ESTVN Project

Decentralised sanitation options for urban and peri urban in Vietnam - DESA sub-project

Rationale of the project

During the last 20 years Vietnam has undergone a dramatic economic and social transformation, which has led to considerable improvements in the overall well being of the vast majority of Vietnamese people. An important drawback of this economic evolution is the increasing pollution of the urban environment. Natural water bodies are heavily polluted, with BOD, COD concentrations exceeding by 300-1000% national quality standards. This quite alarming state of the natural water bodies in urban areas is to an important extend due to the sanitation system in place in almost all Vietnamese cities: Domestic wastewater is discharged, with rudimentary pre-treatment by septic tanks, into combined sewerage systems, open channels and natural ponds. The construction of modern centralised treatment facilities is under consideration, but financial constraints make matters difficult. It must be assumed that in future the (pre-) treatment of domestic wastewater on household level will keep its crucial role for urban environmental protection.

Why decentralised sanitation?

Decentralisation of wastewater management is worldwide increasingly gaining recognition for different reasons. A decentralised approach in wastewater management:

- broadens the technology options permitting tailoring the solutions to the prevailing conditions;

- minimises the freshwater requirements for waste transportation;

- reduces the risks associated with system failure;

- permits a segregation of different wastewater types (greywater, blackwater, stormwater) at source;

- increases local wastewater reuse opportunities;

- permits incremental development and investment in the community wastewater system;

- fits the devolution process of management responsibilities currently experienced in Vietnamese cities.

Devolution of responsibilities

In fact, devolution of management responsibilities from city government to lower levels of administration forms an important part of Vietnam’s recent decentralisation process. While the Sewerage and Drainage Company (SADCO) is the agency with official responsibility for wastewater management in urban areas, they don’t have the resources and capacity to cover all parts of the city. As a consequence, responsibilities for service provision in peri-urban areas or remote urban areas are devolved to local authorities (People’s Committee - PC) and residents. While their responsibilities progressively increase, many continue to be poorly equipped with basic skills and human resources. There is a clear need for guidance on how to plan, design, construct, operate and maintain sanitation systems which fit this specific context which is typical for Vietnam.

Goal of the DESA project

The DESA project at CEETIA, under the leadership of Assoc. Prof. Dr. Nguyen Viet Anh, aims at bridging the gap between responsibilities and capacities of local authorities and practioners in the field of wastewater management by providing scientific based knowledge on appropriate wastewater treatment systems and management options. The main goal of the DESA sub-project is thus to develop technical guidelines for the design, the operation and the maintenance of decentralised, low-cost wastewater treatment systems.

Research on technical options

Text Box:
Baffled septic tank with anaerobic filter implemented for a neighbourhood in Bac Ninh, designed based on the outcomes of CEETIA research activities
The project started in 1998 and focused mainly on the development of appropriate treatment options for domestic blackwater (toilet wastewater) as alternative to the conventional septic tank, which is institutionally well anchored in Vietnam as treatment system for domestic wastewater. It was estimated that 60-80 per cent of the households in urban Hanoi are equipped with such a pre-treatment system. Unfortunately most septic tanks show low treatment efficiencies (COD and suspended solids removal rates are usually below 50%) and thus don’t contribute as expected to the protection of the urban environment.

Lab-scale research on different anaerobic treatment options such as the baffled septic tank or the anaerobic filter has clearly demonstrated that suitable alternatives to the conventional septic tank exist which enable considerable treatment improvements.

In order to confirm the findings of the lab-scale research, more than 10 full-scale treatment systems were implemented in and around Hanoi for the treatment of domestic wastewater on household or neighbourhood level. These units are being monitored and evaluated.

Research on non-technical issues

CEETIA also looks at non-technical aspects of decentralised wastewater management. Several studies were and are currently being conducted in collaboration with international partners. The studies aim at identifying the potential and limitations of applying decentralised wastewater management concepts. The main studies are highlighted below:

- Capacity building for effective decentralised wastewater management (DWWM) in Vietnam”, in collaboration with GHK International, United Kingdom.

- Local Management Schemes for Decentralised Sanitation in Vietnam

- Domestic wastewater flows in Hanoi

- Impacts of solid waste on drainage system in Hanoi city

- Production of synthetic toilet wastewater for research purposes

- Material Flow Analysis for Environmental Sanitation Planning

Outlook

The DESA project under the framework of the ESTNV project will last until end of 2007. The main focus in the remaining period is put on the capitalization and dissemination of the research outcomes through publications and organization of training courses for local authorities and practicioners. Furthermore, a DESA programme concept will be developed, which shall enable CEETIA to conduct research on decentralized wastewater management after completion of the ESTNV project.

Additional information & contact

DESA Sub-project manager: Assoc. Prof. Dr. Nguyen Viet Anh

Email add: vietanhctn@yahoo.com