The abstracts for each of the 15 papers is outlined below:
'A Healthy dose of fibre'
Ian Macbeth (CH2M Beca); Gavin Hutchison (CH2M Beca); and Stuart Donaldson (Marlborough District Council).
Use of fibreglass (or glass-reinforced plastic, GRP) is becoming more widespread in wastewater conveyance due to the significant benefits in corrosion resistance, reduced construction times, less extensive and safer site works and overall project cost savings. This paper provides two case studies of pump stations in sewer networks within Marlborough and outlines some of the benefits of using GRP.
Waimate West - An Energy Neutral Water Treatment Plant
Dennis Bezuidenhout (CH2M Beca); Peter Cook (South Taranaki District Council); Philip La Roche (CH2M Beca); and Francesca Nicklin (CH2M Beca).
This paper discusses the Waimate West Water Treatment plant and it's refurbishment after failing to achieve compliance under the Drink Water Standards for New Zealand. A significant component of this upgrade was to include a Pump As Turbine (PAT) that could generate sufficient energy for the plant to run energy neutral. The paper covers the technical issues in the implementation of PAT and the ways it can be implemented for small scale applications.
Improving the long term management of sewer systems
Caroline Crosby (CH2M Beca) and Josef Cesca (CH2M Beca).
With increasing pressures and demands for public money it is imperative to meet asset management objectives in a cost effective and transparent manner. This paper outlines an applied approach to sewer network management that includes innovative modelling and analysis tools resulting from research into the mechanisms of corrosion and odour generation in sewers. These tools improve the reliability of data needed to develop a long-term sewer network management plan.
Biosolids Incineration at Tahuna WWTP - Fueling a $10 Million Capital Saving
Simon Drew (CH2M Beca) and Chris Henderson (Dunedin City Council).
Dunedin City Council (DCC) operates the only biosolids fluidised bed incinerator in Australasia - Tahuna Wastewater Treatment Plant. DCC is embarking on a project to optimise and recondition the existing incinerator, installing an ash removal system to make the system fully automated. This paper discusses this project in detail and outlines the benefits of an ash removal system, from cost savings, sustainability benefits, and reducing service complaints from the local community.
Digester 8 - Lessons learnt constructing New Zealand's largest mesophilic wastewater digester
Andrew Blow (CH2M Beca); Garry Macdonald (CH2M Beca); John Robson (Watercare); and Chris Turner (Brian Perry Civil).
To meet the needs of Auckland's strong regional growth, the digestion facility at Auckland's Mangere Wastewater Treatment Plant required expansion, which meant the addition of an eighth mesophilic digester. The brownfield site contained within the existing operation plant presented several challenges. This paper outlines these challenges through design, procurement, construction and commissioning phases and the lessons learnt in resolving these issues.
Wellington Waterfront Jump Platform - Improved Water Quality
Ron Haverland (CH2M Beca).
The Jump Platform on Wellington Waterfront is a public facility which is installed above an open section of the Taranaki Wharf and is a popular area for swimmers and spectators. However after monitoring the water it was found that the water quality in the area exceeded the marine guidelines for recreational use. The contamination was a result of two major stormwater catchments which discharged close by. This paper discusses the installation of an innovative enclosure around the Jump Platform area and how this significantly improved the water quality in the area.
Project Wai Taatari - The journey from master plan to delivery of the New Plymouth waste water plant upgrade
Garry Macdonald (CH2M Beca); Mark Hall (New Plymouth District Council); and Nick Berry (CH2M Beca).
Due to industrial and residential growth in the catchment of New Plymouth Wastewater Treatment Plant, and the addition of wastewater from two satellite towns, the capacity of the plant was fully utilised and, it was suspected, at times exceeded. With a decision to connect Waitara to New Plymouth and upgrade was needed. This paper reports on the planning and project delivery processes implemented by New Plymouth District Council to identify the extent of upgrades required, select preferred options for implementing the upgrades, consenting of the plant and construction of the first stage of the upgrades.
Infrastructure Strategy - Benefits to asset management planning for a growing district
Claire Scrimgeour (CH2M Beca); Kristina Hermens (CH2M Beca); and Bryan Everitt (Waikato District Council).
Waikato District is the second largest district in New Zealand and is located between two of the country’s fastest growing cities, Auckland and Hamilton. Some parts of Waikato District are under pressure to develop new infrastructure to keep up with growing communities, while other parts must maintain ageing systems with little growth. This paper describes Waikato District Council’s journey in creating their 2015 Infrastructure Strategy, including successes and lessons learned.
