Bailers Cost compared to Contamination
The bailer is a tube used to retrieve samples from groundwater wells. The wells are drilled and range in depth, but are typically between 20 and 400 feet deep. The bailers are threaded with string or twine and lowered down the well to the water level. The ball check-valve of the bailer releases to allow water in. As the bailer is raised out of the well, the ball then seals off the bottom valve to contain the sample. Many years ago, bailers were made out of stainless steel, which made them expensive and hard to decontaminate. Today, we have disposable bailers that are usually made of plastic, however the types of plastic used can be an important element to the integrity of sampling results.
Today, it seems as if everyone is looking for the cheapest bailer possible, yet does anyone stop to think what materials comprise their bailers? The most harmful resins in sampling are PVC and ABS, two of the most inexpensive. So, the question must be asked, do you choose a bailer based on costs or its ability to sample without contamination?
PVC or polyvinyl chloride is both adsorptive and absorptive; it can leach compounds into samples and adsorb/absorb compounds out of samples. Plus, the vinyl chloride in PVC can be a contaminant issue both during sampling and after disposal of the bailer. Greenpeace, an environmentalist group, has pushed for the global phase-out of PVC because of its harmful effects on the environment (Vinyl, 2009). This is because dioxin, a byproduct of PVC, is linked to immune system failure, reproductive problems, cancer, and endometriosis (Vinyl, 2009). Can you imagine all of the used PVC bailers sitting in landfills emitting dioxins all over the world? This is a major environmental threat.
Another harmful resin known as ABS, is used to make the top and bottom pieces of bailers. ABS stands for acrylonitrile-butadienestyrene (Architecture, 2003). ABS is commonly made with plasticizers that can leach into samples causing severe chemical effects and making it incompatible with certain chemicals. To make matters even worse, colored dye has been added to the plastic, making it even more questionable for sampling.
Integrity of the sample is one of the most important aspects in sampling. In many cases, peoples' lives and our environment depend on results being accurate. Why risk contamination by using bailers that contain harmful PVC and ABS? It is suggested that bailers should always be made from high density Polyethylene Bailers, Clear Polyethylene Bailers, or Teflon Bailers for optimal sample integrity. For environmental professionals, it is imperative to be proactive: know what your bailers are made of before you sample.
