RESUMO
The complex physical-chemical and microbiological composition of leachate in sanitary landfills sets the adequate treatment for different waste types. However, before the final disposal of wastes in receptor waterbodies, it is essential to use specific methods to quantitatively prevent internal flows to find proper treatments. The aim of the present research is to use hydrological models to estimate monthly leachate flow generation in Macapá's Municipal Sanitary Landfill (ASMM), Amapá State, Brazil. Disregarding the temporal trend bias, the average (0.45 m3s-1), minimum (0.07 m3s-1) and maximum (0.72 m3s-1) flows were estimated based on hydrological models in the literature (Rmax = 99%, p < 0.05). The results estimated from different hydrological gauges pointed towards significant spatial variations in final discharge. Thus, estimated flows worked as reference to calculate the loads of coproducts and nutrients concerning different operational stages in ASMM. Therefore, rain intensity estimates have pointed out precipitation variability, and it has significantly affected leachate flow. In conclusion, there would be a proportional increase in leachate flow during extreme maximum precipitation events; overflow would be the effect of such flows and it would assumingly have impact on its surrounding areas. It is also possible estimating some degree of rainfall impact over ASMM's infrastructure in the long term (>10 years), since it could influence its lifespan.