Wastewater treatment plant - MWH Rectification Proposal released

Published on 14 September 2016

14 September 2016

Mayor Annette Main today said the Whanganui District Council has released MWH’s 2014 proposal for an alternative design to reconfigure and upgrade the failed wastewater treatment plant.

“There have been a number of requests for this document and although we are making this available, it is important to put it into context around the events of the time,” Mayor Main said.

“Whanganui District Council was pursuing legal action against MWH over their design of the original wastewater treatment plant. As part of this process the Council prepared a ‘quantum of claim’ - that is, we maximised the amount of money that we believed we could legitimately claim against MWH including the cost of a new plant.

“MWH for their part prepared a counter to this - that is, they tried to minimise the amount of money. They proposed an alternative design concept. As part of this process, we attended a workshop with MWH in February 2014 to discuss this alternative, which we believed would not work. Following this workshop, MWH provided us with yet another alternative design concept which is their ‘rectification’ proposal dated 3 March 2014.

“This further alternative concept was reviewed by Cardno and by CH2MBeca and in their opinion it still would not work. Wastewater expert Humphrey Archer of CH2MBeca raised a number of key concerns in his review of MWH’s alternative design including, amongst other things, the effectiveness of the proposed aeration and the relatively unproven status of the proposed solids separation process.

“We then proceeded with the long and protracted mediation process with MWH and in late 2015 settled this sorry affair.

“Bearing in mind the $27M of wasted costs identified by the Independent Inquiry and the advice received from our independent experts that this design would not work, it was not seen as a feasible alternative, then or now, to again pay MWH millions of dollars to design another plant which wastewater industry experts say will not work.

“We have commenced construction of a fully designed and extensively peer reviewed plant that will work and is able to be completed within the timeframe of our resource consent.”

The proposal (named “Wanganui Waste Water Treatment Plant – Workshop follow up” dated 3 March 2014) is available on our website (PDF, 332KB).