Monmouth

Community water system in Warren County, Illinois, drawing primarily on groundwater.

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

Population served

8,902

Service connections

3,800

Primary source

Groundwater

System type

CWS

Community water system

System record

PWSIDIL1870150

System typeCommunity water system

Activity statusActive

Population served8,902

Service connections3,800

Primary water sourceGroundwater

Owner typeLocal government

Primacy agencyIL state drinking water program

City servedMonmouth

StateIllinois

ZIP—

CountyWarren County →

Violations & enforcement

Began	Violation	Contaminant	Health-based	Status
2005-07-01	02	4010	Yes	Resolved
2005-04-01	02	4000	Yes	Resolved
2004-07-01	02	4010	Yes	Resolved
2004-01-01	02	4010	Yes	Resolved
2003-10-01	02	4010	Yes	Resolved
2003-04-01	02	4010	Yes	Resolved
2003-01-01	02	4010	Yes	Resolved
2002-10-01	02	4010	Yes	Resolved
2002-08-01	02	4000	Yes	Resolved
2001-10-01	02	4010	Yes	Resolved
2001-06-01	22	3100	Yes	Archived
1995-07-12	02	4000	Yes	Resolved

Monmouth: frequently asked questions

Is Monmouth's water safe to drink?

Monmouth is an active community water system regulated under the Safe Drinking Water Act, overseen by the IL state drinking water program. EPA SDWA violation and enforcement records for this system are being added to AquaCensus from EPA ECHO; consult EPA ECHO or your annual Consumer Confidence Report for its current compliance status.

Who runs Monmouth?

Monmouth (PWSID IL1870150) is a local government-owned community water system, regulated by the IL state drinking water program.

How many people does Monmouth serve?

Monmouth reports serving 8,902 people through 3,800 service connections in Warren County, Illinois.

Where does Monmouth get its water?

EPA SDWIS lists this system's primary water source as groundwater.

Other water systems in Warren County

Water system	County	Population served	Type	Source
Warren County Water District	Warren	91,118	Community	Purchased surface water
Warren County	Warren	81,975	Community	Groundwater
Bowling Green Municipal Utilities	Warren	53,601	Community	Surface water
Western Water Company	Warren	39,508	Community	Purchased surface water
Kings Island Pws	Warren	31,753	Non-transient non-community	Groundwater
Warren County Utility District	Warren	29,827	Community	Surface water