Oils and fats should not be released in the drain.
Cooking oil and fats should not be thrown down the drain. They can harden and block the pipes. In an open drain, the fats clog the soil pores reducing their effectiveness in filtering water. Also, they may kill microbes that help purify water. Therefore oil and fats should be always discharged after taking due care in the dustbin or if possible in some suitable dumping place.