ABSTRACT
On July 16, 2000, a crude oil spill occurred at the PETROBRAS refinery Refinaria Presidente Getúlio Vargas-REPAR, located in Araucária, PR, Brazil. A significant quantity of oil was retained within an area known as Ponto 0, between the spill site and Rio Barigüi, contaminating the hanks of a small stream (Arroio Saldanha), the soil adjacent to the stream, and the soil of four small wetlands, over a distance of 2 km. This paper presents an overview of the remediation program for Ponto 0, and draws preliminary conclusions regarding the efficacy of different remediation technologies. The major remediation technologies are: 1) injection and recovery trenches for free-product recovery in the sector adjacent to the spill site; 2) in situ bioremediation along the floodplain of Arroio Saldanha; and 3) a treatment wetland near the discharge of Arroio Saldanha into Rio Barigüi. The trenches appear to have removed most of the free product from the sector adjacent to the spill site. There is preliminary evidence, based on soil monitoring data, for the efficacy of in situ bioremediation, but further data will be required before a firm conclusion can be drawn. The treatment wetland was successful in restoring wetland vegetation (an essential component of this technology), and appears to be capable of removing hydrocarbons from groundwater. Data of the groundwater monitoring program indicates a general decline in TPH concentrations, over the October 2000, August 2001 and April 2002 sampling campaigns. BTEX concentrations are generally below the method detection limit.
