New England Interstate
Water Pollution Control
Commission
www.neiwpcc.org/lustline.htm
Boott Mills South
1OO Foot of John Street
Lowell, Massachusetts
01852-1124
LUS.TUNE
A Report On Federal & State Programs To Control Leaking Underground Storage Tanks
Bulletin 49
March
2OO5
Environmental Forensics
Chemical Fingerprinting Gasoline
and Diesel Fuel at LUST Sites
by Scott fl. Stout, Hllen D. Ubler, and Gregory S. Douglas
The need to identify, delineate,
and differentiate petroleum-
derived contaminants resulting
from leaking underground storage
tanks is often an important part of
site investigations where knowledge
of the source(s) of contamination is
sought, and where an equitable set-
tlement of the resulting remedial
liability and damages is at stake.
Significant advances have been
made over the last 15 years with
regard to detailed compositional
analysis of petroleum in the
environment—often referred to
"chemical fingerprinting."
Some of the earliest applications of
chemical fingerprinting were related to
marine oil spills. The Exxon Valdez grounding,
for example, was a situation in which knowledge
of crude oil or residual fuel geochemistry was
applied to identify and differentiate the spilled
oil in Prince William Sound and to assess its
environmental impacts (Bence et al., 1996). In the
past few years, continued developments in the
chemical fingerprinting of refined petroleum
products, such as gasoline and diesel fuel
(Kaplan et al., 1997; Stout et al., 2002), have aided
in answering environmental forensic questions
surrounding the source and/or age of contami-
nation resulting from LUSTs (Beall et al., 2002;
Kaplan, 2003).
• continued on page 2
Inside
60 Age-Dating Releases at LUST Sites: Part II—Case Studies
U Vapor Attenuation in Petroleum Hydrocarbon Sources
Maryland's MtBE Journey
USGS Study of MtBE in New Hampshire
Message from Cliff Rothenstein: Protecting the Environment
Second European Conference on MtBE
WanderLUST
Small Spills Count: The Spill Drill
Maine—The Way Sumps Should Be
FAQs from the NWGLDE
New Projects from PEI
-------
LUSTLine Bulletin 49 • March 2005
• Environmental Forensics
from page 1
Environmental forensic investi-
gations at LUST sites are typically
asking questions such as: What is the
contamination? Where did it come
from? When was it released?
Answers to such questions are used
to determine the responsible party.
Definitive answers to these questions
are not always achieved, but the
questions are best addressed using a
combined approach involving chemi-
cal fingerprinting, a good under-
standing of the site-specific geologic
and hydrogeologic conditions, and
the operational and regulatory histo-
ries for the site (Stout et al, 1998).
This article focuses on the first of
these—chemical fingerprinting.
We'll describe some of the
advances in forensic chemistry that
have been developed in the last five
years and are routinely used in the
chemical fingerprinting of dispensed
and fugitive automotive gasolines and
diesel fuels at LUST sites. The applica-
tion of these techniques in environ-
L.U.S.T.Line
Ellen Frye, Editor
Ricki Pappo, Layout
Marcel Moreau, Technical Adviser
Patricia Ellis, Ph.D., Technical Adviser
Ronald Poltak, NEIWPCC Executive Director
Lynn DePont, EPA Project Officer
LUSTLine is a product of the New England
Interstate Water Pollution Control Commis-
sion (NEIWPCC). It is produced through a
cooperative agreement (#1-830380-01)
between NEIWPCC and the U.S.
Environmental Protection Agency.
LUSTLine is issued as a communication
service for the Subtitle I RCRA
Hazardous & Solid Waste Amendments
rule promulgation process.
LUSTLine is produced to promote
information exchange on UST/LUST issues.
The opinions and information stated herein
are those of the authors and do not neces-
sarily reflect the opinions of NEIWPCC.
This publication may be copied.
Please give credit to NEIWPCC.
NEIWPCC was established by an Act of
Congress in 1947 and remains the oldest
agency in the Northeast United States
concerned with coordination of the multi-
media environmental activities
of the states of Connecticut, Maine,
Massachusetts, New Hampshire,
New York, Rhode Island, and Vermont.
NEIWPCC
Boott Mills South, 100 Foot of John Street
LoweU, MA 01852-1124
Telephone: (978) 323-7929
Fax: (978) 323-7919
lustline@neiwpcc.org
4J§ LUSTLine is printed on Recycled Paper
FIGURE 1. General analytical approach and inventory of analyses
conducted in the chemical fingerprinting of gasoline and diesel
fuel. See Stout et al. (2002) for detailed descriptions.
PRODUCT FINGERPRINTING
Determine overall characteristics via high
resolution GC/FID or full scan GC/MS
GASOLINE
FINGERPRINTING
DIESEL FUEL
FINGERPRINTING
PIANO analysis
Oxygenate analysis
Organic lead and lead
scavenger analysis
Bulk and compound-
specific stable isotope
analysis
• PAH and alkyl-PAH analysis
• S-, 0-, N-PAC analysis
• n-alkane and acyclic
isoprenoid analysis
• Biomarkerand n-alkylcyclo-
hexane analysis
•Total sulfur analysis
mental forensics investigations is
demonstrated in two abbreviated case
studies.
Analytical Strategies
Impacts at LUST sites can arise from
non-aqueous-phase liquids (NAPLs),
impacted soils with residual NAPL,
and impacted groundwater with
residual/entrained NAPL or dis-
solved-phase hydrocarbons. Regard-
less of the matrix, chemical
fingerprinting data developed for
such sites must provide sufficient
specificity to recognize the particular
type(s) of petroleum, characterize the
degree(s) of weathering, and provide
the diagnostic information necessary
to distinguish and perhaps allocate
among multiple source(s) of petro-
leum and/or assess their likely age(s).
A "turnkey" analytical program
that utilizes standard methods of
analysis (e.g., U.S. EPA Methods
8015, 8020, 8260, and 8270) usually
will not produce the chemical detail
needed to defensibly answer envi-
ronmental forensic questions. The
principal reason for this is that the
conventional target analyte lists for
compliance-driven measurement
methods simply do not include the
dominant and important hydrocar-
bon compounds that make up petro-
leum.
For example, the PAH and BTEX
target compounds measured using
standard EPA 8270 and 8260 typi-
cally make up less than 5 to 8 percent
of the total PAHs
and volatiles in
most petroleum
products, and as
such the data have
little or no diagnos-
tic value (Douglas
and Uhler, 1993).
Instead, methods
suitable for envi-
ronmental forensics
investigations are
performance-based
modifications to
existing EPA SW-
846-series methods
that target a greater
suite of compounds
in gasoline and
diesel fuel that are
useful for source
identification and
differentiation.
For LUST site
investigations of gasoline or middle-
distillate releases, we advocate the
use of a tiered analyticial strategy
that captures a full spectrum of
chemical compositional information
(Figure 1). Such a stratagy allows for
the quantitative measurement of a
large number of gasoline-range
(volatile) and diesel-range (semi-
volatile) hydrocarbons and non-
hydrocarbons.
In gasoline investigations this
strategy involves measurement of
nearly 100 of the so-called "PIANO"
compounds (paraffins, iospaaffins,
aromatics, naphthenes, olefins), oxy-
genates, alkyl lead additives, halo-
genated lead scavangers, and volatile
sulfur compounds. In diesel-fuel
investigations it involves the mea-
surement of n-alkanes, acyclic iso-
prenoids, parent and alkylated PAH,
low-boiling biomarkers (e.g.,
sesquiterpanes), and total sulfur con-
centrations. Detailed descriptions of
the analyses used in measuring these
compounds have been published
elsewhere (Stout et al., 2002; Uhler et
al., 2003; Douglas et al., 2004).
Gasoline Fingerprinting
Automotive gasolines are complex
fuels blended from a variety of inter-
mediate refinery streams, each with
different physical and chemical prop-
erties (Stout et al., 2001). Historic
gasolines were blended primarily to
achieve physical specifications for
-------
March 2005 • LUSTLine Bulletin 49
FIGURE 2. Normalized PIANO distribution for two premium reformulated gasolines (RFGs).
Gasoline from Refiner A achieved octane primarily from the blending of Mt BE and iso-octane
whereas Refiner B achieved octane from MTBEand toluene.
35
30
25
20
• 93 Octane Refiner A
D 93 Octane Refiner A
LJ
LdHi
J] ofla.
S i
FIGURE 3. Histograms showing the PIANO distribution forNAPLs from three locations in a study area.
The absence of trimethylpentane isomers (ISO, 234TMP, and233TMP) in the Street NAPL indicated
it is more closely related to the gasoline from Station A. Supply history research demonstrated that
Refiner B blends alkylate (enriched in trimethylpentanes) into their gasolines while Refiner A does
not. Note that the BTEX compounds' (gray) distribution, as might only have been measured by con-
ventional EPA Method 8260, could not have been used to distinguish these NAPLs from one another.
Non-BTEX Compounds D BTEX Compounds
H Trimethylpentane Isomers
Station A-UST NAPL
Station B - UST NAPL
boiling range, vapor pres-
sure, oxidation stability,
and octane with the goal of
suitable engine perfor-
mance, such as cold/hot
starts, acceleration, knock,
resistance to vapor lock.
How these physical specifi-
cations were achieved was
largely left up to the indi-
vidual refiners. Conse-
quently, historic gasoline
compositions were quite
variable in chemical com-
position in both a temporal
and spatial sense.
Modern reformulated
and oxygenated gasolines
must now meet stricter
physical and chemical
specifications. The latter
include restrictions on the
content of olefins, sulfur,
benzene, total aromatic
hydrocarbons, and oxygen.
These specifications have
reduced the compositional
variability that had existed
within the gasoline pool;
nonetheless, on a molecu-
lar level chemical differ-
ences between different
"types" of gasolines persist
depending on the refining
process (Beall et al., 2002;
Stout et al., 2001). This is
exemplified in Figure 2,
which shows the normal-
ized PIANO distribution
for two premium-reformu-
lated gasolines (RFGs) sold
in the mid-Atlantic region
(an ozone nonattainment
area) during the winter of
1999.
In this example, both
gasolines (presumably)
met federal RFG and
ASTM and performance
requirements, yet each
exhibits distinct hydrocar-
bon distributions. It is
apparent that the RFG
from Refiner A achieved
octane primarily from the
blending of MtBE (RON
115) and iso-octane (RON
100), whereas Refiner B
achieved octane from
MtBE and toluene (RON
124). This probably reflects
a difference in refining
• continued on page 4
-------
LUSTLine Bulletin 49 • March 2005
• Environmental Forensics
from page 3
capabilities. For example, Refiner B
does not employ an alkylation unit
and must rely upon aromatics
(toluene) to achieve the necessary
octane.
So let's see how we use this infor-
mation on gasoline variability to
conduct a gasoline-fingerprinting
investigation.
• Case Study #1 The objective of
this investigation was to deter-
mine if NAPL encountered
under a street separating two ser-
vice stations was correlated to
free-phase gasolines found on
two adjacent service station
properties. Detailed gasoline
analysis was conducted on free-
phase product samples from
each property and from beneath
the street (Figure 3). Weathering
had affected the samples differ-
ently; therefore, some differences
were apparent. In spite of weath-
ering differences, the gasolines
recovered from each station
revealed genetic differences
related to refinery blending. Sta-
tion B's gasoline contained an
abundance of particular iso-
paraffins, namely, 2,2,4-, 2,3,4-
and 2,3,3-trimethylpentane (Fig.
3), which indicate that Refiner B
blended alkylate into its gaso-
lines. Station (Refiner) A appar-
ently did not use alkylate in
production of its gasoline(s). The
relative absence of these iso-
paraffins in the 'Street' indicated
it was consistent with the gaso-
line from Station (Refiner) A.
