A yearlong federal study has determined that levels of contaminated sediment found under obsolete, rotting government ships anchored in Suisun Bay are no higher than those found elsewhere is local waters, according to documents released Thursday.

The National Oceanic and Atmospheric Administration found that levels of zinc, barium, copper and other metals under the ships were about the same as other locations in the Bay and did not call for an immediate cleanup of the Bay bottom. Paint falling from the ships remains an environmental hazard.