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Water Pollution: Causes, Effects and Control Measures

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Water Pollution: Causes, Effects and Control Measures:

Water Pollution

      Water pollution is defined as the contamination of water bodies—such as rivers, lakes, oceans, groundwater, and streams—by harmful substances that degrade water quality, disrupt ecosystems, and pose serious risks to human and animal health. These contaminants can be chemical, physical, biological, radiological, or thermal in nature. When present in significant concentrations, they make water unsafe for drinking, bathing, irrigation, aquatic life, and recreational use.

Sources of Water Pollution

Water pollution originates from both natural and human-induced sources:

1. Natural Causes:

    • Soil Erosion: When topsoil is eroded by wind or water, sediments are carried into nearby water bodies, increasing turbidity and affecting aquatic ecosystems.
    • Leaching of Minerals: Water that percolates through rocks may dissolve naturally occurring minerals and heavy metals. Acid rain can accelerate this process, increasing the concentration of pollutants in the water.
    • Decomposition of Organic Matter: Naturally decaying plant and animal material can release organic compounds and nutrients into water, sometimes leading to oxygen depletion and the growth of harmful bacteria.

2. Human-Induced Causes:

         Human activities are the primary drivers of water pollution and can be categorized into two main types:

 

A. Point Source Pollution:

This type of pollution originates from a single, identifiable source. It is typically easier to monitor and control. Common examples include:

    • Discharge of industrial effluents through drainpipes or outlets directly into rivers or lakes
    • Wastewater release from sewage treatment plants
    • Oil spills from ships or offshore platforms
    • Leakage from underground storage tanks

 

B. Non-Point Source Pollution:

     Unlike point sources, non-point source pollution arises from widespread, diffuse areas and is harder to trace or regulate. It usually occurs as a result of runoff, where pollutants are washed from the land into water bodies. Major contributors include:

    • Agricultural runoff containing fertilizers, pesticides, and animal waste
    • Runoff from urban areas with oil, grease, heavy metals, and litter
    • Sediments from construction sites, deforested lands, and mining areas
    • Acid drainage from abandoned mines and waste pits

Consequences of Water Pollution

    • Environmental Impact: Polluted water affects aquatic flora and fauna, leads to the loss of biodiversity, and disrupts food chains.
    • Human Health Risks: Consumption or exposure to contaminated water can result in serious health issues, such as waterborne diseases (cholera, dysentery), heavy metal poisoning, and long-term chronic conditions.
    • Economic Damage: Water pollution negatively affects fisheries, tourism, agriculture, and increases the cost of water treatment for human use.
    • Eutrophication: Excessive nutrients from fertilizers can lead to algal blooms, which deplete oxygen in water and create “dead zones” where aquatic life cannot survive.

 

Addressing water pollution requires a comprehensive approach involving pollution prevention, stringent regulations, sustainable agricultural and industrial practices, and increased public awareness. Both individual and collective efforts are vital to protect water resources for current and future generations.

Measuring Pollution Load in Water:

Dissolved Oxygen (DO):

    • The optimal dissolved oxygen (DO) levels in aquatic environments are crucial for the survival of marine life. The introduction of organic and inorganic pollutants reduces DO levels due to increased rates of decomposition and oxygen consumption.
    • Various factors, including surface agitation, photosynthesis, oxygen uptake by living organisms, and the breakdown of organic materials, influence the dissolved oxygen concentration in water.
    • Water with DO levels falling below 8.0 mg/L is regarded as contaminated, while levels below 4.0 mg/L indicate severe pollution.

Biological Oxygen Demand (BOD):

    • The assessment of water pollution caused by organic waste is quantified through the Biochemical Oxygen Demand (BOD), which represents the quantity of dissolved oxygen required by bacteria to break down organic matter in water.
    • This measurement is expressed in milligrams of oxygen per liter of water. A higher BOD value signifies greater pollution levels attributed to biodegradable organic materials and a reduced dissolved oxygen (DO) concentration in the water.
    • However, since BOD exclusively pertains to biodegradable substances, it is not a dependable indicator for evaluating overall water pollution.

 

Chemical Oxygen Demand (COD):

    • Chemical oxygen demand (COD) serves as a more effective method for assessing the pollution load in water.
    • It quantifies the concentration of oxygen, expressed in parts per million, necessary to oxidize both organic (including biodegradable and non-biodegradable) and oxidizable inorganic substances present in a water sample.

Causes of Water Pollution:

Industrial Waste Discharges:

      Industrial waste discharges are a major contributor to environmental pollution, particularly to water, soil, and air contamination. These discharges refer to the release of byproducts, effluents, and hazardous substances generated during various industrial processes. When not properly treated, these pollutants can severely harm ecosystems, public health, and the quality of natural resources.

Major Industrial Sectors Responsible for Waste Discharges

Several key industrial sectors are known for producing substantial amounts of waste, including toxic and non-biodegradable materials:

1. Petroleum Refining:

    • Involves the processing of crude oil into usable products like gasoline, diesel, and jet fuel.
    • Generates wastewater containing hydrocarbons, sulfides, and other chemical residues.

 

2. Pulp and Paper Production:

    • Uses large volumes of water and chemicals in the transformation of wood into paper.
    • Discharges contain chlorine-based bleaching agents, lignin, and organic waste materials, which can cause severe oxygen depletion in water bodies.

 

3. Metal Extraction and Processing (Mining and Metallurgy):

    • Includes activities such as ore smelting, refining, and electroplating.
    • Produces tailings and effluents rich in heavy metals like lead, mercury, and arsenic.

 

4. Chemical Manufacturing:

    • Produces a wide array of products including fertilizers, pesticides, plastics, and pharmaceuticals.
    • Effluents often contain toxic organic compounds, solvents, acids, alkalis, and persistent pollutants that can bioaccumulate in living organisms.

Types of Hazardous Substances in Industrial Waste

1. Heavy Metals: These are metallic elements with high atomic weights and densities greater than 5 g/cm³. They are often toxic even in low concentrations and are known for their persistence in the environment.

 

Common Heavy Metals in Industrial Waste:

    • Mercury (Hg): Used in mining, electrical equipment, and chemical manufacturing; causes neurological damage.
    • Cadmium (Cd): Found in batteries, pigments, and metal coatings; known to damage kidneys and bones.
    • Copper (Cu): Used in electrical wiring and plumbing; excessive levels harm aquatic life.
    • Lead (Pb): Common in batteries, paints, and fuel additives; highly toxic to the nervous system.
    • Arsenic (As): Used in mining and pesticide production; linked to cancer and skin lesions.

 

2. Organic Pollutants: These include a wide variety of carbon-based compounds, many of which are synthetic and not easily broken down by natural processes.

 

Examples:

    • Petrochemicals from oil refineries
    • Pesticides and herbicides from agrochemical industries
    • Solvents such as benzene and toluene from paint and chemical industries
    • Polychlorinated biphenyls (PCBs) used in electrical equipment.

 

These compounds can be toxic, mutagenic, or carcinogenic, and often contaminate water and soil for long periods.

Environmental and Health Implications

    • Water Pollution: Untreated or poorly treated industrial effluents can severely degrade water quality, leading to the death of aquatic organisms and the spread of waterborne diseases.
    • Soil Degradation: Hazardous waste can infiltrate the soil, affecting plant growth and entering the food chain through crops.
    • Air Pollution: Volatile chemicals released from industrial sites contribute to air pollution and respiratory illnesses.
    • Bioaccumulation and Biomagnification: Toxins such as heavy metals can accumulate in organisms and magnify up the food chain, posing long-term health risks to humans and wildlife.

 

Effective management of industrial waste is essential for environmental sustainability and public health. This includes the implementation of cleaner production techniques, rigorous waste treatment processes, and strict regulatory compliance. Encouraging industries to adopt eco-friendly practices and invest in pollution control technologies is crucial for minimizing their ecological footprint.

Heavy Metal Contamination in Surface Water:

   Heavy metal contamination in surface water is a growing environmental concern, especially in regions experiencing rapid industrialization and unregulated waste disposal. Heavy metals are elements that have high atomic weights and densities and are known for their toxicity, persistence in the environment, and tendency to bioaccumulate in living organisms.

      Once introduced into rivers, lakes, and streams, these metals can have serious ecological and human health consequences, even at low concentrations.

