Public water system · IL1170600
ActiveModesto
At a glance
Modesto (PWSID IL1170600) is an active community water system in Macoupin County, Illinois. It reports serving 182 people through 120 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in May 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
182
Service connections
120
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Modesto compare with other water systems in Macoupin County?
By EPA's size categories, Modesto is a very small system (500 people or fewer). Macoupin County has 32 active public water systems. Its population served is well below the county average of 1,411 people per system, and accounts for 0.4% of the 45,161 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 Modesto 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 Modesto?
EPA lists Modesto 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. 28 of the 32 active systems in Macoupin County (88%) are also owned by a local government.
Does Modesto have drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in May 2025. The violations listed here began between April 1995 and May 2025. By type: 6 required treatment not met, 3 public notice, recordkeeping or other, 2 contaminant level above the legal limit and 1 monitoring and reporting. The contaminant or rule involved most often is Carbon, total (3 of them). EPA lists 11 as resolved and 1 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. 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 |
|---|---|---|---|---|
| 2025-05-30 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2025-04-01 | Required treatment not metTreatment Technique Precursor Removal · code 46 | Carbon, totalcode 2920 | Yes | Resolved |
| 2025-01-01 | Required treatment not metTreatment Technique Precursor Removal · code 46 | Carbon, totalcode 2920 | Yes | Resolved |
| 2023-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2021-10-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2021-10-01 | Required treatment not metSingle Turbidity Exceed (Enhanced SWTR) · code 43 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2021-09-01 | Required treatment not metMonthly Turbidity Exceed (Enhanced SWTR) · code 44 | Interim Enhanced Surface Water Treatment Rulecode 0300 | Yes | Resolved |
| 2017-04-01 | Required treatment not metTreatment Technique Precursor Removal · code 46 | Carbon, totalcode 2920 | Yes | Resolved |
| 2009-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Inadequate Reporting · code 72 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 1995-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Atrazinecode 2050 | Yes | Resolved |
| 1995-04-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | 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.
Modesto: frequently asked questions
Who runs Modesto?
Modesto (PWSID IL1170600) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Modesto serve?
Modesto reports serving 182 people through 120 service connections in Macoupin County, Illinois.
Where does Modesto 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 Modesto have any drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in May 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 Modesto'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, 8 are health-based, and the most recent began in May 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 Modesto's water quality report?
As a community water system, Modesto 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 Macoupin County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Carlinville | Macoupin | 6,598 | Community | Surface water |
| Staunton | Macoupin | 5,756 | Community | Surface water |
| Brighton | Macoupin | 5,041 | Community | Purchased surface water |
| Gillespie | Macoupin | 3,737 | Community | Surface water |
| Virden | Macoupin | 3,274 | Community | Purchased surface water |
| Mount Olive | Macoupin | 2,193 | 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, “Modesto, PWSID IL1170600, Illinois”, https://aquacensus.com/water-systems/illinois/modesto-il1170600 (data as of October 1, 2026).