Sikkim’s sewerage system ‘remains underdeveloped by national standards’: report
Sikkim has several attributes. It is India’s only fully organic state, its first Open Defecation Free (ODF) Plus model state and each of its nine urban local bodies is ODF+ certified, with Mangan receiving the ‘Promising Clean City Award’ at the Swachh Survekshan 2024-25.
But new ground-breaking research has revealed what happens to wastewater after it’s flushed away, depicting a state caught between celebrated wins and leaking pipes, with a workforce struggling to cope with the Himalayan problem.
The National Alliance for Faecal Sludge and Septage Management (NFSSM) conducted a study titled “Sunaulo, Samriddha, ani Samarth Sikkim: A Strategic Pathway for Liquid and Used Water Management” as part of its ongoing collaboration with the state’s urban development. The report was released recently during a two-day workshop on sustainable sanitation in Gangtok.
According to the report, only 40% of the population of the state capital Gangtok (100,286) (Census 2011) is connected to the piped sewerage network and depends on septic tanks and catch tanks. Statewide, about 50% of the 11,880 households have any sewer connection at all, meaning three households share one connection point.
The survey states that Sikkim’s sewerage system “remains underdeveloped by national standards”.
Citing the NITI Aayog Urban Wastewater Scenario in India report four years ago, the study said the country treats barely 28% of the 72,368 million liters of urban waste water produced every day. This shows that 72% of India’s wastewater flows untreated into rivers, lakes, groundwater and seas.
The draft rules for liquid waste management by 2024 were introduced in this national context and mandated recycling of at least 20% of treated water (40% for industrial use).
Experts say the rules mean Sikkim will have to rebuild its infrastructure in the hills.
Monsoon obstruction
Adding to Sikkim’s pipeline problem is the weather. In 2023, Namchi district experienced a 242% increase in post-monsoon rainfall, while neighboring districts were almost dry. The state’s cascading, landslide-prone terrain means that treatment plants designed for “average” are routinely overwhelmed during the rainy season and underutilized during the dry season.
Conventional, centralized wastewater treatment plants were not designed to handle such a mismatch, the study says. Given Sikkim’s geography – with 84.4% of its 7.09 hectares forested, the state has about 15% of its land available for agriculture or construction – the report prescribes decentralized sewage treatment plants rather than a large one for the city.
The study cites Uttarakhand, another Himalayan state, which faced similar terrain constraints in dealing with wastewater treatment. Uttarakhand’s treatment capacity has jumped 180% in less than a decade – from 24 plants processing 152.9 million liters per day (MLD) in 2015 to 69 plants processing 428 MLD by 2024.
The report says Uttarakhand has 63 more sewage treatment plants under construction, proving that sustained investment, not just political ambition, can transform sanitation outcomes even in difficult mountainous topography.
Beyond ODF+ status
Apart from the award Sikkim won, about 4.8% households in the state have no latrines. Of those with latrines, 55.68% rely on septic tanks rather than a sewer connection, and 92.12% of households with bathrooms have proper sewerage.
The report states that local municipal bodies in Sikkim lack resources for maintenance and dewatering, especially given the mountainous, scattered population.
The report also highlights Sikkim’s sanitation workers, who are better paid than their counterparts in the northeastern region, but underprotected. They earn a daily wage of ₹524, which is above the revised minimum wage of the state. However, only 33% have PPE kits under the national NAMASTE scheme, while 21.3% of the 394 registered workers hold the PM-JAY Ayushman Bharat Health Insurance Card.
NAMASTE stands for National Action for Mechanized Sanitation Ecosystem. PM-JAY is Pradhan Mantri Jan Arogya Yojana.
The report recommends a dedicated state-level sanitation cell to coordinate across departments; standard operating procedures for dewatering, transport and treatment; and investment in decentralized climate-resilient infrastructure suitable for Sikkim’s slopes and seasons.
These steps could help Sikkim move from a poster state for ODF status to a sanitation blueprint in India’s Himalayan belt from Arunachal Pradesh to Ladakh, the authors say.
Published – 17 Sep 2026 15:36 IST