Public water system · WA5396887
ActiveOcosta Mobile Home Park LLC
At a glance
Ocosta Mobile Home Park LLC (PWSID WA5396887) is an active community water system in Grays Harbor County, Washington. It reports serving 26 people through 10 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
26
Service connections
10
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Ocosta Mobile Home Park LLC compare with other water systems in Grays Harbor County?
By EPA's size categories, Ocosta Mobile Home Park LLC is a very small system (500 people or fewer). Grays Harbor County has 88 active public water systems. Its population served is well below the county average of 1,013 people per system, and accounts for less than 0.1% of the 89,150 people reported by systems filed under the county. Across Washington, the 4,705 active systems average 2,172 people each. Nationally, the average active community water system reports serving 6,703 people, so Ocosta Mobile Home Park LLC 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. Washington has 2,392 active community water systems, 51% 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 Ocosta Mobile Home Park LLC?
EPA lists Ocosta Mobile Home Park LLC as privately owned. 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. 62 of the 88 active systems in Grays Harbor County (70%) are also privately owned.
Does Ocosta Mobile Home Park LLC have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2025. The violations listed here began between January 2023 and October 2025. By type: 6 monitoring and 6 monitoring and reporting. The contaminant or rule involved most often is Revised Total Coliform Rule (6 of them). EPA lists 6 as resolved, 5 as archived and 1 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-05-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Archived |
| 2023-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
The 12 most recent 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.
Ocosta Mobile Home Park LLC: frequently asked questions
Who runs Ocosta Mobile Home Park LLC?
Ocosta Mobile Home Park LLC (PWSID WA5396887) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Ocosta Mobile Home Park LLC serve?
Ocosta Mobile Home Park LLC reports serving 26 people through 10 service connections in Grays Harbor County, Washington.
Where does Ocosta Mobile Home Park LLC 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 Ocosta Mobile Home Park LLC have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2025. 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 Ocosta Mobile Home Park LLC'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. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in October 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Ocosta Mobile Home Park LLC's water quality report?
As a community water system, Ocosta Mobile Home Park LLC 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 Grays Harbor County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Aberdeen City of | Grays Harbor | 22,867 | Community | Surface water |
| Hoquiam Water Department | Grays Harbor | 11,456 | Community | Surface water |
| Ocean Shores Water Dept | Grays Harbor | 9,347 | Community | Groundwater |
| Elma City of | Grays Harbor | 6,638 | Community | Groundwater |
| Montesano City of | Grays Harbor | 6,204 | Community | Groundwater |
| Westport Water Department | Grays Harbor | 5,346 | 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, “Ocosta Mobile Home Park LLC, PWSID WA5396887, Washington”, https://aquacensus.com/water-systems/washington/ocosta-mobile-home-park-llc-wa5396887 (data as of October 1, 2026).