Beyond Treatment: Why Process Optimisation Will Define India's Next Water Revolution

The water sector in India is at an important juncture. Within the last ten years, tremendous efforts have been made to enhance water infrastructure to provide clean drinking water and to install wastewater systems. Major programs such as the Jal Jeevan Mission, AMRUT 2.0, the Namami Gange program, and the Swachh Bharat Mission have driven investment in the urban and rural water value chain by laying kilometres of pipelines and increasing treatment capacity. Although these investments have ensured a strong base for India’s water security, future progress in this direction depends not on the construction of more treatment plants but on their efficiency..The discourse on water management thus needs to change. The construction of infrastructure has long been seen as the key sign of progress. Yet, without operational efficiency, the benefits of the infrastructure are realised only to a limited extent. The priority should now be to optimise processes, increase treatment efficiency, reduce energy consumption, and treat every litre of water efficiently..India faces a tough task ahead. The Central Pollution Control Board (CPCB) reports that the volume of sewage produced per day in urban India is estimated at 72,368 MLD, while the treatment capacity is estimated at 31,841 MLD. This figure clearly indicates a need for infrastructure development. However, it also reveals an equally critical problem – the existing infrastructure is operating sub-optimally..The issue of water scarcity is yet another reason for the need for optimisation. The annual per capita water availability in India has fallen from over 5,000 cubic metres in 1951 to 1,486 cubic metres in 2021. (Ministry of Jal Shakti, National Water Mission.) Urbanisation, industrialisation, and climate change will place greater pressure in the coming decades. The efficiency of water use will thus be economically necessary and not merely environmentally desirable..In this context, the role of wastewater is becoming increasingly appreciated not as a burden but as a resource. In every litre of treated wastewater lies the promise of contributing to the freshwater supply, supporting industries, and recharging the groundwater table without relying on overworked rivers and lakes. Realising this promise is possible only through treatment plants that provide quality effluents at low cost and high efficiency..This shift in approach is already underway through initiatives by the Government of India. For example, under the 'National Framework on Safe Reuse of Treated Water' (2022), the government has asked states to increase the reuse of treated wastewater across sectors such as agriculture, industry, construction, and urban uses..Nevertheless, for reuse to succeed, much more than just the installation of treatment facilities is needed. The successful performance of the treatment process itself will determine whether the water produced meets the quality required for use in cooling towers, landscape irrigation, construction, and potable purposes..Energy efficiency is one of the biggest opportunities for operational optimisation. Treatment of wastewater is inherently energy-intensive, with aeration accounting for 50-60% of the electricity consumed in standard activated sludge processes. Hence, even modest optimisation of aeration controls, blower efficiency and dissolved oxygen levels can result in considerable reductions in operational costs during the entire lifespan of treatment facilities..This becomes even more relevant keeping in mind India's sustainable development goals. The country has pledged to reach net-zero emissions by 2070 and to reduce its emissions intensity by 45% from its 2005 levels by 2030. Water infrastructure that consumes large amounts of electricity needs to help achieve these goals..Industrial wastewater provides another equally interesting example where process optimisation is highly relevant. The industrial sector operates in an environment of increasing regulation, rising freshwater costs, and heightened demand for sustainable practices. Instead of treating wastewater management as mere compliance, progressive industries are increasingly adopting advanced wastewater treatment processes to recover freshwater and reduce its use..Process optimisation cannot be discussed in terms of mere technological innovation. This includes intelligent plant design, advanced filtration technologies, process control systems, predictive maintenance, online monitoring, skilled operation, and performance benchmarking..In this regard, optimisation is also critical for making water infrastructure more financially sustainable. Municipal water companies usually face budget constraints, making it crucial to ensure that the existing infrastructure provides the maximum possible benefit. Each percentage of savings achieved through improvements in energy efficiency, chemical consumption, and equipment reliability results in lower operational costs and improved services. Over the plant's life cycle, these incremental gains can yield savings far exceeding the initial expenses of optimisation systems..For this reason, the future development of India’s water industry will depend not only on engineering capabilities but also on the ability to achieve operational success. While constructing new infrastructure remains extremely important, making the most of existing infrastructure will also be crucial. The next generation of water plants will be smarter, more efficient and adaptable..As India progresses towards water security, the focus needs to move from mere