Evolving State of Ecological Risk Assessment at the Former Guadalupe Oil Field, California

摘要

The former Guadalupe Oil Field, in the central Californiacoastal region, is the location of past and ongoing efforts toassess ecological risk. While there are a number of chemicalsof concern, the main focus of the risk assessment is a crude oilthinning agent, known as diluent. Approximately 8 milliongallons of diluent were accidentally spilled within the 3000acre property during its 45 year history of use. The riskassessment must consider the hundreds of plant and animalspecies, both terrestrial and aquatic, that inhabit the site and itsneighboring properties. Among these plants and animals are atleast 40 threatened and endangered species.The first efforts to evaluate ecological risk at the sitewere initiated during a Natural Resource Damages (NRD)lawsuit. These efforts focused on developing a case forbiological injury and establishing a basis for financialdamages. Since settlement of the NRD lawsuit in 1998, riskassessment has focused on providing input to decision-makersso that objective remediation goals can be established. Thispaper reviews the status of the ecological risk assessment, itsrole in site decision-making, and specific technical challengesthat have been encountered.