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s <br /> i <br /> cleanup of indicator compounds will address cleanup of less toxic, less <br /> mobile, and less prevalent species as well. This section will review species <br /> identified on-site in order to identify the indicator compounds for this site. <br /> All of the soil samples analyzed at the former AFPC site have been found <br /> to contain diesel fuel. Diesel fuel is predominantly composed of straight and <br /> branched chain alkanes with 12 to 22 carbons. Further chemical testing of <br /> selected soil samples was performed for volatile and semi-volatile compounds. <br /> The list of substances screened is contained in Table 4-1. The only <br /> substances detected were the polynuclear aromatic hydrocarbon (PAH) compounds l r <br /> Naphthalene, fluorene, .phenanthrene, and methylnaphthalene. Naphthalene wa . <br /> ._._ �.._..:...._. _ u :_..... <br /> detected at concentrations ranging from 3.4 to 7.8 mg/kg. ( Fluorene was <br /> detected 3n dffW—W 'm'ple at a concentration oiE 2.1 `mq�kg. Phenanthrene was <br /> detected at concentrations ranging from 1.0 to 5.1 mg/kg, and <br /> methylnaphthalene was detected at concentrations ranging from 3.9 to 13.0 <br /> mg/kg. Species that would be of primary concern that were not detected in any <br /> k <br /> tests are benzene, phenols, or carcinogenic PAH compounds (i.e., none. of the <br /> above PAHs have been found to be carcinogenic) . Based on prevalence on-site, <br /> E <br /> only the PAH compounds and TPH diesel have been identified as potential <br /> indicator compounds. <br /> To be considered as an indicator compound, a chemical must have air, <br /> water, or soil criteria from a regulatory agency. The applicable health and <br /> environmental criteria for naphthalene are given in Table 4-2. No such <br /> criteria are available for the other substances identified on-site. Diesel in <br /> ground or surface waters can be regulated as oil and grease, but oil and <br /> grease maximum contaminant levels (MCLS) as identified in CAC, Title 22, are <br /> much larger than the water quality criteria or the applied action levels for <br /> naphthalene. If substances were transported off-site, the applied action <br /> levels for naphthalene would be exceeded before the oil and grease MCL was <br /> I� exceeded. 'Thus, based on environmental and health criteria availability, the <br /> choice of indicator compounds is further limited to diesel and naphthalene. <br /> 4-3 <br /> t GGA/0179b <br />