The document provides the background for EPA's technical support for selecting and developing treatment standards for the constituents to be regulated in the phthalate wastes. Sections 2 - 7 present waste-specific information for the K023, K093, and K094 wastes. Section 2 presents the number and location of facilities affected by the land disposal restrictions, the waste generating process, and the waste characterization data. Section 3 presents the technologies used to treat the wastes (or similar wastes). Section 4 presents the available performance data, including data on which the proposed treatment standards are based. Section 5 explains EPA's determination of BDAT, while Section 6 discusses the selection of constituents to be regulated. Proposed treatment standards are determined in Section 7. Section 8 presents a discussion of the development of proposed treatment standards for those phthalate wastes designated as U wastes (U028, U069, U088, U102, U107, and U190).