A fleet of mothballed warships rotting in waters near San Francisco Bay is not a major source of environmental contamination, federal scientists reported Thursday.
A study by the National Oceanic and Atmospheric Administration found that levels of PCBs, toxic metals and other compounds were typically no higher around the Suisun Bay Reserve Fleet than elsewhere in Bay Area waterways.
Because of that, the agency said, it is not recommending any specific cleanup of sediments near the fleet. The more than 70 old ships were kept afloat in case of war, but many have fallen into disrepair.
A congressional order set a 2006 deadline to scrap more than 50 ships, but a regulatory tussle between state and federal officials kept the fleet anchored in place.
A 2007 study commissioned by the U.S. Maritime Administration suggested the floating ships were shedding tons of toxic paint into the bay. State water regulators and environmentalists have sued the federal government, seeking the ships' removal.
It wasn't immediately clear how the NOAA report, requested by Sen. Barbara Boxer, D-Calif., would affect the effort to remove the ships from the bay.
The NOAA official who oversaw the study said the agency does not dispute that the ships dispose toxic paint into the bay.
'Dose is low enough'
The report only finds that the fleet does not appear to exacerbate the concentration of toxins near the ships beyond normal levels, said Rob Ricker, regional manager of NOAA's environmental emergency and restoration division.
"Do they cause a problem here or was the dose low enough? Our conclusion was that the dose is low enough that it doesn't warrant cleanup," Ricker said.
Before the ships can be scrapped and sold, Coast Guard regulations require the removal of barnacles and other sea creatures clinging to their hulls. That process causes heavy metal-laden paint to flake off into the water.
California officials have repeatedly warned the federal government to stop cleaning the ships unless they can develop a method that does not lead to more paint in the water. In December, the Maritime Administration said it had hired a contractor to remove the paint from the ships.
For their study, NOAA researchers examined hundreds of sediment samples and tested mussels and clams collected near the fleet. Scientists analyzed the samples for toxins likely to be found in flaking paint and leaking oil.
Comparisons of the samples found that contaminant levels were generally in line with other parts of San Francisco Bay, according to the report.
Activist group still concerned
A scientist for one of the environmental groups suing the federal government over the ships said he did not believe the NOAA study was broad enough to determine whether the ships were negatively affecting the bay.
Michael McGowan, staff scientist for Arc Ecology, said environmentalists suggested the agency look for a downstream plume of pollution as well as examine sediments near the fleet.
McGowan said the NOAA study's conclusions did not change his opinion of whether the ships should be removed.
"It seems to me that if you have a hazardous waste source shedding toxic material into the bay that something should be done about it," he said.
The Maritime Administration needed time to study the report before answering questions about how it might relate to the fleet's future, said James Caponiti, the agency's acting deputy administrator.
Discussions about how to ultimately dispose of the ships were ongoing, Caponiti said.