To detect the presence of poisionous elements such as lead and to detect if there is contamination of the water source of harmful bacteria such as E Coli
For drinking, foods industry, chemical industry, nuclear reactors, irrigation, sport etc. we need water with well defined chemical, microbiological and radioactive characteristics.
World engineers recognize that solar panels do not provide necessary pumping energy sufficient to overcome large chemical potentials in desalination plants for drinking water because they think there is a way of making it happen.
No drinking water is necessary for your life
water
drinking fluid is good for you because it keeps your body hydrated.
Not drinking water
Drinking water is necessary to live. Drinking green tea, fruit drinks, and milk is healthy. Drinking coffee and soda pop is not necessary, but, it probably will not hurt, as long as they are drunk in moderation. Drinking a little bit of alcoholic beverages will probably do not harm, and might be healthy for the average adult person.
There are so many types of poisons that you'd have to be more specific. Typically, poisons interrupt a process necessary for life. Life is a set of thousands of chemical reactions that must proceed in a certain order and frequency. Even drinking too much water can kill someone by disrupting chemical balances necessary for nerve & cardiac cell function.
It is not necessary to cleanse the colon after drinking alcohol.
Cl+H2O
500 mg/l
L. Ranson has written: 'Multi-element analysis of drinking waters'