Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 451 EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION Dr. Hussein Abdulmuttaleb Ali khan Lecturer at University of Kufa/ Eng. College ABSRACT The principal reason for monitoring water quality has been, traditionally, the need to verify whether the observed water quality is suitable for intended uses. The present study was conducted on Al Kufa river in Al-Kufa city in the aim of studying the concentration levels of some water quality parameters (BOD, PO4, NO3, pH, TU, Cl, and dust particles). Samples of raw water were collected and analyzed from Kufa river station during a period of eight months, starting from November until June 2010. The purpose is to assess the level of parameters measured and their effects on the river. Statistical analysis used to describe the relations between parameters of water quality with regression analysis done by using "Data Fit" program version 9.0 software. This study showed that the discharging of domestic sewage, detergents, agricultural effluents with fertilizers and industrial waste water from adjacent areas causing some contaminants increased. It was noticed that the NO3 has highest positive correlation with PO4 and pH has highest negative relation with PO4 and NO3, Finally, precipitated dust particles have highest negative correlation with pH as a result of acidic chemicals in dust particles. Keywords: Water Quality, Turbidity Unit, BOD, Phosphate, Nitrate, Hydrogen Ion Concentration, Chloride, Dust Particles, Regression Models. 2010 Hussein Abdulmuttaleb Ali khan Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 452 "Data Fit" program version 9.0 software 1.INTRODUCTION Water is vital for life. Not only do we need water to drink, to grow food and to wash, but it is also important for many of the pleasant recreational aspects of life. Each different use has its own requirements over the composition and purity of the water and each body of water to be used will need to be analyzed on a regular basis to confirm its suitability (Reeve, 2002). Aside from the very important issue of clean drinking water, why care about clean water? Clean water and enough of it is essential to any and all life, animals, plants, and microbes. Indeed, there are places in the world where the water is so polluted that fish have disappeared. In many other places fish or shellfish survive, but are not safe to eat because their flesh is contaminated. Humans enjoy being around water, but contamination with infectious organisms makes swimming unsafe; or if water has obnoxious odors or scum, being near it is not pleasant. Clean water is vital (Hill, 2004). Historically, the environmental engineer has found ways and means to provide ample quantities of quality drinking water for domestic use as well as quality water for commercial and industrial uses. Water supply issues include demand projections, quality requirements, surface water and groundwater source evaluations, groundwater production, surface water collection, surface water treatment, saline water treatment, no conventional water production, and treated water distribution (Corbitt, 2004). Water pollutants are categorized as point source or no point source, the former being identified as all dry weather pollutants that enter watercourses through pipes or channels. Storm drainage, even though the water may enter watercourses by way of pipes or channels, is considered non point source pollution. Other non point source pollution comes from agricultural runoff, construction sites, and other land disturbances (Weiner and Matthews, 2003). Water, of course, is used for many purposes associated with human activity. In its natural state it occurs in and on the ground in subsurface and surface reservoirs. The quality and reliability of a source of water will vary considerably, both in time and space. This means that characteristics (chemical, physical, and biological) will EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION 453Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 differ greatly depending upon the location and type of source. It also means that a given source may vary over the seasons of the year (Pfafflin and Ziegler, 2006). Many studies were carried out for different rivers in the world in different forms. Bhargava (1983) studied the quality of Ganga and Yamuna rivers. He found that the assimilation of biochemical oxygen demand (BOD) after the waste outfalls at the urban centers along these rivers was found to be exceedingly fast. During the two stage BOD removal in these streams, the early reaches, resulted from bioflocculation of waste colloidal matter with river. Morrison, 1987, showed that heavy metals in natural waters may occur as