What is the ruling on greeting or mentioning Allah's name in the street next to sewers or drains?

The questioner's excessive waswas (whispers/obsessive thoughts) are evident, and we advise ignoring them. Some scholars have disliked the remembrance of Allah (dhikr) and the recitation of the Quran in impure places, and greeting with salam (peace) is a form of dhikr because it is one of Allah's names. If a place is impure or filthy, one must refrain from dhikr and salam in it. If it is not, then there is no harm in performing dhikr there, even if it is adjacent to an impure place.