This guidance was developed by the WWF Baseline & Monitoring Working Group in June 2021, to support cities as they proceed with their first actions following the signing of their Declaration of Intent. It is not intended to be prescriptive, as cities themselves are best positioned to decide how to conduct their activities, given local challenges, resources and capabilities.

WWF is currently working closely with 25 pilot cities in Southeast Asia and China, and has developed a separate baseline guidance that is relevant to those specific cities. This guidance however, while complimentary to the baseline activities and learnings from the 25 pilot cities, was developed in an effort to create a standard methodology that can be easily and cost effectively replicated across all cities and regions, to enable long-term monitoring and evaluation towards PSC defined plastic targets. This is an evolving guide that will change over time to reflect lessons learned.


What is a baseline?

A baseline assessment provides information on current conditions in which the city seeks to change. It provides a critical reference point for assessing changes and impact over time, as it establishes a basis for comparing the situation before and after interventions, and for making inferences as to the effectiveness of the initiative.

Baseline assessments are most useful when conducted before the City Action Plan is developed, and before interventions are adopted and implemented, so as to serve as a benchmark for monitoring and evaluating change, as well as to guide and inform priorities and decisions.

Baseline assessments should be carried out in a methodical way, ensuring that the same type of data can be collected at different stages in time, in order to compare the results and assess the extent of change, or lack thereof. The type of data to be collected and considered in the baseline is dependent on a number of factors, including, but not limited to, the existing waste management infrastructure, level of informal sector inclusion, current available waste data, the key performance or change indicators expected to be included in the Monitoring and Evaluation methodology, as well as the specific requirements defined within the scope of a project, which can include donor requirements.

Baseline assessments for PSC intents and purposes, can focus on two separate, but closely related assessments:

  1. Waste Flow Scoping Assessment – assessment of solid waste generation, collection and management, identifying a city’s waste management processes, capabilities and possible leakage into the environment; and/or
  2. Litter Baseline Assessment – community-level data on plastic leakage into the environment, obtained through litter data collection in the field. Litter is defined in this context as plastic waste materials that have been discarded improperly, in an inappropriate location, either intentionally or unintentionally.

 While both assessments are recommended, and can be complementary to each other, it is entirely up to the city to decide which types of assessments will best meet its baseline objectives, based on available data, funding, and resources.

In both types of assessments, we must be cognizant of our monitoring capabilities. In instances where we collect robust datasets in our baseline assessments, but cannot collect equivalent datasets through follow-on monitoring efforts, then the baseline can quickly become irrelevant, as there are no mechanisms to measure the effectiveness of interventions and investments. A more streamlined baseline assessment, one that adheres to a monitoring methodology that can be easily and cost effectively replicated, is preferred over an exhaustive baseline assessment that cannot be practicably replicated.  


What are the recommended baseline boundaries?

While there are many credible baseline assessment methodologies that can be used to collect community-level data to inform and guide a city’s PSC approach, given limited time and dedicated resources, we make an effort to define clear boundaries to focus the scope of the assessment. A fully comprehensive baseline assessment can include seven community components: 1) inputs, 2) consumption, 3) product design, 4) use, 5) collection, 6) end-of-cycle management (including collection and waste management), and 7) plastic leakage into the environment.[1]

While all components are relevant to a comprehensive plastics strategy, the upstream components, from inputs through to the use phase, fall outside the scope of our recommended baseline assessment. We therefore suggest a baseline focus on end-of-cycle components (components 5-7 mentioned above) to include at minimum plastic collection, management and leakage – downstream data that can be leveraged to inform local policies and interventions. Secondary components that can also be obtained and used to inform local activities can include data on plastics use, in an effort to better understand how plastic waste is generated at the community-level.


What do we want to know?

The ultimate measure for the success of the PSC initiative is the reduction of plastic leakage into the environment. Inline with this objective, cities join the PSC initiative and commit to two targets:

  1. Achieving a 30% reduction in plastic leakage in the near term; and
  2. No plastics in nature by 2030.

Keeping in mind that the No plastics in nature by 2030 target will require 100% collection rates, full containment and processing capabilities – a hard stop on all plastic leakage - we must set reasonable expectations for PSC’s role in building this sector. PSC does not have the capacity, expertise or financial resources to build and manage public infrastructure to meet this target, and so much of this responsibility must be supported by, or delegated to, other entities.

Further, as the No plastics in nature by 2030 target is largely aspirational, and can be assessed without reference to a baseline, it is the 30% reduction target that is most relevant to our baseline methodology. While the ultimate plastic leakage baseline measure is kg of plastic waste leaked into nature, per capita, per year (kg/capita/year), this can be a challenging number to quantify with a high degree of confidence. Possible alternative quantification approaches can include plastic item counts and/or weighted volumes in specific target areas.

