Integrated hydrochemical and geophysical studies for ...

Integrated hydrochemical and geophysical studies for assessment of groundwater pollution in basaltic settings in Central India Paras R. Pujari, C. Padmakar, L. SuriNaidu, V. U. Vaijnath, Bhusan Kachawe, V. V. S. Gurunadha Rao & P. K. Labhasetwar Environmental Monitoring and Assessment An International Journal Devoted to Progress in the Use of Monitoring Data in Assessing Environmental Risks to Man and the Environment ISSN 0167-6369 Environ Monit Assess DOI 10.1007/ s10661-011-2160-1

1 23

Your article is protected by copyright and all rights are held exclusively by Springer Science+Business Media B.V.. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your work, please use the accepted author’s version for posting to your own website or your institution’s repository. You may further deposit the accepted author’s version on a funder’s repository at a funder’s request, provided it is not made publicly available until 12 months after publication.

1 23

Author's personal copy Environ Monit Assess DOI 10.1007/s10661-011-2160-1

Integrated hydrochemical and geophysical studies for assessment of groundwater pollution in basaltic settings in Central India Paras R. Pujari · C. Padmakar · L. SuriNaidu · V. U. Vaijnath · Bhusan Kachawe · V. V. S. Gurunadha Rao · P. K. Labhasetwar

Received: 5 March 2010 / Accepted: 25 May 2011 © Springer Science+Business Media B.V. 2011

Abstract The Pithampur Industrial sectors I, II, and III, located approximately, 45 km from Indore in Central India have emerged as one of the largest industrial clusters in the region. Various types of industries ranging from automobiles to chemicals and pharmaceuticals have been set up in the region since 1990. Most of the industries have effluent treatment plants (ETP) for treating wastewater before its disposal on land and/or in water body. The present study is an attempt to assess the groundwater quality in the watersheds surrounding these industrial sectors to develop the baseline groundwater quality in order to enable the policy makers to facilitate decisions on the development of industries in this region. The industries are located in two sub-watersheds, namely, Gambhir river sub-watershed and

L. SuriNaidu · V. V. S. Gurunadha Rao National Geophysical Research Institute (CSIR), Uppal Road, Hyderabad 500007, India

Chambal river sub-watershed. Geologically, the study area is located in the Deccan traps of Cretaceous to Paleocene age. The different basaltic flow units underlie clayey soils varying in thickness from 2–3 m. The aquifer is mostly of unconfined nature. Samples have been collected from a network of observation wells set up in the watersheds. The water quality analysis of the groundwater samples has been carried out six times during three hydrological cycles of 2004, 2005, and 2006. The results indicate that a few observation wells in the vicinity of the industrial clusters have very high TDS concentration and exceed the Bureau of Indian Standards (BIS) guideline for TDS concentration. The contamination of groundwater has been more severe in the Gambhir watershed as compared to the Chambal watershed. The presence of the impermeable clay layers has resulted in a slow migration of contaminants from the sources. The findings reveal that there is no significant groundwater contamination in the Pithampur industrial sectors except in the vicinity of the industrial clusters, which indicates that there is good environmental space available for the expansion of industrial units in the Pithampur industrial hub.

Present Address: B. Kachawe Arts, Science & Commerce College, Chikaldhara 444708, India

Keywords Gambhir sub-watershed · Chambal sub-watershed · Groundwater contamination · Basaltic terrain · Pithampur industrial hub

P. R. Pujari (B) · C. Padmakar · V. U. Vaijnath · B. Kachawe · P. K. Labhasetwar National Environmental Engineering Research Institute (CSIR), Nehru Marg, Nagpur 440020, India e-mail: [email protected]

Author's personal copy Environ Monit Assess

Introduction The policies of the Government of India during the 1970s have led to large-scale development of groundwater through subsidies in the form of lower levies on power consumption. This resulted in increased agricultural production in the Green Revolution. However, the absence of regulatory policies on the extraction of groundwater or any mechanism for pricing of groundwater utilization for commercial purpose led to exploitation of the aquifers beyond their optimum yielding capacity. The over exploitation of groundwater especially in the hard rock areas have resulted in a decline in the groundwater level by 15–20 m. The Green Revolution was followed by Industrial revolution to attain self-

