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Point-source application of fine-grained limestone aggregate in seven acidic tributaries of Shavers Fork, West Virginia, resulted in increases in pH, acid neutralizing capacity, and dissolved calcium:hydrogen ion ratio (DCa:H), and decreases in monomeric aluminum (Al{dollar}\\sp{lcub}3+{rcub}).{dollar} In streams affected by atmospheric acid deposition, the increase was large enough to consistently maintain the DCa:H ratio above the critical threshold for trout survival. The most effective method of treatment was found to be the annual application of sand-size aggregate at a single point source using enough limestone to neutralize double the annual acid load. Factors controlling the amount of increase in DCa:H include discharge, influent pH, temperature, channel length, and morphology. Although some limestone particles were transported over 1 km in a single storm event, during a three year period most limestone particles remained within a few hundred meters of the source. There was no evidence of limestone depletion at the stream bed sediment surface during low flow periods. Streams with a high ratio of pool to riffle area had higher increases in DCa:H than streams with low pool:riffle ratios. The influence of channel morphology on calcium concentration increase becomes greater with time after application, and is most influential at low flow conditions. Oxygen availability may be a limiting factor in acid neutralization in streams affected by acid mine drainage.