When a release of hazardous substances has occurred or threatens to occur, federal, state, local government or industrial personnel may have to assume responsibility for immediate and planned removal which is the principal cleanup and treatment phase. The authors must select treatment and disposal processes, or countermeasures, which are effective for the particular hazardous substances and circumstances of the release. The manual contains procedures to assist response personnel in selecting optimum countermeasures. The procedures make up a rational methodology which consists of four decision-making steps in series, starting with identification of the substance(s) involved and site-specific parameters, and ending with an optimization of technically feasible countermeasures in the light of economic, logistic, and other criteria. The methodology uses comprehensive tables, or matrices, which provide technical guidance for almost 700 hazardous substances designated by the Comprehensive Environmental Response, Compensation and Liability Act of 1980, otherwise known as CERCLA or Superfund (PL96-510). Remedial action of a long-term nature, which follows removal, is not addressed here. The manual is designed as a reference for use in field or office and stands alone. It is based on available, sometimes incomplete, sources. Its purpose is to provide persons with a limited background a fast, workable guide to plausible removal countermeasures, given a reasonable amount of knowledge about the release. The user should be cognizant of federal, state and local regulations that may impact the decision to select specific countermeasures, and of the fact that these regulations may be amended from time to time. An example of the application of the manual to a real situation is included.