Fig. 1 Location of study area

sufficiency. This led to the setting up of a large number of wastewater generating industries especially in the vicinity of big cities. However, the waste disposal practices were not well defined. As a result, vast stretches of land have become dumping ground for solid as well as liquid effluents generated from these industries. It is evident from the literature that infiltration of effluents has led to the contamination of aquifers in different parts of India (Raman 1995; Shivkumar and Biksham 1995; Shivkumar et al. 1997; Pawar et al. 1998 Subba Rao et al. 1998; Gurunadha Rao et al. 2001; Singh 2001; Sharma et al. 2003; Pujari and Deshpande 2005; Mondal et al. 2005; Singh et al. 2006; Pujari et al. 2007; Naik et al. 2007). In view of the groundwater quality and quantity being subjected to increasing stress, a holistic


approach integrating hydrogeology, hydrochemistry, and geophysical tools needs to be adopted to study the different processes responsible for the contamination of the groundwater resources and to evolve sustainable management practices to protect the aquifers. The opening of the Indian economy has been a gradual process in the last 20 years and as a result, different states have been opening special industrial clusters to attract the industries. These industries are mostly privately owned and are set up with the licensing provided by the respective government agencies responsible for boosting industrial growth of the states. The Pithampur industrial clusters are located approximately 45 km from Indore, in the state of Madhya Pradesh, India (Fig. 1). The industries in the Pithampur area have been spread over three sectors, viz., Sectors I, II, and III since 1990. Besides, a Special Economic Zone (SEZ) is coming up close to the Sector III. The study area is the largest industrial cluster in the state of Madhya Pradesh. In view of the presence of large number of wastewater generating industries, the aquifer is vulnerable to groundwater contamination. However, no detailed studies have been carried out so far. Hence,

the present study adopts a holistic approach for assessing the extent of groundwater pollution by integrating the tools of hydrogeology, geophysics, and water quality studies. The objective is to assess the present status of groundwater pollution in the different sectors and to suggest the remedial measures for the design of environmental protection measures in future. Accordingly, primary data on the groundwater level and groundwater quality have been collected for three hydrological cycles, i.e., 2004, 2005 and 2006. The results for 2004 only have been reported here as those for 2005 and 2006 are very similar in nature.

Study area The study area comprises the three sectors, namely Sectors I, II, and III as well as the SEZ in the basaltic terrain. The area has been divided into two sub-watersheds viz., the Chambal river subwatershed and the Gambhir river sub-watershed (Figs. 2 and 3). The Chambal sub-watershed hosts the Sectors II, III, and the SEZ units covering an area of 210 sq. km, whereas the Gambhir sub-watershed hosts Sector I covering an area of

Fig. 2 Observation wells in the Chambal sub-watershed, Pithampur Area


like wheat, soyabean, and sugar cane. Some cash crops like cauliflower are also grown in winter. Physiography and geology

Fig. 3 Observation wells in the Gambhir sub-watershed, Pithampur Area

90 sq. km. A wide range of industries like automobiles, chemicals, pharmaceuticals, and textiles has been established in the different sectors. Sector I has mostly automobile and chemical industries whereas chemical and pharmaceutical industries dominate Sector II. Sector III has all types of industries. A treatment, storage and disposal facility (TSDF) has been commissioned in Sector I by the Madhya Pradesh Pollution Control Board (MPPCB) for the disposal of hazardous waste generated in the Pithampur area. The Gambhir sub-watershed hosts more number of industries than the Chambal sub-watershed does. Also the industrial units of the former have been functioning since 1990 while those in the latter are only less than 5 years old. Mostly, the region grows crops

Table 1 Geological succession of Pithampur area in Chambal and Gambhir river sub-watersheds

