General provisions

(a) Primary settling. All sewage entering a pump tank (i.e., a lift station, a flow equalization tank or a low pressure dosing tank) must first pass through a septic tank or a trash tank for primary settling. (b) Pump tank design and construction. Pump tanks shall: 12 (1) be constructed to prevent sewage from leaking out of the tank and to prevent the infiltration of water into the tank; (2) when made of concrete, meet the requirements of 252:641-7-2(a); (3) have a manhole opening of at least twenty inches (20") in diameter or, if rectangular, having no side less than twenty inches (20") in length. The manhole cover shall have a lock, locking bolt, or some type of tamper-resistant fastener, that or requires tools for removal. The manhole opening shall extend a minimum of two inches (2") above ground elevation; (4) have a threaded union installed in the discharge line located within eighteen inches (18") of the manhole opening so that the pump can be removed without entering the pump tank; and (5) have a check valve installed in the discharge line after the threaded union. The check valve shall be the same diameter as the discharge line. (c) Pump design. Pumps shall be: (1) designed to pump sewage or other liquid containing fine particles/suspended solids; (2) rated to pump at least the average daily flow the required distance and elevation; and (3) when used as a low pressure dosing pump, rated to pump at least fifty (50) gallons per minute with no more than eight feet (8') of head pressure. (d) Prevention of back siphoning. Pump discharges shall flow through a structure or device that prevents the back siphoning of wastewater to the pump tank. (e) Example. Appendix J illustrates the requirements for a pump tank. SUBCHAPTER 10. AEROBIC TREATMENT SYSTEMS