MAPPING AND CHARACTERISATION OF GROUND WATER OF RAJASTHAN

MAPPING AND CHARACTERISATION OF GROUND WATER OF RAJASTHAN







MAPPING AND CHARACTERISATION OF GROUND WATER OF RAJASTHAN

Rajasthan is situated in North western part of India between 230 3’ and 300 12’ N latitudes and 690 30’E and 780 17’ E longitudes, the western and northern boundaries touches the boundary of Pakistan while in North and North -East it is bounded by Punjab, Haryana and U.P. The boundary is further shared in East and South -East by M.P. and in the South- West by Gujarat. Being the largest state it covers an area of 34.2 million hectares forming 10.4 per cent of total geographical area of the country.
Physiography;
Physiographically the Aravallis divide the state into western region with desert sandy plain, scattered aeolian dunes and interdunal flats. The eastern part is mostly alluvial and southern part has heavy soils or rocky eroded upland mostly hilly in nature. Nearly 40 per cent of the area located primarily in the Jaisalmer, Barmer, Jodhpur, Bikaner and Churu districts had a variable coverage of dunes being dominated by longitudinal and coalesced parabolic types. The continuity of these is interrupted by hills and sheet rock exposures.Physiographical map of Rajasthan is depicted in Fig-A
Climate:
The climate varies from arid in the western part to humid in the southern part. Rainfall in the state varies from 920 mm in south-east to merely 100 mm in the extreme western districts. The distribution of rainfall is generally erratic, occurring mostly during the period from July to September. Of the total area 57 per cent is arid, 37 per cent semi-arid and 6 per cent is sub humid to humid. There is a wide variation in the temperature ranging from below freezing point in winter to sometime as high as 500 C in summer. Soil temperature at 5cm depth ranges from 35 to 450C during monsoon period. The mean relative humidity in the afternoon during summer ranges from 20 to 35 per cent and during monsoon from 48 to 60 per cent. The mean evaporative rate during summer exceeds 10 mm per day. The highest PET of 2063 mm has been recorded in Jaisalmer in the west and 1745 mm in the East at Jaipur.
Soils and agroclimatic zones:
The soils of the state belong to 5 orders, 8 sub-orders and 16 great groups and 32 sub groups. The Entisols are dominantly observed giving about 37 per cent area followed by Inceptisols, Aridisols , Vertisols covering 21.9, 19.6 and 2.8 per cent of total geographical area, respectively. The Alfisols are least covering 0.73 per cent of total geographical area . The names of the soil orders, sub-divisions up to great group along with their equivalents in old system of soil classification are presented in Table 1 & Fig- B visualize the distribution scenario of soils in the state.
Table 1: Approximate equivalent of old and new system of classification.

Order Sub-Order Great Group** Approximate equivalent in old system*
Aridisols Orthids Camborthids
Calciorthids
Salorthids
Paleorthids
Gypsiorthids Sierozems,desert soils

Saline soils of depression

Gypsiferous
Argids Haplargids
Alfisols Ustalfs Haplustalfs Red loam, black soils, brown soils, yellowish brown soils of foothills, alluvial soils
Entisols Psamments Torripsamments
Quartzipsamments Desert soils and sand dunes
Fluvents Torrifluvents
Ustifluvents Alluvial soils (old and recent )
Orthids Toriorthents
Ustorthents
Inceptisols Ochrepts Ustichrepts Brown soils, red and yellow soils of foothills
Vertisols Usterts Chromusterts
Pellusterts Black soils

Source : Soils of Rajasthan : Survey and classificatioin in Retrospect and Prospect.Department of Agriculture, Rajasthan,Jaipur 1974-75 ** ( Shyampura and Sehgal, 1995)

Based on physiographic divisions of state, its rainfall pattern, soil types, availability of irrigation water, cropping patterns and administrative units, the state of Rajasthan has been classified into ten agro-climatic zones (Fig-C ). Crops and cropping pattern as determined by soil and climatic conditions of the zone differ greatly. Major crops of different districts of Rajasthan are presented in table 2
Vegetation:
A wide variation in the climate of the state has accommodated a large diversity of vegetation. In the arid zone Prosopis, Capparis and Zizyphus, spp. predominate, whereas in the most desertic part Calligonum polygonoides is the main species. The semi-arid tract is dominated by Acacia catechu and Anogeissus pendula. All these vegetation types are associated with a large variety of annual and perennial grasses and shrubs.

Table 2 : Main features , districts, area, rainfall and crops of the agro-climatic zones of Rajasthan.
S.N Name of Zone Area
(Mha) Districts covered % of
state area Normal
Rainfall
(mm) Major Crops
I a Arid Western Plain 4.44 Barmer and part of Jodhpur 13.6 100-370 Pearl millet, kharif pulses, cluster bean
I b

Irrigated North-Western plain 2.06 Sriganganagar &
Hanumangarh 6.0 100-350 Gram, Wheat, mustard, cotton, cluster bean, Pearl millet
I c* Hyper Arid partially irrigated Western plain 7.71 Jaisalmer,Bikaner and part of Churu 22.5 100-300 Pearl millet, kharif pulses, cluster bean
II a Transitional Plain of
Inland Drainage 3.69 Sikar,Nagaur,
Jhunjhunu and part of Churu 10.8 300-350 Pearl millet, cluster bean, kharif pulses, gram
II b Transitional Plain of Luni Basin 3.01 Jalore,Pali, part of Sirohi and Jodhpur 8.8 300-500 Pearl millet, cluster bean, sesame, kharif pulses, wheat, rape and mustard
III a Semi-Arid Eastern
Plain 2.98 Ajmer,Dausa,
Jaipur and Tonk 8.6 500-700 Pearl millet, sorghum, sesame, wheat, barley, gram, mustard
III b Flood prone
Eastern Plain 2.70 Alwar,Dholpur
Bharatpur and part of Swai-.Madhopur 6.9 500-700 Pearl millet, sorghum, mustard, wheat ,gram
IV a Sub-Humid Southern Plain and Aravalli Hills 3.36 Bhilware,Rajsamand and part of Sirohi Udaipur & Chittorgarh 9.8 700-900 Maize, sorghum,
Groundnut, sesame wheat, barley, gram, mustard
IV b Humid Southern Plain 1.72 Dungarpur, Banswara and part of Udaipur and Chittorgarh 5.0 500-1100 Maize, paddy, kharif pulses, wheat, gram
V Humid South-Eastern Plain 2.70 Jhalawar,Kota, Bundi and part of Swai-.Madhopur 7.9 650-1000 Sorghum, maize, sesame, wheat, gram, mustard
* Newly created zone Source : Souvenir -25 years of soil based reaserch (1965-90), RAU,Bikaner.



Water resources and land use pattern:
The water resources in Rajasthan state are very limited. These could be classified into two i e (i) Surface (ii) Ground water. Five rivers viz. Luni, Mahi, Sabarmati, Chambal and Banas flow through the state. The first three rivers drain into Arabian sea and the rest two join Jamuna. With an impressive performance of the state the development of facilities specially through the canal network and tapping of under ground water, the net irrigated area during last four decades has risen from 10.07 lac hectares during 1950-51 to 69.34 lac hectares during 1999-2000 (Table 3).
Table 3: Source wise net irrigated area in Rajasthan ( ‘000 ha)
Year Canals Tanks Wells &Tubewells Others Total
1950-51 224 82 684 17 1007
1960-61 535 166 1014 37 1752
1970-71 755 270 1083 23 2132
1981-82 946 85 1827 45 2903
1991-92 1424 163 2702 54 4343
1994-95 1427 246 3134 50 4858
1995-96 1497 189 3500 46 5232

1997-98 1525 182 3657 57 5421
1998-99 1557 93 3801 48 5499
1999-2000 2319 81 4484 50 6934
Source: Department of statistics, GOR -2001

Available land use pattern in Rajasthan indicates an increasing trend in the net sown area and area under forest (Table 4). The cropping intensity of the state increased from 109.5 per cent (1961-62) to 133.2 per cent (1998-99)
Table 4 Land utilization pattern in Rajasthan (Lac ha.)
Particulars 1961-62 1971-72 1981-82 1991-92 1994-95 1998-99 1999-2k
i) Geographical Area 339.9 342.9 342.3 342.5 342.4` 342.7 342.7
Ii) Forest 8.79 14.01 20..78 23.70 24.51 25.57 25.80
Iii) Not available for cultivation 63.13 60.51 44.71 43.93 43.37 43.08 43.06
Iv) Other cultivated land excluding fallow land 84.33 79.26 80.75 73.66 69.33 68.01 67.15
v) Fallow land 46.26 36.46 40.32 46.33 38.01 45.25 51.48
vi) Net sown area 137.43 152.63 155.78 154.89 170.21 160.74 155.08
vii) Gross cropped area 150.45 167.73 185.97 180.93 203.80 214.01 192.86
Cropping intensity 109.5 109.9 119.4 116.8 119.7 133.2 124.3
Source: Department of statistics, 2000 -2001



Hydrogeology and water quality:
Among the many factors which influence water quality, hydro-geological conditions are among the important ones. As to how this factor governs the general salinity in the ground waters, is discussed with western Rajasthan and Kutch as example. Achuta Rao (1975) has described hydro-geological conditions in typical desert areas of western Rajasthan. On the basis of studies carried out by several institutions, a generalized picture on the water quality of the principal lithological units is as follows:
Pre-cambrian crystallines: These occur mainly in Sirohi, Pali, Jalore, Barmer and Jodhpur districts. These formations depending on the quality of water may serve domestic water supply and to some extent the limited need for irrigation. Generalization of the ground water conditions is not possible.
Pre-cambrian sedimentary rocks: These are trans-Aravalli Vindhyan formations consisting of sandstones, limestones and shales, occurring mainly in Pali, Jodhpur and Nagour districts. The chert dolomitic limestones of Vindhyan formation outcropping near village Borunda in Jodhpur district has proved to be prolific Karstic aquifer in western Rajasthan, yielding fresh water of TSS less than 2000 mgL-1. TSS of the ground waters usually varies from 500 to 2000 mgL-1 (EC 0.75-3 dSm-1). However, saline water with TSS 3000-6000 mgL-1 (EC 5-9 dSm-1) is not uncommon.
Mesozoic sedimentary rocks: The next in important source of ground water in western Rajasthan is a group of mesozoic sedimentary rocks found mostly in Jaiselmer and Barmer districts. The mesozoic sedimentary section includes sandstones, limestones and shales. The sandstone beds are the important lithological horizon and some of them are proved to be potential aquifers.
Lower Jurassic sandstones: These sandstones are designated as Lathi limestones and are proved to be ground water worthy for large scale beneficial exploitation. TSS of the ground water is usually less than 2000 mgL-1 (EC 3 dSm-1).
Middle and Upper Jurassic rocks: These are represented by: (a) Jaiselemer series; (b) Balsakhi series; (c) Bedesai series; and (d) Parihar series. They are mostly marine deposits, predominantly of limestone, shaly sandstones and calcareous sandstones intercalated with carbonaceous shales and clays, which are also identified. These are not good aquifers and the TSS of the water is usually greater than 3000 mgL-1 (EC 5 dSm-1).
Lower cretaceous rocks: These are represented by Abu beds in western Rajasthan. They constitute mostly limestone and undifferentiated shales and clayey sandstones. The quality of water is doubtful and there appear no promising granular zones.
Tertiary sedimentary rocks: Amongst tertiary rocks the significant water bearing formations are the Eocene period sandstones of Barmer and Bikaner district. Barmer sandstones yield water with TSS less than 3000 mgL-1 (EC 5 dSm-1). Palana sandstones yield water of good quality (TSS 500 mgL-1; EC 0.75 dSm-1). The lateral extent of the fresh water aquifer is not precisely known, since the Eocene formation at Kolayat (that is the western extensions) yields brackish water (Cl 2500 mgL-1).
In other tertiary formations, in parts of Jaisalmer, Barmer, Bikaner and Jalore districts, there are not good aquifers. They are mostly intercalated sanstones and clay/shale zones with no appreciable permeability. Invariably in a majority of cases clay predominates and the quality of water is saline (TSS 4000-6000 mgL-1; EC 6-9 dSm-1). Some of the available dugwell water samples data conforming to tertiary formations are given in Table 5.
Table 5: Quality of ground water in tertiary formations

Districts TSS (mgL-1) Chlorides (mgL-1) Sulphates (mgL-1)
Barmer 200 – 26,140 44 – 20,602 0 – 4,785
Jaisalmer 160 – 17,916 29 – 10,903 0 – 2,400
Bikaner 2000 – 15,000 800 – 5,000 200 – 4,000
Jalore 3000 – 8000 1,000 – 3,500 50 – 400
Ganganagar 2000 – 29,016 1,000 – 13,737 200 – 6,066

Quaternary sediments: These deposits are by far the most extensive formations covering all the previous lithological units in the area. Generally, they constitute alluvial deposits associated with wind blown sand and sand dunes. The ground water condition is these deposits are unpredictable due to large variations in the degree of mineralisation in ground waters. Broadly, these deposits can be classified with: (a) older alluvial sediments; and (b) younger alluvial sediments. District wise aquifers in potential zones and area is given in Table 6. And depicted in Fig- D


Table 6 : District wise aquifers in potential zones and area (Sq.Km.)

S.No. District Aquifers in potential zones and area (Sq.Km.)
1 Ajmer Alluvium (332.5), Calc- schist ( 2002.6) , Granite-gneiss(5121.7)
2 Alwar Older Alluvium (5820.7), Quartzites (545.4), Slate (667.4)
3 Banswara Aasalt (1238.4), Lime stone (80.6), Quartzites( 78.4), Phyllite & Schist(1005.5), Granite-gneiss ( 986.5)
4 Baran Sand stone (3830.6) ,Alluvium ( 274.7),Basalt (966.8)Shale (637.1) Lime stone (1183.0)
5 Barmer Younger Alluvium ( 1540.0 ) , Older Alluvium (5614.5) Tertiary sand stone (2084.2) Lathi sand stone (1497.8) , Rhyollite
( 1306.4) Granite (303.3)
6 Bharatpur Older Alluvium(1544.5) Sand Stone (1487.5) , Quartzite ( 76.9)
7 Bhilwara Phyllite & Schist(4325.8), Granite-gneiss ( 4541.7) Sand stone (428.7) , Lime stone (60.7)
8 Bikaner Older Alluvium(1544.5) Tertiary Sand Stone (6287.0) , Nagaur sand stone ( 3248.4),Bilara sand stone ( 172.1)
9 Bundi Alluvium (1158.3) ,Phyllite (1667.5) , Sand stone (404.4) , Lime stone (247.8), Shale (126.7), Lime stone with Shale (635.4)
10 Chittorgarh Basalt ( 1715.3), Granite-gneiss( 1787.5), Sand stone (697.2), Lime Stone(467.1), Shale ( 1991.9), Phyllite & Schist (1551.0)
11 Churu Younger Alluvium (1920.2) , Older Alluvium (1361.2) Tertiary Alluvium (1049.8 , Nagaur lime stone (1267.3), Bilara lime stone (488.0), Jodhpur sand stone ( 353.7)
12 Dausa Younger Alluvium (709.2) , Older Alluvium (1902.9) , Quartzite ( 327.4), Phyllite (52.5), Granite-gneiss (73.7)
13 Dhaulpur Schist Alluvium (1430.0) , Sand stone (801.4)
14 Dungarpur Ultra base (81.2), Biotic Schist (282.1), Phyllite & Schist (1998.2), Granite-gneiss (287.6)
15 Ganganagar Alluvium (1925.4)
16 Hanumangarh Alluvium (920.7)
17 Jaipur Younger Alluvium (4383.5) , Other Alluvium (2829.0) Quartzite (540.7, Phyllite & Schist(704.6), Granite-gneiss ( 1431.9)
18 Jaisalmer Alluvium (2706.5), Tertiary sand stone (716.6),Parwar sand stone (784.1), Bhadesar sand stone (462.0) , Jaisalmer sand stone ( 568.8), Lathi sand stone ( 4502.2), Jodhpur sand stone (695.3), Granite (209.4), Rhyollite (336.3)
19 Jalore Younger Alluvium (1378.4) , Older Alluvium (6098.6), Granite (582.4), Phyllite (68.8)
20 Jhalawar Basalt (4732.1), Sand stone (1374.1
21 Jhunjhunu Younger Alluvium (299.2) , Older Alluvium (4220.4), Quartzite schist ,Phyllite Lime stone and Granite (754.1)
22 Jodhpur Older Alluvium (826.8),Nagaur sand stone (790.4) Bilara Lime stone (2821.4), Jodhpur sand stone (10106.8), Rhyllite (383.1),Granite (1596.7)
23 Karauli Older Alluvium and Quaternary (2338.2), Sand stone (1454.9),
Quartzite (108.7)
24 Kota Alluvium (1410.3), Lime stone (1180.5), Sand stone (235.9), Shale (151.5)
25 Nagaur Other Alluvium (5682.0), Palana sand stone (1005.3), Nagaur sand stone (2505.1) , Bilara lime stone (3363.6), Jodhpur sand stone (1341.3), Phyllite , Schist & Gneiss (2481.2)
26 Pali Younger Alluvium (81.2) , Older Alluvium (236.1), Erinpura Granite (3140.6) , Slate , Phyllite & Schist (1623.4), Granite-gneiss (704.2)
27 Rajsamand Mica Schist , Phyllite & Schist (251.2), ), Granite-gneiss (1735.9)
28 Swai Madhopur Alluvium (2256.3), Lime stone (583.9) , Shale (529.6), Quartzite (164.9) , Phyllite & Schist (790.9),
29 Sikar Younger Alluvium (165.2) , Older Alluvium (6010.9),Quartzite , Dolomite ,Lime stone, Schist, Phyllite & Gneiss (1087.3)
30 Sirohi Alluvium (987.8), Calc. Schist & Gneiss (525.4), Phyllite & Schist (1543.4) , Granite (1550.5)
31 Tonk Alluvium (1307.8), Phyllite & Schist (4203.8), Granite & Gneiss (1014.2)
32 Udaipur Calc. Schist & Calc. Gneiss(825.8), Granite (253.1), Quartzite (151.7) Phyllite & Schist (3729.1) ), Granite & Gneiss (3300.8)

Ground water potential in Rajasthan:
Due to scarcity of surface water , Rajasthan has to depend on ground water resources to a great extent .Ground water potential area in the state is 215142 sq. km.. The ground water resources position as on 1.1.95 is given below ( Annonymous, 2000)
The ground water resources 13157.2 Mcm.
Utilizable ground water for irrigation 11028.2 Mcm.
Utilized for irrigation 6493.7 Mcm
Ground water balance 4534.5 Mcm
Stage of ground water development 58.9%
In general , the chemical quality of ground water Is fresh in the eastern part except in some locations of Bharatpur district, particularly in Sewar, Nagar, Kumher and Deeg blocks , where the ground water is brackish to saline. These waters have residual sodium carbonate. The chemical quality of western Rajashan is moderately to highly saline with high concentration of chloride and sulphate. . Potable water is found in areas covered by sandstone and limestone of Mewar Super Group, Lathi formatin in Jaisalmer and Barmer districts and

Tertiaries in parts of Bikaner, Nagaur, Churu, Barmer, and Jaisalmer district and localised pocket of Quaternaries.
Periodic development of water level in state:
Water level vary with rainfall, physiology drainage and climatic condition . The ground water condition in the state varies widely. To the east of Aravalies , depth of water is comparatively shallower than in the west . It generally varies between 10 to 25m in the eastern part whereas, in the western part it ranges between 20 to 80 m. The water level slopes toward east and south- east on the western site , whereas to the west of Aravalies, it slopes towards west and north-west. Shallow water level ( 7 to 20 m) have been noted in the canal command area of Ganganagar , Banswara, Kota and Bundi districts whereas deeper depth of water level has been observed in the western districts of Rajasthan particularly Jaisalmer , Bikaner Barmer and Jodhpur.
Ground water development is significantly high in eastern part of Rajasthan as compared to the western part, The ground water recharge is relatively less in the western Rajasthan , due to low and erratic rainfall , absence of ground water resources and high evaporation . However, in some of the thick aquifers , the storage many times the annual recharge and hence, sustained pumpage can be achieved even during dry spell.
For evaluating trend of water level and long term fluctuation, year 1984 has been considered as base year. The treend has been analysed between pre monsoon 1984 and pree monsoon ,1997 (Fig .E) on the basis of data collected from a network of 6700 Key wells in the states ground water department of Rajasthan ( Annonymous,2000)
The state has been divided into 594 ground water potential zones. Out of these ,322 zones fall in “white” category, whereas, ground water development is < 65 %, 71 zones fall in the “Grey “ category , having 65 to 85 % stage of development. The remaining 201 zones has been categarised as “ Dark” zone, where stage of ground water development is > 85% out of these 173 zone are over exploited , having a stage of development > 100%.
As per studies , out of 32 districts, 26 districts showed an average depletion of water level and 6 districts showed marginal rise except certain pockets. The districts which showed water level depletion are Ajmer , Alwar, Jaipur , Jalore, Jhunjhunu, Jodhpur, Nagaur, Pali and Sirohi ( Table 7)




Table 7: District critically affected by water level depletion during 1984-2000
S. No. Districts Av. drop (m) S. No. Districts Av. Drop (m)
1 Ajmer (-)5.59 6 Jodhpur (-) 6.60
2 Alwar (-)5.12 7 Nagaur (-)6.50
3 Jaipur (-)5.74 8 Pali (-)6.69
4 Jalore (-)8.00 9 Sirohi (-)6.49
5 Jhunjhunu (-)6.22

The prime reason for water level depletion is excessive with drawl of water to meet out the ever growing demand of agriculture, domestic and industrial purposes. The sustainability of vagaries has further fallen prey to the unplanned development. Thus shrinking of ground water resources due to which wells are getting dried and chemical quality of ground water is getting deteriorated.


