evaluation of water quality with world health organization

Available online at www.worldscientificnews.com

WSN 24 (2015) 18-42 EISSN 2392-2192

Evaluation of Water Quality with World Health Organization and Nigeria Industrial Standards Using

Geographic Information System

S. O. A. Oloyede-Kosoko, Adetimirin Oluwafemi Idowu,

Olaleye Olabisi Ayoni

Department of Geoinformatics, Federal School of Surveying, P.M.B. 1024, Oyo, Oyo State, Nigeria

ABSTRACT

This research determined the physico-chemical parameters of hand dug wells in Eruwa, South-

western Nigeria in relation to the pollution, potability of groundwater by comparing the chemical and

physical quality with World Health Organization and Nigeria Standard for Drinking Water Quality

permissible limits. Twenty hand dug well were analyzed for their physico-chemical parameter. The

physico-chemical investigation includes turbidity, temperature, pH, colour, electrical conductivity,

calcium, fluoride, phosphate, nitrate, and iron. Averagely results show that the analyses are within the

permissible limit of World Health Organization (WHO) and Nigerian Industrial Standards (NIS).

From the analysisof results, observation and comparison with the available standard, it was revealed

that four out the twenty hand dug wells in the research area met the WHO standard and while five met

the NIS standard.

Keywords: GIS; Groundwater; Pollutants; Wells; Spatial Distribution

1. INTRODUCTION

Water is a valuable natural resource that is essential to human survival and the

ecosystems health. Water comprises of coastal water bodies and fresh water bodies (lakes,

World Scientific News 24 (2015) 18-42

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river and groundwater) (Usali and Ismail, 2010). Groundwater resources is one of the most

important resource available to humanity (Christophoridis, C., Bizani, E. and Fytianos, K.

2000), therefore it is more than necessary to provide a tool that can assess its quality over

space. The principal goal of groundwater management in developing countries is to assess and

manage the water resources that are available.

Technically, a Geographic Information System (GIS) is a system that includes mapping

software and its application to remote sensing, land surveying, aerial photography,

mathematics, photogrammetry, and geography. The advantages of using GIS over traditional

methods in groundwater monitoring are: effective storage and analysis system for spatial and

temporal database, spatial analysis of depicting the source- pollutant relationship, graphical

presentation, visual impacts and spatial distribution of graphical outputs on water quality

changes, pollution load and relationship with sources and management of river basin by

generating buffer zones on the basis of water quality criteria. GIS can serve as a very useful

tool for not only groundwater modeling but also for analyses of decadal variations in the

groundwater quality, and development of conceptual groundwater model. Various layers of

information such as canal network, recharge zones, subsurface geology and Digital Terrain

Model (DTM) can also be developed. A.N. Arora and R. Goyel (2003).

The specific objectives set for the research work are listed below:

1. To create a geo-database for the entities in the study area

2. Acquisition of geometric data of the hand dug wells, dumpsites and soakawaywith the

use of hand-held GPS (Garmin 12S) and semantic data with personal interview

method;

3. Determine the physiochemical parameters of groundwater in Eruwa and the pollutantof

the environment;

4. Determine the potability by comparing the physicochemical analysis with World

Health organization (WHO) standard and NigerianIndustrial Standard(NIS);

5. Determine the flow direction of hand dug wells in the research area.

1. 1. Conceptual Clarification

Groundwater is water located beneath the ground surface in soil pore spaces and in the

fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer

when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures

and voids in rock become completely saturated with water is called the water table.

Groundwater is recharged from, and eventually flows to, the surface naturally; natural

discharge often occurs at springs and seeps, and can form oases or wetlands. Groundwater is

also often withdrawn for agricultural, municipal and industrial use by constructing and

operating extraction wells. The study of the distribution and movement of groundwater is

hydrogeology which is also called groundwater hydrology. Typically, groundwater is thought

of as liquid water flowing through shallow aquifers, but technically it can also include soil

moisture, permafrost (frozen soil), immobile water in very low permeability bedrock, and

deep geothermal or oil formation water.

Groundwater is hypothesized to provide lubrication that can possibly influence the

movement of faults. It is likely that much of the Earth's subsurface contain some water, which

may be mixed with other fluids in some instances. Groundwater may not be confined only to

the Earth. The formation of some of the landforms observed on Mars may have been

influenced by groundwater.