Diesel-Fuel Fingerprinting
Diesel fuel #2, used in on-road vehi-
cles, belongs to the distillate family of
fuels. As the name implies, the pro-
duction of distillate fuels involves
vaporizing and recondensing, which
distinguishes these fuels from the
higher-boiling-range residual fuels
(e.g., fuel oil #6). With minor excep-
tions, diesel fuel #2 generally boils
within the range of approximately
100°C to 400°C, which roughly corre-
sponds to a carbon range of C7 to C25.
The specific characteristic of any
given diesel fuel #2 depends on: (a)
the specific "recipe" by which it was
FIGURE 4. Histogram showing the concentration of total sulfur (ASTM D4294) measured in
25 NAPLs (M/) and 8 dispensed diesel fuels /2 (D/). Superimposed on the histogram is the
historic trend in total sulfur (averaged by year) in the northeastern U.S. showing the significant
reduction in 1993 following the new federal regulations. Most NAPLs and all dispensed diesel
fuels from this site fall below the 0.5 wt% (500 ppm) limit (horizontal dashed line) established
in 1993, indicating most NAPLs were released after 1993.
M1 Mi M7 MS M12 D3 D6 M1S M17 M20 M23
M2 MS Dl M1Q M13 D4 D7 M16 M1B M21 M16
M34 M6 MS M11 D2 05 M14 08 M19 M4 M25
Sample ID
refined and/or blended (e.g.,
hydrotreated versus straight-run), (b)
the nature of the crude-oil feedstock
(e.g., sweet versus sour crude), and
(c) the intended market (e.g., on-
road- versus off-road-grade diesel
fuel; Stout et al., 2004). Each of these
factors can introduce considerable
variability in the detailed molecular
composition of distillate fuels. This
variability provides an opportunity
for the environmental forensic inves-
tigator to unravel issues, such as the
source(s) of diesel fuel-derived conta-
mination at LUST sites.
Due to the detrimental effects
(e.g., corrosion, wear, deposit build-
up) sulfur has on engine and furnace
parts, and the implications for delete-
rious air quality impacts, sulfur con-
tent of most distillate fuels has been
long specified (Gruse, 1967). The first
U.S. specification for diesel fuel #2,
dating from 1922, required <1.5 per-
cent volume sulfur (< 15,000 ppm;
Gruse, 1967). However, it was
quickly learned that the higher the
sulfur content, the greater were the
maintenance problems encountered
in diesel engines.
Thus, in practice, most historic
diesel fuels contained <5000 ppm sul-
fur. In 1993, owing to concerns sur-
rounding air emission (not engine
maintenance), U.S. EPA required that
"low-sulfur," on-road varieties of
diesel fuel contain < 500 ppm sulfur.
Prior to 1993, on-road diesel fuels #2
contained an average of 2,500 ppm
sulfur (U.S. EPA, 2000) (i.e., five
times higher than the current limit).
Even more stringent sulfur specifica-
tions for on-road diesel fuels are
planned for the future. U.S. EPA has
proposed a rule that would require
refiners to further reduce the sulfur
maximum in 80 percent of the on-
road diesel fuels sold from the cur-
rent maximum, 500 ppm, to 15 ppm
(0.0015 % vol) by June 1, 2006. (The
remaining 20 percent of the on-road
diesel would need to meet the 15
ppm limit by 2010.)
This difference in sulfur content,
with time, can prove useful in certain
environmental forensic investiga-
tions at LUST sites where the "age"
of diesel fuel determines liability. So
let's look at how we can use this
information to conduct a diesel-fuel
fingerprinting investigation.
• Case Study #2 The objective of
this study was to determine the
age(s) of NAPL at a truck stop
that changed owners in Decem-
ber 1993, with the agreement that
existing contamination was the
responsibility of the former
owner and any new contamina-
tion was the responsibility of the
new owner. In 1997, NAPL thick-
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March 2005 • LUSTLine Bulletin 49
ness was observed to increase
dramatically despite ongoing
recovery, prompting the previ-
ous owner to suspect that a
recent (post-sale) UST release
had occurred.
Because each operator had
received diesel fuel from a variety of
sources over the time of operation,
the conventional fingerprinting data
(e.g., isoprenoid ratios, PAH distribu-
tions, and low-boiling biomarkers),
which might normally recognize dis-
tinct types of diesel, yielded ambigu-
ous results, most likely due to the
long-term nature of the release.
Age-dating based on degrees of
biodegradation (Christensen and
Larsen, 1993) was inappropriate (the
fresh-dispensed diesel fuel was erro-
neously estimated to be eight years
old by this method). However, when
the total sulfur content was measured
in the NAPLs and modern dispensed
samples using ASTM Method D-
4294-03, and then compared to the
historic trend for diesel fuel #2 sold in
the northeastern U.S., as compiled
from National Institute of Petroleum
and Energy Research (NIPER) annual
databases, the apparent NAPL ages
became clear.
Figure 4 clearly demonstrates
that most of the 25 NAPLs (M#) and
all eight of the dispensed diesel fuels
(D#) from the site contained less than
0.5 percent (<500 ppm) sulfur. This
indicated that most of the NAPLs
were consistent with low-sulfur
diesel fuels produced after the 1993
regulation requiring <500 ppm sul-
fur. The few NAPLs containing more
than 500 ppm total sulfur were likely
from the area of the site where the
former owner's USTs storing pre-
1993 diesel fuels were located. These
results demonstrated that the
increase in NAPL thickness observed
in 1997 was the result of recent
releases of diesel fuel, and thus the
responsibility of the new owner.
Defensible Evidence
Chemical fingerprinting of gasoline-
and diesel-fuel-derived contamina-
tion at LUST sites can help resolve
environmental forensic questions
surrounding the source and/or age
of contamination as a means of estab-
lishing the responsible party. Chemi-
cal fingerprinting can be combined
with other environmental forensic
investigation data (e.g., geology/
hydrology, refining history, opera-
tional history, and regulatory his-
tory) to increase the defensibility of
any conclusions. At the heart of
chemical fingerprinting is our ability
to tailor or modify analytical meth-
ods to provide sufficient chemical
detail to identify and distinguish
gasoline and diesel fuel derived from
different sources at LUST sites. •
Scott A. Stout, Ph.D., Allen D. Uhler,
Ph.D., and Gregory S. Douglas, Ph.D.
are senior consultants with NewFields
Environmental Forensics Practice,
LLC, a technology firm that specializes
in environmental liability assessment
management for industry and govern-
ment. The authors have worked
together for almost two decades in the
realm of environmental chemistry, geo-
chemistry, and environmental foren-
sics. Together they have published more
than 200 papers, periodicals, and book
chapters in their respective fields of
expertise. Contact Allen Uhler at
auhler@newfields.com/or
additional information.
References
Beall, P.W., S.A. Stout, G.S. Douglas, A.D. Uhler.
2002. On the role of process forensics in the charac-
terization of fugitive gasoline. Environmental Claims
Journal. 14(4):487-506.
Bence, A.E., K.A. Kvenvolden, and M.C. Kennicutt
11,1996, Organic geochemistry applied to environ-
mental assessments of Prince William Sound,
Alaska, after the Exxon Valdez oil spill—a review.
Organic Geochemistry. 24(1): 7-42.
Christensen, L.B. and T.H. Larsen, 1993. Method for
determining the age of diesel oil spills in the soil,
Ground Water Monitoring and Remediation, Fall Issue,
142-149.
Douglas, G.S., W.A. Burns, A.E. Bence, D.S. Page, and
P.O. Boehm, 2004, Optimizing detection limits for
the analysis of petroleum hydrocarbons in complex
environmental samples, Environmental Science &
Technology, 38: 3958-3964.
Douglas, G.S. and A.D. Uhler, 1993, Optimizing EPA
methods for petroleum-contaminated site assess-
ments, Environmental Testing Analysis, 5: 46-53.
Gruse, W.A., 1967, Motor Fuels. Performance and Testing,
New York: Reinhold Publishing Corporation
Kaplan, I.R, 2003, Age dating of environmental
organic residue. EnvironmentalTorensics. 4: 95-141.
Kaplan, I.R., Y. Galperin, S. Lu, and R. Lee, 1997,
Forensic environmental geochemistry: differentia-
tion of fuel-types, their sources and release time.
Organic Geochemistry 27:289-317.
Stout, S.A., A.D. Uhler, K.J. McCarthy. 2004. Charac-
terizing the source of fugitive middle distillate fuels
A case study involving railroad diesel fuel, Man-
dan, North Dakota. Environmental Claims Journal.
16:157-172.
Stout, S.A., A.D. Uhler, K.J. McCarthy, S.D. Emsbo-
Mattingly, 2002, Chemical fingerprinting of hydro-
carbons, In: B.L. Murphy and R.D. Morrison, eds.,
Introduction to Environmental Forensics. Academic
Press, Boston, pp.137-260.
Stout, S.A., A.D. Uhler, K.J. McCarthy, K.J. and S.D.
Emsbo-Mattingly, 2001, The influences of refining
on petroleum fingerprinting - Part 2. Gasoline
blending practices, Contaminated Soil, Sediment &
Water, November/December Issue: 42-44.
Stout, S.A., A.D. Uhler, K.J. McCarthy, T. Naymik,
1998, Environmental forensics. Unraveling site lia-
bility, Environmental Science & Technology, 32: 260
A-264 A.
Uhler, R.M., E.M. Healey, K.J. McCarthy, A.D. Uhler,
A.D. and S.A. Stout, 2003, Molecular fingerprinting
of gasoline by a modified EPA 8260 gas chromatog-
raphy/mass spectrometry method, International
Journal of Environmental Analytical Chemistry 83(1): 1-
20.
U.S. Environmental Protection Agency (2000), Fuel
standard feasibility. In: Heavy Duty Standards/
Diesel Fuel, RIA EPA420-R-00-026,122 p.
Missouri's PSTIF Takes the Paper Out of Paperwork
issouri tank owners have a new time-saving option available for reduc-
ing paperwork and streamlining communications. The Petroleum Stor-
age Tank Insurance Fund (PSTIF) has established a Web-based
procedure for tank owners to send in their leak-detection records, line-tight-
ness tests, and other documents concerning UST operations. Insured tank
owners or operators who choose to do so can now conduct all business neces-
sary to continue their participation in the Tank Fund via the Internet. Of course,
the paper option is still available.
"As far as I know, we're the first state agency in the country to offer this option
to tank owners," says Carol Eighmey, PSTIF Executive Director. "The option
was announced in late December, and more than 30 tank owners signed up to
use it during January."
Interested LUSTIine readers can see how it works by viewing a seminar on the
PSTIF's Web site, http://www.pstif.org. Tank Fund staff who respond to claims
are expecting this new tool to give them quicker access to pertinent records
about the UST system when a leak from an operating system is suspected or
discovered. •
-------
LUSTLine Bulletin 49 • March 2005
A Model for Estimating the Age of Gasoline
^^ ^^
Releases and Tracing Fuel Oxygenates:
Part II. Case Studies
by Richard W. Hurst
Assuming you've read "Age-Dating Releases at LUST Sites: Part I. Lead [Isotopic] Fingerprints" in LUSTLine #48,
you are now an expert in the ALAS Model and I'll now move on to explain how the model has been applied to age-date
releases and correlate unleaded gasoline releases, including dissolved phase MtBE/BTEX, to their source. In this issue,
I have selected some representative case studies involving the application of the ALAS Model in different situations and
regions throughout the United States.
As a review of Part I in this two-part series: The development of the ALAS Model (Anthropogenic Lead ArchaeoStratigraphy)
began circa 1989 and continues through today. The model utilizes calibrated, temporal changes in stable lead-isotope ratios (e.g.,
zwpb/zwpb) of leaded gasoline to estimate the year leaded gasoline (or refined middle distillates that have been cross-contaminated
with alkylleads, e.g., TEL) was released into the environment. The precision of ALAS Model ages are as follows: ± 1 year for releases
that occurred between ~ 1965 and 1982 and ± 2 years for 1982-1990 releases; the precision for releases prior to the 1960s is on the
order of 10 years. For reference, the ALAS Model curve is shown in Figure 1.
