How To Install a Septic Tank

How To Install a Septic Tank

A septic system is a highly efficient way to take the wastewater out of your home. While some maintenance is required, you have no wastewater bill through the city or town, and you control how you care for your system.

To review, a septic system works by flowing the wastewater through the inlet baffle to a holding tank, where the materials will float and settle. Anaerobic bacteria break down the waste until  clear effluent moves through the outlet baffle to the discharge pipe. Then the system takes the remaining effluent to the leach field via the distribution box.

How to install a septic tank.

Before digging for a septic tank and system installation, contractors must have the proper permits and the local and state health department's approval. In NH, we would contact your township or city and notify NHDES.

Steps to install a tank and system.

  1. First, investigate the location of utilities so they can mark the areas before you dig.

  2. Measure the tank size and dig in a safe location. You’ll need 6-12 inches around the tank. Your typical septic tank will need to be buried 24” from the top of the tank to finish grade. 

  3. Insert 6-12 inches of aggregate and level it before placing the tank in the hole. You cannot put the tank directly on rocks — instead, fill it with a few inches of sand and level it. 

  4. Lower the tank into the center of the recess and settle it in the gravel for about 3 inches. 

  5. Be sure the tank is level before you remove the straps from the tank.

  6. To get the right flow direction, ensure the inlet is higher than the outlet for placement, and then connect the piping.

  7. If you have a high water table, add 1 foot more of the aggregate mixture around the tank as you add water in at the same rate. Continue the backfill with gravel to the top of the tank, making sure you place some around the piping. 

  8. Install the covers.

  9. Backfill the remaining space with topsoil. You want to be sure rainwater flows away from the tank to help the soil settle. 

  10. Once the entire system is functional, test the system thoroughly, and be sure to create a maintenance plan to keep your system at top performance. 

Frequently Asked Questions About Installing a Septic Tank.

Can you install your own septic system or tank?

In New Hampshire, you, as the owner of a primary residence can install your own septic tank. If you plan to remodel the residence to sell or are a licensed contractor, you must follow government regulations and acquire the mandatory permits needed to install the septic system. 

However, a word of caution to homeowners who are excited for a new opportunity to learn. You will need access to a mini excavator and have the right plumbing knowledge and experience to adequately install the system. To avoid legal and potentially dangerous backflow or sewage problems, we always recommend finding the most qualified septic system installer to help you get the right system for your home.

Where is the best place to put a septic tank?

The best location for a septic tank is wherever the ground is most level. Additionally, the tank should be on higher ground to avoid seeping and flooding. Be sure to avoid tree roots and sloping land. Since we have plenty of trees and heavy rain in NH, it’s essential to find the ideal location and treat the earth properly before installing the septic tank.

How close to a house can the septic tank be?

Your tank needs to be at least five feet from your home. We always recommend it be at least 10 feet away with the leach field at least 20 feet from the house. You cannot build structures on or over the leach field or use the land for anything else, so choosing the right direction for the septic tank is equally important for future development. 

Is a concrete septic tank better than a plastic one?

Yes, a concrete tank can last over 40 years, while plastic tanks may need to be replaced sooner.

Installing your septic tank with Townes.

We have been installing and servicing septic tanks and systems in the greater Manchester area for over 60 years. Grandpa Towne created systems that are still going strong today, and we’re incredibly proud of our legacy and future in this community. 

From designing your home’s system to practicing the best methods on how to install a septic tank, we’re the septic system experts you need to guarantee a lasting and effective system. 

Contact us today to get started on installing your septic tank.  

Author: Eldon Townes

Adam Lang