Sustainability assessment of groundwater in south-eastern parts of the western region of Ghana for water supply

Full text

Cleaner Water 1 (2024) 100007
Available online 13 February 2024
2950-2632/© 2024 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-
nc-nd/4.0/).
Sustainability assessment of groundwater in south-eastern parts of the
western region of Ghana for water supply
Ernest Biney
a
,
b
,
*
, Bernard Akwasi Mintah
c
, Ernest Ankomah
a
, Albert Elikplim Agbenorhevi
d
,
Daniel Buston Yankey
a
, Ernestina Annan
b
a
Department of Geomatic Engineering, Kwame Nkrumah University of Science and Technology, University Post Ofce Box PMB, Kumasi, Ghana
b
WASCAL Graduate Research Programme on Climate Change and Land Use, Department of Civil Engineering, Kwame Nkrumah University of Science and Technology,
Kumasi, Ghana
c
Department of Geological Engineering, University of Mines and Technology, Tarkwa, Ghana
d
Graduate Research Program on Climate Change and Water Resources, West African Science Service Center on Climate Change and Adapted Land Use (WASCAL),
University of Abomey-Calavi, Benin
ARTICLE INFO
Keywords:
Health Risk Assessment
Groundwater
GIS
Trace elements
Water Quality Index
ABSTRACT
The study assessed the physicochemical and biological properties of selected groundwater sources in the
Southeastern part of the Western Region, to assess the impact on water quality and health risk. The Piper
Trilinear plot was used to categorize the water samples into water types based on the dominant anion and cation
concentrations. Statistical analysis (One way ANOVA and two sample t-test) was used to determine the sources of
variation in the data at 95% condence interval. The Water Quality Index (WQI) and Hazard Quotient (HQ) were
used to estimate the water quality and health risk respectively. TDS and turbidity were above the acceptable
WHO guidelines in 16.7% of the samples with a mildly acidic pH in 83.3% of the water samples. Also, 91.7% of
the water samples were contaminated with total coliform (TC) and 25% with e-coli. Generally, the groundwater
samples were dominated by Ca
2+
and HCO
3-
ion water types. The variations between parameters were found not
signicant for all the parameters (p>0.05). Water samples in the North are of good quality with a mean WQI of
96, but of poor quality in the South with a mean WQI of 144.6. HQ values for all the samples were less than 0.1,
suggesting less harmful impacts of the heavy metal concentrations on human health. Overall, the results showed
the presence of heavy metals in the groundwater sources sampled, however in quantities with low health risks
either through oral or dermal channels. Groundwater within the communities is good for domestic purposes but
needs treatment for drinking. To improve upon the study, it is recommended that further studies consider a
higher number of samples and include other accessible groundwater stations where possible.
1. Introduction
Water is a critical natural resource upon which all social and eco-
nomic activities and ecosystem functions depend (Kotir et al., 2016). It
occurs abundantly on the earth, covering about 70.9% of the surface,
and also in other planets and galaxies. Existing naturally in three
different forms (solid, liquid, and gaseous); water has been employed
extensively in domestic activities as well as in industrial, commercial,
agricultural, transportation, and tourism sectors of various countries.
Water is also a habitat, harbouring a huge variety of plant and animal
populations, and also contains a lot of mineral reserves (Galicia and
Zarco-Arista, 2014). Slightly over two-thirds of this freshwater is frozen
in glaciers and polar ice caps. The remaining unfrozen freshwater is
found mainly as groundwater, with only a small fraction present as
rivers and streams or in the atmosphere (Dubey and Pandey, 2014).
Groundwater remains one of the most important sources of water supply
in rural communities and small towns in Ghana. Currently, over 95% of
water provided to small communities and towns for domestic use is
extracted from groundwater sources (Yidana et al., 2018). Industrial use
of groundwater in Ghana accounts for less than 1% of the total
groundwater use. This includes large-scale commercial bottled water
companies in the south of the country (Gyau-Boakye et al., 2008).
* Corresponding author at: Department of Geomatic Engineering, Kwame Nkrumah University of Science and Technology, University Post Ofce Box PMB, Kumasi,
Ghana.
E-mail address: ernest_biney@yahoo.com (E. Biney).
Contents lists available at ScienceDirect
Cleaner Water
journal homepage: www.sciencedirect.com/journal/cleaner-water
https://doi.org/10.1016/j.clwat.2024.100007
Received 2 November 2023; Received in revised form 11 February 2024; Accepted 12 February 2024

Cleaner Water 1 (2024) 100007
2
Signicant investments made in the water sector during recent decades
by governments, non-governmental organizations, bilateral and multi-
lateral agencies all over Africa are in danger (Woode et al., 2018).
The Western Region of Ghana is a hub of business due to the
numerous mining companies and also the emerging oil industry and
because of these, there has been a population increase over the years
caused by the migration of people to seek greener pastures. The majority
of the population in the region is rural and is marked by extensive
farming and mining activities, hence their reliance on groundwater. The
southeastern part of the Western Region of Ghana is marked by exten-
sive agro-forestry with palm plantations, cocoa farms, and a lot of sub-
sistence farming. The extensive agricultural activities in the area pose a
threat to groundwater quality concerning elevated nitrate, phosphate,
and salinity levels due to the use of fertilizers. Some mining activities
have also been carried out in the area which can inuence groundwater
quality with low pH and trace metals above-recommended levels.
Mineralization in the area is associated with abundant pyrites and no
arsenopyrite, and the rocks are susceptible to acid mine drainage
(Bourke et al., 2007). The communities in the area depend solely on
groundwater for domestic purposes and use the water without treatment
despite complaints about its poor taste, hardness, and high iron content.
The high iron content of the water is an indication of the possible
presence of other metals which when above-recommended level could
be toxic (Oelofse, 2009; Kinna, 2016). The extensive agriculture and
mining activities in the area, coupled with observations about the
groundwater, bring up the need to evaluate its quality for domestic
purposes.
Geographic Information System (GIS), on the other hand, is an
important tool that can integrate data from many sources and also has
predictive capabilities, allowing it to identify and provide accurate
forecasts that may aid in decision-making. With the aid of GIS, Yammani
(2007) was able to establish a zone of groundwater quality that may be
utilized for various purposes such as irrigation and residential usage.
Babiker et al. (2007) also GIS and water quality index to analyze the
appropriateness and sustainability of groundwater for various purposes
in Japan. Yidana and Yidana (2010), analyzed groundwater quality in
the Southern Voltaian formation in Ghana by using GIS, water quality
indicator, and multivariate statistics. To this aim, it is critical to use GIS
to assess the quality of groundwater for water supply in the
south-eastern parts of the Western Region. The focus of the study is to
assess the water quality of boreholes in the area, determine the
groundwater types, and identify groundwater sustainability areas in the
areas using GIS.
2. Materials and methods
2.1. Study area
The Western Region is located between latitude 4˚10’0"N and 7˚0
′
0"N
and longitude 1˚05’0"W and 3˚20’0"W covering an area of 23 921 km
2
,
which is about 10% of Ghana’s total land surface and has about 75% of
its vegetation within the high forest zone of Ghana, and lies in the
equatorial climate zone that is characterized by moderate temperatures.
It is also the wettest part of Ghana with an average rainfall of 1600 mm.
