What is the ruling on sewage water that has been treated and filtered?

Question:
Honorable Shaykh, may Allah grant you success, is the sewage water, may Allah honor you, that has been treated and filtered pure or purifying?

Answer:
Its treatment. It is of two types: complete treatment such that no smell, color, or taste of the impurity remains. This becomes purifying, though there is a disagreement among scholars as to whether a thing becomes pure through transformation or not. However, the correct view is that it becomes pure through transformation if it returns to its original state and all the attributes of the impurity are stripped away, returning to its original state. The second type of treatment is one where the impurity is removed, but the water is only somewhat clarified, and the impurity does not go away. This does not purify the water; it does not purify the water, but it may be used for watering gardens and the like, and there is no harm in that. They say that this complete treatment is difficult, very difficult in terms of cost, and it is not available because it is costly. Yes.