puts hydrology students in driver's seat
There's a secret
inside the geology department's hulking new field truck - it's loaded
with sophisticated surveillance equipment. And the target under
scrutiny is the region's groundwater.
"This is our spy truck," jokes geology professor Dave
Evans pointing out the rear cab's fully stocked computer station.
There, information from the state-of-the-art borehole geophysical
equipment housed in the truck bed can be downloaded and interpreted.
The rolling laboratory allows students and professors to monitor
water wells at the source.
The truck and its equipment, along with a new set of wells for the
campus water well field, were funded by a $400,000 grant from the
Keck Foundation. The gift is helping the applied hydrogeology program
become one of the most comprehensive in the state.
"It's very rare to have this kind of equipment on a campus.
In fact, a lot of private companies can't afford this type of equipment,"
says Darby Vickery of the Department of Water Resources. "Usually
you have to have a master's degree to even be trained on one of
Evans says the tools are designed to take on-site readings of the
physical properties of a well's subsurface geology. "This type
of equipment has been used in the oil industry for years. Now it's
being used more frequently in environmental settings," he says.
"Where the environment is complex, such as in the foothills
around Sacramento, you need to be more precise in where you put
in wells. With this equipment, we can find out about the geology
we're getting water from within tenths of feet.
"You can make decisions about quality of the aquifer, looking
at the flow and fractures: where the fractures are located, how
they are oriented, how they related to other fractures. Hopefully
this will lead to more success in those environments."
Hydrogeology graduate student Matt Gamble says borehole geophysics
equipment can also be used to look at the movement of contaminants
in the water table. For example, one apparatus, the electromagnetic
flow meter, determines how fast water is moving by measuring the
current it produces. It can detect flows as low as 50 millimeters
per minute, which can show how fast a substance will move through
the layers of aquifer.
Other equipment includes a tool for measuring electrical properties,
natural radiation and water temperature in a well, and an acoustic
televiewer that detects and images fractures that intersect the
wall of the well. Real-time images of what the equipment is seeing
are sent to the truck's computer and together they draw a detailed
picture of the properties of the rock.
The geology department put the setup to use this summer to decide
how to construct a set of 12 new wells along the base of levee on
campus. That project, funded by the California Department of Water
Resources, under the direction of geology professor Tim Horner,
will allow studies of how the American River interacts with the
Keck funding also added a new extraction well on campus. The expanded
well field, which was already the largest on-campus water well field
in the country, provides students first hand experience in the types
of conditions they will encounter as professionals.