It is located in the south western part of Ghana, bordered by Western
North on the West, Central Region on the East, Ashanti and Brong-Ahafo
Regions on the North and the South by 192 km of coastline of the
Atlantic Ocean. Geologically, the study is underlain by four main cate-
gories of rocks and soil types namely; lower Birimian, Dixcove granite,
Cape Coast granite, and Tarkwaian. The area is marked by the occur-
rence of basaltic rocks, shale, tuff, greywackes, conglomerates, quartz-
ites, and volcanic rocks (Sunkari et al., 2020). The Birimian Supergroup
exhibits a sequence of sedimentary rocks, including phyllite, tuff, and
greywacke, topped by conglomerate, sandstone, and shale (Sunkari
et al., 2020). Furthermore, the region is recognized for the existence of
meta-tuffaceous greywacke, quartzites, schistose conglomerates, and
volcanic tholeiitic magma series. More than half of the soil consists of
Cape Coast granitic soils; these rock types are very rich in minerals such
as quartz, alkali feldspar, hornblende, titanite, biotite, and amphibole
which sometimes turned to well foliated. In addition, the Cape Coast
granites are characterized by the existence of many enclaves of gneisses
and schist (Ahenkorah et al., 2018). Nyame (2008) also revealed car-
bonate rocks occur in the marginal areas of the manganese–carbonate
orebody (manganesestone) of the Palaeoproterozoic Nsuta deposit in the
Birimian of Ghana. Carbonate minerals (including distinctly zoned
microconcretions) are essentially Mg kutnahorite and Mg–Ca rhodo-
chrosite in the manganesestone and a host of rock manganiferous
phyllites (Mn-Phyllites). The weathering prole of Tarkwaian rocks
averages 20 m. Groundwater is mainly hosted in the soft and easily
weathered grits of the Banket and fracture zones within the Tarkwaian,
especially in the phyllites. The most important aquifers in both Birimian
and Tarkwaian rocks are expected to be associated with secondary
porosity, hosted in the regolith. Fig. 1 depicts the map of the study area.
2.2. Groundwater sampling and analysis
A sampling of groundwater for analysis followed the American
Public Health Authority (APHA) 1998 groundwater sampling protocol.
Seventeen groundwater samples were taken during the dry season of
October 2021 to February 2022 for analysis. These samples were taken
early morning between 5 am and 6 am and later in the afternoon be-
tween 1 pm and 6 pm. Plastic bottles were used for collecting samples.
The bottles were well-cleansed with detergent, rinsed with HNO
3,
and
ushed with distilled water. Four separate samples were taken at each
sampling point for anion, cation, trace metal, and microbiological
analysis. Samples for anion analysis were collected into 1 l plastic bot-
tles and those for cation, trace metal, and microbiological analysis into
500 ml plastic bottles. Boreholes were purged for at least ten minutes
before sampling to collect fresh water from the aquifer. Before sampling,
the methylated spirit was used to disinfect the nozzle of the pump x-
tures and bore pumped to clear its effect. This was to prevent contam-
ination of samples for microbiological analysis. Measurements of
temperature, pH, conductivity, and TDS were measured in the eld
before laboratory analysis because these parameters change with time.
Groundwater temperature was measured with a mercury-in-glass ther-
mometer. Samples for cation and trace metal analysis were preserved
with 1 ml concentrated nitric acid (HNO
3
) to keep the ions in solution
and to prevent them from sticking to the walls of the bottles. Samples
were then kept in ice between 0 and 4 ◦C to reduce or stop chemical
reactions and bacteria activities. Samples were then transported to the
laboratory within twenty-four hours of sampling for physicochemical
analysis. Coordinates of sampling points were also collected using the
Trimble GPS device.
2.2.1. Physicochemical analysis
The groundwater samples taken were sent to Ghana Water Company
Limited (GWCL), Cape Coast to analyze for physicochemical and
bacteriological properties within 24 hours of sampling. Physical pa-
rameters such as Colour, Total Suspended Solids, and Total Dissolved
Solids were determined using the Hach Direct Reading Spectropho-
tometer DR 2800. Turbidity was also determined using the turbidimeter.
Moreover, chemical parameters such as Nitrates, Phosphates, Sulphates,
Fluoride, and Ammonia were also determined using the Spectropho-
tometer. Total Hardness and Alkalinity were determined using various
laboratory titrimetric methods. Calcium was determined by the EDTA
Titrimetric Method and Magnesium Hardness was derived by calcu-
lating the difference between Total Hardness and then multiplying by a
constant 0.243. Chlorides and potassium were determined by Argento-
metric and Flame Photometric methods respectively. Heavy metals;
Manganese, Copper, Cadmium, Nickel, Mercury, and Lead were
analyzed by Atomic Absorption Spectrometry (AAS). Arsenic was
determined using the Hach colour kit matching method (GWCL, 2018;
E. Biney et al.

Cleaner Water 1 (2024) 100007
3
Mensah-Akutteh et al., 2022).
2.2.2. Bacteriological analysis
The Multiple-Tube fermentation technique was used to analyze the
presence or absence of the coliform group. The group consists of several
genera of bacteria belonging to the family Enterobacteriaceae dened
based on the method used for detection: lactose fermentation. All
facultative anaerobic, gram-negative, non-spore-forming, rod-shaped
bacteria ferment lactose with a gas and acid formation within
24 hours at 37◦C. Total Coliform was determined using the Multiple-
tube fermentation method. Thermotolerant (fecal) Coliform Test, on
the other hand, was also analyzed using the EC Medium Method to
distinguish those total coliform organisms that are fecal coliforms, all
positive presumptive fermentation tubes (i.e. those showing any amount
of gas, or acidity) were submitted within 48 hours of incubation to fecal
coliform test. Moreover, concerning the Escherichia coli (E. coli) Test, an
EC Medium with MUG procedure was used after a prior test for total
coliform. Positive presumptive tubes were used to inoculate E. coli
broth, using a sterilized loop.
2.3. Groundwater quality appraisal
The analytical accuracy of the laboratory results was checked by
computing the electro-neutrality/Ionic Balance Error of the major ions.
Here, major cations including Ca, Mg, Na, K, and anions including Cl
-
,
SO
4
2-
, HCO
3
-
, and NO
3
-
were used. Concentrations of the ions were con-
verted to meq/l for this and any other chemical analysis. The Ionic
Balance Error (IBE) ranged between - 3.91 to +4.69 which were within
the acceptable range of ±10%. Groundwater quality was evaluated by
comparing measured parameters in mg/l to WHO guidelines. Descrip-
tive statistics including range, mean, standard deviation, and variance
were estimated for each parameter. The number of samples above WHO
guidelines for each parameter was tabulated and the percentages
computed. To determine the water type and group hydrochemical
similar samples, a Piper diagram of the major ions is plotted. The plot
also aids in identifying the dominant chemical species of groundwater
and their aquifer geology in the area.
2.4. Generation of groundwater quality map using GIS
The generation of groundwater quality maps for the individual
physicochemical parameters involved the use of spatial and non-spatial
data. The spatial data comprised of geographical coordinates of sam-
pling points and a digital map of the study area. Non-spatial data is also
made up of eld and laboratory analysis of physicochemical parameters.
Results of laboratory analysis were entered into Microsoft excel and
joined with the spatial data in ArcGIS. The joined spatial and non-spatial
data was used to develop groundwater quality maps showing the spatial
distribution of the physicochemical parameters.
2.5. Statistical analysis
One-way Analysis of Variance (ANOVA) was used to test for data
variation between and within replicates (parameters) per each sampled
borehole. The data obtained from the laboratory analysis were tested at
a 95% condence level. The statistical tool used was the Minitab Sta-
tistical Software. The correlation analysis or the 2-sample t-Test analysis
was performed for measured parameters to determine the relationship
between these variables.
