Kolkata: India has sent spacecraft to the Moon, is preparing for deeper journeys into space and is rapidly embracing artificial intelligence and advanced technology. Yet, for decades, it struggled to answer a painfully basic question: why should a human being still have to enter a sewer or septic tank to clean someone else’s waste?
For a manual scavenger, the cost is not limited to the moment spent inside a drain or septic tank. It can break the body, destroy confidence, close future opportunities and push an entire family into generational poverty and stigma.
At Durgapur, however, science is now trying to change that story.
The Central Mechanical Engineering Research Institute (CSIR-CMERI), one of the country’s premier mechanical engineering R&D institutions under the Council of Scientific and Industrial Research, has been developing mechanised solutions that could finally make human entry into hazardous sanitation work unnecessary. Its Durgapur campus has also begun training Sewer and Septic Tank Workers (SSWs) to safely operate modern sanitation equipment.
The need could hardly be more urgent.
Manual scavenging has been prohibited in India since 1993 and was comprehensively outlawed under the Prohibition of Employment as Manual Scavengers and their Rehabilitation Act, 2013. The practice also violates the constitutional promise of dignity under Article 21 and is inseparable from the abolition of untouchability under Article 17.
Yet it has not disappeared.
Manual Scavenging Remains Despite India’s Ban and Rehabilitation Laws
According to a PIB reply to Rajya Sabha Unstarred Question No. 3021, answered on March 13, 2026, 58,098 manual scavengers were identified through the government surveys conducted in 2013 and 2018. Uttar Pradesh accounted for 32,473 and West Bengal for 680. The government says 729 of 766 districts have declared themselves manual-scavenging free after the two surveys.
But these figures remain deeply contested. Safai Karmachari Andolan has estimated that around 7.7 lakh manual scavengers continue to exist in India.
The human cost is even more disturbing.
In March 2023, then Minister of State for Social Justice and Empowerment Ramdas Athawale told the Lok Sabha that 1,035 people had died while undertaking hazardous sewer and septic-tank cleaning since 1993. Safai Karmachari Andolan puts the figure at 1,760. In another recent written reply, Athawale said 332 sanitation workers died across 18 States and Union Territories between January 1, 2021 and June 30, 2026.
These are not merely statistics. Behind every number is a family that lost a breadwinner.
Exposure to human waste, biological hazards and poisonous gases such as hydrogen sulphide can lead to hepatitis, tetanus, cholera, asphyxiation and death. Many workers are contractual or daily-wage workers, often without adequate social security, job security or proper safety equipment. Women face an additional burden of caste and gender discrimination.
This is where technology matters—not as a symbol of scientific achievement, but as a possible lifeline.
CMERI’s Mechanised Machines Could Replace Human Entry Into Sewers
CSIR-CMERI has developed several mechanised sanitation solutions, including a mechanised septic-tank cleaning machine, electric drain-cleaning equipment and a recycling-based drain-cleaning system. Its mechanised septic-tank machine weighs about 1,265 kg, has a 500-litre water storage capacity and can clean at speeds of up to 600 litres per hour.
The question, therefore, is no longer whether machines are possible. It is whether they can be taken out of laboratories and made available wherever workers are still being forced to risk their lives.
CMERI has already conducted field trials of its mechanised drain-cleaning system at the Durgapur Steel Plant’s Water Treatment Plant clarifier slurry line and the DVC, DTPS Colony, third-unit sewage treatment line. Both the Steel Authority of India Limited’s Durgapur Steel Plant and Damodar Valley Corporation acknowledged the machine’s efficiency.
For workers, the promise is deeply personal.
After receiving safety training, Subhash Chandra Dhara, a semi-skilled operator at the Durgapur Municipality sewage treatment plant, says he is hopeful that technology will change the nature of his work. Samiron Mullick, an independent sewage cleaner from Narayanpur, and Sadhana Ruidas, who works under the 100-day employment guarantee scheme, similarly hope that machines will mean they are no longer asked to manually clean someone else’s waste.
Their expectation is simple: if technology can do the dangerous work, let technology do it.
Can CMERI Technology Finally Make Sewer Cleaning Safe for Workers?
On September 3, CSIR-CMERI inaugurated a 30-hour Occupational Safety Training programme for SSWs from Durgapur, Asansol and Burdwan. Conducted in batches of up to 45 workers under Pradhan Mantri Kaushal Vikas Yojana guidelines, the programme covers toxic-gas exposure, confined spaces, biological hazards, PPE and the safe operation of desludging equipment. Workers completing at least 70 per cent attendance receive a certificate and a ₹1,000 stipend.
Inaugurating the programme, West Bengal Urban Development and Municipal Affairs Minister Agnimitra Paul said an ID card would not merely provide workers with an identity but would be “a symbol of recognition and respect” for their work. She said the government’s objective was to completely eliminate manual scavenging and create a safe, dignified and mechanised working environment. The state plans to prepare a database of 60,630 SSWs, while awareness programmes have already begun across 124 municipalities and municipal corporations and three cantonment boards.
When the minister assured workers of PPE kits, Prabhat Kumar Singh, Managing Director of the National Safai Karmacharis Finance & Development Corporation, said Safai Karmis could obtain ₹2 lakh insurance coverage through two major government social-security schemes.
The Supreme Court has already made the direction clear. In Dr Balaram Singh vs Union of India (2023), it stressed complete mechanisation of sewer cleaning and prohibited human entry except in exceptional circumstances with appropriate protective measures. It also emphasised rehabilitation, compensation for sewer deaths and linking workers to social-security schemes, along with a central mechanism to track deaths and benefits.
CMERI now wants to bridge the distance between scientific laboratories and the people who need the technology most.
Its Director, Dr NC Murmu, said the centre would bridge the gap between laboratory research and field implementation by providing facilities for innovators, industries, start-ups and government agencies to develop and deploy practical, sustainable and indigenous sanitation solutions. The effort, he said, would support safer sanitation workers and cleaner cities while advancing SDG 6 on clean water and sanitation and SDG 8 on decent work.
For India, this should be more than another technological success story.
A country capable of sending missions to the Moon should not accept the death of a sanitation worker as an occupational hazard.
The real measure of scientific progress is not only how far a nation can travel into space. It is also whether the person cleaning the sewage beneath its cities can return home alive.
If machines like those developed at CMERI can finally replace human entry into sewers and septic tanks, they will do something far more meaningful than merely modernise sanitation.