Characterization of underground irrigation water

I. AICRP Bikaner Centre:

Survey and characterization of Jaipur, Bikaner, churu and four tehsils of Nagaur district has been done by the center and maps of water quality has been prepared and recommendations have been given to the extension department and concerned KVK for use of poor quality waters.
Jaipur District :
Twelve tehsils of Jaipur district viz. Kotputali, Viratnagar, Amber, Jaipur, Sanganer, Bassi, Dudu, Phagi, Chaksu, Sambhar, Jamva Ramgarh and Dausa were surveyed to know the underground water quality (Vyas et.al,1993). Range of chemical characteristics is reported in table 8. Percentages of samples of tehsil of Jaipur district falling into different pH, EC, RSC and SAR ranges are reported in table 9.
pH :
All the samples analysed fell in the pH range of 7.0 to 9.0 (Table 8). 49.7 percent samples had pH between 7.0 to 8.0 and 50.3 percent samples fell in the pH range of 8.0 to 9.0. About 12.1, 73.2 and 14.7 percent samples had pH<7.5, between 7.5-8.5 and >8.5, respectively.
Table8:Range of chemical characteristics of Tubewells/Open well waters of various Tehsils of Jaipur District
Chemical Characteristics Tehsils
Kotputali (53)* Viratnagar (70) Amber
( 207) Jaipur (107) Sanganer (53) Bassi (59)
pH
EC (Dsm-1)
Ca++ (meL-1)
Mg++ ( ” )
Na+ ( ” )
K+ ( ” )
CO3-2+HCO3-1(”)
Cl-1 ( ” )
RSC ( ” )
SAR 7.0-9.0
0.6-7.0
2.4-22.2**
--
1.0-47.2
0.1-2.0
4.0-16.0
0.8-52.2
Nil-12.4
0.7-19.8 7.3-8.8
0.9-7.0
1.4-22.6**
--
1.0-46.0
0.1-0.5
4.0-18.0
0.8-47.0
Nil-11.0
0.6-15.2 7.2-9.0
0.4-2.9
0.2-4.0
0.0-10.0
1.0-24.0
--
1.8-10.0
0.0-156.0
Nil-11.9
0.6-21.9 7.1-8.2
0.5-6.1
0.2-0.6
0.4-15.7
1.0-41.0
0.01-1.0
1.6-16.0
0.8-46.2
Nil-18.2
0.4-30.8 7.0-8.7
0.6-6.5
0.6-15.6**
--
1.0-54.2
0.1-0.5
3.2-27.0
1.0-46.6
Nil-19.2
0.6-25.5 7.3-8.8
0.5-21.5
0.8-71.4**
--
1.0-140.0
--
3.3-20.6
1.0-182.4
Nil-20.6
0.6-26.1
Dudu
(209) Phagi
(59) Chaksu
(61) Sambhar (162) J. Ramgarh (48) Dausa
(53)
PH
EC (Dsm-1)
Ca++ (meL-1)
Mg++ ( ” )
Na+ ( ” )
K+ ( ” )
CO3-2+HCO3-1(”) Cl-1 ( ” )
RSC ( ” )
SAR 7.1-8.9
0.5-17.6
0.2-0.3
1.5-68.4
1.6-156.0
--
tr-43.0
1.0-158.5
Nil-20.6
1.1-97.8 7.2-8.9
0.7-12.0
2.2-69.6**
--
2.0-84.5
0.1-0.40
4.9-26.4
1.0-120.6
Nil-19.4
1.2-29.3 7.3-8.7
0.6-8.2
1.6-57.6**
--
2.5-46.6
--
3.4-17.4
2.2-53.0
Nil-12.1
1.3-18.3 7.0-8.4
0.6-41.6
0.5-21.5**
6.0-57.0
3.0-260.0
--
4.0-40.0
1.0-235.0
Nil-36.5
1.5-52.0 7.4-8.8
0.4-2.3
3.0-11.1**
--
1.2-72.0
--
2.5-17.5
1.5-66.0
Nil-12.4
0.6-16.8 7.0-8.8
0.6-10.0
tr-35.0**
--
3.5-102.2
--
2.2-20.6
2.0-118.0
Nil-19.6
2.0-41.8

* Number of samples tested ** Figures are of Ca + Mg ions


Table9 : Percentage of samples of Tehsils of Jaipur District falling into different pH, EC, RSC & SAR ranges
Tehsils pH range EC range (meL-1)
7.0 - 7.5 7.5 - 8.0 8.0 - 8.5 > 8.5 < 2 2 - 4 4 – 6 6 - 8 > 8
Kotputali
Viratnagar
Amber
Jaipur
Sanganer
Bassi
Dudu
Phagi
Chaksu
Sambhar
Jamva Ramgarh
Dausa 1.9
2.9
6.8
22.4
3.8
13.6
9.6
11.9
14.8
34.6
4.2
17.0 13.2
28.4
20.3
59.8
52.8
30.2
43.5
62.7
49.2
48.8
22.9
34.0 56.6
57.2
28.5
16.9
33.9
32.2
37.8
20.3
32.8
16.6
66.6
41.5 28.3
11.4
44.4
0.9
9.4
23.9
9.1
5.1
3.3
--
6.3
7.5 64.2
91.4
96.6
88.8
69.8
61.0
14.5
39.7
52.5
29.6
91.7
62.2 22.6
7.1
3.4
2.8
24.5
20.0
24.6
36.2
37.7
30.8
6.3
17.0 7.5
--
--
7.5
3.8
13.6
26.6
13.8
6.6
15.4
2.0
11.3 5.7
1.4
--
0.9
1.9
1.9
14.5
5.2
1.6
10.5
--
5.7 --
--
--
--
--
3.4
19.7
5.2
1.6
13.7
--
3.8
Average 12.1 37.6 35.6 14.7 62.5 17.0 10.0 4.9 5.6
Tehsils RSC (meL-1) range SAR range
< 2.5 2.5 - 5.0 5 - 10 > 10 < 10 10 - 20 20 - 30 > 30
Kotputali
Viratnagar
Amber
Jaipur
Sanganer
Bassi
Dudu
Phagi
Chaksu
Sambhar
Jamva Ramgarh
Dausa 60.4
67.1
66.2
57.0
30.2
45.8
64.3
57.6
62.3
37.7
58.3
54.7 20.8
21.4
22.2
27.1
7.5
17.0
13.9
22.0
18.0
18.2
25.0
15.1 13.2
10.0
11.0
14.0
24.5
27.1
16.9
13.6
18.0
22.0
10.4
17.0 5.7
1.4
1.9
1.9
37.7
10.1
4.8
6.8
1.6
22.0
6.3
13.2 79.2
90.0
91.3
82.6
54.7
67.8
27.8
52.5
65.6
35.1
83.3
37.7 20.8
8.6
7.7
11.6
41.5
28.8
28.8
39.0
34.4
34.6
14.6
41.5 --
1.4
1.0
2.9
3.8
3.4
20.0
8.5
--
17.0
--
13.2 --
--
--
2.0
--
--
23.4
--
--
13.3
2.1
7.6
Average 57.8 19.5 15.0 7.7 62.9 23.8 7.2 6.1



EC :
EC of 79.5 percent samples was less than 4 dSm-1 and about 62.5 percent samples had EC less than 2.0 dSm-1. In case of Bassi, Dausa, Dudu, Phagi and Sambhar Tehsils, more than 10 percent samples had EC>6 dSm-1.
RSC :
Except Sanganer, Bassi and Sambhar Tehsils, more than 54 percent samples had RSC < 2.5 meL-1 and about 7.5 to 27.1 percent samples had RSC between 2.5 to 5.0 meL-1. Sanganer and Sambhar Tehsils had more than 40 percent samples having RSC > 5.0 meL-1. On an average 57.8, 19.5, 15.0 and 7.5 percent of total samples had RSC < 2.5, 2.5-5.0, 5.0-10.0 and > 10.0 meL-1, respectively.
SAR :
In Kotputali, Viratnagar, Amber, Jamva Ramgarh and Jaipur Tehsils more than 80 percent samples had SAR value of < 10. Sanganer, Phagi, Chaksu, Sambhar and Dausa Tehsils had 34.4 to 41.5 percent samples having SAR between 10 to 20. In Sambhar and Dudu Tehsils more than 30 percent samples had SAR>20
On an average 35.5 percent water samples had none of the problem and hence, were of good quality (Table 10). The range of good quality water in different Tehsils however, varied from 11.0 in Dudu and 65.2 percent in Amber Tehsil. In Viratnagar, Amber, Jamva Ramgarh and Jaipur Tehsils, percentage of good quality water was above 50. In Kotputali and Chaksu it was about 37.7 percent and it was low in Bassi, Sanganer, Phagi and Dudu Tehsils and the lowest in Sambhar Tehsil (7.4%).
In general there was low problem of salinity of water and also sodicity alone. The results showed that there was problem of RSC, which was as high as 69.8 percent samples in Sanganer followed by Sambhar (58.0%) and Bassi (54.2%) Tehsils. In other Tehsils it was in the narrow range of 33 to 42 percent. There was both salinity and sodicity problem in Dudu Tehsil (42.6%)


Table 10 : Classification of irrigation waters of some Tehsils of Jaipur District
Water quality Kotputali Virat nagar Amber Jaipur Sanganer Bassi
(53)** (70) (207) (107) (53) (59)
A Good
B Marginally saline
C Saline
D Saline sodic
E1 RSC water
E2 RSC water 37.7
9.4
3.8
9.4
13.2
26.4 61.4
4.3
0.0
1.4
27.1
5.7 65.2
0.5
0.0
0.5
26.1
7.7 52.3
0.0
0.0
4.7
33.6
9.3 22.6
1.0
0.0
5.7
30.2
39.6 30.5
1.7
3.4
10.2
32.2
22.0
Water quality Dudu Phagi Chaksu Sambhar J.Ramgarh Dausa Mean
(209) (59) (61) (162) (48) (53)
A Good
B Marginally saline
C Saline
D Saline sodic
E1 RSC water
E2 RSC water 11.0
10.5
0.5
42.6
17.2
18.2 22.0
13.6
5.1
17.0
16.9
25.4 37.7
13.1
3.3
8.2
16.4
21.3 7.4
5.5
1.9
27.2
22.2
35.8 54.2
0.0
0.0
4.2
29.1
12.5 24.5
5.7
0.0
22.6
7.6
39.6 35.5
5.4
1.6
12.8
22.6
22.0
** Number of samples tested.

Bikaner district :
Survey of underground waters of non-command area of Nokha, Kolayat, Loonkaransar and Bikaner Tehsils of Bikaner District revealed that water table of tubewells varied from 36 to 208 m. EC and pH of tubewell waters varied from 0.8 to 10.3 dSm-1 and 7.1 to 9.0, respectively. Range of chemical characteristics of well waters in Bikaner District is reported in table 11. The percent distribution of water samples in different ranges of EC and RSC is given in table 12 and water quality map is depicted in Fig. F. About 81.3, 16.3 and 2.4 per cent of samples had RSC < 2.5, 2.5 to 5.0 and >5.0 meL-1, respectively. On an average 32.6, 16.3, 17.4, 12.8, 4.1, 9.3, 4.1 and 3.4 per cent water samples were categorized as good, marginally saline, High-SAR saline, High-SAR non-saline, saline, marginally alkali, alkali and highly alkali, respectively. About 11.1, 42.9, 29.7 and 16.3 per cent of the samples had salinity <1.0, 1-2, 2-4 and >4.0 dSm-1, respectively. The waters are mostly Na-Mg-Ca type with dominance of chloride followed by carbonates+bicarbonates (Lal et. al., 1998)



Table 11: Range of chemical characteristics of well waters in Bikaner District

Chemical Characteristics Range of characteristics Bikaner District
Nokha Kolayat Loonkaransar Bikaner
pH
EC (dSm-1)
CO3-2 + HCO3-1(meL-1)
Cl-1 (meL-1)
SO4-2 ( ” )
Ca++ ( ” )
Mg++ ( ” )
Na+ ( ” )
K+ ( ” )
RSC ( ” )
SAR
Adj. SAR
SSP 7.1-8.8
1.0-6.1
2.5-12.5
2.0-55.8
0-7.0
0.4-14.7
0.9-12.8
7.6-37.6
0.03-1.03
Nil-8.1
3.3-22.4
8.4-43.9
28.0-91.3 7.5-8.8
0.8-10.3
2.5-8.4
1.6-101.0
0.1-10.8
0.5-7.5
0.9-18.9
6.6-78.2
0.1-0.6
Nil-5.8
4.7-30.8
7.9-58.2
47.9-90.2 7.6-8.7
2.3-7.9
3.0-5.8
18.6-55.2
--
1.4-8.6
2.9-7.2
21.5-84.0
0.1-0.4
Nil-4.2
12.9-27.4
25.8-68.8
78.6-88.9 8.0-9.0
0.8-7.7
1.6-7.8
3.7-44.2
Nil-31.9
0.3-3.8
0.4-11.8
5.6-65.5
0.1-0.2
Nil-4.8
5.3-41.8
9.3-73.2
60.1-95.1 7.1-9.9
0.8-10.3
1.6-12.5
1.6-101.0
Nil-31.9
0.3-14.7
0.4-18.9
5.6-84.0
0.03-0.6
Nil-8.1
3.3-41.8
7.9-73.2
28.0-95.1

Table12 :Percentage distribution of water samples in different ranges of EC and RSC

RSC (meL-1) EC (dSm-1)
<1 1 - 2 2 - 3 3 – 4 > 4 Total
Nokha Tehsil
< 2.5
2.5 - 5.0
5.0 - 7.5
> 7.5 --
--
--
-- 48.4
9.7
--
1.6 17.7
1.6
1.6
-- 11.3
--
--
1.6 6.5
--
--
-- 83.9
11.3
1.6
3.2
Kolayat Tehsil
< 2.5
2.5 - 5.0
5.0 - 7.5 3.0
3.0
3.0 27.3
18.2
-- 12.1
--
-- 12.1
--
-- 21.2
--
-- 75.7
21.2
3.0
Loonkaransar Tehsil
< 2.5 -- -- 33.3 46.7 20.0 100.0
Bikaner Tehsil
< 2.5
2.5 - 5.0 24.2
1.6 19.4
16.1 11.3
1.6 3.2
-- 19.4
3.2 77.5
22.5
Bikaner District
< 2.5
2.5 - 5.0
5.0 - 7.5
> 7.5 9.3
1.2
0.6
-- 29.6
12.7
--
0.6 15.7
1.2
0.6
-- 11.6
--
--
0.6 15.1
1.2
--
-- 81.3
16.3
1.2
1.2
11.1 42.9 17.5 12.2 16.3 100.0

Churu Distrist:
Five hundred and fifty six water samples were collected from seven tehsils (Sri Dungargarh, Sardarshahar, Sujangarh, Ratangarh, Churu,Taranagar and Rajgarh). The results of chemical analysis (Table 13 & Fig. G ) revealed that EC of water samples ranged between 0.4 to19.7 dS/m-1. About 32 per cent water samples have EC of <2.0 dS/m-1 while EC of 36 per cent samples fell between 2.0-4.0 dS/m-1 Based upon EC it can be stated that Sri Dungargarh tehsil is underlain with relatively better quality waters followed by Sujangarh, whereas , water of North- Eastern tehsils viz. Churu, Taranagar, Rajgarh and Sardarshahar are of marginal quality. pH of water samples ranged between 7.2 to 9.3. pH of more than 57 per cent water samples ranged between 8.1 to 8.5 while only 3.0 per cent samples have pH less than 7.5. Tehsils of Northern part of district viz; Sardarshahar ,Taranagar and Rajgarh have waters of high pH (>8.5), as compared with others . RSC of water varied between nil to 13.1 meL-1 . About 75 per cent water samples recorded RSC <2.5 meL-1 whereas, about 9 and 16 per cent samples had RSC between 2.5 to 5.0 meL-1 and >5.0 meL-1 ,respectively. On an average 27 per cent samples were categorised good ,whereas, 15 ,5, 29 ,4 and 20 per cent samples were marginally saline, saline, high SAR saline, marginally alkali and high alkali, respectively (Table 13). Water table depth of tube wells in the district varied from 7 to 175m. Tube wells are relatively shallow (<50 m) in Eastern part of district i.e. Taranagar, Rajgarh and Chruru tehsils,whereas, tubewells are deeper in Sri Dungargarh , Sardarshahar and Sujangarh. Mg/ Ca ratio >3.0 in ground waters of north-eastern tehsils of Churu district viz. Sardarshahar ,Churu ,Taranagar and Rajgarh tehsils , while, it is between 1.0-2.0 in more than 75 per cent samples of Sri Dungargarh and Ratangarh tehsils .The quality of under ground waters of Churu, Taranagar, Rajgarh and Sardar Shahar tehsils of Churu district is poor ( Verma et. al. 2003). All crops can be irrigated with water of ECiw < 2.0 dSm-1 without any significant effect on crop yields. Salt sensitive crops, particularly pulses are badly affected if ECiw ranges between 2.0 - 4.0 dSm-1 . Most of the crops will be affected by waters of ECiw 4.0-8.0 dSm-1 depending on texture of soil and type of crop and its variety . With sprinkler system of irrigation these EC limits of irrigation waters further get reduced by 25-50 percent.

