Evaporation of treated waste water

Claim 1

In a system for evaporating waste water, a. a generally horizontally elongated evaporation bed comprising multiple layers, the top layer exposed to the atmosphere, b. said layers including an upper layer of rock pieces and a lower sand layer, c. there being piping extending in the upper rock layer and containing perforations to relatively slowly deliver waste water into that rock layer for percolation into the sand layer and ultimate evaporation therefrom, d. there being a lower rock layer under the sand layer to receive drainage of excess water therefrom, and means to recirculate drainage of water in the lower rock layer for return to the upper rock layer, said last named means including a sump in communication with said lower rock layer to receive water drainage therefrom, and a pump taking suction from the sump and having its outlet in supply communication with said piping, and e. a septic tank, and a conduit communicating between said tank and said pump to deliver tank contents to the sump for delivery by the pump to said piping in the upper rock layer.