Gas supply incidents
There were 210 gas supply incidents recorded during the reporting period from 2004/05 to 2013/14. In contrast to gas utilisation incidents, the majority of gas supply incidents occurred within the workplace. Figure 15 displays the number of workplace and non-workplace incidents, with workplace incidents amounting to 82% of all recorded supply incidents. This has increased compared to the previous report analysing the ten years 2003/04 to 2012/13 where 79% occurred in the workplace.
Gas supply incidents – Workplace and non-workplace
Figure 16 illustrates that supply workers were involved in just 3% of the incidents and gas workers in 5%. Workers from other occupations were found to be involved in 75% of incidents and approximately 14% affected the general public.
Gas supply incidents – Workers and general public
Gas supply incidents – by type of gas
Analysis of the type of gas found in recorded supply incidents reveals 94% of incidents involved NG. In comparison, incidents involving LPG accounted for 6% as displayed in Figure 17 below. However, this figure may be more representative of the size of the distribution system for NG and LPG. Figure 17A depicts the number of incidents per 1,000 customers.
Figure 17: Gas supply incidents – Type of gas
Gas supply incidents – Type of gas
Gas supply incidents – Percentage of consumers by type of gas
Further analysis of incidents involving NG, as per Figure 18 below indicates that 82% of incidents resulted in a gas leak or release. In contrast to gas utilisation at 57%, just 13% of gas supply incidents involving natural gas resulted in a fire. If explosions and flashovers are considered in the category of a fire (as they do result in a fire) this percentage increases to 15%.
Gas supply incidents – Type of incidents resulting from NG
Figure 19 below provides percentages for the different types of incidents but they are minimal in number when compared to natural gas. As the data suggests, the percentage of incidents resulting in a fire (inclusive of flashovers and explosions) is 38%.
Gas supply incidents – Type of incidents resulting from LPG
Figure 20 below is an analysis of the type of equipment found in gas supply incidents. It was found that the main gas pipe was a factor in 87% of the incidents. Other incidents involved gas service piping (7%) which incorporates the meter box and the piping from the mains to the meter.
Gas supply incidents – Equipment type
Figure 21 below is an indication of the injury types sustained in supply incidents. There were no fatalities recorded in gas supply incidents until 2012/13 when there was one fatality.
Of all gas supply incidents, 1% resulted in hospitalisation and 1% in minor injuries. The large majority of 97% of incidents have resulted in no injury. 9% of incidents resulted in damage to property.
Gas supply incidents – Incidents resulting in fatality, injury or hospitalisation
Gas supply incidents – Incidents resulting in property damage