Table 13: Range of chemical characteristics of tube wells / open wells water of Churu district
Chemical
Chara teristics Sri Dungar
Garh (87)* Sardar
Shahar
(93) Sujan
Garh
(101) Ratan
garh
(67) Churu
(61) Taranagar
(23) Rajgarh
(124) Churu district

pH 7.8-9.2 8.0-9.1 7.8-8.7 7.6-8.7 7.3-8.4 8.1-9.2 7.9-9.3 7.6-9.3
EC (dS/m) 0.4-4.1 0.6-8.6 0.8-11.6 1.1-4.8 2.1-11.4 1.9-19.7 1.7-18.2 0.4-19.7
RSC (me/l) Nil-7.8 Nil-11.4 Nil-4.3 Nil-10.0 Nil-13.1 Nil-9.3 Nil-12.8 Nil-13.1
SAR 1.0-17.7 2.2-31.4 1.7-21.7 3.4-21.5 6.9-17.7 6.2-33.5 8.4-27.9 2.2-33.5
Adj . SAR 2.2-49.6 4.2-74.0 3.8-62.9 7.5-63.3 18.9-77.3 16.0-80.4 19.2-114.6 2.2-114.6
SSP 23.0-87.5 43.7-95.1 31.6-84.8 49.0-91.7 16.0-90.9 46.6-93.2 46.4-91.0 16.0-93.2
Mg/Ca 0.5-3.3 1.0-7.5 0.6-4.6 0.4-3.3 1.1-6.2 1.1-6.6 1.0-11.0 0.4-11.0
Water Table(m) 35-152 40-87 20-175 38-133 23-50 7 – 37 10-61 7-175
*Figure in Parenthesis indicate number of sample tested
Table 14: Percent distribution of water samples under different categories of water quality in Churu district.
Water quality Sri Dungar
Garh Sardar
Shahar Sujan
garh Ratan
garh Churu Taranagar Rajgarh Churu district
Good 72.4 11.8 49.5 32.9 -- -- 1.6 26.6
Marginally saline 11.5 5.4 31.7 26.9 6.6 -- 12.9 15.3
Saline 1.1 3.2 6.9 1.5 9.8 4.4 6.5 4.9
High SAR Saline 6.9 33.3 9.7 3.0 62.3 73.9 45.2 28.7
Marginally Alkali 3.4 7.5 2.0 11.9 -- -- 3.2 4.3
Alkali -- 1.1 -- -- -- -- -- 0.2
High Alkali 4.6 37.6 -- 23.8 21.3 21.7 30.6 20.0
*Figure in Parenthesis indicate number of sample tested

Nagaur district:
Survey and characterization of underground waters of four tehsils (Nagaur, Jayal , Ladnu and Kheenwasar) of Nagaur district have been completed. EC and pH of water samples ranged between 0.61 to 11.9 dSm-1 and 7.0 to 9.2, respectively. RSC of water varied between nil to 14.1 meL-1 (Table 15). On an average 10.6, 11.8, 4.7, 36.5, 3.5 and 32.9 per cent water samples were under good, marginally saline, saline, high SAR saline, marginally alkali and high alkali categories, respectively in Nagaur tehsil. About 10.2,15.3, 8.4,47.3,8.4 and10.2 per cent water samples were under good, marginally saline, saline, high SAR saline, marginally alkali and high alkali categories, respectively in Jayal tehsil. In Ladnu tehsil 18.6, 40.7, 1.7, 33.9 and 5.1 per cent water samples fell under good, marginally saline, saline, high SAR saline and highly alkali, respectively, whereas, in Kheenvasar tehsil, 28.5, 45.8 and 25.7 per cent water samples were observed good, marginally saline and high SAR saline, respectively (Table 15). SAR, SSP and Mg/Ca ratio of the water samples of four tehsils ranged between 2.2 to 48.6, 32.6 to 95.0 and 0.6 to 6.2, respectively. Fluoride and Nitrate contents in under ground irrigation waters of these tehsils ranged between nil to 16.5 and 0.3 to 66.8 mg L-1 , respectively (Table 16 ). Na+. and Cl - ions were the dominant cation and anion , respectively. The waters were Na: Mg : Ca type dominated with chloride anion. RSC of these water ranged from nil to 14.1 me/L. More than 90% waters of Ladnu and Kheenvasar tehsils were found free from RSC problem . In Nagaur and Jayal tehsils only 35.5 and 18.6 percent water samples, respectively had RSC problem.. Distribution (percent) of water samples in different ranges of EC and RSC in Nagaur district is given in Table 17.
Table15: Range of chemical characteristics of tube wells / open wells water of Nagaur district
Chemical
Characteristics Nagaur tehsil
85* Jayal tehsil
59* Ladnu tehsil
59* Kheenwasar
70 Range
273
pH 7.8 - 9.2 (8.18) 7.9-9.1 8.36) 7.0-8.6 (7.68) 7.24-8.66 (8.08) 7.0-9.2
EC (dSm-1-1-1 ) 0.9 - 9.5 (3.70) 0.7-11.9 4.92) 1.2-7.6 (3.49) 0.61-6.20 (2.74) 0.61-11.9
RSC (meL-1 ) Nil - 14.1 Nil - 9.6 Nil-10.8 Nil-2.1 Nil-14.1
SAR 2.6 - 34.7 2.2 - 48.6 3.5-48..2 2.1-25.5 2.2-48.6
Adj . SAR 4.6 - 72.5 4.0 - 102.1 9.8-90.0 4.0-53.9 4.0—102.1
SSP 36.3 -94.0 32.6 - 95.0 36.1-94.9 38.9-88.6 32.6-95.0
Mg/Ca 0.6 - 4.9 (2.07) 0.7-4.5 (2.73) 0.6-5.7(2.85) 0.96-6.2 0.6—6.2
Nitrate (mg L-1) 0.3-19.3 1.2 - 56.0 0.4-66.8 2.0-62.0 0.3-66.8
Fluoride (mg L-1) Nil - 11.8 Nil - 12.0 0.5 - 16.5 0.7-4.0 Nil-16.5
Water table (m) 32.7-134.0 30.0 - 100.0 40.0-133.3 53.3-153.3 30.0-153.3
*Number of sample tested Figure in Parenthesis are the average value
Table 16: Per cent distribution of water samples under different categories of water quality in Nagaur district.

Water quality categories Tehsils
Nagaur Jayal Ladnu Kheenwasar
Good 10.6 10.2 18.6 28.5
Marginally saline 11.8 15.3 40.7 45.8
Saline 4.7 8.4 1.7 -
High SAR Saline 36.5 47.3 33.9 25.7
Marginally Alkali 3.5 8.4 - -
Alkali - - - -
High Alkali 32.9 10.2 5.1 -

Table 17 : Distribution (percent) of water samples in different ranges of EC and RSC in Nagaur district
RSC (meL-1 ) EC (dSm-1 )
<1 1-2 2-3 3-4 >4 Total
Nagaur Tehsil
<2.5 2.3 8.0 3.4 13.8 36.8 64.3
2.5-5.0 - 3.4 2.3 2.3 - 8.0
5.0-7.5 - 4.6 8.1 3.4 2.3 18.4
> 7.5 - - 3.4 4.6 1.1 9.1
Jayal Tehsil
<2.5 3.4 6.8 13.6 6.8 50.8 81.4
2.5-5.0 - 3.4 3.4 - 8.4 15.2
5.0-7.5 - - - 1.7 - 1.7
> 7.5 - - 1.7 - - 1.7
Ladnu Tehsil
<2.5 - 20.3 35.6 8.5 28.8 93.2
2.5-5.0 - - - - 1.7 1.7
5.0-7.5 - - - 1.7 1.7 3.4
> 7.5 - - - - 1.7 1.7
Kheenwasar Tehsil
<2.5 17.1 12.9 32.9 14.2 22.9 100.0


II. Other sources
The ground water department of Rajasthan has carried out a very systematic survey of the quality of ground waters in Rajasthan. Percentage distribution of ground waters based on about 10,000 samples, with respect to salinity (Table 18) in various districts shows that as rainfall increases from the arid districts of western Rajasthan to the humid districts in eastern Rajasthan, the average quality of ground water improves. In arid-cum-semi-arid districts the percentage of saline water (EC>5 dSm-1) is appreciably high, varying from 30-50 per cent in nine districts, viz. Barmer, Bikaner, Churu, Ganganagar, Jaisalmer, Jalore, Jodhpur, Nagaur and Pali. EC of some ground waters is 10 to 15 or even higher than 15 dSm-1. The highest EC of 49, 35, 34 and 22 dSm-1 have been recorded in ground waters of Bikaner, Ganganagar, Barmer and Jaisalmer districts (Gopal and Bhargava, 1981). The percentage of such waters in Jhunjhunu and Sikar districts is relatively low. In the seven semi-arid districts, EC is generally less than 10 dSm–1, except Bharatpur district where ground waters are of as poor in quality as in the arid districts. The percentage of saline ground waters varies from less than 5 to 15. In mid districts, the percentage of saline waters is negligible except in the Bundi district. In sub-humid districts, EC is largely less than 2.2 dSm-1, except in Kota..
The classification of the ground waters of Rajasthan in three groups, namely, (a) arid and arid-cum-semi-arid districts; (b) semi-arid districts; and (c) humid and sub-humid districts, and their distribution in different salinity classes, brings out a very interesting picture. About 90 per cent of the ground waters in the western arid districts have EC less than 10 dSm-1, whereas in the semi-arid and humid districts 90 per cent waters have EC less than 5 and 2.25 dSm-1, respectively (Table18)
Table18: Percentage distribution of ground waters of Rajasthan in different salinity classes
District No. of samples (10329) EC (dSm-1)
<0.75 0.75 – 2.25 2.25 – 5.0 5 – 10 10 – 15 >15
Arid
Barmer 322 10 11 31 27 15 7
Bikaner 137 2 27 37 21 10 3
Ganganagar 361 7 36 23 20 10 4
Jaiselmer 295 19 37 20 20 4 1
Jodhpur 357 8 38 27 16 8 4
Arid-cum semi-arid
Churu 244 3 16 30 29 15 7
Jalore 505 10 28 30 20 10 3
Jhunjhunu 363 8 47 34 11 - -
Nagaur 459 8 36 28 22 4 3
Pali 498 12 34 20 17 9 8
Sikar 174 12 55 28 5 - -
Semi-arid
Ajmer 388 15 52 26 7 - -
Alwar 764 23 60 14 3 - -
Bharatpur 499 20 31 19 14 16 -
Bhilwara 572 18 52 20 10 - -
Jaipur 939 30 45 18 7 - -
S.Madhopur 505 26 52 16 6 - -
Tonk 333 10 50 26 14 - -
Sub-humid
Chittorgarh 442 35 61 4 1 - --
Bundi 238 38 43 17 - - -
Udaipur 640 23 64 10 2 - -
Sirohi 94 55 37 17 - - -
Humid
Banswara 296 73 26 1 - - -
Dungarpur 189 55 41 3 - - -
Jhalawar 243 60 34 6 - - -
Kota 472 30 57 12 1 - -
Source: Gupta (1979).

SAR value of ground waters in some districts of Rajasthan has been shown in Table 19 . It is apparent that values as high as 96 and 114 are noted in the waters of Nagaur and Jodhpur districts. The ground waters of arid districts have relatively higher values than the semi-arid districts. Whereas in western Rajasthan, SAR values of the ground waters are usually greater than 20, in eastern Rajasthan SAR values rarely exceed 20. For example, in Alwar district, the percentages of ground waters having values of SAR less than 10, 10-20 and greater than 20, are 76, 21 and 3 respectively. Distribution of under ground water according to EC and SAR was reported by Dhir ,1977 ( Table 20)
Table19: SAR values of ground water in Rajasthan
District No. of samples SAR
Range Average
Arid
Barmer 290 1.2 – 32.4 --
Bikaner 137 0.6 – 56.1 --
Ganganagar 200 1.1 – 36.0 --
Jaisalmer 318 1.4 – 26.8 --
Jalore 50 12.0 – 53.6 24.7
Jhunjhunu 9 12.5 – 19.6 33.5
Jodhpur 74 3.7 – 113.6 --
Nagaur 74 15.8 – 95.7 31.7
Pali 84 3.8 – 63.8 21.9
Sikar 14 3.6 – 17.2 --
Semi-arid
Ajmer 19 3.3 – 69.5 --
Alwar 340 0.2 – 61.5 --
Bharatpur 10 2.8 – 77.8 --
Bhilwara 118 4.1 – 73.3 23.3
Jaipur 92 4.8 – 39.9 16.1
Sub-humid
Udaipur 166 1.8 – 18.9 6.4
Source: Gupta (1979).

Table20: Percentage-wise distribution of ground waters of western Rajasthan in SAR classes
EC (dSm-1) No. of samples (2278) SAR
<10 10 – 18 18 – 26 26 – 34 >34
<0.25 3 66.7 33.3 -- -- --
0.25 0.75 167 93.4 5.4 1.2 -- --
0.75 – 2.25 607 72.8 21.9 3.6 1.8 0.3
2.25 – 5 659 31.0 39.4 22.3 4.7 2.6
5 – 10 496 6.6 28.4 31.9 21.2 11.7
10 – 15 225 2.2 12.5 30.7 33.3 21.3
>15 121 3.3 4.1 12.4 22.3 57.9
Source: Dhir (1977).
In the saline waters of western Rajasthan, the incidence of occurrence of RSC in ground waters is less. The percentage of waters having RSC>2.5 meL-1 was 0, 14, 4, 0 and 20 in districts of Barmer, Jaisalmer, Jalore, Jodhpur and Pali respectively (Mehta et al., 1970). In Nagaur district, RSC in ground waters varied from 0 to 21.5 me L-1, with an average of 4.1 meL-1 (Paliwal and Gandhi, 1977). In Ajmer, Jhunjhunu and Sikar districts, RSC was generally less than 10 meL-1 (Singh and Mahnot, 1976). In high rainfall districts namely, Bundi and Jhalawar more than 75 pr cent ground waters have RSC less than 2 meL-1 (Gupta et al., 1974, 1975).
In 11 districts of western Rajasthan, 60 per cent of the total area is occupied with saline ground waters having chlorides greater than 1,000 mgL-1 (EC>1.5 dSm-1) (Table 21).

Table21: District wise Area (sq. Km) under different quality classes

District Total (sq Km) Fresh Water Saline water
Barmer 29,031 7,000 22,031
Bikaner 27,102 5,302 21,800
Churu 16,261 3,140 13,121
Ganganagar 20,384 1,041 19343
Jaiselmer 38,475 11,797 26,678
Jalore 10,428 3,166 7,262
Jhunjhunu 5,648 5,443 205
Jodhpur 22,213 16,213 6,000
Nagaur 17,592 12,300 5,292
Pali 11,808 9,408 2,400
Sikar 7,658 7,328 330
Source: Mehra and Sen (1977).
Sodium dominates invariably in all the waters followed by magnesium and calcium. The percentage of sodium ions varies from 60 to 80 of the total cation concentration. The ratio of magnesium to calcium varies from 1 to 5. Amongst anions, chlorides dominated in all the districts except in Ajmer where sulphates dominated. The second anion was generally bicarbonate in well waters of such districts which had an average EC between 2 and 3 dSm –1. In the remaining districts sulphate was the dominant anion and such districts had an average EC in general higher than 4 to 5 dSm-1.
On an average, potassium ions were either absent or occurred in amounts less than 2 meL-1. Likewise, amongst anions, carbonates contributed the least and did not exceed 4 meL-1. Thus, in general well waters of Rajasthan could be characterized as Na-Mg-Ca cation type and Cl-HCO3-SO4 anion type in the low salinity class (EC <3dSm-1) and Cl-SO4-HCO3 anion type in the higher salinity class (EC>5 dSm-1). As EC of water increases from low to high, percentage of divalent cations decreases (Table 22). A large number of waters which contain Ca+Mg of more than 50 per cent have EC less than 2.25 dSm-1 and waters with EC greater than 4 dSm-1 usually contain Ca+Mg less than 30 per cent (Table 23).
Table22: Mean chemical composition of ground waters in some districts of Rajasthan
District
No. of Samples pH
EC
(dSm-1) Ions (meL-1)
Na K Ca Mg Cl SO4 CO3 HCO3
Ajmer 19 8.7 5.5 37.7 0.28 4.86 5.50 10.2 24.76 0.80 9.70
Alwar 334 8.2 2.4 14.9 - 3.57 6.85 12.2 8.82 2.85 8.42
Barmer 339 7.9 5.2 38.8 1.60 4.73 7.13 38. 6.18 - 6.40
Bharatpur 276 8.3 3.1 20.2 - 3.70 8.70 16.5 8.20 0.50 8.40
Bhilwara 235 8.1 5.5 39.6 0.84 5.05 5.34 42.0 11.43 0.40 8.35
Bikaner 249 7.8 6.3 45.5 0.98 8.10 9.20 46.2 12.20 - 6.90
Jaipur 161 8.3 3.0 35.1 0.32 3.61 11.40 29.7 11.10 3.74 8.34
Jaiselmer 318 7.7 5.0 33.4 0.72 5.42 4.74 30.6 7.16 0.86 6.55
Jalore 472 8.0 3.3 34.8 1.01 4.96 6.19 33.2 5.50 - 6.91
Jodhpur & Nagaur 943 8.0 5.5 38.8 1.24 4.20 8.35 36.7 8.67 - 9.73
Pali 573 8.0 5.1 39.2 - 5.49 6.64 22.7 10.85 1.12 8.21
Sirohi 28 7.6 2.9 23.5 - 4.62 2.49 19.5 3.39 2.00 8.15
Sri ganga nagar** 138 7.6 4.3 18.7 0.6 8.8 10.1 20.5 - 1.1 5.0
Hanumangarh** 72 7.7 2.8 10.7 0.9 3.7 7.6 11.6 - 1.1 6.2
Source: Paliwal, (1972, 1978)
**Yadav et al, 1998)
Table23: Percentage-wise distribution of ground waters of some districts of western Rajasthan on the basis of conductivity and divalent cation percentage
EC
(dSm-1) Divalent cation percentage
(>50) (30 – 50) (<30)
Jaisalmer Bikaner Barmer Jaisalmer Bikaner Barmer Jaisalmer Bikaner Barmer
<0.25 0.8 - - - - - - - -
0.25– 0.75 7.6 0.8 0.9 1.2 0.8 1.3 0.8 - 0.4
0.75– 2.25 18.9 6.4 11.1 4.2 12.0 7.0 6.4 6.3 6.6
2.25 – 4 1.6 2.8 6.6 5.4 8.2 4.8 7.4 11.5 7.4
4 – 6 2.0 2.0 2.2 2.4 0.8 7.1 12.0 6.2 11.5
6 – 12 2.4 3.2 1.8 6.4 5.0 4.1 13.6 17.0 18.2
>12 0.8 0.4 0.4 2.0 3.8 0.4 4.0 13.0 8.2
Source: Bhandari et. al.,(1971)]
Percentage-wise distribution of ions with respect to different salinity classes (Table24) shows that the proportion of sodium and chloride ions increases whereas those of calcium, magnesium carbonate plus bicarbonate decreases with increase in salinity. However, the proportion of sulphate ions increases regularly up to a mean value of 8 dSm-1 and then decreases in highly saline waters (Dhir, 1977).The quality of ground water varies with soil type but it is difficult to correlate the two ( Darra et al., 1964).

