The sump pump protects your home from groundwater forcing its way down through the soil into that hole in the ground we call a basement. A drain tile system below the basement floor will channel water into the sump pump basket. When the water level hits the float in the sump basket, the sump pump lifts this water to the surface outside or into an underground storm sewer pipe that drains away from your home.
The sump pump and drainage system is separate from the sanitary sewer system that drains waste water from your home to the septic system or to a sanitary sewer treatment plant. Your sump pump should not discharge to the sanitary sewer.
During the home inspection, a home inspector will look for indication of water in the sump basket, and will test that the sump pump operates. Test your sump pump every few months. Start the pump by adding water to the sump basket or by lifting the float. The pump should start when the water is 8 to 12 inches below the basement floor slab. The water in the sump basket should be clear, without roots or debris. Watch to be sure the pump removes water from the crock.
The pump may have a float on the end of a rod or wire. Be sure the float operates easily and can't rub against the sump basket or the cover. If the float sticks, the pump will not run, and your basement could have some flooding.
If the pump is older and worn, rusty, or noisy, it should be replaced. The pump should be securely mounted in the sump basket. The power supply should be from an outlet, not an extension cord, and the plug should be securely fastened to the outlet.
If the pump runs more than several times per day or runs often during heavy rain, you should have a spare pump or even a second pump mounted in the sump basket. The second pump could have a float set for a higher water level so that the second pump only runs if the first pump fails. If you live in an area in Southeastern MN where the electrical power fails during storms, I would consider a battery backup for the pump system.
You might also want to consider installing an alarm that will alert you if the sump pump fails. This could save considerable damage from flooding that could result from this failure. Options range from expensive home alarm systems to a simple battery-operated water alarm. You can pick up a water alarm at your locat building supply center.
The Water Detector is a palm-sized unit operated by a 9-volt battery. When in contact with water, it continuously emits an alarm for up to 72 hours. The unit will float and continue to sound an alarm during a flood.