It's telling that when a district scheme to recycle food waste succeeds beyond expectations, the organisers still struggle with excess.
About 550 households signed up when the Cheung Chau Island Women's Association's project began in August. Now enthusiastic volunteers turn up daily to help transport tubs of kitchen waste from two collection points to a community facility, where the material is sorted and turned into compost.
The problem is, there's more food waste than they can handle, says project manager Kwok Wai-man.
Last year the association secured a HK$1.7 million government grant, which was used to construct the waste recycling facility and to lease a composter for two years
"We receive 250kg of leftovers every day, but the [composting] machine can handle only 100kg, so the rest has to be thrown away," Kwok says.
Hong Kong's mounting waste disposal problems, aggravated by a throwaway culture, are well known. Less understood is how food waste now makes up as much as 40 per cent of the material dumped in landfills every day (about 3,500 tonnes). Worse, discarded food accounts for a rising proportion of the solid waste from households, rising from 37 per cent in 2002 to 42 per cent in 2011.
Disposal industry veterans trace the surge in food waste to 2006, when officials began phasing out pig farming in the wake of the Sars outbreak.
In the past, operators would collect scraps from restaurants and other food business for resale to pig farmers as swill for the animals. But with the sector reduced to 43 farms from 265 in 2006, "all the swill has nowhere to go, and Hong Kong is stuck with mounds of kitchen waste", says Wong Yuk-chun, of waste-processing company Kowloon Biotechnology.
Ironically, only a tiny fraction of that excess is channelled to food waste processors, leaving them with plenty of idle capacity.
"My machines can handle 50 tonnes of leftovers every day. But I am only processing 15 tonnes," says Henry Ngai Hon-shun, CEO of the Hong Kong Organic Waste Recycling Centre. "My staff can put their feet up after working for only two hours."
Wong reports a similar excess capacity, even though he has contracts with the Four Seasons Hotel, the Airport Authority, City University and the Bank of China.
As the two operators see it, food waste processing is hampered by fuzzy and outdated regulations.
Ngai, whose centre mainly processes waste into pig feed and compost, says anyone with a business registration can collect food scraps. But unscrupulous companies have been selling feed that hasn't been properly processed. This has made pig farmers wary of buying from local suppliers, so "Now I have to give our feed to farmers for free for them to try," Ngai says.
The government lacks clear guidelines for food waste processing, Ngai complains. "There's no criteria on how our business should be run. What licences should we get? There should be rules to govern our industry."
Wong needs three licences for his plant in Lau Fau Shan, which now converts food scraps into fish meal - one to operate the heavy machinery required to dry the animal feed, another to discharge effluents and the third to operate an "offensive trade".
According to the Environmental Protection Department (EPD), anyone wishing to operate a food waste recycling or composting business is informed about requirements which may include obtaining an Offensive Trade Licence and an effluent discharge licence granted under the Water Pollution Control Ordinance.
However, Ngai suggests the licensing requirements are behind the times. Officials have not issued an offensive trade licence to food waste processors for two decades, he says, and no one would qualify if they applied now because the criteria have not been updated since the 1970s.
"Huge capital investments would be needed to comply with the criteria. It would make our business unviable. The government has also failed to take into account new technologies that make [food waste processing] no longer an 'offensive' industry. We now use Japanese biotechnological methods of fermentation that eliminate bad odours. Our Sheung Shui premises are situated next to a residential estate. Yet we have been coexisting peacefully, which shows that handling leftovers does not necessarily [result in foul-smelling operations]."
Another barrier to environmentally friendlier disposal of food waste may be a lack of financial incentives for catering businesses.
"Most of my customers are hotels and big corporations - those who have a strong sense of social responsibility," Wong says. "But restaurants and local eateries that produce the most kitchen waste are unwilling pay us to collect it. This reluctance is understandable. They already pay expensive fees for effluent discharge. They also pay cleaners to clear their rubbish, so they'd rather just throw it away."
Ngai says the government should offer rebates to businesses that send their waste to proper food-recycling ventures.
"They could pay lower fees for effluent discharge. The government won't lose, as landfills cost money. The social cost of pollution from landfills can also be reduced."
Hong Kong has failed to make much headway against waste disposal problems. Of the city's 13 landfills, only three still operate, and the last is due to close in 2018.
The government has proposed remedial measures, including a plan to build an incinerator on Shek Kwu Chau, off Cheung Chau. But residents and green groups have opposed the proposed incinerator as an environmentally backward measure, and the decision on a court challenge is pending.
Two bio-waste recycling centres due to open in the coming years - at Siu Ho Wan on Lantau (next year) and at Sha Ling in the Northern District (2016) - will ease some of the disposal pressures. They have a combined capacity to convert 500 tonnes of food waste into compost or biogas.
Transforming food waste into methane for power generation should be the way of the future, says Ma Yiu-wa, a water and energy consultant at the Hong Kong Productivity Council.
"Hong Kong cannot absorb that much compost, as we do not have a thriving agricultural industry, and we would not be competitive if we tried to export it," he says, adding that the government should also explore decentralised approaches in which biogas made from leftovers collected in an estate can be used for cooking at nearby restaurants.
But in converting organic waste into biogas, Hong Kong must adapt methods to suit its specific circumstances, says Professor Johnny Chan Chung-leung, City University dean of energy and environment.
"The nature of our leftovers is different from that in other countries. Western leftovers do not contain as much rice or sauce, so we need to identify different bacteria for fermentation," Chan says.
There are other uses for food waste. City University has developed ways to turn it into succinic acid, a solvent used in making plastic, detergent and paint. Ngai says his development team has produced biodegradable cat litter from soy residue, which could be flushed away, and other leftovers can be turned into flower pots and even food containers.
For Wong, however, the best use for food waste is making fish meal, a mere 10-hour process. "Hong Kong absorbs more than 10,000 tonnes of fish feed every year. There's a big market out there," he says.
Chan says only when the government starts charging for waste disposal will there be a solution. Such services need to be paid for, and the fees would also reduce waste.
"All my friends living overseas are surprised to learn that we dispose of our rubbish without paying a cent. Environmental businesses must have government support," he says.
Simon Wong Ka-wo, president of the Federation of Restaurants and Related Trades, concedes environmental protection isn't a high priority for the industry.
"Just 10 to 20 per cent of our [4,500] members recycle their food waste, which takes extra manpower for sorting and storage space for leftovers," he says. "So we aim to reduce waste at the source through education."
For now, the EPD has no plans to introduce tax rebates for waste processing, a spokesman says. Instead, the government aims to reduce waste through its Food Wise education campaign. It has also backed community efforts through the Environment and Conservation Fund, which has approved grants for about 110 projects.
On Cheung Chau, women's association CEO Lee Kwan-chun, says their recycling project, a fund beneficiary, has helped people realise how much food was going to waste. About 5.5 per cent of residents signed up, and it was only after they began sorting the rubbish that residents understood the extent of the problem.
The island community had an incentive for supporting the project, Lee concedes.
"The overwhelming response has to do with the plan to build an incinerator on nearby Shek Kwu Chau," she says. "They want to show the government there's no need to burn rubbish, as people can reduce waste at the source."