What happens to solids that accumulate in a septic tank if not pumped out regularly?

When solids accumulate in a septic tank and are not pumped out regularly, they create sludge accumulation. In a septic system, the tank serves to separate solids from liquids. Over time, organic solids decompose to some extent, but this process is limited. If the tank is not pumped out on a routine basis, the buildup of solids will exceed the tank's designed capacity.

As sludge accumulates, it may rise toward the outlet, which can lead to several problems. The solids can block the outlet baffle, preventing wastewater from flowing into the drain field effectively. This can result in backups, where wastewater may even start to surface in the yard or back up into the home. Regular pumping is essential to remove this sludge accumulation to maintain the system's function and prevent costly repairs or environmental issues.