Public water system · TN0000428
ActiveMallory Valley U.D.
At a glance
Mallory Valley U.D. (PWSID TN0000428) is an active community water system in Williamson County, Tennessee. It reports serving 30,347 people through 10,611 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 6 violations for this system; 1 is health-based, and the most recent began in July 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
30,347
Service connections
10,611
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Mallory Valley U.D. compare with other water systems in Williamson County?
By EPA's size categories, Mallory Valley U.D. is a large system (10,001 to 100,000 people). Williamson County has 7 active public water systems, and Mallory Valley U.D. is the 6th-largest of them by population served. Its population served is about 16% below the county average of 35,917 people per system, and accounts for 12% of the 251,417 people reported by systems filed under the county. Across Tennessee, the 1,383 active systems average 5,780 people each. Nationally, the average active community water system reports serving 6,703 people, so Mallory Valley U.D. is about 4.5 times 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. Tennessee has 450 active community water systems, 33% of the state's 1,383 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 121 Tennessee systems (8.7%) list purchased surface water as their primary source.
Who owns and regulates Mallory Valley U.D.?
EPA lists Mallory Valley U.D. as owned by a local government. The TN state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 6 of the 7 active systems in Williamson County (86%) are also owned by a local government.
Does Mallory Valley U.D. have drinking water violations?
EPA's records list 6 violations for this system; 1 is health-based, and the most recent began in July 2021. The violations listed here began between August 2002 and July 2021. By type: 4 monitoring and reporting, 1 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (2 of them). EPA lists 5 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 |
|---|---|---|---|---|
| 2021-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2012-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2012-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2002-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
All 6 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.
Mallory Valley U.D.: frequently asked questions
Who runs Mallory Valley U.D.?
Mallory Valley U.D. (PWSID TN0000428) is a community water system owned by a local government. It is regulated by the TN state drinking water program.
How many people does Mallory Valley U.D. serve?
Mallory Valley U.D. reports serving 30,347 people through 10,611 service connections in Williamson County, Tennessee.
Where does Mallory Valley U.D. 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 Mallory Valley U.D. have any drinking water violations?
EPA's records list 6 violations for this system; 1 is health-based, and the most recent began in July 2021. 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 Mallory Valley U.D.'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 6 violations for this system; 1 is health-based, and the most recent began in July 2021. For current results, consult the system's annual water quality report, EPA ECHO, or the TN state drinking water program.
Where can I find Mallory Valley U.D.'s water quality report?
As a community water system, Mallory Valley U.D. 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 Williamson County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Franklin Water Dept | Williamson | 77,222 | Community | Surface water |
| H.B.& T.S. Utility District | Williamson | 40,094 | Community | Purchased surface water |
| Milcrofton Utility District | Williamson | 38,032 | Community | Purchased surface water |
| Nolensville-College Grove U.D. | Williamson | 34,159 | Community | Purchased surface water |
| Brentwood Water Department | Williamson | 30,493 | Community | Purchased surface water |
| Gateway Utility Company, Inc.. | Williamson | 1,070 | 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, “Mallory Valley U.D., PWSID TN0000428, Tennessee”, https://aquacensus.com/water-systems/tennessee/mallory-valley-u-d-tn0000428 (data as of October 1, 2026).