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Septic System

FAQ about Septic Systems

How often do I need to pump out my septic tank?
For maintenance, a septic tank should be pumped to keep the system working properly. How often it is pumped depends on the amount of sewage generated, the size of the family and the size of the tank. Generally, a septic tank should be checked every 5 years to see if it needs to be pumped. North Carolina State University's Septic Systems and Maintenance website provides more information.

When should I have my septic system inspected?
A septic system should be inspected at least every 5 years to check if the septic tank needs pumping and for other operational problems. A list of certified inspectors is available from the state certification board website. If you suspect problems with the system including wet areas in that area of your yard, slow draining plumbing or sewage odor, you should contact our office to come out and check out the system.

What do I need to do to maintain my septic system?
To maintain your septic system, you should conserve water, don’t flush chemicals or grease down the drain, maintain the ground cover over the drain field, and have the tank checked every 5 years. North Carolina Cooperative Extension has published information about how to maintain a septic system

What permits are needed in order to build a house?
For homes or businesses built where the sewer system is not available, the following permits will need to be issued by Environmental Health:

  • Improvement Permit: This is a permit that is issued for sites that have acceptable soil to support a septic system. Some lots that have been recently subdivided already have an issued improvement permit. 
  • Construction Authorization: This is the permit that allows for the installation of the septic system and must be issued before the building permit is issued. To get a construction authorization, you must submit an application with a floor plan of the building and a site plan of the property.
  • Well Permit: If the property is not served by public water, you will also need to apply for a well permit

What if I have an existing house that I want to replace or add on to?
If you are not increasing the number of bedrooms and the addition does not encroach on the septic system or well, you will need to apply for an Existing System Authorization. You will need to submit the application along with a floor plan and site plan. Our office will visit the site and if there are no problems, will issue the authorization before the building permit can be issued.

If the number of bedrooms is increasing, or the septic system needs to be relocated, you will likely need to apply for an Improvement Permit and Construction Authorization. Please talk with one of our staff to make this determination.

What is a conventional septic system?
A conventional septic system refers to the type of drain field on a septic system. After sewage passes through the septic tank, it goes to a drainfield (also known as a leach field or absorption field). The drain field consists of a trench filled with gravel and a pipe or some other material that allows the liquid from a septic tank to percolate into the soil.

What size does a septic system need to be?
Septic systems are sized according to the number of bedrooms in a house. The more bedrooms, the bigger the tank size and more area required for the drain field. If a property has a permit for a 3 bedroom home, and you wish to have a 4 or 5 bedroom home, you will need to apply for a new improvement permit and construction authorization in order to increase the size of the septic system.

It is important to note that for the purpose of sizing septic systems that a bedroom is considered to be any room in the home that can reasonably function as a bedroom, regardless of the current use of the room. A typical 4-bedroom septic system and repair area will need about 1/4 to 1/3 of an acre of acceptable soil.

What is a repair area?
A repair area is an area of suitable soil that is reserved in case the original drainfield fails. After the repair field is installed, an owner will be able to switch from the old drain field to the new drain field and back again. While one drainfield is working, the other one is resting and rejuvenated. Alternating the two areas allows for a system with an indefinitely longer life.

What kind of trees can I plant near the septic system?
The best ground cover over a drain field is a well maintained grass cover. While it is not recommended, an owner may choose to plant trees near the drain field area. The exact location of the drain lines need to be known so that a tree is not planted on top of the drain line.

Most modern drain fields have only 6 to 12 inches of back fill over them, and the pipe and trench can be damaged by planting trees too close or on top of the drain line. If trees are planted near the drain field, you should avoid species that are known to have problem roots. These species include:

  • Any tree with fibrous roots.
  • Elms
  • Maples
  • Sweet gum
  • Willows

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