Waste Water Management – Methods, Treatment & Sustainable Practices

Wastewater can be defined as collection, treatment, and reuse of household, industrial, as well as agricultural sewage in order to avoid pollution and preserve health. There are such schemes as SBM 2.0, AMRUT 2.0, which are targeted to escalate the infrastructure in India and enhance deployment of such technologies as ASP, SBR, and MBBR. Policies, laws and people, all play prominent roles in addressing challenges, water conservation, and sustainable reuse of water in irrigation, industrial and urban demand.

For those aiming to conquer the coveted Union Public Service Commission (UPSC) examination, understanding waste water management can indeed turn the scales in your favor.

Wastewater management is relevant for UPSC under GS-II (Governance, Government Schemes, Policies) and GS-III (Environment, Pollution Control, Sustainable Development), plus Essay Paper, covering laws, initiatives, technologies, challenges, and sustainable water resource management in India.

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What is Waste Water?

Wastewater refers to water that has already been used and is no longer fit for its original purpose. It may originate from households, industries, commercial establishments, agriculture, or even rainwater runoff. Its composition varies with the source, often containing contaminants that can harm both human health and, environment, and it is also referred to as sewage. Based on its source, it is generally classified into:

• Domestic/Municipal: Water from toilets, kitchens, bathrooms, laundry, and stormwater runoff from streets and rooftops.
• Industrial: Discharge from manufacturing units, power plants, and other industrial processes.
• Commercial: Wastewater from restaurants, car washes, hotels, and other service-based businesses.
• Agricultural: Runoff and drainage from irrigation and farming activities.

Common Pollutants in Wastewater

• Organic Matter: Food residues, paper, and human waste.
• Chemicals: Detergents, pesticides, and industrial byproducts.
• Pathogens: Bacteria, viruses, and parasites that can cause disease.
• Heavy Metals: Lead, mercury, cadmium, and similar toxic elements.
• Other Contaminants: Oils, grease, and sediments.

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Impact of Excess Nutrients – Eutrophication

When excess nutrients enter a water body, they cause eutrophication — a process where the water becomes overly enriched with minerals and nutrients. This encourages the rapid growth of algae (algal blooms), which in turn depletes dissolved oxygen levels in the water, leading to the death of aquatic life and the gradual deterioration of water quality.

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Waste Water Treatment

Sewage treatment refers to the process that eliminates physical, chemical and biological contaminants in the used water so as to render it safe to be used or safely released. It also guarantees the removal of pollutants prior to the water gaining the aquifers or having access to the water along natural surroundings like rivers, lakes and others, thus safeguarding the health of people and conserving the ecosystem.

On-site Sewage Treatment Plants (STPs) are designed to treat and purify wastewater at its source, making it suitable for reuse. These STPs primarily remove contaminants from household sewage and are a critical part of reducing environmental pollution.

Stages of Treatment:

1. Preliminary Treatment: Removal of large debris (plastics, rags) using screening and grit chambers.
2. Primary Treatment: Sedimentation to separate suspended solids.
3. Secondary Treatment: Biological processes (e.g., Activated Sludge Process, Trickling Filters, Sequencing Batch Reactors) to break down organic matter.
4. Tertiary Treatment: Advanced purification to remove nutrients, heavy metals, and pathogens.
5. Disinfection: Using UV radiation, chlorine, or ozone to kill microorganisms.

Key Technologies:

• UV Disinfection: Breaks down the DNA of pathogens, preventing reproduction.
• Membrane Filtration: Removes fine particles and microbes.
• Anaerobic Digesters: Convert sludge into biogas for energy.

Status of Waste Water Management in India

1. Total Sewage Generation (Urban Areas): ~72,368 MLD

According to the estimates of Central Pollution Control Board (CPCB), the current population growth and rapid urbanisation as well as the industrial activity in India gives rise to more than 72,000 million litres of sewage by towns and cities on a daily basis. This does not include rural sewage which in many cases mixing is not monitored but contributes large amounts to the overall load.

2. Installed Treatment Capacity: ~31,841 MLD (44% of generation)

The current Sewage Treatment Plants (STP) have the capability of treating wastewater in only 44 per cent of the quantities. Most of the plants are underutilized as a result of power deficiency, inefficient maintenance and obsolete equipment.

