Public water system · IL0630250
ActiveDiamond
At a glance
Diamond (PWSID IL0630250) is an active community water system in Grundy County, Illinois. It reports serving 2,508 people through 920 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in September 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,508
Service connections
920
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Diamond compare with other water systems in Grundy County?
By EPA's size categories, Diamond is a small system (501 to 3,300 people). Grundy County has 51 active public water systems, and Diamond is the 4th-largest of them by population served. Its population served is about 150% above the county average of 1,002 people per system, and accounts for 4.9% of the 51,074 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 is about 63% 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?
EPA lists Diamond 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. 12 of the 51 active systems in Grundy County (24%) are also owned by a local government.
Does Diamond have drinking water violations?
Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in September 2015. The violations listed here began between September 2000 and September 2015. By type: 7 contaminant level above the legal limit and 5 monitoring and reporting. The contaminant or rule involved most often is Combined Radium (-226 and -228) (5 of them). EPA lists 12 as resolved. 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 |
|---|---|---|---|---|
| 2015-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2015-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2015-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2004-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-07-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2003-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2002-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 2000-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2000-11-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2000-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2000-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
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: frequently asked questions
Who runs Diamond?
Diamond (PWSID IL0630250) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Diamond serve?
Diamond reports serving 2,508 people through 920 service connections in Grundy County, Illinois.
Where does Diamond 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 have any drinking water violations?
Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in September 2015. 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'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, 7 are health-based, and the most recent began in September 2015. 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's water quality report?
As a community water system, Diamond 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 Grundy County
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, PWSID IL0630250, Illinois”, https://aquacensus.com/water-systems/illinois/diamond-il0630250 (data as of October 1, 2026).