Wetlands work could lead to
breakthrough
By Con Garretson
IJ reporter
Sunday,
January 23, 2005 - The U.S. Army Corps of Engineers is exploring new ways to
store and deliver dredged bay materials for the Hamilton Wetlands Restoration
Project.
The idea being looked at is temporarily redumping dredged
material from elsewhere in the bay back into the bay rather than directly
pumping it from barges, an alternative that might cost less, be more efficient
and be better for the environment.
"Dumping in the bay has been such a
hot-button issue for so long that it initially seems to be counter-intuitive to
dump the materials again," said
Tom Gandesbery, a project
manager with the California
Coastal Commission, which
is working with the Army Corps
on the project.
"I don't think it's been done this way anywhere else in the
country," he said. "It was
one of the rare instances
where the Army Corps took
a look at the process and
thought there may be a better
way to do things."
The dredged materials are needed to help rebuild the former Hamilton
wetlands.
Gandesbery said selection of one of the redumping methods
could lead to the closure of one or two of three bay sites nearby where dredged
materials are currently dumped.
At least four new alternative methods
will be explored as part of an environmental review process, including a
contained storage basin, a semi-contained basin, uncontained storage on the bay
floor and a combination of the proposed method and the approved hydraulic
off-loader method.
There are no firm cost estimates for the storage
options, which include building an underwater berm and a fully enclosed storage
basin, Gandesbery said.
A review of the storage options will culminate
in a report this summer that will be the subject of public review before an
option is selected by the Army Corps.
As part of the process, an initial
public scoping meeting is scheduled for 7 to 9 p.m. Wednesday at the Bay Model
at 2100 Bridgeway in Sausalito. Public comment on the environmental impacts will
be taken.
The project will convert nearly 1,000 acres of Novato's
developed bayside lands, consisting of the runways and antenna fields of the
former Hamilton Field military base, back into tidal and seasonal wetlands. The
possible addition of land at adjacent Bel Marin Keys would expand the wetlands'
size to 2,500 acres.
The original plan was to use a San Pablo Bay-based
hydraulic off-loader to handle environmentally acceptable dredged materials from
the Port of Oakland and other regional locales to be stored five miles off
Hamilton Field, from which the materials would be pumped. The offshore pumping
is necessary because of shallow conditions.
Gandesbery said the possible
changes were prompted by "the
cost to the taxpayer and the
efficiency of doing the project,
which also has an environmental
benefit.
"There would be a
lot less air pollution by using smaller equipment that could run continuously,
over turning larger equipment off and on," he said. "There
would be less diesel emissions,
where most of the pollution
comes from."
The original method
would necessitate the coordination of large barges making the direct transfer
through submerged pipelines, while the new options would allow smaller barges to
also dump at different times and for the pumping to take place continuously
rather than in spurts.
The proposed methods would have to receive
permits and would likely not be put into use until 2007. Gandesbery said initial
restoration work scheduled for this fall with Port of Oakland dredgings will go
forward using the already approved direct-pumping process.
Work on the
airfield portion is expected to take five years, while the overall project,
including the antenna fields and the possible Bel Marin Keys land, could take up
to 19 years.
The initial work would include 2.5 million cubic yards of
materials, and up to 23 million cubic yards would be used for the remainder of
the project.
The overall project cost is estimated to exceed $100
million, 75 percent of which would be paid by the federal government and the
remainder by the state.
Contact Con Garretson via e-mail at cgarretson@marinij.com
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