Have any other factors changed in the 6 months (especially given the winter we have just had): - subsidence/sink hole/washout changing relative underground location? - markers in consideration of the mapping conducted at the time e.g. change in a river bank position? - No works or more correctly no notified/recorded works? Personally would be repeating to eliminate the unknown

Is it such a big deal carrying out another CAT scan? Personally if I was supervising the work I would want to make sure previous plans are correct and carry out a fresh scan.

Would I use the scan as the basis for a hand dig to positively identify the location of the cable before mecahnical excavation yes, why not? Would I use it for the basis of mechanical excavation without positively locating the service? I would not use a 5 minute old CAT scan on that basis.