Integrated Wastewater Management
' Appropriate wastewater management, within an overall water resources management program, is essential to responsible use of the environment and to affordable provision of services. Such management programs are best developed at a river basin or sub-catchment level. An approach is outlined for developing a wastewater strategy and an implementation plan for a river basin.'
The Bank promotes a systematic approach to water resources management, incorporating water resources planning and management issues into policy discussions at a national level. Water quality protection and appropriate wastewater management are two of the essential elements of an overall integrated scheme.
The overall goal of water quality management is to protect the resource. Formal management normally becomes necessary when there are increasing and competing demands on the resource and where uncontrolled access or certain uses are likely to cause (or have already caused) unacceptable deterioration in water quality. The development of a realistic and practical management plan requires discussion, consultation and negotiation, involving not just government and municipal agencies but also industrialists, local communities, other NGOs and representatives of the non-point sources such as agriculture and transport. In many cases the plan should be regarded as a process rather than a single document or agreement.
There are, unfortunately, numerous examples worldwide of poor wastewater planning and management, where there have been government investments have been poorly targeted, addressing low priority problems or tackling them in a piecemeal and ineffective way. The consequences are not only that the predicted benefits are not achieved but also that funds are diverted from other possible investments. At the same time, other more cost-effective measures may be neglected because of perceived administrative or political problems.
Failure of investment projects to achieve the design goals are often blamed on a lack of institutional capacity or on financial weaknesses but a frequent cause may be an insistence on inappropriate technologies and a failure to take into account the socioeconomic circumstances in which the plant must operate.
In order to achieve the overall goal of water quality management, which is to protect the general quality of the water body, it is necessary to address the problems on at least the same scale as the water body itself, whether this is a lake, a river or a coastal ecosystem. A focus on individual discharges, without understanding the broader context, is likely to lead to inefficient and often costly interventions.
Comprehensive water resources management, of which wastewater management is one component, should be based on a number of broad principles:
water can be considered an economic good (this is basic principle of the Bank’s Water Resources Policy);
water management must recognize the social aspects of water uses and therefore must involve the stakeholders at all levels;
maintenance of ecosystems is a legitimate goal of water management; and
there must be an institutional framework and a legal framework which is as broad as the physical water system.
Wastewater Management Approaches
There are a wide variety of wastewater management approaches practiced throughout the world but it is possible to categorize them broadly into three:
- decentralized local action;
- coordinated regional action;
- uniform national standards systems.
The first is essentially the project by project approach, driven by individual initiatives. While it may solve local problems, it is often inefficient and is not capable of dealing with widespread problems or large systems. It is typically the first stage of development in wastewater control but cannot be considered as a desirable long-term approach.
The second approach appears to be the most attractive, in principle, because it can lead to comprehensive, cost-effective programs. However, although a river basin approach is used in a number of European countries, it is by no means the norm in the developed world.
The uniform national standards approach is the system currently used in the US and was essentially also the model underlying the European Union approach (although recent legislation is moving towards an approach which allows more basin level flexibility). It has the advantages of simplicity and uniformity of application.
In broad terms, therefore, the existing models which should be considered for developing countries are the river basin approach or the adoption of uniform national standards.
Uniform Standards Approach
The standards based approach is currently used in both the USA and the European Union but there are concerns in both areas over the high costs resulting from the uniform standards which have been imposed and questions have been raised over the efficiency of the overall system in meeting water quality goals.
The USA at present has a uniform standards based system which has achieved significant improvements in levels of wastewater treatment -- but at a cost which is higher than alternative approaches could have achieved. (It is noteworthy that, for a decade, federal subsidies provided much of the capital investment in municipal wastewater treatment). Before the adoption of this system (in 1972) earlier legislation had in fact established a system where states set water quality standards for different bodies of water and then set limits to discharges at loads consistent with the quality standards. This approach was found to be unworkable, primarily because of the difficulties of apportioning total allowable loads among dischargers and of determining responsibility when water quality standards were breached.
The European Union has adopted uniform wastewater treatment requirements without regard to local conditions (except that in 'sensitive areas' higher requirements are imposed). As the costs of implementing this policy become clearer, there is increasing opposition to the high charges and state subsidies required to finance the required works. (The overall costs had not been seriously considered during the preparation of the legislation). The practical consequence of the high costs is delay in the compliance with the requirements.
