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Sean T. Green, Ph.D.

Data Science Professional
Seattle, WA
stgreen@alumni.princeton.edu
Data Scientist and Environmental Engineer

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Sean T. Green, Ph.D.

  • Areas of expertise
  • Example experience
    • South America - Strengthening informal waste collectors
    • Egypt - Supporting recycler syndicates
    • Ghana - Youth engagement in composting and recycling
    • South Africa - DC microgrid enterprises
    • Ghana - Tax reform
    • Seattle - Optical mark recognition
    • South Asia - Public private partnerships for materials recovery
    • Worldwide - Informal settlement censuses
    • Liberia - Strengthening solid waste management services
    • Seattle - Machine learning for decision support
    • Germany - Supporting grassroots climate change mitigation and adaptation efforts
    • Africa - Waste audits in five cities
  • Bio
  • Blog

South America - Strengthening informal waste collectors

The problem – In South America, as well as in many other parts of the world, informal waste collectors (also called recicladores) serve an essential role in municipal solid waste management: recovery of reusable raw materials from the waste stream. Without the work of informal recyclers, much of the non-biodegradable waste discarded from homes and businesses would end up contributing to the unsustainable and unrelenting congesting of landfills, and to the attendant obligation for manufacturers to deplete natural resources to produce packaging from virgin materials. However; despite the valuable service they provide, informal recyclers in many countries are viewed as nuisances and denied the stability and protection that would come from being officially recognized as business enterprises that are able to formally bid on city waste collection contracts. 

The way forward – By connecting the network of recyclers with resources to improve their governance and logistics the collectives were empowered to improve the perception of their accountability and dependability. The work done on this project was a part of a larger strategic effort to help provide a pathway to formalization for informal groups so they could be included in the market for their services and for the raw materials they collected, and consequently, receive higher wages.

Contribution – Project management of efforts in multiple countries through regular calls, meetings, and site visits; budget review; oversight of efforts to improve operational logistics in order to be able to forecast supply of recovered materials and share the information with buyers; promoting reuse of raw materials by connecting recycler leaders with private-sector manufacturers.

Press for densifying bales of recyclable material

Press for densifying bales of recyclable material

Logistics software

Logistics software

Forklift owned by a collective in Peru

Forklift owned by a collective in Peru

Group -owned recycling center

Group -owned recycling center

Flowers created from soft drink bottles

Flowers created from soft drink bottles

Egypt - Supporting recycler syndicates

The problem – A group of the informal waste collectors in Egypt called the Zabaleen have been providing recycling and composting services for over 50 years, and have much to teach their peers in other countries about pooling resources to smooth volatility in demand, specialization and division of labor, and bargaining to improve their position in the hierarchy of the waste value chain. For years the recycler groups in Egypt enjoyed a tenuous legitimacy, but against a backdrop of discrimination, civil unrest, and finally revolution, the collectives in Egypt suffered a revocation of their hard-earned status and the saw the introduction of complicated bureaucratic barriers to prevent them from reclaiming their position in society as recognized service providers. 

The way forward -  Collectives received grant funding to host training workshops in which they were provided step-by-step instructions on how to receive certification as registered service providers, and therefore, be able to bid on service contracts. Their experience in waste collection, processing, and disposal allowed them to continue working despite the revolution and the civil unrest that followed. They have since been able to regain a level of legitimacy due to their steady, hard work and the recognition of their service from sympathetic members of government. The work done on this project was a part of a larger strategic effort to help provide a pathway to formalization for informal groups so they could be included in the market for their services and for the raw materials they collected, and consequently, receive higher wages.

Contribution -  Light project management through calls and site visits; Learning from their experience and dissemination to other groups; budget review and analysis.

