Correlation Coefficient and Seasonal Variations with Statistical Interpretation of Ground Water Quality of Bhubaneswar Municipal Corporation during Different Seasons of the Year-2010

 

Swopna Mishra¹*, Saswat Kumar Mohanty² and Swoyam Prakash Rout³

¹Research Scholar, Department of Chemistry, Utkal University, Bhubaneswar-751004, India

²Scientist, State Pollution Control Board, Bhubaneswar, Odisha, India.

³Former Professor of Chemistry, Utkal University, Bhubaneswar-751004, India: 

*Corresponding Author E-mail: swopnamishra68@gmail.com

 

Bhubaneswar, the capital city of Odisha, is under the spell of rapid urbanisation.  On account of this the population of Bhubaneswar Municipal Corporation has grown manifold during the last decade.  As a result of the increasing population load, the requirement of water for human activities has also increased considerably.  Because of various human activities, a huge amount of waste water is generated which is discharged into the river Kuakhai which is the main source of water for Bhubaneswar and its adjoining areas.   Thus the water of river Kuakhai is polluted because of huge discharge of waste and waste water generated from the city which has forced the people to use ground water which is known to be safe for drinking.  Presently around forty percent of people of BMC depend on ground water which is also getting polluted day by day.  In view of this it is felt necessary to make an evaluation of the status of ground water quality in Bhubaneswar.

 

Nine different locations have been chosen spreading across Bhubaneswar Municipal Corporation depending upon the population load.  The samples were collected quarterly in the month of January, 2010, May, 2010 and September, 2010 in three different seasons to determine the physical, chemical and biological parameters.  The seasonal variations of different parameters have been compared with standard values and the mean, standard deviation and correlation coefficient among different parameters has been analysed. 

 

From the mean and standard deviation value it was found that the standard deviation is very minimum in pH, F, Iron and Turbidity which indicates that the values obtained are in close proximity with each other while the maximum deviation occurs in conductivity indicating that in the study period conductivity value varies widely.

 

From the correlation coefficient studies it is observed that five parameters are correlated with each other out of which TH with TDS are highly correlated having value 0.971 and TDS and conductivity are also highly correlated having value 0.948.  As all the five parameters are correlated with each other, we can develop equation between them so that one can be found out by knowing the other parameter.

 

 

INTRODUCTION:

Bhubaneswar is the capital city of Odisha.  From a small village in and around Lord Lingaraj Temple, it has grown into a Municipal Corporation consisting of 27 wards and a population of about 10 lakhs. 

 

On account of rapid urbanisation, the population of the city has increased manifold and there has been a rapid growth in terms of huge building and apartments, hotels and restaurants, hospitals and technical institutions, transportation and vehicles etc. Consequently the requirement of water has also been constantly increasing.  River Kuakhai is a major distributary of river Mahanadi and the main source of water for Bhubaneswar city and its adjoining areas. 

 

 

Figure – 1: Seasonal variation of pH value

 

Figure – 2: Seasonal Variation of Turbidity (NTU) value.

 

Figure – 3: Seasonal variation of Total Dissolved Solids (TDS) value.

 

Figure – 4: Seasonal variation of conductivity ((µΩ/cm)) value.

 

Figure – 5: Seasonal variation of Total Hardness (mg/l) value.

 

But due to various human activities and unplanned disposal of domestic and hazardous waste material the water of River Kuakhai is getting polluted which is found below the normal level of drinking water quality.  With the increase of population, the per head availability of water is also decreasing while at the same time the available water is also getting polluted day by day.  In order to meet this challenge, most of the people depend upon ground water as an alternative source and roughly about 40% of the population depends upon ground water.  But the ground water is also getting polluted due to rapid urbanisation and various human activities. (Das, Sahoo, Sinha, 2001, Indian Journal of Environmental Protection).   In view of such grim scenario it is imperative to analyse the quality of ground water in order to know the level of pollution so that appropriate measures could be taken to overcome the pollution problem and to make the ground water pollution free. (Johnson, E.E. 1996).

 

Figure – 6: Seasonal variation of Iron (mg/l) value.

 

Figure – 7: Seasonal variations of Fluride (F) value with Average and Range.

