Mystery of 40 kg of rice clogging apartment sewer pipe leaves lower-floor residents with backed-up toilets

A building notice warning residents about sewage backing up into lower-floor bathrooms after roughly 40 kilograms of rice was found blocking a waste pipe has gone viral online.

A post shared Monday on the social media platform Threads showed the notice, with the user writing: "A building notice says 40 kg of rice was found in the sewer pipe. Why would anyone do this? It's a real mystery."

According to the notice, sewage backed up through toilets into lower-floor bathrooms at the apartment complex on Tuesday afternoon, contaminating some units.

Building management said a pipe-cleaning company worked through two consecutive nights to clear the blockage, ultimately discovering that approximately 40 kilograms of rice had accumulated in the main waste pipe and caused sewage to flow back into the lower-floor units.

The notice warned that flushing non-dissolvable items — including rice, wet wipes, sanitary pads, food waste and socks — down toilets or drains causes buildup in the main sewer line, which can ultimately lead to major sewage backflow incidents.

Management added that the cost of cleaning up and repairing such damage ultimately falls on all residents through shared maintenance fees, and urged residents to flush only waste and toilet paper, disposing of rice, wet wipes, food scraps and other foreign materials in standard garbage bags.

Online commenters reacted with a mix of disbelief and frustration. "The rice itself is surprising, but 40 kilograms is even more shocking," one wrote. Others called for tracking down whoever was responsible and billing them for the cleanup, while some noted that many people seem to treat toilets as all-purpose trash cans. One commenter said a resident at their own complex had once flushed a large quantity of beans.