The Expert Podcast

So one of our other videos we had a question about septic tanks and maintenance and how often should you pump out a tank. And you may have lived in your house for many years and never had to pump it out or never seen it pumped out. But we're going to talk about why that happens, and why it's important to do that, and maybe why you should do it sooner than later.

Here's an example of a cross-section of a septic tank. If you have a septic system, you have something like this buried in your yard, usually made out of concrete. Sometimes fiberglass. Older ones may have been metal. And what happens is you have a pipe coming in from your house with all of the drain lines from your house—every bathroom, kitchen sink, everything with plumbing that exits your house comes into this. And it goes into this tank.

Once it goes into the tank, it's mostly water that comes into the tank. But there are some other substances that are in the various outlets of your home—sewage, oils, that kind of thing. And when it goes into the tank, it's designed to let those settle out. Once it goes into the tank, things that are heavier—sludge or solids—go to the bottom. Things that are lighter, like oils or soaps, float to the top. And if you notice, this inlet drops it into the middle, and the outlet takes the liquid from the center of the tank and goes out to the drain field. And the height of this pipe is set by the code—it has to be a certain distance below the top and a certain distance above the bottom.

And because of that, what mostly goes into this tank is water. It just comes in and it goes out to the drain field. And the drain field is a series of pipes that are underground in your yard with holes in them. So when the water goes out into your yard, usually buried two, three, four feet depending on the type of soil, the water just simply leaches out into your yard underground as water. Basically, it's free water for your yard.

Now you don't have to worry. There are, you know, bacteria and things in that water—it's not solids or anything that's a substance. But by the time that water ever gets to the surface or into your well, those bacterias are long gone. Because it takes a while to get through this tank and the drain field. The natural aerobic and anaerobic processes deteriorate those bacteria, so that's not an issue. That's why the drain field has to be a certain distance away from certain things like wells or rivers or underground or your house. But anyways, so this is how a normal septic tank works.

The amount of solids builds up very slowly over time. Believe it or not, there's very little that builds up, and the scum or oil on top doesn't accumulate that fast either. Now what happens if you get too much of one or the other?

Well, here's a picture of a tank where the sludge has built up from the bottom and the scum from the top. If you have either one of those layers get to the edge of the inlet or outlet, one of two things can happen—they're both bad. If you have, let's say, the solids build up to where it reaches the outlet, you're going to start having solids go to your drain field. That would not be good because now you have the solids that are in your sewage—you can imagine what that is—going out into your yard. And not only will it go out into these tubes, but these tubes are designed to flow water through them. They have very small little holes. If they're solids, it's going to clog the holes, start backing up, and start not only going into the ground but start popping up through the surface of your yard.

If you can imagine the things that are solid in your sewer system start to pop up through your grass—that's what would happen. That's not good. So you want to not let this sludge build up too much. On the other hand, if it builds up and blocks the inlet—sometimes it'll build up on one end versus another—now what you try to remove from your house into the septic system cannot get into the tank. It'll start backing up into your house.

Again, all of the things that you're putting into drains—bathroom fixtures, what have you—instead of going out of your house into the septic system, start to back up into your house. Coming in through, let's say, sink drains, some coming back up through your shower drain or your tub drain. You don't want that to happen either. So not letting this solid build-up is a good thing to make sure of.

Same thing with the scum on the top. If you have oils or detergents or soaps that build up over time, they can start to build a large layer that blocks these entrances. If you start having those soaps or oils block your exit to your drain field, it can have the same effect—where you start backing up into your house.

So how do you prevent that? Well, on a regular basis, you have a company come to your house. And there's a cover—an access port—on your tank. Sometimes it's underground, sometimes it's at the surface. And they open that up and they basically put in a big vacuum like a pump, and they put a hose in and they drain out all the sludge, all the scum, and they empty your tank. Usually, they'll pressure wash the sides too so they can clean it out. They may have a brush that they scrape out things. So now your tank is starting over again.

Because this tank accumulation takes different amounts of time. Look, if you are a single person living in a three-bedroom home that has a large septic system and you don't use your facilities that often, it may take five years, ten years for this to accumulate. If you're a large family living in a two-bedroom home and have five people living in the house and use the facilities often, you may build this up faster—you may only last two years.

So as a good rule of thumb for normal use, if you have your system inspected at least every two, three years—and if it needs to be pumped, go ahead and pump it. In fact, there's no harm in pumping it sooner. You don't need this stuff in there.

How much does it cost? It might cost three or four hundred dollars to pump out your tank in most parts of the country. And by not letting it even get close, you keep your drain field healthier. Even if the sludge or the scum gets close to this entrance, more little bits will start to filter in. The farther you keep either one of these layers away from the outlet, the better.

Because even if the sludge isn't blocking it, if this sludge layer gets even close to it, you may get little bits and pieces of things that go into your drain field and block one or two of the holes—or three of the holes. Or if you get some of the oil or scum from the top that just starts to drift down and get into here, that may start blocking up your drain field.

So if you do it early, that's a good thing. It costs a few hundred bucks. It's not a huge amount of money. And it'll keep your system healthier. Because if this drain field—these pipes that you see here—become clogged or this drain field fails, now what you have to do is you have to dig a new drain field.

You can't repair the old one because the dirt that's around this is very sensitive. So what you'd have to do is find another part of your yard, dig out another drain field—it might be 50 by 50 feet—dig it up, put in new lines, connect it to the tank. So now you have a torn-up part of your yard. You have the expense of digging a new drain field, which can be thousands of dollars—sometimes ten thousand dollars.

Where if you're very careful about managing your system—few hundred dollars every few years—you can avoid ruining this drain field, which is a very delicate system. Even though it's just pipes, the flow of the effluent, they call it, is an important thing. Yeah, this is not a sexy subject to talk about, but as a builder, we see this a lot.

You don't want to use up your yard space unnecessarily for a repair on your drain field. So pumping it out sooner will help you because you also don't want to replace the tank. If the tank gets too deteriorated, you might have to replace that. You're gonna have to pump it out anyways at some point. So whether you do it this year for a few hundred bucks or two years from now for a few hundred bucks, you're not really saving money. You're just doing it a little bit earlier, maybe a little bit more frequent. And that extra couple hundred dollars of expense every couple years can help save your drain field.

So before you think you need it, have it checked out. Even if it's close, just go ahead and pump it. Clean it out. Doesn't hurt anything, and it can save you in the long run some expensive repairs. And if you ever decide to sell your house, you can show that receipt that it was done recently.

And also, you can catch problems. If there's a crack or some type of damage or something with the inlet, you can get that fixed. There's also what's called a clean out here—that is a way to keep this inlet pipe clear so it doesn't have any obstructions. That may be sometimes where you get backups in your sink or your toilets don't flush that fast—that might be part of your clean out.

Again, it's not a sexy subject to talk about, but this system is one of the most important systems in your house. Think about it: if your power goes out for three days, you can still survive—you have a generator, you light candles. If your water goes out for a few days, we can go to the store and buy jugs of water. If your septic system fails, how long can you live in your house before it's a problem? Shorter.

So you want to keep the system good. Even though it's out of sight, out of mind, and not something you want to think about every day, it's an important part of your domestic utilities, and you want to keep it good.

Let us know what you think in the comments.