 

Table -01: Location points of Ground Water in Bhubaneswar Municipal Corporation

Sl. No.	Location of Sampling Points	Code No.
1	Bargarh Brit Colony	L – 1
2	Samantarapur	L – 2
3	Laxmisagar	L – 3
4	Rasulgarh	L – 4
5	Chandrasekharpur	L – 5
6	Nayapalli	L – 6
7	Unit-6	L – 7
8	Unit-3	L – 8
9	Khandagiri	L - 9

Location of Sampling Points:

In order to evaluate the water quality and physiochemical characteristics of ground water 09 different sampling locations were chosen. These locations have been chosen keeping in view the wide coverage of Bhubaneswar Municipal Corporation. The details of the locations of the sampling points are described in Table -01.

 

MATERIAL AND METHOD:

From each location a particular tube well was chosen and grab samples were collected from that particular tube well on January, May and September, 2010.  The samples were collected in plastic and glass bottles as per requirement.  Different physical, chemical and biological parameters such as pH, Turbidity, Conductivity, Total hardness, Total Dissolved Solid, Iron, Fluoride, Total Coliform and Fecal Coliform of these samples were analyzed in the laboratory by following procedure as given in Table -02.  The analysis was done by following Analysis of Water and Waste Water, 19^th Edition, APHA-2005.  All chemicals and reagents used were of analytical reagent grade. (Patel and Sinha 1998 Journal of Envi. Pollution, Trivedy and Goel 1984 Environmental Publications, Karad)

 

Table – 02: Methods of Analysis of different parameters

Sl. No.	Paremeters	Unit	Method of Analysis
1	pH value		pH meter
2	Turbidity	NTU	Nephlo Turbidity Meter
3	Total dissolved solids	mg/l	Gravimetric Methods
4	Conductivity	µΩ/cm	Conductivity meter
5	Total Hardness	mg/l	Titrometric method by using EDTA
6	Iron	mg/l	1, 10 Phenanthroline Colorimetric method
7	Fluoride	mg/l	Ion selective electrode method
8	Total coliform	MPN/100 ml	MPN method
9	Fecal coloform	MPN/100 ml	MPN method

 

 

Table – 03 :Test Characteristics for Drinking Water (IS  10500 : 1991)

Sl. No.	Substance or Characteristic	Unit	Requirement/ (Desirable Limit)	Permissble Limit (In the absence of alternate source)
1	pH value		6.5 to 8.5	No relaxation
2	Turbidity, NTU	NTU	5	10
3	Total Dissolved Solid, mg/l	mg/l	500	2000
4	Conductivity	µΩ/cm	400 at 20°C	2500 at 20°C
5	Total Hardness, mg/l	mg/l	300	600
6	Iron, mg/l	mg/l	0.3	1.0
7	Fluoride, mg/l	mg/l	1.0	1.5
8	TC, MPN/100 ml	MPN/100 ml	<2	-
9	FC, MPN/100 ml	MPN/100 ml	<2	-

 

Table – 04: Seasonal variation of PH value with Average and Range

Sl. No.	Locations	pH
		Winter	Summer	Monsoon	Average	Range
1	L-1	6.3	6.3	6.6	6.4	6.3 to 6.6
2	L-2	6.5	6.5	6.8	6.6	6.5 to 6.8
3	L-3	6.3	6.3	6.5	6.37	6.3 to 6.5
4	L-4	6.2	6.2	6.4	6.27	6.2 to 6.4
5	L-5	6.4	6.4	6.7	6.5	6.4 to 6.7
6	L-6	6.5	6.5	6.8	6.6	6.5 to 6.8
7	L-7	6.3	6.3	6.4	6.33	6.3 to 6.4
8	L-8	6	6	6.3	6.1	6.0 to 6.3
9	L-9	6.4	6.4	6.8	6.53	6.4 to 6.53

 

Table – 05: Seasonal Variation or Turbidity ( NTU) value with Average and Range.

Sl. No.	Locations	Turb. (NTU)
		Winter	Summer	Monsoon	Average	Range
1	L-1	4	6	3.6	4.53	3.6 to 6.0
2	L-2	23	29	20.4	24.13	23.0 to 29.0
3	L-3	38	52	30.8	40.27	38 to 52.0
4	L-4	32	44	26.4	34.13	32 to 44.0
5	L-5	28	36	24	29.33	24.0 to 36.0
6	L-6	8	11.8	6.1	8.63	6.1 to 11.8
7	L-7	4	5.8	2.4	4.07	4.0 to 5.8
8	L-8	26	30.4	22.2	26.20	22.2 to 30.4
9	L-9	3	4.8	2	3.27	2.0 to 4.8

 

RESULT AND DISCUSSION:

The results of different parameters are compared individually by taking 3 seasons data and the results are reflected in Table – 4 to 12 and in Figures 1 to 7.  The mean value, standard deviation and correlation coefficient are shown in Tables 14 and 15 respectively.  The desirable limit and permissible limit of different parameters are given in Table -03.

