A sewer cleanout is a sewer pipe that gives you access to your home's sewer line. Should a backup occur, getting to a sewer cleanout quickly can save you money and reduce the damage from an overflow inside your house. So, it's critical for maintaining your connection to your sewer system.
To make sure they are easily accessible, sometimes a builder will install a sewer cleanout above grade. Sometimes that's because of a local law on how high above ground a sewer cleanout has to be.
But a sewer cleanout that is above ground has its own set of problems. Luckily, I've found a pretty easy and cheap solution.