The bailer test : a simple effective pumping test for assessing borehole success
MacDonald, Alan; Barker, J.A.; Davies, Jeffrey. 2008 The bailer test : a simple effective pumping test for assessing borehole success. Hydrogeology Journal, 16 (6). 1065-1075. 10.1007/s10040-008-0286-1Before downloading, please read NORA policies.
A new pumping test method has been designed around the practical requirements of those working in rural water-supply projects in developing countries. The bailer test needs only simple equipment and can be completed in under 1 h. The test involves removing 20–50 bails from a borehole over a 10-min period and then measuring the recovery. The test is analysed using large-diameter-well analysis (which accounts for well storage) and is appropriate for testing low productivity aquifers (transmissivity 0.1–10 m2 d–1), where water levels are shallow (<20 m depth). The bailer test was developed and trialled in a rural water supply project in Nigeria where it was found to predict similar transmissivity to 5-h constant rate tests (r 2=0.9). Analysis of the test was further simplified to provide guidelines for field staff such as community health workers. The likelihood of a borehole sustaining a handpump for 250 people can be indicated by measuring the maximum drawdown and time for 50 and 75% recovery from a bailer test and comparing to a simple table. This simplified test is now being used in this and other rural water-supply projects, and has been modified to indicate whether a borehole can sustain higher yields for small-scale irrigation.
|Programmes:||BGS Programmes 2008 > Groundwater resources|
|Additional Keywords:||GroundwaterBGS, Groundwater, Aquifer characterisation, Hydrogeological data, Groundwater resources, Africa, Nigeria, Water supply,|
|NORA Subject Terms:||Earth Sciences
|Date made live:||08 Dec 2008 13:37|
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