Journal of Environmental Science Current Research Category: Environmental science Type: Research Article

Seasonal Variations in the Hydrogeochemistry and the Domestic-Agro-Industrial Water Quality of the Granite-Gneiss Fractured Rock Aquiferous formations in Wum, North West Region, Cameroon

Akoachere RA1*, Mbei KK2, Eyong TA1, Egbe SE1, Wotany ER1 and Eduvie MO3
1 Department Of Geology, University Of Buea, Buea, Cameroon
2 Department Of Environmental Science, University Of Buea, Buea, Cameroon
3 National Water Resources Institute, Kaduna, Nigeria

*Corresponding Author(s):
Akoachere RA
Department Of Geology, University Of Buea, Buea, Cameroon
Tel:+237 690153887,
Email:r.akoachere@ubuea.cm

Received Date: Mar 11, 2019
Accepted Date: Jun 13, 2019
Published Date: Jun 24, 2019

Abstract

Wum the capital of Men chum Division is an important agricultural area in the Northwest Region in Cameroon vital for the food security of the country. The study objective was to determine and evaluate the seasonal variations during four hydrogeological seasons; dry (March), drywet (June), wet (September) and wetdry (December) in the groundwater chemistry, groundwater rock interactions and domestic-agro-industrial groundwater quality using hydrogeochemical tools; physicochemical parameters, ionic ratios, gibbs diagrams, piper diagrams, durov diagrams, Total Hardness HT, Water Quality Index WQI, Sodium Adsorption Ratio SAR, Percent Sodium %Na, Kelly’s Ratio KR, Permeability Index PI, Magnesium Adsorption Ratio MAR, Residual Sodium Carbonate RSC and Wilcox index. From field physicochemical parameters; dry season, temperature, 21.5-25.3°C; EC0.01-0.51mS/cm; TDS, 0.01-0.34mg/L; drywet, pH, 2.6-6.9; Temperature, 21.7-23.1°C; EC, 0.01-6.30mS/cm, TDS, 0.01-4.22mg/L; wet pH, 3.3-7.1; Temperature, 20.8-26.6°C; EC, 0.17-3.90mS/cm, TDS, 0.11-2.61mg/L and wetdry, pH, 5.2-7.5; Temperature, 21.8-24.1°C; EC, 0.01-3.29mS/cm, TDS, 0.01-2.20mg/L. The sequence of abundance of major ions varied with seasons; dry season, Ca2+>Mg2+>NH4+>K+>Na+; HCO3->Cl->SO42->NO3->HPO42-, drywet season Ca2+>Mg2+>K+>NH4+>Na+; HCO3->NO3->SO42->Cl->HPO42-,Wet season Mg2++>Ca2+>K+>NH4+>Na+; HCO3->NO3->SO42->Cl->HPO42- and wetdry season Ca2+>Mg2+>K+>NH4+>Na+; HCO3-> SO42->NO3->Cl->HPO42- for cations and anions respectively. Rock-groundwater Interaction has the weathering of the aquifer matrix as the primary dominant process in the acquisition of ions while atmospheric precipitation and evaporation-crystallization are the secondary contributing sources to the hydrogeochemistry through the processes of simple dissolution, mixing and ion exchange. Groundwater has two water types; CaHCO3 the dominant water type in all seasons and CaSO4 the minor water type that occurs only in the dry, drywet and wet dry seasons. Two hydrogeochemical facies occur: CaMgHCO3 hydrogeochemical facies occurring in all seasons, characteristic of freshly recharged groundwater from precipitation and Ca-Mg-Cl-SO4 hydrogeochemical facies occurring only in the dry season, characteristic of groundwater that has travelled some distance along its flow path. The groundwater character in Wum is as a result of ion exchanges between the weathered formations, simple dissolution and mixing within the two groundwater types along its flow path in the flow field. The groundwater in Wum is hard in wetdry season and soft to moderately hard in all seasons. The Water Quality Index (WQI) for groundwater in Wum is excellent-good for domestic use. The groundwater indices of; Sodium Percent (%Na), Residual Sodium Carbonate (RSC), Kelley’s Ratio (KR), Sodium Adsorption Ratio (SAR), Electrical Conductivity (EC), Total Dissolved Solid (TDS), USSL and Wilcox index were determined, evaluated and found to be suitable for agro-industrial uses in all seasons. Permeability Index (PI) and Magnesium Adsorption Ratio (MAR) were not suitable in some areas and in some seasons. These hydrogeochemical facies, parameters and indices will serve as an important part of the toolkit for soil and water parameter evaluation for future development of agro-industries in the area of Wum.

Keywords

Domestic-Agro-Industrial-Water-Quality; Fractured-Rock-Aquifer; Hydrogeochemistry; Seasonal-Variation; Wum-Cameroon

INTRODUCTION

This study of Wum is situated between latitude 6.370 to 6.660N and longitude 10.065 to 10.340E in the Menchum Division of the North West Region of Cameroon shown in Figure 1. Wum subdivision has a population of over 130000 inhabitants and is 83 km from Bamenda, the North West regional capital. It is bordered to the West by Menchum valley, South by Bafut, East by Fundong and North by Fungom subdivisions. The main economic activity is agriculture; Pastoral farming and cattle grazing WCDP/PNDP (2011) [1].

