by Andrew StreetSITA's waste to energy plant on the Isle of Man handles all of the island's waste and exports 5 MW to the grid - around 10% of the island's needs
Image credit: SITA
Due to their relatively small scale, the development and operation of on-island waste treatment and disposal facilities which meet increasingly stringent legislative requirements is a challenge. Whilst many remote island communities are not usually subject to the same level of legislative control as larger mainland states (for example, with regard to key EU Directives relating to waste management), it is usual for an island authority to seek to adopt an approach, and to introduce facilities and technologies that at least go some way to reflecting the high standards set out in European or other similar legislation.
Within EU legislation, including that relating to waste management, such as the Waste Framework Directive and Landfill Directive, there is explicit recognition of the challenge of seeking to apply the same strict standards to small islands, and in these cases exemptions or derogations often apply.
This should not of course be seen as a 'licence' for any local, island based authority to adopt standards which give rise to wholesale environmental damage. Indeed given the reliance many small islands have on maintaining the environment either for the purposes of supporting tourism or local agriculture, that would clearly be counter-productive.
In the past there have been plenty of examples of inappropriate waste management on small or remote islands, with very little attempt at adopting a sustainable approach that protects the local environment. On many small remote islands across Europe – and across the globe – indiscriminate dumping of waste was often the norm, with open burning and sometimes the tipping of the residue in a remote corner of the island. For example, for many years on the Greek island of Santorini waste was tipped over a high cliff. However this is no longer practiced and great strides have been made across many of the Greek islands in addressing these issues.
An extreme example of poor waste management – described in the worldwide press in 2012 as 'apocalyptic' and a 'floating toxic time bomb' – is the island of Thilafushi in the Maldives. With an indigenous population of around 330,000 but with nearly 800,000 tourist visitors each year, the Maldives archipelago is considered one of the most beautiful holiday destinations in the world. Of the 1200 islands in the group, 200 are inhabited and half of these are designated as resorts. Consequently, pressure on the environment is enormous, and waste management has simply not been adequately planned for or invested in.
The result is an open dump receiving over 300 tonnes of rotting waste each day, and on an island that is increasingly threatened by rising sea levels; this clearly means something has to be done.
The relatively small permanent population and the potential impact of a transient tourist population can place considerable pressure on local governments in terms of funding waste management services. Most remote island communities can only afford the most basic of waste management systems without external funding, simply because they do not have the local tax raising capacity to fund the full range of infrastructure required to deal with issues such as power generation and supply, water supply and wastewater treatment, let alone to manage solid waste in line with modern standards.Population critical
There are examples of larger islands having the capacity to develop modern facilities, and to attract the investment required to do so. Two recent examples include the Isle of Man (population of 85,000) and Jersey (population of 98,000), both of which have state-of-the-art waste to energy facilities in place. A third example is the Western Isles (population of 26,000) off the north-western coast of Scotland, where a new integrated waste treatment facility has fairly recently been commissioned.The Western Isles Integrated Waste Management Facility was the first in the UK to use anaerobic digestion to treat source separated organic waste to generate energy
Islands with much smaller populations simply could not support the development of this sort of facility without external funding from central government, or through grants. A current example of this is the Isles of Scilly – one of the most beautiful island archipelagos in Europe - but with a very small indigenous population of just 2200 people. Without the current commitment from the UK government to provide substantial funding it would simply not be possible for the island's local council to address the urgent need to replace an existing but ageing incinerator with a modern waste to energy facility and at the same time remediate a site which has been impacted by waste management over the last 50 years.
A parallel situation also arises for St Helena in the South Atlantic – one of the most remote islands in the world. St Helena, a British Overseas Territory, has an indigenous population of around 6600, and currently a relatively small number of tourists. That is due to change in the coming years with the development of a €240 million airport, which will make the island far more accessible. Major improvements to the Island's waste collection, treatment and disposal system are currently underway, but largely reliant on funding provided by the UK government.