River Basin Approaches
The EU approach is in fact a departure from the river basin approach which was widely used in national systems in western Europe. Germany, France, Spain and the UK all have river basin authorities of one form or another. These all had systems of fees and charges which provided finance (to a greater or lesser degree) for wastewater investments but the systems are now changing to come into compliance with EU requirements. Nevertheless, these systems still have levels of flexibility within their own areas of authority.
Such flexibility to set appropriate local standards (within some national framework) provides the possibility of setting priorities and realistic targets consistent with available resources. However, the implementation of a river basin approach requires a level of institutional sophistication which may take time to develop and therefore practical systems are often a mixture of basin management and standards.
Options For Developing Countries
Many developing countries have established uniform national discharge standards but in most cases these are more often ignored than implemented. Whatever may be the chosen long term system for any country, in most cases the lack of financial and institutional resources will impose a cost minimizing, priority setting approach for the short to medium term and this must be carried out on a water body basis.
In many developing countries inadequate wastewater control and rapidly growing populations have resulted in deterioration of natural water systems, in public health impacts and in increased economic costs, as well as broader losses of environmental benefits. The development of a solution requires numerous decisions on the area to be served, the technology to be used, the location and standard of discharge and the allocation of the cost burden. Solutions must be sought on the same scale as the problems, typically a river basin or a lake catchment.
It would be desirable to have a fully objective method for comparing and ranking alternative upgrading programs but there are difficulties in valuing the environmental impacts of wastewater discharges. More importantly, perhaps, the distribution of costs and benefits will vary with different programs and a process approach is required to reach a consensus among the various parties involved.
The framework suggested here is a practical approach which quantifies the issues wherever possible but allows for identification of alternatives, followed by discussion and selection of a preferred option. No approach will be perfect and therefore there must also be mechanisms for monitoring, review and adjustment over time.
The key steps are:
- establish a lead organization and involve stakeholders;
- identify broad goals;
- define specific measurable objectives;
- formulate and assess possible strategies;
- select preferred strategy, implement and monitor.
For progress to be made, there must be general acceptance of the importance of the problem and there must be an organization or agency which takes the lead in the process. (Ideally this would be an existing river basin agency but in practice the problems may have arisen from the absence of such a body.)
The lead organization must have access to all the relevant ministries and agencies and must have enough influence to ensure the involvement of key private sector stakeholders. It must also be sufficiently persuasive to promote discussion and consensus among the many parties involved. It is not necessary for it to have all the powers and functions necessary for implementation and in fact it may be better if it has only technical and coordination functions as this will reduce concerns over it driving a particular agenda. However, it must have sufficient support at all government levels and with other stakeholders so that all the relevant bodies cooperate in the planning process and are held to the agreements reached.
Broad agreement must be reached on the overall goals of a water resources strategy or of a wastewater management program. These goals can include social concerns (improving public health conditions or extending services to groups which are presently outside the system); economic issues (such as reducing costs of water supply, protecting fisheries or encouraging development); and of course environmental goals such as protecting or restoring certain ecosystems.
All of these goals are important and to some extent they will conflict. None can be given absolute priority over the others but the aim of the planning process is to find the strategy which allows significant progress towards achievement of all of the goals.
The agreed goals must be translated into specific measurable objectives in order for different strategies to be developed and assessed. This is an iterative process and may also include staging the objectives in order to reach a realistic program.
Depending on the scope of the planning process, objectives could include coverage of municipal services, levels of service for water and sanitation customers, protection and provision of treated water etc. For the purposes of this note, however, the focus is on water quality objectives.
Water Quality Objectives
Management of water quality should focus on the ambient state of the water and typically is based on the development of Water Quality Objectives (WQOs) which define target values of key ambient quality parameters. These numerical WQOs can then be used to evaluate the existing conditions; as a basis for the establishment of load limits for inputs to the water body (if this approach is adopted); and as the yardstick against which to measure changes over time.
The concept underlying the WQOs is that of the beneficial uses of the water body (be it a river, lake, coastal zone or whatever.) The beneficial uses represent the ways in which the community would like to make use of the water body and include ecological uses such as preservation in the wild and fish breeding as well as more direct uses such as drinking water abstraction. The clearest example of such uses is the goal set down in US legislation of making surface waters 'fishable and swimmable'. In practice, most systems adopt four to six main uses for which clear numerical parameters can be agreed.