Physiographically, the area exhibits low level plateaus of extrusive origin with young flood plains along the course of both the rivers. The other landforms are middle level plateaus with escarpment, the plains of extrusive origin and denudational slopes. The drainage pattern is subparallel to dendritic in nature. The area has predominantly two geological formations, i.e., the Vindhyan Super Group and the Deccan Traps. The Deccan trap basaltic rocks of the Malwa group of Cretaceous to Paleocene age (68–62 million years) cover the entire area under investigation. In total, eleven predominant flows have been reported in the area (GSI 2002). Some of the flows show lateral variation in physical character and there is a transition from the ‘Aa’ type in the west to the ‘Pahoehoe’ type in the east. The basaltic flows represent a sequence of cyclic eruptions with each cycle comprising very fine-grained, non-porphyritic to moderately porphyritic layers ended by mega porphyritic layers at the top. Each flow consists of a lower massive unit and an upper vesicular unit. Consecutive lava flows are separated by intertrappean redboles which vary in thickness from 0.5–1 m. Thin quaternary alluvium consisting of clay, silt, fine to coarse sand and gravel is restricted to narrow patches along the course of the rivers. The general succession of geological formation is shown in Table 1. Hydrogeology Groundwater occurs in phreatic condition and is mostly of unconfined nature. Groundwater occurs in the weathered, vesicular, jointed, and fractured

Period

Formation

Lithological unit

Recent to Quaternary Upper Cretaceous to Paleocene

Alluvium Deccan Trap Unconformity Vindhyan (Upper Bhander)

Clay, sand and kankar Basalt

Upper Proterozoic

Shale and sandstone


basalt under unconfined conditions. These formations have highly variable yield 10–750 m3 /day. The depth to the groundwater table varies from 4–30 m (bgl) in the pre-monsoon to 1–20 m (bgl) in the post-monsoon season. Due to the shallow groundwater table conditions, hand-pumps and open wells are predominantly used for domestic water consumption. In general, the study area is an undulating terrain of basaltic flows and is drained mainly by the northwest and southwest flowing tributaries of the Chambal river (Fig. 2) and northeast flowing tributaries of the Gambhir river (Fig. 3). The occurrence of groundwater in the region is also controlled by rainfall, topography, vegetation, drainage, etc. Groundwater is generally used for drinking and agricultural purposes, and is also heavily exploited for industrial uses. The hydraulic conductivity varies from 5– 15 m/day and the specific yield is 5–10% (source: www.cgwb.gov.in/ncr).

Fig. 4 Groundwater level (amsl) in Chambal subwatershed, June 2004

measured by surveyors. The reduced level of the observation wells has been subsequently used to obtain the groundwater level (above mean sea level). Groundwater flow directions have been inferred from the groundwater level (above mean sea level) contours prepared for the respective sub-watersheds.

Climate Hydrochemical investigations The climate of the study area is mostly dry except during the southwest monsoon season (June to September). The area receives an average annual rainfall of about 850 mm. Temperature on an average varies from 35◦ C to 40◦ C with the maximum temperature reaching 45◦ C in summer. In winter, the minimum temperature drops to 3◦ C.

Methodology The study area has been demarcated into two sub-watersheds, i.e., the Chambal sub-watershed and the Gambhir sub-watershed. A network of observation wells has been set up in each subwatershed. The observation wells include dug wells, hand-pumps and bore wells. These wells have been used both for groundwater level measurement and groundwater quality monitoring. Field data were collected in pre-monsoon (June) and post-monsoon seasons (October) in 2004, 2005, and 2006. The water level (below ground level) was measured with the help of an electric contact-gauze (KL 010A) with a buzzer. The reduced level of the observation wells has been

Parameters namely, pH and temperature were measured in the field. Groundwater samples were filtered by Whatman filter paper (No. 4) prior to their analysis in the laboratory. Total dissolved solids (TDS) and concentrations of Ca, Mg, Na, K, Cl, NO3 , SO4 , CO3 , F, As, Cu, Mn, Zn, Fe, Cr, and Cd were determined for each of the samples following standard protocols (APHA 1998). The heavy metals (As, Cu, Mn, Zn, Fe, Cr, and Cd)

Fig. 5 Groundwater level (m-amsl) in Chambal subwatershed, October 2004

Author's personal copy Environ Monit Assess Table 2 Groundwater quality range (physico-chemical parameters) in Chambal sub-watershed, 2004 Parameter Unit BIS limits

