Unocal updates contamination assessment for Avila Beach
Santa Maria, Calif., Dec. 19, 1996 -- This week Unocal presented regulators with an updated plume map which further defines the location of petroleum contamination at Avila Beach. The latest map shows an estimated 1.5 percent increase in the total volume of the plume.
"We have been monitoring, defining, and redefining the plume at Avila Beach for years, and this most recent update is part of that process," said Bill Sharrer, Unocal Manager of Environmental Affairs. "We will continue to refine the plume, and any new information can and will be incorporated into our remediation plan."
The majority of the additional contamination is located apart from the main plume, underneath the beach and surf zones, just west of the public pier. The contamination is about two feet thick at its greatest point, and lies under at least seven feet of clean sand cover.
Like other contamination in this area, surface exposure of the plume is highly unlikely and would require severe erosion, such as that caused by a 100 year storm event.
Monitoring has not detected the presence of petroleum hydrocarbons in the ocean. Unocal will continue regular monitoring, which will include monthly sampling of the ocean water along with other defined studies.
"We will continue to test and monitor around known contaminated areas to get the best possible definition of the plume," Sharrer said. "We don't expect this new finding to delay the cleanup, or significantly alter the proposed remedial plan submitted to the Regional Water Quality Control Board (RWQCB) for review and approval."
Updated: December 1996