c. Water Classifications. Water is classified in four different ways:
(1) Contaminated water. Contaminated water contains disease-producing organisms,
poisonous substances, or NBC agents. These make water hazardous and unfit for human consumption
or domestic use. Water can be contaminated, but not necessarily polluted.
(2) Polluted water. Polluted water contains substances such as garbage, sewage, industrial
waste, or mud that makes it objectionable because of appearance, taste, or odor.
(3) Palatable water. Palatability of water is a term, which describes the characteristic of
being pleasing to the sense of taste. To be palatable, water should be significantly free from color,
turbidity, taste, and odor, and should be cool and aerated. At least four human perceptions can be used
in judging these qualities. They are the senses of sight (color and turbidity), taste, smell (odor), and
touch (temperature). However, it must be understood that palatable water is not always safe to drink.
(4) Potable water. Potable water is water that has been properly treated and disinfected so
that it is free from disease-producing organisms, poisonous substances, chemical or biological agents,
and radioactive contaminants which make it unfit for human consumption and their uses. Also, it has
been approved by the command surgeon or his representative as being safe for consumption. Although
potable water is safe to drink, it may not be palatable.
d. Water Sources. Water sources are broken down into types, classifications, and categories.
(1) Types. There are two types of water sources: flowing (rivers, streams, and springs)
and impounded (ponds, lakes, and reservoirs).
(2) Classifications. There are three classifications of water sources: surface (streams,
lakes, and rivers), ground (wells and springs), and seawater.
(3) Categories. There are three categories of water sources. Fresh water has TDS range of
0 to 1,500 PPM. Brackish water has a TDS range of 1,500 to 15,000 PPM. Brackish waters we highly
mineralized and the alkalinity and salinity range is from very high to very low. This makes them
objectionable as drinking water supplies. Saltwater or seawater is water containing a TDS over 15,000
PPM. This is an approximation since no clear-cut line of distinction can be drawn between brackish and
saltwater. Typical salt water has a very high sodium chloride content and a low alkalinity. It is
generally found only in a free body of water such a ocean, sea, or estuary. The most abundant source,
the oceans, can contain total dissolved solids well over 50,000 PPM. Inland seas such as the Great Salt
Lake may have total dissolved solids of 200,000 PPM.
e. Impurities in Water. As water goes through its hydrologic cycle, it gathers numerous
impurities. Dust, smoke, and gases fill the air and tend to contaminate rain, snow, hail, and sleet. As
runoff, water picks up silt, chemicals, and disease organisms. As it enters the earth through seepage and
infiltration, some of the suspended impurities may be filtered out, but at the same