Machine Offers Smaller, Lighter, Faster Water Testing in Field
By Karen Fleming-Michael
Special to American Forces Press Service
FORT DETRICK, Md., Sept. 3, 2004 More than a dozen researchers gathered at the U.S. Army Center for Environmental Health Research here Aug. 25 to see an award-winning water analyzer that cuts in a third the time it takes to tell if water is contaminated.
David Putnam, a microbiologist and immunologist, demonstrates
a machine called the coliform analyzer, which rapidly analyzes bacterial
contaminants in water, is simple to operate, and is smaller and lighter than
the normal water-analysis setup. Photo by Karen Fleming-Michael
(Click photo for screen-resolution image);high-resolution image available.
Demonstrated by David Putnam, a microbiologist and immunologist, the machine, called the coliform analyzer, meets its early goals of rapidly analyzing bacterial contaminants in water while being simple to operate and smaller and lighter than the normal water analysis setup.
"The device takes conventional methods and improves on them with electronics and computers to enhance the entire process," said Thomas Gargan, of Geo- Centers Inc. at USACEHR, who has provided oversight of the machine's progress since 2000. "It's simple, straightforward and very innovative."
The shoebox-sized machine, with its blinking colored lights, cuts the weight of conventional analyzers to eight pounds while providing quick answers on whether water is contaminated. It also incorporates innovations such as replacing a yo- yo-sized filter with one that resembles a dime-sized spinning top and borrowing technology developed by the wine-in-a-box industry for collecting and dispensing water samples.
Further, the machine provides continuous progress reports for up to eight samples, which can be run simultaneously, and gives definitive results in eight hours instead of the 24 hours it normally takes. The machine can be used to test drinking water, source and surface water, treated water and recreational areas.
During the demonstration, Putnam used super-contaminated water, so attendees saw results right away as the machine updated its results.
"In conventional tests, lots of organisms are present and it doesn't matter which one -- it takes a day to find out. You wouldn't know until tomorrow," Putnam said. "The only way to approach it right now is to cover the range and see what you've got."
His machine looks for the presence of both total coliform bacteria and E. coli. The presence of E. coli in a water sample indicates the water is contaminated by fecal matter, and can make drinkers ill.
The procedure is relatively simple, so even people with little training can prepare samples for testing. The user takes a sample, which can be gathered in the kit's six-liter wine-box bag, and runs the water through a filter that grabs particles. The operator then injects the filter's particles into a special media that encourages only coliforms to grow.
As soon as the sample and media are put in the Coliform Analyzer, the machine begins reporting what's in the sample.
"Almost immediately, the operator can know if the sample has contaminants that could pose a danger to drinkers," Gargan said. "And by the end of eight hours, the operator will know if the sample contains coliforms as well as how many."
Military preventive-medicine specialists routinely work behind the scenes to sample water in the field to make sure it's fit to drink, said Paul Knechtges of USACEHR, who manages a program to develop devices to detect contaminants in water and food. Having a light, portable, rapid analyzer can make their jobs much easier, he said.
"We trust that when we turn on the tap, we get good water, and 99.9 percent of the time the (test) results are negative," Knechtges said. "But it's the .01 percent that's going to cause a water-borne disease outbreak. You don't want it to happen during operations."
The magic of the machine is its ability to measure the fluorescence of the coliforms that glow under the machine's ultraviolet lights as they multiply in the media.
The "nifty, golly, gee whiz" part of the device, Gargan said, is that you can see the real-time growth of bacteria because every two minutes the machine takes a reading to see what's growing.
The computer systematically counts the number of bacteria -- a chore that's difficult for most skilled technicians to do under a microscope -- and sends the results to both a graphing program and the machine's display lights. Red and yellow lights mean the sample is contaminated with both total coliform bacteria and E. coli.
"The beauty is that you don't need a computer printout or even the laptop. The machine will tell you with its lights if a sample is clean or not," Gargan said.
Military preventive-medicine teams routinely make decisions on which water is best, and this machine can help them determine which source of water is cleanest. After serving with disaster-relief missions in the Pacific, Knechtges said he can see how useful rapid water analysis is.
"There's a saying that in preventive medicine, the better job you do, the more invisible you become. But in the field you become a VIP," he said. "I used to have docs and nurses come up to me and ask if the water was all right to drink. That's a big responsibility."
(Karen Fleming-Michael is a staff writer for the Fort Detrick Standard.)