Key Contaminants in Surface Water

       According to assessments conducted by the Central Water Commission of India, several heavy metals have been consistently detected in surface water across various regions, with varying concentrations depending on the season:

1. Most Commonly Detected Metals:

    • Iron (Fe): The most frequently reported contaminant, commonly leached from rocks, soil, and industrial effluents.
    • Lead (Pb): A toxic metal found in battery manufacturing and industrial discharges.
    • Nickel (Ni): Associated with metal plating, pigments, and electronic manufacturing.
    • Chromium (Cr): Particularly hexavalent chromium, known to be highly carcinogenic, originating from tanning, electroplating, and dye industries.
    • Cadmium (Cd): A byproduct of mining and plastic manufacturing; extremely harmful even at low doses.
    • Copper (Cu): Commonly used in plumbing and electrical industries; excessive concentrations are toxic to aquatic organisms.

Seasonal Variation in Contamination Levels

     Heavy metal concentrations in surface water often fluctuate based on seasonal changes, particularly influenced by rainfall patterns, runoff, and water flow rates:

 

Monsoon Season (June to September):

    • Elevated levels of iron, lead, chromium, and copper are frequently recorded.
    • Heavy rainfall and surface runoff from industrial zones and urban areas carry large volumes of pollutants into rivers and lakes.

 

Non-Monsoon Season (October to May):

    • Metals such as lead, cadmium, nickel, chromium, and copper continue to persist in surface waters.
    • Lower water volumes result in reduced dilution capacity, causing concentration levels to remain above permissible limits.

Primary Sources of Heavy Metal Pollution

The presence of these toxic metals in surface water can be traced to several industrial and anthropogenic activities:

    • Mining Operations: Extraction and processing of ores often release untreated tailings and wastewater containing various heavy metals into nearby water bodies.
    • Electroplating and Surface Finishing Industries: These processes use a variety of heavy metals for coating and finishing, and improper waste disposal can directly contaminate surface waters.
    • Industrial Discharges: Factories involved in battery manufacturing, metal processing, dyeing, and chemical production frequently emit metal-laden effluents.
    • Urban Runoff and Wastewater: Leaching from old plumbing systems, dumping of e-waste, and untreated sewage contribute significantly to metal pollution in cities.

Health Impacts of Long-Term Exposure to Heavy Metals

      Prolonged or chronic exposure to contaminated water, even at trace levels, can lead to severe and often irreversible health effects in humans. The danger is compounded by the fact that heavy metals can bioaccumulate and enter the food chain through fish, crops, and drinking water.

Neurological and Muscular Disorders:

    • Alzheimer’s-like Symptoms: Metals like aluminum, lead, and mercury are suspected to play a role in the development of degenerative brain diseases due to their neurotoxic effects.
    • Parkinson’s Disease-Like Conditions: Long-term exposure to heavy metals may affect dopamine-producing neurons, potentially triggering movement disorders.
    • Muscular Dystrophy: Certain metals are linked to progressive muscle weakening and loss of muscle mass.
    • Multiple Sclerosis (MS): A degenerative central nervous system condition that may be exacerbated by metal toxicity interfering with nerve function and immune response.

Other Health Risks:

    • Kidney and Liver Damage: Organs responsible for detoxifying the body are highly vulnerable to heavy metal accumulation.
    • Cardiovascular Disorders: Some heavy metals contribute to oxidative stress, leading to hypertension and arterial damage.
    • Reproductive and Developmental Issues: Exposure during pregnancy can impair fetal development and reduce fertility.

 

Heavy metal contamination of surface water is not just an environmental issue—it is a pressing public health crisis. Monitoring, regulation, and remediation strategies are essential to control industrial emissions and ensure safe water for ecosystems and communities alike. Public awareness, stronger enforcement of environmental laws, and investment in wastewater treatment technologies are key to mitigating this invisible threat.

Thermal and Radiation Pollution:

Thermal Pollution:

    • Industrial activities, including thermal and nuclear power generation as well as chemical manufacturing, utilize significant quantities of water for cooling.
    • The release of heated water elevates the temperature of nearby water bodies by 5 to 15 degrees Celsius.
    • This temperature increase poses a threat to aquatic life, as organisms that have evolved to thrive in stable thermal conditions experience thermal stress, which can result in mortality.
    • Additionally, the rise in temperature diminishes the levels of dissolved oxygen, exacerbating the detrimental effects on aquatic ecosystems.

 

Hazards Associated with Radiation from Nuclear Incidents:

    • Causes include radiation leaks during nuclear events, such as the Fukushima Daiichi disaster, and natural disasters like tsunamis and earthquakes that heighten these risks.
    • The effects on marine life are significant, as radiation can cause DNA mutations, which, if not repaired, may result in cancerous cells.
    • For instance, radioactive iodine can be taken up by the thyroid gland, leading to thyroid cancer, while exposure to radioactive radon is linked to lung cancer, and uranium contamination in water sources can result in kidney cancer.

Mining:

    • Water Consumption in Mining Operations: Employed for the processing of raw materials, cooling of mines, and extraction of metals in both open-pit and underground mining environments.
    • Chemical Pollution: The use of substances such as cyanide, sulfuric acid, and mercury in mining activities poses a significant threat to the contamination of both groundwater and surface water.

 

Environmental Consequences:

    • Soil and Rock Disruption: The activities of mining and the transportation of minerals result in the displacement of soil and rock, leading to erosion that contributes sediments and toxic chemicals to aquatic ecosystems.

 

Acid Rock Drainage (ARD):

    • A natural phenomenon in which sulfuric acid is generated through the interaction of sulfide minerals in rocks with water.
    • Impact: This process hastens the weathering of rocks and the leaching of minerals and metals.

 

Acid Mine Drainage (AMD):

    • A more intense variant of ARD, which occurs when substantial amounts of sulfide-rich rocks are removed from the earth.

 

Role of Thiobacillus ferrooxidans:

    • These acidophilic bacteria, thriving in highly acidic conditions (pH 1.5–2.0), facilitate the processes of oxidation, acidification, and the leaching of metals from mining byproducts.

 

Heavy Metal Contamination:

    • Sources of metals such as arsenic, cobalt, copper, cadmium, lead, silver, and zinc arise from excavated or exposed geological formations, where they interact with water.
    • Under neutral pH conditions, these metals exhibit increased mobility.
    • Furthermore, leaching processes are exacerbated in acidic environments, particularly due to Acid Mine Drainage (AMD).

Groundwater and Drinking Water Contamination:

Contamination Sources:

    • Industrial and Municipal Waste encompasses effluents and leachate from industrial activities, such as fly ash deposits from thermal power facilities, alongside municipal waste.
    • The pollutants identified include fluorides, uranium, and heavy metals such as lead, mercury, cadmium, copper, and arsenic, in addition to nitrates and phosphates.
    • Agricultural runoff, primarily from fertilizer application, introduces nutrients like nitrates and phosphates into groundwater systems.
    • Iron is the predominant contaminant found in rural drinking water sources.
    • Salinity is particularly problematic in Rajasthan, which has the highest incidence of salinity contamination in rural regions.
    • The states of West Bengal and Assam are the most severely impacted by both arsenic and iron contamination.

 

Nitrates:

    • Nitrates interact with hemoglobin, resulting in the formation of non-functional methemoglobin, which hinders oxygen transport, leading to conditions such as methemoglobinemia or blue baby syndrome.
    • Elevated concentrations can also generate carcinogenic compounds and contribute to the acceleration of eutrophication.

Trace metals:

These metals are, including lead, mercury, cadmium, copper, chromium, and nickel, are associated with carcinogenic health effects.

 

Arsenic:

    • Arsenic, originating from both natural and anthropogenic sources, is prevalent in industrial, mining, and agricultural contexts.
    • Notable global hotspots for arsenic contamination are found in groundwater within the Ganges Delta (spanning India and Bangladesh), as well as in the United States, China, and Mexico.
    • Chronic exposure to arsenic can result in black foot disease, characterized by progressive gangrene due to vascular damage, and is linked to various health issues, including diarrhea, lung cancer, and skin cancer.
    • Arsenicosis, a condition arising from significant arsenic ingestion or inhalation, manifests as melanosis (the appearance of dark spots) and keratosis (thickening of the palms).

 

 

Fluoride:

    • Fluorosis is a prevalent issue in India, primarily resulting from the consumption of water with elevated fluoride levels.
    • An excessive intake of fluoride can lead to various health complications, including neuromuscular disorders, gastrointestinal issues, dental deformities, bone hardening, and skeletal fluorosis characterized by stiff and painful joints.
    • The condition known as Knock-Knee syndrome is marked by pain in the bones and joints, along with an outward bending of the legs at the knees.

