Keywords

1 Introduction

Ancient settlements were developed in the vicinity of the river bodies because for living water is the main resource for all the living beings. Rivers add up as the primary source of inland water for home, industrial, irrigation and other purposes and they play a significant part in hydrologic and biogeochemical cycles. However, due to extensive human activity, few rivers are kept in pristine condition and surface water contamination is becoming a major environmental concern around the world [1].

The main role of the rivers is to transport and assimilate pollutants from both point sources, that is urban wastewater and industrial emissions and non-point sources like agricultural runoff, etc. We all know that there are many pollutants and effluents found through these sources which when goes into the river makes it polluted. And we are this way destroying our own precious resources. Surface outflows are the seasonal phenomenon that is greatly affected by climatic variables within the river basin, but urban and industrial wastewater discharges are the constant polluting sources. Precipitation, runoffs, interflows, groundwater and urban transfers all have a significant impact on river flow and, as a result, on pollution levels in river water [2]. Industrial, agricultural and domestic consumer processes produce large quantities of waste products for which the natural waterways provide the cheapest form of disposal.

Being the lifeline of millions of people, the river Ganga also known as Bhagirathi is a representation of India's ancient heritage and culture and it holds a hallowed place in people's hearts. Being the holy river, for every citizen, Ganga is just not a river but mother, hence it is called as Maa Ganga. It is renowned for supplying the environment and ecology with a life-giving and life-sustaining progeny. Not only has it been prime source of water supply to farms, household industries, etc., but also remained important from religious point of view. There is a tradition followed till date that taking holy dips into the Ganga vanishes every mistake and wrong thing done by a person and is thought to be the entrance to the heavenly dwelling for virtuous individuals. Its banks have served as sanctuaries of God’s worship. The cultural, spiritual and emotional bond with the civilisation of India has given Ganga its uniqueness.

One of the largest basins that counts of 26% of India’s total geographic area is the basin of Ganga. Figure 1 depicts the Ganga river basin along with the prominent cities/towns situated on the bank of River Ganga. The Ganga begins from confluence of river Bhagirathi and river Alaknanda at Devprayag in Uttarakhand. The Bhagirathi rises from the Gangotri glacier at 30 ° 55′ N, 79° 7′ E, at 4100 m above mean sea level in Uttarakhand. It travels 205 kms from Gaumukh through the Himalayas, passing through Uttarkashi and Tehri on its way to Devprayag, where it merges with the Alaknanda to form the holy Ganga. The Ganga flows through Uttarakhand and Uttar Pradesh (1425 km), Bihar (475 km), Delhi, Punjab, Haryana, Himachal Pradesh, Rajasthan, Madhya Pradesh, as well as West Bengal (625 km) before debouching finally into the Bay of Bengal. Ganga stretches over 2500 kms, is home to 29 class I cities, 23 class II cities, 48 towns and countless of villages. Kali, Yamuna, Ramganga, Gomti, Ghaghara, Gandak and Kosi are among the river’s many tributaries. Its basin is densely populated and is home to 37% of India’s total population.

Fig. 1
An illustration of the river ganga’s basin present in India.

River Ganga’s Basin in India [3]

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The domestic and municipal wastewater from various residential and urban centres, trade effluent from large number of industries and pollution from various other sources are released into the river. This leads to the pollution of rivers but what we all focus upon is just us.

Talking about the holy river, the river Ganges- Mass bathing and offerings in river Ganga takes place at time of ‘Kumbh Mela’, ‘Kanvar Mela’, solar eclipse and major festivals in addition to daily bath and offerings (flowers, food, diyas, milk, oil, etc.) by the pilgrims.

The development of hydropower projects, such as the Tehri dam, is reducing river discharge. The water is recycled to maintain storage in the dam, which is used to generate energy. Further, the diversion of water by Upper Ganga canal at Haridwar and the lower Ganga canal near Aligarh and diversion of water into smaller canals of irrigation and other purposes results in the reduction of flow and deteriorates the self-purifying capacity of river. Dams and barrages constructed for generation of hydropower in the upper stretches and civil constructions in the catchments, canal irrigation, combined with deforestation, mining have shattered much of its ability to flow.

