Thames Water Wholesale Wastewater Learning bulletin

1. Thames Water Wholesale Wastewater Learning bulletin Causation factors Reliance on findings of Ground Penetrating Radar Survey led to complacency in Safe Digging Practices by the project team Assumptions made regarding original CAT scan and not verified Ongoing scanning not checked Handover to site supervisor not adequate as site manager did not expect the supervisor would issue the permits HV Cable Strike When erecting the new boundary fence at Fobney WTW the placement of a fence post damaged a buried HV cable. The damage wasn't noticed at the time of the work being undertaken but came to light when a report was received from the an electricity customer that power was not available. The power company SSE arrived on site to investigate and observed the fencing company working in the area. SSE explained to them what they were looking for and what they thought had taken place. • What can I do differently? • All appropriate drawings to be passed on to sub-contractors when available. • PTBG training to be delivered to all persons currently authorised to issue permits • PTBG training to also be delivered to PMs • Focussed audits to check on implementation of PTBG process • A process to ensure correct handover of important information to be reviewed and developed Tony Ashford Learning from Incidents