Abu 'Amir al-'Aqdi عبد الملك بن عمرو القيسي أبو عامر العقدي · The Book of Water

"It was said: 'O Messenger of Allah, you perform Wudu' from the well into which the bodies of dogs, menstrual rags and garbage are thrown?' He said: 'Water is pure and it is not made impure by anything.'"