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Abs: <\/strong>Intensive investigations of contaminated sites in fractured rock are increasing in North America, \u00a0<\/strong><\/p>\n Intensive investigations of contaminated sites in fractured rock are increasing in North America, A “liner” is an impervious cylindrical sleeve installed in boreholes by inversion with water, such that the sleeve “lines” the hole to form a tight seal. This liner serves as a continuous inflated packer, preventing hydraulic cross-connection in the hole caused by water flowing into the hole from some fractures and then moving up or down to exit the hole from other fractures. In areas where groundwater contamination exists in the bedrock, this cross-connecting flow causes chemical cross-contamination that confuses chemical data interpretation and commonly makes the contamination worse. Therefore, in some jurisdictions of North America (e.g., New Jersey) regulations for contaminated site investigations now require that soon after a hole is drilled, it must be temporarily sealed, immediately have a monitoring system installed, or immediately and permanently be sealed with grout. The FLUTe liner is the only practical method now available to quickly but temporarily seal a hole.<\/p>\n In addition to accomplishing the goal of sealing the hole, these liners are used to acquire data from the hole prior to installation of a well or a multilevel monitoring system, such as the Westbay\u00ae system, Waterloo system, or a Water FLUTe\u2122 system. Prior to 2005, FLUTe liners were installed in hole solely to seal the hole against cross-contamination. However, two other major advantages derived from the liner installation have since been developed: measurement of the borehole hydraulic conductivity as the liner is installed (K profiling) and high resolution temperature measurement in the static water column inside the liner. Figure 1 provides an explanation of the K-profiling method and gives an example profile. This involves monitoring the rate of descent, or velocity, of the inflating liner going down the hole. The liner velocity profile (Figure 1) is used to calculate values for the transmissivity (T) and hydraulic conductivity (K) of permeable zones, which are then plotted in profile. Photographs of the installation and removal of a liner are shown in Figure 2. The results from the FLUTe K profiling are used to select and prioritize intervals for high resolution straddle packer hydraulic testing.<\/p>\n A new temperature profiling probe can be applied inside the liner to identify hydraulically active fractures. This method typically shows many more active fractures than temperature profiles with no liner in the hole. With no liner in the hole, the thermal evidence for most of the active fractures is obliterated by borehole cross-connection effects. Therefore, the liner provides the means for greatly enhancing the sensitivity for fracture identification. Some types of geophysical logging can also be done inside the lined hole to obtain information about the geology. FLUTe liners are temporary; after the K and temperature profiling are done and interpretation of all borehole data is complete, the liner is
\nwith application of many new field methods. A multidisciplinary research team at the University
\nof Guelph (UofG), led by Dr. Beth Parker, has developed a comprehensive approach for such
\ninvestigations aimed at delineation of contaminant distributions and understanding the transport and
\nfate of contaminants in both fracture networks and the rock matrix blocks between the fractures. This
\nis known as the Discrete Fracture Network (DFN) Approach. This approach includes important new methods, several of which involve “flexible liners”, referred to as FLUTe\u2122 technologies.<\/p>\n
\nwith application of many new field methods. A multidisciplinary research team at the University
\nof Guelph (UofG), led by Dr. Beth Parker, has developed a comprehensive approach for such
\ninvestigations aimed at delineation of contaminant distributions and understanding the transport and
\nfate of contaminants in both fracture networks and the rock matrix blocks between the fractures. This
\nis known as the Discrete Fracture Network (DFN) Approach. This approach includes important new methods, several of which involve “flexible liners”, referred to as FLUTe\u2122 technologies.<\/p>\n
\nremoved for installation of a multilevel system or monitoring well, which are designed based on the
\ninterpreted data. The manner by which the FLUTe liner goes down the borehole makes it uniquely
\nsuitable for delivering various types of monitoring devices to many different depths in each hole,
\nsuch as groundwater sampling pumps, pressure transducers, and other types of measurement
\ndevices currently being developed. After sufficient data have been obtained, these monitoring systems
\ncan be removed by pumping the water out of the interior of the liner system. This allows the hole to
\nbe easily decommissioned or used for other purposes. The FLUTe\u2010based methods described
\nabove are being applied intensively by the UofG team and collaborators in the research context at
\neight contaminated bedrock sites in Canada and the United States. The methods are also being used
\nin a non-research context at many other sites across North America and beyond. Although these
\nmethods are now serving the needs of the professional site\u2010investigation community, as for
\nall developing technologies understanding the site circumstances where each technology is best
\nsuited is necessary, as are refinements to the process to address extreme or unusual borehole
\nconditions. This is now the focus of much of the UofG collaboration with FLUTe.<\/p>\n","protected":false},"excerpt":{"rendered":"