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A flexible polyurethane plug—or “pig”—is an essential part the new deep-well sampler. The humble piece of plastic not much bigger than a wine cork forces water to the surface through this bundle of plastic tubing. |
As one of the planet’s most-precious resources, water is getting a lot of attention these days and rightfully so. Whether the subject is drought, resource management or pollution, public awareness is high and water is no longer taken for granted, especially in the arid Southwest.
According to the U.S. Environmental Protection Agency most people rely on surface water from lakes and rivers for drinking. Yet some 80 percent of water systems in America use groundwater sources.
Polluted groundwater is less visible and more difficult to detect than surface water and monitoring often relies on deep-well sampling. Traditionally, well water is pumped to the surface where it can be sampled, a process requiring large equipment, power generators and many hours of labor. A single sample from a remote site can easily cost taxpayers tens of thousands of dollars.
But that’s about to change if a team of DRI researchers and British engineers gets its way. Funded by the U.S. Department of Energy to facilitate the transfer of promising environmental technologies, DRI is working with AEA Technology, one of Great Britain’s leading engineering and technology firms.
Last December, a DRI-AEA team joined forces at Lathrop Wells in Nye County, Nev. for further test and development of a low-flow device for collecting water samples from deep wells.
Rather than relying on electrical power and pumping, this system uses air pressure to propel a flexible polyurethane plug—or “pig”—that pushes a water sample to the surface via a bundle of plastic tubing placed in the well.
Eventually, the system will give hydrologists an extremely portable, inexpensive and automated alternative for deep-well sampling that can be set up quickly and easily and run for long periods of time unattended. It can be used to monitor general chemistry, the presence of radioactive elements and trace metals in the water.
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A prototype sampler head is lowered into a well during a test of a new class of deep-well sampler developed by a DRI-AEA Technology collaborative effort. |
DRI Principal Investigator Chuck Russell is optimistic about the project. “Our prototype is yielding some great results. The prospect of producing a highly mobile sampler that can bring well water to the surface with minimal operator interface is exciting. A portable, easily installed, automated sampler will really decrease the cost of obtaining groundwater samples,” Russell says.
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This portable surface control unit—a key component of a new low-flow deep-well sampler—is mounted on a trailer for ease of deployment. The system’s portability and cost-effectiveness make groundwater monitoring much more affordable. (Photos by Ron Kalb) |
The search for this most elusive of samplers began a few years ago when AEA approached DRI. The United Kingdom-based engineering firm had developed power-fluidics pumps with no moving parts to take samples from storage tanks holding high-level waste. AEA was seeking new applications for the pumps and began contacting research institutions.
After initial meetings in which DRI researchers evaluated the product’s application to groundwater monitoring, AEA and DRI agreed to collaborate on developing a deep-well sampler. In 2003 a prototype was used to collect water samples from a well at a depth of 250 feet in collaboration with Sandia National Laboratories in New Mexico. A modified prototype was next used last year at the Nevada Test Site to sample water some 750 feet below ground.
According to Russell, the most recent tests in Nye County were extremely valuable and resulted in more modifications. “We recently shipped the system back to AEA’s facility in North Carolina where they will make additional changes based on our findings.” Russell anticipates the need for more tests and modifications before the system is ready for marketing.
In Russell’s view, the project is a good example of how private industry, government and academia can work together for the public good. “Everybody wins,” he says. “DRI gets access to AEA’s engineering prowess; AEA gets to call on DRI’s hydrology expertise to develop a new product; DOE is able to advance its technology transfer agenda; and Nye County, by providing a test well, gets a sampler and test results. Ultimately, the general public and taxpayers win, too, because we’ve made some major improvements on how to conduct deep-well sampling quickly, easily and cost-effectively.”
–Ron Kalb |
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