Public water system · CA0707613
ActiveWillow Mobile Home Park
At a glance
Willow Mobile Home Park (PWSID CA0707613) is an active community water system in Contra Costa County, California. It reports serving 481 people through 172 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; none is health-based, and the most recent began in January 2019.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
481
Service connections
172
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Willow Mobile Home Park compare with other water systems in Contra Costa County?
By EPA's size categories, Willow Mobile Home Park is a very small system (500 people or fewer). Contra Costa County has 84 active public water systems. Its population served is well below the county average of 6,726 people per system, and accounts for less than 0.1% of the 564,952 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 Willow Mobile Home Park 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 Willow Mobile Home Park?
EPA lists Willow Mobile Home Park 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. 25 of the 84 active systems in Contra Costa County (30%) are also owned by a local government.
Does Willow Mobile Home Park have drinking water violations?
EPA's records list 7 violations for this system; none is health-based, and the most recent began in January 2019. The violations listed here began between October 1980 and January 2019. By type: 4 monitoring and reporting and 3 public notice, recordkeeping or other. The contaminant or rule involved most often is Gross alpha (excluding radon and uranium) (2 of them). EPA lists 5 as archived and 2 as resolved. 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. 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 |
|---|---|---|---|---|
| 2019-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1984-05-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-03-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-02-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1981-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1980-10-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | 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.
Willow Mobile Home Park: frequently asked questions
Who runs Willow Mobile Home Park?
Willow Mobile Home Park (PWSID CA0707613) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Willow Mobile Home Park serve?
Willow Mobile Home Park reports serving 481 people through 172 service connections in Contra Costa County, California.
Where does Willow Mobile Home Park 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 Willow Mobile Home Park have any drinking water violations?
EPA's records list 7 violations for this system; none is health-based, and the most recent began in January 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 Willow Mobile Home Park'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; none is health-based, and the most recent began in January 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 Willow Mobile Home Park's water quality report?
As a community water system, Willow Mobile Home Park 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 Contra Costa County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Contra Costa Water District | Contra Costa | 198,000 | Community | Surface water |
| City of Antioch | Contra Costa | 115,074 | Community | Surface water |
| Brentwood | Contra Costa | 64,513 | Community | Purchased surface water |
| City of Pittsburg | Contra Costa | 62,500 | Community | Purchased surface water |
| Diablo Water District | Contra Costa | 43,357 | Community | Purchased surface water |
| City of Martinez | Contra Costa | 30,997 | 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, “Willow Mobile Home Park, PWSID CA0707613, California”, https://aquacensus.com/water-systems/california/willow-mobile-home-park-ca0707613 (data as of October 1, 2026).