IS 6935 : 1973 Method for determination of water level in a bore hole

1 Scope

1.1 This standard lays down the procedure for the determinationof the water level in a borehole, cased or uncased, either duringthe boring operation or within a short time of the completion ofthe boring operation. This standard is also applicable todetermining of ground water level in permanent observation holes.

1.2 This standard is not applicable for the determination ofpiezometric pressure changes due to a change in stress conditionsof the soil or rock.

1.3 Borehole water level readings obtained by this procedureshall be supported with additional data if the water level readingsare to be used to infer the elevation of the free ground waterlevel in the vicinity of the borehole. The procedure for thedetermination of the ground water level by the application of theborehole water level is given.

1.4 This standard is not applicable for the concurrentdetermination of multiple water levels in a borhole.

Note - Multiple water levels can only be determined sequentiallyas the borehole progresses, with the upper aquifers completelysealed off from the borehole. Concurrent multiple water levelreadings can only be obtained by the insertion of an adequatenumber of piezometes at appropriate levels or by the installationof multiple packers isolating the different aquifers in a drillhole under the guidance of a qualified engineer or geologist.

2 References

IS 2 :1960 Rules for rounding offnumerical values

IS 4464 : 1967 Codeof practice for presentation of drilling informationand core description in foundation investigation