Note from Editor: This guest perspective explores opportunities to leverage behavior change and human-centered design as a tool to accelerate culturally-appropriate solutions for sewage pollution challenges.

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The world relies on water. Across every human community and ecosystem, it is one of our most critical resources. Unfortunately, it is also one of our most endangered. Extensive and pervasive pollution throughout our ocean and freshwater systems imperils the global ecosystems and our lives. Sewage is among the most widespread sources of this water pollution challenge. Solving it requires that we seize an untapped opportunity to leverage the power of behavioral science as we design effective interventions. By directing our attention towards these solutions, rather than drawing continued attention to the problem, we will improve our ability to reduce some of the most significant drivers of water pollution.

Globally, an estimated 80 percent of wastewater is discharged into the environment without adequate treatment.1 The United Nations estimates that 2 million tons of sewage are disposed into bodies of water every day.2 And with less than 20 percent of the world’s watersheds exhibiting water quality even close to ideal, the environmental impacts from the excessive nutrients, solid waste, chemicals and microplastics are significant.3

This environmental degradation comes at both a financial and human cost. A 2019 study by Forrest et. al. estimated that annual damages from plastic production and waste alone in the ocean total USD 2.2 trillion.4 Humans encountering these polluted waters experience a host of impacts ranging from respiratory and digestive to immunologic and neurologic. Further, sewage pollution compounds the health disparities and inequities that already face underserved communities, including people of color and those that are less economically or politically advantaged. The sewage pollution crisis is an urgent and multi-dimensional problem that requires similarly dynamic solutions.

Yet, while “floating plastic islands” have grabbed international news headlines and the conservation and health communities continue to document a litany of dangers, much less time has been spent on solutions . This is true across the field of conservation science. A recently released study in the journal Conservation Biology noted that among a representative sample of nearly 1,000 articles from studies published in 20 conservation journals over the past 20 years, nearly half of the studies merely described the problem.5 Seventy percent of the studies did not even propose a solution. As the authors note, “there simply is not the luxury of time to edge incrementally towards solutions.”

Identifying solutions that include behavioral insights

At the Center for Behavior & the Environment, we show why and how environmental leaders can leverage behavioral insights and design thinking to solve the world’s most pressing challenges. Tackling the sewage pollution crisis requires that our toolkit is multi-disciplinary and includes culturally-appropriate human-centered design and behavioral strategies. Today , when water pollution solutions are proposed, they often rely heavily on regulatory policy (e.g., waste management laws), infrastructure or technology (e.g., treatment facilities), or material incentives (e.g., plastic bag charges, free reusable tote bags). The burgeoning field of behavioral science indicates that while these are important levers for change, they alone are not enough to achieve durable change. Financial incentives can backfire or send the wrong message.6 Policy requires implementation and enforcement. And bringing the proper infrastructure to scale can be both a costly and time-consuming process.

On-the-ground programs reinforce this perspective. Research indicates that providing toilets to people is not enough to end open defecation; cultural norm shifts are also core to a successful solution.7 Further, research on plastic reduction at coffee shops in Australia found that financial discounts were less effective than social influences in motivating people to bring reusable coffee mugs.8

Changing people’s behavior (what they do or do not do) is critical in tackling the sewage pollution challenge. Behavioral solutions can target key actors across all levels of the pollution and waste streams. Farmers, corporate actors, government officials, households and other stakeholders engage in behaviors that lead to sewage pollution. For example, actors and behaviors related to sewage and nutrient pollution include:

  • Consumers using a proper toilet facility
  • Homeowners transitioning from a pit latrine to other secured waste collection systems, such as septic tanks
  • Sewage collectors transporting waste to a treatment facility, as opposed to dumping it in open fields or waterways
  • Pig farmers adding bio-bedding in livestock stalls (see an example from A Growing Culture)

There is tremendous opportunity for program designers to leverage a behavior-centered process to create change among these audiences. This means accounting for emotions, social influences, and the context and timing of decision-making in the program design.Even when creating policy, providing information, or developing material incentives for change, leaders must ensure that these additional behavioral levers are working in their favor. Research indicates that laws that stray too far from social norms will not be effective.9

Some organizations have already caught on. In Australia, Project Cane Changer is leveraging the power of identity to engage sugarcane farmers in reducing their fertilizer usage, minimizing run-off and  protecting the Great Barrier Reef. As a result, the adoption of its best management practices increased 480 percent and spanned an area equal to 49,000 football fields. In Kenya, Sanergy designed its sanitation solutions around targeted behavior changes and its user audience’s needs, such as safety, convenience, comfort, and cost. Sanergy’s network now supports 150,000 residents, and the per person daily cost of its solution is four times less than what it costs the government to provide sanitation.

It is time to adopt behavior-centered design to help us implement and scale sewage pollution solutions worldwide. This requires a few specific next steps:

  • Expand our toolkit to include behavioral insights. We need to wield emotional appeals, social influences and choice architecture and design as expertly as we use rules and regulations, material incentives, and information sharing.
  • Find what’s working around the world and learn. People are already successfully applying behavioral insights to water pollution challenges, including solutions to sewage pollution. There is no need to reinvent the wheel.
  • Promote and accelerate the most promising approaches. We must invest in spreading solutions widely and document them in such a way that each new leader looking to reduce water pollution does not need to start from scratch.

Together, these steps will help us protect and guarantee one of our most precious resources for the planet, ourselves, and generations to come.


  1. UNESCO World Water Assessment Programme. (2017). “The United Nations world water development report 2017: wastewater: the untapped resource; facts and figures.” Retrieved from
  2. UNESCO World Water Assessment Program. (2003). “Water for people, water for life: the United Nations world water development report; a joint report by the twenty-three UN agencies concerned with freshwater.” Retrieved from
  3. UNESCO World Water Assessment Programme. (2009). “Water in a changing world: the United Nations world water development report 3.” Retrieved from
  4. Forrest, A., Giacovazzi, L., Dunlop, S., Reisser, J., Tickler, D., Jamieson, A. and Meeuwig, J. (2019). “Eliminating Plastic Pollution: How a Voluntary Contribution From Industry Will Drive the Circular Plastics Economy.” Frontiers in Marine Science. Retrieved from
  5. Williams, D., Balmford, A. and Wilcove, D. (2020). “The past and future role of conservation science in saving biodiversity.” Society for Conservation Biology: Conservation Letters. Retrieved from
  6. Kamenica, E. (2012). “Behavioral Economics and Psychology of Incentives.” Annual Review of Economics. 4:1, 427-452. Retrieved from
  7. Gupta, A., Khalid, N., Desphande, D., Hathi, P., Kapur, A., Srivastav, N., Vyas, S., Spears, D., and Coffey, D. (2019). “Changes in Open Defecation in Rural North India: 2014-2018.” IZA Discussion Paper No. 12065. Retrieved from
  8. Crocker, R., Potts, A., Sandhu, S., Lodhia, S., and Orlitzky, M. (2019). “Coffee on The Run: Cultural and Institutional Factors in Waste Behaviors.” Academy of Management Proceedings. 2019. 14805. Retrieved from
  9. Bicchieri, C., & Mercier, H. (2014). “Norms and Beliefs: How Change Occurs.” Iyyun: The Jerusalem Philosophical Quarterly. עיון: רבעון פילוסופי, 63, 60-82. Retrieved from

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