Effect of Depth and Distance of the Borehole from the Septic Tank on the Physico-Chemical Quality of Water

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1 Effect of Depth nd Distnce of the Borehole from the Septic Tnk on the Physico-Chemicl Qulity of Wter Chove Lucy Mlipno Sokoine University of Agriculture (SUA), Deprtment of Food Technology, Nutrition nd Consumer Sciences, P. O. Box 3006, Morogoro, Tnzni E-mil: Mongi Richrd Sokoine University of Agriculture (SUA), Deprtment of Food Technology, Nutrition nd Consumer Sciences, P. O. Box 3006, Morogoro, Tnzni E-mil: Chenge Lwrence Tnzni Bureu of Stndrds, P. O. Box 9524, Dr es Slm, Tnzni E-mil: Received: July 9, 2017 Accepted: Decemer 26, 2017 Pulished: Decemer 28, 2017 doi: /jfs.v7i URL: Astrct A study to exmine the effect of depth nd distnce of the oreholes from the septic tnk on physico-chemicl prmeters of the orehole wter consumed in Dr Es Slm, Tnzni ws conducted. Smples were collected from 48 oreholes in Ill, Kinondoni nd Temeke districts nd sujected to ph, B.O.D (Biologicl Oxygen Demnd), totl hrdness, copper nd led nlyses in reltion to sfety nd qulity levels set y WHO nd TBS. Anlysis y R-sttistics indicted tht ph nd B.O.D significntly (p<0.05) decresed s the depth of orehole incresed, wheres totl hrdness ws significntly (p<0.05) higher in very deep oreholes thn the other heights. Totl hrdness nd ph were not significntly (p>0.05) ffected y distnce etween septic tnk nd orehole nd the B.O.D levels were significntly higher in the orehole wter situted ner the septic tnk thn those which were 41

2 fr. Bsed on the physico-chemicl chrcteristics of wter, 25% of the smples did not comply with WHO nd TBS specifiction limits while 75% complied, most of which hd shllow depths nd were situted ner the septic tnk. It my thus e concluded tht oth the distnce nd the depth etween septic tnk nd orehole influenced physico-chemicl chrcteristics of wter. Keywords: B.O.D, Copper, Led, ph, Totl hrdness 1. Introduction Wter is importnt for the existence of ny forms of life (Khdsn & Mngesh, 2003). There re lot of guidelines, stndrds nd regultions on drinking wter qulity tht cn offer pulic helth protection (WHO, 2011). Drinking wter is defined s potle wter intended for humn consumption (TBS, 2008). Sfe wter is importnt for humn helth nd sustinle development (Sungsitthiswd & Pitksnurt, 2013). In mny developing countries, citizens ccess to relile nd sfe wter is chllenge (Kpongol et l., 2014). Groundwter is commonly lterntive wter resources in res where surfce wter is not ccessile (Sungsitthiswd & Pitksnurt, 2013). Ground wter constitutes 97% of glol fresh wter (Bhrti et l., 2011) whose quntity, qulity, ccessiility nd rechrge depend mostly on geology, geomorphology, lnd use nd levels of precipittion (Elisnte & Muzuk, 2015). There re mny fctors tht hve to e considered when ccessing the qulity nd sfety of ground wter s the drinking wter. The wter qulity nd sfety indictor include the testing for totl coliforms, fecl coliforms (E. Coli), inorgnic contminnts, orgnoleptic (ppernce, tste nd odor) slinity, hrdness, nturl nd rtificilly orgnic pollution nd ph (TBS, 2008). The qulity of ground wter is the result of the processes nd rections tht ct on the wter nd vries from one plce to nother depending on the depth of the wter tle (Aong o et l., 2017; Mohn et l., 2014). Groundwter cn e contminted y chemicls s well s microorgnisms (Bhrti et l., 2011). Furthermore groundwter resources in costl res like Dr Es Slm re lwys in dnger of contmintion y se wter intrusion (Mtoni et l., 2012). Generlly, groundwter ecomes purer with increse in depth (Ojo et l., 2012). Boreholes in Tnzni re clssified s shllow (0-30 m), medium (31-50 m), deep (51-80 m), nd very deep (>80 m) (Kshigili, 2012; Bumnn et l., 2005). It hs een reported y Likmo (2014) tht the further the distnce from the orehole from the potentil source of pollution, the more difficult it will e to ecome contminted. In Tnzni, there is limited informtion on the physico-chemicl qulities of groundwter sed on their depth nd distnce to the septic tnk 2. Mterils nd Methods 2.1 Study Are This study ws crried out t in three districts of Dr Es Slm region nmely Kinondoni (including Uungo), Ill nd Temeke (including Kigmoni). 42

