Leach Field vs. Drain Field: What’s the Difference?

If you have a septic system, you have a series of perforated pipes that lead away from the septic tank and slowly drain its contents into the surrounding soil. Professionals use terms like leach field and drain field to refer to this system. But are there differences in leach fields versus drain fields? Learn about the importance of these septic drainage systems.

Are There Differences in How Leach Fields and Drain Fields Work?

When comparing leach fields versus drain fields, differences don’t really exist. The terms leach field and drain field commonly refer to the area where the liquid waste from the septic tank drains. Most local septic tank professionals use the two terms interchangeably. Some places in the United States primarily use the term leach field, while others use drain field based on regional preferences. Think of it like regional preferences for terms like soda and pop.

The septic system includes perforated pipes attached to the tank and buried a few feet under the ground. Installers surround the pipes with gravel and soil. As liquid waste enters the septic tank, it eventually flows into these pipes, where it seeps into the surrounding gravel and soil through the perforations.

The soil and gravel provide a natural filtration system. The filtered liquid eventually becomes part of the groundwater system.

Leach Fields vs. Drain Fields: Differences in Functionality

Although most people use the terms leach fields and drain fields interchangeably, a few professionals use these terms to refer to specific parts of the septic system.

Perforated Pipes

Some people exclusively refer to the perforated pipes that extend from the septic tank as part of the drain field. 

Trenches and Soil

Some people only refer to the trenches, gravel, and soil as part of the leach field. 

Overall System

If people refer to leach field and drain field interchangeably, they won’t differentiate the parts of the system with these terms. They would use one term to discuss the perforated pipes, gravel, trenches, soil, and septic tank.

Other Terms Beyond Leach Fields vs. Drain Fields

Depending on where you live, you may hear terms other than leach fields or drain fields used to refer to the drainage system of the septic tank. These can include:

• Absorption bed

• Absorption field

• Infiltration system

• Percolation area

• Seepage field

• Septic field

• Septic disposal field

• Soil absorption system