Socio-economic effect on socially-deprived communities of developing drinking water quality problems in arid and semi-arid area of central Rajasthan

Rajasthan is well known for its Great Thar desert. Central Rajasthan has an arid to semi-arid environment. The area faces either scarcity of water or poor quality of drinking water. In some areas water is transported 2 km or more, which uses time, energy and money. Rich people have their own sources, which is restricted for use by others. Such conditions are affecting socially-deprived communities, both socially and economically. Groundwater is a major source of drinking water due to the unavailability of surface water. There is a lack of groundwater quality knowledge in the community and the data available is hard to understand by consumers. The CCME Water Quality Index is a tool to simplify the water quality report by rating the water on quality standards. It provides meaningful summaries of overall water quality and trends, which is accessible to non-technical lay people. In the present study the objective is to examine the groundwater quality of six districts (Ajmer, Bhilwara, Pali, Rajasamand, Nagaur and Jodhpur), centrally located in Rajasthan, with arid and semi-arid conditions. CCME WQI is also evaluated to produce quality data in a form to be understood by the community. A total of 4369 groundwater sources in 1680 villages from six districts (76 546 km2) were collected and examined. Results are outlined in the Bureau of Indian Standards (BIS: 10500, 2012) and 2952 sources are unsafe for drinking. According to CCME WQI groundwater of 93 villages is poor, 343 villages are marginal, and 369 villages are fair in quality. Toxicological studies of unsafe drinking water and their remedial measures are also discussed. A tentative correlation between prevailing water-borne diseases and quality parameter has also been shown.


INTRODUCTION
Water quality is an important factor to monitor environment changes which are strongly associated with social and economic development.The evaluation of water in the developing countries has become a critical issue in recent years, especially due to the concern that freshwater will be scarce in the near future.Water from a certain source may be good enough for domestic or industrial use without any treatment, but it may not be suitable for drinking.It may be good for irrigating certain crops, but not for other crops.
It is estimated that about 21% of communicable diseases in India are water related (Brandon et al. 1995).The water quality issue is now being recognized in India as a major crisis.In most parts of the country, the water supplied through groundwater is beset with problems of quality (CGWB Report 2002).The over dependency on groundwater has led to 66 million people in 22 states being at risk due to excessive fluoride, and around 10 million at risk due to arsenic in six states (Husain et al. 2003, 2013, Ghosh 2007).In addition, there are problems due to excessive salinity, iron, nitrates and others (Desai 1990).Around 195 813 inhabitants are affected by poor water quality due to chemical parameters (CPCB 1999).It has been estimated that once pollution enters the subsurface environment it may remain concealed for many years, becoming dispersed over wide areas of groundwater aquifers and rendering groundwater supplies unsuitable for consumption and other uses.The rate of depletion of groundwater levels and deterioration of groundwater quality is of immediate concern in rural areas of the country.The increased dependency on groundwater has made water conservation the top priority in water management studies.
Groundwater occurs almost everywhere beneath the Earth surface.It is not in a single widespread aquifer, but in thousands of local aquifer systems and compartments that have similar characters.Knowledge of the occurrence, replenishment, and recovery of groundwater has special significance in arid and semi-arid regions due to the discrepancy in monsoonal rainfall, insufficient surface waters and over drafting of groundwater resources.Groundwater quality depends on the quality of recharged water, atmospheric precipitation, inland surface water, and on sub-surface geochemical processes.Temporal changes in the origin and constitution of the recharged water, hydrologic and human factors, may cause periodic changes in groundwater quality.Water pollution not only affects water quality, but also threatens human health, economic development, and social prosperity (Milovanovic 2007).

STUDY AREA
Rajasthan is the largest state in India, covering an area of 34.22 million hectares, i.e. 10.5% of the country's geographical area, but sharing only 1.15% of its water resources.Most of the state (60-75%) is arid or semi-arid.Western Rajasthan is arid to semi-arid, with low and erratic rainfall, high summer temperatures, low humidity and high-velocity wind, a negative water balance and acute water deficit.In the eastern part of the state, the climate is semi-arid to sub-humid with relatively better rainfall, low velocity wind, and higher humidity.Groundwater is overexploited in many districts of the state.The study area includes six centrally located districts of Rajasthan which covers 76 546 km 2 .The study area is shown in Fig. 1 and detail including physical, geological and hydrogeological characteristics is given in Table 1.