3 43 Journl of Food Studies 2.2 Mterils Smples of orehole wter from the three districts of Dr Es Slm were used. Anlyticl grde regents nd chemicls, pprtus nd lortory equipment were otined from TBS (Tnzni Bureu Of Stndrds) nd WDMI (Wter Development nd Mngement Institute) Lortories. Tpe mesure ws purchsed from supplier in Dr Es Slm. 2.3 Study Design Rndomized Complete Block Design ws used in the study, where depth of the orehole (t 4 levels) nd distnce from the septic tnk (t two levels) were the principl fctors. The effects of these fctors on physico-chemicl qulity of wter were ssessed. The mthemticl model is s depicted in Eqution elow 1. Yij = μ +αi + βj +εij (1) Where μ is overll men, αi is the effect of tretment i (depth of the orehole), βj is effect of lock j (distnce to septic tnk) nd εij rndom error 2.4 Smpling Pln nd Dt Collection Purposive smpling pln ws used to collect smples from selected oreholes in the three districts of Dr Es Slm. A totl of 48 smples were collected. Smples of two liters of wter were collected fter sterilizing the wter tp/nozzle using cotton wool soked in 70% (v/v) ethnol nd llowed wter to run for 1 minute. Smpling ws crried out from Novemer 2016 Jnury Smples were collected in the trnsprent clen nd sterile 500 mls glss ottles (Durn, mde in Germny) ut smples for B.O.D nlysis were collected in the mer glss ottles. Smples were stored in n insulted ice ox nd trnsported to the TBS nd WDMI lortories for further nlysis. 2.5 Physico-chemicl Lortory Anlyses ph It ws determined ccording to ISO 10523:2008. Results were expressed nd recorded in two deciml plces Totl Hrdness It ws nlyzed ccording to ISO 6059:1984 procedures. Results were expressed in milligrm per liter of CCO Biochemicl Oxygen Demnd (B.O.D) The Biochemicl Oxygen Demnd of the wter smples for 5 dys t 20 o C were determined ccording to ISO :2003. The smples were equilirted t 20 o C followed y determintion of the dissolved oxygen concentrtion t dy 0 nd dy 5. Results were expressed in milligrm per liter Metl contminnts Copper (Cu) nd Led (P) Copper (Cu) nd Led (P) were nlyzed ccording to ISO 11885:2007. Results were expressed in milligrm per liter. 2.6 Sttisticl Dt Anlysis Dt ws nlyzed using R- sttisticl pckge softwre version Anlysis of Vrince (ANOVA) ws crried out to determine the significnt difference etween the min fctors. Mens were seprted using Tukey s Honest t p<0.05.

4 3 Results nd Discussion 3.1 The Effect of Depth of the Borehole On Physico-chemicl Chrcteristics of the Wter Effect of Depth on ph of Wter The ph of the wter smples collected ws s shown on Figure 1. There were significnt differences (p<0.05) in ph etween the vrious levels of depths in ll the districts. Shllow nd medium oreholes hd higher ph thn the deep nd very deep oreholes which were significntly different (p<0.05) t ll depth levels for ll the districts. Figure 1. Effect of depth on ph. Brs re expressed s men ± SD (n=48). Br with different letters re significntly different t p<0.05 These findings confirm tht the ph of wter from shllow nd medium orehole ws significntly higher compred to deep nd very deep wells. Furthermore ll the shllow nd medium oreholes wter ph fll with the recommended ph of drinking wter is for Tnzni (TBS, 2008) nd (WHO, 2011). It ws further reveled tht 25% nd 16.7% of the deep nd very deep oreholes wter respectively, did not comply with the WHO nd Tnzni stndrds s they showed slightly cidic ph. The lower the ph of wter, the more likely it to e corrosive (WHO, 2011). The slightly higher ph of the shllow nd medium oreholes wter which most of them were round or ner the costl re of Dr Es Slm were ttriuted y resons tht most of them derived from the limestone quifer (Mtoni et l., 2012). The limestone ws found long nrrow costl elt (Mto, 2002). In dditionl, Witte (2012) found higher ph vlue for oreholes wter tht were closer to the cost nd indicted tht it ws possily due to the presence of the corl reefs. When clcite in the reef dissolves, clcium nd cronte re set free. Furthermore Mtoni et l. (2012) reported tht icronte ws the dominnt nion in the upper quifer while in the lower quifer chloride ws the dominnt nion. Ain nd Oshunrinde (2016) confirmed tht lklinity of wter ws due to the presence of crontes, icrontes, nd hydroxides. 44

