One of the final stages of the drilling work series is testing the quantity of water to be exploited. The quantity of water can be determined based on a pumping test so that the measured flow and water level drop data can be obtained from the capacity of the type of well or vice versa the decrease in the type of well. The capacity of a well type is a measure of the production capability of a well. The main targets for implementing this pumping test are:

1. Aquifer Test

Aquifer testing or better known as the long-term constant rate test method is intended for measuring parameters that are horizontal to the test well, so several reinforcement wells are needed around the test well. And this aquifer test is usually accompanied by a recovery test or recurrence test, which is the restoration of the groundwater level after being pumped.

2. Well Test

Aims to determine the capability of the well and does not require a piezometer nearby and is simpler than aquifer testing. This test places more emphasis on recording well data/parameters vertically. From the measured discharge and groundwater level, the specific capacity of the well can be obtained which is expressed by the magnitude of the specific drawdown which is expressed by the magnitude of the decline for each unit of discharge.

Pumping tests are usually carried out using two methods:

1. Step-drawdown Test

Pada dasarnya dilaksanan setelah pelaksanaan konstruksi sumur dan setelah pembersihan/penyempurnaan sumur atau dengan kata lain tahap akhir dari rangkaian pekerjaan pengeboran air tanah. Metode ini dilakukan dengan cara mengukur penurunan muka air tanah di dalam sumur uji dengan debit pemompaan yang ditambah secara bertahap.

2. Long-term constant rate Test

Aims to estimate the hydraulic properties of aquifer systems such as transmissivity, hydraulic conductivity, and storage

The pumping test procedure is carried out as follows:

1. Determine the monitoring well that will be tested for pumping
2. Prepare the Water Level and launch it into the well where the pumping test will be carried out. Measure the groundwater level of the well before the test well is pumped
3. Note the height of the groundwater level at the beginning of the measurement
4. Start the pump and record the groundwater level according to the measurement interval in the measurement table. The measurement interval can be seen in the example pumping test table
5. When the groundwater level remains constant for up to three intervals, the pump can be turned off and the well recovery measured
6. Note the water level in the well when the pump is turned off
7. Repeat the measurement according to the interval in the measurement table. Measurements are carried out to a height so that the ground water returns to the level it was before the pumping test was carried out
8. Data analysis of pumping test results

Source:

Geodynamics, Hydrogeology and Planology Laboratory. Department of Geological Engineering Faculty, Faculty of Engineering, Diponegoro University (2020). Standard Operational Procedure for Pumping Test. Semarang