2.6. Water Quality Index (WQI)
WQI was proposed by Horton in 1965, and improved by Brown et al.,
(1975), Chung et al., (2016), and Singh and Hussian (2016) to show
whether the overall condition of water resources induces potential risk
to consumers or not. The WQI was computed in 3 steps. Firstly, the
aforementioned parameter is given a weight (wi) based on its relative
importance in the water quality for consumption. Secondly, the relative
weight (Wi) is calculated from the Eq. 1 as:
Wi=wi/∑n
i=1wi(1)
Fig. 1. Study area map(A), Ghana map (B), and Africa map(C).
E. Biney et al.

Cleaner Water 1 (2024) 100007
4
Where W
i
and wi is the relative weight and weight considered for each
parameter, respectively, and n is the number of measured parameters.
Thirdly, a quality rating value (Q
n
) for each parameter is given by
dividing its concentration (C
i
) in each water sample by its respective
WHO guideline (S
i
), and the result for the same is multiplied by 100 as
shown in Eq. 2.
Qi=Ci×100/Si(2)
To calculate the WQI, the SI is rst calculated for each water
parameter, using the following formula:
SI =Wi×Qi(3)
Finally, the WQI is calculated using Eq. 4
WQI =∑n
i=1SI (4)
Based on a previous study (Qasemi et al., 2023) WQI values are rated
as excellent (WQI < 50), good (50 < WQI >100), poor (100 < WQI >
200), very poor (200 < WQI >300) and unsuitable for drinking (WQI >
300).
2.7. Health risk assessment of heavy metal (Fe)
To estimate the human health risk of a contaminant, it is necessary to
compute the level of human exposure to that contaminant by tracing its
exposure route to the human body (USEPA, 2018). The USEPA method
for health risk assessment was employed in this study area. The ingestion
and dermal absorption are common routes for water exposure and focus
on non-carcinogenic risk for this study. Eqs. (5–7) were used to compute
the chronic daily intake of Heavy Metals.
CDIoral =CW×IRw ×EF ×EL
BW ×AT (5)
where C
w
is the concentration of heavy metals in water (mg/L), CDI is
for average daily ingestion, also known as exposure rate (mg/ kg/day),
IR
w
for ingestion rate, EF for the exposure frequency, EL is the exposure
length, BW for body weight, AT for Average exposure time, SA represent
skin-surface area, K
p
for permeability coefcient, and ABS also stands
for dermal absorption factor. Table 2 represents the input parameters
and values for the CDI calculations.
CDIdermal =CW×SA ×Kp×ABS ×IRw ×EF ×EL ×CF
BW ×AT (6)
In both the oral and dermal channels, the hazard quotient (HQ) was
calculated to evaluate the non-carcinogenic health risk resulting from
exposure to pollutants containing heavy metals, especially Fe. While it is
at a tolerable threshold if the HQ number is <1 (HQ 1), the opposite is
true. The danger of adverse non-carcinogenic health effects is intoler-
able if the HQ value is higher than 1 (HQ >1) (Onyele, Anyanwu, 2018).
HQ =CDI
RfD (7)
3. Results and discussion
3.1. One-way ANOVA analysis
To understand the variations in the recorded parameters in all four
different districts in the study area, Minitab statistical software was used
to analyze all the data using one-way ANOVA. This was done to ascer-
tain if there had been an external inuence on the concentration level of
the particular Physico-chemical parameters measured from various
boreholes sampled (Rao et al., 2022; Subba Rao et al., 2017). Variations
between and within samples for all parameters were determined at a 5%
level of signicance (
α
=0.05) and the results are presented in Table 3.
From the statistics, all the parameters tested under the one-way ANOVA
yielded a p-value greater than 0.05. This indicates that there is no sig-
nicant variation between and within all the tested parameters in the
four districts. It can therefore be deduced that the effect of external
factors and other biological as well as microbial factors inuencing the
quality of the groundwater in both the Southern and Northern sectors of
the study area is minimal. Hence, the dissolution and intrusion of
seawater into the groundwater is the major factor that affects the quality
of the groundwater in all four districts.
3.2. 2-Sample t-test analysis
Again, to understand the variations between the recorded parame-
ters in the Southern and Northern sectors of the study area, the data
were grouped into two, the South (Ahanta West and Shama District) and
North (Wassa East and Tarkwa Nsuaem District). Minitab statistical
software was used to analyze the two groups of data using 2-sample t-
Test analysis. This was done to ascertain if there is a signicant differ-
ence between the mean of the South and that of the North at a 95%
condence interval or 5% level of signicance (
α
=0.05) and the results
are presented in Table 4. From the 2-sample t-Test statistical analysis on
the Southern and Northern sectors of the study area, it was deduced that
there is no signicant difference between the mean of pH, TDS, electrical
conductivity, hardness, alkalinity, sodium, iron, and manganese con-
centrations in the South and North sectors of the study area. This sug-
gests that there is no external inuence causing the variations in the
concentration of these parameters in the area. Hence, the adverse in-
crease in the concentration of these parameters in the Southern sector of
the study area may be because, when seawater moves onshore, salt is left
on the land after evaporation. This salt is leached into the groundwater
during precipitation. This is the dominant cause of the increase in pa-
rameters such as Sodium, Iron, pH, Electrical conductivity, and TDS in
the southern part of the study area which is close to the sea as compared
to seawater intrusion which is a minor cause of the increase in the
concentration of these parameters. The geochemical composition in the
southern section of the study area suggests a prevalence of dolomitic
limestone carbonate rocks (Abu et al., 2021). The results obtained for
the t-Test sample analysis are summarized in Table 4.
From the 2-sample t-Test statistical analysis, there is a signicant
difference between the mean of SO
4
2-
values for southern and northern
sectors of the study area (P =0.049) as shown in Table 4. This signicant
variation is caused by the sulfur-rich tomaline granodiorite aquifer
hosting the groundwater in the Northern part of the study area as
compared to the carbonate-rich aquifer in the Southern sector of the
study area.
Table 1
Input parameter to characterize CDI values.
Parameters Oral Dermal
Exposure length (EL) 70 years 0.58 hour/event
Average time (AT) 25550 days 25550 days
Body weight (BW) 70 kg 70 kg
Exposure Frequency (EF) 365days/year 350days/year
Ingestion Rate (IRw) 2.2 L/day
Permeability Coefcient (K
p
) 0.001
Conversion factor (CF) 1000 L/m
3
ABS 0.01
Skin-surface area (SA) 1.8
Exposure duration (ED) 70 30
Table 2
10 Oral reference doses (RfD) for heavy metal (Fe).
Heavy metals RfD (mg/kg/day)
Iron (Fe) 0.7
E. Biney et al.

Cleaner Water 1 (2024) 100007
5
3.3. Physico-chemical groundwater quality analysis
An evaluation of the Physicochemical quality of groundwater in the
area is presented in this section. The results for the physical and
chemical parameters are presented in Table 5 and Table 6 consists of
samples from Ahanta West, Shama District, Wassa East, and Tarkwa
Nsuem District compared with WHO guidelines. The results are grouped
into (i) general chemical quality and (ii) major and minor ions. Fig. 2 is
the classied raster map for the general chemical quality.
