2.  pH is a measure of the acidity or alkalinity of a solution  Pure water is said to be neutral or consisting of a pH of 7  When testing pH you are not testing for the presence or absence of pH, you are testing the level of pH

4.  Ammonia and nitrogen may find its way into waterways through fertilizer use.  Aquatic life and fish also add to ammonia and nitrogen levels.  Plants are more tolerant of ammonia than animals, and invertebrates are more tolerant than fish  The major impact of nitrates/nitrites on fresh water bodies is that of enrichment or fertilization called eutrophication.

5.  Chlorine is most commonly used as a disinfectant in water because it is effective against a wide range of microorganisms  Kills disease producing bacteria

6.  Chromium occurs in natural water sources at low levels  High levels of chromium may occur from runoff from electroplating, chrome, or preservatives in wood  Plants and animals do mot bioaccumulate chromium  Acute toxicity occurs in the form of skin lesions and may lead to cancer

7.  Copper is an essential element to the human body  Large doses may cause liver damage  May accumulate in natural water sources from sewage or industrial wastes

8.  Cyanide is extremely toxic  It may be present in water containing waste from metal finishing

9.  Iron is found in most natural waters and tap water (found in abundance in the earths crust)  Iron is a trace element required by both plants and animals (allows blood to transfer oxygen)  There is no real negative health affects from iron

10.  Nitrogen occurs in natural waters as nitrate (NO 3 ), nitrite (NO 2 ), ammonia (NH 3 ), and organically bound nitrogen.  Sewage is the main source of nitrates added by humans to rivers.  Another important source is fertilizers, which can be carried into creeks by stormwater runoff.  Excessive nitrates stimulate growth of algae and other plants, which later decay and decrease the amount of oxygen in the water.

11.  Phosphorus is another nutrient essential for plant growth  Large amounts of phosphates in water can lead to excessive algal growth  Phosphates are commonly used as fertilizers and household detergents

12.  Is often found in natural waters  Silica is found in the exoskeleton of diatoms which are found in most natural waters

13.  Sulfide may be found in water as a result of microorganisms decomposing plants  High concentrations create a rotten egg odor