Decentralized wastewater management in urban area: case study in Vientiane Lao PDR
PHENGKHAMLA PHONVISAI
Pollution Control Division, Department of Environment
Water Resources and Environment Administration, Lao PDR
Tel and Fax: 856-21-218712, E-mail: phonvisai@hotmail.com
Abstract: Urban areas in developing countries, conventional centralize approaches towastewater management have generally failed to address the needs of communities for thecollection and disposal of domestic wastewater and faecal sludges from on – site sanitation, theurban areas are experiencing stagnant pollution. Unsanitary conditions and threat of seasonalpollution in selected spots is likely to occur and increase with the growing urban population.
Decentralized approaches may also offer increased opportunities for local stakeholder
participation in planning and decision-making, and emphasizes the importance of building thecapacity of local organization in all aspects of decentralized wastewater management. Using
examples of functioning systems from the operational sustainability of decentralized
technologies for wastewater management in urban areas and their associated management
requirement. This paper concludes that a concerted capacity building effort is required toovercome the constraints that hinder the implementation and sustainability of decentralized
wastewater systems.
Keywords: Decentralized, policy, decision-making, implementation and institution ofWastewater management in Vientiane Lao PDR

I. INTRODUCTION
Urbanization is one of the most important demographic trends of the twenty-first century, andgrowth is particularly rapid in low-income countries. The majority of urban growth is associatedwith the rapid expansion of small urban centers development. Much of growth in unplanned andinformal, with community members and informal sector developer taking advantage of the factthat the regulatory capacity of government authorities is weak, particularly in those areas thatare outside official municipal boundaries. Urban areas are characterized by mixture of land uses
associated with range of urban and peri-urban livelihoods. Settlements are generally inhabit bycommunities of different economic status relating to land prices, which are affected by locationin relation to the city, and which are considerably, higher than in rural areas. Due to ongoingdevelopment, urban areas are generally in a state of rapid transition that may result in serious
social and environmental tensions.
At the moment, Vientiane has a population of 692,900 people with density of 176 people per
km2.The population density is increasing at a rate of 4.7% per year2. The urban area is divided
into 198 villages with a total area of approximately 30 Km.2, The core urban population was
estimated to be 180,410 people. The urban area of Vientiane is located between the MekongRiver and a hinterland of swamps and ponds. The wastewater from individual households in
Vientiane has been discharged into open drains along the roads and into natural wetlands in andaround the city.
1.1 Deficiencies of centralized approached to service provision in urban of VCC
The environmental problems associated with urban areas are consequence of the number ofpeople producing wastes, and their high concentration. On the other hand, the large
concentrations of people would appear to offer greater opportunities for centralized approaches

to the provision of infrastructure and service, which may actually reduce the per capital cost ofservice provision.
Overtime, Urban VCC land has been going through tremendous transformations due to sprawls
in agricultural, industrial and urbanization. The changes in land use affect the ecosystem interms of land cover, land quality and capability, weather and climate, quantity of land that canbe sustained. The development projects include: (i) Rehabilitation of Sihom Area,
UNCDF/UNDP, 1991-1997, The Vientiane Master Plan identified priority areas suffering fromenvironmental problems related to poor drainage, household sanitation, and access to services
such as waste management, (ii) Wastewater Management of Thatluang Marsh, EU, 1993,
The Thatuang wastewater management project was designed to improve wastewater treatment
and drainage out of the central Vientiane area, (iii) Vientiane Integrated Urban Development
Project, ADB, 1996-200, The overall objective of the Vientiane Integrated Urban Development
Project was to improve access to basic services and infrastructure, thus providing benefits to theurban environmental and health population of Vientiane, (iv) Improvement of Urban
Environment in Vientiane, Lao PDR, Danida, 2001-2004, Project aimed to continue support
to municipal planning with development of linkages between green and brown environmental
issues and increased village involvement in environmental planning, implementation, andmonitoring.
II.

