Public water system · CA4310004
ActiveCity of Gilroy
At a glance
City of Gilroy (PWSID CA4310004) is an active community water system in Santa Clara County, California. It reports serving 59,203 people through 15,701 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list one violation for this system; it is health-based, and the most recent began in June 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
59,203
Service connections
15,701
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Gilroy compare with other water systems in Santa Clara County?
By EPA's size categories, City of Gilroy is a large system (10,001 to 100,000 people). Santa Clara County has 121 active public water systems. Its population served is about 3.4 times the county average of 17,334 people per system, and accounts for 2.8% of the 2,097,447 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 Gilroy is about 8.8 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates City of Gilroy?
EPA lists City of Gilroy 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. 34 of the 121 active systems in Santa Clara County (28%) are also owned by a local government.
Does City of Gilroy have drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in June 2022. By type: 1 contaminant level above the legal limit. The contaminant or rule involved is Nitrate. 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 |
|---|---|---|---|---|
| 2022-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | 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 Gilroy: frequently asked questions
Who runs City of Gilroy?
City of Gilroy (PWSID CA4310004) 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 Gilroy serve?
City of Gilroy reports serving 59,203 people through 15,701 service connections in Santa Clara County, California.
Where does City of Gilroy 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 City of Gilroy have any drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in June 2022. 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 Gilroy'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 health-based, and the most recent began in June 2022. 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 Gilroy's water quality report?
As a community water system, City of Gilroy 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 Santa Clara County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| San Jose Water | Santa Clara | 1,039,920 | Community | Surface water |
| City of Sunnyvale | Santa Clara | 157,566 | Community | Purchased surface water |
| City of Santa Clara | Santa Clara | 130,746 | Community | Purchased surface water |
| Great Oaks Wc Inc. | Santa Clara | 110,088 | Community | Groundwater |
| City of San Jose - Evg/Edv/Coy | Santa Clara | 101,265 | Community | Purchased surface water |
| City of Milpitas | Santa Clara | 81,773 | 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, “City of Gilroy, PWSID CA4310004, California”, https://aquacensus.com/water-systems/california/city-of-gilroy-ca4310004 (data as of October 1, 2026).