Recycling truck being unloaded

Recycling truck being unloaded

Raw shredded plastic for molding

Raw shredded plastic for molding

Press for molding raw plastic

Press for molding raw plastic

Mural at recycling school indicating preferred materials for collection

Mural at recycling school indicating preferred materials for collection

Ghana - Youth engagement in composting and recycling

The problem –  Waste collection and disposal services in informal settlements, besides providing health benefits by eliminating environmental risk factors, provide a potentially viable source of employment given the presence of a market for the materials they recover.

The way forward - This project had two phases and operated in Accra, Ghana; Pune, India; and in Monrovia, Liberia. An NGO partner on the ground helped young entrepreneurs develop and carry out plans to create small businesses focused on recycling or composting. The project demonstrated the complexity of operating a program in vastly different environments especially when a secondary market for recovered materials is nascent or nonexistent.

Contribution – Project coordination through regular calls and site visits; budget review and analysis; small enterprise business model review; development of project metrics.

Loading bales of thin film plastic bags

Loading bales of thin film plastic bags

Composting facility

Composting facility

Composting trough filled with organic waste

Composting trough filled with organic waste

South Africa - DC microgrid enterprises

The problem –  Energy poverty is rampant problem among the urban poor living in informal settlements, and even when subsidies exist to cover variable costs, the fixed costs of electricity provision are often so large that they prevent the economical extension of trunk infrastructure to poor communities. South Africa has a Free Basic Electricity Subsidy that entitles every household to 50 kilowatt hours per month, but the subsidy lies inoperative in communities that aren’t already connected to the grid.

The way forward – A research institute in South Africa developed a business model for electricity provision to poor communities through outfitting local community entrepreneurs with solar-powered, distributed, DC micro grid systems, which can power individual households. Local operators are trained how to maintain units for customers they recruit as part of their service hubs. The initial funding that was provided them allowed the institute to refine the concept, and they were eventually able to find longer-term, in-country investors.

Contribution – Assistance with editing and technical review during proposal development; budget analysis for the proposal; business model review; development of project metrics.

Shack with solar power unit

Shack with solar power unit

Electricity meter and backup battery

Electricity meter and backup battery

Shack with outfitted solar unit

Shack with outfitted solar unit

DC television

DC television

Ghana - Tax reform

The problem – Many African cities have faced a resource crunch within the past two decades-- decentralization has meant that at the same time that they have greater responsibility to provide municipal services like solid waste management, they are receiving less money to provide them. In many countries privatization of has helped to bridge the service gap, but in the absence of subsidies or incentives, privatized services are quickest to reach wealthy customers, from whom user fees can be adjusted cover the cost of service provision.  Revenues from municipal taxes could help to provide a portion of the operating budget for city departments, but cities often lack up-to-date tax codes. As African economies grow, tax revenues loom larger and larger as a potential source of money for cash-strapped cities.

The way forward – Based on the results of a fact-finding mission with an NGO partner a grant was developed to the Sekondi Takoradi Metropolitan Assembly to create a program to review and reform their tax code and set annual targets for tax revenue generation.

Contribution – Project scoping and selection; proposal editing and review; budget analysis; project management through regular calls and site visits; development of metrics for the project and a plan for transition to local ownership.

White board with options for tax reform project

White board with options for tax reform project

Map of Ghana

Map of Ghana

Meeting at the metropolitan assembly

Meeting at the metropolitan assembly

Seattle - Optical mark recognition

The problem – The choice to use paper forms for collecting data is often a matter of convenience in the wired world, but in remote and energy-poor areas of the world they have long been a necessity. The growing ubiquity of mobile phones, even among the poorest of the poor, has a potential to change the way we store and process data and to make life saving information, such as individual medical records, available everywhere someone has a feature phone. One major obstacle to expanding the use of digital records is the potentially high cost of designing new data collection processes and for the conversion of existing data stored on paper to digital format.

The way forward – Researchers at the University of Washington have developed a software application for mobile phones that has the potential to be able to allow someone to scan, digitize, and store information from a paper form simply by taking a picture using the phone’s camera and processing it using their software. A project was funded to help connect their research to real-world use cases so the application can be developed according to specifications generated in the Global South.

