Cook Islands Waste Feasibility Study FINAL
Cook Islands Waste Feasibility Study FINAL
Cook Islands Waste Feasibility Study FINAL
Waste Management
Feasibility Study
Prepared for
Cook Islands Infrastructure
Prepared by
Tonkin & Taylor Ltd
Date
November 2016
Job Number
86125.v1.6
Distribution:
Cook Islands Infrastructure 10 copies
Tonkin & Taylor Ltd (FILE) 1 copy
Table of contents
1 Introduction 1
2 Policy Context 2
2.1 National Waste Policy (2016) 2
2.2 National Sustainable Development Plan 2016-2020 2
2.3 Other relevant policy 3
3 Waste generation and collection 4
3.1 Waste Quantity 4
3.2 Waste System Overview 6
3.3 Waste Composition 7
3.4 Waste generation and composition - issues and constraints 11
4 Waste Infrastructure and Services 12
4.1 Waste Collection 12
4.1.1 Self-managed waste 12
4.1.2 Waste and Recycling Collection 12
4.1.3 Collection Service Performance 13
4.2 Waste Processing and Disposal 15
4.2.1 Waste disposal 15
4.2.2 Waste consolidation and diversion 15
4.3 Waste Infrastructure and Services - Issues and Constraints 16
5 Option Identification 18
5.1 Collection options 19
5.2 Technology options 21
5.2.1 Processing Options 22
5.2.2 Disposal Options 24
5.2.3 Treatment and Disposal Options Considered 26
5.3 Outer Islands Options 29
6 Option Evaluation 30
6.1 Multi-Criteria Evaluation Approach 30
6.2 Multi-Criteria Evaluation Summary 31
6.2.1 Collection Options Evaluation 31
6.2.2 Treatment and Processing Infrastructure 33
6.3 High level cost benefit analysis 35
7 Cost Recovery Mechanisms 39
7.1 Waste disposal charges 39
7.2 Product Charges 39
7.3 Raising Revenue 40
7.4 Incentives for waste minimisation 40
1 Introduction
Tonkin and Taylor International Limited (T+TI) have been commissioned by the Ministry for Cook
Islands Infrastructure (ICI) to complete a study to determine a long term strategy for the
management of waste on Rarotonga. The study Terms of Reference can be summarised as:
“Undertaking a Feasibility Study of alternative treatment technologies for the long term
disposal of solid and hazardous waste for Rarotonga at a centralised facility.
The facility is to receive and process all major waste streams generated in Rarotonga, and
possibly the Outer Islands including, but not limited to, domestic waste, commercial and
industrial waste, tourism waste, medical / healthcare waste, quarantine waste and waste
arising from the clean up after cyclones.“1
The Feasibility Study has been completed by T+TI with specialist inputs from Eunomia Research and
Consulting (Waste Technology) and Covec (Cost Benefit Analysis). The project also involved
extensive stakeholder engagement and the project would not have been possible without their
input.
This report is the output of the Feasibility Study and is structured as follows:
· Section 2 sets out the policy context for solid waste management in the Cook Islands;
· Section 3 summarises available information on waste generation and composition;
· Section 4 summarises available information on waste infrastructure including collections
· Section 5 summarises the identification of potentially feasible options;
· Section 6 Summarises the options evaluation process including high level cost benefit analysis
of landfill vs waste to energy;
· Section 7 summarises cost recovery mechanisms; and
· Section 8 provides conclusions and recommendations.
1 Section 6.1 (About these terms of reference) from the Request for Proposals for a Feasibility Study Of Alternative
Treatment Technologies For The Disposal Of Solid And Hazardous Waste For Rarotonga, Cook Islands (Contract No: 16/02,
Id Number: 151633, March 2016
2 Policy Context
There are a range of key policy documents of relevance to solid waste management in the Cook
Islands. These are summarised below with additional detail provided in Appendix A where
necessary. The policy summarised here sets the direction and desired outcome from the
implementation of the options considered in this report.
These goals are of relevance because of the adverse effects that poor solid waste management can
have on the natural environment.
Household Waste
Food waste is generally fed to household animals (pigs and chickens) rather than disposed of with
other household waste. Garden waste is generally burnt or stockpiled on site.
On Rarotonga the remaining household waste is collected weekly with residents using their own
containers or rubbish bags. Waste is manually loaded into a single compactor truck that services
both residential and commercial customers. Residents separate glass, cans (aluminium and steel)
and plastic bottles (PET and HDPE) for recycling. Recyclables are manually loaded into a dedicated
collection vehicle and trailer.
2 Waste generation in this context refers to material collected i.e. does not include self-managed materials.
On Aitutaki household waste is collected every two weeks with residents using their own containers
or rubbish bags. Waste is manually loaded into an open tray truck that services both residential and
commercial customers. Residents separate glass, cans (aluminium and steel) and plastic bottles (PET
and HDPE) for recycling. Recyclables are manually loaded into a dedicated trailer.
On Atiu household waste is collected every fortnight from households by the Island Council. Each
household was provided with a 120L Mobile Garbage Bins aka Wheelie Bins (MGB) in 20012/13.
Waste is manually loaded on to the Island council truck. There is no collection of recyclables.
Commercial Waste
On Rarotonga and Aitutaki waste from small businesses is generally collected in tandem with
household waste. Larger businesses purchase a collection service or transport their waste directly to
the Rarotonga or Aitutaki Waste Facilities.
Many businesses have their own waste management/disposal arrangements for all or part of the
waste they generate. For example:
· Many businesses provide food waste to animals and burn garden rubbish on site.
· Edgewater Resort have a burn pit opposite the old MOIP Office for disposal of materials not
captured for recycling by their staff or guests. It is likely other Resorts have similar
arrangements.
· The Port of Avatiu have a bunker for burning general waste.
· Pacific Resort on Aitutaki burn combustible waste and crush glass for use as aggregate and
filter media across their operation.
· CITC collect, consolidate and export various recyclable materials from their operations and
other businesses.
· Atiu Villas periodically burn their ‘combustible’ waste in a burn pit. Their organic waste is
composted or buried in shallow pits.