 

Uranium Contamination:

    • Uranium is a weakly radioactive element with an extensive physical half-life of approximately 4.5 billion years for uranium-238. The biological half-life, which refers to the duration required for the human body to eliminate half of the substance, is roughly 15 days.
    • Certain localized areas in India exhibit uranium concentrations exceeding 30 micrograms per liter, surpassing the World Health Organization’s guidelines.
    • In the northwestern states, including Rajasthan, uranium is primarily found in alluvial aquifers, whereas in southern regions like Telangana, it is sourced from crystalline rocks such as granite. The over-extraction of groundwater from these soils can expose uranium to the atmosphere, facilitating its release.
    • Increased levels of uranium in drinking water have been linked to kidney toxicity. The high incidence of chronic kidney disease (CKD) in the Srikakulam district of Andhra Pradesh is believed to be associated with exposure to uranium in groundwater.
    • In response to allegations of groundwater contamination resulting from uranium mining and processing activities by the Uranium Corporation of India Limited (UCIL) in the Kadapa district, the Andhra Pradesh government has initiated an investigation.

 

Guidelines in India:

    • The Indian Standard IS 10500: 2012 outlines the maximum permissible levels for radioactive contaminants in drinking water, specifically addressing alpha and beta emitters, beyond which the water is deemed unfit for consumption.
    • This standard encompasses all radioactive substances, including uranium, without singling out any specific elements.
    • The Bureau of Indian Standards (BIS) is currently in the process of integrating a permissible uranium limit of 0.03 mg/l, in accordance with the provisional guidelines set by the World Health Organization (WHO), into the drinking water regulations.

 

Radioactive Radon:

    • Recent investigations have revealed elevated levels of radioactive radon in the groundwater utilized for drinking purposes in certain regions of Bengaluru.
    • The detected radon concentrations are found to be between 50 to 100 times higher than the acceptable threshold of 11.1 Bq per litre.
    • Radon is released from radioactive granites and uranium through the process of radioactive decay, resulting in the formation of radium and radon.
    • Additionally, the uranium concentration in the water has been measured at 300 micrograms per litre, significantly exceeding the permissible limit of 30 µg/l.
    • This uranium originates from local minerals such as pitchblende, zircon, and monazite found within the geological formations of the area.
    • The presence of radon in both air and water poses a risk of lung tissue damage, which can lead to lung cancer, while elevated uranium levels are associated with adverse effects on the urinary tract, increasing the risk of kidney cancer.

 

Freshwater Salinization Syndrome (FSS):

       FSS refers to the phenomenon where saline runoff adversely affects freshwater ecosystems. While salts are naturally present in freshwater systems, primarily due to the weathering of rocks and the influence of saline groundwater, human activities are exacerbating the levels of salinity in these waters.

 

Factors contributing to this issue include:

    • Extraction of oil, gas, and other natural resources.
    • The application of road salts for de-icing purposes, as these salts lower the freezing point of water compared to the surrounding ice.
    • Accelerated weathering of rocks and soils due to human intervention.
    • Rising sea levels leading to the intrusion of saltwater into freshwater systems.

Sewage Water:

    Sewage water is composed of effluents from residential and commercial sources, containing human and animal waste, food scraps, cleaning agents, and detergents. Both domestic and hospital sewage are rich in pathogenic microorganisms.

 

Ammonia Pollution in Sewage:

    • Ammonia is a colorless gas characterized by a strong odor, naturally present in the air, soil, and water, as well as in plants and animals, including humans.
    • The human body produces ammonia during the metabolic process that breaks down protein-rich foods into amino acids and ammonia, subsequently converting the ammonia into urea.
    • Ammonia serves as a fundamental component in the production of ammonium nitrate fertilizer, which releases nitrogen, a vital nutrient for the growth of plants, including agricultural crops and lawns.
    • Ammonium hydroxide, commonly referred to as household ammonia, is found in numerous everyday cleaning products. For over 70 years, ammonia has been utilized in municipal treatment facilities to enhance the efficacy of chlorine disinfection in water.
    • The introduction of ammonia facilitates the formation of chloramines, which can impart unpleasant tastes, while simultaneously reducing the generation of chlorination by-products that may pose carcinogenic risks.
    • According to the Bureau of Indian Standards (BIS), the permissible limit of ammonia in drinking water is 0.5 ppm. Concentrations exceeding 1 ppm are toxic to aquatic life, and prolonged consumption of water with elevated ammonia levels (≥ 1 ppm) can be detrimental to human health.

Agricultural Sources:

       Agriculture, while essential for food production and rural livelihoods, is one of the leading contributors to water pollution worldwide. In India, intensive farming practices, excessive use of fertilizers and pesticides, and poor waste management have significantly affected the quality of surface water and groundwater. Agricultural runoff—the water that flows over fields during irrigation or rain—often carries a cocktail of harmful substances into nearby rivers, lakes, and streams, impacting ecosystems and human health.

Key Pollutants in Agricultural Runoff

      Agricultural runoff is a complex mixture of both organic and inorganic pollutants. Some of the most common contaminants include:

 

Dissolved Salts and Nutrients:

    • Nitrates (NO₃⁻) and Phosphates (PO₄³): These are water-soluble nutrients that originate primarily from chemical fertilizers. They are crucial for plant growth but can cause serious environmental problems when present in excess.
    • Potassium (K), Ammonia (NH), and Other Nutrients: Vital for crops, but harmful to aquatic life in large concentrations.
    • Toxic Metal Ions: Such as zinc, copper, and cadmium, often introduced through certain fertilizers or soil amendments.
    • Organic Compounds: Include decaying plant matter, manure, and residues from biofertilizers.

 

Chemical Fertilizers:

    • Fertilizers are typically rich in nitrogen (N), phosphorus (P), and potassium (K)—the essential macronutrients for crop production.
    • When applied in excessive quantities or during inappropriate weather conditions, these chemicals can leach into the soil and contaminate groundwater, or be washed away into surface water bodies, leading to nutrient overload.

 

Pesticides and Herbicides:

    • These include a wide range of synthetic chemicals designed to kill pests, weeds, and fungi but often have unintended environmental impacts.
    • Common Chemical Groups:
          • Chlorinated Hydrocarbons: e.g., DDT, Endosulfan – known for their persistence in the environment and potential to bioaccumulate.
          • Organophosphates: e.g., Malathion, Parathion – acutely toxic and can affect the nervous system of humans and wildlife.
          • Metallic Salts and Carbonates: Used in various fungicides and herbicides; they can contribute to soil and water contamination.
    • Many pesticides are non-biodegradable, meaning they resist natural breakdown and linger in the environment as persistent organic pollutants (POPs), posing long-term ecological and health risks.

 

Animal Farming Waste:

    • Runoff from poultry farms, pig farms, and slaughterhouses often carries pathogens, antibiotics, hormones, and organic waste into nearby water sources.
    • This not only increases biological oxygen demand (BOD) in water but also introduces drug-resistant bacteria and other contaminants that threaten aquatic and human life.

Nitrogen Pollution in India: A Growing Environmental Challenge

    Nitrogen is a key nutrient for plant development, but when mismanaged, it becomes one of the most pervasive pollutants affecting both water and air quality. In India, nitrogen pollution is primarily associated with:

Major Sources:

1. Chemical Fertilizer Use:

    • India is one of the largest consumers of nitrogen-based fertilizers, particularly urea.
    • However, studies show that only about 33% of applied nitrogen is actually absorbed by plants, while the remaining 67% remains in the soil or leaches into water bodies.
    • This excess nitrogen can undergo conversion into nitrates, which are highly soluble and can contaminate drinking water sources, especially in rural areas.

 

2. Sewage and Domestic Waste:

    • Untreated or partially treated sewage contains significant amounts of nitrogen, primarily in the form of ammonia and urea, which can degrade water quality and lead to eutrophication.

 

3. Organic Solid Waste:

    • Decomposing organic matter from urban and agricultural sources contributes additional nitrogen to the environment.

Environmental and Health Impacts:

    • Eutrophication: Excess nitrogen leads to explosive growth of algae in water bodies. This process depletes oxygen and creates dead zones, killing fish and aquatic organisms.
    • Contaminated Drinking Water: High nitrate levels in groundwater are particularly dangerous for infants and can cause methemoglobinemia, also known as “blue baby syndrome.”
    • Greenhouse Gas Emissions: Improper nitrogen use also results in the release of nitrous oxide (N₂O), a potent greenhouse gas that contributes to climate change.

