Based on laboratory studies and a review of many of thesemethods, Hampton and Miller (1988) concluded that therelationships investigated in their study were not sufficient toreliably predict hydrocarbon thickness in the formation. Ofthese relationships, the De Pastrovich et al. (1979) equationwas found to yield crude, order-of-magnitude approximationsof mobile LNAPL thickness. Wagner et al. (1989) comparedestimates using various techniques including simple andcomplex relationships, bail-down tests, and chemical analysisof soil samples. The study indicated that estimates from bail-down tests, analysis of soil samples from a test pit, adevelopmental hydrocarbon-sensing probe, and therelationship proposed by De Pastrovich et al. (1979) yieldedcomparable results at one field site. However, none of theaforementioned methods have been adequately evaluatedunder a variety of controlled and field conditions.