Limbe the Fako Divisional headquarters of the Southwest Region in Cameroon is situated between 3.96-4.06N and 9.15-9.24E shown in figure 1. As an urban town with over 130,000 inhabitants [1] and insufficient water supply by the national water supply company CAMWATER, the inhabitants are obliged to turn to other sources of water such as natural springs, community water project catchments, hand-dug wells and boreholes. The inhabitants of parts of Limbe have always complained of low quality of drinking water from wells during the rainy season as such, there was a need to carry out this research to determine the root cause of this loss of quality during the rainy season. With the population explosion and the increased need for groundwater for economic development such as agriculture, industrial and domestic activities, understanding the groundwater chemical character and the aquiferous formations through which this water flows is of great importance for the future development of this region and sustainable use and protection of this aquifer system.
Figure 1: Map of the Study Area, Limbe-Southwest Region Cameroon.
Climate
Limbe experiences a subequatorial climate (hot and humid throughout) with mainly two distinct seasons; a rainy season between April to October and a dry season from November to March with a mean annual rainfall of about 3,100 mm, ±1,100 standard deviation [2]. The annual rainfall is high, with yearly precipitations varying from 1,500 to 6,000 mm in the last 34 years for different stations. Peak rainfall is recorded from June to August or September. June and July are characterized by intense and short-lived rainfall usually lasting less than 5hours a day. Whereas, August and September tend to experience less intense but more prolonged rainfalls that can last for 4 to 5 days in a row. Monthly rainfall totals frequently attain over 500 mm and sometimes up to 1,000 mm in June, July and August. The mean annual temperature is ~26 °C and shows only limited variations of ~4° throughout the year. Humidity is generally above 85%. These characteristics correspond to the Tropical Monsoon Climate according to the Köppen climate classification scheme [3,4].
Drainage
Limbe and Ejengele are the two main rivers in Limbe with the former being the largest. Limbe River takes its rise from Mt Cameroon, through Mile 4, Mile 2, Middle farms, Botanic Garden and into the Atlantic Ocean. Limbe River has a trellis drainage pattern with all its numerous tributaries running parallel down the slopes of Mount Cameroon. The slopes are steep, up to 43%, causing the streams to flow with high velocities. Other smaller streams consist of: Mange, Sange-Mile 4, Grand Lake-Mile 2, Konkikar, Balimba-Mabeta New layout, Motowoh water and Ndiba water. There are numerous springs notably: Likomba, Toma-Mile 4, Busumbu spring-mile 2, Cold source Mile 1 and Crystal garden. Gravity catchments have been constructed around some other smaller springs for additional water supply; Mile 4, Mabeta, Mawoh, Motowoh, Batoke. The serivers empty into the Atlantic Ocean.
Geology
Limbe sits on the plains and south eastern slopes of the ridge of Mount Cameroon separating the Rio del Rey and Douala basins; the Cameroon Volcanic Line presented in figure 2. The geology of Limbe is volcanic being consequent of the eruptive events of Mount Cameroon. The geology is of tertiary basaltic rocks composed of multiple porphyritic basaltic lava flows, punctuated by several strombolian pyroclastic cones to the West and North West and lahar deposit to the East seen in figure 2. These rocks either lie exposed at the surface or are covered by extremely fertile dark brown, reddish brown, yellowish and/or pale yellow sticky, clay, silt and silty clayey soils derived from intense in situ weathering. Soil thicknesses range from a few centimeters to more than 10 m [2]. The mineral content of basalts in Limbe consists mainly of Clinopyroxene (Ca(TiMgAl) SiAl)2O6), Hematite (Fe2O3), and Goethite (FeO(OH) and the soils comprises mainly of Anatase (TiO2), Annite (KFe3AlSiO10(OH,F)2), Augite (Ca2(Al-Fe)4(MgFe)4Si6O24), Goethite, Hematite, and Kaolinitic (Al2Si2O5(OH)4) minerals.
Figure 2: Sedimentary basins sandwiching Mount Cameroon and location of Limbe b. Geologic Map of Limbe and Environs, indicating the main geomorphologic characteristics, trend of the hydrographic network and morphology of some pyroclastic cones [2].
Geomorphology
The topography is marked by ridges and deeply incised ravines with a general W-E orientation, at high angle to the general NE-SW orientation of Mt Cameroon and gently sloping foot slopes of Mt Cameroon. These ridges form part of the Limbe-Mabeta volcanic massif, made up of degraded and deeply weathered Tertiary basaltic lava flows [5] The Limbe-Mabeta massif is an eroded volcanic massif SSE of Mt Cameroon. It is characterized by a series of sub-parallel E-W oriented valleys bordered by the 170°-striking Om be structure on its Eastern side [6]. Individual ridges are separated by asymmetric V-shaped valleys occupied by perennial and/or ephemeral streams. These streams either empty themselves directly into the ocean or into the delta around Mabeta.
Hydrogeology
Very little work has been done on the hydrogeology of Limbe with sparse data to correlate. Some groundwater baseline hydrogeochemical studies have been carried out around Mount Cameroon [7-10]. The Limbe area is made up mostly pyroclastic and of jointed weathered fractured and columnar basalt resulting in volcanic fractured rock aquifers where saturated. In addition, Limbe being a coastal area in contact with the sea may experiences seawater intrusion.