There is no detail available on the quantity of material managed on-site by various businesses on
Rarotonga or other islands. Available data has been used to develop an estimate of the total
amount of waste generated by major businesses on Rarotonga based on businesses that bring all of
their waste to the Rarotonga Waste Facility. This suggests that there could be over 500 tonnes of
waste per year managed outside the Rarotonga Waste Facility - by burning or burial.
Other Wastes
Quarantine waste from the Airport, Port and clinical waste from Rarotonga Hospital is incinerated at
the Airport (Airport, Port) and Hospital. The hospital burns several times a week while the airport
indicates they burn around 2-400 kg per day 3,4 or 50-100 T per year.
Hazardous Waste
There are programmes in place to capture, store and export hazardous wastes including e-waste
(computers, monitors, other electrical appliances), used batteries (lead acid and dry cell batteries)
and used oil. Where materials are captured they are stored until there are sufficient quantities for
export.
3 From around 19 internal flights each week: 16 from Auckland (A320 and B777), 1 from Sydney (B767), 1 from Los Angeles
(B777), 1 from Tahiti (ATR 42).
4 Estimates are based on 0.4 kg/passenger (60T/yr) and self-reported estimate (400kg/day).
Legacy materials
There is a range of other materials generated on Rarotonga and other islands on an ongoing basis
including:
· Tyres
· Old machinery (Outer Islands and Rarotonga)
· Asbestos (from demolitions and storm damage)
· Whiteware
· Generators
· Intermediate Bulk Containers (IBC) used to import emulsion, diesel and similar products.
These materials are generated on an ongoing basis but in many areas have also accumulated over
time. Examples include stockpiles of IBC’s at Infrastructure depots, old machinery on the outer
islands, and used tyres.
For the purposes of this study the data from Rarotonga is assumed to reflect household/small
commercial waste on Aitutaki. This is because the two islands have similar roadside collection
systems and regular transport and shipping links. For islands without recycling services such as Atiu
combining the rubbish and recycling data from Rarotonga provides an indication of likely rubbish
composition. The data presented in Table 2, Figure 4 and Figure 5 provide a picture of the overall
waste composition with a focus on household waste and light commercial materials.
Points to note are:
· While organic waste (food scraps and garden rubbish) is a low proportion of waste compared
with typical household and light commercial urban waste internationally it is a still over 10%
of the waste stream.
· Plastic is a significant portion of the waste stream including a large amount of non-recyclable
material (plastic bags, broken plastic items).
· Metals make up almost 10% of the waste (on Rarotonga) and are almost exclusively
recyclable.
· Glass is a significant portion of the waste stream, again largely recyclable.
· Nappies (disposable) make up a large portion of the waste stream.
5Comparing waste entering the Rarotonga Waste Facility from businesses with their own burning/disposal arrangements
with businesses with no informal arrangements provides an estimate of total waste generated. Allowing for commercial
collection of waste and recyclable materials provides an estimate of 500 T/yr of waste burnt or buried by businesses on
Rarotonga. This is nearly 20% of the total waste stream on Rarotonga (see Table 1).
On Rarotonga households were provided with refuse wheelie bins several years ago and many households still use these
although in many cases the bins are beyond their useful life i.e. are broken or heavily degraded.
The waste and recycle collection system including estimated quantities for 2015 is presented
schematically in Figure 6.
Figure 6 Schematic of Rarotonga Waste and Recycling System
The data presented in Table 3 suggests there are opportunities to capture additional recyclable
material through the roadside collection including cardboard, plastics and glass. Specifically:
· While cardboard is collected from some commercial premises a large proportion appears to
be burnt and there is a significant quantity in the rubbish collected from households. With
existing baling and reuse or export it should be possible to increase the capture of cardboard
at both roadside and from businesses.
· Recovery of Plastic Bottles (PET and HDPE) is reasonable, but again it should be possible to
increase the capture of materials at both roadside and from businesses.
· Aluminium recovery is at a reasonable level but there is potential to increase this.
· Glass recovery is at a reasonable level.
Waste from certain sources can also present challenges or opportunities and is worthy of
consideration. Examples include:
· Business waste - waste from larger businesses is in some cases burnt rather than managed
through government or island council provided services. This reduces the burden on public
waste management services but involves risks to health and the environment as a result of air
emissions (combustion products) and ash.
· Hazardous wastes - there are systems in place for the capture and export (for treatment or
disposal) of hazardous waste from Rarotonga and the outer islands. Storage in some locations
lack cover/containment and in some cases the availability of appropriate export options is not
well understood.
· Bulky/difficult wastes - bulky or difficult wastes include tyres, white ware and end of life
vehicles and machinery. In some cases programmes have been or are in place to capture
materials for appropriate disposal or recycling but uptake has been mixed.
The plastic that has been baled and stockpiled will be difficult to sell. This is because exposure to the
elements has cause deterioration over time.
Cook Islands General Transport - General Transport accept a range of recoverable materials and
consolidates loads prior to export to New Zealand. Materials handled include general scrap
(vehicles, machinery), lead acid batteries, e-waste and whiteware. Some wastes attract funding
support from the Cook Island Government or regional organisations (SPREP) while others are
handled on a purely commercial basis.
Titikaveka Growers Association - the Titikaveka Growers Association compost organic materials for
re-use on their market gardens.
Cook Islands Trading Corporation (CITC) - CITC collect cardboard and plastic film from their
operations and some other businesses. The materials are reused on Rarotonga (some cardboard as
cover eventually converting into compost on taro patches) or exported for recycling on a commercial
basis.
CITC also collect and contain fluorescent light bulb tubes and sent away for safe disposals.
Aitutaki
Aitutaki Waste Facility - materials collected or dropped off for recycling at the waste facility are
sorted (if required) and baled. Aluminium is periodically exported to New Zealand via Rarotonga
with revenue covering shipping costs and providing a small return. Plastics (HDPE and PET) are baled
and stockpiled with returns not covering the cost of shipping to New Zealand via Rarotonga. Glass is
crushed using a single bottle crusher and reused on site. Hazardous materials (e-waste, chemicals,
oil) are stockpiled.
