Water Pollution In India: Understanding The Human Impact

Water pollution is a pressing issue in India, with severe consequences for the environment and public health. The primary causes of water pollution in India include untreated sewage discharge from cities, towns, and villages, as well as industrial and agricultural activities. India's growing urban population and industrialization have led to a substantial increase in wastewater volume, with insufficient treatment capacity to match. This has resulted in the contamination of water bodies with heavy metals, pesticides, and industrial chemicals, causing aquatic ecosystem disruption and degradation of drinking water sources. The health impacts of water pollution are significant, with contaminated water causing waterborne diseases such as cholera, typhoid, and hepatitis, leading to illness and even death. The economic costs associated with water pollution are also high, with environmental degradation costing an estimated INR 3.75 trillion ($80 billion) annually and health costs related to water pollution estimated at INR 470-610 billion ($6.7-8.7 billion) per year. To address water pollution, India needs to invest in wastewater treatment infrastructure and adopt more sustainable practices.

Sewage discharge from cities, towns and villages

Sewage discharged from cities, towns, and villages is the predominant cause of water pollution in India. The country's sewage treatment capacity is far lower than the amount of sewage generated daily. Major cities in India produce 38,354 million litres per day (MLD) of sewage, but the urban sewage treatment capacity is only 11,786 MLD. This has resulted in a large number of Indian rivers being severely polluted due to the discharge of untreated domestic sewage.

The problem is twofold: India lacks sufficient treatment capacity, and the sewage treatment plants that do exist are poorly maintained and do not operate consistently due to issues such as power supply problems, absentee employees, and poor management. As a result, the waste generated percolates into the soil or evaporates, and the uncollected waste accumulates in urban areas, causing unhygienic conditions and releasing pollutants that leach into surface and groundwater.

The lack of adequate sewage treatment infrastructure has severe health and environmental consequences. The discharge of untreated sewage into water bodies causes organic and bacterial contamination, leading to waterborne diseases such as cholera, typhoid, and hepatitis. It also contributes to environmental degradation, with pollutants like heavy metals, pesticides, and industrial chemicals harming aquatic ecosystems, disrupting the balance, and leading to a decline in biodiversity.

The inequity in water and sewage disposal infrastructure between rich and poor areas further exacerbates the problem. High-income zones have access to most of the available amenities, while slum areas in cities like New Delhi receive only a small fraction of piped water. As freshwater sources dry up, water is being pumped over long distances from lakes and rivers, putting additional strain on these sources.

To address this issue, India needs to invest in bridging the gap between sewage generation and treatment capacity. Efforts have been made in recent years to upgrade treatment plants and encourage the reuse and recycling of treated wastewater. However, the implementation of comprehensive waste management programmes that include household collection of segregated waste, recycling, and composting remains a challenge.

Industrial waste and chemicals

Water pollution is a pressing issue in India, severely limiting the amount of water available for consumers, industry, and agriculture. A significant cause of this is industrial waste and chemicals, which have detrimental effects on both the environment and public health.

Industries discharge various chemicals and waste products directly into water bodies or indirectly through drainage systems. Major pollutants include heavy metals, such as lead, cadmium, copper, chromium, zinc, and arsenic, as well as oils and other chemicals. These pollutants have severe impacts, including toxicity to aquatic life and contamination of drinking water sources, leading to waterborne diseases.

Agricultural activities, such as irrigation and the use of fertilizers and pesticides, also contribute to water pollution. The casual disposal of industrial wastewater used for irrigating crops can cause serious damage to crop quality and can even reach the food chain. For example, farmers in India have been known to irrigate their crops with raw sewage and industrial wastewater, which contains heavy metals and chemicals. This has led to the contamination of India's food supply.

The improper disposal of solid and hazardous waste in water bodies is another major contributor to water pollution. This includes plastics, chemicals, and heavy metals, which can be ingested by aquatic animals, leading to toxicity and further contamination of water sources. Atmospheric deposition, such as acid rain, can also acidify water bodies and contaminate drinking water.

The treatment of industrial wastewater is essential to address the environmental and health issues it creates. Adequate treatment with physical, chemical, and biological means can help recycle water for conservation. However, India faces challenges in this area due to a lack of sufficient treatment capacity and poorly maintained or operated sewage treatment plants. As a result, wastewater often percolates into the soil or evaporates, causing unhygienic conditions and releasing pollutants that leach into surface and groundwater.

Overall, industrial waste and chemicals play a significant role in water pollution in India, requiring proper treatment and sustainable practices to mitigate their impact on the environment and public health.

