Public water system · CA3301146
ActiveTerwilliger Association
At a glance
Terwilliger Association (PWSID CA3301146) is an active transient non-community water system in Riverside County, California. It reports serving 2,401 people through 2 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in January 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,401
Service connections
2
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Terwilliger Association compare with other water systems in Riverside County?
By EPA's size categories, Terwilliger Association is a small system (501 to 3,300 people). Riverside County has 197 active public water systems. Its population served is well below the county average of 14,435 people per system, and accounts for less than 0.1% of the 2,843,721 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Terwilliger Association is about 17 times that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. California has 3,016 active transient non-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 Terwilliger Association?
EPA lists Terwilliger Association as privately owned. 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. 130 of the 197 active systems in Riverside County (66%) are also privately owned.
Does Terwilliger Association have drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in January 2021. The violations listed here began between January 1983 and January 2021. By type: 4 public notice, recordkeeping or other, 2 contaminant level above the legal limit, 1 monitoring and 1 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 4 as resolved and 4 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 |
|---|---|---|---|---|
| 2021-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2016-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2015-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2014-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Resolved |
| 1983-12-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1983-03-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1983-02-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1983-01-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
All 8 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.
Terwilliger Association: frequently asked questions
Who runs Terwilliger Association?
Terwilliger Association (PWSID CA3301146) is a transient non-community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Terwilliger Association serve?
Terwilliger Association reports serving 2,401 people through 2 service connections in Riverside County, California.
Where does Terwilliger Association 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 Terwilliger Association have any drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in January 2021. 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 Terwilliger Association'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 8 violations for this system; 2 are health-based, and the most recent began in January 2021. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Terwilliger Association's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Terwilliger Association is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Riverside County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Eastern Municipal Wd | Riverside | 666,581 | Community | Purchased surface water |
| Riverside, City of | Riverside | 298,398 | Community | Groundwater under influence of surface water |
| Coachella Vwd: Cove Community | Riverside | 270,000 | Community | Groundwater |
| Elsinore Valley Mwd | Riverside | 169,455 | Community | Surface water |
| Corona, City of | Riverside | 168,575 | Community | Purchased surface water |
| Rancho California Water District | Riverside | 146,147 | 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, “Terwilliger Association, PWSID CA3301146, California”, https://aquacensus.com/water-systems/california/terwilliger-association-ca3301146 (data as of October 1, 2026).