7 Landfill operation typically includes use of daily cover (a small amount of soil or other temporary cover) and intermediate
cover (for completed landfill cells). This cover minimises access to the waste for vermin (flies, rats, birds) and allows the
landfill operator to more effectively manage rainfall entering the rubbish and the resulting leachate generation. For
Rarotonga Landfill the Landfill Operations Plan sets out operations in defined cells with daily and intermediate cover. For
Aitutaki Landfill the Operations Plan sets out similar requirements including minimising the area being actively filled at any
point in time.
8 The design for Rarotonga Landfill anticipated construction of a second cell including additional liner once filling reached
ground level. This second phase of construction has not occurred and waste is currently stockpiled on top of the landfill
9 Aitutaki Landfill’s liner system was extensively damaged during storms several years ago. Remediation requires design
but is likely to involve repairing and/or replacing the liner in the active filling area with provision to complete further
remediation as filling progress through the site.
5 Option Identification
There are a wide range of approaches to providing waste minimisation and management services
and programmes that could be adopted in the Cook Islands. A useful way to consider options is the
model set out in Figure 7. Simply put, effective waste minimisation and management relies on a
combination of infrastructure (including collection), education/information and regulation or policy.
These are supported by having the right data to inform strategic and operational decision making.
Figure 7: Effective Waste Minimisation and Management
Education Policy
For this project options have been identified by considering key challenges for the Cook Islands
(Refer Sections 3.4 and 4.3), referencing approaches adopted elsewhere and looking for new
solutions where appropriate. Options have also been considered with reference to the current
recovery rates of key materials10 (see Section 4.1). This report focuses on infrastructure options but
offers comment on Education, Policy and Data components where relevant.
Based on the model set out in Figure 7 options that could be considered can be grouped as follows.
Infrastructure
· Providing collection services - collection of waste, recyclable materials (at roadside or waste
facility), organic waste and/or bulky items, litter bins;
· Providing physical infrastructure - drop off facilities, waste processing and/or disposal
facilities;
· Managing the negative impacts of waste - litter/illegal dumping.
Education (outside the scope of this report)
· Changing behaviour - education programmes targeting schools, businesses and/or households
· Working with importers to consider the materials entering the Cook Islands (packaging)
Policy (outside the scope of this report)
· Implementation of existing policy e.g. regarding open burning of waste
· Targeted data collection, for example waste surveys
· Making information on waste issues and opportunities available.
· Seeking funding for infrastructure projects that deliver on the goals and objectives for waste
minimisation and management
10 Key materials include paper/card, plastics, glass, nappies, metals and glass
These options focus on the priority waste streams identified through the review of the current
situation in Sections 3.4 and 4.3 and summarised in Table 4.
Table 4: Priority wastes and waste sources
Current arrangements:
· Refuse collection for households and small businesses is provided by the government
(Rarotonga) or the Island Council, funded by the government.
· Recycling collection for households and small businesses on Rarotonga and Aitutaki is
provided by the government or Council funded by the government.
· Larger businesses employ T&M Heather or Cook Islands General Transport to collect their
waste and recycling or handle their own waste
· Businesses and households can drop waste and recycling at the Rarotonga or Aitutaki Waste
Management Facilities.
Issues
· Illegal dumping of household waste
· No limit on quantity of waste put out by each household 11
· High level of contamination in recycling collections on Rarotonga
· Low capture rates for recyclable materials from households
· Inappropriate disposal of hazardous wastes
· No recycling service on Atiu and outer islands
Rubbish collection options
The current refuse collection system is fully funded by the government. There is no detailed
information on participation in the collection service or quantity of materials collected. There are
some issues with contamination in the recycling collection and recyclable material placed with
refuse for collections. There are also examples of illegal dumping of household refuse.
There are several reasons for considering changes to the way that rubbish is collected. Limiting the
size of the collection container (bag or bin) can encourage households to recycle where recycling
services are available. Limiting the size and/or providing for mechanised collection also minimises
health and safety risks for collection personnel. Referencing approaches adopted elsewhere:
· In Australia roadside waste is almost exclusively collected in wheeled bins with automated
loading.
· In New Zealand there is an active debate contrasting wheeled bins (safety benefits, efficiency)
with bags (smaller, impose direct charges on households).
· In the UK there is a mix of wheeled bin and bag based collections with drivers including user
pays (easier through bags) and the efficiencies (through automated collection).
Considering approaches adopted elsewhere waste collections could be:
· A government run and funded collection service with each household providing their own
receptacle. This is the current approach and cost is assumed to be the same or similar.
· A government run, tax funded service with either official bags or small Objective:
wheelie bins provided to each council. This approach is common with Limit rubbish capacity
examples in New Zealand, UK and Australia. New costs would include the to encourage reuse/
bins or bags (similar total cost over the 5-10 year life of a wheelie bin). recycling and improve
Advantages include limited refuse capacity encouraging diversion of waste collection crew safety
at home or into recycling and limiting weight of materials manually
handled by the collection crew.
11Limits on the quantity of materials households can place for collection can encourage waste reduction (buying less), re-
use (reusing containers, animal food) and/or recycling.
- A government run, user pays refuse collection service. In most cases Objective:
this is through collection of approved rubbish bags that are bought Limit rubbish capacity
as required by households or businesses. In some cases households and impost cost to
pay for a wheelie bin collection service. This is a common approach encourage reuse/
in New Zealand with rubbish bags typically in the range $2.50-3.00 recycling
per bag with prices range up to over $4.00 per bag in some areas.
Assuming a single bag per week at this price for each household
revenue in Rarotonga would be in the order of $3-400,000 per annum. In New Zealand
households typical present bags 30-40 weeks per year, in Rarotonga this would translate
to $100-$120 per household or $200 - $350,000 per annum total revenue.
Recycle collection options
The current recycling collection system is funded by the government. There is some information on
participation in the collection service and quantity of materials collected. Considering approaches
adopted elsewhere council could consider:
· A government run and funded recycle bag service with each household providing their own
container or putting materials out in bags. This is the current approach and cost is assumed to
be the same or similar.
· A government run and funded recycle crate based service i.e. government
Objective:
providing one or more recycle crate(s). This is the most common approach
Increase recycling
currently employed in New Zealand and Australia. Advantages include
rate by providing a
providing a standard container for recyclables to encourage diversion of
standard container
recyclables into the recycling collection. The crate limits the size (and
weight) of materials with safety benefits for the collection crew.
