Water quality is often understood in its narrowest meaning where the focus is limited and reduced to portable water. Often at homes, schools, and communities as well as even among policy-makers and politicians, especially in developing countries, the knowledge is still limited to drinking water. This can be true on short-term and small-scale levels to secure affordable and accessible water resources with acceptable quality to mitigate immediate and epidemic impacts on human health.
However, this understanding has generated serious and widespread global threats with disastrous impacts on ecosystem and human health worldwide. This is evident from historical “palaeo-environmental” data that gives information on evolution of water quality and its degradation in natural water resources, e.g. rivers, lakes, reservoirs, marine coasts, wetlands and groundwater. Long-term and large-scale monitoring of the quality of natural water resources and associated impacts on eco-system and human health are IMPERATIVE and there are standard ways to do such studies. Typically, there are two approaches: (1) continuous monitoring of contemporaneous water quality status, such as those given in the present report given in the provided link; (2) full historical records on the evolution of water quality due to point/diffuse pollution sources.
Both approaches are necessary have different and important benefits. The first one is used for “Early Warning” with direct coupling to enforce regulation and laws on stakeholders regarding production of waste/pollution, also to take necessary measures and solutions to cope with the threats, and to give relevant information to the public. While, the second is important for uncovering long-term and large-scale impacts on water quality, e.g. acidification, eutrophication, chemical pollution, other industry/agriculture associated threats and climate impacts. It is, also, useful for assessing consequences of environmental and ecological impacts of pollution/waste in terms of their cycles from source to sink. This outcome of the seconds approach has feedback impacts on international laws and regulations and for implementation appropriate rehabilitation strategies.