J. MANUSIA DAN LINGKUNGAN, Vol. 17, No.3, Novernber 2010: t9l-199

GROUNDWATER ASSESSMENT IN AGRICULTURAL AREA, CASE STUDY FROM MACHANG - (Penilaian Air Tanah di Dserah Pertanian, Studi Kasus di Machang Malaysia)

Nur Islami Program Studi Fisika - PMIPA - UNIVERSITAS RIAU email : wis74@)yahoo. com

Diterima: l2 Juli 2010 Disetujui: 2l Oktober 2010

Abstract

The study area is located in Machang, North - Malaysia. The North Kelantan plain is covered with Quaternary sedirnents overlying granite bedrock. The drainage system is dendritic with the main river flowing into the South China Sea. Hydrogeochemical method was used to study groundwater of shallow aquifer characters within the area. Based on water samples analysis col- lected tiom the study area, it can be deduced that the cations and anions concentration are good fbr domestic use except in the southern region which the nitrate concentration is higher (more than 20 inglt) compared to the northern region (relatively zerc).The areas that possibly possess nitrate-con- taminated groundwater have been mapped along with groundwater flow patterns. The southenr and middle part of the study area has an east to west groundwater flow pattern, rnaking it irnpossible for contaminated water from the southern region to enter the northern area, despite in the northern area has lower elevation.

Keywords: Groundwater, N itrate.

Abstrak

Lokasi area .studi udalah berada di Machang, Kelantan Utara - Malaysiu. Duturutr tctnuh v,iluyult Kelantan Utura dilapisi oleh batuan Sedimen Kuarter yang n ana batuan granil sebugai butuan dusu'. Sistem pengairun adaluh berbentuk.jaringan dendritik dengan sungai tttunn ntengulir ke Luut Cinu Selatan. Metoclu hl,drogeochemical digunakan untuk mempelajuri kurukter uir lunuh luri ukuilitr' dangkal unttrk keseluruhon qree stucli. Berdusqrkan pacla analisa air yung tliperoleh duri areu stutli, dapat disimpulkan bahwa konsentrasi kation dan anion baik digunakan untuk kehitlupan sehori huri kecuali air tunah di areq sehelah selatan yang mana kandungan nitrutnyu tinggi (lebih duri 20 ng/l) dibandingkan di areo sebeluh utarq (hampir titluk ada kandungan nitrat). Areu S'utrg mentungkinkun memiliki konsentrasi nitrut peda air tanuh dipetakan clengan kombinerci pola ulinm uir tunuh. Polu aliran air tanuh di ureu beluhan selutcrrt clun bagictn tengah udeiluh duri tirrtur kc burut .r'ctttg tnutut tidak ntenrungkinktnnyu air tcmah ))ung terkontaminusi oleh nitrut di beluhutr .st,lututt tttrtuk tttu.sttk ke areu belahun uturu v,ulcutpun cli beluhutr utaru udaluh duturun renduh.

