Public water system · CA4300542
ActiveSan Martin County Water District
At a glance
San Martin County Water District (PWSID CA4300542) is an active community water system in Santa Clara County, California. It reports serving 627 people through 190 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2019.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
627
Service connections
190
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does San Martin County Water District compare with other water systems in Santa Clara County?
By EPA's size categories, San Martin County Water District is a small system (501 to 3,300 people). Santa Clara County has 121 active public water systems. Its population served is well below the county average of 17,334 people per system, and accounts for less than 0.1% 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 San Martin County Water District 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. 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 San Martin County Water District?
EPA lists San Martin County Water District 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 San Martin County Water District have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2019. The violations listed here began between August 1984 and October 2019. By type: 9 monitoring and reporting, 2 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Lead and Copper Rule (3 of them). EPA lists 10 as resolved and 2 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2019-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1999-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1999-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Alachlor (Lasso)code 2051 | No | Resolved |
| 1998-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Alachlor (Lasso)code 2051 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1993-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 1984-09-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
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.
San Martin County Water District: frequently asked questions
Who runs San Martin County Water District?
San Martin County Water District (PWSID CA4300542) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does San Martin County Water District serve?
San Martin County Water District reports serving 627 people through 190 service connections in Santa Clara County, California.
Where does San Martin County Water District 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 San Martin County Water District have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in October 2019. 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 San Martin County Water District'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, one is health-based, and the most recent began in October 2019. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find San Martin County Water District's water quality report?
As a community water system, San Martin County Water District 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, “San Martin County Water District, PWSID CA4300542, California”, https://aquacensus.com/water-systems/california/san-martin-county-water-district-ca4300542 (data as of October 1, 2026).