Min Max June October June

Average Q25 October June October June

Q50 October June

Q75 October June

October

pH TDS Ca Mg Na Cl SO4 NO3 K F

6.8 402 8.64 4.47 35 70 4.63 1.11 1.1 0.68

7.99 1908 160 97 400 1000 106 203 75 2

0 508.25 38.25 11.25 104 152 23 40 6.25 0.4

0 622.5 48 20 161.5 200 36.5 58.5 14.5 0.55

0 798.25 59 31 218.25 250 63 79.5 30 0.775

mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l

6.5–8.5 500 75 30 No limit 250 200 45 No limit 1.5

6.97 286 21 3 11 28 12 6 1 0.2

7.9 2071 492.96 138.12 360 1148.54 265 92.88 31.1 2.8

Fig. 6 TDS level in Chambal sub-watershed, June 2004

P39

22.66

7.26 7.35 738.64 712.48 76.83 55.76 32.54 23.76 147.43 162.76 218.32 232.86 55.03 45.86 22.22 66.97 6.58 19.00 1.46 0.66

0 842 86.24 36.34 210 240 64.9 20.83 6.4 1.7

2000

P49

1750

Sanghvi

22.64

P41

Latitude

0 638 52.8 21 119.6 170 44.73 12.62 2.3 1.4

Hand-pump Dug well

P40

Ghatabilod

Umriya Bakshana

22.62

0 496 33.96 11.27 94 100 29.69 7.9 1.8 0.95

Bardari

P67

P50

P42

P65

P60 P47

22.6

Achana

75.54

P68

1250

P64

P66 P26

P69

1000

P3

P4 P70

Ch am ba l ri ve r 75.52

P52 P53 P46

P45

P44

22.58

1500

Bagdum

P48

750 Bhandiya

Chandankheri

500

75.56

75.58

75.6

75.62

75.64

75.66

75.68

75.7

Longitude

250

Fig. 7 TDS level in Chambal sub-watershed, October 2004

Conc (mg/l)

22.66

P39

Hand-pump

Ghatabilod

Dug well

P49

P40 22.64

Latitude

1500

Bagoda

P41 Bakshana 22.62

Bagdun

P48

P42

P50

Sulawar 22.6

Achana

P45

P44

Ch a m

75.52

P60

P67

P47

bal r

P26

P53 P69 P46

P65 P64

900

P4 P3

Madhopur P70

600 Bhondiya

iver

75.54

1200

Bardari

P66

P52 Sagor P68

Bicholi

22.58

1800

300 75.56

75.58

75.6

75.62

Longitude

75.64

75.66

75.68

75.7 0

Author's personal copy Environ Monit Assess Table 3 Groundwater quality range (heavy metals) in Chambal sub-watershed, 2004 Parameter Zn Pb Cd Mn Fe Cr Al As Cu

Unit mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l mg/l

BIS limits

Min June

October

Max June

October

Average June October

Q25 June

October

Q50 June

October

Q75 June

October

5.0 0.05 0.01 0.10 0.3 0.05 0.03 0.05 0.05

0 0 0 0 0 0 0 0 0

0 ND ND 0 0 0 0 ND ND

7.5 0.05 0.01 2 15.71 0.04 1.4 0.2 0

0.6 ND ND 0.22 9.85 0.02 10.52 0.02 0.93

0.67 0.00 0.00 0.13 1.80 0.00 0.38 0.01 0.00

0 0 0 0 0.13 0 0.1 0 0

0.0.2 0.0 0.0 0.007 0.0 0.0 0.025 0.0 0.0

0.05 0 0 0 0.4 0 0.36 0 0

0.0570 0.0 0.0 0.02 0.091 0.0 0.162 0.0 0.0

0.2 0 0 0.08 1.2 0 0.5 0 0

0.1095 0.0 0.0 0.074 0.4435 0.0 0.2715 0.0095 0.0

were analyzed by ICP-AES (model JY24, make: Jobin Yvon). The detection limits for Fe, Mn, Zn, Pb, Cd, Cr, and Cu are 0.0062, 0.0014, 0.005, 0.05, 0.002, 0.02, and 0.005 ppm, respectively. Na, K, and Ca were analyzed by a flame photometer (Model-CL361). The detection limits for Na, K, and Ca are 0.5, 0.5, and 15 ppm respectively. Geophysical investigations Geophysical measurements using resistivity technique have been carried out at selected profiles in the study area. The resistivity measurements include both 1D sounding as well as 2D imaging. The objective of the resistivity measurement was to assess the aquifer conditions and to determine whether there was any signature of the groundwater saturation and quality on the resistivity parameter interpreted from the resistivity soundings.

