If you are installing a new system or upgrading an existing one with a new tank, a
two-compartment tank offers several advantages. The vertical wall positioned
about two-thirds from the tank inlet helps trap solids more effectively and offers
better protection of the drainfield. The larger size – generally 1500 gallons vs.
1000 gallons for a single compartment tank – means less frequent pump-outs.
Two-compartment septic tanks require only slightly more space than single compartment tanks, but they do cost a little more initially. For most homeowners, this
cost difference is more than outweighed by long-term savings in pump-out and
extra protection to the drainfield.
Some towns believe so strongly in the risk prevention offered by two-compartment tanks that they require all new systems to use them, so check with your
local town hall.
Why You Should Consider Installing a Dual Compartment Septic Tank
Septic tanks play an essential role in wastewater treatment for properties that aren’t connected to a municipal sewage system. When wastewater leaves a home, it goes into the tank where solids are separated, broken down, and stored before the effluent flows out to the drainfield. Traditionally, septic systems have been constructed with single compartment tanks, but it has become increasingly popular to use a dual compartment tank. Below is some insight into why this is beneficial.
Better Solids Removal & Improved Effluent Quality
In single compartment septic tanks, there is still a good chance for solids that haven’t fully decomposed to spill out into the drainfield. Having a second compartment provides an extra treatment area to settle solids and break down more of the waste. The vertical wall is positioned in a way that helps to trap solids more effectively, thus, allowing for clearer effluent flow and better protection of the drainfield.
A dual compartment septic tank will hold substantially more wastewater than one with only a single compartment. This means it won’t need to be pumped as often, which will reduce maintenance costs. Also, without the additional space for solids to go through another purification process, the overflow of contaminated effluent will eventually cause drainfield plugging and failure. In turn, property owners may end up with high cleanup and repair expenses.