Abstract: A barrier of sheet metal elements in pile-driven into the ground in the path of contaminated groundwater. The barrier serves to funnel the contaminated water into an aperture in the barrier, in which is located a receptacle. A caisson is driven into the ground at the aperture, and the soil etc. removed from inside. A receptacle is lowered into the empty caisson, and a seal is provided whereby, when the caisson is removed the receptacle is sealed to the barrier. Baskets containing treatment material may be lowered into and hoisted out from the receptacle. Rubber seals seal the basket to the receptacle.

Abstract: Contaminated groundwater is treated in-situ, by funnelling the water through a gate or gates (23) in a watertight in-ground wall (18). Treatment material in the gate (23) breaks down the contaminant, or otherwise removes the contaminant from the flowing water. A removable caisson is first driven into the ground, excavated, and then a receptacle, for the treatment material, is lowered into the hollow interior.

Abstract: The joints between pile-driven sheet metal barrier elements (12, 14) have edge forms which interlock so as to form cavities (20, 21). The cavities extend from top to bottom of the barrier, and allow a flushing hose to be inserted to the foot of the barrier. Sealant is injected when the cavity is flushed clean. Two cavities are provided side by side at each joint. The cavities are independently sealed for extra reliability.

Abstract: Water draining from a septic tank contains ammonium, which traditionally is oxidized to nitrate in an aerobic soakaway. When the effluent enters the groundwater, the resulting nitrate concentration can be troublesome. A body of organic carbon, e.g. wood chppings, is provided, and the nitrate-laden effluent is passed through the carbon. The carbon is placed in the ground so as to be anaerobic: for example, the carbon may be placed below the water table; or the carbon may be mixed into a layer of fine silt, which is maintained in a state of tension-saturation by the effluent. Under anaerobic conditions, the nitrate is reduced by micro-biological action. The carbon is located such that the effluent naturally flows through the carbon, no pumps etc being required. The carbon may be located directly below the soakaway, or the carbon may be in a trench positioned to the side if the groundwater has a lateral component of flow.

Abstract: The packing-seal is shown in use in a borehole as a level-isolating seal for a groundwater sampler. The packing-seal shown includes an expandable annulus of Dowell (TM) water-expandable material. Surrounding that is a pressure-sleeve of rubber. A sheet of woven Kevlar (TM) is wrapped circumferentially around the sleeve and the Dowell annulus, such that the ends of the Kevlar sheet overlap. Outside the Kevlar is an outer rubber sleeve. Upon expansion of the packing seal to fill the borehole, the Kevlar sheet unwraps to allow the Dowell to expand without restraint. Once the packing seal has filled the borehole, the Kevlar sheet is prevented from unwrapping further. If the borehole contains a fissure the Kevlar provides a rigid bridge over the fissure, and prevents the packing-seal from ballooning out into the fissure.

Abstract: The disclosed sampler comprises a reservoir formed as a stainless steel tube of narrow diameter. Two copper tubes are attached to the reservoir, one each end, and the copper tubes may be crimped so as to seal the sample within the reservoir. The sample (of water) is allowed into the reservoir through a check-valve which is opened and closed by controlling the pressure--from the surface --inside the sampler. The disclosed sampler is sealed into the borehole by means of an inflatable collar, which is also under the control of a surface-manipulated pressure. Samples transported and stored in the sampler are presented for analysis complete with contained gases and uncontaminated.