Water.org co-founders Matt Damon and Gary White say conversations with investors about social responsibility are getting easier.

The numbers prove it: Its WaterEquity impact fund — the first-ever impact investment manager with an exclusive focus on ending the global water crisis — has grown to $60 million since it was created in 2017, and the charity has provided more than 16 million people throughout India, Indonesia, Cambodia and the Philippines with access to safe water and sanitation.

One of the major barriers to safe water and sanitation is affordable financing. Water.org addresses the barrier through access to small, easily repayable loans. According to Damon, it has provided 3 million loans that pay back at 99 percent. "Our model is undeniable now," he said Thursday in an interview with CNBC's "Squawk Box" at the World Economic Forum in Davos, Switzerland.

Within three years of its launch in 2009, the organization had already reached its first million people with clean water, said Damon. "We're at 16 million now, so we are hitting a million a quarter now," he said.

Since the organization started, White has seen a real change. "A lot more corporations and brands are talking about working in social impact investing," he said. "Our first visit here, we had the seed of an idea, like, 'Well, we think we can do this social impact fund and help get water to millions of people, and we came back two years later and we had launched it. And now we came back this year and have $60 million of assets under management."