When wastewater enters your solid waste tank, it is normally divided into three parts. Solid waste sinks to the bottom of the tank, where bacteria in the tank breaks down the solid matter, turning it into sludge. The middle layer of waste is mostly water, whilst fats and oils drift for the top of the tank, forming scum. Once solid waste is damaged down into sludge, the law of gravity moves the water through sloped pipes down in the drainfield, where that is distributed in to the ground.
Repair job and replacements can just be performed once a septic tank have been emptied. De-sludging or emptying a septic tank must be taken out every 12 weeks to 2 years, depending on the size of the tank and usage. In case your septic tank has sustained a crack, groundwater can often flood the system which usually will fill the solid waste tank at a faster rate.
As the on-lot sewage disposal system is used, sludge and scum continue to accumulate in the septic tank. Properly sized solid waste tanks (see Table 1) are large enough to safely store up to about three years of sludge and scum (see Box 1). As the tank volume filled with sludge and scum increases, wastewater is definitely retained in the tank for much less time and the solids removal process becomes less effective. If a lot of sludge accumulates, large amounts from the wastewater's solids will movement to the soil absorption field causing system failure (especially from older reservoirs which in turn not have exit filters. To prevent this, the tank need to be pumped periodically. The material pumped is called septage.
Waste that is certainly not decomposed by the anaerobic digestion must eventually end up being removed from the solid waste tank. Otherwise the solid waste tank fills up and wastewater containing undecomposed materials discharges directly to the drainage field. Not only are these claims detrimental for the environment however if the sludge overflows the septic tank into the leach field, it may clog up the leach field piping or decrease the dirt porosity itself, requiring costly repairs.