i

HYDROCHEMICAL CHARACTERISTICS AND QUALITY

ASSESSMENT OF GROUNDWATER IN WARRI,

SOUTH SOUTH NIGERIA

BY

ISRAEL GODWIN OMANUDHOWHO

PG/M.SC/07/43369

A RESEARCH PROJECT SUBMITTED TO THE

DEPARTMENT OF GEOLOGY, FACULTY OF PHYSICAL

SCIENCES

UNIVERSITY OF NIGERIA, NSUKKA

IN PARTIAL FULLFILMENT OF THE REQUIREMENT

FOR THE AWARD OF A MASTER OF SCIENCE IN

GEOLOGY (HYDROGEOLOGY)

NOVEMBER, 2012.

ii

CERTIFICATION

Israel, Godwin Omanudhowho is a postgraduate student in the Department of Geology with

the registration number PG/M.SC/07/43369 has satisfactorily completed the requirements for

the course and research work for the degree of Master of Science in Hydreogeology.

The work embodied in this project report is original and has not been submitted in part or full

for any degree or diploma of this or any other university.

…………………… ……………………..

Prof. C. O. Okogbue Date

Project Supervisor

Prof. O.P. Umeji ……………………….

Head of Department Date

External Examiner ………………………….

Date

iii

DEDICATION

This paper is dedicated to God Almighty who gave me the direction.

iv

ACKNOWLEDGEMENT

I would like to thank my supervisor, Prof. C.O. Okogbue for taking out some time out of his

busy schedule to read through this thesis. The quality of this work is consequent upon his

criticisms, corrections and suggestions.

I will not forget the efforts of my former supervisor, Prof H.I Ezeigbo, who has gone to meet

with the Lord, may his gentle soul rest in peace.

I am particularly grateful to Mr. S.O. Onwuka for his immense contribution the success of

this project.

My profound gratitude goes to all members of staff of the Department of Geology, University

of Nigeria, Nsukka, for providing a good working environment.

I am grateful to my beloved wife, Mrs. Blessing Israel and children, Ujiro, Ewomazino and

Iruo-Oghene Israel for their support and understanding while this write up lasted.

I will not fail to appreciate the efforts of Dr S.O Olobaniyi of the Department of Geology,

Delta State University Abraka for critical review and discussion on the paper.

I am grateful to Engineer P. Awala of Delta State Water Board for providing some useful

materials for this write up.

I equally recognize the contributions of my fellow researchers, Mr. Victor Omonona, Mr.

Rufai Ayuba, Mr. Ezekiel Agberen and Miss Joseph Mary. You are all wonderful.

Finally to my spiritual fathers, Bishop Chris Okoh and Reverend Emmanuel Afor who have

been praying for the successful completion of this project, I say thank you.

.

v

ABSTRACT

The physicochemical characteristics and quality of the shallow groundwater of the Warri

coastal aquifer were studied by means of chemical composition (groundwater chemistry) and

ionic ratios. Twenty groundwater samples were collected from hand dug wells and analyzed

for major cations like Ca2+

, Mg2+

, K+ and Na

+, anions like SO

2-4, HCO

-3 NO

-3 and Cl

-; heavy

metals like Pb2+

Ni2+

and Cd2+

. Results of the analysis revealed that rock weathering and

anthropogenic processes are the major contributors to the chemical compositions of the

groundwater. They also showed that groundwater is affected by seawater intrusion as it

featured high levels of chloride (Cl) and total dissolved solids (TDS) which are common

indicators of seawater influence. The groundwater classified into three water types namely,

Ca(HCO3)2, CaCl2 and NaCl water types. Among the physiochemical parameters measured

(pH, EC, TDS, TH, fecal coliform, total bacterial, SO4, Cl, HCO3, NO3, Ca, Mg, Na, K, Pb,

Ni, Cd) only nitrate (NO3), sulphate (SO4) and total bacteria (Bac.) have concentrations

below the stipulated WHO (1993) guideline values, indicating that the groundwater of the

area is not suitable as drinking water. It was demonstrated that ionic ratios such as HCO3/Cl,

Ca/Mg, Ca/Cl and Ca/SO4 are useful indices to identify seawater intrusion in the area.

vi

TABLE OF CONTENT

TITLE PAGE i

CERTIFICATION ii

DEDICATION iii

ACKNOWLEDGEMENT iv

ABSTRACT v

TABLE OF CONTENT vi

LIST OF TABLES vii

LIST OF FIGURES viii

LIST OF APPENDICES x

CHAPTER ONE: INTRODUCTION

1:1 Background of the study 1

1.2. Aims of Study 1

1.3. Location and Accessibility 2

1.4 Relief and Drainage 2

1.5 Climate and Vegetation 2

1.6 Literature Review. 6

CHAPTER TWO: GEOLOGY AND HYDROGEOLOGY

2.1 The Geology of the Niger Delta 8

2.2 Local Geology 10

2.3 Hydrogeology of Warri 11

CHAPTER THREE: RESEARCH METHODOLOGY

3.1 Hydro-geological Investigation 13

3.2 Hydro geochemical Investigation 13

CHAPTER FOUR: RESULTS AND DISCUSSION

4.1 Groundwater Chemistry 14

vii

4.2 Groundwater Type 14

4.3 Sources of Ions 26

4.4 Groundwater Quality for Drinking Purposes 26

CHAPTER FIVE: CONCLUSIONS AND RECOMMENDATIONS

5.1 Conclusions 31

5.2 Recommendation 31

REFERENCES 32

APPENDICES 37

viii

LIST OF TABLES

Table 1 Physico-chemical and bacteriological content values of the shallow

groundwater in Warri coastal area 17

Table 2: Groundwater classification based on total hardness (TH) 18

Table 3: Ionic ratios and ionic strength of the shallow groundwater in

Warri coastal area 21

Table 4: Ground water indexes and WHO (1993) Stipulated guideline values 30

ix

LIST OF FIGURES

Figure 1: Satellite image of Warri 3

Figure 2: Location Map of Warri City showing Groundwater Samples Point 4

Figure 3: Map of the Niger Delta Showing the Drainage system 5

Figure4: Geological map of parts of the western Niger Delta 9

Figure 5: Piper Diagram showing the water types and mixing line 19

Figure 6: Spatial Distributions of Groundwater Types 20

Figure 7:Cumulative Frequency Percentage Plots 22

Figure 8: Bivariate plot of Cl and TDS concentrations 23

Figure 9: Ionic ratios of some chemical parameters of groundwater samples, dotted

lines represent ionic ratio of chemical parameters of seawater samples 24

Figure 10: Gibbs Diagram (A-anionic and B-cationic) showing the groundwater

chemical composition controlling processes 27

Figure\11: Stiff Pattern Diagram of groundwater samples showing variation

in chemical compositions in various groundwater samples 28

x

APPENDICES

1. WELL DATA OF WARRI CITY 37

2. LITHOLOGICAL LOGS OF PARTS OF WARRI CITY 38

1

CHAPTER ONE

GENERAL INTRODUCTION

1.1 Background of the study

Water is perhaps the most essential of all natural resources because it is fundamental to all

vital processes of mankind. The quantitative supply of water can be a local issue, but in many

regions the most serious problem hindering the utilization of water resources is the

deterioration of water caused by pollution, which leads to an estimated 25,000 deaths daily

because of water – related sicknesses (United Nations Population Information Network,

Popin1994). Deficient water supplies and sanitation therefore pose the most serious

environmental problems that face developing countries today. Ayoade and Oyebande (1973)

noted that less than 30% of Nigerian cities are served by public water schemes. This fact

remains true and is evident in Warri and its environs where private wells and boreholes

ownership are common.

