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In Port
CHEMICALLY CHALLENGED MUD
The "contaminated" label brings such a stigma to Bay mud dredged up from the region's waterways that managers recently felt compelled to come up with the more pc term, "chemically challenged." Whatever the label, there are at least five million cubic yards of the stuff -- about 10% of the region's projected total volume of dredged material -- to be cleared from local waterways in the next ten years.
Several disposal options - namely placing it in a confined aquatic or landfill site - are now being explored through an interagency, multi-interest effort called LTMS (Long-term Management Strategy). Indeed "confined aquatic disposal," or CAD, is the subject of a proposed new feasibility study. The idea behind a CAD is to place dredged sediments in near-shore shallow areas with high natural deposition and low current activity, and then cap them with clean sediments. The new study, as yet only partially funded, will screen potential CAD sites regionwide, explore environmental impacts and habitat restoration opportunities, and examine different CAD construction methods.
"CADs aren't the cheap and easy panacea that some in the port community think," says the Port of Oakland's Jim McGrath. "It takes a lot to do capping right." Right means a host of expensive engineering and technical acrobatics to ensure the site's seismic integrity and prevent contaminant migration into surrounding waters. The S.F. Regional Board's Tom Gandesbery is optimistic, however, particularly about the availability of promising candidate sites, which may include old Treasure Island and Hunter's Point borrow areas (where sediments were once "borrowed" for fill), several defunct drydocks and the navigation channels and berths of closing military bases.
"We'd be taking some ugly, abandoned industrial backwaters and making something nice or useful out of them," says Gandesbery. Borrow areas brought back up to sea level could become wetlands; Richmond's old graving docks a new container port facility.
Another option is to reuse the material as cover and lining for landfills. A new draft LTMS report (see Now in Print) screens 127 Bay and Delta landfills based on site capacity, disposal costs and distance from major dredging sources. Indeed the cost of trucking or railroading the material to a landfill can be much more expensive than dumping it at the Alactraz aquatic disposal site ($4 versus $18-$22 per cy). Another obstacle is the need to prepare material for landfill use at a rehandling facility, of which there's now a dearth. Despite the obstacles, the screening turned up 16 highly feasible landfill sites with a combined capacity of over 5 million cy.
"Landfills are a good match for most of the material that comes out of the Bay," says the Commission's Steve Goldbeck. He sees landfills as a more stable option than CADs, and questions the region's ability to maintain a CAD over decades. "The Bay's not an easy environment to deal with if something goes wrong," he says.
Gandesbery points out that the chemically challenged material is already out there "uncontrolled" in the Bay system. "When you look at that, the benefits of containment may outweigh the drawbacks," he says. Contact: Tom Gandesbery (510)286-0841 & Steve Goldbeck (415)557-3686 11/92, 6/93 & 12/93
BIRDS OR BULLDOZERS OR BOTH?
Mare Island base closure planners are struggling to strike a land use balance between two means - wetland restoration and dredged material disposal - to the same end - a healthier Bay and Delta. U.S. Fish & Wildlife, hoping to expand its adjacent San Pablo Bay National Wildlife Refuge, has asked the Navy for 670 acres of wetlands on the island, including three active dredged material disposal ponds, as well as nearby surplus Building #505, where the Service hopes to open an interpretive center. But the S.F. Bay Commission, on behalf LTMS (see opposite), wants the Navy to retain the ponds for disposal. "If we don't look at all the alternatives, the dredged material just gets dumped in the Bay or the ocean," says the Commission's Steve Goldbeck. Studies have identified the site as one of few with both a large capacity and an appropriate setting for a drying and rehandling facility. "We just want to reserve the area now so that use for disposal is not precluded," says the Commission's Jeff Jensen.
But an interpretive center marooned in the midst of active disposal ponds won't work, says the Refuge's Marge Kolar. "There are few habitat values while the ponds are being used," she says. "Besides normally in front of an educational center, we would be trying to show wildlife values instead of dredge values." Jensen agrees. "Dirt, dust and heavy machinery are not really conducive to bringing out the public," he says, adding that his agency is already looking at how to screen the facilities from view.
At the same time, the City of Vallejo - seeing a potential cash cow - wants to take over the ponds itself, with revenues from disposal fees flowing to a Mare Island conversion fund. Federal base closure policy requires concurrence from the local reuse group, in this case Vallejo, before property can be transferred. Although the city concurred with Fish & Wildlife's request, it was with a caveat that the city retain use of the ponds. Though this proviso could possibly halt the transfer altogether, the Vallejo's Al Da Silva thinks it's just a timing issue. "The ponds should be available for current regional dredging needs but after that they could be used for wetlands," he says.
Contact: Al Da Silva (707)648-4444; Jeff Jensen (415)557-3686; Marge Kolar (510)792- 0222 4/94
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