5 3.1.2 Effect of Depth on Biochemicl Oxygen Demnd (B. O. D) Although ll smples fll within the mximum B.O.D (6.0 mg/l) estlished y TBS (TBS, 2008), there were significnt differences (p<0.05) in B. O. D. etween the depth ctegories within the districts (Figure 2). Shllow oreholes hd significntly (p<0.05) highest B.O.D compred to the rest of the depth ctegories (Figure 2). Significntly similr lowest vlues in deep nd very deep oreholes were oserved in Ill, Kinondoni nd Temeke. The B.O.D significntly (p<0.05) decresed s depth of the orehole incresed. Also the results showed tht the Temeke oreholes wter contined the highest mount of B.O.D followed y Ill while in Kinondoni hd lest s shown on Figure 2. Figure 2. Effect of depth on B.O.D. Brs re expressed s men ± SD (n=48). Br with different letters re significntly different t p<0.05 The results confirmed tht generlly B.O.D of the orehole wter decresed s the depth of the well incresed. Ojo et l. (2012) reveled tht groundwter ecomes purer with increse in depth. The higher level of B.O.D indictes groundwter pollution (Ojo et l., 2012). The higher level B.O.D on the shllow oreholes compred to deep oreholes indicted tht shllow oreholes wter contined more orgnic mtter compred to deep oreholes. Sindelr (2015) reported tht s wter moved through soil, it ws continuously eing clened. Therefore s wter moved to the deeper quifers, it ws further clened compred to tht which moved on the upper quifers Effect of Depth on Totl Hrdness of Wter Figure 3 showed tht there were significnt differences (p<0.05) in totl hrdness within nd etween the districts t ech level of depth. Very deep oreholes hd the significntly highest levels of wter hrdness compred to shllow oreholes. The highest levels were found in very deep orehole of Kinondoni nd Temeke s shown in Figure 3. The lowest levels were 45

6 found in the shllow oreholes in Ill, Kinondoni nd Temeke respectively. On verge the Kinondoni oreholes hd the highest levels totl hrdness followed y Temeke nd lstly Ill. Figure 3. Effect of depth on totl hrdness. Brs re expressed s men ± SD (n=48). Br with different letters re significntly different t p<0.05 Groundwter is normlly hrder thn surfce wter ecuse of its high soluilizing potentils from rocks contining gypsum, clcite nd dolomite (Ojo et l., 2012). Despite of other negtive effect, minerls dissolved in wter hve enefits of contriute to the tste of drinking wter (WHO, 2011). According to the TBS specifiction the mximum hrdness in drinking wter is 600 mg/l (TBS, 2008). Aout 16.7% of ll smples did not comply wherey 62.5% were from very deep oreholes. Ain nd Oshunrinde (2016) reported tht wter hrdness ws cused y nturl ccumultion of slts from contct with soil nd geologicl formtion. Therefore the longer groundwter tkes to move through the sediments, the more minerlized it ecomes. Thus, groundwter incresed in minerl content s it moved long through the pores nd frcture openings in rocks. This cused deeper wters to e highly minerlized Effect of Depth on Metl Contminnts (Led nd Copper) The levels of the copper nd led were detected in ll districts (Figure 4). There were significnt differences (p<0.05) in copper within nd etween the districts with shllow, medium, deep nd very deep. All the smples met the mximum limits estlished y WHO nd TBS. The highest copper vlues were found in medium depth of Ill nd very deep depth of Temeke while the lest levels were identified in very deep of Ill followed y very deep of Kinondoni (Figure 4). Led ws detected only in deep nd very deep oreholes wherey in Ill nd Temeke were found only in deep oreholes while in Kinondoni were found only in very deep oreholes (Figure 4). 46

