Continuing our task of conducting the pumping test, we then headed to Rainbow Drive on Sarjapura road. Rainbow drive has 4 borewells, out of which we conducted test on one of the borewells which has been used by the residents for purposes other than drinking. The pump test was conducted on 8th of November.
The pump of this borewell has been switched off for 24 hours. Amidst hot sun, another issue that we had to bear with was continuous power cut.
The static water level (SWL) at the start was recorded at 36 m. The pump was started and was switched on for 160 min during which readings were taken at every 1 min, 5 min and 10 min. The discharge was also measured at the start, middle and end. The water discharged was collected in a 2 litre bottle and time taken was recorded to calculate the flow rate. The initial discharge was found to be 576 litre per hour, mid discharge at 421 litres per hour and end discharge same at 421 litre per hour. During pumping, the water level reached was 39.8 m.
Pumping was stopped at 160th min and recovery was started. Recovery readings were measured till 170 min/close to 3 hours during which the water level had reached up to 36.5 m.
The static water level is measured with the help of a water level sensor (http://biometrust.blogspot.in/2014/09/water-level-sensors.html). The sensor gives off sound once it touches the water. While conducting test at this borewell, it was observed that two distinct sounds were observed, one at 37 m level and one later on. We think that there is a possibility of water coming from some aquifer at 37m which had resulted in giving off the sound.
Such observations during the test would help in the gaining knowledge about the urban aquifers in the region.
We would like to thank Mr. Manjunath (the manager), plumbing staff and the residents for their co-operation as well as by giving the chairs to sit and water to drink :)