Public water system · TX2450006
ActiveSebastian MUD
At a glance
Sebastian MUD (PWSID TX2450006) is an active community water system in Willacy County, Texas. It reports serving 1,884 people through 769 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 November 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,884
Service connections
769
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Sebastian MUD compare with other water systems in Willacy County?
By EPA's size categories, Sebastian MUD is a small system (501 to 3,300 people). Willacy County has 4 active public water systems, and Sebastian MUD is the 3rd-largest of them by population served. Its population served is about half of the county average of 4,095 people per system, and accounts for 12% of the 16,378 people reported by systems filed under the county. Across Texas, the 7,078 active systems average 4,789 people each. Nationally, the average active community water system reports serving 6,703 people, so Sebastian MUD 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. Texas has 4,594 active community water systems, 65% of the state's 7,078 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 328 Texas systems (4.6%) list surface water as their primary source.
Who owns and regulates Sebastian MUD?
EPA lists Sebastian MUD as owned by a local government. The TX state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 4 of the 4 active systems in Willacy County (100%) are also owned by a local government.
Does Sebastian MUD have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in November 2025. The violations listed here began between December 2019 and November 2025. By type: 5 public notice, recordkeeping or other, 4 monitoring and reporting, 1 required treatment not met, 1 reporting and 1 monitoring. The contaminant or rule involved most often is Public Notice (4 of them). EPA lists 9 as resolved and 3 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 |
|---|---|---|---|---|
| 2025-11-01 | Monitoring and reportingMonitoring, Turbidity (Enhanced SWTR) · code 38 | Interim Enhanced Surface Water Treatment Rulecode 0300 | No | Resolved |
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Unaddressed |
| 2025-05-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Unaddressed |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2024-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Carbon, totalcode 2920 | No | Resolved |
| 2021-08-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2021-01-11 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2021-01-11 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2020-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-12-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2019-12-01 | Monitoring and reportingMonitoring, Turbidity (Enhanced SWTR) · code 38 | Interim Enhanced Surface Water Treatment Rulecode 0300 | 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.
Sebastian MUD: frequently asked questions
Who runs Sebastian MUD?
Sebastian MUD (PWSID TX2450006) is a community water system owned by a local government. It is regulated by the TX state drinking water program.
How many people does Sebastian MUD serve?
Sebastian MUD reports serving 1,884 people through 769 service connections in Willacy County, Texas.
Where does Sebastian MUD 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 Sebastian MUD 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 November 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 Sebastian MUD'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, one is health-based, and the most recent began in November 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the TX state drinking water program.
Where can I find Sebastian MUD's water quality report?
As a community water system, Sebastian MUD 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 Willacy County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Raymondville | Willacy | 11,288 | Community | Surface water |
| City of Lyford | Willacy | 2,406 | Community | Surface water |
| Port Mansfield PUD | Willacy | 800 | Community | Purchased 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, “Sebastian MUD, PWSID TX2450006, Texas”, https://aquacensus.com/water-systems/texas/sebastian-mud-tx2450006 (data as of October 1, 2026).