The potential for major spills from pipeline and rail transport, as well as along oil-transit highway routes, has highlighted the need for establishing land-based sites to contain and control spilled oil. However, the guidelines for designating containment (C-) sites has to date been unclear. From work in several countries, the following rules are suggested: (1) every location along the pipeline/railway/highway route should have a designated C-site. (2) Locations where water courses could be reached by spilled oil should be prioritized for C-site location. (3) C-sites in flat areas with no spill movement expected can use a ‘typical’ location within that area. (4) The spacing along the route to evaluate potential spill flow should be 50 m (150 ft) or preferably less. (5) C-sites must be placed in locations which enable sufficient time for response equipment to reach it before the oil does; topography and stream flow must be considered realistically. (6) At least two C-sites must be placed on all water courses (creeks/streams/rivers) that can be affected; the second site being necessary if the first fails or is insufficient. (7) Maps (e.g. topographic or GoogleEarth) should indicate a realistic flow pattern from the route by which oil can reach the related C-site. (8) For water courses, C-sites should be selected for accessibility to both banks, ability to safely deploy and retrieve equipment, sufficient space for equipment laydown and oil storage, and ability to capture oil (low flow velocities and stream width).
While there are many formats for displaying C-sites, combining route sensitivity maps containing the physical, biological, and socio-economic characteristics of the area with the C-sites, provides a comprehensive single-map format for displaying C-site location, road access to the C-site, and emphasizes the importance of why oil should be contained at that location. In cases where a long cultural history is present in the area, the combination map also provides warnings regarding archaeological and cultural heritage sites that may be affected by cleanup operations along the route or near a containment site.