THE OSSA II PIPELINE SPILL, BOLIVIA: CLEANUP CRITERIA, CLEANUP OPERATIONS, ENVIRONMENTAL MONITORING, AND COMMUNITY ISSUES

Abstract

ABSTRACT An estimated 29,000 bbl of mixed crude oil and condensate was spilled from the OSSA II pipeline, which was damaged during summer flood conditions, at the Río Desaguadero river crossing on the Bolivian Altiplano. The oil was deposited as far as 250 km downstream along a total of approximately 400 km along the banks of river channels, meander floodplains, and irrigation ditches, as well as on several hundred hectares of low-lying floodplain. Residual oil samples had sediment contents as high as 80%, which indicates that considerable mixing took place during the transport process. The combination of the mixing processes with evaporation resulted in high depletion rates of oil (60%). The region has a rural population of about 30,000 whose primary activity is subsistence agriculture and animal husbandry (mainly sheep, llama, and cows). Downstream, the Lago ?oopó area is an extremely important habitat for aquatic birds. Following an initial assessment, and despite repetitive ground and aerial surveys throughout the entire region, no dead or oiled fish, birds or other animals were found as a result of the spill, hence the ecological concern was low. Water samples collected soon after the spill showed no detectable hydrocarbons in either the river or in potable water sources. Cleanup endpoints were established early in the response, and most of the cleanup was completed over a 2-month period. Cleanup operations were constrained by few crossing points over the river (bridges or hand-drawn ferries) and by the problems of access in the wetlands of the floodplain zone during the summer season. The response involved an outreach program through Community Liaison Officers, and 3,200 local inhabitants were hired to remove the oil from their individual village areas. A team of agronomists, veterinarians, and doctors was established to deal with the social and human-use issues.