organic and inorganic complexes of varying sizes, or be associated with colloidal or particulate material of a heterogeneous nature. Euphrates river has a large importance for Iraqi environment researchers because of the detrimental effect of pollutants resulting from treated and untreated domestic wastewater, treated and untreated industrial wastewater and farming and agricultural pollutants. Chabuk, 2009, studied the Evaluation of selected trace elements in Shatt Al - Hilla river a branch of Euphrates river. He showed There is a slight variation in the concentration of trace metals between the selected locations in his study. This may be attributed to the movement of pollutants along the river and the similarity of human activities and agricultural wastes disposed to these locations. Obais, 2010, studied Water Quality Assessment in Middle-Euphrates Region in Iraq with various locations and different water bodies such as rivers, lake, and drains , showed an environmental assessment procedure is necessary to further characterize conditions of water quality in the middle Euphrates region. 2. OBJECTIVES The objectives of the study are: i. To characterize the water quality of Shatt Al Kufa station ii. To identify the effects of some pollutants discharged by different sources on river. 3. STUDY AREA Kufa is a city in Iraq, about 170 kilometres (110 mi) south of Baghdad (capital of Iraq), and 10 kilometres (6.2 mi) northeast of Najaf. It is located on the banks of the Euphrates River. Euphrates river branches after Al-Kifil town directly about (1Km) to two branches (first one is Shatt Al Kufa and another branch named Al Abbasia river). The main source of water for this river is rain water, stored water as lake and reservoirs. Al Kufa station is located on the river Euphrates / Shatt al-Kufa, near the Al Kufa water treatment plant for surface water monitoring, at coordinates (E044.4075, N32.03941). The water level at the station is not stable at a certain depth, according to the season of the year, in the summer decline is attributed to its lowest level so that the bottom of the river can be seen in some areas near the station, and even in winter the water levels are not rising as required, and the center of the river is not covered with water even in winter and the rainy season (Figure 1). The nature of the land surrounding the station is agricultural land, with some residential buildings at a distance (100 m to the south) and farming land on the other side. Al Kufa River passes through many towns and villages thus it represents the main source for different uses such as: Hussein Abdulmuttaleb Ali khan Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 454 a. Water supply systems: The River represents the supply source for many water treatment plants such as Al-Najaf and Al-Kufa water treatment plants. b. Irrigation: The River is the main source of the irrigation for large agricultural areas locating on both sides of the river. c. Industrial purposes: The river represents the main source for all industrial activities in the area. In addition to these main uses, the river receives many pollutants discharged by different sources, including: a. Municipal wastes: Municipal wastes are discharged from Northern drainage of Al Kufa ) 2 km / north) and raw waste water discharged from Al Jimaah zone at 1 km / north of station. b. Careless use of pesticides can contaminate water sources and make the water unsuitable for drinking. Wastes of animals and plants from agricultural areas are discharged to the river on both sides. c. Industrial wastes: Many industries discharge wastewater to the river such as soft drink factory and many private industries. 4. WATER QUALITY PARAMETERS USED This research covers the study and analysis of monthly water quality parameters which are listed in Table 1 of surface water for river (Euphrates/ Shatt Al Kufa). The water quality parameters used in present study will be described below: 4.1 BOD The amount of oxygen required o oxidize a substance to carbon dioxide and water, and if the oxidation of an organic compound is carried out by microorganisms using the organic matter as a food source, the oxygen consumed is known as biochemical (biological) oxygen demand (BOD) (Davis and Cornwell, 2008). The BOD determination has been standardized and measures the amount of oxygen utilized by microorganisms in the stabilization of water for five days at 20 °C. For domestic sewage the 5-day value or BOD5 represents approximately 2/3 of the demand which would be exerted if all the biologically oxidizable material were, in fact, oxidized (Steel and McGhee, 1979). 