Table24: Percentage-wise distribution of ions with respect to different salinity classes
Ions EC(dSm-1)
<2 2 – 6 6 – 10 >10
Na 51.9 70.3 72.2 74.1
K 1.5 3.2 2.3 1.6
Ca 20.4 9.4 .9 9.2
Mg 26.2 17.1 16.6 15.1
Cl 30.3 54.1 67.2 75.3
SO4 10.3 15.3 20.4 15.2
HCO3 +CO3 59.3 30.6 12.4 9.5
No. of samples 1671 1372 545 344
% 42 35 14 9
Source: Dhir (1977).
Studies conducted by Gupta (1991) revealed that ground waters are sodic in character due to high SAR or RSC values. The SAR ranges from 0.15 to 176.8 with an average value of 13.9. In districts of Barmer, Bikaner and Jaisalmer, more than 33.3 per cent waters have SAR more than 18.High RSC generally occurs in low to medium salinity waters and ranges form nil to 68.8 meL-1 with an average value of 3.1 meL-1. The districts viz. Jhunjhunu (42.5%), Nagaur (32.3%) and Sikar (30.2%) have high RSC in ground water (more than 5 meL-1)
Fluorides and nitrates occur in ground waters in all the districts of Rajasthan, irrespective of salinity . In arid and semi arid regions of Rajasthan the percentage of waters having fluoride higher than 10.0 mg L-1 , is very small (< 5) and the highest concentration is 30 mg L-1 except Nagaur districts, where it occurs up to 90.0 mg L-1 .In arid and semi arid districts , nitrates occurs up to 2800 mg L-1, whereas in humid and sub humid districts it is below 650 mg L-1(Table25) .




Table25: Percentage distribution of fluoride (mgL-1 ) in waters of Rajasthan.

District No. of Samples Fluoride (mgL-1 )
<5 5-10 >10 Max
Barmer 537 88.1 9.1 2.8 19.6
Bikaner 144 90.9 7.6 1.4 12.0
Churu 316 92.1 6.6 1.3 30.0
Jaisalmer 268 97.4 2.6 - 5.0
Jalore 165 92.3 9.1 0.6 14.2
Jodhpur 704 89.9 9.1 1.0 22.0
Nagaur 1080 83.9 11.4 4.7 90.0
Pali 236 89.4 8.5 2.1 18.3
Sriganganagarh &Hanumangarh 84 97.6 1.2 1.2 26.0
Sikar 314 95.6 4.4 15.0
Sirohi 597 98.5 1.5 11.0
Jhunjhunu 295 95.0 5.0 12.0
Jaipure * 120 28.1
Bhilwara* 118 24.0
Udaipur* 166 21.6
Bharatpur* 100 18.4
Tonk 7.6
Alwar* 4.0

Annonymous (2000) (Gopal and Shah (1985)*

Ozha and Jain (1992) noted greatest frequency of water having nitrate above 100 mgL-1in Churu district (76.0%) followed by Nagaur (53.7%),Barmer (53.7%) and Jalore (41.0%).districts. Lower frequency (3.04%) of such water was recorded in Bikaner district. In an another study of Ozha et al.(1993) in Churu district maximum nitrate level was recorded as 2400 mgL-1and only 14.2 per cent of water samples contained nitrate up to 50 mgL-1. In Barmer district the maximum recorded Nitrate value was 1900 mgL-1 and 32 per cent samples contained nitrate up to 50 mgL-1. Rai and Gulati (1997) reported a range of 15 to 590 mgL-1nitrate levels in 60 well water samples of Jodhpur. They recorded the nitrate levels in 55 out of 60 wells beyond maximum permissible limit.About 75% water samples having nitrates >100 mg L-1 was reported in Churu district ( arid zone) ( Anonymous, 2000)) ( Table26)

Table 26: Percentage distribution of nitrates (mgL-1 ) in waters of Rajasthan.
Climatic zone District Nitrate (mgL-1)
Max <50 50-10 >100
Arid (1) Barmer 1600 32.0 13.2 54.8
Bikaner 2100 47.0 16.7 36.2
Sriganganagar 533 72.0 13.9 13.9
Hanumangarh 780 56.0 20.0 24.0
Jaisalmer 1400 62.7 10.4 26.8
Jodhpur 2800 41.0 21.0 37.9
Arid-cum semi-arid (1) Churu 2350 16.2 8.2 75.7
Jalore 600 56.4 10.9 32.7
(including) Jhunjhunu 544 51.8 23.4 24.6
Nagaur 4750 31.0 16.8 52.1
Pali 1400 71.6 16.1 12.2
Sikar 748 47.4 24.0 28.6
Semi-arid(2) Ajmer 730 57.4 20.9 22.1
Alwar 1350 30 30 40
Bharatpur 825 70 -----------30----------
Bhilwara 1010 65 16 19
Jaipure 2640 37 42 21
Tonk 1050 72 12.3 15.8
Sub-humid (2) Bundi 395 92.2 7.8
Rajsamand 370 ------------89---------- 11
Sirohi 395 8 9.3 10.7
Udaipur 472 68.7 21.3 10.0
Humid(2) Banswara 206 83 7.4 3
Baran 370 89.3 6.1 4.6
Dungarpur 408 87.2 4.3 8.5
Jhalawar 397 83 10 7.0
Kot 650 83.4 11.0 5.7
Source: Annonymous (2000)
In Rajasthan Boron in irrigation waters is quite high and ranges from traces to as high as 5 mgL-1 in some well waters of Nagaur, Jaipur, Sirohi, Jodhpur, Bhilwara and Pali districts. Mandal (1967) reported that boron content of different kinds of underground water used for irrigation in Rajasthan varied from 0.28 to 7.66 mg/ L Examination of boron content of 452 ground water samples from several districts of Rajasthan reveal the content lesser than 3 mgL-1 (Paliwal, 1972). However, 10.7 mgL-1 boron has been reported in ground water of Bikaner district having EC15.0 dSm-1 (Gajbhiye et al . 1973). Boron content of well waters of Rajasthan as reported by different workers is given in table 27.



Table 27 : Boron content of well waters of Rajasthan

District No. of samples Range(mgL-1) Av. (mgL-1) Authers
Nagaur 74 0.05-3.1 1.28 Paliwal & Gandhi,1969
Bhilwara 59 0.13-1.62 0.75 Paliwal & Maliwal,1966
Pali 19 0.62-3.1 1.28 Paliwal & Maliwal,1966
Jodhpur 11 0.62-2.18 1.32 Paliwal & Maliwal,1966
Jalour 110 0.50-5.0 1.33 Anonymous,1964
Kota 65 0.10-3.0 0.95 Mathur et al. 1969
Jaipur 85 Tr.-6.0 1.80 Paliwal & Maliwal,1966
Bikaner 137 0.22-10.7 - Gajbhiye et al . 1973

Lithium :
Gupta and Sanganeria (1979) analysed 126 ground water samples from Udaipur district in Rajasthan. Lithium content varied from 0-0.39 mgL-1 with an average value of 0.05 mgL-1 in water having EC from 0.34-9.2 dSm-1



District wise ground water quality in Rajasthan
Ground water Atlas of Rajasthan - 2000
(SRSAC (DST) & GWD, Jodhpur)
AJMER DISTRICT
Salinity map (Fig. 1) shows that fresh to slightly saline ground water (EC below 4.0 dSm-1) occurs in northern, north-eastern, central, south eastern, western, southern and south-western parts of the district. High salinity ground water (EC > 8.0 dSm-1) also occurs in northern, south-eastern, western and north-eastern parts of the district covering parts of Silora, Masooda, Bhinay, Kekri and Pisangan blocks. The EC of underground water of Ajmer district varied between 0.28 to 19.2 dSm-1.with average value 3.86 dSm-1.
The average EC of different blocks i.e. Arain, Bhinay, Jawasa,Kekri, Masooda, Pisangan, Silora and Srinagar are 4.9, 2.8,2.3, 4.9, 4.7, 3.3, 3.9 and 4.1 dSm-1, respectively. In 45% of analyses, conductivity values are below 2.0 dSm-1 while 22.5% and 14.1% analyses fall in the ranges of 2.0-4.0 and 4.0-6.0 dSm-1 respectively. Rest 4.8% and 13.6% analyses are having EC values between 6.0-8.0 and above 8.00 dSm-1 respectively.
About 28 per cent waters have shown bicarbonate type character with either sodium (17.3%) or Ca + Mg (10.4%). These waters occur in Pisangan, Jawaja and Bhinai blocks. Water occurring near foot hill zones and river banks are mostly Ca + HCO3 and Ca + Mg HCO3 type with average EC < 1.0 dSm-1, while sodium bicarbonate type water having EC < 2.0 dSm-1. The chloride type water (48.6%) is mostly associated with sodium dominant cation (43.8%) and 4.8 cases in which dominant cation is Ca + Mg.
Fluoride content in ground water of the district varies from 0.32 mg L-1 (Bada Kheda, block Jawaja) to 17.4 mg L-1 (Bharai block Kekri) with an average of 2.52mg L-1. The fluoride content of less than 1.5 mg L-1 is observed in 40.2% of waters and 1.5 to 3.0 mg L-1 in 32.5% of waters while 27.3% waters have shown the range above 3.0 mg L-1 of fluoride.
The average nitrate content in the district is 78.4 mg L-1 with lowest of 3 mg L-1 at Mehrun Kallan and Nadin Kekri and Pisangan blocks respectively whereas highest of 730 mg L-1 at Kirap block Masooda. 18% well waters have shown nitrate concentration less than 20 mg L-1 whereas 39.4% waters are covered in the range of 20-50 mg L-1 of NO3. The well waters in the range of 51-100 mg L-1 and above 100 mg L-1 are observed in 20.9% and 22.1% water respectively.

ALWAR DISTRICT
The ground water of the district is characterized by fresh to slightly saline type. Nearly 83% of the samples in the district are having EC < 4.0 dSm-1 and considered as fresh to moderately saline in nature. 10% of samples fall in high salinity category (4.0-6.0 dSm-1) whereas only 5% of samples are of very high salinity category with conductivity values between 6.0-8.0 dSm-1. The ground water of villages Titpuri, Bahadurpura, Bhaisdawat, Govindgarh Kaririya, Piproli, Pratapgarh, Rupwas Khari fall in this salinity group. Only two water samples collected from the villages Dauli and Dewara are of very high salinity (>8.0 dSm-1) as they have conductivity values of 15.3 and 12.9 dSm-1 respectively. The minimum salinity is observed at village Garhi Swairan (0.44 dSm-1) of Rani block. Salinity map of Alwar district is depicted in Fig.2.
52.5% ground water of the district is characterized by bicarbonate type of water, in which 50% of the bicarbonate type water is having calcium-magnesium as predominating cation and considered as fresh type of water with EC < 1.5 dSm-1 at 25°C, except at village Masani of Kotkasim block having conductivity value of 2.25 dSm-1. Magnesium is generally higher than calcium in this type of water. Rest of the bicarbonate type waters are of sodium dominating character with higher values of EC as observed at village Rani (2.9 dSm-1), Bhala (2.6 dSm-1) and Kherli and Sayad (2.5 dSm-1) etc. The mixed type of water (28.5%) are of sodium dominating nature with EC normally between 1.5-3.0 dSm-1. These samples are more mineralized than bicarbonate type of water. Only 19% of samples of the district are of chloride type of water in which 15.5% is of sodium dominating while 3.5% is of calcium-magnesium character. The EC of such water is more than 4.0 dSm-1 with the highest value of 15.3 dSm-1 at Dauli village of Thanagazi block.
Regarding Nitrate concentration in the district about 30%, 30% and 40% samples fall in the range of 0-50, 50-100 and > 100 mg L-1, respectively. It is further observed that samples collected from Kishangarh Bas, Kotkasim, Laxmangarh, Mandawar, Neemrana, Ramgarh and Tizara block are of higher values of Nitrate. The maximum value of Nitrate concentration is observed at Bahadarpur (1350 mg L-1) followed by Bambore (774 mg L-1), Baroda Mev (865 mg L-1), Silopka (586 mg L-1) and Rupwas (963 mg L-1) village of the district.
Water samples collected from Bansur, Neemrana and Reni blocks are having less than 1 mg L-1. of fluoride whereas the other blocks of the district except Behror are having 70% of the sample of such type of quality. In Behror block 43% sample are having less than 1.5 mg L-1 of fluoride. Nearly 20% of the samples collected from the block Behror, Kotkasim, Laxmangarh, Ramgarh, Thanagazi, Tijara and Umren are having fluoride concentration between 1.5-3.0 mg L-1. High concentration of fluoride (>3.0 mg L-1.) is observed at Behror (10%), Ramgarh (12%), Thanagazi (11%) and Mandawar (5%) block of the district.

BANSWARA DISTRICT
Ground water in the district is fresh having low salinity characterized by calcium magnesium bicarbonate. 89.6% groundwater in the district have bicarbonate type of character with Ca+Mg as dominant cations. Sodium bicarbonate type of groundwater is seen in 9.1% samples. The mixed anionic character is shown by 7.8% of ground water, out of these 6.5% have calcium+magnesium dominance and only 1.3% have sodium dominance. Mixed type of groundwater is found in blocks - Ghatol, Sajjangarh and Talwara. The rest 2.6% of ground water have sodium chloride type of character. It is also inferred that around 87% of ground water have dominance of Ca+Mg amongst cations. Salinity map of Banswara district is depicted in Fig. 3. EC of underground water in village Chhaja, Jalana, , Delwara, l, Bilari and Chhota Loharia Sajjangarh have EC values in the range of 1.5-2.0 dSm-1.
The nitrate in ground water of the district varies from traces to 206 mg L-1. In 83% of ground water the nitrate values are within 50 mg L-1 whereas 7.4%, samples have nitrate in the range of 51-100 mg L-1. Only 3% groundwater have nitrate above 100 mg L-1. The highest value of nitrate (206 mg L-1) occurs at village Jalana of Garhi block, it is seen that higher range of 51-100 mg L-1 occurs in Bagidora and Ghatol blocks. The nitrate content above 100 mg L-1 is seen only in localised patches distributed throughout the district.
The fluoride concentration in ground water varies from 0.06 mg L-1 in village Umrai of block Talwara to a maximum of 6.45 mg L-1 in village Bilari of Sajjangarh block. 86% of ground water have fluoride within 1.5 mg L-1 whereas 10.9% of ground water have fluoride in the range of 1.5-3.0 mg L-1, which covers substantial part of Ghatol, Garhi and some small part in other blocks. About 3% of ground water having fluoride >3.0 mg L-1 occur in village Bhamarkot of Khushalgarh block, Semlia of Pipalkhoont block, Bilari and Bada Muska of Sajjangarh block and Samgara, Kupra and Shivpura of Talwara block. The district is free from fluoride problem (F<1.5 mg L-1) except some localised patches in northwest (Garhi block), central part (Talwara block) and southwest (Anandpuri block) of the district, where fluoride values above 1.5 mg L-1 are observed.
The sodium is less than 70% of total cations in 96.1% ground water. The 3.9% of ground water having Na above 70% may create alkali hazard. Similarly, 91.3% groundwater have residual sodium carbonate below 2.0 meL-1. Only 8.7% of ground water may impart alkali hazard as their RSC value is more than 2.0 meL-1.

BARAN DISTRICT
The ground water in the district is fresh in nature. The salinity of water in the district ranges from < 0.5 to 3.3 dSm-1. Barring a modest saline stripe in extreme northwest covering Malbamori and Siswali villages of Anta block and some isolated small pockets of moderately saline waters around villages - Kishanpura in Anta block; Bamla, Baran and Phoonsre in Baran block; Daulatpura and Sarthal in Chhipabarod block and Garde in Kishanganj block. The maximum salinity of ground water has been observed as 3.3 dSm-1 around village Sarthal in Chhipabarod block (Fig. 4). The low salinity of ground water in the district is mainly attributed to sub-humid climate and hydrogeological formations (shales, sandstone, limestone and basalt) which are comparatively more resistive to weathering and dissolution.
The ground water in the district is also free of toxic chemical constituents like nitrate and fluoride. 89.3%, 6.1% and 4.6% well waters were found to have nitrate concentration in the range of 0-50 mg/ L, 51-100 mgL-1 and above 100 mgL-1, respectively. High concentration of nitrate (more than 100 mgL-1) in ground water is usually caused by local pollution.
95 per cent well waters in district have fluoride content less than 1.5 mg L-1 which show that the ground, water in the district is free of fluoride problem). Only at a few places namely, Palaitha, Miana and Dugari in Anta block; Dhoti and Motipura in Atru block; Maira and Shaigarh in Baran block; Bhaonra in Chhabra block; Kishanganj proper and Bodhanohera in Shahabad block, the well waters have fluoride more than 1.5 mg L-1 but there too its concentration is below 3.0 mg L-1. The maximum concentration of fluoride in the district is observed as 2.6 mg L-1 at village Bhaonra in Chhabra block.
4.5 per cent and 7.1 per cent ground waters in the district have Na% above 70 and RSC above 2.0 me/L, respectively. Only in Anta, Baran and Atru blocks the ground water at some places is characterized by such problem.


