IL / Markham
IL · Tap water records
Markham tap water, in plain English
Here is what the EPA's own data shows about tap water in Markham. According to EPA SDWIS data retrieved June 2026, Markham is served by 2 active community water systems, together reported to serve about 12,525 people.
As of June 2026, EPA records show 21 violations across the community water system(s) serving Markham, going back to the earliest EPA record. None were health-based; the records are monitoring or reporting violations (a required test or report was late or missed). Each is listed by system below, with its status.
What the EPA has on record, by system
Markham
12,500 served · surface water · PWSID IL0311770 - 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 Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 4 times between July 2011 and July 2025. EPA records do not show all of these as returned to compliance.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times in July 2025. 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 4 times in June 2023. All have since returned to compliance, per EPA records.
- Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times in May 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 April 2022. 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 1994 and December 2020. All have since returned to compliance, per EPA records.
Mid-Mark Water Commission
25 served · surface water · PWSID IL0310230 As of June 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.
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.