The Organic Contract Compliance Screening System (OCCSS) software is a version of a mainframe-based application developed by Viar and Company for the U.S. Environmental Protection Agency's National Contract Laboratory Program (CLP). OCCSS is designed to automate the determination of contractual compliance and completeness of data submitted to EPA under the Routine Analytical Services (RAS) programs of CERCLA (Comprehensive Environmental Response Compensation and Liability Act) and SARA (Superfund Amendments and Reauthorization Act). The manual provides the user with instructions for running OCCSS software on the PC. Descriptions of and instructions for each menu are detailed in the following sections. The user should have a working knowledge of PC DOS prior to utilizing this system. The following sections present the OCCSS operating environment, describe system output (reports), provide instructions for running the system and generating reports, and specify input data requirements. Examples of reports are contained in Appendix A. Appendix B contains descriptions of sample suffix codes and report defect codes. Appendix C is a listing of defect statements by criterion with associated SOW references. Data Formats A and B from the Organic RAS SOW (2/88) are included as Appendix D. Since OCCSS PC software is implemented using Base SAS Software, the 'SAS Language Guide for Personal Computers' from The SAS Institute, Inc. in Cary, North Carolina may be helpful.