Supervisors Support Plan to Dredge Marina Entrance : Environment: Proposal by Army Corps of Engineers would remove toxic sediment from channel and bury waste at L.A. Harbor site.

An Army Corps of Engineers proposal to dump tons of contaminated sediment from Marina del Rey at a site in the Port of Los Angeles has received the unanimous backing of the Los Angeles County Board of Supervisors.

In a letter sent Monday to the California Coastal Commission, board Chairwoman Yvonne Braithwaite Burke urged the agency to allow the corps to remove about 135,000 cubic yards of silt and sand tainted with lead and dozens of toxic substances from the Ballona Creek’s runoff to deepen the marina’s entrance channel.

The Coastal Commission was scheduled to vote on the proposal at a hearing today in Eureka, but Los Angeles Mayor Richard Riordan and Councilman Rudy Svorinich Jr. have asked the commission for a delay so it can conduct the vote in the harbor area to make it easier for residents to attend.

In a related matter Tuesday, the supervisors agreed to allow the county to indemnify the Port of Los Angeles for any problems caused by the transfer and deposit of the material. The county, in turn, would be indemnified by the corps, a federal agency, pending congressional approval, which could take up to a year.

Port officials had expressed concern about dumping the sediment at the harbor site because of its potential interruption of a massive $150-million expansion project that began Sept. 6.

Officials have said the buildup of silt at the marina’s entrance, which is caused by the flow from Ballona Creek, has become a hazard for boats. In addition to the 6,000 pleasure craft that ply the area, officials are concerned about the operations of the U.S. Coast Guard cutter Point Bridge, which would be used for rescues if a plane crashes at sea.

“About 50% of both the north and south entrances have been closed to boating, and in some places off the jetty, depending on the tides, the water is three feet deep or less,” said Jim Fawcett, the chief of planning for the County Department of Beaches and Harbors.

In addition, officials say, shoals have increased in the remaining boating lanes, and there is concern that severe winter storms, which increase the creek’s sediment flow, could impede harbor navigation.

Since the 1960s, the corps has dredged the sediment in the marina, but now faces more stringent federal disposal rules. In 1990, the Environmental Protection Agency rejected a corps request to dump some of the buildup in the ocean six miles off the Palos Verdes Peninsula.

Two years ago, at the urging of county officials, the Coastal Commission reluctantly agreed to a “knockdown,” a flattening of the bottom of the marina channel, as temporary relief. The project was granted with the understanding that the corps would come up with a long-term solution.

With the shoals again high, the corps is asking for another stopgap measure. The federal agency wants to remove the marina’s poisonous buildup, pack it in special plastic tubes and bury it in a shallow 185-acre wildlife area at the San Pedro harbor.

But some environmentalists, including the Heal the Bay group, vehemently oppose the marina dredging plan.