Arizona

Pima County drinking water quality

193 active public water systems serve 1,136,697 people in Pima County. 66 are compliant, 127 had at least one EPA violation in the past three years, 2 are designated serious violators, and 5 carry a health flag.

Active systems 193 142 community systems

People served 1.1M by public water systems

Systems with violations 127 66% of active systems, past 3 years

Serious violators 2 5 systems carry a health flag

Needs attention

Rancho Sierrita Well Assoc AZ0410286 · Tucson · Community water system · Serves 51 3 rules violated in the past three years. Unresolved: Lead and Copper Rule (LCR) and Revised Total Coliform Rule (RTCR).

Siete Casas Joint Venture AZ0410242 · Tucson · Community water system · Serves 25 2 rules violated in the past three years. Unresolved: Public Notification Rule and Revised Total Coliform Rule (RTCR).

Marana Dwid Culver AZ0410070 · Marana · Community water system · Serves 709 4 rules violated in the past three years. Unresolved: Groundwater Rule (GWR) and Lead and Copper Rule Revisions (LCRR).

Tucson Racquet & Fitness Club AZ0410222 · Tucson · Non-Transient non-community system · Serves 330 3 rules violated in the past three years. Unresolved: Revised Total Coliform Rule (RTCR).

Calportland Rillito Cement Plant AZ0420011 · Rillito · Non-Transient non-community system · Serves 184 4 rules violated in the past three years. Unresolved: Lead and Copper Rule (LCR) and Revised Total Coliform Rule (RTCR).

Community water systems

142 systems, largest first

System	Serves	Rules violated, 3 yr	Unresolved
Tucson City of Tucson	732,906	3	0
Metropolitan Dwid Tucson	45,570	4	1
Oro Valley Water Utility Oro Valley	42,316	0	0
Community WC of Green Valley Green Valley	22,085	0	0
Usaf Davis Monthan Afb Tucson	18,640	3	0
Sahuarita Water Company Sahuarita	18,178	0	0
Vail Water Company Tucson	17,500	0	0
Flowing Wells Irrigation District Tucson	16,000	6	1
Marana Municipal Marana Marana	15,162	1	0
Tucson Water Corona de Tucson Tucson	10,217	0	0
Green Valley Dwid Green Valley	8,687	3	1
Quail Creek Water Company Green Valley	6,812	0	0
Avra Water Coop INC Tucson	6,685	2	0
Oro Valley Water Countryside Oro Valley	6,031	0	0
Metropolitan Dwid Diablo Village Tucson	5,542	3	0
Marana Municipal Hartman Vistas Marana	5,408	0	0
Marana Municipal Picture Rocks Marana	5,270	0	0
Marana Municipal Airline Lambert Marana	4,948	0	0
Adoc Tucson Tucson	4,500	1	0
Ray Water Company INC Tucson	4,495	2	0
GW Farmers Water CO Continental Green Valley	4,475	1	0
Metropolitan Dwid Hub Tucson	4,252	1	0
Spanish Trail Water Company Tucson	3,822	3	0
Saguaro Water Company Vail	3,243	1	0
GW Farmers Water CO Santa Rita Springs Sahuarita	3,235	0	0
Voyager Water Company Tucson	3,121	0	0
GW Saguaro Dist Water CO las Quintas Green Valley	3,055	2	1
GW Ocotillo Water Rancho del Sol Lindo Silverbell	2,782	0	0
Ajo Improvement Company Ajo	2,654	2	0
CS los Cerros Water Company INC Catalina	2,613	1	0
Arizona Water CO Ajo Ajo	2,100	1	1
Marana Dwid Derringer Marana	1,950	4	0
GW Ocotillo Water Catalina Catalina	1,102	0	0
Town & Country Estates Tucson	960	2	1
Rincon Country East RV Park Tucson	912	2	1
Lakewood Estates Water Company Tucson	905	1	0
Rancho del Conejo Comm Water Coop Avra Valley	900	0	0
Sandario Water Company Tucson	885	1	1
Metropolitan Dwid E&t System Tucson	880	2	0
Far Horizons East MHP Tucson	870	0	0
Organ Pipe NM Headquarters Organ Pipe Nm	755	3	0
Marana Municipal Silverbell Gateway Marana	750	0	0
Mission Palms Apartments Tucson	720	1	0
Marana Dwid Culver Marana	709	4	1
Winterhaven Water Development Tucson	685	0	0
GW Ocotillo Water Diamond Bell Tucson	649	0	0
LA Casita Water Company 3 Tucson	598	2	0
Vista del Norte MHP Tucson	554	0	0
Anway Manville Water Company Avra Valley	550	2	1
Trails West MHP Tucson	500	2	0

