Answered by Shaykh Yusuf Weltch
Is water collected in a water storage tank from a borehole or rain permissible to be used for wudhu and ghusl?
In the Name of Allah, the Most Merciful and Compassionate
Performing Wudu with Rainwater
It is permissible to make Wudu from rainwater. Allah Most High says, “And We have sent down from the sky purifying water.” [Quran, 25:48]
Performing Wudu with Water Gathered in a Large Container
The principle regarding water is that it is pure until proven otherwise. Therefore, the water collected in a tank or large container is pure and can be used for wudu or ghusl. Note that if any impure substance mixes with the water, it may become impure due to the following considerations.
- If the amount of water is small and any impure substance (e.g., urine, feces, blood, alcohol, etc.) comes in contact with it, it is impure and cannot be used for purification. [Shurubulali, Maraqi al-Falah]
- If the amount of water is large, it will remain pure, despite any impurity coming in contact with it. However, if the impurity traces (i.e., smell, taste, or color) become visible in the water, the water is considered impure. [Mawsili, al-Ikhtiyar]
Specifications of a Small Body of Water versus a Large Body of Water
A large body of water is ten cubits by ten surface areas. As per modern measurements, this equates to over 25 square meters in surface area. Also, the depth of the water, to be considered large, must be such that the surface beneath the water is not exposed when scooping out the water. [Shurunbulali, Maraqi al-Falah; Mawsili, al-Ikhtiyar]
Hope this helps
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani