What Is a Leach Field?

Overhead photo of a house
A leach field, also known as a septic tank drain field or leach drain, is an underground array of perforated pipes adjacent to the septic tank. The leach field is responsible for removing contaminants and impurities from liquid after it leaves the septic tank.

Keep reading to learn why your leach field is important, how it works, and how to maintain your septic tank drain field to keep it working properly over time.

Where Is My Leach Field Located?

Leach fields are typically located in a large, flat, and open area of your yard. They can have multiple trenches between 18 to 36 inches deep, one to three feet wide, and up to 100 feet long. There are typically six feet between each trench. If properly maintained, leach fields can last up to 25 years.

How A Leach Field Works

A septic tank, pipes, and drain field are what make up your septic system. This means to understand how a leach field works, you must also understand how your whole septic system works.

Here is how your septic system and leach field operate:

  1. All the waste and wastewater from the house flows into the septic tank.
  2. The waste begins breaking down due to the bacteria present in the septic tank.
  3. Solid waste sinks to the bottom of the septic tank and becomes sludge, while liquid waste (such as fats, oils and grease) floats to the top of the septic tank to also be broken down by the bacteria.
  4. The liquid waste then flows into the leach field through underground pipes, while the solid waste remains in the bottom of the septic tank and continues to be broken down by bacteria.
  5. As liquids travel through the pipes of the leach field, it seeps into the ground below where it is naturally filtered by the soil.

How to Tell if Your Leach Field is Failing

A properly maintained leach field is invisible and silent. However, there are some key indicators that your leach field is failing:

  • Pipes that gurgle when being turned on.
  • Slow-running drains or plumbing backups.
  • Issues with toilet flushing (low pressure, slow flushing, not flushing).
  • Sewage odors come from drains, septic tanks, or leach fields.
  • Standing water or wet, mushy grass over the leach field.

Can You Repair a Septic Drain Field?

Repairing a clog in a septic drain field is a straightforward task. However, there are possible catastrophic problems that can arise with a leach field, particularly bacterial mat growth. Prevention is key to avoiding costly leach field replacement services.

Follow these household plumbing tips to prevent your leach field from failing:

  • Avoid pouring grease, chemicals (such as bleach and ammonia) or paint down the drain.
  • Do not flush anything other than bathroom tissue and body fluids.
  • Use garbage disposals sparingly (or not at all).
  • Limit laundry to one load per day to spread out water usage.
  • Do not park cars, build structures, or place any heavy objects on top of the leach field.
  • Divert water runoff from excessive rainfall or snow away from the leach field.
  • Schedule regular septic tank pumping typically every three to five years. View the septic tank pump chart to learn how often you should be pumping your septic tank.
  • Commit to annual septic system inspections and diagnosis services.

Local Septic Tank Drain Field Services

Ready to schedule your annual septic tank inspection? Searching for septic tank pumping services? Your local Mr. Rooter® Plumbing is here to support you with quality service and upfront pricing. Call us or find a Mr. Rooter near you to get started.