INTEGRATED WASTE MANAGEMENT AND THE TOOL OF LIFE CYCLE INVENTORY : A ROUTE TO SUSTAINABLE WASTE MANAGEMENT FOR ASIA

F.R. McDougall1 , C-G. C. Peng2 and T. Arakaki3

1Corporate Sustainable Development, Procter & Gamble Technical Centres, UK

2Procter & Gamble, 17, Koyo-cho Naka 1-chome, Higashinada-ku, Kobe 658-0032, Japan

3Procter & Gamble, 17, Koyo-cho Naka 1-chome, Higashinada-ku, Kobe 658-0032, Japan

ABSTRACT: The application of Life Cycle Inventory to an Integrated Waste Management strategy provides a method to identify the overall environmental burdens associated with that strategy. LCI’s for waste management compile detailed data on raw material use, energy and water demand and emissions to air, water and soil. Based on such data, several different waste management strategies can be compared, and informed decisions can be made. This approach allows the determination of the best practical environmental option for total solid waste management in any specific geography. LCI is a decision support tool, not a decision making tool. The information provided by a LCI can help planners and waste managers design more Sustainable Waste Management systems for the future.

KEY WORDS: Integrated Waste Management (IWM), Life Cycle Inventory (LCI), Life Cycle Inventory models, Sustainable Waste Management.

INTRODUCTION

In line with the three pillars of sustainable development, solid waste management needs to be environmentally effective, economically affordable and socially acceptable (Figure 1).

Figure 1 Sustainability balances Environment, Economy and Society

  • Environmental effectiveness requires that the overall environmental burdens of managing waste are reduced, both in terms of consumption of resources (including energy, water) and the production of emissions to air, water and land.
  • Economic affordability requires that the costs of waste management systems are acceptable to all sectors of the community served, including householders, commerce, industry, institutions and government.
  • Social acceptability requires that the waste management system meets the needs of the local community, and reflects the values and priorities of that society.

A key question is how can we assess the overall environmental effectiveness and economic affordability of waste management systems, so that we can plan more sustainable waste management for the future? The tool of Life Cycle Inventory (LCI) is being used to answer this question. Along with the overall need for sustainable waste management, it is also becoming increasingly clear that no one single treatment method can manage all materials in Municipal Solid Waste (MSW) in an environmentally effective way. Following a suitable collection system, a range of treatment options will be required, including materials recycling, biological treatment (composting/biogasification), thermal treatment (Mass burn incineration with energy recovery burning of Refuse-Derived Fuel (RDF), Packaging-Derived Fuel (PDF)) and landfilling (Figure 2). Together these form an Integrated Waste Management (IWM) system.

Figure 2 Elements of an Integrated Waste Management system

Such an approach is advocated in the current UK waste strategy Making Waste Work (DOE, 1995)which states "..it is likely that an integrated approach, where each option contributes to the overall recovery of the waste, will usually be the preferred practice." Whilst it uses a combination of options, the defining feature of an IWM system is that it takes an overall approach to manage all materials in the waste stream in an environmentally effective, economically affordable and socially acceptable way (White, 1995). The implementation of IWM systems in a number of municipality’s within Europe and North America has recently been reviewed by McDougall and White (1998). In all cases significant landfill diversion rates have been achieved through a combination of reduced waste generation, and increased recycling and energy recovery. The resources available in these geography’s are significantly greater than those in many developing economies, however, lessons have been learnt that apply to even the least developed economies. In this paper we attempt to highlight these lessons and the opportunities that they offer to waste managers in Asia, in countries with both developed and developing economies to improve waste management through the implementation of IWM.

WASTE MANAGEMENT IN ASIA

As can be seen from the data presented in Table 1 below, there is considerable contrast between countries in Asia. For example there is a wide range in the Gross National Product per capita, from US$ 200 in Nepal to US$ 39,640 in Japan. This measure of a countries wealth is often reflected in a countries waste management infrastructure.

