At least a fifth of the city's waste can be diverted from landfills if refuse charging is widely adopted by 2016, the undersecretary for the environment says. Making households and businesses pay for rubbish disposal is under serious consideration, Christine Loh Kung-wai said, as the city struggles to reach agreement on landfill extensions and the introduction of incineration. Loh said waste could be reduced by at least 20 per cent by 2020, assuming a charge was introduced across the board from 2016. "This is just a very conservative estimate," she told the South China Morning Post yesterday. "But we are very serious about this. We will be extremely upset if we are not able to do this." Next month the Council for Sustainable Development will launch a four-month consultation to gauge views on how to implement waste charging. The city dumps about three million tonnes of waste a year at the Tuen Mun, Ta Kwu Ling and Tseung Kwan O landfills, which have two to six years to go before they reach capacity. This compares with landfills elsewhere in the world, some of which have about 40 years left. Lawmakers want officials to fine-tune their landfill expansion plans and waste strategies before resubmitting funding requests. "Hopefully, people will see we are doing something," Loh said, adding that more talks and visits to local communities were planned during the summer. The bureau was also reviewing charges for construction waste disposal, introduced in 2006, which had diverted much rubbish from landfills, she said. This is just a very conservative estimate. But we are very serious about this. We will be extremely upset if we are not able to do this It also aims to reduce food waste by one-quarter by 2017 at the earliest, with citywide campaigns and the completion of two organic waste treatment centres. On incineration, however, Loh said she would not underestimate the difficulties, noting strong opposition from residents living close to a proposed site near Shek Kwu Chau.