WATER QUALITY INDEX
The communication and reporting of ambient water quality data to the average person without compromising the technical integrity of the data, has always been a challenging task.However, reporting of water quality has been made easier in recent years by the development and availability of the Canadian Council of Ministers of the Environment (CCME) Water Quality Index (WQI).It was developed with the intent of providing a tool for simplifying the reporting of water quality data (CCME 2001).It is a tool that provides meaningful summaries of water quality data that are useful to technical and policy individuals, as well as the general public interested in water quality.
The application of the CCME WQI requires Water Quality Guidelines (WQGs).The model essentially consists of three measures of variance from selected WQGs (scope, frequency, amplitude) that combine to produce a value between 0 and 100 that represents the overall water quality.A minimum of four variables must be sampled at least four times to be used in the calculation of index values.The calculation is done in the following steps:

F1 (scope)
F1 represents the percentage of variables that do not meet their objectives at least once during the time period under consideration (failed variables), relative to the total number of variables measured:

F2 (frequency)
F2 represents the percentage of individual tests that do not meet the objectives (failed tests):

F3 (amplitude)
F3 represents the amount by which failed test values do not meet their objectives.It is calculated in three steps: -Step 1 Calculation of Excursion: The number of times by which an individual concentration is greater than (or less than, when the objective is a minimum) the objective is termed an ''excursion'' and is expressed as follows.
When the test value must not exceed the objective: For the cases in which the test value must not fall below the objective:

CCME Water Quality Index
Once the factors have been obtained, the index itself can be calculated by following equation: The factor of 1.732 arises because each of the three individual index factors can range as high as 100.This means that the vector length can reach √100 2 + 100 2 + 100 2 = √30000 = 173.2as a maximum.Division by 1.732 brings the vector length down to 100 as a maximum; 0 represents the "worst" water quality and 100 represents the "best" water quality.These numbers are divided into five descriptive categories to simplify presentation (Table 3).

METHODOLOGY
Groundwater samples (4369) were collected from 1680 habitations.After the collection, the samples were preserved as per the requirement of the parameters to be analysed.Determination of pH and conductance was performed on site using a portable meter.For the other parameters, samples were preserved by adding an appropriate reagent and brought to the laboratory in From the results it is clear that Rajsamand district has no habitations with poor groundwater quality; however, 19 habitations are marginal and 35 are fair in quality.The most quality affected district is Nagaur with 34 habitations in poor, 97 habitations in marginal and 118 habitation in fair category of CCMEWQI.Only 34 habitations are in the excellent category.F1 (Scope) represents the number of parameters failed in a habitation.In the study area in all districts except Rajsamand, 88.89 % parameters were found above standard limit for a habitation.F2 (frequency) represents number of tests failed for a habitation.In Pali district it is maximum, where 74.07%tests are failed for a habitation.F3 (Amplitude) represents the amount which is higher than the standard limit.In Bhilwara district the values are 80.96% above the standard for a habitation.

CONCLUSION
The results indicate that most of the water quality parameters were beyond the permissible limits.The overall view of the Water Quality Index of the present study zone had a low WQI value indicating poor water quality.A total of 70% parameters were found unsafe in the area, with at least 50% failed test results.No district can be marked safe for use of groundwater among the six districts.Central government is now concentrating on the 78% rural population by launching a national program, "National Rural Drinking Water Program" with a target to provide safe and sustainable drinking water.The first priority is focused on the coverage of quality affected habitations.

-
Calculation of Normalized Sum of ExcursionsThe normalized sum of excursions nse is the collective amount by which individual tests are out of compliance.This is calculated by summing the excursions of individuals' tests from their objectives and dividing by the total number of tests.Step 3 Calculation of F3 It is calculated by an asymptotic function that scales the normalized sum of the excursions from objectives (nse) to yield a range between 0 and 100.

Table 1
Detail of the study area(physical, geological and hydrogeological).In view of the direct consumption of water by people, domestic water supply is considered to be the most important use of water.Drinking use has been given first priority on utilization of water resource in the National Water Policy.In India, agencies like the Bureau of Indian Standards (BIS) and Indian Council of Medical Research (ICMR) have formulated drinking water standards.According to BIS 10500 (2012), standard values for the basic parameters covered in this paper are given inTable 2.

Table 2
Drinking Water Standards (BIS:10500:2012).In the absence of an alternative source.

Table 3
CCME Water Quality Index categorization.

Table 6
Classification of habitations based on CCME WQI.
Fig. 2 Contour map for study area.