Public water system · IL0975185
ActiveDiamond Lake MHP
At a glance
Diamond Lake MHP (PWSID IL0975185) is an active community water system in Lake County, Illinois. It reports serving 198 people through 60 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
198
Service connections
60
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Diamond Lake MHP compare with other water systems in Lake County?
By EPA's size categories, Diamond Lake MHP is a very small system (500 people or fewer). Lake County has 266 active public water systems. Its population served is well below the county average of 2,442 people per system, and accounts for less than 0.1% 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 Diamond Lake MHP 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. 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 Diamond Lake MHP?
EPA lists Diamond Lake MHP 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. 193 of the 266 active systems in Lake County (73%) are also privately owned.
Does Diamond Lake MHP have drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in July 2025. The violations listed here began between September 1994 and July 2025. By type: 5 contaminant level above the legal limit, 4 monitoring and reporting and 3 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (8 of them). EPA lists 7 as archived and 5 as resolved. 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. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2010-02-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-10-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 2003-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2000-08-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 2000-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1996-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1995-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1995-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1994-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
The 12 most recent 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.
Diamond Lake MHP: frequently asked questions
Who runs Diamond Lake MHP?
Diamond Lake MHP (PWSID IL0975185) is a community water system privately owned. It is regulated by the IL state drinking water program.
How many people does Diamond Lake MHP serve?
Diamond Lake MHP reports serving 198 people through 60 service connections in Lake County, Illinois.
Where does Diamond Lake MHP 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 Diamond Lake MHP have any drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in July 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 Diamond Lake MHP'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. Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in July 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 Diamond Lake MHP's water quality report?
As a community water system, Diamond Lake MHP 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, “Diamond Lake MHP, PWSID IL0975185, Illinois”, https://aquacensus.com/water-systems/illinois/diamond-lake-mhp-il0975185 (data as of October 1, 2026).