4.2 Phosphate Nutrients are chemicals, such as nitrogen, phosphorus, carbon, sulfur, calcium, potassium, iron, manganese, boron and cobalt that are essential to the growth of living things. In terms of water quality, nutrients can be considered as pollutants when their concentration is sufficient to allow excessive growth of aquatic plants, particularly algae (Lal, 2009). Phosphorus is present in fresh waters mostly in inorganic forms such as phosphates. However, being an important constituent of biological system, it may also present in the organic form. The major sources of phosphorus are domestic sewage, detergents, agricultural effluents with fertilizers and industrial waste water. Higher concentration of phosphorus, therefore, is indicative of pollution (Duggal, K.N., 2008). 4.3 Nitrate EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION 455Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 The two nutrients of importance in water/wastewater are nitrogen and phosphorus. They are both essential nutrients for plant and organism growth, but in excess they can be undesirable, often leading to eutrophication. Nitrogen cycles present in inorganic and organic forms. The inorganic form of nitrogen of key interest is: N2, NH3, and NO3 ¯. The organic forms of nitrogen of interest are: NH3, NO2 ¯ , and NO3 ¯ . Plants have the ability to fix N2 and convert it to nitrates. Animals cannot utilize inorganic nitrogen or nitrogen from the atmosphere, unless it is first converted into its organic form. Nitrates in drinking water are harmful, and upper limit values of 40 mg/l are typical for drinking water (Kiely, 1997). Excessive nutrients often lead to large growth of algae, which in turn become oxygen-demanding material when they die and settle to the bottom (Davis and Masten, 2004). 4.4 pH It is the logarithm to the base 10 of reciprocal of hydrogen ion concentration expressed in gms./litre. The pH value of neutral (pure) water is 7.0 and when it is less than 7.0 it is acidic in nature while above 7.0 is alkaline in nature. Too low or too high pH values are both undesirable an hence it is imperative to have the pH value of the water around neutral value. The pH of natural waters depends upon the CO2 equilibrium and lies between 7.0 and 8.0 to 8.5. The pH of distilled water may be 6.5 or lower, because of CO2 solution in it ( Lal, 2009) . 4.5 Turbidity Turbidity is measured in units that relate the clarity of the water sample to that of standardized suspension of silica. The interference in the passage of light caused by suspension of 1 mg/l of silica is equivalent to one turbidity unit (TU). To interpret turbidity data, it is useful to be familiar with the typical ranges that occur. Turbidity in excess of 5 TU is just noticeable to the average person, most people do not complain about the clarity of the water at TU values less than 5. Turbidity in what most people would consider to be a relatively clear lake may be as high as 25 TU. In muddy water, turbidity generally exceeds 100 TU. Modern water treatment plants can routinely produce crystal water with turbidities of less than 1 TU (Nathanson, 2000). 4.6 Chloride Chloride in natural water results from the leaching of chloride-containing rocks and soils with which the water comes in contact and in coastal areas from saltwater intrusion. In addition, agricultural, industrial, and domestic wastewaters discharged to surface waters are a source of chlorides (Metcalf & Eddy, 2004). Chlorides found in domestic sewage is derived from kitchen wastes, human faces and urinary discharges etc., human excreta, for example, contains about 6 g of chlorides per person per day (Punmia and Jain, 1998). 4.7 Precipitated dust particles Airborne particulate matter represents a complex mixture of organic and inorganic substances. Particulate matter is emitted in urban areas from power plants, industrial processes, vehicular traffic, domestic coal burning and industrial incinerators (Kiely, 1997), also particles in the atmosphere can come from windblown dust (Boubel et. al., 2008). Water quality managers are concerned with knowing how water quality is affected by natural factors such as the geometry of the terrain, and the climate of the region (Davis and Masten, 2004). Hussein Abdulmuttaleb Ali khan Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 456 Hence, present study considered the precipitated dust particles in study area in order to identify its effect on the water quality and relations between parameters involved through statistical analysis. 