The document provides background information on EPA's technical support for selecting and developing the proposed treatment standards for the constituents to be regulated in acrylonitrile wastes. Section 2 presents waste-specific information (the number and location of facilities affected by the land disposal restrictions, the waste generating process, and waste characterization data). The technologies used to treat the waste or similar wastes are discussed in Section 3. All the available performance data, including data on which the treatment standards are based, are presented in Section 4. Section 5 explains EPA's determinations of BDAT, and Section 6 discusses the selection of constituents to be regulated. The proposed treatment standards are determined in Section 7.