Figure 1: Location of the study area showing field tested and sampling points.

Climate
Wum Municipality falls within the tropical humid climatic zone with some modifications due to the high and lowland areas found in this region. There is a distinct rainy season from mid-March to mid-November and dry seasons from mid-November to mid-March. The annual rainfall ranges between 2512.5mm and 3829.6mm.The total annual rainy days ranges from 173 to 196. August and February are the coldest and hottest months respectively. 

Vegetation
Lying in the savannah part of Cameroon, Wum has two common vegetation types, forests and grasslands. The forest in this region is the tropical transitional forests. Vegetation is of the Guinea Savanna type constituting mostly eucalyptus trees and raffia palms found mostly in valleys where the water table is considerably low [2] . 

Relief and drainage
Wum is part of the Bamenda highlands, a chain of Precambrian hills with rocky cliffs. Most of the hills are conical and flat topped. The relief is monotonous with continuous chains of hills and valleys. Major hilly areas include Kesu to Mile 40 with spot height of 1130m. Slopes in Wum are steep 35-40°. 

The drainage in Wum subdivision is dendritic with swift running Nweih, Nzala, Muoh and Menchum perennial rivers whose discharges increase significantly in the rainy season; Four lakes abound; Ilum, Oshien and Atwe. The river Menchum falls over one of the highest cliffs in West Africa. The larger rivers and lakes are far off from Wum town. Cameroon is gifted with large volumes of water resources with the second largest volume of available freshwater in Africa (After the Democratic Republic of Congo) estimated at 322 billion m3. Groundwater constitutes 21.5 percent (57 billion m3) of this resource and plays a vital role in the socio economic life of the country. Most rural communities in Cameroon rely on ground water to meet their water needs. Ironically, most of this enormous quantity of groundwater is of dubious quality and inaccessible due to lack of appropriate skilled professionals, equipment or financial resources allocated for this purpose. This is not different in Wum where there is an acute shortage of water with the present increase in population especially during the dry season due to the fact that there are only small surface streams in the town that together with wells dry up. 

Geology and hydrogeology
Wum is located on the oku volcanic field on the Cameroon Volcanic Line CVL. The CVL is a N30E oriented tectonic structure made up of volcanic islands, continental volcanoes, plutonic and volcanic complexes ranging in age from 82 Ma to present. The CVL bears the active Mt Cameroon with latest eruptions in 1999 and 2000, with over 100 cinder cones and 40 maars presumed to be not older than 1 Ma Gaudru and Tchouankoue [3]. The Nyos maar is located in the southern continental part of the CVL and belongs to the monogenetic Oku volcanic field that culminates at Mt Oku (3011m). Volcanic activity in the Oku volcanic field ranges from effusive to explosive, and a wide range of compositions have been erupted including basanite, basalt, hawaiite, mugearite, trachyte, and rhyolite. Basement rocks are gneisses and granitoids, which formed during the Pan-African orogeny (~600 Ma) Pinte et al., [4]. The basement of Wum and its vicinity is mostly formed of granitic rocks of dominant micropegmatitic texture. Basaltic rocks appear as small flows directly overlapping the granitic basement. Pyroclastic surge deposits are found near the Lake Nyos crater and cap the basalt flows to the west of the volcano. The pyroclastic rocks contain broken pieces of basement granites and peridotite xenoliths Schmidt et al., 2017 [5]. The aquiferous formations of Wum are mainly the regolith and the fractured crystalline rocks; granites gneisses and basaltspresented in figure 2. 

Figure 2: Geology of Wum: Area mainly made up of Gneiss, granite and patches of basalts and Maar type volcanoes [5].

The suitability of water for irrigation depends on the effects of the mineral constituents of water on both the plant and the soil [6]. Excessive amounts of dissolved ions in irrigation water affect plants and agricultural soil physically and chemically, thus reducing the productivity, thus parameters such as Electrical Conductivity EC, sodium percentage (Na%), Sodium Adsorption Ratio (SAR), Magnesium Adsorption Ratio (MAR), Residual sodium carbonate and Permeability Index (PI) were used to assess the suitability of ground water for irrigation purposes [7].

Assessment of water for agro-industrial suitability is important inorder to determine whether the water will have an adverse effect on the soil properties if used as irrigation water [8].This is vital for the development of an agricultural zone like Wum where farming is the major occupation of the citizens and there are currently studies going on to create large scale cash crop plantations.

MATERIALS AND METHODS

Materials
The field materials and equipment used in this study are listed in Table 1.

Equipment/Softwares

Specifications

Functions

Bike

Commercial bikes (Bensikin)

To transport fieldworkers to wells

GPS

Garmin GPSMAP 60CSx

To measure longitude, latitude and elevation of wells

EC Meter

Hanna HI 98304/HI98303

To measure electrical conductivity of water.

pH Meter

Hanna HI 98127/HI98107

To measure pH of water.