Warri is a coastal town located strategically in the Niger Delta area of Nigeria and it is an

operational base for many of the oil producing and servicing companies. Its population is

estimated to be over a million people. Potable water supply in the town both from the

government agency (State public water utilities board), parastatals and individuals is

predominantly from groundwater. In Warri town and its environs, rapid urbanization and

industrialization are ongoing, which implies an increase in the generation of domestic and

industrial wastes, preponderance of individual septic tanks, indiscriminate drilling of

boreholes with its attendant over–abstraction problems that enhance pollutant concentrations

and saline water intrusion of the groundwater resources. Therefore, periodic examination to

ascertain the quality of the groundwater is indispensable. The fact that most of the water

consumed does not undergo treatment by the state public water utilities makes it pertinent to

regularly conduct and monitor physical, chemical and biological analysis.

1.2 Aims of Study

The aims of this study include:

I. To examine the physio-chemical and biological attributes of groundwater from the Deltaic

Plain Sands aquifer underlying Warri town and its environs.

II. To determine the suitability of the groundwater resources for drinking and domestic uses.

2

1.3 Location and Accessibility

Warri is located between latitudes 50 30′ and 5

035′ N `and longitudes 5

0 29′ and 5

0 48′ E. It is

within the oil rich province of Nigeria, some 50 km away from the shores of the Atlantic

Ocean. It occupies a low- lying area with a mean height of 6m above sea level. It is a flat land

with very gentle slope towards River Warri and its tributaries that empty their water into the

Atlantic Ocean as shown by Warri satellite image (Fig 1).Warri town has two main entry

points; one from Benin in Edo State and the other from Port Harcourt in Rivers State. Also,

the numerous networks of roads from Effurun area to Warri- Sapele road through

NPA/NNPC express way (Fig.2) make the town easily accessible for groundwater sampling.

1.4 Relief and Drainage

The study area is low-lying with mean height of 6m above sea level. The area is drained by

River Warri and its network of tributaries and creeks, which empty into the sea (Fig. 3). River

Warri has an extensive flood plain and a dendritic drainage pattern with tributaries branching

without a preferred orientation. This signifies a homogenous underlying material where

structural control is lacking. The River is perennial partly because of high precipitation

resulting from the humid tropical climate and it is also tide influenced. As a result of

freshwater-saltwater mixture, a brackish environment is created at the banks of the river and

associated creeks. Consequently, vegetation along the river banks is made up of mangrove

plants of different species (Olobaniyi and Owoyemi, 2006).

1.5 Climate and Vegetation

The climate of the area is the tropical equatorial type dominated by two seasons, a long wet

season (April to October) and a shot dry season (November to March), in response to the

interplay between the southwest and the northeast trade winds that blow over Nigeria. Annual

rainfall is usually in excess of 3000mm, as no month of the year is entirely devoid of rainfall.

Temperature is above 280C and humidity is about 80% (Iloeje 1981). The vegetation is

dominated by mangrove swamp forest, although further inland, it becomes rainforest. This

natural vegetation setting has been extensively altered by human activities such as farming

and lumbering and in many cases, has been replaced by grassland.

3

Figure 1: Satellite image of Warri (source: Google Imagery, 2011)

4

Figure 2: Location Map of Warri City showing Groundwater Samples Point

5

Figure 3: Map of the Niger Delta Showing the Drainage system (Inger, et at., 2005)

6

1.6 Literature Review.

A good number of hydrogeophysical and hydrogeochemical works have been carried out in

the Niger Delta region, of which the study area belongs. Netherlands Engineering Consultant,

(1961) reported average salinity at sea and land boundary gradient to range from 5000 to

10,000ppm in the Niger Delta. Etu – Efeotor, (1981) showed the saline /freshwater interface

to be up to 60 to 80km inland far north of PortHarcourt. Oteri, (1983) carried out electric log

to determine the various depths to fresh water in the western Niger Delta and reported that the

area experiences varying degrees of saltwater intrusion. Amajor, (1986) detailed the

geochemical characteristics of groundwater in Port Harcourt and its environs and found that

the groundwater in the area is enriched with Na+, Ca

2+ ,Mg

2+,Cl

-, HC03 and S04

2-. Amajor

and Ofoegbu, (1988) found fluoride concentrations of 0.2mg/l in groundwater from the

eastern Niger Delta. Oteri, (1988) evaluated saltwater intrusion in the eastern Niger Delta.

Amadi, et al, (1989) found total iron concentration up to 6.2mg/l in the groundwater from the

Niger Delta. Edet, (1993) carried out a detailed groundwater quality assessment in parts of

the eastern Niger Delta and found an increase in Cl- and decrease in HC03

- content towards

the coast indicating saltwater encroachment. Akpokodje, (1999) noted that a staggering

amount of solid waste is generated in the Port Harcourt metropolis each year. Udom et al.

(1999) studied the hydrogeochemical evaluation of groundwater in parts of Port Harcourt and

Tai Eleme Local Government Areas and discovered that the groundwater in the Benin

Formation is soft and low in dissolved constituents except pH and iron with mean values of

6.01 and 0.36 mg/l respectively Akpoborie, et al, (2000) examined the quality of groundwater

from dug wells in Ughelli, Warri, and Okurekpo all in Delta State and reported low values of

pH and high amount of coliform bacterial in wells of the area. Efe, (2000) did an appraisal of

rain and groundwater resources in Warri and found that groundwater has higher values of pH,

TDS, EC, Ca2+

, Mg2+

, HC03- and Cl- while rain water is higher in Pb

2+, S04

2- and N03-.Edet

and Okereke, (2001) found groundwater with total dissolved solids (TDS) concentrations up

to 1250mg/l in the coastal part of the Niger Delta. Orisakwe, et al., (2001) documented the

distribution, migration and fate of micro pollutants in potable water of Warri and its environs.

