In Baltimore, Maryland, these river cleanup devices have become local celebrities. And we have Mister Trash Wheel, Captain Trash Wheel, Professor Trash Wheel and Gwynnda the Good Wheel of the West here in Baltimore. These four wheels are powered by the sun and the waves, and they're one of an increasing number of systems working to remove trash from waterways. Because while the public has become highly aware of the massive gyres of waste swirling in our oceans, we tend to hear less about how it all ended up there. I wouldn't be surprised if the amount of plastics in all the rivers around the world is much more than all the plastics that is in the oceans. Every year, it's estimated that up to 2.97 million tons of plastic enters the ocean through rivers, much of it originating from areas of the world that lack proper waste management infrastructure. And then when it rains, it washes all of this trash through these water stream, that ultimately ends up in the river, that ends up in the ocean. And waste generation overall is only expected to increase in the years to come. So in 2020, the waste that we generated was about 2.2 billion tons. And we're estimating that by 2050, we'll be generating about 3.9 billion tons. The ultimate solution to the waste problem depends on some combination of better waste infrastructure, more sustainable packaging, less consumption, and public awareness around proper disposal. But in the meantime, there's a host of companies around the world developing systems to capture wayward trash from rivers. We've been averaging about 30 tons a month, picking up trash from the waterways of Baltimore. We currently have four types of interceptor deployed in nine rivers. We have cleaned a couple of rivers and maybe 10,000 tons of plastic stopped from reaching the ocean. Heavy rains and winds often carry trash from the land to the rivers, a particular problem in low-income countries such as those in Sub-Saharan Africa, where the majority of the waste generated is never even collected, especially in rural areas. And even when that waste is collected, it doesn't mean it's being properly disposed of. In those countries, nearly 40% of waste is being collected, but then more than 90% is just being openly dumped or burned. So there's still that disconnect that even when waste is collected, it can still be dumped in more informal dump sites. Waste from these informal dump sites often migrates into rivers, and middle-income countries like the Philippines, India, and Malaysia actually contribute the most to oceanic waste, as people have enough money to buy lots of packaged goods, but waste collection infrastructure still lags behind. So that's why this middle ground is where you see most plastic leakage to the oceans, which tend to be areas in Southeast Asia, Central Africa, and Central America. Of all the plastic that enters the ocean through rivers, nearly 80% is transported through 1,000 hyper-polluting rivers. That's according to a 2021 study funded by the Ocean Cleanup, the Dutch nonprofit founded in 2013 by then, 18-year-old Boyan Slat. That's a lot more rivers than The Ocean Cleanup and other researchers had previously thought, as a 2017 study had indicated that a mere ten rivers were the primary culprits. The types of rivers that we now think contribute most to river plastic export into the ocean are smaller rivers flowing through urbanized areas rather than the typical very large river systems. Van Emmerik helped co-author the 2021 study and says that the other primary finding is that the grand majority of plastic pollution never actually makes it into the ocean at all. So if the goal is to reduce the total amount of plastic in our environment, that makes it even more important to tackle plastic pollution closer to the source, as opposed to pulling it from the ocean after the fact. That's something that Clearwater Mills, The Ocean Cleanup and the India-based company AlphaMERS are all trying to do. Baltimore's googly-eyed trash wheels, the first of which debuted in 2014, are one of the original efforts to address river waste. Built by Clearwater Mills, the company's founder, John Kellett, was inspired to design the wheels after years of seeing trash pouring into the Baltimore Harbor after big storms. It comes from land sources, it comes from the streets, the parking lots, the alleys, the highways. And when it rains, it gets washed down the storm drains and into the small creeks and then into the rivers that feed the harbor. Containment booms are set up in a V-shape across the river, with rubber skirts that extend about two feet below the water's surface with weights on the bottom. This catches trash floating downriver and funnels it towards the mouth of the rotating trash wheel, which is powered by the river's current and attached solar panels. As the wheel turns, it powers a conveyor belt that lifts trash out and deposits it into a dumpster. And the dumpster is on a separate floating barge, and when that dumpster is full, we have another floating barge that we bring with an empty dumpster. Take the full one out, slide the empty one in and keep picking up the trash. The four wheels have picked up a total of about 2,000 tons of trash and debris, including organic material like sticks and leaves, which actually make up the bulk of the weight, since plastic is so light. But that haul overall includes about 1.5 million plastic bottles, 1.4 million foam containers and 12.6 million cigaret butts. Everything is then incinerated in a waste-to-energy facility. Installing a new wheel costs anywhere from $400,000 to $1.5 million and up, depending on local river conditions, waste infrastructure, and permitting expenses. Operating costs also vary widely, from $18,000 to over $100,000 per year. Though it can get pricey, Kellett says that solutions like this are cost-effective compared to the massive externalities incurred from plastic pollution in our waters, like the impact on marine life and microplastic contamination of food and drinking water. What we're doing with plastics and the way we're dealing with them now has costs associated with it. You can't really keep doing what we've been doing. So how are you going to fund a new way of doing things? Three of the wheels are owned and funded by the Waterfront Partnership of Baltimore, an NGO, and one is owned by the state government. Additional trash wheels are planned for Texas, California, and even Panama, where a local nonprofit, Marea Verde, has partnered with Clearwater Mills to build the fifth wheel in the family, named Wanda Díaz. This project is funded by the Benioff Ocean Initiative and the Coca-Cola Foundation, which together are supporting a portfolio of river cleanup projects around the world. So we started the construction of the device, of Wanda, a couple of months ago. Clearwater Meals, their team and even the creator, John Kellett, they came down here to Panama to help us with the installation. Wanda will operate on the Juan Díaz River. As one of the most polluted rivers in Panama, it sees a much heavier trash flow than Baltimore's rivers, especially after the first rains of the season. But Watemberg is confident in