New Plymouth sewerage pipes fail risk assessment

More than a third of the exposed sewerage pipes criss-crossing New Plymouth streams and rivers have failed a risk assessment measuring the threat of them discharging raw sewage into the waterways, killing aquatic life and posing a risk to human health.

Four of the exposed pipes – busy shifting their share of up to 800 litres per second of raw sewage – have a risk assessment score of little more than 30 out of a 100.

Last year the effect of ex-cyclone Gita gave New Plymouth a stern warning about the dangers of exposed pipes when a falling tree knocked out 25 percent of the city’s drinking water and forced 80,000 people to boil water for days on end.

Eighteen months on, council records show the 17 exposed sewerage pipes criss-crossing the picturesque Huatoki and Te Henui streams make grim reading.

Just three pipes are considered in good condition and two are deemed poor, but just one pipe is scheduled to be replaced inside the next 10 years.

A further four pipes go under the waterways – including one which accumulates all of the city’s sewage – and could not be inspected.

Taranaki Regional Council iwi representative and freshwater ecologist, Emily Bailey, said the consequences of a sewerage pipe rupturing in a storm event did not bear thinking about.

To read the full article, please visit the Radio New Zealand website.