Singer Bondie Chiu Hok-yee shows how to use the new e.Park cards, which were criticised by an environmental expert yesterday. The plastic cards, which went on sale last week, cannot have value added. The Transport Department has made 750,000 cards, which can be used from Sunday. Democratic Party environment spokesman Dr John Tse Wing-ling said the cards would put further strain on landfills. 'It is a waste of resources,' he said. Chief Transport Officer (Management and Licensing) Leung Wing-hon said a reusable system like the Octopus smart card for public transport was too expensive.