ASTM E2856-13(2021)
(Guide)Standard Guide for Estimation of LNAPL Transmissivity
Standard Guide for Estimation of LNAPL Transmissivity
SIGNIFICANCE AND USE
4.1 Application:
4.1.1 LNAPL transmissivity is an accurate metric for understanding LNAPL recovery, is directly proportional to LNAPL recoverability and tracking remediation progress towards residual LNAPL saturation.
4.1.2 LNAPL transmissivity can be used to estimate the rate of recovery for a given drawdown from various technologies.
4.1.3 LNAPL transmissivity is not an intrinsic aquifer property but rather a summary metric based on the aquifer properties, LNAPL physical properties, and the magnitude of LNAPL saturation over a given interval of aquifer.
4.1.4 LNAPL transmissivity will vary over time with changing conditions such as, seasonal fluctuations in water table, changing hydrogeologic conditions and with variability in LNAPL impacts (that is, interval that LNAPL flows over in the formation and LNAPL pore space saturation) within the formation.
4.1.5 Any observed temporal or spatial variability in values derived from consistent data collection and analysis methods of LNAPL transmissivity is not erroneous, rather is indicative of the actual variability in subsurface conditions related to the parameters encompassed by LNAPL transmissivity (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, and the interval that LNAPL flows over in the formation).
4.1.6 LNAPL transmissivity is a more accurate metric for evaluating recoverability and mobile LNAPL than gauged LNAPL thickness. Gauged LNAPL thickness does not account for soil permeability, magnitude of LNAPL saturation above residual saturation, or physical fluid properties of LNAPL (that is, density, interfacial tension, and viscosity).
4.1.7 The accurate calculation of LNAPL transmissivity requires certain aspects of the LNAPL Conceptual Site Model (LCSM) to be completely understood and defined in order to calculate LNAPL drawdown correctly. The methodologies for development of the LCSM are provided in Guide E2531. The general conceptual site model aspe...
SCOPE
1.1 This guide provides field data collection and calculation methodologies for the estimation of light non-aqueous phase liquid (LNAPL) transmissivity in unconsolidated porous sediments. The methodologies presented herein may, or may not be, applicable to other hydrogeologic regimes (for example, karst, fracture flow). LNAPL transmissivity represents the volume of LNAPL (L3) through a unit width (L) of aquifer per unit time (t) per unit drawdown (L) with units of (L2/T). LNAPL transmissivity is a directly proportional metric for LNAPL recoverability whereas other metrics such as apparent LNAPL thickness gauged in wells do not exhibit a consistent relationship to recoverability. The recoverability for a given gauged LNAPL thickness in a well will vary between different soil types, LNAPL types or hydrogeologic conditions. LNAPL transmissivity accounts for those parameters and conditions. LNAPL transmissivity values can be used in the following five ways: (1) Estimate LNAPL recovery rate for multiple technologies; (2) Identify trends in recoverability via mapping; (3) Applied as a leading (startup) indicator for recovery; (4) Applied as a lagging (shutdown) indicator for LNAPL recovery; and (5) Applied as a robust calibration metric for multi-phase models (Hawthorne and Kirkman, 2011 (1)2 and ITRC ((2)). The methodologies for LNAPL transmissivity estimation provided in this document include short-term aquifer testing methods (LNAPL baildown/slug testing and manual LNAPL skimming testing), and long-term methods (that is, LNAPL recovery system performance analysis, and LNAPL tracer testing). The magnitude of transmissivity of any fluid in the subsurface is controlled by the same variables (that is, fluid pore space saturation, soil permeability, fluid density, fluid viscosity, the interval that LNAPL flows over in the formation and the gravitational acceleration constant). A direct mathematical relationship exists between th...
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E2856 − 13 (Reapproved 2021)
Standard Guide for
Estimation of LNAPL Transmissivity
This standard is issued under the fixed designation E2856; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope ing the relationship of discharge versus drawdown for the
occurrence of LNAPLin a well, which can be used to estimate
1.1 This guide provides field data collection and calculation
the transmissivity of LNAPL in the formation. The focus,
methodologies for the estimation of light non-aqueous phase
therefore,istoprovidestandardmethodologyonhowtoobtain
liquid (LNAPL) transmissivity in unconsolidated porous sedi-
accurate measurements of these two parameters (that is,
ments. The methodologies presented herein may, or may not
discharge and drawdown) for multi-phase occurrences to
be, applicable to other hydrogeologic regimes (for example,
estimate LNAPL transmissivity.
karst, fracture flow). LNAPL transmissivity represents the
volume of LNAPL(L ) through a unit width (L) of aquifer per
1.2 Organization of this Guide:
unit time (t) per unit drawdown (L) with units of (L /T).