7 Figure 4. Effect of depth on copper nd led. Brs re expressed s men ± SD (n=48). Br with different letters re significntly different t p<0.05 Contmintion of metls from pipe fitting ws rre regrdless of the wter cidic ph ecuse of chnges in technology of using metl pipes to PEX pipes (Crosslinked Polyethylene). PEX pipes re eing commonly used nowdys s domestic wter pipes. WHO (2011) relized tht pluming mterils, pipes, fittings nd cotings cn result in elevted hevy metl. Shllow nd medium oreholes showed less mount of led compred to deep nd very deep oreholes s it ws identified y WHO (2011) tht wters with high ph, clcium nd lklinity re less corrosive to the metl prts of wter distriution systems. Furthermore WHO (2011) cknowledged tht high levels of dissolved oxygen hve een shown to ccelerte copper corrosion from copper pipes. Moreover ground wter depth nd qulity vries from plce to plce s it ffected the qulity of wter s it moved in vrious kinds of rocks, soils nd pick up nturl contminnts (Peter-Ikechukwu et l., 2015) Complince of Physico-chemicl Chrcteristic of Wter to TBS nd WHO Limits in Reltion to Depth Tle 1 shows distriution of oreholes depth ccording to complince on physico-chemicl specifictions s set y WHO nd TBS. Despite the oserved vritions, wter smples from different depth levels were within the mximum llowle limits for BOD nd metl contminnts (Copper nd Led) set y WHO nd TBS. 47

8 Tle 1. Distriution of oreholes depth ccording to their complince to WHO nd TBS stndrds on physico-chemicl specifictions Depth Pss (%) Prmeter Fil Totl (%) ph B.O.D Hrdness Comintion Su Totl Shllow 12 (100) (0) 12 (100) Medium Deep V. Deep 9 (75) 9 (75) 6 (50) (25) 3 (25) 6 (50) 12(100) 12(100) 12(100) This indictes tht 16.7% of the smples totl hrdness were ove 600 mg/l estlished y TBS (2008) nd 10.4% of ll smples did not comply with neither WHO nor TBS, whose ph should rnge etween ph nd etween respectively (WHO, 2011; TBS, 2008). 3.2 The Effect of Distnce from the Septic Tnk to the Borehole on Physico-chemicl Chrcteristics of the Wter The Effect of Distnce etween the Septic nd Borehole on ph Figure 5 shows tht there were no significnt differences (p<0.05) in ph resulting from the effect of the distnce etween septic tnk nd orehole ph Ill Kinondoni Temeke Loction Ner Fr Figure 5. Effect of distnce etween orehole nd septic tnk in reltion to ph. Brs re expressed s men ± SD (n=48). Br with different letters re significntly different t p<0.05 Fur-Mnuel nd Jumo (2014) reported tht the effect of the distnce from the septic tnks to oreholes is noticele where the djoining geologicl formtion is fissured. Erth fissures re ssocited with sin susidence tht ccompnies extensive ground wter 48

9 mining. During torrentil rins they erode rpidly presenting sustntil hzrd to people nd infrstructure. Moreover, fissures provide redy conduit to deliver runoff nd contminted wters to sin quifers (AGS, 2011). Fissures hve destroyed pipelines, rods, cnls, nd even homes. Erth fissures crete n esy plce for groundwter to ecome contminted (AGS, 2011) which my result in ph chnges. However, Fur-Mnuel nd Jumo (2014) found no significnt difference in ph in reltion to the distnce etween the septic tnk nd the orehole. Eze nd Eze (2015) confirmed tht there were slight vrition in ph ut vritions did not show ny correltions with the distnce of the orehole from septic tnk The Effect of Distnce etween the Septic nd Borehole on B.O.D There were significnt differences (p<0.05) in Biochemicl Oxygen Demnd (B.O.D) of the oreholes tht were constructed ner ( 15m) nd fr ( 15m) from the septic tnk. The B.O.D significntly decresed (p<0.05) s the distnce etween the orehole nd septic tnk incresed irrespective of the districts (Figure 6). The B.O.D of the oreholes wter ws significntly higher in the oreholes tht were nerer the septic tnk thn those which were further nd vice-vers. Although the highest B.O.D were found in oreholes tht were ner the septic tnk in Ill followed y Temeke nd finl Kinondoni, no significnt differences in B.O.D. levels were found etween the three districts (Figure. 6). 2 BOD (mg/l) Ill Kinondoni Temeke Loction Ner Fr Figure 6. Effect of distnce etween orehole nd septic tnk in reltion to B.O.D. Brs re expressed s men ± SD (n=48). Br with different letters re significntly different t p<0.05 The B.O.D results of ll smples rnged from 0.9 to 1.4 mg/l which complied with the TBS limit of 6 mg/l s mximum (TBS, 2008). There were higher orgnic mtter in oreholes wter which were closer to the septic tnk thn those fr from the septic tnks. The higher orgnic mtter in the wter ws contriuted y effluent from the septic tnk. In view of the ove McQuilln (2004) confirmed tht domestic wter utiliztion dds orgnic mtter 49