Water level indicator

Solinst model 102M

To indicate static water levels of water in wells

Measuring Tape

Weighted measuring tape

Measurement of well diameter and depth.

Digital Thermometer

Extech 39240 (-50 to 200oC)

To measure temperature of water

Total Dissolved Solid meter

Hanna HI 96301 with ATC

To measure Total dissolved solids in water

Water sampler

Gallenkampf 1000ml

To collect well water sample from well

Sample bottles

Polystyrene 500ml

To hold sample for onward transmission to laboratory

Global Mapper

Version 15

GIS Geolocation of wells

Surfer Golden Software

Version 12

GIS plotting contours for spatial distribution

AqQA/Aquachem

Version 1.5

For the analysis/interpretation of water chemistry

Table 1: Field Equipment, specifications and functions.

Methods
Prior to field tests, measurements and sampling, a reconnaissance field survey was carried out to identify and select representative wells and springs ISO 5667-1 [9]. 

Field measurements, tests and sampling were carried out in four hydrogeological seasons: dry (March), drywet (June), wet (September) and wetdry seasons (December). The study area was divided into 5 sections representing the main quarters. 31 representative wells and 7 springs were tested. 10 samples two samples per section were analyzed per season, except in the dry season where one sample was collected per section as many wells got dry. Seasonal measurements were carried out in situ for: coordinates of wells, Surface elevation, Well water level, dug wells depths well diameter, Electrical Conductivity (EC), pH, Total Dissolved Solids (TDS) and temperature. groundwater samples were collected in a High Density Polyethylene (HDPE) 500 ml bottles, sealed and sent to the laboratory using standardprotocols ISO 5667-3 [10], ISO 5667-11 [11] and methods APHA [12] to analyze for:

• Major cations in mg/L: Ca2+, Mg2+, Na+, K+ and NH4+
• Major anions in mg/L: HCO3-, Cl- , SO42-, HPO42- and NO3- 

Ionic ratio for indicative elements is a useful hydrogeochemical tool to identify source rock of ions and formation contribution to solute hydrogeochemistry Hounslow [13]. These were used in this study.

Gibbs diagram is a plot of Na+/ (Na++HCO3- Ca2+) and Cl-/ (Cl-+HCO 3-) as a function of TDS are widely employed to determine the sources of dissolved geochemical constituents Gibbs [14]. These plots reveal the relationships between water composition and the three main hydrogeochemical processes involved in ions acquisition; atmospheric precipitation, rock weathering or evaporation crystallisation. Pipers diagram is a graphical representation of the chemistry of water sample on three fields; the cation ternary field with Ca, Mg and Na+K apices, the anion ternary field with HCO3, SO4 and Cl- apices. These two fields are projected onto a third diamond field Piper [15]. The diamond field is a matrix transformation of the graph of the anions [SO42- + Cl-]/? anions and cations [Na+K]/? cations. This plot is a useful hydrogeochemical tool to compare water samples, determine water type and hydrogeochemical facies Langguth [16].This has been used here for these purposes. Durov diagram is a composite plot consisting of two ternary diagrams where the mill equivalent percentages of cations are plotted perpendicularly against those of anions; the sides of the triangles form a central rectangular binary plot of total cation vs. total anion concentrations Durov [17]. The central rectangle is divided into nine classes which give the hydrogeochemical processes determining the character of the water types in the aquiferous formation Langguth [16], Lloyd and Heathcote [18].

WQI was calculated by adopting Weighted Arithmetical Index method considering thirteen water quality parameters (pH, EC, TDS, total alkalinity, total hardness, Na+, Mg2+, Na+, K+, Cl-, SO42-, NO3-, NH4+) and the WHO guidelines [19] in order to assess the degree of groundwater contamination and suitability table 2 Sisodia and Moundiotiya [20]. 

 

Formula

Reference

Percentage Sodium

Wilcox (1955) [21]

Kelly’s Ratio

Kelly (1940) [22]

Magnesium Adsorption Ratio

Palliwal  (1972) [23]

Total Hardness

TH (CaCO3) mg/L = 2.5 Ca2+ + 4.1Mg2+

Todd (1980) [24]

Residual Sodium Carbonate

Eaton (1950) [25]

Sodium Adsorption Ratio

Richard (1954) [26]

Permeability Index

Doneen (1962) [27]

Water Quality Index

Sisodia and Moundiotiya (2006) [20]

Table 2: Indices used in the calculation of water quality and irrigation water quality.

For the determination of agro-industrial suitability of groundwater in Wum, the following parameters and indices; sodium adsorption ratio SAR, permeability index PI, Magnesium adsorption ratio, percent sodium, Kelly’s ratio, Residual sodium carbonate and Wilcox diagram presented in Table2, together with the following softwares platforms; Surfer 12, Global mapper 11 and AqQA 1.5 AGIS 10.3 were used for data presentation, interpretation and analysis.

RESULTS AND DISCUSSION

Physicochemical parameters
The physicochemical parameters of groundwater in Wum: Temperature, pH, EC and TDS for 10 wells and springs were evaluated and presented in table 3. All physicochemical parameters vary with seasons indicating seasonal influence on the phreatic aquifer.