From geophysical sections and bore well drill cuttings, the lithostratigraphy is sub-divided into three layers as in figure 3; a soil cover formation topmost which constitutes weathered rocks, recent degradation of lava flows, transported materials, black soils and volcanic sands. This formation has a smaller volume as compared to the underlying basalts and has received only minor alterations by tectonic activities. The intermediate layer is made up of younger fractured columnar basalts and volcanic sand that constitute the aquifer. The basaltic rocks show traces of grinding, crushing, fracturing in a SW-NE direction, these fractures are the major fractures determining the storage of groundwater in the aquifers in the basal to-andesitic formation. The Ancient massive basalts bottom Formation make up the oldest formation and these rocks are the oldest in age. This formation has no fractures and as such do not contain water.
Figure 3: Geophysical section of formations in, Limbe
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 200°C) |
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 |
ArcGIS |
Version 10.1 |
GIS Drawing sampling/Tests location maps |
Global Mapper |
Version 15 |
GIS Geolocation of wells |
Surfer Golden Software |
Version 12 |
GIS plotting contours for spatial distribution |
AqQA/Aquachem |
Version 15 |
For the analysis/interpretation of water chemistry |
Indices |
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] |
SN |
Location |
E |
N |
SE (m) |
DS(m) |
WD (m) |
WSL(m) |
WT (0C) |
WpH |
WEC (µS) |
WTDS (mg/L) |
DSL |
DT (0C) |
DpH |
DEC (µS) |
DTDS (mg/L) |
1 |
Motowoh |
9.2183 |
4.0027 |
9 |
574.59 |
2.68 |
1.64 |
27.2 |
7.6 |
119 |
79.73 |
1.86 |
28.3 |
6.7 |
130 |
87.1 |
2 |
New Town |
9.2146 |
4.0158 |
29 |
1113.61 |
42 |
25 |
27.2 |
7.8 |
208 |
139.36 |
29 |
26.2 |
6.9 |
295 |
197.65 |
3 |
Karrata 2 |
9.1896 |
4.0242 |
70 |
1511.49 |
62 |
40 |
26.2 |
7.9 |
217 |
145.39 |
45 |
28.7 |
6.9 |
212 |
142.04 |
4 |
Sokolo |
9.1739 |
4.0208 |
109 |
1011.36 |
36 |
25 |
25.7 |
8 |
225 |
150.75 |
30 |
28.5 |
6.9 |
144 |
96.48 |
5 |
Mawoh |
9.2207 |
4.0093 |
32 |
1144.73 |
5.83 |
3.11 |
27.1 |
6.3 |
162 |
108.54 |
3.45 |
28.7 |
6.6 |
248 |
166.16 |
6 |
Clerks Qters |
9.2102 |
4.0099 |
4 |
776.86 |
2.45 |
1.5 |
25.1 |
8.2 |
245 |
164.15 |
2.25 |
27.8 |
6.9 |
227 |
152.09 |
7 |
Ngeme |
9.1512 |
4.0147 |
34 |
669.06 |
45 |
16 |
25.6 |
7.8 |
238 |
159.46 |
20 |
25.8 |
7 |
224 |
150.08 |
8 |
Karrata |
9.1842 |
4.0231 |
77 |
1200.3 |
55 |
30 |
25.6 |
8 |
282 |
188.94 |
30 |
27.1 |
6.9 |
231 |
154.77 |
9 |
Church Str. |
9.2096 |
4.0164 |
30 |
861.33 |
2.69 |
1.79 |
27 |
7.4 |
334 |
223.78 |
2.18 |
28 |
6.9 |
217 |
145.39 |
10 |
Mbonjo |
9.2146 |
3.998 |
30 |
900.23 |
1.86 |
1 |
26.6 |
7.6 |
180 |
120.6 |
0.71 |
27.8 |
6.9 |
121 |
81.07 |
11 |
Mabeta |
9.2261 |
