The job of a septic tank is to separate the waste water into three separate layers. Trapping the solids and greases inside the tank and only allowing the liquid effluent to leave the tank.
This settling is done through biological activities and retention. If your tank is not settling out into these three layers, something is not right and your tank is not working as it should.
Lets look at the layers:
- Scum – is the top layer and is made up of fats oils and greases.
- Effluent – is the middle section. The tanks outlet T is designed to allow this water and this water only to exit the tank and move on to the absorption field. (Holding tanks do not have an outlet.)
- Sludge – accumulates on the bottom of the tank.
The tank should be pumped when the sludge + the scum layer = 25% to 33% of the liquid depth of the tank. Never pumping your tank allows the sludge and scum to build up to unhealthy levels. Excessive sludge build up will render the tank useless and allow all waste water to bypass the tank, going out into your field system and wreaking havoc.
Have all your sludge and scum removed when it is time.
So for example if your tank is holding 4 foot of water and you have 1 foot of sludge, you would be right at the edge of needing to have that tank pumped.
Having your tank pumped on a regular schedule will keep from excessive sludge build up. Contact us for an estimate on a schedule that will work best for your particular tanks setup.