The litter data can also be used in a more computational manner – litter counts and volumes per measured area can be combined with city population densities to arrive at relative plastic litter densities, among other relevant multipliers. These more advanced calculations can add perspective and another layer of understanding to better support the City Action Plan, proposed interventions, external communications and public information exchanges.

While a Waste Flow Scoping Assessment can provide key insights concerning leakage from the municipal solid waste management (MSWM) system, such plastic leakage can be difficult to measure accurately when advanced MSWM systems are not in place. Providing fundamental collection services and infrastructure in such cases, can often deliver the most immediate and lasting impacts of any waste management activity. But in many such scenarios, the lack of basic infrastructure is already known, making the scoping assessment most relevant to identifying the specific MSWM infrastructure needs in order to achieve the longer term target of No plastics in nature by 2030.


1. Waste Flow Scoping Assessment


  • Understand MSWM infrastructure needs for No plastics in nature by 2030 target
  • Gain insight into the city’s solid waste collection and management infrastructure, including collection performance, costs, community and collector attitudes (including informal sector) and possible sources of leakage into the environment
  • Gain knowledge on quantities, composition and characterization on types of waste
  • Identify current waste policies, practices and overall governance
  • Identify key intervention areas for inclusion in the City Action Plan

There are many options for collecting and analyzing waste flow scoping data. From scaled down approaches, looking solely at available information and data sets, in an effort to establish a general understanding of the MSWM system processes, capabilities and throughput, to more holistic approaches, recommended for cities that have allocated budgets and technical support for a highly detailed Waste Flow Scoping Assessment.


Option 1 – Low Resolution

Expected time commitment: 3-5 days

Team resources: one person

Output: 3-5 page waste flow scoping report

The Waste Flow Scoping Assessment includes community-level data on waste collection and management, in an effort to identify a city's waste management processes and capacities. The scoping assessment, at the minimum, includes a desk study for relevant reports or data sets on MSWM data in the city and/or region, as well as interviews with MSWM authorities. Defined leakage from the system can be based on these existing reports and the assumptions made within these reports. The scoping assessment focuses primarily on the physical components of the MSWM system, but also includes some high level governance aspects as well. At the very least, the scoping assessment should answer the following questions:

  1. Solid Waste Collection and Management
    • How is solid waste collected, processed and managed?
    • What is the composition of the waste stream? (quantification and characterization)
    • How much and what types of plastic are in the waste stream? (quantification and characterization)
    • How and where does storm water drain into other waterways?
    • Plastic leakage assumptions?
  1. Waste Policies
    • What waste policies are in force and/or pending (bans, taxes, refund deposit schemes, extended producer responsibility)?

This option is based on methods developed for the Circularity Assessment Protocol at the University of Georgia and the Sea to Source Methods Toolkit. For all related research questions from this guidance, see Appendix 1.

The scoping assessment will enable the city to obtain core metrics on the functioning of the MSWM system, which should be assessed on an annual basis to observe changes over time. These metrics should be reported to the PSC team as part of the city’s PSC commitment.


Waste Flow Scoping Assessment Outputs and Reporting

Reporting Metrics

Data Source




1.    % people with access to collection services

−      collection frequency

−      separated collection?


2.    % plastics recycled

3.    # items banned or replaced

4.    % landfill properly managed

5.    Estimated plastic leakage



City authorities, waste management agencies, NGOs, Intergovernmental organizations, research institutions



Desk search + interview with MSW staff


WWF/Consultants to assist if resources are available



1 x per year


Cities report this as part of their PSC commitment




Option 2 – Medium Resolution

Expected time commitment: 2-3 weeks

Team resources: 20-30 people dedicated full-time + 2-3 trained experts

Output: 40+ page waste flow scoping report

For cities that have allocated budgets and technical support, either in-house or via third-party consultants, a detailed Waste Flow Scoping Assessment can provide a thorough understanding of the physical components and dynamic workings of the existing MSWM system. In such instances, cities are encouraged to use the Waste Wise Cities Tool (WaCT), developed by our partners at UN-Habitat. Keep in mind however that the WaCT characterization should be conducted across two different seasons - as described in the methodology - to assess for seasonality changes; the WaCT also recommends using the Waste Flow Diagram to assess plastic leakage, as is introduced in Option 3, below.