Aremu, et al., (2002) linked high concentrations of iron, lead and nickel in dug-well water

from the Warri area to contamination from petroleum chemicals. Ogunkoya and Efi, (2003)

examined rainfall quality and sources of rainwater acidity in Warri area of the Niger Delta

and reported that the enormous gas flared into the atmosphere by the oil industries precipitate

acid rain in the area. Olobaniyi and Owoyemi, (2004) found a high coliform count in the

bacteriological determination of groundwater from the Deltaic Plain Sands aquifer underlying

Warri. Spiff and Horsfall, (2004) reported trace metal contamination of the intertidal flats of

7

the Upper New Calabar River in the Niger Delta. Udom and Esu, (2004) carried out a

preliminary assessment of the impact of solid wastes on soil and groundwater in Port

Harcourt city and it’s environ and concluded that the groundwater of that area is

contaminated. Efe et al., (2005) investigated the influence of seasons on the physico-

chemical characteristics of water in the western horn of the Niger Delta and observed fast

deteriorating levels of groundwater quality in the area due to human activity. Emoyan, et al.,

(2006) confirmed high levels of heavy metal contamination of River Ijana – an effluent

receiving stream that flows by Warri refinery. Olobaniyi and Owoyemi, (2006) discovered

that saltwater concentrations in the aquifer underlying Warri decrease away from the tidal

influenced Warri River. Olobaniyi and Efe, (2007) showed elevated levels of lead (0.56mg/l)

and low pH values ranging from 5.10 – 6.35 in rain water collected in Warri and environs.

John, et al., (2008) advocated for the monitoring of physico-chemical parameters of potable

water in Warri to ensure quality water supply to human health.

8

CHAPTER TWO

GEOLOGY AND HYDROGEOLOGY

2.1 The Geology of the Niger Delta

The Niger Delta Basin covers most areas of Rivers, Bayelsa, Edo and Delta States of Nigeria.

Its areal extent is about 75,000km2

and consists predominantly of Cretaceous to Recent

clastic sediment piles of about 8000m thick that rest unconformably on the sialic basement

complex. The Delta consists of broad riverine areas through which the River Niger enters the

Atlantic Ocean, dividing into numerous rivulets, which fan out into the sea. It also includes a

number of tidal creeks separating small islands of less than 10m above sea level (Offodile,

2002).

The geological sedimentary sequence of the Niger Delta is made up as follows:

The Ameki Formation, the Ogwash- Asaba Formation, the Benin Formation, and the

Somebreiro Deltaic Plains Sands (Fig 4).

9

Figure 4: Geological map of parts of the western Niger Delta (Modified from

Akpoborie, et al., 2011).

10

The Ameki Formation was deposited during the regression of the sea in early Eocene. Its

lower unit consists of fine to coarse sandstone with intercalations of calcareous shale and thin

limestone, while the upper unit consists of coarse cross-bedded sandstones and sandy clay

(Reyment, 1965).The Ogwashi-Asaba Formation (Miocene) overlies the Ameki Formation

and extends from just west of the Siluko River on the eastern flank in the Okitipupa area with

a steady widening outcrop towards Onitsha. The formation consists dominantly of clays,

sands, grits and seams of lignite alternating with gritty clays. Within the Ogwashi-Asaba

Formation, the lignites are confined to a narrow belt of about 16 km wide 241 km long

trending northwest-southeast from the Niger in the west of the Nigeria-Cameroun frontiers,

east of Calabar.The Benin Formation is Oligocene to Pleistocene in age. This formation

outcrops in the north east of the coastal belt in the Niger Delta and dips at a low angle in the

southwest. The sediments consist, generally, of lenticular unconsolidated, dominantly sandy

formations. Lenticular clays and shales occur particularly in the eastern areas where they

confine small but moderately high yielding aquifers. The 90-150m confining clay beds

encountered in the Niger Delta area, (Brass, Bonny and Opobo) disappear in the regions,

north of the area, and adjacent to the Benin Formation area (Bodo, Okrika and Port Harcourt)

(Offodile, 2002). The thickness of the Benin Formation is variable, but generally exceeds

2000m.The Somebreiro Deltaic Plains Sands is late Pleistocene to Holocene in age. It

occupies most of the area of the present delta and stretches narrowly eastwards along the

coastline. The sediments consist of medium to coarse –grained unconsolidated sands forming

lenticular beds with intercalation of peaty matter and lenses of soft silty clay and shale. These

beds dip at varying angles towards the sea, forming units, which represent series of old deltas

(Offodile, 2002). The gravelly beds of the formation could be up to 9m thick.

2.2 Local Geology

Warri town is underlain by a sequence of sedimentary formations with a thickness of about

8000metres, which include from bottom to top, the Akata Formation, the Agbada Formation,

the Benin Formation and the Somebreiro Warri Deltaic Plain Sands (Allen, 1965; Reyment,

1965; Short and Stauble, 1967).

The Akata Formation rests unconformably on the migmatite-gneiss basement complex and

forms the basal unit of the Niger Delta stratigraphic pile .This formation consists of an open

marine facies unit dominated by high-pressured carbonaceous shales. The formation ranges in

age from Paleocene to Eocene and its thickness could exceed 1000 meters. The Agbada

Formation consists of a sequence of alternating deltaic sands and shales. It is Eocene to

11

Oligocene in age and exceeds 3000 meters in thickness. This formation is the oil –reservoir in

the Niger Delta basin. The Benin Formation which is Oligocene to Pleistocene in age consists

essentially of massive and highly porous sands and gravels with a few thin clay

intercalations. Its uppermost section is the quaternary deposit which is about 40-150m thick

and comprises rapidly alternating sequences of sand and silt / clay with the later becoming

increasingly more prominent seawards (Etu – Efeotor and Akpokodje, 1990).The Benin

Formation houses the most productive and hence most tapped aquifer in the Niger Delta

region, especially in areas north of Warri where it is shallow. The thickness of the formation

is variable, but generally exceeds 2000m.

The Somebreiro-Warri Deltaic Plain Sand is Quaternary to Recent in age and directly

underlies the study area. It consists of fine to medium unconsolidated sands that are often

feldspathic (with 30-40 % wt feldspars) and occasionally gravely (Wigwe, 1975). The

sequence is locally stratified with peat and lenses of soft and plastic clay that could be sandy

and shally. It generally does not exceed 120m in thickness and is predominantly unconfined.

2.3 Hydrogeology of Warri

The hydrogeology of an area is usually controlled by such factors as geology and climate of

that area. This is because geological formations underlying an area and the structure

contained in them determine the types of aquifer to be encountered and how the aquifers are

recharged, while the climate determines the amount and the rate of recharge the aquifer

receives (Ariyo and Adeyemi, 2005). The study area is drained by River Warri, a major

navigable channel in the Niger Delta southern Nigeria. It takes its source from around Utagba

Uno and flows through zones of fresh water swamp, mangrove swamps and coastal ridges.

The river stretches within latitude 502

1N-6

000

1N and longitude 5

024

1E-6

021

1E, covering a

surface area of about 255 sq. km with a length of about 150km (Netherlands Engineering

Consultants, 1961). It drains various tributaries and empties into the brackish Forcados River

and in turn into the Atlantic Ocean.

Local hydrogeological setting indicates that Warri is underlain by the Somebreiro-Warri

Plain Sands aquifer which consists of fine to medium and coarse grained unconsolidated

sands, gravels and. shales. The aquifer in most cases unconfined, has thickness that ranges

from 60 to 95m and hydraulic conductivity that varies from 8.82 x 10-3

to 9.0 x 10-2

cm/s.

