Arizona
Maricopa County drinking water quality
217 active public water systems serve 4,429,333 people in Maricopa County. 78 are compliant, 139 had at least one EPA violation in the past three years, 4 are designated serious violators, and 5 carry a health flag.
Active systems
217
100 community systems
People served
4.4M
by public water systems
Systems with violations
139
64% of active systems, past 3 years
Serious violators
4
5 systems carry a health flag
Needs attention
Aguila Water Service
AZ0407003 · Aguila · Community water system · Serves 995
3 rules violated in the past three years. Unresolved: Revised Total Coliform Rule and Ground Water Rule.
Apache Lake Marina Resort
AZ0407630 · Apache Lake · Community water system · Serves 123
5 rules violated in the past three years
Two Tanks Community Well
AZ0407524 · Surprise · Community water system · Serves 76
6 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions and Public Notice Rule and Revised PN Rule.
Grandview Water Company
AZ0407039 · Liberty · Community water system · Serves 50
6 rules violated in the past three years. Unresolved: Revised Total Coliform Rule.
Palo Verde Nuclear Generating Station
AZ0407412 · Wintersburg · Non-Transient non-community system · Serves 3,000
1 rule violated in the past three years. Unresolved: Revised Total Coliform Rule.
James R Custer
AZ0407473 · New River · Transient non-community system · Serves 100
2 rules violated in the past three years. Unresolved: Ground Water Rule and Public Notice Rule and Revised PN Rule.
Superior Products of AZ
AZ0407902 · Chandler · Non-Transient non-community system · Serves 85
4 rules violated in the past three years. Unresolved: Nitrate Rule.
67 Ave Property Owners Association
AZ0407280 · Phoenix · Community water system · Serves 40
5 rules violated in the past three years. Unresolved: Ground Water Rule and Public Notice Rule and Revised PN Rule.
Community water systems
100 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Phoenix City of Phoenix |
1,695,000 | 2 | 0 | |
|
Mesa City of Mesa |
466,000 | 3 | 0 | |
|
Gilbert, Town of Gilbert |
247,600 | 9 | 1 | |
|
Chandler City of Chandler |
247,328 | 4 | 0 | |
|
Scottsdale City of Scottsdale |
241,361 | 2 | 0 | |
|
Glendale City of Glendale |
234,766 | 3 | 0 | |
|
Peoria City of Peoria |
187,676 | 4 | 1 | |
|
Tempe City of Tempe |
165,000 | 0 | 0 | |
|
Epcor Agua Fria Surprise |
128,040 | 5 | 0 | |
|
Avondale City of Avondale |
96,130 | 2 | 0 | |
|
Queen Creek Town of Queen Creek |
95,502 | 1 | 0 | |
|
Liberty Water Lpsco Litchfield Park |
57,070 | 1 | 0 | |
|
Goodyear Water Department Goodyear |
50,001 | 4 | 0 | |
|
Surprise City of Mountain Vista Surprise |
40,007 | 1 | 0 | |
|
EL Mirage City of El Mirage |
39,884 | 4 | 0 | |
|
Epcor Sun City Sun City |
38,016 | 0 | 0 | |
|
City of Buckeye Valencia Town Division Buckeye |
30,377 | 3 | 1 | |
|
Epcor Chaparral City Fountain Hills |
26,026 | 2 | 0 | |
|
Epcor Sun City West Sun City West |
25,796 | 0 | 0 | |
|
Desert Oasis Surprise |
23,963 | 1 | 0 | |
|
Epcor Anthem Anthem |
23,826 | 3 | 0 | |
|
City of Buckeye Sonora Sundance Town Of Buckeye-sono |
21,405 | 2 | 0 | |
|
Pima Utilities Chandler |
20,000 | 7 | 3 | |
|
Arizona Water CO White Tanks White Tanks |
18,858 | 2 | 0 | |
|
Epcor North East Agua Fria Phoenix |
14,723 | 2 | 0 | |
|
Epcor Paradise Valley/scottsdale Paradise Valley |
14,107 | 2 | 0 | |
|
Beardsley Water Company 1 Surprise |
10,881 | 1 | 0 | |
|
Festival Ranch Buckeye |
10,313 | 1 | 0 | |
|
City of Buckeye Tartesso Water System Buckeye |
10,123 | 2 | 0 | |
|
Tolleson City of Tolleson |
9,300 | 4 | 0 | |
|
Usaf Luke Air Force Base Litchfield Park |
8,440 | 2 | 0 | |
|
Buckeye City of Buckeye |
7,998 | 2 | 0 | |
|
Wickenburg Town of Wickenburg |
6,581 | 2 | 0 | |
|
Sunrise Water Company Peoria |
6,500 | 1 | 0 | |
|
Rose Valley Water Company Phoenix |
6,202 | 1 | 0 | |
|
Valley Utilities Water Company Glendale Glendale |
6,003 | 0 | 0 | |
|
Cave Creek Water Cave Creek |
5,895 | 0 | 0 | |
|
Epcor Rio Verde Rio Verde |
5,330 | 2 | 0 | |
|
Epcor Tierra del Rio Peoria |
4,868 | 1 | 0 | |
|
Aspc Lewis Complex Water System Buckeye |
4,300 | 6 | 1 | |
|
Desert Hills Water Cave Creek |
4,220 | 0 | 0 | |
|
Carefree Water Company Carefree |
3,588 | 3 | 0 | |
|
Clearwater Utility Company INC Buckeye |
2,747 | 5 | 1 | |
|
Chandler Heights Citrus Irrigation Dist Chandler |
2,620 | 3 | 1 | |
|
Gila Bend Town of Buckeye |
1,922 | 7 | 0 | |
|
Federal Correction Institution Phoenix |
1,500 | 5 | 0 | |
|
Berneil Water Company Paradise Valley |
1,388 | 1 | 0 | |
|
Vwc Buckeye Division Sun Valley Buckeye |
1,378 | 2 | 0 | |
|
West End Water Company Wittman Wittmann |
1,200 | 1 | 0 | |
|
Trillium Water System Buckeye |
1,100 | 0 | 0 |
Non-community systems (117: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
Inactive systems (334, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Arizona records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.