However , if the soils are drained , excavated or exposed to air by a lowering of the water table , the sulfides react with oxygen to form sulfuric acid .
In an undisturbed state below the water table , acid sulfate soils are benign .
If the soils are drained , excavated or exposed to air by a lowering of the water table , the sulfides react with oxygen to form sulfuric acid .
In an undisturbed state below the water table , acid sulfate soils are benign .