Public water system · IL1254840
ActiveSan Jose
At a glance
San Jose (PWSID IL1254840) is an active community water system in Mason County, Illinois. It reports serving 479 people through 239 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 5 violations for this system; none is health-based, and the most recent began in November 2018.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
479
Service connections
239
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does San Jose compare with other water systems in Mason County?
By EPA's size categories, San Jose is a very small system (500 people or fewer). Mason County has 24 active public water systems, and San Jose is the 4th-largest of them by population served. Its population served is about 29% above the county average of 371 people per system, and accounts for 5.4% of the 8,902 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 San Jose 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 San Jose?
EPA lists San Jose 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. 6 of the 24 active systems in Mason County (25%) are also owned by a local government.
Does San Jose have drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in November 2018. The violations listed here began between June 1977 and November 2018. By type: 4 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is Chlorine (2 of them). EPA lists 3 as resolved and 2 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 |
|---|---|---|---|---|
| 2018-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2018-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2006-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 1993-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1977-06-30 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 5 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.
San Jose: frequently asked questions
Who runs San Jose?
San Jose (PWSID IL1254840) is a community water system owned by a local government. It is regulated by the IL state drinking water program.
How many people does San Jose serve?
San Jose reports serving 479 people through 239 service connections in Mason County, Illinois.
Where does San Jose 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 San Jose have any drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in November 2018. 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 San Jose'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 5 violations for this system; none is health-based, and the most recent began in November 2018. For current results, consult the system's annual water quality report, EPA ECHO, or the IL state drinking water program.
Where can I find San Jose's water quality report?
As a community water system, San Jose 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 Mason County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Havana | Mason | 2,963 | Community | Groundwater |
| Mason City | Mason | 2,393 | Community | Groundwater |
| Manito | Mason | 1,552 | Community | Groundwater |
| Easton | Mason | 325 | Community | Groundwater |
| Lost Arrow Campominium | Mason | 223 | Transient non-community | Groundwater |
| Forest City | Mason | 222 | 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, “San Jose, PWSID IL1254840, Illinois”, https://aquacensus.com/water-systems/illinois/san-jose-il1254840 (data as of October 1, 2026).