Public water system · IL0810300

Active

Mount Vernon

At a glance

Mount Vernon (PWSID IL0810300) is an active community water system in Jefferson County, Illinois. It reports serving 15,793 people through 6,655 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 10 violations for this system; 2 are health-based, and the most recent began in July 2024.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

15,793

Service connections

6,655

Primary source

SWP

Purchased surface water

System type

CWS

Community water system

System record

PWSIDIL0810300

System typeCommunity water system

Activity statusActive

Population served15,793

Service connections6,655

Primary water sourcePurchased surface water

Owner typeLocal government

Primacy agencyIL state drinking water program

City servedMount Vernon

StateIllinois

ZIP—

CountyJefferson County

How does Mount Vernon compare with other water systems in Jefferson County?

By EPA's size categories, Mount Vernon is a large system (10,001 to 100,000 people). Jefferson County has 14 active public water systems, and Mount Vernon is the largest of them by population served. Its population served is about 6.2 times the county average of 2,544 people per system, and accounts for 44% of the 35,609 people reported by systems filed under the county. Across Illinois, the 3,872 active systems average 3,204 people each. Nationally, the average active community water system reports serving 6,703 people, so Mount Vernon is about 136% 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. Illinois has 1,773 active community water systems, 46% of the state's 3,872 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 619 Illinois systems (16%) list purchased surface water as their primary source.

Who owns and regulates Mount Vernon?

EPA lists Mount Vernon as owned by a local government. The IL state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 8 of the 14 active systems in Jefferson County (57%) are also owned by a local government.

Does Mount Vernon 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 May 1990 and July 2024. By type: 4 public notice, recordkeeping or other, 4 monitoring and reporting and 2 contaminant level above the legal limit. The contaminant or rule involved most often is Consumer Confidence Rule (4 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	Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72	Consumer Confidence Rulecode 7000	No	Resolved
2023-10-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Haloacetic acids (HAA5)code 2456	No	Resolved
2023-04-01	Monitoring and reportingMonitoring and Reporting (DBP) · code 27	Haloacetic acids (HAA5)code 2456	No	Resolved
2020-12-30	Monitoring and reportingLead Consumer Notice · code 66	Lead and Copper Rulecode 5000	No	Resolved
2017-07-01	Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71	Consumer Confidence Rulecode 7000	No	Resolved
2007-07-01	Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24	Total coliform bacteria (TCR)code 3100	No	Resolved
2005-07-01	Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72	Consumer Confidence Rulecode 7000	No	Resolved
2004-07-01	Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71	Consumer Confidence Rulecode 7000	No	Resolved
2000-06-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Archived
1990-05-23	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Total trihalomethanes (TTHM)code 2950	Yes	Resolved

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.

Mount Vernon: frequently asked questions

Who runs Mount Vernon?

Mount Vernon (PWSID IL0810300) is a community water system owned by a local government. It is regulated by the IL state drinking water program.

How many people does Mount Vernon serve?

Mount Vernon reports serving 15,793 people through 6,655 service connections in Jefferson County, Illinois.

Where does Mount Vernon 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 Mount Vernon 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 Mount Vernon'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 the system's annual water quality report, EPA ECHO, or the IL state drinking water program.

Where can I find Mount Vernon's water quality report?

As a community water system, Mount Vernon 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 Jefferson County

Water system	County	Population served	Type	Source
Northeast Mount Vernon Water Company	Jefferson	5,483	Community	Purchased surface water
Woodlawn	Jefferson	3,587	Community	Purchased surface water
Dix-Kell Water Commssion	Jefferson	1,972	Community	Purchased surface water
Belle Rive	Jefferson	1,930	Community	Purchased surface water
Waltonville	Jefferson	1,901	Community	Purchased surface water
Bluford	Jefferson	1,880	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, “Mount Vernon, PWSID IL0810300, Illinois”, https://aquacensus.com/water-systems/illinois/mount-vernon-il0810300 (data as of October 1, 2026).