Is the water flowing from household taps pure (ṭahūr) or clean (ṭāhir), and is purification (ṭahāra) permissible with it after adding substances like chlorine, based on the opinions of the Four Imams and events from the Prophetic era?

The basic principle concerning water is that it is pure and purifying, based on the Almighty's saying: "And We sent down from the sky pure water" (Quran 25:48), and the Hadith: "Water is pure; nothing makes it impure." If its color, taste, or smell changes due to an impurity, then it is impure by scholarly consensus. However, if it changes due to something pure, like chlorine or dough, while still retaining the name 'water,' then it is pure and purifying according to the correct opinion. This is the madhhab of Abu Hanifa and one of the narrations from Ahmad, and it is the choice of Shaykh al-Islam Ibn Taymiyyah and Shaykh Ibn Baz, as long as another component does not overpower it and remove it from the name 'water,' such as it becoming milk or tea.