Non-community systems (51: schools, campgrounds, workplaces, restaurants)

These systems serve places people visit rather than homes.

System	Serves	Rules violated, 3 yr	Unresolved
University of Arizona Tucson	50,000	0	0
Tucson Medical Center Tucson	3,000	4	1
UA Tech Park Rita Road Tucson	3,000	2	0
Marana High School Marana	2,450	1	0
Marana Estes Elementary School Marana	2,000	1	0
Vail School District Elementary School Vail	1,680	3	0
Saguaro National Park Tucson	1,440	2	0
Salpointe Catholic High School Tucson	1,300	0	0
Tucson Country Day School Tucson	800	0	0
Asarco Mission Unit Green Valley	586	0	0
Usfs Cnf Sabino Canyon Stop 8 Sabino Canyon	550	0	0
Thim Utility Corporation VFW Three Points	413	0	0
Usfs Cnf Loma Linda Mount Lemmon	350	1	0
Usfs Cnf Ski Lodge Mount Lemmon	350	0	0
AZ State Parks Catalina Mountain Catalina	330	1	0
Tucson Racquet & Fitness Club Tucson	330	3	1
Camp Whispering Pines Mount Lemon	240	0	0
Saint Phillips Plaza Tucson	220	2	0
Santa Catalina Catholic Church Tucson	212	2	0
Pcnr Colossal Cave Tucson	210	1	0
Camp Lawton Mount Lemmon	200	2	0
Caterpillar INC Green Valley	200	0	0
Latter Day Saints Church Summerhaven	200	4	1
Silverbell Mining, LLC Marana	200	3	0
Calportland Rillito Cement Plant Rillito	184	4	2
Greenfields Country Day School Tucson	163	6	0
Bayer R&d Services LLC Marana Marana	160	2	0
Caballo Loco Ranch Sasabe	150	3	1
Pcnr Gilbert Ray Tmp Tucson	150	2	0
Tanque Verde Guest Ranch Tucson	150	2	0
Lil Abners Steakhouse Tucson	100	0	0
Pcnr Motor Sports Tucson	100	0	0
Pcnr Picture Rocks Tucson	100	1	0
Hot Rod Water Vail	90	3	0
Pcnr Fairgrounds Tucson	87	0	0
Tucson Ready Mix Orange Grove Tucson	80	0	0
Campbell Avenue Farms Tucson	65	0	0
White Stallion Guest Ranch Tucson	60	1	0
Marana Municipal Airport Marana	55	0	0
Buenos Aires National Wildlife Refuge Sasabe	54	7	1
Pcnr Three Point Three Points	52	2	0
Sopori School Park Tucson	50	0	0
Lukeville Border Station Lukeville	45	1	0
Elkhorn Ranch Sasabe	40	1	0
Hitda Training Center Tucson	35	0	0
Sasabe Border Village Sasabe	31	5	1
Soldier Camp Permittees Summerhaven	30	3	0
EL Mesquital Guest Ranch Tucson	25	0	0
Gringo Pass TP Lukeville	25	1	0
Pcnr la Posta Quemada Tucson	25	0	0
Redwood Lodge Tucson	25	1	0

Inactive systems (322, 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.

Pima County drinking water quality

Needs attention

Community water systems

Compliant

Violations in the past 3 years

Serious violator

Health flag

Inactive system