Thus, to restore, manage and preserve river water quality the government of India established many regulatory bodies like: Central Pollution Control Board (CPCB), State Pollution Control Board (SPCB), National River Conservation Directorate (NRCD) and Ministry of Environment Forest and Climate Change (MoEFCC). Considerable amount of data has been generated on water quality of river Ganga over past few decades by adopting various action plans and projects for, e.g. Ganga Action Plan, The Water (Prevention and Control of Pollution) Act of India, National Mission for Clean Ganga, Clean Ganga Fund, Bhuvan Ganga and Namami Gange, etc. However, river Ganga and many rivers of India is facing an alarming situation which gives an indication of stricter implementation, management, monitoring and strengthening public awareness. This article is an attempt to highlight human intervention and its effects on river Ganga’s ecology as well as key mitigation measures has also been touched upon to suggest and help the authorities for proper restoration strategies.

2 Review of Literature

River Action Plans, with the objective to clean and bring back the purity of river, have been formulated and launched from time to time by Government of India. There are, however several issues raised in the implementation of the river action plans. Some of issues and concerns related to the improvements in the water quality of the river Ganga. Considerable efforts have been made in the latter half of nineteenth-century to assess the water quality of river Ganga. The review of literature presented here focuses on water quality of river Ganga as the present research was initiated to address issues related to the changes that have occurred in the quality of water due to pollution.

According to [4] Overexploitation, dams and diversions, habitat damage, non-native species and pollutants will all interact to devastate native freshwater fisheries. Increased eutrophication and enhancement of numerous biogeochemical processes will result from less water renewal. Water and sewage treatment will become more sophisticated and expensive as industrial agriculture and human populations grow.

In a study by Kiedrzyńska [5], it was observed that The inflow of high loads of nutrients causes eutrophication in the Baltic Sea, which is a severe problem. This is mostly due to pollution from both point and diffuse sources, such as treatment plants for wastewater that dump untreated wastewater into rivers and into the sea. Total nitrogen and phosphorus load discharged from the Pilica watershed were1.655 t TN km2 and 0.057 t TP km2, respectively, which was greater than the yearly average loads.

Gibbons et al. [6] mentioned that metals, pesticides and herbicides and radioactive waste are only a few examples of environmental toxins that have direct and indirect effects on amphibians and reptiles.

Tyler and Bbuckey [7] found that the discharge of wastewaters from tin and wolfram mines has polluted two creeks severely, but the South Esk River in North-East Tasmania has been less polluted.

Agrawal [8] Observed that wash off or seepage from agricultural activities was rare during the 8–10 clear environmental and weather conditions. However, agricultural pollutants were the dominant sources found in surface wash off during floods, while, drainage or seepage were affecting the water quality for a month or two after monsoons. In various locations, such as Punjab and Haryana, high nitrate concentrations in groundwater have been documented, and these can often be traced back to dispersed agricultural sources. Bacterial pollutants and heavy metals from organic wastes were found unsuitable for usage.

Metal pollution is a growing source of worry since it has a bioaccumulative effect on an ecosystem’s entire food chain. Globally, increasing industrialisation and artificial meddling have put enormous strain on self-sustaining ecosystems. The magnitude of metal pollution in the sediment of the Sundarbans mangrove estuary is shown in a study by Roy et al. [9], which also explores the source and distribution of these metals. The findings reveal that this historic site is in critical condition. The progressive decline of this estuarine mangrove is due to metal concentrations over toxicity thresholds.

The study by Suthar et al. [10] observed and assessed the presence of heavy metals like Pb, Zn, Mn, Cd, Fe, Cr and Cu in Hindon River of Ghaziabad. Cd, Cu, Cr, Fe, Mn, Zn and Pb were present in sediments of river. At Hindon’s point and non-point polluted sites, the enrichment factor (percent) for sediment ranged from 0.05 to 99.8%. In the River Hindon in Ghaziabad city, the geo-accumulation index (Igeo) revealed higher concentrations of Zn, Mn, Pb, Fe, Cu and Cr. Heavy metals in rivers were primarily sourced from industrial and urban wastes in river catchment areas.

