Estimación del volumen de lixiviado generado en el vertedero de residuos sólidos urbanos de La Mina mediante balance hídrico

Abstract

Values of leachate production in the urban solid waste landfill of La Mina (Marbella) are certainly an unknown parameter, because of its uncontrolled situation. It has been necessary an estimation of the volume of leachate with the application of a water balance. For doing so, the inflow (precipitation) and outflows of water (evaporation, infiltration to the aquifer and discharge to the surface) have been recognized. A daily calculation of evapotranspiration jointly with the recorded daily rainfall and the areal surface of the landfill yielded the total volume of water (i.e.: leachate) produced during the study period (October 1994 - September 1999). The annual average is between 26.087 m3 and 28.706 m3, with absolute values of 50.000 m3 in wet years and less than 1.000 m3 in dry years. For the research period the whole amount of leachate has been estimated in a range between 143.530 m3 (0’8 L/s) and 130.434 m3 (0’9 L/s). Temporal evolution of leachate generation with values from the water balance method do not reflect leachate production in dry years and/or months, but this statement differs slightly with what it was observed in the field, because during dry periods a constant drainage of leachate (0’1-0’5 L/s) is produced. This is an indication of storage of leachate inside the landfill, something that has been confirmed in the constant leachate level inside the piezometers