Dealing with a former rare earth separation facility site (USIN)

Abstract

São Paulo city has currently 2,224 contaminated lands which are a t different stages of the environmental management process. It is possible to find areas developing environmental analysis and investigations, fields with confirmed risk to human health and w ithout an approved remediation plan, even places during the remediat ion process and revitalized spaces , which could be an otherwise land use . The USIN facility stopped their operation in 1992 and was initially used to store minerals and residues from the p rocessing of minerals. Furthermore, was equipped to process rare earth compounds using solvent extraction techniques, and also store by product material consisting of 2% of U 3 O 8 and 20% of ThO 2 concentrate . The former facility site consisted of 3 sheds con structed in an area of 60,000 m 2 located in a past urban industrial district, Campo Grande, in São Paulo city. Over the years, Campo Grande district was changing its land use, from industrial use to residential and commercial use, hence the number of resid ences in the neighborhood of USIN has increased. According to São Paulo Environment Agency (CETESB), USIN’s area was classified as an area with confirmed risk. This study approach chemical and radiological contaminants present in the area, also the remedia tion actions adopted. Despite CETESB classification, results indicated than the area has been remediated, a segment of 18,400 m² it was already cleaned up, and the remainder currently is in the remediation process.