Table 1 Overview of statistics pertinent to waste management planning in Asia

Population
1998 (000’s) / Gross National
Product per capita (US$) / Per capita solid waste generation
(kg/day) / House-
holds with waste collection (%) / P/B
(%) / Pl.
(%) / Gl. (%) / Met.
(%) / F/G (%) / Tex.
(%) / Oth.
(%)
Bangladesh / 124,043 / 240 / 0.49 / 50 / 6 / 2 / 3 / 3 / 84 / 2
China / 1,255,091 / 620 / 0.8 / - / 4 / 4 / 2 / 0.5 / 35.5 / 54
Hong Kong / 6,200 / 22,990 / 5.07 / 26 / 14 / 2 / 2 / 29 / 4 / 23
India / 975,772 / 340 / 0.46 / 71 / 6 / 4 / 2 / 2 / 42 / 44
Indonesia / 206,522 / 980 / 0.76 / 71 / 11 / 9 / 2 / 2 / 70 / 6
Japan / 125,920 / 39,640 / 1.47 / 38 / 11 / 7 / 6 / 32 / 6
Korea Rep. / 46,115 / 9,700 / 1.5 / 89 / 24 / 5 / 5 / 8 / 32 / 26
Lao PDR / 5,358 / 350 / 0.9 / 5 / 3 / 8 / 9 / 4 / 54 / 22
Malaysia / 21,450 / 3,890 / 0.81 / - / 24 / 11 / 3 / 4 / 43 / 15
Myanmar / 47,625 / 240 / 0.45 / - / 4 / 2 / 0 / 0 / 80 / 14
Nepal / 23,168 / 200 / 0.3 / 60 / 7 / 2 / 3 / 1 / 80 / 7
Pakistan / 147,811 / 460 / 1.2 / 50 / - / - / - / - / - / - / -
Philippines / 72,164 / 1,050 / 0.7 / 85 / 19 / 14 / 2 / 5 / 42 / 18
Singapore / 3,491 / 26,730 / 1.1 / - / 28 / 12 / 4 / 5 / 45 / 7
Sri Lanka / 18,450 / 700 / 0.5 / 94 / 11 / 6 / 1 / 1 / 76 / 5
Thailand / 59,612 / 2,740 / 1.1 / - / 15 / 14 / 5 / 4 / 48 / 14
Vietnam / 77,896 / 240 / 0.55 / 45 / 3 / 0 / 0.5 / 1 / 52 / 1 / 42.5

Key: P/B = Paper/Board, Pl.= Plastic, Gl.= Glass, Met. = Metals, F/G = Food/Garden, Tex. = Textiles, Oth. = Other.

Source: World Resources 1998-1999 (1998), OECD (1997) and World Bank (1999).

A feature of waste management in Asia is the relatively high percentage of organic material (up to 80%) present in the municipal waste stream (compared with North America and Europe). This results in a dense waste that has a high moisture content and a low calorific value. This high amount of organic material makes the separate collection of organic material for composting or biogasification an appropriate treatment technology. Incineration is not a very viable treatment technology in the majority of Asian countries (Japan excepted) due to both the low calorific value of the waste (between 3.4-4.6 MJ/kg, compared to the optimum calorific value for modern incineration processes of around 10.0 MJ/kg) and the large capital costs associated with building, operating and maintaining an incinerator, air pollution control devices and energy recovery units. By contrast, in Europe and North America MSW contains between 30-40% organic material which makes the solid waste stream more suitable for incineration.

Another difference is that in many Asian countries MSW contains relatively low amounts of recyclable materials. In North America and Europe separate collection of recyclables and the further sorting of these recyclables in Material Recovery Facilities (MRF’s) is increasing rapidly. In Asia collection of recyclables is carried out mainly by scavengers (or rag-pickers) both at the kerbside and on the landfill (or open dumps) respectively). Activities need to be taken to improve the health and working conditions of scavengers (see Boswell and Charters, 1997 for details), making them a more effective part of the waste management system compared to the current situation.

PERSPECTIVE ON WASTE MANAGEMENT IN ASIA IN THE FUTURE

Overall it is recommended that the process of converting current waste management systems to IWM (Integrated Waste Management) within countries with developing economies in Asia should contain the following steps:

  1. Data collection on waste composition. This is relevant for planning the collection, transport and treatment of MSW. Good data is the foundation of an effective IWM program.
  2. Progress from uncontrolled dumping to the use of simple sanitary landfill.
  3. Separation of organic waste from MSW which can then be composted or used for biogas production.
  4. Formal involvement of scavengers in the collection of recyclable materials

The concept of IWM and the tool of LCI described in this paper have both been successfully applied to waste management systems in North America, Europe and Latin America, proving that they are appropriate techniques to help countries with both developed and developing economies to establish sustainable waste management systems.

