The bay area refers to Beijing’s ambitious initiative to link Hong Kong, Macau and nine mainland cities into an integrated hi-tech, economic powerhouse by 2035.

Tse said funding and technology from Hong Kong investors could allow for some of the city’s waste to be incinerated and upcycled in the bay area.

But concerns were raised over whether Wednesday’s proposal went against the mainland’s ban since 2018 against taking in waste paper, plastics, textiles or slag – a by-product of separating metal from ore.

The policy, which also covers Hong Kong, imposed stricter limits on the level of contaminants allowed in imported materials.

The mainland was a major destination for Hong Kong’s plastic waste before the ban, receiving almost half of the 14 million tonnes shipped for recycling in 2016.

Hong Kong’s Environment and Ecology Bureau said Tse had meant exploring jointly developing a “green industry and the relevant facilities to push for turning waste into resources and recycling, which cannot only reduce waste, but also reap economic benefits”.

“This can also help reduce some of the waste Hong Kong has to tackle, and not sending waste to the Greater Bay Area for them to handle,” the bureau said in a social media post.

Chan Siu-hung, deputy chairman of the Legislative Council’s environmental affairs panel, on Thursday said he agreed with Tse’s proposal as Hong Kong, as part of the bay area, could make use of the “scale effect”.

But he argued that any such proposal would need to be multifaceted.

“If the bay area already has a recycling production chain, it can achieve economies of scale, but if only some waste can be dealt with this way, we can consider using incinerators in the bay area in the short term,” the lawmaker told a radio programme.

“We should have an open mind as to whether one portion of waste could be incinerated. But it has to be a win-win situation, with economic benefits for residents in the bay area.”

Chan said that even if collaboration was the solution, Hongkongers should still do “as much as we can” to reduce waste.

He suggested the city focus on developing new technologies to make waste recycling and handling more efficient, which could then be adopted on a larger scale across the bay area.

Secretary for Environment and Ecology Tse Chin-wan has said the city is working alongside authorities across the border to integrate their waste-handling processes. Photo: Xiaomei Chen

Appearing on the same radio show as Chan, lawmaker William Wong Kam-fai said Tse’s proposal faced legal limitations under the mainland’s waste import ban.

“The country has restrictions on 24 kinds of waste that are not permitted for import, which also applies to Hong Kong. So this will have to be lifted before the measure can be implemented,” he said.

But the legislator also said incineration facilities in Jiangmen, a city which forms part of the bay area, were “very well developed” and had space to take waste from Hong Kong given the former’s strong recycling programme.

“We shouldn’t focus on sending trash to the mainland, but think of it as a shared economy, where we all have demand and can coordinate efforts in the bay area to determine how to benefit places in need through using incinerators to generate electricity,” he said.

But some critics said such a proposal could upset neighbours across the border, citing how odours given off by Hong Kong’s expanded Ta Kwu Ling landfill had attracted complaints from Shenzhen residents in recent years.

Hong Kong previously announced it would set up an incinerator in Shek Kwu Chau at the end of next year as part of a wider effort to fully transition away from using landfills for waste disposal by 2035.

Legco next month will also discuss a proposal to create a sister facility in Tuen Mun, while a third incinerator could be included in the Northern Metropolis mega-project in the northern New Territories.