COMMERCIAL APPLICATION AND MARKETING OF WATER  PLANT RESIDUALS   The intent of this manual is to provide U.S. water treatment utilities with a guide for locating and developing alternative methods for the disposal of coagulant residuals. The beneficial uses associated with lime-softening water treatment plant residuals have been well documented in numerous past research studies and therefore are only briefly described in this manual. The primary focus of the manual was to research alternative uses for aluminum and iron-based coagulant residuals. State and public acceptance towards recycling water treatment plant residuals has improved due to increased knowledge about the content of coagulant residuals and its successful re-use demonstrated in numerous research studies. The majority of these research efforts have focused on agricultural or nonagricultural land application of the material. Research work has shown that coagulant residuals may or may not provide a benefit to a particular application but studies have consistently demonstrated that residuals pose little hazard potential to the environment or human health. The chemical composition of residuals is primarily inert inorganic material that, with the exception of a few elemental neutral concentrations, is very similar in content to the surround natural soils. Today, research has shifted towards locating uses for residuals as a substitute for other materials commonly used in the production of commercial products. This manual outlines 13 different markets that could potentially benefit by using at least one type of coagulant residuals material. At least some research work on full-scale implementation has been attempted for each of the markets listed. Each market is considered to be a beneficial use of coagulant residuals. Beneficial use is defined in this manual as an alternative form of disposal other than landfilling, sewer disposal, or wastewater treatment plant disposal (for purposes other than sulfide binding) that does not cause harm to the environment or threaten human health. A market description is provided for each of the 13 markets identified which includes information on some or all of the following issues:   General description and potential benefits Market size and geographical locations Manufacturing logistics Residuals application process Residuals physical and chemical quality requirements Case studies of actual utilities experiences   The manual also provides information concerning the economical and non-economical considerations that should be evaluated prior to marketing residuals for a particular application. Capital and operation and maintenance (O&M) cost curves are provided for some of the commonly used techniques for handling and dewatering coagulant residuals. Non-economic factors are also provided along with an example of how to perform an economical analysis for potential alternatives. The final chapter of the manual provides an outline of the basic procedure required to to initiate a successful marketing campaign for finding potential end users. The guidelines provide a general approach that could be tailored by a utility to address their site specific needs and hopefully assist with locating and developing a successful beneficial use program.