Note: Although the initial development of the ALAS Model commenced in 1989, at which time it was called the LABILE Model
(Los Angeles Borderland Industrial Lead), it was not immediately applied to estimating the year of gasoline releases. First applica-
tions of the model began some five years later, circa 19 9 4, following further calibration and evaluation of the technique outside of the
Los Angeles area. The case studies discussed in Part II were chosen because they are both representative applications of the ALAS
Model and cover the time period from the model's inception through 2004.
Lead Fingerprinting in Action
The case studies I've selected will be
used to exemplify the versatility of
the ALAS Model and lead isotopes in
"CSI"-type investigations involving:
• episodic leaded gasoline releases
• releases of leaded gasoline and
unleaded gasoline
• identifying sources of fuel oxy-
genates, specifically MtBE, in
groundwater (as a non-age-dat-
ing, fingerprinting-type approach)
The last point may initially
appear enigmatic, but please bear
with me; the fog will be lifted.
The specifics with regard to each
case study represent a range of sce-
narios and conditions under which
the ALAS Model was tested in vari-
ous locations throughout the U.S.
Each site is introduced via its sce-
nario, followed by the lead isotope
results, the ALAS Model ages, and an
epilogue, if appropriate.
Example #1: A Southern
California Gasoline Incursion
(episodic releases)
Scenario
After the construction in Southern
California of a subterranean parking
structure in the early 1990s, following
a month of heavy rainfall, free prod-
uct began seeping out of the walls of
the parking structure. Subsequent to
emergency team responses, geotech-
nical investigations were conducted
to identify potential source(s) of free
product and remediate the problem
by installing sump pumps to remove
free product that continued to seep
into the structure.
Potential responsible parties
(PRPs) included two operating gaso-
line service stations located up
hydrologic gradient and within 200
meters of the underground structure.
As is the case with many service sta-
tions in operation for decades, there
were records of minor releases; hence
both were designated as PRPs (ser-
vice stations 1 and 3). A third service
station (service station 2), located sig-
nificantly down hydrologic gradient,
was identified, yet not suspected of
having caused the release. All service
stations dispensed unleaded fuel.
Standard gas chromatographic
and light-stable isotope (carbon,
hydrogen) analyses were performed
on free product collected in monitor-
ing wells and via sump pumps,
BTEX-impacted groundwater, and
dispensed unleaded gasolines. The
results were not definitive with
regard to the source of free product
and its age, but potential liability was
assigned to service station 3 based on
the presence of lead-free product dis-
covered in groundwater monitoring
wells proximal to the station.
Lead Data
Lead-isotopic and concentration
analyses were performed on selected
free products, BTEX-impacted ground-
water, and dispensed unleaded gaso-
lines from all three service stations.
The results are plotted on a lead-iso-
tope discrimination diagram (Figure
2; 206Pb/207Pb versus 206Pb/204Pb).
Clustering of lead isotopic data on
this discrimination plot indicates the
source of lead in the samples defining
the cluster is the same.
As observed in Figure 2, it is
immediately apparent that the lead-
isotope ratios of free product and
BTEX-impacted groundwater differ
markedly from those of the dis-
pensed gasoline from the three ser-
vice stations. Hence, these stations
are not the source of the free product.
Liability charges leveled against the
operating service station owners
were dismissed by the courts.
ALAS Model Ages
ALAS Model ages, derived from the
lead-isotope ratios of the free product
and BTEX-impacted groundwater
-------
March 2005 • LUSTLine Bulletin 49
FIGURE 1. ALAS Model Calibration Curve: 37 of ~ 125 calibration samples can be resolved at the
scale of the figure; the line depicts the ALAS Model as calculated from U.S. Bureaus of Mines
annual lead production figures and known lead isotope ratios of lead ores mined globally.
-50
| ALAS (Calculated) • ALAS (Calibration) A ALAS (pre-1955 Calibration) |
FIGURE 2. California Case Study. Lead isotope discrimination plot depicting lead isotope
ratios of free product seeping into an underground parking structure versus those of dispensed
unleaded gasoline from 3 service stations—the lead data and ALAS Model ages released the
service station operators from liability.
19.24
19.11
18.98
.n 18.85
Q.
S 18.72
to
Q
18.59
18.46
18.33
18.20
1
lll!|IUIMll I ilk-lid til ,
Uuolliu- ^
f » *
"
A
A
N
D m " I \LASMncltlAEHi:
• p j IWM-I97J
•
160 1.170 1.180 1.190 1.200 1.210 1.220 1.230 1.240
206Pb/207Pb
| • Free Product g BTEX-lmpacted Groundwater A Service Station 1 • Service Station 2 4 Service Station 3 |
yielded ages ranging from 1968 to
1973, suggesting a series of episodic
releases during this time interval. The
age data further exonerated the
operating service stations, especially
service station 3, whose owners
remained the main focus throughout
the investigation.
Epilogue
Following the submission of the
ALAS Model ages to the courts, new
evidence was introduced. The site of
the underground parking structure
had, in fact, been the site of a gasoline
service station that operated from
1969 to 1975. In fact, Los Angeles
County Fire Department records
indicated emergency responses to
gasoline releases of significant vol-
ume at the site from 1971 to 1975,
ages that corroborated the results of
the ALAS Model.
Example #2: Commingled
Plumes in the Midwest
(multiple episodic releases)
Scenario
This site in the Midwest involves a
large (2-3 km), fairly stationary plume
of free product in an industrial area.
The free product or products appear
to be "old," based on the presence of
alkyllead (1-3 gm/gal). The question,
again, centers on the age of the free
product and the number of releases
responsible for the plume. This is a
forensic investigation in which lead
isotopes were effectively integrated
with high-resolution gas chromatog-
raphy (i.e., in which peak heights/
areas are provided for forensic work).
Lead Data
Lead isotope ratio (e.g., 206Pb/207Pb)
analyses of seven free product sam-
ples from the plume were correlated
with high-resolution gas chromato-
graphic analyses, specifically, meth-
ylcyclohexane - isooctane ratios
(MCHx/Isooct; Figure 3) measured
on split samples. Why use these
organic constituents as a reference?
As we know, the refining of
gasoline, like many other technolo-
gies, has evolved. Pre-1950s gasoline
was refined less than its modern
counterparts; lead was added to
improve the octane rating. Circa
1950, catalytic reforming was intro-
duced. This refining process pro-
duced higher proportions of octane-
enhancing organic constituents in
gasoline (e.g., isooctane, 2,2,4
trimethylpentane; BTEX compounds)
relative to organics, such as MCHx,
that did not enhance gasoline octane
ratings. Hence, as catalytic reforming
was more widely used, gasoline
became more refined chemically, so
the MCHx/isooctane ratio decreased,
albeit not systematically, over time.
Figure 3 provides an excellent
example of a hyperbolic mixing
curve, indicative of two free products
(or endmembers), each bearing their
own distinctive Pb isotope - MCHx/
isooctane signature, that has commin-
gled. The chemical characteristics of
the two endmembers are as follows:
Endmember 1: MCHx/Isooct
206pb/207pb „ L17
0.1;
Endmember 2: MCHx/Isooct ~ 16,
206Pb/207Pb „ L135
• continued on page 8
-------
LUSTLine Bulletin 49 • March 2005
m Isotopic Fingerprints from page 7
It is very important to note that
the data points that plot between the
two endmembers would yield fortu-
itous correlations and/or ALAS
Model ages if interpreted as individual
data; this is a common pitfall, over-
looked by many consultants—each
intermediate datum point is a mixture
of the two endmembers and does not,
in itself, represent the chemical char-
acteristics of a separate release! So,
what are the consequences with
respect to the age of the releases?
ALAS Model Ages
(and apportioning liability)
Endmember 1, with its exceptionally
low 206Pb/207Pb ratio, ~ 1.135, yields
an ALAS Model age of 1962, whereas
the ALAS Model age of endmember 2
is 1967—both ages were totally con-
sistent with known gasoline produc-
tion and refining in the area that
commenced in the mid-1950s and
ended by the late 1960s. However,
the property transferred ownership
circa 1965, which leads to the ques-
tion: Which owner bears more liabil-
ity for site remediation?
The results depicted in Figure 3
indicate that the majority of the data
points (5 of 7) plot closer to endmem-
ber 1 (e.g., 206Pb/207Pb ~ 1.17), whose
ALAS Model age is 1967. The lead
isotope data were used in conjunc-
tion with historical documents to
apportion more liability for cleanup
costs to the post-1965 owners of the
property.
Example #3: Something Old,
Something New in Florida
(leaded + unleaded releases)
Scenario
Free product was not present at the
Florida site; rather, evidence for gaso-
line releases was obtained by gas
chromatographic analyses of BTEX-
impacted sediment (-100 to -7,000
ppm). The facility at the site operated
from the mid-1950s through 1991, but
liability fell solely to the last owner
even though historical inventory
records indicated that there had been
transfer-line failures and repairs dur-
ing the tenure of the first owner (mid-
1950s to 1975). The issue centered on
the presence/absence of an older on-
site gasoline component. Could lia-
bility be shared?
8~
TABLE 1 LEAD GEOCHEMICAL AND ALAS MODEL AGE RESULTS:
BTEX-IMPACTED SOILS, FLORIDA
Concentrations (ppm)
SAMPLE LOCATION BTEX PB 206PB/204PB
Dispenser Islands 2,000 0.2-0.5 19.08
Transfer Lines 100-300 4-8 18.43
206PB/207PB AGE (ALAS)
1.222 1986-1990
1.158 1964-1966
Lead Data
Five BTEX-impacted soil samples
were collected from locations in the
vicinity of suspected sources of gaso-
line releases. Soil sampling locations
included areas proximal to the last
owner's dispenser islands and
trenches proximal to transfer lines.
Each soil underwent a series of five
chemical extractions (Tessier et al.,
1979; Hurst, 2000) using combina-
tions of reagents to extract lead
adsorbed onto the soil matrix in
order to evaluate the possibility of
commingling of multiple sources of
lead (Hurst, 2000). The results are
summarized in Table 1.
Both laboratory ana field data
indicate that water-soluble gasoline
constituents carry the lead isotopic
signature of the source of a leaded or
unleaded gasoline release into
groundwater, making the lead-
isotopic system a viable method to
identity the source as well as trace
the late and transport of MtBE/BTEX
in groundwater systems.
ALAS Model Ages
The data indicate that at least two
releases occurred. The younger
ALAS Model ages, 1986 to 1990 (1988
± 2), derived from soil samples proxi-
mal to the location of the last owner's
dispenser islands, were most likely
the result of an unleaded or low-lead
gasoline, given the history of site
operations. The older release, esti-
mated to have occurred in 1965 ± 1,
occurred within the operating period
of the previous owner. Although
not depicted in a figure herein,
206pb/207pb and 206pb/204pb ratios
from the 25 sequential chemical
extractions of the five soil samples
exhibited a range that was uniformly
distributed between the endmember
lead isotope ratios, 1.158 to 1.222. As
in the previous case study, significant
commingling of lead from the two
gasoline releases had occurred. The
relatively uniform distribution of
lead-isotope ratios between those of
the two endmembers (e.g., dispenser
island and transfer lines) suggested
the two releases were of similar mag-
nitude. With this information in
hand, the parties involved settled out
of court, sharing the cost of site reme-
diation equitably.
Example #4: Non-Age-Dating
Applications of Lead
Isotopes—Tracing Unleaded
Gasoline and Dissolved-
Phase BTEX/MtBE
Scenarios
"Unleaded" gasoline spills from
operating service stations (California,
New Jersey, Washington) were sus-
pected of impacting local groundwa-
ter resources with dissolved-phase
BTEX and MtBE. Each service station
owner denied responsibility. It was
necessary for us to ascertain the
source of the dissolved-phase gaso-
line constituents. Was a release of
dispensed unleaded gasoline from a
suspect service station the source of
BTEX/MtBE?
