Under certain circumstances, regulations require the use of water in pipeline testing. The Pipeline Safety Reauthorization Act of 1988 required that DOT promulgate regulations in several areas for both natural gas and hazardous liquid pipelines. Increased state agency awareness has focused attention on discharges of hydrostatic test water. When using hydrostatic methods, natural gas pipeline companies must discharge the test water. The test water may contain oil and grease, iron, petroleum hydrocarbons, and other trace constituents.
State agencies establish discharge permitting requirements.
Each state also requires sampling and analysis of discharged test water to ensure permit compliance. Depending on a state's specific requirements, hydrostatic test water may require treatment prior to discharge. Typically, hay bale structures in combination with oil booms are used to capture suspended solids and free oil.