Tap Water Taste or Odour
A change in tap water taste or odour may be the result of several factors. Below are potential causes and steps you can take to help resolve the issue.
When only one tap produces water with a taste or odour, this indicates a private plumbing issue. Try these steps to resolve the issue:
- Run the cold water for the affected tap for approximately 10 minutes. This will flush the pipe.
- After 10 minutes, take a sample in a clear glass and move to another room.
- If the odour is gone, you may wish to flush the remaining taps in your home.
- If you have moved the glass to another room and the odour is not detected, the odour is likely coming from the drain in your sink and needs to be disinfected.
How to disinfect a drain
- Pour one cup of household laundry bleach down the drain. Do not use any other product or pour any other substance down the drain. Let the bleach sit undisturbed for 10 minutes.
- After 10 minutes, turn on the cold water tap for five minutes to thoroughly flush the drain.
- Once this is done:
- If the odour is gone, you may wish to flush the remaining taps in the house.
- If the odour persists, contact 311 and the Toronto Water laboratory will contact you within 24 hours, Monday to Friday. Messages left Friday night to Sunday, will be returned on Monday.
Odour from cold water taps
- The odour may be a result of a dry sewer drain, which can cause sewer odours to enter your home.
- The pipe connected to your basement floor drain has a bump (called a P-trap) that retains water. This helps create a barrier to help prevent odours from backing up. In some homes, doing laundry or using a nearby sink will refresh the water in the trap.
- Check the floor drains and if dry, pour in a few litres of clean water.
- If this does not solve the issue, contact 311 and someone from the Toronto Water laboratory will contact you within 24 hours, Monday to Friday. Messages left Friday night to Sunday will be returned on Monday.
Earthy, musty smell or taste
- In late summer or early fall, you may notice an earthy, musty smell and/or taste in tap water.
- The presence of naturally-occurring algae and high water temperatures in Lake Ontario can cause this to happen.
- The water remains safe to drink during these events. Learn more about drinking water quality.
Chlorine smell or taste
- Chlorine is added during the water treatment process to ensure tap water is safe to drink.
- Chlorine addition is regulated by the Province of Ontario’s Safe Drinking Water Act and is continuously monitored.
- Some people may be sensitive to chlorine. If so, fill a pitcher with water and let it stand overnight in the refrigerator.
If taste or odour persists
- If the issue persists after you have read and, where applicable, followed the steps above to resolve the issue, please call 311.
- The Toronto Water laboratory will contact you within 24 hours, Monday to Friday. Messages left Friday night to Sunday will be returned on Monday.