Patent ID: 6969464

Claim:
A method of treating the leach field of a sewage system to improve its functioning, wherein the leach field is comprised of a septic tank in communication with a conduit buried within soil, which soil runs continuously from the conduit to an upper soil surface which is exposed to atmosphere, the conduit having an associated influence zone within the soil into which waste water flows and is acted upon biochemically to make the water more environmentally benign, which comprises: removing the water from said conduit while causing water to flow within the soil to the conduit, then reducing the pressure in the conduit to less than atmospheric pressure, to both further remove water and to cause inward flow of water from the influence zone into the conduit, while impeding vertically downward flow of atmospheric air that is induced by the step of reducing the pressure in the conduit, through that portion of the soil surface which lies directly above the conduit, while allowing downward flow of air in adjacent areas of the soil surface.