Waste Flow Diagram

The Waste Flow Diagram (WFD) tool estimates the amounts of solid waste that leak into nature and oceans by various sources. Through a scenario function, it simulates how improved waste management could reduce environmental pollution and avoid marine litter.

The WFD was developed since insufficient waste management is considered one major source of marine litter, especially along coats and rivers. Understanding the leaks and pathways of plastic waste into the environment is key in developing effective measures to beat plastic pollution.

Marine litter poses a global risk to marine ecosystems, the fishing and tourism industry as well as possibly human health. About 60 to 90% of marine litter consists of plastics, much of which comes from single-use products and packaging. According to estimates, between 4.8 and 12.7 million tons of plastic debris leak into the world’s oceans each year. In a business-as-usual scenario annual marine plastic pollution will triple by 2040.

On behalf of BMZ, the tool was developed in cooperation by GIZ, the University of Leeds, Eawag-Sandec and Wasteaware. It is based on a preliminary method as applied in two case studies as part of the report "Marine Litter Prevention". 

Objectives

  • To estimate the amounts of plastic leakage into the environment
  • To visualise the quantities of municipal solid waste streams within a waste management system
  • To plan waste projects, especially about marine litter prevention
  • To monitor the effectiveness of applied waste interventions

Target audience

  • Local authorities wanting to understand waste flows within municipal solid waste management systems, to estimate amounts of plastic leakage into the environment, and to identify crucial areas to invest in their solid waste management infrastructure
  • Development and donor agencies supporting capacity development and funding for solid waste management to improve the understanding of project impacts
  • Non-Governmental Organisations (NGOs) and civil-society organisations wanting to make an improvement in the solid waste sector
  • Entrepreneurs and private investors intending to set up waste collection, treatment or disposal activities as a business venture or social enterprise
  • Any stakeholder, public or private organisations and individuals concerned with solid waste management and plastic pollution

Methodology

Local inspections and observations of the waste management system provide insights into the current situation and identify potential for improvement. Waste management stations (e.g. waste sorting facilities) are assessed in a systematic and qualitative respect to determine the sources of waste entering the environment. Other aspects, such as the involvement of the informal waste sector in waste collection and treatment, as well as uncontrolled waste incineration, are also considered. Mass flow analysis (MFA) is applied to illustrate the quantities of waste streams. The WFD also supports SDG indicator 11.6.1 (Collection and treatment of municipal waste in controlled facilities) and improves its informative value.

Excel Tool

The WFD is an excel-based tool that maps municipal waste flows using Sankey diagrams and quantifies the sources as well as fates of plastic waste entering the environment. The toolkit is specifically designed to integrate with SDG 11.6.1 by informing on the sub-indicators and can be operated either as a baseline assessment or used for scenario forecasting.

User manual

The User Manual provides an explanation of the WFD toolkit and in-depth guidance on how to apply it. This includes information on data collection issues, how to estimate plastic leakages, how to run scenarios, and how to visualise the waste flows. Decision trees and descriptive tables for each part of the solid waste management system facilitate the calculation of leakage potentials.

Video: Introduction to the Waste Flow Diagram

This video explains the rationale, key functions as well as data requirements of the WFD.

Video: Applying the Waste Flow Diagram

Using the example of a dumpsite, this video explains how the WFD quantifies plastic leakage and determines its fate in the environment.

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