In the present study, an attempt has been to develop a new water quality index (WQI) method that depends on the Iraqi specifications for drinking water (IQS 417, 2009)  to assess the validity of the Euphrates River for drinking by classifying the quality of the river water at different stations along its entire reach inside the Iraqi lands. The proposed classifications by this method are: Excellent, Good, Acceptable, Poor, and Very poor. Eight water quality parameters have been selected to represent the quality of the river water these are: Ion Hydrogen Concentration (pH), Calcium (Ca), Magnesium (Mg), Sodium (Na), Chloride (Cl), Sulphate (SO_4), Nitrate (NO_3), and Total Dissolved Solids (TDS). The variation of the water quality parameters along the river have been represented by graphs using Excel.2013 software. The results revealed that the quality of the Euphrates River ranges from “Good” to “Poor”, it enters the Iraqi borders with “Good” water quality and gradually its quality begins to decrease after it receives pollution from many sources such as domestic sewage and different industrial effluents until its quality becomes “Poor” according to the proposed classification. Finally the proposed WQI can be used as a tool to assess the quality of the river with both place and time.

The hydraulic study of drinking water is one of the things that must be done in order to obtain a realistic perception of the network’s functioning and the problems it suffers from, As well as to reach the scientific method to expand it if required, knowing that the population density is constantly increasing, as is the urban expansion, The aim of this study is evaluated and analyzed al-karada water distribution network to determine the areas of pure water scarcity and its causes, and the study relied on the data of the Baghdad water supply administration for the year 2020 and its divisions, where a hydraulic model of the network was created for the purpose of analysis, it included a review of the pressures and speeds during the average daily demand per person of 350 liters / day and during the maximum operational design capacities of the compacts Units, the results showed that the pressures within the acceptable limits and the flow velocity are not excessive in some pipe due to the low average daily demand.

Darcy-Weisbach (D-W) is a typical resistance equation in pressured flow; however, some academics and engineers prefer Hazen-Williams (H-W) for assessing water distribution networks. The main difference is that the (D-W) friction factor changes with the Reynolds number, while the (H-W) coefficient is a constant value for a certain material. This study uses WaterGEMS CONNECT Edition update 1 to find an empirical relation between the (H-W) and (H-W) equations for two 400 mm and 500 mm pipe systems. The hydraulic model was done, and two scenarios were applied by changing the (H-W) coefficient to show the difference in results of head loss. The results showed a strong relationship between both equations with correlation coefficients of 0.999, 0.998, and 0.993 for 500 mm pipes and 0.998, 0.999, and 0.996 for 400 mm pipes for the applied scenarios. The results also showed that the head loss when using the (H-W) equation for old pipe is more than the (D-W) equation.

This study aims to evaluate drinking water quality at the Al Wahda plant (WTP) in Baghdad city. A conventional water treatment plant with an average flow rate of 72.82 MLD. Water samples were taken from the influent and effluent of the treatment plant and analyzed for some physicochemical and biological parameters during the period from June to November 2020. The results of the evaluation indicate that treated water has almost the same characteristics as raw water; in other terms, the plant units do not remove pollutants as efficiently as intended. Based on this, the station appears to be nothing more than a series of water passage units. However, apart from Total dissolved solids, the mean values of all parameters in the study were of acceptable quality in accordance with World Health Organization (WHO) guidelines.

Turbidity is a visual property of water that expresses the amount of suspended substances in the water. Its presence in quantities more significant than the permissible limit makes the water undrinkable and reduces the effectiveness of disinfectants in treating pathogens. On this basis, turbidity is used as a basic indicator for measuring water quality. This study aims to evaluate the removal efficiency of AL- Muthanna WTP. Water turbidity was used as a basic parameter in the evaluation, using performance improvement evaluation and data from previous years (2016 to 2020). The average raw water turbidity was 26.7 NTU, with a minimum of 14 NTU, with a maximum of 48 NTU. Water turbidity value for 95% of settling daily reading data was (13.7) NTU which is larger than the goal value (10) NTU, which achieves (51.2) % of the optimum goal. In comparison, the water turbidity value for 95% of daily reading data of water filtered was (6.90) NTU which is larger than the goal value (5) NTU, which achieves (68.8) % of the optimum goal. The removal efficiency for previous years (2016 to 2020) was (78.5, 76, 73.5, 72, 68)%, respectively, within acceptable limits.