Public water system · CA5010019

Active

Turlock, City of

At a glance

City of Turlock (PWSID CA5010019) is an active community water system in Stanislaus County, California. It reports serving 72,682 people through 19,716 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 9 violations for this system; 7 are health-based, and the most recent began in January 2017.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

72,682

Service connections

19,716

Primary source

SWP

Purchased surface water

System type

CWS

Community water system

System record

PWSIDCA5010019

System typeCommunity water system

Activity statusActive

Population served72,682

Service connections19,716

Primary water sourcePurchased surface water

Owner typeLocal government

Primacy agencyCA state drinking water program

City servedTurlock

StateCalifornia

ZIP—

CountyStanislaus County

How does City of Turlock compare with other water systems in Stanislaus County?

By EPA's size categories, City of Turlock is a large system (10,001 to 100,000 people). Stanislaus County has 191 active public water systems, and City of Turlock is the 2nd-largest of them by population served. Its population served is about 27 times the county average of 2,684 people per system, and accounts for 14% of the 512,656 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Turlock is about 11 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. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 506 California systems (6.8%) list purchased surface water as their primary source.

Who owns and regulates City of Turlock?

EPA lists City of Turlock as owned by a local government. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 57 of the 191 active systems in Stanislaus County (30%) are also owned by a local government.

Does City of Turlock have drinking water violations?

EPA's records list 9 violations for this system; 7 are health-based, and the most recent began in January 2017. The violations listed here began between April 1993 and January 2017. By type: 7 contaminant level above the legal limit and 2 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (6 of them). EPA lists 9 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
2017-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01	Nitratecode 1040	Yes	Resolved
2011-04-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Arseniccode 1005	Yes	Resolved
2011-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Arseniccode 1005	Yes	Resolved
2010-06-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2009-02-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2002-04-01	Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24	Total coliform bacteria (TCR)code 3100	No	Resolved
1998-06-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
1993-11-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
1993-04-01	Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24	Total coliform bacteria (TCR)code 3100	No	Resolved

All 9 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 Turlock: frequently asked questions

Who runs City of Turlock?

City of Turlock (PWSID CA5010019) is a community water system owned by a local government. It is regulated by the CA state drinking water program.

How many people does City of Turlock serve?

City of Turlock reports serving 72,682 people through 19,716 service connections in Stanislaus County, California.

Where does City of Turlock get its water?

EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.

Does City of Turlock have any drinking water violations?

EPA's records list 9 violations for this system; 7 are health-based, and the most recent began in January 2017. 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 Turlock'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. EPA's records list 9 violations for this system; 7 are health-based, and the most recent began in January 2017. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.

Where can I find City of Turlock's water quality report?

As a community water system, City of Turlock 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 Stanislaus County

Water system	County	Population served	Type	Source
Modesto, City of	Stanislaus	218,771	Community	Purchased surface water
Ceres, City of	Stanislaus	54,513	Community	Purchased surface water
Patterson, City of	Stanislaus	24,977	Community	Groundwater
Riverbank, City of	Stanislaus	24,834	Community	Groundwater
Oakdale, City of	Stanislaus	23,235	Community	Groundwater
City of Modesto - Salida	Stanislaus	14,537	Community	Purchased surface water

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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, “Turlock, City of, PWSID CA5010019, California”, https://aquacensus.com/water-systems/california/turlock-city-of-ca5010019 (data as of October 1, 2026).