Test

Dry

Dry Wet

Wet

Wet Dry

 

Min

Max

Mean

Std

Min

Max

Mean

Std

Min

Max

Mean

Std

Min

Max

Mean

Std

T(oC)

21.5

25.3

23.0

23.0

0.1

23.1

26.7

26.1

20.8

26.6

23.0

22.9

21.8

24.1

22.7

22.7

PH

-

-

-

-

2.6

16.9

6.51

6.40

3.3

7.1

5.44

5.37

5.2

7.5

6.25

6.21

EC(mS/cm)

0.01

0.51

0.11

0.12

0.01

6.30

0.26

1.01

0.17

3.90

1.13

0.95

0.01

3.29

1.05

0.83

TDS(mg/L)

0.01

0.34

0.07

0.08

0.01

4.22

0.17

0.68

0.11

2.61

0.76

0.64

0.01

2.20

0.70

0.55

Table 3: Basic Statistics of the physicochemical found in groundwater, min, max, mean and standard deviation of these elements in both the dry, drywet, wet and wetdry seasons.

Water level fluctuations: Groundwater levels vary in conformity with changes in precipitations in all four seasons typical of phreatic aquiferous formationsas shown in figure 3.

Figure 3: Depth to static water levels in four seasons. High values are at inieng and courtyard for all seasons.

Groundwater flow direction: Water level contours are similar to surface elevation contours. This indicates groundwater table mimics topography typical of phreatic aquifers. Flow is towards the northeastern parts of the study area for all seasons figure 4.
 
Figure 4: Groundwater flow direction in Wum indicating that water flows towards the northeastern parts of the study area all four seasons.

The levels of groundwater in a basement environment like Wum is controlled by the presence and extent of the weathered overburden/regolith as well as fissures, joints and fractures system in the underlying bedrock (Tijani et al.,2010) [28].

Temperature: The temperature of the groundwater in Wum is relatively low, ranged between 21.5-25.3 dry, 21.7-23.1 drywet, 20.8-26.6 wet and 21.8-24.1 wetdry seasons respectively figure 5. The temperature variation was similar in the different areas, suggesting a single aquifer since groundwater in the same aquifers have similar parameter values and temperature is one of them.
 
Figure 5: Temperature variations in Wum: Temperatures are highest in the wet season. High temperatures of groundwater can be found in zongefu, inieng, naikom quarters and mile 50.

pH: The pH of groundwater samples in the study area range from; 2.6-6.9 drywet, 3.3-7.1 wet and 5.2-7.5 wetdry season figure 6. This indicates that groundwater is acidic to per alkaline in all seasons.

Figure 6: Spatial variation of pH in wum for three seasons; Note decrease in pH values wet and wetdry seasons around mile 50 and court yard while in the drywet season the pH values increase around 3 corners.

Electrical conductivity: The observed conductance in the study area was low in all seasons, ranging from 0.01-0.51mS/cm in the dry season, 0.01-6.30mS/cm in the drywet season, 0.17-3.90mS/cm in the wet season and 0.01-3.29mS/cm wet-dry season as shown in figure 7. These low values of EC and TDS are a reflection of low salt content in groundwater. EC is highest in Magha and 3-corners for the dry season; Mile-50 in the drywet: Hausa quarter and naikom for wet and Courtyard for the wetdry season.

Figure 7: Spatial variation of electrical conductivities (mS/cm) in wum for four seasons; EC is at maximum in the drywet season and minimum in the dry season.

Total dissolved solids:
 The values of TDS range from 0.01-0.34mg/L in the dry season, 0.01-4.22mg/L drywet season, 0.11-2.61mg/L wet season and 0.01-2.20mg/L wetdry season with the highest value observed in the wet season as in figure 8. TDS is highest at Magha and 3-corners for dry season: Mile-50 in the drywet season: Hausa quarter and Naikom in the wet season and Courtyard for Wetdry season.TDS is highest in drywet season due to the absence of rain in the formations, at this point the ionic concentration is higher but moving towards the heart of rainy season and groundwater becomes more dilute and keeps decreasing each season until the next drywet season.

Figure 8: Spatial variation of total dissolved solids mg/L in Wum for four seasons. TDS is highest in the drywet season and lowest in the dry season.
 
Groundwater ionic content in Wum
The ionic content varied with seasons as presented in tables 4, 5, 6 and 7. During the dry season the ionic trend was Ca2+>Mg2+>NH4+>K+>Na+, for cations and HCO3->Cl->SO42->NO3->HPO42- for anions. This same pattern was observed in most of the areas with exceptions in Hilltop, where K+ was greater than NH4+. A different trend was observed in the anions where HPO42- was greater than NO3- in Zongefu and Manyi. However, Cl- was absent in most samples but whenever it was present, it usually had a higher value than SO42- giving it a higher total concentration.

