More than 30 restaurants partnered with NextGen Consortium and will give customers reusable to-go cups, which they will then return to provided bins—where they’ll be picked up, sanitized and delivered back to restaurants. The cups are purple with a “Sip, Return, Repeat” reminder printed on them.

More than 60 return bins will be installed across the city for convenient return of the cups, including at Circle K and fueling stations in the city, and advertisements will be placed on billboards, bus stops and other public locations across Petaluma to raise awareness, said a spokesperson from Starbucks.

The coffee retailer has the most store locations participating in the program at eight stores, with six company-operated stores and two licensed stores located in Target and Safeway. The company has dedicated half of its cup's design to the purple "Sip, Return, Repeat" reminder, and Starbucks partners will wear purple aprons.

The groups leading the pilot believe that by making the program ubiquitous through the city, and not just dependent on a single retailer or the need for consumers to come back to the store to recycle a cup, it will remove barriers to making the program successful.

“It’s the first initiative that we’re aware of that will make reusable to-go cups the default option over single-use across multiple restaurants throughout a U.S. city,” Kate Daly, managing director of the Center for the Circular Economy at Closed Loop Partners, one of the groups behind the new pilot, told Fast Company.

“We’ve seen in market testing that customers really want to have a more consistent experience across multiple retailers,” said Daly. “Interoperability is really critical. People are on the go—they shop at one place, they’re disposing of items at other places. Reuse needs to be seen as easy and convenient and not that you have to pay attention to ‘this belongs here and not there.’”

“Last year, Starbucks conducted a similar test in the same area, but we tested on our own,” said Helen Kao, director of reusables at Starbucks. “This year, we expanded on that through our partnership with NextGen Consortium to drive systems change. What if we saturated a community, and reusables became the cultural norm? Now it’s an ecosystem of global brands, local businesses, city leaders and community groups working together. The industry is realizing that it’s easier to partner than do things alone.”

The test will measure consumer engagement when reusable cups are the default option and provide insights on how this model could work on a larger scale to reduce the number of single-use cups. NextGen Consortium estimates that across the United States, more than 50 billion single-use cups are thrown away each year.

In January, Starbucks implemented a program where customers can use their clean, personal cup when ordering in cafe, in the drive-thru or when using the app at all company-operated and participating licensed Starbucks stores across the United States and Canada.