The In’s and Out’s of How a Septic Tank System Works

posted in: Blog | 0


In rural areas where houses are spaced so far apart that a sewer system would be too expensive to install, homeowners have septic tanks instead. A septic tank is simply a large concrete or steel tank that is buried in the yard. Your tank may hold up to 1,000 gallons of water. If your home has a septic tank, and it is your first experience with one, you may have a lot of questions about how exactly a septic tank system works. Basically, wastewater flows into the tank at one end and leaves the tank at the other. Below is a diagram:

A: Wastewater In
B: Scum Layer
C: Water
D: Sludge Layer
E: To Drain Field

There are three layers to your septic system. Wastewater comes into the septic tank from the sewer pipes in the house (A). Anything that floats rises to the top and forms the scum layer (B). Anything heavier than water doesn’t float but instead sinks to form the sludge layer (D). In the middle is a relatively clear water layer. This body of water contains bacteria and chemicals like nitrogen and phosphorous that act as fertilizers. As new water enters the tank, it displaces the water that’s already there. This water flows out of your septic tank and into your drain field (E). A drain field is made of perforated pipes buried in trenches filled with gravel.

Overhead, your entire unit looks like this:

A: Your Home
B: Septic Tank
C: Distribution Box
D: Drainfields

A septic system is normally powered by nothing but gravity! Water flows down from the house (A) to the tank (B), and down from the tank through the distribution box (C) to the drainfield (D). It is a completely passive system, not needing any sort of motor or electricity to power it at all.

A septic tank can be pretty easy to understand, but it doesn’t mean you should try to fix or maintain it on your own. Trying to do any work on your septic tank without a professional can end up costing you big in the future. If you’re looking for a professional to perform regularly scheduled maintenance or need the tank to be pumped out, Diversified Plumbing can help. We specialize in septic tanks, servicing all of Southwest Florida. Call today for a free estimate!