Patent ID: 7493954

Claim:
A method of monitoring a borehole defined within ground with sensor arrangements, the method comprising: providing the borehole; providing a central pipe; providing at least one riser pipe arrangement comprising: a riser pipe; a filter at a distal end of the riser pipe; a sensor arrangement within the riser pipe, the sensor arrangement comprising: a sensor isolation tip adjacent the riser pipe and comprising one or more O-rings around an outer surface of the sensor isolation tip adjacent an inner wall of the riser pipe; a sensor at a distal end of the sensor isolation tip and communicatively coupled to a control system; and a groundwater sample return line coupled to the sensor isolation tip and comprising at least one inlet at a distal end and an outlet at a proximal end outside the borehole; moving the central pipe into the borehole; guiding the at least one riser pipe arrangement with a centralizer along the central pipe into the borehole; moving a very fine-grained filter pack material through the central pipe such that it is around each filter and an adjacent wall of the borehole; providing a pressurized gas into each riser pipe to force groundwater therein through the at least one inlet and through the groundwater sample return line; periodically testing hydraulic pressure within the borehole with each sensor; periodically providing a pressurized gas into a selected riser pipe to force groundwater therein through the at least one inlet and through the groundwater sample return line; and testing groundwater obtained from the groundwater sample return line; wherein prior to directing the pressurized gas into the selected riser pipe, the sensor isolation tip is moved to allow groundwater to enter the selected riser pipe through the filter.