Levelogger Series User Guide
Page 72
10.1.2 Fixed Installations
10.1.2.1 Flowing Artesian Monitoring
Monitoring of flowing artesian conditions using Leveloggers can be quite straight forward. Continuous artesian
conditions infer that the piezometric surface never drops below the level of the ground surface, or particularly
the top of casing elevation, and the casing is sealed with a wellhead. In this case, where freezing is not a
concern, the Levelogger need only be installed on the wellhead itself by means of an Artesian Well Fitting
Assembly, as illustrated in Figure 10-17. This same fitting allows the use of a Direct Read Cable to install the
Levelogger at depth in a well, for cases when the piezometric surface falls below top of casing. See separate
installation instructions.
Figure 10-17 Artesian Well Fitting Assembly
Note:
The Artesian Well Fitting Assembly is not recommended for pressures in excess of 30 psi (20 m (66 ft)) of
water column).
When conducting artesian monitoring with Leveloggers, a number of issues should be considered.
First, ensure that the maximum hydraulic pressure the datalogger will encounter at its installation point,
will not exceed the specified range of the datalogger. Second, artesian conditions do not preclude the
necessity for barometric compensation of Levelogger data. Artesian conditions are caused by aquacludes
forming confined aquifers. Confined aquifers, while not acted on by barometric pressure to the same
extent as unconfined aquifers, are typically subject to barometric pressure at some barometric efficiency
(See Section 10.1.3.1). Finally, bear in mind that the total pressure and subsequent water column equivalent
depth measured by the Levelogger after barometric compensation may not represent the actual water level
within the artesian well. Sealed intermittent artesian wells can be pressurized when artesian, but can also be
de-pressurized when non artesian. The Levelogger’s reading after barometric compensation represent the
height of the piezometric surface.
10.1.2.2 Vacuum Monitoring
Vacuum monitoring is usually conducted by first installing pressure transducers such as the Levelogger in
monitoring wells and then shutting-in or sealing those wells to the atmosphere with pressure sealed wellheads.
Air is pumped out from an extraction well amongst the cluster or matrix of monitoring wells, theoretically
dropping air pressure in the vicinity of the extraction well. For short-term tests in which data is not required
during the extraction event, the Leveloggers can be programmed and simply suspended from hooks or
eyelets on the underside of the sealed wellheads, the test run and the data collected at the end of the test by
extraction and downloading of the loggers. However, if ongoing data from the Leveloggers is required during
the extraction event, the loggers must be installed in a manner similar to the artesian monitoring scenarios
described previously in this section. Leveloggers or Barologgers can be used to monitor the drop in pressure.
