Validity assessment of some spring water in Akra District, Kurdistan region, Northern Iraq as a safe drinking water

In this study, lasted for six months from October 2016 to April 2017 in the Akra district of Duhok governorate, we found out the validity of the spring water of the area to be used as drinking water. Indeed, the aim of this study was to assess the validity of the water of spring of the Akra area for human consumption as potable water. The results showed us after the analysis and laboratory examinations (i.e., electrical conductivity (EC), total alkalinity (TA), total dissolved solids (TDS), pH, total hardness (TH), magnesium (Mg 2+ ), Calcium (Ca 2+ ), Dissolved oxygen (DO), and Chloride (CL - )) of all springs water of the region in terms of physical and chemical properties are safe to drink and can be identified as a good source of human consumption. Although there is a difference in some physical and chemical properties in some springs of water in that area, it did not exceed the limits and international standards for drinking water. Therefore, the people of this region can use the water of those springs to drink without fear of any health effects.


Introduction
*Springs are the principal source of domestic water supply for rural communities in the Kurdistan region. The quality of the spring water is highly related to the local environmental and geological conditions. The regular withdrawal and hence changes the groundwater table of a source. There are many water springs in many countries vary in physical and chemical properties depending on the geology of the region where some of them are characterized by high temperature and increase in the proportion of sulfur salts and the lack of potable water to drink as the area of Bath Alalil in the province of Nineveh in Iraq as well as in the city of Aachen in Germany Federal and similar institutions in the State of Iceland and the quality of groundwater also changes (Tamilarasi et al., 2015). To provide safe drinking water especially to rural population, groundwater has been sought as the source in many developing and undermined by both natural processes, (Dissolution and precipitation of minerals, groundwater velocity, quality of recharge waters and interaction with other types of water aquifers) and anthropogenic activities (Devic et al., 2014). If water is suitable for drinking, it can also be safe for all other purposes. Usually, groundwater is safer than surface water in normal conditions, as it is naturally protected from the contamination caused by the infiltration of recharge water through soil cover. However, soils can be contaminated as a result of human activities. On the other hand, toxicity of minerals present in soils and rocks can also be caused by groundwater contamination following geochemical processes. Thus, fresh infiltrating recharge water can affect the quality of pure groundwater (Rao, 2008). This spring serves as a water source for the inhabitants of the area who utilize the water for their daily activities. Hence there arose the need to assess the quality of this spring to make recommendations where necessary. The present study was carried out to assess the spring water quality around Akra District.

Geology of the study area
The geological formations of the area consist of deposits of the Eocene age represented by following formation 1-Kolosh: represented by an alteration of clay marl, dolomite marl, and clay limestone polemicist. 2-Gecus: represented by an alteration of dolomite marl and siltstone with some gypsum rocks. 3-Fragmental Detritus: represented by small rocks fragments. The quaternary is represented by alluvial and diluvia deposit. 4-pelaspi limestone: represented by slightly dolomite limestone and dolomite. An important here is the mineral spring water which appears on the limit between the Eocene and chalk deposit in the tail of reservoir. Their discharge is not constant and decreases considerably during the dry summer period (Ameen and Karim, 2009).

Materials and methods
Nine springs were collected from Akra district, Kurdistan region, Iraq (Fig. 1). Monthly samples were collected from the springs during the period October 2016 to April 2017. The samples, electrical conductivity (EC), pH, total dissolved solids (TDS), total alkalinity (TA), total hardness (TH) magnesium (Mg 2+ ) and Calcium (Ca 2+ ). Were brought to laboratory and analyzed for the selected parameters using the standards methods (White, 1988). The pH, temperature and electrical conductivity parameters of the samples were determined in the field at the point of collection of the samples with appropriate instruments of measurement. The collected data were statistically analyzed to compare between the spring water quality using ANOVA and Duncan multiple range test.

