A significant amount of water either naturally (such as lakes, rivers, and oceans) or man-made (such as ponds, lakes, and harbors).
A substance that may be harmful to humans or other forms of life when released into the environment.
a widespread outbreak of a contagious disease.
The force of attraction exerted between objects. Often, this is the force of attraction that the earth exerts on objects at its surface.
A disease-producing organism.
(potential of Hydrogen)
A measure of the activity of hydrogen ions in a solution. This is a measure of the solution’s acidity or alkalinity. is the logarithm of the reciprocal of the effective hydrogen-ion concentration and is a number between and ; the number has no units. A of indicates neutrality, that is, the solution is neither acidic nor alkaline. numbers lower than indicate acidity, while numbers higher than indicate alkalinity. Each change of represents a tenfold change in acidity or alkalinity.
To make something dirty, foul, or unclean.
Potable water is water that is clean enough to drink.
Water that falls from the atmosphere to the earth’s surface. The most common form of precipitation is rain. Snow, sleet, hail, and freezing rain are also forms of precipitation.