Public water system · IL0970040
ActiveGreen Oaks
At a glance
Green Oaks (PWSID IL0970040) is an active community water system in Lake County, Illinois. It reports serving 1,470 people through 490 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 11 violations for this system; 2 are health-based, and the most recent began in August 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,470
Service connections
490
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Green Oaks compare with other water systems in Lake County?
By EPA's size categories, Green Oaks is a small system (501 to 3,300 people). Lake County has 266 active public water systems. Its population served is about 40% below the county average of 2,442 people per system, and accounts for 0.2% of the 649,474 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 Green Oaks is well 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. 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 Green Oaks?
EPA lists Green Oaks 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. 60 of the 266 active systems in Lake County (23%) are also owned by a local government.
Does Green Oaks have drinking water violations?
EPA's records list 11 violations for this system; 2 are health-based, and the most recent began in August 2025. The violations listed here began between April 1995 and August 2025. By type: 5 monitoring and reporting, 2 public notice, recordkeeping or other, 2 reporting and 2 required treatment not met. The contaminant or rule involved most often is Lead and Copper Rule Revisions (3 of them). EPA lists 6 as resolved, 3 as unaddressed 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement. 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 |
|---|---|---|---|---|
| 2025-08-22 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Unaddressed |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2009-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2009-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 1997-12-22 | Required treatment not metOCCT/SOWT Study/Recommendation · code 57 | Lead and Copper Rulecode 5000 | Yes | Resolved |
| 1997-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1996-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1995-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
All 11 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.
Green Oaks: frequently asked questions
Who runs Green Oaks?
Green Oaks (PWSID IL0970040) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Green Oaks serve?
Green Oaks reports serving 1,470 people through 490 service connections in Lake County, Illinois.
Where does Green Oaks 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 Green Oaks have any drinking water violations?
EPA's records list 11 violations for this system; 2 are health-based, and the most recent began in August 2025. 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 Green Oaks' 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 11 violations for this system; 2 are health-based, and the most recent began in August 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find Green Oaks' water quality report?
As a community water system, Green Oaks 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 Lake County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Waukegan | Lake | 87,149 | Community | Surface water |
| Vernon Hills - Lake Co Pw | Lake | 33,207 | Community | Purchased surface water |
| Mundelein | Lake | 31,500 | Community | Purchased surface water |
| Gurnee | Lake | 30,193 | Community | Purchased surface water |
| Highland Park | Lake | 30,176 | Community | Surface water |
| Round Lake Beach | Lake | 27,200 | 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, “Green Oaks, PWSID IL0970040, Illinois”, https://aquacensus.com/water-systems/illinois/green-oaks-il0970040 (data as of October 1, 2026).