As observed in the southern
California case study and through
laboratory gasoline/water exchange
experiments (Hurst et al., 2001),
water-soluble gasoline constituents,
BTEX/MtBE, carry lead derived from
their gasoline source into groundwa-
ter without changing (i.e., fractionat-
ing) the lead-isotopic signature of the
source leaded or unleaded gasoline.
Furthermore, while natural (unim-
pacted) groundwater lead concentra-
tions are very low, typically <1 ppb,
gasoline-derived lead that enters
groundwater via "hitchhiking" on
these water-soluble organic phases
raises groundwater lead concentra-
tions by orders of magnitude, which
"swamps out" the natural lead.
-------
March 2005 • LUSTLine Bulletin 49
FIGURE 3. Midwestern U.S. Case Study. Lead isotope discrimination diagram identifying two
distinct sources of leaded gasoline in a large, commingled plume. Note that lead isotopes can be
used effectively with organic geochemical analyses to discern the number of sources, the age of
each source, and apportion liability to operators.
1.175
1.170
1.165
1.160
.a
£ 1.155
_n
g 1.150
CM
1.145
1.140
1.135
1.130
Mixmy Curve
0.0
2.0
4.0
6.0
8.0 10.0
MCHx/lsooct
12.0
14.0
16.0
18.0
»MW1A DMW9B AMW2A BMW9A *MW3A •MW9C +MW10|
FIGURE 4. Lead Isotope Ratios of Unleaded Gasoline and Dissolved Phase MtBE/BTEX. The strong
similarity between lead isotope ratios of unleaded gasoline suspected of impacting groundwater
and MtBE/BTEX-impacted groundwater demonstrates the application of lead isotopes to finger-
print such release.
o_
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19 4
19.3
19 2
18 9-
18.7
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• "
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& a
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- • - - - Of**
AA* CA. NJ
18 1.19 1.20 1.21 1.22 1.23 1.24 1.
206Pb/207Pb
| BMFGI2 D*2GW AMFGI3 A*3 GW •MFGI5 O»5GW »MFG»8O*8GW|
25
What this all means, isotopically
speaking, is that measured lead-iso-
tope ratios of gasoline-impacted
groundwater bear the lead-isotopic
ratios (the fingerprint) of the offend-
ing gasoline rather than those of nat-
ural lead in the area (Hurst et al.,
2001; Hurst 2002a). With this deter-
mination we can now identify the
source of the dissolved phase via
comparative isotopic fingerprinting.
Lead Data
At each site, samples of dispensed
unleaded gasolines (all grades) from
the suspected source of free product
and gasoline-impacted groundwater
located downgradient were collected
and analyzed. The results are plotted
in Figure 4 on a lead-isotope discrim-
ination diagram (sample designa-
tions are dispensed unleaded
gasoline from different manufactur-
ers).
Figure 4 shows that in each case
the lead-isotopic ratios of gasoline-
impacted groundwater containing
dissolved-phase BTEX and MtBE
form a well-defined cluster with
those of unleaded gasoline dispensed
by the service station suspected of
being the source of the release. For
example, unleaded gasoline dis-
pensed by MFG #2 is isotopically
indistinguishable from downgradi-
ent gasoline-impacted groundwater,
#2 GW. The minimum lead concen-
tration of gasoline-impacted ground-
water at any site was ~ 10 ppb, with
maxima ranging up to ~ 150 ppb. By
comparison, at each site of concern,
lead concentrations of unimpacted
groundwater were significantly
lower (0.08 to 0.95 ppb), indicating
the predominance of gasoline-
derived lead in groundwater.
The unleaded gasoline-ground-
water data indicate that lead-isotopic
ratios of water-soluble unleaded
gasoline components, such as BTEX
and MtBE, carry the isotopic signa-
ture of their source into groundwa-
ter. At each site, given the agreement
between the lead isotope ratios of the
dispensed unleaded gasolines and
those of MtBE/BTEX-impacted
groundwater, the current service sta-
tion owner at the site was designated
as the responsible party and required
by the appropriate environmental
agency to remediate the gasoline-
impacted groundwater.
What Can We Learn from the
Case Studies?
The results of the case studies pre-
sented here, as well as results from
numerous investigations involving
free product releases throughout the
U.S. (see Part I), exemplify the utility
and accuracy of the ALAS Model as a
tool in forensic investigations in
which estimates of the age and iden-
tification of sources of leaded-gaso-
line releases are an important issue.
Lead isotopes can also help us to
discriminate among sources of dis-
solved-phase hydrocarbons (e.g.,
MtBE and BTEX) in groundwater.
• continued on page 23
-------
LUSTLine Bulletin 49 • March 2005
Making Sense of Subsurface Vapor Attenuation
in Petroleum Hydrocarbon Sources
by Robin Davis
Many of us in the profession of managing petroleum leaks from underground storage systems have pondered the question of
why there are so many contaminated sites due to leaks from these systems, including sites where buildings overlie the
contamination, yet so few sites where vapor intrusion into overlying buildings is actually detected. Issues associated with
the vapor-intrusion exposure pathway generated considerable interest with the advent of Risk-Eased Corrective Action (RBCA)
evaluations. These evaluations typically use the Johnson Ettinger model (J&E) (Johnson and Ettinger, 1991) to estimate concentra-
tions of contaminants that may remain in place without causing human exposure to vapors due to vapor intrusion to indoor air.
The J&E model is an excellent screening tool; however, it often predicts results indicating that the vapor-intrusion pathway is
complete when that pathway may be incomplete. This overprediction may be due to the fact that the model does not account for
biodegradation and the resulting attenuation of petroleum vapors that takes place in the subsurface before those vapors reach an
overlying receptor.
The U.S. EPA published draft guidance entitled "Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater
and Soils" in November 2002 that advocates the use of the J&E model. Recognizing that the November 2002 guidance may be overly
conservative at petroleum sites, the U.S. EPA formed a workgroup in early 2004 to study the behavior of petroleum products in sub-
surface soil. As a member of this group, I reviewed and compiled multidepth vapor data from numerous published references and
public-domain documents to evaluate biodegradation of petroleum vapors in the subsurface. This paper presents the results of the
compilation.
Data Compilation
The references I reviewed contained
data for 38 vapor-sampling events.
The events took place at 32 individ-
ual sample points from 16 separate
geographic locations in the U.S. and
Canada. Four of the sample points
had multiple sample events over
time. Thirteen of the sampling events
included analysis of both benzene
and total petroleum hydrocarbons
(TPH). Benzene vapor concentrations
were reported for 29 sampling
events; TPH vapor concentrations
were reported for 22 events. Figure 1
shows a map of the 16 geographic
locations where 38 multi-depth
vapor-sampling events took place.
Table 1 lists the 38 sample events
where multidepth concentrations of
vapor-phase benzene and/or TPH
were measured and the attenuation
factors calculated for each event.
Attenuation factors were calculated
for benzene and TPH for an individ-
ual event by dividing the vapor
concentration collected from the shal-
lowest location at a sample point by
the vapor concentration collected
from the deepest location at the same
sample point.
Most of the events included mea-
surement of oxygen and carbon diox-
ide and a record of soil type. Benzene
and TPH concentrations in the soil
and groundwater and presence of
10
Assumed # of unkno
location&of refinery sites
~] Number of Geographic Locations (total 16)
Number of Sampling Events (total 38)
free-phase product on groundwater
were noted where available. Type of
ground cover overlying contaminant
sources was also tabulated, including
presence or absence of pavement or
buildings. This information is impor-
tant because of a concern that pave-
ment and buildings may block
oxygen exchange between the atmos-
phere and the subsurface, potentially
causing vapors to accumulate in
the building or under the slab
(Laubacher, et al., 1997; Hers, et al.,
2000; Chuck Schmidt, personal com-
munication, 2004).
Data Reduction and Results
The data indicate that biodegradation
is a likely mechanism of petroleum
vapor attenuation in the subsurface.
The following sections describe the
data collected and the nature of atten-
uation at the sampling events.
• continued on page 12
-------
March 2005 • LUSTLine Bulletin 49
TABLE 1 SAMPLE POINTS, CONSTITUENTS ANALYZED AND ATTENUATION FACTORS 1
Site Name
Refinery VW-93
Refinery VW-96
Refinery VW-99
Akron, OhioVMP-1
Akron, OhioVMP-2
Columbiana, OhioVMP-1
Conneaut, Ohio VMP-1
Kent, Ohio VMP-1
Paulsboro, New Jersey Site
(Area) 1A
Paulsboro, New Jersey Site
(Area) 2
Paulsboro, New Jersey Site D
Port Hueneme, Calif. MP 7,
Site 1, source area 7/98
Port Hueneme, Calif. MP 7,
Site 1, source area, 8/98
Port Hueneme, Calif. MP 12,
Site 1, source area, 7/98
Port Hueneme, Calif. MP 12,
Site 1, source area, 8/98
Port Hueneme, Calif. VPo,
Site 2, source area, 7/98
Handi Mart, Midvale, Utah
Hal's, Green River, Utah,VW-3
Hal's, Green River, Utah,VW-5
Hal's, Green River, Utah,VW-10
Hal's, Green River, Utah, VW-11
Beaufort, South Carolina, NJ-VW2
Coachella, Calif., COA-2
Coachella, Calif., COA-3
Huntington Beach, Calif., HB-3
Huntington Beach, Calif., HB-5
Chatterton, British Columbia,
SG-BC, 9/2/97
Chatterton, British Columbia,
SG-BC, 10/97
Chatterton, British Columbia,
SG-BR, 5/97
Chatterton, British Columbia,
SG-BR, 6/24/97
Chatterton, British Columbia, S
G-BR, 7/2/97
Chatterton, British Columbia,
SG-BR, 12/1/97
NE U.S. SVMP-1A
NE U.S. Basement Location A
GP-01, Ottawa, Ontario
Stafford, New Jersey
Building #73 and VP-9
Stafford, New Jersey
Building #63, VP-13
Stafford, New Jersey
Building #14, VP-10
Soil Type
Sand and gravel with
fine-to-medium sand
Sand and gravel, permeable,
with clayey sand and gravel
Sand and gravel
Sand, silty sand with clayey silt
Sand, silty sand with clayey silt
Silt and sandy silt
Sand and silty sand
Clayey sand and gravelly sand
Sand, fine-medium-grained,
minor silt and coarse sand
Sand, fine-medium-grained,
minor silt and coarse sand
Sand, fine-medium-grained,
minor silt and coarse sand
Silts and sands
Silts and sands
Silts and sands
Silts and sands
Silts and sands
Sand, fine-to-coarse
Silt and clayey silt
Silt and clayey silt
Silt and clayey silt
Silt and clayey silt
Silt and fine-grained sand
Sand (very permeable) with sev-
eral thin interbeds of clayey silt
Sand (very permeable) with sev-
eral thin interbeds of clayey silt
Sand, coarse-grained
Sand, coarse-grained
Fill (dredged river sand)
Fill (dredged river sand)
Fill (dredged river sand)
Fill (dredged river sand)
Fill (dredged river sand)
Fill (dredged river sand)
Sand, fine- to coarse-grained
Sand, fine-to-coarse-grained
Clay
Sand
Sand
Sand
C022
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
023
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Adsorbed
Benzene
X
X
X
X
X
X
X
X
Adsorbed
TPH4
X
X
X
X
X
X
X
X
X
X
X
X
Dissolved
Benzene
X
X
X
X
X
X
X
X
X
X
X
X
Dissolved
TPH
X
X
X
X
X
X
Vapor
Benzene
AF5
0.05
0.0007
0.00004
0.002
0.004
0.0004
0.7
0.002
0.00001
0.00003
0.5
0.01
0.0001
0.00004
0.003
0.02
0.0001
0.0001
0.00008
0.00009
0.0006
0.00002
0.001
0.00002
0.00001
0.002
0.001
0.00008
0.001
Vapor
TPH
AF
0.00001
0.0002
0.0002
0.001
0.004
0.01
1.2
0.002
1.3
0.6
0.01
1.3
0.00006
0.02
0.02
0.0004
0.0002
0.004
0.0008
0.01
1.0
0.3
NOTES 3 02 = Oxygen
1 X indicates constituent was analyzed at multiple depths 4y0ta| petroleum hydrocarbons
2 c°2 = Carbon dioxide 5 Vapor Attenuation Factor
11
-------
LUSTLine Bulletin 49 • March 2005
TABLE 2
Constituents
Benzene
TPH
EVALUATION OF VAPOR ATTENUATION DATA FOR BENZENE AND TPH
Number
of Sample
Events
29
22
Number
of Sample
Events with
Significant
Attenuation
(<0.05)
27
16
%of
Sample
Events with
Significant
Attenuation
(<0.05)
93%
73%
Number of Sample
Events with
Insignificant
Attenuation
(>0.1)
2
6
% of Sample
Events with
Insignificant
Attenuation
(>0.1)
7%
27%
• Vapor Attenuation from page 10
Sampling events exhibiting significant
attenuation of benzene and TPH
Table 2 shows that 93 percent and 73
percent of the sampling events that
analyzed for multidepth benzene and
TPH vapors, respectively, exhibit
vapor attenuation factors of 0.05 or
less. Attenuation factors range from
0.05 to 0.00001. I consider these
events to represent "significant atten-
uation" because the contaminant
vapor concentrations decrease signif-
icantly upward from a contaminant
source.
