Wellington Water has been convicted and fined $67,500 for an illegal discharge of sewage sludge from the Porirua City
Wastewater Treatment Plant.
Greater Wellington Regional Council laid the charge back in April. The case concluded on Friday (13 September 2019) with
a conviction and fine imposed by Judge Dwyer in the Wellington District Court following an earlier guilty plea by the
The discharge from the treatment plant occurred during dry weather in October last year (2018). A plume of sewage was
seen from Titahi Bay by an off duty Greater Wellington compliance officer who immediately alerted the Council and
assisted with the initial investigation. Wellington Water quickly found the cause of the problem and shut off the
discharge which had been occurring for approximately 3 hours.
The investigation by Greater Wellington, with full cooperation from Wellington Water, showed that human error was the
principal cause of the discharge. There had been a series of poor operational decisions and a failure to follow
procedures. This resulted in approximately 1000m3 of sewage sludge discharging at Rukatane Point.
In passing sentence the Judge commented that, “there was a high degree of carelessness in this case…characterised by a
cascade of mistakes”. He also stated that since the events Wellington Water had, “behaved as a responsible rate payer
The Wastewater Treatment Plant is owned by Porirua City Council but has been managed by Wellington Water since 2015. In
2014, Porirua City Council was prosecuted for a discharge resulting from failures at the plant following heavy rain. The
outcome of that case was a fine of $40,000, which was directed to environmental restoration projects in the area
“The public expects us to take non-compliance seriously”, said Greater Wellington Environmental Regulation Team Leader,
James Snowdon, “Local authorities should operate their services adequately and safely. Whilst other options will always
be considered, there comes a point when prosecution is required to hold individuals and organisations to account and to
deter others from undertaking activities that may break the law.”
Wellington Water issued an apology for the incident at the time, and has since been working hard with the local
community and Ngāti Toa on ways and achieve better outcomes for the harbour. With the agreement of Wellington Water and
Ngāti Toa, the money from this fine will be directed through the council towards environmental projects in the Porirua
catchment led by iwi.
Wellington Water is prioritising improvements to the wastewater network over the treatment plant to reduce overflows and
leaks, and help improve the health of Porirua Harbour and its coastal environment. It has worked collaboratively with
Porirua City Council, Ngāti Toa, Greater Wellington, Wellington City Council, the Whaitua Committee and other
stakeholders in developing a proposed wastewater improvement programme.