Summary: The Office of Pipeline Safety (OPS) is implementing a new approach to overseeing the safety of a 2.2-million-mile network of pipelines in the United States that transports potentially dangerous materials, including hazardous liquids, such as oil and natural gas. OPS has to complete several important steps to implement its integrity management approach within an ambitious, self-imposed schedule. The agency began applying this new regulatory approach to hazardous liquid pipelines in 2000 by issuing final rules requiring operators of these pipelines to develop integrity management programs. While implementing its integrity management approach, OPS must also perform ongoing oversight duties, such as inspecting the construction of new pipelines and investigating pipeline incidents. In addition to meeting its ambitious schedule, OPS faces a number of other challenges in implementing this new regulatory approach. These challenges include (1) enforcing the integrity management requirements consistently and effectively, (2) ensuring that natural gas transmission pipeline operators use assessment methods appropriately, (3) establishing an inspection interval for natural gas transmission pipelines, (4) measuring and reporting on the effectiveness of the approach, and (5) developing and implementing an approach for overseeing pipeline security. OPS's efforts to identify the resources and expertise needed to implement its integrity management approach are hampered by the lack of an up-to-date assessment of current and future staffing and training needs and an examination of the workforce's deployment across the organization--essential elements of a "workforce plan."