Water Quality Index Assessment of Groundwater in Todaraisingh Tehsil of Rajasthan State, India-A Greener Approach

This study deals with the statistical analysis and study of water quality index to assess hardness of groundwater in Todaraisingh tehsil of Tonk district of Rajasthan state. The study has been carried out to examine its suitability for drinking, irrigation and industrial purpose. The presence of problematic salts contains in groundwater due to local pollutants and affected the groundwater quality adversely. The estimated values were compared with drinking water quality standards prescribed by B.I.S. It was found that drinking water is severely polluted with hardness causing salts. This study reveals that people dependent on water sources of the study area are prone to health hazards of contaminated water and quality managements to hardness urgently needed.


Introduction
Rajasthan is India's largest state with an area of 3,42 km 2 , which is 10.41% of the total area of our country and with an estimated population of 54 million spread over its 41,583 villages, which is 5.5% of nation's population but being just 1% of the total water sources of the country. Due to the scarcity of the surface water in Rajasthan 1-3 , 70% of its population is dependent on groundwater resources for drinking, irrigation and other purposes. Water is not only essential for the lives of animals and plants but also occupies a unique position in industries. It is used for irrigation 4 , sanitation, power and steam generation 5 , airconditioning, navigation, ecological and afforestation needs 6,7 and recreation. It is also used as a coolant in power and chemical plants. In addition, water is widely used in other fields like production of paper, sugar, steel, atomic energy 8 , textile, chemicals 9 and ice 10 .
Water is the first need of all vital life processes, hence called "Liquid of Life". According to Greek medieval philosophy, matter consists of four elementary substances namely water, air, stone and fire. Indian medieval also opines that the matter is composed of five Panch Mahabhut (Five elementary substances) namely water, air, light (fire), earth (stone) and sky (space). Among the all known plants only earth is blessed by these all five elements. So, distinctive properties (physical, chemical and biological) of water and its essential role in the life supporting systems are our earth's most important characteristics, and no other living planet in the universe according to Bourne. Water is absolutely essential for healthy living. It plays an indispensable role in the life of every species that survive in this world and required by all living organisms for their existence improper management causing availability and quality of water [11][12][13] Water is universal solvent so it has the capability to dissolve nearly all natural compounds. So alarming salts contain in ground water due to local pollutants and affected the groundwater quality adversely [14][15] In recent years an alternative approach based on statistical has been used to develop mathematical relationship for comparison of physicchemical parameters 16 . It is parameter of water quality used to describe the effect of dissolved minerals (Mostly Calcium and magnesium) and suitability of water for domestic, industrial and drinking use. Minerals cause deposits of scale in hot water pipes and they also interfere with the lathering action of soap. According to degree of hardness it is classified as soft water (0-75 mg/L), moderately (75-150 mg/L), hard water (150-300 mg/L) and above 300 mg/L is very hard water 17 . Hardness of drinking water is a problem found in both ground & surface water and may cause too many problem in human physiological system and domestic & industrial purpose. So attention on hardness of water and its management has become need of hour.

About the study area
Tonk district is located in north eastern part of the state bordering Jaipur in north, Swaimadhopur in the east, Bundi & Bhilwara in south & Ajmer in the west. Tonk is known for its unity among Hindu and Muslims for which it is same time called as "Hindu Muslims Ekta ka Maskan". The history of Tonk is very old it was called as Nawabi-Nagari "Tonk". The Tonk is also known as the "Lucknow of Rajasthan"due to its elegance. Tonk is popular among tourists for its Magnificent Mosques, Mansion and havelis. In the ancient time Tonk was ruled by the tribes of "pathans" from Afghanistan. The old town boasts of the architecture prevalent in Mugal era. The focal point of Tonk is the Suneri Kothi, Hathibhata and Juma Masjid.
If hardness is in unlimited concentration than it may cause disease and such water is known as impure water and it should not be used as drinking water. In Tonk district geographically a ground strip, in the base of Aravali series contains fluorspar CaF 2. 3Ca(PO 4 ) 2 and fluoropatite (CaF 2 ). Some districts viz Jalore, Sirohi, Pali, Bhilwara, Tonk, Ajmer and Alwar 18-23 are in high concentration of water quality parameters due to this ground strip of Aravali series 15,24 .The main object of this study is to identify and analyze hardness of water of rural area of Todaraisingh area of Tonk district.

Experimental
20 Water samples were collected from tube well, open well and hand pumps out of these five samples were collected from each direction of Todaraisingh Tehsil of Tonk. Samples examined for total hardness 25 , Ca +2 as CaCo 3 & Mg +2 as CaCo 3 as per standards methods prescribed in APHA 26 . The statistical analysis has been performed using standard methods 27 .

Water quality index
The concept of WQI first proposed by horten 28 . Water quality index indicate single number like a grade that express overall water quality index at certain area and time. It gives general idea of the possible problem with water in a particular region to public.

Calculation of water quality index (WQI)
In the first step, unit weight (Wi) was calculated by using the following formula: Wi = k/Si Where k = proportionality constant, Si = Standards desirable value of parameter. In second step the sub index (Qi) was calculated by using

Results and Discussion
In this study, a total of twenty water samples from groundwater of Todaraisingh area of Tonk district of Rajasthan (India) were analyzed for water quality. In this five samples collected from each side of Tehsil for study and were analyzed for total hardness (TH) and compared with BIS standards. It has been found that total hardness range in the area was from 150 to 1350 mg/L. In the north direction TH range was 220 to 810 mg/L, in east direction TH range was 330 to 1350 mg/L, in west direction TH range was 200 to 970 mg/L & in south direction TH range was 390 to 1070 mg/L. The total average TH in the study area was 595 mg/L. In north direction average TH was 606 mg/L which is over than BIS, ISI & WHO standards. In east direction average total hardness was 680 mg/L which is more than BIS, ISI & WHO limit and in west direction maximum value of TH was 970 mg/L & minimum value was 150 mg/L and average value was 464 mg/L which is over than prescribed limit and in south direction maximum value was 1070 mg/L & minimum value was 390 and average was 630 mg/L, it is also more than BIS, ISI & WHO standards (Table 1).

HDL -Highest Desirable Level; MPL -Maximum Permissible Level
In Todaraisingh Tehsil maximum value of TH was 1350 mg/L and minimum value was 150 mg/L and maximum average value was 680 mg/L and minimum average value was 464 mg/L and all analyzed value of total hardness of different site in each direction of Todaraisingh area of Tonk district are show in Tables 2-6.

Conclusion
In this study we have analyzed twenty water samples from various sources including hand pumps, tube well and open well of different areas in each direction of Tehsil Todaraisingh of Tonk District. Results shown in the tables were not within the limit as per the BIS, ISI & WHO standards. The observed range of WQI was 154.6 to 226.6 in Todaraisingh area of Tonk. It has been found that the WQI of west direction of Todaraisingh area was lowest and WQI of east direction of Todaraisingh area was highest. In this area water quality of drinking water sources were not suitable for drinking purpose as well as domestic purpose. Highest priority should be given to water quality monitoring and the indigenous technologies should be adopted to make water fit for drinking after treatment.