Waste disposal and underground waters

Abstract

Underground waste management, environmental ìmplications and artificial recharge were the subjects discussed in two symposia, respectively in Houston, Texas, in 1971 and in New Orleans, Louisiana, in 1973. In the present paper the author summarizes aspects of the injection of liquid wastes into reservoir rocks by deep wells in the U.S.A. These aspects concern legislation and policy, statistics and actual conditions in some regionally important disposal Zones. Attention is given to the protection of useful subsurface waters Ground waters, i.e, those waters that take part in the present hydrologic cycle, and formation waters, i.e. those that are isolated from the present cycle, are distinguished. Disposal in the former constitutes a potential hazard to the environment, in the latter under certain precautions disposal may be considered safe. In The Netherlands conditions are such, that aquifers that are properly isolated from the present hydrologic cycle occur at depths greater than between approximately 500 and 1000 m. Below these depths disposal prospects are present in sandstone/ claystone alternations of upper Palaeozic to Tertiary age and possibly in upper Cretaceous limestones. In the northern and eastern parts of the country solid or liquid (including radioactive) wastes could be disposed of in artificial caverns in rock-salt deposits.