1.2.1 Section 2 presents documents referenced.
LNAPL transmissivity is a directly proportional metric for
1.2.2 Section 3 presents terminology used.
LNAPL recoverability whereas other metrics such as apparent
1.2.3 Section 4 presents significance and use.
LNAPL thickness gauged in wells do not exhibit a consistent
1.2.4 Section 5 presents general information on four meth-
relationship to recoverability. The recoverability for a given
ods for data collection related to LNAPL transmissivity calcu-
gauged LNAPLthickness in a well will vary between different
lation. This section compares and contrasts the methods in a
soil types, LNAPLtypes or hydrogeologic conditions. LNAPL
way that will allow a user of this guide to assess which method
transmissivity accounts for those parameters and conditions.
most closely aligns with the site conditions and available data
LNAPLtransmissivity values can be used in the following five
collection opportunities.
ways: (1) Estimate LNAPL recovery rate for multiple tech-
1.2.5 Sections 6 and 7 presents the test methods for each of
nologies; (2) Identify trends in recoverability via mapping; (3)
the four data collection options.After reviewing Section 5 and
Applied as a leading (startup) indicator for recovery; (4)
selecting a test method, a user of this guide shall then proceed
Applied as a lagging (shutdown) indicator for LNAPL recov-
to the applicable portion of Sections 6 and 7 which describes
ery; and (5) Applied as a robust calibration metric for multi-
the detailed test methodology for the selected method.
phase models (Hawthorne and Kirkman, 2011 (1) and ITRC
1.2.6 Section 8 presents data evaluation methods. After
((2)). The methodologies for LNAPLtransmissivity estimation
provided in this document include short-term aquifer testing reviewing Section 5 and the pertinent test method section(s) of
Sections6and7,theuserofthisguideshallthenproceedtothe
methods (LNAPL baildown/slug testing and manual LNAPL
skimming testing), and long-term methods (that is, LNAPL applicable portion(s) of Section 8 to understand the method-
ologies for evaluation of the data which will be collected. It is
recovery system performance analysis, and LNAPL tracer
testing). The magnitude of transmissivity of any fluid in the highly recommended that the test methods and data evaluation
procedures be understood prior to initiating data collection.
subsurface is controlled by the same variables (that is, fluid
pore space saturation, soil permeability, fluid density, fluid
1.3 The values stated in inch-pound units are to be regarded
viscosity, the interval that LNAPL flows over in the formation
as standard. The values given in parentheses are mathematical
and the gravitational acceleration constant). A direct math-
conversions to SI units that are provided for information only
ematical relationship exists between the transmissivity of a
and are not considered standard.
fluid and the discharge of that fluid for a given induced
1.4 This standard does not purport to address all of the
drawdown. The methodologies are generally aimed at measur-
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
ThisguideisunderthejurisdictionofASTMCommitteeE50onEnvironmental
priate safety, health, and environmental practices and deter-
Assessment, Risk Management and CorrectiveAction and is the direct responsibil-
mine the applicability of regulatory limitations prior to use.
ity of Subcommittee E50.04 on Corrective Action.
Current edition approved April 1, 2021. Published June 2021. Originally
1.5 This document is applicable to wells exhibiting LNAPL
approved in 2011. Last previous edition approved in 2013 as E2856 –13. DOI:
consistently (that is, LNAPL transmissivity values above zero).
10.1520/E2856–13R21.
This methodology does not substantiate zero LNAPL transmis-
The boldface numbers in parentheses refer to the list of references at the end of
this standard. sivity; rather the lack of detection of LNAPL within the well
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2856 − 13 (2021)
combined with proper well development and purging proce- 3.1.8 equilibrium fluid levels—gauged fluid levels that rep-
dures are required to confirm zero LNAPL transmissivity. resent the oil head and the water head or the calculated
1.6 This document cannot replace education or experience water-table elevation of the formation. Under equilibrium fluid
and should be used in conjunction with professional compe- levels no net oil or water flow occurs between the formation
tence in the hydrogeology field and expertise in the behavior of and the well.
