310 C.M.R. 15.222 – Building Sewers

(1) The building sewer shall be sufficient to serve the connected fixtures. In no case shall the building sewer be less than four inches in diameter.
(2) The minimum distance between a building sewer, and a private water supply well or suction line shall be ten feet.
(3) The building sewer shall be constructed of corrosion resistant material and equipped with water tight joints; cast-iron, schedule 40 PVC pipe or the equivalent.
(4) All pipe joints of the building sewer shall be made water-tight and protected against damage by roots. Poured-type joints shall be properly wiped on the inside to eliminate obstruction of flow.
(5) The building sewer shall be laid on a compacted firm base.
(6) The building sewer shall be designed to provide a minimum velocity of sewage flow of two feet per second when flowing full. This requirement is met when a four-inch building sewer is laid at a slope of not less than 0.01 (c inch per foot). A slope of 0.02 (¼ inch per foot) is preferable.
(7) The building sewer shall be laid on a continuous grade and as nearly as possible in a straight line in accordance with accepted engineering practice.
(8) Manholes, with metal frames and covers at grade, sweeping bends, or a cleanout accessible at the surface of the ground, shall be provided at the junction of two or more sewers, at all changes in direction or a change in grade of the sewers, and at intervals no greater than 100 feet. All gravity sewer manholes shall have an open channel depth equal to or greater than the diameter of the inlet sewer and the change of direction in each manhole shall not exceed 90(cid:69). (Change of direction is the interior angle between the new direction of flow and the projected extension of the original direction of flow.)
(9) The building sewer shall be vented through the vent stack or main vent of the building served by it. No trap shall be installed in the building sewer or building drain.
(10) All building sewers shall be constructed in accordance with the State Plumbing Code, 248 CMR 2.00.