BELL GARDENS, Calif. -- The humble bailer has been reinvented by Applied Biogenics, Inc. (ABI). What started out as a problem with a crooked borehole has developed into an engineering delight.
"The bore produced by the drilling company for a groundwater monitoring well had a dogleg in it," recalled ABI's Jay Stern. "Of course, we didn't know about it until we tried to take a water sample. The bailer stuck down around 140 feet or so."
The driller said he could put in a new hole, but if would cost another $10,000, and he couldn't guarantee that it would be any straighter than the first one.
"It made me angry. But I also started thinking. We needed a bailer that wouldn't get caught in crooked well bores. The idea of using a tiny bailer is no solution because the composition of the water sample changes from the first specimen to the last."
Stern, whose background includes a masters degree in Chemical Engineering, went to work on the problem. He, developed a sampler that was flexible and would snake through narrow, crooked boreholes with ease.
"I wanted to get away from the idea of metal ballast. In some applications, even stainless steal will contaminate the water, corrupting the results. Further, I didn't approve of the use or quality of stainless steel in what was, essentially, a throw-away device."
In Stern's design, only polyethylene contacts the water. The ballast -- ordinary sand or clay -- is contained within compartments that also comprise part of the bottom valve.
"The valve is a one-way device similar to the valves inside our arteries. Fluid pressure causes the valve to open, trapping water within the sampler body. When retrieved, the water now closes the valve, preventing leakage. Since the valve is not rigid, it is not affected by sand, sediment, or slime.
Stern also has a B.S. degree in biology. "Any time I have a technical problem," he says, "I ask how nature solved it. Chances are, my answer is already there."
To construct the valve, he studied flow of fluids and applied Bernoulli's theorem. "I'm just amazed how soft, floppy low-density polyethylene can be used as an engineering material. Until I tested it, it just wasn't obvious.
In fact, nothing about the samplers was obvious. This may be why all of the claims were approved the first time through the U.S. Patent Office. There are three styles of samplers. One is bottom loading and is equipped with the valve to collect vapor and water. A septum on the side allows grabbing a vapor specimen via syringe needle.
The second sampler is open at the top, but will remain closed until the desired water depth is reached. Then, it opens and collects a water sample at that point. It is mainly designed to determine if stratification has occurred at various depths, but is also useful as a plain, bucket sampler.
The third is open at the top and has the bottom-opening valve. This model competes directly against the so-called disposable samplers made of rigid, high-density polyethylene.
"With our samplers, there is no question as to disposability," says Stern. "They are cheap and really portable, so the technician shouldn't be tempted to reuse a sampler and thereby cross-contaminate wells."
Neither the EPA nor the regional Water Quality Control Board where ABI is located endorses products. However, the EPA Region 9 staff, who appreciated the fact that ABI consulted with them while the product was in development, gratefully received the samplers. Similarly, the water board has agreed that two-inch monitoring wells may be installed, instead of four-inch, if ABI's samplers are used.
Considering the cost difference between installation of the different size wells, use of the ABI samplers will save about $8/ft in drilling costs even before a sample is taken.
The samplers are provided in standard lengths and diameters, but custom fabrication is available. "We've made them small enough to fit down a 3/4-inch bore," Stern remembered. "Until then, stainless steel tubes costing $100 each were the only alternative. We made a couple dozen for that price."
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