An aerobic septic system pumps oxygen into the septic tank to speed up how quickly the bacteria in the tank break down the waste that enters. They're designed to completely treat waste before it leaves the septic system.
Conventional septic systems don't fully treat waste, so they discharge wastewater into a large underground drainfield where the soil bacteria continue to break it down. With an aerobic system, on the other hand, you can safely discharge the wastewater above ground.
While an aerobic septic system is more expensive, it's the only choice for certain properties. To find out when you may need to install an aerobic septic system instead of a conventional one, read on.
Your Property Is Too Small to Support a Drainfield
One of the most common reasons why it's necessary to install an aerobic septic system is when the property is too small for a drainfield. Part of septic system installation is making sure that the drainfield is large enough.
All of the wastewater exiting the septic tank needs to be spread around a large area by a network of pipes in the drainfield. If the drainfield is too small, it will quickly become waterlogged because of the large volume of wastewater being discharged into it. Once the soil in the drainfield is fully saturated, wastewater will no longer drain into it, and your septic system will start to back up inside your home. An aerobic septic system doesn't require a drainfield, making it suitable to use on small properties.
Your Live in an Area With a High Water Table
If you live in an area that has a very high water table, even if it's only during the rainy season, then you'll most likely need an aerobic septic system. If the water table rises close to the level of the pipes in the drainfield, it will saturate the soil and turn it into mud. Wastewater won't drain into the soil anymore, and the high water table will eventually start pushing it up onto the surface. This is another issue you can avoid by installing an aerobic septic system instead.
Your Have Shallow Bedrock Underneath Your Land
If the bedrock underneath your soil is very close to the surface, you may also need an aerobic septic system. Conventional septic drainfields work by allowing the discharged wastewater to percolate down slowly through the soil. If there's bedrock right underneath it, it won't have anywhere to drain.
Letting the wastewater drain through the soil also gives the soil bacteria a chance to process it and remove pathogens. Bedrock sometimes has small cracks that can allow bacteria-containing wastewater through it into the local aquifer, where it can end up in nearby wells.
If your property is small, has a high water table, or is situated over shallow bedrock, installing a conventional septic system with a drainfield may not be possible. You'll need to install an aerobic system instead. Contact a septic system installation service in your area and have them survey your land to determine if there's a suitable location for a drainfield. If there's not, ask them about having an aerobic septic system installed so that you can completely treat all of the wastewater while it's in the septic system and don't have to rely on a drainfield.