IL / Monmouth
IL · Tap water records
Monmouth tap water, in plain English
Here is what the EPA's own data shows about tap water in Monmouth. According to EPA SDWIS data retrieved June 2026, Monmouth is served by 4 active community water systems, together reported to serve about 12,734 people.
As of June 2026, EPA records show 34 violations across the community water system(s) serving Monmouth, going back to the earliest EPA record. 12 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.
What the EPA has on record, by system
Monmouth
8,902 served · groundwater · PWSID IL1870150 - Health-based Combined Radium (-226 and -228): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 3 times in October 2024. The EPA record lists a level of 6 PCI/L; the limit (MCL) is 5 PCI/L. EPA records do not show all of these as returned to compliance.
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in November 2024. All have since returned to compliance, per EPA records.
Abingdon
3,275 served · groundwater · PWSID IL0950050 - Health-based TTHM: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 6 times between October 2018 and January 2019. The EPA record lists a level of 0.085 MG/L; the limit (MCL) is 0.08 MG/L. All have since returned to compliance, per EPA records.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between July 2005 and July 2025. All have since returned to compliance, per EPA records.
- Monitoring Public Notice: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in December 2018. All have since returned to compliance, per EPA records.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in October 2017. All have since returned to compliance, per EPA records.
Little Swan Lake Sd
438 served · groundwater · PWSID IL1875050 - Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between December 2022 and July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2011. All have since returned to compliance, per EPA records.
St Augustine
119 served · groundwater · PWSID IL0950500 - Health-based Arsenic: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 2 times in July 2023. The EPA record lists a level of 19 UG/L; the limit (MCL) is 10 UG/L. EPA records do not show all of these as returned to compliance.
- Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in July 1998. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in December 2022. All have since returned to compliance, per EPA records.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between July 2003 and July 2012. All have since returned to compliance, per EPA records.
What this means
A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.
This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.
Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.