5. MODEL FORMATION Data of water quality of the Euphrates River (at Kufa river station) are being analyzed monthly, and the pollution levels are being determined. In present study the statistical models are described the relations between parameters of water quality. The regression analysis was done by using "Data Fit" program version 9.0 software. Also, two statistical methods were utilized for analyzing data collected from the sampling site: correlation analyses, regression variable (t-ratio and Prob(t)), and Variance analyses (Prob(F)). Correlation analyses were performed on the individual water quality parameters to identify relationships between them. Variance analyses to determine the overall significance of the regression model Accordingly, multiple non-linear regression models in three forms were used for each design requirements to choose which form gives the best fitting of data. The regression models that were proposed and investigated can be seen in Table 2. 6. Data Analysis Data for Euphrates river in Al Kufa station were collected, from the period extended from November to June 2010. These data represent the Phosphate (PO4), Nitrate (NO3), Hydrogen Ion concentration (pH), turbidity unit (T.U.), Chloride (Cl), precipitated dust particles (PM, g/m 2 ) as independent variables, and Biological Oxygen Demand (BOD), as dependent variable, as shown in Table 3. Table 4 shows the data statistics of water quality parameter used, while the correlation matrix is shown in Table 5. The optimum correlation equation from rank A in an exponential form with coefficient of determination R 2 equal to 0.2465 was shown in Table 6, and Table 7 shows regression variables results and 95% confidence intervals. Finally, (ANOVA) analysis is shown in Table 8. Fig 2 shows the plot model of Euphrates River at Al Kufa station. 7. DISCUSSION From Table 5 BOD in station has poor negative relation with turbidity unit and poor positive relation with phosphate, while NO3 has highest positive correlation with PO4, because of they are together represent major nutrients found in domestic sewage that discharged to Al Kufa river from Northern drainage of Al Kufa (2 km/north) and raw waste water discharged from Al Jimaah zone at 1 km / north of station . pH has highest negative relation with PO4 and NO3, apparently as a result of discharging of domestic sewage mentioned above and the wastewater effluent from the water softening factory precede the station causing altering the concentration in the Kufa water body. Negative correlation between turbidity and phosphate was found, this results can be explained by considering the discharging domestic sewage, detergents, agricultural effluents with fertilizers and industrial waste water from adjacent areas which represent major sources of phosphates that affecting turbidity value with considering tiny fragments of organic matter with clay and silt cause turbidity. EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION 457Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 Precipitated dust particles have highest negative correlation with pH as a result of acidic chemicals in dust particles resulting from gases emitted from numerous illegal private brick factories. Some chemical substances exist as dry particles in the air while others enter water body as wet particles such as rain, snow, sleet, hail dew or fog (Meenambal et. al., 2005). Particles may be precipitated directly to the river or indirectly, such as with rain that falls on land is drained through the sewage system eventually make their way into river. The introduction of these acids and chemicals into river causes a sudden drastic change in the pH value. Figures 3 and 4 show the variation of BOD and phosphate levels in the river water during the period of the study. All values measured are below the allowable Iraqi limits for rivers, less than 5 mg/l and 3 mg/l respectively (values detailed in table 4). Figures 5 and 6 illustrate nitrates and pH; also, all values are at acceptable limits. Figure 7 shows the turbidity concentration during period of study, highest value occurs in June was 47.7 NTU, while Iraqi standard is (10- 18 NTU), all measured values were allowable. Chloride values throughout the period of the study shown in Figure 8, values ranged between (153.8-236.9 mg/l), highest level was at May, as a result of pesticides used for agriculture in adjacent land while Iraqi standard is 200 mg/l. Table (9) shows the allowable limits of water quality parameters in river water body and drinking water according to IRAQI, WHO, US EPA, and CANADIAN standard. Most values measured agreed well with the limits given in Table 9. 