The illegal dumping of garbage and toxic agrochemicals used in sugarcane farming poses a serious threat to Latin America’s largest groundwater reservoir, the Guaraní Aquifer, according to the Institute for Technological Research (IPT) in the southern Brazilian state of São Paulo. Areas of potential risk in São Paulo were identified by the IPT and other state government agencies. The aquifer covers around 850,000 square kilometres beneath the surface of southern Brazil, Argentina, Paraguay and Uruguay.

“We evaluated degrees of vulnerability in accordance with the depth of the aquifer, the presence of native forests as protection, and the types of materials produced in the soil,” IPT researcher José Luiz Albuquerque told Tierramérica.

The study divided the 143,000 square kilometres of the aquifer located beneath the state of São Paulo into three categories: areas of restricted occupation, such as riverbanks and legally protected forest reserves; areas of supervised occupation, due to their vulnerability to pollution; and areas of environmental recovery, which have already been degraded by erosion, garbage dumps or overcrowded residential areas.

The resulting risk map is meant to serve as the basis for developing draft legislation and preventive measures.