Public water system · WA5357400
ActiveMUD Bay
At a glance
MUD Bay (PWSID WA5357400) is an active community water system in Thurston County, Washington. It reports serving 145 people through 60 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 September 2020.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
145
Service connections
60
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does MUD Bay compare with other water systems in Thurston County?
By EPA's size categories, MUD Bay is a very small system (500 people or fewer). Thurston County has 322 active public water systems. Its population served is well below the county average of 1,233 people per system, and accounts for less than 0.1% of the 397,060 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 MUD Bay 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 MUD Bay?
EPA lists MUD Bay 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. 237 of the 322 active systems in Thurston County (74%) are also privately owned.
Does MUD Bay have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in September 2020. The violations listed here began between July 2007 and September 2020. By type: 11 monitoring and reporting and 1 monitoring. The contaminants or rules involved are Revised Total Coliform Rule, Tetrachloroethylene, 1,1,1-Trichloroethane and 1,2-Dichloropropane. EPA lists 12 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 |
|---|---|---|---|---|
| 2020-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Trichloroethylenecode 2984 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2007-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
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.
MUD Bay: frequently asked questions
Who runs MUD Bay?
MUD Bay (PWSID WA5357400) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does MUD Bay serve?
MUD Bay reports serving 145 people through 60 service connections in Thurston County, Washington.
Where does MUD Bay 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 MUD Bay 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 September 2020. 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 MUD Bay'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 September 2020. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find MUD Bay's water quality report?
As a community water system, MUD Bay 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 Thurston County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Olympia City of | Thurston | 126,966 | Community | Groundwater |
| Lacey Water Department | Thurston | 105,178 | Community | Groundwater |
| Tumwater City of | Thurston | 51,802 | Community | Groundwater |
| Yelm City of | Thurston | 17,355 | Community | Groundwater |
| Tanglewilde Thompson Place 600 | Thurston | 7,900 | Community | Groundwater |
| Pattison 500 | Thurston | 4,643 | 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, “MUD Bay, PWSID WA5357400, Washington”, https://aquacensus.com/water-systems/washington/mud-bay-wa5357400 (data as of October 1, 2026).