Types of Septic Systems for Your Home

If you live outside of a major urban area, you might not be able to hook up to city sewage. In that case, you will need an Onsite Waste Management System (OWTS), better known as a Septic System. A Septic System is your own wastewater treatment plant but on a significantly smaller scale. These systems typically consist of tanks that collect the waste and leach fields or seepage pits for the disposal of liquids. Which type of system you need depends on a few factors- your site’s topography and the amount of waste the system needs to handle on a regular daily basis.

Below are some of the common types of septic systems and what sites they work well with.

Conventional Septic System

The heart of a conventional septic system is the septic tank. Wastewater from the house flows into the tank through an inlet. Scum stays at the top, while waste solids remain at the bottom of the tank. What remains is called effluent, which is still characterized as waste. As the effluent rises, it goes through a filter and gets pumped through an outlet.

The outlet leads to a drainfield, which consists of perforated pipes resting on a bed of gravel. The pipes are between one to three feet below the surface. The water percolates through the gravel, which treats the water. It then soaks into the soil below, which further purifies the water with bacteria before the water returns to the groundwater.

Chamber Septic System

The chamber system uses many of the same principles as a conventional system. However, the trenches don't get filled with gravel and perforated pipes. Instead, they install leaching chambers, which consist of a solid top and louvered sides to allow access to the soil. We then cover the chambers in soil.

The leaching chambers store the effluent while the soil leaches the waste portion of the water. The louvered sides allow microbes in the soil to treat the effluent. The bottom of the chamber is open, so the water then sinks into the regular soil, where it's further treated before entering the groundwater. Chamber systems work better than conventional ones in areas with high water tables.

Aerobic Septic System

An aerobic system starts with a different tank than with the above two systems. The aerobic treatment unit consists of one or two chambers and features an inlet and outlet. However, the big difference is it also includes pipes that jet oxygen into the effluent. The oxygen encourages the growth of bacteria that quickly break down the solids. Some solids still sink to the bottom.

You can piggyback the aerobic treatment unit to other forms of waste treatment. The advantage of an aerobic system is it doesn't require as large of a drainfield, which is ideal for smaller lots. It's also suitable when local regulations are tight on what wastes a septic tank can release into the soil.

Sand Filter Septic System

The recirculating sand filter system adds an additional step to wastewater treatment. Contractors have to install a pump tank after the septic tank or aerobic unit. The filter is essentially a big box filled with sand material.  The pump tank sends the effluent through perforated pipes at the top of the sand filter.

The effluent percolates through the sand, which treats it. The water then returns to the pump tank for redistribution to the drainfield. Conversely, some sand filters are bottomless. In that case, the water soaks into the drainfield directly from the filter. This system is an option for sites with high water tables or close proximity to a body of water.

Mound Septic Systems

A mound system starts with the same septic tank or aerobic unit as the other systems. However, the effluent isn't released into a drainfield. Instead, it enters a mound that serves the same purpose. Mound systems work on a gravity flow principle.

We set up a mound of sand and gravel covered in topsoil. The water is dispersed from a perforated pipe above the gravel and sand field. The effluent percolates through the sand and gravel, which treats it. The water sinks through the soil and is cleansed further before it enters the groundwater. Mound systems are for lots with high groundwater or shallow soil.

Talk to the experts at Hastings Construction Inc., about which of the above Onsite Wastewater Treatment Systems is right for your home.