A sediment capping system is adapted to create, and distribute, a homogenized mixture of capping material. Where distributing the capping material, the system is configured to militate against the capping material forming clumps of a size and weight that would disturb the sediment on a bottom of a body of water. This in turn militates against the sediment being disturbed, and a disturbing of pollutants and toxins into the water surrounding the sediment. The sediment capping system militates against the clumping of capping material through a vibrating spreader and baffle system, producing a sediment cap with a more consistent depth that will minimally disturb the sediment on the floor of the body of water where the sediment cap is being deposited.

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.

An articulating mattress of blocks interconnected with tensiles seated therein, said blocks having opposing longitudinal and transverse sides and a top surface each of a smooth surface by contact with a mold surface during casting and a bottom surface having a rough surface by screeding the flowable casting material from an open side of a mold formwork. The mattress inverted with a rolling apparatus for installation with the rough surface in frictional contact on a ground surface for erosion control, said mattress rolling apparatus having base, front wheels, and steerable rear wheels, with a rolling mechanism for rolling the articulating mattress. An apparatus and a method of casting an articulable mattress with a rough bottom surface for erosion control are disclosed.

Described herein are embodiments of a control system that automatically (1) determines whether a gas extraction system is in a state in which landfill gas is being released into the atmosphere, and (2) automatically controls landfill gas flow to mitigate, prevent and/or stop the release of landfill gas. The control system may control a valve to control flow of landfill gas through well piping of the gas extraction system. The pressure of landfill gas in the well piping at a location upstream of the valve may indicate whether there is a risk of landfill gas being released into the atmosphere. The control system may adjust a position of the valve in response to determining that the pressure at the location upstream of the valve indicates that there is a risk of landfill gas being released into the atmosphere.

A tufted geotextile cover system, comprising a backing sheet tufted with first tuft lines of tufts on a first spacing and second transverse tuft lines of tufts on a second spacing greater than the first spacing to dispose the second tufts intermediate opposing pairs of the first tuft lines that define interstices for receiving infill, the tufts in the second tuft lines increasing resistance of the infill to displacement and dry flow movement in response to loading on the geotextile overlying a surface for covering a ground site. A closure system is disclosed using the tufted geotextile as a component overlying an impermeable geomembrane for resisting inflow of water below the ground surface.

A bund system for the retention of solid or liquid or pourable waste material; bunds of the bund system comprising retaining structures; the retaining structures including at least one vertical structural element relative a base; the base covering a portion of a ground surface; the bunds maintained in a selected position on the ground surface by interaction of the retaining elements with a mass of compacted material.

Also disclosed is a method of forming a waste retention area by enclosing the waste retention area by bunds; the bunds comprising at least one substantially vertical retaining structure relative a base extending over a portion of a ground surface; the method including the steps of; positioning retaining structures on the ground surface to form an enclosed area; horizontal base panels of the retaining structures facing inwards to the enclosed area, welding overlap portions of sealing elements at adjacent vertical and horizontal joints between adjoining retaining structures, placing an impervious liner over the ground surface of the enclosed area, welding edges of the impervious liner to edges of sealing elements at inward edges of the horizontal base panels.

A vertical manhole apparatus for use in a waste facility to provide access to one or more leachate collection pipe access points. The vertical manhole is stabilized using stabilizing features extending out from a vertical pipe of the vertical manhole apparatus.

The invention relates to a low-permeability geotechnical barrier material including a blend of approximately equal parts of: aggregate particles, sand-size particles and manufactured composite particles that include a hydratable sealant material composed of naturally-occurring clay minerals and/or polymer-enhanced clay minerals, such that the actual percentage of clay mineral component is less than 10% by weight in the blended material. In a particular embodiment, the construction of a low-permeability geotechnical barrier using predominantly coarse grain materials by conventional compaction efforts is rarely attempted due to the difficulty of maintaining a uniform mix of well-graded sand and aggregate blends necessary to achieve low permeability. The regularly achievable permeability offered by this material blend when installed with specific proscribed techniques using conventional equipment can be 5×10.sup.−8 cm/sec or lower.

A geocomposite covering for placement atop the ground including a lower carrier layer and an intermediate layer of particulate material positioned above the lower carrier layer. A synthetic turf is positioned over the particulate material and is affixed to the lower carrier layer to contain the particulate material between the lower carrier layer and the synthetic turf. The synthetic turf is affixed to the lower carrier layer by one or more of stitches, needle-punched staple fibers, linking fibers, heat bonded fibers, or mechanical fasteners. The particulate material can include clays, cementitious materials, granular material, powder-like material, and the like.

A capping assembly (10) for mounting on a covering (12) is disclosed. The capping assembly (10) comprises a cap (14) which can be disposed on the covering (12), a securing arrangement (18) to enable the capping assembly (10) to be secured on the covering (12). The capping assembly (10) further includes an insertion member (16) for insertion through the covering (12). The cap (14) can be attached to the insertion member (16). The securing arrangement (18) comprises a securing device (20) and a holding formation (44) to hold the securing device (20), the holding formation (44) being provided on the insertion member (16).