This report documents the first 2 years of a 3-year demonstration projected sponsored by EPA and Sonoma County, Calif. The purpose of the project is twofold: (1) to investigate the stabilization of solid waste in a sanitary landfill by analyzing leachate, gas, temperature and settlement parameters, and (2) to determine the effect on solid waste stabilization of applying, under various operational modes, excess water, septic tank pumpings, and recycled leachate in a sanitary landfill. This report describes the investigation of the test site, construction, instrumentation, and site operations and discusses the data produced thus far through extensive monitoring. Tables and figures following this report summarize the detailed data presented in the appendices.