Results and discussion
In the present study, the temperature value of all water samples ranged from 8.2 to 18.2°C. As shown in Fig. 2 from Table 1, there was significant variation in water temperature between the studied springs. The mode of variation was different with a month. This reflects the variation of the nearby feeding source. Table 1 shows that the temperature of the spring's water varies throughout the study period, dropping in winter and rising in summer in all the studied springs. This indicates that these springs are of conduit type, which is affected by the runoff in winter and spring which does not allow them to come in chemical equilibrium due to the low residence time and short path length because of the mountainous topographic nature of the area. This will lead to the monthly variation in the water quality of these springs (APHA, 1999).  In the present study, the concentration of electrical conductivity (EC) in all sampling points were ranged from 480.7 to 1322.7 μs/cm as shown in Fig. 3. Significant variation of electrical conductivity was recorded among the studied springs (Table 2). Kadane, Dostaka and Hanare springs have the lowest electrical conductivity along the studied period. On the other hand, Banee spring water has the highest electrical conductivity among the studied springs during the studied period. The conductivity is produced by the erosion of the natural deposits and the dissolution of minerals from the media which the water passes through. In this study are significantly higher than those reported by Asadi et al. (2007).  In the present study, the concentrations of TDS in all sampling sites were ranged from 341.7 to 859.7 mg/l as shown in Fig. 4 for total dissolved solids (TDS). Table 3 shows a significant variation between the studied springs. As it has strong relationship with conductivity, TDS demonstrate the same mode of variation between springs. Kadane, Hanare and Dostaka springs have the lowest TDS with a significant difference from the others. In construct Banee spring water has the highest TDS along the study period. According to WHO (2009) andEPA (2006) classification of water for drinking, TDS of this spring was above the recommended level (500 mg/l). In this study are significantly higher than those reported by Zidi et al. (2017).
The pH of all water samples ranged from (7.17 to 8.84). As shown in Fig. 5 from Table 4, all the results of spring's pH values were on the alkaline side of neutrality. This is probably due to the increase of runoff in this season and accordingly the dissolution of carbonates. Also, they are within the range of UK Regulation (5.5 to 9.5) of drinking water (Twort et al., 2001). In this study are significantly higher than those reported by Lebrahimi et al. (2018).
High dissolved oxygen concentration was recorded in the studied springs between 7.13 to 10.53 mg/l in the water springs. As shown in Fig. 6 Table 5. This indicates the absence of any organic pollution in these springs and the shallow feeding sources of these springs. The highest dissolved oxygen values were distributed between Hanare spring five times and once for each Kadane and Baze spring. In this study are significantly higher than those reported by Gawai and Nandre (2017).    For total hardness, it ranged from 286.33 to 604.33 mg/l as shown in Fig. 7 from Table 6. These values were very far from the hardness of the springs of bottled water (more than10mg/l). Little variation was recorded between springs. Halora and Baze have more hardness than the others, at about all the studied months. According to the classification of WEDC (1997) all the springs produce very hard water. On the other hand and according to WHO (2009), most of the springs were lower than the recommended level of hardness 500mg/l, except Halora, Banee, Dostaka, and Baze. The carbonaceous nature of the geological formation of Akra District especially limestone and dolomite contribute to hardness increase as the water pass through them. In this study are significantly higher than those reported by Toure et al. (2017).    Calcium hardness is part of the total hardness. The results in Fig. 8 from Table 7 show little variation in calcium hardness among the studied springs. The variation in calcium hardness was convenient with that of the total hardness. Halora and Banee springs have the highest values along the study period. It represents the major part of hardness. Table 7 shows a significant difference in calcium hardness along the study period except in Napakhe spring. The nearby feeding source and the seasonal variation in them contribute to this variation. Similar results reported by Kilwake et al. (2017).   The principal source of magnesium hardness in the springs in the studied area is dolomite. Magnesium hardness ranged from 6.2 to 61.9 mg/l as CaCo3. As shown in Fig. 9 from Table 8, Hanare springs have the lowest magnesium hardness along the study period. On the other hand, Napakhe, Kafea, Deawe, baze, and Dostaka springs have the highest magnesium hardness. The values of magnesium hardness were very low in comparison with calcium hardness. Which reflects the geological formation of the study area. Similar results reported by Gawai and Nandre (2017).  Chloride ion concentrations ranged between 11.63 to 49.6 mg/l. As shown in Fig. 10 from Table 9 the lowest values were recorded in Hanare, and Banee along the study period and in Dostaka spring at January to April. All the values were lower than the recommended values by EPA of 250 mg/l. Table   0  shows that Napakhe and Deawe springs have the highest seasonal variation in chloride. This is probably due to the variation in the feeding source flow rate and level. In this study are significantly lower than those reported by Zidi et al. (2017).  The alkalinity of water comprises the sum of bicarbonate and carbonate of Calcium, Magnesium, Sodium, and Potassium. It provides the buffering effect of PH. The lowest alkalinity values were recorded in Banee spring with a minimum value of 161.33 mg/l in November, while the highest values were recorded in Nabakhe and Deawe spring with the highest value of 426.33mg/l in Deawe spring. As shown in Fig. 11 from Table 10. All the springs exhibit seasonal variation in Alkalinity, except Kadane spring. In this study are significantly lower than those reported by Batool et al. (2018).

Conclusion
 The water quality of the studied Akra district springs was not so fresh but it is acceptable for drinking for the studied parameters.
 Akra springs within the studied area were of conduit type as they exhibit monthly variation in temperature and water quality.  Akra springs within the studied area have very hard water due to the geological formation.

Site
 The water of Akra springs within the studied area cannot be utilized for the bottled water without treatment.