Public water system · IL0374850
ActiveSandwich
At a glance
Sandwich (PWSID IL0374850) is an active community water system in DeKalb County, Illinois. It reports serving 7,156 people through 2,777 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, 3 are health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,156
Service connections
2,777
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Sandwich compare with other water systems in DeKalb County?
By EPA's size categories, Sandwich is a medium system (3,301 to 10,000 people). DeKalb County has 43 active public water systems, and Sandwich is the 3rd-largest of them by population served. Its population served is about 3.2 times the county average of 2,220 people per system, and accounts for 7.5% of the 95,450 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 Sandwich is roughly in line with 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 Sandwich?
EPA lists Sandwich 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. 13 of the 43 active systems in DeKalb County (30%) are also owned by a local government.
Does Sandwich have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in January 2026. The violations listed here began between April 1989 and January 2026. By type: 8 monitoring and reporting, 3 contaminant level above the legal limit and 1 reporting. The contaminant or rule involved most often is Lead and Copper Rule (2 of them). EPA lists 6 as archived, 5 as resolved and 1 as unaddressed. 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. 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 |
|---|---|---|---|---|
| 2026-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Resolved |
| 1999-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 1998-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
| 1997-10-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1994-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1993-01-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Archived |
| 1992-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Archived |
| 1990-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Trichloroethylenecode 2984 | Yes | Archived |
| 1990-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Trichloroethylenecode 2984 | Yes | Archived |
| 1989-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | 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.
Sandwich: frequently asked questions
Who runs Sandwich?
Sandwich (PWSID IL0374850) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Sandwich serve?
Sandwich reports serving 7,156 people through 2,777 service connections in DeKalb County, Illinois.
Where does Sandwich 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 Sandwich have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in January 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 Sandwich'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, 3 are health-based, and the most recent began in January 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find Sandwich's water quality report?
As a community water system, Sandwich 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 DeKalb County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Dekalb | DeKalb | 40,290 | Community | Groundwater |
| Sycamore | DeKalb | 18,500 | Community | Groundwater |
| Northern Illinois University-Dekalb | DeKalb | 6,500 | Community | Purchased groundwater |
| Genoa | DeKalb | 5,298 | Community | Groundwater |
| Cortland | DeKalb | 4,398 | Community | Groundwater |
| Hinckley | DeKalb | 2,006 | 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, “Sandwich, PWSID IL0374850, Illinois”, https://aquacensus.com/water-systems/illinois/sandwich-il0374850 (data as of October 1, 2026).