Water Quality Assessment of AL-Mahawil Stream/Babylon/Iraq Using Canadian Water Quality Index

This study aimed to know the water quality in Al-Mahawil stream which is a stream from Euphrates River in Babylon governorate by using Canadian water quality index by determining the values of the most important physical and chemical parameters in water stream after taken three study sites along the stream [site 1 (S1), site 2 (S2), site 3 (S3)]. the data was determined seasonally after collection the samples monthly from December 2021 to November 2022. The results first finding out whether the values of these parameters within or above of Iraqi limiting standards of drinking water after that the Canadian water quality index (WQI) has been calculation, then determined if water stream can possibly directly used for drinking purpose or other uses. Generally, results pointed that some of physical and chemicals parameters were in Iraqi permissible limiting of drinking water, while others parameters were above Iraqi limiting standard. Also, the results showed that WQI for Al-Mahawil stream after used all study parameters for calculating was marginal and cannot used directly for drinking purpose. Also, results showed there was a significant differentiation among some parameters with positive correlation coefficients among it.


1-Introduction
Because of the important and urgent need to know the quality of water, whether raw, or for drinking, or for irrigation as a reason of direct and indirect impact of human life and other living organisms, for that the need to use reliable index appeared and some of these index internationally approved in evaluating water quality, and among these indicators was the Canadian Water Quality Index, which was used in many studies in evaluating water quality, for example in the study of Nashaat et al. [1] the WQI was used to evaluate the quality of al-kufa water river by using four sites on long river after determined some physical and chemicals tests which the results appeared that water quality index for river water was ranges between good and marginal.Other study used WQI to evaluate raw and treated water in Tigris water river and some treatment stations on the same river where the results showed that WQI for raw water was bad and need to advance treatment while treated water samples were good [2].Another study used WQI to evaluate the quality of tap water in four district (almahawil, almusawab, almoharebeen and aljameeya) in babylon governarate in period from 1/2016 to 3/2016 where the results showed the water quality index was good [3].Also, there was study on al-hindiya dam to almishjab regulator to evaluate water quality of Euphrates water river by using WQI where the result pointed to find varieties in WQI between studied months [4].In the study of Al-Saffawi [5] the index was used to determine the water quality of twelve wells distributed in Al-Mahalabiya district north west of the city of Mosul to evaluate water quality wells for drinking purposes, and according to the study, the water quality was between marginal to poor quality.While the study of Mohammed was used the index to know the water quality of Lake Dalamj in Al-Qadisiyah Governorate, which according to the study it was fluctuating [6].while the study of Obayes et al. [7], the index was used to evaluate five stations along the Shatt Al-Hilla River in Babil Governorate, and according to the study, the water quality was good.Also, there are other studies that used WQI such as the study of Al-Fattamah et al. [8], which used the Canadian Water Quality Index to evaluate the waters of the Orontes River in the Syrian governorate of Hama, and according to the study, the water quality was poor to be suitable for drinking purpose.In another study such as study of Yang et al. [9] to demonstrate water quality when diverting a water project from the south to the north as one of the most important water diversion projects in China along the SNWDPC-ER delivery channel derived from Yangtze River mainstream near Yangzhou City in Jiangsu Province, from 2014 to 2018, the results showed that the water quality was good and more consistent year after year.
Rivers and streams of freshwater are the most important sources of life in nature, which play a prominent role in the assemblies of plants and animals' life, gatherings of populations and developing the human societies around the world.Therefore, it is normal to be exposed to pollution as a reason for the activities of living organisms in addition to the activities of humans, which are usually led to change in characteristic of water [10], or in some cases destroyed of fresh aquatic environments [11], or can cause limited in self-purification processes [12] and all these reasons can lead to lose water their quality or decreased the water quality.
The aim of this study was to determine the water quality of Al-Mahawil stream by using canadian water quality index after determined the values of some physical and chemical parameters.This stream of freshwater was important water resource that use for drinking, irrigation and other uses in Al-Mahawil city, and play essential role in human and animals health with a great impact on the agricultural reclamation process.Also, showed if possible can directly use the stream water for drinking water purpose after evaluating the water stream by using the Canadian water quality index.