Waste Wise Cities Tool (WaCT)
The WaCT is the step-by-step guide to the SDG indicator 11.6.1 on municipal solid waste, for which UN-Habitat is the custodian agency. Specifically, this indicator measures the “proportion of municipal solid waste (MSW) collected and managed in controlled facilities out of total MSW generated by cities”. Two sub-indicators are set underneath: 11.6.1a proportion of MSW collected out of total MSW generated, by cities, and 11.6.1b proportion of MSW managed in controlled facilities out of total MSW generated, by cities.
Download the user guide at:


Option 3 – High Resolution

Expected time commitment: 5-6 weeks

Team resources: 20-30 people dedicated full-time + 2-3 trained experts

Output: 60+ page waste flow scoping report

For a deeper understanding of the leakage points within the MSW system as well as key pressure points in the physical and governance systems, we recommend Option 2 (WaCT) + the Waste Flow Diagram (WFD) and the Wasteaware Benchmark Indicators (WABI’s). This high resolution methodology is the adopted methodology for the Plastic Smart Cities pilot cities.

Waste Flow Diagram
The WFD tool consists of a rapid and observation-based assessment to measure and visualize plastic leakage from MSW management systems into the environment. The tool also determines the fates where this amount of plastic leakage will end up, namely, water bodies, storm drains, land or burnt. The tool is harmonized with the WaCT (SDG 11.6.1 methodology), in that it has been incorporated as part of the 7th step of the methodology. The WFD tool directly inputs data obtained through the WaCT and combines it with additional data points obtained through the WFD tool. 
Download toolkits and user guides at:


Wasteaware Benchmark Indicators
The Wasteaware Benchmark set of Indicators (WABI’s) consists of an indicator set for integrated sustainable waste management (ISWM) in cities both North and South, to allow benchmarking of a city’s performance, comparing cities and monitoring developments over time. It complements the previous two methodologies because it provides a structured way of how to look at and assess “governance aspects” of a MSWM system (e.g. operator models, financial flows, legislation, etc.).
The WABI’s provide a systematic and structured way of looking at these elements.  The set builds on pioneering work for UN-Habitat’s Solid Waste Management in The World’s Cities.
Download the user guide at:


Completing the three methodologies in a city will provide detailed data that can be used to prioritize ‘next steps’ in developing the city’s municipal solid waste management system, identifying local strengths that can be built on and weak points to be addressed. It represents the first building blocks before defining a tailor-made City Action Plan and a Monitoring and Evaluation strategy.

For comprehensive guidance on the high resolution methodology, please contact your regional Plastic Smart Cities lead.


2. Litter Baseline Assessment


  • Provide the framework and methodology to measure trends in litter in/near pilot areas over time.
  • Gain knowledge on quantities, composition and sources of litter entering the environment to enable a targeted approach
  • Key intervention/improvement areas can be identified and later addressed in the City Action Plan
  • Harmonized litter monitoring across cities
  • Use data to drive change by government, business, public/households/individuals

The Litter Baseline Assessment will include community-level data on plastic leakage into the environment that will be obtained through litter data collection in the field.

Litter Data

  • What types of litter are found on the ground / types of plastic? (characterization)
  • What is the litter density (litter item count/area) in sample locations? (quantification)
  • How much plastic is flowing through the storm water system? (quantification)

Litter Baseline Assessment Outputs and Reporting

Reporting Metrics

Data Source




Quantities, composition, sources and trends in amounts of litter 

Trends in SUP items in pilot areas



WWF, Citizen Science, Implementing Partners



Surveys on selected reference sites/litter transects near pilot areas



2 x per year at minimum (consider seasonality differences, particularly for tourist destinations)



There are 3 widely adopted monitoring methodologies: OSPAR (Europe), NOAA (USA) and CSIRO (Australia). All methodologies are quite similar, and all can serve your monitoring methodology as reference resources, keeping in mind however that the methodology most frequently used in your region may lend some additional advantages and regional considerations. We recommend using survey field forms from these well-established methodologies. The first survey carried out will serve as the reference for future monitoring. All subsequent monitoring results will be evaluated against the first survey.

For the selection of survey locations, we recommend the Sea to Source Methods Toolkit for land-based systems, as described on pages 10-16 of that toolkit. This toolkit was developed by an interdisciplinary group of scientists and engineers co-led by National Geographic Fellows Jenna Jambeck and Heather Koldewey. The toolkit provides researchers with a common framework and methodology that can be deployed rapidly, with small teams, and provide useful scientific data. The methods provide outputs and results that are either complementary or comparable to current methods in use by other global programs to assess plastic pollution and adhere to accepted scientific sampling methods and standards in peer-reviewed literature.