wastewater treatment to efficient operation of each step in the treatment process. State-of-the-art filtration methods, smart automation, digital monitoring and data-led operations would be the key characteristics of the next-generation water treatment system. Combined, they would allow utilities and businesses to produce higher-quality water while consuming less energy and creating a resilient, circular water economy..This progress has been initiated in India, and the next step is to ensure that all treatment plants, whether municipal or industrial, function not only as infrastructure but also as efficient assets..Filtration, Separation Technologies and Energy Optimisation—Redefining Treatment Efficiency While the initial phase of the water journey in India might be characterised as building treatment infrastructure, the next phase will need to focus on ensuring that each treatment process achieves maximum efficiency. This shift will necessitate a deeper look into what goes on within a treatment plant, not only at the points where wastewater enters and leaves, but also at every point where pollutants are separated, energy is consumed, and decisions affect results..Within every sewage treatment plant (STP) and effluent treatment plant (ETP), there exists a series of processes - physical, chemical, and biological - aimed at removing suspended solids, organic matter, nutrients, and emerging contaminants. Although the treatment trains have worked wonders for the industry for decades, water stress, stringent discharge norms, and increasing demand for water reuse make it necessary for plants to optimise their processes.Optimising Every Stage of TreatmentRarely is the efficiency of treatment plants reliant on a single technology. On the contrary, the efficiency of each step of the process starting from screening to grit removal, clarification, biological, filtration and disinfection determines the efficiency of the whole plant..Primary treatment facilities separate the large solid matter and floatable particles. Secondary biological treatment reduces the organic content of wastewater through microorganisms, whereas tertiary treatment ensures the water is cleaned to meet more stringent reuse and environmental standards..Optimising each process enables increased recovery and lower energy and chemical use, even without expanding physical facilities. Low efficiency of solid-matter separation at primary clarifiers increases the amount of organic content entering biological units and, therefore, the need to use more oxygen..This systems-based approach is becoming increasingly important as municipalities and industries seek to maximise output from existing infrastructure rather than relying solely on new capital investments.Advanced Filtration is Becoming Central to Water ReuseReuse of water is no longer just a goal for the future but rather an immediate necessity.According to the Ministry of Housing and Urban Affairs (MoHUA), India's urban water requirement will nearly double by 2050 due to population growth, urbanisation, and industrialisation.Relying solely on freshwater extraction to meet this increased demand will not be sustainable, either financially or environmentally. Therefore, advanced filtration systems have become essential for producing treated water for use in industries, landscaping, cooling towers, and other non-potable applications..Advanced separation methods are much more efficient than traditional sand filtration at removing suspended solids, pathogens, dissolved substances, and trace pollutants. Among the most widely adopted technologies are:Pressure Sand FiltersActivated Carbon FiltersUltrafiltration (UF)Microfiltration (MF)Nanofiltration (NF)Reverse Osmosis (RO)Membrane Bioreactors (MBRs)Each technology has its own function depending on the influent quality and end-use application..For cities interested in obtaining high-quality reclaimed water, membrane-based systems are rapidly becoming an alternative to traditional tertiary systems because they offer more consistent removal efficiencies and are physically smaller. Membrane technology has now become one of the fastest-growing segments in advanced wastewater treatment because of its ability to produce consistently high-quality reuse water..Membrane Bioreactors: Combining Biology with SeparationOne of the most important developments in wastewater treatment is the use of Membrane Bioreactors (MBR).MBRs consist of activated sludge biological processes together with membrane filtration and do not require a secondary clarifier, providing very high-quality effluent..Compared with traditional activated sludge systems, MBRs offer:Higher biomass concentrationsSmaller land requirementsSuperior pathogen removalLower suspended solids in treated waterImproved suitability for water reuse.While the membrane-based system usually requires greater initial capital expenditure, lifecycle assessment studies indicate that smaller footprints, reduced sludge generation, and greater reusability can ultimately offset these costs. This indicates a shift in the approach to infrastructure construction from the lowest initial cost to the lowest lifecycle cost..Separation Technologies are Unlocking Resource Recovery In the past, wastewater treatment was primarily about pollutant removal. However, contemporary treatment philosophy has changed drastically. Wastewater treatment plants now have the potential to be seen as resource recovery facilities.Advanced separation technologies enable recovery of valuable resources including:PhosphorusNitrogenIndustrial saltsProcess chemicalsOrganic matter for biogas generation.Enhanced resource