THE END OF THE ROAD FOR THE WASTE MANAGEMENT HIERARCHY?

Past decisions on waste management strategy and the structure of waste management systems have relied on the "waste management hierarchy". This usually gives the following order of preference: waste reduction; re-use; materials recycling; biological treatment; incineration with energy recovery; incineration without energy recovery; landfilling. Such use of a priority list for the various waste management options has serious limitations:

  • The hierarchy has little scientific or technical basis. There is no scientific reason, for example, why materials recycling should always be preferred to energy recovery.
  • The hierarchy is of little use when a combination of options is used, as in an IWM system. In an IWM system, the hierarchy cannot predict, for example, whether composting combined with incineration would be environmentally preferred to materials recycling plus landfilling.
  • What is needed is an overall assessment of the whole system, which the hierarchy cannot provide.
  • The hierarchy does not address costs and cannot assess the economic affordability of waste systems.

The limitations of the waste management hierarchy are becoming increasingly apparent, especially in relation to IWM systems. The United Kingdom`s Waste Strategy, Making Waste Work (United Kingdom Department of Environment, 1995) for example, suggests that although useful as "a mental checklist", "the waste hierarchy will not always indicate the most sustainable waste management option for particular waste streams...". Similarly, a study comparing different solid waste management options in the European Union concluded: “the social cost-benefit analysis of MSW management systems in the European Union seems to support the conclusion that the “waste hierarchy” is too simplistic, and that blind adherence to its tenets can lead to welfare losses.” (Brisson, 1997) What is needed is less waste to deal with in the first instance, and then an IWM system to handle the waste that is still produced in an environmentally efficient, economically affordable and socially acceptable way. Rather than rely on the waste hierarchy, the environmental management tool of Life Cycle Inventory (LCI) can be used to help reach this objective.

LIFE CYCLE INVENTORY OF SOLID WASTE

The LCI of Municipal Solid Waste starts the moment a material becomes waste (i.e. loses value) and ends when it ceases to be waste by becoming a useful product, inert landfill material or an emission to either air or water. The inputs for an IWM system are solid waste, energy and other raw materials. The outputs from the system are both useful products in the form of reclaimed materials, energy and compost, and emissions to air and water and residual landfill material. Once the waste management system has been described, the inputs and outputs of each chosen treatment process must be calculated, using fixed data for each process. The lack of quality data with respect to waste management practices is a recognized problem in this part of an LCI methodology in all countries.

The results of LCI models for solid waste are expressed as: net energy consumption, air emissions, water emissions, landfill volume (residual), recovered materials, compost, material recovery rate and landfill diversion rate. The usefulness of LCI in waste management is in assessing environmental efficiency. Given that all the individual operations, such as composting, incineration, landfilling etc. are safe, LCI will help determine the optimal integrated combination of these options that minimizes energy and raw material consumption, and the generation of air and water emissions and final residual solid wastes.

It also needs to be stressed that an LCI will not actually make any decisions about the “best” waste management strategy. A LCI for solid waste management will provide a list of energy consumption, and emissions to air, water and land, over the whole life cycle, and will also predict the amounts of useful products that arise from waste, such as compost, secondary materials and useful energy (Figure 3). The best system for any region will depend on local needs and priorities, such as the need to reduce landfill requirements, or the desire to reduce water emissions or air emissions. Thus, LCI is a decision-support tool, not a decision-making tool. The selection of the best IWM system for any region will still require a decision to be made, but LCI can provide additional, overall environmental information for use in the decision-making process.

Figure 3 Using Life Cycle Inventory to assess an Integrated Waste Management System

CURRENT STATE OF THE ART: LCI MODELS FOR IWM SYSTEMS

The first complete LCI computer model for waste management was released in 1995 as part of the book Integrated Waste Management: A Lifecycle Inventory (White et al., 1995). The model predicted overall environmental inputs and outputs of MSW management systems and included a parallel economic model. The model was designed as a decision-support tool for waste managers in both industry and local government, who needed to decide between various options for waste management. The model was (and still is) used in Europe, South America and Asia to help design regional and local waste management systems. An improved version of this model, more flexible, transparent and user friendly, containing updated data is due for release in the middle of the year 2000.

