(a) Pump Systems. The use of sewage ejectors, lift stations or pumps on raw sewage lines to septic tanks when exterior to the structure are prohibited unless designed by a professional engineer. Pumps must be hardwired outside the pump chamber. A flow velocity reducing device must be installed on force mains prior to entering a distribution box. For systems producing septic tank effluent, pump systems may be designed for time dose and/or enhanced flow distribution.
(b) Corrosion of distribution boxes. All interior portions of distribution boxes must be resistant or treated to be resistant to corrosion including microbial induced corrosion. Treatments for corrosion shall incorporate a dye or inherent color to identify that treatment has occurred.
(c) Non-concrete distribution boxes. Header lines must be attached to the distribution box using approved fittings. Concrete shall be poured around the sides of the box from the base to the top of the box allowing room for the lid to be secured. The concrete shall surround the box completely.
(d) Gravity building sewers. Gravity building sewers shall have a minimum inside diameter (ID) of four inches.
(e) Sewer and conveyance lines. The minimum slope for four-inch gravity sewers is 1-1/4 inches per 10 feet, and for a six-inch sewer is 3/4 inch per 10 feet. Ells on gravity sewer lines shall not exceed 45 degrees. Gravity conveyance lines shall have a slope of not less than six inches per 100 feet.
(Ord. 94-05. Passed 2-16-94; Ord. 17-03. Passed 1-19-17; Ord. 19-17. Passed 11-13-19.)