BAKU, Azerbaijan (AP) — In the sprawling pavilion section of the United Nations climate talks, where countries, nonprofits and tech companies use big, flashy signs to get the attention of the thousands of people walking through, small aqua and purple beverage cans sit conspicuously on a counter at the Singapore display.

Those who approach learn that the cans are beer — a brand call NEWBrew — and free for anybody who asks. But there is something not everybody who cracks one open finds out right away, if at all: the beer is made with treated wastewater.

“I didn’t know. I was really surprised,” said Ignace Urchil Lokouako Mbouamboua, an international relations student from Congo, who recently sipped one while taking a break from the conference.

“I can even suggest that they make more and more of this kind of beer,” added Mbouamboua with a smile, sharing it was his third day in a row he stopped for a can.

NEWBrew is made in Singapore with NEWater, the name of treated wastewater that's part of a national campaign to conserve every drop in one of the world’s most water-starved places.

The drink, which some attendees jokingly call “sewage beer,” is one of many examples of climate- and environment-related innovations on display during this year's climate talks, COP29, taking place in Azerbaijan. Highlighting the use of treated wastewater underscores one of the world's most pressing problems as climate change accelerates: providing drinking water to a growing population.

For years, Singapore has been a leader in water management and innovations. The city-state island of 6 million people in Southeast Asia, one of the most densely populated countries, has no natural water sources. In addition to water imports from Malaysia, the other pillars of its national strategy are catchment, desalination and recycling. Authorities have said they need to ramp up all water sources, as demand is expected to double by 2065.

While drinking treated wastewater is a novelty for many at the climate conference, for Singaporeans it's nothing new. National campaigns — from water conservation pleas to showing the wastewater recycling process — go back decades. In 2022, then-Prime Minister Goh Chok Tong was famously photographed drinking a bottle of NEWater after a tennis match, done to normalize its use.

Ong Tze-Ch’in, chief executive of the Public Utility Board, Singapore's national water agency, said NEWBrew was developed by a local brewery in 2018. The idea was to showcase treated wastewater at the country's biennial International Water Week. The beer was next produced in 2022, then again this year.