health and safety plan solid waste management unit assessment

JP-4 (JET FUEL 4) 64-13
solubility. The alkyl benzenes have higher water solubilities and
transport with infiltrating water may be important for these compounds:
volatilization, on the other hand, may be less important. In saturated,
deep soils (containing no soil air and negligible soil organic
carbon), a significant percent of both aliphatic (particularly less
than C,) and aromatic hydrocarbons is predicted to be present in the
soil-water phase and available for transport with flowing ground water.
In interpreting these results, it must be remembered that this
model is valid only for low soil concentrations (below aqueous solubility)
of the components. Large releases of JP-4 (spills, leaking
underground storage tanks) may exceed the sorptive capacity of the
soil, thereby filling the pore spaces of the soil with the fuel. In
this situation, the hydrocarbon mixture would move as a bulk fluid and
the equilibrium partitioning model would not be applicable.
Overall, ground water underlying soil contaminated with JP-4
hydrocarbons is expected to be vulnerable to contamination by at least
some of these components. The type of spill (surface vs. sub-surface)
is of particular importance, since volatilization from the surface is
expected to be a significant removal process for low molecular weight
aliphatics. At this point, it should be mentioned that environmental
fate/exposure/toxicology chapters for several of the components in
Table 64-4 were included in Volume 1 of the IRP Toxicology Guide. T'he
JP-4 components addressed in Volume 1 include: benzene, toluene,
xylenes, ethyl benzene, and naphthalene.
64.2.1.2 Transport Studies
Due to the extensive use of JP-4 and other aviation fuels and
their potential for environmental release during use, storage or
transport, several groups have addressed its fate. The fate of JP-4 in
the soil environment is basically a function of the solubility, volatility,
sorption, and degradation of its major components. The relative
importance of each of these processes is influenced by the type of
contamination (e.g., surface spill x. underground release, major vs.
minor quantity), soil type (e.g., organic content, previous history of
soil contamination), and environmental conditions (e.g., pH, temperature,
oxygen content).
Transport processes have been shown to be more significant than
transformation processes in determining the initial fate of petroleum
hydrocarbons released to soil/ground-water systems (1845,1848,1846).
For JP-4 released to surface soils or waters, transport to the
atmosphere through volatilization has been shown to be the primary fate
pathway for most of the JP-4 hydrocarbons; subsequent atmospheric
photolysis is expected to be rapid (1845). Using a model fuel mixture
containing approximately fifteen compounds representative of major JP-4
hydrocarbons, Spain & a. (1846) demonstrated that compounds having up
to nine carbons are weathered almost exclusively by evaporation; larger
compounds were weathered primarily by evaporation and biodegradation:
dimethylnaphthalene and highly substituted aromatics (X,,) were shown
to be persistent in these tests. Reduced temperatures tend to increase
JP-4 persistence by retarding the rates of volatilization and biodegradation
(1846.1822).
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