Assessing the deteriorating water quality in wards of Jaipur city through GIS interpolation

As the urban population is increasing it is having a huge impact on our natural resources including our ground water systems which are our primary sources of drinking water supply. With the change in climatic patterns, erratic and scanty rainfall, global warming has created imbalance in our ecosystems. With less rainfall, recharging of ground water sources is minimized or almost nil as artificial concrete jungles are giving less space for recharge. In almost all the towns and cities in India this is a very common phenomenon and depletion in ground water sources has aggravated the water scarcity. In a city like Jaipur the depletion of ground water is of the order of more than 3 metres every year.

Due to the depletion in ground water resources, there has been severe scarcity of water giving rise to issues of higher concentrations of total dissolved solids (TDS), arsenic, fluoride and nitrate in ground water. According to the United Nations Water report of 2017 (UN Water 2017), almost 2 billion people across the world are relying on contaminated, unsafe water sources. Almost 80% of waste water in developing nations is not treated. This untreated water contains human excreta which is going back into the ecosystem.

When compared to surface water sources, the bulk of ground water sources typically contain high amounts of fluoride. Fluoride in the soil is a result of the weathering of rocks, precipitation, and untreated water, primarily from the fertilizer industry (Ali et al. 2016). The majority of regular fluoride consumption comes from drinkable water (Bibi et al. 2017). Once a child's teeth have developed, the enamel fluorosis, which appears as spots on the enamel, never goes away (Karmakar et al. 2016). It is regarded as a negative consequence of fluoride interfering with ameloblasts in the growing tooth, manifesting in a disruption of the process of enamel production and increasing its porosity. The fracture risk is also increased and the bones are weakened (Bhattacharya et al. 2017).

Nitrate is regarded as a hazardous substance in drinking water, which is often derived from the ground. Methemoglobinemia is a common diseases where nitrate levels are too high. Blue-baby syndrome among infants is brought on by a blood condition (infant cyanosis). Infants’ digestive tracts are thought to be where methemoglobin is generated when bacteria convert nitrate ions to nitrite ions (Satayeva et al. 2018). One nitrite molecule reacts with two hemoglobin molecules to produce methemoglobin. In an acidic atmosphere, this reaction happens quickly. The infant experiences prolonged, potentially fatal asphyxia because the changed blood protein stops blood cells from absorbing oxygen (Knobeloch et al. 2000). Additionally, excessive nitrate consumption can cause human disorders like Alzheimer's, vascular dementia, and multiple sclerosis (Akber et al. 2020).

The total amount of active charged particles dissolved in water that contains minerals, salts, and metals, is known as total dissolved solids (TDS). TDS is relevant to the quality and consistency of water as well as water filtration systems (Aher et al. 2017). Dissolved solids are any salts, metals, minerals, anions, or cations that may dissolve in water. The TDS concentration is determined by the quantity of anions and cations in the water (Weber-Scannell & Duffy 2007).

The main purpose of this study is to analyse the key water quality parameters such as fluoride, nitrate and TDS in Jaipur city's ground water. Detailed data collected were further analysed through GIS interpolation, and concentration of these contaminants at each ward level was determined. This is an important criterion for city planners, urban local bodies and the Public Health Engineering Department (PHED) for future city planning and zones in terms of water quality.

Till now no study has been done in Jaipur city where the concentration of major parameters has been found for each ward. This study is innovative in finding key parameters for each ward.

This has been done in steps.

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  Study area: Jaipur City

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  Jaipur drinking water scenario which includes zones, abstraction of tube wells, deteriorating ground water quality, waste water management scenario, higher concentration of various contaminants including fluoride, nitrate and TDS

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  Extensive data collection in various zones

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  Interpolation of data through GIS

Jaipur, the ‘pink city’ of India and capital of the biggest state, Rajasthan, is presently facing huge water issues in terms of quality and quantity. The city has a population of 4.1 million according to the Macrotrends estimate for the year 2022 (Macrotrends 1950–2022). This is a population increase of 2.5% in comparison to 2021 and 33% in comparison to 2011. The city had 91 wards under the 2019 classifications; in this study the basis of study was confined to these 91 wards (Vyas et al. 2020). During 2020 the city wards were reclassified into 250 wards. With 150 wards Jaipur greater has more wards than Heritage Jaipur which has 100 wards. In this study the analysis was done for 8 zones and 91 wards as shown in Table 1.

