In the US, LNG proponents need to assess potential hazards all along LNG tanker routes. Not so in BC. On the map below we’ve superimposed hazard zones used by the Department of Homeland Security | US Coast Guard during review of LNG proposals in the US onto the tanker route from the proposed Tilbury LNG site on the Fraser River. Scroll out to see the entire route to international waters. Zoom in to see where the hazard zones fall in Richmond, Delta and the Gulf Islands. Switch the map to full screen using the button at left.
Requiring LNG proponents to conduct hazard zone mapping allows government regulators to assess risks to public safety and property along LNG tanker routes.
The hazard zone guidelines reflect a worst case scenario — the complete loss of LNG containment due to an intentional act. Summary description:
- 500 m zone: extreme hazard of combustion and thermal damage from pool fire if evaporating LNG is ignited. Cryogenic burns and structural damage from exposure to supercooled LNG. Asphyxiation hazard for those exposed to expanding LNG vapor plume.
- 1600 m zone: hazards as for the 500 m zone, with severity of consequences declining over distance.
- 3500 m zone: conservative maximum distance within which an expanding LNG vapour cloud may still ignite if in contact with a source of ignition. Resulting fireball would burn back to the spill source and could cause intense pool fire.
Further details on hazard zones and waterway suitability assessments required in the United States — but not in Canada — found here.