· A government run and funded recycle wheelie bin based service i.e.
Objective:
government providing recycle crate(s). This is a common approach in
Increase recycling
New Zealand and the default system in Australia. Wheelie bins are
by providing a
typically employed alongside automated collection. Advantages include
standard container
providing a large storage container for recyclables and efficient
collections.
In many cases options considered in other locations are likely to be too large, too complex and/or
too costly for Rarotonga. In identifying options for this study we have:
· Looked at options for key waste streams - plastics, glass, special waste (medical, biosecurity,
confidential) and residual waste
· Reviewed options designed for small, remote communities or small quantities of waste
· Considered options that simplify and scale down conventional approaches for larger
communities
Current arrangements
· Rarotonga Waste Facility - sorting and baling of recyclables.
· Cook Islands General Transport - sorting and export of metals (including whiteware) and e-
waste.
· CITC cardboard collections
· Commercial composting by Titikaveka Growers Association.
· Rarotonga Landfill for general waste disposal.
Issues:
· Landfill capacity - projected to be full around 2020.
· Illegal burning of commercial and household waste.
· Access to markets for recyclable materials.
render medical and quarantine waste suitable for landfill disposal, often with grinding of pasteurised
material following heat treatment.
Mechanical heat treatment processes typically employ automated sorting technology combined with
heat and/or heat with pressure processes. Each of the components involve relatively complex
mechanical engineering combined with sophisticated process control systems. These in turn require
access to specialised maintenance and repair skills as well as trained operators.
Composting
Commercial scale composting of food and garden waste is common in many parts of the world, the
resulting product can be sold for use in home gardens or used by commercial growers. The
Titikaveka Growers Association have a composting operation providing compost for their market
gardens. Some households on Rarotonga compost garden waste for use on site.
In many cases the biological component of Mechanical Biological Treatment process involve
composting food, garden waste, other organic material, paper, cardboard and other biodegradable
materials in the waste stream such as disposable nappies13. There is potential to compost specific
components of the currently landfilled waste stream to either pre-treat prior to landfill or produce a
useable, compost like product.
Composting can involve:
· Complex, enclosed composting systems involving mechanical mixing of the composting
material and sophisticated process control.
· Forced aeration of open composting piles e.g. via perforated pipes.
· Open composting in windrows or pile. The composting material can be left to compost over
an extended period (static pile, 12-18 months) or regularly turned to improve aeration and
reduce processing time (turned windrow).
Enclosed systems, and to a lesser extent forced aeration systems, are complex biological processes
involving relatively complex mechanical engineering (enclosed systems) combined with
sophisticated process control systems. These in turn require access to specialised maintenance and
repair skills as well as trained operators.
Anaerobic Digestion (AD)
Commercial scale anaerobic digestion of putrescible waste material is increasingly common in the
UK and Europe with the technology also applied elsewhere. Anaerobic digestion is well established
for the treatment of wastewater treatment sludge providing stablisation, volume reduction and
energy recovery. Anecdotally in Rarotonga putrescible material (food waste) is largely captured for
animal feed. There could be potential for combining food waste with septage but on Rarotonga
septage is already treated through ponds at the Waste Facility.
Anaerobic digestion is a complex biological process with the operator balancing residence time the
digestion vessel, water content, temperature and agitation. Typical systems for solid waste or solid
waste components involve relatively complex mechanical and process engineering combined with
sophisticated process control systems. These in turn require access to specialised maintenance and
repair skills as well as trained operators.
13Enclosed composting of nappies in New Zealand has met with mixed success - key challenges include securing sufficient
bulking material (garden waste, sawdust) and screening out physical contaminants (plastic) from the compost product.
Biodrying
Normally the objective of aerobic decomposition processes such as composting is to stabilise and
produce a compost or composting like product. The composting process produces a significant
amount of heat and this heat can be used to drying waste. Effectively the heat produced through
aerobic decomposition of organic matter in the waste stream dries the overall waste mass. This
process is known as biodrying. Biodrying is typically used as pre-treatment for waste to energy. This
technology is applicable where there is a significant proportion of biodegradable material in the
waste stream and a downstream process that requires or would benefit from a dry feedstock 14.
14For example incineration or advanced thermal treatment. Other pre-processing is likely to be required - to remove
recoverable materials and bulky items, to produce a consistent ‘fuel’ for the downstream process.
15 SPREP have funded a number of small scale medical waste incinerators across the Pacific including for Aitutaki
16 In New Zealand all medical and quarantine waste is treated by this method
17 As noted previously the design for Rarotonga Landfill anticipated construction of a second cell including additional liner
once filling reached ground level. This second phase of construction has not occurred and waste is currently stockpiled on
top of the landfill with minimal containment.
18 The cost for a new clinical and quarantine waste incinerator will vary depending on specifications, location for
installation and supporting equipment and services. Based on a recent tender process for healthcare waste incinerators
across the Pacific by SPREP the cost may fall in the range NZD$75-150,000 with installation, operator training and ongoing
maintenance additional to this figure.
· MBT plants are typically large scale, application for such a small quantity of general
waste is relatively unknown.
· The mechanical component of the process targets recoverable materials which then
require a viable market.
· The biological component of process involves processing of degradable material in an
aerobic or anaerobic environment. The aerobic process is analogous to composting and
produces a compost like output. The anaerobic process produces biogas and solid
residue that can be further composted.
· A MBT plant will require a suitable location, with access to power, suitable separation
from land uses sensitive to odour and space for managing incoming waste, recovered
materials and treated waste.
· The treated waste is potentially suitable as a fuel (subject to a suitable facility requiring
fuel), a low grade soil amendment or can landfilled. The treatment process reduces the
volume of waste by 40-50%.
· Treat - Incineration: Solid waste that is currently landfilled could be processed through a
conventional incineration plant. Waste incineration is a well-established with plants operating
in Asia, USA and Europe with typical scale range from 60,000 Tonne per year (very small) to
well over 500,000 tonnes per year. There are a range of variations with a focus on
arrangements feeding waste and managing ash. Key residuals include bottom ash and air
pollution control residues. Key considerations include:
· Incineration plants are typically large scale, application for such a small quantity of
general waste is unknown.