3.3.1. pH
The pH of water in the area ranged from 5.25 to 9.07 pH units. This
gives the general indication that the groundwater understudy ranges
from being slightly acidic to slightly basic. The highest desirable level
for pH stipulated for drinking and domestic purposes is within the range
of 6.5–8.5 (WHO). The pH value of the Southern sector varied from a
minimum of 5.25 (at Homkrase) to a maximum of 9.07 (at Nyankrom)
whereas the Northern sector pH was from 6.2 (at Dadwen) which is
slightly acidic to 8.16 (at Asratoase) which is neutral. Most of the
boreholes within the Northern sector were within the WHO standard
(Fig. 2a). The southern sector of the study area (Ahanta West and
Shama) which is closer to the sea recorded low pH values with an
average of 6.19 except two boreholes in Ahanta Anyinase and Nyankrom
which recorded 7.64 (neutral) and 9.07 (slightly basic) respectively.
These samples were out of the range of 6.5–8.5 recommended by WHO.
Boreholes with low pH levels have the potential to enhance the corro-
sion of pump parts but may not affect their use for domestic purposes.
Slightly acidic groundwater may also enhance the dissolution of trace
elements while high pH levels may facilitate the leaching of others such
as Mo into the water. Low pH values may be a result of the production of
CO
2
from microbial respiration, which leads to the lowing of pH of the
water. 64.7% of the samples were slightly acidic. Slightly acidity in
groundwater could be a result of the dissolution of CO
2
from the decay of
Table 3
Statistical summary of one-way ANOVA analysis.
Parameter Source of Variation SS df MS F P-Value
pH Between Groups 5.62 3 1.87 1.86 0.198
Within Groups 13.57 13 1.04
TDS Between Groups 432194 3 144065 0.36 0.783
Within Groups 5200663 13 400051
EC Between Groups 1428833 3 476278 0.36 0.783
Within Groups 17184432 13 1321879
Hardness Between Groups 12270 3 4090 0.58 0.641
Within Groups 92369 13 7105
Alkalinity Between Groups 15997 3 5332 2.4 0.115
Within Groups 28861 13 2220
Sodium Between Groups 43838 3 14613 1.08 0.392
Within Groups 176153 13 13550
Sulphate Between Groups 77155 3 25718 1.56 0.246
Within Groups 214287 13 16484
Iron Between Groups 4.813 3 1.604 3.1 0.064
Within Groups 6.732 13 0.518
Manganese Between Groups 0.426 3 0.142 0.89 0.471
Within Groups 2.068 13 0.159
Table 4
Statistical summary of 2-sample t-test analysis.
Station Parameter Mean St. Dev p Remarks
South
North
pH 6.194 1.175 0.109 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
6.998 0.757
South
North
TDS 523 717 0.278 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
258.1 86.8
South EC 951 1302 0.278 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
North 469 387
South
North
Hardness 112 95.5 0.361 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
80 43.6
South
North
Alkalinity 97.7 46.6 0.269 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
63.7 61.1
South
North
Sodium 113.8 134.9 0.114 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
35.8 53.7
South
North
Sulphate 125 156.6 0.049 There is a
signicantly different
between the mean of
South and North (P >
0.05)
17.8 18.28
South
North
Iron 0.372 0.606 0.577 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
0.685 1.224
South
North
Manganese 0.273 0.377 0.912 The mean of South is
not signicantly
different from the
mean of North (P >
0.05)
0.298 0.463
Table 5
Summary of Physico-chemical groundwater parameters in the study area.
Parameter Minimum Maximum Mean SD WHO Guide
Line
pH 5.25 9.07 6.48 1.01 6.5–8.5
EC (µS/cm) 154 4590 780.82 1078.58 2500
TDS (mg/l) 84.7 2525 429.42 593.34 1000
Total Hardness 23 370 100.74 80.87 500
Ca Hardness 12 185 58.95 40.26 500
Mg Hardness 10 185 41.76 45.28 500
Alkalinity 12.4 184 85.72 52.95 400
Hardness and Alkalinity are in mg/L of CaCO
3
.
E. Biney et al.

Cleaner Water 1 (2024) 100007
6
organic matter which forms weak carbonic acid (H
2
CO
3
) in the water as
shown in Eq. (1)
H
2
O +CO
2
↔ H
2
CO
3
(1)
.
There is no signicant difference between the mean pH values for the
Southern and Northern sectors of the study area (P =0.109) as shown in
Table 4. A reclassied raster map of the pH levels in the area is shown in
Fig. 2a.
3.3.2. Electrical conductivity (EC)
Recorded EC values for water in the study area varied between 154
and 4590 µS/cm with a mean of 780.82. Almost all these values were
within the WHO guideline limit of 2500 µS/cm stipulated for drinking
and domestic use. The conductivity values for the Southern sector
ranged between 179 and 4590 µS/cm whereas the Northern sector
values were from 154 µS/cm to 1235 µS/cm. Only one station within the
Southern sector of the study area recorded a very high conductivity
value of 4590 µS/cm at Asemkaw which is above the WHO standard
(Fig. 2b). Borehole logs within the southern part of the study area
recorded the highest EC values which suggest the intrusion and disso-
lution of saltwater from the sea. This could be a result of saltwater
intrusion into groundwater in the area. The EC values recorded in the
northern part of the study area were relatively low. These areas have no
saltwater intrusion because they are far away from the sea. The rocks in
these areas are predominantly granitic rocks and phyllites which bear
the groundwater. Conductivity values for the Southern and Northern
sectors of the study area were observed to be statistically insignicant (P
=0.278) as shown in Table 4. The reclassied raster map of conductivity
in the study area is shown in Fig. 2b.
3.3.3. Total dissolved solids (TDS)
TDS values ranged from 84.7 to 2525 mg/L with a mean of 429.42
below the WHO guideline of 1000 mg/L. TDS concentration below
500 mg/l indicates that groundwater is fresh and indicates sources of
ions from hard crystalline rocks mainly silicates. Above 500 mg/L there
could be a saltwater intrusion or the dissolution of soft rocks like car-
bonates or extremely weathered rocks (granites in the bedrock). Bore-
hole logs within the southern part of the study area recorded the highest
TDS values ranging from 114 mg/L recorded at Cape 3 Points to a
maximum of 2525 mg/L recorded at Asemkaw (Fig. 2c) which suggests
the intrusion and dissolution of saltwater from the sea. TDS values
recorded in the northern part of the study area were relatively low.
These areas have no saltwater intrusion because they are far away from
the sea. The rocks in these areas are predominantly granitic rocks and
phyllites which bear the groundwater. There was no signicant differ-
ence between the mean TDS values for the Southern and Northern sec-
tors of the study area (P =0.278) as shown in Table 4.
3.3.4. Alkalinity
Alkalinity ranged from 12.4 to 84.0 mg/L of CaCO
3
Table 5. The
alkalinity of the water in the area is a result of the bicarbonate ions
(HCO
3
-
) in the water, which ranged from 15.1– 282.0 mg/L as shown in
Table 5. The southern part of the study area recorded high alkalinity due
to the presence of carbonate rocks in the coastal areas. The northern part
of the study area recorded relatively low alkalinity due to the presence of
silicate rocks. This is a result of the absence of bicarbonate ions (HCO
3
-
)
in these areas. There was no signicant difference between the mean
alkalinity values for the Southern and Northern sectors of the study area
(P =0.269) as shown in Table 3.
3.3.5. Total hardness
Total hardness ranged from 23 to 370 mg/L of CaCO
3
. Five (5)
groundwater samples representing 29.4% were soft. The remaining 12
(70.6%) ranged from moderately hard to very hard. Only 2 samples
representing 11.8% were very hard and the remaining 10 samples were
moderately hard 58.8%. None of the samples exceeded the WHO
guideline for the total hardness of 500 mg/L. The type of hardness of
groundwater in the area is illustrated in Table 6 and Fig. 3. Total
hardness values for the Southern and Northern sectors of the study area
were observed to be statistically insignicant (P =0.361) as shown in
Table 4.
