Public water system · TX1011599
ActiveNorthwest Harris County MUD 9
At a glance
Northwest Harris County MUD 9 (PWSID TX1011599) is an active community water system in Harris County, Texas. It reports serving 7,848 people through 2,616 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 3 violations for this system; none is health-based, and the most recent began in April 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,848
Service connections
2,616
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Northwest Harris County MUD 9 compare with other water systems in Harris County?
By EPA's size categories, Northwest Harris County MUD 9 is a medium system (3,301 to 10,000 people). Harris County has 1,246 active public water systems. Its population served is about 62% 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 9 is about 17% 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 9?
EPA lists Northwest Harris County MUD 9 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 9 have drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in April 2026. The violations listed here began between July 1992 and April 2026. By type: 3 monitoring and reporting. The contaminant or rule involved most often is Lead and Copper Rule (2 of them). EPA lists 3 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 |
|---|---|---|---|---|
| 2026-04-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2011-09-22 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 1992-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
All 3 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 9: frequently asked questions
Who runs Northwest Harris County MUD 9?
Northwest Harris County MUD 9 (PWSID TX1011599) 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 9 serve?
Northwest Harris County MUD 9 reports serving 7,848 people through 2,616 service connections in Harris County, Texas.
Where does Northwest Harris County MUD 9 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 9 have any drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in April 2026. 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 9'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 3 violations for this system; none is health-based, and the most recent began in April 2026. 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 9's water quality report?
As a community water system, Northwest Harris County MUD 9 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, “Northwest Harris County MUD 9, PWSID TX1011599, Texas”, https://aquacensus.com/water-systems/texas/northwest-harris-county-mud-9-tx1011599 (data as of October 1, 2026).