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I a� UPDATE Multi-level MonitoringSySteM (patentpending) Waver levels and water samples from up to T discrete-depths The Precision Multi-Level Monitoring System (patent pending) is ae0ow new multi-level monitoring system that can be used to monitor , piezometric pressure and water quality in as many as seven zones in a single borehole The key component of the system is custom-made multi-chamber tubing The 1 7"OD tubing,made of either polyethylene or Teflon,is extruded at the factory with internal partitions,forming seven discrete internal chambers within the larger tube The chambers can be accessed by drilling ports in the external wall of the tubing opposite i the desired chamber(the tubing is scribed along its entire length to •, Y �_ allow for easy identification of specific chambers) The chambers are approximately 1/2"diameter,facilitating measurement of water levels using electronic well sounders and pressure transducers Multi-level monitoring well Custom- Groundwater samples can be collected from the chambers using small extruded polyethylene tubing contains 7 diameter bailers,check valve tubing pumps,or peristaltic pumps chambers The multi-chamber tubing comes on a 5-foot-diameter coil that can be as long as several hundred feet The desired length is cut from i Wshe coil at the field site based on the hydrogeologic data obtained rom the exploratory boring Having a continuous length of tubing is a key feature of the system since it eliminates the problem of needing td have strong,water-tight joints in the monitoring well Nojoints exist because the tubing is one piece This dramatically decreases the cost(and increases the reliability)of the system The multi-level well is built completely above ground and inserted I into the borehole prior to withdrawing the Enviro-Core®drive casing The screened intervals are selected based on the boring log and ports are drilled into the appropriate chamber at the selected depth Stainless steel screen is then wrapped around the tubing to prevent sediment from entering the internal chambers In homogeneous heaving sands,the multi-level well is inserted directly through the Ports are drilled into individual chambers at drive casing When the drive casing is withdrawn,the sand collapses desired depths stainless steel screens are secured around the tubing and stainless steel screens around the open ports An injected sealant seals The multi-level well can also be installed with integrated,pre- the chamber below the ports packed sand around the sampling ports and bentonite seals between the monitored intervals The sand is first poured into non-expanding nylon mesh sleeves that encompass the sampling ports and then are affixed to the tubing with stainless steel clamps The bentonite seals are installed prior to insertion in a similar way,except that the bentonite pellets are contained in a coarser nylon mesh that expands as the bentonite swells upon hydration The fully-built well is inserted into the borehole as described above,and the drive casing is withdrawn When groundwater contacts the bentonite in the packers, the bentonite begins to swell The packers will completely seal the 3 5-inch diameter borehole between the seven monitored zones within a few hours Tubing comes in 300'coils Tubing is cut to specified length and the multi-level well is Leaders in Innovative Direct-Push Technology assembled at the ground surface t