Public water system · CO0115185

Active

Coalby Domestic Wc

At a glance

Coalby Domestic Wc (PWSID CO0115185) is an active community water system in Delta County, Colorado. It reports serving 239 people through 128 service connections. Its primary water source is groundwater under influence of surface water, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in December 2025.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

239

Service connections

128

Primary source

Groundwater under influence of surface water

System type

CWS

Community water system

System record

PWSIDCO0115185

System typeCommunity water system

Activity statusActive

Population served239

Service connections128

Primary water sourceGroundwater under influence of surface water

Owner typePrivate

Primacy agencyCO state drinking water program

City served—

StateColorado

ZIP—

CountyDelta County

How does Coalby Domestic Wc compare with other water systems in Delta County?

By EPA's size categories, Coalby Domestic Wc is a very small system (500 people or fewer). Delta County has 42 active public water systems. Its population served is about 64% below the county average of 660 people per system, and accounts for 0.9% of the 27,718 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 Coalby Domestic Wc is well below 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. Groundwater under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules. 166 Colorado systems (7.5%) list groundwater under influence of surface water as their primary source.

Who owns and regulates Coalby Domestic Wc?

EPA lists Coalby Domestic Wc 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. 30 of the 42 active systems in Delta County (71%) are also privately owned.

Does Coalby Domestic Wc have drinking water violations?

Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in December 2025. The violations listed here began between July 2021 and December 2025. By type: 9 monitoring and reporting, 2 required treatment not met and 1 reporting. 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
2025-12-01	Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36	Surface Water Treatment Rulecode 0200	No	Resolved
2025-12-01	ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B	Revised Total Coliform Rulecode 8000	No	Resolved
2025-10-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Chlorinecode 0999	No	Resolved
2022-05-01	Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44	Interim Enhanced Surface Water Treatment Rulecode 0300	Yes	Resolved
2022-01-01	Required treatment not metTreatment Technique (SWTR and GWR) · code 41	Surface Water Treatment Rulecode 0200	Yes	Resolved
2022-01-01	Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36	Surface Water Treatment Rulecode 0200	No	Resolved
2021-10-01	Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52	Lead and Copper Rulecode 5000	No	Resolved
2021-07-01	Monitoring and reportingMonitoring, Regular · code 03	trans-1,2-Dichloroethylenecode 2979	No	Resolved
2021-07-01	Monitoring and reportingMonitoring, Regular · code 03	1,2-Dichloroethanecode 2980	No	Resolved
2021-07-01	Monitoring and reportingMonitoring, Regular · code 03	Tetrachloroethylenecode 2987	No	Resolved
2021-07-01	Monitoring and reportingMonitoring, Turbidity (Enhanced SWTR) · code 38	Interim Enhanced Surface Water Treatment Rulecode 0300	No	Resolved
2021-07-01	Monitoring and reportingMonitoring, Regular · code 03	cis-1,2-Dichloroethylenecode 2380	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.

Coalby Domestic Wc: frequently asked questions

Who runs Coalby Domestic Wc?

Coalby Domestic Wc (PWSID CO0115185) is a community water system privately owned. It is regulated by the CO state drinking water program.

How many people does Coalby Domestic Wc serve?

Coalby Domestic Wc reports serving 239 people through 128 service connections in Delta County, Colorado.

Where does Coalby Domestic Wc get its water?

EPA SDWIS lists this system's primary water source as groundwater under influence of surface water. Groundwater under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules.

Does Coalby Domestic Wc have any drinking water violations?

Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in December 2025. 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 Coalby Domestic Wc'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, 2 are health-based, and the most recent began in December 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the CO state drinking water program.

Where can I find Coalby Domestic Wc's water quality report?

As a community water system, Coalby Domestic Wc 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 Delta County

Water system	County	Population served	Type	Source
Delta City of	Delta	8,700	Community	Purchased surface water
Orchard City Town of	Delta	3,100	Community	Groundwater under influence of surface water
Upper Surface Creek Domestic Wua	Delta	2,800	Community	Surface water
Paonia Town of	Delta	2,499	Community	Groundwater under influence of surface water
Cedaredge Town of	Delta	2,400	Community	Surface water
Hotchkiss Town of	Delta	2,050	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, “Coalby Domestic Wc, PWSID CO0115185, Colorado”, https://aquacensus.com/water-systems/colorado/coalby-domestic-wc-co0115185 (data as of October 1, 2026).