If you live or want to build a home or commercial building on land that isn’t connected to the municipal sewage test, a septic system is your only option for dealing with sewage waste. In fact, you won’t even be able to get a building permit for the construction until the soil has been tested and a septic system installed.

Nevertheless, we get questions from customers all the time wondering whether it is possible to have a septic system without also having a leach field, and the answer is no. All septic systems are required by law to have a leach field. That being said, there are alternative options for situations in which a traditional leach field won’t work. With this in mind, here is everything you need to know about leach fields, including why they are important and potential alternatives if a traditional leach field isn’t an option.

What Does a Leach Field Do?

A septic system consists of two main components: the septic tank and the leach or drain field. When you flush a toilet or use the sink, everything flows into the septic tank. Inside the tank, solid waste and toilet paper sink to the bottom and the wastewater floats on top. There is usually a third layer of fat, oil, and grease that collects on top of the water.

A septic system utilizes bacteria to help break down solid waste and treat wastewater. Bacteria inside the tank break down the solids into a sludge, which is important because otherwise the solids would quickly build up and possibly cause the tank to overflow or need to be pumped out constantly.

Whenever water flows into the tank, it causes an equal amount of water to flow out of the tank and into what is known as the leach or drain field. In traditional systems, the leach field consists of a series of perforated pipes buried underneath the ground somewhere near the backside of the tank.

Having a leach field is essential because it helps to treat and clean the wastewater from the tank. Without a leach field, you would essentially have raw sewage spilling out into the area and polluting the soil and potentially the groundwater. The leach field is designed to disperse the wastewater over a large area of soil. As water seeps out of the pipes, it slowly filters down into the soil, where bacteria and microbes work to break down any remaining waste.

The Importance of a Percolation Test

Before a septic system is installed, the soil must first be tested to make sure that it is porous enough for the leach field to work properly. The area also is evaluated to determine how high the water table is to ensure that the system won’t pollute the groundwater. If the water table is too high, it will be necessary to install an alternative septic system or a different type of leach field. There are also laws that dictate how close to water sources a septic system and leach field can be.

There are two other factors that are used to determine whether a traditional septic system is possible. The first is the slope of the ground since conventional septic tanks cannot work properly if the ground is too steep. The other factor is whether the proposed area for the system might be affected by runoff during rainstorms or from snowmelt since this could flood the system and cause it to overflow.

To ensure that the ground is porous enough for the leach field to work properly, it is necessary to perform a percolation test. This involves digging one or more holes in the ground and seeing how fast water is absorbed by the soil. To pass the percolation test, the water must meet a minimum absorption rate, or else the septic permit will be denied. The most common reasons for a failed percolation test are that either the soil has too high of a concentration of clay or that there is impermeable rock too close to the surface.

In this case, you will usually need to hire an engineer to design an alternate septic system or a different type of leach field to ensure that the system works properly and doesn’t pollute the groundwater. However, it is important to note that this could greatly add to the cost of installing the septic system and may also potentially require far more maintenance than a convention septic system.

Since getting a permit to build your home or other structure will be dependent on passing a percolation test and installing a septic system, this is something to keep in mind if you’re shopping for property to build on. In this situation, it is always a good idea to make the purchase dependent on the property passing the perc test to ensure you can actually build on it. You should also ask if a perc test was already performed as the results of the test are usually valid for between three and five years from the date the test was done.

Alternative Septic and Leach Field Options

If the water table is too high or if the ground doesn’t pass the percolation test, you will need to come up with an alternative solution and have it approved by the government. The most common alternative is a mound septic system. Instead of having the tank and leach field buried underground, this type of system places the leach field into a large mound of sand and dirt on top of the ground.

A mound system is usually the best choice for situations where the water table is too high or the ground isn’t permeable enough for a standard leach field. However, a mound system is more expensive and requires much more maintenance. This is because this type of system requires an additional tank known as the dosing or pump chamber as well as a pump to take the water from this tank to the leach field above it.

The dosing chamber sits next to the septic tank and is connected to the mounded leach field. With this system, wastewater first flows from the septic tank into the dosing chamber and is then pumped up and out into the leach field. These systems usually use a float and a pump system that controls the amount of water that goes into the leach field at any time. Most mound systems also have an alarm that will trigger if the pump stops working or the water inside the pump chamber rises too high.

There are also aerobic treatment systems that function similarly to a sewage treatment plant except on a smaller scale. However, the high installation cost and maintenance requirements mean that these systems are generally only used as a last resort in areas that are too close to water for a normal septic system.

Septic System Installation and Services

If you’re looking to have a septic system installed on your property, the team at Express Septic Pumping can help you determine what type of system is best. We install septic tanks and leach fields, and we can also inspect, repair and maintain existing septic systems. If you need your septic tank pumped, we can handle that as well. We have been providing professional septic services to customers in Nampa and the Treasure Valley area since 2006, so contact us today for any and all of your septic system needs.

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