Public water system · TX1012913
ActiveHarris County MUD 321
At a glance
Harris County MUD 321 (PWSID TX1012913) is an active community water system in Harris County, Texas. It reports serving 807 people through 269 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 11 violations for this system; none is health-based, and the most recent began in June 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
807
Service connections
269
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Harris County MUD 321 compare with other water systems in Harris County?
By EPA's size categories, Harris County MUD 321 is a small system (501 to 3,300 people). Harris County has 1,246 active public water systems. Its population served is well below the county average of 4,849 people per system, and accounts for less than 0.1% of the 6,041,784 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 Harris County MUD 321 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 1,192 Texas systems (17%) list purchased surface water as their primary source.
Who owns and regulates Harris County MUD 321?
EPA lists Harris County MUD 321 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. 508 of the 1,246 active systems in Harris County (41%) are also owned by a local government.
Does Harris County MUD 321 have drinking water violations?
EPA's records list 11 violations for this system; none is health-based, and the most recent began in June 2023. The violations listed here began between July 2013 and June 2023. By type: 8 monitoring and reporting, 2 public notice, recordkeeping or other and 1 monitoring. The contaminant or rule involved most often is Lead and Copper Rule (6 of them). EPA lists 11 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 |
|---|---|---|---|---|
| 2023-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2016-03-31 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2015-05-03 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2015-02-10 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2015-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2014-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2014-04-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2013-09-29 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2013-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2013-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2013-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
All 11 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.
Harris County MUD 321: frequently asked questions
Who runs Harris County MUD 321?
Harris County MUD 321 (PWSID TX1012913) is a community water system owned by a local government. It is regulated by the TX state drinking water program.
How many people does Harris County MUD 321 serve?
Harris County MUD 321 reports serving 807 people through 269 service connections in Harris County, Texas.
Where does Harris County MUD 321 get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Harris County MUD 321 have any drinking water violations?
EPA's records list 11 violations for this system; none is health-based, and the most recent began in June 2023. 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 Harris County MUD 321'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 11 violations for this system; none is health-based, and the most recent began in June 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the TX state drinking water program.
Where can I find Harris County MUD 321's water quality report?
As a community water system, Harris County MUD 321 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 Harris County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Houston | Harris | 2,970,543 | Community | Surface water |
| City of Pasadena | Harris | 152,000 | Community | Purchased surface water |
| Clear Lake City Water Authority | Harris | 89,702 | Community | Purchased surface water |
| City of Baytown | Harris | 86,004 | Community | Purchased surface water |
| City of Houston Ud 5 - Kingwood | Harris | 80,073 | Community | Groundwater |
| Harris County MUD 165 | Harris | 40,503 | 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, “Harris County MUD 321, PWSID TX1012913, Texas”, https://aquacensus.com/water-systems/texas/harris-county-mud-321-tx1012913 (data as of October 1, 2026).