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There is also evidence that liquid water may also exist in the subsurface of Jupiter's

moon Europa. It is naturally replenished by precipitation and naturally lost through discharge

to oceans, evaporation and subsurface seepage.

1. 2. Research area

Eruwa town is located between latitudes 7o

31’ and 7

o34

’north of the Equator and

longitudes 3o24' to 3

o27' east of the Greenwich Meridian. Eruwa town is a sparsely populated

African settlement grown over centuries with an estimated population of over 10,000 which

compose of mainly Yoruba, Sagbe, Fulani and Egun. The inhabitants are mainly farmers.

Geologically, the study area lies within the Precambrian basement complex of southwestern

Nigeria and is underlain by rocks of igneous and metamorphic types. However, granite

gneisses predominantly underlie the area and characterized by weathered regolith that varies

in thickness from place to place. The granite gneiss has been crosscut at several places by

quartz veins. The hydrogeologic setting of the study area is typical of what obtains in

basement complex terrain where availability of groundwater is a function of the presence of

thick overburden material as well as availability of joints, fractures and faults within the

untethered fresh bedrock. Due to the geological setting of Eruwa (humid tropical), the rocks

of the study area have been particularly deeply weathered and this serves as porous and

permeable zones for shallow water accumulation. The recharge into this weathered aquiferous

zone is predominantly through infiltration of rain water. Furthermore, the absence of basal

weathered clay (as sealing) within the weathered horizons made this aquiferous weather

regolith to be susceptible to pollution.

Fig. 1. Diagram showing the location of the research area.


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1. 3. Literature review

Groundwater is a medium commonly used for heavy metal pollution assessment.

Pollutants in water include a wide variety of chemicals and pathogens and physical chemistry

or sensory changes. Many of the chemical substances are toxic. Pathogens can obviously

induce diseases in either human or animal hosts. Alteration of water’s physical chemistry

includes acidity, conductivity, temperature, and excessive nutrient loading which is otherwise

known as eutrophication. These alterations among many others bring undesirable changes in

the environment and affects man directly or indirectly (Eniola and Olayemi, 1999). Water

pollution is a serious problem in the global context. It is one of the greatest concerns of the

world today, mainly caused by the improper disposal of untreated wastewaters, direct or

indirect dumping of domestic/municipal, agricultural or industrial wastes to the waterways. It

has been reported that nearly 1.5 billion people around the world have no access to safe

drinking water, and at least 5 million deaths per year are attributed to diseases linked to water

pollution. It has also been suggested that it is the leading worldwide cause of death and

disease (Pink, 2006) and accounts for the deaths of more than 14,000 people daily (West,

2006). Diarrhea, a water-borne disease, is the major cause of the death of more than two

million people per year of children under the age of five worldwide. It is a symptom of

infection or result of combination of a variety of enteric pathogens (Anon, 2000).

Fig. 2. Photographs of hand dug wells in some part Africa.


-22-

Groundwater sources should be protected as much as possible from contamination by

harmful pollutants. Completely protecting source water may not be possible because

pollutants from the atmosphere can enter surface water through precipitation and

contaminated groundwater can introduce pollutants through recharge. They can also be

polluted by industrial and municipal discharges as well as alterations to the natural

environment, which may cause runoff of pollutants. Both direct discharges and runoff can

include human and animal wastes.

Proliferation of industries coupled with non-compliance with set rules regarding

disposition of wastes and used chemicals has been a threat to lives in the developing world,

Nigeria inclusive. Potential pollutants include but not limited to inorganic chemicals, organic

chemicals and radionuclides (USEPA, 2005).Pollutants may also include suspended solids,

biodegradable organics, pathogenic organisms and dissolved inorganic and heavy metals. The

major problem in Nigeria had been environmental problem hence the establishment of Federal

Environmental Protection Agency (FEPA) in 1988 which later became the Federal Ministry

of Environment.

The responsibility of which is the monitoring and control. Groundwater pollution is

classified into two main categories viz; point source pollution and non-point source pollution.

Non-point source pollution often in the form of runoff comes from diffuse or scattered

sources in the environment, while point source pollution comes from a defined outlet such as

a pipe (USEPA, 2005). Non-point source pollution may be difficult to identify and control

while point source pollution can be identified easily.

