Public water system · AZ0410128
ActiveCs Los Cerros Water Company Inc.
At a glance
Cs Los Cerros Water Company Inc. (PWSID AZ0410128) is an active community water system in Pima County, Arizona. It reports serving 2,613 people through 902 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 January 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,613
Service connections
902
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Cs Los Cerros Water Company Inc. compare with other water systems in Pima County?
By EPA's size categories, Cs Los Cerros Water Company Inc. is a small system (501 to 3,300 people). Pima County has 193 active public water systems. Its population served is about 56% below the county average of 5,896 people per system, and accounts for 0.2% 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 Cs Los Cerros Water Company Inc. is about 61% 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 Cs Los Cerros Water Company Inc.?
EPA lists Cs Los Cerros Water Company Inc. 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 Cs Los Cerros Water Company Inc. 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 2023. The violations listed here began between July 2012 and January 2023. By type: 9 monitoring and reporting, 1 reporting, 1 monitoring and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Chlorine (4 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 |
|---|---|---|---|---|
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2019-10-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2018-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2017-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2017-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | 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 and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2015-09-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2012-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | 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.
Cs Los Cerros Water Company Inc.: frequently asked questions
Who runs Cs Los Cerros Water Company Inc.?
Cs Los Cerros Water Company Inc. (PWSID AZ0410128) is a community water system privately owned. It is regulated by the AZ state drinking water program.
How many people does Cs Los Cerros Water Company Inc. serve?
Cs Los Cerros Water Company Inc. reports serving 2,613 people through 902 service connections in Pima County, Arizona.
Where does Cs Los Cerros Water Company Inc. 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 Cs Los Cerros Water Company Inc. 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 2023. 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 Cs Los Cerros Water Company Inc.'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 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the AZ state drinking water program.
Where can I find Cs Los Cerros Water Company Inc.'s water quality report?
As a community water system, Cs Los Cerros Water Company Inc. 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, “Cs Los Cerros Water Company Inc., PWSID AZ0410128, Arizona”, https://aquacensus.com/water-systems/arizona/cs-los-cerros-water-company-inc-az0410128 (data as of October 1, 2026).