The VERY First Step: Septic Approval
It doesn’t matter whether you are going to build a house from scratch, buy a manufactured home or a pre-fab or modular home, no matter what size it is, you have to worry about sewage. If city sewage hookups are available, it’s easy. But if not, you really should get approval for a septic system BEFORE you buy land. At least have a contingency contract that if a septic system cannot be located on the property, the purchase can be canceled.
You can’t get any kind of building permit without showing them your Septic System Permit.
I live in North Carolina and these are the rules that apply to me. But, the rules where you live are probably about the same.
The Commission for Health Services has compiled rules and regulations addressing the placement, design, installation, and maintenance of subsurface ground absorption sewage disposal systems. The Environmental Health Section of the Department of Public Health acts as authorized agents of the Department of Environment and Natural Resources and ensures that these rules and regulations are enforced and the public’s health is protected.
First, submit an Application for Permits for Sewage Disposal Systems at the Environmental Health Offices near you. You may be able to apply online.
Once you pay the application fee, an Environmental Health Specialist will make a site evaluation.
This is what they will be looking for;
- Topography and landscape position
The inspector will be looking at where you want to put the septic system relative to the slope of the land to determine the drainage patterns. You don’t want rainwater or flood water filling up your septic tank.
A steep slope won’t give even the best soil a chance to percolate and treat wastewater before it reaches the groundwater system.
- Soil characteristics
The soil in the drainfield area of your septic system acts as a filter.
A perc test is one way to find out whether the soil is right to filter effluent while allowing it to seep through.
- Soil wetness
If the soil is too wet, the septic system won’t work. The drain field has to be able to drain. If it’s already wet, it won’t drain. This is another thing the perc test finds.
- Soil depth
A conventional septic system has trenches around three feet deep. If the soil is not that deep, if you dig down and hit solid rock, you have a problem.
- Restrictive horizons
Soil is made up of horizons or horizontal layers. A restrictive horizon is a layer of soil that water or sewage cannot flow through.
- Available space
A septic system will need at least 1/4 to 1/3 of an acre of acceptable soil as a drain field.
There are possible work-arounds if a traditional septic system won’t work, but they are more expensive and may need continual maintenance.*
Once your land has been evaluated, if it is approved you will be issued an Authorization to Construct a Subsurface Sewage Disposal System Permit. This is what you take to the County Inspections Department to get a building permit.
The septic system has to be constructed by a Certified Septic Installer contractor. You can’t just dig it yourself. Where I live contractors are certified by the North Carolina Onsite Wastewater Contractor Inspector Certification Board. You can find a contractor certified for where you live by searching for the Onsite Wastewater Contractor Inspector Certification Board for where you live.
Once the septic system is installed, you have to pass inspections to get a Certificate of Occupancy to move into your new home. The contractor should handle this part for you.
* It is doable. My aunt put in an Aerobic Treatment Unit. It was like running her own sewage plant just for her house. There was a a pre-treatment tank to add nutrients to keep the bacteria healthy and working, then a treatment tank with an aerobic system to give the bacteria enough oxygen to keep up, then a final tank for disinfection to make sure nothing dangerous got out. She had to test and pay for inspections regularly. She fell in love with a piece of land right on the water and this was her only option.
More Information: NC State Extension: Investigate Before You Invest
Featured Photo of septic system drain field on steep slope by Soil Science