· Incineration typically follows removal of bulky materials and metals.
· An incinerator will require a suitable location, with access to power, suitable separation
from land uses sensitive to air emissions and space for managing incoming waste,
recovered materials and ash.
· The bottom ash may be suitable as a low grade aggregate or could be landfilled. The
incineration process reduces the volume of waste by 60-80%.
· The air pollution control residues are hazardous waste and require stabilisation prior to
disposal in a suitable facility.
· Treat - Advanced thermal treatment: Solid waste that is currently landfilled could be
processed through an advanced thermal treatment plant with gasification the most advanced
technology form a commercial perspective. Gasification is emerging at a commercial scale
with plants operating in Europe and Asia. The technology is best suited to consistent
feedstock - specific waste streams or pre-processed refuse. Commercial plants are similar in
scale to other processing technologies but are often modular with relatively small modules
combined making use of common pre-processing and energy utilisation infrastructure. There
are a range of variations with a focus on waste consistency, batch vs. continuous processing
and use of gasification products (char, syn gas). Key residuals include char and air pollution
control residues. Key considerations include:
· Advanced thermal plants are typically large scale, combining pre and post processing
infrastructure to reduce cost. There are small scale examples operating on a pilot basis.
· Advanced thermal treatments require a consistent feedstock. This is typically achieved
through pre-processing ranging from grinding/shredding of waste through to complex
refuse derived fuel production and additional to removal of bulky materials and metals.
· An advanced thermal plant will require a suitable location, with access to power,
suitable separation from land uses sensitive to air emissions and space for managing
incoming waste, recovered materials and char.
· The char may be suitable as a carbon black type product, a low grade aggregate or
should be landfilled. The process reduces the volume of waste by 60-80%.
· The air pollution control residues are hazardous waste and require stabilisation prior to
disposal in a suitable facility.
· Treat - Target specific materials: As noted above many of the advanced waste treatment
approaches involve removal of recoverable materials before thermal (heating, burning or
gasification) or biological treatment of the residual material. There is potential to focus on
specific materials within the residual waste stream drawing on components of MBT, MHT and
pre-processing of materials prior to incineration or advanced thermal treatment. Examples
include removal of recyclable materials prior to landfill19 or putting in place processing for
source separated waste streams e.g. food waste, garden waste, disposable nappies. Key
considerations include:
· Markets for captured materials. Recyclable materials captured from general waste are
likely to be of lower quality (contaminated). Logical targets would be aluminium cans
(over 1% of rubbish) and glass bottles (over 14% of rubbish).
· Capacity to collect and process materials. The current arrangement at Rarotonga Waste
Facility is an addition to a conveyor designed for feeding material into the baler, not for
sorting. This means there is limited capacity to process/capture additional material
with the current arrangements.
· Additional materials will need stockpiling, processing and storage prior to dispatch on
site.
19Currently materials are ‘picked’ off the conveyor feeding the waste baler at the Rarotonga Landfill. Larger scale systems
designed for material capture typically have automated sorting, specifically designed sorting stations and conveyors
designed for ease of sorting and capture.
20WASTE MANAGEMENT IN SMALL COMMUNITIES - web-resource with several guidance documents. Accessed August
2016 at http://www.lgant.asn.au/policy-programs/sustainability-environment/waste-management-in-remote-regional-
indigenous-communities
6 Option Evaluation
Cost to Government Objective 4 - Develop sustainable Options that minimise government funding
financing to manage solid waste. requirements are preferred. Cost can be
modelled for different scenarios under
consideration.
Landfill disposal/ Objective 3 - Develop appropriate Options that make it easy to avoid waste or
Diversion % waste management infrastructure divert unwanted material from landfill are
including separation and storage preferred, measured as anticipated % diversion.
facilities.
Local economic To maximise local employment and Options that provide opportunities for local
development business opportunities businesses and community groups are preferred
opportunities
Technology risk Addressing implementation risk(s) Options that employ well established
technology are preferred - the simpler the
better.
Market risk Addressing implementation risk(s) Options that have a viable market for the
outputs are preferred e.g. for compost or
recyclable materials
Community views Addressing implementation risk(s) Options that are, or are likely to be supported
by the community are preferred.
For the treatment and processing options the leading options have then be subjected to a high level
cost benefit analysis. The assumptions used in the Cost Benefit analysis have been employed for
deriving indicative annual costs (amortised capital and operating). The Cost Benefit Analysis (Section
6.3) is presented after the Multi-Criteria Assessment (Section 6.2).
Option Description
Collection - Status Quo Government funded roadside collection of household and small commercial
rubbish and recycling. Households and businesses use own container.
Estimated cost $450,000 / year for collection21
Collection - New Rubbish Government funded roadside collection of household and small commercial
Bins rubbish and recycling. Households and businesses provided with new, small
(80L) wheeled bin.
Estimated cost $450,000 / year for collection
$50,000 / year for bins (amortised over 5 years)
Collection - New Recycle Government funded roadside collection of household and small commercial
Bins rubbish and recycling. Households and businesses provided with new
recycling crate.
Estimated cost $450,000 / year for collection
$30,000 / year for crates (amortised over 5 years)
Collection - New Rubbish Government funded roadside collection of household and small commercial
& Recycle Bins rubbish and recycling. Households and businesses provided with new, small
(80L) wheeled bin and recycling crate.
Estimated cost $450,000 / year for collection
$80,000 / year for bins (amortised over 5 years)
Collection - Education Government funded roadside collection of household and small commercial
rubbish and recycling. Households and businesses use own container.
$20,000 per year allocated to education targeting contamination, materials
recognition and participation in the recycling scheme.
Estimated cost $450,000 / year for collection
$20,000 / year for education.
Table 7 summarises the multi-criteria evaluation of collection options. Costs have been estimated
based on current collection costs and incorporating likely capital costs for new collection containers.