DECENTRALIZED APPROACHES TO WASTEWATER MANAGEMENT

In response to the deficiencies of centralized approaches to service delivery, in recent years
there has been increasing emphasis on the potential benefits of adopting decentralized
approaches to sanitation and wastewater management, which are considered to be particularly
appropriate for urban areas. According to the governor of Vientiane capital city, decentralized
wastewater systems may provide a cost-effective and long-term option for meeting publichealth and water quality goals, particularly in less densely populated area. Broadly speaking,the implication of decentralization on wastewater management system relate to planning anddecision – making, design of physical infrastructure, and management arrangements operationand maintenance. More generally, decentralization is also seen as a way of strengthening therole of local government and democracy in general, and as an effective means of addressing
environmental and health concerns.
As known, urban centers are always attractive places for both educational institutions andemployment opportunities, increasing in-migration from rural to urban areas is commonly
observed. Currently, VCC lacks of effective systems of development control, and therefore themeans to control future development and its concomitant environmental degradation are
inefficient. Drainage system is shown to be inadequate. Added to that, the contamination ofcarried liquid waste, with faucal matter from latrines has been directly discharged into drainage
channels or drains where oviform from septic tank effluents. Although decentralized systemhave yet to be widely accepted and implemented in practice, these do appear to offer a numberof potential advantages. These relate to opportunities for grater advantages, and to the benefitsof segregation of wastewater at source and compatibility with local demands for wastewater
treatment.
III. DECENTRALIZED DECISION – MAKING AND PARTICIPATORY PLANNING
Decentralize planning and decision-making in wastewater management offers potential benefits
relate to increased responsiveness to local demands and needs and hence, increased willingnessof communities to pay for improved services. An integrated environment plan has beendeveloped by the inhabitants of informational settlement in urban area of VCC, and this hasformed the basis for local action and also for negotiating support from external agencies. Where
the poor people are already involved in local agricultural system, there is possibility that
improving decentralized management system will achieve a better distribution of benefits that

more centralized management approaches. Increased stakeholder involvement at the local level
is often promoted by the local governments, which encourage a demand – responsive andparticipatory approach and often act as intermediaries to improve the flow of communication
and broker agreements between community and local government authorities. In relate to theinfrastructure provision, the local authority can pay a key role in assisting communities todevelop their basic services, but it must also be recognized the local authority and indeed
community involvement as a whole, do not offer a panacea to the deficiencies of public sector.
In particular, local authority may lack the technical know – how requited to plan and design
effective decentralized schemes, whilst community organization will not automatically provide
the stability and reliability required to provide long-term management to those schemes.
3.1 Financial advantages of decentralized management
The capital investment for decentralized wastewater system is generally less than for centralized
system in urban areas. By the tackling wastewater problems close to source, the large capital
investment of trunk sewers and pumping cost associate with centralized system can be reduced,
thus increasing the affordability of wastewater management system. Decentralized approaches
to faecal sludge collection and are particularly appropriate for urban area, as that reduce haulage
distances and thus reduce the cost of transportation. The investment may require little more that
improvement to existing informal wastewater collection system and the introduction of an
appropriate form of treatment prior to disposal.
3.2 Segregation of wastewater at source
Domestic wastewater consists of “back” water, the mixture of water and faeces flushed from
Water Classis (WCs) and pour-flush toilets, and “grey” water, the sullage from kitchens andbathrooms. Grey water contains much lower pathogen levels and has a low oxygen demandthan black water and therefore represents a much smaller health and environmental healththreat. Grey water and black water are produced separately, and ensuring that they remain
separate can facilitate management of two wastewater streams. Grey water can than be used for
irrigation or discharged into local water course with little or no treatment. Wastewater discharge
in VCC, there are three main drainage channel systems including Hong Xeng, Hong Ke andHong Khoua Khao. Hong Xeng mainly drains (Figure 1).
The absence of overall urban
drainage
plans
with
a
functioning integrated network
combined with lack of clear
arrangements for maintenancecause flooding and stagnant
water pools over large parts of
the urban center. Sanitation
system in VCC entails an onsite disposal of human waste
without an introduction of fullwater bone sewerage withtreatment facility and safe
disposal arrangements (STEA,
2000s).
Figure 1: Wastewater Discharge in VCC
3.3 Compatibility with local demands for wastewater.

