Public water system · CA1700730
ActiveThomas Water System
At a glance
Thomas Water System (PWSID CA1700730) is an active transient non-community water system in Lake County, California. It reports serving 110 people through 6 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list one violation for this system; it is not health-based, and the most recent began in October 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
110
Service connections
6
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Thomas Water System compare with other water systems in Lake County?
By EPA's size categories, Thomas Water System is a very small system (500 people or fewer). Lake County has 81 active public water systems. Its population served is well below the county average of 895 people per system, and accounts for 0.2% of the 72,454 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 Thomas Water System is about 24% below 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 Thomas Water System?
EPA lists Thomas Water System 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. 60 of the 81 active systems in Lake County (74%) are also privately owned.
Does Thomas Water System have drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in October 2014. By type: 1 monitoring and reporting. The contaminant or rule involved is Total coliform bacteria (TCR). 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 |
|---|---|---|---|---|
| 2014-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | 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.
Thomas Water System: frequently asked questions
Who runs Thomas Water System?
Thomas Water System (PWSID CA1700730) is a transient non-community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Thomas Water System serve?
Thomas Water System reports serving 110 people through 6 service connections in Lake County, California.
Where does Thomas Water System 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 Thomas Water System have any drinking water violations?
EPA's records list one violation for this system; it is not health-based, and the most recent began in October 2014. 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 Thomas Water System'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 not health-based, and the most recent began in October 2014. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Thomas Water System's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Thomas Water System 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 Lake County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Highlands Mutual Water Company | Lake | 7,772 | Community | Surface water |
| Hidden Valley Lake Csd | Lake | 6,235 | Community | Groundwater |
| Konocti County Water District | Lake | 5,928 | Community | Surface water |
| Lakeport, City of | Lake | 4,762 | Community | Surface water |
| Golden State Water Co.-Clearlake System | Lake | 4,644 | Community | Surface water |
| Mt. Konocti Mutual Water Company | Lake | 4,360 | Community | 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, “Thomas Water System, PWSID CA1700730, California”, https://aquacensus.com/water-systems/california/thomas-water-system-ca1700730 (data as of October 1, 2026).