4.0129 |
39 |
1778.22 |
7.59 |
2 |
26.3 |
7.2 |
46 |
30.82 |
5.6 |
30.4 |
7 |
166 |
111.22 |
12 |
Mile 4 |
9.2269 |
4.0552 |
240 |
5512.49 |
2.73 |
1.64 |
25.5 |
8 |
221 |
148.07 |
2.19 |
27.5 |
6.7 |
259 |
173.53 |
13 |
West end |
9.2165 |
4.0092 |
18 |
742.41 |
3.59 |
1 |
26.9 |
7.7 |
378 |
253.26 |
2.02 |
28.4 |
7.1 |
544 |
364.48 |
14 |
Mile 1-2 |
9.2205 |
4.0249 |
79 |
2311.69 |
2.85 |
1.93 |
26.1 |
8.5 |
138 |
92.46 |
2.37 |
27.5 |
6.8 |
187 |
125.29 |
15 |
Kulu |
9.2142 |
4.0044 |
24 |
217.83 |
2.65 |
1.07 |
26.3 |
7.9 |
330 |
221.1 |
1.9 |
28.1 |
7.2 |
414 |
277.38 |
16 |
Mile 2 |
9.2097 |
4.0342 |
49 |
2674.45 |
2.86 |
1.6 |
25.4 |
7.2 |
196 |
131.32 |
1.6 |
27.8 |
7 |
452 |
302.84 |
17 |
Dockyard |
9.2125 |
3.9998 |
1 |
46.57 |
2.82 |
1.17 |
27.1 |
7.7 |
963 |
645.21 |
1.85 |
28.8 |
7.2 |
1240 |
830.8 |
18 |
Mile 1 |
9.2154 |
4.0241 |
60 |
1889.36 |
3.83 |
3.45 |
26.3 |
8 |
335 |
224.45 |
3.75 |
27.3 |
6.8 |
334 |
223.78 |
19 |
Sokolo 2 |
9.1743 |
4.0213 |
81 |
1120.28 |
40 |
25 |
25.8 |
8.2 |
150 |
100.5 |
25 |
29 |
6.9 |
144 |
96.48 |
20 |
Dockyard 2 |
9.2126 |
3.9998 |
14 |
92.24 |
2.65 |
1 |
26.3 |
7.7 |
947 |
634.49 |
1.73 |
28.6 |
7 |
1515 |
1015.05 |
21 |
Kulu 2 |
9.2138 |
4.0029 |
8 |
124.36 |
2.89 |
1.04 |
26.8 |
8 |
284 |
190.28 |
1.79 |
28.6 |
7.3 |
742 |
497.14 |
22 |
Mbonjo 2 |
9.2152 |
3.9975 |
22 |
466.78 |
3.88 |
2.4 |
26.2 |
7.8 |
142 |
95.14 |
3.39 |
27.7 |
6.7 |
218 |
146.06 |
23 |
Motowoh 2 |
9.2186 |
4.0008 |
20 |
669.06 |
6.48 |
2.64 |
27.2 |
7.3 |
101 |
67.67 |
6.23 |
27.5 |
6.7 |
156 |
104.52 |
24 |
Mawoh 2 |
9.2251 |
4.0126 |
52 |
1811.56 |
11.38 |
3.74 |
26.5 |
7.2 |
98 |
65.66 |
11.17 |
27.3 |
6.8 |
404 |
270.68 |
25 |
Mabeta 2 |
9.2252 |
4.0131 |
37 |
1794.89 |
6.09 |
4.65 |
26.6 |
6.6 |
81 |
54.27 |
5.48 |
27.5 |
6.7 |
156 |
104.52 |
26 |
Westend 2 |
9.2163 |
4.0101 |
22 |
761.3 |
4.6 |
2.45 |
27.7 |
7.5 |
502 |
336.34 |
2.45 |
28.2 |
7.1 |
466 |
312.22 |
27 |
Church Str. 2 |
9.2091 |
4.0171 |
21 |
865.77 |
3.81 |
2 |
26.2 |
7.7 |
237 |
158.79 |
3.7 |
28 |
6.8 |
260 |
174.2 |
28 |
Mile 2-2 |
9.2108 |
4.0337 |
78 |
2622.88 |
4.34 |
4.16 |
26.1 |
7.1 |
226 |
151.42 |
4.16 |
27.1 |
7 |
254 |
170.18 |
29 |
Mile 4-2 |
9.2266 |
4.0522 |
245 |
5223.53 |
4.14 |
3.5 |
25.3 |
7.3 |
124 |
83.08 |
3.5 |
26.6 |
7 |
167 |
111.89 |
Parameters |
Wet |
Dry |
||||||
Min |
Max |
Mean |
Std. |
Min |
Max |
Mean |
Std. |
|
T(oC) |
22.3 |
27.9 |
26.43 |
0.71 |
24.1 |
30.4 |
28.04 |
0.88 |
PH |
6.1 |
8.5 |
7.28 |
0.51 |
6.4 |
7.8 |
6.84 |
0.23 |
EC (µS/cm) |
38 |
963 |
213.87 |
160.35 |
59 |
1515 |
282.64 |
208.51 |
TDS (mg/L) |
30.15 |
645.21 |
166.93 |
107.4 |
81.07 |
830.8 |
204.25 |
139.70 |
Wet (mg/L) |
|||||||||||
SN |
Names |
Na+ |
K+ |
Ca2+ |
Mg2+ |
NH4+ |
HCO3- |
NO3- |
SO42- |
Cl- |
HPO42- |
1 |
Motowoh |
0.04 |
0.88 |
0.00 |
1.83 |
2.61 |
34.16 |
0.14 |
