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GUIDANCE FOR ASSESSING PETROLEUM HYDROCARBONS IN SOIL
PURPOSE:
To assist regulators and responsible parties in assessing the risk from soil impacted by
petroleum hydrocarbons at remedial response sites.
KEY WORDS:
Petroleum hydrocarbons; soil; Total Petroleum hydrocarbons (TPH); gasoline; diesel;
oil; light petroleum fractions; middle petroleum fractions; heavy petroleum fractions
BACKGROUND:
Ohio EPA-DERR addresses sites contaminated by petroleum hydrocarbons as a result
of spills (emergency response and post-response activities), as co-contaminants at
hazardous waste and CERCLA sites, as water pollution abatement actions under ORC
6111, and as Voluntary Actions under ORC 3746 and OAC 3745-300. Evaluation and
remediation of petroleum hydrocarbon sites is difficult, owing to the complex regulatory
and technical challenges associated with evaluating such sites.
This guidance document was developed to assist both the regulators and responsible
parties in assessing the risk from soil impacted by petroleum hydrocarbons. The
guidance document is part of the overall assessment of risk at the site, and is meant to
be used in conjunction with the available regulations and other appropriate risk
assessment guidance.
This guidance presents a risk-based approach for the assessment of soil impacted by
petroleum hydrocarbons. This approach includes the evaluation of indicator chemicals
and residual petroleum constituents. Necessary inputs to calculate human health risk-
based numerical standards, such as physicochemical and toxicity data, are provided.
Analytical sampling requirements necessary for site assessment are also provided to
ensure that sample results are compatible with the proposed risk assessment process.
The guidance does not address petroleum hydrocarbons leaching to ground water. If
leaching from soil impacted by petroleum hydrocarbons to ground water is a concern at
the site, refer to the DERR Total Petroleum Hydrocarbons (TPH) leaching guidance.
Also, in a spill situation where an immediate response is needed to address the release,
it is expected that the Petroleum Contaminated Sites Guidance Document for
Emergency Response Actions (ER-013, March 2005) will be the protocol followed.
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DISCUSSION:
In Ohio, as in many other areas of the country, petroleum hydrocarbon contamination is
widespread. Contamination results from mishandling, spilling, or leaking products,
including gasoline, motor and lubricating oils, diesel fuel, heating oils and aircraft fuels.
Each of these petroleum products are complex mixtures containing hundreds to
thousands of different chemical compounds. Various petroleum products may also
contain additives. The diverse chemical compounds exhibit a large range of behavior in
environmental media governed by their physicochemical properties. As a result of
these characteristics, the assessment of risk from exposure to petroleum hydrocarbon
mixtures is difficult.
In the environment these mixtures can change through weathering (that may include
volatilization, biodegradation, partitioning, oxidation, photo-degradation, etc.), further
complicating the determination of risk from exposure. The more soluble or volatile
compounds will migrate to other locations. The mostly non-mobile components are left
behind at the release site. As a result, the receptors can be exposed to a different
mixture than that originally released to the environment. Factors including location of
release, length of time between the release and exposure, media of exposure, etc. can
all contribute to these differences.
Ohio EPA-DERR has developed a tiered approach to assess the risk presented by
petroleum contamination in soils as discussed below. Information from the Total
Petroleum Hydrocarbon Criteria Working Group (TPHCWG), as well as that available
from states, including Massachusetts and Louisiana, were used to develop this
guidance. The TPHCWG is a national workgroup comprised of representatives from
federal and state agencies, industry and academia. The group was formed to address
the disparity among cleanup requirements at sites contaminated with hydrocarbon
materials, and develop scientifically defensible soil clean up levels.
If leaching from soil impacted by petroleum hydrocarbons is a concern at a site,
reference should also be made to the DERR Soil Leaching to Ground water Evaluation
for Total Petroleum Hydrocarbons (TPH) Guidance (RR-036, January 14, 2004).
