Section 250-RICR-150-10-6.32 - Distribution BoxesA. A distribution box shall be installed immediately preceding the leachfield unless otherwise approved by the Director.B. Construction - The distribution box shall be constructed of concrete or other durable material. It shall have a top load carrying capacity of three hundred (300) pounds per square foot and minimal sidewall deflection. Minimum bottom area shall be three (3) square feet.C. Inlet - The distribution box shall be provided with an inlet tee or a suitable baffle. The invert elevation of the inlet pipe shall be not less than two inches (2") above the invert elevation of the outlet pipe.D. Outlets 1. Outlet Elevations - The invert elevation of all the outlet pipes shall be a minimum of four inches (4") above the floor of the distribution box. All outlet inverts shall be at the same elevation.2. Number of Outlets - There shall be a separate outlet for each distribution line. In all cases following a pump tank, the outlets shall be of sufficient size to accept the wastewater flow at the rate wastewater is delivered to the distribution box.E. Distribution Pipes into the Distribution Box1. The distribution pipes shall extend into the distribution box one inch (1").2. Jointing of the distribution piping with a distribution box shall be made with non-shrinking gasket materials which shall maintain a watertight seal.3. All inverts shall be set level after the leachfield is installed. Leveling devices may be installed on the distribution pipes.F. Cover - The distribution box shall be provided with a readily removable, fitted cover of durable material. Distribution boxes are not required to have access openings at finished grade except as follows. When a tipping distribution box is used, the distribution boxes shall have a minimum ten inch (10") diameter access opening brought to finished grade. OWTSs with a design flow over two thousand (2,000) gallons per day shall have a minimum eighteen inch (18") manhole over each distribution box with extra heavy duty metal frames and covers to finished grade. When manholes to grade are not provided, it is recommended that a marker over the cover be provided at grade.G. Foundation - The distribution box shall be installed on a level stable base that will not settle.250 R.I. Code R. 250-RICR-150-10-6.32
Amended effective 11/25/2018
Amended effective 12/28/2021
Amended effective 7/1/2022