The Accountable Pipeline Safety and Partnership Act of 1996 requires that the Office of Pipeline Safety adopt rules requiring interstate gas pipeline operators to provide maps of their facilities to the governing body of each municipality, in which the pipeline is located. The National Pipeline Mapping System (NPMS) was removed for a number of months from public use after September 11, due to security concerns. In 2012, it returned with restriction of use. National Pipeline Maps can still be bought from PennWell Corporation.