If heavy transfer of fluids is required, it is beneficial to determine the quality of the fuel as quickly as possible at the very beginning. This can be achieved by a quick flush tank (also known as a dewatering tank). It is basically a system designed to allow the operator to visually see water bubbles or contaminants very clearly when a lot of product is pumped in. Should the quality not meet the specifications, none of the product will be transferred in and everything can be safely drained.
On a smaller and more accurate scale, an Aljac sampler can also be used in conjunction. This smaller device has a glass enclosure and has an inlet to allow a water detector to be introduced. A change in colour of the detector will determine if there is any traces of water.