The traditional leach field is a series of perforated tile lines laid in a trench prepared with a gravel bottom. The trench and the tile lines are designed to temporarily store the liquid until the surrounding soil can absorb the received liquid and permit the soil microbes time to destroy pathogens that may be carried in the liquid. The following drawing illustrates a simple system design, with alternating fields. Whether buying an existing home or buying a lot on which to build, once the purchase is made the new owner is faced with the challenge of managing an existing system or constructing a new system based on the soil resource on the chosen site. Soil types frequently vary significantly within short distances.
Different soils vary in their ability to accept and absorb liquid from the septic system.
Therefore, it is important to gather the facts to resolve your major concerns before purchase commitments are made. Purchase contracts may be written contingent upon acquiring soil test information or approval. The soils in the area where the leach field is placed will determine if a system will work well or poorly and determine the simplicity or the complexity and cost of the design required to provide satisfactory service. For a soil to absorb liquid, it must have adequate air space in the soil profile throughout the year to accommodate the liquid moving from the leach lines to the soil surrounding them. Soils that have limited air space or are periodically saturated with water will not accept liquid discharged into them quickly enough to service the wastewater from modern homes.