Public water system · LA1103189
ActiveMagnolia-Guste Island
At a glance
Magnolia-Guste Island (PWSID LA1103189) is an active community water system in St. Tammany Parish County, Missouri. It reports serving 2,847 people through 949 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 5 violations for this system; none is health-based, and the most recent began in October 2013.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,847
Service connections
949
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Magnolia-Guste Island compare with other water systems in St. Tammany Parish County?
By EPA's size categories, Magnolia-Guste Island is a small system (501 to 3,300 people). St. Tammany Parish County has 27 active public water systems, and Magnolia-Guste Island is the 6th-largest of them by population served. Its population served is about 68% above the county average of 1,698 people per system, and accounts for 6.2% of the 45,833 people reported by systems filed under the county. Across Missouri, the 2,943 active systems average 2,049 people each. Nationally, the average active community water system reports serving 6,703 people, so Magnolia-Guste Island is about 58% 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. Missouri has 1,612 active community water systems, 55% of the state's 2,943 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,521 Missouri systems (86%) list groundwater as their primary source.
Who owns and regulates Magnolia-Guste Island?
EPA lists Magnolia-Guste Island as privately owned. 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. 27 of the 27 active systems in St. Tammany Parish County (100%) are also privately owned.
Does Magnolia-Guste Island have drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in October 2013. The violations listed here began between January 2006 and October 2013. By type: 3 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 2 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 |
|---|---|---|---|---|
| 2013-10-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2013-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2008-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2006-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2006-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
All 5 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.
Magnolia-Guste Island: frequently asked questions
Who runs Magnolia-Guste Island?
Magnolia-Guste Island (PWSID LA1103189) is a community water system privately owned. It is regulated by the LA state drinking water program.
How many people does Magnolia-Guste Island serve?
Magnolia-Guste Island reports serving 2,847 people through 949 service connections in St. Tammany Parish County, Missouri.
Where does Magnolia-Guste Island 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 Magnolia-Guste Island have any drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in October 2013. 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 Magnolia-Guste Island'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 5 violations for this system; none is health-based, and the most recent began in October 2013. For current results, consult the system's annual water quality report, EPA ECHO, or the LA state drinking water program.
Where can I find Magnolia-Guste Island's water quality report?
As a community water system, Magnolia-Guste Island 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. Tammany Parish County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Magnolia-Eden Isles | St. Tammany Parish | 10,155 | Community | Groundwater |
| Magnolia-Greenleaves | St. Tammany Parish | 8,031 | Community | Groundwater |
| Magnolia-Resolve Whisperwood | St. Tammany Parish | 6,867 | Community | Groundwater |
| Magnolia-the Meadows | St. Tammany Parish | 4,701 | Community | Groundwater |
| Magnolia-Lakeshore Estates | St. Tammany Parish | 4,146 | Community | Groundwater |
| Magnolia-Monterey Subdivision | St. Tammany Parish | 1,356 | Community | Groundwater |
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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, “Magnolia-Guste Island, PWSID LA1103189, Missouri”, https://aquacensus.com/water-systems/missouri/magnolia-guste-island-la1103189 (data as of October 1, 2026).