Maurya et al. [11] evaluated the upper Ganges River's water quality index at Haridwar, Uttarakhand and observed the relationship on water quality change due to land-use change. Water samples were taken from five locations along the upper channel of the Ganges, spanning a 78-km area. Physicochemical parameters such as Fe2+, K+, Na+, F, Mg2+, CaCO3, Cl, TDS, EC, pH and DO were evaluated for water quality index. Spatial correlation and error estimation were used to assess geographical analysis. At selected sampling sites, the root mean square error between spatial land use and water quality index was estimated to be 0.1443. With R2 = 0.8455, the site-wise and land-use changes were spatially correlated in water quality index which was found highly favourable.

Analysis of water samples done by Kumar and Garg [12] of river Ganga was monitored from Rishikesh to Brijghat (Hapur) for pH, dissolved oxygen, total hardness, heavy metals like As, Fe, Mn, Cu, Pb, Cd, Hg, Cr, Zn, Ni, nitrate, nitrogen, phosphate and phosphorous at different sampling locations. The examination of physicochemical parameters suggests that water quality has significantly deteriorated and is destroying river water quality. Consumers of drinking water and organisms in the Ganga River basin may be exposed to health concerns as a result of this.

Kamboj and Kamboj [13] used Overall Index of Pollution over the years 2017–2018 to investigate riverbed mining-affected areas of Ganga at Haridwar for seasonal dynamics of surface quality. The Overall Index of Pollution value for surface water quality was observed as acceptable in summer and monsoon and excellent in winter while slightly polluted in rainy season. The observations revealed that the selected sites had a high Overall Index of Pollution score when compared to sites where mining was not done. As a result, it was determined that mining at riverbeds had adverse impact on surface water quality of river Ganga.

3 Some of the Initiatives Taken by the Country to Maintain the Water Quality of Rivers

  • The Water (Prevention and Control of Pollution) Act of India, 1974: This Act deals with the prevention and control of water pollution [14], as well as the restoration and maintenance of water as well as to look forward the aforementioned motives of strengthening water regulatory boards. Under the provisions of this Act, Pollution control boards in India were established. In 1978, the Water Act was revised for the first time. It was revised once more in 1988 to comply with the 1986, Environment Protection Act.

  • National Water Policy-Ministry of Water Resources (2012) [15]: The Ministry of Water Resources (MoWR) has released this document that emphasises the importance of water for mankind. It emphasises the issue of water shortage and the necessity to preserve this resource in the most efficient, cost-effective, long-term and fair manner possible.

  • Ganga Action Plan [16, 17]: Based on a thorough examination of the Ganga Basin, the Central Pollution Control Board set up the Ganga Action Plan or GAP in 1984 under the “‘Evaluation and Development Study of River Basin Series (ADSORB)’. The underlying objective of GAP was to bring the Ganga's water quality up to satisfactory levels by keeping contamination from entering the stream.

  • National Ganga River Basin Authority (NGRBA) [18, 19]: NGRBA was established by the Central Government of India on February 20, 2009, under Section 3 (3) of the Environment Protection Act, 1986. It designated the Ganges as India’s ‘National River.’ The length of the Ganga between Gaumukh and Uttarkashi was designated as an ‘eco-sensitive zone’ by the government in 2010.

  • National Mission for Clean Ganga (NMCG) [20, 21]: The National Mission for Clean Ganga (NMCG) is the functional arm of the National Ganga River Basin Authority (NGRBA. The Ganga Rejuvenation Vision involves re-establishing the stream’s healthiness by guaranteeing ‘Aviral Dhara’ (Continuous Flow), ‘Nirmal Dhara’ (‘Unpolluted Flow’), just as geologic and natural uprightness. The mission of the National Mission for Clean Ganga is to satisfy the command of the National Ganga River Basin Authority (NGRBA), which is to accomplish successful contamination reduction and restoration of the stream Ganga.

  • Namami Gange: The Government of India established “‘Namami Gange,’ an integrated Ganga Conservation [20, 22,23,24] Mission, with a budget of Rs. 2037 crores. ‘Namami Gange’ approaches Ganga Rejuvenation by combining current initiatives and putting in place a comprehensive activity plan for the future.

