The impact of initial organic carbon concentration, powdered activated carbon (PAC) dose and type, contact time, coagulation and oxidation on the adsorption of natural organic matter (NOM), as measured by total and dissolved organic carbon (DOC) and ultraviolet absorbance (UVA), was evaluated on seven raw water sources. Two models were developed based on the results of four waters and applied to predict the results of three external waters. A simple relationship between DOC fraction removal and UVA fraction removal was found to be successful in predicting DOC fraction removal. Three empirical models based on powdered activated carbon (PAC) type were developed for predicting DOC removal by PAC as a function of initial DOC concentration, PAC dose, and contact time. Includes 2 references, table, figures.