Long-term options for the former state-of-the-art sewerage system in Yangon
The project consists of two phases, Phase 1 (Inspections and Asset Condition Study) has now been completed and Phase 2 (options for the future of the downtown sewerage network) is underway.
The once state-of-the-art sewerage system in downtown Yangon was designed and installed by Mr. Octavus Deacon Clark in 1889 to serve a population of about 40,000. Currently Yangon has over 350,000 persons in six downtown townships. The questions that pop up now is how the system can still serve the drastic growth population and how a 130 year-old system can maintain functionality.
Why it keeps operating for a long time
The Shone System
In the late 1800s, the designers introduced a new sewer system to solve the problems with contaminated groundwater and outbreaks of disease in Yangon. The Shone Hydro-Pneumatic Drainage System was one of the proposed solutions and it was already successfully used in the United Kingdom and cities across the globe. A localised gravity sewer network carries sewage to respective collectors, then 35 pneumatic ejectors raise the sewage to a high-level force main and transport it to disposal points.
The shone system relies on a network of pneumatic ejectors and air compression stations to pump sewage to a treatment facility in Botahtaung Township at the eastern end of the downtown area.
"This is a revolutionary piece of construction left behind by a veteran engineer during the golden age of civil engineering" Christopher Davies said. He is a senior consultant from the Water and Sanitation team at IMC worldwide.
Although the system is running beyond its limits, as it was designed for 40,000 people, it is still working – nowadays we should call it sustainable. Of course, the word "Sustainability" wasn't commonly used yet during that days.
Furthermore, local YCDC water and sanitation operatives manage to clean and maintain the whole sewage system with very limited training and resources. "I'm amazed at the commitment from the YCDC staff to keep this system functioning in very difficult working conditions" Davies said. "Moreover, they are battling with long-term underinvestment."
How can the system can still serve the population?
Let's go back to the history before the system.
In 1874, there was no attempt to deal with the excreta of the population of Rangoon. Cesspools were permitted everywhere, and the well water became awfully polluted as the soil of the city became honeycombed with cesspools. Additionally, cholera and small-pox were widespread.
Mr. Deacon Clark suggested the Shone system, which had proved effective in many places, and the Municipal Committee inquired for a detailed project and estimate for the drainage of Yangon on this system.Serving the needs of future population is a big challenge that YCDC face. For the future of the downtown sewerage network, it is critical that YCDC are supported to develop long-term options for the city.
How Yangon can benefit
Phase 1 of the project (assessment of the existing network) has been completed and Phase 2 is working with YCDC to provide long-term options for the future of the downtown sewerage network.
The outcome of the project is that they are able to provide YCDC with the information required to keep the existing sewerage network functioning, either as a long term like-for-like replacement or with short-term repairs to improve the system whilst a new modern network is being constructed. Many parts of ejector pumps (especially the check valves and isolation valves) and compressed air network need to be replaced or repaired, this is understandable given the age of the network. In addition, IMC have been providing YCDC with independent advice for the future of the sewerage system so that they make informed decisions.
The Rangoon sewage system was once regarded as one of the most advanced in the world. This system could be seen in the Egyptian capital, Cairo, and Karachi, Pakistan's biggest city. Besides these, it is the same system which continues to serve the Westminster's Houses of Parliament in London.
"Let's just discuss about common benefits rather than sewage system this time. "
Yangon could collect more attraction on local and international tourists due to the fact that people are willing to come to visit and feel the moments of industrial and colonial era. The old air compressors and ejector pumps could be included as one of the historical places during the colonial era. The main compressor building, the machinery and the original tools are displayed in Yangon. The antique maps and ancient cultural letters are able to be used in cultural heritage sites, defining authentic work-of-art in casting and moulding during those ages.
Notes on the original design from the 1880s: https://www.gracesguide.co.uk/Octavus_Deacon_Clark
- UK aid is funding the rehabilitation of Yangon's downtown sewer system, which relies on a network of pneumatic ejector stations and air compressor stations to pump and move waste to YCDC's wastewater treatment plant in Botahtaung.
- Yangon's system is very robust and its pipework and pneumatic components have stood the test of time. Currently, the system is not working at full capacity because of equipment failures and breakages. The population has also significantly increased since it was installed.
- DFID is working with YCDC to conduct a condition survey of the system. The aim is to identify where cost-effective repairs can be made and how to increase its capacity to support the expanded population in downtown Yangon.
- DFID is fully funding the UK engineering team led by IMC Worldwide, including specialist expertise from SATEC, BAM Nuttall and locally-based engineers from Royal HaskoningDHV.
About DFID: The Department for International Development (DFID) leads the UK's work to end extreme poverty. We are tackling the global challenges of our time including poverty and disease, mass migration, insecurity and conflict. Our work is building a safer, healthier, more prosperous world for people in developing countries and in the UK too.
About IMC Worldwide: IMC Worldwide is a UK consultancy that partners with local communities, multilateral and bilateral donors, NGOs, and the private sector to address some of the world's greatest development challenges. With over 50 years of experiences and nine offices worldwide, we employ over 400 staff working in water and sanitation, rural livelihoods, communications, private sector development, engineering, economics, trade and investment, innovation, resilient and urban development, and programme evaluation.