7.4.6.

(1) No vertical soil or waste pipe shall conduct both sanitary sewage and storm sewage.

(2) There shall be no unused open ends in a drainage system and dead ends shall be so graded that water will not collect in them.

(1) A soil or waste pipe shall not be located directly above,

(a) non-pressure potable water storage tanks,

(b) manholes in pressure potable water storage tanks, or

(c) food-handling or processing equipment.

(1) Only piping that is too low to drain into a building sewer by gravity shall be drained to a sump or receiving tank.

(2) Where the sump or tank receives sanitary sewage it shall be water and air-tight and shall be vented.

(3) Equipment such as a pump or ejector that can lift the contents of the sump or tank and discharge it into the sanitary building drain or sanitary building sewer shall be installed.

(4) Where the equipment does not operate automatically the capacity of the sump shall be sufficient to hold at least a 24 hours accumulation of liquid.

(5) Where there is a building trap the discharge pipe from the equipment shall be connected to the sanitary building drain downstream of the trap.

(6) The discharge pipe from every pumped sanitary sewage sump shall be equipped with a union, a check valve and a shut-off valve installed in that sequence in the direction of discharge.

(7) The discharge piping from a pump or ejector shall be sized for optimum flow velocities at pump design conditions.

(8) The discharge pipe from every pumped storm sewage sump shall be equipped with,

(a) a union and a check valve installed in that sequence in the direction of discharge and pumped to above grade level, or

(b) a union, a check valve and a shut off valve installed in that sequence in the direction of discharge.

(1) Except as permitted in Sentence (2), a backwater valve that would prevent free circulation of air shall not be installed in a building drain or in a building sewer.

(2) A backwater valve may be installed in a building drain provided that,

(a) it is a “normally open” design conforming to,

(i) CAN/CSA-B70, “Cast Iron Soil Pipe, Fittings, and Means of Joining”,

(ii) CAN/CSA-B181.1, “ABS Drain, Waste, and Vent Pipe and Pipe Fittings”,

(iii) CAN/CSA-B 181.2, “PVC Drain, Waste, and Vent Pipe and Pipe Fittings”, or

(iv) CAN/CSA-B182.1, “Plastic Drain and Sewer Pipe and Pipe Fittings”, and

(b) it does not serve more than one dwelling unit.

(3) Except as provided in Sentences (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.

(5) A subsoil drainage pipe that drains into a sanitary drainage system that is subject to surcharge shall be connected in such a manner that sewage cannot back up into the subsoil drainage pipe.

(1) A building sewer intended to serve a mobile home shall,

(a) be not less than 4 in. in size,

(b) be terminated above ground,

(c) be provided with,

(i) a tamperproof terminal connection that is capable of being repeatedly connected, disconnected and sealed,

(ii) a protective concrete pad, and

(iii) a means to protect it from frost heave, and

(d) be designed and constructed in accordance with good engineering practice.

(1) Where a building drain enters a building above the elevation of the bottom of the wall of a building, the building drain may be deemed to terminate at the first point that the drainage pipe changes direction from the horizontal to the vertical.