Abstract
The current study was conducted on the two projects of Al-Awja and Al-Zaliya water plants, which are located on right side of the river within Salah Al-Din Governorate, with five water stations for the period from September 2019 to May 2020, except for the month of March 2020, which did not collect samples due to the curfew, as well as the months of April and May, no chlorine was added in projects due because of the Corona pandemic.
The results of the study showed that the water temperature ranged between (12.3 - 21.7) Celsius, while the air temperature ranged between (15-37.3) Celsius. As for the pH values, it ranged between (6.7 - 8.8), and dissolved oxygen values were observed ranged between (0.7 - 6.8) mg / liter. As for the values of the vital oxygen requirement, which ranged between (0.4-5.3) mg / liter, the rates of the total number of aerobic bacteria recorded a slight increase in water models (river - basin - drinking) and it was noticed that the total number of bacteria did not exceed the permissible limits in water. Drinking liquid water models, where the highest rate of bacteria was (11812) cells / 1 ml in the third station and the lowest rate in the first station was (7362) cells / 1 ml.