BARMER DISTRICT
There is wide variation in salinity of ground water. It varies from 0.5 dSm-1 to as high as 17.0 dSm-1. The ground water with salinity ranging between 2.0-4.0 dSm-1 is encountered mostly in Chohtan, Banner & parts of Sheo, Siwana and Dhorimanna blocks. However, the ground water is practically saline (EC>8.0 dSm-1) in Baytoo, Sindhari and Dhorimanna blocks. The ground water quality is also saline in west of Sheo, south of Chohtan, south-east of Banner and north-west of Balotra. Only 17.4% ground water have salinity less than 2.0 dSm-1 while 38.9% & 18.8% fall in the slightly saline (2.0-4.0 dSm-1) and moderately saline (4.0-6.0 dSm-1) class of salinity respectively. The saline ground water having EC> 6.0 dSm-1 and covers almost 50% region of the district (Fig.5). The prevalence of high salinity in ground water is due to the hydrogeological barriers like clay formations which covers around sixty per cent of the region. These formations restrict the circulation of water through aquifers and extreme arid climatic conditions help in salinization of ground water.
The water analysis results reveal the presence of unusually high nitrate in ground water. The maximum concentration of nitrate i.e. 730 mg L-1 is found in the well water of Akdara in Baytoo block. The contamination of nitrate (>100 mg L-1) is high in ground water of Baytoo (66.7%), Banner (60.9%), Chohtan (58.8%), Dhorimanna (55.5%) and Sindhari (52.9%) blocks. The nitrate concentration (<100 mg L-1) is relatively low in ground water of Balotra, Sheo and Siwana blocks. No significant relationship exists between nitrate and salinity. Low salinity ground water at many places near Siwana, Chohtan and Banner are characterized with high nitrate. On the contrary, saline ground water of Sindhari, Dhorimanna and Balotra blocks have low nitrates. The ground water of Sheo block along with few small areas in Banner, Chohtan, Balotra & Siwana are free from nitrate contamination. Thus the high concentration of nitrate in ground water is the main problem for locating potable ground water.
Fluoride contents of ground water do not exhibit any specific relationship with salinity. Low salinity ground water IS free from fluoride contamination in the district. High concentration of fluoride are normally associated saline ground water in Baytoo, Sindhari, Dhorimanna blocks. The ground water in the east of Balotra, Siwana and south of Chohtan block has fluorides more than 4.0 mg L-1. The ground water in Baetu (50%), Dhorimanna (78.9%), Sindhari (88.2%) and Sheo (57.1%) blocks have unpotable fluorides in comparison to rest of the blocks. The highest concentration of 18.0 mg L-1 of fluoride is noticed in a highly saline ground water having EC of 14.8 dSm-1.
More than 75% ground water, exhibit dominance of sodium & chloride ions. Such waters yield high dissolved solids and fall in the very high class of salinity. The water analyses reveal that only 7.6% ground water occurring near foot hill zones of Siwana and isolated patches in Sheo have shown bicarbonate type character. These ground waters have dominance of sodium and characterized by low dissolved solids. Further 16.7% ground water exhibit mix type character and the most of these waters occur in north and west of the district. Such type of waters also show dominance of sodium and fall in moderately saline/ class of salinity.
BHARATPUR DISTRICT
Twenty six per cent of ground water in the district is characterized as bicarbonate type while 11.1% is characterized as calcium-magnesium bicarbonate type of water. The electrical conductivity (EC) of bicarbonate type of water is generally < 1.5 dSm-1. However, the EC of these water is between 1.5-3.0 at some places such as Birampur, Pubaikhera, Tarsuman (Bayana block), Tilakpuri (Kaman block), Karei, Unch (Nadbai block), Jaluki (Nagar block), Bansi Paharpur, Bhaut (Roopwas block) and Khairora (Weir block). This type of water is fresh to slightly saline in nature. The mixed type of water constitutes 26.4% of ground water in which 16.4% is sodium mixed and 10.1% is calcium-magnesium mixed type of water. This type of water generally have EC between 1.5-3.0 dSm-1. Sometimes it may exceed to 4.0 dSm-1 at some places such as Didawali, Seu (Deeg block), Manapuri (Naguar), Khansurajpur (Roopwas) etc. Mix type of ground water is more mineralized than fresh water. Nearly 48% ground water in the district is characterized by chloride type of water. The EC of such water is between 4.0-8.0 dSm-1 and sometimes it may exceed 10.0 dSm-1. Villages Anchara Baori, Talphaira (Kumher block), Gandsora & Gulpada (Nagar block) and Kanjauli (Weir block) are having such type of water. Salinity map of Bharatpur district is depicted in Fig. 6.
Fresh to slightly saline water having EC below 2.0 dSm-1 occurs mostly in Bayana block and some parts of Roopwas block. The ground water of the district is characterized as moderately saline to saline water having EC ranging from 2.0 to 8.0 dSm-1. The marginallyf salinity (EC 2.0-4.0 dSm-1) is observed mostly in Kumher, Nadbai and Weir / blocks. The villages Fatehpur, Dhilawati, Dhiman, Garh Ajan, Naugaon in Kaman block, Gazipur, Baraulichhar in Nadbai block, Ajau, Dhanwara, Rarh etc. in Kumher block and Bansichak, Bharsauni, Hingota in Weir block also fall in this range. The medium to high salinity (EC 4.0-6.0 dSm-1) water is observed in villages - Januthar, Mabai, Malipura of Deeg block and Awar, Pichumar, Saint etc. of Kumher block. The next range of saline water (EC 6.0-8.0) is observed at Gopalgarh, Nakatpur, Pahari villages of Nagar block and Dhurmai, Rampi Unchnagla of Sewar block. The maximum salinity (EC 15.0 dSm-1) is observed at Kanjauli village Sewar block and the minimum value (EC 0.39 dSm-1) occurs at Thanasong of Bayana block.
Ground water of EC < 2.0 dSm-1 range is available in 68% in Bayana block 38% in Kaman, 48% in Roopwas and 35% in Weir block. Similarly, the medium to high salinity of water (EC 2.0-4.0 dSm-1) is seen in 47% samples in Kaman, 53% in Nadbai and 50% in Roopwas block. The ground water of next range i.e. 4.0-6.0 cm occurs in 33% in Deeg block and 30% in Kumher block. High to very high salinity i.e. EC 6.0 to 8.0 dSm-1 is seen only in 10% samples of Deeg block 10% of Kumher block, 11% of Nagar block and 18% samples of Sewar block. The ground water of high salinity range i.e. more than 8.0 dSm-1 is represented by 19% samples in Deeg, 20% in Kumher and 18% in Nagar block.).
About 57%, 85%, 75%, 77%, 64%, 60%, 62%, 80% and 94% ground water samples in Bayana, Deeg, Kaman, Kumher, Nadbai, Nagar, Roopwas, Sewar and Weir blocks respectively represent good quality of water having nitrate upto 50 mg L-1. In general, 70% of the number of samples in the district have nitrate upto 50 mg L-1. Other range is 51-100 mg L-1 of nitrate in 36%, 29% and 20% is found in ground water samples of Bayana, Nadbai and Nagar block, respectively. The high values of nitrate more than 100 mg L-1 are observed in Nagar, Kaman and Roopwas blocks in 15%, 20% and 33% samples respectively. The maximum nitrate concentration is 825 mg L-1 which is observed at village Sikripatti in Nagar block.
As regarding fluoride distribution about 73% samples fall in the range of 0-1.5 mg L-1 whereas only 18% samples fall in the range 1.5- 3.0 mg L-1 of fluoride. Only 9% samples fall in higher range of fluoride > 3.0 mg L-1 are observed at villages Birampur (4.0 mg L-1), Salabad (4.0 mg L-1) of Bayana block (3.6 mg L-1) of Deeg block, Tilakpuri (6.0 mg L-1) Kaman block, Baraulichhar (5.3 mg L-1) of Nagar block, Naylatulsi (3.6 mg L-1), Nekpur (5.6 mg L-1) Roopwas block.
BHILWARA DISTRICT
In the district reveal that about 40% groundwater is of bicarbonate type. These types of water is fresh in nature and have EC generally < 2.0 dSm-1. The mixed type of water, constitutes about 29% of the ground water samples while about 31% of the ground water samples show sodium chloride type character. Nearly 39% well waters show calcium and magnesium dominating character while 61% samples show sodium and potassium dominating character. About 75% of water samples showed RSC < 2.0 Me/L.
The EC of ground water varies from 0.31 dSm-1 at Sarsia (Jahazpur) to 11.2 dSm-1 at Dhikola (Shahpura) indicating fresh to highly saline ground water. About 67% of water samples have EC below 2.0 dSm-1 and are characterized as fresh to slightly saline. These waters are found in most parts of northeastern and southeastern side, comprising entire Mandalgarh block and major parts of Jahazpur, Kotri and Shahpura blocks. Such waters are also found in the central part of block Banera and in some parts of block Suwana. Nearly 20% of the waters fall in the salinity level of 2.0-4.0 dSm-1. Such ground waters are found in major parts of northwest and southwest of the district covering Sahada, Raipur, Asind and Mandalgarh blocks and a small part of Hurda block in north. Only 13% samples show EC values above 4.0 dSm-1 and are characterized as high to vary high salinity waters. Such ground waters are found in southern part of block Shahpura and a few patches in Suwana, Sahada, Raipur, Mandal and Hurda blocks (Fig. 7).
About 65% of ground water samples have nitrate concentration in the range of 0-50 mg L-1, while, 16% waters have nitrate concentration in the range of 51-100 mg L-1. Only 19% samples have nitrate values above 100 mg L-1. The high nitrate waters (>100 mg L-1) are mostly found in western side of the district comprising Asind, Raipur, Sahada, Mandal and Suwana blocks. Besides, some small patches of high nitrate waters are also seen in Kotri and Mandalgarh blocks in east. The minimum value of nitrate is found to be 2.0 mg L-1 at Ganeshpura, Kachola and Bijoliyan (block-Mandalgarh) while the maximum value is 1010 mgL-1 found at Dhikola (block-Shahpura).
In the district nearly 57 and 30 % well waters have fluoride < 1.5 mg L-1 and 1.5-3.0 mg L-1., respectively. The rest 13% groundwater’s in the district show fluoride content above 3.0 mg L-1. Low fluoride waters (F<1.5 mg L-1) are found in southeastern part comprising Mandalgarh block and in northeastern side covering major part of Jahajpur and Kotri blocks. In rest of the blocks, the well waters containing fluoride content l.5-3.0 mg L-1 values are equally distributed. The well waters containing high fluoride (F>3.0 mg L-1) values are found-in scattered patches in Jahazpur, Shahpura, Hurda, Asind and Mandal blocks. The lowest value of fluoride has been observed as 0.23 mg L-1 at Resunda (block-Mandalgarh) and the highest value is found to be 8.1 mgL-1 at Phuliakhurd (block-Shahpura).

BIKANER DISTRICT
The native ground water is highly mineralized, a characteristic feature of arid climate. No specific trend in variation of salinity is observed. Fresh to slightly saline water with EC< 2.0 dSm-1 occur in east and south east. Moderately saline ground water (2.0 to 4.0 dSm-1) are available in the east, west and southern parts of Kolayat and Bikaner blocks. About 3.18% waters occur in the salinity range of 6.0 to 8.0 dSm-1 and cover the areas of moderate to high salinity. Rest of 14.66% of ground waters in West and north-west of Kolayat, Bikaner and Lunkaransar blocks and South of Nokha block is highly saline with electrical conductivity of more than 8.0 dSm-1 (Fig.8).
The salinity varies from as low as 0.22 to as high as 28.0 dSm-1. with an average of 4.3 dSm-1. The water analyses reveal that 10.47%, 70.67% and 78.52% well waters have electrical conductivity less than 1.0, 3.0 and 5.0 dSm-1,,respectively. It is observed that the ground water of Kolayat (27.27%) and Lunkaransar (20.57%) have more salinity in comparison to Nokha (3.70%) and Bikaner (11.96%) blocks. The 92.59% well waters of Nokha block has salinity less than 4.0 dSm-1, showing the occurrence of better quality of water. However, the eastern parts of Bikaner and south-eastern parts of Kolayat block have similar ground water quality. Sodium and Chloride are the principal cation and anion in ground waters irrespective of hydrogeological aquifers. More than 47% ground waters covering major region are of sodium-chloride type and fall in high to very high class of salinity. The high average values of chloride in ground waters of Koyalat (1464 mg L-1) and Lunkaransar (1385 mg L-1) blocks illustrate the ultimate stage of mineralization and waters in most of the aquifers in North and West exists in sluggish conditions. Besides this an arid climate and wind blown sand also adds up to salinity in soils and ground waters. Further salinity is also due to hydrogeological barriers like clayey formation, gypsum hardpans etc. present except in East and south-east.
Nitrate is the significant form of nitrogen present in ground water and its concentration has not shown any relationship with salinity. Low salinity waters in East and south-east of Nokha, north-east of Bikaner, north-west of Kolayat and south-east of Lunkaransar blocks, have high nitrates ranging from 100 to 500 mg L-1 whereas high salinity waters in west of Lunkaransar block have less than 100 mg L-1 of nitrate except west of Bikaner. The ground waters have high contents of nitrates in East and south-east and have maximum values in the well waters of Chhatargarh (1160 mg L-1) in Bikaner, Mankasar (840 mg L-1) in Kolayat, Raipura Hudda (1500 mg L-1) in Lunkaransar and Mainsar (1050 mg L-1) in Nokha blocks, respectively. Nitrate exceeds 100 mg L-1 in 51.85% well waters from Nokha block, showing that the quality of ground water is seriously affected by nitrate contamination. While 41.18% and 23.73% waters of Lunkaransar and Bikaner blocks are relatively free from nitrate hazard. Thus, the ground waters of the above regions have a bearing on the potable water supplies due to high contents of nitrate.
The ground water of the Nokha block is free from fluoride hazard. About 88.68% water have less than 1.5 mg L-1 of fluoride while 11.32% fall above 1.5 mg/ L. The presence of fluoride in alarming concentration in ground water of Lunkaransar block where 31.25% and 37.50% well water have its concentration above 3.0 mg L-1 and between 1.5-3.0 mg L-1, respectively. However, the ground water of Bikaner (43.86%) and Kolayat (41.86%) are also characterized by high fluorides i.e. above 1.50 mg L-1. It ranges from 0 to 8.68 mg L-1 in the well water of Hariysar (Lunkaransar block), a highly mineralized water with salinity of 20.0 dSm-1 and sodium-chloride character. The chemical analyses reveal that the saline water in Lunkaransar (average EC-5.3 dSm-1) and Kolayat (average EC-5.5 dSm-1) blocks are characterized by high fluorides with an average value of 2.66 mg L-1 and 1.70 mg L-1 respectively. On the contrary ground waters of Nokha (average EC-2.5 (dSm-1 & F-0.98 mg L-1) and Bikaner (average EC-4.5 dSm-1 & F-1.77 mg L-1) blocks have comparatively low fluorides as well as salinity. The high fluorides (above 4 mg L-1) are associated with high salinity ground waters and found in north-east and central parts of the district.

BUNDI DISTRICT

Ionic concentration or salinity of water varies according to hydrogeological, geomorphological and climatic condition of the region. The lowest electrical conductivity of 0.26 dSm-1 and highest of 8.5 dSm-1 has been observed in the district. The percentage of water samples in various electrical conductivity ranges observed as 88.8% below 2.0 dSm-1 while 8.0% and 3.2% fall in the range of 2.0-4.0 and 4.0-6.0 dSm-1, respectively. The average EC observed in different blocks i.e. Hindoli, Nainwa, Talera and Keshoraipatan blocks is 0.9, 1.1, 1.2 and 1.7 dSm-1 respectively.
Fresh ground water (EC < 2.0 dSm-1) is found almost in whole iindoli and Nainwa blocks. The moderately saline vater of EC above 2.0 dSm-1 is observed in Keshoraipatan block (South-east) and a small part in Patera block (South-west). About 88.8, 8.0 and 3.2 per cent water samples showed EC < 2.0, 20-4.0 and > 4.0 dSm-1, respectively (Fig. 9).
The fluoride content in ground water varies from minimum of 0.13% mg L-1 to a maximum of 5.96 mg L-1 with an average of 0.89 mg L-1. The fluoride content remains within 1.5 mg L-1 in 86.8% of well water while 10.2% of well water falls in the range of 1.5-3.0 mg L-1 of fluoride concentration. Rest 2.99 per cent ground water has fluoride concentration above 3.0 mg L-1. Alluvium, schist and lime stone are the source of fluoride in ground water which is evident from the fact that average fluoride content observed in the wells tapping these formations is above 1.0 mg L-1. Most of the area in the district is free from fluoride problem (F<1.5 mg L-1).
Nitrate content in ground water varies from 1.0 mg L-1 to 395 mg L-1 with an average of 46 mg L-1. 7.8% of well waters show nitrate content more than 100 mg L-1. Water having high nitrate content generally have high content of potassium. Most of the area of the district is free from nitrate problem (NO3 < 100 mg L-1).

CHITTAURGARH DISTRICT
Ground water of the district is fresh to slightly saline in nature. No specific trend in variation of salinity is observed except in north-west. Fresh waters occurs in Pratapgarh, Chhoti Sadri, Gangrar, Nimbahera blocks. Few instances of slightly saline water are also observed along with fresh water of Arnod, Chittaurgarh, Begun, Bhainsrorgarh and Bhadesar blocks. The ground water with moderate salinity (2.0-4.0 dSm-1) is noticed in north-west of the district covering parts of Bhopalsagar. Kapasan & Rashmi blocks. However, scattered cases of such waters are observed in west of Bari Sadri and north of Dungla blocks. Rest of the ground water having EC >4.0 dSm-1 are saline and encountered in Bhopalsagar and Rasmi blocks. The salinity varies from 0.35 dSm-1 to 6.20 dSm-1 with an average value of 1.34 dSm-1. The presence of saline water was observed in Bhopalsagar and Rasmi blocks. While Bari Sadri, Dungla & Kapasan blocks have slightly saline to moderately saline ground water besides saline ground waters. The water analyses reveal that 85.55%, 12.72% and 1.73% well waters have electrical conductivity varying between 0-2.0, 2.0-4.0 and above 4.0 dSm-1. Salinity map of Chittaurgarh district is depicted in Fig. 10.
Fluoride has not shown any close relationship with salinity. The sodium bicarbonate type of waters have been found to contain appreciable fluorides. The ground water of Arnod, Bari Sadri, Chhoti Sadri, Pratapgarh, Chittaurgarh, Bhadesar, Kapasan and Rashmi blocks are free from fluoride hazard. Similarly the Begun, Bhaisrorgarh and Nimbahera blocks also have ground water fluorides less than 1.5 mg L-1 in 93%, 93% and 91% well waters respectively. The fluoride contents between 1.5 to 3.0 mg L-1 are observed in well waters of Bhopalsagar (50%), Gangrar (14%), and less frequently in Nimbahera (9%), Begun (7%) and Bhainsrorgarh (7%) blocks. The ground waters of Dungla (34%), Bhainsrorgarh (15%) and Gangrar (7%) blocks have flourides above 3.0 mg L-1 and may cause fluorosis if used for a long period. The average value of fluoride is 0.79 mg L-1 and the highest concentration of 7.41 mg L-1 is found in the well water of Tana of Bhopalsagar block. The water is sodium bicarbonate type with RSC value of 8.10 meL-1..
Nitrate is present in significant concentrations in ground water in north-west of the district. In general, its concentration has not shown any specific trend with salinity. Low salinity water at few places in Bari Sadri, Chhoti Sadri, Rashmi, Gangrar and Bhadeshar blocks have high nitrates ranging between 100 to 200 mg L-1. The nitrate contamination may be due to the localized cases of pollution. These waters with moderate salinity (EC > 2.0 dSm-1) are observed at Rashmi (30%), Kapasan (30%), Bhopalsagar (37%), and Dungla (30%), block respectively. Besides above, the ground waters of Gangrar (22%), Nimbahera (48%), Bari Sadri (23%) and Chhoti Sadri (9%) blocks are impotable. The ground water in Arnod, Pratapgarh, Chittaurgarh, Begun, Bhainsrorgarh and Bhadesar blocks have nitrate contents less than 100 mg L-1 and thus suitable for drinking. The highest value of 270 mg L-1 of nitrate is found in the well water of Nikoon with salinity of 2.5 dSm-1 in Bari Sadri block. The water is having mix type character.