Olatunji, Tijani, Abimbola and Oteri (2001) evaluated water resources from the surface

and underground in Oke–AgbeAkoko, southwestern Nigeria. The study revealed that the total

dissolved solid for the surface water samples range from 11.00 – 325.00 mg/l while the

electrical conductivity is from 19.00 – 628.00 uh/cm. the pH ranges from 7.1 – 7.5 which

shows the water to be neutral. The calcium content ranges from 1.0 – 4.30 mg/l while that of

magnesium is from 0.24 – 17.94 mg/l. The sodium and potassium content on the other hand

range from 1.50 – 6.60 mg/l and 1.10 – 32.0 mg/l respectively. Bicarbonate remains as the

dominant anion as shown from its range of value which is 6.10 – 238.0 mg/l followed by

chloride which has 7.10 – 138.20 mg/l.

The constituent of the ground water is markedly different from that of the surface water

with higher value obtained from the chemical constituent. The calcium and magnesium

content ranges from 2.0 – 90.0 mg/l and 1.78 – 58.14 mg/l respectively for the ground water

samples while for surface water samples, calcium and magnesium have their values ranging

between 0.90 mg/l and 17.94 – 93.88 mg/l respectively. Sodium and potassium range from

9.0 – 42.0 mg/l and 2.4 – 43.0 mg/l for the ground water samples and 1.50 – 18.60 and 32.0 –

130.4 mg/l for the surface water samples respectively.

The iron content on the other hand is relatively very low for both sources as seen from

the range of values of 0.1 – 0.32 mg/l and 0.01 – 1.73 mg/l. The relatively higher

concentration of these cations is similarly reflected in the anion content especially bicarbonate

and chloride.

From the chemical analyses, it shows that the samples from the ground water sources

are rich in chemical component compared to those samples from the surface. This may be

attributed to the fact that surface water has a very little time to interact with the bedrock,

unlike percolating groundwater.


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Fig. 3a. Diagram showing different depth of well & Water table.


-24-

Fig. 3b. Photographs of hand dug wells in some part Asia.

Ntekim and Wandate (2001) in their study of ground water chemistry in Adamawa area

revealed that water quality is dependent on physical, chemical and biological characteristics

of the water samples and of course with reference to their intended use. Drinking water

qualities are assessed based on the presence of objectionable characteristics (tastes, odour,


-25-

colour) and chemical parameters with harmful effects while the quality of irrigation water is a

function of the electrical conductivity, percentage concentration of sodium ion, type of plant,

soil and climate (Devis & Dewist, 1966; Johnson, 1975, Close, 1987). Results of the analysis

given showed that the ionic concentrations and parameters of groundwater in the study area

are largely within the WHO recommended standards. Exceptions are few in isolated cases

where parameters are remarkable above the maximum permissible level. Based on the

chemical data and the complete lack of objectionable properties in the examined sampled,

groundwater in the study area is in the average, notable and suitable for drinking and

household uses.

2. METHODOLOGY

The techniques used in carrying out the research are data acquisition, processing and

information presentation. Spatial data display an important role in any Geographic

information system study, the primary source of the data collection was based on field survey

which involved the collection of borehole coordinates using hand held GPS, HI 8633 Hanna

conductivity meter, was used for temperature and electrical conductivity, measuring tape

suspended with an iron rod and interview was conducted to the occupants of the building.

Secondary data were also sourced from previous maps and satellite imagery copy of the

research area

3. GEOGRAPHIC INFORMATION SYSTEM

It is important to understand what Geographic Information System (GIS) is In fact,

geographic information processing has a rich history in a variety of disciplines. In particular,

natural resource specialists and environmental scientists have been actively processing

geographic data and promoting their techniques since the 1960’s. The history of GIS barely

spans four decades now, and it’s a story that springs from many origins, and mingles many

disciplines. Where its future lies is not at all certain. Geographic Information System are

computer based system that are used to capture, store, check, integrate, manipulate, analyze

and display geographic information which can be related to specific location of portion on the

earth surface.

Spatial information covers a larger range of natural resources and infrastructures. A

geographic information supports spatial decision making and is capable of linking description

of location with characteristic of phenomena around there. This technology is capable of

solving most land related problem; Data acquisition for any GIS project can be accomplished

by making use of analog or digital methods. With the availability of GIS technology, which

enable data acquisition, database management and information presentation, it is possible to

capture both Spatial and attribute data of each object in a location, study for the purpose of

processing, analyzing, storing, up-dating, retrieval and presentation of information for

decision-making.