• Tier 1: (1) The analysis and assessment of individual petroleum-related
compounds (indicator compounds) using chemical-specific toxicity
criteria and physicochemical properties and
(2) the analysis for total petroleum hydrocarbons (TPH) oil, gasoline
and diesel ranges and
(3) Total TPH should not exceed soil saturation concentrations.
• Tier 2: (1) The analysis and assessment of individual petroleum-related
compounds (indicator compounds) using chemical-specific toxicity
criteria and physicochemical properties and
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(2) TPH fractions using fraction-specific toxicity criteria and
physio-chemical properties and
(3) Total TPH should not exceed soil saturation concentrations. It
should be noted that the decision to assess petroleum
contamination by the methods provided in Tier 2 is not a
requirement of the proposed process.
Tier 2 is optional and it is provided for those situations where greater site-specific study
is desired and warranted.
Each Tier documents the assessment process, determination of human health effects of
chemicals of concern, and relevant physicochemical and toxicity values. Once the
inputs to the risk assessment have been developed per these guidelines, these
petroleum constituents are to be taken through the human health risk assessment
procedures. The DERR Ecological Risk Assessment guidance document should be
consulted for appropriate ecological-specific assessment procedures.
Tier 1: Analysis of Indicator Compounds and TPH
In Tier 1, the evaluation of petroleum-impacted soil includes the assessment of:
(1) Individual petroleum-related compounds (indicators) using chemical-specific
toxicity criteria and physicochemical properties, and
(2) Total petroleum hydrocarbons (TPH) (TPH-gasoline range organics (G), TPH-
diesel range organics (D), and/or TPH-oil range organics (O)) and
(3) Evaluate TPH soil saturation concentrations. The indicator compounds
required for analysis are dependent on the source of the petroleum product and
are summarized in Table 1. (note: if additional additives or oxygenates are found,
these should be assessed as additional individual contaminants) The appropriate
carbon ranges for the TPH determination (e.g., gasoline, diesel or oil ranges) are
also dependent upon the source of the petroleum product and are summarized in
Table 1. The physicochemical properties and appropriate composite surrogate
toxicity criteria (chronic reference doses) are provided in Tables 2 and 3,
respectively. Table 6 contains the TPH soil saturation concentrations.
If the source of petroleum hydrocarbons in soil is light petroleum fractions, such as
gasoline, gasohol and naphtha solvents, the soil needs to be analyzed and assessed for
benzene, toluene, ethylbenzene, total xylenes, lead, methyl tertiary-butyl ether (MTBE),
and TPH.
If the source of petroleum hydrocarbons in soil comes from middle petroleum fractions,
such as kerosene, diesel fuel and jet fuel, the soil needs to be analyzed for benzene,
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toluene, ethylbenzene, total xylenes, MTBE, naphthalene, benzo[a] anthracene,
benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, chrysene,
dibenzo[a,h]anthracene, indeno[1,2,3-cd] pyrene, acenaphthene, anthracene,
fluoranthene, fluorene, pyrene, and TPH.
If the source of petroleum hydrocarbons in soil is from heavy petroleum fractions, such
as hydraulic oil, lube oil, and residual fuel oils, the soil needs to be analyzed for
benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene,
chrysene, dibenzo[a,h]anthracene, indeno[1,2,3-cd]pyrene, acenaphthene, anthracene,
fluoranthene, fluorene, pyrene, and TPH. Where petroleum hydrocarbons come from
products of heavy petroleum fractions that have been used in a process such as used
motor oil, used cutting oil, or hydraulic oil, additional chemicals of concern that may be
typical impurities of the used heavy petroleum fractions product should be identified and
included in the analysis as appropriate.
If the source of petroleum hydrocarbons in soils is unknown the soil needs to be
analyzed for benzene, toluene, ethylbenzene, total xylenes, MTBE, lead, naphthalene,
benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene,
chrysene, dibenzo[a,h]anthracene, indeno[1,2,3-cd]pyrene, acenaphthene, anthracene,
fluoranthene, fluorene, pyrene, methyl ethyl ketone, methyl isobutyl ketone, and TPH. If
the source of petroleum hydrocarbons is across two or more fractions, as in the case of
quench oils, the relevant indicator compounds need to be assessed. Also, all associated
impurities will need to be assessed.
