Described herein is a composition for use in a geosynthetic clay liner, the composition comprising particles, at least some of which are discrete particles and each comprise: a compacted swelling clay, the clay having been compacted such that it at least partially surrounds a fluid-loss preventing polymer. Also described herein is a clay liner formed from the composition, a method for producing particles for use in a geosynthetic clay liner, and a method of forming a clay liner.

A sewer manhole cover includes a frame having an access aperture and a cover for covering the access aperture. A primary seal is generated when the cover is placed on the frame either by way of contact between the frame and cover or by way of a gasket received within a groove formed into one of the frame or cover, wherein the gasket is compressed between the frame and cover. A method is provided for generating a secondary seal between the frame and cover by applying an amount of a viscous compound to a circumferential surface of the frame or cover, wherein the secondary seal is formed when the cover compresses the compound when the cover is received within the frame.

Systems and methods of the present invention include a method for the treatment of drilling wastes and coal combustion residues, comprising combining at least a first drilling waste with coal combustion residues to form a paste, combining at least a second drilling waste with coal combustion residues to form a compactable fill, and placing the paste and the compactable fill in a landfill. Other embodiments include a method of treating drilling wastes and coal combustion residues, comprising combining at least one drilling waste with a coal combustion residue to form a paste. Further embodiments include containing the paste within at least one geotextile container. Still further embodiments include placing the geotextile container in a landfill.

A membrane-lined wall for levee reinforcement or leak prevention, prevention of water migration, and pollution control of impoundments. The membrane-lined wall generally includes a cementitious or concrete wall formed within an excavated trench. The concrete may be internally reinforced, and the wall may also comprise a double-layer of impermeable geomembrane liner that forms a barrier between the concrete and the sides and bottom of the trench. The membrane or liner reduces water migration, prevents levee leakage, and prevents the escape of contaminants in impoundments.

A method for forming a geomembrane liner testable for leaks by securing adjacent panels together with the conductivity of the lower surface of an overlying panel broken along a line adjacent the panel overlapping edge, and the overlapping edges sealed along the line. A heat welder has slots for the overlapping panel edges, with a heated wedge between the slots and having a projection to break the conductivity of the overlying panel bottom surface as it passes the wedge. The slots merge to press the liner edges together to heat weld them along the line of broken conductivity as the welder is moved along the panel edges.

Provided is a polyvinyl chloride (PVC)/ethylene-vinyl alcohol (EVOH) multilayer sheet used for the fabrication of liners and covers for the geotechnical industry (geomembrane), which sheet has both good flexibility and excellent barrier properties to organic solvents and gases.

A geosynthetic clay liner for containing low pH, acidic fluids including a dry blended mix 90%-99% by weight bentonite and 1%-10% by weight high molecular weight cellulose ether polymer, and a method and containment including the liner to protect an environment around a site having low pH, acidic fluids.

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 510.sup.8 cm/sec or lower.

A cementitious composite for in-situ hydration includes a structure layer having a first side and an opposing second side, a cementitious material disposed within the structure layer, a sealing layer disposed along and coupled to the first side of the structure layer, and a containment layer disposed along the opposing second side of the structure layer. The structure layer has an intersection at the sealing layer and the containment layer that is at least partially fiberless. The cementitious material includes a plurality of cementitious particles. The containment layer is configured to prevent the plurality of cementitious particles from migrating out of the structure layer.

Improved containment mats and systems of containment mats may include multiple adjoining mats with a top surface and a bottom surface. The multiple mats may provide a modular structural mat system that may be installed at a drill site, with multiple mats placed adjacent to each other with a lap joint connecting adjacent mats. A geotextile may be used to cover the lap joints and a coating applied to the geotextile. Such a system may provide containment of potential spills, a reliable working surface for drilling operations, and relatively fast and less expensive installation.