Kutu kunci: Airtunuh, Nitt'ut. t92 J. MANUSIA DAN LINGKUNGAN Vol. 17, No.3

INTRODUCTION Review oJ'Geology Srudy Area The total extent of study area covers ap- Groundwater is among the Norlh Kelantan's proximately 98 square kilorneters (kma). The most important natural resources. It provides southern part of the area is defined by Kam- drinking water to urban and rural communities, pung Tok Bok and is bounded in the north by supports inigation and industry, sustains the Kampung . The study area is covered flow of streams and rivers, and maintains ripar- with Quaternary sedirnents overlying granite ian and wetland ecosystems. The importance of bedrock. It is drained mainly by short rivers groundwater for the existence of human sociefy and streams which flow into the South China cannot be overemphasized. Sea. The thickness of the Quatemary deposits Like other places, in the study area, chemi- varies from 20 m inland to about 200 m near the cal fertilizers are rigorously used to enhance the coast. The loose quaternary sediments consist agricultural establishment (Yang, et al., 2006) of alternating layers of coarse gravels to silts of crude palm oil. Fertilization is conducted or mixtures of the two (Saim, 1999). lt can be every two months using fertilizers of different clearly seen that the study area is bounded by chemical content. For example, at the begin- at the west side and the high ning of the year, 400 kilograms of Urea with hill at the east side (Figure l). The hill is a part 60% nitrogen is used for a two hectare palm of the Boundary Range Composite Batholith. It plantation. Two months later, another fertilizer consists of two major components, the Mach- with 15% Nitrogen, 30% Phosphorus, and ang Batholith which is 100 x 20 km, and the 55% Potassium (NPK) is applied to further smaller Kerai Batholith situated on the western improve the production of palm. This process flank (Cobbing, and Pitfield, 1992).Around the is repeated in the middle of the same year and hill, a lot of exposed granite can be found espe- continues till the end of the year. All in all, at cially at Sungai Buluh Quarry. Other exposed least 800 kilograms of urea is employed for granite can also be found in Kampung Pulai the fertilization of palm trees in a two hectare Condong around 4 km to the west of Machang area per year. Batholith Boundary Range. Figure I shows the Other agricultural activities within study location map of the research area. The RSO area include the cultivation of paddy fields West Malaysia and Kertau 1946 are used as the and rubber trees. However, in comparing the coordinate system and datum in the map. intensity of the fertilization process for paddy and rubber trees with that of palm oil, it is much METHODOLOGY less than that of palm oil. The farmers in study area plant paddy only once ayear on average, A hydrogeochemical method was used to although some plant paddy up to twice a year study the groundwater characters in this area. ln over several areas. Paddy fields consume a the study, special emphasis was given to the first mere 100 kilograrns of urea per two hectare a aquifer (shallow aquifer) because it is the main year:For rubber trees, 200 kilograms of urea is sourcp of the water supply for domestic uscs. utilized for every two hectare per year. Samples of groundwater were collected frorn Contaminant leaching (especially nitrate) the existing wells, and in-situ parameters suclr from agricultural soils has been widely studied as welldepth, water level, total dissolved solid, (Almasri and Kaluarachchi, 2004; Saadi and pH, conductivity, salinity and temperaturc wel'e Maslouhi 2003). In this study attention has been measured. Water sarnples of 500mlwcre kept in focused mainly on assessment of groundwater plastic bottles and maintained at a ternperaturc within sandy soils in the shallow aquifer. Clay of 40C. This was done for detcrmining thcir soils are usually not considered to have a high major ion contents analysis with IC and ICP nitrate leaching potential. in the hydrogeology lab. Physical infonuation November 2010 ISLAMI, N. : GROUNDWATER ASSESSMENT r93 about water samples were retrieved directly RESULTS AND DISCUSSION from existing wells or piezometers whereas the physical information about these well, like The amounts of different clements includ- well location, well depth, depth to water were ing in-situ wafer, physical well parameters and obtained from the well owner. hydrogeochemical content have been presentcd The hydrogeochemical data obtained from in milligrams per litre (mg/l) for the testcd this study were used in the interpretation of the water samples, these figures are tabulated in overall data. Major ion concentration, electricpl Table l. condpctivity, and total dissolved solids were Ninety five percent of the groundwater in among the hydrogeochemical parameters used the shallow aquifer possssses a hydrogen ion in the characterization of the groundwater. concentration (pH) that is moderately acidic (4