3.4. Analysis of major and minor quality parameters
Descriptive results of the major and minor ions of groundwater
samples analyzed are summarized in Table 7 and compared with WHO
guidelines. The classied raster map highlights the spatial range of some
of the major and minor quality parameters as shown in Fig. 4. The
number of samples exceeding WHO guidelines are shown and their
percentages are computed.
Except for Na, SO
4
2-
, Fe, and Mn, All the major and minor ions/trace
metals analyzed were all below WHO guidelines as shown in Table 7.
Possible sources of the ions and metals are the geology of the area,
especially from the rocks within which the aquifers occur.
3.4.1. Sodium (Na)
The Na value of the Southern sector varied from a minimum of
7.0 mg/L (at Cape 3 Points) to a maximum of 393 mg/L (at Nyankrom)
whereas the Northern sector had Na values between 70 mg/L (at
Ahwitieso) and 145 (at Ewiadaso). All the boreholes in the Northern
sector were below the WHO standard. The southern sector of the study
area (Ahanta West and Shama) which are closer to the sea recorded the
highest Na concentration values with two boreholes recording higher
values above the WHO standard at Asemkaw and Nyankrom (Fig. 4a).
High Na
+
in groundwater has been sourced from halite or seawater
intrusion. The area descends into the coast hence samples with high Na
+
could be attributed to saltwater intrusion. High chloride is also attrib-
uted to saltwater intrusion. Na
+
exceeded the WHO guideline of
250 mg/L in 2 samples. There was no signicant difference between the
mean Na values for the Southern and Northern sectors of the study area
Table 6
Types of the hardness of groundwater in the area.
Borehole ID Hardness Ca
Hardness
Mg
Hardness
Type of Water
Ahanta
Anyinase
BH 1 99 55.1 43.5 Moderately
Hard
Cape 3 Points BH 2 48 25.1 23.8 Soft
Fretsi BH 3 202 74.9 127.0 Very Hard
Dixcove BH 4 63 41.9 20.9 Moderately
Hard
Asemkaw BH 5 370 185.0 185.0 Very Hard
Miemia (BZ) BH 6 51 32.3 18.7 Soft
Agona
Nkwanta
BH 7 94 70.9 22.9 Moderately
Hard
Azani BH 8 82 43.9 37.7 Moderately
Hard
Homkrase BH 9 85 50.3 35.1 Moderately
Hard
Antseambua BH
10
85 52.9 32.1 Moderately
Hard
Nyankrom BH
11
53 28.9 24.5 Soft
Ewiadaso BH
12
99 55.1 43.5 Moderately
Hard
Asratoase BH
13
119 89.4 29.8 Moderately
Hard
Adiyie
Junction
BH
14
60.8 50.7 10 Moderately
Hard
Kedadwen BH
15
133 105 27.8 Moderately
Hard
Ahwitieso BH
16
45.4 28.7 16.7 Soft
Dadwen BH
17
23 12 11 Soft
E. Biney et al.

Cleaner Water 1 (2024) 100007
7
(P =0.114) as shown in Table 3.
3.4.2. Sulphate (SO
4
2-
)
The SO
4
2-
value of the study area ranges from 1.32 mg/L to 475 mg/L
with an average of 87.16 mg/L. The Southern sector ranges from a
minimum of 8.17 mg/L (at Cape 3 Points) to a maximum of 475 mg/L
(at Nyankrom) whereas the Northern sector has SO
4
2-
values between
1.32 mg/L (at Adiyie Junction) and 50.7 mg/L (at Ewiadaso). All the
boreholes in the Northern sector were below the WHO standard. The
southern sector of the study area (Ahanta West and Shama) which are
closer to the sea recorded the highest SO
4
2-
concentration values with one
borehole recording a higher value above the WHO standard at Nyank-
rom (Fig. 4b). High SO
4
2-
in groundwater has sources from the rocks in
these areas. The Sulphate rich Tonalite to granodiorite rocks in these
coastal areas bears the groundwater. There is a signicant difference
between the mean SO
4
2-
values for the Southern and Northern sectors of
the study area (P =0.049) as shown in Table 4, hence statistically
signicant.
3.4.3. Nitrate/nitrite/ammonia/phosphate
Nitrate, nitrite, phosphate, and ammonia were low and below WHO
guidelines. Nitrate ranged from 0.01 to 9.46 mg/L with a mean of 0.86.
Although there are agricultural activities in the area, agriculture has not
had any strong inuence on groundwater in the area. Nitrite, ammonia
and phosphate ranged from 0.017 to 0.186, <0.001 and 0.231–0.925
with means of 0.06, <0.001 and 0.49 respectively. This could be a result
of good farming practices in which fertilizers are not used in excess and
decaying organic matter has less inuence on groundwater in the area.
Low levels of these ions indicate low levels of nitrogen and phosphorus
that get to the soil and the use of most of the nitrogen and phosphorus
that get to the root zone by plants.
3.5. Trace/heavy metals
3.5.1. Iron (Fe)
Iron ranged from 0.005 – 3.180 mg/L with a mean of 0.48. Four of
the boreholes representing 23.5% of samples had iron above WHO
guideline. The Fe value of the Southern sector varied from a minimum of
0.01 mg/L (at Asemkaw) to a maximum of 2.05 mg/L (at Nyankrom)
whereas the Northern sector had Fe values between 0.134 mg/L (at
Kedadwen) and 3.18 mg/L (at Asratoase). All the boreholes in the
Northern sector were below the WHO standard except one borehole at
Asratoase which recorded a high value of 3.18 mg/L above the WHO
standard. The southern sector of the study area (Ahanta West and
Shama) which are closer to the sea recorded the highest Fe concentra-
tion values with three boreholes recording higher values above the WHO
standard at Antseambua, Cape 3 Points, and Nyankrom (Fig. 4c). The
source of iron in the water is from ferromagnesian minerals such as
biotite, hornblende, pyroxene, and olivine in silicate rocks. These min-
erals are richer in the intermediate to mac rock types (diorite and
Fig. 2. Reclassied raster map of general physicochemical groundwater quality analysis; (a) pH, (b) Electrical conductivity (Cond), and (c) Total Dissolved
Solids (TDS).
E. Biney et al.

Cleaner Water 1 (2024) 100007
8
gabbro) than felsic types (granite). Biotite and hornblende are the only
ferromagnesian minerals in granites. The granites contain a variety of
minerals, including quartz, alkali feldspar, biotite, amphibole, horn-
blende, and titanite, which are at times well foliated. Additionally, the
granites are characterized by the presence of many enclaves of schists
and gneisses (Ahenkorah et al., 2018). Iron in the water is not associated
with sulphates. Sulphate in the waters is generally low. Fe values for the
Southern and Northern sectors of the study area were observed to be
statistically insignicant (P =0.577) as shown in Table 5.
3.5.2. Manganese (Mn)
Mn ranged from 0.021 to 1.3 mg/L with a mean of 0.28 below WHO
guidelines. Three of the boreholes representing 17.6% had manganese
exceeding the WHO guideline. The Mn value of the Southern sector
varied from a minimum of 0.021 mg/L (at Azani) to a maximum of
1.3 mg/L (at Asemkaw) whereas the Northern sector had Mn values
between 0.037 mg/L (at Kedadwen) and 1.24 (at Asratoase). All the
boreholes in the Northern sector were below the WHO standard except
one borehole at Asratoase which recorded a high value of 1.24 mg/L
above the WHO standard (Fig. 4d). The southern sector of the study area
(Ahanta West and Shama) which is closer to the sea recorded the highest
Mn concentration values with two boreholes recording higher values
above the WHO standard at Asemkaw and Homkrase. Manganese could
be from minerals such as hornblende and biotite. There is no signicant
difference between the mean Mn values for the Southern and Northern
sectors of the study area (P =0.912) as shown in Table 4.