10 (typiclly mesured s iochemicl oxygen demnd, BOD) to sewge. Therefore the higher orgnic mtter in orehole wter ner the septic tnk werecontriuted y sewge in the tnk The Effect of Distnce etween the Septic nd Borehole on Totl Hrdness There were significnt differences (p<0.05) in totl wter hrdness of oreholes locted t distnces ner ( 15m) nd fr ( 15m) from the septic tnk in Ill nd Kinondoni districts (Figure 7). However, no significnt differences (p>0.05) in totl wter hrdness etween the two distnces in Temeke district. In Ill district, the frther the distnce etween orehole nd the septic tnk, the higher the levels of totl wter hrdness. The sitution of the Kinondoni district however, ws the opposite (Figure 7). 500 Totl Hrdness (mg/l) Ill Kinondoni Temeke Loction Ner Fr Figure 7. Effect of distnce etween orehole nd septic tnk in reltion to wter hrdness. Brs re expressed s men ± SD (n=48). Br with different letters re significntly different t p<0.05 In view of the ove Figure, since there ws no cler pttern to explin the differences in the three districts, there re proly other fctors which contriuted to wter hrdness more thn distnce etween septic tnk nd the oreholes. Plmuleni nd Akoth (2015) mentioned other fctors which contriuted to groundwter minerls composition included sesonl chnges of the wter depending on the types of soils, rocks nd surfces through which it moved. As groundwter psses through the sediments, metls dissolved nd these would e found in high concentrtions in the wter. Hrdness ws cused y clcium nd mgnesium nd it hd no helth effect ut it ffected the qulity of the wter (WHO, 2011). According to Wskom nd Buder (2009) in order to protect the oreholes from septic tnk regrdless the distnce etween them, oreholes should e uphill from septic systems in reltion to the soil type, the hydrologeology nd ge of the orehole. This ment tht even if the distnce etween the septic tnk nd oreholes ws long, the oreholes might still e contminted if it is locted downhill from the septic tnk. It ws reported tht groundwter moved to the direction of the lowest hydrulic hed (where groundwter ws relesed into strems, lkes) from high hydrulic hed which ws 50

11 rechrge re (Witte, 2012). Wskom nd Buder (2009) reported tht totl dissolved solids (TDS) in groundwter my vry depending on well rechrge chrcteristics nd TDS mesures the totl mount of dissolved minerls, metls, slts nd my contin undesirle mounts of clcium, mgnesium, sulfte, chloride, or other slts. Peter-Ikechukwu et l. (2015) concluded tht distnce etween septic tnk nd orehole hd little or no correltion with TDS nd totl hrdness The Effect of Distnce etween the Septic nd Borehole on Metl Contminnts (Led nd Copper) Distnce from the septic tnk showed significnt differences (p<0.05) in copper levels of oreholes wterwhich were locted ner nd fr from the septic tnk in ll districts (Figure 8). The levels of copper incresed significntly (p<0.05) s the distnce etween the orehole nd septic tnk incresed. The significntly high vlues of copper were found in the orehole wter which locted fr wy from the septic in the Ill nd Temeke districts. The significntly low levels were found in the oreholes wter locted ner to the septic tnk in Kinondoni followed y Temeke nd finlly Ill districts (Figure 8). Led ws much lower thn copper. Led ws detected only in the oreholes which were ner to the septic tnk in Temeke nd Kinondoni districts wheres it ws detected in orehole fr wy from the septic tnk in Ill district (Figure 8) Cu (mg/l) Ill Kinondoni Temeke Loction Ner Fr 51

