This study included the selection of three stations, two of them on the Tigris River passing through the city of Samarra, and the second station representing industrial wastewater - Samarra. The study period was for six months, starting from October 2021 until March 2022. The study included knowing the chemical, physical and biological properties of the industrial wastewater plant and river water and observing the effect of industrial wastewater on the water quality in the Tigris River. The chemical factors included pH, dissolved oxygen and the biological requirement for oxygen, while the physical factors included air temperature, water temperature and total dissolved salts. The results showed that the pH values tended to be alkaline , ranging between 6.6 - 8.7, and dissolved oxygen showed similar values, ranging between 3.8 - 9 mg / l, and the values of the vital oxygen requirement ranged between 0.8 - 30 mg / l, the air temperature ranged between 7 - 32 ° C, the water temperature ranged between 5 - 26 ° C, the values of total dissolved salts ranged between 210 - 1380 mg / l, the total number of coliform bacteria (TC) 0 - 1100 cells / 100 ml.

This study included the selection of three stations, two of which are on the Tigris River passing through Samarra and the other station representing the household wastewater - Samarra, and the duration of the study was six months from October 2021 to March 2022. The study included knowledge of the chemical, physical and biological properties of the domestic wastewater plant and river water and the observation of domestic wastewater on the water quality of the Tigris River. Chemical agents included pH, dissolved oxygen, and the bio requirement of oxygen, while physical factors included air temperature, water temperature and total dissolved salts. Results showed that pH values tended to be base,  ranging from 6.6 - 8.7, dissolved oxygen showed converging values ranging from 3.8-9 mg/L, and the bio-oxygen requirement values ranged from 0.8-8 30 mg/L, the air temperature ranged from  7-32°C, the water temperature ranged from  5-26°C, and the total melt salt values ranged from 210°C  - 1380 mg/L, total number of air bacteria (TPC) ranged between (0.06 – 74000*) cell/mL .