Freshwater is a precious resource that we are rapidly running out of. While millions have no access to safe drinking water in India, agriculture is also hit. Cultivation of staple crops such as rice and wheat is under stress as groundwater levels across the country are plunging. But the greatest danger is perhaps posed to the manufacturing industry in India, which is dependent on water for numerous processes. When drought regulations come in, industries would be the first to be deprived of freshwater. This poses a danger, especially to water-guzzling industries such as textiles. But as witnessed very often, scarcity is driving innovation. Gujarat, one of the most industrialized states in the country, is showing the way.
One of the earliest industrial clusters in the country came up in Surat, Gujarat, owing to the Tapi river, the sole source of fresh water for the city. Due to Surat's proximity to the Arabian Sea, the groundwater is saline, rendering it unsuitable for many domestic and industrial applications.
As Surat expanded in the 1980s, the Pandesara industrial area was subsumed under the Surat Municipal Corporation (SMC) in 1986. Pandesara's industrial units (about 90-100 textile processing businesses) were mostly water-intensive. In 1999, Mr Jitendrabhai Vakharia, an industrialist—currently the President of South Gujarat Textile Processors Association (SGTPA)—along with Mr S Jagdeesan, the then SMC commissioner, entered a strategic alliance for the supply of fresh water to the industries; it not only generated revenue for SMC but also solved the problem of high TDS (Total Dissolved Solids) due to groundwater use.
But the SMC and SGTPA were always aware that the authorities would have to prioritise domestic water supply as Surat grew in population and area, so there was a need of a permanent and reliable solution for uninterrupted supply of water to the industries. The water supply constraint became grave in 2010-11. At this time, SMC used to drain more than 600 MLD (Million Litres per Day) of treated sewage water into the Arabian Sea.
Mr Eliyas Khan Pathan, an Executive Engineer at SMC's Drainage Department, took up the challenge of creating a unique solution in association with Pandesara Green Environment and Water Welfare Cooperative Society Ltd. (PAGREW). "The idea to utilize municipal sewage water as an input to industries was bold at that time, as we were the first municipal corporation in the country that would try and achieve it. Several meetings were held between multiple stakeholders to decide the way forward," says Mr Pathan.
It was decided that a new Tertiary Treatment facility would be constructed at Bamroli-Vadod STP to supply treated municipal sewage water to the Pandesara cluster as Industrial Grade water. After several attempts and under the able guidance of Ms S. Aparna and Shri M K Das (SMC Commissioners in 2007-2011 and 2011-2014 respectively), a regular supply of tertiary treated recycled water (approximately 30-40 MLD) was achieved.
The cost of the new plant and auxiliary infrastructure amounted to about Rs 85 crores. The Government of Gujarat had sanctioned this amount to SMC under Swarnim Jayanti Mukhya Mantri Shaheri Vikas Yojana - a program implemented by the Government of Gujarat to build infrastructure for urban mobility, healthcare, sanitation, affordable housing, etc. The facility was commissioned in February 2014.
In August 2014, SMC began supplying treated domestic sewage water to industries in the Pandesara cluster at Rs 18.20 per Kilolitre. This has gradually gone up to Rs 28.58 per Kilolitre, currently (March 2021). For this new system, SMC has made some necessary changes in the existing pipeline network to cater potable water supply of about 5-10 MLD for Industrial Employees and workers, etc.
Many processing units are forced to rely on groundwater (with high TDS) whenever water supply is hit, further posing challenges for the Common Effluent Treatment Plant (CETP) at Pandesara. "The usage of groundwater is restricted; however, there are instances when we face an upshoot in the TDS of the input water to the tune of 5000-8000, which is much higher than the inlet norms of CETP," says Ms Ankita Jain, CEO of the Pandesara CETP.
Even though some kinks need to be ironed out, the Surat Model is a win-win situation. SMC earns revenue of about Rs 140 crores per year by selling treated sewage water to the industry. In Surat, about 200 MLD of treated water is reused as non-potable water in various industrial clusters, landscaping at STPs, and sprinkling at Municipal Solid Waste disposal sites. An additional 550 MLD could be supplied to industrial areas such as Hazira and Palsana by augmenting capacity if some ongoing discussions fructify.
Ahmedabad, another leading industrial city in Gujarat, is about to adopt a similar model. The World Bank has recently sanctioned a loan of Rs 3000 Crores for Ahmedabad Municipal Corporation (AMC), earmarked for infrastructure development, including the up-gradation of 3 of its 11 STPs. AMC treats about 1300 MLD sewage. After upgrading the three STPs (for tertiary treatment), AMC will supply about 120 MLD of treated sewage water to the industrial clusters in Ahmedabad.
Reusing treated municipal wastewater is a great way to conserve freshwater. But all stakeholders must contribute to the fight against the water crisis and environmental pollution. Wastewater reuse must be augmented with other relevant interventions such as technology up-gradation in processing mills, waterless dyeing techniques, etc., to reduce the water footprint of the Indian industry, especially textiles. As freshwater demand grows and supplies shrinks, continuous innovation is needed to sustain industrial growth.
The "Surat Model" was borne out of necessities as well as proactive collaboration and decision-making between the government and industry. Several social and cultural barriers around wastewater reuse remain still, but the stark necessity may soon force governments and municipalities around the world to seriously consider more uses of sewage as well as industrial wastewater.
"Next time you visit us, we might as well greet you with a glass of recycled sewage, treated and tested to the highest standards", adds Mr Pathan with a chuckle, raising his eyes briefly from the steady flow of paperwork in front of him.
Travel and interviews for this article was sponsored by The Refashion Hub. The author thanks the Surat Municipal Corporation and South Gujarat Textile Processors Association for their valuable inputs.