Events where significant attenua-
tion was observed exhibited all of the
following distinct characteristics:
• At least two feet of uncontami-
nated soil overlie the contami-
nant source.
• Hydrocarbon vapors decrease
significantly away from the
source.
• Oxygen is present in concentra-
tions ranging from 5 to 10 per-
cent.
• Oxygen depletion and carbon
dioxide enrichment occur near
the contaminant source, and
gradual oxygen enrichment and
carbon dioxide depletion take
place with increasing upward
vertical distance from the source.
Figures 2 and 3 show some typi-
cal sampling events where significant
attenuation occurred in the presence
of the distinct signature characteris-
tics described above.
Sampling events exhibiting insignificant
benzene attenuation
Insignificant attenuation is repre-
sented by the lack of upward-
decreasing contaminant vapor
concentrations and is associated with
those sampling events exhibiting
12
attenuation factors of 0.1 or greater.
Attenuation factors range from 0.1 to
1.3. In every sampling event evalu-
ated in this study where insignificant
attenuation was observed, one or
more of the following characteristics
existed:
• No uncontaminated soil overlays
the contaminant source.
• Little or no change in contami-
nant vapor concentrations takes
place upward from the contami-
nant source.
• Oxygen concentrations are less
than 5 to 10 percent.
• Oxygen depletion and carbon
dioxide enrichment is constant.
Figures 4 and 5 show the charac-
teristics of some representative
events where no significant attenua-
tion was observed. Of the 29 events
where benzene was analyzed, only
two (7%) exhibited little or no attenu-
ation, with attenuation factors of 0.1
or more. Despite the low percentage
of attenuation in these events, any
route benzene could take through a
complete exposure pathway war-
ranted some serious discussion,
because benzene is a known human
carcinogen. Those two benzene sam-
ple events exhibit the following char-
acteristics:
• Paulsboro, New Jersey, Site D
(Figure 4): This event took place
beneath a building where no
clean soil overlies the contami-
nant source, as evidenced by con-
stant high benzene vapor
concentrations and constant
oxygen depletion and carbon
dioxide enrichment vertically
upward through the soil column.
• Conneaut, Ohio, VMP-1 (Figure
5): This event shows fairly con-
stant contaminant concentrations
and strong oxygen depletion and
carbon dioxide enrichment, indi-
cating that no clean soil overlies
the source.
Sample events exhibiting insignificant
TPH attenuation
TPH vapor attenuation was evalu-
ated in the 22 events where TPH
vapor was analyzed. Six events, or 27
percent of the TPH vapor sample
events, exhibited insignificant attenu-
ation. All of those events exhibited all
of the signature characteristics of
insignificant attenuation.
Evaluation of attenuation based on
ground-surface cover
The type of ground-surface cover is
known for 27 of the 29 events ana-
lyzed for benzene, and all 22 of the
events where TPH was analyzed. Sig-
nificant attenuation of benzene was
observed at ten paved sites, ten
unpaved sites, and beneath five
buildings. Insignificant attenuation
of benzene was observed at one
paved site, no unpaved sites, and
beneath one building.
Significant attenuation of TPH
was observed at eight paved sites,
eight unpaved sites, and none
beneath a building. Insignificant
attenuation of TPH was observed at
five paved sites, no unpaved sites,
and beneath one building.
These data do little to assist in
making determinations about vapor
attenuation and ground-surface
cover. The Coachella data (Table 1),
for example, exhibit significant atten-
uation under both paved and
unpaved surface cover, and no build-
up of vapors beneath the pavement.
Similarly, the Chatterton data exhib-
ited significant attenuation both
under bare soil and beneath the
building. The Stafford data collected
beneath buildings #73, #63 and #14 all
exhibited significant attenuation.
These data serve to demonstrate that
more information is needed at a
• continued on page 14
-------
March 2005 • LUSTLine Bulletin 49
FIGURE 2
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13
-------
LUSTLine Bulletin 49 • March 2005
m Vapor Attenuation from page 12
greater number of sites with various
types of ground-surface cover.
Evaluation of attenuation based
on soil type
All of the sample events took place in
relatively permeable soil such as
gravel, sand, and silt. The one excep-
tion was GP-01, Ottawa, Ontario,
which took place in clayey soil (Table
1). This sample event exhibited
insignificant attenuation of TPH, but
TPH vapors were not measured
throughout the entire soil column.
Overall, the results of this analysis
show that attenuation takes place in
coarse soil types such as sand and
gravel. These results, however, also
indicate that there is not enough data
to conclude anything about attenua-
tion in fine-grained soil due to
inconsistencies in multilevel sample
collection.
Limitations and Uncertainties
The data compiled for this study
show evidence that petroleum
vapors are being biodegraded at
many of the sampling points where
clean soil overlies a contaminant
source and where oxygen is present
between 5 and 10 percent. Despite
the relatively large data set analyzed
in this study, there is still some
uncertainty as to why some data do
not exhibit subsurface vapor attenua-
tion. The following information is
needed to reduce these uncertainties:
• More data collected from a
greater number of geographic
locations because of regional
variability in subsurface soil
types
• Analysis of benzene, TPH, oxy-
gen, and carbon dioxide from all
sample points
• More sampling events per sam-
ple point to understand potential
temporal variability of attenua-
tion
• Consistency in data collection for
multiple sampling events, in-
cluding sampling at the same
depths for each event
• A better understanding of the
potential for vapors to accumu-
late beneath buildings to deter-
mine if replenishment of oxygen
to the subsurface is impeded by
overlying pavement and build-
ings and if building ventilation
systems have an effect on vapor
behavior in the subsurface
Moving Forward in Making
Important Decisions
The findings of this study indicate
that biodegradation of petroleum
hydrocarbon vapors is a probable
mechanism of attenuation in subsur-
face soils. These finding are consis-
tent with other similar studies and
show that the vapor intrusion path-
way may not be complete at sites
where at least two feet of uncontami-
nated soil overlies the contaminant
source, and subsurface oxygen con-
centrations are 5 percent or greater.
The results of this study show that
bioattenuation factors can be evalu-
ated at leaking UST sites and incor-
porated into the J&E model.
While evaluation of the vapor
intrusion pathway is site-specific,
and the question of why attenuation
is not observed at some sites remains
unanswered, some helpful strategies
for managing sites where vapor
intrusion may be a complete path-
way include: the use of multidepth
vapor sampling outside a building
foundation to determine if the posi-
tive indicators of attenuation are pre-
sent (Hartman, 2004; Hartman, 2005
personal communication); the use of
more intrusive investigative tech-
niques such as sub-slab soil vapor
sampling if those indicators are not
present or are inconclusive; and/or
installing a vapor-extraction system.
Disclaimer
Any opinion expressed herein is that
of the author and does not represent
opinions of the State of Utah or the
U.S. EPA.
Acknowledgements
I am grateful for the support pro-
vided by Joe Vescio, U.S. Environ-
mental Protection Agency; John
Menatti, Utah Department of Envi-
ronmental Quality; Adam Harris,
California State Water Resources
Control Board; Dr. Paul Sanders,
New Jersey Department of Environ-
mental Protection; Dr. Chuck
Schmidt; Dr. Blayne Hartman; and
Dr. Todd Ririe. •
Robin Davis is a Project Manager with
the Utah Department of Environmental
Quality, Leaking Underground Storage
Tank program and member ofEPA's
petroleum hydrocarbon vapor intrusion
workgroup. She specializes in fate and
transport of petroleum hydrocarbons
and data acquisition, reduction and
analysis, most recently for the vapor
intrusion exposure pathway. Robin can
be reached at (801) 536-4177 or
rvdavis@utah.gov.
References
American Society for Testing and Materials (ASTM).
1995. Standard guide for risk-based corrective
action applied at petroleum release sites. E 1739-95.
Dupont, R. R., 2000, Final data summary report of in
situ respiration test/bioventing system design eval-
uation, Utah State University, Division of Environ-
mental Engineering.
Hartman, B., 2004, How to collect reliable soil-gas
data for risk-based applications-Specifially Vapor
Intrusion, Part 3-Answers to frequently asked ques-
tions. LUSTLine Bulletin 48, November 2004.
Hartman, B. 2005, personal communication
Hers, I., J. Atwater, L. Li, and R. Zapf-Gilje, 2000,
Evaluation of vadose zone biodegradation of BTX
vapours, Journal of Contaminant Hydrology, 46
(2000): 233-264.
Johnson, P.C. and R.A. Ettinger, 1991. Heuristic
model for predicting the intrusion rate of contami-
nant vapors into buildings, Environmental Science
Technology 25,1445-1452.
Lahvis, M. A., A. L. Baehr, and R. J. Baker, 1999,
Quantification of aerobic biodegradation and
volatilization rates of gasoline hydrocarbons near
the water table under natural attenuation condi-
tions, Water Resources Research, 35, No. 3, 753-765.
Laubacher, R. C, P. Bartholomae, P. Velasco, and H. J.
Reisinger, 1997, An evaluation of the vapor profile
in the vadose zone above a gasoline plume, Proceed-
ings of the Petroleum Hydrocarbons and Organic Chem-
icals in Ground Water, November.
Pearce, P., W. Parker, and P.Van Geel, 2002. Long
term monitoring of hydrocarbon contamination
using multi-level vapor phase piezometers, Envi-
ronmental Forensics volume 3 p. 163:177.
Ririe, G. T., R. E. Sweeney, and S. J. Daugherty, 2002,
A comparison of hydrocarbon vapor attenuation in
the field with predictions from vapor diffusion
models, Soil and Sediment Contamination, AEHS
publishers, No. 11(4): 529-554.
Roggemans, S. 1998, Natural attenuation of hydro-
carbon vapors in the vadose zone, thesis for Master
of Science, Arizona State University.
Roggemans, S., C.L. Bruce, P.C. Johnson, and R.L.
Johnson, 2001, Vadose zone natural attenuation of
hydrocarbon vapors: An empirical assessment of
soil gas vertical profile data. American Petroleum
Institute, December 2001, No. 15.
Sanders, P., I. Hers, M. Lewis, 2004, Investigation of
vapor intrusion in homes over petroleum-contami-
nated groundwater in Stafford Township, New Jer-
sey. Presented at the March 15, 2004 Vapor
Intrusion Workshop, San Diego, California.