Criteria Coll - Status Quo Coll - New Coll - New Coll - New Coll - Education
Rubbish Bins Recycle Bins Rubbish &
Recycle Bins
Annual cost to $450,000 $500,000 $480,000 $530,000 $470,000
Government
Landfill No change No change Greater than 40% Greater than 40% Greater than 40%
disposal/ landfill diversion landfill diversion diversion diversion diversion
Diversion %
Local economic No change in No change in Small increase in Small increase in Small increase in
development economic activity economic activity economic activity economic activity economic activity
opportunities in Cook Islands in Cook Islands (recycle (recycle (recycle
processing) processing) processing)
Technology risk Commercially Commercially Commercially Commercially Commercially
implemented in implemented in implemented in implemented in implemented in
the Pacific the Pacific the Pacific the Pacific the Pacific
Market risk Single viable Single viable Single viable Single viable Single viable
market market market market market
Community Community Community likely Community likely Community likely Part of
views unlikely to have to be supportive to be supportive to be supportive community
as strong view of change of change of change supportive -
schools and
motivated
households
Summary score 31/45 31/45 34/45 32/45 35/45
Conclusion Do not progress Do not progress Seek funding Do not progress Recommended
The assessment summarised in Table 7 suggests that several options are not worthy of further
consideration at this point in time. These include continuing with the current service with no
changes and introducing new rubbish bins. There may however be an opportunity to investigate
changing the approach to collection of rubbish when the current collection contract is renewed in
201922.
Introducing containers for roadside recycling warrants further investigation with a view to
identifying a suitable source of funding for the containers. Containers could be crates (commonly
employed in New Zealand and Europe) or wheeled bins (commonly employed globally, tend to be
used with mechanised collection). Crates could be employed within the current collection system
while effective introduction of wheeled bins may require new equipment and by implication changes
to the current collection contract.
22Any review of collection service should focus on collection staff safety, impact on recyclables recovery, overall cost
effectiveness and setting performance criteria for the contractor to reward the contractor achieving a high level of
customer satisfaction and waste diversion.
Targeted education to improve the use of the current service and once new containers for recycling
are introduced is also recommended. The data collected for this feasibility study suggests that key
messages could address:
· Contamination - there is a relatively high level of contamination in the recyclable material
collected. Messages may be focussed on targeted materials or on the impact of
contamination (nappies, food waste) on the recyclable materials, people processing materials
and the value of the product.
· Capture of recyclable materials - the composition data suggests there is a significant amount
of recyclable material in rubbish (rather than recycling) put out for collection. Messages may
focus on clearly explaining what can be recycled via the roadside collection and encouraging
households to separate all that they can.
· Participation in the recycling collection - messages may focus on creating a community
‘expectation’ that all households participate in the recycle collection.
Option Description
Treat - New Landfill A new, government funded and operated, landfill on Rarotonga accepting
household (collections) and commercial waste.
Estimated cost $5-6M Capital Cost
$100,000 / year operating cost
Treat - MHT A new, government funded and operated, Mechanical Heat Treatment process on
Rarotonga accepting household (collections) and commercial waste.
Estimated cost $6M Capital Cost
$225,000 / year operating cost
Treat - MBT A new, government funded and operated, Mechanical Biological Treatment
process on Rarotonga accepting household (collections) and commercial waste.
Estimated cost $5-6M Capital Cost
$225,000 / year operating cost
Treat - Incineration A new, government funded and operated, incineration plant on Rarotonga
accepting household (collections) and commercial waste.
Estimated cost $8-10M Capital Cost
$200-250,000 / year operating cost
Treat - Gasification A new, government funded and operated, Mechanical Biological Treatment
process on Rarotonga accepting household (collections) and commercial waste.
Estimated cost $8-12M Capital Cost
$200-250,000 / year operating cost
Treat - Target specific Targeted activity to capture and recycle, reuse or treat specific materials
materials potentially including food waste, garden waste and disposable nappies.
Estimated cost alongside new landfill
Alongside new landfill, additional $20,000 operational
expenditure
Table 9, presented below, summarises the multi-criteria evaluation of treatment and processing
options. Costs have been estimated based on existing commercial examples or based on work
completed in similar locations. As noted previously the small scale of the Rarotonga for advanced
technologies means there is considerable uncertainty in the capital and operational costs estimates.
The annual cost includes an estimate of annual operating costs and the amortised capital costs 23.
Table 9:- Treatment and Disposal Options Evaluation
Criteria Treat - New Treat - MHT Treat - MBT Treat - Treat - Treat - Target
Landfill Incineration Gasification specific
materials
Annual cost to $310,000 $500,000 $450,000 $670,000 $670,000 $330,000
Government
Landfill No change Greater than Greater than Greater than Greater than Greater than
disposal/ landfill diversion 40% diversion 40% diversion 50% diversion 50% diversion 40% diversion
Diversion %
Local No change in Small increase Small increase Small Small increase Small increase
economic economic in economic in economic increase in in economic in economic
development activity in Cook activity activity economic activity activity
opportunities Islands (recycle (recycle activity (recycle (recycle
processing, processing, (recycle processing, processing,
processing processing processing, processing processing
plant plant processing plant plant
operations operations plant operations operations
and and operations and and
maintenance) maintenance) and maintenance) maintenance)
maintenance)
Technology Commercially Commercially New New New Commercially
risk implemented in implemented technology technology technology implemented
the Pacific but not in the in the Pacific
Pacific
Market risk Landfill as the No viable No viable Single viable Single viable Limited
final destination markets for markets for market for market for markets for
for materials is heat treated compost like energy, energy, recovered
a secure residual, output. limited limited materials
‘market’ limited limited markets for markets for
markets for markets for recovered recovered
recovered recovered materials materials
materials materials
Community Community Community Community Community Community Part of
views unlikely to have unlikely to unlikely to unlikely to unlikely to community
as strong view have as strong have as strong have as have as strong supportive -
view view strong view view motivated
households
and
businesses
Summary 28/45 23/45 21/45 24/45 24/45 31/45
score
Conclusion Recommended Do not Do not Do not Do not Investigate
progress progress progress progress further
While there are a range of waste processing and treatment approaches implemented globally
continuing the current arrangements with a new landfill is the recommended option. This means
that a new landfill site, or an extension of the current site, will be required from around 2020. The
recommended option reflects a number of factors including:
· The comparatively high capital and operating costs for alternative technologies.
