Well Development or Sampling The stainless steel bailer is ideal for both groundwater sampling & well development. The all stainless steel construction and check ball allows for rapid decontamination between wells. The tapered top is designed to avoid hang ups in the well, and smooth raising & lowering. A 45mm diameter enables it to be used in standard 50mm monitoring wells. Reusable equipment such as this helps reduce the amount of disposable waste, and adds sustainability to your operation.