 

While agriculture is the backbone of the Indian economy, its unchecked practices are contributing significantly to the degradation of water quality. Addressing agricultural pollution requires a shift towards sustainable farming, integrated nutrient management, precision agriculture, and strict regulation of pesticide use. Raising awareness among farmers about proper fertilizer and pesticide application, promoting organic farming, and investing in biofertilizer research are critical steps toward preserving India’s water resources and ensuring food and water security for future generations.

Invasive Aquatic Species:

Water hyacinth: 

    • Water hyacinth, an aquatic species originating from the Amazon basin, is recognized as the most troublesome aquatic weed globally.
    • It is referred to as the ‘Terror of Bengal’ in India, ‘German Weed’ in Bangladesh, ‘Florida Devil’ in South Africa, and ‘Japanese Trouble’ in Sri Lanka.
    • This plant thrives in eutrophic (nutrient-rich) water bodies, disrupting the ecological balance.
    • Its rampant growth creates significant issues by causing water stagnation and depleting oxygen levels in aquatic environments, which ultimately leads to the decline of fish populations.

 

 

Forked Fanwort: 

    • In certain regions of Kerala, the extensive proliferation of forked fanwort has transformed the appearance of water bodies, giving them a pink hue.
    • This submerged perennial aquatic plant thrives in stagnant to slow-moving freshwater environments.
    • Originating from Central and South America, it is classified as an invasive species. Its growth demands a significant amount of oxygen, which poses a serious threat to freshwater biodiversity.

 

Pollution in River Ganga:

    • A significant portion of the wastewater and industrial discharges from various urban and industrial hubs, including Haridwar, Kannauj, Kanpur, Allahabad, Varanasi, Patna, and Kolkata, is released into the Ganga River.
    • The primary industrial sectors, such as tanneries, sugar and distillery operations, as well as pulp and paper mills, contribute substantially to the pollution load affecting the Ganga and its tributaries.
    • The Ganga River is contaminated with Faecal Coliform bacteria throughout its entire length, and the levels of Biochemical Oxygen Demand (BOD), which serves as an indicator of organic pollution, are significantly higher than acceptable limits in the section between Kannauj and Tarighat.
    • The diversion of river water through the Upper and Lower Ganga canals has resulted in minimal flow in the main river, complicating the dilution of even treated sewage.

 

Presence of microplastics in the Ganga includes:

    • Ethylene-vinyl, which is particularly suitable for packaging food, pharmaceuticals, and cosmetics.
    • Polyacetylene, utilized as a doping agent in the electronics sector.
    • Polypropylene, commonly found in packaging materials, plastic sheets, fibers, fabrics, and ropes.
    • Persistent Inorganic Pollutants (PIPs), primarily used in the production of footwear and baby bottle nipples.
    • Polyamide, widely recognized as nylon, is employed as a natural fiber and metal wire in textiles and industrial applications.

Marine Pollution: Oil Spills and Plastic:

      Marine pollution encompasses the introduction of chemicals into oceanic environments and the detrimental consequences that arise from this contamination. Potentially hazardous substances adhere to microscopic particles, which are subsequently ingested by plankton and benthic organisms that serve as deposit or filter feeders, thereby accumulating toxins as they ascend the food chain. Given that animal feed often contains significant amounts of fish meal or fish oil, these toxins can also be present in food products derived from livestock and animal farming.

Oil Spills:

   The primary sources of oil spills include leaks during maritime transportation, seepage from underground storage tanks, and incidents occurring during offshore oil extraction.

 

Recent incidents of Oil spills:

    • In 2018, an oil spill incident in the East China Sea resulted in the discharge of over 136,000 tonnes of volatile petroleum.
    • The Deepwater Horizon drilling incident, which occurred in 2010, stands as the most significant oil spill disaster in history, releasing 779 million liters of crude oil into the Gulf of Mexico.
    • More recently, in 2020, the MV Wakashio spill near Mauritius led to approximately 1,000 tonnes of oil contaminating a sanctuary for endangered wildlife after the Japanese vessel collided with a coral reef.

 

Impact of Oil Spills on Marine Life:

    • Oil, being less dense than water, forms a thin layer on the surface, effectively blocking oxygen from reaching floating plants and other primary producers.
    • Within a few hours following an oil spill, fish, shellfish, and plankton succumb to suffocation and metabolic disruptions.
    • Additionally, birds and marine mammals that feed on these deceased organisms may suffer from poisoning.
    • The remediation of oil spills in aquatic environments can be facilitated through the use of bregoli—a by-product of the paper manufacturing process that resembles sawdust—along with oil-absorbing agents and microorganisms.

 

Marine Plastic Pollution: 

    • Marine plastic pollution is estimated to inflict approximately $13 billion in economic losses to marine ecosystems each year, with projections indicating that plastic will surpass fish populations by 2050.
    • The leaching of chemicals from plastic waste disrupts the growth, photosynthesis, and oxygen production of Prochlorococcus, the most prevalent photosynthetic cyanobacteria in the ocean.
    • Plastic contamination has been recorded even in the ocean’s most profound regions, such as Challenger Deep in the Mariana Trench.
    • The most apparent and alarming consequences of marine plastic pollution include the ingestion, suffocation, and entanglement of numerous marine species.
    • Marine animals, including seabirds, whales, fish, and turtles, often confuse plastic debris for food, leading to starvation as their stomachs become filled with non-digestible materials.
    • Microscopic plastic particles have been detected in salt and are present in samples collected from all of the world’s oceans, including the Arctic region.

Effects of Water Pollution:

Impact on Human Health: 

    • Domestic and hospital wastewater is laden with numerous harmful pathogenic microorganisms, and its release into water bodies without adequate treatment can trigger severe disease outbreaks, including typhoid and cholera.
    • Industrial effluents containing metals such as lead, zinc, arsenic, copper, mercury, and cadmium pose significant risks to both human and animal health.
    • The ingestion of water contaminated with arsenic leads to its accumulation in various body tissues, including blood, nails, and hair, resulting in skin lesions, roughness, dryness, thickening of the skin, and ultimately, skin cancer.
    • In wastewater, mercury compounds are transformed by bacterial activity into the highly toxic methylmercury, which can induce symptoms such as numbness in the limbs, lips, and tongue, hearing loss, blurred vision, and cognitive disturbances. Exposure to mercury in water is associated with Minamata disease, a neurological disorder in humans.
    • Lead exposure results in lead poisoning, which disrupts multiple bodily functions and is toxic. Lead compounds can lead to anemia, diminished muscle strength, and a characteristic bluish line along the gums.
    • Water contaminated with cadmium can lead to Itai Itai disease, also known as ouch-ouch disease, characterized by severe pain in the bones and joints, as well as an increased risk of lung and liver cancer.

Effects on the Environment:

    • Microorganisms that play a role in the biodegradation of organic matter in sewage waste utilize significant amounts of oxygen, leading to oxygen depletion in water and resulting in the death of aquatic life.
    • The presence of excessive nutrients in water can trigger algal blooms, characterized by rampant growth of planktonic algae, which contributes to the aging of lakes.
    • Additionally, certain toxic substances commonly found in industrial wastewater can experience biological magnification within the aquatic food chain.
    • This phenomenon is particularly notable in the case of mercury and DDT.
    • Elevated levels of DDT disrupt calcium metabolism in birds, leading to the thinning and premature breakage of eggshells, ultimately resulting in a decline in bird populations.

Effects on Aquatic Ecosystem:

Effects of Elevated Temperature and Contaminated Water:

Discharge of Contaminated Water:

    • Industrial wastewater that includes biocides, polychlorinated biphenyls (PCBs), heavy metals, and heated water results in diminished levels of dissolved oxygen (DO).
    • This reduction in DO, along with the presence of toxic substances, leads to the decline of sensitive aquatic species such as plankton, mollusks, and fish.

 

Bioindicators of Water Pollution:

    • Species that exhibit tolerance, such as Tubifex (a type of annelid worm) and specific insect larvae, are capable of surviving in environments with high pollution and low DO levels.
    • These organisms serve as indicators of the extent of water pollution.

 

Rising Ocean Temperatures and Methylmercury Contamination in Fish:

Trends: Although the levels of methylmercury in seawater have declined since the late 1990s, concentrations in predatory fish higher in the food chain have risen.

