Public water system · CA4310007
ActiveCity of Mountain View
At a glance
City of Mountain View (PWSID CA4310007) is an active community water system in Santa Clara County, California. It reports serving 81,501 people through 17,907 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; 3 are health-based, and the most recent began in March 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
81,501
Service connections
17,907
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does City of Mountain View compare with other water systems in Santa Clara County?
By EPA's size categories, City of Mountain View is a large system (10,001 to 100,000 people). Santa Clara County has 121 active public water systems. Its population served is about 4.7 times the county average of 17,334 people per system, and accounts for 3.9% 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 Mountain View is about 12 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 Mountain View?
EPA lists City of Mountain View 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 Mountain View have drinking water violations?
EPA's records list 7 violations for this system; 3 are health-based, and the most recent began in March 2015. The violations listed here began between November 1988 and March 2015. By type: 3 required treatment not met, 3 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Surface Water Treatment Rule (3 of them). EPA lists 6 as resolved and 1 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 |
|---|---|---|---|---|
| 2015-03-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
| 2013-07-01 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2001-05-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Resolved |
| 2001-03-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Resolved |
| 1995-03-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
| 1992-03-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
| 1988-11-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 7 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 Mountain View: frequently asked questions
Who runs City of Mountain View?
City of Mountain View (PWSID CA4310007) 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 Mountain View serve?
City of Mountain View reports serving 81,501 people through 17,907 service connections in Santa Clara County, California.
Where does City of Mountain View 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 Mountain View have any drinking water violations?
EPA's records list 7 violations for this system; 3 are health-based, and the most recent began in March 2015. 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 Mountain View'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 7 violations for this system; 3 are health-based, and the most recent began in March 2015. 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 Mountain View's water quality report?
As a community water system, City of Mountain View 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 Mountain View, PWSID CA4310007, California”, https://aquacensus.com/water-systems/california/city-of-mountain-view-ca4310007 (data as of October 1, 2026).