The identified human health chemicals of concern, including indicator compounds for
the TPH, oil, gasoline and diesel ranges, should then be taken through the human
health risk assessment process.
In addition to the indicator compounds listed above, the soil saturation concentrations
for TPH should also be evaluated to address free-phase product. These have been
determined based on the vertical hydraulic conductivity of the unsaturated soil and the
specific source of petroleum hydrocarbons in the soil, and are provided in Table 6.
Tier 2: Analysis of TPH Fractions and Indicator Compounds
The TPH Fraction and Indicator Method as described in the TPH Criteria Working
Group (TPHCWG) Series Volumes 1-5 provides an alternative method for the risk
assessment of TPH. The TPH Fraction and Indicator Method is based on the
assessment of:
(1) Individual petroleum-related compounds (indicators) using compound-specific
toxicity criteria and physical/chemical properties (as is done in Tier 1);
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(2) TPH fractions using fraction-specific toxicity criteria and physical/chemical
properties, followed by the cumulative assessment of the TPH fractions; and
(3) Evaluate TPH soil saturation concentrations.
The hydrocarbon fractions for the TPH Fraction and Indicator Method were defined by
the TPHCWG based on: (1) environmental behavior and (2) equivalent carbon number.
Fractions were defined separately for aliphatics and aromatics due to the great variation
in environmental behavior between these two chemical groups. To define the TPH
fractions, the potential for individual TPH compounds to leach from soil to ground water
and to volatilize from soil to air was modeled using equations from the ASTM (1995).
The individual constituents were grouped into fractions based on their modeled
environmental behavior. Fractions of these TPH constituents were then defined such
that the difference in modeled environmental behavior between the fractions was no
greater than an order of magnitude.
Each of these TPH constituents was then further subdivided based on the equivalent
carbon number index. The equivalent carbon number index is related to: (1) boiling
points and (2) retention times in a gas chromatographic column of individual TPH
constituents, normalized to the n-alkanes. Fate and transport parameter values were
assigned to each fraction based on the average values of the individual constituents
comprising the fraction (TPHCWG Series, 1997a). These values are presented in Table
4 (For addi
tional information on how these fractions were defined refer to TPHCWG
1997a).
The indicator compounds and hydrocarbon fractions are identified for different types of
petroleum mixtures in Table 1. (Again, if additional oxygenates or additives are found,
these should also be evaluated as indicator compounds. The physicochemical
properties and fraction-specific chronic surrogate Reference Dose values (RfDs) and
surrogate Reference Concentration values (RfCs) are listed in Table 5, respectively. For
additional information on the derivation of these values, refer to the TPHCWG 1997b.
Fraction-specific analytical data must be obtained to apply this approach. The laboratory
requirements are discussed in more detail below.
As in the case of Tier 1, in addition to the indicator compounds listed above, the TPH
soil saturation concentrations provided in Table 6 should also be evaluated to address
free phase product.
Toxicity Criteria
Ohio EPA’s TPH subgroup encountered the same types of problems determining
toxicity criteria such as reference doses (RfDs) and slope factors for petroleum products
as U.S. EPA. Ohio EPA researched the methods proposed by the TPHCWG, the
Massachusetts Department of Environmental Protection and the Louisiana Department
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of Environmental Quality. It was found that some toxicity data and a few U.S. EPA-
derived provisional reference doses (RfDs), reference concentrations (RfCs), and
cancer assessments and Agency for Toxic Substances and Disease Registry (ATSDR)-
derived Minimal Risk Levels are available for whole, un-weathered petroleum products.
However, toxicity data for whole petroleum products, that are relatively heterogeneous,
are not necessarily applicable to the fractions the receptor is exposed to in the
environment.
Limitations exist to using the whole product data including that the type of each
petroleum product is variable and depends on the crude oil from which it was refined,
differences in the refining processes, and differences in formulation of the final product.