Results and discussion Hydrochemical investigations Chambal river sub-watershed A network of 32 observation wells has been set up in this basin. Groundwater level contours (amsl)

Table 4 Groundwater classification based on TDS in Chambal sub-watershed (Freeze and Cherry 1979)

0.12 0.0 0.0 0.6 1.20 0.001 0.74 0.005 0.059

have been prepared for June 2004 (pre-monsoon) and October 2004 (post-monsoon). The contours (Figs. 4 and 5) indicate that the groundwater flow direction is from Sectors II, III, and SEZ towards the Chambal river. On average, the water table rises by 15 m due to the monsoon. The TDS shows a maximum of 2,071 mg/L in the pre-monsoon whereas it goes down to 1,908 mg/L in the postmonsoon (Table 2) and it is evident that 75% of the samples have TDS below 1,000 mg/L. It is noticed that the high TDS values (>1,500 mg/L) prevail in the vicinity of the iron and textile industries (Figs. 6 and 7). It is observed that 75% of the samples have Cl and NO3 concentration within the permissible BIS limits of 250 and 45 mg/L, respectively (Table 2). In addition, maximum fluoride concentration of 2.4 mg/L has been found in the pre-monsoon which goes down to 2.0 mg/L in the post-monsoon (Table 2). Among the trace elements, Fe is the problem parameter with a maximum value of 15.2 mg/L in the pre-monsoon and 9.85 mg/L post-monsoon (Table 3). However, 50% of the samples have Fe concentration exceeding 0.4 mg/L whereas the permissible limit (BIS 1991) for drinking purpose is 0.3 mg/L. Based on the TDS values, the groundwater is of the fresh type in about 80% of the samples collected during the pre- and the post-monsoon period, about 20% samples being brackish (Table 4).

Type of water

TDS range (mg/L)

% in pre-monsoon

% in post-monsoon

Fresh water Brackish water Saline water Brine water

0–1,000 1,000–10,000 10,000–1,00,000 >1,00,000

82.35 17.65 Nil Nil

80.00 20.00 Nil Nil


Gambhir river sub-watershed A network of 23 observation wells has been set up in this watershed. The sources are mostly handpumps and dug wells scattered in the vicinity of the industries. The water levels (amsl) for the preand post-monsoon seasons (Figs. 8 and 9) indicate that the groundwater flow direction is towards the north-east and that it flows from the industrial cluster towards the Gambhir river. The water level contours (Fig. 9) indicate that the water table rises by approximately 10 m in the post-monsoon season (October, 2004). The analysis shows that the maximum TDS level varied from 3500 mg/L in pre-monsoon (June, 2004) to 2100 mg/L in postmonsoon (October, 2004). It is evident from the contours (Figs. 10 and 11) that the TDS shows a high in the southwest and northeast corners of the study area where most of the chemical industries are situated. The results indicate that the pre-monsoon TDS concentration (Fig. 10) is always more than the post-monsoon concentration (Fig. 11). In both the pre- and the

Fig. 9 Groundwater level (amsl) in Gambhir subwatershed, October 2004

22.69 Hand-pumps

P31

Dug well

G am

22.68

Conc (mg/l)

bh ir riv er

22.67 P13

3500

P17

22.66

3000

P19 22.65

Latitude

Gaula

2500

P11

P10 Chiragkhan

22.64

Bagoda P12

P8 Silotiya

Tarpura

22.63

P57 P1

P18 22.62

P7 P26

22.61

P6

1500 P21 P22

P2

1000 P20

P28

P23

P27 P25

22.6

2000

500 Tihi

P24

0

Bhatkheri 22.59

22.58 75.68

75.69

75.7

75.71

75.72

75.73

75.74

75.75

Longitude

Fig. 8 Groundwater level (amsl) in Gambhir subwatershed, June 2004

Fig. 10 TDS concentration in Gambhir sub-watershed, June 2004

Author's personal copy Environ Monit Assess 22.69

22.68

P31

Hand-pump Dug well

Conc (mg/l)

