Data acquisition

Description of methods to obtain relevant parameters

Hydraulic parameters

Pump tests

Interpretation of water works data

Water works can offer the opportunity of getting cheap pump test data. Usually, they are operating one or several wells, where loggers monitor the water table levels. We show an example, where the water works in Fløng operates an alternating pumping scheme in 4 drinking water wells. Therefore, a high measurement frequency was set for the head logging. When the pumps are switched on and off, drawdown and recovery curves are obtained and can be analyzed.

Slug tests

Slug tests provide a cheap and quick way to get information about the local hydraulic conductivity. If several boreholes are close by, it can be a good option to do several slug tests. This will yield some information about local heterogeneities etc.

The principal idea behind slug tests is that the water level in a borehole is changed and the recovery, i.e. the change back to the original state is monitored. Therefore, the hydraulic head has to be measured. This can be done with manual measurements using common dip-meters or with automated measurements with pressure transducers. If the hydraulic conductivity close to the borehole is high (f.e. in a heavily fractured aquifer), the recovery happens very fast and it is necessary to have automated measurements.

There are different types of slug tests. A main distinction can be done between rising-head and falling-head slug tests.

Falling-head slug test

For a falling-head slug test, the water level in the borehole is abruptly increased. This can be done on different ways. Water can be added in a slug into the borehole

Rising-head slug test

For a rising-head slug test, water is removed from the borehole and the recovery of the water level is recorded afterwards.

Transport parameters

Tracer test, poroperm measurements from cores etc.

Fracture characterization

Fractures are usually described by their aperture, spacing, main orientation. When open boreholes are available, optical televiewers can give an idea of the fractures around the borehole. Flow logs can indicate high-flow zones within a borehole.

Contaminant data

Different sampling and monitoring techniques for contaminants have been developed. The following list gives an overview of some common ones:

• Snap samplers
• Diffusion cells
• Bladder pump
• NAPL-FLUTe
• FACT-FLUTe
• Passive flux meters
• etc.

Integral pump tests can be used to quantify the contaminant mass discharge.

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