Multilevel Ground-Water Monitoring
نویسنده
چکیده
CONTENTS Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 808 Why Three-Dimensional Plume Delineation is Necessary . . . . . . . . . . . . . . . . . . . . . . . 812 Measurement of Vertical Hydraulic Heads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 814 One Time Sampling versus Permanent Multilevel Monitoring Devices . . . . . . . . . . . 814 Where You Monitor is as Important as How You Monitor . . . . . . . . . . . . . . . . . . . . . . 816 Options for Multilevel Ground-Water Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 819 Multilevel Sampling within Single-Interval Monitoring Wells . . . . . . . . . . . . . . . . . 819 Multiple Diffusion Samplers Installed inside Single-Interval Monitoring Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 819 Diffusion Multilevel System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 820 Passive Diffusion Bag Samplers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 821 Active Collection of Samples from Multiple Depths within a Single-Interval Well Using Grab Samplers or Depth-Discrete Pumping . . . . . . . . . . . . . . . . . . . 821 Grab or Thief Samplers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 822 Collecting Depth-Discrete Samples by Pumping from Different Depths in Well Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 822 Nested Wells (Multiple Tubes or Casings in a Single Borehole) . . . . . . . . . . . . . . . . 823 Bundle Wells Installed in Collapsing Sand Formations . . . . . . . . . . . . . . . . . . . . . 824 Nested Wells Installed with Seals between Monitored Zones . . . . . . . . . . . . . . . . 824 Well Clusters (One Well per Borehole) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 829 Dedicated Multilevel Ground-Water Monitoring Systems . . . . . . . . . . . . . . . . . . . . . 830 Drilling and Installation Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833 Installations in Open Boreholes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 833 Installations in Unconsolidated Sedimentary Deposits . . . . . . . . . . . . . . . . . . . . 833 Minimizing Cross-Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 836 Development of Multilevel Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 836 Westbay MP System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 837 Solinst Waterloo System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 839 Solinst CMT System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 841 Water FLUTe System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 843 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 845
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