Agricultural activities and fertiliser runoff

Fertilisers and animal manure provide crops with the necessary nitrogen and phosphorus for growth. However, when not fully utilised by plants, these nutrients can be washed from fields into waterways during rainfall or snowmelt and can also leach into groundwater over time. This excess nitrogen and phosphorus contribute to eutrophication, leading to hypoxic "dead zones" that decimate fish populations and reduce aquatic life. Additionally, high nutrient levels can cause harmful algal blooms (HABs), further disrupting aquatic ecosystems and producing toxins harmful to wildlife and humans.

The improper management of livestock waste exacerbates water pollution. In confined animal feeding operations (CAFOs), animal waste is often spread untreated on land. When applied beyond the ground's absorption rate, this waste runs off into water sources. Poultry waste, in particular, contains high levels of phosphorus, making it especially harmful to waterways. The disposal of untreated manure in vast manure lagoons further contributes to water pollution risks.

Agricultural runoff also introduces pesticides into water bodies. Many pesticides, such as Dichlorodiphenyltrichloroethane (DDT) and Aldrin, have been banned worldwide due to their environmental damage but remain commonly used in India. These chemicals are resistant to degradation and bioaccumulate in the environment, posing potential carcinogenic and mutagenic risks.

To mitigate fertiliser and pesticide runoff, farmers can adopt improved nutrient management techniques. This includes applying nutrients in the right amounts, at the appropriate times of the year, and with suitable methods and placement. Implementing conservation tillage practices, such as reducing tilling frequency and intensity, can also help improve soil health, reduce erosion, and decrease the chances of nutrient runoff into waterways.

While India faces challenges in adequately treating domestic wastewater, efforts to upgrade treatment plants and infrastructure are underway. Addressing the gap between sewage generation and treatment capacity requires investment and improved management of existing facilities.

Poorly-maintained government-owned sewage treatment plants

Water pollution is a pressing issue in India, severely limiting the amount of water available for consumers, industry, and agriculture. A significant cause of this is the discharge of sewage from cities, towns, and villages, which contaminates water sources. While India has many government-owned sewage treatment plants, they are often poorly maintained and face several operational challenges.

One major issue is the improper design and poor maintenance of these plants, leading to frequent closures. This is compounded by an unreliable electricity supply, absentee employees, and inadequate management. As a result, most government-owned sewage treatment plants remain closed, contributing to the water pollution crisis.

The inefficiency of these plants has dire consequences for the environment and public health. Untreated sewage percolates into the soil or evaporates, leading to the accumulation of waste in urban areas. This creates unhygienic conditions and releases pollutants that leach into surface and groundwater, causing further contamination.

The lack of proper sewage treatment exacerbates the problem of waterborne diseases in India, including cholera, typhoid, and hepatitis. These diseases pose significant risks to public health, leading to illnesses, hospitalizations, and even deaths among those exposed to polluted water sources.

To address these issues, India needs to invest in upgrading and maintaining its sewage treatment infrastructure. This includes improving plant design, ensuring a reliable electricity supply, and enhancing management practices to reduce absenteeism among employees. By addressing these challenges, India can improve its water treatment capacity and mitigate the adverse effects of water pollution on the environment and public health.

Atmospheric deposition and acid rain

Atmospheric deposition is the process by which pollutants are deposited from the atmosphere onto water bodies. Atmospheric deposition and acid rain are major contributors to water pollution in India. Acid rain is a broad term for any form of precipitation with acidic components, such as sulfuric or nitric acid, that falls to the ground from the atmosphere in wet or dry forms. The burning of fossil fuels to generate electricity, vehicles and heavy equipment, manufacturing, and oil refineries are major sources of the sulfur dioxide (SO2) and nitrogen oxides (NOx) that cause acid rain. While normal rain has a pH of about 5.6, acid rain usually has a pH between 4.2 and 4.4.

India is the second-largest emitter of SO2, and emissions of both SO2 and NOx are expected to grow until at least 2030. The occurrence of acid rain in India has been increasing over the past four decades. This is due in part to the country's growing energy demand, which has outpaced global energy growth. Fossil fuel consumption in India increased from 208 million tons per year in 2000 to 708 million tons in 2017. The rise in industrial and vehicular activities has led to significantly increasing trends in the presence of SO4 and NO3 in precipitation.

The effects of acid rain are widespread and detrimental to the environment and public health. Acid rain can harm soil, forests, and aquatic ecosystems, leading to the decline of fish and other aquatic organisms, loss of biodiversity, and degradation of habitats. It also affects drinking water sources, causing severe health problems for millions of people in India who depend on groundwater for drinking. High levels of contaminants such as arsenic and fluoride have been found in groundwater due to industrial discharge and agricultural runoff.

To address the issue of acid rain and its impact on water pollution, India has taken several steps to reduce emissions. These include switching to low-sulfur fuel, implementing stricter engine standards, introducing a National Automobile Scrappage Policy, and increasing the distribution of electric and hybrid vehicles. Additionally, the use of anti-smog guns and smog towers helps to reduce pollution in the atmosphere.

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