Public water system · AZ0410112
ActiveTucson City of
At a glance
City of Tucson (PWSID AZ0410112) is an active community water system in Pima County, Arizona. It reports serving 732,906 people through 191,264 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
732,906
Service connections
191,264
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Tucson compare with other water systems in Pima County?
By EPA's size categories, City of Tucson is a very large system (more than 100,000 people). Pima County has 193 active public water systems, and City of Tucson is the largest of them by population served. Its population served is about 124 times the county average of 5,896 people per system, and accounts for 64% of the 1,137,975 people reported by systems filed under the county. Across Arizona, the 1,769 active systems average 4,369 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Tucson is about 109 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Arizona has 936 active community water systems, 53% of the state's 1,769 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,612 Arizona systems (91%) list groundwater as their primary source.
Who owns and regulates City of Tucson?
EPA lists City of Tucson as owned by a local government. The AZ state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 33 of the 193 active systems in Pima County (17%) are also owned by a local government.
Does City of Tucson have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026. The violations listed here began between January 2026 and January 2026. By type: 12 monitoring and reporting. The contaminants or rules involved are Ethylbenzene, 1,1,1-Trichloroethane, Gross alpha (excluding radon and uranium) and Trichloroethylene. EPA lists 12 as archived. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Trichloroethylenecode 2984 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Xylenes, Totalcode 2955 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Uraniumcode 4006 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | Archived |
The 12 most recent violations in EPA's records, newest first. Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
City of Tucson: frequently asked questions
Who runs City of Tucson?
City of Tucson (PWSID AZ0410112) is a community water system owned by a local government. It is regulated by the AZ state drinking water program.
How many people does City of Tucson serve?
City of Tucson reports serving 732,906 people through 191,264 service connections in Pima County, Arizona.
Where does City of Tucson get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does City of Tucson have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is City of Tucson's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the AZ state drinking water program.
Where can I find City of Tucson's water quality report?
As a community water system, City of Tucson must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Pima County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| University of Arizona | Pima | 50,000 | Non-transient non-community | Groundwater |
| Metropolitan Dwid | Pima | 45,570 | Community | Groundwater |
| Oro Valley Water Utility | Pima | 42,316 | Community | Groundwater |
| Community Wc of Green Valley | Pima | 22,085 | Community | Groundwater |
| Usaf Davis Monthan Afb | Pima | 18,640 | Community | Groundwater |
| Sahuarita Water Company | Pima | 18,178 | Community | Groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Tucson City of, PWSID AZ0410112, Arizona”, https://aquacensus.com/water-systems/arizona/tucson-city-of-az0410112 (data as of October 1, 2026).