Aging cement water pipes in New Zealand are eroding faster than expected, with many community members concerned about the presence of asbestos in drinking water as a result.
A University of Otago study showed “abundant evidence” of asbestos fibres in drinking water samples from 35 locations across Christchurch and has expressed that the results would be similar in other locations in the country.
According to the study, the country currently has more than 9000 kilometres of asbestos piping that is earmarked for replacement, which estimates suggest could cost as much as $2.2 billion.
Asbestos cement was widely used in water pipes from the 1930s to the 1980s.
The authors of the study say that these pipes are now at risk of failing and beyond being fit for use. Corrosion, caused by water supplies low in calcium and magnesium, has allowed the piping to degrade faster than expected.
“The rate of that corrosion was quite swift, so the pipes were decaying from the inside much faster than overseas examples,” the study’s authors explained.
Asbestos fibres were detected in fire hydrant and domestic water tap samples. They did not exceed safe levels, but there is no clear, safe level of ingestion of asbestos, despite the danger of the material when airborne.
“The World Health Organisation, the current NZ Guidelines for Drinking Water Quality Management, and the Australian Drinking Water Guidelines state there is insufficient data available worldwide to derive a health-based link to asbestos in drinking water.”
Christchurch City Council’s acting head of three waters, Tim Drennan, said that there was an “ongoing renewal programme” in place, which has been underway since the 1990s.