the technology. So we are very hopeful that this will be a very big success for our country. But at the end of the day, this is not something sustainable. We cannot have thousands of projects like this running forever. You know, the real solution to this problem is behavioral change, education, changing the way we're consuming goods. The Ocean Cleanup is probably best known for its efforts to clean the Great Pacific Garbage Patch, an endeavor the company's young founder, Boyan Slat, started pursuing in 2013 after a TED talk he gave on the topic went viral. Now though, the company is pursuing a dual focus, as it's built a series of river cleanup technologies. Our goal is to rid the oceans of plastic. And the reason why we look at rivers is because we believe it's the fastest and most cost-effective way to prevent further plastic from being emitted to the ocean. The Ocean Cleanup's first river cleanup device, called the Interceptor Original, was released in 2019. It's a fully solar-powered barge that operates much like Baltimore's trash wheels, just on a larger scale. Sitting at the mouth of a river, it funnels trash onto a conveyor belt and automatically distributes the waste across six giant dumpsters, which can hold over 17,000 cubic feet of trash. Where the trash goes after that depends on the country and the infrastructure that it has. Some is sorted and recycled, some is burned in waste-to-energy facilities, and some is landfilled. But since this giant interceptor doesn't fit in smaller rivers, the team developed another solution too. That's why we also introduced now something called the Interceptor Barrier, essentially a barrier you put at the mouth of the river. We have an Interceptor Tender, which is a mobile conveyor belt, which then can scoop out the trash from these barriers, which we now applied in Jamaica, where the rivers are simply too narrow and too shallow to fit an original interceptor. And for the most severely trash-choked rivers, The Ocean Cleanup is developing another solution called the Trashfence, which it's piloting in Guatemala. The concept is simple. A 26-foot high steel fence, anchored to the bed of the river, stops the flow of trash during a big storm. Then, after the water level recedes, excavators remove the waste. But the onslaught of trash in one of the world's most polluted rivers proved too intense for version 1.0. The force of the trash was so high that the Trashfence failed, unfortunately. So we're now working on the version two that will hopefully be ready for the next rainy season. Like Baltimore's trash wheels, costs are very location dependent. But Slat says that getting an interceptor up and running is generally a multimillion-dollar project, paid for by philanthropic donations, corporate partnerships, and local governments. Eight Ocean Cleanup interceptors are currently installed in Indonesia, Malaysia, Vietnam, the Dominican Republic, and Jamaica. The Trashfence in Guatemala is undergoing maintenance, and more cleanup devices are in the pipeline, including one in Los Angeles. We'll be about 20 towards the end of the year, beginning of next year. And ultimately, we hope to scale this exponential trend. India-based company AlphaMERS makes another version of a river barrier. With 34 installations in eight different cities, this barrier is relatively low-tech and low-cost. It's much smaller than the Ocean Cleanup's Trashfence, and not designed for the same extreme trash flow. But it's still pretty heavy duty. Made of stainless steel mesh, the AlphaMERS fence floats a couple feet above and below the water level. The hydrodynamics and the hydrostatics of this is very simple but excellent for the job. And it's made very rugged, very heavy duty, with steel chains holding it on both sides. So it's able to withstand the monsoon flows immediately after the rain. Sekhar says his floating fence excels at stopping trash and rivers with fast currents, whereas designs that rely on a boom and a skirt might fail when currents pick up, since the water will instead run over the barrier, bringing trash with it. Eight floating barriers were deployed at various points along the Cooum River in Chennai in 2017, at a cost of about $125,000. And in their first year of operation, Sekhar says they captured about 2,400 tons of plastic. The barriers are angled to direct trash towards the riverbank, where traditionally excavators have been used to pluck the trash from rivers, a cost not factored into the installation expense. But lately, AlphaMERS has been using conveyor belts as Clearwater Mills in The Ocean Cleanup do. Now we have started with the conveyor belts. One end is floating, one and is on the land. And now it's run with electrical power, with portable generators, but very soon we will run it with the flow of river water. Sekhar says the barriers are financed by municipal governments and corporations with social responsibility budgets. While in the future, he hopes to use AI to identify the types of waste being collected and where it originates from, for now, AlphaMERS is focused on its straightforward cleanup strategy. We like to take the simplest solution and work upwards. And artificial intelligence and machine learning is the last priority in our scheme of things. As these various wheels, barriers, and fences are deployed in more locales around the world, it will become clearer and clearer what technologies are best suited to what environments. And given the magnitude of the waste problem, there's more than enough room for all the players in this space. The goal is not to have 1,000 interceptors in the world, but to solve the top 1,000 heaviest polluting rivers. And any river that anyone else solves is one river less for us to to worry about. So the more the merrier. But all these organizations are well aware that these river cleanup systems are not the ultimate solution to our waste problem. One of the things we're looking forward to is when trash wheels are no longer needed, when we're addressing the problem upstream to the extent where no trash is entering our waterway and we don't need to have a trash wheel. Of course, financing waste cleanup, collection, and management around the world is a challenge. And Kaza says that the World Bank is always thinking about ways to incentivize citizens and governments alike to pay for long-term waste management solutions. There are models where there's cross subsidization. Wealthier communities pay a bit more than than lower-income communities. We've seen models where people pay based on the volume of waste they generate. And we've seen waste fees increase over time as services are proven, that was very effective. Funding models aside, though, Watemberg emphasizes that the desire for change has to first come from the communities themselves. If we don't change our habits and if we don't work with communities and if we don't look for alternatives and different solutions on land, this is not going to end. So we need people to come together as a community, as a country, with authorities, without authorities. We need everything. At the end of the day, funds are important, but we need to start with our will to do it.