Comparison of Groundwater Quality in Southern Province · Government of Netherland Funded Hydrology Project, 1999), increment of the ion concentration is proportionate to the electric

5th International Symposium on Advances in Civil and Environmental EngineeringPractises for Sustainable Development (ACEPS-2017)

Comparison of Groundwater Quality in Southern Province

B.M.J.K. Balasooriya1, G.G.T. Chaminda1, K.C. Ellawala1 and Tomonori Kawakami21Department of Civil and Environmental Engineering

Faculty of EngineeringUniversity of Ruhuna

Hapugala, GalleSRI LANKA

2Department of Environmental EngineeringToyama Prefectural University

JAPANE-mail: [email protected]

Abstract: Groundwater quality in southern province is varying considerably in between Galle, Mataraand Hambantota. Hambantota district has recorded as Chronic Kidney Disease in unknown etiology(CKDu) prevailing districts. Some researchers suggested that it has a relationship with contaminatedground water. Fluoride, Hardness, Heavy metals and other typical inorganic water quality parametershave been analysed in the samples collected from 303 stations. The parametric values of F-, Cl-, SO4

2-

, Na+, NH4+, Mg2+,Ca2+, Hardness and Mn in Hambantota are higher than the recommended maximum

level allowed according to the Sri Lankan Standard (SLS) for drinking water while NH4+, Al and Mn are

recorded in Matara. But in Galle district Pb shows high concentration by giving a clue towards thevehicle gas emission. Principal Component Analysis has identified 7 components in Galle whichexplains 75.4% of total variance. In Matara and Hambantota, 6 components explain 75% and 76% ofthe total variance respectively.

Keywords: Groundwater, Southern Province, Water quality, Fluoride, Hardness, CKDu

1. INTRODUCTION

By the consideration of global water resources, freshwater resources are unevenly distributed, withmuch of the water located far from human populations. Groundwater represents about 90% of theworld's readily available freshwater resources, and around 1.5 billion people depend upongroundwater for their drinking water because of its availability and constant quality and also it is thepreferred source of drinking water in rural areas, particularly in developing countries, because notreatment is often required. Clean water supplies and sanitation remain major problems in many partsof the world, with 20% of the global population lacking access to safe drinking water. (UNEP, 2008).Clean, safe and the adequate fresh water is very important for all the living organisms and also for theproper functioning of the ecosystems, communities and economies. So the quality of water is playingan important role in the global and local levels too.

On a national basis, proportion of the population having access to water supplies from piped watersystems, protected wells, or rainwater systems is currently almost 85%. About 44% of the populationhave access to piped water, 3% have access to hand pump tube wells, 36% of the rural populationhas access to safe drinking water through protected dug wells, and 1% of the population usesrainwater harvesting systems. However, 15% of the population is unable to access a safe watersource within 200 meters of their residence (Fan, 2015). Contamination of Ground water which isresulting from human activities or from inherent aquifer material composition reduces the supply ofsafe drinking water, posing a threat to public health. Dental and skeletal fluorosis, Chronic KidneyDisease due to Unknown etiology (CKDu), Oesophageal cancer and blue-baby syndrome are some ofthe seriously reported and discussed health impacts related to groundwater in Sri Lanka.

During the last two decades, most of the Dry Zone communities have shifted from surface watersources to groundwater resources and it is noted that both shallow and deep wells show similar levelsof natural contamination with fluoride (Chandrajith et al., 2012). In Sri Lanka, Anuradhapura,Trincomalee, Polonnaruwa, Puttalam, Kurunegala, Hambantota and Monaragala districts have theFluoride problem in endemic proportions (Nagasawa et al., 2013). The maximum Fluoride

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concentration has been reported as 7.0 mg/L in Anuradhapura district while maximum average concentration was reported in Moneragala (1.4 mg/L). In southern province, Fluoride concentration varies up to 5.8 mg/L (Kawakami, 2014). But, Sri Lankan standard for Fluoride in drinking water is 1.0 mg/L and that of WHO guideline is 1.5 mg/L (SLS, 2013)

According to the Kawakami et. al., (2014), maximum hardness concentration has been recorded in Hambantota district and it is about 1734 mg/L as CaCO3 while maximum permissible level according to the Sri Lankan Standard is 250 mg/L as CaCO3 (SLS, 2013). Chronic Kidney Disease in unknown etiology (CKDu) prevailing in the dry zone is supposed to have a relation with Fluoride and Heavy metals contamination in drinking and cooking water (Nagasawa et al., 2013). Soil type and climatic changes also may affect in depletion of water quality and change the toxic level. Therefore, detailed analysis of water quality in each district is needed to have clear idea about the quality of the ground water. This is an overview of groundwater quality in southern province and a comparison of between each district.

