**Abstract**

 Environmental impacts caused by urban and industrial waste disposal are one of the greatest worldwide concerns, since contaminants may migrate to the local environment and contaminate soils and groundwater. Geophysical investigations have been widely used in environmental investigations of waste disposal contaminated sites, not only imaging the affected area but also evaluating the evolution of contamination plume in a timeframe. Geophysical studies in contaminated sites consist of detecting and mapping the area affected by a contamination source and providing information related to the groundwater flow and depth of saturated zone and bedrock. Particularly, electrical methods, such as resistivity and induced polarization, can identify the presence of contaminant and help to map and delineate the contaminated area and provide information related to contaminant mobilization and attenuation. Therefore, these methods are a powerful tool for noninvasive longterm monitoring of waste disposal contaminated sites. In this chapter, we will show case studies conducted in Brazil, over different types of municipal waste disposal sites.

**Keywords:** waste disposal sites, landfills, contamination plume, resistivity imaging, induced polarization
