Public water system · CO0135291
ActiveFt Collins City of
At a glance
City of Ft Collins (PWSID CO0135291) is an active community water system in Larimer County, Colorado. It reports serving 179,901 people through 35,866 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in April 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
179,901
Service connections
35,866
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does City of Ft Collins compare with other water systems in Larimer County?
By EPA's size categories, City of Ft Collins is a very large system (more than 100,000 people). Larimer County has 134 active public water systems, and City of Ft Collins is the largest of them by population served. Its population served is about 47 times the county average of 3,842 people per system, and accounts for 35% of the 514,860 people reported by systems filed under the county. Across Colorado, the 2,207 active systems average 3,400 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Ft Collins is about 27 times 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. Colorado has 1,068 active community water systems, 48% of the state's 2,207 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 228 Colorado systems (10%) list surface water as their primary source.
Who owns and regulates City of Ft Collins?
EPA lists City of Ft Collins as owned by a local government. 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. 21 of the 134 active systems in Larimer County (16%) are also owned by a local government.
Does City of Ft Collins have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in April 2026. The violations listed here began between April 2017 and April 2026. By type: 11 monitoring and reporting and 1 required treatment not met. The contaminant or rule involved most often is Surface Water Treatment Rule (3 of them). 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 |
|---|---|---|---|---|
| 2026-04-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2026-03-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorine dioxidecode 1008 | No | Resolved |
| 2026-02-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorine dioxidecode 1008 | No | Resolved |
| 2026-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorine dioxidecode 1008 | No | Resolved |
| 2024-07-01 | Monitoring and reportingMonitoring, Turbidity (Enhanced SWTR) · code 38 | Interim Enhanced Surface Water Treatment Rulecode 0300 | No | Resolved |
| 2024-07-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2021-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2021-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2017-12-01 | Monitoring and reportingMonitoring, Turbidity (Enhanced SWTR) · code 38 | Interim Enhanced Surface Water Treatment Rulecode 0300 | No | Resolved |
| 2017-12-01 | Required treatment not metSingle Turbidity Exceed (Enhanced SWTR) · code 43 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2017-05-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2017-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | 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.
City of Ft Collins: frequently asked questions
Who runs City of Ft Collins?
City of Ft Collins (PWSID CO0135291) is a community water system owned by a local government. It is regulated by the CO state drinking water program.
How many people does City of Ft Collins serve?
City of Ft Collins reports serving 179,901 people through 35,866 service connections in Larimer County, Colorado.
Where does City of Ft Collins get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does City of Ft Collins have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in April 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 of Ft Collins' 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, one is health-based, and the most recent began in April 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the CO state drinking water program.
Where can I find City of Ft Collins' water quality report?
As a community water system, City of Ft Collins 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 Larimer County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Loveland City of | Larimer | 91,077 | Community | Surface water |
| Ft Collins Loveland Wd | Larimer | 63,532 | Community | Purchased surface water |
| East Larimer County Wd | Larimer | 27,944 | Community | Purchased surface water |
| Csu Main and West Housing Campus | Larimer | 27,375 | Community | Purchased surface water |
| Little Thompson Wd | Larimer | 25,654 | Community | Purchased surface water |
| Estes Park Town of | Larimer | 16,722 | 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, “Ft Collins City of, PWSID CO0135291, Colorado”, https://aquacensus.com/water-systems/colorado/ft-collins-city-of-co0135291 (data as of October 1, 2026).