  • Clean Ganga Fund: The ‘Clean Ganga Fund’ was established by the Government of India [21, 25] as part of the ‘Namami Gange’ programme to encourage contributions to Ganga Rejuvenation.

  • Bhuvan Ganga: It is a geospatial support for the National Ganga Clean-up Mission. Bhuvan Ganga is a mobile application that allows members of the public to contribute photos of pollution sources along the Ganga River for further investigation by the authorities. This mobile app serves as a crowd-sourcing platform for monitoring pollution in the Ganga River and assisting decision-makers in prioritising solutions.

4 Materials and Methods

Study aims to know the variations in water quality of river Ganga from Rishikesh to Haridwar. The information was gathered at five distinct locations along the Rishikesh–Haridwar route. A scientific study was conducted in order to analyse the influence of human involvement on the Ganga’s ecology. The study and sampling sites were Tapovan (Site 1), Raiwala (Site 2), Bhimgoda (Site 3), Devpura (Site 4) and Jagjeetpur (Site 5).

Based on the state-of-the-art review of the literature dedicated to study of river Ganga’s water quality key parameters that have been taken under consideration are pH, Temperature, Dissolved oxygen (DO), Total Solids (TD), Total Dissolved solids (TDS), Chloride, Alkalinity, Hardness which deteriorates the quality of river Ganga.

Study is an attempt to evaluate the changes in river water quality of Ganga from Rishikesh to Haridwar. The data is collected from the five different sites lying in the route of Rishikesh to Haridwar. In the current study, a scientific attempt has been taken to assess impact of human interference in the ecology of river Ganga. Tapovan (site 1), Raiwala (site 2), Bhimgoda (site 3), Devpura (site 4) and Jagjeetpur (site 5) were selected as the study and sampling sites.

The samples are analysed as per standard methods for different Physicochemical parameters that is total dissolve solids, pH, alkalinity, hardness, temperature, total solids, chloride, dissolve oxygen (DO), biological dissolve oxygen (BOD). In-situ approach was taken on to find out unstable parameters including; pH, DO by versatile meters. Test of every device was put in focus of the stream in roughly 50% of its absolute profundity. Examination of different parameters was completed by volumetric investigation as per standard strategies for APHA (Fig. 2).

Fig. 2
An illustration of the different steps considered for identification of impacts. 1. Collection of primary and secondary data. 2. Correlation between primary and secondary data. 3. Identification. 4. Critical suggestions.

Different steps considered for identification of impacts

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In this study, for the computation of water quality records, significant parameters, which have quite significant role in fluctuation of water quality are picked for examination of water quality. The water quality has been determined by involving the norms of drinking water quality as suggested by the World Health Organisation (WHO), Bureau of Indian Standards (BIS) and Central Pollution Control Board (CPCB) (Table 1).

Table 1 Depicting key water quality parameters and their permissible and maximum limits to maintain water quality according to Drinking water quality standards
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5 Study Areas

Rishikesh

Rishikesh, Uttarakhand, India, is managed by the Rishikesh Municipal Corporation and a tehsil in the Dehradun district. It's around 25 kms (16 miles) north of Haridwar and 43 kms (27 miles) southeast of Dehradun, the state capital. Rishikesh has a population of 102,138 people in 2011, according to the Indian Census, making it the eighth-most populous city in Uttarakhand.

Rishikesh has a number of ancient and new temples along the banks of the Ganges. Adi Shankaracharya built ancient temples such as Shatrughna Mandir, Bharat Mandir and Lakshman Mandir. Ram Jhula is close to Shatrughna Temple, while Lakshman Jhula is close to Lakshman Jhula (Fig. 3).

Fig. 3
An illustration of the flow of ganga river at Rishikesh, India.

Representing the flow of river Ganga at Rishikesh, India [26]

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Haridwar

Haridwar is a sacred city in Uttarakhand, situated at the foothills of the Shivalik range. Rishikesh is 28.3 kms away. Haridwar is located between 29° 58′ north latitude and 78° 13′ east longitude. Haridwar district has a population of 1,890,422 people according to the 2011 India census. The Ganga joins the Indo-Gangetic Plains of North India at Haridwar after flowing for 253 kms from its source at Gaumukh on the Gangotri Glacier's edge. For Hindus, it is one of the seven holy locations (Sapta Puri).

