February 2, 2015 2:11 AM EST

Mrs. Zhou avoids the city. In the seven years she’s lived and worked in Beijing’s vast northern suburbs, she’s ventured only once to the capital’s peak-roofed core. Raised in a village in Henan province, she never learned to read or write much. Subway maps and street signs are impenetrable. She frets about getting lost.

But Zhou, 36, knows the capital. It appears to her each day in the fragments of plastic she sorts. Garbage collectors from across the city lumber in with waste stacked high on their motorbikes. Zhou spends her days picking through twisted tubing, abandoned appliances, and take-away containers still splattered with sauce.

From the hearth of her brick and concrete shelter, she’s also learned a little about the world beyond Beijing. The ever growing city sheds plastic like snakes shed skin, yielding no shortage of waste. But her livelihood depends on the worth of the material, which is linked to the global price of oil. The past two months have been brutal: what once earned her two yuan, or 32¢, now earns 80 jiao, or about 13¢. “More plastic, less money,” she says.

Big cities produce a lot of trash. In Beijing, home to more than 21 million people, the task of collecting, sorting and recycling it falls primarily on migrant workers. In a place that is constantly rebuilding, they clear away the old to make way for the new. Some, in turn, will save enough to make the leap to more comfortable urban life. Others will stay on the margins, making just enough to send a little back home.

It is these links between city and country, core and periphery, that drew Getty photographer Kevin Frayer to Dongxiakou, where Mrs. Zhou lives. The district was once home to tens of thousands of recyclers, but as Beijing bulges northward, the land is being developed. Though half-built apartment blocks now loom in the distance, a few hundred have stayed to keep toiling until the last trucks roll through. “These people make the city work,” says Frayer. “Beijing needs them.”

Yet the city offers little by way of welcome. Though they work about 10 minutes by motorbike from the closest subway station, they live a world apart. Their kids are not eligible for Beijing’s public schools and they often can’t afford private tuition. On a Monday afternoon in January, several children traipsed about the trash heaps in padded jackets and fuzzy slippers, digging for treasure with chapped, blackened hands.

Beijing’s dry, cold weather makes living and working in Dongxiakou tough. Some families give about half of their net income to the local laoban, or boss, for a place to stay and a shot at incoming scrap. (The boss also advised them not to talk to visitors, which is why we’ve withheld their names.) Others simply squat in temporary shelters built from the discarded lumber, scrap metal, and plastic sheets they sort.

Mr. Zhao, a 60-year-old from Sichuan province, more that 1,000 miles away, built his own hut of particleboard, reclaimed bricks and old cement bags. When the camp closes, it will be sold off piece by piece. Then he, and Beijing’s leftovers, must move somewhere, anywhere, else.

Write to Emily Rauhala at emily_rauhala@timeasia.com.

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