Jaipur city's total water demand is more than 500 MLD. Out of this demand 275 MLD is fetched from Bisalpur dam situated 120 km from Jaipur (Jain 2020), 100 MLD is fetched from government-owned tube wells and there is demand deficit of 125 MLD. With population increasing the peak summer demand deficit presents an alarming situation. In order to cater for the remaining deficit demand there are thousands of private individual tube wells and public tube wells which are supplying water to the residents through water tankers. Residents of city have been regularly complaining about the shortage and low water supply (Times of India 2018). For example, in Barkat Nagar area the situation is critical as residents receive water only for 10–15 minutes/day. The situation gets worse when many residents use boosters. On the other hand PHED reduced the water supply by 15% in the city in 2018 due to scarcity of rains. All 13 blocks of Jaipur city are overexploited and come under category dark zone according to Central Ground Water Board (CGWB 2017). A study done on Jaipur water quality by Jain et al. (2014) determined that more than 95% of samples have high TDS, in some cases more than 1,800 mg/l. Another study done by Roberts et al. (2013) predicted that there has been a declining rainfall pattern in the last two decades. Some key issues pertaining to supplying potable drinking water are outlined below.

Besides rapid urbanization in some cases ground water exploitation was done at a rate of more than 500%, one of the key factors for severe degradation of ground water quality. Illegal mining of ground water in absence of effective regulation and monitoring of drilling new tube wells have aggravated the situation. An estimated 20,000–30,000 tube wells in Jaipur city are unaccounted for (Soni 2015). Due to extreme abstraction contaminants like nitrate, fluoride, and TDS are dominant in the ground water. All 33 districts of Rajasthan are partially or fully affected by higher concentrations of fluoride in ground water.

Seventy percent of Jaipur city water distribution through pipes has either high bacterial contamination or high TDS or may have both issues as projected by the India water portal based on the reports from Public Health Engineering Department Rajasthan and National Environmental Engineering Research Institute (NEERI). Jaipur district is among other districts where average concentration of fluoride is more than 2 mg/l (Singh et al. 2011). On the other hand, due to low rainfall, concentration of nitrate is high as ground water gets less water for dilution (Saxena & Saxena 2014). A study by Ayyasamya et al. (2009) states that concentration of nitrate in the Rajasthan state reaches a maximum of 1,000 mg/l. Rajput et al. (2019), using GIS techniques, assessed the ground water deterioration of Jaipur city. That study found that geogenic processes are more responsible for the high fluoride concentrations in ground water. Similarly excessive usage of fertilisers and domestic sewage discharge are key factors for high concentration of nitrate in the city.

Research by Sharma et al. (2020) found that in Jaipur city only 62% of total sewage is treated through various waste water treatment plants. Only 235 MLD waste water is treated out of a total 378 MLD generation. This is one of the reasons for bacterial contamination of drinking water sources as waste water finds its way to drinking water reservoirs. On the other hand, 36% of the Jaipur city population is served by the underground sewerage system.

A study done on 477 outpatients at Rajasthan dental college and hospital (Agrawal et al. 2014) at Jaipur revealed that only 10.9% (52) of total patients had no fluorosis. On the other hand, 89.0% (425) of total patients had fluorosis issues: 28.5% of patients (136) had moderate level of fluorosis; 30.6% of patients (146) had mild level of fluorosis symptoms; questionable level of fluorosis was 7.1% (34); and very mild level of fluorosis was 11.3% (54). Almost 58% (275) were using government supplied water as main source of drinking water and 42% (202) were relying on ground water. The severity of fluorosis is increasing at an alarming rate and the impact on school-going children is immeasurable.

In 2021, PHED Rajasthan chemical team collected 184 samples of water from 15 places in Jaipur (Bhaskar.com 2021). In some cases nitrate concentration was around 125 ppm against 45 ppm as prescribed by the Central Pollution Control Board. To overcome the water shortage PHED mixed the tube well water with Bisalpur dam water supply in water tankers and in clean water reservoirs (CWR) for a population of 250,000.

Extensive data were collected for parameters related to water quality of Jaipur. These data were collected at Rajasthan state ground water department where the scientists used to collect it manually at each of the wells. Some of the data used was not primary data, i.e. it has not been collected first hand and is based on availability of data from secondary sources. Further density of data collection points for ground water quality is not optimal. A GIS database was prepared and GIS-based interpolation and zonal statistical tools were used to calculate average values at each of the wards.

