Septic Lesson#1 How a Septic System Works

In this video I'm going to show you how a septic system works

This is the tank, part one of the system. There's something called a leaching bed that I'm going to

be talking to you about in a minute. But this is a standard concrete septic tank of the usual sort

And here we have the inlet, the sewage inlet from the house. This is usually a four inch diameter

PVC pipe. And the sewage first comes into this first chamber here. There's a dividing wall

between the two chambers and at least a couple of holes part way up that wall

When the sewage level rises to the point of those holes then it spills out into the second part of

the chamber here. And eventually after several days use we have the sewage rising to this level

here and eventually going out into the weeping bed. Now you might wonder why there are two halves

to this septic tank. The odd tank doesn't have two. The very old ones don't and some have more than

two. But by far the standard is two compartments. And the reason for that is because not all of the

sewage that comes in, not all of the solids in that sewage, is digestible. The vast majority of it gets

liquefied and eventually with the water goes into the second part of the chamber. But the indigestible

bits, the system is designed so that they settle out into the bottom here. Because the ultimate goal

is to only have liquid going from the septic tank to the leaching bed. We don't want solids going

out there for reasons that I'll explain. And this two-part arrangement is designed to prevent that

salt the solids from moving out there. Now there should never be any solids in the second part of

the tank. And the way that you can ensure against that is by having your tank pumped out

oh every two or three years. Certainly no less often than every three years. And the reason is

because this the solid sludge here continually builds up. The level of it is constantly getting

higher and eventually as time goes on this the storage capacity of the liquid in this first half

of the tank will decline to the point where insufficient digestion is happening here

If things get even worse then we have some solid sludge making its way to this second half of the

tank. And that's what you see here. That shouldn't be the case. But eventually if things really get

out of hand solids will make their way to the leaching bed and that's a problem. Now a couple

of other things I want to point out to you here just at the beginning. These are access hatches

to the tank and traditionally they've been just buried underground. So every time you want to have

the septic tank pumped you've got to dig down find them open them up and then when the pumping is

over replace them and put some dirt back on and re-establish the grass. And that's kind of a pain

and it's something of a discouragement for having your tank pumped out. So later in the course I'm

going to show you how to make very easy access to these hatches so the job of calling in the

pump-out truck is as easy as possible. That's it for the tank for now. Let's go and take a look at

the leaching bed. So here we have the second part of any standard septic system. The liquid sewage

partially digested is coming from the tank here. So the tank is, imagine the tank to the left

the liquid sewage, no solids, is coming through here and eventually makes its way to these pipes

with holes in them. Now this is a cutaway drawing so normally you'd just see grass here. You're not

going to see any of this stuff but what we have are pipes with holes in them. The holes are about

three quarters of an inch in diameter and the idea is to allow the partially digested

sewage water to leach out of the holes into the surrounding soil. Now when this leaching bed was

built some looser material was intentionally put around the pipes in order to allow that

sewage to flow out. Sometimes, but not always, that's surrounded by some sort of landscape fabric

in order to stop fine particles of the native soil from percolating into this lighter stuff

and plugging things up. When a septic system has trouble it's almost always because

the pipes and the soil around the pipes has lost its ability to allow sewage to percolate out

About 90% of the purification created by a septic system happens here in the soil and in this loose

dirt and these chunks of rock here. That's where the biological activity goes on and the real

purification happens. But these holes and the soil around the pipes are in danger of becoming plugged

and that's what causes septic systems to back up most often. So this course is mostly about

clearing up this problem without hiring expensive help and digging out your whole leaching bed

and rebuilding it