Section 250-RICR-150-10-6.25 - Building SewersA. Size - The building sewer shall be designed with a capacity, when running full, of not less than twice the peak rate of flow of the connected fixtures. In no case shall the building sewer be less than three inches (3") in diameter.B. Material - The building sewer shall be constructed of PVC pipe SDR 35 minimum or equivalent. When any portion of the building sewer will be subject to vehicular traffic, it shall be constructed of Schedule 40 PVC or equivalent.C. Joints - All pipe joints for the building sewer shall be made watertight and be firmly connected.D. Base - The building sewer shall be laid on a compacted, firm base.E. Horizontal Alignment 1. The building sewer should be laid in a straight line wherever possible. Changes in direction shall not exceed ninety degrees (90°).2. Where a change in direction is greater than forty-five degrees (45°), a manhole is required, unless the change in direction is achieved through the use of a thirty-six inch (36") radius sweep.F. Vertical Alignment 1. The slope of the building sewer from the dwelling to the septic tank shall be not less than one percent (1%) and not greater than five percent (5%).2. A manhole is required at changes of grade requiring a drop box in order to maintain the maximum five percent (5%) slope.G. Manholes and Cleanouts - A manhole with a removable cover of concrete, cast iron, or other durable material shall be provided at the junction of two (2) or more building sewer lines and at all sharp changes in direction greater than forty-five degrees (45°), unless the alignment complies with § 6.25(F) of this Part. A cleanout shall be provided at intervals not greater than seventy-five feet (75').H. Ventilation - The building sewer shall be vented through the stack or main vent of the building it serves. No trap shall be installed in the building sewer.250 R.I. Code R. 250-RICR-150-10-6.25
Amended effective 11/25/2018
Amended effective 12/28/2021
Amended effective 7/1/2022