<p><p><strong>Reference(s):</strong></p><p><em>Bjerrum et al. (1967)<br>Casagrande (1983)</em></p><p><strong>Method Summary</strong></p><p>Piezometers are used to monitor ground water table and pore pressures developed in the ground. Monitoring the groundwater table is important in slope stability applications (particularly with collapsible soils), where electro-osmosis treatment has to be implemented as water level rises. Piezometers can also be used in dewatering applications to observe the lowering rate of water table during treatment and also to ensure that the water table is lowered to the desired depth, which is critical in cases with excavation instability problems.</p><p><strong>Accuracy and Precision</strong></p><p>The accuracy and precision of these devices has greatly improved with the advancements in instrumentation methods. Vibrating wire piezometers have been successfully used with 1% of measurement range precision.</p><p><strong>Adequacy of Coverage</strong></p><p>The number of piezometers to be installed depends on the ground terrain and treatment area size. Experience is required in proper selection of the location and number of piezometers.</p><p><strong>Implementation Requirements </strong></p><p>Some experience and special equipment is necessary for installation. Obtaining readings is very simple. The use of vibrating wire type piezometers requires electronic datalogger systems to record or read the data.</p><p><strong>General Comments</strong></p><p>Piezometers are useful for process control (QC), while it can be used sometimes for QA.</p></p>