Water New Zealand says there are thousands of kilometres of asbestos water pipes throughout New Zealand and replacing them will cost billions of dollars.
Chief executive Gillian Blythe says the water industry has known about the looming costs of repairing and replacing deteriorating asbestos piping for many years.
“We know that asbestos piping is not as resilient as it was thought to be when it was widely installed throughout the country in the mid 20th century.
“It was believed at the time that asbestos pipes would last around 100 years but we now know they deteriorate much faster and that many pipes in the ground are now in very poor condition.
“As well as leaching asbestos, they are likely to be leaking water and therefore a potential source of contamination.
“Leaking pipes are a big source of network water loss in New Zealand. Water New Zealand’s National Performance Review has revealed that 20 percent of our water supply is lost through pipe leakage before it reaches the tap.
“But it is difficult to assess the condition of asbestos pipes underground because deterioration can depend on a number of environmental factors including the level of seismic activity and ground conditions.
“That’s why we have produced a guide, the National Asbestos Cement Pressure Pipe Manual, aimed at helping water infrastructure asset managers understand the condition and likely remaining life of their asbestos pipelines.”
It is available on the Water New Zealand website.