A line of purple, plastic cups grows longer on the counter at Avid Coffee as Sam Gearhard takes orders at the Petaluma, California, store on a recent weekday morning. The cups might seem unassuming, but they’re part of a groundbreaking new scheme that has the community buzzing. Instead of the single-use paper or plastic cups that Gearhard would usually line up for the barista slinging espresso, he’s passing over shiny new reusable cups that bear the slogan “Sip, Return, Repeat”. Customers who need their lattes to go can take the purple cups with them, then return them to one of 60 bins scattered across downtown Petaluma when they’ve finished. Each cup comes with a trackable QR code to help monitor results. So far, Gearhard says, 30 businesses have opted into the program in downtown Petaluma, a charming wine country city about 50 miles (80km) north of San Francisco. And at Avid, they’ve handed out only reusables since the project started – except to the occasional out-of-towner who asks for a paper cup to take on the road. “It’s been a really nice and easy adjustment for us,” said Gearhard. “I was worried that people wouldn’t take to it as well as they have.” Holding a cup of coffee as we talk, I’m impressed that the espresso doesn’t burn my hand through the plastic wall. And while their purple hue is very purple, I appreciate that cups are immaculate – clearly more professionally sanitized than similar cups I’ve encountered in food courts and cafeterias. The shops aren’t having to clean the cups themselves – they’re washed by an outside logistics company – meaning there’s one less thing for businesses to factor in as they make the switch. This month, Petaluma became the first in the US to introduce a city-wide reusable cup program, aimed at reducing the 50bn single-use cups that are bought and thrown away in the US each year. Thirty businesses, ranging from mom and pop shops like Avid to chains like Starbucks and Taco Bell, have agreed to distribute the reusable cups as part of a pilot project. The initiative comes as California leads the US in the fight to phase out single-use plastics. The states passed a law in 2022 that will require all packaging to be recyclable or compostable by 2032. Last year, Los Angeles county implemented a ban on single-use plastics in restaurants, and earlier this year, the city of Berkeley rolled out the country’s most comprehensive law on food packaging. “We have a really high interest in climate mitigation because we’ve experienced our own climate challenges,” said Leslie Lukacs, executive director of Zero Waste Sonoma, a local environmental agency, referencing recent wildfires and flooding in the region. It’s “an environment that’s politically driven to address climate change, as well as community driven”. The Petaluma Reusable Cup Project officially began on 1 August, when local businesses began handing out reusable cups; chains followed on 5 August. So far, restaurants and their customers appear to be adapting well to the change – and are proud of it. Outside Stellina Pronto, one of the participating cafes, mother and daughter Bonnie and Claire McDonell – who were meeting for lunch halfway between their homes in Sebastopol and San Francisco – noted that they might specifically choose a restaurant in the future based on whether it offered the reusable option. Down the block, at Fiber Circle Studio, the store owner, Alisha Bright, said she had already used four cups in the first week of the program – one was on her front desk – and praised the quality of the cups for keeping beverages cold longer than typical single-use plastic cups. She’d had a lemonade from The Bagel Mill earlier in the week and noticed the ice was still solid in the cup an hour after purchasing it – though she also noted that she had collected a few cups at home that she needed to return. A host of corporations, investment firms and startups came together to design, organize and fund the project, including Closed Loop Partners, a New York investment firm focused on the circular economy; Starbucks; Coca-Cola; PepsiCo; Peet’s Coffee and Yum! Brands. Together, they have partnered with the city of Petaluma, Zero Waste Sonoma and local recycling program Recology to study whether the program is viable and could be scaled up in other cities. One of the most important metrics that they are watching is how many cups actually get returned. Reusables almost always have a heavier environmental impact to produce and clean, so the number of times they are reused is key to determining whether they are better for the environment than disposables, says Jessica Heiges, a project director in zero waste and circularity at WSP, an environmental consulting firm. Heiges isn’t affiliated with the project, but she was involved with Vessel, a reusables program tested in the city of Berkeley before the pandemic, while working on her PhD. She’s hopeful about the future of the Petaluma project because it makes “the reusable option as convenient as the disposable option”. Every reusable cup in the project has been equipped with a QR code, so Closed Loop can collect data on which return bins are used most often, if cups end up in the trash or recycling instead, and whether allowing residents to schedule pick-ups from their own homes would be helpful. Kate Daly, managing director and head of the Center for the Circular Economy at Closed Loop Partners, said in an email that the firm will also collect data on how far the cups travel, and how much water and energy they require to wash. Choosing a plastic reusable cup was another part of that calculus. “While metal, glass and ceramics are ideal materials for personal and for-here reusable mugs, it still makes more sense to use plastic for to-go cups,” said Daly, since they’re lighter, easier to transport and are less likely to break. While local enthusiasm is high, experts point out the scheme is likely to face hurdles. “The focus on a fairly small downtown helps, but there’s still going to be a lot of transportation, picking up cups and washing,” Alastair Iles, a professor of sustainability transitions at UC Berkeley, said in an email. He added that it will require closely monitoring return bins (so they don’t overfill), consumer behavior (and whether customers are willing to return cups) and business needs. “The social norm of using disposable cups is very deeply engrained in our contemporary life.” In Petaluma, the reusable cup project is slated to run through November. What comes next depends on how it goes – and how it might be implemented and funded by future cities or businesses. In the first week alone, Petaluma’s already learned a ton, said Ashley Harris, owner of Petaluma Coffee and Tea, which is participating in the project. “As a coffee shop, we see a crazy amount of waste. It’s painful and it’s heartbreaking and it’s also part of our business. So if there’s any way that we could be better, we’re going to do it.”