Approaches to reducing sanitary protection zones of coastal groundwater intakes

Abstract

Introduction. The article discusses methods to reduce the 2nd and 3rd Sanitary Protection Zones (SPZ) on the surface watercourse for the intake of onshore groundwater. There are presented basic hydrodynamic and geo-migration analytical solutions allowing the estimation the time of the pollution migration from the river to the underground water intake. These basic analytical solutions also estimate the degree of dilution of river waters by groundwater. Materials and methods. Laws & Acts regulating relations in the Design and Establishment of SPZ, SPZ Projects & related Scientific References. The methodological basis for reducing the zones of sanitary protection of coastal water intakes was undertaken using the hydrodynamic and geo-migration analytical calculations included within the ANSDIMAT software package. Results. When designing a coastal groundwater intake and developing a SPZ project, the following sequence of actions are recommended to reduce or completely avoid the management of the SPZ on a surface watercourse: 1. Locate the onshore groundwater intake in such a way that the 3rd belt of the SPZ is not close to the surface watercourse. 2. Estimate the pollution migration time. If it is more than four hundred days, then it is possible to abandon the management of the 2nd zone of the SPZ on the surface watercourse, and if the migration time of the pollution is more than 25 years, then the 3rd belt can also be completely abandoned. 3. Even with a constant excess of MPC (Maximum Permissible Concentration) in river waters, it is still possible to justify such a well flow rate that will not lead to an excess of MPC in water intake. 4. If it is impossible to fulfill the required project conditions, then it is necessary to manage the SPZ belts both for underground water intake and for the surface watercourse. Conclusion. Our recommendations for developing underground onshore water intakes make it possible to use all the advantages of onshore water intakes, whilst not withdrawing large areas from economic use.