Pervious surround method of waste disposal

Claim 1

A method of disposal of waste deposits involving the steps of: (a) obtaining a cavity in the ground below a level of present or anticipated groundwater tables; (b) providing a continuous pervious zone of natural, durable material about the interior of the cavity, said pervious zone being characterized by having a significantly greater permeability than the adjacent ground and the waste deposit and being of a thickness predetermined to provide adequate transmissivity to transmit the flow of all groundwater intercepting said pervious zone from the ground about the waste deposit; (c) providing a filter zone of natural, durable material next within the pervious zone, said filter zone characterized by having materials of a grain size and gradation common to conventional graded filter materials and being intermediate in size to the grain size of the waste deposit material and the pervious zone material, and having a permeability and a thickness predetermined to suppress dispersion of the waste deposit and to control the concentration gradient of molecular diffusion from the waste deposit through the filter zone to the pervious zone to predetermined acceptable levels; (d) providing a waste disposal zone within the filter zone, said disposal zone being adapted to receive waste deposits; (e) depositing waste deposits in the disposal zone beneath the groundwater table; (f) covering the cavity by continuing the filter zone and the pervious zone over the cavity beneath the level of present or anticipated groundwater tables; and (g) allowing the groundwater level to reinstate over the deposited waste.

Claim 2

A method of disposal of waste deposits involving the steps of: (a) obtaining a cavity in the ground below a level of present or anticipated groundwater tables; (b) providing a continuous pervious zone of natural, durable material about the interior of the cavity, said pervious zone being characterized by having a significantly greater permeability than the adjacent ground and the waste deposit and being of a thickness predetermined to provide adequate transmissivity to transmit the flow of all groundwater intercepting said pervious zone from the ground about the waste deposit; (c) providing a filter zone of natural, durable material next within the pervious zone, said filter zone characterized by having materials of a grain size and gradation common to conventional graded filter materials and being intermediate in size to the grain size of the waste deposit material and the pervious zone material, and having a permeability and a thickness predetermined to suppress dispersion of the waste deposit and to control the concentration gradient of molecular diffusion from the waste deposit through the filter zone to the pervious zone to predetermined acceptable levels; (d) providing a waste disposal zone within the filter zone, said disposal zone being adapted to receive waste deposits; (e) depositing waste deposits in the disposal zone beneath the groundwater table; (f) covering the cavity by continuing the filter zone and the pervious zone over the cavity beneath the level of present or anticipated groundwater tables; and (g) allowing the groundwater level to reinstate over the deposited waste.

Claim 5

The method of claims 2, or 3 in which the filter zone is constructed by making up layers of materials of gradations selected to prevent migration of the solid particles of the stored deposits into the pervious zone while being of such permeability as to permit drainage of the water from the waste deposits during waste deposition thereby facilitating consolidation of the deposits under self-weight, but maintaining sufficiently low seepage velocities through the filter zone so that mechanical dispersion becomes insignificant as a mechanism of contaminant transport from the waste deposits through the filter zone into the pervious zone.

Claim 9

A method of reducing to acceptable levels contaminant transport from deposits placed in a disposal zone beneath groundwater level comprising the improvement of providing a continuous highly pervious zone beneath the groundwater level and about the disposal zone to reduce hydraulic gradients across the disposal zone thereby reducing contaminant transport by seepage from the disposal zone to acceptable levels and said pervious zone being sufficiently distant from said disposal zone to reduce contaminant transport by diffusion to acceptable levels.

Claim 10

A method of reducing to acceptable levels contaminant transport from deposits placed in a disposal zone beneath groundwater level comprising the improvement of providing a continuous highly pervious zone beneath the groundwater level and about the disposal zone to reduce hydraulic gradients across the disposal zone thereby reducing contaminant transport by seepage from the disposal zone to acceptable levels and said pervious zone being sufficiently distant from said disposal zone to reduce contaminant transport by diffusion to acceptable levels.