How Long Does A Septic Leach Field Last?

Last Updated On July 14, 2024

Updated on September 14, 2022



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How Long Does a Septic Leach Field Last

While we might only pump our septic tank every two to three years, we must check the tank levels and also the septic leach distribution box annually. 

Every septic system consists of three parts. Our septic tank is responsible for breaking down all of our solid waste. 

The second part of the system is the sewer pipes themselves. These pipes are what allow the sewage to go to the required destination. When solid waste drops to the bottom of our septic tank, the liquids rise to the top and flow into the leach lines. 

The leach field is the third part of every septic tank system.

The leach field consists of multiple rows of perforated pipes. The distribution box disperses the liquid waste evenly down each line.

A typical septic leach field lasts fifty years as long when maintained. Treatments can be added to the tank as well as the distribution box in the event of clogs inside the absorption field. 

With the leach lines working, the impurities get removed from the contaminated wastewater. The liquid filters through the soil after seeping through the holes of the leach lines

What's In This Guide?

      How Long Do Leach Fields Last, On Average?

      Many factors can affect how long a leach field lasts on average. A leach field, or drain field, requires open space to work right. 

      The pipes are buried about two to three feet under the surface. Before they get backfilled with the soil, they get packed in crushed granite and sand. The granite keeps the dirt from clogging the holes in the leach pipes. 

      The system should work properly as long as the water is dispersed evenly down all the different rows in the leach field and the drain holes are free of debris. 

      A well-maintained leech field can last up to fifty years. It is crucial to check solids levels regularly and also pump our septic tank every two to three years. This helps us keep any solids from entering the leech distribution box, preventing septic system failure. 

      Our leech distribution box should be checked and maintained once a year. Adding a leech line treatment to the distribution box can help ensure that all the pipes in our drain field are clear.

      Factors for How Long Does A Leach Field Last

      The weather conditions play a factor in how long a leech field will last. Excessive rain and downpours leading to flooding are one of the most common problems for leech field failure.  

      We rely on the soil to absorb the organic material out of the leach lines. There’s nowhere else for our sewer water to go when the dirt is soaked. 

      Trees can also do damage to the leech field. Tree roots can easily penetrate the PVC pipe and can even use them as a raceway. They can eventually fill our sewer pipes and lead to septic tank problems. 

      We must keep all traffic from the area to get the most life out of our leech field. Excessive weight can crush our leech lines. It’s best to keep any vehicles or livestock away from the area. If the weight doesn’t physically damage the pipe, it can create excessive compaction. 

      The leach field requires oxygen to drain. If the soil around the drain holes gets overly compact, they will be unable to drain. 

      How Long Is Leach Field Good For?

      If we’re questioning how long a leach field is good for. The answer is up to us. Leech fields can last upwards of fifty years but require some discipline on our part. 

      Things we do in our everyday routine can prevent a faulty leech field. Taking shorter showers can make a significant impact. 

      It’s also a good idea to get the entire family involved in running the dishwasher and clothes washer machine only when they are full. Less waste going down our sewer line means less work for a leech field. Spread out laundry vs. doing loads all day long.

      Outside of the home, we need to divert any excess water away from the leech field area of the yard. Another good way to save water is by using rain gutters and grey water as irrigation for our plant life. 

      These small changes in our daily routine are just as important as keeping up with the routine maintenance of the septic tank. If we can stop any solids from entering the leech lines,  it will prevent any clogging of the leech pipe holes. 

      We should pump our septic tank every three to five years. They make treatments for the septic tank and the leech distribution box to help with unforeseen issues. 

      Compaction is another thing that can stop a leach field from working. Also known as a drain field, the leech pipes allow the organic material to filter through the soil. If the ground is too compact or too wet, it won’t be able to absorb any more liquids after it leaves the septic tank.

      This video shows how much work goes into replacing our leach lines.

      Soil Conditions: How Long Does A Leach Field Last In A Clay Lot?

      Depending on the amount of water flowing throughout the septic system, a leech field in a clay lot may need to be cleaned out more frequently than most. 

      The perfect soil for any leech field is neither too dense nor is it too loose. It needs to be thick enough to act as a filter to allow the water to flow continuously.  Heavy soil can pose problems to the leech field. 

      A lot of work has to be done before installing leech pipes in the ground. Once the trenches get dug, layers of gravel and sand are packed around the perforated pipes to allow for filtering and drainage. 

      Additionally, acidic soil must be tested for “perc” prior to installation. Local building codes will regulate these standards. If they were skipped or bypassed, this could lead to septic system failure and costly repairs.

      Maintaining Your Drain Field

      Maintaining our drain field starts with reducing the sewage we put into our septic tank. Being water-wise can impact how long our septic tank and leech field last. As long as we care for the rest of our sewer system, the leach field should have no reason to clog. 

      Avoid planting trees, pouring concrete, or driving on the leach field. Too much weight can crush the perforated PVC. If the dirt around the pipes is too compact, the wastewater won’t be able to drain into the soil at all.

      Did you know? Most leach field failures are due to biological or hydraulic overload. Simply put, too much water is forced into the septic tank. Any chores that require a lot of water use should be spread out and not done all at once.

      did you know how long do leach fields last

      How Often Should You Clean Your Leach Field?

      There are leech field treatments used to unclog leach pipes when necessary. In serious leech line cleaning, a jet spray can also help. 

      How often should we clean up our leach field? The distribution box should be inspected annually. Our septic tank needs to be pumped every three to five years.

      The best way to maintain our drain field is to keep our septic tanks working efficiently. 

      The more untouched we can keep the leech field area of our yard, the better. If we can avoid excess compaction, water, and traffic on that part of our property, we avoid damaged pipes restricting water flow in our leech field. 

      Our leech field could last fifty years or longer by taking all the necessary precautions and maintaining the rest of the septic system.

      How Do I Know If My Leach Field Is Failing?

      The most common signs of a failing leech line are the same as every other household plumbing problem.  From slow drains, bubbling or clogged toilets, gurgling pipes, and the stinky smell of sewer gas, issues in our leech field are more common than we think. 

      Evidence that our leech field is failing will be in the area designated for the septic tank or the drain field. From sinkholes to standing water, we must watch for signs of excess Drainage in our yard. 

      What Can Ruin A Leach Field?

      The leech field consists of multiple perforated PVC pipes buried at three feet deep, and in some areas as low as eighteen inches. 

      Any machinery, vehicle, or large animals can crush our leech lines. If the dirt around these pipes gets too compacted, It can restrict the flow of water through the holes. Roots also cause a potential risk as they can grow into the lines. 

      What we flush down the drain can also ruin a leech field. Anything unable to decompose could make it through the septic tank and into the leech lines. Use septic friendly toilet paper that isn’t super thick, or filled with chemicals or dyes.

      When a leech field isn’t working, the water has only one way to go. (Back to our septic tank and into our home.)

      Final Thoughts On How Long A Leach Field Should Last

      Fifty years is how long a leach field should last in perfect conditions. 

      It is up to us to maintain good septic system habits. The less we run down our drains, the better. As long as we take care of our septic tank, we don’t have to worry about much getting into our leach field. 

      We need to maintain the yard around the leech field to keep any excess water or large roots from penetrating through the pipes. Any compaction on our leach pipes can affect the filtering process of our leech field. 

      With a well-maintained septic tank, clean sewer pipes, and a bit of discipline, our leech field should last twenty-five to fifty years without any issues.

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      About Plumbing Navigator

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      We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.

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