How Can You Solve Leach Field Problems?

Do you know where the water from your septic system is going? How can you solve leach field problems?

While many homeowners know how their septic tank functions, many are unaware of the leach field. This part of the septic system is responsible for draining wastewater into the soil.

But since the leach field is not visible to the naked eye, we tend to forget about it. As a result, we often neglect it, even if it is a vital part of our plumbing systems. As a result, various leach field problems can develop.

This post will present the most common leach field problems and ways to solve them. We will also be looking at best practices and leach field maintenance tips.

Our objective is to have wastewater going where it belongs, so bacteria can safely decompose it.

How can you solve leach field problems? – Short Answer


There is no single answer to this question.

Leach field problems can have multiple causes, and, consequently, you can use numerous solutions. So, keep on reading to find out!

What is a leach field?

The leach field is an integral part of the septic system. Also called drain field, it is an underground system collecting wastewater from septic tanks and sending it in the soil.

But what does a leach field look like?

It is a network of perforated PVC drain pipes surrounded by crushed stone. The leach field stays on a layer of unsaturated soil, absorbing water. [1]

Most septic systems use gravity to send the wastewater to the leach field. However, a pumping station can send the water to the leaching bed in some scenarios.

The water reaches the leaching bed, runs through the crushed stones, and infiltrates the receiving soil.

The efficiency of a leach field depends on its construction and the quality of the surrounding soil. Therefore, before building a leach field, you should conduct a percolation test with help from an engineer. This test measures how fast water percolates down 1 inch in a hole until the soil is saturated.

What causes leach field problems?


No system is foolproof, and drain fields can suffer from problems, too. There are multiple causes for leach field failure:

  • Pouring harmful substances down drains

Prohibited substances include chemicals, grease, paint, and other complex substances. Bacteria cannot disintegrate these, and clogs can develop in the septic system.

  • Excessive water use

Even a leaking toilet or drain can increase water consumption and cause the septic tank to overfill. As a result, too much water reaches the leach field and oversaturates the soil.

  • Damage on top of the field

Construction work and parking on top of the leach field can compact the soil, preventing wastewater from draining.

  • Excessive rainfall or snow

Water runoff from precipitations can make the leach field oversaturated. In such situations, the drain field will not absorb wastewater as fast as it should.

  • Tree and plant roots

These can interfere with drain pipes and cause them to malfunction.

  • Not pumping regularly

A septic tank should be pumped every 2 to 3 years to remove sludge. If not, the sludge layer becomes too thick, and solids can enter the leach field, clogging it.

  • Old age

Many homeowners are afraid that leach field replacement costs could be too high. However, a replacement can be the best option if the drain field is too old. If used properly, a leach field can last anywhere between 15 and 25 years.

What are the main signs of a leach field problem?


Determining that something is wrong with your septic system is relatively easy.

What’s more complex, however, is realizing what exactly is going wrong.

If the problem is in the leach field, you will probably notice the following symptoms:

  • The grass is greener on top of the leach field compared to the rest of the yard;
  • The area surrounding the leach field is wet and mushy or even has standing water;
  • You notice sewage odor around the leach field;
  • Your drains are running slowly, or your plumbing is backing up;
  • Soil is sinking or collapsing over the leach field.

Problem 1: clogged leach field

The leach field can clog if the sludge layer is too thick, causing solids to enter the leach field pipes.

However, if your leach field pipes are clogged, it does not necessarily mean you have abused your septic system.

Bio-mat could be the culprit for your problem. Wastewater flowing through the leach field causes a black, gelatinous layer that is watertight. It reduces the percolation of effluent into the soil, and water will back up where it meets the least resistance.


How can you eliminate imbalances in the natural water filtration system?

A standard solution is applying shock treatments to your septic system. These solutions contain bacteria and enzymes capable of reducing bio-mat. You pour the mixture into the septic tank without having to dig!