In this research the focus was on fluoride, nitrate and total dissolved solids due to the deteriorating impacts on human health and their predominance in Jaipur region. The Government of India's Central Pollution Control Board (CPCB) permissible limit for fluoride is prescribed as 1.5 mg/l; this is 45 mg/l for nitrate and 500 mg/l for TDS. For this study data from 2015 to 2018 and 2021 was collected and analysed. Data for 2019 and 2020 was not available due to Covid restrictions and were not collected manually by the scientists at CGWB. For our analysis purpose we took 2015 and 2018 data. These data are shown in Tables 2–5.

Table 2

Water quality parameters (F^−, and TDS), 2015 data

Location .	Latitude .	Longitude .	F− (mg/L) .	(mg/L) .	TDS (mg/L) .
Harmara	27.01	75.77	0.4	22.94	564
Amer	26.99	75.86	0.46	9.92	896
Kukas	27.03	75.89	0.5	76.88	465
Ravinramanch	26.91	75.82	0.6	182.28	1,076
Galtagi	26.92	75.86	0.9	4.96	164
Kalwar	26.96	75.68	1.3	6.82	554
Niwaroo	26.97	75.69	1.3	6.82	331
A. Cantt. Pz	26.98	75.71	0.4	9.92	221
Jhotwara	26.95	75.75	0.4	3.1	170
Sirsi Pz	26.91	75.68	1.9	19.22	432
Niwaroo	26.97	75.71	0.8	13.02	331
Kanakpura	26.92	75.72	1.9	19.84	313
Vidhyadhar nagar	26.97	75.78	0.6	63.86	440
Govt. Hostel	26.92	75.80	0.4	151.9	779
Goner	26.78	75.91	0.9	27.9	330
Heerapura	26.87	75.74	2.3	107.26	1,479
Khori	26.86	75.91	0.6	73.78	666
Mahel	26.81	75.86	1.9	40.92	1,144
GWD Campus Pz	26.87	75.82	0.6	153.76	595
O T S	26.87	75.81	2.3	21.7	335
Bilwa	26.76	75.85	0.9	40.3	899
Muhana	26.79	75.73	1	14.88	740
Nevta	26.80	75.68	1.3	14.26	685
Sanganer	26.82	75.78	0.3	14.26	265
Dahmi kalan Pz	26.84	75.57	0.9	3.1	391
Bhankrota	26.87	75.70	0.3	66.96	524

Location .	Latitude .	Longitude .	F− (mg/L) .	(mg/L) .	TDS (mg/L) .
Harmara	27.01	75.77	0.4	22.94	564
Amer	26.99	75.86	0.46	9.92	896
Kukas	27.03	75.89	0.5	76.88	465
Ravinramanch	26.91	75.82	0.6	182.28	1,076
Galtagi	26.92	75.86	0.9	4.96	164
Kalwar	26.96	75.68	1.3	6.82	554
Niwaroo	26.97	75.69	1.3	6.82	331
A. Cantt. Pz	26.98	75.71	0.4	9.92	221
Jhotwara	26.95	75.75	0.4	3.1	170
Sirsi Pz	26.91	75.68	1.9	19.22	432
Niwaroo	26.97	75.71	0.8	13.02	331
Kanakpura	26.92	75.72	1.9	19.84	313
Vidhyadhar nagar	26.97	75.78	0.6	63.86	440
Govt. Hostel	26.92	75.80	0.4	151.9	779
Goner	26.78	75.91	0.9	27.9	330
Heerapura	26.87	75.74	2.3	107.26	1,479
Khori	26.86	75.91	0.6	73.78	666
Mahel	26.81	75.86	1.9	40.92	1,144
GWD Campus Pz	26.87	75.82	0.6	153.76	595
O T S	26.87	75.81	2.3	21.7	335
Bilwa	26.76	75.85	0.9	40.3	899
Muhana	26.79	75.73	1	14.88	740
Nevta	26.80	75.68	1.3	14.26	685
Sanganer	26.82	75.78	0.3	14.26	265
Dahmi kalan Pz	26.84	75.57	0.9	3.1	391
Bhankrota	26.87	75.70	0.3	66.96	524

Bold values indicate more than permissible limit.

