Public water system · MO6180570
ActiveMemc LLC
At a glance
Memc LLC (PWSID MO6180570) is an active non-transient non-community water system in St. Charles County, Missouri. It reports serving 350 people through 16 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 10 violations for this system; 2 are health-based, and the most recent began in July 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
350
Service connections
16
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Memc LLC compare with other water systems in St. Charles County?
By EPA's size categories, Memc LLC is a very small system (500 people or fewer). St. Charles County has 54 active public water systems. Its population served is well below the county average of 5,867 people per system, and accounts for 0.1% of the 316,837 people reported by systems filed under the county. Across Missouri, the 2,943 active systems average 2,049 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Memc LLC is about 19% below that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. Missouri has 228 active non-transient non-community water systems, 7.7% 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 Memc LLC?
EPA lists Memc LLC as privately owned. The MO state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 33 of the 54 active systems in St. Charles County (61%) are also privately owned.
Does Memc LLC have drinking water violations?
EPA's records list 10 violations for this system; 2 are health-based, and the most recent began in July 2024. The violations listed here began between March 1991 and July 2024. By type: 7 monitoring and reporting, 1 required treatment not met, 1 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (6 of them). EPA lists 9 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 |
|---|---|---|---|---|
| 2024-07-01 | Required treatment not metTreatment Technique No Certif. Operator · code 12 | Stage 1 Disinfectants and Disinfection Byproducts Rulecode 0400 | Yes | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2013-01-18 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2011-12-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2011-11-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2006-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2004-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-02-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1991-03-21 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
All 10 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.
Memc LLC: frequently asked questions
Who runs Memc LLC?
Memc LLC (PWSID MO6180570) is a non-transient non-community water system privately owned. It is regulated by the MO state drinking water program.
How many people does Memc LLC serve?
Memc LLC reports serving 350 people through 16 service connections in St. Charles County, Missouri.
Where does Memc LLC 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 Memc LLC have any drinking water violations?
EPA's records list 10 violations for this system; 2 are health-based, and the most recent began in July 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 Memc LLC'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 10 violations for this system; 2 are health-based, and the most recent began in July 2024. For current results, consult EPA ECHO, or the MO state drinking water program.
Where can I find Memc LLC's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Memc LLC is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in St. Charles County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| St Charles County Pwsd 2 | St. Charles | 100,587 | Community | Purchased surface water |
| St Charles Pws | St. Charles | 78,961 | Community | Purchased surface water |
| St Peters Pws | St. Charles | 52,575 | Community | Purchased surface water |
| Wentzville Pws | St. Charles | 41,784 | Community | Groundwater |
| Ofallon Pws | St. Charles | 32,515 | Community | Purchased surface water |
| St Paul Pws | St. Charles | 1,700 | 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, “Memc LLC, PWSID MO6180570, Missouri”, https://aquacensus.com/water-systems/missouri/memc-llc-mo6180570 (data as of October 1, 2026).