2. METHODOLOGY

2.1. Water Quality Analysis

The study was limited to Southern Province Sri Lanka. Analysis has been conducted for 303 sampling locations covering all three districts. It includes 86 locations in Galle, 75 locations in Matara and 142 locations in Hambantota as shown in the locations Map in Figure 1.

Figure 1 Sampling Locations

2.2. Sample Analysis

All the parameters have been measured using standard methods (APHS, 1998). Measured parameters and analysis methods are summarized below (Kawakami, et al., 2014).

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pH : pH MeterEC : Electric conductivity MeterNa+, NH4

+, K+, Mg2+, Ca2+ : Ion Chromatography for cationsF-, Cl-, NO3-, SO4-,PO4- : Ion Chromatography for anionsAl, Cd, Pb, Zn, Cu, As : ICP-MS

2.3. Statistical Analysis

Statistical analysis was carried out using SPSS 16.0 version. Pearson Product moment correlation coefficient analysis and the Principal component analysis were applied for the data set. The analysed groundwater parameters include; Fluoride, pH, Electric Conductivity, Hardness, Chloride, Nitrate, Ammonium, Sulphate, Sodium, Potassium, Magnesium, Calcium, Cadmium, Arsenic, Led, Aluminum, Chromium, Manganese, Iron, Nickel and Zinc. Values were compared with Sri Lankan Standards (SLS) for potable water.

2.3.1. Pearson Correlation

For the first screening, the Pearson product moment correlation coefficients were calculated for eachdistrict to identify relationships between parameters. Correlation coefficients obtained from thecorrelation matrix were categorized under three different categories as highly correlated, moderatelycorrelated and lightly correlated. The range of coefficients for each case was (1<X<0.7), (0.7<X<0.4),(0.4<X<0) respectively when X is the correlation coefficient.

2.3.2. Principal Component Analysis

Then, Principal Component Analysis was (PCA) performed on experimental data. PCA was applied totransmute the original variables into new, uncorrelated variables, called the principal components,which are linear combinations of the original variables (Pejman et. al., 2006). It also providesinformation on the most meaningful parameters, which describe the whole data set interpretation, datareduction, and to summarize the statistical correlation among constituent in the water with minimumloss of original information.

3. RESULTS AND DISCUSSION

Ground water quality data at 303 stations in Southern province were analyzed and compared with theSri Lankan Standard (SLS, 2013) for drinking water. The parametric concentrations of NH4

+, Pb inGalle are higher than the standard values while NH4

+, Al and Mn in Matara are exceeded theirstandard values for potable water. In Hambantota district, concentrations of F-, Cl-, SO4

2-, Na+, NH4+,

Mg2+, Ca2+, Hardness and Mn are higher than the recommended maximum level allowed according tothe Sri Lankan Standard (SLS) for drinking water (Table 1).

3.1. Pearson Correlation

According to results obtained from the correlation matrices EC is having a high correlation with most of

the ionic parameters such as Cl-, SO42-, Na+, Mg2+ and Ca2+ in Galle and Hambantota districts. Matara

district also, EC is highly correlated with Cl-, Na+, Mg2+ and Ca2+. As discussed in (World bank and

Government of Netherland Funded Hydrology Project, 1999), increment of the ion concentration is

proportionate to the electric conductivity of water. Therefore, it may be the reason for increasing EC

values in southern province. Further, As is having moderate correlation with F-, Mg and total hardness

in Galle district. In Matara district also As is moderately correlated with F- while correlation with

hardness is high. But, in Hambantota As and F- correlation is law although As-Hardness correlation is

high. It also explains in Nagasawa et al., (2013). Acording to the analytical results, areas having

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groundwater with high Hardness concentrations are overlap with the areas having high As

concentrations. Therefore further investigations are required to find the relationship between As and

Hardness with CKDu issue.

Table 1 Water quality parametric values in each District

(Mean ± SD) (Mean ± SD) (Mean ± SD)

Values exceeded SLS standards are shown in italic font.

3.2. Principal Component Analysis

The scree plot was used to identify the number of PCs in each district. PCs having Eigen value greater than one was considered. Seven components were retained which have eigenvalues greater than unity and explain 75.4% of the variance or information contained in the original data set in Galle. In Matara and Hambantota, extracted components number was 6, which explain 75% and 76% of the total variance respectively.

