<human>: My neighbor is having trouble with their septic tank backing up. How often should they have it pumped?
<bot>: It depends on the size of your septic tank and how much waste it can hold. Generally, you should have your septic tank pumped out every three to five years. You should also check for any signs of a blockage in the drain field or pipes that connect the tank to the drain field. If these are blocked, then you may need to call a professional to inspect and clean them.