2-1-1-Description of the study area
Al-Mahawil stream is one of the Euphrates streams that irrigates the lands of the Mahawil and the Al-Imam Districts, it is one of the ancient streams that irrigate agricultural lands relatively far from Shatt al-Hilla [7].This stream flows towards southeast direction then east for distance proximality about 20.600 km, and irrigation agriculture areas located in Al-Mahawil center and Al-Imam District.The total area that irrigated by the stream is about 101,000 dunums, in irrigating rate about 10,750 m 3 /sec.It has small branches at its end, which are the first most important of these branches are Alabara branch, which is located on the right side of the stream at a distance about 17,298 km from the Mahawil stream and extends for a distance about 12,600 km, this branch also irrigates agricultural lands that far from the stream itself, the discharges rate of this branch is about 1,017 m 3 /sec, and can water approximately about 11.30 dunams from surrounding land.While the second branch is call Umiya Al-Basha, which appeared at a distance about 20,600 km from stream and extends for a distance about 9,500 km to irrigate agricultural lands far from the Mahawil stream in the Al-Imam district, at discharge rate about 1 m 3 /sec, which irrigate about 11,170 dunums from land [13].

2-1-2-Study site in stream
The current study included three sites along the AL-Mahawil stream, as the first site was before enter the stream to the center of the city of Mahawil it is about 6.250 km west from the center of the city [site 1 (S1)] in (lat.: 32.661070; long.: 44.373974), the second site was inside the center of the city of Al-Mahawil near from commercial market [site 2 (S2)] in (lat.: 32.657951; long.: 44.401207), the third site was after exiting the stream from the center of al-Mahawil [site 3 (S3)] maps (1 and 2), its approximately about 4.5 km east from the second site in (lat.: 32.657964; long.: 44.444658).The water samples were collected monthly and calculated the results seasonally from (December 2021 to November 2022).The results showed in the form of seasons by calculating the data of every three months in the form of a seasonally average (December 2021, January 2022, February 2022) as Winter season, and (March 2022, April 2022, May 2022) as Spring season, while (June 2022, July 2022, August 2022) as Summer season, and (September 2022, October 2022, November 2022) as Autumn season, for each parameter that was taken.

Map (1). Location of the AL-Mahawil stream Map (2). Position of study sites on AL-Mahawil stream 2-2-Collection of the water samples
The way of APHA [14] has been used to collect samples in sterilized plastic bottles 1.5 liters to store and preparation to do some measurement, the tests have been done in college of science in Al-Qasim green and Babylon university.Some parameters have been tested by using ecological and laboratory devices after calibration such as water temperature, electrical conductivity (EC), turbidity, pH, total suspended solids (TSS), total dissolved solids (TDS), dissolved oxygen (DO) and biochemical oxygen demand (BOD).The alkalinity and total hardness have been determined by using the standard method according to APHA [15; 16], where hardness calculated by using Na2EDTA as titration solution and Eric chrome black -T as indicator, while in calcium hardness has been used meroxide as indicator, after that magnesium hardness has been found by using multiple equations that depending on relation between concentration of total hardness and calcium hardness.While alkalinity calculated by using sulpheric acid as titration solution and phenonephthaline and methyl orange as indicators.The nitrate and nitrite concentrations have been tested by using the method of cadmium column [17].The phosphate concentration has been tested by using the method of molybedo-phosphoric acid [18; 19], after that all NO2, NO3 and PO4 samples measured by spectrophotometer and find concentration after using straight line equation.

2-3-Canadian Water quality index 2-3-1-Definition of CCMECWQ
The Canadian Water Quality Index (WQI) is the scientific method for expressing water quality, because it is used many water quality variables and formulated it in a numerical and descriptive expressively, that includes the integrated impact of those variables on water quality, and has an effective role in the process of controlling water quality and strategic water management.According to the index the water can be qualitatively classified IOP Publishing doi:10.1088/1755-1315/1325/1/012004 to appear various activities of using water within every specific category that showed in a simple and useful scientific way.The Canadian Water Quality Index value can be range from 0-100.[20; 21].

