。
Today is non-combustible trash day.
Literal
Today [topic-は] non-combustible-items [possessive-の] trash [possessive-の] day is.
不燃物 (non-combustible items) is a compound of 不 (non-) + 燃 (burn) + 物 (items), part of Japan's detailed waste-sorting vocabulary. Trash collection days are a fixture of daily life in Japan, with designated days for 燃えるゴミ, 不燃物, 資源ゴミ, etc.