Skip to main content
Open Access Publications from the University of California

Enhancing protection for unusually sensitive ecological areas from pipeline releases

  • Author(s): Sames, Christina
  • Fink, Dennis
  • et al.

The Research and Special Programs Administration (RSPA) of the Department of Transportation is required to identify areas unusually sensitive to environmental damage in the event of a hazardous liquid pipeline accident. Pipeline operators that can affect these "unusually sensitive areas" (USAs) must develop and follow an integrity management program to continually assess and evaluate the integrity of their pipelines. After extensive consultation and pilot testing with conservation biologists, government agencies, drinking water experts, and other stakeholders, a process has been developed to identify USAs for both ecological resources and drinking water. The process begins by designating and assessing environmentally sensitive areas (ESAs), then determining which ESAs are potentially more susceptible to permanent or long-term damage from a hazardous liquid release. Finally, criteria were identified to determine which resources can be affected by a release and sustain permanent or long-term damage. Ecological USAs are defined and mapped based on the presence of critically imperiled species, assemblages of multiple imperiled or endangered species, the presence of sensitive species that are aquatically dependent or have a limited terrestrial range, and concentrations of migratory waterbirds.Mapping these areas nationwide made use of ecological data from several sources, the majority coming from the Association for Biodiversity Information (ABI). Once created, maps of the USAs are posted on the RSPA Internet website in viewable format (, and electronic versions of the GIS data layers are made available to pipeline operators for use with their GIS pipeline mapping systems. To identify and locate USAs, RSPA needed ecological data in a timely and standardized format. This included the location of imperiled, threatened, and endangered species. ABI aggregated data on the location and condition of species produced by its member organizations—the Natural Heritage Programs. This project represents the first time that detailed natural heritage data on specific locations of imperiled and endangered species have been aggregated nationwide for natural resource protection purposes. Previously, accomplishing this would have required a planning or regulatory agency to seek data from over fifty organizations across the country. ABI’s aggregated dataset represents the most authoritative collection of locational information on imperiled species available. This paper focuses on the process developed to identify USAs, development and provision of ecological data, and the mapping of USAs across the country.

Main Content
Current View