11.41 |
10.00 |
1.36 |
2 |
St Ann |
0.04 |
0.88 |
0.00 |
1.53 |
2.88 |
142.74 |
0.66 |
8.09 |
8.00 |
2.29 |
3 |
Elegance |
0.25 |
3.86 |
3.10 |
2.71 |
0.27 |
107.97 |
1.13 |
3.98 |
8.00 |
3.56 |
4 |
Sokolo |
0.34 |
4.21 |
3.10 |
2.45 |
0.54 |
88.45 |
0.00 |
3.32 |
6.00 |
2.63 |
5 |
Mawoh |
0.21 |
2.28 |
0.00 |
1.51 |
0.18 |
18.91 |
0.00 |
5.43 |
22.00 |
1.70 |
6 |
ClerksQuarters |
0.39 |
4.39 |
6.20 |
4.51 |
1.35 |
121.39 |
0.00 |
3.13 |
8.00 |
1.52 |
7 |
Limbe River |
0.3 |
3.51 |
3.10 |
2.99 |
0.00 |
127.49 |
0.00 |
2.67 |
6.00 |
2.89 |
8 |
Ngeme |
0.26 |
3.16 |
3.10 |
3.11 |
0.18 |
116.51 |
0.00 |
2.2 |
6.00 |
3.23 |
9 |
Karrata |
0.30 |
3.86 |
6.20 |
4.22 |
0.00 |
101.87 |
0.43 |
2.25 |
7.00 |
23.87 |
10 |
Church Street |
0.21 |
1.93 |
0.00 |
1.23 |
0.00 |
99.43 |
0.63 |
4.63 |
25.00 |
2.63 |
11 |
Mbonjo |
0.30 |
2.46 |
0.00 |
2.1 |
0.00 |
83.57 |
2.58 |
3.6 |
10.00 |
6.11 |
12 |
Mabeta |
0.00 |
0.53 |
0.00 |
1.76 |
0.00 |
0.61 |
0.02 |
3.32 |
10.00 |
0.08 |
13 |
Mile 4 |
0.26 |
2.81 |
3.10 |
2.67 |
0.00 |
48.19 |
0.00 |
5.33 |
18.00 |
0.00 |
14 |
Westend |
0.86 |
10.00 |
2.79 |
1.46 |
0.00 |
100.65 |
0.00 |
10.66 |
32.00 |
0.00 |
15 |
Towe |
0.09 |
1.05 |
0.00 |
1.63 |
0.00 |
57.95 |
0.00 |
3.23 |
9.00 |
0.00 |
16 |
Kulu |
0.30 |
3.69 |
3.1 |
2.71 |
0.00 |
165.31 |
0.00 |
6.03 |
23.00 |
9.85 |
17 |
Mile 2 |
0.09 |
1.76 |
0.00 |
1.61 |
0.99 |
71.37 |
0.00 |
3.65 |
14.00 |
0.00 |
18 |
Dockyard |
4.11 |
60.37 |
161.2 |
31.45 |
0.00 |
173.45 |
0.00 |
16.14 |
77.00 |
5.95 |
19 |
Spring |
0.13 |
2.98 |
3.00 |
1.90 |
0.00 |
112.85 |
0.08 |
2.11 |
5.00 |
0.60 |
20 |
Rain |
0.00 |
0.70 |
0.00 |
1.65 |
0.00 |
0.00 |
0.00 |
4.91 |
8.00 |
0.00 |
Min |
0.00 |
0.53 |
0.00 |
1.23 |
0.00 |
0.00 |
0.00 |
2.11 |
5.00 |
0.00 |
|
Max |
4.11 |
60.37 |
161.20 |
31.45 |
2.88 |
173.45 |
2.58 |
16.14 |
77.00 |
23.87 |
|
Mean |
0.42 |
5.77 |
9.90 |
3.75 |
0.45 |
88.64 |
0.28 |
5.30 |
15.60 |
3.41 |
|
Std |
0.89 |
13.02 |
35.67 |
6.58 |
0.87 |
49.78 |
0.62 |
3.65 |
16.32 |
5.45 |
Dry (mg/L) |
|||||||||||
Names |
Na+ |
K+ |
Ca2+ |
Mg2+ |
NH4+ |
HCO3- |
NO3- |
SO42- |
Cl- |
HPO42- |
|
1 |
Motowoh |
0.30 |
1.6 |
14.00 |
13.78 |
0.00 |
41.48 |
0.00 |
2.31 |
2.00 |
0.12 |
2 |
St Ann |
0.25 |
1.25 |
14.00 |
22.16 |
0.00 |
103.70 |
0.00 |
0.60 |
0.00 |
0.41 |
3 |
Elegance |
0.62 |
6.28 |
32.40 |
20.82 |
0.00 |
124.44 |
0.01 |
0.00 |
0.00 |
0.20 |
4 |
Sokolo |
0.55 |
5.85 |
27.80 |
16.26 |
0.00 |
76.86 |
0.00 |
0.00 |
0.00 |
0.20 |
5 |
Mawoh |
0.3 |
4.29 |
23.20 |
18.85 |
0.00 |
84.18 |
0.01 |
0.00 |
9.00 |
0.24 |
6 |
Clerks Quarters |
0.74 |
7.53 |
37.20 |
18.14 |
0.00 |
136.64 |
0.00 |
1.86 |
0.00 |
0.14 |
7 |
Limbe River |
0.58 |
6.28 |
32.40 |
21.76 |
0.00 |
135.42 |
0.00 |
0.15 |
0.00 |
0.16 |
8 |
Ngeme |
0.58 |
5.46 |
32.40 |
20.93 |
0.00 |
123.22 |
0.00 |
0.91 |
0.00 |
0.16 |
9 |
Karrata |
0.55 |
