Tank in Brazil

The incident

On 5th May 1983, a road tanker collided with a chemical storage tank, causing 500 m3 of chemicals (including carbon tetrachloride, chloroform, 1,2-dichloroethane and 1,1,2-trichloroethane) to be released into the Pinheirinho and Avecuia rivers in Brazil.

Impact

The accident occurred at a plant located on a plateau. The chemicals leaked into the two nearby rivers, Pinheirinho and Avecuia, which provide water for the municipality of Porto Feliz in the Brazilian State of Sao Paulo. Thorough testing was performed on a series of deep walls directly connected to the municipality's water supply. The company's main well was closed due to the high concentration of organic compounds detected. The streams and lakes on several farms were also contaminated. Fish mortality was reported on the banks of Pinheirinho River.

Response

The chemicals released were chlorinated solvents, which are heavier than water. When spilt in water, they sink without dissolving. Pumping operations began in the deep waters near the spillage area. In 5 days, 20 m3 of chemicals were recovered. Dredging operations removed a layer of between 0.5 and 1 metre of contaminated mud from the bottom of the lake.