Existing Federal regulations require that underground tanks and pressurized pipelines containing petroleum and other hazardous substances be tested for leaks on a regular basis and that once a leak is detected it must be repaired. This is an onerous task considering the enormous number of miles of pipeline associated with retail gasoline service stations, airport hydrant systems, and Army and Navy fueling depots, etc. nationwide. Over 300,000 releases from underground storage systems have been confirmed to date, and the Environmental Protection Agency (EPA) estimates that as many as 15 to 20 percent of the approximately 1.8 million regulated underground systems nationwide either are leaking or are expected to leak in the near future. The environmental threat from these leaking systems has a direct impact on public health because approximately half of the nation’s drinking water supply comes from groundwater.

The project objective was to develop and demonstrate a non-invasive and non-destructive system for detecting and locating small leaks in pressurized pipelines. The technology needed to be accurate, simple to use, and applicable to a wide variety of pipelines and products. This technology will be utilized to detect and locate small leaks from the thousands of miles of Department of Defense (DoD) and Department of Energy (DOE) pressurized pipelines worldwide, enabling the DoD and DOE to comply with environmental and safety regulations.

The technical approach involved five key steps. An existing pipeline test facility at the EPA Edison, NJ, location was modified by installing additional pipelines to allow the necessary testing. Preliminary experiments were conducted to characterize acoustic signals associated with leaks and to determine the acoustic effects of factors such as multiple leaks, pipe fittings, corrosion, and backfill. Data from the experiments was used to develop a prototype test system that was evaluated first at the test location and then in the field at DoD and DOE locations. A users manual was prepared and technology transfer undertaken to provide for rapid commercial availability of the resulting technology.

Preliminary experiments were conducted to characterize acoustic signals associated with leaks and to determine the acoustic effects of factors such as multiple leaks, pipe fittings, corrosion, and backfill. Data from the experiments are being used to develop a prototype test system that will be evaluated first at the test location and then in the field at DoD and DOE locations. This project was completed in FY 1997.

This project benefitted the DoD and DOE by providing technology to assure rapid compliance with regulatory requirements. The ability to locate leaks in critical pipelines quickly insures a state of readiness on the part of DoD facilities to fulfill their missions. For example, a forced shutdown of fuel handling operations because of leaks would immobilize military equipment and delay transport of military personnel and equipment. The timely detection and location of leaks would reduce the costs of environmental cleanups, mitigate legal liabilities because of damages, and maintain good community relations.