On November 22, 1989, the Environmental Protection Agency (EPA, the Agency) proposed a rule to prohibit the land disposal of the final third of the schedule of restricted hazardous wastes, known as the Third Third. The proposal outlined treatment standards and effective dates of prohibition for these wastes as well as for some First and Second Third 'soft hammer' wastes, characteristic wastes, certain waste groups (e.g., multisource leachate, radioactive mixed waste), and newly listed wastes. The proposed rule was issued pursuant to the 1984 Hazardous and Solid Waste Amendments (HSWA) to the Resource Conservation and Recovery Act (RCRA). The Agency requested public comment on the proposal. The regulated community, environmental organizations, trade associations, State and Federal agencies, and concerned citizens submitted over 300 written letters on the proposed rule. EPA developed three volumes of a comment response document. The document (Volume 3 of 3) presents a summary of and responses to comments received by the EPA docket clerk up to (and after) the end of the public comment period on January 8, 1990.