U.S. Environmental Protection Agency scientists are heading offshore tomorrow to an ocean dumping site five miles off the Point Loma coast to sample the sediment on the seafloor to see whether pollution levels there are significant.
It’ll be the agency’s first trip to the site since it was formally designated as a place to dump dredged sediment from San Diego Bay in 1991.
The sediment sampling will be an opportunity for the EPA to determine the effectiveness of the extensive biological testing it requires before sediment can be dumped.
Scientists will take eight six-inch deep samples of the ocean bottom from across the mile-wide section of ocean where dredged sediment from San Diego Bay is dumped.
Allan Ota, an oceanographer with the EPA’s dredging and sediment management team, described the sampling trip as “reconnaissance.” If no significant results come back — they’re expected in about a year — no more monitoring work will be scheduled.
Ota doesn’t expect to find anything unusual, but he said he’s curious about the results because of the concerns raised by Ed Parnell, a Scripps Institution of Oceanography professor. Parnell has pointed to the dump site as a possible location of PCB pollution transported in dredged sediment from San Diego Bay.
PCBs, polychlorinated biphenyls, are cancer-causing chemicals that were used as coolants and lubricants in electrical equipment until their 1977 ban.
The surveys are part of an EPA research vessel’s 14-day trip off the California coast. The EPA’s Ocean Survey Vessel Bold will check two other dredge dump sites off the Southern California coast. Scientists aboard the 224-foot long boat surveyed the ocean bottom around the dredge disposal site late last week.
Ota said the sonar scan didn’t find anything unusual at the dump site. But it did find a couple of World War II-era airplanes off the coast. “They’d been down there for awhile,” Ota said.