Drain Fields

How Your Drain Field Works & What to Do When it Doesn’t

Not all septic systems rely on a leach field, but the wastewater they release always has to go somewhere. However, the most common option today is a leach field, which may also be called a drain field, septic field, septic drain field, and a few other terms. They all refer to the same thing- an open area for the water to go. Other common alternatives include pits or graywater recycling systems. At Ms. Rooter Septic Atlanta, our partner technicians are familiar with all the popular systems, as well as with those that aren’t.

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Precursor to Understanding a Septic Drain Field

Before we get into how the septic tank drain field works, it’s important to understand how the whole system works together. When wastewater enters the tank, it divides into three layers. The “sludge” sinks to the bottom of the tank. This is the solid waste and heavy particles, such as soap residue. The lighter things, such as fat, oil, and toilet paper, float to the top and create a layer called “scum.” In the middle sits the “effluent” or liquid. The bacteria that enters with the waste digests the organic material and pathogens and helps clear out the water. As the level of the tank rises, the effluent leaves the tank and heads to the drain field.

How the Drain Field Works

The septic drain field consists of a series of drain lines and it tends to cover a fairly expansive space. The lines are laid out in a pre-dug bed, which is then filled in with gravel or a similar material. The lines, themselves, are full of tiny holes that allow the water to leak out, and by placing the gravel right next to it, it’s able to evenly disperse and be soaked up by the soil. At this point, the effluent still has some organic matter and pathogens in it, but Mother Nature deals with it. In this case, it’s the bacteria that naturally exists in the top layers of the soil that finish the job. However, the lines and the field will also develop a layer of biomat. This is good and expected. It slows the flow of effluent, so the pathogens have more time to be taken care of.

Signs a Drain Field is Failing

There are a number of ways a drain field can fail. If the sludge isn’t pumped out of the tank, it can breech the filter and seep into the lines of the septic leach field. Eventually, the opening and the lines will become so backed up that effluent cannot exit the tank properly and it will backup into the building. The biomat can also overwhelm a system and clog up all the holes in the lines. In this case, you may see a backup into the building or one of the lines will burst. It may show itself in an obvious flow or so much effluent will escape that the water pools on the ground above the drain field.

Contact Ms. Rooter for All Your Drain Field Needs

Our expert employees at Ms. Rooter Septic handle every aspect of a drain field, from initial designs and installation, to repairs, maintenance, and replacements. If you need help with yours, call us at

(470) 999-7668 to book an appointment.