Public water system · LA1101010
ActiveSt Mary Water & Sewer Comm #3
At a glance
St Mary Water & Sewer Comm #3 (PWSID LA1101010) is an active community water system in St. Mary Parish County, Louisiana. It reports serving 7,828 people through 1,957 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, 7 are health-based, and the most recent began in January 2025.
This page covers its drinking water system only; sewer and wastewater service are not part of EPA's drinking water records.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,828
Service connections
1,957
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does St Mary Water & Sewer Comm #3 compare with other water systems in St. Mary Parish County?
By EPA's size categories, St Mary Water & Sewer Comm #3 is a medium system (3,301 to 10,000 people). St. Mary Parish County has 16 active public water systems, and St Mary Water & Sewer Comm #3 is the 5th-largest of them by population served. Its population served is about twice the county average of 3,945 people per system, and accounts for 12% of the 63,113 people reported by systems filed under the county. Across Louisiana, the 1,121 active systems average 4,685 people each. Nationally, the average active community water system reports serving 6,703 people, so St Mary Water & Sewer Comm #3 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. Louisiana has 815 active community water systems, 73% of the state's 1,121 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 53 Louisiana systems (4.7%) list surface water as their primary source.
Who owns and regulates St Mary Water & Sewer Comm #3?
EPA lists St Mary Water & Sewer Comm #3 as owned by a local government. The LA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 12 of the 16 active systems in St. Mary Parish County (75%) are also owned by a local government.
Does St Mary Water & Sewer Comm #3 have drinking water violations?
Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in January 2025. The violations listed here began between January 1994 and January 2025. By type: 5 contaminant level above the legal limit, 4 monitoring and reporting, 2 required treatment not met and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Haloacetic acids (HAA5) (4 of them). EPA lists 9 as resolved and 3 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 |
|---|---|---|---|---|
| 2025-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2017-10-31 | Monitoring and reportingFailure Submit IDSE/Subpart V Plan Rpt · code 35 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2017-10-31 | Monitoring and reportingFailure Submit IDSE/Subpart V Plan Rpt · code 35 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2017-07-31 | Monitoring and reportingFailure Submit IDSE/Subpart V Plan Rpt · code 35 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2017-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2017-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2016-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloritecode 1009 | No | Resolved |
| 2011-10-18 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2011-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 2009-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1994-02-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Archived |
| 1994-01-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Archived |
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.
St Mary Water & Sewer Comm #3: frequently asked questions
Who runs St Mary Water & Sewer Comm #3?
St Mary Water & Sewer Comm #3 (PWSID LA1101010) is a community water system owned by a local government. It is regulated by the LA state drinking water program.
How many people does St Mary Water & Sewer Comm #3 serve?
St Mary Water & Sewer Comm #3 reports serving 7,828 people through 1,957 service connections in St. Mary Parish County, Louisiana.
Where does St Mary Water & Sewer Comm #3 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 St Mary Water & Sewer Comm #3 have any drinking water violations?
Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in January 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 St Mary Water & Sewer Comm #3'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, 7 are health-based, and the most recent began in January 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the LA state drinking water program.
Where can I find St Mary Water & Sewer Comm #3's water quality report?
As a community water system, St Mary Water & Sewer Comm #3 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 St. Mary Parish County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Morgan City Water System | St. Mary Parish | 12,703 | Community | Surface water |
| Water & Sewer Commission 4 of St Mary | St. Mary Parish | 9,709 | Community | Surface water |
| City of Patterson Water System | St. Mary Parish | 8,456 | Community | Surface water |
| City of Franklin Water Supply | St. Mary Parish | 8,325 | Community | Surface water |
| St Mary Parish W&S #2 Bayou Vista | St. Mary Parish | 5,379 | Community | Purchased surface water |
| City of Berwick | St. Mary Parish | 5,024 | Community | Purchased surface water |
Related pages
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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, “St Mary Water & Sewer Comm #3, PWSID LA1101010, Louisiana”, https://aquacensus.com/water-systems/louisiana/st-mary-water-sewer-comm-3-la1101010 (data as of October 1, 2026).