Imagine yourself at McDonalds drinking a soda from a straw. If you put your thumb over the straw, you can pull liquid up from the cup. When liquid goes down a pipe, air needs to follow it. A waste and vent system should keep sewer gas out of the dwelling and drain every fixture well. A. A sewer ejector pump is the answer.
Kits come with the sump basin, sewer ejector pump, check-valve.
The waster line is run into the sump basin, pumped through a checkvalve into the sewer line that grades with gravity. If you add a high water alarm, which is a good idea. The check valve makes sure, that what you pump out, stays out. Otherwise the pump will keep cycling. Plumbing codes call for a gap between potable water and a drain.