 

1.       pH:

The maximum pH was observed at L2 and L-6, i.e. 6.6 and the minimum was observed at L-8, i.e. 6.1. It was found that in all the locations, the pH range is within the permissible limit i.e. 6.5 to 8.5.  (Table-04, Fig-01).

 

 

Table – 06: Seasonal variation of Total Dissolved Solids ( TDS ) value with Average and Range.

Sl. No.	Location	TDS  (mg/I)
		Winter	Summer	Monsoon	Average	Range
1	L-1	112	148	108	122.67	108 to 148
2	L-2	74	98	64	78.67	64 to 98
3	L-3	288	336	232	285.33	232 to 336
4	L-4	106	124	92	107.33	92 to 124
5	L-5	92	109	78	93.00	78 to 109
6	L-6	108	126	94	109.33	94 to 126
7	L-7	278	308	250	278.67	250 to 308
8	L-8	118	130	102	116.67	102 to 130
9	L-9	82	106	68	85.33	68 to 106

 

Table – 07: Seasonal variations of Conductivity (µΩ/cm) value with Average and Range.

Sl. No.	Location	Cond. (µΩ/cm)
		Winter	Summer	Monsoon	Average	Range
1	L-1	194	240	162	198.67	162 to 240
2	L-2	158	144	97	133.00	97 to 158
3	L-3	476	509	346	443.67	346 to 509
4	L-4	184	185	335	234.67	184 to 335
5	L-5	152	160	114	142.00	114 to 160
6	L-6	168	188	140	165.33	140 to 188
7	L-7	438	459	373	423.33	373 to 459
8	L-8	210	191	154	185.00	154 to 210
9	L-9	160	155	101	138.67	101 to 160

 

Table – 08: Seasonal variation of Total Hardness 9mg/l) value with Average and Range.

Sl. No.	Location	TH (mg/I)
		Winter	Summer	Monsoon	Average	Range
1	L-1	52	64	44	53.33	44 to 64
2	L-2	44	52	38	44.67	38 to 52
3	L-3	136	158	120	138.00	120 to 158
4	L-4	48	56	36	46.67	36 to 56
5	L-5	38	44	32.4	38.13	32.4 to 44
6	L-6	48	56	40.6	48.20	40.6 to 56
7	L-7	108	116	98.4	107.47	98.4 to 116
8	L-8	42	50	32.6	41.53	32.6 to 50
9	L-9	32	42	28.4	34.13	28.4 to 42

 

Table – 09: Seasonal variation or Iron (mg/l) value with Average and Range.

Sl. No.	Location	Iron  (mg/I)
		Winter	Summer	Monsoon	Average	Range
1	L-1	0.48	0.52	0.4	0.47	0.4 to 0.52
2	L-2	2.4	2.6	1.9	2.30	1.9 to 2.6
3	L-3	5.8	6.2	4	5.33	4 to 6.2
4	L-4	4.6	4.8	3.8	4.40	3.8 to 4.8
5	L-5	5.5	5.9	4.8	5.40	4.8 to 5.9
6	L-6	1.4	2	0.96	1.45	1.4 to 2
7	L-7	3.6	4.2	3	3.60	3 to 4.2
8	L-8	6.8	7.4	4.4	6.20	4.4 to 7.4
9	L-9	0.2	0.4	0.12	0.24	0.2 to 0.4

 

Table -10: Seasonal variations of Fluoride ( F¯) value with Average and Range.

