Bolivia: Assessment – Santa Rita Mine in Oruro
A Preliminary Site Assessment (PSA) to examine soil contamination from the Santa Rita Mine in Oruro, Bolivia, was completed in March 2019.
The site was identified for a PSA based on earlier ISS (Initial Site Screenings) conducted in 2017 by Pure Earth in partnership with the Plagbol Foundation, and in collaboration with the Bolivian Ministry of Environment and municipal autonomous governments. Of the 26 sites evaluated under the ISS, 18 sites contained significant contamination by toxic heavy metals, including lead, mercury, cadmium, chromium, zinc and arsenic. Follow-up activities were recommended at 3 of these sites, including Santa Rita.
Mining operations in the municipality of Oruro, Bolivia have been active for approximately four centuries. During this period, the mines generated significant volumes of tailings from milling and processing. Among the most significant waste deposit sites is Santa Rita. Currently considered a mining liability, the site contains various minerals associated with mine deposits, including high concentrations of the heavy metals lead, arsenic and cadmium, among others.
Although the government has conducted various interventions in the Santa Rita site to mitigate its environmental impact, an area along a hillside in close proximity to homes and approximately 100 meters from a school still contains untreated mining deposits. The school is attended by about 1,000 children between ages 4 and 12 years.
55 soil samples were collected during the PSA. In total, 17% of samples fell below the EPA’s standard for lead for residential soils of 400 ppm, while 74% exceeded it.
Local stakeholders expressed a desire to form alliances with institutions that can help mitigate contamination and health impacts on the population. Furthermore, residents in the area, including neighbors whose homes border the contamination site, expressed a strong need for assistance with the problem.