8. CONCLUSIONS The following conclusions are drawn on the basis of the results obtained from the present analysis: - It was found, BOD and chloride have poor relation with other parameters used, also, it was noted that moderate existence of its concentration in Kufa station compared with local and international allowable limits of water quality parameters. - it was found that there is highest positive correlation between NO3 and PO4. Also, pH has highest negative relation with PO4 and NO3, these results can be explained by considering the discharging of domestic sewage and the wastewater effluent from some industrial activities to the river. - Negative correlation between turbidity and phosphate was found. - it was found that there is a negative relation between dust concentration and hydrogen ion, agreed well with Obais, 2010, and also with nitrates, while poor relation was found with phosphate, turbidity and chloride. 9. RECOMMENDATIONS -Environmental monitoring programs to control the water quality of Al Kufa river, and how they are affected by various environmental factors. -Further studies on other potential pollutants in Al Kufa River and the hydrocarbon compounds such as pesticides and other residues in the river water and sediment. -More studies on the relationships between air pollution from industrial and traffic sources, and trace elements concentration within river water and sediment. -Conduct more studies on the relationships between different types of pollutants and human and animal health. Hussein Abdulmuttaleb Ali khan Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 458 10. REFERENCES - Bhargava, D. S., 1983, "Most Rapid Assimilation in Ganga and Yamuna Rivers ". Journal of environmental Engineering Division, ASCE, 109(1): 174-188. - Boubel, R. W., Fox, D. L., Turner, D. B., Stern, A.r C., Vallero, D. A., 2008,"Fundamentals Of Air Pollution" Fourth Edition, Elsevier Inc. - Chabuk, A. J., 2009, " Evaluation Of Selected Trace Elements In Shatt Al - Hilla River", M. SC. Thesis, College of Engineering, University of Babylon. - Corbitt, R. A. "Standard Handbook of Environmental Engineering", McGraw-Hill (www.digitalengineeringlibrary.com) , 2004. - Davis, M. L., and Cornwell, D.A., 2008 "Introduction to Environmental Engineering " , Fourth Edition, McGraw-Hill. - Davis, M. L., and Masten, S. J., 2004 "Introduction to Environmental Engineering " , McGraw-Hill. - Duggal, K.N., 2008, "Elements of Environmental Engineering", S. Chand&Company Ltd. - Hill, M. K., 2004, " Understanding Environmental Pollution", Cambridge university press. - Hocking,,Martin B., 2005, "Handbook OF Chemical Technology and Pollution Control",Third Edition, Elsevier Inc. - Kiely, G., 1997, "Environmental Engineering", McGraw-Hill, International (UK) Limited. - Lal, D., 2009, "Water Supply And Waste Water Engineering", S. K. KARATIA & Sons, New Delhi. - Liu , I., 1999, " Environmental Engineers Handbook", CRC Press LLC - Masters, G, M., and Ela, W., P., 2008, "Introduction to Environmental Engineering and Science",3 rd Edition Prentice Hall, Inc. - Meenamble, T., Uma, R. N., and Murali, K., 2005, "Principles of Environmental Science and Engineering", S. CHAND & COMPANY LTD, New Delhi. - Metcalf & Eddy, 2004, " Wastewater Engineering Treatment And Reuse", Fourth Edition, McGraw-Hill. - Ministry of environment, Iraq, Iraqi environmental legislations book. - Morrison, G. M. P., 1987, "Approaches to mater speciation analysis in natural water, sediment and soil systems", Springer-Verlage, New York. http://www.digitalengineeringlibrary.com/ EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION 459Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 - Nathanson, J. A., 2000," Basic Environmental Technology", Prentic-Hall, Inc. - Obais, A. A., 2010, " Water Quality Assessment in Middle-Euphrates Region in Iraq", M. SC. Thesis, College of Engineering, University of Babylon. (Obais, , 2010) - Pfafflin , J. , And Ziegler, E.N., 2006, "Environmental Science And Engineering", Crc Press Taylor & Francis Group. - Punmia, B. C., and Jain, A. K., 1998, "Wastewater Engineering- Including Air Pollution", LAXMI PUBLICATIONS (P) LTD-New Delhi. - Reeve , R. N., 2002, " Introduction To Environmental Analysis ", University of Sunderland, John Wiley & Sons, Ltd. - Salvato, J. A. , Dee, P.E., Nemerow, N. L., and Agardy , F. J., 2003," Environmental Engineering", Fifth Edition, John Wiley & Sons, Inc. - Steel, E. W., and McGhee, T. J., 1979, " Water Supply and Sewerage", Fifth Edition, McGraw-Hill. - Weiner, R. E, And Matthews, R. A. , 2003, "Environmental Engineering", Fourth Edition, Elsevier Science (USA). Table 1 Water quality parameters which are used in this study Parameter Symbol Unit Biological Oxygen Demand BOD mg/ L Phosphate PO4 mg/ L Nitrate NO3 mg/L Hydrogen Ion concentration pH Hydrogen Ion concentration Turbidity TU NTU Chloride Cl mg/ L Precipitated dust particles PM g/m 2 /month Table 2 The proposed models. Rank Equation Description A M)xj...bxexp(axy kk21  B Mxj...bxaxy kk21  C kk21 xj...xbxay  Where; y = dependent variables. x1, x2, …, xk = the independent