One of the rules of plumbing is waste runs downhill. Except for when it doesnt! Sometimes in plumbing you just dont have the fall for your sewer and you need waste to go uphill. Thats where the sewer pump comes in. Sewer pumps, lift stations, grinder pumps, sump pumps, etc. are all very similar in nature. Check this video out to learn more about how a plumbing sewer pump works.