1. Proposal
It is proposed that the capital expenditure envelope of $6 mil ion be approved to upgrade the Meremere
WWTP by the instal ation of a MBR plant.
2. Business Requirements
2.1
Strategic alignment
The Meremere Township’s wastewater is presently treated in an oxidation pond (surface aerator and baffle
system), where treated wastewater then flows through a planted rock filter to a day pond. This is fol owed by
UV treatment prior to being discharged to the Waikato River between 10pm to 5am through an outlet with
diffuser.
At present the Meremere Wastewater treatment plant is non- compliant with resource consent conditions.
2.2
Customer focus / business need
The upgrade works wil ensure:
Compliance with Resource consent conditions and reduce environmentally damaging discharges
to the Waikato River. The current noncompliance has caused WRC to issue WDC with an
Abatement Notice.
Enable medium term growth within Meremere Village (current population 500 with capacity for
growth to 710).
2.3
High-level outcome
The high level outcome of the project is a fully compliant wastewater treatment plant operating within consent
parameters for the next 35 years .
3. Proposed Solution
3.1
Possible options
To address the business requirements, the fol owing options have been considered:
Do minimum – minor upgrades to the existing WWTP
Decommission Wastewater Treatment plant and pump influent to either Pukekohe WWTP or Te
Kauwhata WWTP
Upgrade Meremere WWTP to a MBR plant
3.2
Most likely or preferred option
The preferred option is to upgrade the Meremere Wastewater Treatment Plant with the instal ation of a
Membrane Bioreactor (MBR) plant. The membrane upgrade wil treat most of the flow from Meremere
through the dual units (up to 250m³/d), where any higher flow wil bypass the new treatment process but
continue to be pond treated and disinfected as per the existing system.
3.3
Includes:
The design, supply, delivery to site, construction, installation, testing and commissioning of the complete
MBR plant including:
o MBR Influent Tie-in
o Primary screening
o Influent pipes, sump and pumps
o MBR Plant and Associated Equipment
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o All tie ins between Influent, MBR, pond and wet well
o Solids stream (discharge into pond)
o Utilities
o Electrical upgrade to accommodate additional power demands;
o Control and Instrumentation
o Chemical dosing system for MBR CIP and/or for alkalinity control and/or for phosphorus removal
o All Pond reclamation and Civil Works required
o Curtain replacement in oxidation pond
o Operator Training
o Documentation and Drawings
3.4
Excludes:
Network Upgrades to reduce inflow and infiltration.
Consenting – The Meremere discharge consent preparation and application will be completed in a
separate project.
4. Project Considerations
4.1
Assumptions, constraints and dependencies:
Temporary construction laydown area wil be required in neighbouring property, an arrangement with
land owner has yet to be sort.
4.2
Environmental and consenting Requirements:
A parallel process to obtain discharge consent wil occur, the plant will require a consent with modification
to al ow 24 hour a day discharge of treated effluent.
4.3
Risks / Issues:
Contaminated Land – the site is near the decommissioned Meremere Power station and there is a
potential that contaminated fil may be discovered and require disposal to an appropriate landfil .
5. Procurement Strategy
Watercare’s Supply Chain Team invited two parties to submit Design and Build Proposals, both parties have
experience delivering MBR plants for Watercare in the Auckland region. Watercare’s procurement process’s
and policies have been fol owed in obtaining tender proposals.
During April, proposals have been evaluated for technical, commercial compliance in addition a detailed nett
present value analysis has been undertaken to whole of life costs.
6. Stakeholder Engagement and Consents
A meeting with Ngāti Naho Trust was held in January, at that meeting was proposed to a similar MBR plant
in Clark’s Beach; this will hopefully be able to proceed once COVID-19 restrictions are lifted. Mercer
Community committee have been given an update and liaison wil continue as this project and the discharge
consent renewal project progress. Following the completion of the consultation an application to vary the
discharge timing will be lodged with the WRC . This variation wil be in place until the new discharge consent
is gained,
Discussions are on-going with WRC and an application for a new 35-year discharge consent will likely be
lodged in September.
Engagement is likely to be required with neighbouring landowners prior and during construction phase.
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Appendix 4 – s7(2) Environmental Site Layout
s7(2)(h)
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