Outfall pipe likely to be an expensive fix in an outdated system
A fibreglass pipe joint that was once state of the art is now the centre of a wastewater issue which could see the Napier City Council having to borrow more than $20 million.
But neither its failure — after more than 40 years — nor associated costs are unexpected in a world where urban authorities around the world grapple constantly with keeping upto-date with “three waters” infrastructure. The joint in question sits about 700 metres out to sea in the city’s 1500m wastewater outfall off Awatoto.
Generally, infrastructure has aged, sometimes with pipes which might be a century old, installed originally for small boroughs with horses and carts up the main street.
Progress never allowed for it all to be disinterred at once and replaced with better stuff so Napier, as part of keeping apace, has $109 million set aside in its 10-year plan for meeting the next stage of the growing stormwater, wastewater and drinking water needs of the city.
But at a meeting today, the council, with a mayor seven months in the chair and five of the 12 councillors just as new to their roles, finds itself considering a recommendation to add $11.6 million to replace its controversial outfall — amid suggestions costs could go as high as $40 million depending on possible new legislative requirements.
Mayor Kirsten Wise, facing greater big-ticket cost issues in those seven months than possibly any predecessor in a full tenure, says the council has been aware of the outfall issue since a leak was found in the fibreglass joint in late 2018.
Wise said, as does a report to the council, that constant monitoring had shown no adverse impacts, allowing time to work on the options for the future.
The joint was “probably thought to be state of the art” when it was put in in the 1970s, she says, adding: “Now it would probably never be done.”
“What we need for full replacement is know what regulations we may face in the future,” she says. “If we’re going to be told in five years we don’t want you discharging 1500 metres out to sea, we need to know that. We need to be sure.”
There are complications across the city, pipes of different ages, different compositions and varying longevity expectations, something which has faced Wellington in recent times.
The capital faced a double whammy with a central city pipe failure in December, leading to discharges into its harbour, and a failure of 25-year-old pipes in January, which led to 150 truckloads of sludge having to be removed to a landfill each day for about five weeks while repairs were made. The transport alone cost $200,000 a week.
Decisions about upgrading such infrastructure are, according to international experts, about risk management — “failure likelihood and future security”, says one report.
The report to the Napier council says repairing the outfall leak has risks and issues, but that a dive team could affect the lowest-risk repairs for the short term, and seeks a nearimmediate start on planning for a new outfall.
There’s some urgency to act now, with staff telling the council wanting a variation of the discharge consent so treated wastewater can be released at the point of the failure 700 metres offshore, amid a Hawke’s Bay Regional Council direction to repair the leak, come up with the plan for long-term solutions, by October 30, or face possible prosecution.
Costs would likely have to be met by loans, repayment of which could impact rates.
Upgrading in 2014 of the treatment plant at Awatoto leading to the outfall system had a budgeted cost of about $30 million, supported by ongoing dedicated rates components.