Public water system · WA53HD300
ActiveHorn School Rest Area
At a glance
Horn School Rest Area (PWSID WA53HD300) is an active transient non-community water system in Whitman County, Washington. It reports serving 833 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as owned by a state government. EPA's records list 6 violations for this system; none is health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
833
Service connections
1
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Horn School Rest Area compare with other water systems in Whitman County?
By EPA's size categories, Horn School Rest Area is a small system (501 to 3,300 people). Whitman County has 33 active public water systems, and Horn School Rest Area is the 6th-largest of them by population served. Its population served is about 59% below the county average of 2,055 people per system, and accounts for 1.2% of the 67,820 people reported by systems filed under the county. Across Washington, the 4,705 active systems average 2,172 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Horn School Rest Area is about 5.8 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. Washington has 1,913 active transient non-community water systems, 41% of the state's 4,705 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 4,370 Washington systems (93%) list groundwater as their primary source.
Who owns and regulates Horn School Rest Area?
EPA lists Horn School Rest Area as owned by a state government. The WA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 3 of the 33 active systems in Whitman County (9.1%) are also owned by a state government.
Does Horn School Rest Area have drinking water violations?
EPA's records list 6 violations for this system; none is health-based, and the most recent began in January 2026. The violations listed here began between April 1995 and January 2026. By type: 4 monitoring and reporting and 2 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 4 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 |
|---|---|---|---|---|
| 2026-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 2024-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2013-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2011-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
All 6 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.
Horn School Rest Area: frequently asked questions
Who runs Horn School Rest Area?
Horn School Rest Area (PWSID WA53HD300) is a transient non-community water system owned by a state government. It is regulated by the WA state drinking water program.
How many people does Horn School Rest Area serve?
Horn School Rest Area reports serving 833 people through 1 service connection in Whitman County, Washington.
Where does Horn School Rest Area 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 Horn School Rest Area have any drinking water violations?
EPA's records list 6 violations for this system; none is health-based, and the most recent began in January 2026. 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 Horn School Rest Area'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 6 violations for this system; none is health-based, and the most recent began in January 2026. For current results, consult EPA ECHO, or the WA state drinking water program.
Where can I find Horn School Rest Area's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Horn School Rest Area 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 Whitman County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Pullman Water Department City of | Whitman | 31,315 | Community | Groundwater |
| Washington State University | Whitman | 21,506 | Community | Groundwater |
| Colfax Water Department City of | Whitman | 3,507 | Community | Groundwater |
| Palouse Water Dept City of | Whitman | 1,298 | Community | Groundwater |
| Tekoa City of | Whitman | 1,076 | Community | Groundwater |
| Rosalia Town of | Whitman | 831 | Community | Groundwater |
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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, “Horn School Rest Area, PWSID WA53HD300, Washington”, https://aquacensus.com/water-systems/washington/horn-school-rest-area-wa53hd300 (data as of October 1, 2026).