Dry Season (mg/L)

Location

Na+

K+

Mg2+

Ca2+

NH4+

HCO3

NO3-

SO42-

Cl-

HPO4

Zongefusp

0.13

0.54

5.00

5.00

4.95

6.1

0

1.29

0

0.12

Twins wl

0.45

5.02

19.9

19.9

3.91

23.18

1.23

1.94

16

0.03

Hilltop sp

0.03

0.16

5.00

5.00

5.73

8.54

0

2.07

0

0

Manyiwl

0.1

0.54

9.85

9.85

5.01

8.54

0

1.75

0

0.11

Jopaccst

0.19

2.15

9.8

9.8

6.15

51.2

1.86

4.08

2

0

Min

0.03

0.16

5

5

3.91

6.1

0

1.29

0

0

Max

0.45

5.02

19.9

19.9

6.15

51.2

1.86

4.08

16

0.12

Mean

0.18

1.68

9.91

9.91

5.15

19.51

0.62

2.23

3.60

0.05

Std.

0.16

2.02

6.08

6.08

0.85

18.00

0.88

1.08

6.99

0.06

Table 4: Basic statistics of results from chemical Analysis of groundwater for dry season, Wum.
 

Drywet Season (mg/L)

Location

Na+

K+

Ca2+

Mg2+

NH4+

HCO3-

NO3-

SO42-

Cl-

HPO4-

Zongefu

0.18

3.99

9.11

1.23

0.19

45.01

2.34

0.84

0.42

0.00

Kesu

0.14

3.24

7.38

1.45

0.15

40.26

1.05

0.96

0.32

0.00

Checksense

0.40

4.34

13.21

9.21

0.89

20.03

12.90

2.12

0.84

0.00

Twins

0.60

5.97

22.16

3.69

0.00

45.14

4.28

1.69

3.68

0.00

Hilltop

0.16

3.00

6.22

1.35

0.13

39.91

1.01

0.91

0.31

0.00

Ndangasen

0.70

6.90

25.01

5.33

0.50

48.99

7.99

3.19

4.95

0.00

Canteen

0.00

0.00

2.46

0.92

1.61

17.08

3.03

8.71

0.84

0.00

Manyi

0.41

5.53

14.22

9.65

0.75

21.45

11.67

3.65

0.84

0.00

Jopacc

0.05

1.44

2.46

2.11

0.10

56.12

0.07

1.82

0.63

0.00

Jean

0.30

4.41

12.32

8.63

0.69

18.30

10.33

1.19

0.74

0.00

Min

0.00

0.00

2.46

0.92

0.00

17.08

0.07

0.84

0.31

0.00

Max

0.70

6.90

25.01

9.65

1.61

56.12

12.90

8.71

4.95

0.00

Mean

0.29

3.88

11.46

4.36

0.50

35.23

5.47

2.51

1.36

0.00

Std.

0.23

2.08

7.61

3.58

0.50

14.54

4.82

2.38

1.60

0.00

Table 5: Basic statistics of results from chemical Analysis of groundwater for drywet season, Wum.
 

Wet Season (mg/L)

Location

Na+

K+

Ca2+

Mg2+

NH4+

HCO3-

NO3_

SO42-

Cl-

HPO4-

Zongefu

0.15

4.11

4.11

8.91

0.12

48.27

2.26

0.74

0.51

0.00

Kesu

0.21

5.01

5.01

12.11

0.25

54.05

3.42

0.62

0.63

0.00

Checksense

0.44

5.21

5.21

12.11

0.91

40.05

14.10

1.95

0.89

0.10

Twins

0.90

5.90

5.90

23.31

0.04

65.25

9.30

1.05

4.89

0.20

Hilltop

0.13

4.11

4.11

5.35

0.21

49.17

3.05

0.75

0.52

0.00

Ndangasen

0.90

7.01

7.01

24.05

0.80

51.25

8.95

2.81

4.99

0.00

Canteen

0.10

0.21

0.21

3.11

1.95

27.09

6.08

7.11

0.94

0.00

Manyi

0.45

6.22

6.22

15.51

0.81

20.95

11.95

2.44

0.96

0.00

Jopacc

0.08

2.41

2.41

3.51

0.25

58.11

1.18

1.02

0.85

0.00

Jean

0.50

5.01

5.01

15.21

0.85

20.95

11.45

0.99

0.93

0.10

Min

0.08

0.21

0.21

3.11

0.04

20.95

1.18

0.62

0.51

0.00

Max

0.90

7.01

7.01

24.05

1.95

65.25

14.10

7.11

4.99

0.20

Mean

0.39

4.52

4.52

12.32

0.62

43.51

7.17

1.95

1.61

0.04

Std.

0.31

1.98

1.98

7.45

0.58

15.67

4.58

1.97

1.76

0.07

Table 6: Basic statistics of results from chemical Analysis of groundwater for wet season, Wum.
 