 

Contributing Factors:

    • Increased Ocean Temperatures: Warmer ocean waters enhance the metabolic rates of fish, resulting in reduced energy available for growth and an increased accumulation of methylmercury in predatory species.
    • Changes in Diet: Overfishing compels predatory fish to target larger prey, which tend to have higher methylmercury concentrations than smaller fish.
    • Health Implications for Humans: The rising levels of methylmercury in predatory fish heighten health risks for humans who consume these fish, a situation that is further intensified by the impacts of climate change.

Eutrophication and Ageing of Lakes:

    • Lakes obtain their water primarily from surface runoff, which also brings along various chemical substances and minerals.
    • Over thousands of years, these bodies of water undergo a process of aging as they accumulate both mineral and organic matter, gradually leading to their filling.
    • The enrichment of nutrients in lakes fosters the proliferation of algae, aquatic plants, and diverse animal life, a phenomenon referred to as natural eutrophication.
    • In contrast, human activities can accelerate this nutrient enrichment, resulting in a process known as cultural eutrophication.
    • Lakes are classified based on their nutrient levels into three categories: Oligotrophic (characterized by very low nutrient levels), Mesotrophic (with moderate nutrient levels), and Eutrophic (rich in nutrients).
    • In India, the majority of lakes fall into the eutrophic or mesotrophic categories due to the influx of nutrients from their surroundings and organic waste.

 

The consequences of eutrophication include:

    • Disruption of food chains: Eutrophic water bodies, which are nutrient-rich, support dense populations of plants and phytoplankton. The subsequent death and decay of these organisms can deplete oxygen levels in the water, leading to the death of aquatic animals.
    • Invasion of new species: Eutrophication can alter the competitive dynamics within ecosystems by transforming normally limiting nutrients into abundant resources, resulting in shifts in species composition.
    • Diminution of freshwater lakes: Over time, eutrophication leads to the formation of a detritus layer within lakes, causing a gradual reduction in water depth. Ultimately, this process can convert a lake into a marsh, transitioning its plant community from an aquatic to a terrestrial environment.
    • Decline of coral reefs: This occurs as a result of reduced water clarity due to increased turbidity.
    • Additional impacts: Eutrophication can hinder navigation because of heightened turbidity, produce unpleasant colors (such as yellow, green, and red) and odors, and lead to an increase in the biomass of inedible toxic phytoplankton, as well as blooms of gelatinous zooplankton and various benthic and epiphytic algae.

Eutrophication and Algal Blooms:

Eutrophication: 

    This refers to the process by which aquatic ecosystems become enriched with nutrients, particularly nitrates and phosphates, through both natural and anthropogenic means.

 

Impact: 

    • The influx of excess nutrients leads to rapid increases in phytoplankton populations, resulting in algal blooms that blanket the water’s surface and inhibit sunlight penetration.
    • The reduction in sunlight availability causes the decline of aquatic vegetation and disrupts the replenishment of oxygen, thereby adversely affecting aquatic ecosystems.

 

Phytoplankton:

    • These are microscopic autotrophic organisms present in marine environments, equipped with chlorophyll that enables them to convert sunlight into chemical energy through photosynthesis.
    • Energy Sources: Although all phytoplankton engage in photosynthesis, some species also obtain energy by consuming other organisms.

 

Types: 

    Phytoplankton includes various groups such as diatoms, dinoflagellates, cryptomonads, green algae, and cyanobacteria. They are essential components of aquatic food webs and serve as important ecological indicators. 

 

Contribution to Climate and Oxygen: 

    • Oxygen Production: Phytoplankton are responsible for producing more than half of the oxygen that humans rely on for respiration.
    • Climate Impact: They play a significant role in absorbing anthropogenic CO₂, thereby influencing the regulation of the global climate.

 

Phytoplankton Chlorophyll:

    • Chlorophyll Function: This green pigment is crucial for photosynthesis, as it primarily absorbs blue and red light wavelengths, which imparts a green hue to plants.

 

Chlorophyll Types: 

    • Chlorophyll a: Present in higher plants, algae, and cyanobacteria.
    • Chlorophyll b: Found in higher plants and green algae.
    • Chlorophyll c: Located in diatoms, dinoflagellates, and brown algae.
    • Chlorophyll d: Unique to red algae.

 

Algal Blooms: 

      These blooms often manifest as red or brown discolorations in the water, commonly referred to as red tides or brown tides. 

 

Conditions: 

      The occurrence of warm water conditions promotes the proliferation of algal blooms, making climate change a significant factor in their increasing frequency and severity. Such blooms can create hypoxic zones, adversely affecting aquatic life.

 

Mechanism: 

    • Phytoplankton engage in photosynthesis during daylight hours, contributing oxygen to the aquatic environment.
    • However, at night, their respiration rates increase significantly, leading to a higher consumption of oxygen. Consequently, algal blooms exacerbate oxygen depletion due to the substantial population of phytoplankton present.
    • This oxygen deficiency results in the mortality of primary consumers, such as zooplankton and small fish, thereby disrupting the food chain.
    • Additionally, the decomposition of deceased algae, plants, and fish further depletes oxygen as microorganisms break down these organic materials.
    • The resulting anaerobic conditions foster the proliferation of bacteria like Clostridium botulinum, which produces toxins harmful to aquatic life, birds, and mammals.

 

Harmful Algal Blooms (HABs):

    • These are a specific category of algal blooms that can be detrimental, as they produce toxins, including neurotoxins and hepatotoxins.
    • These toxins can be lethal to aquatic life, such as shellfish, and may also pose risks to human health. In addition to their ecological impact, HABs negatively influence commercial and recreational fishing, tourism, and important natural habitats.

Eutrophication and Dead Zones:

The oxygen levels in the world’s oceans have diminished: 

    • A study conducted by the International Union for Conservation of Nature (IUCN) indicates that from 1960 to 2010, there has been approximately a 2% reduction in oxygen levels in the oceans.
    • The main contributors to this deoxygenation are eutrophication and nitrogen deposition resulting from fossil fuel combustion, along with the extensive effects of ocean warming.
    • Elevated ocean temperatures lead to deoxygenation for two reasons: oxygen’s solubility decreases in warmer water, and temperature-induced stratification occurs.
    • The melting of ice and glacial runoff creates a less saline and, consequently, less dense layer of water that remains on the surface.
    • This stratification obstructs the upward movement of nutrients from deeper waters to the upper ocean layers.
    • As a result, the reduced availability of nutrients is likely to lower the rates of photosynthesis in the surface ocean, where the majority of oceanic photosynthesis, primarily by phytoplankton, takes place.

 

Dead Zones:

    • Dead zones, also referred to as biological deserts or hypoxic zones, are regions in the ocean characterized by significantly low oxygen levels, known as hypoxic conditions.
    • These areas develop as a result of an influx of excessive chemical nutrients, which stimulates the growth of algae, leading to algal blooms.
    • Typically, these zones are found at depths ranging from 200 to 800 meters within the saltwater layer beneath the ocean’s surface.
    • Hypoxic zones can arise naturally, often due to the upwelling of nutrient-rich waters. However, human activities can also create or exacerbate these conditions, resulting in the formation of dead zones.
    • The presence of dead zones poses a serious threat to marine life, as most organisms either perish or relocate to more hospitable environments.
    • The prevalence of dead zones is on the rise, particularly in coastal delta and estuarine areas.
    • One of the most significant dead zones appears annually in the Gulf of Mexico during the spring, a phenomenon linked to agricultural practices where fertilizers are applied to crops and subsequently washed into rivers by rainfall. Additionally, the dead zone in the Gulf of Oman is also expanding.

 

The process of dead zone formation involves three key stages: 1) Eutrophication, 2) Algal Bloom, and 3) Hypoxic conditions.

 

Blue Tide:

    • Bioluminescent tides, characterized by their light-emitting properties, occasionally manifest along polluted coastlines where seawater exhibits low levels of dissolved oxygen—often a consequence of climate change—and elevated nitrogen concentrations due to eutrophication.
    • The phenomenon known as the blue tide occurs when luminescent dinoflagellates or other marine organisms cause the ocean to appear a vivid blue through chemical reactions involving their proteins.
    • While smaller instances of this phenomenon may pose little threat, larger, slower-moving tides can adversely affect deep-sea fishing activities.
    • Bioluminescence refers to the ability of certain living organisms to generate and emit light. This trait serves as an antipredator mechanism, intimidating potential predators and facilitating the formation of colonies among these organisms.
    • Various life forms, including animals, plants, fungi, and bacteria, exhibit bioluminescence. It is particularly prevalent among numerous marine species, such as bacteria, algae, jellyfish, crustaceans, sea stars, and fish, including sharks.
    • Generally, luminescence is more pronounced in organisms that inhabit deeper waters and those that are planktonic, compared to their shallow-water counterparts.

