Posted on Fri, Feb. 11, 2005
By Martin Snapp
CONTRA COSTA TIMES
IT'S BARELY
SUNRISE, but Jon Nguyen
is already at work dipping
tiny glass vials into the
waters of Lake Merritt,
testing the nitrogen levels.
Throughout the
Oakland hills, other volunteers
are taking water samples
from the creeks that feed
into the lake, including
Wildwood Creek, Pleasant
Valley Creek, Bushy Dell
Creek, Trestle Glen Creek,
Indian Gulch, Broadway Branch,
Glen Echo Creek, Cemetery
Creek, and Rockridge Branch.
The volunteers are all members
of the UC Berkeley chapter
of Engineers for a Sustainable
World, known as ESW-B for
short. Nguyen, a senior
at Cal, is project manager
of ESW-B's Lake Merritt
Project.
"We're trying to pinpoint where the nitrogen pollution in the
lake is coming from," he said. "A
few years ago, the EPA declared
Lake Merritt an 'impaired
body of water' because of
the low oxygen levels, and
everybody started studying
oxygen levels.
"But we think that may be
a symptom of a larger problem:
nitrogen pollution from urban
runoff, which has hardly been
studied at all. We aim to
correct that."
Two people jogging around
the lake stop and ask Nguyen
what he's doing. When he
tells them, they break into
smiles and say, "Hey, that's
great! Thank you!"
"I know how they feel,"
he said later. "I've jogged
around this lake so many
times myself. Knowing that
this project will safeguard
the lake for the enjoyment
of future visitors and inhabitation
of wildlife makes getting
up in the morning easy."
That
same day, Ashley Murray
is at The Potter's Studio
in Berkeley, dropping off
the latest batch of ceramic
disks for firing. Murray,
a second-year grad student,
is project manager of another
ESW-B project: developing
low-cost water filters for
people to use in a slum
in Mumbai, India, called
Bheram.
"They're
getting sick from sewage-contaminated drinking water," she said. "We're
trying to design a filter
that's long-lasting, easy
to maintain, constructed
from local materials and
-- above all -- cheap. If
it costs more than $5, nobody
will be able to afford one."
There are water purification
devices already on the market,
but Murray thinks they're
not good enough.
"Their flow rates are
too slow," she said. "The
people in Bheram have running
water for only two hours
a day for all their needs
for the whole day, including
washing and bathing. If
the flow rate is less than
four liters an hour, they
won't have enough."
She and her team are experimenting
with several prototypes,
each with a different mixture
of clay and combustible
material.
"The combustibles
burn off when we fire the disks in the kiln, leaving a porous ceramic," she
said. "What we're looking
for is the perfect mixture.
If the ceramic isn't porous
enough, the water won't
flow easily. But if it's
too porous, the filtration
won't work."
After firing, the prototypes
are dipped in a silver nitrate
solution, dried, then soaked
in salt water. The salt
binds with the nitrate and
precipitates out, leaving
a microscopic coating of
pure silver, which is the
actual germ-killer.
The final selection won't
be made until next month,
when Murray and her suitcase
full of prototypes fly to
Bombay, where she'll confer
with her colleagues at a
local Indian non-governmental
organization, the Committee
for Right Housing. Next
summer, production of the
filters will begin in Bheram.
"We have three goals," she said.
"Eliminate contamination in
the drinking water, empower
the community by reducing
their dependence on government
intervention to improve the
water supply, and create an
economic opportunity for the
local craftsmen who will produce
the filters."
In addition to the Lake
Merritt and Bheram projects,
a third ESW-B project will
be launched this spring:
installing solar desalinization
units in 12 remote fishing
villages in the Baja California
peninsula. In the past two
years, ESW-B has also sent
student interns to work
on projects in Mexico, China
Chile, Haiti and Guatemala.
"We're a new
generation of engineers," said Murray, "inspired
by the ways appropriate
technologies can improve
the quality of life for
those who are most in need."
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