The size of the local economy and industrial/agricultural base often cannot sustain consistently high levels of material reuse, limiting local markets for recycled materials and for compost products. This is particularly pertinent for an extremely remote location, where the transfer of materials off-island would be both expensive, and difficult to justify in terms of sustainability. This is clearly less of an issue for islands close to a mainland market, and in these cases recycling should be encouraged and established transport routes utilised to transfer materials to mainland markets for recycling.
There will however always be some scope for local reuse and recycling. Particularly in the developing world the imagination of the local population appears to have no limit when it comes to converting waste into something of real value. In most cases however, the market is limited by the size of the local economy, or impacted by the transient nature of any tourist traffic to the island. Therefore a degree of realism is needed when it comes to the level of recycling and reprocessing that can be sustained.
Additionally, on many islands there are seasonal increases in waste generation, and high levels of packaging associated with the necessary importation of food and other goods. These variations make it difficult to sustain both local and off-island commitment to resource efficient recycling and composting. Seasonal variations are often related to tourist activity, which although valuable to the local economy, will always bring additional pressures to the local environment, including the generation and importation of wasteViable options
Experience indicates that there are normally just a few viable approaches to waste management that could be said to reflect 'good practice' (although not necessarily 'best practice') within a western, mainland state subject to strict legislative controls (such as would be the case for European Member States).
As outlined, it would not be appropriate to adopt the same approach to dealing with waste on a small remote island as one would for a large European metropolitan authority with access to local and central funding, a range of options for collection, treatment and disposal, and an established and mature market for a range of segregated materials and process outputs.
For a remote island community, or indeed any remote location, the range of realistic options for managing waste are inevitably much more limited. Experience across the globe shows that the most likely options to be adopted are:Existing landfill operation of St Helena in the South Atlantic – soon to be upgraded with funding from the UK government
Landfill: Reliance on landfill as the principal disposal route, with some limited recycling and reuse, but within the limits of local markets. Efforts are typically focused on ensuring that the landfill site (normally a single site, unless the island happens to cover a very large area, or is made up of an archipelago of islands) is developed and operated on a sanitary basis and is subject to appropriate levels of management and control so as to minimise the environmental impact. There are many islands across the world where this approach remains the strategy, and is the preferred approach going forward.Jersey's recently commissioned waste to energy plant will process up to 105,000 tonnes of waste per year and generate around 7% of the island's electricity Credit: Hopkins Architects Ltd
Thermal treatment: On some larger islands, where the quantity of waste is sufficient to justify the investment, it is quite common for the principal disposal route to be thermal processing through incineration. The preferred technology would be conventional incineration, and it would be unusual for a plant to be smaller than 10,000 – 15,000 tonnes/annum (although there are a few examples of smaller sized facilities on islands). Rarely is this on a combined heat and power (CHP) basis, simply because typically there will be few opportunities for use of the heat, but almost without exception power will be generated and exported to the local network. Any residual wastes that cannot be incinerated would be sent to landfill, along with incinerator residues.
What is notable is that it is very rare for other waste treatment technology to be introduced on small remote islands – whether that be the treatment of residual waste to create RDF for thermal processing (simply because it would not make sense to introduce two expensive treatment processes for such a small quantity of waste), or the treatment of organic waste by anaerobic digestion or composting.
Anaerobic digestion would normally be inappropriate in a remote island situation due to the relative complexity of the technology, and also the challenges of disposing of the digestate. There are often similar challenges in disposing of organic waste derived composts, simply because the local demand for such materials on remote islands is often minimal, and it could therefore end up being sent to landfill – which somewhat defeats the object of investing in a relatively expensive treatment process in the first place.Conclusion
Developing and implementing a truly sustainable waste strategy for small islands can be challenging, and this becomes all the more difficult for those islands that are very remote. However, with appropriate levels of realism and pragmatism it is possible to adopt an approach that provides adequate protection to the local environment. Funding is often a major issue, and external support is an inevitable requirement if modern standards of environmental protection are to be met.
Andrew Street is a director at SLR Consulting Limited
Waste Management World Issue Archives