Recent EPA-funded research into the onsite, mechanical evaporation of wastewater from single family homes revealed that a rotating disk evaporator (RDE) could function in a nondischarging mode. Such a device has potential use where site limitations preclude conventional methods of onsite disposal. This report documents a marketing analysis made of the RDE. The marketing analysis defined the market potential for RDE systems, developed a practical design, estimated production and installation costs, and refined market estimates based on cost comparisons. Total installed cost of an RDE system (including storage tank) was estimated to be in excess of $20,000 (1979). Because of the high cost, the potential RDE market is limited to very expensive homes, second homes with no winter occupancy, and high cash flow - low sewage flow commercial establishments. Furthermore, unfavorable climatic conditions eliminate much of the nation from consideration.