National Stocktake of Municipal Wastewater Treatment Plants and Cost Estimates for Upgrading Wastewater Treatment Plants that Discharge to the Ocean
These are two of four reports commissioned by the Department of Internal Affairs as part of the Three Waters Review, which DIA is undertaking to gain a better understanding of the challenges facing three water services in New Zealand and to improve the regulation and supply arrangements for three waters (drinking water, wastewater and stormwater) following the Havelock North campylobacter outbreak in 2016. The reports give a national-level assessment of the state of New Zealand’s local authority wastewater services.
Sharon Dines led the preparation of the wastewater treatment plant stocktake report with support from the staff listed below. Dr Ian Boothroyd and Dr Sharon de Luca provided technical expert input into the cost estimates report.
National Stocktake of Municipal Wastewater Treatment Plants
This report provides a national-level stocktake of the regulation of municipal wastewater treatment plants (WWTPs) by regional councils. In particular, the stocktake provides an assessment of resource consents and relevant plan rules in place for the primary discharges from municipal WWTPs, and the compliance, monitoring, enforcement arrangements and practices for these consents and rules.
The stocktake was conducted by GHD and Boffa Miskell and the regulatory aspects of this report were peer reviewed by Dr Marie Doole, The Catalyst Group.
Some key trends are evident in the data collected with the following implications:
Cost Estimates for Upgrading Wastewater Treatment Plants
that Discharge to the Ocean
GHD Limited and Boffa Miskell were engaged by DIA to provide a national level cost estimate for the potential upgrade of municipal WWTPs that discharge to the ocean in New Zealand if national minimum discharge standards for key contaminants are imposed. The Wastewater Specialists (TWWS) provided technical support and localised knowledge of WWTP operation around New Zealand.
A literature review of standards applied internationally was undertaken. Minimum discharge standards are a common feature of many overseas jurisdictions, including the European Union, Canada, USA, and Australian states. Based on this review, and taking into consideration the New Zealand coastal environment, relevant regulatory settings (including the National Policy Statement for Freshwater Management) and local infrastructure, three categories of minimum standards were developed.
The findings of the study are that 48 WWTPs would require upgrades to meet the proposed minimum standards. The total capital investment to achieve this target is estimates to be between $1.1 and $1.5 Billion, with an annualised cost of $73 to $110 Million.
Report preparation and technical advisory
|Client||Department of Internal Affairs|
|Project team||Ian Boothroyd|
Dr. Sharon De Luca
The Wastewater Specialists
The Catalyst Group