Contribution – Proposal review; metric development; budget analysis.

 

Rig for scanning forms using smart phone camera

Rig for scanning forms using smart phone camera

South Asia - Public private partnerships for materials recovery

The problem – Materials recovery as a business enterprise is based upon the principle that waste is a resource, but how big must an operation be and how much material must it recover in order to be able to cover the costs associated with waste collection and storage, and with worker salaries?  An individual waste collector has the benefit of complete ownership of his business and all of its profits, but has to deal with uncertainty in supply created by competition, a greater potential perception of illegitimacy of his business, lack of collective bargaining power, and limits in the amount of material he can collect in a day. At what size of an operation is the revenue from sale or usage of recovered materials large enough to cover the variable costs of operating the business along with any fixed costs associated with financing the ownership of a facility?

The way forward – A not for profit in Dhaka, Bangladesh developed a model for funding and incubating resource recovery centers in secondary cities in Asia using profits from the sale of receivables and from carbon finance.  Start-up capital was provided to them to create a new organization that could duplicate their model in other cities in Asia and in Africa, and to explore the use of additional sources of revenue such sale of green energy.

Contribution – Project management through meetings, regular calls, and site visits; budget analysis and review; development of metrics for growth and sustainability; business plan review; dissemination of learning.

Organic waste awaiting transfer to composting windrows

Organic waste awaiting transfer to composting windrows

Workers sifting mature compost

Workers sifting mature compost

Mature compost being sifted

Mature compost being sifted

Truck laden with green waste from local market

Truck laden with green waste from local market

Worldwide - Informal settlement censuses

The problem – Concrete data about the conditions in which they live is a powerful tool that residents of informal settlements can use to advocate for service provision in their communities. By detailing the number of people who live within a settlement and the number and locations of amenities such as schools, ATMs, water standpipes, and toilets they can more effectively communicate to municipal authorities the degree to which they are in need.  However, it is important that the data used are unassailable to guard against possible accusations of number manipulation with an eye towards presenting a more compelling case for upgrading.

The way forward – Slum and Shack Dwellers International, a community-based organization comprised of residents of informal settlements in over 30 countries, was paired with researchers at the Santa Fe Institute to capture profile information for thousands of new slums, vet the data collection process, and to create a database to hold settlement profile information that had been collected by the network over many years.

Contribution – Proposal and project plan feedback; development of metrics and scheduling of deliverables; project management through regular calls, meetings, and site visits.

Performing a settlement profile

Performing a settlement profile

Model of revised settlement layout

Model of revised settlement layout

Models of improved settlement unit layouts

Models of improved settlement unit layouts

Sign from rental shack in yard of another settlement residence in Namibia

Sign from rental shack in yard of another settlement residence in Namibia

Liberia - Strengthening solid waste management services

The problem – A clean neighborhood can be a source of civic pride as well as a signal that government is functioning properly. For Monrovia, Liberia, a city in a country that exited two decades of civil war at the beginning of the millennium, municipal solid waste management was also viewed as a source of employment for ex combatants. A side consequence of the disorder and horror of war was a mass exodus skilled individuals from Liberia that left a dearth of experienced administrators and an inability to provide basic city services.

The way forward – A program sponsored by the World Bank provided waste pickup for sections of the city. Funding and consulting expertise were provided to stand up a new section of city government that would be responsible for supplemental waste collection and transferal.

Contribution – Project management; progress review.

Construction in a neighborhood in Monrovia, Liberia

Construction in a neighborhood in Monrovia, Liberia

Downtown Monrovia

Downtown Monrovia

Seattle - Machine learning for decision support

The problem – Data incompleteness and transcription error are possible sources of the inconsistent quality in data that are sometimes collected from resource-poor settings. By collecting large amounts of data and applying predictive algorithms to place uncertainty bounds on the value of the missing or errant data, the effect of perturbations and omissions can be reduced. Machine learning (or data mining) algorithms provide a way to determine patterns in data by separating the signal from the noise so policy makers are able to make inferences from predictive models.