· Technical risks: the lack of commercially proven applications of advanced waste treatment
technology at a scale comparable to Rarotonga.
· Market risks: the lack of markets for ‘products’ of the processes, in particular for heat treated
residual waste (MHT), compost like output (MBT), bottom ash (Incineration) and char
(gasification).
· The likelihood that a new landfill will be required for residuals from the various advanced
waste treatment options considered.
There is also potential to build on the current capture of recyclable materials from the waste
immediately prior to baling for landfill by targeting specific materials. This is a basic version of the
mechanical sorting component of MHT and MBT or the pre-processing component of both
conventional and advanced waste to energy plant.
ADB projects are generally analysed using a discount rate of 10-12%. 24 However, a recent ADB
review25 questions this practice and notes that rates might differ depending on whether inter-
generational issues are at stake, and whether the primary impact is on consumption or investment.
Because the project being discussed is a significant capital project requiring Government funding,
our assumption is that it is displacing capital expenditure, i.e. investment. For simplicity we have
used a rate of 10% in our analysis.
Options for consideration
The Options
The existing landfill is close to capacity. A new disposal option is required to be in place by 2020. The
options considered in this analysis are:
· a new landfill; and
· an advanced waste treatment plant (advanced thermal). It would require the disposal of
residual ash /char and unsuitable materials.
In addition, there is the potential for increased recycling of waste. This would be in addition to one
of the options above, although it could mean reduced quantities of waste require management.
Costs and other data
The costs for the individual options are summarised in Table 10. The advanced waste treatment
plant requires both a plant and a new landfill for the disposal of the residuals. The total costs would
include both components. For this assessment it is assumed that the capital costs of the new landfill
would be similar but that the quantity of waste (and thus the operational costs) would be 10% of the
landfill only option26.
Table 10 Volume and cost data
24 Asian Development Bank (2013) Cost-Benefit Analysis for Development: A practical guide.
25 ADB (op cit)
26 Operational costs may be higher, reflecting high fixed costs regardless of scale although operational costs on Rarotonga
have been relatively low with simple and cost effective approaches to waste handling and placement. Capital cost may be
lower if it is decided that a smaller void space can be developed. On balance the total annual cost incorporating finance
costs (for capital) and operational costs are indicative of likely overall annual costs for the disposal component.
The other information relevant to the consideration of costs and benefits and their timing, is that of
the costs of finance. It is assumed that the capital costs for the project will be financed from an Asian
Development Bank loan. The costs of borrowing depend on the period of the loan, which is assumed
to be 25 years. The assumptions are shown in Table 11.
Table 11 Interest rate assumptions (25-year ADB loan)
Factor Rate
Fixed swap rate (average 20 & 30 years USD) 1.88%
Contractual spread 0.50%
Maturity premium (17+ years) 0.20%
Total 2.58%
Source: Asian Development Bank Treasury Department (2016) Indicative Lending Rates for Loans under the LIBOR-Based
Loan Facility Foreign Exchange Rates & Cap/Collar Premiums for Floating Rate Loans; ADB (2014) Financial Management
Technical Guidance Note. Preparing and Presenting Cost Estimates for Projects and Programs Financed by the Asian
Development Bank.
These are nominal interest rates, whereas the costs data included in Table 10 are in constant dollar
(real) terms. We use an inflation rate of 2.1% based on estimated annual inflation rates over the
previous five years.27 To adjust the nominal interest rate to a real rate we use the following formula:
(1 + )
= −1
(1 + )
Where: rreal = interest rate in real terms
rnominal = interest rate in nominal terms
i = inflation rate
A nominal rate of 2.58% is equivalent to a real interest rate of 0.47% with an inflation rate of 2.1%.
In Table 12 we show the profile of costs between the two waste management options, including
capital expenditure (capex), the finance costs which spread the capex costs over 25 years and the
operating costs from the first year of opening of the landfill or waste treatment plant.
Table 12 Profile of costs
Results
The overall results are shown in Table 13, in terms of an overall NPV to 2016 and an estimate of
costs per tonne (in 2016 $ values).
Table 13 Cost benefit analysis results
A new landfill is clearly the lower cost option; advanced waste treatment costs are over double the
cost.
Product charges are used in a large number of countries, but often for specific products, e.g.
electronics, tyres, packaging, hazardous wastes and vehicles.28 The charge bases include unit
numbers, e.g. charge per product sold, by volume or by weight. A charge as a percentage of value,
equivalent to a goods and services charge, would be an alternative approach. The best approach to
use would depend on the objectives being pursued.
28 OECD Database on instruments used for environmental policy (http://www2.oecd.org/ecoinst); St Brown M, Yoder J
and Chouinard H (2011) Revenue sources to fund recycling, reuse, and waste reduction programs. Prepared for
Washington State Department of Ecology
29 Cook Islands Ministry of Finance and Economic Management (2016) Cook Islands Statistical Bulletin Taxation Statistics.
will depend, in turn, on the existence of substitute products. The relevant elasticities are for the
range of individual products rather than for waste disposal itself. 30
The reduction in expected revenue does not matter if the amount charged per product is equal to
the disposal costs per product. However, because there are significant fixed costs of disposal (the
capital costs of the landfill or treatment facility), the reduction in revenue is likely to be greater than
the reduction in costs; average costs of disposal are greater than marginal (or variable) costs.
An alternative approach is to make the level of charge equal to the marginal costs of disposal, i.e.
the change in total costs of disposal resulting from one less tonne or cubic metre of waste. Such a
charge would not recover all the costs of disposal but it would be optimal from an economic
perspective. People would make a decision to purchase a product which produced more waste when
the additional amount that they paid was equal to the costs which their purchase imposed on the
community because of the costs of final disposal. In theory, this results in the optimal amount of
waste produced. The remaining costs of disposal can then be recovered using the least cost means,
i.e. taxation as discussed above.
30Price elasticities of demand for disposal are low. See: Covec (2012) Economic Factors of Waste Minimisation in New
Zealand. Report to NZ Ministry for the Environment.
