How Does a Septic System (Leach Field) Work?

We can manage any of your Septic Design needs. We can help with system replacements, pump systems or tough terrain. We are also up to date on the newest alternative systems like an Enviro Septic or the Advanced Enviro Septic. 

If your looking to subdivide your property we can work with you and the state of NH to get your subdivision approved. 

We also can provide test pit analysis to determine soil type and percolation rates, which can help you in making some important decisions in regards to your property's development.

If you have any questions please call 603-235-0899 or email us at edwardssurveydesign@gmail.com we'll be glad to discuss and assess your property needs with you.

What is A Subsurface Disposal System?

A lot of people are unsure about what exactly is a Subsurface Disposal System (Septic System) so we'd like to help clarify any questions or concerns about Septic Systems.

So What Is A Septic System?

          A Septic System is an on-site recycling system which treats waste water and returns it to the groundwater. If properly designed, installed, used, and maintained, a septics system can do its work safely and efficiently for many years. Improper design, installation, use and/or maintenance can lead to premature and costly failure.
          A Septic System typically consists of two components: the septic tank and the effluent disposal area (leach field). These components treat and renovate the waste water so that it may safely return to the groundwater.

The Septic Tank

         The Septic Tank provides the first step in treatment. It's primary purpose is to protect the drain field or other system components from becoming clogged by solids suspended in the waste water. The waste water is discharged from the home directly into the tank where the heavier solids settle to the bottom to form a sludge layer and lighter solids, greases, and oils float to the top to form a scum layer.
         The Septic Tank also digests or breaks down the waste solids. Micro-organisms that thrive without oxygen feed on the solids to reduce the volume of sludge and scum. Only 40% of the sludge and scum volume can be reduced in the manner however, so the tank must be pumped regularly toremove the accumulated solids. If the tank is not pumped regularly, it will fill with sludge and the solids will be washed out into the drain field where they will quickly clog the soil. This may require significant cost to repair or replace. During the treatment  process, gases are produced which must be vented from the tank either through plumbing vent on your building's roof or through other system vents.

Effluent Disposal Area (Leach Field)

          The Effluent Disposal Area is the place where the liquid flowing from the Septic Tank (called effluent) is treated and returned to the groundwater. The leach field must be placed on permeable, dry soil. Rules generally specify a Vertical separation between the bottom of the leaching area and the water table, bedrock, or other limiting factors. Horizontal separation distances to wells, streams, and other features are prescribed in the rules as well. When these are maintained, the soil acts as a biological filter and treatment unit, removing pathogenic (harmful) bacteria and viruses from the effluent stream, recycling the waste water safely to the water table.

Design and Installation of Your System

           The New Hampshire Department of Environmental Services regulates the design and installation of Septic Systems using the Subdivision and Individual Sewage Disposal System Design Rules Chapter Env-Wq 1000. Env-Wq 1002.42 states "Individual Sewage Disposal System (ISDS)" means any waste water disposal or treatment system, other than a system regulated under  Env-Wq 700, which receives sewage or other wastes, gas-operated, electric, fossil-fueled or any combination thereof.

            The state of New Hampshire conducts the testing and permitting of all Designers and Installers. Licenses are re-newed on a bi-yearly basis. Designers and Installers are required to obtain 6 continueing educations units (CEU) every 2 years.


            For Further Information Please visit the Granite State Designers and Installers Association at www.GSDIA.org. You can also learn more about the use and maintenance of your Septic System.