The Central Pollution Control Board’s (CPCB) latest report has revealed that the Sewage Treatment Plants (STPs) in India are presently capable of treating slightly over one-third of the daily generated sewage. Set up in September 1974 under the Water (Prevention and Control of Pollution) Act, CPCB is a statutory organization tasked with managing pollution in the country.
Overview: Current STP Capacity and Distribution
India produces 72,368 MLD (Million Litres per Day) of sewage, while the country’s STPs have a total installed capacity of 31,841 MLD, or 43.9% of this output. Maharashtra, Gujarat, Uttar Pradesh, Delhi, and Karnataka – collectively account for 60% of the country’s total treatment capacity. However, several states and Union Territories, including Arunachal Pradesh, Andaman & Nicobar Islands, Lakshadweep, Manipur, Meghalaya, and Nagaland, currently lack any installed sewage treatment plants. Among all regions, Chandigarh has the highest ratio of treated sewage to total sewage produced.
Employing Treated Sewage
The reuse of treated sewage is at its peak in Haryana, followed by Puducherry, Delhi, and Chandigarh. Treated sewage water can be effectively reused for horticulture, irrigation, washing activities, firefighting, industrial cooling, toilet flushing, and gardening. This practice can significantly decrease water demand from various aquatic and groundwater sources, yet many state governments have not incorporated this crucial aspect into their policy planning.
Foreseen Issues: Rising Sewage Generation and Treatment Gaps
CPCB anticipates that daily sewage generation will surge to over 120,000 MLD by 2051. The gap in treatment capacity is more pronounced at local levels since STPs are predominantly located in larger cities, and Common Effluent Treatment Plants (CETPs) are unevenly spread across states.
Economic Factors: The Cost of Modern WTPs
Modern Wastewater Treatment Plants (WTPs) require substantial capital investment along with advanced technology like sensors, Internet of Things (IoT) devices, and AI-based trackers. The high initial capital outlay for machinery and equipment, coupled with unpredictable revenue streams, makes this sector a high-risk proposition, discouraging private sector investment.
Government Initiatives
The Indian government has recently shifted its focus towards solid waste, sludge, and greywater management under the Swachh Bharat Mission 2.0 (SBM 2.0). Post-achievement of Open Defecation-Free (ODF) status, the Ministry of Housing and Urban Affairs (MoHUA) rolled out detailed criteria for cities to reach ODF+, ODF++, and Water+ statuses in May 2020.
Way Forward
India’s water and wastewater treatment market, worth US$4 billion, has been growing at an annual rate of 10-12% pre-COVID-19. Post-pandemic, central and state governments need to collaborate to develop markets for treated water. The country’s economic growth is directly tied with sustainable water use, particularly recycling and reuse, which will be critical in future urban planning and policy. Wastewater could serve as a cost-effective and sustainable source of energy, nutrients, and other by-products like organic and organic-mineral fertilisers. Extracting such resources from wastewater has far-reaching implications on food and energy security, as well as climate change mitigation.
