This three-month program was a limited study of the feasibility of applying the pyrographic analytical technique to the characterization of municipal waste as it passes through a treatment plant. The pyrographic method is based on (1) pyrolysis of the waste in the presence of water, (2) separation of the resulting organic pyrolytic products with a gas chromatographic column, (3) measurement of the eluted products with a hydrogen flame ionization detector, and (4) analysis of the pyrogram. For this program, a breadboard pyrographic apparatus, which was initially assembled and used in 1967, was reactivated. Aqueous solutions of several different organic compounds were pyrolyzed to establish operating conditions and to verify the performance of the apparatus. Then samples of raw sewage and primary, secondary, and tertiary effluents from the Pomona Water Renovation Plant were pyrolyzed. The complexity of the pyrograms decreased as the wastewater passed through the plant.