Rayne and Guernsey soil material that had had 525 cm of acid mine water (AMW) passed through it was analyzed. The pH, Ca content, and percent base saturation of the soil material were lowered, and its CEC, acidity, and Fe and Al contents increased. The increase in Al and Fe contents was much greater than was the amount of Al and Fe added by the acid water. Thus, the acid treatments mobilized some native soil Al and Fe in the treated soils. The acid water treatment also created some new CEC sites. Phosphorous data showed a depletion of P in the Rayne and a redistribution of it downward in the Guernsey. Little or no change in particle size distribution and clay mineralogy occurred as a result of the treatment. The various effects of the acid water on the soil were the greatest in the upper parts of the soil.