ABOUT THE NPMS

The National Pipeline Mapping System (NPMS) is a geographic information system (GIS) created by the U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration (PHMSA), Office of Pipeline Safety (OPS) in cooperation with other federal and state governmental agencies and the pipeline industry. The NPMS consists of geospatial data, attribute data, public contact information, and metadata pertaining to the interstate and intrastate gas and hazardous liquid transmission pipelines, liquefied natural gas (LNG) plants, and hazardous liquid breakout tanks jurisdictional to PHMSA.

The nominal accuracy of geospatial data in the NPMS is +/-500 feet. Therefore, the NPMS should never be used as a substitute for contacting a one-call center before excavating. Attributes in the NPMS pipeline data layer include:

PHMSA-assigned operator identification number
Operator name
System name
Subsystem name
Diameter (voluntary data element)
General commodities transported
Interstate/intrastate designation
Operating status (in service, abandoned, retired)
Geospatial accuracy estimate
The NPMS does not contain information on interconnects, pump and compressor stations, valves, direction of flow, capacity, throughput, or operating pressure. In addition, distribution and gathering pipelines are not included in the NPMS.