Public water system · CO0112300
ActiveCostilla County Ws
At a glance
Costilla County Ws (PWSID CO0112300) is an active community water system in Costilla County, Colorado. It reports serving 561 people through 396 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
561
Service connections
396
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Costilla County Ws compare with other water systems in Costilla County?
By EPA's size categories, Costilla County Ws is a small system (501 to 3,300 people). Costilla County has 12 active public water systems, and Costilla County Ws is the 2nd-largest of them by population served. Its population served is about 134% above the county average of 239 people per system, and accounts for 20% of the 2,872 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 Costilla County Ws 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 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 Costilla County Ws?
EPA lists Costilla County Ws 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. 7 of the 12 active systems in Costilla County (58%) are also owned by a local government.
Does Costilla County Ws have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2022. The violations listed here began between April 2016 and January 2022. By type: 12 monitoring and reporting. The contaminants or rules involved are Total trihalomethanes (TTHM), Haloacetic acids (HAA5), Di(2-ethylhexyl) phthalate and Gross alpha (excluding radon and uranium). 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 |
|---|---|---|---|---|
| 2022-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2022-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2020-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) phthalatecode 2039 | No | Resolved |
| 2016-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Resolved |
| 2016-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2016-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Resolved |
| 2016-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 2016-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Resolved |
| 2016-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 2016-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2016-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 2016-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Tetrachloroethylenecode 2987 | 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.
Costilla County Ws: frequently asked questions
Who runs Costilla County Ws?
Costilla County Ws (PWSID CO0112300) is a community water system owned by a local government. It is regulated by the CO state drinking water program.
How many people does Costilla County Ws serve?
Costilla County Ws reports serving 561 people through 396 service connections in Costilla County, Colorado.
Where does Costilla County Ws 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 Costilla County Ws have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2022. 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 Costilla County Ws' 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, none is health-based, and the most recent began in January 2022. For current results, consult the system's annual water quality report, EPA ECHO, or the CO state drinking water program.
Where can I find Costilla County Ws' water quality report?
As a community water system, Costilla County Ws 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 Costilla County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| San Luis Wsd | Costilla | 629 | Community | Groundwater |
| Ft Garland Wsd | Costilla | 477 | Community | Groundwater |
| Blanca Town of | Costilla | 469 | Community | Groundwater |
| Sierra Grande School District | Costilla | 304 | Non-transient non-community | Groundwater |
| Blanca Ft Garland Md | Costilla | 108 | Transient non-community | Groundwater |
| Garcia Domestic Wua | Costilla | 100 | 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, “Costilla County Ws, PWSID CO0112300, Colorado”, https://aquacensus.com/water-systems/colorado/costilla-county-ws-co0112300 (data as of October 1, 2026).