  • The US Environmental Protection Agency (EPA) is currently working to apply recent life cycle methods to develop tools for evaluating IWM (Thorneloe, 1995). The research began in 1994 and is expected to be completed with the write up of case studies in 2000.
  • The UK Environment Agency’s Life Cycle Research program also began in 1994. The aim of the program is “to provide an objective basis for the comparison of waste management strategies and of options for individual waste types” (EA, 1998). The research program was completed in 1999 and case studies are due for publication in 2000.
  • Two Canadian industry groups, Corporations Supporting Recycling (CSR) and the Environment and Plastics Industry Association (EPIC) have co-sponsored the development of a site specific tool that municipalities can use to evaluate the environmental and economic effects of proposed changes to their IWM system, strategies and practices. The model has been designed with significant municipal input from the co-participant in the project, the City of London, Ontario. London’s participation has provided an excellent case study in which data inputs, analysis, interpretation and results have been provided by municipal staff and communicated to municipal stakeholders (London, Ontario, 1997).

The benefit of using a tool like LCI is that it provides flexibility by allowing assessment of the optimal waste management strategy for a given region, on a case-by-case basis rather than to try to identify a single solution for a whole country or continent. The role of policy should be to set the desired outcomes from waste management, such as energy conservation, or reduction of GWP (Global Warming Potential). LCI can then provide an overall accounting tool to help reach these outcomes. Hierarchies, in contrast, try to specify the means, rather than the desired end results.

WHERE TO FROM HERE?

The earliest LCI models for IWM were no more than a first attempt to apply the technique to this field. If LCI results are going to be used as the basis for discussion between the many and varied stakeholders in waste management decisions, the tool needs to be credible. The methodology and assumptions must be transparent, and the basic data relevant and reliable. Having endorsement from the UK Environment Agency or the US EPA may help in some way to establish the credibility of models.. It is through the experiences of waste planners and managers with the tool of LCI that its full value will be understood, and the best ways to include it in the decision-making process determined. A few case studies are available in the literature (see references below). The tool is clearly appropriate for use in Asian countries, at a local or regional level. To facilitate the acceptance and application of such LCI models in Asia we are currently working to collect and publish the experience of users. Together with user-friendly, credible, reliable and flexible models, this will help fully explore the potential of this environmental management tool in Integrated Waste Management systems.

ACKNOWLEDGMENT

Figures 2 and 3 in this paper are taken from Integrated Solid Waste Management: A Life cycle Inventory. byWhite, P.R, Franke, M. and P. Hindle. 1995. See reference below.

REFERENCES

Area Metropolitana de Barcelona (1997) Programa Metropolita de Gestio de Reisus Municipals. (1997-2006).

Boswell, J.E.S. and Charters, G.J. (1997) Scavenging, salvaging and recycling on landfills. Proc. Sardinia 97, 6th International Landfill Symposium, Vol. 5, pp. 403-414.

Brisson, I.E. (1997). Assessing the Waste Hierarchy - a Social Cost-Benefit Analysis of Municipal Solid Waste Management in the European Union. AKF, Institute of Local Government Studies, Denmark. Available at

DOE (1995). Making Waste Work; a strategy for sustainable waste management in England and Wales. Department of the Environment. HMSO, London. 117pp.

Environment Agency. (1998). Life cycle Program for Waste Management. Program profile. UK Environment Agency.

Franke, M., McDougall, F. and Sher, F. (1999). Integrated Waste Management in Europe-An Analyses of 11 Case Studies-. Conference Proceedings in English and Chinese presented at the United Nations Chinese Mayors Conference on Municipal Solid Waste Management and Landfill Gas Utilization, March 23-25, 1999, Nanjing.

ISO 14040 Environmental management - Life Cycle Assessment- Principles and framework. (ISO, 1997).

ISO 14041 Environmental management - Life Cycle Assessment- Goal and scope definition and Life Cycle Inventory analysis. (ISO, 1998).

ISO 14042 Environmental management - Life Cycle Assessment- Life Cycle Impact Assessment. (ISO/FDIS 1999).

ISO 14043 Environmental management - Life Cycle Assessment- Life Cycle Interpretation. (ISO/FDIS 1999).

ISO Technical Report 14049 Environmental management - Life Cycle Assessment - How to apply ISO 14041 Goal and scope definition and Life Cycle Inventory analysis. (ISO, 1999).