3. Complete Rarotonga Landfill Design completed Q4 2016 Design $30-50,000 Infrastructure Consultants
design and construction Construction Q1-2 2017 Construction Cook Islands
4. Implement operational Operations Plan and training Completed Q1 2017 Additional $50,000 per year Infrastructure Consultants
improvements at Rarotonga 6 monthly ‘audit’ against plan operational funding for Cook Islands
and Aitutaki Landfills Rarotonga Waste Facility.
5. Replace clinical and Confirm specification for new incinerator Q4 2016 TBC Airport/ Infrastructure
quarantine waste Permitting and Procurement of new incinerator Q1-2 2017 Hospital Cook Islands
incinerators
6. Commence new Rarotonga Site identification and community engagement Q1-2 2017 Permitting approx. $250,000 Infrastructure Consultants
Landfill process Design and permitting Q3 2017 - Q2 2018 Construction approx. $5 - Cook Islands
Procurement and Construction Q3 2018 - Q4 2019 7,000,000
7. Implement improvements in Education - link to Recommendation 1 Annual Budget Appropriation for Te Pa Enua Infrastructure
solid waste management on Develop guidance for effective solid waste management on solid waste management and an Island Cook Islands
outer islands remote island communities. estimated $200,000 capital per Governments
island one off
9 Acknowledgements
Many stakeholders have contributed to the development of this report including providing valuable
insights into solid waste management across the Cook Islands, sharing information and ideas about
options for the future and risks to be considered. Tonkin and Taylor extends thanks to all who have
offer their input to the study.
10 Applicability
This report has been prepared for the exclusive use of our client Cook Islands Infrastructure, with
respect to the particular brief given to us and it may not be relied upon in other contexts or for any
other purpose, or by any person other than our client, without our prior written agreement.
Report prepared by: Authorised for Tonkin & Taylor Ltd by:
CHP
p:\86125\issueddocuments\86125 cook islands waste feasibility study final.docx
CONVENTIONAL INCINERATION
Technology The technology involves the thermal combustion of waste in the presence of
description oxygen, liberating energy, usually in the form of steam. It is used to treat
municipal solid waste (MSW) as well as other streams such as hazardous
materials (e.g. clinical waste); the latter typically requires the use of more
sophisticated emissions abatement equipment. Where MSW is the feedstock
there is usually some generation of energy – most typically electricity,
sometimes heat – from using the resulting steam in a steam turbine. Electrical
generation efficiencies for the incineration of MSW (in the absence of any heat
utilisation) range from 13%-29%, not taking into account the energy used
within the plant itself. In addition to energy, ash is produced (around 25% of
the tonnage treated at the plant). Depending on the abatement equipment
being used, a portion of this solid output is usually hazardous, requiring
additional precautions to be undertaken to reduce environmental impacts
where it is landfilled.
Scale The technology itself does not preclude the development of very small facilities
(less than 10,000 tonnes per annum), whilst very large facilities treating in
excess of 1 million tonnes per annum have also been developed. The energy
generation potential decreases as the size of the facility decreases, whilst costs
per tonne increase.
Risk The technology has been widely used all over the world for many years, so
operational risks are relatively low.
Indicative costs Costs are dependent on facility size, pollution abatement requirements, and
the approach to procurement. Indicative per tonne costs for a CHP facility in
Shetland Islands (UK) treating 20,000 tonnes of waste annually were NZ$51
capex and NZ$131 opex. Smaller facilities would be more expensive but the
generation of electricity only (as opposed to CHP) would be expected to reduce
costs.
Scale These technologies are commonly marketed as modular and there are a
number of pilot facilities in operation, so the development of very small
facilities is not precluded. However, as with incineration, costs increase and
energy generation performance decreases for small scale plant.
Risk Much higher risk than conventional incineration; many plant treating MSW
have experienced operational difficulties due to the heterogeneous nature of
the material. Risks are especially high for technologies using gas engines – there
are very few reference facilities operating globally at any scale for this type of
technology.
Indicative costs Costs are dependent on facility size, pollution abatement requirements, and
the approach to procurement. Costs for pyrolysis and gasification are unlikely
to be cheaper than that of incineration.
Technology A generic term for facilities comprising a multi stage treatment process,
description combining a mechanical phase with at least one biological treatment step. The
mechanical phase involves the removal of recyclable material (metals, plastics
and sometimes others) using mechanised sorting processes. The biological
phase can involve aerobic or anaerobic degradation; depending on the process
objectives, the former can be used to produce a dried refuse derived fuel (RDF)
or stabilised output reducing the impact of material subsequently sent to
landfill. The use of anaerobic digestion results in energy generation (via a gas
engine), whilst the RDF may be sent to an incinerator or an advanced thermal
treatment process.
Scale Facilities typically treat around 50-150,000 tonnes of waste per year. Very small
facilities (operating commercially) are rare, as the unit cost of the equipment
increases as scale decreases, although there is no technical reason to preclude
the construction of very small plant.
Indicative costs Dependent on the combination of technologies being employed; costs are also
dependent on facility size, pollution abatement requirements, and the
approach to procurement. Lower technology approaches (e.g. stabilisation)
could result in costs similar to that of incineration; higher technology processes
(e.g. AD-based systems) will result in higher costs.
Technology A variant of the mechanical biological treatment process. In this case, the waste
description is heated at high temperatures both to sterilise the material and to make it
easier to subsequently remove a cleaner stream of recyclable materials using
mechanical separation processes. A variation on the mechanical heat treatment
process involves the use of elevated pressures as well as high temperatures in a
process known as autoclaving. Depending on the approach used, the heat
treatment step may also be followed by a biological treatment step. Some kind
of RDF is also usually produced which may be used in an incinerator or an
advanced thermal facility.
Scale Pilot facilities have been developed at very small scale for some technology
variants. However, the more typical operational capacity is 50-150,000 tonnes
per annum.
Risk Risks are high. There have been very few facilities operating globally using this
type of technology in the past decade, and a number of those have experienced
significant technical difficulties.
Indicative costs Dependent on the combination of technologies being employed; costs are also
dependent on facility size, pollution abatement requirements, and the
approach to procurement. Costs for systems involving a mechanical heat
treatment step are unlikely to be cheaper than that of incineration.