1.1 This standard lays down the procedure for the determination of the water level in a borehole, cased or uncased, either during the boring operation or within a short time of the completion of the boring operation. This standard is also applicable to determining of ground water level in permanent observation holes.
1.2 This standard is not applicable for the determination of piezometric pressure changes due to a change in stress conditions of the soil or rock.
1.3 Borehole water level readings obtained by this procedure shall be supported with additional data if the water level readings are to be used to infer the elevation of the free ground water level in the vicinity of the borehole. The procedure for the determination of the ground water level bv the application of the borehole water level is given in Appendix A.
1.4 This standard is not applicable for the concurrent determination of multiple water levels in a borehole.
Note — Multiple water levels can only be determined sequentially as the borehole progresses, with the upper aquifers completely sealed off from the borehole. Concurrent multiple water level readings can only be obtained by the insertion of an adequate number of piezometers at appropriate levels or by the installation of multiple packers isolating the different aquifers in a drill hole under the guidance of a qualified engineer or geologist.
IS 6935-1973 history
1973IS 6935-1973 Methods of Determining Water Level in Boreholes