Wetdry Season (mg/L)

Location

Na+

K+

Ca2+

Mg2+

NH4+

HCO3-

NO3_

SO42-

Cl-

HPO-4

Zongefu

0.18

6.10

10.03

1.03

0.12

50.71

2.84

2.84

0.73

0.20

Kesu

0.56

5.51

15.91

15.84

0.99

26.13

13.03

13.03

1.39

0.10

Checksense

0.46

5.65

13.51

12.51

0.95

55.25

15.95

15.95

0.99

0.10

Twins

0.95

5.89

25.93

17.03

0.82

73.99

11.47

11.47

6.22

0.30

Hilltop

0.11

4.52

5.74

8.03

0.51

69.07

5.94

5.94

0.59

0.00

Ndangasen

0.85

7.44

23.94

23.71

0.85

53.97

9.54

9.54

5.85

0.10

Canteen

0.15

0.19

3.85

5.84

1.99

35.03

8.94

8.94

10.51

0.20

Manyi

0.55

6.35

15.11

15.95

0.94

25.11

11.99

11.99

0.97

0.00

Jopacc

0.15

2.59

4.05

4.05

0.31

61.01

1.21

1.21

1.43

0.00

Jean

0.35

8.08

13.84

1.51

0.34

74.32

5.96

5.96

0.94

0.00

Min

0.11

0.19

3.85

1.03

0.12

25.11

1.21

1.21

0.59

0.00

Max

0.95

8.08

25.93

23.71

1.99

74.32

15.95

15.95

10.51

0.30

Mean

0.43

5.23

13.19

10.55

0.78

52.46

8.69

8.69

2.96

0.10

Std.

0.30

2.32

7.64

7.60

0.53

18.40

4.67

4.67

3.39

0.11

Table 7: Basic statistics of results from chemical Analysis of groundwater for wetdry season, Wum.

In the drywet season the trend was Ca2+>Mg2+>NH4+>K+>Na+ for cations and HCO3->NO3->SO42->Cl->HPO42- for anions though at Canteen, Ndangasen, Jopacc and Twins Cl->SO42-.

Wet season: The trend was Mg2+>Ca2+>K+>NH4+>Na+ and HCO3->NO3->SO42->Cl->HPO42-. In Zongefu, Twins and Ndangasen for cations as Na+>NH4+and for the anions in Twins and Ndangasen Cl-> SO42-.

Wetdry season: The trend was Ca2+>Mg2+>K+>NH4+>Na+ for cations though Na+>NH4+ in Kesu and Zongefu. For Anions, it was in the order; HCO3-> SO42->NO3->Cl->HPO42- even though Cl->NO3- in Canteen.

Ionic ratios of groundwater
Ionic ratios of groundwater in Wum have been determined as presented in tables 8, 9, 10 and 11 and used to infer the sources and formation contribution to groundwater ionic contentin table 12.

No

SO4
/Cl

Na
/Cl

Mg
/Cl

Na
/HCO3

Ca
/HCO3

Ca
/SO4

Ca
/Mg

(Ca+Mg)
/(Na+K)

HCO3
/∑An

NO3
/∑An

SO4
/∑An

Cl
/∑An

Na+K+Cl
/Na+
K-Cl+Ca

Na
/Na+Cl

Mg
/Ca+Mg

Ca
/Ca+SO4

Ca+Mg
/SO4

Mg
/Ca

1

0.00

0.00

0.00

0.02

0.82

3.88

1.00

14.93

0.81

0.00

0.17

0.00

0.12

1.00

0.50

0.79

7.75

1.00

2

0.12

0.03

1.24

0.02

0.86

10.26

1.00

7.28

0.55

0.03

0.05

0.38

2.29

0.03

0.50

0.91

20.52

1.00

3

0.00

0.00

0.00

0.00

0.59

2.42

1.00

52.63

0.80

0.00

0.20

0.00

0.04

1.00

0.50

0.71

4.83

1.00

4

0.00

0.00

0.00

0.01

1.15

5.63

1.00

30.78

0.82

0.00

0.17

0.00

0.06

1.00

0.50

0.85

11.26

1.00

5

2.04

0.10

4.90

0.00

0.19

2.40

1.00

8.38

0.87

0.03

0.07

0.03

0.43

0.09

0.50

0.71

4.80

1.00

Min

0.00

0.00

0.00

0.00

0.19

2.40

1.00

7.28

0.55

0.00

0.05

0.00

0.04

0.03

0.50

0.71

4.80

1.00

Max

2.04

0.10

4.90

0.02

1.15

10.26

1.00

52.63

0.87

0.03

0.20

0.38

2.29

1.00

0.50

0.91

20.52

1.00

Mean

0.43

0.02

1.23

0.01

0.72

4.92

1.00

22.80

0.77

0.01

0.13

0.08

0.59

0.62

0.50

0.79

9.83

1.00

Std.

0.90

0.04

2.12

0.01

0.36

3.27

0.00

19.14

0.13

0.02

0.07

0.17

0.97

0.52

0.00

0.09

6.53

0.00

Table 8: Ionic ratios of groundwater ions: Summary statistics for dry season.
 

CONCLUSION

Groundwater levels vary in rhythm with changes in precipitations in all four seasons, water level contours are similar to surface elevation contours and groundwater table mimics topography typical of phreatic aquifers with all physicochemical parameters varying with seasons indicating seasonal influence on the phreatic aquifer. An evaluation of the ionic ratios indicates ions in the groundwater in Wum are from rock weathering and rainwater; portrays a cation-exchange and silicate weathering environment.

