Seaview Wastewater Treatment Plant. Photo: Supplied / Wellington Water
Wellington Water is warning of the potential for increased odour at its Seaview sewage treatment plant due to critical works.
The facility has been notorious in the local community for causing a smell which some described as being so bad it made them dry retch.
The problem stemmed from the treatment plant's sludge dryer which removed water from the solid material left over in treated sewage before it was disposed.
The dryer was near the end of its working life and required constant maintenance before it was replaced.
Part of that work would start next week between 3 June and 17 June and would require the dryer to be shut down which could cause a stench.
Wellington Water chief operating officer Charles Barker said that it was due to wet sludge being transported out of the facility and to a landfill rather than a dry material.
"It is stickier more odorous stuff."
Barker said the maintenance was to ensure the dryer remained operational while work was underway to get a new dryer in operation by the end of 2027.
He said he expected the plant's smell not to be "that bad" and nothing like what was experienced by the community during summer.
Local resident Chris Hetherington told RNZ the site was "just disgusting" at its worst.
Hetherington said he had no problem with the plant it just had to operate within its consent.
He said it was good that Wellington Water had told the community that if the smell got too bad it would bring the dryer back online.
"Now the community is at the forefront of their decisions, so I do believe there has been a massive change."
Barker acknowledged the community experienced an extended period of intense odour last summer and that it was right for them to be anxious about dryer work.
In March RNZ reported that in December Wellington Water attempted to reprimand Seaview's operator - the Veolia multinational over the stench.
Chief executive Pat Dougherty wrote to Veolia country director Emma Brand on 4 December, saying: "Wellington Water has not historically sought a financial penalty.
"That historical practise will no longer be followed."
The breaches at Seaview and several other plants were "significant and repeated", and every breach "amounts to a potential criminal offence", Dougherty said in the letter released to RNZ under the Official Information Act.
"Contract penalty payments are likely to be enforced by Wellington Water in the future."
Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.