Meter

200

100

50

40

35

30

25

20

15

10 465000 470000

E o,"", fl Area 1 fl nuuuer riero [] ,"'' r,u'o t_-j Paddy Field

Figure l. Location of study area. t94 J. MANUSIA DAN LINGKUNGAN Vol. 17, No.3

- 6.5) whercas the remaining 5% is indicative from mineral breakdown. Also, in seditnentary of a more neutral pH condition (6.5-7.8), Thus rocks, fhe major soqrce of chloride in ground- it is generally good for some other domestic water is due to evaporate. The conceutration uses. Thirty percent of the water sample is of rain water by evapotranspiration tnay be an less than 5 on the pH scale and is considered important source of chloride in the area (Egbu- not good for human consumption if untreated. nike, 2007),Another comlnon source of chlo- The fact that the hydrogen ion concentration is ride in groundwater is the leaching ol'chloride more or less neutral affects the aggressiveness fertilizing over longperiods time. The influenco of the solution. ofthe fertilizing factor in the chloride content of Malnesium ion (Mg2+) concentration is the groundwater around thc southcrn part of the generally low. The availability of magnesium study area can be found in water sarnple frotn ion in the groundwater of the area can be ex- the borehole at A006 with chloride concentra- plained by the occurrence of magnesium with tion of 12.10 mgl. The chloride concentration calcium carbonate cetnent in sedimentary in the water samples are within the accepted formation. The low values of magnesium ion limits for human consumption. concentration may be a result of deficiency of The concentration of nitrate in the mapped minerals capable of yielding magnesium ion in area is generally good and falls within the water. This implies, however, that the magne- accepted limit except in the palnr oil field sium content of groundwater in the area renders area around surface water termination (,{002, it suitable for human use. A003,4004, S00l and 5002). However, out of There are notably low values of sodiurn (Na) the exceptional area, the nitrate safe drinking and potassium (K) in the water samples of the water concentration of l0 rng/l (WHO, 1984). mapped area. The possibility of contributory The potential source of nitrate in the area may factor is an impurity in the cementing material include fertilizing activities, animal exc remen t, where sodium ions permeate the carbonate lat- and probably the atmosphere. tice. Other natural sources include the weather- Aluminium ion (Alt-) content in the study ing of feldspars and leaching of clay rninerals area varies from 0.00 - 1.505 mg/l and is (Egbunike,2007,Hounslow, I 995). Potassium, within the accepted limit. There are only two an important fertilizer, is strongly held by clay groundwater samples (LROI6,\ and S00l ) in particles in soil. Therefore, leaching of potas- which bicarbonate are absent. The presence of sium through the soil profile and into ground bicarbonates in the shallow aquit-erwithin study water is important only on coarse-textured soils. area is predicted to be as a result of agricultural Potassiunt is comrnon in many rocks. Many of activities that utilize dolon-rite for various pur- these rocks are relatively soluble and potas- poses. Sulphate (SO4) concentration ranges siurn concentrations in ground water increase fiorn 0 - 12.339 rng/l which is considcred low with tirne. Important sources of sodiurn include and lies within the acceptcd limit, fertilizing activities and animal wastes. Sodium Overall, correlation between couductivity is more rnobile in soil than potassium and so it and other water chemical content can be calcu- is used often as an indicator of human impacts lated statistically using the Pcarpon product-mo- to shallow ground water. Sodium is also a coln- ment correlation (Till, 1914). Based on the darta mon chemical in minerals. Like potassium, in Table l, the correlation coeflicient bctwccn sodiurn is gradually released from rocks. Con- conductivity and TDS is 0,9899, conductivity centrations therefore increase with tirne. and chloride is 0.2532, conductivity and nitratc The chloride concentration of the grorndwa- is 0.8024, and conductivity and sulphatc is ter was reported to be relatively low bccausc of 0.0432. Bascd on this fact, it is concludcd that the tact that chloride docs not show any con'ela- the anrount of, nitratc in thc groundwatcr rvill tion with thc cornponents of pore watcr derived influence total conductivity rcatlings. Table l. In-situ parameters and chemical results of groundwater samples within study area. In the bottom row ofthe table,limit con- z centration for domestic use by WHO 1992 is displayed. (D oC' Ground Depth to Water Level Sample Location X Location Y Well Depth Conductivity Salinity pH t.J Level Water (a.m.s.l) O ID (m) (m) (m) (m) (m) (m) mg/l pSicrn 0/00

A001 471343 646277 <7 28 2.56 25.44 76 159 0 27.8 4.77

A002 470511 646770 <7 24 2.1 21.9 323 654 0.1 30.5 5.98

A003 468507 648571 E 22 1.96 20.04 407 830 0 29.4 4.93

<7 4.63 A004 466884 648964 21 0.86 24.14 76 159 0 29.2 a A005 467562 650522 <7 22 0.98 21.02 78 163 0 29.1 5.72 r

A006 470178 649987 <7 18 0.67 17.33 151 313 0 27A 5.75 t'

A007 471890 651687 <15 40 10.62 29.38 57 120 0 28.5 6.14 v A008 471962 653352 <7 24 1.35 22.65 83 173 0 31.7 4.86 Fc A009 468452 650985 <7 2A 0.91 19.09 50 104 0 u.4 5.72 z c' LRlOA 470/,04 658785 <7 19 1.02 17.98 183 381 0 42.2 5.77 t LR12A 473733 656574 <7 14 0.23 13.77 84 170 0 31.1 6.4 - 7 LR14A 470689 656930 5 17 0.65 16.35 89 r80 0 25.7 6.42 cn (h LR15A 473804 654980 6 28 2.11 25.89 64 130 0 28.7 6.22 F]o cn LRl6A 47U75 654957 <7 17 0.61 16.39 106 217 0 27.2 4.11 7

s001 467159 646187 5 24 1.43 2.57 370 751 0 28.3 6.88 *.iz s002 467455 645676 5 26 1.9? 24.08 247 501 0 28.3 5.98

s003 469175 646657 3 28 2.38 25.62 49 98 0 30.5 5.09

s004 469982 645778 7 38 2.46 35.54 60 121 0 28.1 4.49

s005 470622 646025 5 29 1.n 27.78 35 70 0 28.5 6.19

s006 470630 645415 <7 33 2.96 30.04 48 97 0 30.1 6.42

6-8 Table l. Continued \o o\

Sarnple Chloride Nitrate Sulfate Fluoride K Ca Mg Na AI .Fe co3 HCO3 ID mgil mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l