Schmidt, C.E., 2004, personal communication.
SECOR International, 2004, Soil vapor sampling
report for Hal's Chevron, 138 W. Main St., Green
River, Utah, March 5, 2004, prepared for the Utah
Department of Environmental Quality, Leaking
Underground Storage Tank Section.
U.S. EPA, 2003, Indoor Air Vapor Intrusion database.
-------
March 2005 • LUSTLine Bulletin 49
Maryland's MtBE Journey
As States Continue to Tackle the MtBE
Problem on Their Own.,
by Herbert Meade
The tracking and response to
MtBE contaminations in Mary-
land has been an interesting
journey for those of us at the Mary-
land Department of the Environment
(MDE) Oil Control Program. This
journey continues with the proposal
of changes to Maryland's UST regu-
lations that will increase the level of
monitoring associated with gasoline
storage tanks.
As background, over the past
several years, MDE has seen an
increase in groundwater cases that
involve the gasoline additive MtBE.
MtBE makes up to 11 to 15 percent by
volume of the gasoline sold in Mary-
land as oxygenated gasoline, a.k.a.
reformulated gasoline, used to meet
the federal Clean Air Act require-
ment for reducing carbon monoxide
and volatile organic compound emis-
sions. In Maryland this type of gaso-
line is required to be sold in the most
highly populated central portions of
our state. However, MDE has found
that all gasoline in Maryland contains
some level of MtBE.
Tracking MtBE
Since 1998, MDE has separately
tracked the number of known private
wells impacted with MtBE across
Maryland. These well impacts come
to our attention through data col-
lected from LUST site remediation
activities, private homeowner sam-
pling, or sometimes through routine
evaluations by local health officials.
Our data indicate that more than 600
private wells have been impacted
with MtBE at 5 ppb or higher. Addi-
tional data show that approximately
20 public water supply wells have
been impacted in the state.
Except for Anne Arundel
County, the largest impacts tend to
be across the top of the state in areas
with fractured rock geology—Har-
ford, Cecil, Carroll, Baltimore, and
Frederick counties. The geology in
these counties allows for the rapid
transport and spread of MtBE in the
groundwater. The MtBE impacts in
Anne Arundel County, which has
coastal plain geology, may have to do
with the large number of shallow
wells still in use.
Action Levels
In the early 1990s, Maryland estab-
lished a 50 ppb action level for MtBE.
The current state action level for
MtBE is 20 ppb. This level is not an
MCL but a level where a water treat-
ment or alternative source should be
secured. Our investigation level, at
which we formally open a case for
investigation activities, is 10 ppb.
The Sources?
MtBE by its nature is hydrophilic. In
the early 1980s, MDE was seeing
MtBE as the leading-edge component
of groundwater gasoline contamina-
tion plumes. MtBE would be the pre-
cursor to other gasoline components,
such as benzene and toluene. The
sources of these early plumes were
normally traced back to a liquid
release from a gasoline UST system.
In the early 1990s, we noticed
MtBE contamination from other
sources, such as home heating oil
tanks and underground diesel fuel
tanks. We determined that MtBE had
cross-contaminated into all petro-
leum products shipped in bulk.
Today, approximately half of our
groundwater MtBE cases can be
traced back to a nongasoline source,
such as a privately owned home
heating oil tank. However, the largest
numbers of impacted wells continue
to be gasoline-UST related.
In the late 1990s, MDE observed
an unusual occurrence at service sta-
tions in our state. We noticed MtBE
levels in the groundwater around ser-
vice stations that were in full compli-
ance with state and federal
regulations. All of these stations had
complied with the storage system
upgrade requirements and deadline
of 1998. We attributed these contami-
nations to poor
maintenance of
overfill catchment
basins, lack of sumps
under dispensers,
poor product han-
dling by the public,
and lack of contain-
ment around the Stage I
vapor recovery dry break fit-
ting. Even after the stations
addressed our concerns and
we mandated overfill protec-
tion at the Stage I dry-break,
we saw the trend of MtBE
impacts continue to climb.
Indeed, many UST regulators
recognize that a good many compli-
ant tanks are likely to be leaking, but
below the leak detection threshold of
0.2 gallons per hour (which is equiva-
lent to 1,752 gallons per year...and at
11 to 15 percent MtBE, this means
that 193 to 263 gallons of MtBE per
tank may be released into the envi-
ronment)
In early 2000, MDE technical staff
felt that a contributor to MtBE in the
groundwater at these stations was
the release of enriched MtBE vapors
into the storage tank backfill. How-
ever, without the resources to con-
duct scientific studies, our concerns
fell on deaf ears. The theory of MtBE
vapor causing groundwater contami-
nation has finally been substantiated
by studies conducted in other states,
such as California, New Hampshire,
and Vermont.
At a lot of our sites we are seeing
that underground gasoline storage
systems that utilize Stage II vacuum-
assist vapor recovery systems, which
recover gasoline vapors from motor
vehicles during fueling and return
those vapors to the facility's storage
system, are being continuously pres-
surized. These storage tanks were
never designed as pressure vessels but
as liquid-containing devices. The pres-
sure is forcing MtBE-enriched gaso-
line vapors into the tank backfill area.
• continued on page 16
15
-------
LUSTLine Bulletin 49 • March 2005
m Maryland and MtBE/rom page 15
Once out of the storage system,
hydrophilic MtBE seeks soil mois-
ture, attaches to the soil water
droplets, and ultimately contami-
nates the groundwater. By the nature
of service station construction, soils
surrounding the storage tanks do not
vent into the atmosphere. The vapors
are retained subsurface by the con-
crete caps over the tank field and the
asphalt over the majority, if not all, of
the service station lot. MDE has
found MtBE as the only contaminant
in water under UST backfill at levels
as high as 900,000 ppb.
What is MDE doing?
MDE has taken several steps to
address the MtBE problem. First, we
formally investigate any detection of
MtBE at or over 10 ppb. We have a
policy agreement with the local
county health departments to share
all case data for detections over 10
ppb. Historically, we have been able
to find a point source for levels over
10 ppb. However, our ability to prop-
erly staff such investigations is
becoming strained. Levels below 10
ppb are becoming very common
across the state and may be attrib-
uted to contaminated stormwater
runoff, poor petroleum handling, and
groundwater recharge.
In August 2004, in response to
citizen concerns, Governor Ehrlich
asked MDE to write technical regula-
tions that will require early detection
and better containment of MtBE
within underground gasoline stor-
age systems in "high-risk groundwa-
ter use areas." These high-risk
groundwater-use areas were defined
by MDE in direct response to the
MtBE issue in Maryland. All UST
construction, containment, and leak
detection regulations to date have
focused on liquid releases, not vapor.
We met with the regulated commu-
nity, heard citizen concerns, and
published our proposed regulations
in December 2004. A legislative com-
mittee, under emergency conditions,
approved these regulations on Janu-
ary 26,2005.
Emergency Regulations
The emergency regulations focus on
all existing and new underground
gasoline storage systems in "high-
risk groundwater-use areas" of
Maryland:
Requirements for New Gasoline UST
Systems within the High-Risk Areas
• Install double-walled piping and
containment sumps with intersti-
tial monitoring (statewide).
• Install four monitoring pipes in
the tank field with connected
soil-vapor extraction (SVE) pip-
ing.
• Use state-of the art leak detec-
tion, including detection for
vapor releases, by performing a
helium test yearly.
• Sample site water supply well
yearly.
• Use of one of the following meth-
ods for improved control, detec-
tion, and prevention of releases:
a. three or more monitoring
wells and sample yearly
b. a pressure-control device that
maintains the UST's < nega-
tive pressure
c. an SVE system on the tank
field
d. an alternative method ap-
proved by the MDE.
• Submit a Corrective Action Plan
to MDE if "levels of concern" are
detected at any time.
Requirements for Existing Gasoline
UST Systems
• Test for vapor leaks by perform-
ing a helium test yearly, and test
UST catchment basins and con-
tainment sumps yearly.
• Install three or more groundwa-
ter-monitoring wells.
• Sample site supply well and
monitoring wells twice a year.
• Install one of the following:
a. an SVE system on the tank
field
b. a tank-pressure-control device
c. an alternative method ap-
proved by the MDE.
• Submit a Corrective Action Plan
to MDE if "levels of concern" are
detected at any time.
Other MDE Actions
• Working with industry to
develop new programs to edu-
cate the public on petroleum-
product handling and home
heating oil storage.
• Developing a third-party inspec-
tion program that will require
the detailed inspection of motor-
fuel UST systems across the state.
MDE's staffing levels do not
allow for frequent inspections.
We are averaging three to five
years in our current cycle. We
hope that this inspection pro-
gram will note deficiencies in
UST operations and ensure that
those problems are corrected
before releases occur. Our target
for implementation is July 2006.
• Continuing to require the reme-
diation of MtBE and other petro-
leum-contaminated sites across
the state. MtBE can be cleaned
up; however, the plumes of cont-
amination tend to be larger than
petroleum plumes without MtBE,
and MtBE resists natural bio-
degradation. So MtBE cleanups
take longer and are more costly.
Unfinished Business
Even with the measures mentioned,
the ability of our state to respond to
groundwater contamination is lack-
ing in many ways. Our current needs
include:
• Improved state laboratory sup-
port to analyze samples and turn
reports around in a timely man-
ner
• Funding for alternative water
supplies or point-of-use filtration
systems, where appropriate
• Adequate staff to investigate and
oversee groundwater contamina-
tion cases.
• Increased oversight of heating oil
tanks that should be required to
have tightness testing and sys-
tem upgrades
• A review of Stage II vapor recov-
ery technology
• A review of the use of MtBE as
an oxygenate and the overall
need for oxygenates in our
nation's gasoline supply
• A requirement for VOC sampling
before property transfer and
occupancy
-------
March 2005 • LUSTLine Bulletin 49
Actions by Our Elected
Officials/MtBE Ban
We suspect that there will be several
MtBE-related bills introduced in the
Maryland General Assembly this
year. These bills may range from res-
olutions to Congress asking for help
to the outright ban on MtBE.
It is simple to say, "Let's just ban
MtBE." However, such an action
must be carefully considered. If MtBE
is banned and the RFG requirement
is still in place, then an MtBE ban is
the equivalent of mandating ethanol.
Both chemicals have environmental
and health concerns that need to be
weighed, not to mention supply,
transport, and market concerns. MDE
has not taken a position on the MtBE-
versus-ethanol discussion.
Are We in Crisis?
From a public perception standpoint,
and if MtBE is in your well water, the
answer is yes. Health studies, which
are admittedly old, do not show
adverse health effects from MtBE at
levels that we normally see in
impacted drinking water wells. How-
ever, we find that any degree of
impact is unacceptable to the public
involved. We feel that our new tech-
nical regulations and increased over-
sight can prevent and provide early
detection of petroleum releases. •
Herbert Meade is the Administrator of
the Oil Control Program, Maryland
Department of the Environment. He
can be reached at
hmeade@mde.state.md.us.
USGS Study Looks at MtBE
Occurrence in Rockingham
County, New Hampshire
by Gary Lynn
The U.S. Geological Survey, in
cooperation with the state
Department of Environmental
Services Waste Management Divi-
sion, completed a cooperative study
on the occurrence of MtBE in ran-
domly sampled private and public
water supply wells in Rockingham
County, New Hampshire. The full
study was published in the January
2005 edition of Environmental Science
and Technology and can be accessed at
http://nh.water.usgs.gov/Publications/
2005/es049549e.pdf.
The occurrence of MtBE in Rock-
ingham County was studied because
of the county's high risk for MtBE
contamination of water supplies due
to its heavy dependence on ground-
water for water supplies (94% of resi-
dents) and participation in the
reformulated gasoline program. The
major findings of the report are as
follows.