CHURU DISTRCT
Ground water in the district is characterized by medium to high salinity. Fresh to slightly saline ground water having EC < 2.0 dSm-1 occurs in the West, i.e., parts of Dungargarh blocks. The western parts of Sardarshahar, Sujangarh, Ratangarh alongwith some small patches near Churu and Rajgarh blocks have ground water with salinity less than 4.0 dSm-1. The saline ground waters are widely distributed in the north, east and south-east. Thus, the ground water is exclusively saline in Rajgarh, Taranagar, Ratangarh and Churu blocks where salinity of ground water exceeds 8.0-10.0 dSm-1. The salinity of ground water ranges from as low as 0.85 to as high as 25.0 dSm-1. That the ground water from Dungargarh (93,10%) and Ratangarh (72.72%) blocks have more or less low salinity (EC<4.0 dSm-1) as compared to rest of the blocks. On the contrary, the ground water of Rajgarh (38.09%), Taranagar (60%), Churu (21.05%) and Sardarshahar (15%) are salinity infested, i.e., electrical conductivity of ground water are more than 8.0 dSm-1. In general, Churu district has saline (20.9%) to highly saline (17.15%) ground water having electrical conductivity ranging between 5.0-8.0 and more than 8.0 dSm-1 (Fig. 11). The predominant cation and anion in ground waters are sodium and chloride respectively. More than 56% waters are of sodium-chloride type and are distributed throughout the district covering north east, central and south-east part. Few localized patches are also found in west. Sodium-chloride type waters have high electrical conductivity and usually exist in discharge zone. The influence of aridity and base exchange phenomenon taking place between the infiltrating water and information material is clearly seen in north, east and south-east of the district by the presence of highly saline ground waters.
The concentration of nitrate ranges from 6 to 995 mgL-1 in the well water of Sarothia in Sujangarh with salinity of 4.6 dSm-1. Nitrate concentration is present in hazardous- levels. More than 79% ground water in the district have nitrate contents above l00 mg L-1, with an average value of 270 mg L-1. The average nitrate concentration in various blocks is 294mg L-1 in Churu, 259mg L-1 in Dungargarh, 199mg L-1 in Rajgarh, 285 mg L-1 in Ratangarh, 247mg L-1 in Sardarshahar, 327mg L-1 in Sujangarh and 185mg L-1 in Taranagar. Only 31.25%, 28.95% & 50% ground water from Rajgarh, Sardarshahar and Taranagar blocks have nitrates less than 100 mg L-1. Most of these waters are saline.
Fluoride contents in 81.25%, 82.76% & 78.12% well waters of Churu, Dungargarh and Sujangarh ranges between 0 to 1.5 mg L-1. The fluoride concentration above 1.5 mg L-1 are noticed in well waters of Rajgarh (75%), Ratangarh (57.89%), Sardarshahar (55%) and Taranagar (100%) blocks. The highest concentration is 11.6 mg L-1 in the well water of Sobhasar with salinity of 4.6 dSm-1.


DAUSA DISTRICT
Fresh to slightly saline water having EC < 2.0 dSm-1 occurs in most part of the district except around villages Dausa, Bhandarej, Baniyana, Japra, Sikandra and Bamanwas in the central part where the water is of higher salinity ranging from 2.0 to 8.0 dSm-1. The ground water is fresh to slightly saline in entire Lalsot block of the district where the EC is < 2.0 dSm-1 except at Lakhanpur village where the EC of water is 3.2 dSm-1. The groundwater is fresh in Sikrai block in south eastern part of the district except at Sikandra village where the water is saline. The eastern part of the Mahwa block of the district is characterized by groundwater of medium salinity of the range 2.0-4.0 dSm-1. The groundwater of salinity range 4.0 to 6.0 dSm-1 occurs in western part of the district comprising villages of Dausa block namely- Bhandarej, Jhonpara and Kalakho. The groundwater of the EC range 6.0-8.0 dSm-1 is seen only in Alloda in west part of the district. The EC of groundwater ranges from 0.47 dSm-1 to 7.7 dSm-1 with an average salinity of 1.68 dSm-1 (Fig.12).
The ground water in the district is mostly characterized by bicarbonate type of water (51.5%) in which 27% is sodium bicarbonate type while 24.5% is characterized as calcium magnesium bicarbonate type of water. The mixed type of water constitutes 27% of groundwater in which 17% is sodium mixed and 10% is calcium magnesium mixed type of water. These types of water generally have EC ranging between 1.5 to 3.0 dSm-1 and in some cases it may exceed upto 4.0 dSm-1. 21.5% ground water is of chloride type in which 15.5% are sodium chloride type and 6% are of calcium magnesium type. These waters are usually more mineralised and have EC value 3.0 dSm-1 or more.
The fluoride concentration in the district is within the limits i.e. upto 1.5 mg L-1 in most part except in west around Dausa and around Hudla, Mahwa and Lalpuri in east. The higher concentration of the range 1.5-3.0 mg L-1 is found around Dausa, Khorikalan and Diganiya as mentioned above. The concentration of fluoride of the range more than 3.0 mg L-1 is encountered around Malarna village of Dausa block and Kheda Sumersingh, Dhardi and Mahwa village of Mahwa block. The maximum concentration of fluoride is found at Malarna (5.09 mg L-1) in Dausa block. The average fluoride concentration in the district is 1.0 mg L-1..
High concentration of nitrate of the order of more than 100 mg L-1 is distributed in central and eastern region covering Dausa, Sikrai and Mahwa blocks. A small patch of high nitrate water is also encountered in south around Lalsot and Ramgarh villages. About 56%, 40%, 0%, 30% and 50% groundwater in the block Dausa, Lalsot, Sikrai, Mahwa and Bandikui respectively represent good quality of water upto 50 mg L-1 of nitrate concentration. Similarly, higher concentration of nitrate i.e. more than 100 mg L-1 is seen in Dausa, Lalsot, Sikrai, Mahwa and Bandikui blocks in 31%, 27%, 60%, 40% and 8% samples respectively. The maximum nitrate concentration is seen as 780 mg L-1 at village Bagri in Lalsot block whereas its minimum value occurs at village Khedla in Mahwa block (NO3-12mg L-1). The average nitrate value for the district is 116 mg L-1.).
DHAULPUR DISTRICT
The ground water is mostly characterized by fresh to slightly saline type. Fresh to slightly saline water having electrical conductivity values below 2.0 dSm-1 is found in entire district except a few patches in Bari, Baseri, Dhaulpur and Rajakhera blocks. Medium salinity water of the range 2.0-4.0 dSm-1 is found in villages Dhurwas, Umreh in Bari block, Baseri in Baseri block, Baserinib, Manpur and Saipur in Dhaulpur block and Sawaliapur, Hatwari, Karka-Khera. Singhawalikallan, Unheri and Mangrol villages in Rajakhera block as seen from the salinity map of the district. Water samples with EC range between 4.0-6.0 dSm-1 are found only in villages Chilikhur in Baseri block and Suakabag in Dhaulpur block of the district whereas Angai in Baseri and Purani Chhaoni in Dhaulpur block have water samples in the range of 6.0-8.0 dSm-1. The minimum EC value occurs in Nibbi village of Dhaulpur block and maximum value is seen at Angai of Baseri block (7.4 dSm-1). Salinity map of Dhaulpur district is depicted in Fig. 13.
About 76.4 per cent ground water of the district is characterized by bicarbonate type of water in which 52% is characterized as calcium-magnesium type of water whereas 24.4% is sodium bicarbonate in nature having electrical conductivity (EC) values generally < 1.0 dSm-1. The mixed type of water constitutes 12.6% of the ground water in the district in which 8.6% is of sodium dominating and 4% is having higher values of calcium and magnesium. Normally, these samples are having EC values between 1.0-3.0 dSm-1 and even more. Only 11% samples fall in chloride type of water in which 6.3% samples are having calcium-magnesium and rest having sodium as predominating cation. In Khanpur, Umreh, Jarga, Basai, Hanota, Purani Chhaoni, Sankabag and Singwatikallan villages, waters are having more conductivity values. The maximum conductivity in chloride type is observed at Purani Chhaoni (6.8 dSm-1) and Sankabag (4.9 dSm-1).
About 50%, 69%, 75% and 45% of the groundwater in the block Bari, Baseri, Dhaulpur and Rajakhera respectively represents waters having fluoride concentration less than 1.5 mg L-1 whereas 45%, 27%, 19%, and 43% ground water in the above blocks respectively have higher values of fluoride (1.5-3.0 mg L-1). Only 5%, 4%, 6% and 11% samples in blocks Bari, Baseri, Dhaulpur and Rajakhera respectively have fluoride more than 3.0 mg L-1. Most of the water of the district are having fluoride concentration less than 1.5 mg L-1 except area around Baseri, Kotra, Jitpura, Salampur, Takimpur, Sapan forming a big patch in northwest portion of the district which is having more fluoride in the range of 1.5-3.0 mg L-1 or even more. Similarly, another patch of fluoride concentration more than 1.5 mg L-1 is seen in Rajakhera block in northeastern part of the district. The higher values of fluoride concentration are also observed at Barauli in Baseri block, Malani pawar and Saipur in Dhaulpur and Bajna, Dan and Faraspur in Rajakhera block with the maximum at Bajna village (5.2 mg L-1).
About 56%, 78%, 79% and 83% ground water in the block Bari, Baseri, Dhaulpur and Rajakhera respectively represents good quality of water having nitrate concentration upto 50 mg L-1. Similarly other ranges of nitrate i.e. 50-100 mg L-1 as 19%, 15%, 15% and 10% respectively in above blocks. The higher nitrate values above 100 mg L-1 are mostly found in Bari block (25%) followed by Baseri and Rajakhera blocks (7% each) and Dhaulpur block (6%). The maximum value of nitrate is observed at Purani Chhaoni (300 mg L-1) of Dhaulpur block.
DUNGARPUR DISTRICT
EC of groundwater of the district varied from 0.23 to 4.3 dSm-1 with an average value of 1.03 dSm-1. Nearly 91.5% water sources in the district fall in the salinity level of fresh to slightly saline water (EC < 2.0 dSm-1) whereas 7.8% ground water have moderately saline character (EC 2.0-4.0 dSm-1). Occurrence of fresh water is more frequently in Bichhiwara, Dungarpur, Seemalwara and parts of Aspur and, Sagwara blocks. Moderately saline ground water found in the southern part of Aspur block and northern part of Sagwara block. Only one village Kariyana in Sagwara block has EC 4.3 dSm-1(Fig 14); Such moderately saline waters are derived from phyllite and schist aquifers .
The nitrate in the ground water varies from 4 mg L-1 (Bichriya in Seemalwara block) to 408 mg L-1 (Talora in Aspur block) with an average value of 45 mg L-1. In 87.2% of ground waters the nitrate values are within 50 mg L-1, whereas 4.3% well waters fall in the nitrate range of 50-100 mg L-1. Above 100 mg/ L of nitrate content are observed in 8.5% well waters, mostly in Aspur and Sagwara blocks, besides some localised patches About 63.8% of well waters have fluoride within the range of 1.5 mg L-1. This type of well waters can be seen at Bichhiwara, Seemalwara, Dungarpur, parts of Sagwara and Small part of Aspur block. Higher range (1.5-3.0 mg L-1) of fluoride content is seen in 19.2% water samples. In 17% water samples which cover the area in entire north-eastern part of the district, southern part of Aspur, northern part of Sagwara and western part of Dungarpur blocks, the ground water has fluoride content more than 3.0 mg L-1.
Irrigation with waters containing sodium percentage more than 70 and RSC more than 2 meL-1 impart alkalinity to the soil. 99.3% well waters have sodium percentage below 70 and 96.4% well waters have RSC below 2 meL-1. Water of only Gamaridewal village (Bichhiwara block) has sodium percentage more than 70 and well waters of Amartia (Aspur), Banwasa (Aspur), Gamari dewal (Bichhiwara), Vamasa (Sagwara) have RSC more than 2 meL-1.
SRIGANGANAGAR DISTRICT
The salinity varies from slightly saline in north west to highly saline in east and south of the district. About 35% well waters covering more than 50% of area in east, south and south-west are of sodium-chloride type. The electrical conductivity of waters (21.19%) are often far above 8.0 dSm-1. The slightly saline waters with EC < 4.0 dSm-1 are observed in north-west and covers most of the regions of the Ganganagar and Karanpur blocks. Further north-west of Padampur, north of Raisinghnagar and few patches around Anoopgarh and Suratgarh have similar salinity (Fig. 15). Due to influence of the seepage more than 40% ground waters have salinity < 2.0 dSm-1. The ground water is highly saline with conductivity more than 8.0 dSm-1 in Anoopgarh (47.06%), Sadulshahar (33.33%) and Suratgarh (28.57%) blocks. The well waters from Ganganagar (70.59%), Karanpur (82.95%), Padampur (61.11%) and Raisinghnagar (73.92%) blocks have low salinity ground water (EC < 4.0 dSm-1) The minimum and maximum salinity are noticed in the well waters of Kesharsinghpur (0.4 dSm-1) in Karanpur block and Tatarsar (2.7 dSm-1) in Padampur blocks respectively. The average salinity of ground water of various blocks clearly illustrates the highly saline character of ground water in Padampur (5.1 dSm-1), Suratgarh (5.6 (dSm-1), Anoopgarh (6.2 dSm-1) and Sadulshahar (8.6 dSm-1). The sodium and chloride are the dominating ions in 35.59% ground waters. These sodium-chloride type waters have high salinity and occur in Anoopgarh, Raisinghnagar, Sadulshahar and Suratgarh blocks. More than 42% ground waters with mix type character are encountered in Karanpur, Padampur and parts of Raisinghnagar and Suratgarh blocks, showing the occurrence of ground water in transitional state. The presence of bicarbonate type waters in Karanpur and Padampur reveals the influence of seepage from canal. Thus the factors like seepage, water logging and arid climate conditions play an important role in governing the chemical quality of the ground water in the district.
The low salinity ground waters of Ganganagar, Karanpur, Padampur and Raisinghnagar in north-west of the district contain nitrate less than l00 mg L-1. The saline ground water have very high concentration of nitrate i.e. above 100 mg L-1. Ground water from Anoopgarh, Sadulshahar and Suratgarh have been contaminated by the presence of nitrate contents of more than l00 mg L-1. The nitrate content ranges from nil to 870 mg L-1 in the well water of Bhojasar in Suratgarh. About 79% waters have less than 100 mg L-1 of nitrate while 21% ground waters with more than 100 mg L-1 are confined usually in east, south and south-west where ground water is already saline. Thus the ground water is more or less free from nitrate contamination.
Fluorides more than 1.5 mg L-1 are found in saline ground water. At few places in south-west of Padampur, north and east of Karanpur and in north of Ganganagar, the low salinity ground water also contain high fluorides. The ground water in Raisinghnagar (80%), Sadulshahar (75%), Padampur (68.75%), Suratgarh (60%) and Ganganagar (62.56%) are characterized by low fluoride (<1.5mg L-1) as compared with ground water of Anoopgarh and Karanpur blocks where fluoride contents are more than 1.5mg L-1 in 44.44% and 52.63% respectively. Fluoride ranges between 0 to 9.2 mg L-1 in the well water of Pipran (Suratgarh block) having electrical conductivity of 1.6 dSm-1.
HANUMANGARH DISTRICT
The electrical conductivity varies from 0.45 dSm-1 to as high as 22.0 dSm-1 in the well water of Chhayan in Nohar block. About 81.25%, 69.23% & 68% well waters from Bhadra, Hanumangarh and Nohar blocks respectively have salinity less than 4.0 dSm-1. The salinity at many places is influenced by seepage of canal water. Further 10.2% & 8% ground water of Hanumangarh and Nohar blocks have electrical conductivity values between 4.0-6.0 dSm-1. More than 16% of waters occurring mostly in 10.25% in north-west and south of Hanumangarh and 12.50% have salinity more than 8.0 dSm-1 (Fig.16).. The average EC of Nohar block is observed 4.8 dSm-1 .The overall average value of EC in the district is 3.86 dSm-1, showing the impact of aridity.
The chemical character of ground water is not uniform. The presence of mix bicarbonate type waters (25%) clearly shows the contribution of seepage from the canal or any fresh water source. Such waters are mostly observed in Hanumangarh and Nohar blocks. About 36% well waters have mix character with sodium as predominant cation. Sodium-Chloride type waters (22%) are characterized by high salinity.
Ground water is free from the nitrate hazard. About 13.64% well waters containing nitrate contents above 100 mg L-1 are observed in south-west of Nohar and 14.28% ground water in few patches of Hanumangarh block. In general, Bhadra block (21.43%) has high nitrate (>100 mg L-1) as compared to rest of the region.
The ground water is free from fluoride hazard. More than 81.8% ground water have fluoride concentration below 1.5 mg L-1 in Bhadra and Nohar blocks. The presence of fluoride around 1.0 mg L-1 in drinking water is beneficial for the development of sound teeth. the ground water of Hanumangarh and Nohar blocks are characterized by high fluorides as compared to Bhadra block. About 22.86% & 13.64% well water of Hanumangarh and Nohar blocks have fluoride contents above 3.0 mg L-1 and may cause fluorisis if used for a long periods.
JAIPUR DISTRICT
The ground water of Jaipur district is characterized by low to high salinity. The fresh to slightly saline water having EC below 2.0 dSm-1 occurs in most part of the district. Waters with higher EC are observed in south eastern part of the district around village Chaksu, central eastern part of Jamwa Ramgarh block, northwest side near Govindgarh and part of Sambhar block. Two small patches of this range one around Kotputli and other between Shahpura and Amber block are also observed. In southwest a patch between Phagi, Dudu, Sambhar and Sanganer block also have such type of water. The maximum salinity of water is found at village Untirampura (EC 12.0 dSm-1) in Sanganer block and the minimum at village Mozmabad (EC 0.39 dSm-1) in Dudu block. Salinity map of Jaipur district is depicted in Fig. 17.
The ground water in the district is mostly characterized by bicarbonate type of water (56%) out of which 42% is classified as sodium bicarbonate, 8% is of calcium plus magnesium bicarbonate type and 6% is mixed bicarbonate type. This type of water is generally fresh in nature with electrical conductivity < 1.5 dSm-1 except at some places where EC of water is between 1.5-3.0 dSm-1. The mixed type of water constitutes only 22% in which 14% is of Na-mix, 5% is Ca-Mg- mix and rest 3% is mix-mix type of water. The EC of these water ranges between 1.5-3.0 dSm-1 but at some places it may exceed upto 4.0 dSm-1. The rest 22% ground water is chloride type having sodium as the dominant cation. These waters have EC ranging between 3.0-12.0 dSm-1.
The ground water in 0-2.0 dSm-1 range is available in 69% in Amber, 82% in Birath, 72% in Bassi, 64% in Chaksu, 54% in Dudu, 59% in Govindgarh, 69% in Jamwa Ramgarh, 79% in Jhotwara, 63% in Kotputli, 42% in Phagi, 41% in Sambhar, 57% in Sanganer and 91% in Shahpura block and is characterised as fresh to slightly saline water. The next range of moderately saline water i.e. EC 2.0-4.0 dSm-1 is represented by 12% in Amber, 8% in Bairath, 21% in Chaksu, 22% in Dudu, 8% in Govindgarh, 12% in Jamwa Ramgarh, 37% in Kotputli, 26% in Phagi, 33% in Sambhar, 14% in Sanganer and 9% in Shahpura blocks. EC 4.0 and above is represented by 15% in Chaksu, 24% in Dudu, 31% in Jamwa Ramgarh, 12% Jhotwara, 17% in Sambhar and 29% in Sanganer block.
The distribution pattern of nitrate concentration shows that 37% samples fall in 0-50 mg L-1 range, 42% in 51-100 mg L-1 range and rest 21% samples fall in more than 100 mg L-1 of nitrate. The maximum nitrate value is observed at village Untirampur (2640 mg L-1) in Sanganer block.
The fluoride concentration is below 1.5 mg L-1 in part of the district. The north part of the district in Kotputli block, area between Amber and Shahpura, northwest part in Govindgarh and southern part in Dudu and Phagi blocks are having fluoride concentration in the range 1.5 to 3.0 mg L-1. The villages Gonera, Ponyala, Putli, Chaturbhuj in Kotputli, Mohanpura in Shahpura block, Tigria in Govindgarh block, Dhamana, Korsina, Sarwad, Chatyali, Phagi, Choru in Phagi block, Kadera, Kohlye, Sheodaspura in Chaksu block are having fluoride concentration more than 3.0 mg L-1.
About 75, 17 ad 7 % of water samples in the district have fluoride cotent in the range 0-1.5, 1.5-3.0 ad > 3.0 mg L-1, respectively. The higher range (>3.0 mg L-1) of fluoride is found in 20% samples in Chaksu, 15% in Dudu, 8% in Govindgarh, 19% in Kotputli and 35% in Phagi block. The maximum fluoride concentration in the district is found at village Manoharpura in Shahpura block.
JAISALMER DISTRICT
The hydrogeochemical investigations reveal that fresh to slightly saline ground water occur in Lathi and Parewar sand stone aquifers. In certain ranges of Vindhyans and Quaternary and Tertiary aquifers yield moderately saline ground water while the rest of the region is salinity infested. The salinity ranges between 0.4 and 48.0 dSm-1 with an average of 3.95 dSm-1. The ranges of salinity and per cent samples are given in bar diagramme. It is observed that ground water in Jaisalmer block is relatively less saline due to the presence of Lathi basin. The ground water in Sam and Sankra block is saline as more than 45% and 36% well water fall in the range of 4.0-6.0 dSm-1 respectively. The high salinity (>8.0 dSm-1) are usually observed in north of Jaisalmer, Sam and in middle & south of Sankra block. Low salinity ground water (EC < 2.0 dSm-1 are only available in the Lathi basin region (south-east of Jaisalmer) and Sanu-Parihar region. The ground water with moderate salinity (EC 2.0-4.0 dSm-1) are encountered in south, east, north-west and west. The ground water in rest of the region is saline and its salinity exceeds 8.0 dSm-1 particularly in north and southeastern parts of the district. Salinity map of Jaisalmer district is depicted in Fig. 18.
Nitrate occurs within common range of 0-100 mg L-1 in ground water. The ground water is more or less free from nitrate contamination as only 17.2% well water have been found to contain more than 100 mg L-1 of nitrate.
In general, the fluoride exceeds 1.5 mg L-1 in 54.7%, 50% and 76% ground water of Sankra, Jaisalmer & Sam blocks respectively. The fluoride in ground water of the district does not reveal any close relationship with salinity or type of water. However, saline ground water of Sam & Jaisalmer blocks are associated with high concentration of fluoride.
JALORE DISTRICT
Jalore district being a part of arid region has ground water of varying salinity and diverse chemical character. The electrical conductivity (EC) of water ranges from 0.53 dSm-1 (Wara; Raniwara block) to 21.0 dSm-1 (Chilwara; Sanchore block). Fresh to slightly saline ground waters (EC <2.0 dSm-1) mostly occur in Raniwara (65% samples) and Jaswantpura (60% samples) blocks and along the rivers Jawai, Sukri and Sagi flowing through the central part of the district in Jalor and Bhinmal blocks (Fig. 19). Fresh water pockets are also observed along foothill zones of Jaswantpura, Raniwara and extreme northern part of Saila block. These waters are mostly bicarbonate type and have either sodium or calcium and magnesium as the predominant cation. The ground water is relatively saline in most part of Sanchore block and eastern part of Ahore and Jalore blocks. These waters have sodium-chloride type of chemical character.
The concentration of nitrate in ground water is generally low. Only 20.6 per cent well waters show nitrate values above 100 mg L-1. High nitrate waters (NO3 >100 mg L-1) occur in two elongated stripes in north and south of Sanchore block, some confined pockets in Sayla, Bhinmal, Raniwara and Jalor blocks and as a few isolated spots in Ahore block. Statistically, groundwater falling in nitrate concentration range of 0-50, 50-100 and above 100 mg L-1 are 51.3, 28 and 20.6 per cent respectively. Maximum concentration of nitrate (570 mg L-1) is observed at village Dhanta in Sanchore block. Blockwise, the ground water in Bhinmal and Sanchore blocks has higher concentration of nitrate as compared to its concentration in other blocks.
Fluoride in ground water is cause of endemic fluorosis in the district. Nearly, 60.3 per cent well waters have fluoride concentration more than 1.5 mg L-1. The frequency of occurrence of such waters is even more in Ahore (78%), Jaswantpura (64%), Sanchore (67%) and Sayla (65%) blocks. Fluoride rich waters are seen in almost all the formations viz., alluvium, granite and rhyollite etc. which constitute potential aquifers in the district.
Fluoride concentration is low (<1.5 mgF/L) in south around the villages Ratanpura, Rampura, Rewara, Golwara and Melwa in Raniwara block, Kotra, Valona, Khara and Jherat in Sanchore block, in north around villages Kuaber and Nimbalana in Sayla block, a narrow stripe from Jalore extending southward and covering villages Bakra, Sarat and Bibalsar and a small patch in northeast around Ghana and Bakli villages in Ahore block. The maximum fluoride concentration in the district is observed as 14.0 mg L-1 village Dhanpur in Jalor block.
JHALAWAR DISTRICT
The salinity map Fig 20) clearly reveals the occurrence of fresh ground water in the district. Barring a saline stripe in south east around Harispura and Jhirniya villages of Jhalawar block and a isolated small patch of saline water around Garnawad in Jhalrapatan block, the salinity of water is less than 4.0 dSm-1. It is observed that out of 167 water samples, 146 well waters have electrical conductivity less than 1.5 dSm-1. The lowest value of salinity is observed at Reechawa (0.26 dSm-1) in Dag block whereas its maximum value is observed as 8.3 dSm-1 at Thirniya in Jhalrapatan block. It is also observed that waters having EC more than 4.0 dSm-1 are localised in nature and occur only as small pockets in east and west of the district.
The ground water in the district is mostly free of toxic and health hazardous constituents like nitrate and fluoride. 83%, 10% and 7% well waters in the district have nitrate concentration in the range 0-50 mg L-1, 51-100 mg L-1 and more than 100 mg L-1 respectively. High concentration of nitrate (>100 mgL-1) is mainly caused by local pollution which is evinced by relatively higher salinity of such waters. The maximum nitrate concentration is observed at Dehikhara in Khanpur block (EC 3.2 dSm-1, NO3 397 mg L-1) followed by Kalikhara (EC 2.5 dSm-1, NO3 282 mg L-1) in Pirawa block and Anawali kalian (EC 1.5 dSm-1, NO3 14 mg L-1) in Jhalrapatan block.
Above 99 per cent well waters in the district have fluoride content less than 1.5 mg L-1 which shows that the ground water in the district is free from fluoride problem. Only at Golana in Khanpur block the concentration of fluoride in ground water has been observed as 1.6 mg L-1.
JHUNJHUNUN DISTRICT
The ground water in the district is mostly characterized by low to medium salinity as seen from the salinity map of the district. Fresh to slightly saline water having EC below 2.0 dSm-1 is found in most part of the district specially in Udaipurwati, Nawalgarh, Khetri and Buhana blocks. The moderately saline water (EC 2.0-4.0 dSm-1) is found in block Alsisar in north-west, block Buhana in east, block Surajgarh in northeast and block Jhunjhunun in west of the district. Besides these, some scattered patches in other blocks also have such quality of water. The ground water of higher salinity (EC range 4.0-6.0 dSm-1) is seen mainly in Alsisar, Buhana and Chirawa blocks. The village Alsisar, Juharpura, Tamkor, Birmi, Jawasar and Nalwa are having very high salinity (EC >6.0 dSm-1) in groundwater (Fig. 21). The maximum salinity is observed at village Jawasar (11.2 dSm-1) and minimum salinity at village Bharundakallan (0.5 dSm-1).
About 63 and 28 % of water samples showed EC range between 0-2.0 and 2.0-4.0 dSm-1, respectively.and are observed mostly in Alsisar and Buhana blocks. The higher range of salinity having EC 4.0-6.0 dSm-1 is represented by 6% samples and very high salinity group (EC >6.0 dSm-1) represented by 3% samples mainly occurring in Alsisar block.
The nitrate distribution of the district shows that higher concentration of nitrate ( >100 mg/l) occurs in most of the area except south of Chirawa block, north of Nawalgarh block, west of Buhana block and west of Jhunjhunun city. The nitrate concentration of the range 51-100 mg L-1 is seen in Chirawa, Nawalgarh and Buhana blocks of the district. The nitrate concentration 0-50 mg L-1 is observed only at few places.
On the basis of nitrate distribution, 50% ground water in the district are having nitrate content above 100 mg L-1 whereas 33% samples fall in 51-100 mg L-1 range. Only 17% of the samples are having lower values of nitrate. The maximum nitrate concentration is observed as 680 mg L-1 at village Mandrela in Chirawa block.
The fluoride distribution map shows that higher concentration of fluoride (>3.0 mg L-1) is found in east of Alsisar around Bassau, Bajla, Dhandhuri, Nathasar and Jawasar villages; south-west of Jhunjhunun around Hemtasar, Hanumanura and Binjusar villages and in some area between Surajgarh and Chirawa around village Sahikallan, Gimmi and Tigias. The fluoride concentration between 1.5 to 3.0 mg L-1 is seen in west of Jhunjhunun and south of Alsisar blocks. The rest of the area in the district has fluoride concentration more than 3.0 mg L-1 whereas 75% samples have fluoride concentration less than 1.5 mg L-1. The rest 10% samples have fluoride content between 1.5 to 3.0 mg L-1. The maximum fluoride (14.5 mg L-1) is observed at Nathasar (Alsisar block).
JODHPUR DISTRICT
The ground water in Jodhpur district has varied nature of chemical quality which is influenced to great extent by regional geomorphic and hydrogeologic features. The salinity of ground water varies from less than 0.5 dSm-1 to more than 10.0 dSm-1 when measured in terms of electrical conductivity (EC). Nearly 37 per cent water sources fall in the salinity level of moderately saline to saline class having EC more than 4.0 dSm-1. Further, nearly 23.4 per cent area in the district is occupied by saline waters having salinity more than 8.0 dSm-1. Occurrence of saline water is more frequent in Bap block in north and Bilara, Luni and Mandore blocks in south. Saline water is generally associated with alluvial aquifers which in general, yield water of higher salinity. Salinity map of Jodhpur district is depicted in Fig. 22.
Sodium occurs as major cation in 73.9 per cent water samples and its concentration varies from 5 mg L-1 to 8700 mg L-1. The major source of sodium is weathering of plagioclase feldspars which are abundant in igneous and metamorphic rocks of the district. It is preferentially associated with chloride (63.3%) followed by mixed anions (27.5%) and bicarbonate (9.1%) among anionic species. Potassium is though a minor element in ground water, its abnormal concentration usually occurs in polluted water of Jodhpur urban area.
Occurrence of high fluoride in ground water is a serious health hazard. Nearly 48% well waters have fluoride above 1.5 mg L-1. Frequency of occurrence of such waters is even more in Balesar, Bap, Bhopalgarh, Bilara and Luni blocks. Though values 5 to 10 mg L-1 of fluoride are observed at many places, ground water at village Daikara in Mandore block has been found to contain highest fluoride concentration of 22 mg L-1. High fluoride values are generally observed in moderately saline to saline waters. High bicarbonate alkalinity also favours fluoride solubility and at many places such water have fluoride above 1.5 mg L-1 despite of low salinity. The ground water also shows high nitrate value at many places. Usually high nitrate water occurs as isolated pockets, while in some blocks namely, Shergarh, Balesar and Osian extensive belts of nitrate rich ground water have been observed. These waters are often rich in calcium and magnesium content. The inner peripheral region of Jodhpur town is also characterized by high nitrate in ground water which could be accounted for pollution by extraneous sources.

