In a report issued on March 22, 2012, GAO found that gathering pipelines could present an increased safety risk based on encroaching development due to land use changes and the development of new gathering lines for shale deposit extraction, some of which are larger in diameter and operate at a higher pressure than older pipelines. As a result of the study, GAO recommended that DOT collect data on federally unregulated hazardous liquid and natural gas gathering pipelines and establish an online clearinghouse, or other resource, for sharing information on pipeline safety practices for these pipelines. Click here for the report.