Environmental sanitation


The objective of this policy is to ensure that the financial assistance and technical cooperation which the Bank provides in the basic environmental sanitation sector effectively helps the member countries in their efforts to improve the health and welfare of their inhabitants. The Bank will continue to support both the construction of new systems and the expansion, rehabilitation and improvement of current systems.

In accordance with this objective and bearing in mind past experience, the Bank provides the countries with cooperation in order to assist them in their efforts to:

  • Undertake the planning and programming of their investments in basic environmental sanitation, in harmony with their priorities and their investments in other interrelated sectors and based on socioeconomic, technical and financial criteria;

  • Strengthen the technical, financial, administrative and operating capacity of the institutions in the basic environmental sanitation sector;

  • Encourage health education and community promotion activities, which are basic to the success of water supply and sewerage programs, especially in rural areas and marginal urban areas; and

  • Strengthen permanent systems that improve the identification, selection, preparation and evaluation of projects, in accordance with generally accepted standards.

Fields of Activity

The Bank can provide financing and/or technical cooperation for basic environmental sanitation projects in:

l. Rural and urban potable water supply, including production, treatment, transmission, distribution and macro and micrometering;

2. Collection, treatment and disposal of sewerage in urban and rural areas. This includes the possible recycling of treated water for irrigation purposes and the recharging of aquifers, as well as the production of energy through biodigestion;

3. Collection and disposal of urban storm–water runoff;

4. Drainage of the project area, when technically recommendable, in order to ensure both the installation and proper operation of the water supply and sewerage systems;

5. Collection, treatment and disposal of urban solid wastes, including the possible production of by–products for agriculture and of recycling materials for industry; and,

6. Removal of pollutants and prevention of pollution of the soil, watersheds, water courses and the air.

Technical cooperation will be directed toward the strengthening of institutions in the basic environmental sanitation sector and emphasis will be given to the following activities: operation and maintenance, community promotion, training, administration and management; preparation of sectoral plans and studies and project preparation; evaluation of methods to improve future project preparation and implementation; support of the countries' efforts to adapt their legislation and improve operational performance; horizontal cooperation; the study of losses and wastage in order to make water use more efficient; the application of technologies geared to the level of development; and research projects.

Basic Criteria

The fundamental basic criterion is the need to have available the benefits derived from basic environmental sanitation. The Bank's assistance will be based on the following specific guidelines:

In expansion programs, the Bank will assign priority to those projects that envisage the rehabilitation and improvement of existing systems in order to make more efficient use of the services and ensure that the works and equipment are maintained in accordance with the standards established by Operations Policy 717 (Maintenance and Conservation of Physical Works and Equipment).

To finance the construction of projects it is required that an adequate organization exist, with suitable personnel to guarantee efficient operation and maintenance of the systems. At the same time, the Bank will encourage the strengthening of national agencies capable of advising other public sector institutions in the identification, formulation and execution of their projects.

The participation of the community and of various groups of beneficiaries may be a critical factor in the success of projects in the sector. Consequently, in the design and dimensioning of the projects, both the interest in the service as well as the degree of participation of beneficiaries in the various phases of the project, such a construction, administration, operation and maintenance, shall be determined, having available for this the technical cooperation of the Bank.

The levels of service and coverage must be defined in each project on the basis of socioeconomic information on the community to be served, as well as to its financial and administrative capacity. Making use of the most appropriate technologies will be encouraged in order to employ national capacities and endeavor to achieve the design of systems that are easy to operate and maintain.

Water supply and sewerage projects must satisfy appropriate selection criteria that take into account, inter-alia the following factors:

a) their relationship with the national development plans;

b) larger population centers without service;

c) availability of water sources of adequate volume and quality;

d) sanitation problems that require urgent attention; and,

e) motivation of the community to make rational use of the services.

Parallel to the provision of potable water, there must exist or be included some solution for the disposal of human wastes using technologies best suited to the specific situations.

The tariff structure for services will be governed by Operations Policy 708 (Public Utility Tariffs).

The water supply and sewerage systems with house connections for which financing is provided must include an appropriate plan for the incorporation of users. The availability of resources to cover the cost of the following must be assured:

a) household connections a part of the project works;

b) future household connections; and,

c) minimum in–house connections (wash basin, water closet and shower), which may be financed by the Bank when pertinent.

In water supply projects the source of supply must be reliable and its flow determined on the basis of appropriate records and measurements. In this regard, special attention will be given to measures for watershed protection in accordance with Operation Policy 723 (Forestry Development). In the case of groundwater supply, hydro–geological studies must be available and yield from the wells must have been proven. For surface water, the treatment must be in accordance with the physical and chemical properties of the raw water. The physical–chemical and bacteriological quality of the water delivered to the user must meet generally accepted standards. Studies will be required oriented towards reducing the level of water unaccounted for and preference will be given to financing works and activities resulting from those studies, as a rational and economic means of extending the service to sectors with deficit and of postponing, whenever recommendable, expansions of capacity.

In urban sewerage projects, special attention will be given to the problem of pollution and the possible recycling of waste–water in accordance with the general idea of making more rational use of water resources. Waste–water must be properly treated so as to ensure that the minimum characteristics of bacteriological quality of the receiving body of water are maintained. These characteristics will depend upon the use of that water body and the pertinent national legislation. Owing to the high cost of water–flushing public sewerage systems, in small cities and outlying districts the level of service will be based on the use of low–cost technologies and in situ disposal as a first stage of system development. In the rural areas, in situ disposal will be encouraged.

Solid waste disposal projects will be considered by the Bank when they meet existing or foreseeable urgent environmental needs related to health. Special attention will be given to the use of treatment methods whose by–products contribute to the economic benefits of the project.

The Bank's assistance in air pollution control projects will be consistent with the norms of Operational Policy 703 (Environment).

In integrated rural and urban development projects, the basic environmental sanitation components must be compatible with the provisions of this policy. The Bank will try to ensure that the benefits of basic environmental sanitation are adequately extended to low–income groups.

In projects in which it is necessary to acquire rights to sites, water sources, easements, etc., it will be required that procedures be clearly established for the purpose of ensuring that those rights are acquired before the call for bids for the works to be executed on those sites, or if such works are lo be executed by force account, before they are begun.


Prevailing Reference Document: GP–111–12, September 1984.

* The operational policies of the Inter-American Development Bank are intended to provide operational guidance to staff in assisting the Bank's borrowing member countries. Over the course of the Bank's 40 years of operations, the approach to developing operational policies has taken various forms, ranging from the preparation of detailed guidelines to broad statements of principle and intent. Many policies have not been updated since they were originally issued, and a few reflect emphases and approaches of earlier years which have been superseded by specific mandates of the Bank's Governors, the most recent being the Eighth Replenishment mandates of 1994.

In accordance with the Bank's information disclosure policy, the Bank is making all of its operational policies available to the public through the Public Information Center. Users please note that the Bank's operational policies are under a process of continuous review. This review process includes preparation of best practice papers summarizing experience at the Bank and other similar institutions, and sector strategy papers.