A good geographic information system provides accessibility of data and information

which goes a long way to improve the quality of life and social-economic wellbeing

proficiency of the society in all ramification.


-26-

The main components of any GIS are: Data acquisition, Data management, Data

manipulation and analysis, Data presentation spatial database is one of the components of a

GIS and is often referred to as the heart of any GIS. In fact, what account for the cost of GIS

is the spatial database.

Figure 4. Geographic information system Processes.

The field of geographic information system has many applications among which are

the finding solutions to real life problems as the one at the hand which is the finding solutions

to the water quality of hand dug wells in the study area. This study wascarried out by bringing

data from array of sources ranging from imageries of the study area to references from

existing map of the area and integrating these with data that were picked using modern

technology of and GPS.

4. ANALYSIS AND PRODUCT GENERATION

This is the use of spatial and non-spatial attribute data in GIS database to answer some

generic questions like querying, buffering, classification and other GIS analysis about the real

world by modeling (Heywood et al, 1998).

The model may reveal new or previously unidentified relationships within and

between datasets, therefore increasing of our understanding of the real world (ESRI, 1990).

The dataset used in this research are shown in the composite map of the research area in

figure5.

4. 1. Criteria for evaluating water quality of hand dug wells

For any hand dug well project, there are certain rules and regulations that must be

followed. In other words, experts have set out a set of criteria that must be followed for depth

of a hand dug wells and the standard forquality for human consumption such include among

others, the followings:

a) A hand dug well depth must range between 5-30 meters

b) Hand dug well must be lined and covered.


-27-

c) The minimum distance (m) of some structure to the hand dug well are also stated

d) For water to be portable there are standards for the physiochemical composition

for the water set by the World Health Organization and Nigerians Industrial

Standards which are stated below in table 1

Table 1. Physiochemical Composition Standard.

S/N PARAMETER WHO

STANDARDS NIS STANDARDS

1. PH 6 to 8.5 6 to 9.2

2. Electrical Conductivity 1 ms\cm 1 ms\cm

3. Temperature (°C) Not mentioned Not mentioned

4. Colour 15 TCU 15 TCU

5. Turbidity 5 NTU 5 NTU

6. Nitrate 50 mg\l 50 mg\l

7. Iron 1.0 mg\l 0.3 mg\l

8. Phosphate 0.3 mg\l 0.3 mg\l

9. Calcium 75 mg\l 75 mg\l

10. Fluoride 1.5 mg\l 1.5 mg\l

Source: WHO in Lenntech (2009) and NSDWQ (2007)

Table 2. Allowable minimum distance to some infrastructures to hand dug well.

Existing structure Minimum distance (m)

Buildings 3

Soakaway 30

Dumpsites and burial

grounds 500

Source: Ministry of Water Resources


-28-

Fig. 5. Composite Map of the Research Area.

4. 2. Spatial analyses

In order to make a GIS answer the generic question of location, condition, routing and

pattern. There is need for manipulation and analysis of the database. It is the capability of

spatial analytical function that distinguishes Geographical information system from other

information systems, Aronoff (1991).


-29-

Spatial search

Spatial search was used to access and retrieve information from the database. Queries

specific questions in the form of what is where and so on which provides answers to the

needed information through processing or manipulating spatial data. Spatial search are very

essential when searching for attribute within the neighborhood, which must be defined

systematically. There are two kinds of query that can be carried out in a well-structured

database. Single criteria query is a query when attached only one condition with a criteria and

multiple criteria query is a query with more than condition. In this case, a single and multiple

criteria were performed on the database.

Queries

The most basic of all tools provided in Geographical information system are those

marked with database query. Queries are specific question asked (what is where? and what is

the distribution of a phenomenon over time?) and answers provided through manipulation and

processing of the spatial database. All these are made possible as a result of the link between

the graphic (geometric) data and attribute (semantic) data being acceptable to be

implementing software (ArcGIS 10.1). These queries may be structured using a single

condition or more.


-30-

Fig. 6. Query and Result of hand dug wells that the depth is greater than or equal to 5 m.


-31-

Fig. 7. Query and Result of hand dug wells that the PH is greater than or equal to 6.5 and less than 8.5.


