Public water system · IL0550500
ActiveThompsonville
At a glance
Thompsonville (PWSID IL0550500) is an active community water system in Franklin County, Illinois. It reports serving 486 people through 275 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; none is health-based, and the most recent began in February 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
486
Service connections
275
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Thompsonville compare with other water systems in Franklin County?
By EPA's size categories, Thompsonville is a very small system (500 people or fewer). Franklin County has 23 active public water systems. Its population served is well below the county average of 1,860 people per system, and accounts for 1.1% of the 42,771 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 Thompsonville 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 Thompsonville?
EPA lists Thompsonville 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. 21 of the 23 active systems in Franklin County (91%) are also owned by a local government.
Does Thompsonville have drinking water violations?
EPA's records list 7 violations for this system; none is health-based, and the most recent began in February 2026. The violations listed here began between July 2007 and February 2026. By type: 4 monitoring and reporting, 2 monitoring and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Chloramine (3 of them). EPA lists 4 as archived and 3 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 |
|---|---|---|---|---|
| 2026-02-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2026-02-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | No | Archived |
| 2026-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2026-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | No | Archived |
| 2023-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2012-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | No | Resolved |
| 2007-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
All 7 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.
Thompsonville: frequently asked questions
Who runs Thompsonville?
Thompsonville (PWSID IL0550500) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does Thompsonville serve?
Thompsonville reports serving 486 people through 275 service connections in Franklin County, Illinois.
Where does Thompsonville 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 Thompsonville have any drinking water violations?
EPA's records list 7 violations for this system; none is health-based, and the most recent began in February 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 Thompsonville'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. EPA's records list 7 violations for this system; none is health-based, and the most recent began in February 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 Thompsonville's water quality report?
As a community water system, Thompsonville 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 Franklin County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| West Frankfort | Franklin | 8,650 | Community | Purchased surface water |
| Benton | Franklin | 8,104 | Community | Purchased surface water |
| Rend Lake Inter-City Water System | Franklin | 3,650 | Community | Surface water |
| Christopher | Franklin | 3,072 | Community | Purchased surface water |
| Sesser | Franklin | 2,556 | Community | Purchased surface water |
| Greenwood-Creek Nation Water Company | Franklin | 2,530 | 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, “Thompsonville, PWSID IL0550500, Illinois”, https://aquacensus.com/water-systems/illinois/thompsonville-il0550500 (data as of October 1, 2026).