How do people get rid of buildup inside a septic tank?
Septic tanks are usually emptied with the help of waste removal tankers operated by licensed professionals. Most areas of the world require special licenses for people doing this kind of work, which reflects how important it is to make sure this kind of waste is removed and managed properly. A business offering septic tank emptying Norfolk services in the UK, for example, will need a wide variety of licenses, as this website shows: https://www.fes247.co.uk/.
If you’re wondering what happens to the sludge after removal, that depends on local regulations. But typically, the waste from septic tanks is processed by water treatment plants. I guess that sludge is not that different from the sewage those plants handle every day.
It’s also worth noting that some build-up inside a septic tank is not necessarily a problem. It is only a problem if the build-up is getting close to the point where the tank may overflow or if the build-up is clogging the tank. If you’re not sure how full your tank is, call for an inspection.