Collaborated with 

Choi Chan Mee,

The head of Holt Dream Centre in Mongolia

Mongolia is facing a critical moment in its urban evolution. The economic reforms following Soviet withdrawal in 1990 coupled with the discovery of vast reserves of coal, gold, and copper led to massive rural migration to the capital city: Ulaanbaatar.

Predicted GDP growth rates of 17% in 2011 and the promise of development projects lead nomadic herdsman to sell their livestock and move to the city in search of a better life.

The population of the city doubled since 1989 and city’s territory expanded from 130km2 to 4700 km2. The extremely cold winter (zud) in 2010 that killed many livestock sealed the fate of many, leaving them little choice other than to move to the city.

The nomads settle on any available land, occupying residual inner areas, slopes and the periphery of the city. When migrants arrive they erect a traditional felt tent - a ger – and surround the plot with a wooden fence. The extent and rapidity of their growth has meant that the provision of the most basic services of urban life has not been viable: water is fetched from kiosks; pit latrines are dug on site; and garbage goes uncollected. Coal smog hovers throughout the city during the winter as ger residents burn fuel to stay warm. As this population has no prior experience living amongst others - there is no word for “community” in Mongolian - or in situ, in one home on a single plot of land, other problems ensue such as solid waste disposal and a consideration of shared public space. Compounding these issues is widespread unemployment, alcoholism and health problems.

Unlike other informal settlements in developing countries, these districts are not illegal as each new migrant, as a Mongolian national, has the right to land ownership. However, they are still stigmatized as problem areas - effectively slums - that are seen as a hindrance to Ulaanbaatar’s evolution into a “modern” capital.

_Google images


_ Sourced from Rural Urban Framework

Ulaanbaatar, capital of Mongolia, is a growoing city of about 1.5 million. Growth happens both within the city with high rise apartments, but also in the surrounding suburban area that has no sewer. Although the main part of the city is sewered and there are four wastewater treatment plants, about 900,000 of the inhabitants have only unimproved pit toilets or no sanitation.  Mongolia offers some really unique conditions for sanitation - in the winter it can get to -50°C for prolonged periods. So it is difficult to deal with hygienic problems properly, caused from the pit toilets.

Mongolia offers some really unique conditions for saniation - in the winter it can get to -50°C for prolonged periods. 

R e s e a r c h   Q u e s t I o n s :

What is the suitable toilet system which can not only solve the environmental problems, but also bring economic profits to the local community?


By providing the properly designed toilet system for the geological property of the local area, how the local people can take the benefits environmentally and economically? 


Poople&People is a local cooperative project according to Green Developement Strategic Action Plan 2020 for the nomads in suburb of Ulaanbaatar living without any access to proper toilet system.  It is based on running the Fixed Dome digester(bio-toilet system) which can provide a solution for economic and environmental(atmospheric) issues. 

Research & Drawings for suitable toilet system





A fixed-dome plant consists of a digester with a fixed, non-movable gas holder, which sits on top of the digester. When gas production starts, the slurry is displaced into the compensation tank. Gas pressure increases with the volume of gas stored and the height difference between the slurry level in the digester and the slurry level in the compensation tank. 

Fixed Dome Digester


Low initial costs and long useful life-span; no moving or rusting parts involved; basic design is compact, saves space and is well insulated; construction creates local employment. Advantages are the relatively low construction costs, the absence of moving parts and rusting steel parts. If well constructed, fixed dome plants have a long life span. The underground construction saves space and protects the digester from temperature changes. The construction provides opportunities for skilled local employment.


Masonry gas-holders require special sealants and high technical skills for gas-tight construction; gas leaks occur quite frequently; fluctuating gas pressure complicates gas utilization; amount of gas produced is not immediately visible, plant operation not readily understandable; fixed dome plants need exact planning of levels; excavation can be difficult and expensive in bedrock. Disadvantages are mainly the frequent problems with the gas-tightness of the brickwork gas holder (a small crack in the upper brickwork can cause heavy losses of biogas). Fixed-dome plants are, therefore, recommended only where construction can be supervised by experienced biogas technicians. The gas pressure fluctuates substantially depending on the volume of the stored gas. Even though the underground construction buffers temperature extremes, digester temperatures are generally low.