If you put a new building on a hilltop, the need for a sewage lift station may be the last thing you would expect. However, if you discover that the plumbing waste pipe leaving the building is below the end of the previously installed outside sewer pipe that goes to a newly constructed septic system, you may realize that gravity acting alone will not get the sewage into the septic tank. A sewage lift station – purchased through a change order – may be the most economical way to get the sewage to its intended destination.
It would be better, if possible, for the engineers to coordinate their work so that the inside pipe and the outside pipe would meet at the same elevation. Apparently, someone did not understand that plumbing waste lines below the floor inside a building usually slope to drain, and that a run of a few hundred feet inside the building could put the waste pipe outlet several feet below the floor level, not just one foot, as suggested by the elevation at the end of the outside sewer pipe.
The person who presented the change order to the owner may have explained that it would be better to have a lift station, because you can’t always count on gravity.