argues that a fresh look at methods
monitoring water quality is essential
needs are to be met
We have hitherto tended to worry more about water quantity than water quality. Fear of scarcity has dominated the debate and many recent studies have painted a picture of diminishing water resources in countries around the world. But water resource managers are now beginning to be more concerned about quality. Already, in some parts of the world and especially in many developing countries, shortages of freshwater of good quality are threatening economic development.
Impairment of water quality, usually manifested when certain water sources cannot be used for all purposes, can make a direct contribution to water scarcity. For example, water polluted by agricultural and urban runoff, or by municipal and industrial wastes discharged directly into rivers and lakes with little or no pre-treatment, may no longer be suitable for drinking. This represents a loss of water for specific purposes. Alternatively, where polluted water is given expensive pre-treatment, it represents a direct cost to the national economy.
The effective management of water resources demands that attention be paid to three essential activities, all of which require accurate information about water quality:
Water monitoring is also required for political purposes - such as management of international rivers -
or for national reporting to meet international treaty obligations.
- Water resource planning at local, regional and national levels.
- Regulatory activities, including effluent control and enforcement.
- Investment in infrastructure for remedying and preventing pollution.
Many countries began water quality monitoring in the 1960s or early 1970s, focusing on issues that were then important: namely the presence of major minerals, microbiological hazards such as fæcal coliform, and aquatic plant nutrients such as phosphorous and nitrogen.
By the mid-1970s the role of heavy metals in public health had become important and by the 1980s the presence of man-made micro-organic contaminants, especially chlorinated compounds such as PCBs, and pesticides such as DDT, became important to environmental management, and were included in many monitoring programmes.
Inadequacies in monitoring
In the late 1980s and early 1990s it began to be clear that the perceived link between monitored chemical parameters and human and environmental health was often tenuous. For environmental health, it was even inappropriate. Consequently, monitoring programmes, especially in developed countries,
began to include direct measures of environmental response - often known as 'effects assessment'. This type of monitoring included both the direct testing of the toxic effects of water chemistry using laboratory organisms (bioassays) and the in-stream evaluation of the health of aquatic ecology. The rationale for this approach was that it was better to determine the health of the aquatic ecosystem directly than to attempt to make assumptions about the links between chemical monitoring and ecosystem behaviour.
Chemical monitoring at fixed sites and at fixed intervals of time has become the main form of data collection for most developing countries. But over the past few years, and especially in developing countries, as the requirements for water quality data have increased, it has become clear that it is inefficient and costly to try to answer all types of water quality issues with a single approach to data collection. It has also become clear that the reliability of data from many monitoring programmes is poor. As a result, some countries are seeking greater value, reliability and efficiency from monitoring.
This process involves a fundamental shift of perspective. In the past, for example, it was assumed that conventional monitoring programmes produced data that were useful for a broad range of planning and environmental management purposes. However, it has become apparent that conventional data programmes are insufficiently linked to the specific data needs of water managers and planners.
One example of a country that has carried out a revaluation of its water quality data programmes is Mexico. Here the Government has undertaken a complete modernization of water programmes, including monitoring. This has necessitated modifications in water quality legislation, as well as institutional change.
The process of looking afresh at monitoring needs includes a revaluation of the purpose of monitoring, as well as greater cooperation with organizations and individuals who use the data. It can also involve a fundamental rethinking of the role of the state and answer some important questions. Should the state carry out monitoring? Should the role of the state be one of establishing national standards for both public and private sector monitoring?
This fresh look at the purpose and method of water quality monitoring is urgently needed in many developing countries. This is especially true where water quality has become a major impediment to economic development, and where the lack of coordination between different data collection organizations is hampering governments' abilities to plan national water policies
Ed Ongley is Director, UNEP and Collaborating Centres for GEMS/Water, Canada Centre for Inland Waters, Burlington, Ontario, Canada.
UNEP's Global Environment Monitoring System (GEMS) runs a Global Water Quality Monitoring Programme. GEMS/Water has developed a particular expertise in evaluating and advising public agencies on the modernization of programmes for monitoring water quality. Modernization can include not only technical issues (e.g. laboratory and field monitoring procedures), but also institutional development and, in some cases, modifications in legal requirements that have become barriers to change. More information can be obtained from the GEMS/Water Programme at UNEP Headquarters (P.O. Box 30552, Nairobi, Kenya) or the GEMS/Water Programme Office at the World Health Organization (Avenue Appia, CH-1211 Geneva 27, Switzerland). Additional information is available on the GEMS/Water Web Site (http://www.cciw.ca/gems).