12 Led (mg/l) Ill Kinondoni Temeke Ner Fr Loction Figure 8. Effect of distnce etween orehole nd septic tnk on copper nd led. Brs re expressed s men±sd (n=48). Br with different letters re significntly different t p<0.05 Copper nd led levels were low nd complied with the mximum limits estlished y TBS nd WHO. Mkude (2015) explined tht the levels of copper in oreholes of Dr Es Slmwere very miniml nd could e due to the intrusion of industril nd domestic wstes. Plmuleni nd Akoth (2015) lso explined tht nturlly occurring metls present in the rocks nd sediments my e dissolved in the wter nd lter e found in wter. Furthermore led contmintion to ground wter my e the result of entry from industril effluents, old pluming, household sewges, griculturl run-off contining phosphte fertilizers, humn nd niml excret (Mkude, 2015). The ph vlues of neutrl nd slightly lkline decreses the vilility of the metls ions in wter s the metl would remin ttched in sustrte nd complexes, therefore significntly lower levels of metls contminnts could result from the neutrl ph of the orehole wter smples from oth ner nd fr wy from the septic tnk (Kihmp, 2013) Complince of Borehole Wter to WHO nd TBS on Physic-chemicl Prmeters sed on Distnce etween Borehole nd Septic Tnk The effect of distnce etween orehole nd septic tnk on physico-chemicl limits complince set y WHO nd TBS re s shown on Tle 2. Aout 79.2% of wter smples drwn from oreholes tht were ner the septic tnk complied with the WHO nd TBS specifiction nd 70.8% were from smples further from the septic tnk. The rest did not comply, neither with WHO nor TBS stndrds (Tle 2). Although in generl, most smples complied with the stndrds nd few did not, it is importnt to monitor the qulity of wter so s to ensure the sfety of consumers. Bsed on the findings of this study, it is recommended tht ll oreholes wter should e treted regrdless of the distnce from potentil pollutnts. In ddition, efore drilling orehole, drillers should tke into considertion of ll the fctors tht will ffect the wter qulity such depth, distnce to the potentil pollutnts, groundwter flow direction nd soil structure. 52

13 Tle 2. Distriution of oreholes distnce to septic tnk ccording to their complince on WHO nd Tnzni physico-chemicl specifictions Distnce Pss (%) Prmeter Filed Totl (%) ph B.O.D Hrdness Comintion Su Totl Ner 19 (79.2) (20.8) 24 (100) Fr 17 (70.8) (29.2) 24 (100) 4. Conclusion This study showed tht oth the depth of the orehole nd the distnce from the orehole to the septic tnk hve effect on the physico-chemicl qulity of the wter. Both the ph nd B.O.D decresed significntly s the depth of the oreholes incresed, while for very deep oreholes wter hd significntly higher levels of totl hrdness compred to shllow oreholes. The distnce etween the septic tnk nd oreholes hd no effect on ph nd totl hrdness, while the B.O.D decresed significntly s distnce etween the septic tnks nd oreholes incresed. Generlly, regrdless of the depth of the oreholes nd distnce to the septic tnk, the levels of copper nd led detected were very low. Thus, except for ph nd totl hrdness of some smples, ll physico-chemicl prmeters were within the limit stipulted y TBS nd WHO. References Aong o, D. H. A., Mugu, H., & Onytt, J. O. (2017). The effect of septic tnks sewge disposl system distnces on orehole wter qulity in Ongt Rongi, Kjido County, Keny. Europen Interntionl Journl of Science nd Technology, 6(3), 2-9. Ain, A. T., & Oshunrinde, O. O. (2016). Comprison of wter qulity from oreholes nd hnd-dug wells round nd within the University of Lgos, Lgos, Nigeri. Journl of Reserch in Environmentl Studies, 3, Arizon Geologicl Survey. (2011). Erth Fissure Centre visited on 25th Novemer, 2017 t 9.30m Bhrti, D., Syyd, I. A., Gikwd, G. G., Tikr, D. R., & Dhore, J. (2011). Physico-chemicl chrcteristics of Bore well wter qulity in Ngpur region (South zone). Journl of Chemicl nd Phrmceuticl Reserch, 3(2), Elisnte, E., & Muzuk, A. N. N. (2015). Occurrence of Nitrte in Tnznin Groundwter Aquifers: A Review.Springer Pulisher, New York, USA. Eze, C. L., & Eze, E. M. (2015). Investigtion of possile groundwter contmintion from septic system sitting in Port Hrcourt, Nigeri. Journl of Nturl Sciences Reserch, 5(10), Fur-Mnuel, I., & Jumo, R. B. (2014). The effect of septic tnk loctions on orehole wter qulity in Port Hrcourt, Nigeri.Interntionl Journl of Engineering nd Technology, 4(5),

