Position the sewer ejector system's basin at the end of the building's main drain pipe. Rotate the basin until its intake pipe aligns with the drain pipe. If the basin's intake hole rests higher than the drain pipe's opening, remove soil from under the basin with a shovel until the intake hole meets the drain pipe. If the basin's intake hole rests lower than the drain pipe, place concrete blocks under the basin until the drain pipe meets the basin's intake hole.
Connect the building's drain pipe to the basin's intake hole, using the manufacturer's instructions as a guide. If the building uses a PVC drain pipe, cement the drain pipe to the intake's connection fitting with PVC glue. If the building uses a flanged drain connection, slip the basin's gasket between its intake flange and the drain pipe's flange. Tighten the flange bolts with the proper-size wrench.
Attach the discharge pipe to the sewer ejector system's pump discharge port, using the manufacturer instructions as a guide. Cement PVC fittings with PVC glue and tighten flange fittings with the correct wrench. If the sewer ejector system uses a free-standing submersible ejector pump, pull the pump out of the basin and make the discharge pipe's connection. Set the submersible pump onto the basin's floor and connect the end of the discharge pipe to the pipe leading to the septic system.
Mount the sewer ejector system's vent, if it is so equipped, using the manufacturer's ventilation instructions. Not all ejector systems use a vent. Some ejector systems use a vent piped directly to the outside of the building and others use a manufacturer-supplied air-admittance-valve, sometimes called an AAV, for ventilation. The AAV allows air to enter the basin but will not allow odors or sewer gases out.
Plug the sewer ejector system's electrical cord into a 120-volt wall receptacle.
Open the basin's manhole cover. Pour clean water into the basin until the pump's float starts the ejector pump. If the pump starts before the water level reaches the manufacturer-suggested level, raise the float. If the pump starts after the water level passes the manufacturer-suggested level, lower the float. Replace the manhole cover.