recovery in wastewater treatment plants is a great way to cut greenhouse gas emissions while reducing costs. In modern times, rather than viewing sludge as waste, treatment plants use it to create energy via anaerobic digestion. Also, chemical recovery in industries has been done to improve the environmental performance and economic value of the process. The shift from waste treatment to resource recovery is one of the most transformative paradigms in the global water industry..Energy: The Largest Controllable CostEnergy is the biggest cost of operation for most wastewater treatment plants.Several international scientific studies indicate that electricity accounts for 25-40% of the operating costs of municipal wastewater treatment plants, depending on plant characteristics and energy costs. During water treatment, aeration is the largest energy consumer.Scientific investigations suggest that aeration alone accounts for about 50-60% of the total electricity consumption in the activated sludge water treatment process. Therefore, optimisation strategies increasingly focus on improving oxygen transfer efficiency rather than simply increasing blower capacity.With Variable Frequency Drives (VFDs), smart blower controls, and oxygen concentration sensors, treatment plants can add oxygen only where and when needed, rather than running at a constant load. This leads to energy savings without affecting treatment efficiency..Chemical Optimisation Matters TooHowever, while energy seems to get all the attention, there are many opportunities for chemical optimisation. Overdosing coagulants, disinfectants, and pH adjustment chemicals not only increases operational costs but also produces extra sludge that needs to be disposed of. Dosing systems nowadays use online sensors that continuously measure turbidity, conductivity, pH, and oxidation-reduction potential..This means that instead of manual dosing, the dosing rate varies with the influent. This approach delivers multiple benefits:Reduced chemical consumptionImproved process consistencyLower sludge generationEnhanced complianceReduced operating costsThe principle is simple apply only what the process requires, when it requires it..Designing Plants for Operational ExcellenceEquipment accessibility, instrumentation placement, maintenance planning, redundancy philosophy and automation architecture are no longer secondary considerations—they directly influence lifecycle performance. Traditionally, treatment facilities were engineered with an eye on hydraulic capacity and compliance requirements. Modern-day treatment facilities need to balance the same with operational flexibility. The plant should be able to handle seasonality, changing pollution levels, industrial discharges, and any future reuse applications without requiring major changes to the design..Such optimisation can only be achieved through the collaborative efforts of engineers, technology suppliers and operations teams from the very start of the design process. Instrumentation, access, maintenance schedules, redundancy concepts and automation architecture are no longer secondary issues but are fundamental to achieving performance during decade-long lifetimes. It is for this reason that tomorrow's treatment infrastructure needs not just engineering skill but also the ability to create systems that can efficiently and flexibly serve the community over decades of use.Process optimisation starts with engineering skills but finds value through continuous optimisation using operational data and advanced treatment technologies. It is through such process optimisation that India's water infrastructure can become more efficient and reliable in the coming years..How Digitalisation and Operational Excellence are Transforming STPs and ETPsWhile advanced filtration and separation technologies form the backbone of modern treatment systems, the true differentiator in today's water sector lies in how intelligently these systems are operated. Across the world, wastewater treatment is transitioning from a largely mechanical process to a digitally enabled ecosystem in which data, automation, and predictive intelligence drive operational decisions. In India, where utilities and industries must maximise the performance of existing assets while operating under financial and resource constraints, digital transformation has become indispensable..The next generation of sewage treatment plants (STPs) and effluent treatment plants (ETPs) will not simply treat wastewater—they will continuously analyse, learn and optimise their own performance. This evolution is enabling operators to reduce energy consumption, improve treatment efficiency, minimise downtime and extend the lifecycle of critical assets..From Reactive Operations to Predictive ManagementTraditionally, treatment plants have relied on periodic manual sampling and operator intervention. Though this process has been quite effective to some extent, it tends to detect deviations only after performance has worsened, leading to increased energy waste or excessive chemical use, not to mention failing to meet discharge requirements. The current treatment plants are being fitted with sensors that can monitor various factors including flow rate, dissolved oxygen (DO), pH value, oxidation reduction potential (ORP), turbidity, ammonia, nitrates and sludge blankets among other variables. These measurements provide operators with real-time visibility into plant performance, allowing corrective actions before issues escalate..According to Markets and Markets, the global smart water management market is projected to reach USD 31.6 billion by 2029, driven