Public water system · WA5350290
ActiveMahaffey
At a glance
Mahaffey (PWSID WA5350290) is an active transient non-community water system in Cowlitz County, Washington. It reports serving 49 people through 23 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 January 2005.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
49
Service connections
23
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Mahaffey compare with other water systems in Cowlitz County?
By EPA's size categories, Mahaffey is a very small system (500 people or fewer). Cowlitz County has 77 active public water systems. Its population served is well below the county average of 1,628 people per system, and accounts for less than 0.1% of the 125,351 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 Mahaffey is about 66% 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. 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 Mahaffey?
EPA lists Mahaffey 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. 58 of the 77 active systems in Cowlitz County (75%) are also privately owned.
Does Mahaffey have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2005. The violations listed here began between October 1979 and January 2005. By type: 12 monitoring and reporting. The contaminant or rule involved most often is Nitrate (2 of them). EPA lists 11 as archived and 1 as resolved. 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. 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 |
|---|---|---|---|---|
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2000-09-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1999-12-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Bariumcode 1010 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Cadmiumcode 1015 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Mercurycode 1035 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chromiumcode 1020 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Seleniumcode 1045 | No | Archived |
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.
Mahaffey: frequently asked questions
Who runs Mahaffey?
Mahaffey (PWSID WA5350290) is a transient non-community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Mahaffey serve?
Mahaffey reports serving 49 people through 23 service connections in Cowlitz County, Washington.
Where does Mahaffey 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 Mahaffey 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 January 2005. 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 Mahaffey'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 January 2005. For current results, consult EPA ECHO, or the WA state drinking water program.
Where can I find Mahaffey's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Mahaffey 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 Cowlitz County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Longview Water Department | Cowlitz | 57,617 | Community | Groundwater |
| Kelso City of | Cowlitz | 15,775 | Community | Groundwater under influence of surface water |
| Beacon Hill Water & Sewer District | Cowlitz | 11,969 | Community | Purchased groundwater |
| Woodland City of | Cowlitz | 10,640 | Community | Groundwater under influence of surface water |
| Kalama City of | Cowlitz | 8,020 | Community | Groundwater under influence of surface water |
| Castle Rock Municipal Water | Cowlitz | 4,367 | 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, “Mahaffey, PWSID WA5350290, Washington”, https://aquacensus.com/water-systems/washington/mahaffey-wa5350290 (data as of October 1, 2026).