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A
measure of the relative acidity or alkalinity of water. Water with a pH
of 7 is neutral; lower pH levels indicate increasing acidity, while pH levels
higher than 7 indicate increasingly basic solutions. Lead, copper, zinc,
cadmium, aluminum, iron, manganese and selenium are some of the most commonly
found heavy metals
in the runoff from mining areas. There are also significantly high levels
of acidity in these areas. It has been found that pH levels of about 3-4
are common in mine discharge waters. A pH level of 3 corresponds to an increase
of 10,000 times the acidity in 'neutral' water, which has a pH level of
7. Many species of water creatures, such as frogs and salamanders are known
to have reproductive problems in waters with pH levels much below 5.5. Click
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