Sewage Management in India | Environment | Mains Current Affairs

Why in the news?

• The National Mission for Clean Ganga (NMCG) under the Ministry of Jal Shakti, issue a notification to amend the Rejuvenation, Protection and Management program Order, 2016
• Recent Amendment by NMCG for Sewage Discharge into River Ganga.
• NMCG now allowed to discharge treated effluent into river Ganga.
• Aimed to improve water flow and biodiversity.

Sewage Generation and STPs in India:

• Estimated sewage generation from Class 1 cities and Class II towns in India is over 33,000 MLD.
• Current STP treatment capacity is only 18.6%.
• STPs treat wastewater from various sources to remove pollutants before release into the environment.

Mechanism of Off-site wastewater treatment system:

• Involves treating domestic sewage outside the property.
• Sewage is transported through a sewer network to a sewage treatment plant.
• Periodic transport of sludge for treatment and disposal.

Mechanism of On-site wastewater treatment system:

• Involves treating sewage on the property.
• Uses a septic tank for storage and initial treatment.
• Sewage is then transported to a sewage treatment plant for further treatment.
• Faecal sludge/septage treatment is also part of the process.

Types of Sewage Treatment Plants (STPs):

• Membrane BioReactor (MBR): Combines membrane filtration with a bioreactor for treatment.
• Activated Sludge Plant (ASP): Aerates sewage to promote bacteria growth for waste metabolism.
• Sequencing Batch Reactor: Activated sludge process for wastewater treatment.
• Moving Bed Biofilm Reactor: Biofilm treatment process that requires less space.

Institutional Arrangement and Initiatives for Sewage Treatment in India

• Water is under the jurisdiction of states as per the Seventh Schedule (Article 246).
• States/UTs are responsible for ensuring cleanliness and development of rivers States/UTs responsible for cleanliness and development of rivers.

• • National Urban Sanitation Policy (2008) assigns local governments responsibility for sanitation and waste disposal.

Decentralization of Services:

• 74th Constitutional Amendment (1993) decentralized water supply and sanitation services to Urban Local Bodies (ULB).

• • The Environment (Protection) Act, 1986 and Water (Prevention & Control of Pollution) Act, 1974 require industrial units and local bodies to install STPs and ETPs for sewage treatment.
  • No specific act dedicated to wastewater management in India.

Initiatives:

• Atal Mission for Rejuvenation & Urban Transformation (AMRUT).
• Smart Cities Mission.
• Namami Gange program.
• National River Conservation Plan.

Challenges Associated with Sewage Treatment Plants (STPs):

• Lack of Capacity in Urban Local Bodies (ULBs): ULBs struggle to plan and implement sewage treatment projects within their jurisdictions, leading to untreated wastewater discharge.
• Lopsided Implementation by States: A few states account for a majority of the total installed treatment capacity, creating disparities in sewage treatment infrastructure across the country.
• Lack of Specific Framework: There is no clear policy at the Central or State level that addresses the treatment of polluted water or its ecological restoration, leading to inconsistencies in approach.
• Differences in Discharge Standards: Discharge standards vary for different types of water bodies, creating confusion and challenges in meeting regulatory requirements.
• Low Compliance Rate: Only a small percentage of treatment capacity meets the parameters set by State Pollution Control Boards, indicating a lack of adherence to environmental regulations.
• Low Economic Viability: STPs require significant investment and time to become financially sustainable, discouraging private sector investments in sewage treatment projects.
• Aging Infrastructure: Many STPs were built decades ago and are in need of upgrades or replacements to meet current environmental standards.
• Energy Consumption: STPs require a significant amount of energy to operate, contributing to greenhouse gas emissions and overall environmental impact.
• Chemical Usage: Some STPs rely on chemicals for treatment processes, which can have negative effects on water quality and aquatic ecosystems.
• Nutrient Pollution: STPs can contribute to nutrient pollution in water bodies, leading to algal blooms and other harmful effects on aquatic life.
• Sludge Disposal: The disposal of sludge generated during the treatment process can be a challenge, as improper disposal can lead to contamination of soil and water.
• Odor and Noise Pollution: STPs can produce unpleasant odors and noise pollution, impacting the quality of life for nearby residents and wildlife.
• Climate Change Resilience: STPs may be vulnerable to extreme weather events and rising sea levels due to climate change, requiring adaptation measures to ensure continued operation.

Way forward:

• Establishing multiple monitoring points: Implementing various monitoring points for sources, environmental systems, exposure pathways, and recipients to better control pollution loads.
• Utilization in Irrigation: Research by the Indian Agricultural Research Institute in Karnal has recommended an irrigation method for sewage-fed tree plantations, which can be widely adopted.
• Focus on alternative usage: Local bodies can focus on using treated sewage for non-potable purposes such as horticulture, irrigation, fire fighting, and industrial cooling.

• • The government of Karnataka has instructed the use of tertiary treated sewage for non-drinking purposes such as gardening in various locations like parks, resorts, and golf courses.

• Defining better and uniform water quality standards: Setting clear water quality standards and monitoring pollution levels to trace them back to the source and estimate impacts.
• Setting up of underground STPs in land-scarce cities: Establishing underground Sewage Treatment Plants in crowded cities to eliminate negative environmental impacts like noise, odour, and aesthetics.
• Implementing Nature-based Solutions (NbS): Utilizing nature-based solutions such as artificial wetlands, planted soil filters, and vegetated submerged beds to address pollution issues.