Public water system · CO0207122
ActiveCity on the Hill
At a glance
City on the Hill (PWSID CO0207122) is an active transient non-community water system in Boulder County, Colorado. It reports serving 82 people through 2 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 5 violations for this system; none is health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
82
Service connections
2
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does City on the Hill compare with other water systems in Boulder County?
By EPA's size categories, City on the Hill is a very small system (500 people or fewer). Boulder County has 81 active public water systems. Its population served is well below the county average of 5,397 people per system, and accounts for less than 0.1% of the 437,116 people reported by systems filed under the county. Across Colorado, the 2,207 active systems average 3,400 people each. Nationally, the average active transient non-community water system reports serving 144 people, so City on the Hill is about 43% 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. Colorado has 956 active transient non-community water systems, 43% of the state's 2,207 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,437 Colorado systems (65%) list groundwater as their primary source.
Who owns and regulates City on the Hill?
EPA lists City on the Hill as privately owned. The CO state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 53 of the 81 active systems in Boulder County (65%) are also privately owned.
Does City on the Hill have drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in January 2026. The violations listed here began between July 1995 and January 2026. By type: 3 monitoring and reporting and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 5 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 |
|---|---|---|---|---|
| 2026-01-12 | Public notice, recordkeeping or otherSample Siting Plan Errors (RTCR) · code 5A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-03-28 | Public notice, recordkeeping or otherPublic Notification Violation without NPDWR Violation · code 76 | Public Noticecode 7500 | No | Resolved |
| 2012-08-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-03-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 5 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.
City on the Hill: frequently asked questions
Who runs City on the Hill?
City on the Hill (PWSID CO0207122) is a transient non-community water system privately owned. It is regulated by the CO state drinking water program.
How many people does City on the Hill serve?
City on the Hill reports serving 82 people through 2 service connections in Boulder County, Colorado.
Where does City on the Hill 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 City on the Hill have any drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in January 2026. 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 City on the Hill'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 5 violations for this system; none is health-based, and the most recent began in January 2026. For current results, consult EPA ECHO, or the CO state drinking water program.
Where can I find City on the Hill's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. City on the Hill 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 Boulder County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Boulder City of | Boulder | 166,080 | Community | Surface water |
| Longmont City of | Boulder | 104,178 | Community | Surface water |
| Erie Town of | Boulder | 47,444 | Community | Surface water |
| Lafayette City of | Boulder | 28,700 | Community | Surface water |
| Louisville City of | Boulder | 20,975 | Community | Surface water |
| Left Hand Wd | Boulder | 20,280 | 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, “City on the Hill, PWSID CO0207122, Colorado”, https://aquacensus.com/water-systems/colorado/city-on-the-hill-co0207122 (data as of October 1, 2026).