Although not necessarily agents of disease, fecal coliform bacteria indicate the presence of disease-carrying organisms, which live in the same environment as the fecal coliform bacteria. A certain minimum amount of dissolved oxygen must be present in water for aquatic life to survive. Temperature is important because it governs the kinds of aquatic life that can live in a stream. For instance, streams must be cooler than 64 degrees Fahrenheit for salmon to successfully spawn. Neutral pH is 7.0.
Acidity increases as the pH gets lower.
Banned from production in mid-1970s. Accumulates in fish tissue. Highly persistent organic chemicals. Harm aquatic organisms. Accumulate in fish tissue.