I am assured that every precaution has been taken to ensure the safety of the Corrib gas field pipeline. At no point along the pipeline route will the gas pipeline pass closer than 70 m to any dwelling. A condition imposed in the pipeline consent includes as absolute requirement that the pipeline passes no closer than 70 m to any inhabited dwelling.
In addition, a quantified risk assessment has been undertaken for the onshore section of the pipeline which included a detailed analysis of the risk of damage to the pipeline and consequences of any such damage. This showed that even in the very worst case of the pipeline being ruptured and the gas being ignited, the occupants of a building 70 m away would be safe. The design of the pipeline means that the risk of such an event or any other type of gas escape is very small. Also the pipeline will be buried to a depth of at least 1.2 m.
The design of the pipeline is in accordance with international design codes and is to a pressure of 345 barometers. The pressure in the pipeline will initially be 150 barometers, reducing over the life of the field. In 2002, my Department commissioned an independent expert to confirm that the design is fully in compliance with international codes.
As regards the feasibility or usefulness of adding mercaptans for safety, I am advised by my technical expert that there would be no benefit from doing so. Gas is lighter than air and in the very unlikely event of gas escaping from the pipeline, it would be rapidly dispersed away from ground level and any people in the area. Mercaptans are added to enable leaks to be detected by smell in confined areas such as buildings.
While the control umbilical will carry high pressure liquids, the volumes are very small. The umbilical will be buried to a depth of at least 1.2 m so these liquids pose no threat to people in the area.