Religious ceremonies and other activities (cremation of dead bodies, emission of ashes, etc.) have polluted the ghats of Haridwar to the point where the water is unfit even for bathing. Aside from that, diverting water from the main river to the Upper Ganga Canal interrupts the main river’s flow even more. With the fast-growing industrial estate as well as its affiliated ancillaries, the city is developing beyond its religious significance.

Samples were analysed according to standard procedures for different Physicochemical parameters namely pH, Temperature, Total solids, Total dissolve solids, Alkalinity, Hardness, Chloride, Dissolve Oxygen (DO) and Biological Oxygen Demand (BOD) (Fig. 4).

Fig. 4
An illustration represents the flow of ganga river at Rishikesh, India.

Representing the flow of river Ganga, India [26]

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In-situ measurements, such as pH and DO, were used to determine unstable parameters using portable meters. Each meter device’s probe was put in the middle of the stream at about half of its total depth. The other parameters were analysed using volumetric analysis in accordance with APHA-approved standards.

6 Results and Discussion

The sacred river Ganga in Haridwar is heavily impacted by wastewater from various industries as well as untreated sewage discharged due to a lack of sewage treatment systems. Along with the pilgrims who take a holy bath in the holy river throughout the year, all of these factors contribute to the deterioration of the situation. The quantity and quality of a river's surface water. Natural elements like as rainfall, temperature and rock weathering, as well as anthropogenic changes, influence the basin, which reduces the river's natural flow or changes its hydrochemistry River water quality indexing was the subject of a study. Analysing the results obtained from different physicochemical parameters (Figs. 5, 6, 7, 8, 9, 10 and 11), i.e. pH, Temperature, Total solids, Total dissolved solids, Alkalinity, Hardness, Chloride, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), respectively, between Rishikesh and Haridwar indicate the influence of human interference in the ecology of river Ganga.

Fig. 5
A graph depicts the p H values at five selected sites of River Ganga. There are two diminishing trends, a solid connecting line and a dashed linear trend.

pH values at different selected sites (S1–S5) for river Ganga

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Fig. 6
A graph of temperature for five selected sites of River Ganga has two diminishing trends. The solid line denotes temperature and the dashed line denotes linear temperature.

Temperature at different selected sites (S1–S5) for river Ganga

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Fig. 7
A graph plots the content level of Dissolved Oxygen, in milligram per liter, for 5 selected sites of River Ganga. There are 2 trends, a solid line for dissolved oxygen and a dashed linear trend.

Dissolved Oxygen at different selected sites (S1–S5) for river Ganga

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Fig. 8
A graph plots the content of Total Solids and Total Dissolved Solids, in milligram per liter, for 5 selected sites of River Ganga. There are 3 trends, one for T S and T D S each, and a dashed linear upward trend.

Total solids and total dissolved solids at different selected sites (S1–S5) for river Ganga

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Fig. 9
A graph plots the Chloride content, in milligram per liter, for 5 selected sites of River Ganga. There are 2 trends, a solid line for Chloride levels and a dashed linear upward trend.

Chloride values at different selected sites (S1–S5) for river Ganga

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Fig. 10
A graph plots the alkaline content, in milligram per liter, for 5 selected sites of River Ganga. There are 2 trends, a solid line for alkalinity level and a dashed linear diminishing trend.

Alkalinity values at different selected sites (S1–S5) for river Ganga

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Fig. 11
A graph plots the total hardness content, in milligram per liter, for 5 selected sites of River Ganga. There are 2 trends, a solid line for level of total hardness and a dashed linear upward trend.

Total Hardness at different selected sites (S1–S5) for river Ganga

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Potential of Hydrogen (pH) pH is a basic characteristic that is incredibly essential since it controls the majority of chemical reactions in the aquatic environment. The study shows in Fig. 5 a drastic variation in pH, i.e. between 7.47 and 8 for the selected study area and it’s due to multiple anthropogenic activities and inclusion of disposal of waste from various sources.

