Gasoline TOTAL PETROLEUM HYDROCARBONS

California Department of Health Services, 1989, Total Petroleum Hydrocarbons (TPH) Analysis — Gasoline and Diesel In California Water Resources Control Board Leaking Underground Fuel Tank (LUFT) Manual, Appendix C. 

Chemicals that may be included in the total petroleum hydrocarbons are hexane, heptane (and higher-molecular-weight homologs), benzene, toluene, xylenes (and the higher-molecular-weight homologs), and naphthalene as well as the constituents of other petroleum products, such as gasoline and diesel fuel. It is likely that samples of the total petroleum hydrocarbons collected at a specific site wiU contain only some, or a mixture, of these chemicals. 

It is not surprising that the data produced as total petroleum hydrocarbons (EPA 418.1) suffer from several shortcomings as an index of potential ground-water contamination or health risk. In fact, it does not actually measure the total petroleum hydrocarbons in the sample but rather, measures a specific range of hydrocarbon compounds. This is caused by limitations of the extraction process (solvents used and the concentration steps) and the reference standards used for instrumental analysis. The method specifically states that it does not accurately measure the lighter fractions of gasoline [benzene-toluene-ethylbenzene-xylenes fraction (BTEX)], which should include the benzene-toluene-ethylbenzene-xylenes fraction. Further, the method was originally a method for water samples that has been modified for solids, and it is subject to bias. 

The total petroleum hydrocarbons represents a summation of all the hydrocarbon compounds that may be present (and detected) in a soil sample. Because of differences in product composition between, for example, gasoline and diesel, or fresh versus weathered fuels, the types of compounds present at one site may be completely different from those present at another. 

Accordingly, the total petroleum hydrocarbons at a gasoline spill site will be comprised of mostly Cs to Cu compounds, while total petroleum hydrocarbons at an older site where the fuel has weathered will likely measure mostly Cg to Cn compounds. Because of this inherent variability in the method and the analyte, it is currently not possible to directly relate potential enviromnental or health risks with concentrations of total petroleum hydrocarbons. The relative mobility or toxicity of contaminants represented by total petroleum hydrocarbons analyses at one site may be completely different from that of another site (e.g., Ce to Cn compared to Cio to C25). There is no easy way to determine if total petroleum hydrocarbons from the former site will represent the same level of risk as an equal measure of the total petroleum hydrocarbons from the latter. For these reasons it is clear that the total petroleum hydrocarbons value offers limited benefits as an indicator measure for cleanup criteria. Its current widespread use as a soil cleanup criterion is a function of a lack of understanding of its proper application and... 

The PetroClean bioremediation system treats biodegradable contaminants (i.e., gasoline, diesel fuel, aviation fuel, solvents, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), total petroleum hydrocarbons (TPH), and other organic compounds in soils and groundwater. 

Biodegradation can be accelerated in a prepared bed reactor with forced aeration. These reactors (Figure 1.2) are used at many Superfund sites for bioremediation of PAHs and BTEX (benzene, toluene, ethylbenzene, and xylene) (Alexander, 1994). This method, with recirculating leachate, was used to reduce the average total petroleum hydrocarbon concentration in a diesel-contaminated soil from 6200 mg/kg dry soil to 280 mg/kg in approximately 7 weeks (Reynolds et al., 1994). A bed reactor with forced aeration was also used to treat 115 000 m3 of soil contaminated with bunker C fuel oil (Compeau, Mahaffey Patras, 1991) and 23 000 m3 of soil contaminated with gasoline and fuel oil (Block, Clark Bishop, 1990). 

Total petroleum hydrocarbons as gasoline and other volatile petroleum products SW-846 5035/8015 G, ACD 5 to 25 g 2 to 6°C, NaHS04 to pH <2 Methanol 48 h for unpreserved samples 7 days for samples preserved, with NaHS04 14 days for samples preserved, with methanol... 

DRO = diesel range organics GRO = gasoline range organics TPH = total petroleum hydrocarbons... 

Petroleum products are an integral part of our modern lives. It is nearly impossible to avoid exposure to hydrocarbons from petroleum products, whether it is from gasoline fumes at the pump, spilled crankcase oil on asphalt, solvents used at home or work, or pesticide applications that use petroleum products as carriers. There are concerns with both short-term (accidents) and long-term exposures to petroleum hydrocarbons (e.g., contaminated drinking water). Gross measures of Total Petroleum Hydrocarbons (TPH) in soil or water are not particularly valuable for assessing either the potential for exposure to TPH or the impacts of such exposure on public health. This chapter addresses questions related to the first point what are the levels of contamination in the environment, what happens to petroleum hydrocarbons in the environment, and what is the likelihood that individuals or populations will be exposed to petroleum hydrocarbons at levels thought to be of concern ... 

This profile covers total petroleum hydrocarbons (TPH), which is defined as the measurable amount of petroleum-based hydrocarbon in an environmental medium (Chapter 2). TPH is measured as the total quantity of hydrocarbons without identification of individual constituents. Sources of TPH contamination in the environment range from crude oil, to fuels such as gasoline and kerosene, to solvents, to mineral-based crankcase oil and mineral-based hydraulic fluids. These products contain not only a large number and variety of petroleum hydrocarbons, but also other chemicals that, strictly speaking, are not the subject of this profile, such as non-hydrocarbon additives and contaminants. The TPH issue is further complicated by the number of petroleum-derived hydrocarbons that have been identified—more than 250—and the variability in composition of crude oils and petroleum products (see Section 3.2 and Appendices D and E for details). 

The international, national, and state regulations and guidelines regarding total petroleum hydrocarbons (TPH) in air, water, and other media are summarized in Table 7-1. No health or environmental benchmarks have been developed for TPH as a general category, though many exist for individual petroleum chemicals or products, such as gasoline. 

Universal across-the-board cleanup criteria are not commonly used as end points for soil and groundwater cleanup, because of the wide range of risks found at these sites. However, two classes of contaminants have been subject to universal action levels for cleanup petroleum and polychlorinated biphenyls (PCBs). Most petroleum hydrocarbon action levels are regulated by state and local agencies the parameters used and their corresponding action levels vary widely from state to state. The specific petroleum parameters that are regulated include total petroleum hydrocarbon— gasoline fraction (TPH-G) total petroleum hydrocarbon—diesel component (TPH-D) ... 

For some of the treatment profiles, the specific components that make up the total cost were not provided in the source materials, such as for capital or operation and maintenance activities. In other cases, the types of contaminants present at the sites, other than MTBE, were not identified in the source materials. Sites may have been contaminated with gasoline components such as petroleum hydrocarbons, as well as oxygenates, and the treatment costs reported are for cleanup of both the gasoline components and oxygenates. 

The reason for the availability of a large number of methods for the measurement of total petrolenm hydrocarbons centers on the compositional complexity of petroleum and petroleum products, and subsequently, there is no single suitable or adequate method for measuring all types of petroleum-derived contamination. For example, methods that are appropriate for samples contaminated by gasoline are not often suitable for the measurement of diesel fuel contamination in other samples. 

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