At the end of the line, workers wearing earplugs to block out the deafening noise serve as final goalkeepers to remove material that can't be recycled.

An optical sorter identifies the resin in plastics to determine what kind it is, while paper gets machine-sorted according to size and weight.

Trucks from Recology, the company that picks up the material curbside and delivers it to to the center, drive in and dump their loads in huge piles inside the building. Meanwhile, bulldozers push the piles higher to make room for more material before they place it into a system of conveyor belts. The belts lead to machines that separate out glass, plastics, cardboard and other materials.

The consortium that runs the facility, known as Rethink Waste, serves Menlo Park and Atherton along with eight other cities, unincorporated San Mateo County and customers of the West Bay Sanitary District.

The Shoreway Environmental Center in San Carlos hums with activity six days a week processing the garbage and recycling from more than 400,000 customers in the southern part of San Mateo County.

Workers at the Shoreway Environmental Center in San Carlos pick out papers for recycling by hand before the remaining material is sent to the landfill. Photo by Magali Gauthier/The Almanac

All this noisy activity is being affected by a serious crisis that has been developing for more than a year. Beginning around March 2018, the effects of National Sword, a program instituted by the Chinese government to raise the standards of the recycling it is willing to buy from the rest of the world, took effect.

At the end of the line after all the sorting, the material that's left travels on a conveyor to the transfer station next door, where it is loaded on trucks and hauled to the Ox Mountain Sanitary Landfill in Half Moon Bay.

The center processes 500,000 tons of material per year overall, according to Julia Au, the education coordinator for Rethink Waste, the operator of the center. Much of the 80,000 tons per year of recycling that the center takes in has for years been shipped to China.

The goal is to divert as much of the material that can be recycled away from the garbage pile that will be sent to landfill.

The consortium has found alternative markets for the mixed-paper products in Indonesia, South Korea, Taiwan, Vietnam, Malaysia and India, although those countries pay a lower price for the material than China had paid, Svoboda said.

"We were sending everything overseas, and we were more focused on sending it overseas because China was taking care of it for us," said Dylan Svoboda, with Californians Against Waste in Sacramento. "Now the purity standards are forcing us to look for other markets."

China has raised the standards on the materials it will accept to a 0.5% level of purity that amounts to a virtual ban on accepting paper, which is about 60 percent of Shoreway's output, said Joe La Mariana, executive director or Rethink Waste.

Another problematic new restriction by China has to do with contamination, which occurs when people put plastics and other recycled materials that are wet or contaminated with food debris in their recycling bins.

Under the program, China is accepting only the most desirable plastics — those designated as 1 and 2, which include things like water bottles and milk and detergent containers. It has completely stopped accepting plastics in the 3 through 7 categories, which include, for example, Ketchup bottles and newspaper bags.

Confused about what can be recycled and what can't? And which bin the material should be deposited in?

GreenWaste itself is in negotiations for rate increases with Portola Valley, Woodside and other cities and towns where it collects as well as processes recycling, she said.

"Right now the hauling company is taking the hit and subsidizing the ratepayer," Hanson said. "So most haulers are going back to their jurisdictions and negotiating for some rate relief."

The contents of the average recycling bin used to be worth about 65 cents, now it costs the hauling company about 47 cents to take it away, Hanson said.

GreenWaste collects about a third of the recycling it processes at its San Jose facility and receives the rest of what it processes from other hauling companies.

At the same time, the Chinese pullout from the market has caused the company to raise its prices for the recycling it processes.

GreenWaste has upgraded its processing equipment in an effort to produce paper that is cleaner and more appealing to international customers, she said.

Like Rethink Waste, GreenWaste is sending paper to Southeast Asia, where their customers are paying less for it than the Chinese did and it has domestic buyers for its 1 and 2 plastics, Hanson said.

These materials arrive at the GreenWaste Materials Recovery Center in San Jose, which has seen its recovery rate fall from 95% to about 80% since National Sword went into effect because it has to meet the higher contamination standards now in effect worldwide, according to Emily Hanson, GreenWaste's director of business development.

San Jose-based GreenWaste Recovery picks up and processes garbage and recycling in Woodside and Portola Valley, the two southern San Mateo County communities that are not being served by Recology and Rethink Waste.

In addition, if paper is dumped rather than recycled it creates a need to cut down more trees to make new paper from scratch, adding to the carbon dioxide load, he said.

Land-filling also needs to be avoided because it creates an environmental deficit, Lapis said, since landfills emit methane and other toxic gases that contribute to global warming.

The state of California is trying to help out with that. AB 1583, among a host of recycling measures now before the Legislature, would provide funding for developing paper-pulping mills locally that could process the materials that are being shipped overseas, stockpiled or dumped into landfills, said Nick Lapis of Californians Against Waste in Sacramento.

"We're also working at the state level to build domestic paper processing markets back up so we don't have to ship paper around the world," he said.

"The sensors use artificial intelligence to recover more material and more higher-grade material at a very rapid rate," La Mariana said. "Our current equipment was designed about 12 years ago and it is dated, and we need to modernize it to get top dollar in the marketplace.

In response, the consortium is planning a $15 million upgrade to the facility over the next two years that will include adding another sorting line and more optical scanners that will help guarantee the purity of the plastics, paper and other materials that emerge from the line.

As a result, Rethink Waste's recovery rate for materials has fallen from about 92% to 88% since March of last year, with the potential to fall much farther if its overseas market for paper collapses, La Mariana said.

But it has lost its market completely for low-grade plastic film, plastic grocery bags and rigid plastics, and those materials that are now being dumped in the landfill.

Rethink Waste has domestic markets for high-quality 1 and 2 plastics and products like yogurt cups and cottage cheese containers that amount to about 40 percent of its production, La Mariana said.

But Rethink Waste isn't counting on that arrangement to continue. Those countries are now being inundated with material that China is no longer accepting, and it's only a matter of time before they will begin enacting their own restrictions, he predicted.

Talking trash

Where will our recyclables be sent for processing now that China has changed its rules?