Public water system · WI2686118
ActiveChapman Oil Inc.
At a glance
Chapman Oil Inc. (PWSID WI2686118) is an active non-transient non-community water system in Waukesha County, Wisconsin. It reports serving 386 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
386
Service connections
1
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Chapman Oil Inc. compare with other water systems in Waukesha County?
By EPA's size categories, Chapman Oil Inc. is a very small system (500 people or fewer). Waukesha County has 589 active public water systems. Its population served is about 30% below the county average of 549 people per system, and accounts for 0.1% of the 323,265 people reported by systems filed under the county. Across Wisconsin, the 11,056 active systems average 469 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Chapman Oil Inc. is about 10% below that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. Wisconsin has 891 active non-transient non-community water systems, 8.1% 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 Chapman Oil Inc.?
EPA lists Chapman Oil Inc. 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. 452 of the 589 active systems in Waukesha County (77%) are also privately owned.
Does Chapman Oil Inc. have drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2024. The violations listed here began between January 2018 and October 2024. By type: 8 contaminant level above the legal limit, 2 public notice, recordkeeping or other and 2 required treatment not met. The contaminant or rule involved most often is Arsenic (8 of them). EPA lists 10 as resolved and 2 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. 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 |
|---|---|---|---|---|
| 2024-10-26 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2024-10-26 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2024-10-26 | Required treatment not metFailure To Address Deficiency · code 45 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2024-10-26 | Required treatment not metFailure To Address Deficiency · code 45 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2019-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2019-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2019-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2019-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2018-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2018-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2018-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2018-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | 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.
Chapman Oil Inc.: frequently asked questions
Who runs Chapman Oil Inc.?
Chapman Oil Inc. (PWSID WI2686118) is a non-transient non-community water system privately owned. It is regulated by the WI state drinking water program.
How many people does Chapman Oil Inc. serve?
Chapman Oil Inc. reports serving 386 people through 1 service connection in Waukesha County, Wisconsin.
Where does Chapman Oil Inc. 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 Chapman Oil Inc. have any drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2024. 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 Chapman Oil Inc.'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, 10 are health-based, and the most recent began in October 2024. For current results, consult EPA ECHO, or the WI state drinking water program.
Where can I find Chapman Oil Inc.'s water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Chapman Oil Inc. is a non-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 Waukesha County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Waukesha Water Utility | Waukesha | 70,718 | Community | Purchased surface water |
| Brookfield Water Utility | Waukesha | 29,070 | Community | Groundwater |
| New Berlin Water Utility | Waukesha | 27,899 | Community | Purchased surface water |
| Menomonee Falls Ww - Surface Water | Waukesha | 23,867 | Community | Purchased surface water |
| Oconomowoc Waterworks | Waukesha | 15,805 | Community | Groundwater |
| Sussex Village Hall & Water Utility | Waukesha | 11,750 | 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, “Chapman Oil Inc., PWSID WI2686118, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/chapman-oil-inc-wi2686118 (data as of October 1, 2026).