Public water system · AZ0411128
ActiveEpcor - San Tan
At a glance
Epcor - San Tan (PWSID AZ0411128) is an active community water system in Pinal County, Arizona. It reports serving 87,435 people through 26,986 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in March 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
87,435
Service connections
26,986
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Epcor - San Tan compare with other water systems in Pinal County?
By EPA's size categories, Epcor - San Tan is a large system (10,001 to 100,000 people). Pinal County has 94 active public water systems, and Epcor - San Tan is the 2nd-largest of them by population served. Its population served is about 16 times the county average of 5,375 people per system, and accounts for 17% of the 505,241 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 Epcor - San Tan is about 13 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 Epcor - San Tan?
EPA lists Epcor - San Tan as privately owned. 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. 44 of the 94 active systems in Pinal County (47%) are also privately owned.
Does Epcor - San Tan have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in March 2026. The violations listed here began between January 2024 and March 2026. By type: 12 monitoring and reporting. The contaminant or rule involved most often is Chlorine (4 of them). EPA lists 11 as resolved and 1 as archived. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed. 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 |
|---|---|---|---|---|
| 2026-03-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Archived |
| 2024-12-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2024-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2024-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbon tetrachloridecode 2982 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | No | Resolved |
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.
Epcor - San Tan: frequently asked questions
Who runs Epcor - San Tan?
Epcor - San Tan (PWSID AZ0411128) is a community water system privately owned. It is regulated by the AZ state drinking water program.
How many people does Epcor - San Tan serve?
Epcor - San Tan reports serving 87,435 people through 26,986 service connections in Pinal County, Arizona.
Where does Epcor - San Tan 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 Epcor - San Tan 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 March 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 Epcor - San Tan'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 March 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 Epcor - San Tan's water quality report?
As a community water system, Epcor - San Tan 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 Pinal County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Arizona Water Co - Pinal Valley | Pinal | 134,432 | Community | Groundwater |
| Gw Santa Cruz Water Co | Pinal | 84,000 | Community | Groundwater |
| Arizona Water Co - Apache Junction | Pinal | 62,055 | Community | Groundwater |
| Lago Del Oro Water Company | Pinal | 18,132 | Community | Groundwater |
| Florence Water Company | Pinal | 15,900 | Community | Groundwater |
| Apache Junction Water District | Pinal | 15,610 | Community | Surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Epcor - San Tan, PWSID AZ0411128, Arizona”, https://aquacensus.com/water-systems/arizona/epcor-san-tan-az0411128 (data as of October 1, 2026).