Groundwater is a natural resource exploited worldwide causing danger due to the lixiviation of waste deposited, which presents high potential degradation. Internationally, regulation aims for the maintenance of the quality of this resource. But the local lithology, mainly in countries with tropical weather, was not considered. This paper has an objective to propose two methodologies of contaminant identification of municipal solid waste (MSW) considering the Brazilian regulation, the local lithology and the temporal aspect. The study site is located in the midwest of São Paulo, at the Marília Formation, Bauru Aquifer, which presents sandstone rich in calcite. At first, the historic monitoring data accumulated between 2002 and 2015 were statistically organized. Then, methodologies of classification of major constituents and contamination method were developed. After these analyses, the compounds that possibly cause anomaly in the local environment are Al, As, Ba, Ca, Cd, Co, Cr, Cu, phosphatic, nitrogenous, and sulfated compounds, Fe, K, Mn, Ni, and Pb. Some of these have lithogenic genesis typical of tropical environment, and others come from the disposed waste. Despite different approaches, both methods demonstrate efficiency in identifying the pollutants presenting distinctions among themselves in conjunction with actual local regulation and the lithogenic source of certain compounds.