We recommend a six-step process to planning, implementing and reporting your Baseline Litter Assessment:

1. Define criteria for site selection and select sites:

    • 100 meters x 1 meter transects as referenced in the 3 options below;
    • 1 square kilometer sites across a city/community; or
    • use stratified random sampling to select sites within a 10-kilometer x 10-kilometer area of the city, with population density considerations
2. Organize surveyors – staff, volunteers, trainers
    • Organize teams of 2 people per site
3. Set-up data collection and management tool
    • Leverage Debris Tracker, Litterati, Ellipsis or other tool to ensure consistent data collection and reporting of outcomes; though we recommend the free and open-source Debris Tracker, which aligns with the Sea to Source methodology
4. Plan survey schedule
    • at least 2 x per year, but could be as frequently as 1 x per month if resources are available
5. Conduct first survey
    • collect data at designated sites, upload to database
6. Write Baseline Litter Assessment report using initial survey data
    • Report data and analyze trends

Depending on a city’s available resources and time schedule, the litter assessment can be a low resolution and highly concentrated assessment on limited but carefully selected sites and litter categories, or it can be scaled up to capture higher resolution data by adding sites and more detailed litter categories. The three options below can be adapted to fit the local context, with resources and capacity considerations. These low-medium-high resolution options are based on common practices and methodologies that are deployed in the field, by Litterati, Debris Tracker, the Circularity Assessment Protocol and the Sea to Source Methods, among others.


Option 1 – Low Resolution

Expected time commitment: 2 hours training + 1 hours per site (for low-quantity litter areas less than 100 pieces per 100-meter transect)

Team resources: 10 people + 1-2 trained experts

Survey sites: 10 sites (3 segments per site), equal to 3 km of linear research

Litter Classification: 1-6 litter categories

Output: 3-5 page litter baseline report


Option 2 – Medium Resolution

Expected time commitment: 2 hours training + 1 hours per site (for low-quantity litter areas less than 100 pieces per 100-meter transect)

Team resources: 10-15 people + 1-2 trained experts

Survey sites: 30 sites (3 segments per site), equal to 9 km of linear research

Litter Classification: 1-60 litter categories

Output: 5-7 page litter baseline report


Option 3 – High Resolution

Expected time commitment: 2 hours training + 1 hours per site (for low-quantity litter areas less than 100 pieces per 100-meter transect)

Team resources: 15-20 people + 1-2 trained experts

Survey sites: 60 sites (3 segments per site), equal to 18 km of linear research

Litter Classification: 1-90+ litter categories

Output: 7-10 page litter baseline report




Waste Flow Scoping Assessment - Research Questions[2]


Waste and Recycling Collection

  1. Who collects waste? Who collects recycling? Is there informal sector involvement? (If so, describe system)
  1. How is waste collected? Door to door, by community dumpster, etc.?
  2. How often is waste collected?
  3. What percentage of the community has access to waste collection?
  4. How is waste collection paid for in the community? Is there a cost to households? How much does it cost?
  5. Are there any specific obstacles to reaching 100 percent collection?


Waste Generation, Characterization, and Management

  1. How much waste is generated per capita? Total generation rate for city/community?
  2. How much does each type of waste material contribute to the overall output? What percentage of overall waste is organic, paper, plastic, metal, or other materials?
  3. What is the biggest source of waste in the community? How much is generated by industry, tourism, households, and by other means? Consider seasonality changes in population, particularly in tourist destinations.
  4. How and where is the city/community waste managed? How much of it ends up in a landfill or recycling? Tabulate by percentage if possible. Is there an informal sector involvement? If so, describe the system and how it operates.
  5. How many facilities does the city/community use or operate to manage its waste? What types of facilities does each community use?
  6. Are there any other waste management practices that I might not have observed?



  1. Does the community have any bans on plastic, or regulations or policies addressing plastic? Examples: bag bans, taxes on certain products, or bottle deposit schemes.
  2. How is this policy enforced?



  1. Does street sweeping or gutter cleaning occur in the community? If so, how often?
  2. Are there any other litter cleaning practices or policies in place, such as skimmer boats, grate collection devices, or other methods?
  1. Is litter abundant in adjacent ecosystems (beaches, rivers, mangroves, seagrass, etc.), and are community cleanups arranged by local groups?




[1] Circularity Assessment Protocol (CAP) is a hub and spoke model that provides a snapshot of a city’s circularity that can provide data for local, regional, or national decision‐making to reduce leakage of waste (e.g., single‐use plastic) into the environment and increase circular materials management;

 [2] Research questions derive from the Sea to Source Methods Toolkit