Here is what the EPA's own data shows about tap water in Mchenry. According to EPA SDWIS data retrieved October 2026, Mchenry is served by 9 active community water systems, together reported to serve about 27,183 people.
As of October 2026, EPA records show 37 violations across the community water system(s) serving Mchenry, going back to the earliest EPA record. 2 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.
Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in April 1992. 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 between October 2023 and July 2025. 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 once in January 2023. All have since returned to compliance, per EPA records.
Monitoring 1,2,4-Trichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring cis-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Xylenes, Total: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring DICHLOROMETHANE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring o-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring p-Dichlorobenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring 1,1-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring trans-1,2-Dichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring 1,1,1-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Carbon tetrachloride: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring 1,2-Dichloropropane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Trichloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring 1,1,2-Trichloroethane: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Tetrachloroethylene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring CHLOROBENZENE: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Benzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Toluene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Ethylbenzene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Monitoring Styrene: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. All have since returned to compliance, per EPA records.
Prairie Path Water Company-Westlake
1,493 served · groundwater · PWSID IL2010070
Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2023. 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.
Prairie Path Water Company-Lake Marian
1,022 served · groundwater · PWSID IL0895200
Health-based Lead and Copper Rule: a health-based violation (a contaminant recorded above the limit the EPA tracks), recorded once in April 2014. 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 3 times between October 1993 and July 2013. All have since returned to compliance, per EPA records.
Prairie Path Water Company-Coventry Hill
608 served · groundwater · PWSID IL2015150
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Prairie Path Water Company-Northern Hill
600 served · groundwater · PWSID IL1775050
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Prairie Path Water Company-Wildwood
490 served · groundwater · PWSID IL2015400
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 once in January 2023. All have since returned to compliance, per EPA records.
Prairie Path Water Company-Rockvale
298 served · groundwater · PWSID IL1415350
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 2024. 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 once in January 2021. All have since returned to compliance, per EPA records.
Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2021. All have since returned to compliance, per EPA records.
Prairie Path Water Co-Coventry Creek
270 served · groundwater · PWSID IL2015160
As of October 2026, EPA records show no reported violations for this system in the period covered. This is not a guarantee about every substance, or about the water inside your home's plumbing.
Prairie Path -Port Barrington Shores
67 served · groundwater · PWSID IL0971120
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 January 1998. 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 October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.