Temperature (Temp) is one of the most significant ecological factors in an aquatic habitat because of its influence on chemistry and biological reactions in organisms. Changes in temperature in the selected study area (11.65–20 °C) are an evident reason (Fig. 6) for loss of multiple aquatic life and diversity in river Ganga it’s probably due to mixing of multiple drainages, industrial effluent and other activities like rafting and pilgrims’ activities. Metabolism of aquatic organisms increases with the increase in sudden temperature which can be harmful for them to survive. It regulates organism behaviour, as well as the solubility of gases and salts in water. All biological processes are based on a complex collection of biochemical reactions that are affected by physical elements like temperature.

Dissolved oxygen (DO) Dissolve oxygen and its trends (Fig. 7) in the selected study area (6.9–9.5 mg/L) suggest mixing of high amount of organic waste in water and its evident at Haridwar and Rishikesh as its famous for multiple rituals and pilgrims. Site-4 was found below the permissible limit depicting the contaminated water quality. There is a need of restriction on this activity to control water quality parameters. The survival of most aquatic biota depends on dissolved oxygen. When there is a lot of organic stuff in the water, oxygen is considered a limiting factor. Water temperature affects the concentration of DO in surface waters; colder water can contain more DO than warmer water, and saturation occurs at a higher concentration in winter.

Total Solids (TS) and Total Dissolved Solids (TDS)

The current observations (Fig. 8) show that satisfactory concentration of solid (TS: 80–461 mg/L; TDS 80–377.67 mg/L) this suggests presence of excessive salts in Site-3, Site-4 and Site-5 which can be due to multiple anthropogenic activities, nallas nearby, organic waste disposal, agriculture runoff and various other activities. This support the probability for the presence of more concentration of phosphates, nitrates of calcium, sulphates, sodium, potassium, magnesium, iron, manganese, chlorides, Carbonates and bicarbonates and other common salts in water. Density of water is affected by the presence of dissolved solid components, which impacts osmoregulation of freshwater in organisms, as well as the solubility of gases (such as oxygen) and the utility of water for drinking, irrigation and industry. The depth of light penetration in a water body is reduced when the TDS level is high. Photosynthesis is also reduced due to higher TSS and TDS.

Chloride (Cl) presence in Ganga between Haridwar and Rishikesh shows (Fig. 9) variation and moderate increase in concentration on Site-4 and Sitre-5 and it’s a threat to aquatic life which is probably due to industrial waste effluents and other anthropogenic activities nearby. A river’s high chloride level could be a sign of contamination. Excess of chloride in drinking water is not especially dangerous, and the requirements for this anion are mostly focused on its palatability and potential corrosiveness. Excess chloride (> 250 mg/L) gives water a salty flavour, and persons who aren't used to high chlorides may experience laxative effects.

Alkalinity: The current study reveals that Carbonates, bicarbonates and hydroxide complexes of Ca, Mg, Na and K are present in Ganga’s water at said location (Fig. 10) due to presence of higher range of alkalinity. Site-2 depicts the range nearby permissible value which is posing threat in upcoming future. It's usually due to the geology of the area and bicarbonates being leached from the soil. When alkalinity exceeds hardness, it indicates the existence of basic salts such as Na, K, Ca and Mg. When alkalinity (here referred to as Alk) is less than hardness, neutral calcium and magnesium salts are present.

Total Hardness (TH): Current study clearly shows the alarming sign for water of river Ganga and increment in its hardness due to multiple anthropogenic activities along its course as it passes by. Results were found very close to the permissible value at Site-3 and Site-4 (Fig. 11). The majority of ions reach the water body through contact with soil and rock formations. In natural waters, Calcium (Ca) and Magnesium (Mg) make up the majority of the hardness. Groundwater is softer than surface water. Encrustations in water supply structures are caused by high TH. Hardness of water ranging from 0 to 60 mg−1 is considered as mild, 61–120 mg−1 as moderately hard, 121–180 mg−1 as hard and values beyond 180 mg−1 as very hard, according to the United States Geological Survey (USGS) (Table 2).

