Yangyel Lhaden

Thimphu Thromde is working to compost the city’s wet waste, which has significant potential to reduce the amount sent to the landfill, safeguard the environment, and produce organic manure.

Thimphu Thromde plans to construct a state-of-the-art composting plant, set to be operational by March next year at the Memeylakha Landfill, to convert the city’s food waste into organic manure.

Food scraps account for nearly half of the country’s waste, with much of it ending up in landfills, worsening environmental degradation. Managing wet waste has become a pressing challenge, particularly in urban centres like Thimphu.

While rural households often reuse food waste as compost, much of the waste in cities ends up in overburdened landfills.

A recent survey by Recykal and Ugen Trading House found that Thimphu generates about 400kg of waste daily, over half of which is food waste. Similarly, according to the National Waste Inventory Survey 2019, food waste accounts for 50 percent of country’s total waste.

When food waste decomposes anaerobically in landfills, it releases methane, a potent greenhouse gas contributing to 8 percent of global emissions. Methane is a greenhouse gas that is 25 times more potent than carbon dioxide.

Also, landfilling food waste generates toxic leachate, which can contaminate water sources, waste valuable resources like water and energy, and degrade soil quality.

Thimphu Thromde’s chief environment officer, Sonam Wangchuk, said that the new composting plant aimed to improve soil health by reducing wet waste going into landfill and reduce the outflow of leachate at landfill site which is toxic to soil and environment.

He said that the thromde is currently in the initial phase of implementing the project, and the operation of the composting plant would be handed over to the two waste service providers once completed. “The organic manure produced will be sold by them at an affordable price.”

Transforming wet waste into organic manure could significantly benefit Bhutanese farmers by reducing the country’s reliance on imported chemical fertilizer and addressing the current shortage of organic alternatives.

According to the National Fertilizer Strategy and Action Plan (NFSAP) 2023–2030, Bhutan imports around 3,500 metric tonnes (MT) of chemical fertilisers annually, with usage averaging 13.41 kg per hectare of arable land—much lower than neighbouring countries like Nepal (86.9 kg/ha) and Bangladesh (318.5 kg/ha).

To promote sustainable farming, the NFSAP aims to boost annual organic fertilizer production from 3,200 MT in 2023 to 15,260 MT by 2030, with a 25 percent annual increase in output.

The Low Emission Development Strategy for Food Security 2021 also emphasises transitioning from synthetic to organic fertilizers as a key mitigation measure, targeting a five percent annual reduction in chemical fertiliser use.

The new composting plant worth about Nu two million will be constructed with financial support from the Institute for Global Environmental Strategies, based in Japan, under the United Nations Environment Programme.

The new composting plant will use the Takakura composting method. The Takakura composting method is an eco-friendly technique that uses fermented starter microorganisms, kitchen waste, and sawdust to efficiently decompose organic matter. It produces nutrient-rich manure, ideal for gardening and soil enrichment.

Currently, Thimphu lacks a dedicated composting or treatment plant for wet waste. Its only landfill, located in Memeylakha, was established in 1993 with a planned lifespan of ten years but has been operating for over two decades beyond its intended capacity, handling both wet and dry waste and facing significant strain.

Efforts to mitigate its impact include installing pipes to channel leachate to the Babesa sewage plant for treatment. However, the landfill’s limitations underscore the need for sustainable waste management practices like composting.

The thromde is focusing on a sustainable solution by planning to compost wet waste into manure, marking a shift towards better waste management practices.

In addition, other initiatives such as the Bhutan Waste Bank, launched in August by Greener Way, aims to tackle Thimphu’s waste management challenges by incentivising waste collectors. This initiative has made notable strides in reducing both dry and wet waste disposed of in the landfill.

Before the launch of the Bhutan Waste Bank, Thimphu Thromde collected an average of 926 tonnes of dry waste and 794 tonnes of wet waste monthly. Following the implementation of the waste bank, collection through nine drop-off centres resulted in 841 tonnes of dry waste and 786 tonnes of wet waste in July 2024.

By August, these figures further declined to 668 tonnes of dry waste and 680 tonnes of wet waste, demonstrating significant progress. Daily disposal at the landfill also decreased from 52.5 tonnes in July to 43.5 tonnes in August, representing a 17.14 percent reduction.