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Table 3

Water quality parameters (F⁻, and TDS), 2018 data

Location .	Latitude .	Longitude .	F− .	.	TDS .
Harmara	27.01	75.77	0.58	11.78	1,098
Amer	26.99	75.86	1.02	104.78	1,209
Kukas	27.03	75.89	0.9	57.04	1,153
Ravinramanch	26.91	75.82	0.04	187.24	1,855
Galtagi	26.92	75.86	1.5	27.9	340
A. Cantt. Pz	26.98	75.71	0.8	96.72	821
Jhotwara	26.95	75.75	1.84	19.22	716
Sirsi Pz	26.91	75.68	1.48	19.84	670
Niwaroo	26.97	75.71	2.36	91.76	782
Kanakpura	26.92	75.72	2.04	81.84	727
Goner	26.78	75.91	4.2	70.06	1,835
Heerapura	26.87	75.74	2.7	27.9	569
Khori	26.86	75.91	5.56	70.06	1,555
Durgapura	26.85	75.79	0.64	14.88	341
Mansarovar	26.85	75.76	0.84	68.82	565
Sanganer	26.82	75.78	0.54	19.22	360
Bhankrota	26.87	75.70	1.16	13.02	540

Location .	Latitude .	Longitude .	F− .	.	TDS .
Harmara	27.01	75.77	0.58	11.78	1,098
Amer	26.99	75.86	1.02	104.78	1,209
Kukas	27.03	75.89	0.9	57.04	1,153
Ravinramanch	26.91	75.82	0.04	187.24	1,855
Galtagi	26.92	75.86	1.5	27.9	340
A. Cantt. Pz	26.98	75.71	0.8	96.72	821
Jhotwara	26.95	75.75	1.84	19.22	716
Sirsi Pz	26.91	75.68	1.48	19.84	670
Niwaroo	26.97	75.71	2.36	91.76	782
Kanakpura	26.92	75.72	2.04	81.84	727
Goner	26.78	75.91	4.2	70.06	1,835
Heerapura	26.87	75.74	2.7	27.9	569
Khori	26.86	75.91	5.56	70.06	1,555
Durgapura	26.85	75.79	0.64	14.88	341
Mansarovar	26.85	75.76	0.84	68.82	565
Sanganer	26.82	75.78	0.54	19.22	360
Bhankrota	26.87	75.70	1.16	13.02	540

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Table 4

Ward-wise distribution of water quality parameters (F⁻, and TDS)

Zone name .	Ward No .	F− 15 .	F− 16 .	F− 17 .	F− 18 .	15 .	16 .	17 .	18 .	TDS 15 .	TDS 16 .	TDS 17 .	TDS18 .
Vidyadhar Nagar	1	0.7	1.1	0.6	0.7	40.3	26	59.7	57.0	426.8	730.7	458.8	701.5
Vidyadhar Nagar	2	0.7	0.9	0.6	0.8	40.3	26.0	59.7	57.1	426.7	732.4	392.7	700.3
Vidyadhar Nagar	3	0.6	1.0	0.5	0.5	40.0	37.5	59.5	55.8	423.5	730.7	580.0	694.2
Vidyadhar Nagar	4	0.7	0.7	0.6	0.8	40.3	30.6	59.7	57.1	426.7	741.7	416.8	673.9
Vidyadhar Nagar	5	0.7	0.6	0.6	1.0	40.7	26.4	57.5	54.2	410.3	708.8	362.0	661.7
Vidyadhar Nagar	6	0.8	0.7	0.7	1.3	47.3	21.0	54.6	51.6	468.6	657.2	312.9	640.2
Vidyadhar Nagar	7	0.7	0.4	0.7	1.3	46.7	24.7	53.5	50.2	452.3	629.3	346.5	612.6
Vidyadhar Nagar	8	0.7	0.6	0.6	0.8	41.6	31.4	55.2	51.5	400.4	676.7	434.1	634.0
Vidyadhar Nagar	9	0.6	0.9	0.5	0.3	40.4	41.1	58.3	55.1	424.4	736.7	593.0	661.4
Vidyadhar Nagar	10	0.6	0.6	0.6	0.5	43.6	37.3	55.7	50.9	421.4	693.5	526.6	620.0