The way forward - Machine learning algorithms were applied to national-level and regional data to predict cause of death and disability, and to determine the determinants of diarrheal illness and their relative importance.

Contribution – Developing algorithms; analyzing data; publishing and presenting findings.

Seattle skyline

Seattle skyline

Paper on machine learning for verbal autopsy

Paper on machine learning for verbal autopsy

Paper using machine learning to predict determinants of national diarrheal disease

Paper using machine learning to predict determinants of national diarrheal disease

Germany - Supporting grassroots climate change mitigation and adaptation efforts

The problem – The Kyoto Protocol created flexible mechanisms for countries to reduce their greenhouse gas emissions in order to account for the increasing cost of interventions emissions the more a country reduces its emission. The treaty allows countries to trade funding emission reductions in their country for reductions in another country provided they are able prove that the foreign reductions would not have otherwise happened without their funding. Lost in the international debate concerning a follow-up treaty to the Kyoto Protocol are the simple actions that are already taking place worldwide by nongovernmental actors at the grassroots level.

The way forward – A program was created to evaluate and recognize exemplary mitigation and adaptation activities in order that they might be emulated and replicated worldwide.

Contribution– Project scoping, proposal review and editing; budget analysis and review; project management through regular calls, meetings, and site visits.

Panel of award recipients at 17th Annual Conference of Parties

Panel of award recipients at 17th Annual Conference of Parties

Africa - Waste audits in five cities

The problem– Lack of solid waste management in cities can be considered a market failure since the costs of disposal of waste and the health burden of an unsanitary environmental are an externality not covered by the price of material packaging. People who live in cities that lack proper resource recovery and waste disposal often have the desire to have clean surroundings, and most are willing to pay to have this service provided, but imperfect information about the value of the materials, and the high cost of planning efficient resource recovery routes can be a significant barrier to setting up recycling businesses. Publicly-available information about the quantity and composition of waste in a city by area can help would-be service providers to plan routes more efficiently.

The way forward –  A study was funded to perform an analysis of the waste quantity and composition by households of different income strata  in five different African cities (Abidjan, Cairo, Harare, Monrovia, and Sekondi-Takoradi).  The resulting report, study methodology, and data were made publicly available.

Contribution – Development of terms of reference and budget for the project; selection of cities and study consultant; procurement of collaborators in each city; project management; report feedback; results dissemination. 

Table showing fraction of each type of material in a waste sample

Table showing fraction of each type of material in a waste sample

Waste collectors at a dump

Waste collectors at a dump

Pie chart showing composition of waste sample in Monrovia

Pie chart showing composition of waste sample in Monrovia

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Back to Example experience
Press for densifying bales of recyclable material
5
South America - Strengthening informal waste collectors
Recycling truck being unloaded
4
Egypt - Supporting recycler syndicates
Loading bales of thin film plastic bags
3
Ghana - Youth engagement in composting and recycling
Shack with solar power unit
4
South Africa - DC microgrid enterprises
White board with options for tax reform project
3
Ghana - Tax reform
Rig for scanning forms using smart phone
1
Seattle - Optical mark recognition
Organic waste awaiting transfer to composting windrows
4
South Asia - Public private partnerships for materials recovery
Performing a settlement profile
4
Worldwide - Informal settlement censuses
Construction in a neighborhood in Monrovia, Liberia
2
Liberia - Strengthening solid waste management services
Seattle skyline
3
Seattle - Machine learning for decision support
Panel of
1
Germany - Supporting grassroots climate change mitigation and adaptation efforts
Table showing fraction of each type of material in a waste sample
3
Africa - Waste audits in five cities