Source: Chevron Refinery, Richmond, California. Historically there have been other industrial, commercial, and municipal sources of contamination to Castro Cove however, at this time the trustees are not pursuing a case against other potentially responsible parties.

Release: Until the relocation of the wastewater outfall for the Chevron Richmond refinery in 1987, the refinery discharged approximately 13 million gallons of wastewater per day into Castro Cove. The principle contaminants of concern found at high levels in the sediments are PAHs and mercury. In addition, lead shot has been found in a portion of Castro Cove where a former skeet range was operated.

Primary Injury:

The trustees, in cooperation with Chevron, have agreed to follow an expedited approach to injury assessment, in which the parties make reasonable, worst-case assumptions regarding the extent of injuries to natural resources. This avoids costly and time consuming injury studies and instead devotes more resources toward the planning and implementation of appropriate restoration activities.

The trustees used existing site investigation data and results from studies of other contaminated sites in the region, to assess potential past, present, and future injuries to natural resources. The trustees have determined that the following resources have potentially been injured:

• Benthic resources and their habitat. Benthic species and the food web services they provide in Castro Cove have likely been adversely impacted due to the release of hazardous substances.
• Birds, fish, and mammals. Several species of birds, fish, and mammals use Castro Cove as habitat and either directly or indirectly depend on benthic invertebrates as food sources.

After reviewing other case examples from around the country, the trustees and Chevron developed an injury assessment approach that utilized paired sediment chemistry and benthic toxicity data, and a logistic growth model to estimate benthic toxicity over the entire site. In addition to benthic toxicity data, potential injuries to birds, fish, and mammals were also examined.