-32-

Fig. 8. Query and Result of hand dug wells that the turbidity is less than or equal to 5 m.


-33-

Fig. 9. Query and Result of hand dug wells that the phosphate is less than or equal to 0.3.


-34-

Fig. 10. Query and Result of hand dug wells that the nitrate is less than or equal to 50 mg/l.


-35-

Fig. 11. Query and Multiple query based on WHO standard.


-36-

Fig. 12. Query and Multiple query based on NIS standard.

Fig. 13. Flow Direction of the Hand Dug Wells Water.


-37-

4. 3. Graphical analysis of the well

(1) For chemical and physical analysis (fluoride, phosphate, calcium, iron, nitrate, Electrical

conductivity, pH).

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

PO

LY R

D

OK

E-O

LA

AB

OR

ERIN

1

AB

OR

ERIN

2

AB

OR

ERIN

3

ISA

BA

AN

KO

OK

E-ER

UW

A

OK

E-O

BA

NEW

ER

UW

A

GA

A R

D

SAN

NG

O 1

SAN

NG

O 2

BA

REK

E

SAN

NG

O 3

SAN

NG

O4

SAN

NG

O 5

NEW

ER

UW

A 2

HO

SPIT

AL

RD

AP

OD

E

WH

O*

NIS

*

EC(Ms/cm)

pH

0

5

10

pH


-38-

Nitrate(mg/l)

0

50

100

Nitrate(mg/l)

Ca(mg/l)

0

20

40

60

80

100

Ca(mg/l)


-39-

Fe(mg/l)

0

0,5

1

1,5

Fe(mg/l)

Phosphate(mg/l)

0

0,5

1

1,5

2

2,5

Phosphate(mg/l)


-40-

5. DISCUSSION OF RESULTS

Table 3. Table showing the results of hand dug wells analysis and comparing them

with WHO and NIS.

Par

amet

er/L

oca

tio

n o

f w

ell

Po

ly r

d

Ok

eola

Ab

ore

rin

1

Ab

ore

rin

2

Ab

ore

rin

3

isab

a

ank

o

Ok

eeru

wa

Ok

eob

a

New

eru

wa

Gaa

rd

San

ngo

1

San

ngo

2

bar

eke

San

ngo

3

San

ngo

4

San

ngo

5

New

eru

wa

2

Ho

spit

al r

d

apo

de

WH

O*

NS

DW

Q*

EC

((M

s/cm

)

0.1

2

0.2

2

0.3

4

0.2

0

0.5

9

0.4

4

0.6

6

0.8

2

0.8

4

0.9

6

0.1

9

0.4

1

0.8

0

0.3

6

0.3

5

0.1

5

0.2

0.1

6

0.6

9

0.3

8

1

1

Tem

p

(0c)

52.5

41.6

52.4

52.6

53.6

53.5

51.7

32.2

33.0

41.2

30.8

39.9

31.7

37.9

34.6

34.5

32.7

35.2

32.4

31.1

_

_

Colo

ur

(TC

U)

383

36

16

125

22

87

39

0

10

11

40

1

15

105

224

34

21

174

36

12

15

15

pH

6.4

3

6.1

6.9

5

6.4

4

6.9

7

6.9

4

7.1

7

7.3

7.0

7

7.2

8

7.6

4

6.5

3

7.1

6

7.1

7

6.6

9

6.6

2

6.9

2

6.8

6

7.1

7

6.8

3

6_8

.5

6_9

.2

Tu

rbid

ity

(NT

U)

74

11

6

22

6

14

7

2

0

0

9

0

5

18

42

6

5

43

4

4

5

5

Nit

rate

(mg

/l)

51.9

2

13.9

8

66

17

58.9

6

14.8

1

26.0

9

3.4

5

82.2

8

45.3

2

3.8

9

68.6

4

1.8

9

60.7

2

4.5

5

18.7

8

28.8

2

0

12.8

7

10.1

1

50

50


-41-

Ca

(mg

/l)

10.4

24.6

34.4

11.2

48

22.4

34.4

80

80

41.6

24

48.8

80.8

39.2

36.8

24.8

36

34.4

49.6

40

75

75

Fe(

mg

/l)

1.0

9

0.1

9

0.1

2

1.2

6

0.3

1

1.1

8

1.0

8

0.4

0

0.0

9

0.2

3

0.0

9

0.2

7

0.1

3

1.0

6

0.2

2

0.9

8

1.0

9

0.4

4

0

1.0

0.3

Ph

osp

hat

e (

mg

/l)