Zone name .	Ward No .	F− 15 .	F− 16 .	F− 17 .	F− 18 .	15 .	16 .	17 .	18 .	TDS 15 .	TDS 16 .	TDS 17 .	TDS18 .
Vidyadhar Nagar	1	0.7	1.1	0.6	0.7	40.3	26	59.7	57.0	426.8	730.7	458.8	701.5
Vidyadhar Nagar	2	0.7	0.9	0.6	0.8	40.3	26.0	59.7	57.1	426.7	732.4	392.7	700.3
Vidyadhar Nagar	3	0.6	1.0	0.5	0.5	40.0	37.5	59.5	55.8	423.5	730.7	580.0	694.2
Vidyadhar Nagar	4	0.7	0.7	0.6	0.8	40.3	30.6	59.7	57.1	426.7	741.7	416.8	673.9
Vidyadhar Nagar	5	0.7	0.6	0.6	1.0	40.7	26.4	57.5	54.2	410.3	708.8	362.0	661.7
Vidyadhar Nagar	6	0.8	0.7	0.7	1.3	47.3	21.0	54.6	51.6	468.6	657.2	312.9	640.2
Vidyadhar Nagar	7	0.7	0.4	0.7	1.3	46.7	24.7	53.5	50.2	452.3	629.3	346.5	612.6
Vidyadhar Nagar	8	0.7	0.6	0.6	0.8	41.6	31.4	55.2	51.5	400.4	676.7	434.1	634.0
Vidyadhar Nagar	9	0.6	0.9	0.5	0.3	40.4	41.1	58.3	55.1	424.4	736.7	593.0	661.4
Vidyadhar Nagar	10	0.6	0.6	0.6	0.5	43.6	37.3	55.7	50.9	421.4	693.5	526.6	620.0

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The most severe sufferers from ground water quality are the urban poor who migrate to large cities for employment, education and so on, and are bound to live on the periphery or outskirts of the city area which are served water through costly individual water tankers from unsafe sources.

In this study three key parameters, fluoride, nitrate and TDS, pertaining to Jaipur city water quality were taken into consideration. Through the use of GIS software the concentration of all three water quality parameters was determined through spatial distribution. Through this step the concentration of fluoride, nitrate and TDS in all 91 wards for the years 2015, 2016, 2017 and 2018 was found. Based on these values the concentration of each pollutant is further shown through GIS maps in 91 wards. For the purpose of this study data for 2015 and 2018 were used. Water quality parameters of different areas of Jaipur city for 2021 were also studied.

Comparing to previous years, except in Vidyadhar Nagar zone, the remaining seven zones have a better nitrate concentration in Jaipur city. This may be attributed to dilution of ground water aquifers due to rainfall. This is shown in Figure 8. Fortunately, the densely populated areas of Sanganer and Mansarovar all have better quality.

The most severe sufferers from ground water quality are the urban poor. They migrate to large cities for employment and education, and so on, and are bound to live on the periphery of the city. They are served water through costly individual water tankers from unsafe sources. Jaipur city has annual average rainfall of 504 mm, which is less than half of India's annual average rainfall of 1,100 mm. Climate change impact, ecological imbalance, erratic rain patterns and reduction in rainfall combined with rapid urbanization, steep increase in population and extension of concrete floors is giving much less space for ground water recharge. Without more dilution of ground water the issues of fluoride, nitrate and TDS is increasing at a very high rate. Effective rain water harvesting structures and developing green zones are two of the ways to mitigate the issue. An effective environmental management plan is urgently needed.

This study demonstrated that it is possible to compare the observed water quality parameters value favourably with the estimated water quality parameters value. As a result, the proposed model can be utilized to reasonably anticipate and manage the water quality. In order to prevent additional pollution of this major area of Jaipur city, the study advises the necessity of ongoing water monitoring in order to identify the causes of pollution.

The authors acknowledge the kind support from various regulatory agencies in Jaipur city including Central Ground Water Board (CGWB), PHED, JDA, JMC, MNIT (Malviya National Institute of Technology), and MUJ (Manipal University Jaipur). The authors would also like to acknowledge the support of Mr Kushal Mahale, research scholar from Manipal University Jaipur with a special thanks to Dr Rohit Goyal, Professor of Civil Engineering, Malviya National Institute of Technology, Jaipur.

All relevant data are included in the paper or its Supplementary Information.

The authors declare there is no conflict.