Prevention and control of groundwater pollution

REGIONAL SITUATION

Groundwater plays an important role in drinking water supply and often constitutes the only source available in urban and rural areas of Latin America and the Caribbean. However, in the majority of cases little attention has been paid to preventing the pollution of groundwater sources and even less to the protection of aquifers as a whole.

In some areas, principally within the large urban centers or in the surrounding areas, groundwater pollution has already occurred resulting in potential public health risks and the abandonment of water sources with the consequent loss of financial investments and natural resources. Groundwater pollution is a gradual phenomenon that appears slowly but is persistent and acquifer recovery is technically difficult, excessively expensive and frequently, not practical.

The most common groundwater pollution of the Region is associated with sanitation of areas that do not have sewers, inadequate final disposal of industrial effluents and inappropriate agricultural practices. The increase of nitrate concentrations in groundwater and the frequent episodes of contamination with volatile halogenated hydrocarbons, pose a serious danger for drinking water quality in compliance with the current guidelines established by WHO for drinking water.

OBJECTIVES

To contribute to the improvement of water quality of groundwater and the aquifers of the Region, the Pan American Health Organization (PAHO), through its Division of Health and Environment (HEP) and the Pan American Center for Sanitary Engineering and Environmental Sciences (CEPIS, Spanish acronym), initiated, in 1984, an action plan for the prevention and control of groundwater pollution, the objectives of which are:

1. To identify the principal problems of groundwater pollution of the Region.
2. To identify the institutions with appropriate infrastructure and sufficient human resources to absorb and apply the technology to control groundwater pollution.
3. To mobilize the Member Country institutions through an informal cooperating network that will receive orientation of CEPIS and the British Geological Survey (BGS).
4. To prepare a series of technical documents on the control of groundwater pollution applicable to the context of Latin America and the Caribbean.
5. To disseminate this technology through Regional workshops and seminars.

STRATEGY

The mechanism used to reach a harmonious work plan is the technical steering committee, composed of experts of the BGS and CEPIS and the professionals of the national/regional institutions with an awareness of the problems and national needs as well a knowledge of the technical and economic capacity of their institutions to confront these problems. This technical steering committee, which convened for the first time in 1984, provides knowledge and orientation and establishes the general guidelines of the work plan at the Regional level.

RESULTS

The Regional action plan for the prevention and control of ground water pollution has fulfilled its first four objectives.

Currently, the activities are in the technology dissemination stage through the promotion of regional workshops and seminars, based on the manuals and reports that have been developed.

During 1991-1998 national courses have been held in São Paulo, Salvador, and Porto Alegre (Brazil); Cartagena (Colombia); Córdoba (Argentina); Santo Domingo (Dominican Republic) and Bridgetown (Barbados), Querétaro and Metepec (Mexico), and Buenos Aires, Argentina.

The coordination of this program is the responsibility of:

Mr. Henry J. Salas
Regional Coordinator
CEPIS

The primary consultant to the program is:

Dr. Stephen Foster
Technical Coordinator
BGS

PRODUCTS

• CEPIS (1987). Groundwater: an undervalued resource in need of protection. Lima, CEPIS. (English and Spanish)

• FOSTER, S., VENTURA, M. & HIRATA, R. (1987). Groundwater pollution: an executive overview of the Latin American-Caribbean situation in relation to potable water supply. Lima, CEPIS. (English and Spanish).

• FOSTER, S., LEWIS, W.J. & DRASAR, B.S. (1988). Analysis of groundwater pollution due to basic sanitation systems, Lima, CEPIS. (Spanish only).

• FOSTER, S. & HIRATA, R. (1991). Groundwater pollution risk assessment: a methodology using available data. Lima, CEPIS. (English and Spanish).

• FOSTER, S. & GOMES, D. (1989). Groundwater quality monitoring: an appraisal of practices and costs. Lima, CEPIS. . (English and Spanish).

• FOSTER, S., et al. (1992). Groundwater protection strategies: a guide towards implementation. Lima, CEPIS. (English and Spanish).

• FOSTER, S., et al. (1994). Impacts of wastewater use and disposal on groundwater. Technical report WD/94/95. British Geological Survey, WHO/PAHO, Overseas Development Administration. Keyworth, Nottingham (English and Spanish).

The above publications are available at the CEPIS web site or may be requested to the CEPIS Publications Office.