by increasing adoption of IoT, artificial intelligence, and digital water technologies. Although global in nature, this trend is particularly relevant for India as municipalities modernise ageing infrastructure and industries seek greater operational efficiency..SCADA: The Digital Backbone of Modern Treatment PlantsOne of the key facilitators of operational excellence is the prevalence of SCADA (Supervisory Control and Data Acquisition) systems. SCADA combines sensors, programmable logic controllers (PLCs), and centralised software applications, giving the operator an overview of plant performance through a single interface. Plant operators do not need to walk around the site manually checking the status of their equipment, pumps, blowers, chemicals and filtration systems. They can set up alarms to alert them to any changes in the process when certain parameters exceed predefined limits, which significantly reduces response time and minimises disruptions to operations..The International Water Association (IWA) identifies digital monitoring and SCADA integration as one of the most effective approaches for improving energy efficiency, reducing non-revenue water and enhancing treatment reliability.For municipal authorities operating multiple treatment facilities, SCADA also enables centralised supervision, allowing geographically dispersed assets to be monitored from a unified control centre. This not only improves operational consistency but also facilitates benchmarking between plants, helping identify best-performing assets and opportunities for optimisation.Artificial Intelligence: Optimising Processes in Real Time No longer is AI limited to experimental research and laboratory testing. Instead, AI is becoming an operational tool that will help treatment plant operators make quicker and better-informed decisions. Unlike conventional automation systems, AI analyses historical operating data alongside real-time process information to identify patterns that may not be immediately apparent to human operators. Machine learning algorithms continuously refine operational models, enabling treatment systems to adapt to changing influent characteristics, seasonal variations and fluctuating hydraulic loads..For instance, artificial intelligence may optimise dissolved oxygen concentration control by regulating the aeration rate based on the organic load, rather than using a constant aeration rate. This is because aeration is the largest energy consumer in the activated sludge process.Recent studies have demonstrated that AI-assisted aeration optimisation can reduce energy consumption by 20–35% while maintaining or improving effluent quality. Beyond aeration, AI is increasingly being applied to optimise chemical dosing, sludge management, nutrient removal and membrane cleaning schedules, improving both operational efficiency and regulatory compliance.Digital Twins: Simulating Performance Before Problems OccurA second emerging technology transforming water infrastructure is the concept of Digital Twins. A digital twin is a computerised, dynamic model of a physical treatment plant that continuously receives real-time data from sensors deployed throughout the plant. Using a digital twin allows engineers to test process changes, operational possibilities, and future performance without disrupting operations..Using a digital twin, utilities can assess how their treatment systems will behave under higher inflows during monsoons, how performance will be affected after equipment replacement, or whether new regulatory discharge standards apply. This way, operators do not have to base their decisions purely on past experiences but rather on simulations and predictions..Globally, digital twins are increasingly adopted by utilities seeking to optimise asset lifecycle management and improve infrastructure resilience. Their relevance is expected to grow significantly as Indian cities invest in smart urban infrastructure under initiatives such as the Smart Cities Mission and AMRUT 2.0.Predictive Maintenance: Extending Asset LifeMaintenance has been carried out using either reactive or preventive strategies. Reactive maintenance involves the maintenance of equipment after failure, usually causing expensive downtimes. Preventive maintenance involves maintaining equipment according to a schedule that is not based on its condition, sometimes leading to unnecessary servicing..Data Analytics: Turning Information into ActionEach modern treatment facility creates millions of data points annually from its operations. It is not a matter of collecting data anymore but using the collected information for making informed decisions. Key Performance Indicators (KPIs) increasingly monitored include:Energy consumed per cubic metre of wastewater treatedChemical consumption per MLDSludge generation ratesEquipment availabilitySpecific oxygen uptake ratesMembrane permeabilityTreated water recovery percentages.Modern analytics software allows comparing the performance of different facilities, finding bottlenecks in the process, calculating energy intensity and evaluating equipment efficiency. These metrics provide management teams with objective measures of operational performance, enabling continuous improvement rather than periodic intervention..Cybersecurity: Protecting Critical Water InfrastructureWith greater connectivity of treatment facilities, cybersecurity has become an important element of operational resilience.While SCADA networks, cloud-based monitoring software, and remote-control capabilities have increased operational efficiency for utilities, they have also created new opportunities for cyber