Specific capacities recorded from different locations outside Warri city where the unit has

been penetrated vary from 6700 lit/hr/m to 13500 lit/hr/m, (Ofodile, 2002).The water table is

very close to the ground surface and varies in depth from 2 to 4m. Low groundwater

12

fluctuation is reflection of the high amount of precipitation often recorded in the Warri area

over a greater part of the year.

13

CHAPTER THREE

RESEARCH METHODOLOGY

3.1 Hydro-geological Investigation

The hydrogeological investigation involved measurement of well diameters, static water level in

wells and depth to water table using tape meter. Topographic elevations of well locations above

mean sea level and geographical co-ordinates were measured with the GPS. Lithology logs

covering parts of the area and obtained from Delta State Water Board were examined to

authenticate the claims of other researchers about the nature and types of the aquifer.

3.2 Hydro geochemical Investigation

A total of twenty (20) groundwater samples from hand-dug wells within Warri city were

collected in two-liter plastic containers during the month of February. The depths of wells

measured ranged from 4.1m to 5.4m below ground level. Physical parameters (pH, temperature,

total dissolved solid (TDS) and electrical conductivity) were measured in the field by EC/TDS

meter, (Wissencheflich Technische Werkstetten (WTW) LF 91 model) while colour and turbidity

were determined with Hach DR/2000 spectrophotometer. Other parameters were determined in

the laboratory and included total hardness (TH) which was determined with Hach digital titrator,

sodium (Na+), calcium (Ca

2+), magnesium ( Mg

2+), potassium (K

+) and iron (Fe

2+) which were

analyzed using atomic absorption spectrophotometer (Perkin – Elemer AAS 3110), bicarbonate

(HCO-3), Chloride (Cl

-), nitrate (NO

-3) and sulphate (SO4

2-) which were analyzed using the

colorimetric method with UV spectrophotometer (WPAS110). Lead (Pb), Nickel (Ni), and

Cadmium (Cd) were determined with digital bulk 205 atomic absorption spectrophotometer

(AAS) while biological analyses (total bacteria and fecal coliform) were determined by multiple

tube fermentation technique.

14

CHAPTER FOUR

RESULTS AND DISCUSSION

4.1 Groundwater Chemistry

The results of the physiochemical and biological analyses of the groundwater samples are

presented in Table 1. The pH value varies from 6.45 to 7.80 with an average of 7.03 which

reveals that the groundwater is slightly acidic to slightly alkaline. Total dissolved solids (TDS)

values ranged from 328mg/l to 857mg/l with a mean value of 492mg/l indicating that the

groundwater of the area is all of the fresh water type (Hem, 1970). Total hardness measured

ranged from 74mg/l to 328mg/l with an average of 198mg/l. Hardness classification of

groundwater (after Sawyer and McMcartly, 1967) reveals that the Warri groundwater falls into

the four categories, namely soft, moderately hard, hard and very hard with 5% of the samples

being soft, 15% moderately hard, 70% hard and 10% very hard (see Table 2). The relative

abundance of cations and anions is in the order; Ca2+

> Na+ > Mg

2+ > K

+ and Cl

- > HCO

-3 >.

SO42+

respectively. Calcium and chloride are the most dominant ions with average concentration

values of 3.063meq/l and 3.852meq/l respectively while potassium and sulphate have the least

average concentrations of 0.819 and 0.124meq/l respectively among the major ions.

4.2 Groundwater Type

The 20 groundwater samples analyzed were classified using the Piper diagram (Fig. 5). The ions

classified by the diagram are Ca2+

, Mg2+

, Na+, K

+, HCO3

-, Cl

- and SO4

-. Three groups of

groundwater types were observed namely: calcium bicarbonate (Ca(HCO3)2) water type, calcium

chloride (CaCl2) water type and sodium chloride (NaCl) water type. The Ca(HCO3)2 water type

reflects groundwater of recharge zone area that is characterized with low EC and TDS, while the

NaCl water type reflects groundwater of the discharge zone area that is generally characterized

with high EC and TDS. The CaCl2 water type is the transition zone between the two types. The

spatial distribution of the groundwater types is presented in figure 6 and reveals that the NaCl

water type is closer to the low lying sea shore while the CaHCO3 water type is confined to the

upland area. The presence of sodium chloride (NaCl) water type in the Warri area suggests

possible salinization of groundwater in the area. The possible sources of salinization were

investigated using the concentrations of the major ions and ionic ratios (see Table 3). Pulido-

15

Bosch, et al.,(1999), Sanchez-Martos, et al., (2000), Kim, et al., (2003b), Park, et al., (2005), El

Moujabber, et al., (2006), Lee and Song, (2007), and Nwankwoala and Udom, (2011) have all

shown that concentrations of major ions and ionic ratios can be used to decipher the contributing

sources of saline water in coastal aquifers. Figure 7 is the cumulative frequency percentage plots

of the major chemical constituents ( SO2-

4, Cl-, Ca

2+, Na

+, Mg

2+ and TDS) of the Warri city

groundwater. Only two threshold values those of ( Cl- and TDS) could be determined from the

figure as the mean value for the two groundwater threshold values for SO2-

4, Ca2+

, Mg2+

and Na+

could not be determined because of the difficulty in establishing a singular break in their plots

(see also Fig. 7). The threshold values for TDS and Cl (parameter indicators of salinization) are

724.44mg/l and 5.07meq/l respectively. Groundwater sample 6 that lies above the TDS threshold

line/value (724.4mg/l) and groundwater samples 1, 2, 3, 4, 5, 6 and 7 which lie above the Cl

threshold line/value (5.07meq/l) can be said to be salinitized by salt water intrusion. water

samples closest or nearest to the major break in the plots (see plots for TDS and Cl- in Fig. 7).

Threshold values for SO2-

4, Ca2+

, Mg2+

and Na+ could not be determined because of the

difficulty in establishing a singular break in their plots (see also fig. 7). The threshold values for

TDS and Cl (parameter indicators of salinization) are 724.44mg/l and 5.07meq/l respectively.

Groundwater sample 6 that lies above the TDS threshold line/value (724.4mg/l) and groundwater

samples 1, 2, 3, 4, 5, 6 and 7 which lie above the Cl threshold line/value (5.07meq/l) can be said

to be salinitized by salt water intrusion. However, bivariate plot of TDS and Cl concentrations

(Fig. 8) suggests that only groundwater sample 6 is affected by seawater intrusion implying that

cumulative frequency plots and bivariate plot are not enough to establish salinization of the

groundwater. Figure 9 is a plot of ionic ratios of Ca/Cl, Ca/Mg, HCO3/Cl and Ca/SO4 (ionic

ratios of the major ions) against TDS for groundwater samples that have correlation coefficients

greater 0.40 (correlation coefficient considered to be significant; values varied from 0.2 to 0.6)

and plotted very close to the seawater ratio line (see Fig.9). Only groundwater sample 6 which

has high TDS, Cl and SO4 (as revealed by low Ca/SO4 and Ca/Cl values) in all the four ionic

ratios plotted close to the sea water ratio line, implying that only this sample was influenced by

sea water intrusion. As groundwater of the NaHCO3 type does not exist in the study area, the

results imply that salinitization in the study area is caused mainly by recent sea water intrusion.

