This paper will provide the reader with an overview of pipeline leak detection technologies and current US regulations and standards. In enacting the Pipeline Inspection, Protection, Enforcement and Safety Act of 2006 (PIPES), the U.S. Congress directed the U.S. Department of Transportation’s (DOT’s) Pipeline and Hazardous Materials Safety Administration (PHMSA) to prepare a report on leak detection systems utilized by operators of hazardous liquid pipelines. Specifically, Congress asked for a discussion of the inadequacies of current leak detection systems, including their ability to detect ruptures, small leaks that are ongoing or intermittent, and for solutions to foster development of better technologies as well as address existing technological inadequacies. Operators’ choices about methods of leak detection will be as varied as the types of pipeline construction, operation, and the environments in which they operate. The US pipeline infrastructure is comprised of a wide variety of materials installed over many decades in environments as widely diverse as Florida and Alaska. Environmental factors, many of which can fluctuate over the course of a day, a month, or a year, affect the performance of these leak detection systems. These include soil type, moisture, temperature, topography, and seismicity. Operational factors also fluctuate widely due to seasonal or demand factors. These operational factors include flow volumes, product transported from crude oil to jet fuel and potentially ethanol, leaks caused by corrosion to excavation to equipment failure and more, and time of day. Technical capabilities to detect leaks vary in terms of sensitivity, accuracy and responsiveness. This paper will provide the reader with an overview and summary of the above referenced US “Leak Detection Technology Study” for the PIPES Act (H.R. 5782) supplemented by current and pending research from the Pipeline Research Council International (PRCI).