Rock-Groundwater Interaction in Wum has the weathering of the aquifer matrix as the primary dominant process in the acquisition of ions while atmospheric precipitation and Evaporation-Crystallization are the secondary contributing processes to the hydrogeochemistry in Wum. 

Groundwater in Wum is made up of two water types; CaHCO3 is the dominant water type in all seasons and CaSO4 the minor water type occurs in the dry, drywet and wetdry seasons. 

There are two hydrochemical facies: Ca-Mg-Cl-SO4 hydrogeochemical facies characteristic of groundwater some distance along its flow path and Ca-Mg-HCO3 hydrogeochemical facies characteristic of freshly recharged groundwater that has equilibrated with CO2 and soluble carbonate minerals under open system conditions in the vadose zone typical of shallow groundwater flow systems in crystalline phreatic fractured rock aquifers.

Hydrogeochemical character of Wum groundwater varies with season: In the wet season, fresh recently recharging water exchanges ions with the matrix of the formation, while simple dissolution or mixing also goes on between the recently recharging precipitation and the existing groundwater in the formation. In the dry season, recharging groundwater having spent more time in the formation continues to exchange ions to a lesser extent with the matrix of the formation while increasingly; simple dissolution or mixing also goes on between the recently recharging groundwater and the pre-existing groundwater in the formation, piston flow. 

The groundwater in Wum is hard in wetdry season and soft to moderately hard in all seasons. The Water Quality Index for groundwater in Wum is excellent-good for domestic use. The groundwater indices of; Sodium Percent, Residual Sodium Carbonate, Kelley’s ratio, Sodium Adsorption Ratio, Electrical Conductivity, Total Dissolved Solid, USSL and Wilcox index were determined, evaluated and found to be suitable for agro-industrial uses in all seasons.

Permeability Index and Magnesium Adsorption Ratio are not suitable in some areas and in some seasons, Therefore, more attention should be paid on groundwater quality monitoring (PI and MAR) in Wum, for ensuring dependable, affordable groundwater and protecting the quantity available for future use during the planning stage of large scale farming in Wum.

