Mandate and use of national data sources

Currently data on groundwater quality is scarce due to the lack of national monitoring programmes for groundwater quality in many countries and the limited public accessibility of data from those who have national monitoring networks. With exceptions such as the requirements of the European Union (EU) Water Framework Directive (WFD), many states and national agencies are not required to make available data and information on groundwater quality. Even if data is publicly available, questions arise about its reliability, representability and quality, unless there was a quality assurance process to international standards.

Additional challenges arise from existing monitoring programmes that are focused towards drinking water quality (for human health) or irrigation water quality and less frequently for ecosystems. All of these require different standards of “good” water quality. Especially in the Global South, existing monitoring programmes may focus on few basic quality indicators of palatability (e.g. major ions) with less capacity to measure parameters of health concern (As, F and bacteria). The impacts of groundwater quality on the operation of groundwater abstraction schemes and wellfields is also rarely accounted for or monitored. Once again this is especially the case in the Global South, where poor groundwater management (e.g. incorrect borehole pumping regimes) can lead to clogging of boreholes (resulting in declining yields) and failure of abstraction infrastructure as a result of iron/manganese oxide/hydroxide precipitation, and the consequential “failure” of groundwater supplies.  

For interpretation, individual monitoring data need to be seen in the context of the sampling methods, locations, sampling wells or boreholes, depths, sampling protocols and lab analyses performed. Often this additional information is not available. Additionally, data may be stored at different institutions and not in a central national repository or at one institution responsible for keeping and making available groundwater quality data. 

Public accessibility of groundwater quality data is further hampered by national restrictions to make groundwater data available for research or multi-lateral reporting and assessment purposes. There are, however, examples of international norms that offer guidance how such data can be better made available for the public (e.g. United Nations Economic Commission for Europe [UNECE] Aarhus convention, EU WFD, etc). Additionally, incentives can be developed to encourage academia and industries to contribute to regional and national assessments.

Most monitoring programmes for groundwater quality are based on national level legislation and regulations, where these exist. Special care is required for groundwater quality challenges in transboundary aquifers. To fill knowledge gaps and prepare an improved and fair basis for transboundary cooperation requires development of comparable standards for the aquifers, data sharing and joint capacity development programmes.