• The frequency of MtBE detec-
tions in public water supplies in
New Hampshire continues to
increase both statewide (12.7% in
2000 to 15.1% in 2002) and in
Rockingham County (20.3% to
23.1% in the same time period),
based on a 0.5 ug/L detection
limit.
• MtBE was frequently detected in
both public (40%) and private
(21%) water supplies above a 0.2
ug/L detection limit.
• MtBE detections correlated well
with the degree of urbanization.
• Public water supply wells
located further from under-
ground storage tanks had statisti-
cally significantly lower levels of
MtBE than wells located closer to
tanks.
• MtBE concentrations were higher
in relatively deep bedrock wells
with low water yields.
In New Hampshire, the percent-
age of public water supplies with
MtBE detections continues to
increase. All of the MtBE detections
in the study's randomly sampled pri-
vate wells were below the state's
drinking water standard of 13 ug/L;
however, 4 of the 120 public water
supply wells exceeded the MtBE
standard.
The detection of higher concen-
trations of MtBE in deep bedrock
wells was an unexpected finding.
There are a number of potential
explanations; one of the most plausi-
ble explanations is that the deeper
wells are in tighter bedrock forma-
tions with lower yield. For this
reason, they are less likely to sig-
nificantly dilute water in fractures
containing MtBE.
The private well detections did
not correlate well with distance from
underground storage tanks. These
data suggest that there are significant
sources of MtBE contamination unre-
lated to tank-system releases. Based
on my personal communications
with the study's primary author,
Joseph Ayotte, the public water sup-
ply MtBE contamination detections
correlated better with UST installa-
tions than known LUST sites. This
unpublished finding establishes that
a stronger statistical relationship
exists for UST installations versus
LUST sites, but does not establish a
causal relationship. A potential
explanation could be that the UST
installations are more commonly
associated with high urban densities
or other factors that also correlate
with MtBE water supply detections.
Another plausible explanation,
however, is that UST sites pose a
potentially more significant threat to
public water supplies than known
LUST sites because, (a) existing leak-
detection technologies do not detect
vapor and small liquid releases from
sumps/spill buckets at active instal-
lations, (b) UST installations are more
numerous than LUST sites, and (c)
LUST sites are being actively remedi-
ated, while undiscovered releases at
active UST installations are not. DES
believes that the Rockingham County
data tend to confirm the need for our
stepped up inspection and leak pre-
vention efforts. •
Gary Lynn is the Petroleum Remedia-
tion Section Manager at the State of
New Hampshire Department of Envi-
ronmental Services. He can be reached
at glynn@des.state.nh.us.
-------
LUSTLine Bulletin 49 • March 2005
A MESSAGE FROM CLIFF ROTHENSTEIN
Director, U.S. EPA Office of Underground Storage Tanks
We're Here To Protect
America's Environment
I've been the national tank program director for almost five years, and in my
tenure, I've seen outside forces that are significantly impacting our work
and how we do it. I think the start of a new year is a good time to reflect on
the forces that are changing our program, how we've adapted to meet those
changes, and our ultimate job.
The Forces Changing Our Program
Over its 20-plus-year history, the national tank pro-
gram has been evolving, and it will continue to evolve
over the next decade. But during the last five years,
I've noted certain factors that are significantly impact-
ing the program.
• Resources are continuing to tighten. Both state and
federal budgets have gotten tighter over the years.
And state tank cleanup funds have come under
increased financial pressures. In fact, approxi-
mately one-third of the funds have claims exceed-
ing their fund balances and several have
experienced fund diversions, leaving less money
for tank cleanups.
• Remaining sites to be cleaned up are more complex.
In the earlier years of the program, cleanups were
easier and completed more quickly. We're now
seeing that one-half to two-thirds of the remaining
sites require groundwater remediation or include
technical difficulties because of complicated geol-
ogy, such as fractured bedrock. These circum-
stances make cleanups more costly and take
longer to complete, compared with soil-only cont-
aminated sites.
• MtBE is being discovered at two-thirds of all leaking
UST Sites. These discoveries result in longer and
more costly cleanups. Cleaning up MtBE can dou-
ble the cost of an average petroleum cleanup—and
this increases the demands on limited cleanup dol-
lars. Because MtBE plumes are typically larger
than other contamination plumes, cleanup can
take as much as one and one-half to three times
longer than sites without MtBE. And some states
are reopening closed sites and reevaluating for
MtBE, diverting resources away from sites not yet
cleaned up.
How We've Adapted
In spite of these significant changes, EPA and our tank
partners have adapted and developed tools and tech-
niques to help us continue our progress in preventing,
detecting, and cleaning up petroleum releases.
We have:
• Identified opportunities to reuse abandoned gas sta-
tions. Rosalia, Washington, citizens are enjoying a
new community visitor center, located at a site
that was previously an old, abandoned gas station
and an eyesore in their rural community. This
reuse scenario is a great example of what stake-
holders can accomplish when they partner in
order to accomplish a common goal.
• Developed ways to improve compliance, improved
compliance will translate into fewer releases of
gasoline products to the environment. To improve
compliance, we've developed tools—such as the
Environmental Results Program, previously
applied to small business sectors like dry clean-
ers—for use in the tank program.
• Worked to reduce the cleanup backlog. Over the last
few years, states and U.S. EPA have focused on
reducing the cleanup backlog. Now, at less than
130,000 cleanups, the backlog has decreased to its
lowest level since 1992.
• Focused on preventing new leaks. If we prevent
leaks, we'll have fewer cleanups. And as a result of
our focus on prevention and compliance, we've
seen confirmed releases drop significantly—
approximately 35 percent over the last year.
Our Ultimate Job
With the day-to-day crunch of work—be it looking for
reuse opportunities, conducting inspections, assessing
sites, or cleaning up sites—it's imperative that we
remember our ultimate purpose. Our bottom-line job,
day after day, is to protect the environment and
human health from underground storage tank releases
and keep America's land and water clean and safe for
all citizens and future generations. •
18
-------
March 2005 • LUSTLine Bulletin 49
The Second European Conference on
MtBE: A View from the U.S.
Continental Divide
byJeffKuhn
A:
s I write
this article
.in Helena,
Montana, the effects of global
climate change seem tangible,
even to the greatest skeptic. There is
no snow, and every coffee shop is
abuzz with talk of another bad fire
year should the spring rains fail
again. The annual "Race to the Sky"
dogsled race has been cancelled, and
our local ski resort has become "the
Rock," as we affectionately call it in
the spring when the weather warms
and the slopes turn to brown rock
and bare soil. Only trouble is, it's
January. And when it should be 20
degrees below 0 outside, it's 45
above. I find the "tropical" weather
very unsettling. It reminds me of
other times, other changes.
For example, 1979, the year MtBE
was first introduced into the United
States—Jimmy Carter was president,
U.S. citizens were being held hostage
at the embassy in Teheran, and I was
an exchange student living in central
Germany. It was cold war Europe—
detente complete with "Checkpoint
Charlie" in Berlin, Russian soldiers
garrisoned in most East German
cities, and a hated wall that rifted east
from west separating many German
families.
The New Europe
Twenty-five years later, I found
myself back in Europe attending the
Second European Conference on
MtBE in Barcelona, Spain. Being
there was delightful and unsettling—
like spring weather in Montana in
January. There were obvious cultural
changes in Europe since my student
days; others I could not quite put my
finger on—changes that could only
be sensed, like an all-too-early shift in
the seasons. Europe was not the same
place I remembered. The fall of the
Berlin Wall in 1989 signaled the end
of the cold war. "Checkpoint Char-
lie" is now in a museum in Berlin.
Since that time the population shift
from east to west has deeply affected
the fabric of German culture and
society and changed the face of
Europe as well.
More recently, terrorism touched
European soil with the Madrid train
bombings, allegedly in retaliation for
Spain's support of the U.S. in the war
on terror. With this backdrop in mind
I was not so sure how Americans
would be received at a scientific con-
ference on MtBE in Spain. Our arrival
in Barcelona also happened to coin-
cide with the U.S. election results—
the headline on Spain's morning
paper La Prada announced the relec-
tion of President Bush.
But in contrast to the political
tensions that I expected to encounter,
Barcelona was warm and welcoming.
Students crowded the streets at night.
The cafes were packed. It reminded
me more of post-Olympic Game cele-
brations—the Olympics were held
here in 1992. Maybe the party had
never stopped. But one thing was
sure—the warmth of Barcelona was
no illusion.
And the Conference?
The Second European Conference on
MtBE was held in a medieval
monastery now used by the Institut
d'Estudis Catalans—the Institute of
Catalonian Studies—a university
dedicated to the preservation of the
Catalonian language and culture. As
one of six Americans who attended
the meeting, I was very happy to rec-
ognize a number of European col-
leagues from previous international
meetings held in the U.S., and truly
appreciated the warm greeting that
our group received.
The two-day conference focused
on the use of oxygenates in Europe
and the successes of various remedia-
tion technologies in Europe and the
U.S. The meeting provided a plat-
form for researchers, regulatory
officials, public agencies, and con-
sultants to present scientific studies,
discuss the extent of MtBE contami-
nation in Europe and other countries,
compare various remediation alter-
natives being used, and review
innovative treatment technologies
implemented in a variety of different
pilot projects.
"Where Are the Regulators?"
While the meeting was well attended
by academic representatives from
many European countries, U.S. par-
ticipants noted the absence of regula-
tory representatives. Our inquiries as
to their absence led to responses indi-
cating that regulatory representatives
did not typically attend such techni-
cal meetings. They said regulators
often worked independently of the
scientific community and had little
contact with actual remediation pro-
jects.
I was curious how an approach
so different from that taken in Amer-
ica was status quo in so many Euro-
pean countries. The most common
answer to our question seemed to
indicate that stronger divisions exist
in Europe between government offi-
cials, corporations, and academia.
These divisions, in turn, translated to
a lack of communication in sharing
advances in technologies at a number
of different levels.
Differences between languages
and cultural identities were much
less of an obstacle than I originally
anticipated—European society is
well adjusted to these challenges and
even more so in scientific meetings,
where all presentations and discus-
sions occur in English.
Participants and Topics
The scientific organizing committee
for the conference included the fol-
lowing individuals: Damia Barcelo,
IIQAB-CSIC, Barcelona, Spain
(chair); Erik Arvin, Technical Univer-
sity of Denmark, Denmark; Peter
Werner, Dresden University of Tech-
nology, Germany; Thomas Track,
DECHEMA, Frankfurt, Germany;
Juergen Busing, European Commis-
sion, DG Research, Brussels,
Belgium; and Mira Petrovic, IIQAB-
• continued on page 20
19
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LUSTLine Bulletin 49 • March 2005
m European MtBE Conference
from page 19
CSIC, Barcelona, Spain (scientific sec-
retary).
The conference included speak-
ers and attendees from Germany,
Switzerland, Spain, France, Den-
mark, Belgium, Lithuania, England,
Scotland, the Netherlands, Sweden,
Austria, the Czech Republic, and, of
course, the U.S. Speakers gave talks
in five general subject areas:
• Occurrence fate and behavior of
MtBE and other fuel oxygenates
in soil-water systems
• Analysis of MtBE in water and
soil matrices
• Biotic and abiotic degradation of
MtBE
• In-situ and ex-situ treatment of
MtBE-contaminated soil and
water
• Risk assessment and legal
aspects of MtBE contamination
Specific presentations focused on
a number of different studies involv-
ing MtBE contamination. There were
several very interesting presentations
involving the Leuna MtBE site
located near Halle in the former East
Germany. Leuna was the site of a
large chemical manufacturing plant
that was repeatedly bombed during
World War II. The plant later served
as a major refining location and pro-
duced MtBE for use at service sta-
tions in East Germany.
The massive MtBE plume present
at the site has been the focus of ongo-
ing research under the European pro-
ject entitled "METLEN." Martin
Bittens (UFZ Germany), who pre-
sented an overview of the Leuna site
at the National UST/LUST Confer-
ence in 2004, was also present at the
meeting and coauthored a number of
papers presented at the meeting.