6.28 |
27.80 |
20.71 |
0.00 |
115.90 |
0.01 |
0.15 |
0.00 |
0.12 |
10 |
Church Street |
0.37 |
2.5 |
23.20 |
18.85 |
0.00 |
109.80 |
0.00 |
1.66 |
25.00 |
0.20 |
11 |
Mbonjo |
0.32 |
2.33 |
18.60 |
14.5 |
0.00 |
43.92 |
0.00 |
1.11 |
0.00 |
0.10 |
12 |
Mabeta |
0.25 |
1.25 |
14.00 |
14.5 |
0.00 |
18.30 |
0.00 |
1.86 |
3.00 |
0.24 |
13 |
Mile 4 |
0.64 |
5.85 |
32.40 |
19.48 |
0.00 |
101.26 |
0.01 |
0.91 |
8.00 |
0.08 |
14 |
Westend |
1.59 |
18.72 |
74.20 |
21.96 |
0.00 |
153.72 |
0.00 |
10.06 |
17.00 |
0.39 |
15 |
Towe |
0.07 |
1.99 |
23.20 |
16.56 |
0.00 |
87.84 |
0.01 |
0.91 |
0.00 |
0.31 |
16 |
Kulu |
0.62 |
5.03 |
32.40 |
31.92 |
0.00 |
208.62 |
0.00 |
3.12 |
9.00 |
0.31 |
17 |
Mile 2 |
0.94 |
7.89 |
46.40 |
24.96 |
0.00 |
145.18 |
0.00 |
5.68 |
10.00 |
0.61 |
18 |
Dockyard |
3.77 |
62.74 |
155.20 |
44.54 |
0.00 |
602.68 |
0.00 |
16.8 |
67.00 |
0.12 |
19 |
Spring |
0.58 |
5.58 |
37.20 |
23.3 |
0.00 |
125.66 |
0.00 |
0.60 |
0.00 |
0.20 |
20 |
Alpha Club |
0.37 |
1.79 |
23.20 |
29.16 |
0.00 |
163.48 |
0.00 |
0.20 |
6.00 |
0.18 |
Min |
0.07 |
1.25 |
14.00 |
13.78 |
0.00 |
18.30 |
0.00 |
0.00 |
0.00 |
0.08 |
|
Max |
3.77 |
62.74 |
155.20 |
44.54 |
0.00 |
602.68 |
0.01 |
16.80 |
67.00 |
0.61 |
|
Mean |
0.70 |
8.02 |
36.06 |
21.66 |
0.00 |
135.12 |
0.00 |
2.44 |
7.80 |
0.22 |
|
Std |
0.79 |
13.44 |
31.11 |
7.09 |
0.00 |
118.70 |
0.00 |
4.14 |
15.49 |
0.13 |
SN |
SO |
Na |
Mg |
Na |
Ca |
Ca |
Ca/Mg |
Ca+Mg |
HCO3/ |
NO3 |
SO4 |
Cl |
Na+K+Cl |
Na |
Mg |
Ca |
Ca+Mg |
Mg/Ca |
1 |
1.16 |
0.15 |
6.89 |
0.01 |
0.34 |
6.06 |
1.02 |
14.62 |
0.90 |
0.00 |
0.05 |
0.04 |
-0.01 |
0.13 |
0.50 |
0.86 |
12.03 |
0.98 |
2 |
0.00 |
0.00 |
0.00 |
0.00 |
0.14 |
23.33 |
0.63 |
24.11 |
0.99 |
0.00 |
0.01 |
0.00 |
0.10 |
1.00 |
0.61 |
0.96 |
60.27 |
1.58 |
3 |
0.00 |
0.00 |
0.00 |
0.00 |
0.26 |
0.00 |
1.56 |
7.71 |
1.00 |
0.00 |
0.00 |
0.00 |
0.18 |
1.00 |
0.39 |
1.00 |
0.00 |
0.64 |
4 |
0.00 |
0.00 |
0.00 |
0.01 |
0.36 |
0.00 |
1.71 |
6.88 |
1.00 |
0.00 |
0.00 |
0.00 |
0.19 |
1.00 |
0.37 |
1.00 |
0.00 |
0.58 |
5 |
0.00 |
0.03 |
2.09 |
0.00 |
0.28 |
0.00 |
1.23 |
9.16 |
0.90 |
0.00 |
0.00 |
0.10 |
-0.23 |
0.03 |
0.45 |
1.00 |
0.00 |
0.81 |
6 |
0.00 |
0.00 |
0.00 |
0.01 |
0.27 |
20.00 |
2.05 |
6.69 |
0.99 |
0.00 |
0.01 |
0.00 |
0.18 |
1.00 |
0.33 |
0.95 |
29.75 |
0.49 |
7 |
0.00 |
0.00 |
0.00 |
0.00 |
0.24 |
216.00 |
1.49 |
7.90 |
1.00 |
0.00 |
0.00 |
0.00 |
0.17 |
1.00 |
0.40 |
1.00 |
361.07 |
0.67 |
8 |
0.00 |
0.00 |
0.00 |
0.00 |
0.26 |
35.60 |
1.55 |
8.83 |
0.99 |
0.00 |
0.01 |
0.00 |
0.16 |
1.00 |
0.39 |
0.97 |
58.60 |
0.65 |
9 |
0.00 |
0.00 |
0.00 |
0.00 |
0.24 |
185.33 |
1.34 |
7.10 |
1.00 |
0.00 |
0.00 |
0.00 |
0.20 |
1.00 |
0.43 |
0.99 |
323.40 |
0.74 |
10 |
0.07 |
0.01 |
0.75 |
0.00 |
0.21 |
13.98 |
1.23 |
14.65 |
0.80 |
0.00 |
0.01 |
0.18 |
-20.68 |
0.01 |
0.45 |
0.93 |
25.33 |
0.81 |
11 |