3.6. Biological groundwater quality
Table 8 is a summary of the results of the microbiological analysis
carried out on the twelve groundwater samples. Fig. 5 also highlights the
range of biological impacts on the groundwater quality of the sampling
sites of the study area.
Fig. 3. A graph showing the level of hardness in various sampling areas of the study area.
Table 7
Major and Minor quality parameters.
Parameter
(mg/L)
Range Mean SD WHO Guide
line
No. Above Guideline % Above Guideline
Na 7.0 – 393.0 86.26 117.258 200 2 11.8
K 0.8–13.5 3.54 2.930 30 0 0
Ca 1.5 – 74.0 20.77 16.578 200 0 0
Mg 2.5–45.1 10.18 11.026 150 0 0
Cl 4.0 – 379.0 75.95 103.157 250 1 5.9
SO
4
1.32 – 475.0 87.16 134.963 250 2 11.8
HCO
3
15.1 – 282.0 103.69 73.440
CO
3
0.0 0.000 0.000
NO
2
-N 0.017–0.186 0.06 0.045 1 0 0
NO
3
-N 0.01–9.46 086 2.268 10 0 0
NH
3
<0.001 0.0–1.5 0 0
F <0.005–1.02 0.42 0.294 1.5 0 0
PO
4
0.231–0.925 0.49 0.234
Fe 0.005 – 3.18 0.48 0.852 0.3 4 23.5
Mn 0.021–1.3 0.28 0.395 0.4 3 17.6
E. Biney et al.

Cleaner Water 1 (2024) 100007
9
3.6.1. Total coliform (TC)
TC was present in ve (5) of the samples representing 29.4%.
Insanitary conditions (no proper waste disposal sites), animal droppings,
and unsewered septic systems can be possible sources of bacteria in the
water. Some could be affected by unsewered septic systems. TC in water
is indicative of the possible presence of other microorganisms (viruses)
in the water. Fig. 5a shows the TC level. Areas such as Fretsi and Cape 3
Points recorded moderately high Total Coliform as compared to areas
such as Dadwen, Kedadwen, Adiyie Junction, Antseambua, Homkrase,
Ewiadaso, and Nyankrom. Groundwater in the area is generally good but
a few needs treatment (boiling and chlorination) before drinking.
3.6.2. E-Coli
E-coli was present in four (4) of the samples representing 23.5% of all
samples. E-coli in groundwater is indicative of contamination by faecal
matter, which could be as a result of leakage from a septic tank or animal
droppings. It also indicates that the boreholes may be shallow. Areas
such as Fretsi, Asratoase, and Cape 3 Points recorded high E-Coli which
were above the WHO standard as compared to areas such as Dadwen,
Kedadwen, Adiyie Junction, Antseambua, Homkrase, Ewiadaso, and
Nyankrom (Fig. 5b).
3.6.3. Faecal Coliform (FC)
Groundwater showed faecal matter in ve (5) of the samples, which
indicates contamination from animal droppings or unsewered septic
systems or leakage from septic tanks. Cape 3 Points recorded the highest
Faecal Coli which is above the WHO standard as compared to the rest of
the study area as shown in Fig. 5c.
3.7. Water-type
From the Piper diagram shown in Fig. 6, groundwater in the area is
mainly of mixed types. However, the major water type is NaHCO
3
. Other
water types include NaCl, NaSO
4
, CaHCO
3,
and CaCl as shown in
Table 9. The weak acid (HCO
3
) dominates the strong acids (Cl and SO
4
)
while the alkalis (Na and K) dominate the alkaline earth (Ca and Mg). Na
is the dominant cation of groundwater in the area probably because the
area is underlain by granites (felsic igneous rocks) rich in Albite (Na
Plagioclase) than Arnothite (Ca Plagioclase). Groundwater occurs
mainly within weathered granites. A summary of the water types in the
Fig. 4. Reclassied raster map of analysis on major and minor quality parameters; (a) Sodium (Na), (b) Sulphate (SO42-), and trace metals; (c) Iron (Fe), and (d)
Mangenese (Mn).
Table 8
Descriptive results for Microbiological analysis.
Parameter
(cfu/
100 ml)
Range Mean SD WHO
Guide
Line
No. Above
Guideline
% Above
Guideline
TC 0–20 4 6.5 0 5 29.4
E-Coli 0–10 1 2.8 0 4 23.5
Faecal Coli 0–13 2 3.5 0 5 29.4
E. Biney et al.

Cleaner Water 1 (2024) 100007
10
area is included in Table 9.
3.8. Water Quality Index (WQI)
The status of water quality was decided by the WQI for an environ-
mental impact assessment. WQI method was conducted on the southern
and northern sampling locations in addition to their respective WHO
guidelines. Parameters such as sodium, sulphate, potassium, bicarbon-
ate, nitrate, total hardness, and calcium were considered for the WQI
calculations (Table 10).
Table 11, showed the computed WQI values in the study area. The
groundwater sampled in the south of the study area recorded a lower
mean WQI value of 96.05 compared to the north of the study area
recording a mean WQI value of 144.59. The quality of the water in the
study area falls within the 50–100 range to the north and is classied as
‘Good Water Quality’ according to Chung et al. (2015), Rao et al. (2012),
and Singh and Hussain (2016). To the south fell within the 100–200 WQI
range signifying a ‘Poor Water Quality’. This implies, that the physico-
chemical quality of the water in the north is good for consumption but to
the south will require further treatment before use for drinking pur-
poses. Both sites fell within different WQI ranges, however, the values
showed high concentrations levels of Manganese, Iron, and Nitrate in
the study area (Table 10). This could be due to the intensive agricultural
activities and alluvial mining in the region. The chemical quality of the
water requires attention to make it safe for domestic consumption. This
study’s ndings show the physical and chemical quality of groundwater
is inuenced by location and human-induced activities (Rao et al. 2018;
Subba, 2018). This differs from ndings reported by other studies where
the same WQI model computation method was used. The ndings in the
case of Chung et al. (2015) reported that 86.0% of groundwater samples
collected had excellent physicochemical quality to 8.0% of groundwater
samples were unt for drinking. In addition, Kumar et al. (2015) showed
that only 20.8% of groundwater samples collected from boreholes had
excellent physicochemical quality.
3.9. Health risk assessment
If the HQ >1, then heavy metals negatively impact human health. If
HQ < 1, heavy metals have no negative impact on human health (Zhang
et al., 2017). Thus, a four-group classication of non-carcinogenic
hazard based on HQ values: insignicant (HQ< 0.1; i.e., risk level 1),
low (HQ ≥0.1 < 1; i.e., risk level 2), moderate (HQ ≥1 < 4; i.e., risk
level 3), and severe (HQ ≥4; i.e., risk level 4). As shown in Table 12, the
mean HQ values for all the sampling points for HQ dermal and HQ oral
are below 1 suggesting an acceptable level of non-carcinogenic harmful
health risk.
4. Conclusion
Analysis of the physical, chemical and biological parameters in the
borehole samples from the four different districts in the Western Region
of Ghana indicates that borehole samples taken from the Northern sector
Fig. 5. Reclassied raster map of biological analysis for (a) Total coliform, (b) Faecal coliform and (c) E-coli.