Water Pollution Control Measures:

Bioremediation:

      Bioremediation employs microorganisms, such as bacteria and fungi, to transform environmental pollutants into less harmful substances. Through genetic engineering techniques, these microorganisms can be specifically tailored for bioremediation purposes.

In-situ bioremediation:

    • It refers to the treatment of contaminated sites directly at their location.
    • Bioventing involves the introduction of nutrients via wells into contaminated soil to promote bacterial growth.
    • Biosparging entails the pressurized injection of air beneath the water table, which increases the oxygen levels in groundwater and accelerates the biological breakdown of contaminants by bacteria.
    • Bioaugmentation is the process of introducing specific microorganisms to a contaminated area to improve the degradation of pollutants.
    • Utilizing these bioremediation methods, TERI has created a bacterial mixture known as ‘Oilzapper and Oilivorous-S,’ which effectively degrades pollutants found in oil-contaminated environments without leaving any harmful residues.

Ex-situ bioremediation:

    • Ex-situ refers to the process of extracting contaminated materials for treatment at a different location.
    • Landfarming: This technique involves the excavation of contaminated soil, which is then spread over a specially prepared area and regularly tilled to promote the degradation of pollutants. The primary objective is to enhance the activity of native biodegradative microorganisms, thereby facilitating their aerobic breakdown of contaminants.
    • Bioreactors: This method entails the treatment of contaminated solid materials (such as soil, sediment, or sludge) or water within a designed containment system.
    • Composting: Composting is a natural process that transforms decomposed organic matter into nutrient-rich soil, commonly referred to as compost.

 

Bioremediation of Arsenic: 

       Utilizing water contaminated with arsenic (in its toxic forms of arsenate and arsenite) for agricultural activities can result in elevated arsenic levels in crops, posing health risks to humans. The removal of arsenic from polluted soil can be facilitated by the bacteria Bacillus flexus and Acinetobacter junii, both of which possess specific genes that contribute to arsenic detoxification. Notably, B. flexus demonstrates resistance to arsenate, while A. junii shows resistance to arsenite. 

 

Advantages of bioremediation: 

    • Effectively eliminates a broad range of contaminants.
    • Capable of degrading targeted pollutants.
    • More cost-effective and environmentally sustainable.

 

Disadvantages of bioremediation 

    • Limited to compounds that are biodegradable.
    • Not all substances are amenable to biodegradation.
    • Typically requires more time compared to alternative treatment methods.

Riparian buffers for Mitigation of Eutrophication:

    • Riparian buffers serve as vegetative interfaces situated between flowing water bodies and adjacent land, established near waterways, agricultural fields, and roadways to mitigate pollution.
    • These buffer zones facilitate the deposition of sediments and nutrients, preventing their accumulation in aquatic environments, such as wetlands and estuaries, which function as natural riparian buffers.
    • The process of phytoremediation is crucial in the filtration of pollutants.

Phytoremediation:

    • It refers to the application of plants to extract contaminants from both soil and water. Natural phytoremediation is performed by mangroves, estuarine flora, and various wetland plants.
    • Phytoextraction, or phytoaccumulation, involves the uptake of contaminants into the roots and aboveground parts of plants.
    • For instance, the water hyacinth, an invasive aquatic weed, has the capability to cleanse water by absorbing toxic substances and heavy metals.
    • It is recommended to plant eucalyptus trees around sewage ponds, as these trees can efficiently absorb excess wastewater and subsequently release purified water vapor into the atmosphere.

Sewage Water Treatment for Domestic Use:

    Contaminants in Sewage Water: Sewage water contains various pollutants, including suspended solids, bacteria, algae, viruses, fungi, and minerals such as iron and manganese.

Treatment Processes:

Coagulation / Flocculation: 

    • Coagulation: The addition of coagulants such as aluminum sulfate (alum), ferric sulfate, or sodium aluminate to untreated water facilitates the aggregation of smaller dirt particles into larger clusters known as flocs.
    • Flocs: These larger particles are more easily removed through processes like settling or filtration.
    • Filtration: This process employs layers of sand, gravel, and occasionally crushed anthracite (a type of coal) to capture suspended impurities, thereby enhancing the efficacy of subsequent disinfection efforts.
    • Sedimentation: The water, along with the flocs, is directed to sedimentation basins where the flocs settle as sludge due to the slow movement of water, simplifying their removal.

 

Disinfection: 

    • Chlorination: Chlorine is introduced to eradicate pathogens, with residual levels providing ongoing biological protection within distribution systems. However, the use of chlorine can result in the formation of trace by-products, such as chloroform.
    • Ozone Disinfection: Ozone gas effectively eliminates microbes without altering the taste or odor of the water and does not leave any residual substances.
    • Limitation: Ozone must be generated on-site due to its instability, which makes it more expensive than chlorination. The absence of residue complicates the monitoring of its long-term effectiveness.

 

Fluoridation: 

    • This process adjusts the fluoride concentration to help prevent dental cavities. However, excessive fluoride levels (greater than 1.5 mg/l as specified by BIS) can lead to fluorosis, characterized by bone deterioration.
    • Defluorination: This is achieved using alum, lime, or sodium carbonate, depending on the water’s alkalinity and fluoride concentration.
    • pH Correction: Lime is added to adjust the pH, which stabilizes soft water and minimizes corrosion of pipes within the distribution network. 

 

Removal of Iron: 

    • Iron is frequently found in regions such as Northeast India, where its presence can negatively impact the taste and odor of drinking water (BIS limit: 0.3 mg/l).
    • The removal process involves oxidizing iron and converting it into insoluble ferric hydroxide through aeration and lime treatment, followed by filtration to eliminate the insoluble particles.
    • Elimination of Arsenic: Arsenic, with a permissible limit of 0.05 mg/l, is effectively removed through the application of bleaching powder and alum. Prolonged exposure to arsenic can result in serious health issues, including black foot disease and various forms of cancer.

Bio-Toilets:

Terminology Related to Bio-Toilets: 

    • Bio-digesters: Steel structures designed for the anaerobic decomposition of human waste.
    • Bio-tank: Concrete containers utilized for the anaerobic digestion of human waste.
    • Aerobic Bacteria: Microorganisms that thrive in environments with free dissolved oxygen in wastewater, consuming organic matter as their food source and converting it into stable end products through oxidation.
    • Anaerobic Bacteria: Microorganisms that thrive in environments devoid of dissolved oxygen, relying on bound molecular oxygen found in compounds such as nitrates (NO3) and sulfates (SO4). They reduce these compounds to stable end products while producing unpleasant gases like hydrogen sulfide (H2S) and methane (CH4).
    • Facultative Bacteria: Microorganisms capable of functioning in both aerobic and anaerobic conditions.
    • Anaerobic Microbial Inoculums: A diverse mixture of bacteria that facilitate the breakdown of complex polymers into simple sugars, which are subsequently converted into low-chain fatty acids and ultimately into biogas.

Anaerobic (Digester) Biodegradation System:

    • Anaerobic digestion encompasses a series of processes wherein microorganisms decompose biodegradable substances without the presence of oxygen. The end products of this process include methane (biogas), carbon dioxide, and biofertilizer.
    • Recycling one tonne of food waste through anaerobic digestion, as opposed to disposal in a landfill, averts the release of approximately 0.5 to 1.0 tonnes of CO2 into the atmosphere, highlighting one of the numerous advantages of anaerobic digestion.

Anaerobic Biodegradation vs. Aerobic Biodegradation:

    • Anaerobic biodegradation occurs under completely oxygen-free conditions, while aerobic biodegradation requires forced aeration, which is energy-intensive.
    • The former achieves over 99% inactivation of pathogens, whereas insufficient aeration in aerobic processes can result in unpleasant odors.
    • Anaerobic microorganisms are capable of breaking down substances such as detergents and phenols, a feat that aerobic bacteria cannot manage due to their sensitivity to these compounds.
    • Additionally, anaerobic processes produce significantly less sludge compared to aerobic methods, which generate a substantial amount of sludge.
    • A single inoculation of bacteria is sufficient for anaerobic systems, whereas aerobic systems necessitate the repeated addition of bacteria or enzymes.
    • Furthermore, anaerobic systems require minimal maintenance and incur no recurring costs, in contrast to the high maintenance and ongoing expenses associated with aerobic systems.

