Water quality monitoring in the different waterbodies all around the world is an important issue which all authorities and environmental organisations deal with. When water quality is poor, it affects not only aquatic life but the surrounding ecosystem as well. Therefore, in most countries an environmental water quality monitoring has been developed and is under operation.
The water quality of rivers change frequently during the day and depending on the weather conditions.
This was monitored on a project in the Elbe River: In this project for the first time the "Elbe swimming relay" accompanied with a research ship which was equipped with measuring water quality instruments. It made possible for researchers to characterize the quality of the water of the river Elbe for a 575 km long in detail which is shown below figure.
In many countries, there are water quality standards for the effluent of the sewerage treatment plants. In these standards, the different parameters like pH, conductivity besides organic load expressed as COD or BOD should be monitored. Further, in addition to these parameters, the quality of the water is important for the environment and living organisms anyhow.
Source water for desalination has a significant content of naturally occurring inorganic ions, and the objective of treatment is to reduce the concentration of, or remove, these substances. There are also many marine algae that can produce toxins of concern to human health. These issues are covered in detail in desalination technology: health and environmental impacts.
Bathing and swimming in the natural water bodies are one of the most popular recreational activities in the world. The most probable problem can be caused by nutrient inputs, in particular phosphates and nitrogen compounds, which may lead to eutrophication and facilitate a massive growth of algae (algal blooms).