The third model presented during the conference is complementary to the other two. It is derived from the experience of another Bengali NGO, WasteConcern, which has succeeded in reframing the problem of the vast amount of waste generated by cities such as Dhaka and turning it into a business opportunity.

Dhaka's more than 11 million inhabitants found themselves living alongside mountains of waste, which the city government had neither the labour resources nor the money to cope with. Open tips and soil pollution were causing serious health and environmental problems, which were steadily spreading.

WasteConcern devised an organic waste collection mechanism that allowed it to produce compost, which could then be processed and sold. To do that, it created a door-to-door collection service, set up composting plants in the city, and offered training and technical assistance to the community to enable them to run the plants. At the same time, it sought out a partner, MAP Agro, that was willing to buy the compost produced by the local communities, turn it into fertilizer, and distribute it to rural areas.

Besides significantly reducing methane emissions and the problems associated with waste accumulation in the city, the project has generated 16,000 new jobs, brought about a 30% reduction in the amount of chemical fertilizer used, and achieved major savings for the city government. What’s more, the project’s promoters now plan to exploit their ability to reduce methane emissions to obtain financing from developed countries, which must pay to meet the targets set by the Kyoto protocol.

As Mair and Seelos put it, "WasteConcern’s complementary model is tied to a profit loop in which everybody is a winner: the public sector, the private sector, the local community, and the NGO itself".