After chlorine treatment
Disinfecting water is a big public-health win. Small byproducts can form when disinfectant meets natural organics in source water — and those are tracked.
Disinfectant
protects the water
Organic matter
from source water
Byproducts
THMs / HAAs measured
What people notice
Names like “trihalomethanes” (THMs) in a report or news story. In plain words: disinfectant meeting natural matter in the source, with amounts that vary by season and source.
What records usually show
When a result is above an Ontario standard, it is flagged on the system page like any other flagged test. We show what was recorded — we do not invent limits or give health advice.
What you can do
- Check your system page for any flagged results named as byproducts.
- Ask your city for the official annual report if you want the fuller testing picture.