MARKHAM: EPA violation history, explained
MARKHAM has a health-based violation on record, but none in the last five years - an older issue, not necessarily a current one. 12,500 people get their water from it, across 4,138 connections.
Ranked against every other system in this dataset
MARKHAM has 42 violations on record in total, 7 of thems health-based - ranking it 2,627th of 12,903 systems by violation count, the 80th percentile nationally.
How MARKHAM compares within IL
IL's 560 covered systems average 5.0 health-based violations each; MARKHAM carries 7, more than typical for the state. The filter guide explains what a violation like this actually calls for.
Most recent violation on record
The last violation EPA has on record for MARKHAM is from 2025-02-07 (health-based: 2013-01-08). Last reported to EPA: 05/27/2026.
What kind of problem, specifically
MARKHAM's flagged contaminants and rule violations, grouped by what they actually mean for a filter choice rather than left as EPA's raw code list:
- Microbial contamination / treatment technique - flagged from: Coliform (TCR)
The most severe category on record is microbial contamination / treatment technique, which points toward a microbial-class filter if you want to address it directly.
What this data is and is not
Everything on this page is MARKHAM's own reported record under the Safe Drinking Water Act - a regulatory filing, not a sample of your tap. Water quality can still change between the meter and the faucet - household plumbing sits outside what a record of 42 logged violations can see. The guide to what this data misses covers that gap.