 

EcoSan Toilets:

    • Ecological sanitation represents a sustainable approach to managing human waste through the use of dry composting toilets.
    • This method is practical, hygienic, efficient, and cost-effective, allowing for the recycling of human excreta into natural fertilizer.

 

Bio-Toilets in Indian Trains:

    • The bio-toilets implemented in Indian trains were developed by Indian Railways in collaboration with the Defence Research and Development Organisation (DRDO).
    • These bio-toilets are installed beneath the lavatories, where human waste is processed by specialized bacteria that convert it into non-corrosive neutral water.
    • The traditional direct discharge of human waste from train toilets has been known to cause corrosion of the tracks.

 

Water Pollution Control Measures in India and Indian River Systems:

    • The Government of India enacted the Water (Prevention and Control of Pollution) Act in 1974 to protect water resources.
    • The Central Pollution Control Board (CPCB), which serves as the leading authority in water quality management, has partnered with relevant State Pollution Control Boards (SPCB) to establish a framework for “designated best use.”
    • This framework categorizes water bodies into five classes—A, B, C, D, and E—based on various parameters such as pH, dissolved oxygen, biochemical oxygen demand (BOD), total coliform levels, free ammonia, and electrical conductivity.
    • This classification system aids water quality managers and planners in setting specific water quality objectives and determining the needs and priorities for water quality improvement initiatives.
    • The Ganga Action Plan and the subsequent National River Action Plan are outcomes of this systematic approach.

Major River Conservation Initiatives:

Ganga Action Plan (GAP): 

    • Initiated in 1985 by the Ministry of Environment and Forests (MoEF), GAP was the first comprehensive river action initiative implemented as a centrally funded program. The primary focus of this initiative was to address pollution in the Ganga River.
    • Following this, GAP Phase-II was launched, which expanded the scope to include significant tributaries of the Ganga, specifically the Yamuna, Gomti, and Damodar rivers.
    • Parameter
    • Upon its inception, the principal aim of GAP was to enhance the water quality of the Ganga to meet acceptable standards.

 

Over time, this objective was revised to align with the ‘Bathing Class’ standards, which are defined as follows: 

Parameter

GAP Bathing Class 

Biochemical Oxygen Demand (BOD)

3 mg/l maximum   

Dissolved Oxygen (DO)

5 mg/l minimum  

Total Coliform 

10,000 per 100 ml 

Faecal Coliform 

2,500 per 100 ml 

 

Although GAP I was deemed partially successful and officially concluded on March 31, 2000, it did lead to notable improvements in water quality. Nevertheless, in several locations, BOD levels remained above the acceptable threshold of 3.0 mg/l.

National River Conservation Plan (NRCP):

    • Established in 1995, the National River Conservation Plan (NRCP) expanded the scope of the Ganga Action Plan (GAP) to include additional national rivers under a centrally sponsored initiative.
    • The Ministry of Jal Shakti is currently executing the NRCP in 160 towns situated along the polluted segments of 34 rivers across 20 states, excluding those within the Ganga basin.
    • The NRCP offers both financial and technical support to states and union territories on a cost-sharing basis.

 

Its primary aim is to implement various pollution abatement strategies to achieve bathing quality standards for the rivers, which include: 

    • The collection and treatment of untreated sewage prior to its discharge into the river (a responsibility assigned to the respective State Governments and Urban Local Bodies);
    • The prevention and regulation of industrial pollution (managed by the relevant Pollution Control Boards);
    • Implementation of low-cost sanitation initiatives to eliminate open defecation along riverbanks;
    • Establishment of electric crematoria to facilitate the proper cremation of bodies at cremation sites;
    • Development projects along riverfronts, including enhancements to bathing ghats and related facilities.

National Ganga Council: 

    • The National Council for the Rejuvenation, Protection, and Management of the River Ganga, commonly referred to as the National Ganga Council, was established through the River Ganga (Rejuvenation, Protection, and Management) Authorities Order of 2016.
    • This council succeeded the National Ganga River Basin Authority (NGRBA).
    • The National Ganga Council is tasked with the comprehensive responsibility of mitigating pollution and revitalizing the Ganga River Basin.
    • The National Mission for Clean Ganga (NMCG), which operates as a society under the Societies Registration Act of 1860, serves as the operational arm of the NGC, overseeing the implementation of the Namami Gange Programme.

 

The composition of the National Ganga Council includes the following members: 

    • The Prime Minister serves as the Chairperson.
    • The Union Minister for Jal Shakti acts as the Vice-Chairperson.
    • The Union Ministers responsible for Environment, Finance, Power, Housing, Science and Technology, as well as the State Ministers for Tourism and Shipping.
    • Chief Ministers from the states that are traversed by the Ganga or its tributaries.
    • The Vice Chairperson of Niti Aayog.

National Ganga River Basin Authority (NGRBA): 

The Government of India established the NGRBA in 2009 under Section 3 of the Environment Protection Act of 1986, designating the Ganges as India’s “National River.” In 2016, it was succeeded by the National Ganga Council. 

Project Arth Ganga: 

    • Project Arth Ganga represents a sustainable development initiative aimed at promoting river-related economic activities along the Ganga River’s banks.
    • The project aspires to contribute a minimum of 3% to the GDP from the Ganga Basin, a concept first introduced during the inaugural meeting of the National Ganga Council in 2019.
    • The Jal Marg Vikas Project (JMVP) seeks to enhance the Ganges as a reliable navigation route and is being executed with support from the World Bank. Project Arth Ganga aims to re-engineer the JMVP by engaging local communities and emphasizing economic development.
    • To stimulate community-level economic activities, small jetty terminals will be constructed along the riverbanks, which will reduce logistics costs for farmers transporting their local produce.

Namami Gange Programme: 

    • In addition to the National River Conservation Plan (NRCP), the Ministry of Jal Shakti is executing the Namami Gange initiative, which is an Integrated Conservation Mission.
    • This initiative was recognized as a ‘Flagship Programme’ by the Government of India in 2014, with a financial allocation of Rs. 20,000 Crore aimed at achieving the dual goals of reducing pollution and promoting the conservation and rejuvenation of the Ganga River.

 

The core components of the programme include: 

    • Development of Sewerage Treatment Infrastructure
    • Riverfront Development
    • Cleaning of River Surfaces
    • Biodiversity Enhancement
    • Afforestation Efforts
    • Public Awareness Campaigns
    • Monitoring of Industrial Effluents
    • Ganga Gram Initiative.

Clean Ganga Fund: 

     Established in 2014 as a trust under the Indian Trust Act of 1882, the Clean Ganga Fund enables contributions from resident Indians, Non-Resident Indians (NRIs), Persons of Indian Origin (PIOs), and both public and private sector corporations to support the conservation of the Ganga River.

   Donations made to the Clean Ganga Fund are considered part of Corporate Social Responsibility (CSR) initiatives.

Swachh Bharat Mission (SBM):

    • SBM was initiated on October 2, 2014, and is overseen by the Ministry of Drinking Water and Sanitation, which has been known as the Ministry of Jal Shakti since 2019.
    • The program aims to achieve comprehensive sanitation coverage by ensuring that Gram Panchayats are declared Open Defecation Free (ODF).
    • Under SBM, financial incentives are available for all Below Poverty Line (BPL) and Above Poverty Line (APL) households, specifically targeting Scheduled Castes (SCs), Scheduled Tribes (STs), individuals with disabilities, and households led by women for the construction of individual latrines.
    • These incentives are co-funded by the Central and State governments at a ratio of 75% to 25%. In the Northeastern and Special category States, the Central government’s contribution increases to 90%.

Mission Performance: 

      Since the inception of the mission, over 100 million individual toilets have been constructed. As of October 2, 2019, all rural areas across the states were declared Open Defecation Free (ODF). In contrast, sanitation coverage was only 38.7 percent in 2014. 

Swachh Iconic Places: 

    • The Swachh Iconic Places (SIP) initiative, launched by the Ministry of Drinking Water and Sanitation (now known as the Ministry of Jal Shakti since 2019), is part of the Swachh Bharat Mission (SBM).
    • The objective of SIP is to elevate the cleanliness standards of iconic locations and their surroundings. This initiative is a collaborative effort involving three other central ministries: Urban Development, Culture, and Tourism, along with the relevant state governments.
    • Projects undertaken under the Swachh Iconic Places initiative include enhancements to sewage infrastructure and sanitation facilities, installation of water vending machines, solid and liquid waste management (SLWM), improvements in lighting, beautification of parks, road maintenance, and upgrades to transportation facilities, among others.