The number of individual identified hydrocarbon components of various petroleum
products has been estimated to be at least 250. Toxicity data are available for about 95
of these compounds. However, only about 25 were found by the TPHCWG to ha
ve
U.S. EPA toxicity values or sufficient data to develop toxicity criteria.
For Tier 1 TPH toxicity values in Table 3, the methodology used by the Louisiana Dept.
of Environmental Quality (1998) was followed. A conservative surrogate RfD for the
TPH fractions comprising the hydrocarbon mixtures was selected to represent the total
petroleum hydrocarbon mixture for gasoline (TPH-G), diesel (TPH-D) and oil (TPH-O).
TPH-G is represented by the RfDs for Aromatics C>8-C10 and C>10-C12. TPH-D is
represented by the RfDs for Aromatics C>8-C10, C>10-C12 and C>12-C16. TPH-O i
s
represented by the RfD for Aromatics C>16-C21 and C>21-C35. Note that the TPH
fraction ranges in Table 3 are different from the range of surrogate toxicity values used
to address the three main petroleum fractions described in Tier 1; this is a function of
the availability and appropriateness of the surrogate toxicity values.
The toxicity criteria recommended here for the TPH fractions in Tier 2 are those
recommended through the extensive research conducted by the TPHCWG. Toxicity
criteria were derived for each TPH fraction based on the best available toxicity data for
individual constituents, well defined petroleum mixtures, and whole petroleum products.
Some fractions have the same toxicity criterion due to similarity in toxicity or limitations
in the available toxicity data. The toxicity criteria were developed in accordance with
U.S. EPA methodologies and provide a representative and conservative estimate of
each fraction’s toxicity. These values are equivalent to chronic oral Reference Dose
values (RfD) and chronic inhalation Reference Concentration values (RfC) (TPHCWG,
1997c). The surrogate RfDs and RfCs for the TPH fractions are presented in Table 5.
For additional information on how these toxicity criteria were derived for the TPH
fractions refer to the TPHCWG 1997b. In addition, TPHCWG 1999 provides specific
guidance on applying this methodology and should be consulted. Toxicity criteria for the
individual indicator compounds, including oxygenates and additives, can be obtained via
IRIS, or see Ohio EPA DERR Technical Decision Compendium (TDC): Assessing
Compounds Without Formal Toxicity Values Available for Use in Human Health Risk
Assessment (April 14, 2004, with April 2, 2010 updates).
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Requirement to Cap Standards at Residual Saturation Concentrations
The total petroleum hydrocarbon concentration in the soils should not exceed the soil
saturation concentrations to address free-phase product as listed in Table 6.
Laboratory Analytical Requirements
Ohio EPA recommends that the following analytical methods from the most recent
edition of the U.S. EPA’s Test Methods for Evaluating Solid Waste (SW-846) be
applied. These methods were chosen on the basis of their universal availability and
acceptability. Other methods may be available for the quantification of these
compounds, e.g., ASTM methods. Ohio EPA concurrence on the acceptability of
alternative methods should be sought on a case by case basis:
a. The indicator compounds benzene, toluene, ethyl benzene, o,m,p - xylenes
should be quantified by Method 8021B or by Method 8260B;
b. Polycyclic aromatic hydrocarbon indicator compounds should be quantified by
Method 8100, Method 8270C, or by Method 8310;
c. Gasoline range organics, diesel range organics, and oil range organics should
be quantified by Method 8015B.
d. The analysis of the aliphatic and aromatic TPH fractions as required by the
Tier 2 Approach should be determined using the
Method for the Determination of
Extractable Petroleum Hydrocarbons (EPH), Commonwealth of Massachusetts,
Department of Environmental Protection (May 2004, Revision 1.1). This method
was chosen by Ohio EPA’s TPH subgroup because it appears to offer a
functional analytical approach to quantifying the fractions in question, and it has
been formally validated. It is recognized that this method may not yet be
available through certain laboratories, and the ability of the laboratory to conduct
the analysis may need to be verified prior to sending out the samples for
analyses.
