State, federal agencies briefed for study examining sediment impacts from oil platform installations

SCCWRP has begun briefing multiple federal and State agencies about plans to evaluate sediment quality near offshore oil platforms in the Santa Barbara Channel – part of a three-year study to understand how contamination from the original construction activity may still be adversely affecting marine life.

Researchers – who briefed the U.S. Bureau of Ocean Energy Management, U.S. Army Corps of Engineers and U.S. Environmental Protection Agency, Region 9 in March – will be focusing on piles of seafloor debris known as shell mounds that were created during installation of 26 offshore oil platforms in the Santa Barbara Channel decades ago. The shell mounds may be leaching chemical contaminants into the water column over time, creating potential exposure routes for sediment-dwelling marine life.

Sediment quality will be evaluated via two methods: Traditional sediment quality triad analyses, which are used widely in programs like the Southern California Bight Regional Monitoring Program, and passive sampling, an alternate method that will be used for the shell mounds. Shell mounds cannot be sampled via traditional sediment grab or core sampling because of their density.

The insights from the study will help inform ongoing development of plans by federal and State agencies to decommission and potentially remove the Southern California oil platforms in the coming years. It also could become a template for management of other oil and gas platforms across the country.