‘Interceptor' aims to capture plastics before they hit oceans

The nonprofit Ocean Cleanup group says it has developed an autonomous, solar-powered technology that will stop plastic from entering the oceans at its main sources: 1,000 of the most polluted rivers around the world.

The Rotterdam, Netherlands-based group unveiled its invention called Interceptor during an Oct. 26 livestream event.

The technology uses a floating barrier to guide river litter to the mouth of the Interceptor, where a conveyor belt sends it to one of six dumpsters on a separate barge. When the dumpsters are filled with plastic, the barge takes the haul to shore for recycling.

Ocean Cleanup founder and CEO Boyan Slat said the Interceptor is the first scalable solution to capture plastic before it reaches the ocean. Two Interceptors are already at work, he added, cleaning rivers in Jakarta, Indonesia, and Klang, Malaysia. A third Interceptor will be deployed to the Mekong Delta in Vietnam, and a fourth will go to Santo Domingo, Dominican Republic.

Adam Lindquist, the director of Waterfront Partnership's Healthy Harbor Initiative, which installed a similar device called Mr. Trash Wheel, invented by Clearwater Mills, in Baltimore in 2014, noted its river system has collected more than 2 million pounds of trash from Baltimore harbor, the Chesapeake Bay and ocean.

"We were surprised to learn on [Oct. 26] that the Ocean Cleanup announced the "invention" of a river cleaning device that is strikingly similar to our Mr. Trash Wheel. Having conceived of and overseen sustainably-powered trash interceptors that have collected more than 2 million pounds of trash from rivers, we can attest that this is the right approach, especially when combined with campaigns to reduce plastic consumption," Lindquist noted in a written statement.

"Trash wheels are continuing to make the world a cleaner place, including new projects currently being developed in five major cities, and we applaud all efforts to keep plastics out of our oceans," he said.

The Interceptor unveiling came just a few weeks after the Ocean Cleanup announced the success of its redesigned passive collection system for marine plastic in the Great Pacific Garbage Patch. Made of a high density polyethylene pipe and a polyester skirt, the system is collecting garbage ranging in size from microplastics to ghost nets halfway between California and Hawaii.

The Ocean Cleanup team was often criticized for trying to clean an accumulation patch for trash instead of capturing it at a point of origin. However, during the last four years, Slat said the group was quietly working on the Interceptor.

"To truly rid the oceans of plastic, we need to do two things," he said. "One, we need to clean up the legacy pollution — the stuff that has been accumulating for decades and hasn't gone away by itself. But two, we need to close the tap, which means preventing more plastic from reaching the oceans in the first place."

The Ocean Cleanup says its research shows 1,000 of the most polluted rivers are responsible for 80 percent of the marine debris carried to sea. The group plans to shut off these spigots by strategically locating Interceptors in the rivers. Their goal is to halt 80 percent of the plastic making its way to the oceans in the next 5 years.

The Interceptor is designed like a catamaran with a low center of gravity so it is stable and will stay upright. The vessel is anchored to the riverbed while floating barriers funnel waste to the opening of the collection system.

River currents move the waste onto a conveyor belt, which extracts it from the water and delivers it to an automated shuttle. The shuttle uses sensors to evenly distribute the waste across the six dumpsters, which are on a separate barge.

The Interceptor is solar-powered with lithium-ion batteries so the sensors, lights, conveyor belt, shuttle and data transmission will operate day and night and during the winter. It also has an internet-connected computer that monitors the system's performance, energy usage and component health.

When the dumpsters are almost full, the Interceptor sends a text message to local operators to come collect the waste. The barge is taken to shore and the dumpsters are emptied.

The Interceptor can extract 50,000 kilograms of trash per day. The Ocean Cleanup says its team is working with partners to recycle the plastic into durable goods.

During the livestream, Slat held up a part of the Interceptor's "fendering" and he said it's one of his favorite things about the invention.

"We had to make it from plastic, so then we thought let's make it from plastic we've taken from the ocean," Slat said. "I think that's just full circle, so it's pretty cool."

Thailand and Los Angeles County will be the next places to get Interceptors as the scale-up of the Ocean Cleanup initiative kicks into higher gear. Government officials from the two locations were at the unveiling but no details were given about their specific roles.

The Ocean Cleanup website says Thailand has signed up to deploy an Interceptor near Bangkok, and an agreement is nearing completion with LA county officials.

The group is working with government agencies and local waste operators to determine the best setup for Interceptors in terms of the highest "extraction output" and the least interference with river vessel traffic.

In addition, the Ocean Cleanup continues to seek funding, sponsors and investors to make all the river cleanups possible. The group hasn't said how much Interceptors cost to build and operate.

Slat said a recent report done in collaboration with Deloitte LLP puts the yearly economic costs of marine plastic between $6 billion and $19 billion. The cost factors in the impact on tourism, fisheries and aquaculture, and governmental cleanups.

"Deploying Interceptors is even cheaper than deploying nothing at all," Slat said. "This means that every day countries are not investing in intercepting plastic in rivers, they are losing money. To clean or not to clean? That is no longer a question."