The standard of water can be summarized into three parts: physical, chemical and biological.
The ultimate goal of standdization of water is to provide pure water at its most quality.
For Biological, microorganisms tend to thrive in water sample thus affecting the health of the living creatures dependent to it. there are standards of level of microorganisms that is allowable in an open water. waters in refilling station assures a 100% microorganism free by methods specified by their machinery (e.g distillation, bacterial count etc.)
for chemical, the allowable content of soluble and non-soluble compounds are measures. for example
if it exceeds it can cause damage on living organisms. water stations ensudres that limit is not attained everyday.
for physical, we consider the topology of the water sources. It would be beneficial for the manufacurer to locate water sources with the most pure content. ut would be a lot easier to clean a water sample from a source with less pollution. This areas also include the proper waste management of the institutions for example the factories and the mining companies that produces large waste that affect the purity of water samples in terms of chemical content.
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