Ammonia is a naturally occurring form of nitrogen. As aquatic
plants and animals die, bacteria decompose nitrogen-containing
proteins into ammonia. Sewage, however, is a much more
significant source of ammonia than decomposing organic matter. A
high concentration of ammonia in a river system may be an
indicator of a recent sewage release to the river. High levels
of ammonia can be toxic to aquatic life. Water quality criteria
for ammonia are dependent on temperature, pH, and the presence
of salmonids. Assuming pH = 7.5, temperature = 15 oC, and
salmonids are present, the current water quality criteria for
ammonia (expressed as total ammonia) are: -Acute criteria for
protection of aquatic life: 15 ug/L -Chronic criteria for
protection of aquatic life: 130 ug/L Dissolved Oxygen (DO) The
majority of the oxygen in water comes from the atmosphere;
however, a large amount comes from photosynthesis of aquatic
plants. Decay of organic wastes such as sewage and dead plants
and animals are the main cause for decreases