North Fork Watershed Association
Friday, January 22, 2021



Acid deposition is 'deposited' on the earth's surface in different ways.  The one we are most familiar with is  rain, but snow and ash can also be abnormally acidic and contribute to the same problems acid rain does.  This is why you will often see acid rain referred to as 'acid deposition'. 

Acid deposition is found around the globe at varying pH levels since it is directly related to sulfur and nitrogen containing compounds found in polluted air.  These compounds create sulfuric acid and nitric acid when mixed with water and are deposited in the form of rain and/ or snow up to, or over, 1000 miles away depending on the prevailing winds.  As would be expected, winds coming from the west are subjecting areas east of more populated cities to a greater degree of acid deposition.  Since our watershed, as with Pennsylvania in general, receives a large amount of rainfall on average each year, we are particularly susceptible to the affects of acid deposition.      

There are many interesting sites dedicated to acid deposition.  For further explanation on wet and dry deposition visit: