CHINA: The Laogang landfill turns gas from waste into energy, and is one of the largest projects of its kind in Asia
by Michele Travierso
The roar of a Lufthansa A380 at full power taking off from Shangai’s Pudong International Airport interrupts the peace and quiet of the countryside. Apart from the noise of the planes, the only other disturbance on the muddy road around the perimeter of the neighboring Laogang landfill comes from crickets and birds.
Laogang operations manager Sun Yan Feng is carrying out his daily inspection to ensure that on-site activities run as smoothly as possible. In the distance, half a dozen different machines are busy flattening a large but not high hill, partly covered in black tarpaulin. The site, which resembles the set of a dystopian science fiction film, is the resting place for as much as a third of Shanghai’s municipal daily waste production. The city is home to more than 23 million people, so the job done by the Laogang landfill is no mean feat. Surprisingly, there is no smell.
A Volvo A40D articulated hauler heading towards Sun is aiming for a pile of freshly dug soil bordering the edge of the landfill. For reasons of hygiene, the soil is used to cover the trash: it traps the smell, avoids the proliferation of insects and other pests, and fosters the hypoxic environment needed to produce the gas to generate electricity. “We cover the garbage with a 20cm layer of soil,” explains Sun, before giving a simple description of the continuous process of feeding the landfill: “Garbage, add soil, remove the soil, add garbage, add soil; then remove the soil, and add garbage.”
The Laogang landfill, 60km from Shanghai city center, is operated by Shanghai Old Port Garbage Disposal Co Ltd, a joint venture between the French company Veolia, which owns a 60% stake, and the municipal government’s investment arm. The facility’s original life expectancy was 45 years, but following an increase of 8,000 tonnes in its daily capacity, it is expected to operate for at least another decade, until peaking at 80 million cubic meters.
As with many infrastructure projects in China, its defining statistics are mind-boggling. At 4.2km long and 800m wide, it covers a total area of 361 hectares of reclaimed land extending into the East China Sea. To put things into perspective, on a daily basis the landfill swallows up the equivalent of 114 A40D articulated haulers fully loaded with trash. Since its inception, Laogang landfill has absorbed an estimated 27 million tonnes of waste.
Having picked up the soil, the A40D returns to the active area to dump its load which is then spread over the older layer and covered with soil and geo-membranes – impermeable membranes used to contain the waste and its leachates. The flow of traffic is impressive – every 30 seconds, a bright yellow, container-sized truck arrives fully loaded and an empty one leaves.
“There are about 100 of those, each making five trips a day,” says Sun, explaining that the trucks are loaded with solid waste at a nearby docking and sorting station, delivered by a flotilla of barges which collect it from downtown Shanghai.
“We have four Volvo haulers and they are useful because they suit our terrible road conditions,” says Sun, describing how the haulers are used to move the leachate – about four or five loads a day – and sometimes the waste itself, if necessary.
The key driver in the choice of equipment is high reliability, explains Sun. “Apart from the need for regular maintenance, the A40D has a very low failure rate, so we can use it continuously.”
He goes on to shed light on the financial side of the project. “Yearly, we can earn the equivalent of $32.2 million from what is a relatively low-margin enterprise,” he says, adding that the company made a $4.8 million profit last year. The biggest cost, by far, is treating the chemical compounds in the leachate.
But there is more to running a modern landfill than simply digging a hole and filling it with rubbish. Leachate pools collect the sludge that percolates through the mound of waste – this has to be treated before it can reach and contaminate the ground-water system.
The landfill operators also collect gas from the decomposing waste which is burnt to generate power. While this process does not achieve huge financial gains, it reduces the potent greenhouse gases being released into the atmosphere. The operation also earns carbon credits, which can be traded on the international markets. The power generation is carried out by a subsidiary, because this line of business requires a joint venture with the controlling stake owned by a Chinese party.
Back in the city, while separate bins for recyclables are widespread, government waste services do not have the resources to run a recycling system, which means everything ends up in the unsorted municipal solid-waste pile.
“The recycling job is done well only in the little bin,” says Sun, referring to public recycling bins and the informal army of migrant workers in cities across China who hand-pick whatever they can sell to scrap traders. The scrap business is thriving, offering those with no other source of income a strong incentive to collect paper, glass, wood, metal and other materials and sell them on. Although it is not formally documented, this system proves efficient and is thought to be helping recycle up to 38% of municipal solid waste produced in China every year.
The Volvo haulers were imported by Veolia at the beginning of the venture, says Volvo CE’s Kino Zhao, key account and industrial sales manager for China. “But our local dealer, Shanghai Fullback Full Construction Equipment, is responsible for the service and parts,” he says.
The Laogang landfill is a powerful reminder of China’s economic growth and its unavoidable consequences. As millions of people in China have been lifted out
of poverty over the last three decades, the production of municipal waste has soared, requiring updated waste management techniques and tools to manage it.
“In this decade, we have filled 27 million tonnes of waste,” says Sun. “As our equipment reaches the end of its product lifespan, we are planning to purchase more Volvo machines to satisfy our growing capacity.”
China, says Sun, is moving towards incinerators, as landfills are not very popular with the public. However, although incinerators smell less, especially in summer, they do emit more harmful chemicals into the atmosphere and cost – per tonne of disposed waste – almost three times as much. The difference in costs, he explains, is due to the unsorted nature of the municipal waste, which requires more energy to burn efficiently. “We get anywhere between $10 and $13 per tonne from the government, but incinerators cost the government closer to $32 per tonne.”
It is a complex business, agrees Sun, taking a moment to peer into the distance at the past decade in the form of a 27-million-tonne hill, while pondering on his part in building a cleaner future for China: “It’s my way of contributing to the well-being of society.”