0.00 |
0.00 |
0.00 |
0.01 |
0.42 |
16.76 |
1.28 |
12.49 |
0.97 |
0.00 |
0.02 |
0.00 |
0.12 |
1.00 |
0.44 |
0.94 |
29.82 |
0.78 |
12 |
0.62 |
0.08 |
4.83 |
0.01 |
0.77 |
7.53 |
0.97 |
19.00 |
0.78 |
0.00 |
0.08 |
0.13 |
-0.12 |
0.08 |
0.51 |
0.88 |
15.32 |
1.04 |
13 |
0.11 |
0.08 |
2.44 |
0.01 |
0.32 |
35.60 |
1.66 |
7.99 |
0.92 |
0.00 |
0.01 |
0.07 |
-0.05 |
0.07 |
0.38 |
0.97 |
57.01 |
0.60 |
14 |
0.59 |
0.09 |
1.29 |
0.01 |
0.48 |
7.38 |
3.38 |
4.73 |
0.85 |
0.00 |
0.06 |
0.09 |
0.04 |
0.09 |
0.23 |
0.88 |
9.56 |
0.30 |
15 |
0.00 |
0.00 |
0.00 |
0.00 |
0.26 |
25.49 |
1.40 |
19.30 |
0.99 |
0.00 |
0.01 |
0.00 |
0.08 |
1.00 |
0.42 |
0.96 |
43.69 |
0.71 |
16 |
0.35 |
0.07 |
3.55 |
0.00 |
0.16 |
10.38 |
1.02 |
11.38 |
0.94 |
0.00 |
0.01 |
0.04 |
-0.12 |
0.06 |
0.50 |
0.91 |
20.62 |
0.99 |
17 |
0.57 |
0.09 |
2.50 |
0.01 |
0.32 |
8.17 |
1.86 |
8.08 |
0.90 |
0.00 |
0.04 |
0.06 |
-0.03 |
0.09 |
0.35 |
0.89 |
12.56 |
0.54 |
18 |
0.25 |
0.06 |
0.66 |
0.01 |
0.26 |
9.24 |
3.48 |
3.00 |
0.88 |
0.00 |
0.02 |
0.10 |
0.00 |
0.05 |
0.22 |
0.90 |
11.89 |
0.29 |
19 |
0.00 |
0.00 |
0.00 |
0.00 |
0.30 |
62.00 |
1.60 |
9.82 |
0.99 |
0.00 |
0.00 |
0.00 |
0.14 |
1.00 |
0.39 |
0.98 |
100.83 |
0.63 |
20 |
0.03 |
0.06 |
4.86 |
0.00 |
0.14 |
116.00 |
0.80 |
24.24 |
0.96 |
0.00 |
0.00 |
0.04 |
-0.20 |
0.06 |
0.56 |
0.99 |
261.80 |
1.26 |
Min |
0.00 |
0.00 |
0.00 |
0.00 |
0.14 |
0.00 |
0.63 |
3.00 |
0.78 |
0.00 |
0.00 |
0.00 |
-20.68 |
0.01 |
0.22 |
0.86 |
0.00 |
0.29 |
Max |
1.16 |
0.15 |
6.89 |
0.01 |
0.77 |
216.00 |
3.48 |
24.24 |
1.00 |
0.00 |
0.08 |
0.18 |
0.20 |
1.00 |
0.61 |
1.00 |
361.07 |
1.58 |
Mean |
0.19 |
0.04 |
1.49 |
0.01 |
0.30 |
39.94 |
1.56 |
11.39 |
0.94 |
0.00 |
0.02 |
0.04 |
-0.99 |
0.53 |
0.41 |
0.95 |
71.68 |
0.75 |
Std |
0.32 |
0.05 |
2.07 |
0.00 |
0.14 |
61.31 |
0.73 |
6.10 |
0.07 |
0.00 |
0.02 |
0.05 |
4.64 |
0.48 |
0.10 |
0.05 |
109.24 |
0.31 |
|
SO |
Na |
Mg |
Na |
Ca |
Ca |
Ca |
Ca+Mg |
HCO3 |
NO3 |
SO4 |
Cl |
Na+K+Cl |
Na |
Mg |
Ca |
Ca+Mg |
Mg |
1 |
1.16 |
0.15 |
6.89 |
0.01 |
0.34 |
6.06 |
1.02 |
14.62 |
0.90 |
0.00 |
0.05 |
0.04 |
-0.01 |
0.13 |
0.50 |
0.86 |
12.03 |
0.98 |
2 |
0.00 |
0.00 |
0.00 |
0.00 |
0.14 |
23.33 |
0.63 |
24.11 |
0.99 |
0.00 |
0.01 |
0.00 |
0.10 |
1.00 |
0.61 |
0.96 |
60.27 |
1.58 |
3 |
0.00 |
0.00 |
0.00 |
0.00 |
0.26 |
0.00 |
1.56 |
7.71 |
1.00 |
0.00 |
0.00 |
0.00 |
0.18 |
1.00 |
0.39 |
1.00 |
0.00 |
0.64 |
4 |
0.00 |
0.00 |
0.00 |
0.01 |
0.36 |
0.00 |
1.71 |
6.88 |
1.00 |
0.00 |
0.00 |
0.00 |
0.19 |
1.00 |
0.37 |
1.00 |
0.00 |
0.58 |
5 |
0.00 |
0.03 |
2.09 |
0.00 |
0.28 |
0.00 |
1.23 |
9.16 |
0.90 |
0.00 |
0.00 |
0.10 |
-0.23 |
0.03 |
0.45 |
1.00 |
0.00 |
0.81 |
6 |
0.00 |
0.00 |
0.00 |
0.01 |
0.27 |
20.00 |
2.05 |
6.69 |
0.99 |
0.00 |
0.01 |
0.00 |
0.18 |
1.00 |
0.33 |
0.95 |
29.75 |
0.49 |
7 |
0.00 |
0.00 |
0.00 |
0.00 |
0.24 |
216.00 |
1.49 |
7.90 |
