Recycling systems can include a conveyor system, an optical device, and a processor operable to detect, identify, and count redeemable objects. The conveyor system can include a plurality of bins and be configured to move the bins from a first end of the conveyor system to a second end of the conveyor system. The optical device can be situated and configured to capture an image of a plurality of objects within a bin of the conveyor system. A processor including computer-readable instructions can be configured to detect and identify the objects within an image captured by the optical device as belonging to one or more object classes. Each object class can determine whether an object is redeemable or unredeemable. The processor can be configured to provide a count of only those objects identified as redeemable.

A hazardous material storage system includes a drillhole extending into the Earth and including an entry at least proximate a terranean surface. The drillhole includes a substantially vertical portion, a curved portion, and a horizontal portion that includes a hazardous waste repository formed within a first portion of the horizontal portion of the drillhole, the hazardous waste repository vertically isolated, by a rock formation, from a subterranean zone that includes mobile water, and a safety runway formed within a second portion of the horizontal portion exclusive of the hazardous waste repository and adjacent the curved portion, the safety runway defined by a particular length.

Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

Devices and techniques related to landfill gas extraction are disclosed. A technique for controlling extraction of landfill gas from a landfill through a gas extraction system is described. The method may include measuring a plurality of values indicating conditions associated with the landfill; computing, based at least in part on the plurality of values and on a model of the landfill, a predicted future state of the landfill; determining, based at least in part on the predicted future state of the landfill, one or more control parameters for one or more respective control devices configured to control operation of the gas extraction system; applying the one or more control parameters to the one or more respective control, and with the one or more control devices, controlling extraction of the landfill gas from the landfill based, at least in part, on the one or more respective control parameters.

A control system for controlling extraction of landfill gas, comprising: at least one sensor configured to measure one or more characteristics of landfill gas; at least one flow control mechanism disposed in well piping and configured to control flow of the landfill gas through the well piping; and at least one processor configured to: obtain a measured concentration of a first gas in landfill gas; determine whether the measured concentration of the first gas is either less than a first threshold concentration or greater than a second threshold concentration; when it is determined that the measured concentration is less than the first threshold concentration, control the at least one flow control mechanism to reduce flow rate of landfill gas; and when it is determined that the concentration is greater than the second threshold concentration, control the at least one flow control mechanism to increase the flow rate of landfill gas.

A hazardous material storage system includes a drillhole extending into the Earth and including an entry at least proximate a terranean surface. The drillhole includes a substantially vertical portion, a curved portion, and a horizontal portion that includes a hazardous waste repository formed within a first portion of the horizontal portion of the drillhole, the hazardous waste repository vertically isolated, by a rock formation, from a subterranean zone that includes mobile water, and a safety runway formed within a second portion of the horizontal portion exclusive of the hazardous waste repository and adjacent the curved portion, the safety runway defined by a particular length.

A landfill gas recovery system includes a waste layer disposed in a landfill and a capping layer overlying the waste layer. The capping layer includes a cured sealing layer and a loose fill layer between the waste layer and the cured sealing layer. The loose fill layer includes a granular fill material. The cured sealing layer includes a composite of the granular fill material and a cured water soluble polymer. The cured sealing layer is substantially impermeable to landfill gases formed within the waste layer.

A landfill gas recovery system includes a waste layer disposed in a landfill and a capping layer overlying the waste layer. The capping layer includes a cured sealing layer and a loose fill layer between the waste layer and the cured sealing layer. The loose fill layer includes a granular fill material. The cured sealing layer includes a composite of the granular fill material and a cured water soluble polymer. The cured sealing layer is substantially impermeable to landfill gases formed within the waste layer.

A control system for controlling extraction of landfill gas from a landfill via a gas extraction system, the gas extraction system comprising well piping for coupling a plurality of wells to a gas output. The control system comprises a controller configured to: obtain a value indicating measured energy content of landfill gas collected at the gas output from the plurality of wells; determine whether the measured energy content is different from a target energy content; and in response to determining that the measured energy content is different from the target energy content: control a plurality of valves disposed in the well piping to change flow rates of landfill gas being extracted from at least some of the plurality of wells at least in part by changing degrees to which the plurality of valves are open.

A control system for controlling extraction of landfill gas from a landfill via a gas extraction system, the gas extraction system comprising well piping for coupling a plurality of wells to a gas output. The control system comprises a controller configured to: obtain a value indicating measured energy content of landfill gas collected at the gas output from the plurality of wells; determine whether the measured energy content is different from a target energy content; and in response to determining that the measured energy content is different from the target energy content: control a plurality of valves disposed in the well piping to change flow rates of landfill gas being extracted from at least some of the plurality of wells at least in part by changing degrees to which the plurality of valves are open.