UK Mining company research Solinst Leveloggers for Innovative Hydrogeological Monitoring

UK Mining company research Solinst Leveloggers for Innovative Hydrogeological Monitoring

Groundwater researchers at a UK Mining company in the UK wanted to conduct studies to determine the suitability of Solinst waterlevel Leveloggers for hydrogeological monitoring of their mining operations.

Through pumping tests and other studies, they showed that continuous, high-frequency water level data is critical to accurately track the effects of mining operations on groundwater resources and surface water-groundwater interactions.

As part of the hydrogeological studies carried out, Solinst, Levelogger 5 Junior dataloggers were used to measure changes in the position of the groundwater table, allowing automatic measurement of water table fluctuations. They are absolute dataloggers, measuring the total pressure exerted on the sensor (water column and atmospheric pressure). Accurate results are obtained by installing a Barologger, a surface recorder that measures atmospheric pressure. It is used to compensate readings from Levelogger 5 Junior by atmospheric pressure. Such a set allows measurements with an accuracy of 0.01-0.02% for the full measurement scale and logging at a frequency of 0.5 sec to 99 h. The recorder can store up to 40,000 sets of data. In addition, it is equipped with a Platinum RTD temperature sensor, which allows measurement with an accuracy of ±0.1°C. Temperature measurements take place at the same frequency as water level measurements. Programming and reading data from the loggers are done using an optical docking station for a PC (Field Reader 5). Levelogger software allows viewing data stored in the logger as a table and graph, exporting data to other formats, and programming the logger.

Automatic groundwater level dataloggers were used for measurements in the region of the lower reservoir of the pumped storage power plant. A Piezometer was installed, and a levelogger was lowered to measure groundwater fluctuations. The measurements were carried out about 300 m from the reservoir’s shoreline, capturing the first aquifer of medium and coarse-grained sands with an admixture of sand and gravel. The piezometer was installed for 191 hours, with an automatic water level datalogger programmed to log at an hourly frequency. The data indicates the influence of the surface water level of the lower reservoir of the pumped storage power plant on the groundwater of its immediate vicinity. These fluctuations are closely related to the rhythm of operation of the pumped storage power plant, filling and emptying the lower reservoir of the power plant.

The Model 615 Drive Point Piezometer is designed to provide an inexpensive solution to monitoring shallow groundwater and soil vapour in suitable applications, they can be used for short term monitoring applications, but are more commonly installed as permanent well points. The Drive-Points attach to inexpensive 20 mm (3/4”) NPT steel drive pipe. Groundwater sampling and hydraulic head measurements can be taken within the tubing using small diameter equipment. Drive Point Piezometers can be driven into the ground with any direct push or drilling technology, including the Manual Slide Hammer. Piezometers are ideal for both groundwater sampling (using peristaltic pump, mini-inertial pump or bailers) or level monitoring with leveloggers.

Groundwater is an element of the environment that undergoes constant quantitative changes. Changes occur by natural factors, such as seasonal fluctuations, different recharge amounts, and artificial factors – including mine dewatering, groundwater intake operations or surface water damming. Observations and studies of the water environment are carried out in natural conditions, for example, during the exploration and documentation of a deposit, and at later stages related to a mine deposit opening and exploitation, and then reclamation of post-mining excavations. Recognising the natural conditions and changes occurring under the influence of dewatering makes it possible to reliably assess the impact of dewatering on surface watercourses and natural and artificial water reservoirs, groundwater resources, the functioning of groundwater intakes, soils, vegetation, agricultural land and forests, surface and groundwater chemistry, and land subsidence.