The legacy of asbestos includes an $80 million bill for the Dunedin City Council as it works to replace a network of ageing asbestos water pipes across the city.
Documents released to the Otago Daily Times, as part of an ODT Insight investigation, show the council expects to spread the cost over the next 50 years, as it works to replace the old asbestos pipes.
The money will come from the council's renewals budget, but is on top of the cost it faces to remove, or control, asbestos inside council-owned buildings.
That includes an estimated $850,000 needed to address asbestos found inside Moana Pool earlier this year, as well as at least five other buildings the council is responsible for.
But it is the replacement of the city's ageing stock of water pipes that will bring the most eye-watering costs.
About 260km of asbestos water pipes had been laid across the city from the late 1930s to the 1990s, almost all of which remained in the ground, council asset and commercial manager Tom Osborn said.
Some of the pipes were still in use, but posed no health risk to consumers, Mr Osborn said.
The rest of the pipes had been "abandoned'' in the ground after replacement pipes were laid nearby, he said.
Amalgamated Workers Union representative Steve Scandrett said that posed a risk to contractors laying other services, as the abandoned pipes turned to "Weet-Bix'' over time.
There was a risk they could generate an asbestos dust cloud if exposed inadvertently, he said.
Mr Osborn said the pipes' locations were recorded, covered by an easement and treated as "contaminated'' sites, to avoid just such an incident.
However, the practice was being reconsidered by the industry group Water New Zealand, which was working with WorkSafe on new guidelines.
That could have implications, including extra costs, for councils including the DCC, he said.
"I think it's something we definitely need to address ... as an industry, we probably need to decide whether the best thing long term is to remove that from the ground."
If the guidelines required councils to remove old asbestos pipes from the ground when they were replaced, excavation would have to include the potentially contaminated earth around the pipe, he said.
That could result in up to 6cu m of earth excavated for every metre of pipe lifted, he said.
The pipes would still have to be dumped in a certified landfill, but the change would help contractors and others avoid inadvertently exposing the old pipes.
It would also create more space in the service corridor under roads for other services, such as telecommunications ducts, he said.
Exactly how much extra cost the change in approach would add to the council's books was not yet known, but spreading the cost over time meant it would not be "insurmountable'', he said.
"We just need to know what we're dealing with.
"It's about making sure we're doing the right thing at the end of the day, but that being well thought out ... rather than as a knee-jerk reaction from one council suddenly deciding to take all the asbestos out of the ground.''
