For those residents of Whispering Pines, North Carolina who were not able to hear our radio broadcast March 21, 2010 dedicated solely to the care and maintenance of Septic Systems in Whispering Pines, North Carolina, (WEEB - Talk Radio 990 on "All Things Real Estate"), here is the first of seven short articles summarizing the most important points we discussed that morning about septic systems.
Every home in Whispering Pines, North Carolina has its own private wastewater septic system which consists of a watertight container (usually a precast reinforced concrete tank although it may be made of plastic or fiberglass) connected to a drainfield. When properly designed and maintained, it is a both a cost effective and environmentally friendly way to dispose of wastewaters produced in a home's bathroom, kitchen and laundry.
A typical septic system in Whispering Pines works as follows. As wastewater flows into the tank from the home, the heavier solid materials settle to the bottom forming a sludge layer, while the lighter greases and fats float to the top, forming a scum layer. After about two days in the tank, the liquid portion flows out of the tank through the outlet pipe into a set of leach lines (the solids are normally held back by an outlet baffle). Often the effluent is distributed equally between a series of leach lines by what is known as a distribution box or D-Box.
While some anaerobic digestion of the solids takes place in the septic tank, the real treatment of the wastewater occurs in the soil beneath the drainfield. The drainfield is much more than just a perforated pipe placed at will lying underground. First, the soils under the leach lines must be of a type that they are able to absorb and purify the effluent. Secondly, the watertable of the surrounding area must be deep enough that it is not contaminated by the wastewaters. And, thirdly, the leach lines must be positioned in such a way as to be gravity fed from the tank, or a pump is required to lift the effluent to a height above the leach lines. Not every lot within a subdivision of Whispering Pines, North Carolina which relies on wastewater septic systems will automatically be able to support this type of treatment system. Accordingly, an Improvement Permit from the Moore County Environmental Services should be obtained prior to purchasing a lot, and/or the sale made subject to the securing of such a permit. That way, a Buyer does not end up purchasing a lot upon which a house cannot be built because it cannot support a septic wastewater treatment system.
The leach lines consist not only of perforated pipes, but a trench below the pipes made either of gravel, polystyrene aggregate or tire chip aggregate. These materials provide a void space in the trench to allow distribution of the effluent to the trench bottom. A special zone, called a biomat, normally forms in the upper 1 to 6 inches of the soil at the soil/trench interface. The biomat zone helps to remove many of the germs and chemical pollutants in the wastewater as it passes through this layer.
If the solids in the septic tank are never pumped out, they can enter the trenches and produce an excessively thick biomat layer that will eventually prevent the normal flow of water through this layer. When this happens, a backup is created, causing the system to fail. That is why proper maintenance of all septic systems in Whispering Pines, North Carolina is critical, both for the health and safety of an individual homeowner, but also the purity of one of our most important natural resources, the eight community lakes that make Whispering Pines, North Carolina so beautiful and sought after as a place to live.
Have you had enough technical septic system jargon for one sitting? I think so. Please bookmark this article, and we will be back with our second segment in a couple of days.