KARAULI DISTRICT
The fresh ground water of EC range 0-2.0 dSm-1 is available in 68% samples of Todabhim, 55% of Hindaun, 40% of Nadoti, 88% of Karauli and 91% samples of Sapotra block. The medium to high salinity water (EC 2.0-4.0 dSm-1) is represented by 21% samples in Todabhim, 40% in Hindaun, 53% in Nadoti, 12% in Karauli and 9% samples in Sapotra block. High to very high salinity water (EC more than 4.0 dSm-1) occurs at a few places in the district and are represented by 11% in Todabhim, 5% in Hindaun and 7% in Nadoti block.
The ground water in the district is mostly characterized as bicarbonate type of water (48.4% samples) in which 16% is sodium bicarbonate while 29.6% is calcium-magnesium bicarbonate type of water. This type of water is fresh in nature and has electrical conductivity (EC) less than 1.5 dSm-1 in most cases. The mixed type of water constitutes 43.2% of the ground water in which 17.3% each are calcium-magnesium-mix and sodium-mix type. The rest of the samples have mixed cationic character. This type of water generally has EC between 1.5-3.0 dSm-1. Only 8.4% ground water in the district is chloride type with sodium as Dominating cation and is saline in nature having EC above 3.0 dSm-1.
The salinity map of the district shows (Fig. 23) that fresh to moderately saline water having EC less than 4.0 dSm-1 occurs in most part of the district except some part of Todabhim, Hindaun and Nadoti block in north of the district. The maximum salinity (EC 6.7 dSm-1) of ground water is found at Shahar in Nadoti block and the minimum (EC 0.45 dSm-1) at village Ghata in Todabhim block.
The nitrate distribution shows that low nitrate water (NO3 < 50 mg L-1) occurs in 58%, 33%, 40%, 41% and 28% samples in Todabhim, Hindaun, Nadoti, Karauli and Sapotra blocks espectively. The ground water having nitrate range of 51 to 100 mg L-1 occurs in 42%, 22%, 20%, 24% and 36% samples in Todabhim, Hindaun, Nadoti, Karauli and Sapotra blocks respectively. High nitrate values (>100 mg L-1) are seen in 45% in Hindaun, 40% in Nadoti, 35% in Karauli and 36% samples in Sapotra block.
The fluoride concentration of the range 0-1.5 mg/ L is found in 42%, 84%, 67%, 94% and 82% in Todabhim, Hindaun, Nadoti, Karauli and Sapotra blocks respectively. Similarly, the next range 1.5-3.0 mg L-1 is found in 32%, 16%, 27%, 6% and 189 samples in Todabhim, Hindaun, Nadoti, Karauli and Sapotra blocks respectively. The higher range of fluoride (>3.0 mg L-1) is found in 26%, 8% and 6% samples in Todabhim, Hindaun and Nadoti blocks.

