The salt deposits under parts of the Holderness Coast are the most extensive in the UK and are ideally suited to the development of salt cavern gas storage. In 2006, the area's suitability was confirmed by a programme of seismic testing.

We considered a number of factors in selecting Whitehill including the area's remoteness and proximity to existing dwellings, the natural screening and ecology of the surroundings, access to electricity, gas, sea-water and transport routes, as well as the geology of the area.

Whilst the exact size, location and final number of caverns will be decided in the ongoing design process, the figure below shows, to scale, the size, depth and indicative location of the caverns within the salt layer. It also shows the other layers of rock and roughly when they were created as well as the main areas of the project to be built above ground.

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