Additivity
These procedures should be employed assuming that the cumulative risk of a mixture is
additive. Risks from indicator compounds, if present, are added to those the TPH
fractions. If a mixture of fractions is present, as is often the case, simple additivity of the
risks should be assumed.
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Weathering
A common view for petroleum is that the weathering which occurs over time will shift the
components toward the heavier fractions. Because the heavy end components are
generally less toxic, the soil standards initially generated by these procedures will be
protective, and may be overly conservative. Weathering should be considered as part of
the uncertainty analysis, and overall risk management decisions for the site.
References
Standard Guide for Risk-Based Corrective Action Applied at Petroleum Release Sites,
American Society for Testing and Materials, Designation ASTM E 1739-95 (2002).
Risk Evaluation/Corrective Action Program (RECAP), Appendix D - Guidelines for
Assessing: Petroleum Hydrocarbons, Polycyclic Aromatic Hydrocarbons, Lead,
Louisiana Department of Environmental Quality, Corrective Action Group, 2000.
Method for the Determination of Extractable Petroleum Hydrocarbons (EPH),
Massachusetts Department of Environmental Protection, May 2004, Revision 1.1.
TPHCWGa: Total Petroleum Hydrocarbon Working Group Series, Volumes 1:
Petroleum Hydrocarbon Analysis in Soil and Water, Wade Weisman, 1998, Association
for Environmental Health and Sciences.
TPHCWGb: Total Petroleum Hydrocarbon Working Group Series, Volume 2:
Composition of Petroleum Mixtures, Thomas L. Potter and Kathleen E. Simmons, 1998,
Association for Environmental Health and Sciences.
TPHCWGc: Total Petroleum Hydrocarbon Working Group Series, Volume 3: Selection
of Representative TPH Fractions Based on Fate and Transport Considerations, John
Gustafson, Joan Griffith Tell, and Doug Orem, 1997, Association for E n v i r o n m e n t
a l H e a l t h a n d S c i e n c e s.
TPHCWGd: Total Petroleum Hydrocarbon Working Group Series, Volume 4:
Development of Fraction Specific Reference Doses (RfDs) and Reference
Concentrations (RfCs) for Total Petroleum Hydrocarbons, A Tveit, L.A. Hayes, S.H.
Youngren, and D.V. Nakles, 1997, Association for Environmental Health and Sciences.
TPHCWGe: Total Petroleum Hydrocarbon Working Group Series, Volume 5: Human
Health Risk-Based Evaluation of Petroleum Contaminated Sites: Implementation of the
Working Group Approach, Donna Vorhees, John Gustafson and Wade Weisman, 1999,
Association for Environmental Health and Sciences.
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Table 1 Tier 1 and 2 Indicator Compounds and Hydrocarbon Fractions
1, 2, 3
Indicator Compound/TPH
Fraction
Gasoline
Kerosene
Jet Fuel
Diesel,
light
fuel
oils
heavy
fuel
oils
crude
oil
Highly
Refined
Base Oils
2
Used
Motor
Oil,
Lubricating
Oil
Unknown
Benzene
X
X
X
Toluene
X
X
X
Ethylbenzene
X
X
X
Xylene (total)
X
X
X
Acenaphthlene
X
X
X
X
X
X
anthracene
X
X
X