Mercado, (1985) and Sung-Work Jean, et al., (2000) had established that NaHCO3 water type

16

represents the partly flushed remains of an ancient entrapped saline water body. Its absence in

the study area implies that the sea water intrusion confirmed in sample 6 is a recent intrusion

17

Table 1: Physico-chemical and bacteriological content values of the shallow groundwater in

Warri coastal area LoLocati

onon

pH EC# TDS

α

THα Ba

c‡

Col

i+

SO4 Cl HC

O3

NO3 Ca Mg Na K

Fe Pb Ni Cd Water

type

1 7.02 850 516 150 3 0 0.089 5.53

3

1.8

39

0.20

1

1.1

79

1.2

32

4.00

0

0.4

31

0.2

2

0.0

1

0.0

06

0.001 NaCl

2 6.45 1010 520 152 6 0 0.105 5.67

3

2.5

59

0.20

1

1.4

00

1.1

05

4.00

0

0.3

44

0.2

4

0.0

1

0.0

21

0.001 NaCl

3 6.85 805 622 74 4 0 0.108 7.05

0

2.7

93

0.42

4

1.1

68

0.3

14

4.93

8

0.7

64

0.4

2

0.0

0

0.0

11

0.000 NaCl

4 7.50 1002 701 231 3 0 0.133 6.99

4

3.3

32

0.33

6

2.9

05

1.7

11

4.70

9

0.9

06

0.4

0

0.0

4

0.0

32

0.002 NaCl

5 6.72 920 707 154 5 1 0.142 6.75

1

3.9

70

0.56

1

1.2

49

1.8

44

3.92

4

1.1

97

0.4

2

0.0

3

0.0

40

0.003 NaCl

6 6.84 912 857 155 7 0 0.142 6.49

2

3.1

16

0.46

6

1.3

58

1.7

52

3.68

0

1.9

59

0.4

0

0.0

4

0.0

38

0.004 NaCl

7 6.62 790 613 114 6 3 0.140 6.06

4

3.5

53

0.48

4

1.0

38

1.2

43

1.98

5

1.6

22

0.3

4

0.0

2

0.0

28

0.004 NaCl

8 6.60 602 598 205 8 2 0.140 4.21

9

3.8

35

0.46

9

2.2

46

1.8

60

1.68

9

1.7

56

0.3

8

0.0

2

0.0

22

0.006 CaCl2

9 7.12 600 538 228 9 3 0.142 3.95

0

3.4

42

0.42

6

2.8

94

1.6

77

1.70

6

1.9

52

0.2

4

0.0

2

0.0

09

0.005 CaCl2

10 6.90 504 539 155 6 0 0.142 2.88

8

3.2

48

0.23

0

2.2

76

0.9

89

1.74

1

1.5

35

0.2

8

0.0

1

0.0

16

0.018 Ca(HC

O3)2

11 6.80 480 510 184 4 0 0.129 2.54

4

2.9

63

0.24

4

3.0

00

0.6

93

1.96

6

0.9

03

0.3

0

0.0

1

0.0

12

0.016 Ca(HC

O3)2

12 6.92 492 518 194 5 1 0.130 2.66

8

2.9

24

0.32

4

3.2

07

0.6

74

1.74

4

0.7

94

0.2

5

0.0

1

0.0

19

0.008 Ca(HC

O3)2

13 6.84 440 450 229 6 0 0.125 1.98

0

3.0

90

0.25

9

3.5

23

1.0

53

0.87

5

0.5

14

0.3

0

0.0

2

0.0

11

0.009 Ca(HC

O3)2

14 6.96 585 462 298 3 1 0.125 2.54

9

2.7

25

0.27

3

4.9

12

0.8

40

0.51

2

0.3

94

0.2

9

0.0

1

0.0

02

0.001 Ca(HC

O3)2

15 6.88 645 468 316 7 0 0.125 2.48

8

3.1

60

0.22

7

4.9

90

1.3

16

0.45

4

0.2

61

0.3

6

0.0

1

0.0

15

0.003 Ca(HC

O3)2

16 7.44 423 440 275 0 0 0.104 1.69

8

3.6

06

0.24

6

4.2

92

1.2

15

0.44

2

0.2

10

0.3

8

0.0

1

0.0

13

0.002 Ca(HC

O3)2

17 7.32 460 358 272 6 1 0.105 2.00

2

3.2

48

0.16

3

4.4

13

1.0

13

0.40

1

0.1

62

0.2

6

0.0

0

0.0

12

0.006 Ca(HC

O3)2

18 7.50 410 410 328 8 0 0.117 2.37

5

2.5

24

0.16

8

5.8

94

0.6

50

0.27

8

0.1

64

0.2

8

0.0

1

0.0

10

0.004 Ca(HC

O3)2

19 7.80 362 340 289 7 0 0.119 1.41

6

1.9

54

0.24

6

5.0

96

0.6

79

0.43

7

0.2

57

0.2

5

0.0

0

0.0

14

0.001 Ca(HC

O3)2

20 7.20 342 328 253 8 1 0.117 1.70

5

1.6

93

0.23

8

4.2

25

0.8

34

0.55

4

0.2

57

0.2

7

0.0

1

0.0

21

0.002 CaCl2

Mea

n

7.03 621 492 198 5.5 0.6

5

0.124 3.85

2

2.9

81

0.30

9

3.0

63

1.1

35

2.00

2

0.8

19

0.3

1

0.0

1

0.0

18

0.005

Sea* 8.10 53

n.a n.a n.a n.a 59.60 503.

6

1.8

44

n.a 21.

34

10

5.3

413.

2

9.9

76

n.a n.a n.a n.a

*values obtained from the off coast of Warri (n=2); #- µS/cm; α-mg/l; ‡-total bacteria

(/100ml);+-fecal coliform (/100ml), other parameters are measured in meq/l; n.a- not available

18

Table 2: Groundwater classification based on total hardness (TH) (after Sawyer and

McMcartly), 1967

Total hardness

(TH)

as CaCO3 (mg/l)

Water type Sample number Number of

Samples

Percentage of

samples (%)

<75 Soft 3 1 5

75-150 Moderately

hard 1, 2 and 7 3 15

150-300 Hard 4, 5, 6, 8, 9, 10, 11, 12, 13,14,

16, 17, 19 and 20

14 70

>300 Very hard 15 and 18 2 10

19

Figure 5: Piper Diagram showing the water types and mixing line

20

Figure 6: Spatial Distributions of Groundwater Types

21

Table 3: ionic ratios and ionic strength of the shallow groundwater in Warri coastal area