Sl. No.	Location of the sampling points	F¯ (mg/I)
		Winter	Summer	Monsoon	Average	Range
1	L-1	0.028	0.036	0.02	0.03	0.02 to 0.036
2	L-2	0.034	0.04	0.026	0.03	0.026 to 0.04
3	L-3	0.072	0.078	0.058	0.07	0.058 to 0.078
4	L-4	0.058	0.066	0.04	0.05	.04 to 0.066
5	L-5	0.062	0.069	0.05	0.06	0.05 to 0.069
6	L-6	0.084	0.096	0.072	0.08	0.072 to 0.096
7	L-7	0.096	0.14	0.078	0.10	0.078 to 0.14
8	L-8	0.072	0.088	0.06	0.07	0.06 to 0.088
9	L-9	0.164	0.18	0.132	0.16	0.132 to 0.164

 

2.       Turbidity:

Maximum turbidity was observed at L-3 i.e. 40.2 and the minimum was observed at L-9 i.e. 3.2.  It was found that the ground water at L-1, L-7 and L-9 is clear, that is the turbidity values are below the prescribed values (the desirable turbidity value is 5 NTU in drinking water) but in the rest of the locations, the ground water is highly turbid.  This may be attributed to the presence of high amount of Iron. (Table 05, Fig-02).

 

3.       Total Dissolved Solids (TDS)

Maximum amount of total dissolved solids were found in the ground water of L-3, i.e. 285.3 and the minimum was found at L-2 i.e. 78.6.  It reveals that the total dissolved solids in the ground water of all the locations meet the water quality standards i.e. 500 mg/L (Table-06, Fig-03)

 

4.       Conductivity:

Maximum conductivity was found in the ground water at L-3 i.e.443.6 and the minimum was found at L-9 i.e. 138.6.  The conductivity value of ground water at L-3 and L-7 are slightly more than the permissible limit i.e. 400 µΩ/cm.  This may be due to the presence of high chloride content.  In the rest of the locations the conductivity value are within the permissible limit.  (Table – 07, Fig. – 04).

 

5.       Total Hardness (TH):

Maximum total hardness was found in the locations at L-3 i.e. 138.0 and the minimum was found in the location at L-9 34.1.  It is significant to note that in all the locations the total hardness are below the permissible limit, that is 300 mg/l.  (Table – 08, Fig. – 05)

 

6.       Iron:

Maximum amount of iron was found in the ground water at L-8 i.e.6.20 and the minimum was found at L-9 i.e. 0.24.  It was observed that except at L-9, in all the locations the iron content does not meet the prescribed standards i.e. 0.3 mg/l.  The high iron content in ground water of BMC is due to lateritic soil.  (Table – 09, Fig.-06)

 

7.       Fluoride (F):

Maximum amount of fluoride was found in the ground water at L-9 i.e. 0.16 and the minimum was found at L-1 and L-2 i.e.0.3.  It was observed that in all the locations the ground water quality meets the prescribed standard of fluoride content i.e. 1.0 mg/l .  (Table – 10, Fig. – 07)

 

8.       Total Coliform (TC):

Total coliform indicates the presence of bacteria, some of them are useful and some other are harmful.  It was observed that the value of total coliform in all the locations is <2 which is within the prescribed standard of water quality i.e. <2MPN/100 ml.  (Table – 11).

 

9.       Fecal Coliform (FC) :

Fecal coliform generally indicates the presence of pathogenic bacteria which is harmful to human being.  It was observed that the value of fecal coliform in all the locations is <2 which is within the prescribed standard of water quality i.e. <2 MPN/100 ml.  (Table – 12).

 

Mean and Standard Deviation:

A close analysis throughout the year 2010 reveals that maximum deviation from the mean value was found in conductivity (122.8).  Slight deviation was found in turbidity, total dissolved solids and total hardness (14.5, 80.31, 35.6 respectively).  Very slight deviation was found in pH, iron and fluoride value.  {Mohanty, S.K., J.T.R. Chemical, 5(1)}

 

Table – 11: Seasonal variations of Total Coliform ( TC) with Average and Range.

Sl. No.	Location of the sampling points	TC (MPN/100ml)
		Winter	Summer	Monsoon
1	L-1	<2	<2	<2
2	L-2	<2	<2	<2
3	L-3	<2	<2	<2
4	L-4	<2	<2	<2
5	L-5	<2	<2	<2
6	L-6	<2	<2	<2
7	L-7	<2	<2	<2
8	L-8	<2	<2	<2
9	L-9	<2	<2	<2

 

Table – 12: Seasonal variation of Fecal Coliform ( FC) with Average and Range.

