Wellington Scoop

“Vile” sewage smells continue from Moa Point, after ten years of promises

Media release – Moa Point Waste Water Community Liaison Group – (CLG)
After more than 10 years of operation, there are still major odour problems in the vicinity of the Moa Point Inlet Pump Station (IPS). This is after the wider community and the CLG had been promised and guaranteed from the outset that there would be no odour beyond the plant boundaries.

Moa Point as a site
Prior to its construction the Council disregarded a 14,000 signature petition stating that the site of a sewage plant at Moa Point was ill conceived, as it was less than 100 metres from commercial properties and residential homes. If the Valley West option had been accepted, discussions of this nature would not now be taking place. The closest bach was 800 metres away. Internationally, sewage plants maintain an odour buffer zone of 300 metres.

The Problem
There are site constraints of the treatment plant, and as a result sewage has to be pumped to it. This meant that the Inlet Pump Station (IPS) had to be constructed on its current site where the major odour problems continue to occur. It is during times of routine maintenance and the removal of fats, oils and greases (FOG) where the wet well covers must be opened. When the covers are closed, accumulated odour-causing gases are extracted and treated in a separate odour chemical scrubber. When the covers are opened, vile odours are released uncontrolled, into the atmosphere.

The design of the plant did not consider the problems associated with outdoor maintenance. On occasions, odours are so strong that they can be detected in nearby homes and causing considerable distress.

Cause of the Problem
Wellington sewage pipes suffer from seawater intrusion that can result in the production of high levels of Hydrogen sulphide, much higher than would normally be produced under normal operating conditions. It is this hydrogen sulphide along with the normal odour-causing compounds derived from the initial breakdown of sewage waste during transit in the sewer system that gives rise to the uncontrolled emission of serious vile odour problems anytime the IPS wet well covers are opened.

Why covers need to be opened
There are two issues. Routine pump and associated pump control maintenance; and the removal of the build-up of FOG. The length of time for FOG removal can vary from minutes to all day.

Simple solution to problem
The placing of a building over the IPS wet well could contain all of the odorous gases from this source and would be dealt with by the existing odour treatment system or by an additional system. The ‘Report’ commissioned by UWI (the contractor) recommended this approach.

CLG submission to WCC Draft Annual Plan
The CLG requested that WCC allocate such funds in its 2010/2011 annual plan. This was declined.

“By declining funds for the construction of a building over the wet well, council demonstrates that it has once again delayed the inevitable. The decision clearly illustrates how WCC has scant regard for the continued discharge of vile odours into the sensitive local surrounding environment at Moa Point,” said Stan Andis, speaking on behalf of the CLG.

“Over the past 12 years the council have depended on the lack of funds, the goodwill of the community and a useless complaints system, to convince us that a solution is at hand.” he said. “Added to this, the CLG understands that both parties have become embroiled into a “stalemate” situation where the contractor will not pay for the construction and neither will the Council.

“The build-up of FOG in the wet well is on the increase as evidenced by the removal of an unbelievable 126 tonnes over the past 2 years. This has been due to the apparent failure of the various Grease Converter treatment systems installed at hotels, restaurants, cafes and fast food outlets. Council may have inadvertently approved systems that do not appear to work, and leaves Council responsible to remedy the problem. Now that it is in place, there is no telling how long it will take, at what cost and who pays to replace it.

“If the WCC is not prepared to take action over FOG treatment systems, then it should seriously consider making funds immediately available for the construction of a building over the IPS as we have requested, and would only take a matter of months,” Mr Andis believes.

“Furthermore the District Plan does not permit odour to be discernible at or beyond the boundary, and yet WCC has rejected any funding to remedy odour emissions from the IPS, thereby condoning illegal actions contrary to its own rules.

“The guarantees and promises mean a zero tolerance toward odour emissions regardless of any interpretation that Council may place on it and no one can deny that odour is emitted.”

“Council has dedicated funds into constructing a Super Stadium, a Superloo and a Super Sculpture as show pieces for the Rugby World Cup, and yet the rules for the sewage treatment plant governing compliance are waived all in the case of show.

“The role and function of the CLG together with its technical advisor (who is funded by WCC) was set up as a result of appeals in 1994 to liaise with the Council, the Treatment Plant Contractor, and the Community. The process has been in place since that time. Discussions have been frank and in accord with signed Terms of Reference and transparency. After the CLG made its submission, it learned of an ‘Inlet Pump Station Investigation Upgrade Report’ dated December 2008 that had recommended construction of such a building costing $1.1million. The ‘guestimate’ in the CLG’s submission was within 10% of this.

“There is no doubt that it had been deliberately withheld from the CLG and only released after application through the Official Information Act. Earlier, the CLG was informed in September 2008 by the contractor that, a structure would proceed over the IPS within 12 months, costing between $300,000 and $400,000. Three months later there was a complete reversal of the commitment, for no apparent reason. By withholding the recommendations of this report, contrary to our Terms of Reference, and then use it against our submission as a reason to refuse funding is arrogant, underhand and an insult to the integrity of the voluntary members of the CLG by all concerned.

“We agreed to a building block approach during the Renewal of Consents process in 2007 and this has yet to be formally implemented, what is more our submission did not lay claim to a 100% remedy to all the odorous emissions. The enclosure would only be the beginning of it.

“The question remains as to why WCC has devoted $6.2 million into installing an Ultra Violet disinfection plant that would operate on a part time basis 5 or 6 times a year during “excess stormwater flows” through the long outfall, when the real problem at Moa Point is the regular discharge of odour into the receiving environment over the past 12 years.”

Mr Andis concludes by saying “that if this matter is not resolved promptly prior to the Rugby World Cup, the CLG will be forced to seek further advice to resolve these issues that are of the Council’s making.”


  1. Dianne Buchan, 1. July 2010, 13:58

    For those of you who don’t know, Stan Andis has been battling on this issue for at least 16 years, seemingly never giving up that what the engineers promised at the consent hearing – ie. an odourless treatment plant – will be delivered. I take my hat off to you Stan and hope one day the council will honour its undertaking. it is cases like this that undermine public trust in the Resource Management Act process. When the undertakings of experts are not realised, it is the public who pay the price.

  2. Tom Mulholland, 2. July 2010, 13:02

    The silence from Ward councillors has been deafening during construction of the sewage plant, and the smells have continued for the 11yrs we have lived at Moa Point; the extension of the airport with noise, dust, extra travel and expense; the consent given to build a facillity to manufacture radioactive material at the end of our street, without at least consultation as to safety etc. Our elected Councillors have been absent .

  3. ViV, 2. July 2010, 17:17

    I’m a great believer in practical examples. I would suggest a strong and smelly point needs to be made to those decision makers who don’t have the same opportunity to experience, and savour, the same odours as those effected residents.
    A ten litre bucket of pong should be taken into council during public participation and shared with the decision makers.