'Best For Waipa' - Delivering the 2012-2015 LTP - A legacy for the future
Ian Garside (CH2M Beca Ltd); Lorraine Kendrick (Waipa District Council); Bilyana Podrumac (Waipa District Council); and Robin Walker (Opus International Consultants Ltd).
During early 2012 the Waipa District Council approved a large increase in their Long Term Plan (LTP) spend on Water Services to increase the level of service provided across the three waters, to improve resilience in their operations and to cater for future growth. This paper describes the steps that were taken to deliver the first three (2012-2015) long term plan and includes the tools that were developed to track and encourage innovation, reviews and appropriate spending through the project.
Resilience Examples in Reservoirs, Pump Stations and Pipelines - Lessons learned from the Canterbury earthquakes
Dennis Hunt (CH2M Beca) and Gavin Hutchison (CH2M Beca).
As a result of the Canterbury earthquakes in 2010-2011, key Christchurch City Council (CCC) water and wastewater infrastructure was severely damaged. This paper looks at important resilience lessons learned for three core components: reservoirs, pump stations and pipelines. This paper will look at examples of CCC infrastructure that proved to be resilient during the earthquakes, along with examples of failures and the lessons learnt.
Can performance of waste stabilization ponds be improved?
Humphrey Archer (CH2M Beca Ltd).
Waste stabilisation ponds (WSP) are not old technology but this can seem the case as there are many operating inefficiently around the world. This paper discusses the modest costs to upgrade WSP and how it can significantly increase performance. By upgrading the ponds to remove nutrients, solids and pathogens, odours can be minimised by mechanical aeration and also using nitrifying rock filters to reduce ammonia. In return green energy benefits (solar/wind) can be realised without the negative factors such as odour, colour and pathogens in the final effluent.
Upgrading of the Blenheim Sewage Treatment Plant with wetlands and irrigation to land
Humphrey Archer (CH2M Beca); Graeme Jenner (CH2M Beca); and Stuart Donaldson (Marlbourough District Council).
The existing Blenheim Sewage Treatment Plant consists of two separate treatment systems one for domestic flows and one for industrial flows. Marlborough District Council has recently upgraded the pond-based system by combining the domestic and industrial effluents steams in a common maturation pond; followed by a polishing treatment in a 2km long wetland system. This paper will describe the project from the evaluation of options, through to commissioning of the wetlands treatment and irrigation system, to demonstrate the sustainable benefits of this upgrade.
New Water Scheme in Historic Akaroa
Rae Stewart (CH2M Beca Ltd); Philip La Roche (CH2M Beca Ltd); and Colin Currie (Christchurch City Council).
CH2M Beca has assisted Christchurch City Council (CCC) to upgrade the water supply system in Akaroa and Takamatua to meet the Drinking Water Standards for New Zealand (DWSNZ). Although only a small community water supply, many challenges were faced during the upgrade - during both design and construction. The project illustrates how upgrading water supplies for small communities can be both costly and complex and outlines the constraints and considerations throughout the project.
Waste Water Treatment Plants - you can't switch them off for maintenance and repairs
Becky Macdonald (CH2M Beca) and Mark Christison (CH2M Beca).
Waste Water Treatment Plants (WWTP) operate 24 hours a day, seven days a week, 365 days of the year with no off season for undertaking repairs and maintenance. This paper discusses the importance of considering repairs and maintenance during the design phase as an essential part of plant resilience. It outlines the inherent challenges that arise when undertaking major maintenance and repairs. This paper focuses on a single case study, the earthquake repairs and general maintenance of the Christchurch Wastewater Treatment Plant Trickling Filter 1.
Calculating uncertainty in the supply-demand balance
Jonathan Reed (CH2M Beca); Charlotte Reed (Tonkin & Taylor); and Carmel Green (Watercare Services Ltd).
Management of water resources requires prudent decision making in the face of both short and long term uncertainties. Outage and headroom methodologies have been developed by United Kingdom Water Industry Research to quantify these uncertainties. Outage represents an allowance for a reduction in source or treatment capacity. Headroom represents uncertainty of either the yield that sources can supply, or the demand that is forecast. This paper summarises these methodologies and details how Watercare has applied them to the metropolitan Auckland supply demand balance and a small town outside of this main network.
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