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 certified ODF+, with Mangan bagging the ‘Promising Clean City Award’ at the Swachh Survekshan 2024-25.

However, a new baseline survey has revealed what happens to wastewater after it is flushed, portraying a State caught between celebrated wins and leaking pipes, with a workforce struggling to cope with a Himalayan problem.

The National Faecal Sludge and Septage Management (NFSSM) Alliance conducted the study titled ‘Sunaulo, Samriddha, ani Samarth Sikkim: Strategic Pathways for Liquid and Used Water Management Report’ as part of its ongoing engagement with the State’s Urban Development. The report was released during a two-day workshop on sustainable sanitation in Gangtok recently.

According to the report, only 40% of the State capital Gangtok’s population of 100,286 (Census 2011), dependent on septic tanks and holding tanks, is connected to a piped sewerage network. Across the State, about 50% of the 11,880 households have any sewer connection at all, indicating three households share a single connection point.

The survey notes that Sikkim’s sewerage system “remains underdeveloped compared to national benchmarks”.

Citing NITI Aayog’s Urban Wastewater Scenario in India report four years ago, the study says that the country treats barely 28% of the 72,368 million litres of urban used water generated every day. This indicates that 72% of India’s sewage flows untreated into rivers, lakes, groundwater, and the seas.

The Draft Liquid Waste Management Rules 2024 were introduced against this national backdrop, mandating the recycling of at least 20% of treated water (40% for industrial use).

Experts say the rules mean Sikkim will have to rebuild its hill-town infrastructure.

Monsoon hurdle

The weather adds to Sikkim’s pipe problem. In 2023, Namchi district recorded a 242% spike in post-monsoon rainfall while neighbouring districts ran almost dry. The State’s cascaded, landslide-prone terrain means treatment plants designed for “average” are routinely overwhelmed in the wet season and underused during dry spells.

The study says conventional, centralised sewage plants were not designed to handle such a mismatch. Given Sikkim’s geography—with 84.4% of its 7.09 hectares under forest, the State has about 15% of land available for farming or building—the report prescribes decentralised, terrain-hugging treatment plants, not a huge one per town.

The study cites Uttarakhand, another Himalayan State that faced similar terrain constraints while dealing with wastewater treatment. Uttarakhand’s treatment capacity jumped by 180% in less than a decade—from 24 plants treating 152.9 million litres per day (MLD) in 2015 to 69 plants treating 428 MLD by 2024.

The report says Uttarakhand has 63 more sewage treatment plants in the pipeline, proving that sustained investment, not just policy ambition, can transform sanitation outcomes even in difficult mountain topography.

Behind ODF+ status

Beyond the awards Sikkim has won, about 4.8% of households in the State do not have any latrines. Of those with latrines, 55.68% rely on septic tanks rather than a sewer connection, and 92.12% of households with a bathroom have proper drainage.

The report says Sikkim’s urban local bodies lack the resources for maintenance and desludging, especially given the mountainous, dispersed population.

The report also highlights Sikkim’s sanitation workers, who are better paid than their counterparts in the northeastern region but under-protected. They earn a daily wage of ₹524, above the State’s revised minimum wages. However, only 33% have personal protective equipment kits under the national NAMASTE scheme, while 21.3% of the 394 registered workers hold PM-JAY Ayushman Bharat health insurance cards.

NAMASTE is short for National Action for Mechanised 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 desludging, transport and treatment; and investment in decentralised, climate-resilient infrastructure suited to Sikkim’s slopes and seasons.

These steps could help Sikkim move from being a poster State for ODF status to a blueprint for sanitation across India’s Himalayan belt from Arunachal Pradesh to Ladakh, the authors say.