These relatively inert materials will accumulate with time, no matter what miracle products you put down the drain. Since waste is flowing into the tank on a regular basis, something must also leave the tank as well. Further decontamination must take place in the soil treatment system, called the leachfield, drainfield, or soil absorption field. Effluent is distributed through a series of perforated distribution pipes laid in the ground. The effluent moves slowly out of the pipes and is absorbed into the soil, hopefully at a rate that doesn t exceed the ability of beneficial soil microbes and natural chemical processes to break down remaining wastes.
Soils vary in their ability to absorb and treat wastewater.
Coarse gravel or sandy soils, such as those present in much of Washoe Valley, may allow wastewater to flow too quickly for treatment. This can be a source of contamination to well water supplies. In fine clay or compacted soils, water moves too slowly, and a lack of oxygen may interfere with bacterial action. If solids are not pumped out of the tank on a regular basis about every three years, you run the risk that they will be carried into the leachfield, where they may plug the holes in the distribution pipes, or plug the pores in the soil. When this happens, waste may back up into the house or you may smell nasty odors in the leachfield area.