How to Make a Septic Tank Drain Field

If you have a septic tank you will need a septic tank drain field. While all septic tank drain fields require regular inspection, you can save a lot of money by digging one yourself. If the septic tank drain field is done wrong, however, you will have a back-up problem, so follow the directions carefully. This tutorial will also include some steps you can take to make your field less of an eyesore.  With the correct plants and bushes it can be almost as nice as a park.

Step 1. Choose Your Site

You will want to choose a site that is away from the house, but close to the tank. The field should be at least 10 feet away from your edible garden and any water, such as a lake, river, or well.

Step 2. Contact the Authorities

Verify if you need a permit to build the septic tank drain field or if you need to have the site inspected prior to starting work. Digging the field is a lot of hard work, but having to remove it and start over again is even worse. Verify all of the relevant laws and regulations prior to starting this project.

Step 3. Make Sure the Soil is Appropriate

You will need to have the soil tested in the area you will be putting the leach field. If the absorption capacity is too low you will have trouble with back-ups.

Step 4. Start Digging

You will need to dig either four 25 feet long trenches or two 50 feet long trenches for a 1000 gallon septic tank.  Each trench should be 3 to 4 feet wide and 3 to 4 feet deep. You should make your trenches so that they tilt downward slightly, but no more than ¼-inch per 8 feet. You do not want the water to pool at the bottom and back up.

Step 5. Place Gravel

Once the trenches are dug you will put at least 1 foot to 1 1/2 feet of gravel along the bottom of each trench. This will allow for drainage under the pipe.

Step 6.  Add the Pipe

Place the pipe from the septic tank all along each trench. You will use the clamps to hold the pipe in place at the septic tank drain so it does not shift and misalign.

Step 7. Add More Gravel

Once the entire pipe is in place fill the trench with another 1 to 3 inches of gravel and let the gravel work its way down around the pipe.

Step 8. Add the Cloth

When you have laid the pipe and gravel, put your cloth over it. The cloth can be of any type that breathes.  Its function is to keep dirt and sand from blocking the drainage from the gravel.

Step 9. More Dirt

When you are done with the pipe and gravel your next step is to fill the rest of the trench in with dirt so that your field is level with the ground around it. You will need to wait two weeks for the ground to settle. When the ground settles you will probably need to add more dirt to level your field.

Step 10. Plantings

There are several plants that will do well in the septic tank drainage field. Keep in mind that you cannot aerate or till the soil. You also cannot add more than 2 to 3 inches of top soil. The plants you use need to require very little water and have shallow root systems. Some suggestions include Japanese surge, carpet bugle, periwinkle, Irish moss and some wildflowers.