'An old habit is to throw toilet paper in the trash can beside the toilet, which causes a major stink that's bad for public sanitation,' city Environmental Protection Bureau Director Chang Hwang-jen told Reuters.
'Japanese and Western visitors who come to Taiwan find this Taiwan toilet habit to be quite poor,' she added.
Taiwan's plumbing can now handle toilet paper without clogging the pipes, a break from the past, the city of Tainan told its 764,000 citizens at a news conference on Monday.
Leaders in other Taiwan cities haven't gotten off the pot on the issue, Ms Chang said.
Toilet sitters in Taiwan and China customarily target trash bins instead of the porcelain because of pipe backup worries.
Clogged pipes in Tainan are caused by the flushing of other objects, such as toothbrushes, Ms Chang said.
Sticking non-recyclabe toilet paper in the trash also costs the city T$4,600 (S$206) per tonne, or T$600 million per year, to treat, local media said.
See also: How to use a toilet in India!!!