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 systems217100 community systems
People served4.4Mby public water systems
Systems with violations13964% of active systems, past 3 years
Serious violators45 systems carry a health flag
Needs attention
Aguila Water ServiceAZ0407003 · Aguila · Community water system · Serves 9953 rules violated in the past three years. Unresolved: Revised Total Coliform Rule and Ground Water Rule.
Apache Lake Marina ResortAZ0407630 · Apache Lake · Community water system · Serves 1235 rules violated in the past three years
Two Tanks Community WellAZ0407524 · Surprise · Community water system · Serves 766 rules violated in the past three years. Unresolved: Lead and Copper Rule Revisions and Public Notice Rule and Revised PN Rule.
Grandview Water CompanyAZ0407039 · Liberty · Community water system · Serves 506 rules violated in the past three years. Unresolved: Revised Total Coliform Rule.
Palo Verde Nuclear Generating StationAZ0407412 · Wintersburg · Non-Transient non-community system · Serves 3,0001 rule violated in the past three years. Unresolved: Revised Total Coliform Rule.
James R CusterAZ0407473 · New River · Transient non-community system · Serves 1002 rules violated in the past three years. Unresolved: Ground Water Rule and Public Notice Rule and Revised PN Rule.
Superior Products of AZAZ0407902 · Chandler · Non-Transient non-community system · Serves 854 rules violated in the past three years. Unresolved: Nitrate Rule.
67 Ave Property Owners AssociationAZ0407280 · Phoenix · Community water system · Serves 405 rules violated in the past three years. Unresolved: Ground Water Rule and Public Notice Rule and Revised PN Rule.
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.
Compliant
Compliant
No violations reported to EPA in the past three years.
At least one violation on record with EPA in the past three years. Many are monitoring or reporting lapses rather than contamination; the system page lists which rules were involved and whether each is still open.
EPA's designation, also called an enforcement priority, for a system with unresolved serious, multiple, or continuing violations. EPA expects the system and its state to act quickly to resolve them.
At least one open health-based violation: an exceedance of a maximum contaminant level or residual disinfectant level, or a treatment technique violation. Monitoring and reporting lapses do not raise this flag.