Marin Independent Journal
Water district looks at
pilot facility
By Mark Prado
IJ
reporter
Monday, July 12, 2004 - Board expects
feasibility report on desalination by July 21
Marin Municipal Water District
officials may try to build a mini-desalination plant before doing the real
thing.
Water officials are considering
pulling water from the bay in order to meet Marin's future water demands and
to protect the county against a drought. Earlier plans to take more water
from the Russian River have been put aside because of uncertainty over how
much water from that source will be available.
But before desalination moves
forward, the water district's board of directors wants to see how the
technology might work. When it meets in a couple of weeks, the board will
get details on a pilot plant, including how much it would cost and how it
would work.
"It is essential that we do
this to determine costs and water quality," MMWDboard member Charles
McGlashan said. "It will help us understand the impacts of this type of
operation."
The pilot could also produce
other important information, such as how the water would taste.
If all goes to plan, a test
plant could be up and running later this year. McGlashan said the idea is to
test water when there is the least amount of fresh water in the bay at the
end of the summer, and again in the winter when there is the most.
The "plant" is likely to be
nothing more than a set of pipes that could be fenced off, district
officials said. The district hopes to have a water intake at the Marin Rod
and Gun Club. Water officials are discussing the idea with Marin Rod and Gun
Club representatives.
"The board will get a full
report on the plan July 21," said Libby Pischel, an MMWD spokeswoman.
A similar test plant was built
in 1990 by the district. Although that test demonstrated that desalinated
water tasted normal and was free of contamination, concerns still persist
about its purity.
A real plant would be built on
district-owned land at Pelican Way in San Rafael, with San Rafael Bay water
being pulled in at the end of a rebuilt Marin Rod and Gun Club pier near the
west end of the Richmond-San Rafael Bridge.
The bay water would be piped
west along existing roads to the plant. The salt pulled from the water would
be piped to the Central Marin Sanitation Agency's wastewater treatment plant
and sent back into the bay. Sludge captured by filters in the process would
be trucked to the Redwood Landfill north of Novato.
The plant could be built in
increments - with each segment able to produce 5 million gallons of water a
day - and could ultimately deliver 15 million gallons of water daily. The
desalination process would convert about half of the volume of raw water
taken from the bay into drinking water.
Blending of brine with treated
wastewater from the Central Marin Sanitation Agency could reduce the
concentration of salt going back into the bay. |
