November 11, 2002

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 these."

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 aquifer.

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.

####