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04-Septic Excavation

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Excavation

Per your approved permit please follow installation instructions:

All septic tanks must be installed according to state and/or local regulations, which supersede the manufacturer’s installation instructions. If unsure of the installation requirements for a specific site, see your permit, and /or contact the health department or permitting authority. All drainage must work correctly since it must pass a final inspection.

Consider including some grey water going into your septic tank, so that there is enough liquid to process solids.

Excavation (Excavate before delivery of concrete septic tank so that you are ready for the OSR Crane Operator or your vendor):

The site should be excavated properly and the base leveled  prior to setting the tank.  (Inspector will check that the septic tank is level).

The depth of tank correlates to the pipe coming out of your house. The top of the tank needs to be at one foot below the ground surface.

The length and width of the excavation should provide adequate space to allow for proper compaction and backfilling, and most importantly, provide a safe working environment for the crew. It’s so much easier to place the tank in a larger hole!

You will need rock no bigger than 2” to backfill in the front of the septic tank of inlet area.

The heel of the bucket can be used to compact the excavation bottom prior to setting the tank.

Setting the Septic Tank: The base of the septic tank should be carefully lowered into the excavation. Check to ensure the tank is level in both directions and adjust the tank as needed.

Leach /Drain Field & Pipe. Follow permit instructions for trenching the leach /drain field, and installing pipe.

Inspection. Leave your system exposed until after your final inspection. Call Cody Griffith in Nephi Central Public Health to arrange an appointment for your final inspection. Be sure to be on your lot during your final.

After inspection: After inspection, you must first cover the drainage pipe with straw or felt or landscaping weed barrier as a temporary barrier so that sand and dust does not get into the perforated pipe while you are backfilling the drain field.


Only For Dutson Supply Septic Tanks

Use a 16’ ladder to go down into the base. Install tar on the top of the base. After leaving the hole, the crane operator will set the lid on the base. It’s easier if you use a tie down strap with a double hook on the end to help guide the lid onto the base.

If the base is set on the lid, and it’s not in the proper place, when the lid is lifted up, the tar strip may move and need to be relocated back on to the top of the base. A 1”x2”x8’ board is useful to get the strip back in place. Additionally, seal any gaps between the base and the lid with tar. You do not want the septic tank to leak or you will fail the final inspection.

Backfill and Compaction: Backfilling of the tank (see sample of approved permit). Backfilling can be done with rock, no larger than 2” at the front of the septic tank, up and over the inlet pipe.

In the back of the septic tank where the outlet is, return dirt in 3’ increments and compact it with the teeth of a bucket.

Native soil in lifts of 12 inches on all sides of the tank. Compact the soil with the heel of the bucket in 12” lifts and by walking-in the soil around the tank.

Do not cover the top of the tank until after final inspection. The inspector will want to ensure that the tank is not leaking.

Add horse manure and fill the septic tank with water.

Install inlet and outlet tees at the designated locations, and also risers should be installed per plan. Install septic drain fields or leach fields /leach drains.

After Final Inspection – Cover the septic tank: Once the septic tank is properly backfilled and compacted, place topsoil up to the final grade and provide positive drainage away from the septic tank. Additionally, the site should be seeded to minimize erosion and divert surface water.

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