1 Mar 98
4. Test Methods.
a. The level of contamination is an important parameter in determining the suitability of a
contaminated soil for use in a ASB. Several states and other agencies use Total Petroleum
Hydrocarbons (TPH) as a measure of contamination (Bell 1990, Bauman 1991, and Friend 1996).
The problems with using TPH as the measure of contamination include a lack of national
standards for measuring TPH and some analytical inconsistencies. Also, the parameter does not
measure risks or indicate availability to humans or the environment (Bauman 1991 and Friend
1996). Several states use total benzene, toluene, ethyl benzene, and xylene (BTEX) or specific
compound levels as the measure of contamination (Bell 1990). The relative mobility of the BTEX
compounds make them the toxics of concern in many petroleum materials (Bauman 1991). While
these are more effective than the TPH-based approaches, they may not allow for cleanup levels to
be based on ability to achieve desired leachate levels (Friend 1996). The use of chemical-specific,
risk-based approaches will allow a greater range of remediation technologies including ASB in
dealing with contaminated soils. Benzene, listed in the 40 CFR 261.24 Toxicity Characteristics
table, is the fuel related component must likely to cause concern. In an UST remediation project
the 40 CFR 261.4(b)(10) exclusion can be applied to streamline the use of contaminated soil in
ASB. However, if the contaminated material is not from an UST then the material is fully
regulated under 40 CFR 260-268. The use of these materials in an ASB would be subject to 40
CFR 261.6 Requirements of Recyclable Materials. This section defines what constitutes
recyclable materials and references 40 CFR 266 Subpart C. These regulations govern the use-
limits for disposal (i.e. applied to or place on the land) of recyclable hazardous waste. If the
original soils fail TCLP for organics, then the universal treatment standards are triggered under
the land disposal restrictions (40 CFR 268.40/268.48) and the ASB produced will need to meet
the regulatory limits identified in these.
b. Determination of the type or types of petroleum materials present in a contaminated soil
will involve first an extraction process followed by an analysis of the extract. The type of test
equipment most widely used to investigate this extract is the gas chromatograph (Fan,
Krishnamurthy, and Chen 1994). This test is ideally suited for BTEX and all aromatic volatile
organic compounds (API 1989 and Fan, Krishnamurthy, and Chen 1994). Test methods such as
the EPA 8000 series are widely used methods that employ the gas chromatograph (API 1989).
EPA 8020 and EPA 8240 are test methods often used for BTEX contaminates. EPA 8105
Modified and EPA 8100 Modified are test methods often used for kerosene, gasoline, diesel fuel,
and jet fuel. Other sources of test procedures are the American Petroleum Institute and several
states which have developed test methods of their own.
c. The amount of hydrocarbon leachate obtained from a sample of ASB material is used to
measure the effectiveness of the asphalt mixture procedure. A Toxicity Characteristic Leaching
Procedure (TCLP) extract test on various mixtures of ASB with the contaminated soil as part of
the mixture will provide information on the mixture's ability to contain the contamination within