A bibliographic review and a further analysis on the chemical quality of Chilean continental waters used for irrigation are presented. The natural chemical charge of surface waters is directly related to desertic ecological conditions; thus, salinity increases toward the north, starting with a clear break in the salinity level between the V and the IV Region. Also, northern surface waters are characterized by high arsenic and boron, both potentially toxic elements, according to concentration. From the Aconcagua river south, the natural charge remains at sufficiently low levels correspondingto waters with good aptitude for irrigation. It seems that water quality standards for irrigation, defined by the Chilean Official Technical Guide (NCH-1333) are not adapted to the ecological conditions present in Northern Chile. It is becoming clear that environmental pollution processes are deeply changing the natural chemical status of waters; this phenomenon is not envolving continental waters only. Although a complete survey on water pollution is not available, it is evident that the maximum magnitude of this process is represented by Santiago untreated waste waters discharged into the water resources of the Metropolitan Region. |
ChileanJAR
