India is facing challenges in the effective treatment of sewage generated in its cities and the efficient operation and maintenance (O&M) of its sewage treatment plants (STPs). Currently, a mere 30 per cent of wastewater generated in India undergoes treatment. The O&M aspect of these STPs is not considered a lucrative revenue stream for operators. However, a gradual shift is being witnessed in this approach, given the increasing opportunities in the sale of treated water. A circular economy is being developed for the recovery and reuse of wastewater, which is being recognised as “used water” instead.
Government programmes such as the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) 2.0 aim to augment wastewater treatment capacity and create new avenues for improving wastewater treatment technologies. Several key elements are necessary to ensure the success of these efforts, including conducive policies, better planning, a suitable financial model, appropriate technology and effective operational management.
Key trends in the O&M of STPs
Shift towards energy efficiency, resource recovery and circular economy
The government is making efforts to reinvent the approach to effective wastewater management. At present, the surplus wastewater generated in India is reused in hydrothermal plants, horticulture and agriculture while the remaining is discharged. This approach is being reversed by assessing the market demand for wastewater before planning, designing and constructing STPs. State governments are mandated to treat their wastewater for reuse purposes under AMRUT 2.0. In line with this initiative, the Uttar Pradesh, Gujarat and Kerala governments are planning to construct dedicated water networks to supply treated wastewater in their cities. This innovative approach would compel cities with large industrial footprints, such as Kanpur, to predetermine the appropriate technology for the O&M of STPs along with the required quantity of treated wastewater.
Another critical component of O&M is the energy efficiency of STPs, which can be ensured during the water treatment process through aeration. Optimisation of secondary treatment alone can help achieve around 30 per cent of energy efficiency. Moreover, the conversion of waste to energy is being undertaken through the extraction of biogas from sludge at new and upcoming STPs, creating a potential to fulfil 40-70 per cent of the plants’ energy requirements. Additionally, minerals like nitrogen and phosphorus can be recovered from bio-solids for sale as fertilisers. However, the understanding of sludge disposal is in its nascent stage in India, with no existing standards established yet.
Digitalisation and automation
The adoption of the Industry 4.0 model is gaining traction in new STPs to improve their overall efficiency and operations. The model is adopted in three phases — digital adoption, digitalisation and digital transformation. Currently, India is in the first phase as many STPs are still adopting specific technologies for specific operations. The second phase involves the digitalisation of the entire wastewater management process and its infrastructure, while the third phase focuses on the digitalisation of customer-centric services. This model enables data-driven decision-making with the use of several technologies. For instance, internet of things (IoT)-enabled devices are used to collect real-time data for STP functions related to influent and effluent quality metrics, chemical dosing, energy needs, etc. In addition, artificial intelligence and machine learning are employed for preventive maintenance to avoid failures and reduce repair costs. Moreover, digital systems like Programmable Logic Control System enhance energy generation from sludge by 20-30 per cent. Similarly, automation techniques such as the use of aeration blowers with variable frequency drives can reduce energy requirements for aerobic process-based plants.
Shift in the O&M governance paradigm
A gradual shift is under way in the governance of O&M of STPs in India through various measures. One such measure is the extension of the concession period for O&M projects, increasing it to 25-30 years from the shorter periods previously. This extension aims to enhance private sector accountability, ensuring better project efficiency as private players by avoiding recurring maintenance costs. The implementation of the “One City One Operator” model would encourage private operators to undertake more projects and ensure their timely completion. Further, state governments like Odisha are increasingly exploring a mix of both decentralised and centralised sewage treatment systems. Decentralised and smaller fecal sludge treatment plants (FSTPs) are being taken up for comprehensive coverage and simpler O&M practices. Several plants with a capacity to treat 1-5 million litres of sludge per day are coming up in India. However, there are no clear standards for the O&M of FSTPs as of now.
Evolving skill set requirements
The integration of digital technologies in the water sector has been relatively sluggish due to a lack of requisite skills to use or manage them. Water utilities do not have trained staff capable of working with technologies like IoT and digital twin. In order to increase digital adoption, STP operators need to be proficient in real-time data analysis and interpretations. They have to be adept at troubleshoot problems related to digital intervention. Therefore, the state governments are now requesting private developers to incorporate the upskilling of operators in their project contracts, with skill development becoming a key performance indicator. Moreover, lifelong learning modules that equip plant operators with new technologies are gaining traction among private service providers.
Key challenges and the way forward
The sector faces several issues in the successful operational management of STPs. These include high operational costs and energy consumption, and inefficient plant management. Currently, the cost of O&M of STPs significantly exceeds their capital costs. O&M costs include the cost of consumed energy, chemicals for treatment, manpower and repair costs, which vary based on the capacity and complexity of the project. Among these, the cost of energy required to run the plants constitutes 40-70 per cent of operational costs. Further, the complexity of plant management is compounded by the lack of experience of operators, resulting in human errors. This leads to additional costs. Another important operational challenge is the procurement of appropriate technology by the government. For instance, many technology start-ups in the sector do not meet the requirements for procurement, limiting their entry into the market.
Addressing these challenges entails exploring various possibilities. These include pool financing to provide consistent O&M and technical support and guidance, a multi-stakeholder platform to improve collaboration and facilitate knowledge and experience sharing, and preparation of annual maintenance contract documents for standardisation of the scope and expectation of operators. While the National Green Tribunal has enforced penalties for non-compliance with standards for treated and discharged sewage, stricter monitoring and inspection are required. Furthermore, there is a need to establish a market-oriented business model for the reuse of wastewater, which ensures stable revenue and promotes innovative technologies. w
Based on a presentation and remarks by Kumar Saket, Technical Director, Government and Public Services Advisory, KPMG, at a recent India Infrastructure conference
