Pumping to Septic Tanks

(1) System designs specifying pumping of sewage to a septic tank may be approved by the Approving Authority for a single family dwelling provided that the volume of sewage pumped is less than 25% of the design flow of the system, the pump discharge pipe is connected to the building sewer and: (a) where a sewage ejector pump (non-grinder pump) is used, the discharge flow rate shall be fewer than 60 gallons per minute at the design total dynamic head (TDH) and capable of passing a two-inch diameter solid, and the septic tank shall have a minimum effective volume of 1,500 gallons; or (b) where a grinder pump is used, the discharge flow rate shall comply with the discharge capacity specified in the State Plumbing Code for sump and ejector pumps in sanitary drainage systems, and the septic tank shall either be a multi-compartment tank or two tanks in series. (2) It is not recommended to pump greater than 25% of the design flow of the system to a septic tank; however, when necessary system designs specifying pumping of sewage to a septic tank may be approved by the Approving Authority for a single family dwelling discharging a volume of sewage greater than 25% of the design flow of the system, provided the pump discharge pipe is connected to the building sewer and: (a) the requirements of 310 CMR 15.229(1)(a) or 15.229(1)(b) are met; (b) the building sewer discharges to a multi-compartment septic tank or two tanks in series designed in accordance with 310 CMR 15.223 and 15.224; and (c) standby power, a hookup for standby power or storage capacity in the pump chamber equal to at least the volume of the design flow for one day is provided. Non-grinder pumps are the preferred alternative. (3) All other uses of sewage pumps prior to the septic tank without the prior written approval of the Approving Authority are prohibited.