Abstract: The present invention provides a spray method and spray apparatus for bentonite-based material that allow forming a bentonite layer of high dry density. A spray apparatus 1 comprises a supersonic nozzle 2, to which a compressor 5 and a bentonite container 6 are connected. The supersonic nozzle 2 is fed compressed air from the compressor 5 and a bentonite-based material from the bentonite container 6. The compressed air, mixed with the bentonite-based material, is accelerated to supersonic speed when passing through a constriction portion 14 of the supersonic nozzle 2, and is sprayed at supersonic speed out of a jet orifice 11.

Abstract: The present invention provides a spray method and spray apparatus for bentonite-based material that allow forming a bentonite layer of high dry density. A spray apparatus 1 comprises a supersonic nozzle 2, to which a compressor 5 and a bentonite container 6 are connected. The supersonic nozzle 2 is fed compressed air from the compressor 5 and a bentonite-based material from the bentonite container 6. The compressed air, mixed with the bentonite-based material, is accelerated to supersonic speed when passing through a constriction portion 14 of the supersonic nozzle 2, and is sprayed at supersonic speed out of a jet orifice 11.

Abstract: Systems and methods for installation and operation of a groundwater monitoring system in a borehole of any angle using a coaxial gas displacement pump with a unique O-ring assembly that serves as a two-position valve for groundwater purging and sampling and also as a housing and sealing mechanism for isolating an optical pressure sensor. The optical sensor measures in-situ hydraulic pressure directly subjacent and adjacent to the surrounding rock fractures and sediment pores without hydraulic interferences from potentiometric equilibration lag time from recovery fluid pressure inside a borehole, in a zone above the optical sensor, or on the inside of a riser pipe that rises to the ground surface.

Abstract: Systems and methods for installation and operation of a groundwater monitoring system in a borehole of any angle using a coaxial gas displacement pump with a unique O-ring assembly that serves as a two-position valve for groundwater purging and sampling and also as a housing and sealing mechanism for isolating an optical pressure sensor. The optical sensor measures in-situ hydraulic pressure directly subjacent and adjacent to the surrounding rock fractures and sediment pores without hydraulic interferences from potentiometric equilibration lag time from recovery fluid pressure inside a borehole, in a zone above the optical sensor, or on the inside of a riser pipe that rises to the ground surface.