2-3-2-Calculation of water quality index (WQI)
The Canadian water quality index was calculated after calculating three mathematical factors that expressed the state of water quality, which are scope F1, frequency F2, and amplitude F3, according to the equations that mentioned below; The water quality was expressed after compare the result with the classification of the water quality index scale that given by The CCME Water Quality Index (CCME WQI).Which are if the value of the CCMEWQI was 100 that means the best possible index score has been indicated, while if the value was 0 that means the worst possible index score has been indicated [20; 21; 22].

3-Statistical analysis of data
The statistical analysis of the data has been done by used ANOVA analysis to find descriptive statistical analysis.The correlation factors have been found after used Pearson correlation coefficient analysis also found linear regression.

4-1-Physical parameters
Table (1,4) showed seasonal average values of physical parameters (water temperature, turbidity, ) in three sites on Al-Mahawil stream, which the seasonal average of water stream temperature showed high value in summer (44) C o in site (S2), and lower value in winter (21) C o in site (S2), with a significant differentiation between seasons (figure 1), that could be return to surrounding climate, which was dominated by a semi-desert climate as a reason of Iraq site [23] that known as an extreme climate with hot and dry summer appear during most seasons of the year, with intermittent and few rains falling during the winter.In addition, the basin of the stream was narrow in site (S2), and the flow of stream water was slow, with surrounding plants and buildings barriers on the sides of the stream that can gave the stream hot spot and protect its water from the extreme climatic changes [24].Also, the table showed seasonal average of turbidity values for three sites, which have higher concentration (96) NTU in autumn in site (S3), and lower concentration (46) NTU in winter in site (S1), the results (figure 2) showed that the values of turbidity in all sites were upper of permissible limiting standard for Iraqi drinking water [25; 26], and there was a significant differentiation among seasons.These values could be returned to erosion and wash the surrounding areas into the stream water [27], or it can be returned also to the pumping of the reservoirs and dams' water [28], or to the throwing sewage and wastewater in to the stream water [29], in addition to the effect of topographic of the stream region that make it near from agriculture areas [26; 30].Also, the table pointed to seasonal average concentrations of total suspended solid (TSS), where higher concentration of TSS was (211) mg/l in summer in site (S1), and lower concentration (169) mg/l in summer and autumn in site (S2), the results (figure 3) showed there was a significant differentiation among sites and seasons, also, in spite of the site (S2) appeared lower concentrations but the result showed that all concentrations of TSS were above Iraqi standard limiting for drinking water.These results could be return to high content of sediments, sand storm and soil erosion in the study sites [31], also, some studies refer to find in some cases, that dry periods can lead to increase suspended matrials [32; 33; 34] in the surface water and sometimes can caused disappeared the flow of streams or change their direction.
At the end, the table showed the higher concentration of TDS was (518) mg/l in summer (S2), and lower concentration (411) mg/l in spring in site (S1), results (figure 4) pointed to find a significant differentiation among sites and seasons, and positive correlation coefficient with temperature (r=0.73), with higher annual concentration in site (S3) that can be because of discharging processes to the water stream from surrounding lands or human activities [35].The results referred to all concentrations of TDS were within standard limiting of Iraqi drinking water [25; 26].
Finally the results in table (1) pointed that the value of the Canadian water quality index that calculation depending on the physical parameters only showed that the water quality according to the index was 38.36 %, which means the water quality in the fourth category according to the Canadian classification, which also means that the water quality is marginal, which means the water quality is frequently threatened or impaired, and the conditions often depart from natural or desirable levels, and this can be due to decrease in the water flow that raised the water temperature, in addition to the frequently weathering of the lands surrounding the stream that can raised the turbidity, TSS and TDS as a reason of the decrease in the vegetation cover [36], or because of increasing wastes thrown into the stream flows [14] that can contributed to decreased the water quality index.Which means also the water of the stream couldn't use directly for drinking or human activity's purpose.