A typical set of uses (in more or less descending order of water quality) would be:
- source of potable water;
- maintenance of fisheries ecosystems;
- agricultural uses (irrigation and livestock);
- amenity and conservation.
These uses are sometimes also presented as a Classification, with Class I typically being the highest and the lowest (e.g. Class V, in the current example) representing those waters which fail to meet even the lowest of the desired uses. For each of these uses of classes a set of basic numerical parameters can be defined, often focusing on key factors such as dissolved oxygen (DO) levels and nutrients (see Annex).
Given an agreed classification, an initial step is usually to map the basin into Classes or Uses based on (estimates of) the present water quality. From this baseline, the broad goals can be translated into desired Beneficial Uses for all the waters of the basin. The key point of debate will be the realistic long term achievement of high level uses for areas that are now very polluted (although the return of salmon to the formerly very heavily polluted Thames River in London is often quoted as an example of what can be achieved with consistent effort over a long period).
Once a first set of quantified goals has been prepared, the critical step in the whole process is to develop an improvement strategy which details the costs and other constraints on achieving these goals. This should be the beginning of an iterative process to reach agreement on short to medium term goals which can be achieved with the resources that can be made available.
A management strategy is a set of decisions, policies, regulations, infrastructure investments and other activities which if implemented, is expected to reach the selected goals. A wastewater management strategy would typically include: industrial and non-point source controls (including standards, charges and other instruments), development of reuse, redefinition of municipal sewer catchment boundaries, upgraded treatment, relocation of discharge points, changes to regulated water flows and a range of other actions.
Strategy formulation should include the preparation of a number of dissimilar options which are all relatively cost effective but which may depend on non-quantifiable factors such as the degree of industrial discharge that can realistic be achieved with the time frame or different distributions of the cost burden through taxes and charges. A key variable will be the rate of progress than can be achieved at different levels of resource availability. All reasonable configurations of technologies, regulations and system components should be included, with realistic costs assigned to each configuration.
The stakeholders need to be involved both in the determination of the options to be analyzed in detail and in the selection of the preferred strategy. (Advice on public involvement in environmental assessment and similar projects is provided in a number of documents available through the Environment Department.)
The development of the strategy should involve, where necessary, the questioning of existing institutions, regulations and fiscal constraints, to determine the benefits and costs of possible changes in these constraints. Achievement of significant progress may require changes in some of the existing systems but the arguments for such changes must be made clearly and persuasively.
The outcome of the process should be the selection of a preferred strategy which is acceptable to all the key stakeholders and which sets out clearly the actions to be taken, the resources required and the legal and administrative responsibilities for each of the actions.
The agreed strategy should include an implementation schedule, covering not only the adoption of standards, regulations and policies and the construction of new facilities but also the generation of long term political and financial support for the operation and maintenance of the old and new systems.
The design of the strategy must include the capability to monitor its implementation. This monitoring should cover both the progress of implementation of the agreed strategy and also progress in achieving improvements in the overall condition of the environment as the strategy is put into place. A successful monitoring program requires time, money and appropriate expertise and the location of the responsibility for monitoring has to be given careful consideration so as to achieve an independent review while taking advantage of existing operational expertise.
The strategy should include formal reviews of progress as implementation proceeds to allow for adjustment in response to changing circumstances or improved information. A high level Advisory Group can be a good mechanism for providing such reviews.
The preparation of a comprehensive river basin strategy can require significant time and resources. However, the first steps -- acceptance of the need for a comprehensive approach, designation of a lead agency, and identification of broad goals -- require breadth of vision and political commitment more than financial resources.
The level of detail in the analytical work required to define the objectives and to evaluate the strategies will depend on the complexity of the river basin and of its problems. In some cases, a simple model using estimated loads from a few critical sources may be adequate. For large complex water bodies the exercise can cost hundreds of thousands of dollars. (For further information see notes on: Optimizing Wastewater Management, and Water Quality Models.)
The involvement of specialist modelers (consultants or academics) is normally required but it is important that the analytical work is used a tool for the development of the strategy rather than as an end in itself.