Auckland faces the prospect of days without natural gas supplies, with all commercial and industrial gas users in the upper North Island ordered to "curtail" their consumption until further notice this afternoon.
The industry's emergency management plan has been activated after a leak closed the main gas pipeline between the Taranaki gas fields and Auckland, affecting gas consumers in a line from the King Country north, and in the Bay of Plenty.
Household gas users are not yet affected by the order, but are being asked to use gas sparingly.
However, hospitals, schools, restaurants, food processors such as Fonterra, and manufacturers such as O-I Glass (formerly ACI Glass) in Penrose, Auckland are among affected customers ordered to "curtail" gas use in a statement this afternoon by the industry's critical contingency coordinator, the Gas Industry Company.
"We're just assessing the impact now," said a Melbourne-based spokesman for O-I, Dieter Lehmann, minutes after the gas curtailment notice was issued.
Electricity generators with gas-fired units in the affected area were ordered earlier in the day not to use their plant, as plans are activated to eke out the remaining gas, known in the industry as "linepack", that is still available for use in the Maui pipeline to the north of the repair point.
The curtailment order applies to all upper North Island gas consumers apart from residential users at this stage, but householders are also asked to "limit" their use of natural gas, while a break in the Maui pipeline at White Cliffs, north of New Plymouth, is repaired.
"The directive is intended to manage available gas supplies while the cause of the gas escape is determined and the likely extent of the resulting outage assessed," the industry coordinator, the Gas Industry Company, said in a statement.
Linepack gas can continue to be available for several days, with domestic users being both the smallest source of demand and the last to be subjected to a curtailment order.
Repairs for the "serious gas escape" are being assessed and the possible length of the outage is as yet unknown, but could take some days, based on past experience.
"Technical experts are preparing to excavate the section of pipeline to determine the cause of the gas escape. This is expected to take most of today and, until the cause is identified, there can be no estimate of when repairs will be effected," the GIC statement said.
"An alternative smaller pipeline is being used to maintain limited gas supplies into the affected residential areas, but supply could be at risk without immediate curtailment by commercial and industrial users."
The Maui Pipeline is owned by Maui Development, a Shell New Zealand and Todd Energy joint venture, with Vector contracted as technical operator.
Linen shortage cancels surgery
A linen shortage sparked by the ruptured gas pipeline has forced the cancellation of some elective surgery in Manukau, while Auckland and Waikato hospitals could also feel the impact.
Spotless today warned Auckland, Counties Manukau and Waikato district health boards (DHBs) the gas crisis would affect all linen and sterile items it is contracted to supply.
It asked hospitals in a memo to conserve the use of all linen as much as possible.
A Counties Manukau DHB spokeswoman said the shortage would affect some elective surgery at the Manukau SuperClinic.
Auckland DHB said no decisions had been made and more would be known tomorrow, while Waikato DHB said there were not yet any issues and planning was underway.
Spotless said in the memo it was developing contingency plans.