Any water that is used within a home travels through the homes main sewer line. The main sewer line will run outside the home and connects into a septic tank(s). Once wastewater enters the septic tank a separation process begins and should last a minimum of forty eight hours. This process allows for wastewater to be seperated into three different layers. All heavier solids will sink to the bottom of the septic tank known as the sludge layer. Fats, grease, oil, and any lighter debris will float to the top of the septic tank known as the scum layer. This leaves a layer in the middle of the tank that is the remaining water, also known as the clear or effluent layer. Once this separation is complete the effluent is able to leave the septic tank and continue on to the leach field. The effluent layer should be the only layer leaving the septic tank and being absorbed into the leach field. The scum and sludge layers will continue to accumulate as the years pass and it is imperative that homeowners have their septic tank pumped out every 3-5 years. The purpose of a septic tank pumping is to remove all sludge and scum before it accumulates to the point that those contaminants are able to exit the septic tank and enter into the leach field. If allowed to enter the leach field the sludge and scum will clog the pores of the soil in the leach field and inhibit the field from absorbing effluent efficiently. Once the leach field fails to absorb effluent it will have to be replaced.

Under normal operation, once the effluent leaves the septic tank it will then be processed in the leach field. The responsibility of the leach field is to finalize the treatment of wastewater. The soil contains natural bacteria that consumes the harmful pathogens that live in the effluent, purifying the water as it is absorbed into the soil. The water will continue to make its way through the ground layers until it eventually returns back to the water table for re-use. Leach fields are not designed identically because not all soil has the same capacity for treating wastewater. The type and size of a leach field will be determined based on the soil present to make sure all wastewater is treated efficiently. The bacteria within the soil that is responsible for removing harmful pathogens in wastewater are heavily dependent on oxygen being present in the soil. In order to maximize the life of a leach field, it is important that homeowners avoid compacting their field with vehicles, equipment, or even animal traffic.