In Galle district PC1 explains 29% of the total variance while PC2 and PC3 explain 12% and 10% respectively (Table 1). F-, EC, Cl-, SO4

2-, Na+, Mg2+ and Ca2, Total hardness and the As are highly contributed to PC1 by explaining the natural patterns of mineral solubility in ground water. Normally, the salinity status of a water sample is determined by its electrical conductivity (Amarasiri, 2015). As, Galle, Matara and Hambantota are belonging to coastal belt, saline water can be mixed to the groundwater. It may be the reason for high Electrical Conductivity. According to the Cooray (1994) and Chandrajith, et al., (2012), Sri Lanka is geologically dominated by Precambrian high-grade metamorphic rocks and it can be divided into three major lithotectonic units namely, the Highland Complex, the Vijayan Complex and the Wanni Complex. Galle and Matara lie in Highland Complex and Hambantota lies in Vijayan Complex (Anon., 2017). Metamorphic rocks like Quartz, feldspar, garnet, sillimanite, graphite schists, quartzites, marbles and calc-silicate gneisses are prominent

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rock types in Highland Complex. Hornblende gneisses, charnockitic gneisses and granites are common in Vijayan complex. It consists of fluoride-bearing minerals such as micas, hornblende, sphene and apatite.

Further, minerals such as fluorite, tourmaline and topaz are also found in many locations and these also contribute to the general geochemical cycle of fluorine in the physical environment. These gaseous compounds may dissolve in groundwater with the presence of rains. Therefore, these natural phenomena can be the reason to categorize all hardness and other mineral compounds into one component with highest variance. Al, Ni and Cu are the contributing factors for PC2. Al can be released from anthropogenic activities such as Laundry detergent, cement, aspirin, roofing, soda cans, house siding, spark plugs, foil containers, foil wrap, makeup, appliances, fluorescent light bulbs, dishwashers, cookware coatings, chemicals, deodorant, polishing compounds, household siding, antacids, toothpaste, multiple types of transportation vehicles (Leigh, 2010).Ni and Cu can be added through industrial, agricultural, pharmaceutical, domestic effluents, and atmospheric sources(Tchounwou, et al., 2014). But natural weathering processes far exceed the contribution of releases these metals to the environment (Anon., n.d. and Cempel, 2005). Therefore, it gives a clue towards a natural trend than the anthropogenic impact. In other componants individual parameters has been invade a whole componants, but there is no patterns in the variation. Last component is mainly contributed by Pb and it may happen due to the dissolution of resiudes of vehicle emission in the groundwater (Ministry of Environment, 2001).

Table 2 Major Principal components in Galle District

Dominated ions in each component are shown in bold, italic font.

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Table 3 Major Principal components in Matara District

Dominated ions in each component are shown in bold, italic font

In Matara district also shows similar componanets in PC1 and PC2. But NH4+ invades PC3 possitively

while Zn contributes it negatively. As Matara is paddy cultivated district fertilizer washout may show an increment in NH4

+.Other componant are not showing any pattern as they invade as single elements.

In Hambantota district, pattern is different from other two districts. Hambantota lies in Vijayan Complex (Cooray 1994 and Chandrajith, et al., 2012). It may be the reason for the avaiability of high mineral compounds into one PC than other two districts. Metals are distributed from second PC in Hambantota but patterns can not be concluded.

4. CONCLUSION

According to the statistical analysis of groundwater quality, parametric values of and Pb exceeded the accepted permissible level according to the SLS: 2013 in Galle. Matara district showed

exceeded concentrations for , Al and Mn according to SLS standards. Hambantota exceeded accepted permissible levels of SLS for F-, Cl-, SO4

2-, Na+, NH4+, Mg2+, Ca2+, Hardness, Mn. Invaded by

Vijayan rock Complex, climatic differences between three districts and other natural phenomena may be the major reasons for quality reduction as Hambantota is not much populated, cultivated or industrialized area. Vehicle gas emission may be the reason for the high Pb concentration in Galle district. Therefore, further investigations are required for the preventive actions and to enhance the quality of ground water.

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Table 4 Major Principal components in Hambantota District

Dominated ions in each component are shown in bold, italic font

5. ACKNOWLEDGMENTS

Matara is sincerely acknowledged.

6. REFERENCES

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Anon., 2017. The Mahaweli River and climatic zones. [Online] Available at: https://www.google.lk/search?q=soil+type+map+of+sri+lanka&biw=1366&bih=662&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjco4CRv9fRAhWHQI8KHUITCCQQ_AUIBigB#q=soil+type+map+southern+province,+Sri+Lanka&tbm=isch&tbs=rimg:CVn8FrBBOKKfIjgNsDOU2hzABUv-gXax6PCkioPQcchg9

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Comparison of Groundwater Quality in Southern Province · Government of Netherland Funded Hydrology Project, 1999), increment of the ion concentration is proportionate to the electric