Decentralized wastewater system are likely to be compatibility with local demands for
wastewater re-use in urban areas where water and the nutrient content in the wastewater
increase agriculture productivity and contribute to the livelihoods of urban communities.
Wastewater may also be reused for aquaculture, in which aquatic plant biomass is used either
directly or as an ingredient in a feed – mix raise fish or livestock for human consumption.
Wastewater re-use can be promote incentives for local people to operate and maintain local
system, and thus help to ensure long – term operation and financial sustainability. The re –useof wastewater can increase local agricultural productivity, resulting in increase revenue for local
producers.
IV. OPTIONS FOR DECENTRALIZED WASTEWATER TREATMENT
In order to ensure that decentralized wastewater management system protect against adverse
impacts on health and the environment, some form of treatment will be required before
effluents are discharge or re-use. The relative sophistication of conventional treatment processes
presents difficulties for operation and maintenance at the local level, and these technologies areunlikely to be appropriate for local use because they require carefully and skilled attendance.
Although these technologies are less dependent upon power for operation that more advanced
technology, that require increasing amounts of land, especially where wastewater re-use. A
potential constraint on localized management is therefore the limited availability of land fortreatment facility. This is particularly important in the case of simple option such as waste
stabilization ponds and construction wetland. Land ownership can constrain the implementationof decentralized wastewater management system due to the infective planning and control over
information development.
4.1 Wastewater stabilization ponds
Wastewater stabilization ponds include anaerobic ponds, facultative ponds that combine aerobic
and anaerobic processes, and purely aerobic maturation ponds. The obvious advantage of ponds
system is their simplicity. A second advantage is their long retention time means that they are
better than most treatment option at reducing pathogen levels. They can produce economic
benefits in that maturation ponds provide good environment for growing fish such as tilapia.
The effluent from ponds has fairly high algae concentration, so it is good resource for irrigation.
One disadvantage of waste stabilization ponds is that they require a relatively large areas ofland, especially when combined with wastewater re-use. Wastewater stabilization ponds may be
integrated with re-uses systems for the production of plants (e.g. duckweed and water hyacinth).
4.2 Construction wetland
Construction wetland (reed beds) can provide a low cost and appropriate technology for thetreatment of domestic wastewater and feacal sludge’s, but will normally require pretreatment
and so can only be considered as a second treatment option. Like waste stabilization ponds, they
can fairly good at removing pathogen, but facilities have to be designed and operated in a waythat controls disease vectors, especially mosquitoes, and odours. Little examination of industrial
wastewater production around the city is little known about the extent of industrial waterpollution. According to the country’s Environmental Law (Provisions on discharge of waste
water from factories, Ministry of Industry and Handicraft decree No. 180/H) industries are
responsible for the treatment of all wastewater and by-products produced as part of industrial
processes. The Water Resources and Environment Administration (WREA) are responsible forassessment and monitoring of wastewater quality. WREA is currently in the process ofdeveloping an environmental monitoring system for the country as a whole but at this point
very little information is available about the industrial waste.

In relation to Sanitation and Wastewater purification, Thatluang Marsh is currently performing
wastewater treatment services of domestic wastewater that is being drained into the marsh.
There are two major types of costs that are associated with artificially replacing the wastewater
treatment and water purification services of Thatluang marsh:•••

Construction or improvement of household sanitation facilities in areas that drain directlyin the marsh
Extension of the waste treatment plant so that it can deal with increased waste load.
According to the ADB survey in Sanitation, Drainage, and Wastewater Management, thehouseholds which directly discharge their sewage directly into surface water and draining
their wastewater into Hong Ke and Thatluang marsh.

It should be noted that with high water table and impermeable soils throughout Vientiane
Municipality, sanitation using cesspools or elevated soak ways are largely inefficient andprovide inadequate services.
V. RECOMMENDATIONSThere are a range of technologies for the treatment of wastewater that are suited to decentralized
management systems and which may be adopted for use in low – income urban communities.
However, most of these have not been utilized widely and remain in localized areas and pilot
project. The constraints to sustainability of these systems and the opportunities for replication
have been described. In order to overcome these barriers to widespread implementation, aconcerted capacity – building strategy is required. As proposed below, this is based upon fourtargeted levels associated with advocacy, development of appropriate policies, institutional
strengthening and training.
5.1 Advocacy
Due to the demand for improved wastewater management, the main challenge for planners andpractitioners. Vientiane urban development administration authority (VUDAA) is to create
informed demand for improved systems, focusing not only on health but also on the
improvements in the local environment and in the household finances that may be achieved
through improved wastewater management. Advocacy at the political level is required and, at thecommunity level, awareness campaigns to promote the benefits of improved wastewater
management, involving extensive social communication and mobilization, are necessary.
VUDAA has technical assistant support from JICA’s technical; and urban research institute todevelop the master plan of VCC. This suggests and need to document experience and encourage
the implementation and monitoring of additional demonstration project in order to stimulate awider interest in the benefits of decentralizes wastewater management.
5.2 Policy and recommendations
VUDAA is a need to incorporate wastewater management systems within an integrated
framework of water resources management and other services of water supply and solid waste
management. Official design standards may not be framed in a way that supports the develop ofdecentralized systems. There is therefore a need to develop appropriate standards to utilize fordesign and construction of decentralized wastewater system, and also to promote realistic andacceptable standards for treatment where wastewater is re-used. The policy need to be developed
in close collaboration with organization involved with those communities that the decentralized
wastewater system are designed to serve. The processes of planning and implementation
VUDDA addressed in partial aspects of environmental problem, since there are may be an ability
to handle wastewater disposal within municipality borders. However, water and sanitation
disposal often calls for city-wide solution, metro-level authority to plan, coordinate, and executea wastewater disposal program. The planning has generally not been an effective environmental
tool, although monitoring varies according to the city’s level of economic and human resource
development. In terms of environmental coordination and decision making process, intersected
coordination to manage urban environmental affairs has been lacking and has become a problem
in VCC, although below coordinating mechanism has been established for urban development in
VCC:
•
•
•

