08-19 Backwater valves

Question: 08-19Code Section: 7Date: 13 March 2008OBC 2006 Reference:

Question submitted: Has anyone else received the letter from (a backwater valve manufacturer) relating to the requirement for a backwater valve anytime a fixture is located below the level of the adjoining street? They quote Sentence & (4) (3) “Except as provided in Sentence (4) and (5), where a building drain or a branch may be subject to backflow, a backwater valve shall be installed on every fixture drain connected to them when the fixture is located below the level of the adjoining street.” (4) “Where more than one fixture is located on a storey and all are connected to the same branch, the backwater valve may be installed on the branch.” It also suggests that you contact the Ministry , “…for clarification on whether drains located below the level of the adjoining street may be subject to backflow.” The letter seems to be suggesting that anytime you have a fixture located below the street you have to have a backwater valve installed on the fixture, branch or main building drain.

Interpretation: It is true that the words “may be subject to backflow” is very subjective and any pipe installed below the level of the adjoining street could be subjected to backflow. However, it is written that way in order give the inspector some discretion. If an area of the municipality is known for surcharging then Sentence (3) kicks in and if another area has NO history of problems, then Sentence (3) does not apply. Hence the word “may”. Salespeople will interpret this to mean that one MUST install their product if it “may” happen.

Approved at AMES 2008 (Code Change Proposal Pending)