threats.It is therefore no surprise that utilities are adopting secure network infrastructure, two-factor authentication, encryption, and threat monitoring alongside their digitalisation efforts.Digitalisation thus needs to go hand in hand with strong governance mechanisms that ensure operational resilience amid technology adoption. .Technology Alone is Not EnoughThough digital solutions play a vital role in improving the performance of treatment units, technology alone cannot ensure operational excellence.The most efficient treatment units result from a combination of technology, skilled operators, a proper maintenance schedule, and continuous improvement..Operator training, benchmarking, preventive inspection and process audit form an integral part of the optimisation process. Operational excellence can only be attained not by relying on technological improvements alone, but by combining engineering skills with digital solutions and plant operations..Ultimately, the future of India's water sector will depend on how effectively utilities and industries harness digital technologies to maximise the value of every treatment asset. Intelligent infrastructure is no longer a futuristic concept; it is rapidly becoming the foundation of resilient, efficient and sustainable water management. As India moves towards greater water reuse and resource efficiency, digitalisation will be instrumental in transforming treatment plants into adaptive systems capable of delivering superior environmental, operational and economic outcomes..Building a Circular Water Economy Through Process OptimisationWith India entering a new era of growth, water will continue to play an increasingly prominent role in dictating the tempo and sustainability of development. As cities grow, industrial clusters emerge, and as climate uncertainties loom, the way in which governments, corporations, and citizens understand water resources is changing. In this context, wastewater can no longer be considered an output to be discharged; rather, it should be treated as a strategic resource with the potential to improve India's water security..This shift in perspective marks the transition from a linear "use-and-discharge" model to a circular water economy; one where every drop is treated, recovered, reused and reintegrated into the economic cycle. However, achieving this transformation requires far more than additional treatment capacity. It demands process optimisation at every stage of the treatment lifecycle..India's water resources are facing unprecedented stress. According to the National Water Mission, per capita water availability in India has fallen from 5,177 cubic meters per year in 1951 to about 1,486 cubic meters per year in 2021, categorising India as a water-stressed country. At the same time, the amount of wastewater produced by urban areas is increasing..As per the data of Central Pollution Control Board (CPCB), the amount of sewage generated in India's cities is approximately 72,368 MLD, while the amount of sewage treatment plant (STP) capacity is much lower at 31,841 MLD..These figures highlight two parallel opportunities:The first is to continue expanding treatment infrastructure where gaps exist.The second and arguably more transformative is to maximise the efficiency and performance of every treatment asset already in operation.Every additional percentage point of treatment efficiency translates into thousands of litres of reusable water every day.For water-scarce urban centres, this represents an opportunity to diversify supply sources while reducing dependence on freshwater reservoirs and groundwater extraction..The Economics of Optimisation Historically, discussions around water infrastructure have focused primarily on capital expenditure. Yet, over the lifespan of a treatment plant, operational expenditure often exceeds initial construction costs. Energy costs, chemicals, manpower, maintenance, sludge treatment, and equipment replacement make up the largest share of lifecycle costs..Consequently, improving operational efficiency by even a modest margin can generate significant long-term savings. For instance, blower optimisation, enhanced oxygen-transfer efficiency, and predictive maintenance result in lower energy bills and increased equipment longevity. In addition, advanced process control systems help decrease unnecessary chemical dosing and minimise sludge generation..Viewed collectively, these improvements enhance not only environmental performance but also the financial sustainability of treatment infrastructure. Thus, instead of considering the cheapest way to build treatment plants, we should focus on making them work in the most economically efficient way possible.Water Reuse Will Become a Strategic Business ImperativeFrom power generation to the steel industry, from the pharma sector to the food processing industry, and from textiles and chemicals, all industries have begun to feel the pinch of reduced freshwater availability..While water was previously seen only in terms of regulatory compliance, it is now a matter of operational and continuity issues. In recognition of this, the Government of India launched the National Framework for Safe Reuse of Treated Water (2022), urging states to maximise the productive use of wastewater..This policy direction reflects a broader understanding that wastewater reuse strengthens water resilience while reducing stress on rivers, lakes and groundwater resources. However, successful reuse depends upon consistently producing treated water that meets stringent quality standards. That consistency can only be achieved through robust process optimisation