Public water system · TX1011901
ActiveNorthwest Harris County MUD 12
At a glance
Northwest Harris County MUD 12 (PWSID TX1011901) is an active community water system in Harris County, Texas. It reports serving 7,764 people through 2,588 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 4 violations for this system; none is health-based, and the most recent began in January 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,764
Service connections
2,588
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Northwest Harris County MUD 12 compare with other water systems in Harris County?
By EPA's size categories, Northwest Harris County MUD 12 is a medium system (3,301 to 10,000 people). Harris County has 1,246 active public water systems. Its population served is about 60% above the county average of 4,849 people per system, and accounts for 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 Northwest Harris County MUD 12 is about 16% above 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. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 5,215 Texas systems (74%) list groundwater as their primary source.
Who owns and regulates Northwest Harris County MUD 12?
EPA lists Northwest Harris County MUD 12 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 Northwest Harris County MUD 12 have drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in January 2024. The violations listed here began between January 2004 and January 2024. By type: 2 monitoring and reporting and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Consumer Confidence Rule (2 of them). EPA lists 3 as resolved and 1 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2024-01-01 | Monitoring and reportingWater Quality Parameter M/R · code 53 | Lead and Copper Rulecode 5000 | No | Archived |
| 2008-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2005-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2004-01-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
All 4 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.
Northwest Harris County MUD 12: frequently asked questions
Who runs Northwest Harris County MUD 12?
Northwest Harris County MUD 12 (PWSID TX1011901) is a community water system owned by a local government. It is regulated by the TX state drinking water program.
How many people does Northwest Harris County MUD 12 serve?
Northwest Harris County MUD 12 reports serving 7,764 people through 2,588 service connections in Harris County, Texas.
Where does Northwest Harris County MUD 12 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 Northwest Harris County MUD 12 have any drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in January 2024. 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 Northwest Harris County MUD 12'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 4 violations for this system; none is health-based, and the most recent began in January 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the TX state drinking water program.
Where can I find Northwest Harris County MUD 12's water quality report?
As a community water system, Northwest Harris County MUD 12 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 |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Northwest Harris County MUD 12, PWSID TX1011901, Texas”, https://aquacensus.com/water-systems/texas/northwest-harris-county-mud-12-tx1011901 (data as of October 1, 2026).