E. Biney et al.

Cleaner Water 1 (2024) 100007
11
of the study area (Wassa East and Tarkwa Nsuaem district) which are
further away from the sea were generally below the WHO standard. On
the other hand, those within the Southern sector of the study area
(Ahanta West and Shama district) hard their concentrations above or
outside the WHO standard as indicated using the Water Quality Index
map generated. The pH values recorded range from slightly acidic to
basic. One sample had a TDS value to be above the threshold limit
(2525 mg/L). This makes the sample saline. Some samples recorded
coliforms. This is due to seepage from septic tanks and poor environ-
mental conditions. From the Piper diagram, most of the water samples
were dominant in Na-HCO
3
and Ca-HCO
3
water types. From the statis-
tical analysis using one-way ANOVA and the 2-sample t-Test, the
Southern and Northern sectors of the study area showed no signicant
difference between the mean of pH, TDS, electrical conductivity,
hardness, alkalinity, sodium, iron, and manganese concentrations. The
concentration of sulphate was statistically signicant with p=0.049. It
can therefore be concluded that boreholes within the Northern sector of
Fig. 6. A trilinear piper plot of groundwater samples.
Table 9
Water types of groundwater from piper plot.
Community Water Type Geology of Aquifer
AW Ahanta Anyinase NaHCO
3
Cl Basaltic and Volcaniclastic
AW Cape 3 Point Mixed HCO
3
Basaltic and Volcaniclastic
AW Fretsi NaCl Tonalite to Granite
AW Dixcove NaHCO
3
Tonalite to Granite
AW Asemkaw NaCl Basaltic and Volcaniclastic
AW Miemia (BZ) Na HCO
3
Tonalite to Granite
AW Agona Nkwanta CaHCO
3
Tonalite to Granite
AW Azani Mixed HCO
3
Tonalite to Granite
S Homkrase Na Mixed Tonalite to Granite
S. Antseambra Na Mixed Tonalite to Granite
S. Nyankrom NaSO
4
Basaltic and Volcaniclastic
WE Ewiadaso NaHCO
3
Cl Tonalite to Granite
WE Asratoase CaClHCO
3
Shale/Tuff/Greywacke
TN Adiyie Junction CaHCO
3
Conglomerate/Quartzite/Phyllite
TN Kedadwen NaMgHCO
3
Basaltic and Volcaniclastic
TN Ahwitieso NaMgHCO
3
Conglomerate/Quartzite/Phyllite
TN Dadwen NaCl Conglomerate/Quartzite/Phyllite
Table 10
Groundwater Quality Index of the South-Eastern part of the Western Region.
W
n
Q
n
@North W
n
Q
n
@South
Parameters Mean Mean
pH (unit) 0.887761293 0.002198738
EC (µs/cm) 0.002138166 0.001054469
TDS (mg/L) 0.007349242 0.003626844
Na (mg/L) 0.039978189 0.012576618
K (mg/L) 0.055271544 0.055271544
Ca (mg/L) 0.007296546 0.007296546
Mg (mg/L) 0.006357789 0.006357789
Cl (mg/L) 0.017076097 0.017076097
SO4 (mg/L) 0.028104175 0.004002035
NO2-N (mg/L) 0.84312525 0.84312525
NO3-N (mg/L) 12.08479526 12.08479526
Fe (mg/L) 58.08196169 106.9519994
Mn (mg/L) 23.97637431 24.59115314
Total Hardness (mg/L) 0.006295335 0.004496668
Mg Hardness (mg/L) 0.002347525 1.67501E-05
Ca Hardness (mg/L) 0.003313317 0.003313317
WQI 96.04954573 144.5883604
Table 11
Classication of WQI.
Site WQI values WQI range Type of water
North 96.04954573 <50 Excellent water quality
South 144.5883604 50–100 Good water quality
100–200 Poor water quality
200–300 Very poor water quality
>300 Water unsuitable for drinking purposes
E. Biney et al.

Cleaner Water 1 (2024) 100007
12
the study area are safe for drinking and other domestic purposes.
Boreholes within the Southern sector had the majority of the concen-
trations above the WHO standard which is a result of the inuence of
seawater in contact with the groundwater making it unsafe for drinking
and other domestic purposes.In addition, the water quality index
revealed good water quality to the north and poor water quality to the
south. However, the health risk assessment on Fe ingestion and dermal
both had HQ Values less than 1 suggesting there is no health impact from
the daily intake and exposure of heavy metals. It is recommended that
groundwater quality in the area be monitored for possible contamina-
tion by heavy metals because of the low pH waters. Disinfection and
quality assurance for boreholes need to be carried out regularly to pre-
vent microbial contamination. There should be a groundwater vulner-
ability analysis to know which areas are prone to contamination to
protect them.
CRediT authorship contribution statement
Ankomah Ernest: Writing – review & editing, Visualization. Mintah
Bernard Akwasi: Writing – review & editing, Visualization, Supervi-
sion, Software, Methodology, Conceptualization. Biney Ernest: Writing
– review & editing, Writing – original draft, Visualization, Software,
Methodology, Formal analysis, Conceptualization. Annan Ernestina:
Writing – review & editing. Yankey Daniel: Writing – review & editing,
Visualization. Agbenorhevi Albert Elikplim: Writing – review & edit-
ing, Methodology.
Declaration of Competing Interest
The authors declare that they have no known competing nancial
interests or personal relationships that could have appeared to inuence
the work reported in this paper.
Data availability
Data will be made available on request.
References
Abu, M., Adeleye, M.A., Ehinola, O.A., Asiedu, D.K., 2021. The hydrocarbon
prospectivity of the Mesoproterozoic–Paleozoic intracratonic Voltaian Basin, West
African Craton, Ghana. J. Petrol. Explor. Product. 11, 617–625.
Ahenkorah, I., Awuah, E.M., Ewusi, A., Affam, M., 2018. Geotechnical and petrographic
characterisation of the birimian granitoids in southern Ghana as an aggregates for
sustainable road construction. Int. J. Adv. Eng. Res. Sci. 5 (3), 237396.
APHA (1998) Standard Methods for the Examination of Water and Wastewater. 20th
Edition, American Public Health Association, American Water Works Association
and Water Environmental Federation, Washington DC.
Babiker, I.S., Mohamed, M.A., Hiyama, T., 2007. Assessing groundwater quality using
GIS. Water Resour. Manag. 21 (4), 699e715.
Bourke, P., Arthur, J., Marshall, N., MacIntyre, J., Wasel, S.M., Urbaez, E., 2007.
Technical Report, First-time disclosure of mineral reserves, Hwini-Butre and Benso
properties, Southwest Ghana. Golden Staring Res. Ltd, Denver, Colorado, USA.
Chung, S.Y., Venkatramanan, S., Kim, T.H., Kim, D.S., Ramkumar, T., 2015. Inuence of
Hydrogeochemical Processes and Assessment of Suitability for Groundwater Uses in
Busan City, Korea. Environ., Develop. Sustain. 17 (3), 423–441. https://doi.org/
10.1007/s10668-014-9552-7.
Dubey, S.C., Pandey, S.K., 2014. Fresh Water Availability and Global Challenge.
Watershed Manag. Sustain. Develop.
Galicia, L., Zarco-Arista, A.E., 2014. Multiple ecosystem services, possible trade-offs, and
synergies in a temperate forest ecosystem in Mexico: a review. Int. J. Biodivers. Sci.,
Ecosyst. Serv. Manag. 10 (4), 275–288.
Ghana Water Company Limited (GWCL), 2018. Proposals for Review of Aggregate
Revenue. Requirement and Tariff.