LNAPL in the subsurface.
3.1.9 fluid level—the level of a fluid interface (either air/oil,
1.7 This document cannot be assumed to be a substitute for
LNAPL/water, or potentiometric surface).
orreplaceanylawsorregulationswhetherfederal,state,tribal
3.1.10 formation thickness (b )—the interval that LNAPL
nf
or local.
flows over in the formation. For unconfined conditions this is
1.8 This international standard was developed in accor-
approximatelyequaltothegaugedLNAPLthickness.Confined
dance with internationally recognized principles on standard-
and perched conditions the gauged LNAPL thickness under
ization established in the Decision on Principles for the
equilibrium conditions is not equal to the formation thickness.
Development of International Standards, Guides and Recom-
(L)
mendations issued by the World Trade Organization Technical
3.1.11 gauged LNAPL thickness (b )—The difference be-
Barriers to Trade (TBT) Committee.
n
tween the gauged air/LNAPL interface and the water/LNAPL
interface in a well. (L)
2. Referenced Documents
3.1.12 hydraulic conductivity (derived via field aquifer
2.1 ASTM Standards:
tests)—the volume of water at the existing kinematic viscosity
D653 Terminology Relating to Soil, Rock, and Contained
that will move in a unit time, under a unit hydraulic gradient,
Fluids
through a unit area, measured at right angles to the direction of
D5088 Practice for Decontamination of Field Equipment
flow. (L/t)
Used at Waste Sites
D5521 Guide for Development of Groundwater Monitoring
3.1.13 LNAPL—Light Non Aqueous Phase Liquid.
Wells in Granular Aquifers
3.1.14 LNAPL baildown test—a procedure which includes
E2531 Guide for Development of Conceptual Site Models
the act of removing a measured LNAPL volume from a well
and Remediation Strategies for Light Nonaqueous-Phase
and filter pack to induce a head differential and the follow-up
Liquids Released to the Subsurface
gauging of fluid levels in the well.
3.1.15 LNAPL borehole volume—the volume of LNAPL
3. Terminology
existing within the casing and the drainable volume existing
3.1 Definitions:
within the filter pack of a well. Based on effective radius and
3.1.1 air/LNAPL interface (Z )—The surface shared by air
an
gauged thickness of LNAPL. (L )
and LNAPL in a control well. (L)
3.1.16 LNAPLslug test—a procedure which includes the act
3.1.2 calculated water-table elevation (Z )—thetheoreti-
CGW
of removing or displacing a known volume of LNAPL from a
cal location of the air/water surface based on a density
well to induce a head differential and the follow-up gauging of
correction if LNAPL were not present in a well. (L)
fluid levels in the well.
3.1.3 confined LNAPL—LNAPL trapped in an aquifer be-
3.1.17 LNAPL specific yield (S )—the volume of LNAPL
yn
neathalayerthatexhibitsaporeentrypressuregreaterthanthe
an aquifer releases or takes into storage per unit surface area of
capillary LNAPL head, thereby impeding the upward migra-
the aquifer per unit change in LNAPL head for gravity
tion of LNAPL limits the upward movement of the LNAPL.
drainage conditions. (unitless)
The term confined LNAPLis used because the mobile LNAPL
3.1.18 LNAPLspecific yield filter pack (S )—thevolumeof
is under pressure greater than gauge pressure against the yf
LNAPL released or takes into storage per unit surface area of
underside of the LNAPL confining layer.
the filter pack per unit change in LNAPL head for gravity
3.1.4 control well—well by which the aquifer is stressed or
drainage conditions. (unitless)
tested.
3.1.19 LNAPL storage coeffıcient (S)—the volume of
n
3.1.5 discharge—the flow of a fluid into or out of a well.
