Actor Matt Damon is on a mission to improve access to one of the world's most precious resources: water.
"It's really hard for people like us to relate to it, because it's just never been something we had to think about," Damon told "This Week" anchor Christiane Amanpour. "Clean water is only as far away as the nearest tap, and there are taps everywhere. There's a faucet everywhere. But the reality is, the water in our toilets is cleaner than the water that most people are drinking."
While water covers 70 percent of the earth's surface, less than 3 percent is drinkable. Beyond the challenges of drought and overuse in some parts of the world, lack of access to clean water has a wide impact.
The figures are staggering: Nearly a billion people -- one in eight people worldwide -- lack access to safe, clean drinking water, mostly in large portions of Africa and South Asia, and about 2.5 billion are without proper sanitation. More than 3 million people die every year from water-related disease, with a child dying every 20 seconds due to lack of clean water and sanitation.
It's these kinds of startling statistics that moved Damon to team up with environmentalist Gary White in 2009 to start water.org, a non-profit organization "committed to providing safe drinking water and sanitation to people in developing countries."
Damon said he was inspired to take action to improve access to clean water after meeting a 14-year-old girl in Zambia going out to collect water for her family from a local well.
"It just hit me that had someone not had the foresight to sink a bore well a mile from where she lived, she wouldn't be in school, because her entire life would revolve around scavenging for water," Damon said. "And she wouldn't have any hope, she wouldn't have any dreams. She'd be stuck in this kind of death spiral of poverty."
The depth of the crisis has long been a focus of White, Damon's partner and water.org co-founder. Lack of access to clean water affects different populations -- "whether you're in the rural areas and walking hours or whether you're in the urban slums, forced to pay seven to 15 times more per liter of water to the water mafia because you can't afford to get a house connection," White said.
After meeting an impoverished woman in India who spent hours each day collecting water, White came up with the novel idea of WaterCredit, a microfinance loan system, to help those in poor areas afford to get access to a regular clean water source.
"She was paying a loan shark 125 percent interest so she could get enough money to build a toilet," White said. "So, we thought, why can't we bring more affordable credit to people like her so that they can solve this on their own?"
PepsiCo Foundation, the philanthropic arm of PepsiCo, recently gave an $8 million grant to water.org to expand access to micro loans for water projects in India.
"There are these market-based solutions that will really help lift people out," Damon said, noting that 97 percent of the loans are paid back. "It's the old adage of ... give a man a fish, he eats for a day, and teach a man to fish, and he eats for a lifetime."
Regular access to clean water also has a dramatic economic impact, according to White, allowing individuals to find other employment with the time they used to spend collecting water.
"They're spending hours each day trying to get their water," White said. "Once they get that water connection, they have water security. ... So it really means that people have this new-found time that they can then turn to their economic benefit and then repay their loan."
"It not only gives them water, it gives them more dignity," he said. "It gives them that ownership of their own lives and making their own way."
Access to water also allows young girls like the one Damon met in Zambia to improve their economic prospects through education.
"Everything changes. Suddenly the girls who are collecting water all day suddenly are in school," Damon said. "It's a huge, huge, huge issue for girls and women."
Damon and White said they hope to attract more donors by showing that they are making smart investments, with Damon leveraging his celebrity to reach people who would not know about the water issue.
"I think that there's an emotional element to this, of course, in terms of the suffering with it," White said. "But people also want to know that the dollar that they're investing is going further."
"If you can prove that there's a solution that works, people are into that. And people want to help with that," Damon added.
"You See How Life Changes"
Damon's philanthropic work was influenced by his mother, who when he was a teenager took him on trips to Guatemala, where he saw extreme poverty in person.
"A few years ago, I started to think, I want to go back and learn more about this," Damon said. "My sphere of influence has increased. I know there's something that I can be doing to help with some of these things."
Damon now regularly travels overseas to see the impact of water.org's projects in places like Africa and India.
"Those trips ... they're very powerful, because you see what happens when people suddenly have clean water. You see how life changes," he said. "It's a very powerful, emotional journey to go on, and so we try to do those trips as much as we can just ... to check up on all of our projects.
"It's the other side to these trips, you see some really hard things," he said. "But to see the life-changing joy is really, really quite something."
Damon said he hopes to pass on his passion for philanthropy to his four daughters.
"They all will start coming with me to these places because, like the gift that my mother gave me, I think it's a really wonderful thing to share with your children," Damon said. "And to give them some context about the world they're living with, understand just how lucky they are."
And while he maintains an active acting career, Damon said his work on access to clean water provides a unique satisfaction.
"When you see the difference that water can make in a community, that feeling of pure joy, there's nothing really that can compete with that in my day job," Damon said.