Public water system · IL3130997

Active

Four Willows Golf Course

At a glance

Four Willows Golf Course (PWSID IL3130997) is an active transient non-community water system in Mason County, Illinois. It reports serving 25 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 8 violations for this system; 1 is health-based, and the most recent began in March 2026.

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

Population served

Service connections

Primary source

Groundwater

System type

TNCWS

Transient non-community water system

System record

PWSIDIL3130997

System typeTransient non-community water system

Activity statusActive

Population served25

Service connections1

Primary water sourceGroundwater

Owner typePrivate

Primacy agencyIL state drinking water program

City served—

StateIllinois

ZIP—

CountyMason County

How does Four Willows Golf Course compare with other water systems in Mason County?

By EPA's size categories, Four Willows Golf Course is a very small system (500 people or fewer). Mason County has 24 active public water systems. Its population served is well below the county average of 371 people per system, and accounts for 0.3% of the 8,902 people reported by systems filed under the county. Across Illinois, the 3,872 active systems average 3,204 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Four Willows Golf Course is well below that figure.

What does “transient non-community water system” mean?

A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. Illinois has 1,703 active transient non-community water systems, 44% of the state's 3,872 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,808 Illinois systems (73%) list groundwater as their primary source.

Who owns and regulates Four Willows Golf Course?

EPA lists Four Willows Golf Course as privately owned. 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. 14 of the 24 active systems in Mason County (58%) are also privately owned.

Does Four Willows Golf Course have drinking water violations?

EPA's records list 8 violations for this system; 1 is health-based, and the most recent began in March 2026. The violations listed here began between January 2009 and March 2026. By type: 4 monitoring and reporting, 2 public notice, recordkeeping or other, 1 monitoring and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Nitrate (4 of them). EPA lists 6 as resolved and 2 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.

Began	Violation	Contaminant or rule	Health-based	Status
2026-03-07	Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75	Public Noticecode 7500	No	Unaddressed
2025-01-22	Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75	Public Noticecode 7500	No	Unaddressed
2024-01-01	MonitoringMonitoring, Routine (RTCR) · code 3A	Revised Total Coliform Rulecode 8000	No	Resolved
2023-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
2019-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
2018-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
2009-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
2009-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved

All 8 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.

Four Willows Golf Course: frequently asked questions

Who runs Four Willows Golf Course?

Four Willows Golf Course (PWSID IL3130997) is a transient non-community water system privately owned. It is regulated by the IL state drinking water program.

How many people does Four Willows Golf Course serve?

Four Willows Golf Course reports serving 25 people through 1 service connection in Mason County, Illinois.

Where does Four Willows Golf Course 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 Four Willows Golf Course have any drinking water violations?

EPA's records list 8 violations for this system; 1 is health-based, and the most recent began in March 2026. 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 Four Willows Golf Course'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 8 violations for this system; 1 is health-based, and the most recent began in March 2026. For current results, consult EPA ECHO, or the IL state drinking water program.

Where can I find Four Willows Golf Course's water quality report?

The annual Consumer Confidence Report requirement applies to community water systems. Four Willows Golf Course is a 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 Mason County

Water system	County	Population served	Type	Source
Havana	Mason	2,963	Community	Groundwater
Mason City	Mason	2,393	Community	Groundwater
Manito	Mason	1,552	Community	Groundwater
San Jose	Mason	479	Community	Groundwater
Easton	Mason	325	Community	Groundwater
Lost Arrow Campominium	Mason	223	Transient non-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, “Four Willows Golf Course, PWSID IL3130997, Illinois”, https://aquacensus.com/water-systems/illinois/four-willows-golf-course-il3130997 (data as of October 1, 2026).