Na/Cl Ca/Cl SO4/Cl Ca/Mg Ca/HCO3 HCO3/Cl Na/Ca Ca/Cl Mg/Cl Ca/SO4 Mg/Ca Cl/HCO3 I.Sa

1 0.723 0.213 0.016 0.957 0.641 0.332 3.393 0.213 0.223 13.247 1.045 3.009 0.0084

2 0.705 0.247 0.019 1.267 0.547 0.451 2.857 0.247 0.195 13.333 0.789 2.217 0.0088

3 0.700 0.166 0.015 3.720 0.418 0.396 4.223 0.166 0.045 10.815 0.269 2.524 0.0093

4 0.673 0.415 0.019 1.698 0.872 0.476 1.621 0.415 0.245 21.842 0.589 2.099 0.0127

5 0.581 0.185 0.021 0.677 0.315 0.588 3.142 0.185 0.273 8.796 1.476 1.701 0.0111

6 0.567 0.209 0.022 0.775 0.436 0.480 2.710 0.209 0.270 9.563 1.290 2.083 0.0092

7 0.327 0.171 0.023 0.835 0.292 0.586 1.912 0.171 0.205 7.414 1.197 1.708 0.0089

8 0.398 0.529 0.033 1.208 0.641 0.849 0.752 0.532 0.438 16.043 0.828 1.100 0.0010

9 0.432 0.732 0.036 1.726 0.841 0.871 0.589 0.733 0.425 20.380 0.579 1.148 0.0085

10 0.603 0.788 0.049 2.301 0.701 1.125 0.765 0.788 0.342 16.028 0.435 0.889 0.0081

11 0.773 0.179 0.051 4.329 1.012 1.165 0.655 1.179 0.272 23.256 0.231 0.858 0.0080

12 0.654 1.202 0.049 4.758 1.097 1.096 0.544 1.202 0.253 24.669 0.210 0.912 0.0074

13 0.442 1.779 0.063 3.346 1.779 1.561 0.248 1.779 0.532 28.184 0.299 0.641 0.0079

14 0.201 1.927 0.049 5.848 1.803 1.069 0.104 1.927 0.330 39.296 0.171 0.935 0.0089

15 0.182 2.006 0.050 3.792 1.830 1.270 0.091 2.006 0.529 39.920 0.264 0.787 0.0095

16 0.260 2.528 0.061 3.533 1.190 2.124 0.103 2.528 0.716 41.269 0.283 0.471 0.0091

17 0.200 2.204 0.052 4.356 1.359 1.622 0.091 2.204 0.506 42.029 0.230 0.616 0.0084

18 0.117 2.482 0.049 9.068 2.335 1.063 0.047 2.482 0.274 50.376 0.110 0.941 0.0093

19 0.309 3.599 0.084 7.595 2.608 1.380 0.086 3.599 0.480 42.824 0.133 0.725 0.0079

20 0.325 2.478 0.069 5.066 2.496 0.993 0.131 2.478 0.489 36.111 0.197 1.007 0.0073

Mean

Seab 0.734 0.042 0.118 0.208 11.574 0.004 19.36 0.040 0.204 0.358 4.806 273.10 >0.005

a- Ionic strength; b-values of seawater obtained from the off coast of Warri (n=20)

22

Figure 7: Cumulative Frequency Percentage Plots for some chemical Constituents of Groundwater

23

Figure 8: Bivariate plot of Cl and TDS concentrations

24

Figure 9: Ionic ratios of some chemical parameters of groundwater samples, dotted lines

represent ionic ratio of chemical parameters of seawater samples

25

Figure 9: contd.

26

4.3 Sources of Ions

In order to evaluate the processes that control the chemical composition of groundwater from

Warri coastal area, the hydrochemical data of groundwater from the area were plotted in Gibbs

diagram (Fig. 10). The diagram reveals that groundwater chemistry or chemical composition is

controlled dominantly by rock weathering processes. The differences in concentrations of the

various ions in the groundwater as revealed by the Stiff diagram (Fig. 11) may be attributed to

the amounts of ions in the rock matrix, reaction characteristics and transport history.

4.4 Groundwater Quality for Drinking Purposes

Table 4 presents a comparison of the results of the biological and physiochemical analysis of

groundwater of the study area with the standard guideline values recommended by the World

Health organization (WHO, 1993) for drinking water purposes. It is observed from the Table

that 60% of the

samples show TDS values above the guideline value of 500mg/l. while 35%, 50% and 40% of

the samples are contaminated by the heavy metals of Pb, Cd and Ni respectively. Also, 40% and

30% of the groundwater samples have fecal coliform and Cl concentrations respectively above

the stipulated guideline values. All the groundwater samples, however, have total bacteria, SO2-

4

and NO-3 concentrations below guideline values for drinking water.

27

Figure 10: Gibbs Diagram (A-anionic and B-cationic) showing the groundwater chemical

composition controlling processes.

28

Figure 11: Stiff Pattern Diagram of groundwater samples showing variation in chemical

compositions in various groundwater samples.

29

Figure 11: contd.

30

Table 4: Ground water indices and WHO (1993) stipulated guideline values

Water quality Index

WHO (1993) guideline value

(mg/L)

Samples exceeding guideline values

Percentage of Samples exceeding guideline values

TDS 500 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 60 Total bacteria

a 10 nil 0 Fecal coliform

a 0 5, 7, 8, 9, 12, 14, 17, 20 40 SO4* 4.16 nil 0 Cl* 5.64 2, 3, 4, 5,6, 7 30 NO3* 0.73 nil 0 Pb 0.01 4, 5, 6, 7, 8, 9, 13 35 Cd 0.03 6, 7, 8, 9, 10, 11, 12, 13, 17, 18 50 Ni 0.03 1, 2, 3, 4, 5, 6, 7, 8 40

a-measured in /100ml; *measured in meq/l

31

CHAPTER FIVE

5.1 CONCLUSIONS

The chemical composition of the groundwater of the study area is strongly influenced by

weathering of the litho units of the rocks of the area along with anthropogenic activities.

Groundwaters of the area are slightly acidic to slightly alkaline in nature and also class as soft,

moderately hard, hard and very hard with about 70% of the water being hard.

Three groundwater types were recorded namely, calcium bicarbonate water type, calcium

chloride water type and sodium chloride water type with the sodium chloride type being closest

to the low-lying sea shore while the calcium bicarbonate type is confined to the upland area. The

calcium chloride type is in the transition zone.

Bivariate plot of TDS and Cl (parameter indicators of salt water intrusion) and ionic ratios of

Ca/Cl, Ca/Mg, HCO3/Cl and Ca/SO4 against TDS revealed that only one of the twenty

groundwater samples investigated had been influenced by salt water intrusion. Absence of

sodium bicarbonate water type which is indicative of partly flushed remains of ancient entrapped

saline water implied that the salt water intrusion recorded in the sample is that of recent intrusion

rather than being the flushed remains of ancient entrapped saline water.

Groundwater quality indices such as TDS, fecal coliform, Cl, Pb, Cd and Ni have concentrations

above the stipulated WHO (1993) guideline values, indicating that the groundwater of the area is

not suitable as drinking water.

