case study:

Department of Environmental Protection

Mindful waste disposal


Some of the biggest challenges the Department of Environmental Protection (DEP) face in their sewers and wastewater treatment plants (WWTPs) are caused by the behaviors of people who live and work in New York City. In 2017, 70% of sewer backups were traced to the build-up of fats, oils, and grease (FOG) that were poured down toilets and drains. Between 2007 and 2017, the total number of items caught in the screens at the WWTPs more than doubled. These items include flushable wipes, paper towels, and other household items. This build-up causes extensive damage, impedes critical operations, and costs the City hundreds of millions of dollars each year to address.

The Department of Environmental Protection enlisted Zebra Strategies to test a new campaign encouraging New Yorkers to change their behaviors and think about what they pour down the sink or flush down their toilets. To gain insight into the flushing habits of New Yorkers, Zebra Strategies conducted focus groups targeting English- and Spanish-speaking New Yorkers who identified as users of disposable wipes.

Our Findings

Discussions revealed that participants held a predominantly self-concerned point of view that lacked insight into the larger effects of their individual actions. Those who flush wipes and cooking oil hadn’t given thought to what happens after the materials leave their homes’ pipes. Participants didn’t consider what issues flushing wipes could cause beyond those concerning their own homes’ plumbing. While many participants knew that even “flushable wipes” shouldn’t be flushed, there was a limited understanding of how it affects NYC’s sewer system.

We tested four campaign concepts to see which one best communicates the desired “trash, don’t flush” message. The winning campaign, “Keep Running Smoothly”, hit just the right tone: serious but not authoritarian.

It was “informative”, “educational”, and “very clear”. Participants felt that depictions of the pipes beneath the toilets clarified why flushing inappropriate things is a problem. It helped them to understand the consequences of these items getting into the sewer system, and gave them “the whole picture.”

Participants were alarmed by the statistics and felt that if people were better informed, they would stop flushing inappropriate materials down the drain. We found that these New Yorkers want to learn not just why what they’re doing is bad, but what they should be doing instead. Presenting alternatives to this kind of behavior is essential to curbing it.


Zebra’s careful research uncovered that the key to an effective campaign is to shift the framing of the issue so that viewers feel an increased responsibility towards their neighbors and the environment. We found that showing the widespread effects of individual actions is the best way to spur viewers into changing their flushing habits. The chosen campaign succeeds by bridging the cognition gap and acting as a “wake up call”.

Ready to work together?