Subsurface waste disposal system

DETAILED DESCRIPTION An artificial perched bed of selected granular soil media including a plurality of layers is adapted to intensively receive sludge and other wastes in a semi-liquid form, to retain the solids from such wastes within the bed, and to allow the liquid portion of the wastes to percolate through the bed into an underdrain system for removal from the bed.
The bed includes at least two layers, in which an upper layer is formed from a relatively fine grained material and is aerobic, and a lower layer is formed from relatively coarser grained material.
The underdrain system is located in the lower layer, which may be suitably separated from the upper layer to permit the passage of liquid to the lower layer while maintaining the solids in the upper layer.
The underdrain system carries the collected liquid to a collection basin for monitoring, discharge, or return to the bed for further treatment.
An impervious liner under the perched bed prevents seepage of effluent from the bed into the natural underlying ground and water table.
In combination with the artificial bed, a subsurface sludge injector operates to permit intensive use of the bed.
The injector maintains a soil covering over the sludge at all times, thereby eliminating all potential problems such as odors, vector control, surface runoff, unsightliness, and other visual aesthetics.
The deflector nozzle meters the flow of the waste forward, sideways and backwards into a subsurface cavity being continuously formed by the moving injector, thus providing even distribution of the waste material into the soil media.
The deflector design both insures maximum distribution of the waste and prevents surface exposure as might be caused by excessive flow in any one direction.
A shallow injection depth into the aerobic zone of the upper soil layer facilitates the microbiological decomposition of the sludge and also allows for maximum evaporation of the liquid, thereby decreasing the bed's repeat loading cycle.
The subsurface injector also disrupts the surrounding soil the facilitate maximum absorption of the liquid stream