5.2 RECOMMENDATION

It is hereby recommended that the centrally located waterworks scheme drilled into the Benin

Formation (205m) in the area should be empowered so as to discourage the indiscriminate

digging of hand dug wells and shallow boreholes into the shallow aquifer. Companies and

individuals under the supervision of Hydrogeologists are advised to sink their boreholes beyond

the Deltaic Plain Sand aquifer into the Benin Formation (>150m), so as to tap from the high

quality water of the formation devoid of bacteriological, heavy metals and saltwater

contaminations. In this current situation whereby some water samples are bacteriologically

32

contaminated, boiling and chlorination should also be carried out on such samples after

laboratory analysis so as to make the water fit for drinking.

33

REFERENCES

Allen, J.R.L. (1965). Late Quaternary Niger Delta and Adjacent Areas: Sedimentary

Environments and Lithofacies. Bull .AAPG 49, 547-600.

Akpoborie, I.A, Ekakite, O.A, Adaikpon, E.O. (2000). The quality of groundwater from dug wells in

parts of western Niger Delta. Knowledge Review 2/5: 72-79.

Akpokodje, E.G., (1999). Principles of Applied and Environmental Geology.Paragraphic Publisher,

Port Harcourt 147.

Allen, J.R.L. (1965). Late Quaternary Niger Delta and adjacent areas: Sedimentary environments

and lithofacies. Bull .AAPG 49:547-600.

Amadi, P.A., Ofoegbu, C.O. and Morrison. (1989). Hydrogeochemical assessment of

groundwate quality in parts of the Niger Delta, Nigeria. Environmental Geology and

Water Sciences, 14:195-202.

Amajor, L.C. (1986). Geochemical characteristics of groundwater in Port Harcourt and environs.

Proc. Symp. on Groundwater resources in Lagos, Nigeria.358-375.

Amajor, L.C and Ofuegbu, C.O. (1988). Determination of polluted aquifers by stratigraphically

controlled bio-chemical mapping: example from the eastern Niger Delta, Nigeria. In:

Groundwater and Mineral Resources of Nigeria, ed: Ofoegbu, C.O. Vieweg and Sohn,

Braunschweig, 61-74.

Aremu, D.A., Olawuyi, J.F, Meshitsuka, S., Sridhar, M.K. and Oluwande, P.A. (2002). Heavy

metal analysis of groundwater from Warri, Nigeria. International journal of

Environmental Health Research, 12: 261-267.

Ariyo, S.O. and Adeyemi, G.O., (2005). Geochemical characterization of aquifers in the

Basement complex-sediment transition zone around Ishara, Southwestern Nigeria.

Journal of NAH . 16 28-31.

Ayoade, J.O and Oyebande, B.L (1973). Water Resources. In: Oguntonyinbo J.S., Areola O.D

and, Filan M,: A Geography of Nigeria’s Development. 2nd Edition , Heineman Books

Nig. Ltd, Ibadan.

Bahar, M, and Reza, S. (2010). Hydrochemical characteristics and quality assessment of shallow

groundwater in a coastal area of Southwest Bangladesh. Environmental Earth Science

61: 1065-1073

34

Beka, F.T. and Oti, M.N. (1995). The distal offshore Niger Delta: frontier prospects of a mature

petroleum province. In: Geology of Deltas, eds: Oti M..N and Postma, G.237-

241.Balkema, Rotterdam.

Edet, A.E. (1993) .Groundwater quality assessment in parts of Eastern Niger Delta. Nigeria

Environmental Geology. Vol.14: 1-46.

Edet, A.E. and Okereke, C.S. (2001). A regional study of salt water intrusion in southeastern

Nigeria based on the analysis of geoelectrical and hydrochemical data. Environmental

Geology,40:1278-1289

Efe, S. I. (2000). An Appraissal of the Quality of Rain and Groundwater Resources in Nigerian

Cities. The case of Warri Metropolis. A Ph.D seminar paper presented to the Dept. of

Geography and Regional planning, Delta State University Abraka Dec. 2003.

Efe, S.I., Ogban, F.E., Horfall, M.J.and Akporunor, E.E (2005). Seasonal variation of physico-

chemical characteristics in water resources quality of the Western Niger Delta region,

Nigeria. Jour.Appl.Sci.Environ. Mgt. Vol.9: 191-195.

El Moujabber, M., Bou Samra, B, Darwish, T. and Atallah, T., (2006). Comparison of

different indicators for groundwater contamination by seawater intrusion on the

Lebanese coast. Water Resources Management, 20, 161-180.

.Emoyan O O, Akporhonor, E E; Akpoborie, I A;Adaikpoh, E O (2006), Water

QualityAssessment of River Ijana, Ekpan, Warri,Delta State, Nigeria. Journal of

Chemical Society of Nigeria, 31: 154 – 160.

Etu – Efeotor, J.O (1981). Preliminary hydrochemical investigations of subsurface water in parts

of the Niger Delta. Nig. J.Mining and Geol. 18 (1), 103-107.\

Etu – Efeotor, J.O and Akpokodje, E.G (1990) Aquifer systems of the Niger Delta Jour. Min.

Geol. 26 (2):279 – 284.

Iloeje, N.P. (1981). A new Geography of Nigeria, Longman, Nigeria.

Inger, A., Ousmane, D., Martha, J., Holder,J. and Claude, O.(2005). The Niger River Basin: A

Vision for Sustainable Management. Edited by Katherin George Golitzen. The World

Bank Washington, DC.

John, K.N., Orish, E.O. and Linus, O.E. (2008). Some physico-chemical parameters of potable

water supply in Warri, Niger Delta area of Nigeria. Journal of Scientific Research and

Essay.3 (11):547-551.

35

Kim, J. H., Yum, B. W., Kim, R. H., Koh, D. C., Cheong, T. J., Lee, J.H. and Chang, H. W.

(2003b). Application of cluster analysis for the hydrogeochemical factors of saline

groundwater in Kimje, Korea, Geosciences Journal, 7(4), 313-322.

Lee,J. Y. and Song, S. H. (2007). Evaluation of groundwater quality in coastal

areas: implications for sustainable agriculture. Environment Geology, 52: 1231-1242.

Lenntech B.V.\(2011).Rotterdamseweg 402m 26 29 HH Delft the Netherlands

www.lenntch.com/periodic/elements.htm

Mercado, A. (1985). The use of Hydrochemical patterns in carbonate sand and sandstone

aquifers to identify intrusion and flushing of saline water, Ground Water, 23, 635-645.

Ministry of Solid Minerals Development, (MSMD), 2006. Geological map of Nigeria,

1:2,000,000 scale.

Netherlands Engineering Consultant (1961). The waters of the Niger Delta. Nadeco, the Hague.

Nwankwoala, H. O. and Udom G. J. (2011). Hydrochemical facies and ionic ratios of

groundwater in Port Harcourt, Southern Nigeria. Research Journal of Chemical

Sciences 1(3): 87-101.