Table 2 Observed values of chosen parameters at different selected sites (S1–S5) for river Ganga
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7 Major Observations, Which Affect the Quality of River Ganga at Study Sites

Animal carcasses, half-burned and unburned human dead bodies thrown into the river, ritualistic practises, defecation on the riverbanks by low-income people and ashram’s discharge of untreated sewage slow down the river's self-purifying capacity. The entire ecology gets degraded by gradual disappearance of fishes and other aquatic fauna along the course of river. In addition, it is recorded that there is a massive increase in the urban areas along the course of the river. Hence, the outcome is that the river has been reduced to a channel receiving and transporting the waste away from the towns.

Due to the discharge of a large amount of solid wastes into river, it submerges in-depth of the river and as river continues to flow, sand and garbage combine to form a mountain of garbage, obstructing the river's flow. This results in a drop in river depth, which results in less water conservation and, during wet seasons, floods outside the river's banks. Inhabited areas along the river, sewage and industrial waste management are one of the significant causes of Ganga pollution. Many people and companies, including as paper mills, textile mills, fertiliser plants and chemical factories, are located along the river. They consume the river's water and then return it to the river. All industrial waste materials are sometimes metallic and polymers that never degrade and pollute the environment; liquid waste is chemically treated and causes ecosystem imbalance. 138 main drains transporting industrial and domestic wastewater with an average BOD load of 999 tonnes per day.

Throughout the year, millions of devotees flock to the river to take a sacred dip. Another environmentally hazardous habit is mass bathing in the Ganga river during festivals. When thousands of devotees go for bath in holy river Ganga, the biological oxygen demand (B.O.D.) increases drastically. On the riverbanks, dead bodies are incinerated and partially burned carcasses are thrown into the water. For spiritualistic reasons, people throw flowers, ash and ancient figurines into the Ganga after religious devotion of God. As a result, the risk of bacterial contamination rises. The use of renewable energy in agricultural and solid waste management systems is also a major source of harmful substances as waste, which harms the ecosystem. People in our country employ toxic chemicals and fertilisers to contaminate soil and kill all of its microbes, as well as damage the water, due to increased demand and decreased supply. The most serious hazard to the Ganga river is DDT, a common fertiliser. Plastic is widely used in cities, and polythene-made things are mass-produced, with tonnes of plastic and other rubbish dumped into the Ganga river. Major effects on water quality of river Ganga due to above-mentioned reasons can be decrease in the amount of dissolved oxygen, rise in BOD levels, excessive eutrophication, gases’ solubility in water decreases, sediment load in water settles quickly and disturbance in aquatic food supply.

8 Current Scenario and Hurdles in Conservation of River Ganga

The establishment of sewage treatment facilities for the communities along the Ganga's banks has been the main focus of efforts to preserve the river's water quality. This entails constructing a sewage transportation system for the city/town, as well as treatment. Sewage is discharged into a river after treatment. Due to their poor performance, the establishment of sewage treatment facilities, as well as their operation and upkeep, has prompted many concerns. Only the regulatory criteria are being met by the industries.

Due to a lack of suitable infrastructure for home stormwater/sewage, carrying drains that eventually meet the Ganga directly or via tributaries. Excessive river water abstraction for human consumption and agriculture is causing a decline in the Ganga’s flow, which is a major worry. Though water can be used, the question of how to supplement and replace the river flow has yet to be resolved. The public’s participation in government and non-government organisations has not been consistent or on a regular basis. The shows were sporadic, on a regular basis, or with special drives (Fig. 12).

Fig. 12
A map labels the sources of pollution for the five selected sites of River Ganga.

Observed pollution sources in between S-1 and S-5

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9 Conclusion and Recommendations

Observation of the study concludes that to cleanse the river Ganga and restore it to its pristine quality, the government of India started many initiatives. Considerable efforts have been made to arrest the discharge of pollutant from various points and diffused sources in order to improve the river water quality. Water quality monitoring programme has been undertaken by CPCB, New Delhi and other monitoring agencies prior to the implementation of GAP. Also, such programme forms a part of GAP since its beginning under the legal power of National River Conservation Directorate (NRCD), Ministry of Environment Forest and Climate Change (MoEFCC), Government of India and is being carried out with the assistance of state pollution control boards, academic and research institutes. Significant amount of data has been generated on water quality of river Ganga over past few decades. However, river Ganga and many rivers of India is facing an alarming situation which gives an indication of more strict implementation, management, monitoring and strengthening of public awareness. Its due to the daily inflow of huge industrial and untreated home wastewater. The diversion of river through upper and lower canals leaves the main stem with essentially no flow, making dilution impossible even if cleaned wastewater is discharged.

