Abu Dawud Book 1, Hadith Number 65.
Chapter : Things that pollute water.
Narated By ‘Abd Allah b. ‘Umar : The Apostle of Allah (PBUH) said: When there is enough water to fill two pitchers, it does not become impure.
Abu Dawud said: Hammad b. Zaid has narrated this tradition on the authority of ‘Asim (without any reference to the Prophet).