A New Method of Detecting Leaks in Reservoirs or Canals Using Labelled Bitumen Emulsions

The paper describes a method of detecting and localizing leaks in natural or artificial stored-water bodies such as lakes, canals, basins, reservoirs or wells. The method consists of injecting into the stored water an emulsion labelled with a radioactive tracer. The labelled emulsion is entrained into the leakage areas where emulsion particles separate from the water and accumulate. The distribution of these particles, which can be considered as proportional to the specific infiltration flow for structures with interstitial permeability, is then determined ''in situ'' simply by measuring the radioactivity. Where the labelled emulsion is an emulsion of bitumen, the plastic properties of this product are useful in promoting the agglomeration of the particles and their adhesion to the materials of the revetment or wall to be studied. The paper describes the preparation of an emulsion of bitumen labelled with iodine-131 and its application in determining permeability gradients and detecting leaks in canal revetments. It is pointed out in conclusion that this original method has a vast range of applications. It can, for example, be successfully used to study the relative permeabilities of strata in which wells, pits or boreholes have been drilled, and to distinguish between areas of varying permeabilities. (author)