Offodile, M.E. (2002). Groundwater supply and development in Nigeria. 2nd

Ed, Mecon

Services Ltd Jos, Nigeria.

Ogunkoya,O.O and Efi,E.J.(2003).Rainfall quality and sources of rainwater acidity in Warri area

of the Niger Delta, Nigeria. Journal of Mining and Geology.39 (2):125-130.

Olobaniyi, S.O. and Owoyemi, F.B. (2004) . Quality of groundwater in the Deltaic plain sands

aquifer of Warri and environs, Delta state, Nigeria. Water Resources Journal of Nigeria

Association of Hydrogeologist.15: 38-45.

Olobaniyi, S.O and Owoyemi, F.B (2006).Characterization by Factor Analysis of the chemical

facies of groundwater in the Deltaic Plain sands aquifer of Warri, African Journal of

Science and Technology (AJST). Science and Engineering Series. 7 (1): 73-81.

Olobaniyi, S.B.; Efe, S.I. (2007), Comparative assessment of rainwater and groundwater quality

in an oil producing area of Nigeria: environmental and health implications, Journal of

Environmental Health and Res. 6(2): 111-118

Oteri, A.U. (1983). Electric Logs Interpretation for Groundwater Exploration in the Niger Delta

.Quart.Journ.Eng. Geol.16, 43-51.

36

Oteri, A.U. (1988). Electric Log Interpretation for the Evaluation of Saltwater intrusion in the

Eastern Niger Delta. Journ.of Hydrological Sciences, 33, (1) 19-29.

Park, S. C., Yun, S. T., Chae, G. T. Yoo, I. S., Shin, K. S., Heo, C. H. and Lee, S. K., (2005),

Regional Hydrochemical study on salinization of coastal aquifers, Western coastal area

of South Korea. Journal of Hydrology, 313, 182-194.

Plunkett, E. R. (1976). Handbook of industrial toxicology. Chem publ Coy Ltd, New York, 99-

101.

Pulido-Bosch, A., Sanchez-Martos, F., Martinez-Vidal, J. L. and Navarrete, F. (1992).

Groundwater problems in a semiarid area (Lower Andarax river, Almeria,

Spain). Environ. Geol. Wat Sci. 20 (3), 195-204.

Pulido-Lebeouf, P. (2004). Seawater intrusion and associated processes in a small coastal

complex aquifer (Castell de Ferno, Spain). Applied Geochemistry, 19: 1517-1527.

Reyment, R.A. (1965). Aspects of the geology of Nigeria. Ibadan University Press.145.

Sanchez-Martos,F., Pulido-Bosch, A., Molina-Sanchez,L.and Vallejos-Izquierdo,A.(2002).

Identification of the origin of salinization in groundwater using minor ions (Lower

Andarax, Southeast Spain). Science of the Total Environment, 297, 43-58.

Sawyer, C.N. and McCarty, P.L., 1967. Chemistry for sanitary Engineers 2nd

ed., McGraw-Hill,

New York, 58.

Short, K.C.; Stauble, A.J. (1967) Outline of Geology of Niger Delta, Bull. AAPG .51(5):761-

779.

Sung-Wook Jean, Jun-Mo Kim,Kyung-Seok Ko,Byoungwoo-Yun and HowanChang

(2001). Hydrogeochemical characteristics of groundwater in a mid- western coastal

aquifer system, Korea. Geosciences 5(4): 339-348.

Spiff, A I; and Horsfall, M Jnr (2004), Trace Metal Concentrations in Inter-Tidal flat Sediments

of the Upper New Calabar River in the Niger Delta area of Nigeria. Scientia Africana. 3:

19-28.

Standards Organization of Nigeria (2007) Nigerian Standard for Drinking Water Quality ICS

13.060.20

Udom,G.J.,Etu-Efeotor,J.O.and Esu,E.O.(1999).Hydrochemical Evaluation of Groundwater in

parts of Port Harcourt and Tai Eleme Local Government areas, Rivers state. Global

Journ. Of Pure and Appl.Sc.5(5.)545-551

37

Udom G.J., and Esu, E.O., (2004). A Preliminary Assessment of the Impact of Solid Wastes on

Soil and Groundwater systems in parts of Port Harcourt City and its Environs. Rivers

State Nigeria. Global Journal of Environmental Sciences. 4 No.1UN, (1988).

Groundwater in North and West Africa. Natural Resources/Water Series No 18, United

Nations, New York.

United Nations Population Information Network – Popin (1994).Population and water resources,

contributed by FAO, UN Population Division.

World Health Organization (1993) Guidelines for drinking water quality incorporating

first addendum: Vol. 1.Recomendations, 3rd edition, Geneva

38

APPENDICES

APPENDIX 1:

WELL DATA

ND (not determined)

Sample

code

Well location Well

depth

(m)

SWL

(m)

Well

Diameter

(cm)

Ground

Elevation

(m)

Latitude Longitude

1 Warri GRA 4.6 1.0 80 6.0 50.32.2’N 5

033.5’E

2 Ajamimogha 4.8 1.1 80 6.6 5032.5’N 5

035.3’E

3 Edjeba 4.1 1.1 80 7.0 50.32.8’N 5

0.35.2’E

4 NNPC 1 4.7 1.3 60 7.8 50.34.1’N 5

0.35.4’E

5 NNPC 2 5.1 1.1 60 7.1 50.34.2’N 5

0.35.5’E

6 Refinery Rd ND ND ND ND 50.32.3’N 5

0.36.3;E

7 Ugboroke ND ND ND ND 50.32.5’N 5

0.35.2’E

8 Ok layout 5.2 7.1 60 7.1 50.32.4’N 5

0.35.6’E

9 Okere 4.9 1.1 80 6.1 50.32.5’N 5

0.35.6’E

10 Sokoh Estates 5.1 1.1 80 6.7 50.33.2’N 5

0.38.4’E

11 Effurun 5.4 1.2 60 6.9 50.33.5’N 5

0.38.8’E

12 Okuokoko 4.8 1.0 60 6.7 50.33.8’N 5

042.6’E

13 DSC Road 5.0 1.2 80 6.2 50.33.7’N 5

0.44.6’E

14 Enerhen 5.1 1.2 80 6.7 50.32.5’N 5

0.40.1’E

15 Ekete 4.6 1.1 80 6.1 50.31.5’N 5

0.40.3’E

16 Nmofor 4.8 1.2 80 6.6 50.33.5’N 5

0.44.2’E

17 Orhunwhorun 4.5 0.9 80 6.9 50.31.5’N 5

0.43.1’E

18 DSC Township 1 4.9 1.0 60 6.5 50.31.9’N 5

0.44.2’E

19 DSC Township 2 ND ND ND ND 50.30.2’N 5

0.45.7’E

20 Ovwian 5.1 1.1 80 6.6 50.31.4’N 5

0.39.2’E

39

APPENDIX 2: LITHOLOGICAL LOGS OF PARTS OF WARRI CITY