The Government establishes limits for bacteria and pollutants in water and controls the quality of drinking water in public water systems. But occasionally, public drinking water is contaminated with dangerously high concentrations of microbes and pollutants. At the water's source (such as groundwater or water from lakes or rivers) or while the water is being distributed, after the water treatment plant has already removed germs and chemicals from the source water, the bacteria and chemicals can enter the water.
Some persons are more susceptible to illness from waterborne pathogens and chemicals:
individuals with compromised immune systems, such as those who are HIV positive, receiving chemotherapy, or taking transplant drugs.
Crytosporidium, Legionella, campylobacter, Norovirus,E.coli, Enterovirus,Salmonella, Giardia, Shigella, Hepatitis A virus.
People who drink contaminated water are exposed to certain water contaminants that may cause some waterborne diseases. Waterborne infections are those that are brought on by pathogens like viruses, bacteria, and protozoa. Some of these diseases are also brought on by the poisons that toxic algae and cyanobacteria release. Chemicals from manufacturing and industrial facilities, farming and agricultural practices, human activities, and many more are examples of other primary sources.
Why does the taste of water changes when boiled?
In addition to dissolved carbon dioxide and oxygen, potable water also contains a number of other dissolved substances, such as salts of calcium, magnesium, sodium, and potassium.
Together, the pH and its composition give the water its distinct flavour. The taste will still be compromised to that degree even if one or two of these solutes are missing or altered.
When carbon dioxide is dissolved in water, it interacts to form carbonic acid, which then irreversibly dissociates to form low amounts of hydrogen ions and bicarbonate ions.
Therefore, the concentrations of dissolved carbon dioxide and bicarbonate ions (from all sources) control pH.The bicarbonate ions, on the other hand, are heat-sensitive and go through thermolysis to produce carbonate ions and carbon dioxide. When water is boiled, both of these types of carbon dioxide—along with dissolved oxygen—are released.
The reentry of carbon dioxide cannot entirely compensate for the loss of bicarbonates, even after cooling. All of this results in a decrease in the concentration of hydrogen and bicarbonate ions (raised pH) and an increase in the concentration of carbonate ions in boiled water. Consequently, the taste of boiled water has changed (even after cooling).
If one is certain that there are no microorganisms present in the water, there is no need to boil it. However, if pathogenic bacteria are likely present, there is every reason to boil and cool the water, even if it means a slight loss of flavour.