1.00 |
0.00 |
0.00 |
0.00 |
0.17 |
1.00 |
0.40 |
1.00 |
361.07 |
0.67 |
8 |
0.00 |
0.00 |
0.00 |
0.00 |
0.26 |
35.60 |
1.55 |
8.83 |
0.99 |
0.00 |
0.01 |
0.00 |
0.16 |
1.00 |
0.39 |
0.97 |
58.60 |
0.65 |
9 |
0.00 |
0.00 |
0.00 |
0.00 |
0.24 |
185.33 |
1.34 |
7.10 |
1.00 |
0.00 |
0.00 |
0.00 |
0.20 |
1.00 |
0.43 |
0.99 |
323.40 |
0.74 |
10 |
0.07 |
0.01 |
0.75 |
0.00 |
0.21 |
13.98 |
1.23 |
14.65 |
0.80 |
0.00 |
0.01 |
0.18 |
-20.68 |
0.01 |
0.45 |
0.93 |
25.33 |
0.81 |
11 |
0.00 |
0.00 |
0.00 |
0.01 |
0.42 |
16.76 |
1.28 |
12.49 |
0.97 |
0.00 |
0.02 |
0.00 |
0.12 |
1.00 |
0.44 |
0.94 |
29.82 |
0.78 |
12 |
0.62 |
0.08 |
4.83 |
0.01 |
0.77 |
7.53 |
0.97 |
19.00 |
0.78 |
0.00 |
0.08 |
0.13 |
-0.12 |
0.08 |
0.51 |
0.88 |
15.32 |
1.04 |
13 |
0.11 |
0.08 |
2.44 |
0.01 |
0.32 |
35.60 |
1.66 |
7.99 |
0.92 |
0.00 |
0.01 |
0.07 |
-0.05 |
0.07 |
0.38 |
0.97 |
57.01 |
0.60 |
14 |
0.59 |
0.09 |
1.29 |
0.01 |
0.48 |
7.38 |
3.38 |
4.73 |
0.85 |
0.00 |
0.06 |
0.09 |
0.04 |
0.09 |
0.23 |
0.88 |
9.56 |
0.30 |
15 |
0.00 |
0.00 |
0.00 |
0.00 |
0.26 |
25.49 |
1.40 |
19.30 |
0.99 |
0.00 |
0.01 |
0.00 |
0.08 |
1.00 |
0.42 |
0.96 |
43.69 |
0.71 |
16 |
0.35 |
0.07 |
3.55 |
0.00 |
0.16 |
10.38 |
1.02 |
11.38 |
0.94 |
0.00 |
0.01 |
0.04 |
-0.12 |
0.06 |
0.50 |
0.91 |
20.62 |
0.99 |
17 |
0.57 |
0.09 |
2.50 |
0.01 |
0.32 |
8.17 |
1.86 |
8.08 |
0.90 |
0.00 |
0.04 |
0.06 |
-0.03 |
0.09 |
0.35 |
0.89 |
12.56 |
0.54 |
18 |
0.25 |
0.06 |
0.66 |
0.01 |
0.26 |
9.24 |
3.48 |
3.00 |
0.88 |
0.00 |
0.02 |
0.10 |
0.00 |
0.05 |
0.22 |
0.90 |
11.89 |
0.29 |
19 |
0.00 |
0.00 |
0.00 |
0.00 |
0.30 |
62.00 |
1.60 |
9.82 |
0.99 |
0.00 |
0.00 |
0.00 |
0.14 |
1.00 |
0.39 |
0.98 |
100.83 |
0.63 |
20 |
0.03 |
0.06 |
4.86 |
0.00 |
0.14 |
116.00 |
0.80 |
24.24 |
0.96 |
0.00 |
0.00 |
0.04 |
-0.20 |
0.06 |
0.56 |
0.99 |
261.80 |
1.26 |
Min |
0.00 |
0.00 |
0.00 |
0.00 |
0.14 |
0.00 |
0.63 |
3.00 |
0.78 |
0.00 |
0.00 |
0.00 |
-20.68 |
0.01 |
0.22 |
0.86 |
0.00 |
0.29 |
Max |
1.16 |
0.15 |
6.89 |
0.01 |
0.77 |
216.00 |
3.48 |
24.24 |
1.00 |
0.00 |
0.08 |
0.18 |
0.20 |
1.00 |
0.61 |
1.00 |
361.07 |
1.58 |
Mean |
0.19 |
0.04 |
1.49 |
0.01 |
0.30 |
39.94 |
1.56 |
11.39 |
0.94 |
0.00 |
0.02 |
0.04 |
-0.99 |
0.53 |
0.41 |
0.95 |
71.68 |
0.75 |
Std |
0.32 |
0.05 |
2.07 |
0.00 |
0.14 |
61.31 |
0.73 |
6.10 |
0.07 |
0.00 |
0.02 |
0.05 |
4.64 |
0.48 |
0.10 |
0.05 |
109.24 |
0.31 |
Ionic Ratio |
Wet |
Dry |
Comments |
Interpretation |
SO4/CL |
0.19 - 1.14 |
0 - 1.16 |
Very High |
Suggests additional sources of Sulphate. |
Na/Cl |
0 - 0.06 |
0 - 0.15 |
Low |
Silicate weathering, some marine water. |
Mg/Cl |
0.05 - 0.6 |
0 - 6.89 |
Very High |
Depict a silicate weathering environment |
Na/HCO |
0 - 0.02 |
0 - 0.01 |
Very Low |
Low weathering of Na-silicates. |
Ca/HCO |
0 - 0.93 |
0.14 - 0.77 |
Low |
Ca-silicate weathering from the basalts of Limbe. |
