Book excerpt: An Installation Restoration Program (IRP) Phase II, Stage 1 investigation was conducted at USAF Plant 42 in Palmdale, California, to confirm the presence or absence of contamination at 3 sites. Contamination was suspected at the sites as a result of past spills, leaks, or waste disposal practices. A field investigation program was conducted, consisting of soil boring and sampling, and chemical analysis selected soil samples for suspected contaminants. Soil samples were analysed for total petroleum hydrocarbons (EPA 418.1), volatile organics (EPA 8240), semivolatile organics (EPA 8270), and 8 RCRA metals plus 4 other metals. No significant contaminants were found at any of the sites. No further action was recommended for these sites because contaminants were indetectably low or occurred at such low concentrations that they did not pose a threat to health or the environment. Keywords: Hazardous waste, Contamination, Hydrogeology, Monitoring. (MJM).