Wastewater: A conflict of facts

CLIVE BOONHAM, KAIPARA CONCERNS

One of the most bizarre and unsettling aspects of the Plan Change 78 hearing was the issue of the capacity of the Mangawhai Wastewater Sewerage Scheme (MCWWS) and its ability to accommodate the proposed loading from Mangawhai Central. There were two parallel and conflicting processes.

On the one hand, in respect of the plan change process, the KDC planners, engineers and independent expert engineers all stated unequivocally the MCWWS ‘has capacity’ to accommodate Mangawhai Centre. That conclusion was reached, apparently, without any consideration of the current capacity of the scheme or the additional capacity required by Mangawhai Central. Naturally, those statements were adopted by Mangawhai Central. In short the capacity of the scheme was not an issue.

On the other hand, in a parallel process, over the past few years the KDC elected members have been receiving reports from KDC staff that the MCWWS was facing capacity issues even with annual incremental growth, and that was without any consideration of the loading for Mangawhai Central. Decisions would have to be made soon, especially about a new disposal method.

The truth lies in a report on the MCWWS -Future Options Development, commissioned by KDC staff last year and dated November 2019. The WSP-Opus report sets out the current limitations of the MCWWS capacity and concludes that the scheme is facing substantial upgrades in the near future. At an annual increase of 100 connections per year a completely new disposal field (or other method) will be required by 2026 and upgrades to the plant will be needed soon after. Considering options, planning, consulting, consenting and building will take six years so that process should have already started by now. The cost of a new disposal farm is estimated at $38 million. Disposal to the estuary would cost $26 million, and discharge out to sea $47 million. This would be funded by debt and would be added to the historic debt for EcoCare which will take decades to repay.

The WSP figures do not take into account the current increase in growth and do not consider any loading from Mangawhai Central.

KDC staff have kept the report secret from the elected members. They have also failed to make the report available to the community despite the fact that the report itself states that it is intended to ‘inform the KDC and community stakeholders of the expected costs and preferred options for the future upgrades’.

Fortuitously, the WSP report was discovered a few days before the hearing. The conflict between what the KDC staff were saying about capacity and the facts revealed in the WSP report were laid before the Commissioners. Consequently the Commissioners have required the KDC to provide a report by 16 December 2020 setting out the KDC infrastructure planning for water supply and wastewater services, whether there is

capacity for Mangawhai Central, or how increased capacity is going to be achieved, and what funding decisions have been made or will be made in respect of those matters.

The issue of why KDC staff kept the elected members and the community in the dark about the looming crisis in wastewater capacity has yet to be resolved.

Tough questions are still being asked about Mangawhai’s wastewater capacity.

PHOTO/JULIA WADE