Wastewater is a reusable resource. It can be treated and recycled back into groundwater. This article takes a look at the wastewater system and answers the question, How do I choose an appropriate onsite wastewater system?

Cities and towns use a central wastewater system. On the other hand, in smaller communities or homes separated away from the city, the onsite wastewater system must be used. First, take a look at your land. Is your land hilly or flat as in the plains? Second, is your property located near rivers or lakes? Third, what kind of soil is your property on?

Onsite wastewater systems are made up of a septic tank, a treatment unit, a filter, and a dispersal unit. Some systems may combine the treatment unit with the filter unit. Picture a pit latrine or outhouse. The hole in the pit is a septic tank. If there is a ventilation pipe that is put into the pit, it allows for air to flow out of the pit. The bad odor is transported out of the pit through heat convection during summer.

In winter, the excreta get frozen. In this case, inside the pit, wastewater is filtered out through the sand into the surrounding soil. The sand acts as a filter and a natural dispersal unit. The treatment takes place naturally in the pit with bacteria but it is not efficient. This system can still be used until the pit is full. The pit is covered up and a new one dug and the cycle repeats.

The only thing bad about this is if there is a river or lake nearby, the effluents from the pit latrine will contaminate the river or existing well water. This system would probably be used in cabins or in a remote location.

The other more common type of onsite wastewater system is the one which uses the flush latrine located within the home. The wastewater flows into a septic tank, out into an aerobic treatment unit (ATU) and a gravity effluent distribution device. The septic tank is a watertight covered container. The sewage comes from the sewage pipe running from the flush latrine. The septic tank is normally placed underground.

As the wastewater goes into the tank, solids and liquids are separated through gravity. Solids sink and become sludge while fat and grease float. In between is a clearer layer of effluence which flows out of the septic tank into the ATU. In the ATU, air is mixed into the wastewater and aerobic bacteria break down and remove the solids. The wastewater flows into the effluent distribution device through gravity. Here, sand or peat can be used as filters. As the wastewater goes through the sand, particles are trapped and clearer water is obtained. The wastewater is then dispersed to the surrounding soil.

So, it really depends on your locality and what type of home you are staying in. The above should help answer the question nagging you, How do I choose an appropriate onsite wastewater system?