0.3

4

0.4

5

0.0

1

0.1

1

0.0

6

0.9

9

0.0

6

1.8

7

0.0

2

0.4

5

0.0

5

0

2.1

1

0

0.3

4

1.0

4

0.5

4

1.2

3

1.0

2

0.1

2

0.3

0

0.3

F (

mg

/l)

0.3

9

1.9

8

0.2

8

0.3

5

0.1

1

0.3

4

0.1

2

0.0

3

1.7

8

0.1

6

0.2

2

0.2

5

0.0

9

0.6

6

0.3

4

0.3

0.1

1

0.6

6

0.3

4

0.1

2

1.5

1.5

6. SUMMARY, CONCLUSIONAND RECOMMENDATION

This research work has shown the water quality of hand dug wells and the likely effect

of pollution in the research area (Eruwa). This research is developed as a Spatial Decision

Support System which is an aid to support decision making.

Four (4) wells met the WHO standard and five (5) wells met NIS standard. Results of

the chemical analysis of the hand dug wells reveal that water samples to be enriched in PO32+

and NO3ˉ which is as a result of the sewage and fertilizer runoff since the main occupation

there is farming.The physico-chemical characteristics of the examined hand dug wells are safe

for human consumption and domestic use, except for few locations that require water

treatment.

The following suggestions are hereby recommended for the purpose of decision making

and environmental management viz:

(i) There should be given a setback distance of 30m for soak-ways and 500m distance for

dumpsite from hand dug wells which should be more than sufficient to reduce the rate

of pollution.

(ii) Government should assist the inhabitants of the area by providing good, safe and

potable water that is fit for drinking with WHO maximum permissible level for

drinking water supply because most residents in the study area do not have access to

pipe borne water and they make use of groundwater as an alternative. Improved

groundwater treatment and supply by the government or corporate organization


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(NGO) through the provision of boreholes will lessen water scarcity and reduce

groundwater-related problems.

(iii) Public Health and Environmental Officers should be given a mandate to inspect and

check wells to ensure they are safe for drinking and free from all forms of pollution.

Polluted wells should be sealed.

(iv) The Urban And Regional Planner (Town Planner) should be charged and mandated to

ensure every building approved for construction, adhere to soakaway and dumpsite

standard distances from hand dug wells.

(v) The use of green manure should emphasize over fertilizer since farming is main

occupation in the area

(vi) Government should encourage and finance groundwater research by hydrologist and

hydrogeophysical scientists to detected areas that can easily pollute groundwater.

(vii)Decision makers should apply GIS technology in solving spatial problems.

References

[1] A.N. Arora and R. Goyel (2003). National Conf. on GIS/GPS/RS/Digital

Photogrammetry and CAD, Jaipur.

[2] Anon (2000): Rural water sources under the microscope SA. Water Bulletin 26(3) 18-21

[3] Christophoridis, C., Bizani, E. and Fytianos, K. (2000). Environmental Quality

Monitoring, Using GIS as a Tool of Visualization, Management and Decision-Making:

Applications Emerging from the EU Water Framework Directive EU 2000/60.

[4] Eniola, K.I.T, Olayemi A.B. (1999). Impact of effluent from a detergent producing

plants on some water bodies in Ilorin, Nigeria, International Journals of Environmental

Health Research 9, 335-340.

[5] Ntenkim E.E and Wandate S.D. (2001). Ground water chemistry of the basement rock

unit of Adamawa area, North-Eastern Nigeria; a reflection of the aquifers rock type,

Water Resources Journal of NAH, 12, 67-73.

[6] NIS, (NIS_544:_2007). Nigerian Standard for Drinking Water Quality.

http://www.unicef.org/nigeria/ng_publications_Nigerian_Standard_for_Drinking_Water

_Quality.pdf

[7] World Health Organization (WHO). Drinking Water Standard: in Lenntech (2009).

Water Treatment and purification holding; sources of groundwater pollution.

Rotterdanseweg, 402 m.2629 HH Delft, Netherlands.

http://www.lenntech.com/groundwater/pollutionsources.html (Retrieved 8/5/2011)

( Received 08 October 2015; accepted 22 October 2015 )

evaluation of water quality with world health organization

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