Selected Locations for Implementation: 

    • Phase I: The sites include Ajmer Sharif Dargah, CST Mumbai, Golden Temple, Kamakhya Temple, Maikarnika Ghat, Meenakshi Temple, Shri Mata Vaishno Devi, Shree Jagannath Temple, The Taj Mahal, and Tirupati Temple.
    • Phase II: This phase encompasses Gangotri, Yamunotri, Mahakaleshwar Temple, Charminar, Church of St. Francis of Assisi, Kalady, Gommateswara, Baidyanath Dham, Gaya Tirth, and Somnath Temple.
    • Phase III: The locations for this phase are Raghavendra Swamy Temple (Kurnool, Andhra Pradesh), Hazardwari Palace (Murshidabad, West Bengal), Brahma Sarovar Temple (Kurukshetra, Haryana), Vidur Kuti (Bijnor, Uttar Pradesh), Mana Village (Chamoli, Uttarakhand), Pangong Lake (Leh-Ladakh), Nagvasuki Temple (Prayagraj), Ima Keithal Market (Imphal, Manipur), Sabarimala Temple (Kerala), and Kanvashram (Uttarakhand).

Swachh Bharat Mission II: 

    • The Government of India has sanctioned the second phase of the Swachh Bharat Mission (SBM II), which is set to be executed from 2020-21 to 2024-25, with an estimated budget of approximately Rs 52,000 crore from both central and state sources.
    • This phase will emphasize Open Defecation Free Plus (ODF Plus), which aims to ensure the sustainability of ODF initiatives alongside solid and liquid waste management (SLWM).
    • The ODF Plus initiative will integrate with the Mahatma Gandhi National Rural Employment Guarantee Act (MGNREGA), particularly focusing on the management of greywater (wastewater from non-toilet plumbing systems such as hand basins, washing machines, showers, and baths), and will support the newly initiated Jal Jeevan Mission.
    • The funding distribution between the Centre and States will be structured as follows: 90:10 for North-Eastern States and the Himalayan States and Union Territory of Jammu and Kashmir; 60:40 for other States; and 100:0 for other Union Territories.

National Water Quality Monitoring Programme: 

    • The Central Pollution Control Board (CPCB), in collaboration with State Pollution Control Boards (SPCBs), has been actively assessing the water quality of rivers across the nation through a network of monitoring stations established under the National Water Quality Monitoring Programme.
    • The CPCB periodically conducts pollution assessments of rivers based on the results obtained from these monitoring efforts.
    • In accordance with directives from the National Green Tribunal (NGT) concerning polluted river segments within the country, States and Union Territories (UTs) are mandated to execute action plans sanctioned by the CPCB aimed at the restoration of these segments within the designated timeframes.

 

Measures to Curb Marine Pollution:

         To address marine pollution and manage the utilization of the world’s oceans by individual nations, countries globally have united to establish two significant conventions and an organization:

    1. The Convention on the Dumping of Wastes at Sea (1972), which was succeeded by the 1996 Protocol,
    2. The United Nations Convention on the Law of the Sea (UNCLOS), and
    3. The International Maritime Organization (IMO).

Convention on the Dumping of Wastes at Sea: 

    • In 1972, an intergovernmental conference convened in London to establish the Convention on the Dumping of Wastes at Sea, commonly referred to as the London Convention.
    • This treaty possesses a global scope and is designed to facilitate international oversight and eliminate marine pollution.
    • According to the Convention, “dumping” is defined as the intentional disposal of waste or other materials into the sea from vessels, aircraft, platforms, and other human-made structures.
    • It is important to note that this definition excludes waste generated from the exploration and extraction of seabed minerals.
    • Initially, the Convention allowed for the dumping of low-level radioactive waste and industrial waste, as well as the incineration of waste at sea. However, an amendment in 1978 prohibited the incineration of waste in marine environments.
    • A subsequent amendment in 1993 prohibited the dumping of low-level radioactive waste into the ocean and mandated the cessation of industrial waste dumping by 1995.

 

 1996 Protocol: 

    • The Protocol, which came into effect in 2006, supersedes the 1972 Convention. It is significantly more stringent than its predecessor, which permitted dumping under certain conditions. The International Maritime Organization (IMO) is tasked with the Secretariat responsibilities related to the Protocol.
    • The 1996 Protocol mandates the implementation of suitable preventive measures when waste disposal at sea poses a potential risk of harm, even in the absence of definitive evidence linking the waste to adverse effects.
    • According to the Protocol, the principle of “the polluter pays” is emphasized, requiring that the parties involved ensure that the Protocol does not merely shift pollution from one environmental area to another.
    • The Protocol explicitly forbids Contracting Parties from dumping “wastes or any other matter” except for those specified in Annex I, which includes dredged materials, sewage sludge, and fish waste from industrial processing, primarily concerning physical impacts.
    • Additionally, the Protocol bans the incineration of waste at sea, a practice that was allowed under the 1972 Convention but prohibited by the 1993 amendments. It asserts that “Contracting Parties shall not permit the export of wastes or other materials to other nations for the purpose of dumping or incineration at sea.”

2006 Revisions to the 1996 Protocol:

    • The revisions, which were adopted in 2006, came into effect in 2007. They established a framework within international environmental law for the regulation of carbon capture and storage in sub-seabed geological formations. This initiative is part of broader efforts to combat climate change and ocean acidification.
    • These revisions permit the storage of carbon dioxide (CO2) beneath the seabed while imposing regulations on the sequestration of CO2 streams derived from carbon capture processes in sub-seabed geological formations.

The United Nations Convention on the Law of the Sea (UNCLOS):

    UNCLOS outlines fundamental responsibilities for the protection of the marine environment and the preservation of scientific research freedoms in international waters. It holds states accountable for damages resulting from breaches of their international commitments through its three governing bodies: 

1) International Tribunal for the Law of the Sea, 

2) International Seabed Authority (ISA), and 

3) Commission on the Limits of the Continental Shelf. 

 

The convention also offers precise definitions for Internal Waters, Territorial Waters, Contiguous Zone, Exclusive Economic Zone, and Continental Shelf. Additionally, it grants landlocked nations the right to access the sea and transit through neighboring states without incurring taxes on their passage.

International Seabed Authority (ISA): 

    • The United Nations Convention on the Law of the Sea (UNCLOS) establishes a legal framework for the management of resource extraction in deep-seabed regions that lie outside national jurisdiction, overseen by the International Seabed Authority, which comprises 168 member states, including India.
    • The ISA is responsible for the organization, regulation, and oversight of all mineral-related operations in the international seabed area that extends beyond the boundaries of national jurisdiction.

International Maritime Organization (IMO): 

    • The IMO serves as the worldwide authority responsible for establishing standards related to the safety, security, and environmental efficiency of international shipping. Its main office is located in the United Kingdom, making it the only United Nations Special Agency headquartered in this country.
    • The primary aim of the IMO is to enhance maritime safety and to prevent marine pollution.
    • The Maritime Environment Protection Committee of the IMO oversees the coordination of the organization’s efforts to prevent and manage marine pollution, addressing both accidental and operational oil spills.

Ballast Water Management Convention (2004): 

    • This convention established by the International Maritime Organization (IMO) seeks to mitigate the dissemination of harmful aquatic organisms across different regions via ballast water, which is recognized as a primary means of transporting potentially invasive alien species.
    • Ballast water refers to the water stored in a ship’s ballast tanks to enhance its stability and equilibrium.
    • This water is taken on board or released during the loading or unloading of cargo. In the absence of specific measures, this practice can lead to a significant transfer of marine organisms from their indigenous environments to regions where they are not naturally found.

Bunker Convention (2001): 

    • The Bunker Convention guarantees that sufficient compensation is provided to individuals who experience damage resulting from oil spills.
    • It encompasses damage occurring within the territory, including the territorial sea and exclusive economic zone of the contracting states. This convention is based on the International Convention on Civil Liability for Oil Pollution Damage, established in 1969.
    • India has ratified both conventions set forth by the IMO.

Regional Oil Spill Contingency Plan:

     This initiative was collaboratively established by the South Asia Co-operative Environment Programme (SACEP) and the International Maritime Organization (IMO) to enhance international collaboration and support in the preparation for and response to significant oil pollution events occurring in the waters surrounding Bangladesh, India, the Maldives, Pakistan, and Sri Lanka.

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