Same two characters as qīngdǎo, to topple over, but a different word. Here the second character is fourth-tone 倒, the one that means to pour. If something is being tipped out of a container or a truck, the reading is qīngdào.
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This reading lives in official and environmental language: 非法倾倒 illegal dumping, 倾倒废物 to dump waste. In ordinary speech people just say 倒.