LNAPL an aquifer releases from or takes into storage per unit
(L /t)
surfaceareaoftheaquiferperunitchangeinLNAPLhead.For
3.1.6 drawdown—a pressure differential in terms of fluid
a confined aquifer, it is based on the volume of fluid released
head. (L)
due to decompression. For an unconfined aquifer, the storage
3.1.7 effective well radius—the radius that represents the coefficient is approximately equal to the LNAPLspecific yield.
area of the well casing and the interconnected porosity of the (unitless)
filter pack. (L)
3.1.20 LNAPL transmissivity (T )—the volume of LNAPL
n
at the existing kinematic viscosity that will move in a unit time
under a unit hydraulic gradient through a unit width of the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
aquifer. (L /t)
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.1.21 observation well—a well screened across all or part
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. of an aquifer.
E2856 − 13 (2021)
3.1.22 oil/water interface (Z )—The surface shared by development of the LCSM are provided in Guide E2531. The
nw
LNAPL and water in a control well. (L) general conceptual site model aspects applicable to this guide
include:
3.1.23 perched LNAPL—mobile LNAPL that accumulates
4.1.7.1 Equilibrium fluid levels (for example, air/LNAPL
in the vadose zone of a site for some time period above a layer
and LNAPL/water).
that exhibits a pore entry pressure greater than the capillary
4.1.7.2 Soil profile over which LNAPL is mobile.
LNAPL head, thereby impeding the downward migration of
LNAPL. 4.1.7.3 LNAPL hydrogeologic scenario (for example,
unconfined, confined, perched, macro pores, and so forth).
3.1.24 potentiometric surface—see calculated water-table
4.1.7.4 LNAPL density.
elevation.
4.1.7.5 Hydraulic conductivity for each soil type within the
3.1.25 radius of influence—the distance from a well that the
well screen interval.
pumping induced head differential from non-pumping condi-
4.1.7.6 Well screen interval in the vadose and saturated
tions is zero, head differentials due to background gradients
zones.
may still exist at this radius. (L)
4.1.8 Incorporation of LNAPL transmissivity can further
3.1.26 slug—a volume of water or solid object used to
LCSMsbyprovidingasinglecomparablemetricthatquantifies
induce a sudden change of head in a well.
LNAPL recoverability at individual locations across a site.
3.1.27 test well—a well by which the aquifer is stressed, for
4.1.9 Each of the methods provided in this document is
example, by pumping, injection, or change of head.
applicable to LNAPL in confined, unconfined, and perched
3.2 For definitions of other terms used in this test method conditions. Any differences in evaluation are discussed in
refer to Terminology, Guide D653. Section 5.
4.2 Purpose—The methods used to calculate LNAPL trans-
4. Significance and Use
missivity have been published over the past 20 years; however
4.1 Application: littleefforthasbeenfocusedonprovidingqualityassurancefor
4.1.1 LNAPL transmissivity is an accurate metric for un- individualtestsorrefinementoffieldprocedures.Inadditionto
summarizing the existing methods to calculate LNAPL
derstanding LNAPL recovery, is directly proportional to
LNAPL recoverability and tracking remediation progress to- transmissivity, this document will provide guidance on refined
field procedures for data collection and minimum requirements
wards residual LNAPL saturation.
for data sets before they are used to calculate LNAPL
4.1.2 LNAPLtransmissivity can be used to estimate the rate
transmissivity.
of recovery for a given drawdown from various technologies.
4.2.1 Considerations—The following section provides a
4.1.3 LNAPL transmissivity is not an intrinsic aquifer
property but rather a summary metric based on the aquifer brief review of considerations associated with LNAPL trans-
properties, LNAPL physical properties, and the magnitude of missivity testing.
LNAPL saturation over a given interval of aquifer.
4.2.1.1 Aquifer Conditions (confined, unconfined,
4.1.4 LNAPLtransmissivitywillvaryovertimewithchang-
perched)—In general, each testing type is applicable to
ing conditions such as, seasonal fluctuations in water table, confined, unconfined, and perched conditions; however, con-
changing hydrogeologic conditions and with variability in
sideration should be given to how LNAPL drawdown is
LNAPLimpacts (that is, interval that LNAPLflows over in the calculated from well gauging data relative to formation condi-
formation and LNAPL pore space saturation) within the
tions. Calculation of LNAPL transmissivity for confined and
formation.
perched conditions is possible; however, the soil profile needs
4.1.5 Any observed temporal or spatial variability in values to be considered in combination with the fluid levels to
derive
...
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