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Monitoring and reporting of the Transco Distribution Mains Replacement Programme 2002-2007

Executive summary

On 18th September 2001, the Health and Safety Executive (HSE) published, in the form of an enforcement policy, details of a programme for the replacement of the iron distribution mains operated by Transco and located within 30 metres of property. This programme had been developed in conjunction with both Transco and the Office of Gas and Energy Markets (OfGEM) and discussed with other interested parties, including Energywatch. The enforcement policy can be found on the HSE website at

Transco's responsibilities for maintaining the integrity of its distribution networks are defined by health and safety legislation, principally the Health and Safety at Work etc. Act 1974 and the Pipelines Safety Regulations 1996 (SI 1996/825). Under this legislation, the HSE have powers to enforce programmes of work designed to mitigate or eliminate the risks arising from the operation of pipeline systems that are used to transport hazardous fluids.

The enforcement policy published by HSE in September 2001 contains details of the options considered by HSE in arriving at its recommendation that Transco should reasonably be expected to carry out mains replacement activity at an annual rate consistent with a target to replace all iron mains within 30 metres of property in a 30-year period. This position will be subject to review on a 5-yearly basis.

This report sets out HSE's monitoring requirements and associated enforcement action criteria for the iron mains replacement activity planned by Transco for the period 1st April 2002 to 31st March 2007. It is anticipated that the basis for the replacement programme will be reviewed in advance of 31st March 2007 and subsequent monitoring and enforcement requirements may be amended in conjunction with any necessary changes to the nature of the programme.

The report begins with a brief outline of the basis for the mains replacement programme and is then structured around the following key areas to provide details of HSE's monitoring requirements:

In preparing this report, consultation has taken place with both Transco and OfGEM to review current practice and determine future monitoring needs. The reporting arrangements aim to be consistent with Transco's existing mains replacement reporting procedures whilst also recognising the OfGEM output reporting requirements made under the new 5 year Transco Price Controls.

It is intended to implement these arrangements from the 1st April 2002