3. Untreated Sewage: ~40,527 MLD (56% remains untreated)

More than half of the wastewater generated flows untreated into rivers, lakes, and groundwater systems, severely contaminating water sources and posing a public health risk through waterborne diseases like cholera, diarrhoea, and typhoid.

4. Coverage Gap

• Class-I cities (population above 1 lakh) have better sewage networks, though still insufficient.
• Class-II towns and rural areas mostly rely on septic tanks or soak pits, with minimal or no centralized treatment facilities.
  This gap highlights a clear infrastructure deficit in wastewater management.

5. Industrial Effluents

Vapi (Gujarat), Patancheru (Telangana) and Baddi (Himachal Pradesh) are some of the industrial hotspots that tend to release unchecked or partially treated effluents, composed of heavy metals, chemicals and pharmaceuticals. There is a lack of consistency in the enforcement of Effluent Treatment Plants (ETPs), therefore, non-compliance occurs.

6. Reuse of Treated Wastewater

A little less than 20 percent of lands given water is re-used in form of irrigation, industrial cooling, and landscaping. Given that most treated water is released, there is an instance of wastage of a precious resource since the water has not been part of a circular water economy.

7. Pollution Impact

Rivers such as the Ganga, Yamuna, Musi, and Sabarmati rank among the most polluted in India. High levels of Biochemical Oxygen Demand (BOD), chemical pollutants, and microbial contamination are common, causing ecological degradation and affecting livelihoods dependent on these rivers.

8. Government Focus

Wastewater management has been one of the priorities of the Government of India in its overall agenda of environmental and public health. The most important activities are:

Swachh Bharat Mission 2.0 (SBM 2.0)

The Swachh Bharat Mission – Urban 2.0 is an expanded phase of the original Swachh Bharat Mission (Urban) launched in 2014. While the first phase focused largely on eliminating open defecation by building toilets, SBM 2.0 broadens its scope to address the next stage of urban sanitation challenges.

Its focus areas now include:

• Solid Waste Management (SWM) – ensuring segregation of waste at source, door-to-door collection, transportation, treatment, and scientific disposal.
• Sludge Management – safe handling, transportation, treatment, and disposal of faecal sludge from septic tanks and pit latrines.
• Greywater Management – treatment and safe reuse/disposal of household wastewater from kitchens, bathrooms, and wash areas.

ODF+, ODF++, and Water+ Status

To monitor progress in sanitation, the mission introduced progressive certification levels for cities:

1. ODF+ (Open Defecation Free Plus)
    
   • Cities must not only remain open defecation free, but also ensure all public and community toilets are functional, accessible, and well-maintained.
   • Focuses on sustaining cleanliness through regular operation and maintenance.
      
2. ODF++ (Open Defecation Free Double Plus)
    
   • Goes beyond ODF+ by ensuring safe containment, collection, transportation, treatment, and disposal of faecal sludge and septage.
   • This certification ensures no untreated human waste is released into the environment.
      
3. Water+
    
   • The highest sanitation standard.
   • Requires 100% treatment of all wastewater generated in the city (including sewage and greywater) before it is discharged into water bodies or the environment.
   • Encourages wastewater recycling and reuse.

AMRUT Mission – Sewerage and Septage Management

The Atal Mission for Rejuvenation and Urban Transformation (AMRUT), under the Ministry of Housing and Urban Affairs (MoHUA), complements SBM 2.0 by focusing on urban infrastructure.

Under AMRUT:

• Sewerage Projects – construction and expansion of underground sewer networks, sewage treatment plants (STPs), and pumping stations.
• Septage Management – systems for safe desludging, transportation, and treatment of septage from areas not connected to sewer networks.
• The aim is to ensure universal coverage of sewage treatment in mission cities, thereby improving urban sanitation and reducing pollution in rivers and lakes.

Regulatory Framework for Wastewater Management in India

Wastewater management in India is governed by a combination of water-specific and umbrella environmental laws. These legislations establish legal standards, institutional mechanisms, and enforcement powers to control pollution and promote safe disposal or reuse.

1. The Water (Prevention and Control of Pollution) Act, 1974

• Purpose: To prevent, control, and abate water pollution, and to maintain or restore the wholesomeness of water.
   
• Key Provisions:
   
  • Builds up Central and State Pollution Control Boards to control and oversee water quality.
  • There are mandates on prior approval of SPCBs to put up any industry or operation that might release sewage or effluents.
     
