SAN FRANCISCO (CN) – A major oil spill in one of the nation’s most economically important waterways could become more likely unless a plan to dredge two San Francisco Bay channels less frequently is reconsidered, lawyers for the state of California and a conservation group argued in court Wednesday.
“That kind of catastrophe can obviously have very intense environmental impacts,” attorney Erica Maharg said at a hearing on the plaintiffs’ motion for summary judgment.
Maharg represents San Francisco Bay Keeper, an environmental group that intervened as a plaintiff in a federal lawsuit to block a U.S. Army Corps of Engineers plan to dredge the Pinole Shoal and Outer Richmond Harbor channels every other year instead of annually.
The Corps, which has a duty to maintain federal navigation channels, announced its plan in 2015, saying it needed to dredge two bay channels less often to cut the costs of complying with stricter water quality standards imposed by the state.
Under the Clean Water Act and Coastal Zone Management Act, federal agencies must comply with water quality standards enacted by states.
In 2015, two state agencies – the San Francisco Bay Regional Control Board and San Francisco Bay Conservation and Development Commission – rolled out new conditions aimed at protecting two species of endangered fish and reducing the amount of dredged sediment dumped in the bay.
The state agencies based their decision in part on studies finding hydraulic “hopper” dredging that sucks up sediment from the seafloor like a vacuum kills more endangered Delta smelt and longfin smelt than mechanical “clamshell” dredging, which acts like a bucket scooping up sediment.
The Corps says clamshell dredging costs about three times more and takes up to 10 times longer than hopper dredging.
Despite those representations, the Corps did not specify how much more it would cost to use clamshell dredging every year or conduct a cost-benefit analysis, California Deputy Attorney General Tara Mueller argued in court.
Citing a federal standard that requires it to use the lowest-cost alternative, the Corps said it had no choice but to adopt a plan to stop dredging in those channels every other year. Mueller called the Corps’ reliance on that standard misplaced.
“They relied on we believe an erroneous interpretation of the federal standard that they say allows the cost factor to trump every other consideration,” Mueller said, adding that more studies are needed to assess the environmental impact of the plan.
Department of Justice lawyer Jacqueline Leonard said the Corps did consider that less frequent dredging would reduce the amount of cargo ships can carry and possibly increase traffic and accidents in those channels.
“The Corps did look at potential spills or collisions resulting from alternating dredging,” Leonard said. “The Corps found the risk was not significant enough to call for any supplemental environmental assessment.”
Another condition imposed by California agencies limits the amount of dredged material that can be dumped in the Bay to 20% and requires at least 40% of dredged sediment go to beneficial reuse, such as restoring wetlands and fish habitat sites.
The Corps maintains that it is not required to comply with that condition because it is merely “a goal created by management agencies” and not an enforceable policy.
California and Baykeeper say the agencies set those percentages as enforceable standards based on goals established though a collaborative Long Term Management Strategy process.
“They’re saying we will not implement water quality standards that the state has imposed,” Maharg argued.
After two hours of debate, U.S. District Judge Richard Seeborg took the arguments under submission.
In June, a separate proposal by the Corps to deepen 13 miles of the bay to accommodate larger ships traveling to and from oil refineries drew criticism from several environmental groups, including the Sierra Club, Center for Biological Diversity and San Francisco Baykeeper.