This reminded me of when I worked at Camper & Nicholson's, the Marina company built some water front apartments in the late nineties and reclaimed a large area of the mud flats to the side of the marina and after that they were pile driving for months to form the foundations, my office over looked the site and I remember thinking what would happen if just one of the many piles were to find a UXB that could have sunk in the mud over seventy years, so glad they didn't %)Joe.
Joe. In the early 60's, the old wooden groynes along the beach at Hythe in Kent were being replaced with supports made by pile-driving redundant railway lines (post-Beeching!) into the beach. After work was in progress for some weeks, some kind person informed the Council that the beach had been mined during WW2, and wasn't this piling a bit dodgy? Enter Nemo, as one of a Bomb Disosal Squad where we worked for many weeks sweeping the beach for mines, prior to the piling taking place. We found only one live mine - but this justified all the precautions taken - and would have allayed the fears of many - similar to Joe!
A difficult judgement to make depending on all the circumstances and difficulties.
Bob.