X
X
X
Benzo(a)pyrene
X
X
X
X
X
X
Chrysene
X
X
X
X
X
X
Dibenz(a.h)anthracene
X
X
X
X
X
X
Indeno(1,2,3-cd)pyrene
X
X
X
X
X
X
Benzo(k)fluoranthene
X
X
X
X
X
X
Benzo(a)anthracene
X
X
X
X
X
X
Benzo(b)fluoranthene
X
X
X
X
X
X
Fluoranthene
X
X
X
X
X
X
Fluorene
X
X
X
X
X
X
Naphthalene
X
X
X
X
X
X
Pyrene
X
X
X
X
X
X
3
Lead
X
3
X
3
Metals
X
X
3
Methyl tertbutyl ether
(MTBE)
X
X
X
X
X
3
Methyl ethyl ketone
X
3
Methyl isobutyl ketone
X
3
Total petroleum
hydrocarbons (TPH)
X
X
X
X
X
X
X
X
Aliphatics > C
6
- C
8
X
X
X
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Indicator Compound/TPH
Fraction
Gasoline
Kerosene
Jet Fuel
Diesel,
light
fuel
oils
heavy
fuel
oils
crude
oil
Highly
Refined
Base Oils
2
Used
Motor
Oil,
Lubricating
Oil
Unknown
Aliphatics > C
8
- C
10
X
X
X
X
X
Aliphatics > C
10
- C
12
X
X
X
X
X
Aliphatics > C
12
- C
16
X
X
X
X
X
Aliphatics > C
16
- C
28
X
X
X
X
X
X
Aromatics > C
8
- C
10
X
X
X
X
X
Aromatics > C
10
- C
12
X
X
X
X
X
Aromatics > C
12
- C
16
X
X
X
X
X
Aromatics > C
16
- C
21
X
X
X
X
X
Aromatics > C
21
- C
35
X
X
X
X
X
1
ASTM 1995 and TPHCWG Series 1997a and 1998b; for large releases additional indicator constituents may be identified for
evaluation.
2
Applies to oils formulated with highly refined base oils including hydraulic fluids (Mineral-oil Based Hydraulic Fluids,
Toxicological profile
for
Mineral
Oil
Hydraulic Fluids, Organophosphate Ester Hydraulic Fluids and Polyalphaolefin
Hydraulic
Fluids, ATSDR 1994), motor oils, industrial oils, and automatic transmission fluid-type oils. (i.e., severely refined base oils).
3
When suspected to be present. Also, note that if additional impurities, additives or oxygenates are found, these should be
assessed as additional individual contaminants.
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Table 2 Composite Physicochemical Properties for Tier 1: TPH-G, TPH-D and TPH-O
4
Composite of
Fractions
Boiling
Point
0
C
Molecular
Weight
(g/mole)
Solubility
(mg/1)
Vapor
Pressure
(atm)
Henry’s Law
Constant
(cm
3
/cm
3
)
log Koc
TPH-G represented
by: C
>8
-C
10
and
C
>10
-C
12
Aromatics
1.8E+02
1.2E+02
4.5E+01
3.5E-03
3.1E-01
3.3E+00
TPH-D represented
by: C
>8-
C
10
, C
>10--
C
12
and C
>12-
C
16
Aromatics
2.0E+02
1.3E+02
3.2E+01
2.3E-03
2.2E-01
3.4E+00
TPH-O
4
represented
by: C
>16--
C
21
and C
>21-
C
35
Aromatics
3.3E+02
2.2E+02
3.3E-01
6.0E-07
6.8E-03
4.6E+00
4
Composite Physical/Chemical Properties are the mean values of the Physical/Chemical data from fractions on which
toxicity values are based (See Table 3). The fractions are from the TPHCWG Series 1997a and 1998a,b.
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Table 3 Tier 1 TPH Chronic Reference Doses
5
TPH range Oral
RfD
(mg/kg-day)
Inhalation
RfD
(mg/kg-day)
TPH-G (C
6
-C
12
)
0.04
0.06
TPH-D (C
10
-C
20
)
0.04
0.06
TPH-O (C
20
-C
35
)
0.03
NA
5
Composite Physical/Chemical Properties are the mean values of the Physical/Chemical data from fractions on which
toxicity values are based (See Table 3). The fractions are from the TPHCWG Series 1997a and 1998a,b.
