 85380 Peoria 67 C 14
100 85385 Peoria 67 C 14
101 85269 Fountain Hills 65 C 7
102 85087 New River 64 C 17 (8 health) $511K
103 85345 Peoria 64 C 14 $278K
104 85322 Arlington 63 C 0 $237K
105 85329 Cashion 63 C 0 $244K
106 85343 Palo Verde 63 C 0 $550K
107 85355 Waddell 63 C 0 $444K
108 85353 Tolleson 61 C 6 $345K
109 85326 Buckeye 59 C 19 $342K
110 85331 Cave Creek 59 C 22 $674K
111 85387 Surprise 59 C 24 (1 health) $454K
112 85001 Phoenix 58 C 126 (19 health)
113 85003 Phoenix 58 C 126 (19 health) $578K
114 85004 Phoenix 58 C 126 (19 health) $366K
115 85005 Phoenix 58 C 126 (19 health)
116 85006 Phoenix 58 C 126 (19 health) $377K
117 85027 Phoenix 58 C 126 (19 health) $316K
118 85028 Phoenix 58 C 126 (19 health) $583K
119 85030 Phoenix 58 C 126 (19 health)
120 85035 Phoenix 58 C 126 (19 health) $244K
121 85036 Phoenix 58 C 126 (19 health)
122 85037 Phoenix 58 C 126 (19 health) $291K
123 85040 Phoenix 58 C 126 (19 health) $295K
124 85042 Phoenix 58 C 126 (19 health) $353K
125 85043 Phoenix 58 C 126 (19 health) $289K
126 85044 Phoenix 58 C 126 (19 health) $437K
127 85048 Phoenix 58 C 126 (19 health) $539K
128 85050 Phoenix 58 C 126 (19 health) $564K
129 85054 Phoenix 58 C 126 (19 health) $618K
130 85060 Phoenix 58 C 126 (19 health)
131 85061 Phoenix 58 C 126 (19 health)
132 85064 Phoenix 58 C 126 (19 health)
133 85067 Phoenix 58 C 126 (19 health)
134 85083 Phoenix 58 C 126 (19 health) $573K
135 85085 Phoenix 58 C 126 (19 health) $589K
136 85335 El Mirage 55 C 66 (2 health) $282K
137 85007 Phoenix 53 D 126 (19 health) $447K
138 85009 Phoenix 53 D 126 (19 health) $215K
139 85012 Phoenix 53 D 126 (19 health) $701K
140 85017 Phoenix 53 D 126 (19 health) $243K
141 85019 Phoenix 53 D 126 (19 health) $256K
142 85022 Phoenix 53 D 126 (19 health) $386K
143 85023 Phoenix 53 D 126 (19 health) $359K
144 85029 Phoenix 53 D 126 (19 health) $308K
145 85032 Phoenix 53 D 126 (19 health) $388K
146 85033 Phoenix 53 D 126 (19 health) $246K
147 85034 Phoenix 53 D 126 (19 health) $397K
148 85041 Phoenix 53 D 126 (19 health) $310K
149 85051 Phoenix 53 D 126 (19 health) $288K
150 85086 Phoenix 53 D 126 (19 health) $554K
151 85147 Sacaton 53 D 0 $107K
152 85264 Fort Mcdowell 53 D 0 $390K
153 85363 Youngtown 53 D 0 $283K
154 85374 Surprise 52 D 24 (1 health) $356K
155 85378 Surprise 52 D 24 (1 health) $235K
156 85379 Surprise 52 D 24 (1 health) $414K
157 85388 Surprise 52 D 24 (1 health) $420K
158 85002 Phoenix 50 D 126 (19 health)
159 85010 Phoenix 50 D 126 (19 health)
160 85011 Phoenix 50 D 126 (19 health)
161 85024 Phoenix 50 D 126 (19 health) $430K
162 85025 Phoenix 50 D 126 (19 health)
163 85026 Phoenix 50 D 126 (19 health)
164 85038 Phoenix 50 D 126 (19 health)
165 85039 Phoenix 50 D 126 (19 health)
166 85045 Phoenix 50 D 126 (19 health) $591K
167 85046 Phoenix 50 D 126 (19 health)
168 85053 Phoenix 50 D 126 (19 health) $330K
169 85055 Phoenix 50 D 126 (19 health)
170 85062 Phoenix 50 D 126 (19 health)
171 85063 Phoenix 50 D 126 (19 health)
172 85065 Phoenix 50 D 126 (19 health)
173 85066 Phoenix 50 D 126 (19 health)
174 85068 Phoenix 50 D 126 (19 health)
175 85069 Phoenix 50 D 126 (19 health)
176 85070 Phoenix 50 D 126 (19 health)
177 85071 Phoenix 50 D 126 (19 health)
178 85072 Phoenix 50 D 126 (19 health)
179 85073 Phoenix 50 D 126 (19 health)
180 85074 Phoenix 50 D 126 (19 health)
181 85075 Phoenix 50 D 126 (19 health)
182 85076 Phoenix 50 D 126 (19 health)
183 85078 Phoenix 50 D 126 (19 health)
184 85079 Phoenix 50 D 126 (19 health)
185 85080 Phoenix 50 D 126 (19 health)
186 85082 Phoenix 50 D 126 (19 health)
187 85097 Phoenix 50 D 126 (19 health)
188 85098 Phoenix 50 D 126 (19 health)
189 85008 Phoenix 48 D 126 (19 health) $324K
190 85013 Phoenix 48 D 126 (19 health) $476K
191 85014 Phoenix 48 D 126 (19 health) $448K
192 85015 Phoenix 48 D 126 (19 health) $313K
193 85016 Phoenix 48 D 126 (19 health) $508K
194 85018 Phoenix 48 D 126 (19 health) $806K
195 85020 Phoenix 48 D 126 (19 health) $401K
196 85021 Phoenix 48 D 126 (19 health) $433K
197 85031 Phoenix 48 D 126 (19 health) $240K

Recommended Buyer Guides for Maricopa County

Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.

Overview

Maricopa County in Arizona covers 197 ZIP codes with an average Home Safety Score of C (64/100).

188 of 197 ZIP codes have recorded EPA violations. 1668 health-based violations have been documented.

← Back to Arizona water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Maricopa County?
Maricopa County receives a grade of C. Some ZIP codes have recorded violations and residents in affected areas may want to test their water.
How many water systems serve Maricopa County?
Maricopa County is served by 87 public water systems that supply drinking water to residents across 197 ZIP codes.
What is the biggest environmental risk in Maricopa County?
The primary environmental risk factor in Maricopa County is wildfire. This contributes to an estimated additional annual cost of $1,753 per homeowner.
How old are homes in Maricopa County?
The median home build year in Maricopa County is 1991. 39.2% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Maricopa County compare to Arizona?
Maricopa County has an average water safety score of 64/100, which is above the Arizona state average of 64/100.

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