Public water system · WI7440623
ActiveWillow Haven
At a glance
Willow Haven (PWSID WI7440623) is an active transient non-community water system in Oneida County, Wisconsin. It reports serving 260 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in September 2009.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
260
Service connections
1
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Willow Haven compare with other water systems in Oneida County?
By EPA's size categories, Willow Haven is a very small system (500 people or fewer). Oneida County has 345 active public water systems. Its population served is about 121% above the county average of 117 people per system, and accounts for 0.6% of the 40,498 people reported by systems filed under the county. Across Wisconsin, the 11,056 active systems average 469 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Willow Haven is about 81% above 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. Wisconsin has 9,112 active transient non-community water systems, 82% of the state's 11,056 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 10,978 Wisconsin systems (99%) list groundwater as their primary source.
Who owns and regulates Willow Haven?
EPA lists Willow Haven as privately owned. The WI state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 299 of the 345 active systems in Oneida County (87%) are also privately owned.
Does Willow Haven have drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in September 2009. The violations listed here began between January 1997 and September 2009. By type: 6 monitoring and reporting and 2 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 7 as resolved and 1 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 |
|---|---|---|---|---|
| 2009-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 2009-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2002-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2000-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1997-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1997-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 8 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.
Willow Haven: frequently asked questions
Who runs Willow Haven?
Willow Haven (PWSID WI7440623) is a transient non-community water system privately owned. It is regulated by the WI state drinking water program.
How many people does Willow Haven serve?
Willow Haven reports serving 260 people through 1 service connection in Oneida County, Wisconsin.
Where does Willow Haven 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 Willow Haven have any drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in September 2009. 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 Willow Haven'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 8 violations for this system; 2 are health-based, and the most recent began in September 2009. For current results, consult EPA ECHO, or the WI state drinking water program.
Where can I find Willow Haven's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Willow Haven 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 Oneida County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Rhinelander Water & Wastewater | Oneida | 8,234 | Community | Groundwater |
| Lakeland Sanitary Dist 1 | Oneida | 2,381 | Community | Groundwater |
| Minocqua Hazelhurst Elem Sch | Oneida | 650 | Non-transient non-community | Groundwater |
| Three Lakes Sanitary District | Oneida | 500 | Community | Groundwater |
| Scouting America Camp Tesomas Program Center and Dining Hall | Oneida | 500 | Transient non-community | Groundwater |
| Wi Dnr Clear Lk Cmpgd 8 | Oneida | 450 | Transient non-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, “Willow Haven, PWSID WI7440623, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/willow-haven-wi7440623 (data as of October 1, 2026).