Table 4 Tier 2 Physicochemical Properties for Hydrocarbon Fractions
6
Fraction
Boiling
Point
0
C
Molecular
Weight
(g/mole)
Solubility
(mg/1)
Vapor
Pressure
(atm)
Henry’s Law
Constant
(cm
3
/cm
3
)
log Koc
C
5
-C
6
Aliphatics
5.1E+01
8.1E+01
3.5E+01
3.5E-01
3.3E+01
2.9E+00
>C
6
-C
8
Aliphatics
9.6E+01
1.0E+02
5.4E+00
6.3E-02
5.0E+01
3.6E+00
>C
8
-C
10
Aliphatics
1.5E+-02
1.3E+02
4.3E-01
6.3E-03
8.0E+01
4.5E+00
>C
10
-C
12
Aliphatics
2.0E+02
1.6E+02
3.4E-02
6.3E-04
1.2E+02
5.4E+00
>C
12
-C
16
Aliphatics
2.6E+02
2.0E+02
7.6E-04
4.8E-05
5.2+02
6.7E+00
>C
16
-C
21
Aliphatics
3.2E+02
2.7E+02
1.3E-06
1.1E-06
4.9E+03
8.8E+00
>C
8
-C
10
Aromatics
1.5E+02
1.2E+02
6.5E+01
6.3E-03
4.8E-01
3.2E+00
>C
10
-C
12
Aromatics
2.0E+02
1.3E+02
2.5E+01
6.3E-04
1.4E-01
3.4E+00
>C
12
-C
16
Aromatics
2.6E+02
1.5E+02
5.8E+00
4.8E-05
5.3E-02
3.7E+00
>C
16
-C
21
Aromatics
3.2E+02
1.9E+02
6.5E-01
1.1E-06
1.3E-02
4.2E+00
>C
21
-C
35
Aromatics
3.4E+02
2.4E+02
6.6E-03
4.4E-10
6.7E-04
5.1E+00
6
From TPHCWG Series Volume 4 1997b
Number:
ISSUED:
STATUS:
PAGE:
UPDATE:
DERR-00-DI-033
September 22, 2004
Final
14 of 15
2010
Table 5 Tier 2 TPH Fraction-Specific Chronic Reference Doses
7
Carbon Range
Oral RfD
(mg/kg-day)
Inhalation RfD
(mg/kg/day)
Target Organ/
Critical Effect
Aliphatics >C
6
-C
8
5.0
5.3
kidney
Aliphatics >C
8
-C
10
0.1
0.3
liver, hematological
system
Aliphatics >C
10
-C
12
0.1
0.3
liver, hematological
system
Aliphatics >C
12
-C
16
0.1
0.3
liver, hematological
system
Aliphatics >C
16
-C
35
2.0
NA
liver
Aromatics >C
8
-C
10
0.04
0.06
decreased body
weight
Aromatics >C
10
-C
12
0.04
0.06
decreased body
weight
Aromatics >C
12
-C
16
0.04
0.06
decreased body
weight
Aromatics >C
16
-C
21
0.03
NA
kidney
Aromatics >C
21
-C
35
0.03
NA
kidney
7
From TPHCWG Series Volume 4 1997b and Volume 5, 1999
Number:
ISSUED:
STATUS:
PAGE:
UPDATE:
DERR-00-DI-033
September 22, 2004
Final
15 of 15
2010
Petroleum
Fraction
Residual
Saturation
Concentrations
for:
Sand and
Gravel;
Unknown Soil
Type
-3 -4
Residual Saturation
Concentrations
for:
Silty/Clayey Sand
-4 -5
Residual Saturation
Concentrations for:
Glacial Till and Silty
Clay
-5
Light (C
6
-C
12
)
1,000 5,000 8,000
Middle (C
7
-C
16
)
2,000 10,000 20,000
Heavy (C
16
-C
35
)
5,000 20,000 40,000
Table 6 Total Petroleum Hydrocarbon Soil Saturation Concentrations (values are
in mg/kg).
K
V
:
10
- 10 cm/s
K
V
: 10
- 10 cm/s
K
V
: < 10
cm/s
Where: “mg/kg” means milligrams per kilogram,“K
V
” means vertical hydraulic conductivity
of the unsaturated soil, “cm/s” means centimeters per second, and “C
x
” means carbon
chain length.