REFERENCES

  1. WCDP/PNDP (2011) Wum Council Development Plan, Municipal Decision.
  2. Kometa SS, Akoh NR (2012) The Hydro-geomorphological implication of urbanization in Bamenda, Cameroon. Journal of Sustainable Development 5: 64-73.
  3. Gaudru H, Tchouankoue JP (2002) The 1999 eruption of Mt. Cameroon, West-Africa. Cogeoenvironment Newsletters 18: 12-14.
  4. Pinte r Z, Patko L, TeneDjoukam JF, Kovacs I, Tchouankoue JP, et al. (2015) Characterization of the sub-continental lithospheric mantle beneath the Cameroon volcanic line inferred from alkaline basalt hosted peridotite xenoliths from Barombi Mbo and Nyos Lakes. J Afr Earth Sci 111: 170-193.
  5. Schmidt C, Tchouankoue JP, Nkouamen Nemzoue PN, Ayaba F, Nformidah-Ndah SS, Nformi Chifu E (2017) New thermoluminescence age estimates for the Nyos maar eruption (Cameroon Volcanic Line). PLoS ONE 12: 0178545.
  6. Raihan F, Alam JB (2008) Assessment of groundwater quality in sunamganj of bangladesh, Iranian
    Journal of Environmental Health Science and Engineering, 5: 155-166.
  7. Abdul Qader UN, Ghazal IK (2008) Hydrochemistry and assessment of ground water quality of al-shekhan bartellah area (northern iraq).
  8. Akoachere RA, Eyong TA, Eduvie MO, Egbe SE, Yaya,OO, et al., (2018) Hydrogeochemical model and water quality of groundwater in the granito-basaltic fractured rock aquiferous formations in bafoussam, west region-cameroon. Journalof Water Resource and Protection, 10: 1148-1174.
  9. ISO (2006) Standard ISO 5667 1: Water quality-sampling-Part 1: Guidance on the design of sampling programs and sampling techniques. International Organization for Standardization, Geneva, Switzerland.
  10. ISO (2003) Standard ISO 5667 3: Water quality-sampling-Part 3: Guidance on the preservation and handling of water samples. International Organization for Standardization, Geneva, Switzerland.
  11. ISO (2009) Standard ISO 5667-11: Water quality-sampling-Part 11: Guidance on sampling of groundwaters. International Organization for Standardization, Geneva, Switzerland.
  12. APHA (1995) Standard methods for examination of water and waste water, (22nd), American Public Health Association, American Water Works Association and Water Pollution Control Federation, Washington DC, USA.
  13. Hounslow AW (1995) Water quality data: Analysis and interpretation, (1st), Lewis Publishers CRC press New York, USA.
  14. Gibbs RJ (1970) Mechanisms controlling world’s water chemistry. Science 170: 1088-1090.
  15. Piper AM (1944) A geographic procedure in the geochemical interpretation of water analysis, Eos, Transactions American Geophysical Union 25: 914-923.
  16. Langguth HR (1966) Groundwater verhaltisse in Bereiech Des Velberter. Sattles. Der Minister Fur Eraehrung, Land Wirtsch Forste Duesseldorf: NRW, 127
  17. Durov SA (1948) Classification of natural waters and graphical representation of their composition: Dokl. Akad. Nauk. USSR 59: 87-90.
  18. Lloyd JA, Heathcote JA (1985) Natural inorganic hydrochemistry in relation to groundwater: An introduction. Oxford Uni Press, New York, USA.
  19. WHO (2017) Guidelines for drinking-water quality: 4th edition incorporating the first addendum. World Health Organization, Geneva, Switzerland.
  20. Sisodia R, Moundiotiya C (2006) Assessment of the water quality index of wetland Kalakho Lake, Rajasthan, India. J Environ Hydro 14: 1-11.
  21. Wilcox LV (1955) Classification and use of irrigation waters. United States department of agriculture circular, Washington, D. C, USA.
  22. Kelley WP (1940) Permissible composition and concentration of irrigation waters, Proceedings of the American society of civil engineers 66: 607-613.
  23. Paliwal KV (1972) Irrigation with saline water. Indian Agricultural Research Inst, New Delhi, India.
  24. Todd DK (1980) Groundwater hydrology, (3rd edn), Wiley, New York, USA.
  25. Eaton FM (1950) Significance of carbonate in irrigation water. Soil science 69: 123-133.
  26. Richards LA (1954) Diagnosis and improvement of saline and alkali soils, United States Department of Agriculture, Agricultural Handbook No. 60, Washington, D. C, USA.
  27. Doneen LD (1962) The influence of crop and soil on percolating water. Proceedings of the Biennial conference on Groundwater Recharge 1961, California, USA.
  28. Tijani NM, Alichi UA, Diop S (2010) Characterization of Weathered Basement Aquifers: Implication for Groundwater Recharge, 7th International Symposium on Managed Aquifer Recharge (ISMAR-7): Abu-Dhabi, UAE.
  29. Pradhan SK, Patnaik D, Rout SP (1998) Ground water quality –an assessment around a phosphatic fertilizer plant at paradip. Indian Journal Environment Protection 18: 769-772.
  30. Asadi JJ, Vuppala P, Reddy MA (2007) Remote Sensing and GIS Techniques for Evaluation of Groundwater Quality in Municipal Corporation of Hyderabad (Zone-V), India. Int J Environ Res Public Health., 4: 45-52.
  31. Sawyer CN, McCarty PL (1967) Chemistry for Sanitary Engineers, (2nd edn), McGraw Hill, New York.
  32. USSL (1954) Diagnosis and improvement of saline and alkali soils, United States department of agriculture, Agricultural handbook, Washington, D. C, USA.
  33. Pandian K, Sankar K (2007) Hydrochemistry and groundwater quality in the Vaippar river basin, Tamil Nadu. Jour Geol Soc India 69: 970-982.

Citation: Akoachere RA, Mbei KK, Eyong TA, Eduvie MO, Engome RW, et al. (2019) Seasonal Variations in the Hydrogeochemistry and the Domestic-Agro-Industrial Water Quality of the Granite-Gneiss Fractured Rock Aquiferous formations in Wum, North West Region, Cameroon. J Environ Sci Curr Res: S1001.

Copyright: © 2019  Akoachere RA, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


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No

SO4
/Cl

Na
/Cl

Mg
/Cl

Na
/HCO3

Ca
/HCO3

Ca
/SO4

Ca
/Mg

(Ca+Mg)
/(Na+K)

HCO3
/∑An

NO3
/∑An

SO4
/∑An

Cl
/∑An

Na+K+Cl
/Na+
K-Cl+Ca

Na
/Na+Cl

Mg
/Ca+Mg

Ca
/Ca+SO4

Ca+Mg
/SO4

Mg
/Ca

1

2.00

0.43

2.93

0.00

0.20

10.85

7.41

2.48

0.93

0.05

0.02

0.01

0.36

0.30

0.12

0.92

12.31

0.14

2

3.00

0.44

4.53

0.00

0.18

7.69

5.09

2.61

0.95

0.02

0.02

0.01

0.35

0.30

0.16

0.88

9.20

0.20

3

2.52

0.48

10.96

0.02

0.66

6.23

1.43

4.73

0.56

0.36

0.06

0.02

0.33

0.32

0.41

0.86

10.58

0.70

4

0.46

0.16

1.00

0.01

0.49

13.11

6.01

3.93

0.82

0.08

0.03

0.07

0.41

0.14

0.14

0.93

15.30

0.17

5

2.94

0.52

4.35

0.00

0.16

6.84

4.61

2.40

0.95

0.02

0.02

0.01

0.38

0.34

0.18

0.87

8.32

0.22

6

0.64

0.14

1.08

0.01

0.51

7.84

4.69

3.99

0.75

0.12

0.05

0.08

0.45

0.12

0.18

0.89

9.51

0.21