supported by advanced treatment technologies and disciplined operational management..Public-Private Partnerships Can Accelerate TransformationThe past decade in India has been one in which success has been achieved through a combination of public investment and the expertise and competence of the private sector.Examples like the Hybrid Annuity Model (HAM) in projects run by the National Mission for Clean Ganga (NMCG) have emphasised plant performance over mere construction..Unlike conventional engineering contracts, HAM projects link payments to operational outcomes over extended periods, encouraging contractors to optimise design, improve reliability and reduce lifecycle costs.This shift from asset creation to asset performance represents an important evolution in India's infrastructure philosophy.It encourages innovation, promotes accountability, and ensures that treatment plants continue to deliver value long after commissioning..Measuring Success Beyond Installed CapacityFor many years, the amount of treatment capacity in MLD has been the key factor for determining success. While capacity remains important, future success should increasingly be evaluated through operational performance indicators such as:Percentage of safe treatment of wastewaterPercentage of water treated being recycledEnergy used per cubic metre of treatmentAvailability of equipmentDischarge qualityCarbon footprint per unit of treatmentOperating costs on a life cycle basisResource recovery rate.These indicators provide a far more comprehensive assessment of infrastructure performance than capacity alone.Ultimately, the objective is not merely to build treatment plants but to ensure they consistently deliver environmental, economic and social value throughout their operational lives..Sustainability is Now an Engineering DisciplineSustainability is typically defined in terms of policy statements or in corporate ESG aspirations. However, sustainability increasingly depends on engineering decisions made every day in wastewater treatment plants.Pump efficiencySensor calibration for dissolved oxygenOptimisation of the membrane cleaning processTiming of preventive maintenanceImplementation of real-time monitoring.Every one of these engineering decisions affects energy use, greenhouse gas emissions, operating costs, and even the quality of treated water. Engineering excellence therefore becomes the practical expression of sustainability. If it is backed by digital technology, advanced filtering techniques, and trained operators, a treatment plant transforms from merely a compliance-oriented facility into an important strategic asset that ensures national water security..Looking AheadIndia has already shown what it can do when it comes to building water infrastructure on an enormous scale. The next challenge is ensuring that this infrastructure consistently performs to its full potential. Climate variability, population growth, industrial expansion and increasing environmental expectations will continue placing pressure on finite water resources. Meeting these challenges requires a fundamental shift in mindset..The future will belong to utilities and industries that optimise rather than merely operate, who plan rather than respond to situations, who recover resources rather than simply dispose of them, and whose facilities improve through continual engineering and technological progress..Membrane technologies are becoming more advanced, increasing water recovery; AI improves process efficiency; digital twin enables predictive decision-making; SCADA provides real-time visibility into facility operations; predictive maintenance prolongs equipment lifespan; and resource recovery technologies turn waste into valuable products. Thus, the opportunity now lies in integrating these capabilities into a cohesive operational philosophy..India's water narrative is about to move into an exciting new chapter. The efforts of the past ten years have built a robust platform to ensure better access to water, manage wastewater, and protect the environment. However, infrastructure will not guarantee India's water future..The next phase of water efficiency will be achieved through the smart design, operation and optimisation of these facilities.Process optimisation is no longer a technological upgrade; it is a strategic necessity. By harnessing cutting-edge filtration solutions, intelligent separation technologies, digital monitoring, predictive analytics and process efficiency, India can increase treatment efficiency while decreasing energy consumption and operational costs and increasing the potential for water recycling..As engineers, policymakers and industry professionals, we are responsible for more than just building water treatment facilities. We are responsible for building a system that remains efficient, resilient and flexible over its entire lifetime. Only then will wastewater become a resource, infrastructure a tool for sustainability, and water treatment plants engines of a circular water economy.About the AuthorMr. Manish Jain is a leader in the Wastewater Treatment industry with over 27 years of experience. A Chemical Engineering graduate from Punjab University, he excels in managing large-scale projects and optimizing resources for efficiency. His expertise includes end-to-end project execution and compliance with regulatory frameworks, resulting in improved profitability and sustainable growth for Enviro Infra Engineering Limited. As a hands-on leader, Mr. Manish aligns business goals with operational excellence, committing to innovation and sustainability in the rapidly evolving wastewater sector.