Where such stations did not exist, new ones were established. At that time it was estimated that a total of about 1200 stations might ultimately be required to achieve representative global coverage. Measurement of water quality variables at these stations include natural as well as anthropogenic constituents. The years 1977 to 1979 were used as a preparatory phase during which time guidelines were prepared, specialists were trained in the different regions, and national, regional and global centres were established. In addition, laboratories were designated to conduct the routine sampling and analysis at the selected monitoring sites.
Technical support is provided by two WHO regional centres for environmental health.
In addition, institutes have been designated as regional reference laboratories for implementing the analytical quality assurance component of the project. The Global Data Centre is located at the Canada Centre for Inland Waters, Burlington, Canada, which was designated both a WHO Collaborating Centre on Surface and Ground Water Quality and a UNEP GEMS Collaborating Centre for Freshwater Monitoring and Assessment. The Environmental Monitoring and Support Laboratory, Cincinnati, of the U.S. Environmental Protection Agency serves as the global centre of analytical quality control. WMO has concentrated on network design criteria and hydrological monitoring methods. The initial phase of the project, 1977-81, has led to the completion of a basic monitoring network, and routine operations with regard to data flow were established for most stations during 1978 or 1979.