• 1988 Amendment: Strengthened enforcement powers, introduced penalties, and allowed boards to close non-compliant industries.

2. The Water (Prevention and Control of Pollution) Cess Act, 1977

• Purpose: To raise financial resources for the Pollution Control Boards through a cess (tax) on water consumption by certain industries and local authorities.
• Amendment (2003): Revised rates and expanded coverage to include more industries.
• Function: Encourages industries to adopt water-efficient and pollution control measures by offering rebates for compliance with prescribed standards.

3. The Environment (Protection) Act, 1986

• Purpose: An umbrella legislation enacted after the Bhopal Gas Tragedy to provide a framework for environmental protection.
   
• Relevance to Wastewater:
   
  • Authorises the Central Government to set standards for sewage and effluent discharge.
  • Empowers authorities to inspect facilities, issue directions, and take measures for compliance.
  • Promotes environmental research and lays down procedures for handling hazardous substances.
• Scope: Covers all forms of environmental pollution — water, air, land, and noise.

Challenges in Waste Water Management

Several existent government schemes and regulatory frameworks are insufficient since there is a lack of treatment capacity, old infrastructures, non-compliance by industry, and reuse rates, contributing to water pollution, community health effects, and environmental degradation.

• Constitutional Structure:
  Water is a State subject under Schedule 7, but Parliament has powers over inter-state water regulation.
  This results in overlapping jurisdiction and ambiguity between the Centre and the States.
   
• Fragmented Governance:
  Rural and urban water management responsibilities are split under the 73rd and 74th Constitutional Amendment Acts, leading to a disjointed approach.
   
• Inter-State Disputes:
  Inaction in one state can negatively impact others downstream.
   
• High Costs of Centralised Treatment:
  Large sewage networks are expensive, labour-intensive, and time-consuming to construct.
   
• Operational Inefficiencies:
  Many STPs under flagship river cleaning projects are non-functional.
   
• Industrial Discharges:
  Pharmaceutical and chemical industries significantly contribute to wastewater pollution, aggravating AMR.

Way Forward

• Integrated Governance:
  Recognise wastewater as both an environmental and water-sector issue, with all levels of government working together.
   
• Decentralised Treatment:
  Establish wastewater treatment units in smaller townships, gated colonies, industrial parks, and rural clusters.
   
• Nature-Based Solutions:
   
  • Bioremediation: Utilising microbes such as bacteria and fungi to degrade pollutants.
     
  • Phytoremediation: Using plants and their associated soil microbes to reduce pollutant concentrations — successfully implemented in cleaning lakes and ponds across India.
     
• Strengthen Regulatory Enforcement:
  CPCB and State Pollution Control Boards (SPCBs) must ensure strict compliance with discharge standards.
   
• Industry Responsibility:
  Promote Zero Liquid Discharge (ZLD) systems in industries.

UPSC Civil Services Examination – Previous Year Questions

Q1. (2017)
Biological Oxygen Demand (BOD) is a standard criterion for:
(a) Measuring oxygen levels in blood
(b) Computing oxygen levels in forest ecosystems
(c) Pollution assay in aquatic ecosystems
(d) Assessing oxygen levels in high altitude regions

Explanation:
BOD measures the dissolved oxygen needed by aerobic organisms to break down organic material in water. High BOD indicates polluted water, low BOD indicates clean water.

Q2. (2017)
Advantages of bioremediation in solving pollution problems:

1. It enhances the natural biodegradation process for cleanup.
    
2. Any contaminant, including heavy metals, can be fully treated by microorganisms.
    
3. Genetic engineering can develop specific microorganisms for bioremediation.

Correct answer: (c) – 1 and 3 only

Conclusion

Wastewater management has now become a public health, economic and sustainability issue apart from being an environmental issue. Water scarcity and pollution has escalated in India due to the quick urbanisation, industrialisation, and climate stress. The activities represented by SBM 2.0, AMRUT 2.0 and Namami Gange are government schemes that are filling the infrastructure gaps but success will rely on the regulator compliance, decentralised treatment systems, industry responsibility and community involvement. Sustainable wastewater treatment and reuse are not only beneficial as they conserve the ecosystems, prevent diseases, but also lead to water security and climate resilience; hence, wastewater treatment and reuse is one of the main pillars of sustainable development.

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