vol20no4pa3

The studying of water quality (WQ) is to determine the competence of water source for different uses. Water Quality Index (WQI) is a mathematical device used to translate huge data for water testes to simple number, This number gives comprehensive idea to the water source quality level. In this study, many samples from selected points of Tigris river stage within the intakes of eight Water Treatment Plants (WTPs) of Baghdad city were collected and tested during (2009-2010) , These (WTPs) arranged according to itsposition from the north of Baghdad city to it’s south respectively as follows (Karkh ,Tigris– East ,Wathba, ,Karama ,Qadisiya ,Dora ,Wahda and Rashid in the south).Twenty parameters were tested for an average one sample of each parameter in each month within the year(2009-2010).Canadian Council of Ministry of the Environment (CCME,2001) procedure was used to determine (WQI) of the raw water in the intake of these (WTPs). Results showed that the best (WQI) was in the intake of Al-Karkh and the worst was in Al- Rashid (WTP). Another comparison for the suitability of the raw water in irrigation purpose was tested by comparing the average of each (T.D.S and EC. ) for a one year with the criteria of each of American Salinity Library (ASL) and with Russian classification(R.C), and the results showed high concentrations of salinity , so the irrigated soil with this raw water needs good drainage system.