Public water system · AZ0410119
ActiveWinterhaven Water Development
At a glance
Winterhaven Water Development (PWSID AZ0410119) is an active community water system in Pima County, Arizona. It reports serving 685 people through 274 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 September 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
685
Service connections
274
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Winterhaven Water Development compare with other water systems in Pima County?
By EPA's size categories, Winterhaven Water Development is a small system (501 to 3,300 people). Pima County has 193 active public water systems. Its population served is well below the county average of 5,896 people per system, and accounts for less than 0.1% 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 Winterhaven Water Development is well below 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 Winterhaven Water Development?
EPA lists Winterhaven Water Development 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. 76 of the 193 active systems in Pima County (39%) are also privately owned.
Does Winterhaven Water Development have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in September 2025. The violations listed here began between January 2014 and September 2025. By type: 11 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is Chlorine (5 of them). EPA lists 12 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2017-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) phthalatecode 2039 | No | Resolved |
| 2017-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) phthalatecode 2039 | No | Resolved |
| 2016-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2016-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2016-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2016-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) phthalatecode 2039 | No | Resolved |
| 2016-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) phthalatecode 2039 | No | Resolved |
| 2015-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2014-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2014-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | 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.
Winterhaven Water Development: frequently asked questions
Who runs Winterhaven Water Development?
Winterhaven Water Development (PWSID AZ0410119) is a community water system privately owned. It is regulated by the AZ state drinking water program.
How many people does Winterhaven Water Development serve?
Winterhaven Water Development reports serving 685 people through 274 service connections in Pima County, Arizona.
Where does Winterhaven Water Development 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 Winterhaven Water Development 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 September 2025. 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 Winterhaven Water Development'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 September 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the AZ state drinking water program.
Where can I find Winterhaven Water Development's water quality report?
As a community water system, Winterhaven Water Development 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 |
|---|---|---|---|---|
| Tucson City of | Pima | 732,906 | Community | Groundwater |
| 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 |
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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, “Winterhaven Water Development, PWSID AZ0410119, Arizona”, https://aquacensus.com/water-systems/arizona/winterhaven-water-development-az0410119 (data as of October 1, 2026).