Sl. No.	Location of the sampling points	FC (MPN/100ml)
		Winter	Summer	Monsoon
1	L-1	<2
2	L-2	<2
3	L-3	<2
4	L-4	<2
5	L-5	<2
6	L-6	<2
7	L-7	<2
8	L-8	<2
9	L-9	<2

 

Table – 13: Arithmatic Mean and Standard Deviation.

Sl No	Parameter	Mean	Standard Deviation
1	pH	6.4	0.2
2	Turbidity	19.4	14.58
3	TDS	141.89	80.31
4	Conductivity	229.37	122.854
5	TH	61.34	35.64
6	Iron	3.26	2.24
7	F	0.07	0.04

 

 

Table – 14: Correlation Cofficient value among the parameters.

	PH	Turb	TDS	Cond	TH	Iron	F
ph	1	-0.345	-0.335	-0.373	0.256	-0.586**	-0.09
turb	-0.345	1	0.167	0.196	0.274	0.777**	-323
tds	-0.335	0.167	1	0.948**	0.971	0.357	0.183
cond	-0.373	0.196	0.948**	1	0.917	0.366	0.118
th	-0.256	0.274	0.971**	0.919**	1	0.334	0.083
iron	-0.586**	0.777**	0.357	0.366	0.384	1	-0.138
f	-0.096	-0.323	0.183	0.118	0.83	-0.138	1

 

 

Bhubaneswar City Map

 

Correlation coefficient:

After making a thorough analysis of all the parameters, correlation coefficient was found out and it was revealed that many parameters are correlated with each other.  It was observed that 6 no. of parameters are considered to be correlated by taking correlations coefficient more than 0.5 to 1.0.  The details are given below:  (Mohanty, S.K. Ph.D. Thesis, WHO, 1971 and WHO, 1993)

 

1.        pH is correlated with Iron (With correlation coefficient value – 0.586)

2.        Turbidity is correlated with Iron (With correlation coefficient value 0.777).

3.        TDS is correlated with conductivity and Total hardness (with correlation coefficient value 0.948 and 0.971 respectively).

4.        Conductivity is correlated with TDS and Total hardness (with correlation coefficient value 0.948 and 0.919 respectively).

5.        Hardness is correlated with TDS and conductivity (with correlation coefficient value 0.971 and 0.919 respectively)

6.        Is correlated with Turbidity (with correlation coefficient value 0.777).

CONCLUSION:

From the above study it is observed that the ground water quality at Khandagiri area out of 9 selected location is meeting all the standard for drinking water quality.  It is also further observed that the bore well at Unit-6 near Capital Hospital is also meeting the drinking water quality standards except for iron.  The correlation study also indicates that 3 to 4 parameters are highly correlated which can help to find out one parameter theoretically by calculating the other parameters.

 

Therefore, the authors are of the opinion that the ground water of Khandagiri area may be used directly for drinking water purpose while the ground water of other 8 locations require treatment for which necessary measures need to be taken immediately to maintain the prescribed standard for drinking water quality.

 

REFERENCE:

1.        APHA – 2005, Standard Methods for Examination of Water and Waste Water. American Public Health Association, Washington D.C., 1^9th Edition.

2.        Das Joytirmaya, Ramakant Sahoo and B.K. Sinha, 2001. Urban Ground Water Pollution: A Case Study in Cuttack city. Indian Journal of Environmental Protection: 22(3): 95.103.

3.        Johnson, E.E. 1996:  Ground Water and Wells.  Inc. Saint Paree, Minnesota.

4.        Mohanty, S.K.: Water Pollution from major industries in Koraput district.  J.T.R. Chem, 5(1) : 32.40

5.        Mohanty, S.K.:  Strategy to control environment pollution in Koraput area, Ph.D. Thesis, Utkal University, Bhubaneswar.

6.        Patel, Niroj K and B.K. Sinha, 1998:  Study of the pollution load in the ponds of Burla area near Hirakud Dam of Odisha.  J. Envi. Pollution, 5(2) : 32.40

7.        Trivedy, R.K. And Goel, P.K., 1984:  Chemical and Biological Methods for Water Pollution Studies Environmental Publications, Karad (1 – 112).

8.        WHO, 1971.  International Standard for drinking water (3^rd Edn.), World Health Organization, Geneva;

9.        WHO, 1993, Guidelines for drinking water quality: World Health Organisation, Geneva.

 

 

Received on 12.11.2012         Modified on 06.12.2012

Accepted on 20.12.2012         © AJRC All right reserved