What Is A Seepage Pit Used For?

Ossiana Tepfenhart
by Ossiana Tepfenhart

When you first start learning about the plumbing process, you’ll start to uncover a lot of different parts of your home you might not have realized existed. This can include things like septic tanks, drainage fields, and a lesser-known part of your system called a seepage pit. So, what is this thing, and why do people have them?

A seepage pit is used to collect and filter out black and grey water from septic tanks. The pit contains bacteria that eats organic matter and lets the pure water gradually seep out of the stone and into the ground. It is also referred to as a “dry well” and release household waste without damaging the environment.

Not all homes have seepage pits, and there’s a chance that you might not have one. If you’re wondering if you need one or what your seepage pit does, this article will help you clear up the air.

What Is A Seepage Pit?

Often referred to as a “dry well,” a seepage pit is an underground pit lined with porous masonry where the household waste from a septic tank is discharged. A seepage pit is often used as a replacement for a drain field.

It is built around six feet deep, away from the house, takes the fluids from your septic tank and uses anaerobic bacteria to break down the organic waste inside of it. From there, the rest of the fluid ends up passing through the porous concrete surface at the base of the seepage pit. Once it passes through the pit, the ground and other sediments filter out any remaining waste.

The end result? Clean water being released into the water table near you, without damage to the environment.

What Is A Seepage Pit Used For?

A seepage pit is one of many methods that are used to help clear out septic tanks and is typically used in place of a drain field or leach field. If you don’t have a way to make space for a drainage field, you probably will have a seepage pit instead.

The primary difference between a seepage pit and a leaching field is the vertical orientation that seepage pits are dug into the ground. Most seepage pits are built in a way that allows at least four to six feet of soil to cover the pit. Since the pit is buried so deep into the ground, the majority of the waste water processing is achieved via anaerobic bacteria.

Seepage pits are constructed of either poured or cast concrete and are enclosed with rocks to allow the waste water to permeate into the ground after processing.

Where Is A Seepage Pit Found?

Most municipalities won’t allow a seepage pit to be within three feet of a water table. Aside from that, seepage pits are found underground, close to the septic tank. In terms of size, these pits are usually four to six feet deep.

How Can I Tell If My Seepage Pit Is Failing?

During most of your time at home, your seepage pit will work like a dream. It’s a reliable way to purify water that’s being reintroduced into the environment. Unfortunately, seepage pits can still fail. It can happen to you. So, how can you tell if your seepage pit is faulty? Look for these signs:

  • Your septic tank is backing up. Did you notice that your drains aren’t clearing as quickly as they once did? Have you been noticing septic tank backups? If you have a seepage pit, this could be a sign that your pit’s full or clogged.
  • There’s a puddle of water right above the seepage pit. If your pit becomes too full, you will start to see water appear right above the pit, in full visibility. This usually happens after you start noticing septic tank problems.
  • There’s a strange, sewage smell in and around your yard. Sometimes, you might not see a puddle of effluvia starting to pool in your yard. Instead, you might smell it.
  • You notice a ridiculously lush grass growth above your seepage pit. This may seem like a good thing, but it’s actually a sign that the moisture from your tank is pushing upwards due to a failed pit. So, cut down the grass and pump your pit.

How Do I Fix A Seepage Pit That’s Failing?

If your seepage pit is starting to get clogged, the best thing you can do is call up a professional and get it pumped. Pumping will remove extra effluvia from the pit and also clean out the sides of your pit. This is considered to be basic maintenance and should be done once every several years at the very least.

Most of the time, pumping a seepage pit will be enough to fix things. If you can’t, a call to a repairman who specializes in septic servicing may be able to help you figure out what’s going on here. However, not all seepage pits can be fixed.

How Much Does it Cost to Replace a Seepage Pit?

If pumping your seepage pit isn’t enough to save it from failing, it may be due for a replacement. In this case, you’re likely wondering how much installing a new seepage pit will set you back. If you need to get a seepage pit replaced, you should expect to pay around $2,700 or more for the replacement, with the national average being roughly $3,100.

The actual price will largely depend on the size of the seepage pit, its location, the labor involved, and the materials required. It’s important to note that most municipalities require a permit to install a seepage pit. Be sure to check with your particular district first before you start digging.

How Long Do Seepage Pits Last?

Worried about shelling out thousands for a replacement? There’s some good news to be had. You probably won’t need to replace a seepage pit in your lifetime. So long as your septic tank system is properly maintained, a typical seepage pit can last for as long as 50 years or more.

However, if you take care of it poorly, the pit’s lifespan can shrink fairly noticeably. In most cases, due to improper maintenance and abuse, seepage pits last between 15 and 20 years.

How Do You Properly Maintain a Seepage Pit?

The best way to protect your seepage pit is to know how to use it properly, along with maintaining it. The important thing to remember is that the key to maintaining your seepage pit is to properly service your whole septic system, as they work in conjunction with each other. These tips below can help you prolong your seepage pit’s life:

  • Don’t overwork your water system. Stressing out your plumbing with excessive laundry loads or heavy bathing sessions may put stress on your seepage pit. Stick to one batch of laundry per day and do your best to conserve water.
  • Do use a biological cleaner in your pipes. If you want to make sure that you don’t end up with additional clutter, pour some enzyme cleaner (the type that kills drain flies) down your drain and let it sit at least once every two months.  This can help remove clogs and decompose any grit that could possibly end up down your drain.
  • Don’t pour grease or wax down your drain. Putting grease down a drain is a surefire way to make a fatberg that gets stuck in your drain or clogs your seepage pipe.
  • Fix your seepage pit and septic tank problems as soon as you notice them. Leaving things unfixed and hoping the problems will go away won’t work with seepage pits. It’s better to nip issues in the bud before they worsen. Otherwise, you might not have a choice when it comes to your replacement.
  • Never flush items that are not meant to be flushed. Things like paper towels, baby wipes, cotton bolls, and feminine products have no place in a septic tank or a seepage pit. These items don’t just clog pipes. They can cause serious damage to your septic tank and also cause your seepage pit to get cluttered.
  • Treat your seepage pit. The goal of treating a seepage pit is to attack the bottom of the pit and allow it to absorb water more effectively. The most efficient way to do this is to pump out the water first and then backwash to help break up the bottom. Leave about 100 gallons of water in the pit. Then, add in a commercial treatment product, such as Septic-Scrub, according to the manufacturer’s instructions.

Our Final Take

Seepage pits are one of the most reliable parts of a septic system that you can have. They are small pits that help filter out the dirt and organic messes in your septic tank, then slowly direct clean water in the ground for further purification. Though they are not the only type of septic tank processing tool you can have, they are highly regarded.

If you have a seepage pit, that’s great. They’re remarkably durable and can last for decades if taken care of properly. As long as you make sure to avoid putting the wrong things down the drain, make sure that you pump it regularly, and keep an eye out for signs of trouble, you should have great results.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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