Gyau-Boakye, P., Kankam-Yeboah, K., Darko, P.K., Dapaah-Siakwan, S., Duah, A.A.,
2008. Groundwater is a vital resource for rural development: An example from
Ghana. Applied groundwater studies in Africa. CRC Press, pp. 159–180.
Kinna, R., 2016. Non-discrimination and liability for transboundary acid mine drainage
pollution of South Africa’s rivers: could the UN Watercourses Convention open
Pandora’s mine? Water Int. 41 (3), 371–391.
Kotir, J.H., Smith, C., Brown, G., Marshall, N., Johnstone, R., 2016. A system dynamics
simulation model for sustainable water resources management and agricultural
development in the Volta River Basin, Ghana. Sci. Total Environ. 573, 444–457.
Kumar, K., Logeshkumaran, A., Magesh, N.S., Godson, P.S., Chandrasekar, N., 2015.
Hydro-geochemistry and Application of Water Quality Index (WQI) for Groundwater
Quality Assessment, Anna Nagar, Part of Chennai City, Tamil Nadu, India. Appl.
Water Sci. 5 (4), 335–343. https://doi.org/10.1007/s13201-014-0196-4.
Mensah-Akutteh, H., Buamah, R., Wiafe, S., Nyarko, K.B., 2022. Raw water quality
variations and its effect on the water treatment processes. Cogent Eng. 9 (1),
2122152.
Nyame, F.K., 2008. Petrography and geochemistry of intraclastic manganese–carbonates
from the~ 2.2 Ga Nsuta deposit of Ghana: Signicance for manganese sedimentation
in the Palaeoproterozoic of West Africa. J. Afr. Earth Sci. 50 (2-4), 133–147.
Oelofse, S.H., 2009. Mine water pollution-acid mine decant, efuent and treatment: a
consideration of key emerging issues that may impact the state of the environment.
The Icfai University Press.
Onyele, O.G., Anyanwu, E.D., 2018. Human health risk assessment of some heavy metals
in a rural spring, southeastern Nigeria. Afr. J. Environ. Nat. Sci. Res. 1 (1), 15–23.
Qasemi, M., Darvishian, M., Nadimi, H., Gholamzadeh, M., Afsharnia, M., Farhang, M.,
Zarei, A., 2023. Characteristics, water quality index and human health risk from
nitrate and uoride in Kakhk city and its rural areas, Iran. J. Food Compos. Anal.
115, 104870 https://doi.org/10.1016/j.jfca.2022.104870.
Rao, N.S., Sunitha, B., Das, R., Kumar, B.A., 2022. Monitoring the causes of pollution
using groundwater quality and chemistry before and after the monsoon. Phys. Chem.
Earth, Parts a/b/c, 103228.
Rao, N.S., Sunitha, B., Rambabu, R., Rao, P.N., Rao, P.S., Spandana, B.D., Marghade, D.,
2018. Quality and degree of pollution of groundwater, using PIG from a rural part of
Telangana State, India. Appl. Water Sci. 8, 1–13.
Rao, N.S., Rao, P.S., Reddy, G.V., Nagamani, M., Vidyasagar, G., Satyanarayana, N.L.V.
V., 2012. Chemical characteristics of groundwater and assessment of groundwater
quality in Varaha River Basin, Visakhapatnam District, Andhra Pradesh, India.
Environ. Monit. Assess. 184 (8), 5189–5214.
Singh, S., Hussian, A., 2016. Water quality index development for groundwater quality
assessment of Greater Noida sub-basin, Uttar Pradesh, India. Cogent Eng. 3 (1),
1177155.
Subba Rao, N., 2018. Groundwater quality from a part of Prakasam district, Andhra
Pradesh, India. Appl. Water Sci. 8, 1–18.
Subba Rao, N., Marghade, D., Dinakar, A., Chandana, I., Sunitha, B., Ravindra, B.,
Balaji, T., 2017. Geochemical characteristics and controlling factors of chemical
Table 12
Summary of health assessment carcinogenic risks (Fe) for each sampling point of the study area referencing children and adults’ risk.
Sample Points Fe. Conc CDI dermal CDI oral HQ dermal HQ oral
Ahanta Anyinase 0.132 8.09049E-06 4.14857E-05 1.15578E-05 5.92653E-05
Cape 3 Points 3.14 0.000192456 0.000986857 0.000274937 0.001409796
Asemkaw 0.01 6.12916E-07 3.14286E-06 8.75594E-07 4.4898E-06
Miemia (BZ) 0.25 1.53229E-05 7.85714E-05 2.18899E-05 0.000112245
Agona Nkwanta 0.22 1.34841E-05 6.91429E-05 1.92631E-05 9.87755E-05
Azani 0.16 9.80665E-06 5.02857E-05 1.40095E-05 7.18367E-05
Homkrase 0.51 3.12587E-05 0.000160286 4.46553E-05 0.00022898
Antseambua 2.93 0.000179584 0.000920857 0.000256549 0.00131551
Nyankrom 2.05 0.000125648 0.000644286 0.000179497 0.000920408
Ewiadaso 0.48 2.942E-05 0.000150857 4.20285E-05 0.00021551
Asratoase 3.18 0.000194907 0.000999429 0.000278439 0.001427755
Adiyie Junction 0.13 7.96791E-06 4.08571E-05 1.13827E-05 5.83673E-05
Kedadwen 0.134 8.21307E-06 4.21143E-05 1.1733E-05 6.01633E-05
Ahwitieso 0.14 8.58082E-06 0.000044 1.22583E-05 6.28571E-05
Dadwen 0.07 4.29041E-06 0.000022 6.12916E-06 3.14286E-05
Fretsi 0.16 9.80665E-06 5.02857E-05 1.40095E-05 7.18367E-05
Dixcove 0.24 1.471E-05 7.54286E-05 2.10143E-05 0.000107755
E. Biney et al.

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13
composition of groundwater in a part of Guntur district, Andhra Pradesh, India.
Environ. Earth Sci. 76, 1–22.
Sunkari, E.D., Abu, M., Zango, M.S., Wani, A.M.L., 2020. Hydrogeochemical
characterization and assessment of groundwater quality in the Kwahu-Bombouaka
Group of the Voltaian Supergroup, Ghana. J. Afr. Earth Sci. 169, 103899.
Woode, P.K., Dwumfour-Asare, B., Nyarko, K.B., Appiah-Effah, E., 2018. Cost and
effectiveness of water, sanitation and hygiene promotion intervention in Ghana: the
case of four communities in the Brong Ahafo region. Heliyon 4 (10), e00841.
Yammani, S., 2007. Groundwater quality suitable zones identication: application of
GIS, Chittoor area, Andhra Pradesh, India. Environ. Geol. 53 (1), 201–210.
Yidana, S.M., Bawoyobie, P., Sakyi, P., Fynn, O.F., 2018. Evolutionary analysis of
groundwater ow: application of multivariate statistical analysis to hydrochemical
data in the Densu Basin, Ghana. J. Afr. Earth Sci. 138, 167–176.
Yidana, Sandow Mark, Yidana, Adadow, 2010. Assessing water quality using water
quality index and multivariate analysis. Environ. Earth Sci. 59 (7), 1461–1473.
Zhang, Y., Chu, C., Li, T., Xu, S., Liu, L., Ju, M., 2017. A water quality management
strategy for regionally protected water through health risk assessment and spatial
distribution of heavy metal pollution in 3 marine reserves. Sci. Total Environ. 599,
721–731.
E. Biney et al.