This paper presents a modified static total pressure method coupled with appropriate data analysis procedures which provide infinite dilution activity coefficients (gamma(infinity)) and solubility (x(sat)) for volatile organic compounds in water. A large, calibrated vapor space minimizes the impact of noncondensable compounds. The degassed solute is micrometered incrementally into the cell containing water. The meterings continue into the two-liquid-phase region. This results in a discontinuous P,z curve. The number of measurements taken for each experimental composition are greater than the number required to establish equilibrium. Data reconciliation methods accounting for the errors allow use of all measurements to provide estimates of gamma(infinity) and x(sat). Experimental design methods testing the impact of experimental errors, potential sources of bias, and the number and volume of the solute meterings verify the accuracy and precision of the resultant gamma(infinity) and x(sat) values. Experimental results for acetone + water and experimental design studies of partially miscible systems are presented.