IL / Ottawa
IL · Tap water records
Ottawa tap water, in plain English
Here is what the EPA's own data shows about tap water in Ottawa. According to EPA SDWIS data retrieved June 2026, Ottawa is served by 7 active community water systems, together reported to serve about 19,288 people.
As of June 2026, EPA records show 496 violations across the community water system(s) serving Ottawa, going back to the earliest EPA record. 63 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
Ottawa
18,097 served · groundwater · PWSID IL0990800 - Health-based Combined Radium (-226 and -228): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 6 times in July 2023. The EPA record lists a level of 8 PCI/L; the limit (MCL) is 5 PCI/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 December 1992. The EPA record for these does not include a measured level. All have since returned to compliance, per EPA records.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 15 times between November 2018 and October 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 15 times between November 2018 and October 2025. EPA records do not show all of these as returned to compliance.
- Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Gross Alpha Particle Activity: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 9 times between October 2018 and October 2022. All have since returned to compliance, per EPA records.
- Monitoring Combined Radium (-226 and -228): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 7 times between July 2022 and October 2022. All have since returned to compliance, per EPA records.
- Monitoring Vinyl chloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. EPA records do not show all of these as returned to compliance.
- Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 8 times in January 2020. 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 2005. 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 once in July 1998. All have since returned to compliance, per EPA records.
Naplate
465 served · groundwater · PWSID IL0990600 - Monitoring Mercury: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. EPA records do not show all of these as returned to compliance.
- Monitoring Chlordane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. 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 11 times between April 2004 and July 2011. 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 once in January 2010. All have since returned to compliance, per EPA records.
Fields Hill Improvement Association
312 served · groundwater · PWSID IL0995150 - Health-based LEAD AND COPPER RULE REVISIONS: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in October 2024. The EPA record for these does not include a measured level. EPA records do not show all of these as returned to compliance.
- Health-based Combined Radium (-226 and -228): 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 8 PCI/L; the limit (MCL) is 5 PCI/L. 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 28 times between January 2004 and December 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 62 times between July 2022 and December 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 44 times between July 2022 and December 2025. EPA records do not show all of these as returned to compliance.
- Monitoring LEAD AND COPPER RULE REVISIONS: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between October 2024 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 7 times between July 2002 and July 2025. EPA records do not show all of these as returned to compliance.
- 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 October 1993 and October 2023. EPA records do not show all of these as returned to compliance.
Retz Addn Improvement Association
168 served · groundwater · PWSID IL0995400 - Health-based Combined Radium (-226 and -228): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 4 times in July 2023. The EPA record lists a level of 8 PCI/L; the limit (MCL) is 5 PCI/L. 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 8 times between January 2023 and October 2024. 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 5 times between July 2002 and July 2022. All have since returned to compliance, per EPA records.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times in October 2021. All have since returned to compliance, per EPA records.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 5 times in January 2021. EPA records do not show all of these as returned to compliance.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2010. All have since returned to compliance, per EPA records.
La Salle County Nursing Home
100 served · groundwater · PWSID IL0995329 - Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in April 2025. The EPA record for these does not include a measured level. 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 once in November 2025. EPA records do not show all of these as returned to compliance.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2025. All have since returned to compliance, per EPA records.
- Monitoring Chlorine: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2025. 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 between October 2013 and July 2016. 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 2006 and August 2006. All have since returned to compliance, per EPA records.
Land And Wtr Assn
83 served · groundwater · PWSID IL0995050 - Health-based Combined Radium (-226 and -228): a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded 48 times between April 2022 and October 2025. The EPA record lists a level of 9 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 8 times between January 2023 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 2 times between July 2005 and July 2013. 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 once in January 2010. All have since returned to compliance, per EPA records.
Oaklane Sbdv
63 served · groundwater · PWSID IL0995250 - Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2023. EPA records do not show all of these as returned to compliance.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in January 2023. 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 2 times in July 2019. 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 once in December 2013. 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.