Bulugh al-Maram
And Al-Baihaqi reported: “Water is pure unless any impure thing is added which changes its smell, taste and colour”.
وَلِلْبَيْهَقِيِّ: { اَلْمَاءُ طَاهِرٌ إِلَّا إِنْ تَغَيَّرَ رِيحُهُ, أَوْ طَعْمُهُ, أَوْ لَوْنُهُ; بِنَجَاسَةٍ تَحْدُثُ فِيهِ } 1 .
Reference