I A00l 5.86 2.77 5.915 0 1.309 4,782 0.304 7.912 0.045 0.054 0.000 8s.320 2 A002 6.66 22.28 t.7t6 0.058 1.693 24.790 0.588 5.124 0.015 0.006 0.000 47.t60

J A003 7.60 28.79 0.25 0 2.181 19.540 r.887 10.010 0.000 0.220 0.000 52.56 4 A004 6.75 r2.90 0.622 0 1.785 3.295 0.44'7 6.057 0.331 0.023 0.000 62.230

12.5 r 0 -6 A005 4.ll 3.84 3.544 0.049 2.505 8.306 0.622 3.581 0.r22 0.058 0.000 A006 12. r0 4.46 4.t54 0 3.228 12.2t0 0.536 10.550 0.072 0.055 1.160 73.340

7 A007 2.14 0.00 t.2t3 0 t.329 2.469 0.327 3.059 0.025 0.s40 0.000 2.700 - t-? tt A008 3.5 r 1.443 0 3.681 0.258 3.078 0.059 0.021 0.000 1.300 2.r8 t.t72 z 9 A009 7.2t r 2.58 0 0.22 1.487 3.628 0.698 r r.240 0.1 30 0.025 L600 23.800 C 2 t0 LRIOA r8. t6 0.00 7.953 5.&3 2.303 2.972 0.326 0.000 0.072 0.000 0.000 195.200 il LRI24' 2.43 0.00 0.263 0.032 4.151 3.048 0.888 3.22'l 0.130 1.993 0.000 7.000 l2 LRI4A 4.36 0.00 0.2t2 0.000 7.581 2.739 1.094 I.7t5 1.505 0.541 0.000 10.100 z tr r3 LRI5A 1.83 0.00 0.000 0.073 3,797 3.340 0.915 r.t83 0.448 0.164 0.000 13.200 z l4 LR16A 19.90 0.00 0.663 0.0s2 5.547 3.309 r.127 3.609 1.338 0.280 0.000 0.000 7( C r5 s00r 6.28 24.t8 0.3r8 0.000 2.534 6.025 1.558 7.835 0.000 0.032 0.000 0.000 z c t6 s002 8.18 18.93 5.571 0.000 5.044 22.250 2.4t8 13. r90 0.034 0.146 4.800 80.600 z l7 s003 5.23 6.83 1.605 0.000 t.457 6.2tr 0.433 8.004 0.304 0.029 0.000 4.200 r8 s004 8. r5 6.06 r 2.339 0 4.343 6.238 1.048 10.350 0.266 0.00r 0.000 7.300 t9 s005 3.65 9.72 1.394 0.000 2.064 3.9t7 0.666 4.83 t 0.t4 0.004 0.000 4.500 20 s006 2.1I 0.34 0.231 0.000 4.6t6 4.146 0.575 3.949 0.082 0.t22 0.000 12.000 250 l0 1.5 150 0.2 0.3

A\

;Jz L, November 2010 ISLAMI, N. : GROUNDWATER ASSESSMENT 197

100

50

40

35

30

25

20

15

10

Figure 2. Combination rnap of three sets of contour date. The solid contour represents water level relative to filean S€a level end the line contour above the solid contour ls nitrate concentratiofi itr shallow nqulf€r (less then 1l rneter deep) with well tD ffiarks. The rernainirtg corrtour lirres ref,ect stlrface elevrtion. 198 J. MANUSIA DAN LINGKUNGAN Vol. 17, No.3