KOTA DISTRICT
The quality of ground water in Kota district is fresh in nature. The electrical conductivity (EC) of the water is generally less than 2.0 dSm-1. which indicates that the total dissolved solids (TDS) is mostly less than 1.5 mg L-1. The ground water of the area is mostly of bicarbonate type. Nearly 76% well waters of the district have bicarbonate chemical character followed by 13% mixed anion type and remaining 11 % are of chloride type in nature. Salinity map of Kota district is depicted in Fig. 24.
The ground water in the district is also free from hazardous components like nitrate & fluoride. Generally 83.4%, 11% & 57% well waters have been found to have nitrate concentration in the range of <50, 50-10 & >100 mg L-1 respectively. High concentration of nitrate in the ground water may be caused due to excess use of nitrogenous fertiliser or pollution by sewage. In the whole district highest nitrate value of 650 mg L-1 is observed in Mandawara village of Sultanpur block having EC 7.5 dSm-1, Chloride-1035 mg L-1 and sulphate 1033 mg L-1.
With regards to fluoride - a health affecting constituent, 88% well waters in the district have fluoride content less than 1.5 mg L-1 which indicates that the area is free from fluoride induced problems. Some pockets in Ladpura & Sultanpur have fluoride content between 1.5-3.0 mg L-1 & only in Kherlitoran village of Sultanpur, highest fluoride, value of 3.6 mg L-1 has been observed.
NAGAUR DISTRICT
Nagaur district ranks as the most problematic district with reference to ground water quality in western Rajasthan. High concentration of dissolved salts, nitrate and fluoride are the major quality problems associated with the ground water. The salinity measured as electrical conductivity (EC) varies from less than 0.5 dSm-1 to as high as 32.0 dSm-1 (Jaswantgarh; Ladnun block). Water analyses reveal that 34.1% ground waters have EC more than 4.0 dSm-1 showing moderately saline to saline character. Such waters occur mostly in Nagaur block (60.8%), Degana block (54.5%) and Jayal block (52.2%). In other blocks, the occurrence of such water is 30.4% in Didwana, 25% in Merta, 23% in Riyan, 42.1% in Makrana, 30% in Kuchaman and 28% in Ladnun blocks (Fig. 25). In Mundwa and Parbatsar blocks, the ground water is relatively fresh in nature. Alluvium, Palana sandstone, Nagaur sandstone, Bilara sandstone, Jodhpur sandstone, schist and gneiss are the main water bearing formations. The quality of water is poor in alluvium as compared to other formations.
Nearly 61.3% well waters have fluoride above 1.5 mg L-1. Occurrence of such water is even more in Degana (79%), Nagaur (89.8%), Makrana (70.1%), Ladnun (64.3%), Riyan (61.8%) and Jayal (65.7%) blocks. High value of fluoride is found at many places viz., Baorla (30.0 mg L-1; Degana block), Galdi (32.1 mg L-1; Jayal block), Somera (75.0 mg L-1; Jayal block), Leri (34.0 mg L-1; Ladnun block) and Mori (17.0 mg L-1; Makrana block). The highest value of fluoride is observed as 90.0 mg L-1 in the well water of Ditiad in Jayal block.
Nitrate occurs as a major toxic constituent in ground water of the district. Nearly, 41.4% ground waters have nitrate concentration above 100 mg L-1. The percent distribution of such waters is even more in Didwana block (73.9%), Jayal block (60.9%), Nagaur block (45.5%) and Ladnun block (68.0%). The maximum nitrate concentration of 4750 mg L-1 has been observed in ground water in Jaitpura (Degana block). However, high values of nitrate also occur at many places viz., Motus (2900 mg L-1; Merta block), Basni Baliwa (1033 mg L-1; Nagaur block), Panchori (1650 mg L-1; Mundwa block), Geiroda Khara (1780 mg L-1; Ladnun block), Dhawa (1300 mg L-1; Ladnun block) and Daorat (2100 mg L-1; Didwana block).
The ground water in Degana (81.8%), Didwana (86.9%), Jayal (60.9%), Nagaur (77.3%), Merta (75%), Parbatsar (68.8%), Riyan (53.8%), Makrana (77.8%), Kuchaman (50.0%), Mundwa (47%) and Ladnun (56%) blocks have sodium percentage above 70. Likewise, the RSC is observed more than 2.0 meL-1 in Degana (59.1%), Didwana (69.6%), Jayal (34.8%), Nagaur (31.8%), Merta (31.3%), Parbatsar (56.3%), Riyan (23.1%), Makrana (72.2%), Kuchman (35%), Mundwa (29.4%) and Ladnun (44%) blocks.
PALI DISTRICT
The salinity of ground water varies from fresh to highly saline ranging from 0.33 dSm-1 (Ranalan; Desuri block) to 36.0 dSm-1 (Chanod; Sumerpur block). The fresh water pockets are mainly observed in Bali, Desuri and Rani blocks of the district. In these blocks the electrical conductivity (EC) of water is less than 2.0 dSm-1 in more than 70% well waters. In Pali and Rohat blocks, the ground water is more saline. 40% and 65% well waters have EC more than 8.0 dSm-1 (Fig. 26). Among various aquifers, the wells sunk in calcschist and calc-gneiss generally yield water of low salinity whereas those in alluvium yield ground water mostly of saline character. Granite and gneisses form potential aquifers in the district and yield water of moderate quality (Average EC-3.6 dSm-1).
Geo-chemically, 40,2% ground water in the district of chloride type followed by 33% bicarbonate type and 26.3% mix type of water. Among the cations, sodium occurs as the major species in 75.4% water samples followed by 22% as calcium-magnesium dominating and 2.5% as calcium dominating.
The concentration of nitrate in ground water is generally low. Only 7.2 per cent well waters show nitrate value above 100 mg L-1. The area around Juni Endla, Kirwa, Dhola, Akadara and Sanderao in west of Rani and around Chhang in northeast is characterized by such waters. Spot values of high nitrate in ground water are also observed at Manihar in Pali block (NO3; 350 mg L-1), Khinwara in Rani block (NO3; 203 mg L-1), Chandanwal in Sojat block (NO3; 123 mg L-1) and Palri in Sumerpur block (NO3; 310 mg L-1). The maximum nitrate is observed in ground water at Manihari in Pali block and Palri in Sumerpur block.
About 71 per cent ground waters in the district have fluoride content above 1.5 mg L-1. In Bali, Desuri, Pali and Sumerpur blocks the percentage of such waters is 86, 75, 83 and 78 respectively. Fluoride rich waters are seen in almost all the formations viz., alluvium, granite, gneisses etc. which constitute major potential aquifers in the district.
Most of the eastern and northern parts of the district being occupied by ground water having fluoride concentration more than 1.5 mg L-1. At Gudalas and Malnu in Bali block, Jetaran, Jajanwas and Latoti in Jetaran block, Bithura Khurd, Marwar Jn. in Kharchi block, Bhalelao, Bhumdara, Khorwa, Madri and Ramsia in Pali block, Haripur, Nok and Sabalpura in Raipur block, Bhakariwala gaon in Rohat block. Lundawas and Sardarsamand in Sojat block, and Gogra and Kenpura in Sumerpur block, the ground water has fluoride content above 5.0 mg L-1. The highest value of fluoride 12.0 mg L-1 is observed at Gogra in Sumerpur block.
RAJSAMAND DISTRICT
The salinity varies from fresh in north, west and southwest to saline in east and southeast. The average values of salinity of ground water in Kumbhalgarh (0.90 dSm-1), Bhim (1.28 dSm-1), Khamnor (1.5 dSm-1) blocks reveal the presence of fresh water while slightly saline in Rajsamand (1.58 dSm-1), Deogarh (1.6 dSm-1) , Amet (1.7 dSm-1) and Railmagara ( 2.34 dSm-1)blocks. The minimum and maximum salinity are noticed in the well water of Aret ki Bhagal (0.4 dSm-1) in Kumbhalgarh block and Kotri (8.6 dSm-1) in Railmagra block respectively. About 79.8% of ground water have EC less than 2.0 dSm-1 and are found mostly in Kumbhalgarh, Bhim, Khamnor, Rajsamand, Deogarh and parts of Amet and Railmagra blocks. The moderately saline ground water (15.61%) with salinity between 2.0-4.0 dSm-1 occur frequently in north and south east of Railmagra block, small areas in north small patch in north of Khamnor, south of Deogarh and north of Bhim blocks. The saline ground water (12.89%) falling in the range of 4.0-6.0 dSm-1 and above are found at Kelwa-Pasoond and Galwa-Jhar sections in Rajsamand and Amet block respectively. Few localised saline ground water pockets also exists in Railmagra block (Fig. 27).
The mix cationic character is predominant in ground waters with bicarbonate as the principal anion. The mix-bicarbonate type of water (50.79%) are widely distributed in north, west and south of the district. These mix-bicarbonate type of water have salinity less than 1.0 dSm-1 with dominance of alkaline earths showing the water are fresh in nature. However, salinity of such waters in Deogarh, Khamnor, Railmagra and Rajsamand blocks range between 1.0-1.5 dSm-1. More than 31.5% ground water have mix-mix type character and fall in the slightly saline class of salinity. The chloride type of water (18%) having salinity above 2.0 dSm-1 occurs in middle & south east of Amet, north of Rajsamand, north-east and south of Railmagra, north of Khamnor, south-east of Deogarh and entire north of Bhim blocks.
Ground water of Rajsamand district is free from fluoride hazard. Fluoride contents < 1.5 mg L-1 in more than 75% well waters of Amet (75%), Bheem (76%), Khamnor (100%), Kumbhalgarh (79.16%), Rajsamand (77.78%) blocks. While the percentage of well waters having fluoride less than 1.5 mg L-1 is 58.33 and 40.91% in Deogarh and Railmagra blocks respectively. The fluoride contents between 1.5 to 3.0 mg L-1 are observed in 22% well waters and rest of the 4% water have been found to be associated with fluorides above 3.0 mg L-1. Such waters occur mostly in Deogarh and Railmagra blocks which have the high average values of 1.45 and 1.81 mg L-1 of fluoride respectively. Fluoride contents varies from 0 to 5.94 mg L-1 with maximum in well water of Arnaratiya in Kumbhalgarh block, a moderately saline water (EC 2.3 dSm-1) with sodium-chloride bicarbonate type character.
The nitrate content ranges from 0 to 370 mg L-1 with an average value of 48 mg L-1. Its Concentration in more than 89% ground waters has been less than 100 mg L-1. The ground waters in Bhim, Khamnor, Kumbhalgarh, Railmagra and Rajsamand blocks are free from nitrate contamination. High nitrates are normally found in moderately saline water with electrical conductivity of 2.0-4.0 dSm-1. About 11% ground water have nitrates above 100 mg L-1 and includes well waters from Amet, Bhim, Deogarh, Khamnor, Kumbhalgarh, Rajsamand and Railmagra blocks respectively. The contamination of ground water by nitrates is significant in Amet (35%) & Khamnor (16.67%) blocks and to some extent in Deogarh.
SAWAI MADHOPUR DISTRICT
The ground water is characterized by low to high salinity. The area of low salinity i.e. below 2.0 dSm-1 occurs in most part of the district except the central part of Gangapur block, southern part of Bonli block, around Bamanwas proper, southwest part of Sawai Madhopur block and the area around Khandar proper. The ground water at villages Barnoda and Khandar in Khandar block, Bilopa and Sinoli in Sawai Madhopur block, Kodiyal and Pipalwara in Bonli block, Binegu, Chaliadai, Wazirpur, Badhkeyala, Phulwara in Gangapur and Bamanwas blocks have higher values of salinity.
The fresh ground water of the EC range below 2.0 dSm-1 is available in 93% of Sawai Madhopur, 77% in Bonli, 89% in Khandar, 41% in Bamanwas and 54% in Gangapur blocks. Similarly, the next range of medium to high salinity i.e. 2.0-4.0 dSm-1 is represented by 7% in Sawai Madhopur, 23% in Gangapur, 9% in Bonli, 25% in Bamanwas and 11% in Khandar block. The ground water of high to very high salinity i.e. EC above 4.0 dSm-1 is represented by 23% in Gangapur, 14% in Bonli and 34% in Bamanwas blocks. Salinity map of Sawai Madhopur district is depicted in Fig. 28.
In the district the ground water is mostly characterized by bicarbonate and mixed type of water in which 43% is bicarbonate and 43% is mixed type. In bicarbonate type of water sodium bicarbonate type is 19%; calcium-magnesium bicarbonate type water is 21% and rest 3% water is of mixed cationic character. This type of water is generally fresh in nature with electrical conductivity (EC) generally less than 1.5 dSm-1.
About 60%, 46%, 58%, 70% and 55% of the samples in Sawai Madhopur, Gangapur, Bonli, Bamanwas and Khandar blocks respectively represents nitrate upto 50 mg L-1. Similarly, 33% in Sawai Madhopur, 27% in Gangapur, 21% in Bonli and 28% samples in Khandar block have nitrate concentration between 51-100 mg L-1. The higher concentration of nitrate (>100 mg L-1) is observed at Sawai Madhopur, Gangapur, Bonli, Bamanwas and Khandar blocks as 7%, 27%, 21%, 30% and 17% samples respectively. The maximum nitrate is seen in village Bassi-banesingh (1100 mg L-1) of Bonli block.
About 80%, 73%, 70%, 100% and 61% samples in Sawai Madhopur, Gangapur, Bonli, Bamanwas and Khandar blocks respectively are having fluoride concentration upto 1.5 mg L-1 whereas 20%, 27%, 13% and 28% samples in Sawai Madhopur, Gangapur, Bonli and Khandar blocks have fluoride concentration in the range of 1.5-3.0 mg L-1. The fluoride concentration more than 3.0 mg L-1 is seen only in 17% ground water of Bonli and 11% of Khandar block.

SIKAR DISTRICT
The salinity of ground water varies from 0.28 dSm-1 (Raghunathpura; Piprali) to 5.9 at Mataji Ka Bas in Danta Ramgarh block. Fresh to slightly saline water having EC below 2.0 dSm-1 occurs in most part of the district covering Neem Ka Thana, Srimadhopur, Khandela, Danta Ramgarh, Piprali, Dhond and easier part of Lachhmangarh block. The ground water of medium salinity of the range of 2.0 to 4.0 dSm-1 occurs as a big zone in Fatehpur and Lachhmangarh blocks and two small pockets in central part surrounded by villages Kharana, Katiwas, Jeenwas, DhaniThakar and Nagal Bamsar in Khandela block. The ground water of higher salinity of range 4.0-6.0 dSm-1 occurs only at one place in Fatehpur block in northwest of the district (Fig. 29).
The ground water in the district is mostly characterized by bicarbonate type of water (66.5%) in which 44% are of sodium bicarbonate type while 16% are mix type and 6.5% are calcium-magnesium type. This type of water is fresh in nature and has electrical conductivity (EC) around 1.5 dSm-1 at 25°C. At some places such as Dukia in Danta Ramgarh; Dewas, Ramgarh, Rukansar Khuri, Karanga Chhota and Nawawas in Fatehpur block; Royal and Barsinghpura in Khandela block; Jagod and Bumbar in Lachhmangarh block and Kathral in Piprali block, the EC of ground water is higher even though the water at these places has bicarbonate character. The mixed type of water represent 30% of the ground water in which 8% are calcium-magnesium mix type, 7% are mix cation type and 15% are sodium type of water. This type of water mostly have EC ranging between 1.5-3.0 dSm-1. Mix type of water is found throughout the district. The chloride type of water is represented by 3.5% of samples and is seen in villages Chalkmali, Chotishyam etc. in Danta Ramgarh block.
Fluoride concentration varies widely in ground water. Low fluoride content in the range of 0-1.5 mg/ L is seen in east of Sikar, Piprali and Dhond and part of Khandela, Neem Ka Thana and Srimadhopur blocks. A small zone is also seen in southwest of Lachhmangarh block. The next range of fluoride i.e. 1.5-3.0 mg L-1 is seen in Fatehpur and Lachhmangarh blocks. This range of fluoride is also seen in south of Danta Ramgarh block besides a small patch in central part of the district. The higher concentration of fluoride i.e. more than 3.0 mg L-1 is seen as small pockets in Khandela and Fatehpur blocks. The maximum concentration of fluoride of 13.0 mg L-1 is encountered in village Dukia in Danta Ramgarh block.
Higher concentration of nitrate of the order of more than 100 mg L-1 is seen widely distributed in western part of the district comprising northern part of Fatehpur block and western part of Dhond and Lachhmangarh blocks. Besides these zones some small patches of high nitrate water are also seen in central part and northeastern part of the district. The medium concentration of nitrate in the order of 51-100 mg/ L range is encountered in most part of the district specially in central part. Some small patches in north and west of Lachhmangarh and Srimadhopur blocks are also having nitrate concentration of 51-100 mg/ L. The low nitrate waters (0-50 mg L-1) are seen in eastern part of Neem ka Thana and in part of Khandela. Piprali and Lachhmangarh blocks. A small patch of this range is also seen in west of Danta Ramgarh block. The maximum concentration of nitrate 748 mg L-1 is encountered at village Madholi in block Neem Ka Thana.
SIROHI DISTRICT
Sirohi district lying in sub humid-humid agroclimatic zone is characterized by ground water of low to medium salinity (Electrical Conductivity < 4.0 dSm-1). Fresh water quality occurs in Abu Road and Revdar blocks in south of the district. Nearly 74 and 88 per cent ground water respectively in the two blocks have electrical conductivity (EC) less than 2.0 dSm-1. In Pindwara and Sirohi blocks the quality of water ranges from fresh to medium saline with EC less than 4.0 dSm-1. The ground water is, however, more inferior in Shivganj block where nearly 24 per cent water samples have EC more than 4.0 dSm-1. The minimum value of EC has been observed as 0.38 dSm-1. in village Achalgarh in Abu Road whereas maximum value has been observed as 8.5 dSm-1 in village Khejana of Shivganj block (Fig. 30). The average salinity of ground water in the district is 1.87 dSm-1 which corresponds to salinity in terms of total dissolved solids (TDS) as 1140 mg L-1.
The chemical character of ground water in the district also varies from primary bicarbonate type to tertiary chloride type. Nearly 42% samples in the district have bicarbonate type water out of which 27.6% are of mixed cation bicarbonate type and 11.6 are of sodium-bicarbonate type of water. Only in a few samples (2.8%) calcium-magnesium dominating cation character has been observed. Nearly 30 percent ground water in the district have secondary character wherein no major anion is seen dominating. The rest 29% ground water in the district have tertiary water character with chloride as major anionic species.
Nearly 33 percent water samples of the district have fluoride concentration more than 1.5 mg/ L. At many places, viz., Anthala in Abu Road; Sangwan in Pindwara; Jirawa and Nimbaj in Revdar; Bithura, Gola, Mochal and Sugarliya in Shivganj and Belagiri, Mirpur and Mahabatnagar in Sirohi block, fluoride concentration has been found to be more than 5.0 mg L-1. The maximum fluoride value is observed as 11.6 mg L-1 at Gola in Shivganj block. High fluoride is not only confined to shallow aquifers but in deep tubewells too. In Amli, Amthala, Padiv, and Gol villages fluoride content ranges between 4.4 to 6.0 mg L-1.
Nitrate in ground water is generally low. Only 10.7% water samples show nitrate content above 100 mg L-1. High nitrate waters usually occur only in confined pockets but in some portion in east falling in Sirohi and Pindwara blocks extended belts of nitrate rich groundwater are observed. The maximum nitrate concentration is observed as 395 mg L-1 in village Nandia of Pindwara block. Some other locations of significance are Birwara and Swaroopganj in Pindwara block; Revdar and Sorda and Goeli, Kalandari, Rajpura and Tawri in Sirohi block. Nitrate content more than 100 mg L-1 in groundwater of these locations is randomly seen. The salinity of many of these waters is high with high potassium content.
TONK DISTRICT
It is seen from salinity map that most part of the district is occupied by ground water of salinity less than 2.0 dSm-1. Only in Northwest part covering most of the Malpura block, medium to high salinity ground water is observed. In this block nearly 52% ground water have salinity more than 2.0 dSm-1. The maximum salinity in the district is observed as 13.0 dSm-1 in village Bachhera of Malpura block. Besides this, some medium salinity pockets are also seen around village Borkhandi, Jhirana, Arniyamal and Sonwa in Tonk block; Uniara, Ranipura and Gothara in Uniara block and Bhotunda, Ratwai and Sunwaria in Todaraisingh block. However, the EC of these waters are mostly less than 4.0 dSm-1. Salinity map of Tonk district is depicted in Fig. 31.
Both low to high fluoride concentrations have been observed in ground water of the district. Nearly 2/3 part of Malpura block, the northern part of Todaraisingh, central part of Tonk and Uniara blocks, northeastern part of Niwai block and the lower part of Deoli block is characterised by fluoride concentration between 1.5 to 3.0 mg L-1. Some closed pockets of high fluoride ground water (more than 3.0 mg L-1) are seen around villages Jhanpura, Sirohi and Thala in Deoli block; Chandsen, Chosla, Dewal, Diggi and Tordi in Malpura block; Akodra, Kareriya and Sunara in Niwai block; Bawara and Hadikalan in Tonk block and Nayagaon in Uniara block. In rest of the district the fluoride concentration is below 1.5 mg L-1. The maximum fluoride is observed as 7.6 mg/ L in village Kareriya of Niwai block.
The concentration of nitrate in ground water varies from nil to 1050 mg L-1. Nearly 72% ground water have nitrate below 50 mg L-1 and hence most of the area in the district is free of nitrate problem. In 12.3% water samples the nitrate content ranges from 51 to 100 mg L-1 and in rest 15.8% ground water the nitrate concentration is above 100 mg L-1. High nitrate water (>100 mg L-1) are observed mostly in western part of Todaraisingh block, north of Tonk block and southern part of Uniara block.
UDAIPUR DISTRICT

Salinity depicted as electrical conductivity expressed in dSm-1 varies from 0.37 to 7.8 with an average of 1.24 dSm-1. 79.1% ground water of the district have electrical conductivity within 1.5 dSm-1.
The salinity map (Fig. 32) depicts that 88.8% ground water with electrical conductivity value within 2.0 dSm-1 is found occurring in almost whole of the district except two big patches one in eastern part covering parts of Mavli and Bhinder blocks and second in southern part covering parts of Salumber and Sarada blocks. These patches have ground water in the range of 2.0-4.0 and 4.0-6.0 dSm-1. Some localised scattered patches in Badgaon, Dhariawad, Girwa and Jhadol blocks have ground water with electrical conductivity in the range of 2.0-4.0 dSm-1.
The ground water in Udaipur district is fresh to slightly saline. It is mostly bicarbonate type with dominance of calcium and magnesium ions. 68.9% of water has bicarbonate type of character associated with either Ca+Mg (51.8%) or Na (12.1%) as dominant cation. 23% well water show mix type of character which are transitional in nature and lies in between bicarbonate and chloride type of water. Rest 12.9% waters are of chloride type. The fresh bicarbonate type water generally have TDS below 1.0 mg L-1 whereas the chloride type of water are more mineralised and have TDS more than 1.5 mg L-1.
Nitrate concentration in ground water of the district varies from traces to 472 mg L-1 with an average of 51 mg L-1. About 68.7% of ground water have nitrate concentration within 50 mg L-1 and found in almost all the blocks. In western half of the district the ground water have nitrate within 50 mg L-1 except a patch in block Gogunda and a few scattered localised patches having nitrate in the range 50-100 mg L-1. In eastern half of the district, the nitrate concentration is mostly in the range of 50-100 mg/ L and above, covering parts of the block Mavli, Girwa, Bhinder in the north-east and Sarada and Salumber blocks in south-east. 21.3% of ground water in the district have nitrate value in the range of 50-100 mg L-1 and 10.0% have nitrate value above 100 mg L-1.
The fluoride concentration in ground water of the district varies from 0.24 mg L-1 to 4.9 mg L-1 with an average of 1.01 mg L-1. 84.7% of ground water have fluoride within 1.5 mg L-1 mainly in blocks Bhinder, Salumber and Sarada. Most part of the district has ground water with fluoride values within 1.5 mg L-1 except the two big patches, one in eastern part (block Bhinder) having fluoride in the range of 3.0 mg L-1 and another in southern part covering parts of blocks Salumber and Sarada having fluoride values in the range of 1.5 -3.0 mg L-1 and above 3.0 mg L-1. Around 11% ground water in blocks Mavli, Kotra, Dhariawad and 3% in block Girwa also have fluoride in the range of 1.5 - 3.0 mg L-1.

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