Clean, easy-to-get water is vital for healthy communities. It’s crucial for ecosystems and a must-have for a strong economy. But with the recent water crisis, getting clean drinking water is getting harder. Really hard.

Water.org says 750 million people worldwide don’t have safe water. That’s about one in nine. More than double the US population lives without safe water. This makes the current water crisis the number one global risk by “devastation impact,” and the number eight global risk by “likelihood of happening within 10 years,” according to the World Economic Forum in January 2015.

The World Health Organization predicts that by mid-century, four billion people-almost two-thirds of the world’s current population-will face serious fresh water shortages. With the human population expected to grow another 50 percent by 2050, resource managers are looking for new ways to meet our water needs.

One big way is wastewater management. Stats show that 90 percent of wastewater in the developing world goes right into the environment without any treatment. Wastewater is just any water that people have messed up the quality of. It can come from homes, factories, businesses, farms, surface runoff, stormwater, or even leaky sewers.

We have many ways to clean up wastewater. It depends on what’s in it and how bad it is. We can treat wastewater in treatment plants using physical, chemical, and biological processes. City wastewater goes to sewage treatment plants, which are also wastewater treatment plants. Farm wastewater gets its own treatment, and industrial wastewater uses industrial treatment processes. This cleaned water can then be reused as drinking water, in factories (like for cooling towers), to refill aquifers, for farming, and even to help natural ecosystems recover.

Using recycled water for irrigation offers many benefits. It’s often cheaper than other sources, especially in cities. The supply is consistent, no matter the season, weather, or water restrictions. And the quality is generally steady. Irrigating with recycled wastewater also helps fertilize plants, adding important nutrients. Industrial wastewater treatment plants are necessary when city sewage treatment isn’t available or can’t handle specific industrial wastewater. These industrial plants can cut raw water costs by turning some wastewater into reclaimed water for different uses.

Wastewater management can use centralized systems, which are large systems that collect wastewater from many users for treatment at one or a few spots. Or, we can use decentralized systems. These are usually on-site systems, handling wastewater from individual users or small groups of users in a neighborhood or small community.

Even a company like Coca-Cola is getting smarter about its water use. They’re cutting down how much water they use per liter of product, even as they make more. They’re recycling wastewater, sometimes returning it to nature even cleaner than the law requires. And their system is replenishing, or balancing, the water they use in their finished drinks. They’ve hit about 35 percent so far, with a goal of being “water neutral” by 2020. They’re doing this through projects that, among other things, protect water resources or bring safe drinking water and sanitation to communities they serve.