When it comes to septic systems, the kind of soil you have in your backyard can make a world of difference. The soil plays a vital role in the waste treatment process, acting as a natural filter to remove harmful bacteria and viruses from wastewater before it re-enters the groundwater. But not all soils are created equal.
According to the EPA, Septic systems consist of two primary components: the septic tank and the drain field. While the tank holds wastewater allowing solids to settle, it’s the drain field, or leach field, that does the heavy lifting of waste treatment. The wastewater trickles out from the tank into the drain field, where the soil takes over to filter and treat the wastewater.
The ideal soil for a septic system is sandy or loamy soil. These soil types have the right texture and particle size to allow water to flow freely, yet slow enough for the soil to treat the wastewater effectively.
Sandy soil is excellent for septic systems because of its large particle size and low capacity to retain water. This allows wastewater to move through it quickly, preventing the drain field from becoming waterlogged.
Loamy soil is a balanced mixture of sand, silt, and clay. It provides an optimal environment for the bacterial activity necessary for wastewater treatment. Loamy soils also have good water flow characteristics, which is crucial for a functioning septic system.
On the other end of the spectrum, clay and silt soils can be problematic for septic systems.
Clay has the smallest particle size of all soil types, leading to poor drainage. This can cause wastewater to back up into the septic tank, or worse, your home.
Silt, while having slightly larger particles than clay, still retains water too well, leading to poor drainage and potential septic system issues.
When faced with less-than-ideal soil conditions, different types of septic systems can help:
