What do the following terms mean in relation to drinking water quality:
disinfection, pathogenic, toxic, pH, aesthetic, culinary and potable.
Disinfection: The chemical process of killing or inactivating most microorganisms in
water. See also Sterilization.
Pathogenic: Organisms or bugs that cause disease. These include bacteria, viruses,
cysts and anything capable of causing disease in humans, like cryptosporidiosis, typhoid,
cholera and so on. There are other organisms that do not create disease, these are called
non-pathogenic organisms.
Toxic: Stuff that will kill you. A substance which is poisonous to living organisms.
pH: A measure of the acidity of water. The pH scale runs from 0 to 14 with 7 being
the mid point or neutral. A pH of less than 7 is on the acid side of the scale with 0 as the
point of greatest acid activity. A pH of more than 7 is on the basic (alkaline) side of the
scale with 14 as the point of greatest basic activity. For example, the acidity of a sample
with a pH of 5 is ten times greater than that of a sample with a pH of 6. A difference of 2
units, from 6 to 4 , would mean that the acidity is one hundred times greater, and so on.
Normal rain has a pH of 5.6 – slightly acidic because of the carbon dioxide picked up in
the earth's atmosphere by the rain.
Aesthetic: Attractive or appealing water or things in water that will not make you sick
but may appear to change the water’s color or taste.
Culinary: Having to do with cooking food. Potable water is often called culinary water.
Potable: Water that is free of objectionable pollution, contamination, or infective
agents. Generally speaking, we serve only potable water and not palatable water.
Palatable is pleasant tasting water.
What is hardness in water and what chemicals cause it?
Hardness: Water that contains high amounts of dissolved minerals, specifically calcium
and magnesium. Ion Exchange: A method of water softening where hardness causing
ions are exchanged with sodium ions; also effective in removing many inorganic
contaminants such as nitrates, copper, and lead; and treating aesthetic water problems.
What is Escherichia Coliform and what does it indicate in relation to drinking
water?
E. coli is a sub-group of the fecal coliform group. Most E. coli bacteria are harmless and
are found in great quantities in the intestines of people and warm-blooded animals. Some
strains, however, can cause illness. The presence of E. coli in a drinking water sample
almost always indicates recent fecal contamination meaning there is a greater risk that
pathogens are present.
