Grinder pumps cost much more than effluent pumps. Both have issues with lightening damage especially if not grounded etc. The topography of the site will determine your best option.

A second tank at the half bath discharging into the same effluent disposal field is the cheapest option. Local HD may require both tanks to discharge into a distribution box. You could also set a tank with effluent pump if gravity flow is not possible. Third option would be a grinder pump and vault discharging into line ahead of first tank.

Pump control circuit and high water alarm should be on separate breakers.


"Cull" is just another four letter word...