To ask the Secretary of State for Transport, which geological surveys undertaken by HS2 Ltd since 17 July 2013 have considered (a) subsidence and (b) the effects of shifting land movement owing to salt movement or other effects of salt mining in Eddisbury constituency.
4 May 2016
No intrusive geological surveys have been carried out at this stage. HS2 Ltd has commissioned from a mining engineer (in consultation with the Cheshire Brine Subsidence Compensation Board) a study of the historical subsidence effects and ongoing extractive processes in relation to salt. This includes review of ground movements in the time between two successive (2014 and 2015) HS2 LIDAR surveys of the route in Cheshire, and earlier where relevant third party LIDAR data has been made available.
A re-review of the usefulness of satellite interferometry to evaluate historical ground movement across Cheshire (including the Eddisbury constituency) is ongoing.
Following a route decision in autumn 2016 HS2 Ltd will begin production of a full Environmental Impact Assessment.