Do you have a sump pump in your home? What is it connected to? If it kicks on when you run the laundry or flush a below-grade toilet, you may have an ejector pump. These pumps are used when the appliances that create dirty water are positioned lower than the main sewer line leaving the house. Ejector pumps are very common with septic systems.
Ejector pumps look similar to sump pumps and function in a very similar way; the big difference is the water they output. Any ejector pumps need to be connected to the sanitary sewer where they can discharge water from sinks, washing machines, and basement toilets. Sump pumps put out clean water which needs to be discharged into your lawn or the storm sewer system. This frees up valuable space in the sanitary sewer pipes for dirty water and reduces your chances for a sewer backup in your home.