Integrated waste management: A solution to the environmental problem?
Thursday, 12 February 2015 01:20
By Pierre Lecocq
Municipal waste management is a critical issue that impacts the daily life of all citizens: poor waste collection may cause bad smell and flooding due to litter blocking storm water drains; landfill sites may affect the life of residents due to scattered plastic bags and result in both olfactory and visual pollution. Waste management is critical for our well-being but most people are unaware of it. How does it actually work?
Well, if you live in Colombo, such as the author of the article; you probably sort glass and may use some organic waste for producing homemade compost but all your other trash is combined in the same bin. This bin is emptied by a garbage truck one to three times a week and sent to one of the two main open dumps in the Western Province.
Dumping waste is an easy and an inexpensive way of disposing waste. However, on the long term, this is not sustainable because of the negative consequences on ground and water pollution on the environment and public health.
Colombo is a clean city and waste collection does not appear to be a problem; however there is a lot of potential for improvement on the treatment and disposal of waste. With technological improvement, a combination of technologies is now available to ensure proper treatment and conversion of waste in valuable energy or recycled material.
State-of-the- art recycling technology
The obvious resource comes from recycling. There are a few small recycling facilities within the city but no large scale public sector-led recycling program that would allow waste sorting in a systematic manner to fully take advantage of the various resources contained in the waste (metal, plastics, glass…).
In addition, recent developments enable taking advantage of types of waste that are not directly reusable. Through state-of-the-art technologies, bearing names such as anaerobic digestion, gasification or pyrolysis, it is now possible to convert organic waste in bio-methane, an inflammable gas that can be used to produce electricity and steam or to be used as a fuel in CNG (compressed natural gas)-driven vehicles. Plastic can also be converted in value-added oil, or in electricity.
Incineration may be a complement for the inorganic portion of the waste and some energy can also be produced from the combustion.
A combination of all of these processes (recycling, sorting, biogas production and incineration) is usually required to get the most out of waste.
Well, no one knows for sure what the future holds but it is likely that the current trend toward increasing energy price will make recycling and waste-to-energy more profitable on the medium term. Landfill mining – the extraction of stabilised waste from old open dumps to feed an incinerator – may be the next big thing. This will become viable when the cost of energy rises at a level which makes extraction profitable.
On the longer term, the society will hopefully move toward a circular economy, to get out of the ‘take-make-consume and dispose’ growth model to move toward an economy based on the re-using, repairing, refurbishing and recycling of waste. The goal is to turn waste into a resource. All resources need to be managed more efficiently throughout their life cycle.
Cities vs. countryside
State-of the-art waste treatment technologies are not always feasible because they often require a minimal amount of waste to be profitable. Even if some products are recycled and sold, thus generating an income, this income does not fully outweigh the cost of processing and treating waste.
Most of the benefits come from the improvement of environmental conditions; this improvement is difficult to quantify and is not taken into account in the financial model of a project (how could contamination of groundwater or generation of uncontrolled landfill gas be taken into account?).
Typically, these solutions may not be feasible in small towns or in the country side, where simple and robust waste management systems should be considered. The solutions should be customised to every local authority as they will have different needs and challenges (quantity of waste produced, density of population, use for compost produced). The example of the city of Anuradhapura could be a positive example to the rest of the country.
In Anuradhapura, municipal waste is segregated in households and collected by municipal services and sorted within the city. Plastic is crushed and sent to factories which use it in their production process, the organic matter is sent to a facility outside the city to produce compost for agriculture.
In smaller villages and hamlets, the waste is not collected due to the lack of money and other more urgent priorities of local authorities and often ends up dumped illegally directly on the side of the road or to a bare land.
Integrated waste management
Sustainable exploitation of waste requires sorting waste and using different highly technical and specialised techniques for different types of waste. This, in technical jargon, is called integrated waste management. Integrated waste management requires a strong involvement of the private sector which will bring the specialist knowledge for each segment of the waste management chain.
In practice, setting up a waste management chain requires reforms because the private sector always requires security before investing time and money. The establishment of a regulatory framework which provides a secure environment and the right incentives is required to push things in the right direction. For a waste-to-energy plant, this includes a secure Supply Agreement to guarantee that ensures steady quality and quantity of waste supply and an off take agreement for the electricity produced. Another key point is the off take, i.e. compost projects are just not sustainable if the compost produced has to compete with subsidised compost or if the feed-in tariff for electricity are too low.
There are several challenges to be met in order to achieve a successful system. What I believe to be one of the main challenges in Sri Lanka is to find a trade-off between private sector involvement and preservation of public jobs. The local authorities will have to deal with the difficult task of diverting unskilled labour to other position or favouring staff transfer to the private sector when possible. There should be a way to mitigate the Not-In-My-Back-Yard (NIMBY) objection of residents that do not want waste near their properties.
Change requires the involvement of key stakeholders. Political will is the first requirement, but non-governmental shareholders can be of help such as international donors and private companies. Some companies with experience in these complex projects may bring their technical knowledge in and help with the transition from the everything-goes-in-a-hole-and-stays-there-forever system to an integrated waste management system. Development Partners such as the Agence Française de Développement (AFD) and PROPARCO – AFD’s private sector funding arm – will play a key role in providing finance to allow this change to happen.
(The writer is a professional with experience in the waste and wastewater sector in South and South East Asia. He now works as a project officer infrastructure at AFD in Sri Lanka.)