4-2-Chemical parameters
Table (2,4) showed average values of chemical parameters in three sites on Al-Mahawil stream, where the seasonal average of electrical conductivity (E.C.) were recorded higher concentration in summer (1257) us/cm in site (S2), and lower concentration (887) us/cm in winter in site (S1).The site (S2) showed higher concentration of E.C. compare to another study sites which could be returned to higher evaporation average [31] in this site.Generally, results appeared that concentrations of E.C. in permissible limiting standard of Iraqi drinking water [25; 26], also the results (Figure 5) showed there was positive correlation coefficient with temperature and total dissolved solids (r=0.77;0.99) respectively which mean both high temperature and TDS can increase values of electrical conductivity in water.
The table also showed seasonal average values of pH in three sites on Al-Mahawil stream, where results pointed to find a significant differentiation among sites, and lower annual average value appeared in site (S2) compare to other sites (figure 6), that can be returned to the possibility to throwing organic wastes into the water [37], or because of high level of erosion that happened on both sides of the stream [38].The results pointed the value of pH were above permissible limiting standard of Iraqi drinking water [26] which return also to the quality of the rocks that forming the river bed.
The alkalinity was Also recorded in the table which showed higher concentration of alkalinity was (311) mg/l in summer and autumn in site (S1), and lower concentration (268) mg/l in winter in site (S3), the results showed (figure 7) there was negative correlation coefficient with temperature (r=-0.85),also, the site (S2) appeared lower annual average than other's sites that could be because of activity of bacteria on organic matters that can lower the capacity of acid neutralization in stream water [39], the results showed the value of alkalinity was above Iraqi standard limiting of drinking water, and found positive relation coefficient between pH and alkalinity (r=0.97).generally, some studies refer to the reason of high values of pH and alkalinity can due to the fact that the Iraqi soils are calcareous soils that contribute to increase the alkalinity in resource of surface water and this alkalinity work to raise the pH values.These results were matched to similar studies such as a study of Alabdraba et.al., [40].
The table pointed also to total hardness that has higher seasonal average concentration (928) mg/l in summer in site (S2), and lower concentration (865) mg/l in winter in site (S1), Results referred that total hardness was higher in all seasons and sites, and above of Iraqi standard limits of drinking water [25; 26] that could be return to high concentrations of CaCO3 and CaSO4 in sediments and the near soils that gave more calcium ions to water [12].Also, the results (figure 8) showed there was a significant differentiation and positive correlation coefficient with temperature, TDS and E.C. (r=0.98;0.58; 0.63) respectively.
The hardness of calcium was indicated in the table where higher concentration of calcium hardness was (478) mg/l in autumn in site (S1), and lower concentration (411) mg/l in winter in site (S1), generally all concentrations of calcium hardness were above of Iraqi standard limits of drinking water [25; 26], because of highest concentration of CaCO3 in bedrock as mention in many studies such as study of Al-Khafaji and Al- Taee [41].while magnesium hardness showed higher concentration was (71) mg/l in autumn in site (S1), and lower concentration (44) mg/l in winter in site (S3).Results (figure 8) pointed that values of magnesium were in permission Iraqi standard limiting of drinking water [26; 42], and there was a significant differentiation among results, and negative correlation coefficient with temperature, TDS, total hardness and E.C. (r=-0.87;-0.97; -0.75; -0.98) respectively, that could be refer that concentration of magnesium in study stream didn't effect by these parameters but rather it depending on what mention in some study can be affected by the presence of dolomite rocks and clay minerals rocks in the study area [43].Also, results pointed that all concentrations were within Iraqi standard limiting of drinking water [25; 26].
At the end the table pointed to variation in seasonal average of dissolved oxygen (DO) and biochemical oxygen demand (BOD) concentrations in stream water, which the higher concentration of dissolved oxygen was (12) mg/l in winter in site (S3), and lower concentration (4) mg/l in summer in site (S2), the lower concentration could be return to the increasing the processes of aerobic decomposition to the organic matter and increasing of the average of the respiration of living forms [44], also, it can be due to the low rates of solubility of oxygen in the water due to higher temperatures [45] than the normal rates in most of the studied months.the results pointed (figure 9) to find positive correlation coefficient with pH and alkalinity (r=0.95;0.99) and negative with temperature, E.C. and total hardness (r=-0.88;-0.38; -0.96) respectively which means high temperature and high concentrations of salts can decrease dissolved oxygen.As for biological oxygen demand (figure 9) were higher concentrations showed in summer in site (S3) than other sites.Which could be returned to direct discharge organic wastes to water stream that decreasing the concentration of dissolved oxygen [46], also, the high concentration of BOD indicates to presents of microorganisms that decomposed organic compounds in water [47].