At the central government level, there is a planning body that is in charge forsynchronizing interdepartmental coordination for urban activities.
At the VCC level, there is a community to coordinate sectoral program and projects fromloans (i.e., ADB loans).
For implementation of infrastructure activities, there is a program to coordinate
investment and institutional strengthening (i.e., VUDAA, PWREO).

5.3 Institutional strengthening
This involves a change of focus of activities, whereby traditional centralized agencies take on adifferent role, focusing on the need for capacity strengthening to develop new skills to respond to
the need and demands of communities. This places greater emphasis on the role of recentralized
agencies as facilitating organization, providing technical assistance and focusing on improved
system for coordinating the activities of different stakeholder group involve in decentralized
wastewater management. Lao government strategies on the development and maintenance ofurban environment infrastructure are based on achieving sustainable and affordable
environmental improvement of its main urban center (WREA, 2004). Implementation priorities
relate to specific urban center needs, which would be identified along with urban hierarchy
adopted by government. Such urban drainage plans with the need for creating and maintaining
functioning drainage network, including identification of final points of discharge must beemphasized.
5.4 Training and dissemination of technical information
The choice of technology is limited by the need to ensure that the operation and maintenancerequirements of the chosen technology are compatible with the levels of knowledge and skill
available at the local level. There is often a lack of knowledge of decentralized option and ashortage of qualified workforce and skill for operation and maintenance. The management
requirement in terms of the local availability of skills and knowledge to operate and maintaintechnologies and service for wastewater and faecal sludge management are therefore criticallyimportant. There is therefore focus on the training of stakeholders to enable them to understandhow various technologies operate their operation and maintenance requirements, and theimplication in term of possible effluent re-use. There is also the need to disseminate technicalinformation in appropriate forms and languages, in ways that are understandable and relavant toneed of those who are responsible for the design and operation of decentralized wastewater andfeacal sludge collection and disposal systems.
VI.
CONCLUSIONS
Sanitation, including wastewater treatment is an important environmental service that is closely
linked to water management. In VCC, outfall from poor functioning central sewage system
contaminates water resources. Moreover, urban VCC land has also been going throughtremendous transformations due to sprawls in agricultural, industrializations and urbanization,
there has been little sustainable built of project design resulting in discontinued use of thewastewater stabilization ponds and limited use of the waste treatment plant in Thatluang marsh.
Access to and affordability of adequate sanitation is always a problem for the poor, especially inthe low-income household.

6.1 Public-Private Participation
In response to the deficiencies of centralized approaches to service delivery, in recent years there
has been increasing emphasis on the potential benefits of adopting decentralized approaches tosanitation and wastewater management. These relate to opportunities for stakeholder
involvement in decision-making and planning, financial advantages, and benefits of segregationof wastewater at source and compatibility with local demands for wastewater reuse. In general,
central elements that shape the institutional setting for environmental management include: a)the key actors in the public and private sectors whose motives and mandates significantly affectthe urban water and sanitation, b) management functions that can be use to addressenvironmental issues in urban city, including instruments of intervention and mechanism forcoordination, and c) existing initiatives that affect effort to wastewater and sanitation problems.
6.2 Wastewater and Sanitation Management Function
Management function consists of policy and other instruments that actors can apply to affectenvironmental quality and mechanisms in coordinating environment-oriented decision. Urban
governance often adopts policies to deal with wastewater and sanitation management problems.
Based on that, the government will formulate a long-term national wastewater and sanitation
strategy to guide any future investment in water and sanitation activity. The most prevalent toolfor environmental management that affect city is that of legislation and regulation. The
sophistication and effectiveness of this tool is low in Laos, since there are only few environment
standards and an incomplete set of environmental laws. Moreover, lacking of enforcement is apervasive problem. However, environmental impact assessment (EIA) process is being positively
promoted and selectively implemented in Lao PDR.

ACKNOWLEDGMENTS
The authors are grateful to the assistance of Water Resources and Environment Administration(WREA), Vientiane Urban development Administration Authority (VUDAA), Vientiane Capital
City Cabinet, as well as Department of Public Works and Transport.
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