Recycle and Reuse

Wastewater management trends, requirements and outlook

In light of the dwindling water reserves, the need to manage water resources judiciously has become imperative. In this regard, the concept of recycling and reuse of wastewater has gained traction. Treated wastewater can be reused for agricultural, industrial and other non-potable purposes.

Indian Infrastructure takes a look at the emerging trends, developments, issues in the sector and the outlook for wastewater management in the country…

Notable trends and developments

The government has been instrumental in introducing a number of programmes and schemes for the sector over the past four to five years. Schemes such as the Atal Mission for Rejuvenation and Urban Transformation and the Namami Gange Mission have been designed to help scale up capacities.

Given the limited resources with government agencies and the lack of financial autonomy and capacity at the local level to execute projects, the private sector has an important role to play in the water supply and sewerage sector. Thus, the case for more public-private partnerships in the sector is strong. Further, the evolution of the hybrid annuity model in the sewerage sector has led to a more integrated approach, with greater involvement of the private sector through the one city, one operator model. The government is working towards attracting private investment in the sector to enhance service delivery and reduce fiscal pressures. Flagship programmes such as Namami Gange and the Smart Cities Mission are instrumental in increasing private participation.

Over the years, the use of technology in the management of wastewater services has increased. Urban local bodies (ULBs) are introducing online portals for civic services and deploying advanced treatment technologies for wastewater treatment and automation, and instrumentation tools and solutions for asset monitoring and maintenance. Also, advanced solutions such as supervisory control and data acquisition system (SCADA) and remote sensors are being deployed for monitoring collection, distribution and treatment systems. For example, the upcoming sewage treatment plant (STP) at Okhla will be an integrated plant that will not only treat sewage but will also have a complete sludge management facility. The plant will have the largest ultraviolet disinfectant system in the country for the removal of faecal coliform from water. The plant will be fully automated with a SCADA system. The faecal sludge management plant at Devanahalli uses the biological treatment technology instead of chemicals to treat human waste. The first-of-its-kind town-scale facility successfully handles 100 per cent faecal sludge generated in the town without sanitary workers coming into direct contact with the sludge. Meanwhile, the Pimpri Chinchwad Municipal Corporation has installed a SCADA system at six newly built STPs at Chinchwad Phase II (30 mld of water), Ravet (20 mld), Akurdi (30 mld), Dapodi (20 mld) and Charholi (21 mld). The coverage of the system has been expanded and all old STPs have also been brought under its ambit.

Given the huge amount of investments needed for the acquisition of large tracts of land for setting up centralised systems, a number of projects remain only on paper and actual implementation does not take place. To address this issue, several ULBs have set up decentralised wastewater treatment facilities that use less energy and land, require less by way of operations and maintenance, and have lower construction and operation costs. Cities such as Ambikapur, Jashpur, Leh and Devanahalli have taken up pilot projects and subsequently replicated successful small-scale decentralised systems at a pan-city level for effective wastewater management. Chhattisgarh has set up decentralised treatment systems across its cities in a phased manner as part of the Mission Nirmal City. In Phase I, pilot projects were taken up in Ambikapur, Rajnandgaon and Jashpur and 165 other ULBs in the state to develop small-scale decentralised faecal STPs. These plants were developed using different technologies such as plant-bed, hybrid and reed-bed based on the type of wastewater.

Over the past few years, the concept of recycling and reuse of wastewater has started to gain significance. A number of ULBs have taken initiatives to encourage the use of treated wastewater for various non-potable purposes such as industrial use, gardening, car washing and construction. Regulations and guidelines making wastewater recycling mandatory for bulk users on  new properties have also been formulated. The Delhi Jal Board has developed 36 treatment plants in the city to treat wastewater for non-potable purposes. At present, 420 million gallons per day of treated water is being produced at these wastewater treatment plants (WWTPs). Similarly, the Chennai Metropolitan Water Supply and Sewerage Board supplies 36 mld of treated wastewater to industries. It has also developed two tertiary treatment plants, at Kodungaiyur and Koyambedu, with a combined capacity of treating 90 mld. The Nagpur Municipal Corporation recycles over 90 per cent of its generated sewage and is in the process of increasing the capacity of its WWTPs with the aim of recycling 480 mld. Meanwhile, the Bruhat Bengaluru Mahanagara Palike has made it mandatory for treated wastewater to be used at construction sites in order to conserve groundwater.

The central government has increased its focus on rivers to ensure that untreated sewage is not discharged into them directly. To this end, it is supplementing the efforts of state governments and union territories to address the challenges of pollution of rivers by providing financial and technical assistance through schemes such as the National River Conservation Plan and Namami Gange.

Pain points

The process of wastewater management is marred with a plethora of issues. There are compliance issues for industries with respect to the use of treated water, especially taking into consideration the availability of fresh water at a lower price. A large number of Indian cities and towns have an inadequate sewerage network and insufficient sewage treatment capacity. The majority of treatment plants do not meet their capacity of treating sewage. There is also a lack of a uniform policy for wastewater recycling and reuse in the country and only a handful of states such as Gujarat and Maharashtra have formulated wastewater reuse policies. Moreover, the strict enforcement of these policies is missing.

Setting up of STPs is an expensive process. Funds are not only required for building the STP and treatment process but also for power supply, maintenance and augmentation of sewage collection networks. Advanced wastewater treatment systems that generate better quality of water are even costlier. The availability of treated wastewater does not guarantee increased use, as social and psychological barriers prevent its reuse, including emotional disgust associated with using treated wastewater, low awareness regarding wastewater treatment and lack of trust in implementation agencies.

Poor billing and collection practices have also prevented ULBs in the country from recovering costs sufficiently for the operations and maintenance of infrastructure facilities. Moreover, lower revenue collections have hurt the creditworthiness of many municipal agencies.

The way forward

Rapid urbanisation and steady economic growth are increasing the demand for water, thereby increasing the sewage generated. The demand for water in Tier I and Tier II cities is expected to increase to 110,000-120,000 mld by 2025 and sewage generation is expected to increase to 87,000-97,000 mld by 2025. Given the existing service backlog, delivering acceptable levels of service will require a multi-pronged approach. To this end, ULBs will need to build financial and operational capacity; strict regulations will have to be enforced; and adequate participation from the private sector will be required.

Considering the increased thrust on improving efficiency levels, the use of IT for various aspects of water supply and wastewater management (collection, transportation, treatment, disposal, asset mapping, management and customer service) is expected to increase significantly in the coming years. Given the government’s commitment and support to the development of efficient water supply and waste management infrastructure, the outlook for the sector seems bright.

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