The map shown in Figqre 2 exhibits fhe ilfeaE [o lowlaqd areas. If is ohserved that tlris well position fbr groundwater sampling. It mentioned factor may also affsct the potential also shows the contour of nitrate concentration nitrate concentration of an area. Groundwater from 20 well samples and water levels relative in lower elevation areas with palm oil field at to mean sea level. Relative high concantr4- itS bqrdErs fend to have higher poncenfrations of tion of nitrate can be found in the Palm oil nifrate ryhegeas groundw4ter in higher elevalion field zone. The remaining rubber tree fields' arpas have fower concentration of nitrate. and paddy fields exhibit ggnerally low nifatp In tfe zone between 645+0A to 655000 of concentrations. the Y-axis, the groundwater flow within the In the well with sample ID A002, concentra- shallow aquifer in Kampung Merbau Condong tion of nitrate is considered to be high (12.58 (also known as zone 3 in Figure 2) is also mg/l) although no palm oil field is adjacent known to originate from the Boundary Range [o the well. Here, there ars minor agriculfural Hill area. The flow is from an Flevation of more activities, including corn plantation. For thess than 250 meters above mean sea lpvel at the activities, chemical fertilizer activities are not Boundary Range Hill area to about 30 meters employed. Only organic fertilizers like cow above mean sea level at the Kampung Merbau manure are used. Condong area. According to Figure 2, zone I is the area At around the 4,007 well in the nor eastern between_ the y-coordinate lines 64500 and region of Zone 2, groundwater flow is deemed 65500 which are parallel to the x-axis. The to occur in three directions as a nearest of the groundwater in the shallow aquifer in this zone well being located at the top of a hill. The three flows northwest from Boundary Range Hill to directions of flow are northeast-southwest, kampong Tok Bok. Boundary Range Hill is east-wgst, and southeast-northwest, a$ Ehewn elevated at more than 250 m above mean sea in Figure 2. Nonetheless, all groundwater flows level whereas Kampung Tok Bok is situated at toward the Kelantan River which is elevated at around 35 m above mean sea level. 15 meters above mean sea level. The groundwater around the wells S00l Zone 3 is located between the Y-coordinate and 5002 at the zone I (Figure 2) flows toward liRps 65500 and 66000, which are parallel to the Kelantan River. The direction is consistent the X-axis. The southeastern part of this zone to the groundwater flow of the wplls near the possesses the lowest groundwater level in the eastern boundary ofzone l. If is noted that well whole area, positioned at a lower elevation than S004 of eastern zone is located adjacent to the that of the Kelantan River. Thus, groundwatcr palrn oil field in Kampung Tok Bok. does not flow toward the Kelantan River in Thus, generally, groundwater movement this zone. Instead, the groundwater in this zot'te within zone I is frorn southeast to northwest. flows downward itto the next aquifer below thc Comperatively, in zone 2 (the area between the first shallow aquifer. Y-coordinate lines 65500 and 66500, which are parallel to the X-axis) the groundwater move- ment occurs in two directions: southeast-north- CONCLUSION west and northeast-southwest flow direction is minor and after calculating the vector resultant The hydrogeochemical method was suc- for groundwater flow of zones I and 2. The cessfulto study groundwater of shallow aquif e r general direction of flow is from the southeast characters withirt the agricultural area. ln thc to the west, toward the Kelantan River, area around palnr oil field, nitratc coucentration It can thus be generalizecl that the direction is higher contparcd to the area with no pahn oil of groundwater lnovelrlcnt and surface runoff is Iield. Application of chernical anrl natural l'crti- influenccd by elcvation, moving frorn high land lizer is the reason [iglr of nitlate cotrccntraliurr November 2010 ISLAMI, N. : GROUNDWATER ASSESSMEN.I 199 found in the palm oil field. The groundwater Egbunike, M.E., 2007. "Hydrogeocltcmical which has high level of nitrate concentration Analysis of'Water Sanrplcs in Nando have been mapped along with groundwater and Environs of thc Anarnbra llasin of flow patterns. The southern and middle par-t of South E4stern Nigeria". Pacific Journatl the study area has an east to west groundwater of Scicncc and Tcchnology. 8( I ):32-35. flow pattern, making it impossible for contami- Hounslow, A.W., 1995, Water quality clata: nated water from the southern region to entpr analysis and intcrprctation, Lcwis the northerl area, despite the lower elevation Publishers. of the,area. Saadi, 2., and Maslouhi, A., 2003, Modcling nitrogen dynamics in unsaturated soils for evaluating nitratc contamination of REFERENCES the Mnasra groundwater. Advances in Environmcntal Rescarch, 7, 803-823. Almasri, M,N., and Kaluarachchi, J.J.,2A04. Saim Suratman, 1999,Groundwater protection Asscssment and managcrnent of long- in North Kelantarr, Malaysia. SOURCE: term nitrate pollution of ground water Seminar ot't Water : Forestry aucl in agriculture-domiuated watcrsheds. Landuse Pcrspectivcs (30-31 Mar 1999 Journal of Hydrology, 295. : Kuala Lurnpur) : Paper I I (l lp.) Cobbing, 8.J., Pitficld, P.E.J., 1992, Thc Till, R., 1974, Statistical rnethods for thc cartlt Granites of the South-East Asian scientist, The Macmillan Press Ltd. tin belt, British Geological Survcy, World Health Organization (WHO), 1984. Overseas Mernoir 10. Guideline fbr Dlinking-Water, vol. l. Recommcndatious. World Hcalth Organi-zation, Geueva.