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 23 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, groundwater sampling, and chemical analysis of environmental samples (water and soils) for suspected contaminants. No significant contaminants were found at 17 of the sites. Fuel contamination (petroleum hydrocarbons or oil & grease) was detected at 5 sites, 3 of which also had volatile organics present. Remedial action was recommended for 2 sites because of the location and amount of contaminants detected.