G

22.67

bh am

P13 22.66

r ir

P17

2100

e iv r

P19

Goula

22.65

Latitude

P11 22.64

2000

P10

Bagoda

P8

P12 22.63 P58 22.62

P21

P1

P7 P6

22.61

1500

P57 Sulotiya

1000

P22

P2

P29 P28 P25

22.6

Karondiya

P20

P23

500

Tihi P24

22.59

200

Bhatkheri

concentration reach a maximum of 3,578 mg/L and 405 mg/L, respectively, that are much above the desirable BIS limits. The pH values (Table 5) indicate that the groundwater is slightly alkaline. High iron concentration (21.3 mg/L) is reported in the area (Table 6). The high concentration of iron is also noticed in the vicinity of the iron based industries. Arsenic and cadmium have not been detected in any of the samples in the Gambhir sub-watershed (Table 6). Based on the TDS (Table 7), the majority of the samples are of fresh type (0–1,000 mg/L), whereas it is brackish type in 27% of the samples. There is only one sample with TDS exceeding 3,500 mg/L. It is also evident that the percentage of fresh water samples increases in the post-monsoon season.

22.58 75.68

75.69

75.7

75.71

75.72

75.73

75.74

Geophysical investigations

75.75

Longitude

Fig. 11 TDS concentration in Gambhir sub-watershed, October 2004

post-monsoon seasons, the position of the high TDS concentration roughly coincides with the location of the industries in Sector-I. The maximum concentration is noticed at sources P1 and P3 that are located behind the chemical industries in Sector I. The results indicate that a few samples exceed the permissible limit of 2000 mg/L set for TDS by the Bureau of Indian Standards (1991). The water quality ranges presented in Tables 5 and 6 also indicate that TDS and Cl

1D resistivity sounding Geophysical surveys form a relatively quick, inexpensive and a non-destructive way to gain subsurface information of the Earth. Among the different geophysical techniques, the direct current (DC) resistivity method has emerged as a useful tool in environmental, hydrogeological, and engineering applications (Vandam and Meulankamp 1967; Zohdy 1969; Urish 1983; Griffth and Turnbull 1985; Griffth et al. 1990; Urish and Frohlich 1990; Frohlich et al. 1994; Loke and Barker 1996; Ebraheem et al. 1997; Nowroozi et al. 1999; Bernstone and Dahlin 1999; Meju 2000; Dahlin et al. 2002; Wilson et al. 2006).

Table 5 Water quality range (physico-chemical parameters) in Gambhir sub-watershed, 2004 Parameter Unit BIS limits

Min Max June October June

Average October June

Q25 Q50 Q75 October June October June October June October

pH TDS Ca Mg Na Cl SO4 NO3 K F

6.8 364 13.28 0.1 54 90 6.54 0.6 0.7 0.65

7.9 2226 187 99 663 740 330 342 54 2

7.46224 794.25 85.20834 27.29167 140.375 204.5 69.54166 73.29166 11 0.7375


6.5–8.5 500 75 30 No limit 250 200 45 No limit 1.5

7.06 315 47 2 19 20 12 2 1 0.4

7.9 3578 716.64 288.08 375 2100 162 156.59 40.5 3

7.22379 1032.607 132.4086 80.01357 121.875 405.9929 48.14 36.14178 5.79286 1.45107

0 481 31.45 19.65 80.1 120 16.2 6.75 1.3 1.1

0 432 61 13 58 80 24 18 2 0.5

0 616 45 45 100 160 35.72 16.27 2.1 1.3

0 642 77 19 75 154 39 64 7 0.6

0 952 102 33 178 240 65 96 10 0.8

Author's personal copy Environ Monit Assess Table 6 Water quality range (heavy metal parameters) in Gambhir sub-watershed, 2004 Parameter Unit BIS Min Max limits June October June

