Area of sewer testing in WoodstockAs part of Oxford County’s sanitary sewer maintenance, additional testing and inspection is being planned for this spring in Woodstock (see map of testing area). This will be carried out through a method known as fog testing.

Please note: If your area is being tested, you will receive a notice delivered to your home in advance of testing.

Fog testing uses a quick release of vapour through sewer manholes and pipes to identify sources of rainwater entering the sanitary sewers. The vapour has no odour, disappears in a few minutes, and is not harmful to your health or to pet health.

Testing will take place:

May 22 – June 16, 2023

Rotating schedule by street
Monday–Friday between 9:00 a.m. and 5:00 p.m.

Oxford County has contracted Civica Infrastructure to complete the testing. The project contact for Woodstock is Nirujaan Kanagendran, 1-905-417-9792, ext. 2303.

If you have a health condition you think may be affected by the testing, please call your Civica Infrastructure contact.


How to prepare

If your home will be tested, a notice will be delivered to your home in advance.

To prepare for testing, please ensure there is water in plumbing traps in any sinks or appliances that you do not use on a regular basis and in your basement floor drain (water will already be present in sinks and appliances you regularly use). To do this, please pour one pail (5-6 litres) of water into the drains or sink.


How fog testing is carried out

You may remain in your home while testing takes place, but it is not required that someone is present at the home.

On the day of the fog testing in your area, a representative from Civica Infrastructure will knock on your door, inform you that the fog testing is about to take place, and ensure you have prepared your plumbing traps.

After fog testing, Civica Infrastructure staff will complete a quick walk around your property to mark locations where fog is exiting the sewer system. It will not be necessary for staff to enter home at any time during or after the testing.



Nirujaan Kanagendran
Civica Infrastructure
1-905-417-9792, ext.2303

Reuben Davis, P.Eng.
Oxford County
519-539-9800, ext.3012

Brent Bouteiller, P.Eng.
GM BluePlan Eng. Ltd.
1-519.824.8150 ext.1212


About fog testing

Fog testing is used to help monitor and maintain the sanitary sewer system. It consists of blowing a harmless vapour into the sewer manholes and pipes and checking where the fog exits the system. This could be through manholes, the sewer plumbing stack at the top of your house, stormwater catch basins, or roof downspouts at the side of a house. With this information, we are able to discover the need for potential repairs or upgrades to the system to avoid overflow or even potential basement flooding.


Q. Is fog testing harmful? Should I be concerned about pets?
A. The vapour used in fog testing is not harmful to your health or to your pet’s health, dissipates quickly, and will not harm clothing, draperies, or furniture. You may choose to leave your windows partially open for ventilation in the event any fog enters your home.

Q. What is the purpose of fog testing the sanitary sewer system?
A. Fog testing helps to make sure the sanitary sewer is working at its best. It is a simple and quick method of testing the sanitary sewer system to locate where rainwater or groundwater is entering the system.

Q. Will fog enter my home?
A. The fog or vapour is not intended to enter your home, only the internal plumbing system. Each drain should have a gooseneck installed that will prevent fog from entering your home. If you are home and the fog enters during testing, note the location of the fog and contact Civica or speak with one of the crewmembers conducting the test to let them know the location of the fog. If you think there is smoke present from a source other than the testing, call 911.

Q. If fog gets into the house, how long does it take for the fog to fade?
A. The fog will dissipate in a few minutes. If you are home and the fog is bothering you, leave the room, turn on an exhaust fan.