Ca/SO4 |
0 - 9.99 |
0 - 216 |
Very High |
There is no gypsum dissolution in volcanic coastal regions |
Ca/Mg |
0 - 5.13 |
0.63 - 3.48 |
High |
Typical of coastal regions due to cation-exchange |
Mg/Ca |
0 - 1 |
0.29 - 1.58 |
Very Low |
Silicate rock weathering |
(Ca+Mg)/(Na+K) |
0.39 - 3.32 |
3 - 24.24 |
Very High |
Occurrence of silicate weathering. |
HCO3-/∑Anions |
0 - 0.94 |
0.78 - 1 |
Low-High |
Silicate weathering reactions and some seawater |
NO3/∑Anions |
0 - 0.02 |
0 -(2.38E-05) |
Low |
No anthropogenicactivities. |
SO4/∑Anions |
0.02 - 0.38 |
0 - 0.08 |
Low |
No oxidation of sulphides. |
Cl-/∑Anions |
0.04 -0.71 |
0 - 0.18 |
Low |
Rock weathering |
-4.96-4.92 |
-20.68-0.20 |
Low-High |
Plagioclase weathering unlikely |
|
0 - 0.05 |
0.01 - 1.0 |
Low-High |
Some halite Solution; Reverse softening and seawater; Sodium source other than halite-albite, ion exchange |
|
0.16 - 1.0 |
0.22 - 0.61 |
Low-High |
Silicate weathering. Ferromagnesian minerals but no evidence of granitic weathering |
|
0 - 0.91 |
0.86 - 1.0 |
Low-High |
Ion exchange/Calcium removal and Calcium source from silicates |
|
0.16-11.94 |
0 - 361.07 |
Low-High |
No dolomite at all, Dedolomitization |
Type of Rock-water Interaction |
TDS mg/L |
Wet |
Dry |
||||||
Cation |
% |
Anion |
% |
Cation |
% |
Anion |
% |
||
Rock - Weathering dominance |
50-1000 |
20 |
100 |
18 |
90 |
20 |
100 |
20 |
100 |
Atmospheric Precipitation dominance |
1-50 |
- |
- |
2 |
10 |
- |
|
- |
|
Piper-Langguth Classification Limbe |
Wet |
Dry |
|||
Class |
Characteristic-Water type |
No |
% |
No |
% |
Diamond Field |
|||||
A |
Normal earth alkaline water ; prevailing HCO3- |
5 |
25 |
20 |
100 |
B |
Normal earth alkaline water ; prevailing HCO3-or Cl- |
3 |
15 |
- |
- |
C |
Normal earth alkaline water; prevailing Cl- |
2 |
10 |
- |
- |
D |
Earth alkaline water ; increased portions of alkalis; prevailing HCO3- |
8 |
40 |
- |
- |
E |
Earth alkaline water with added portions of alkalis with prevailing chloride |
1 |
5 |
- |
- |
G |
Alkaline water with prevailing bicarbonate |
1 |
5 |
- |
- |
Cation Field |
|||||
1 |
Ca-rich waters |
1 |
5 |
6 |
30 |
2 |
Mg-rich waters |
18 |
90 |
14 |
70 |
3 |
Na+K |
1 |
5 |
- |
- |
Anion Field |
|||||
4 |
HCO3- waters |
17 |
85 |
20 |
100 |
6 |
Cl- waters |
3 |
15 |
- |
- |
Fields |
Hydrogeochemical facies |
Wet |
Dry |
||
No |
% |
No |
% |
||
Field I |
Ca2+ - Mg2+ - Cl- -SO42- |
3 |
15 |
- |
- |
Field III |
Na+ - K+ - HCO3- |
1 |
5 |
- |
- |
Field IV |
Ca2+ - Mg2+ - HCO3- |
16 |
80 |
20 |
100 |
Citation: Akoachere RA, Egbe SE, Eyong TA, Yaya OO, Mbua RL, et al. (2019) Characterization of Groundwater in the Basaltic Fractured Rock Aquiferous Formations of the Limbe Coastal Region of Mount Cameroon, SWR-Cameroon. J Environ Sci Curr Res: S1002.
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.