Problem 2: not using the septic system correctly

Septic systems should last and service households for decades. However, if you abuse your plumbing systems, they will stop working as intended. The most common mistakes are:

  • Using too much water;
  • Pouring chemicals down the drain;
  • Flushing anything else but human waste and toilet paper down the toilet;
  • Not pumping your septic tank regularly.


There is no simple solution for a septic system that you have not used correctly.

The first course of action is to comply with guidelines and best practices. Avoid excessive water consumption, harsh chemicals, and flushing wipes.

Has one of the bad practices from the past has caused damage to your septic system? You will have to solve every one of those punctually.

Problem 3: compacted soil around the leach field

Soil compaction can have severe consequences on septic system performance. However, non-compacted soil will absorb wastewater properly. For instance, sandy soils allow a faster percolation rate, while clay soil will not suck in water efficiently.

There are multiple causes of soil compaction around a leach field:

  • Vehicle traffic

Avoid driving and parking your vehicle over the leach field, especially when the soil is wet.

  • Foot traffic

People and animals walking on top of a leach field can also cause compaction. Don’t install play areas such as swing sets near a soil treatment area. [2]

  • Construction work

Intense activity and vibrations on top of the leach field can also affect its performance.


If the soil is too compacted, you will have to dig and aerate it.

Before that, consider good practices such as avoiding working the soil when wet, including mowing. If needed, you can even install a barrier to prevent traffic in the leach field area.

Problem 4: tree roots disrupting the leach field

How do you know tree roots are into your septic system and leach field?

As long as you know the leach field size and location, you can check for surrounding trees. Their root systems can be larger and more complex than you imagine, interfering with your drain pipes.

A few signs suggesting that tree roots have invaded your leach field include:

  • Poorly draining fixtures;
  • Greener grass above the leach field;
  • Soaked lawn and standing water in leach field;
  • Sewer odors.


First of all, keep trees away from the leach field. If you already have trees planted in risky areas, the best is to remove them.

Next, make sure you avoid trees with aggressive roots that grow deep. Instead, opt for shallow root trees such as dogwood, Japanese maple, cherry, and white pine trees.

A good idea is to install a root barrier around your leach field from the beginning. You can do it later, too, when removing a tree, so you avoid dealing again with the same problem.

Perform periodic video inspections to check for tree root invasions. A tiny camera attached to the end of a plumbing snake will enable you to detect various problems.

The last resort uses copper sulfate or another chemical to kill invading tree roots. Flush copper sulfate down the drain a couple of times every year. This chemical kills existing roots and prevents the growth of new ones.

Problem 5: rainwater saturating the leach field

Can heavy rain affect septic systems?

Yes, it can.

If you use a conventional septic system and the rainfall causes floods, the septic system will stop working. What happens is that effluent from the septic tank has no place to drain due to the ground being already soaked with water.

As a result, you will notice that wastewater starts backing up the drain and overflowing the lawn.


A septic system can withstand heavy rainfall and melting snow, but you must maintain it properly. Maintenance means pumping your septic tank on schedule and ensuring the health of tank bacteria with biological additives.

If forecast warns of impending floods, take precautions to protect your septic system:

  • Seal points of entry into the septic systems;
  • Make sure downspouts don’t direct rainfall near the septic system;
  • Limit water usage during heavy rains;
  • Waterproof electrical connections in your septic system.

How can you prevent leach field problems?

You can avoid leach field problems such as clogged pipes and saturated soil through maintenance. Of course, you can use a septic system without caring for its maintenance, but you will eventually run out of luck. [3]

Good practices for caring for your septic system include:

  • Inspecting the septic system and pumping frequently;
  • Limiting water usage by installing high-efficiency appliances;
  • Not flushing items that don’t belong to the toilet;
  • Avoiding chemicals;
  • Maintaining the drain field by keeping excess water away and not parking on top of it.

How can you solve leach field problems?- Final Word

Every problem affecting your septic system will have negative consequences on the leach field, too.

Generally, you will have to maintain the drain pipes in good condition. Also, do not use excessive amounts of water and ensure the soil is not saturated. Proper maintenance and timely repairs can keep your leach field down (pun intended) and running for a long, long time.