14 Kpongol, N., Mrtinez, J., Wesselink, A., Lungo, J. H., & Georgidou Y. (2014). Accessing wter services in Dr es Slm: Are we counting whtcounts? Journl of Hitt Interntionl, 44, Kshigili, J. J. (2012). Report on ssessment of groundwter vilility nd its current nd potentil use nd impcts in Tnzni. In:Groundwter Avilility nd Use in Su-Shrn Afric: A Review of 15 Countries. (Edited y Pvelic, P., Giordno, M., Kerit, B., Rmesh, V. nd Ro T.), Interntionl Wter Mngement Institute, Colomo, Sri Lnk. pp Khdsn, R. E., & Mngesh, V. K. (2003). Drinking wter qulity nlysis of some ore-wells wter of Chikhli Town, Mhrshtr. Journl of Industril Pollution Control, 20(1), Kihmp, C. (2013). Hevy metl contmintion in wter nd sediment downstrem of municipl wstewter tretment plnts, Dr es Slm, Tnzni. Interntionl Journl of Environmentl Sciences, 3(5), Likmo, W. (2014). Assessment of orehole wter qulity nd consumption in yei county South Sudn. Disserttion for Awrd of MSc Degree t Mkerere University, Kmpl, Ugnd. Mto, R. R. A. M. (2002). Groundwter Pollution in Urn Dr es Slm, Tnzni: Assessing Vulnerility nd Protection Priorities.Eindhoven Technische Universiteit, Eindhoven. McQuilln, D. (2004). Ground-wter qulity impcts from on-site septic systems.in: Proceedings Ntionl Onsite Wstewter Recycling Assocition, 13 th Annul Conference Novemer, 2004 Aluquerque, New Mexico. pp Mkude, I. T. (2015). Comprtive nlysis of hevy metls from groundwter sources situted in Keko nd Kigogo residentil res, Dres Slm. Journl of Wter Resources nd Ocen Science, 4(1), Mohn, K. C., Suresh, J., & Venkteswrlu, P. (2014). Physio-chemicl nlysis of ore-well wter of Kurnool environs, Andhr Prdesh. Journl of Chemicl nd Phrmceuticl Reserch, 6(9), Mtoni, Y., Mjemh, I. C., Msindi, K., Cmp, M. V., & Wlrevens, K. (2012). Sltwter intrusion in the quternry quifer of the Dr Es Slmregion, Tnzni. Journl of Geologic Belgic, 15(2), Ojo, O. I., Otieno, F. A. O., & Ochieng, G. M. (2012). Groundwter: Chrcteristics, qulities, pollutions nd tretments: An overview. Journl of Wter Resources nd Environmentl Engineering, 4(6), Plmuleni, L., & Akoth, M. (2015). Physico-Chemicl nd Microil Anlysis of Selected Borehole Wter in Mhikeng, South Afric. Interntionl Journl of Environmentl Reserch nd Pulic, 12, Peter-Ikechukwu, A., Omeire, G. C., Okfor, D. C., Eluchie, C., Odimegwu N. E., Nze, S. N., Angwu, F. I., & Okeke, K. C. (2015). Assessment of the qulity of orehole wter smple in federl housing estte nd sites nd services res of Owerri, Imo Stte, Nigeri. Journl of Food Science nd Qulity Mngement, 42,

15 Sindelr, M. (2015). Soils Clen nd Cpture Wter. Soil Science Society of Americ, Mdison, Wisconsin, USA. Sungsitthiswd, W., & Pitksnurt, S. (2013). Groundwter qulity index for wter supply production. Journl of EnvironmentAsi, 6(2), Tnzni Bureu of Stndrds. (2008). Tnzni Stndrd on Drinking (Portle) Wter - TZS 789. Tnzni Bureu of Stndrds, Dr es Slm, Tnzni. Wskom, R. M., & Buder, T. A. (2009). Report on Protecting Your Privte Well. Wter Institute Colordo Stte University, Colordo. WHO. (2011). Guidelines for Drinking-wter Qulity. (4th Edition), World Helth Orgniztion, Genev, Switzerlnd. Witte, I. D. (2012). Chrcteriztion of the sttus of Dr Es Slmquifer in view of slt-wter intrusion nd nitrte contmintion. Disserttion for Awrd of MSc Degree in Geology t Ghent University. Copyright Disclimer Copyright for this rticle is retined y the uthor(s), with first puliction rights grnted to the journl. This is n open-ccess rticle distriuted under the terms nd conditions of the Cretive Commons Attriution license ( 55