MakeSpace founder and former CEO Samuel Rosen is ready to launch his next venture, and it has little or nothing to do with the on-demand economy. This time, Rosen is setting his sights on the world of water.

Tap aims to be the world’s first public index and global search engine for drinking water.

Plastic water bottles are, in many ways, the scourge of the planet. More than 90 percent of the environmental impact of plastic water bottles happens during manufacture, and the Guardian reported that more than 1 million plastic water bottles were sold a minute across the globe in 2016.

Some people have switched over to reusable water bottles and canteens, but once they do, there is no way to search for water fountains or sources of drinking water. That’s where Tap comes in.

In its first iteration, Tap is a bit like the Waze for water. Using a combination of user-generated content and data from water fountain manufacturers, Tap aims to be a public search engine for where to find water. As it stands now, Tap has more than 34,000 Refill Stations across 30 countries indexed on the app.

But Tap also has ambitions to offer a backend system for water fountain companies. Normally, these companies sell a number of units to airports or other commercial or government properties. Those customers then install the fountains wherever they see fit, and the water fountain company is more or less uninvolved.

However, those companies then need to maintain the fountains, installing new filters and repairing broken parts, etc. But one fountain may be far more trafficked than another, and thus need higher frequency maintenance.

Tap wants to offer an SDK to these companies so that when users report bad filters or a broken water fountain, that information shows up on their dashboard.

Rosen sees an opportunity to generate revenue in a manner similar to Google, offering an advertising product for companies down the line.