Leachate quantification in sanitary landfills has always been a difficult task for designers. In the semi-arid northeast of Brazil, where meteorological and geological characteristics are very peculiar, this task becomes even more complicated. With the aid of the computer program HELP-Hydrologic Evaluation of Landfill Performance developed by Schroeder et al (1984), and using local meteorological and geological data, various scenarios were simulated altering trench bottom inclination, drainage system configurations, and adding a layer with high hydraulic conductivity. With those changes, leachate head accumulated in the waste, leachate soil infiltration and collection were studied. The results showed that in the trench without drainage layer the increase in trench bottom inclination had practically no effect in the studied variables while drainage configuration changes affected those variables in a small scale. With the addition of the drainage layer, it was observed a significant decrease in the leachate head and soil infiltration. The addition of the drainage layer also makes the effects of bottom inclination and drainage system configuration changes, unimportant.
Hydrologic simulation; sanitary landfill of Caucaia (Ceará); leachate; solid waste
