The provisions of this Article are intended to limit the probability that failure of an in-ground building drain or building sewer would lead to the contamination of potable water in a water service pipe.
Sentence (1) requires that a minimum 2 440 mm horizontal clearance be provided between a water service pipe and a building drain or a building sewer.
Sentence (2) describes certain exceptions which would permit the water service pipe to be closer than 2 440 mm to the building drain or building sewer.
Sentence (3) recognizes that in certain instances, the water service pipe and a building drain or building sewer may have to cross each other. In this case, the greatest risk of contamination to the potable water is through joints in the water service pipe under backflow conditions. In order to avoid this, the Code requires that there be no joints in the water service pipe within 2 440 mm horizontally of the intersection with the building drain or building sewer. The illustration below appears to meet this requirement, however it is intended that no joints in the water service line be located within 2 440 mm of the closest point on the building drain/sewer.