Average Q25 Q50 Q75 October June October June October June October June October

Zn Pb Cd Mn Fe Cr Al As Cu

1.54 0.09 0.0 0.57 1.75 0.01 2.88 0.02 0.0


5.0 0.05 0.01 0.10 0.3 0.05 0.03 0.05 0.05

Table 7 Groundwater classification based on TDS in Gambhir sub-watershed (Freeze and Cherry 1979)

Fig. 12 Resistivity sounding locations in Chambal sub-watershed

0 0 0 0 0 0 0 0 0

0.0 0.0 0.0 0.01 0.0 0.0 0.0 0.0 0.0

27.3 0.5 0 0.8 21.3 0.01 2.4 0 0.147

1.127 0.017 0 0.10893 1.8575 0.00043 0.57643 0 0.00525

0.32 0.01 0.0 0.083 0.17 0.0004 0.58 0.006 0.0

0 0 0 0 0.1 0 0.2 0 0

0.085 0.0 0.0 0.09 0.086 0.0 0.264 0.0 0.0

0 0 0 0 0.2 0 0.3 0 0

0.275 0.0 0.0 0.027 0.235 0.0 0.301 0.007 0.0

0.1 0 0 0.1 0.7 0 0.7 0 0

0.39 0.006 0.0 0.04 0.501 0.0 0.469 0.011 0.0

Type of water

TDS range (mg/L)

% in pre-monsoon

% in post-monsoon

Fresh water Brackish water Saline water Brine water

0–1,000 1,000–10,000 10,000–1,00,000 >1,00,000

78.30 21.70 Nil Nil

86.96 13.04 Nil Nil


Fig. 13 a Resistivity depth section on A–A in Chambal sub-watershed. b Resistivity depth section on B–B in Chambal sub-watershed. c Resistivity depth section on

C–C in Chambal sub-watershed. d Resistivity depth section on D–D in Chambal sub-watershed. e Resistivity depth section on E–E in Chambal sub-watershed


The DC resistivity is becoming popular as variation in resistivity of the subsurface is often linked to variation in hydraulic properties, such as presence of fluid, extent of fluid saturation, and its quality. The accuracy of DC resistivity method depends on how best the physical properties are interpreted in terms of hydrogeological parameters. The electrical resistivity method gives fairly reliable results in hydrogeological investigation, wherein the disposition of the aquifer can be suitably delineated. It can also be effectively employed to map contaminated zones (Kelly 1976; Urish 1983; Mazac et al. 1987; Benson et al. 1991, 1997; NGRI report 2007; Pujari and Soni 2009). The aquifer geometry in the study area has been deciphered by carrying out 1D sounding using the conventional four-electrode resistivity meter. The resistivity measurements obtained in sounding have been interpreted by curve matching technique to estimate the layer parameters (resistivity and thickness) and subsequently to reconstruct the depth sections of the profiles. Based on the range of resistivity values, the weathered and fractured zones are deciphered. The contacts between certain saturated and dry formation zones having different resistivity values can be identified from the resistivity section. About 21 soundings have been carried out in the Chambal and Gambhir river sub-watersheds at selected locations in the direction of A–A , B–B , C–C , D–D , and E–E vertical sections (Fig. 12). The resistivity soundings have been carried out using the Schlumberger electrode configuration with a maximum current electrode separation (AB) of 600 m. The interpreted apparent resistivity sections in the Chambal river sub-watershed indicate resistivity in the range 5–180 ohm m for the selected profiles. The interpreted results (resistivity and thickness of layers) are correlated with geological features exposed in the vicinity of the sounding stations. Based on field observations, it is suggested to associate 30–40 ohm m zone with the saturated weathered zone. The depth sections (Fig. 13a–e) indicate that the depth to the saturated zone varies from place to place. The resistivity sections roughly indicate that the weathered and fractured zones constitute the water-saturated zones. These low resistivity zones near P23, P27,

and P37 roughly coincide with the depth to the water table in these sources. Similar findings are noted in respect of the Gambhir sub-watershed (Figs. 14, 15a–e). It is observed that the low resistivity zones in the depth sections are at locations (near P10, P14, P15, P16, and P17) close to the streams which carry the effluent from the industries. A close look at the resistivity section in the Gambhir sub-watershed (Fig. 15b) indicates a very wide zone of low resistivity zone (