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With a range of naturally occurring concentrations controlled by geology, pH is very important to both aquatic and terrestrial life. Carbonate units—limestone and dolomite—serve as natural pH buffers. Shales and slate units often times are comprised of low pH rock, such as the Anakeesta Formation in the Blue Ridge or shales associated with coal in Pennsylvanian-aged units in the Cumberland Plateau. Resource extraction such as mining can expose these units, leading to acid mine drainage, also known as "yellow boy."

Acute acid deposition occurs in higher elevations in Appalachia from emissions of sulfur dioxide and nitrogen oxides. Acid deposition causes acidification of lakes and streams and contributes to the damage of trees at high elevations (i.e. red spruce trees above 2,000 feet) and many sensitive forest soils.

Acid Neutralizing Capacity

Acid neutralizing capacity of water is a measure of the overall buffering capacity against acidification. It is often used in models to calculate acidification levels from acid rain pollution in different geographical areas, and as a basis for calculating critical loads for forest soils and surface waters.


Salinity is the amount of dissolved ions (salts) in water. We use measurements of specific conductance to provide a general idea about the magnitude of ionic concentration, but water quality measurements are necessary to quantify the exact ionic composition of water. Where land disturbances such as mining, urbanization, and deforestation occur, the affected waters will have elevated salinity. Road salting in the winter also will increase salinity; elevated salinity can effect aquatic life.

Last modified: 
03/30/2016 - 14:20