variables. a, b, c, …jk = are model coefficients, and M = model constant term. Hussein Abdulmuttaleb Ali khan Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 460 Table 3 Description of independent and dependent variables in Al Kufa river station. Table 4 Data Statistics of variables in Al-Kufa station Variable X1 X2 X3 X4 X5 X6 Y Number of Points 8 8 8 8 8 8 8 Missing Points 0 0 0 0 0 0 0 Maximu m Value 0.17 11.1 8.5 47.7 236.9 197.5 1.56 Minimu m Value 0.05 7.9 7.3 5.9 153.8 15.33 0.91 Range 0.12 3.2 1.2 41.8 83.1 182.17 0.65 Average 0.105625 8.8425 7.76875 14.9375 200.65 108.3575 1.215 Standa- rd Deviati- on 0.0428816 89 0.9631903 83 0.3826015 27 14.001218 06 25.389480 39 67.336704 86 0.1933169 12 Table 5 Correlation matrix of variables in Al-Kufa station Correlation Matrix X1 X2 X3 X4 X5 X6 Y X1 1 X2 0.57894986 1 X3 -0.5754979 -0.557396 1 X4 -0.3047245 -0.217717 0.079453 1 X5 -0.0964742 -0.235383 0.072612 -0.083726 1 X6 -0.0976143 -0.304151 -0.448784 0.143449 -0.12878 1 Y 0.07884085 0.21083 -0.368425 -0.120786 0.173557 0.163968 1 Table 6 Model Selected of variables in Al-Kufa station Model Std. Error Residu- al Sum Residual Avg. RSS R 2 exp(a*x1+b*x2+c*x3+d*x4+e*x5+f*x6+g) 0.44396 0.00262 0.00033 0.1971 0.2465 Type of variables Variables Detail x1 Phosphate (PO4, mg/L) x2 Nitrate (NO3, mg/L) x3 Hydrogen Ion concentration (pH) x4 Turbidity unit (T.U., NTU) x5 Chloride (Cl, mg/L) In d ep en d en t X6 Precipitated dust particles(PM, g/m 2 /month) Dependent Y Biological Oxygen Demand (BOD), mg/L) EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION 461Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 Table 7 Regression coefficients results and 95%confidence intervals Regression Variable Results Var. Value Standard Error t-ratio Prob(t) a -1.15428204598879 4.63880197013395 -0.24883193 0.84474 b 2.57272568082175E-02 0.306630909038197 0.083903012 0.94671 c -0.210957288638414 0.890306811982229 -0.236948977 0.85189 d -1.57638676748872E-03 1.07365540860054E-02 -0.146824275 0.90719 e 1.06726909016662E-03 6.44172699694457E-03 0.165680584 0.89547 f 4.60759543139453E-05 4.17928764012567E-03 0.011024834 0.99298 g 1.52921066131658 10.4046948661851 0.146973139 0.9071 Table 8 Variance analysis of variables in Al-Kufa station Variance Analysis Source DF Sum of Squares Mean Square F Ratio Prob(F) Regression 6 6.449608182228E-02 0.01074934697038 0.054536445 0.99481 Error 1 0.19710391817772 0.19710391817772 Total 7 0.2616 Table 9 Allowable limits of water quality parameters in river water body and drinking water according to IRAQI , WHO, US EPA, and CANADIAN standards water standards p a ra m et er Unit Iraqi* drinking water standards Iraqi * river water stand. WHO* * drinking water standards U.S. ** Envir. Protection Agency, 1994 drinking water stand. CANADIAN * * Guidelines For Drinking Water Quality (1987) BOD mg/ L None < 5 None None None PO4 mg/ L …… < 3 ……. …… ……. NO3 mg/L 0 - 40 50 10 10 10 pH Hydr- ogen Ion conce 6.5-8.5 6.5-8.5 6.5-8 6.5-8.5 6.5-8.5 TU NTU < 10 10-18 5-25 1 1 Cl mg/ L 200 200 250-600 250 < 250 95% Confidence Intervals Var. Value 95% (+/-) Lower Limit Upper Limit a -1.15428204598879 58.941545592916 -60.0958276389048 57.7872635469272 b 2.5727256808E-02 3.89611365642113 -3.87038639961292 3.92184091322935 c -0.21095728863841 11.3124164144086 -11.523373703047 11.1014591257702 d -1.576386767E-03 0.136420803527602 -0.13799719029501 0.134844416760114 e 1.067269090E-03 8.184987156857E-02 -8.0782602478E-02 8.29171406587E-02 f 4.6075954313E-05 5.310286461296E-02 -5.3056788658E-02 5.3148940567E-02 g 1.52921066131658 132.204133908722 -130.674923247405 133.733344570038 Hussein Abdulmuttaleb Ali khan Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 462 * Source: Iraqi environmental legislations book ** Source: (Liu , 1999) Figure 1 Map of the studying area in the national context. EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION 463Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 Figure 2 Plot model of water in AL Kufa station Figure 3 Variations of BOD with Time Variation of PO4 with Time 0 1 2 3 4 NOV DEC JAN FEB MAR APR MAY JUN Time (month) P O 4 , m g /l PO4 Concentration Iraqi Standard Figure 4 Variations of PO4 with Time Hussein Abdulmuttaleb Ali khan Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 464 Figure 5 Variations of NO3 with Time Figure 6 Variations of pH with Time Figure 7 Variations of Turbidity with Time EVALUATION OF SURFACE WATER QUALITY IN AL KUFA RIVER STATION 465Al-Qadisiya Journal For Engineering Sciences, Vol. 5, No. 4, 451-465, Year 2012 Figure 8 Variations of Chloride with Time a, b, c, …jk = are model coefficients, and M = model constant term. Table 3 Description of independent and dependent variables in Al Kufa river station.