Home septic systems aren’t as popular as they used to be, but there are still a lot of them. They can be placed anywhere both in front of back yards and are usually more towards open areas.
Because of this, septic systems will be close to or where people want to put their above ground pools.
Since it takes up the biggest area of a septic system, the leaching or drain field is usually what gets in the way of where a homeowner wants to place an above ground pool. An above-ground pool should never be placed on top of the leaching/drain field. It should only come within a couple of feet of the edge of the drain field at its closest.
THE ANATOMY OF A HOME SEPTIC SYSTEM (So you know what to look for)
A septic system is an easy design and only comes with three main components – the tank, a distribution box, and a leaching or drain field.
The tank is where the household waste makes its first stop, so it’s usually the closest component to the home and is usually not in the way of where someone wants to put a pool.
Right next to the tank is the distribution box. After the waste hangs out in the tank for a while, its liquid form is ready to head out and be safely reintroduced into the earth. It does this by overflowing from the full tank and goes to the distribution box where it’s then decided on which part of the drain/leaching field it goes.
The distribution box is never a concern for a pool placement because it’s so close to the tank and usually between the tank and drain field.
The last and biggest part of a septic system is the leaching or drain field. This takes a big open area and has to be either elevated or close to the top of the earth and just under the sod.
This is where the house waste reconnects with nature and goes from being smelly and toxic to turning into healthy bacteria good for the earth. The drain field has to high up so there’s enough earth between it and any water table far below in the ground.
WHY AN ABOVE GROUND POOL CANNOT GO ON TOP OF A DRAIN FIELD
Just in case you didn’t already know, the septic system (including the drain field) is processing mainly human waste. This process, first off, is something that you don’t want to be next to as it’s nasty and toxic.
This process needs it’s space all the way around. It needs room to seep into the earth below and be unobstructed both on top and on the sides. It’s a natural process and needs nature all around it so it can work.
So, the weight of an above ground pool pressing down on the drain field isn’t the issue. Most drain fields will not be affected by the weight. It’s the covering of the top of the drain field environment that is the issue here.
You don’t want to obstruct the outward process of the waste in any direction, including the top.
Plus, when you know that a drain field is processing human waste, do you really want you and your family hanging around that area for any period of time (even if it’s buried)? Yeah, no.
SO, HOW CLOSE TO A LEACHING/DRAIN FIELD CAN YOU INSTALL AN ABOVE GROUND POOL?
To my knowledge, there is no absolute official distance for how close an above ground pool can be to a drain field. Certainly, out of the thousands of local governments existing in the US, there will be some local restrictions depending on where you live.
As an example of this, one municipality here in Central Florida requires an open distance around a leach field to be no less than three meters (around ten feet). This includes everything, so I’m sure an above ground pool is on the list.
As an above ground pool installer of 36 years and counting, I have seen and installed pools onto and very close to drain fields with little issue. Every yard is different and some don’t have the room to get their pool in, so they will elect to install directly next to their drain field.
Personally, the closest that I would install an above ground pool to a drain field is maybe two feet away from its very edge. What I mean by “edge” is where the drain field rocks begin and not the actual pipes or unit.
Now, if you are pulling a permit for your pool, then you may want to find out what your local building department says about this. Keep in mind that some building departments suffer from a case of “over-importance.” They will seem to look for an excuse to refuse you a permit. Depending on your situation, you may want to keep this septic location issue to yourself when dealing with them. You may not too. It’s up to you.
HOW TO LOCATE YOUR SEPTIC SYSTEM
Not all homeowners and renters are equal. You might be surprised to know how many times I’ve come across a septic system and the homeowner didn’t even know they had one, let alone where it was located.
So, first off, make sure you have a septic system. If your water bill is cheap, then you are not having to pay for sewerage and most likely have a septic tank somewhere in either the front or backyard.
The easiest and fastest way to know where the drain/leaching field of your septic system is in your yard is to look for a rectangle patch of grass that is greener and healthier than any other grass. If you have a rectangle of beautiful green grass surrounded by a normal or brown grass yard, then yeah, that’s where the drain field is doing its thing processing.
If you don’t see any green or healthy sign of a drain field, then it’s best to look for the clean-out plug coming out from the house somewhere.
The clean-out plug is part of the line coming from the house bathrooms and kitchen to the septic tank. It’s a plug that will allow you access to this important waste line leaving the home. This is usually something like a 4” PVC threaded plug just under the dirt and a foot or two away from the house’s exterior wall.
When you find this clean-out plug, you have found the line that goes to the septic tank. Now, locate the septic tank by following the line in the direction away from the house.
When you have found the septic tank, the drain field won’t be far away. Look at any open, clear areas close to the septic tank that could accommodate a drain field. This should be easy to find, but not always.
If you must, you will have to dig around the septic tank to find the line going out from it. You already found the line going in. It was the line between the house and the tank with the clean-out plug in it. The line going out will go to the distribution box. And once you find that, you can locate where the drain field is.
HOW TO TELL WHERE THE DRAIN FIELD BEGINS AND ENDS
Now that you know where the drain field is located! Or, you already knew from the bright green grass. You can locate its perimeter.
NOTE: Newer drain/leaching field designs don’t use and rocks or gravel around them. For the sake of this article though, l will assume that most septic systems in the way of or next to an above ground pool install site will have gravel.
Most drain fields use pea rock all around the drain field piping. This is where the drain field starts. The only real way to tell where the drain field starts is by digging down into the yard 6-10 inches in the area that you think the drain field begins.
When you dig into white gravel, then viola, you found the edge of the drain field. If you have a new type of drain field that doesn’t use rocks, then you have to dig to find the actual drain field chambers.
After finding either where the rocks begin or the edge of the new chamber type, you now know where you should not put your above ground pool. Mark the entire perimeter of the drain field with stakes or something that won’t wash away.
NOW THAT YOU HAVE MARKED THE DRAIN FIELD, KEEP THE POOL INSTALL AWAY AS MUCH AS YOU CAN
If you read above, then you know what is going on with that drain field. Keeping your above ground pool install away from it should be common sense.
“I would say even just a couple feet away from the edge of the drain field is ok, but some have to do what it takes to make a pool fit.”
INSTALLING A POOL ON AN OLD, UNUSED DRAIN FIELD
I have run into old drain fields when installing above ground pools more times than I want to remember. It’s a real pain in the ass to run into an old drain field. There will be tons of rocks in the earth. And you don’t want a bunch of rocks left in the earth under the pool’s liner.
Although it sucks when I run into an old drain field and have to either dig most of the rocks out or put a clean layer of earth over them, it perfectly ok.
Old drain fields usually haven’t been processing waste for years. So it’s fine to install a pool on top of them. It’ll take some extra doing to deal with all the rocks, but no issues will result with that location.