Hydrotesting is a critical step in evaluating the integrity of a pipeline. The pipeline is filled with water and pressurized beyond normal operating pressure. A pressure drop indicates a breach somewhere in the system.
The challenge is that hydrotest water is corrosive, and disposal of the water is costly. Hydrotest water contains micro-organisms, oxygen and sediment that are known to accelerate corrosion progression. Also, because of the large volume of water used, treatment can be very expensive. The water must be cleaned of any chemical contaminants prior to release or disposed down a well. In some cases, because of these added costs, the water is not treated at the expense of pipeline integrity.