Public water system · CA5010031
ActiveCity of Modesto - Walnut Manor
At a glance
City of Modesto - Walnut Manor (PWSID CA5010031) is an active community water system in Stanislaus County, California. It reports serving 175 people through 54 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list one violation for this system; it is not health-based, and the most recent began in July 1993.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
175
Service connections
54
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does City of Modesto - Walnut Manor compare with other water systems in Stanislaus County?
By EPA's size categories, City of Modesto - Walnut Manor is a very small system (500 people or fewer). Stanislaus County has 191 active public water systems. Its population served is well below the county average of 2,684 people per system, and accounts for less than 0.1% 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 Modesto - Walnut Manor 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. 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 Modesto - Walnut Manor?
EPA lists City of Modesto - Walnut Manor 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 Modesto - Walnut Manor have drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in July 1993. By type: 1 monitoring and reporting. The contaminant or rule involved is Lead and Copper Rule. EPA lists 1 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 |
|---|---|---|---|---|
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
The one violation in EPA's records.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 Modesto - Walnut Manor: frequently asked questions
Who runs City of Modesto - Walnut Manor?
City of Modesto - Walnut Manor (PWSID CA5010031) 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 Modesto - Walnut Manor serve?
City of Modesto - Walnut Manor reports serving 175 people through 54 service connections in Stanislaus County, California.
Where does City of Modesto - Walnut Manor 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 Modesto - Walnut Manor have any drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in July 1993. 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 Modesto - Walnut Manor'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 one violation for this system; it is not health-based, and the most recent began in July 1993. 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 Modesto - Walnut Manor's water quality report?
As a community water system, City of Modesto - Walnut Manor 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 |
| Turlock, City of | Stanislaus | 72,682 | 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 |
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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, “City of Modesto - Walnut Manor, PWSID CA5010031, California”, https://aquacensus.com/water-systems/california/city-of-modesto-walnut-manor-ca5010031 (data as of October 1, 2026).