Finally the results in table (2) pointed that the value of the Canadian water quality index that calculation depending on the chemical parameters only showed that the water quality according to the index was 42.69 %, which means the water quality was in the fifth category according to the Canadian classification, which also means that the water quality is poor, and the water quality is almost always threatened or impaired, and the conditions usually depart from natural or desirable levels, and these could be return to the low levels of the stream and the large number of evaporation processes because of high temperature [48], in addition to the increased discharge of wastes that consume oxygen and raise the pH [44].All that can contribute to decrease the water quality index and pointed to reduce the value of water for direct human using and drinking.The table (3,4) showed there were nutrients such as (nitrate, nitrite and phosphate) in the stream water in all study sites, which the seasonal average of nitrate and nitrite appeared variation, where higher concentration of nitrate (90) mg/l in spring and summer in site (S2), and concentration of nitrite was (8.5) mg/l in spring in site (S3).While lower concentration of nitrate (59) mg/l in winter site (S1), and for nitrite was (2.1) mg/l in autumn in site (S1).Results (figure 10) appeared that concentrations of nitrate and nitrite were above Iraqi standard limiting of drinking water, also, showed a significant differentiation among seasons and among sites, with positive correlation coefficient with temperature and TDS (r=0.99,0.75) respectively.The high concentrations of NO2 and NO3 could be return to position of stream that passed through agricultural and urban areas [49] with higher possibility to reach fertilizers and nitrogen wastes to the water stream [50].
Also the table showed the concentrations of phosphate (PO4) were high in all sites, where higher concentration (9.9) mg/l in summer in site (S2), and lower concentration (0.8) mg/l in winter in site (S1).Results (figure 11) showed the concentration of phosphate was above Iraqi standard limiting of drinking water that allowed for phosphorus in freshwater [22; 23], and there was a significant differentiation among seasons with positive correlation coefficient with temperature, TDS and nitrate (r= 0.95; 0.49; 0.94) respectively which can be pointed to the possibility to find chemicals fertilizers in water.The higher concentrations of phosphate in stream water could be returned to discharge of sewage wastewater that rich in detergents [51], and could be pointed to reach agriculture land wastes that treated with phosphate and nitrogen fertilizers to the stream water [52].
Finally results in table (3) pointed that the value of the Canadian water quality index that calculation depending on the nutrients parameters only showed that the water quality according to the index was 17.48 %, which also means the water quality was also in the fifth category according to the Canadian classification, which also means that the water quality is poor, and the water quality is almost always threatened or impaired, and the conditions usually depart from natural or desirable levels, that means the water didn't suitable for drinking purpose, but can be used for watering agricultural lands because it is rich in nutrients, also, the low value of Canadian index could be return to the overloading of the stream by nutrients that exceed the permissible limits in the water stream.Generally, the Canadian quality index for Al-Mahawil stream after determined all physical, chemical and nutrients parameters, and gathering all variables and tests with combined all individual factors to provide a final index value, were 57.89 %, and there wasn't different between sites in WQI which means the water quality were in the fourth category according to the Canadian classification, and the water quality is marginal, which means the water quality is frequently threatened or impaired, and the conditions often depart from natural or desirable levels [CCME, 2001], and for that it can't use directly in drinking purpose.

5-Conclusions
Some physical and chemical parameter values were in permissible limiting standard of drinking water, but others were upper the permissible limiting standard of fresh water, also, nutrient compounds such as NO3, NO2 and PO4 were generally increased in water stream, make the value of canadian water quality very low, that make the water stream are suitable only for agricultures.In the other hand the concentration of O2 and BOD5 refereed to find high concentration of organic matters in water stream, that can be led to find microorganisms such as bacteria in water, for that the water of stream can't be benefit for drinking purpose without treatments.

6-Recommendations
1-Watching any changing in water flows in stream 2-Try to make a barrier between the water stream and agriculture lands that passed through it.
3-Cleaning the basin of stream and removed unpleasant plants from the stream from time to time 4-Educate people for Preventing discharge sewage, sludge, wastes or any other organic and inorganic compounds in stream water 5-Preventing throwing waste near the river or in the river, and the method of imposing fines can be used to prevent throwing waste into the river water.