According to findings, sewage treatment plants and a proper sewage conveyance infrastructure throughout the Ganga river basin are found as the necessity. Because the Ganga river is regarded a living ecosystem, the ultimate motive must be to safeguard the ecosystem's optimal functioning. River and its tributaries are heavily polluted by major industrial sectors like as tanneries, sugar and distilleries and pulp and paper mills. Industries that discharge solid and liquid wastes into the river must be directed to implement best available practises for handling solid and liquid wastes, achieving total water recycling and proper waste disposal as per regulating authorities’ standards.

The water of Ganga river is primarily used for bathing. The Ganga water was judged to be unfit for bathing after several months of research. Defensive and proactive techniques to resuscitating the Ganga river’s water quality are possible. The defensive approach includes actions such as improving the sewage network, increasing sewage treatment capacity and preventing pollution load from tributaries, all of which should be implemented as soon as possible. The construction of a barrage on the Ganga river and its tributaries appears to be a viable alternative for reducing pollution levels in the Ganga river. To reduce non-point source pollution, term measure approaches must be employed.

Nutrients such as N, P and K reach water bodies as a result of indiscriminate use of chemical fertilisers, resulting in algal bloom. During the post-rainy season, a layer of algae can be visible on the Ganga river’s surface. Long-term strategies such as wetlands and riparian zones could be built to reduce nutrient intake. It is also noted that, due to an inefficient trash collection system, mounds of solid garbage are frequently spotted at multiple locations; due to this, leachate coming out of solid waste affects the water quality of river Ganga. The entire catchment region along the banks of the Ganga river should be utilised for afforestation. This will aid in the reduction of soil erosion and air pollution, as well as the prevention of silt, nutrients and pesticides entering the Ganga river.

10 Suggested Recommendations

  • Operation and maintenance research: The government's Ganga Action Plan is critical to the river’s long-term viability. The operation and work of government bodies must be maintained at all times. Maintenance of treatment plants and ongoing work on increasing the capacity of sewage treatment plants in order to regulate sewage in metro cities. If the state government, with the support of the federal government, expands such resources. To manage the plants and other operations, properly trained personnel is also required. It is also necessary for the government to give some funds for research work on new technologies to deal with major pollution-causing situations.

  • River water quality monitoring: has an exceptionally intensive program that gathers information from multiple observing areas. Abroad Development Agencies (ODA) may incidentally aid the establishment of such stations. It also concludes that water toxicity should be monitored on a regular basis. Independent researchers have been brought in to analyse the results of water purification.

  • Implementation of law: It is critical to properly enforce those laws that apply to the river's benefit and well-being. The “‘National Green Tribunal’ zealously enforces these laws and punishes those who break them.

  • Technological approach and awareness to cure Ganga: To improve the Ganga's state, a technological solution is needed. Polluted water can be purified using machines like river cleaners and water treatment plants. It is extremely harmful to discharge chemicalised water straight into rivers in order to avoid the usage of water treatment plants, which remove highly polluted water and solid waste materials, causing long-term river instability. Along with these, several equipment has been designed to clean the surface pollution of rivers, which collect tonnes of garbage and have no harmful impact on the environment. Along with the government, increased public awareness results in significant reforms. It is each of us unique responsibilities to help us keep our promise to clean up the Ganga.

  • Government plans for clean Ganga: The legislature of India chipping away at many tasks to clean Ganga and its supporting waterways. For this in the yearly financial plan meeting 2016–2017 rupees 2000 centres are authorised for ‘Namami Gange’ mission however this mission has specific disadvantages. To help this mission the cooperation of every single individual is vital and supportively execution of laws clean Ganga is to be finished.