As part of its monitoring strategy, HSE is committed to carrying out a number of audits of Transco's performance. Following the audit of West Midlands distribution network in December 2002, a further two are planned for December 2004 in Scotland and Wales & the West Networks.
Over the period April 2003 to March 2004, Transco planned to replace 2549 km of iron mains. Transco actually replaced 2673 km, some 124km in addition to the target.
As a part of this work, Transco abandoned a further 33km of Medium Pressure Ductile Iron (MPDI) mains*. These additional lengths of MPDI were discovered during the course of the planned work and were removed as soon as was reasonably practicable, as agreed with HSE.
Transco achieved their mains replacement targets for the period April 2003 - March 2004, which has resulted in the removal of further risk from the network.
HSE will continue to audit Transco's systems and management arrangements for delivering their programmed mains replacement activity.
* MPDI mains are known to fail suddenly and unexpectedly, presenting an unacceptable risk to the public. In September 2000, HSE served an Improvement Notice on Transco requiring them to replace all MPDI mains within 30 metres of buildings.