Is any of the following happening at your house?
Puddles forming in your backyard may be a sign of drain field failure. The soil may have turned into a hardpan and stopped absorbing water, which causes the puddles.
Septic odors in your backyard may be a sign of drain field problems. Without proper drainage, wastewater may collect in the field and release odors. This is a sign for a maintenance check.
Water backing up into your house may be a sign of drain field failure. Wastewater from the house normally moves to the septic tank. If the field is not accepting more water, the wastewater backs up into your house.