Other talks focused on the European
"WATCH" (Water Catchment Areas:
Tools for management and control of
hazardous compounds) Program.
Talks from the U.S. contingent
focused on MtBE remediation pro-
jects in New York, New Hamsphire,
Montana, and Kansas.
Issues Raised
A Danish colleague, Dr. Erik Arvin
20~
(Technical University of Denmark),
and I were invited to chair a round-
table session to conclude the meeting
and summarize significant issues,
problems, and solutions discussed
during the session. We prepared a
short list of questions for the partici-
pants and focused conversation from
the audience on each question. Many
interesting points were raised,
including:
• Concern over the reopening of
closed sites in the Netherlands
and Denmark, where no previ-
ous characterization for MtBE or
other oxygenates has occurred.
How should this be done and
what has been the experience of
the U.S.?
• Debate over whether European
tank systems are sufficiently
designed to prevent MtBE
releases.
• Concern from German represen-
tatives that Germany and other
European Union countries are
beginning to increase their use of
MtBE and expect that they will
see concentrations increase in
groundwater.
• Concern from the World Health
Organization (WHO) about
establishing standards for MtBE
and other recalcitrant com-
pounds for European countries
in view of other more pressing
world needs.
• Debate over whether country-by-
country standards are appropri-
ate or whether a broader
standard adopted by the Euro-
pean Union would adequately
address the needs of each coun-
try.
• Discussion about how to dissem-
inate technical information and
data on the use of innovative
technologies.
• Acknowledgement from most
countries that they did not know
the extent of groundwater conta-
mination from MtBE, since test-
ing for MtBE has not been
required.
• A desire for a greater degree of
collaboration on groundwater-
contaminant issues between
Europe and the U.S.
Catching Up
Many of the arguments discussed
during our roundtable discussion
were reminiscent of the many
debates that occurred in the U.S. as
EPA's Blue Ribbon Panel gathered
scientific data and public input dur-
ing its series of meetings in the late
1990s. The wide range of opinions
expressed by the European countries
was quite similar to those expressed
by our states in the early days of the
MtBE debate.
At the conclusion of the round-
table, it appeared that most partici-
pants were willing to admit that
groundwater testing must be com-
pleted by each country to determine
whether MtBE and other oxygenates
should be recognized as compounds
of concern in Europe. A hopeful sign,
but still an indication that although
academic research efforts at sites
such as Leuna are quite advanced,
European regulatory policy may be
lagging 10 years behind the U.S. in
the field of oxygenates.
Damia Bacelo from the Institut
d'Estudis Catalans, Barcelona, Spain,
concluded the meeting with closing
comments, thanking all participants,
especially the U.S. contingent, whose
participation and presentations
helped make the conference a great
success.
Tearing Down Walls
So what did we take home from
Barcelona other than wonderful cui-
sine and a severe case of jet lag? The
end of the cold war has created a
huge need for technology transfer in
Eastern Europe, especially in the area
of contaminant research. European
scientists and academic researchers
are hungry for U.S. remediation tech-
nology, and especially the results of
pilot-project research efforts involv-
ing innovative technologies. They
also want to take advantage of the
advances we have made in the devel-
opment of groundwater-modeling
software and learn from our collec-
tive research experience—much of
which we readily share with the
world via the Internet.
As I finish this article, snow is
falling again in Helena. Yet, I'm not
entirely convinced it's still winter
rather than a brief intermission from
global climate change. I wonder how
• continued on page 31
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March 2005 • LUSTLine Bulletin 49
We Can Do This the Easy Way Or....
A Stream-of-Consciousness Diatribe on LUST Stuff That
Can Really Get on Your Nerves
Do you ever feel that there's a
little black cloud just follow-
ing you around, waiting to
rain on you every chance it gets?
Well, there are certainly days that I
do. I guess if life were easy, it
wouldn't be very interesting. I'd like
to tell you about one of my little
black clouds. It's a project that has
taken up a considerable amount of
my time for about the past two years.
Actually, it's taken up a lot more of
my time than it should have, because
of the actions—or lack of actions—of
one of my responsible parties. I've
avoided names to protect both the
innocent and the guilty.
It all started with a phone call
late one Friday afternoon, just before
a holiday weekend. (Most problem
phone calls come in late on a Friday
afternoon, when there are usually
only a few people left in the office.)
"My water tasted funny," says the
caller, "so I had it analyzed, and it
has one part per million MtBE and
one part per million benzene. What
are you going to do about it?"
Of course, the site couldn't have
been any farther from the office and
still remain in the state. I scramble for
the carbon-filter vendor and plead
with him to get filters installed
ASAP. I'll worry about a purchase
order later, when there's someone
around to authorize it. Next, I
arrange with the lab for glassware
and mobilize to sample the nearby
wells starting Monday.
ARRGHH About a week later lab
results show that seven more wells
are contaminated. How can these
people not taste or smell this stuff? So
now we need to install more filters
and expand the sampling radius even
farther.
Eventually, 16 contaminated
wells are identified. By now I decide
I'd better get a contractor to handle
the routine well sampling and filter
change-outs, because it's costing me
two or three full days per month to
handle the sampling. Why are the big
sites never anywhere near the office?
This one is a two-hour or longer
drive each way. (I know, that's no big
deal to Big Sky readers.) But, the
wells are temporarily under control,
even if it means changing out filters
every month or two.
Sorting Out the RP(s)
A search of the database shows three
nearby operating gas stations. Why is
it never just one? Two of the sites
have been leakers before. One of the
sites had a line break back in the mid
1980s that dumped more than 3,000
gallons of gasoline overnight. Ten
years of investigation and remedia-
tion later, it got its closure letter.
Amazingly, during the entire time
that it was an active LUST site, the
consultant included MtBE as an ana-
lyte—and it was absolutely non-
detect the entire time.
About the time that the closure
letter was issued, the tanks were
removed, and a new property owner
installed a new double-walled sys-
tem. The owner was not very happy
with DNREC back when he installed
his tanks; he was required to install a
double-walled system because he
was in a wellhead protection area. At
least double-walled tanks should
have a decreased chance of leaking,
so maybe this one is not the source of
well contamination.
The second station had also been
a LUST site. At the time that tanks
were removed in the mid-1990s and
before a new system was installed in
the same hole, a moderate amount of
overexcavation was done to remove
highly contaminated soil. Unfortu-
nately, the limit of reach of the exca-
vation equipment and the water table
were both reached at about 20 feet, so
a little residual contamination was
left in the ground^,800 ppm BTEX
and 2,100 ppm TPH. A few wells
were installed at the site, with 12
ppm BTEX being the hottest ground-
water sample collected in a year of
monitoring in the downgradient-
most well.
A quick Bioscreen-modeling run
• continued on page 22
-------
LUSTLine Bulletin 49 • March 2005
m WanderLust/rom page 21
said the contamination shouldn't go
more than about 300 feet. Probably a
few assumptions in the model were
wrong—like the default grain size.
Recent well installations have docu-
mented the presence of a few great
coarse sand and gravel layers that
might help speed things on their way
downgradient.
The 12 ppm BTEX as a starting
number for the model might not have
been a good assumption either, since
the plume was not very thoroughly
defined. This was coupled with
assumptions of first-order decay
rates. And, at the time of the earlier
project, MtBE was not a required ana-
lyte. Well, as it turns out, not just the
MtBE has traveled 1,200 feet, but also
the benzene.
The consultant for the earlier
LUST project also stated that the sur-
rounding area was all served by a
public water supply—except that he
missed the 200-or-so trailers hidden
in the trees directly downgradient of
the station. They don't show up on a
search of the well permit database
because they predate 1968, when the
permitting process first began.
I had better feelings about the
chances that the third station was not
a source. It is about three years old,
has double-walled tanks, double-
walled pipes, a bells-and-whistles
leak-detection system, and an opera-
tor with an excellent compliance
record in the state and in surround-
ing states. There actually was another
former LUST in the area, but the
tanks hadn't been used since 1974, so
I doubted that it could have con-
tributed to the MtBE contamination
in the wells.
Armed with my consultant, a
Geoprobe, and umpteen individual
well permits (Geoprobe investiga-
tions require well permits for each
individual property, signed by the
property owner), we set out to finger
the guilty party. The investigation
narrowed it down to two of the possi-
ble sources. Of course, one of them is
pretty much directly downgradient
of the other. Both have had releases,
but have both contributed to the cur-
rent well contamination? Both RPs
were sent notices to begin hydrogeo-
logic investigations to determine the
nature and extent of their releases.
22
Obstruction!
So far, one of the RPs has been very
responsive. During several phases of
well installation, using multilevel
cluster wells to define the plume ver-
tically as well as horizontally, a
plume of groundwater contamina-
tion has been identified between the
station and the impacted wells, and a
work plan for remediation is getting
its final touches prior to submission
to DNREC.
As for the second RP, it's been a
totally different story. When DNREC
initially conducted its investigation,
this RP refused us access for Geo-
probe sampling, so we sampled
immediately downgradient from his
property, and came up with elevated
MtBE in the groundwater. That's
when he got the letter requiring an
investigation.
It was hard to hide my satisfaction
when some of the samples came up
somewhat smelly, and really hard to
keep from gloating when I could
smell product as they were drilling
from ahout 30 feet away, and the
auger was hringing up dark gray sand
instead of light hrown sand. At least
I didn't jump up and down and
sing "I told you so!"
When he didn't respond by the
deadline, he got a phone call. He
claimed he couldn't possibly have a
leak because the #@%##* state made
him install a double-walled tank sys-
tem, and he had no plans to investi-
gate. When he still wouldn't respond,
he received a Notice of Violation. Still
no investigation.
In the meantime, more impacts
were identified in a second cluster of
homes with domestic wells located
much closer to our problem station.
Rather than issuing a Secretary's
Order with a penalty, we issued a
Notice of Intent to take over the
investigation and cost-recover all
expenses plus overhead. Finally, he
scheduled a meeting with us.
After two hours of discussion and
a few threats to walk out of the meet-
ing, our recalcitrant RP still had no
answer as to whether or when he
would conduct the investigation. A
few weeks later, a somewhat wimpy
investigation work plan arrived. The
plan was short on the required multi-
level sampling on the downgradient
side of the property, which had been
required because of the locations and
known depths of some of the
impacted wells in the neighborhood
nearest the station.
The plan had more than ade-
quate coverage in the upgradient
direction, because the RP was intent
on showing that his contamination
(including the MtBE) had come from
the upgradient tanks that were last
used in 1974. Rather than reject the
plan entirely, we approved it with
the condition that additional sam-
pling be conducted at specified
deeper intervals on the downgradi-
ent side.
Rather than giving the required
five days notice prior to fieldwork,
the consultant snuck a fax into my
office at about 4:55 one afternoon
informing me that the investigation
work would be conducted the next
day. I guess he hadn't counted on my
getting the fax in time to show up at
the site, but I did make it down there
by about 10 a.m.
It was hard to hide my satisfac-
tion when some of the samples came
up somewhat smelly, and really hard
to keep from gloating when I could
smell product as they were drilling
from about 30 feet away, and the
auger was bringing up dark gray
sand instead of light brown sand. At
least I didn't jump up and down and
sing "I told you so!"
Watch Out for the...Oops
I should mention that the RP had
been warned that since he insisted on
sticking to the perimeter of his prop-
erty for drilling, so as not to put any
holes in his beautiful asphalt, there
was the potential for encountering
underground utilities on all four
property boundaries.
"Miss Utility" had marked the
utilities. On the day of the sampling,
the consultant had stepped about two
feet off one of the spray-painted mark-
ings. Using a 4-inch (in diameter)
hand auger, he drilled for about four
or five feet to make sure the location
was clear. Then, the drill rig was put
in place. It had an 8-inch auger. The
holes were drilled. The extra diameter
was just BIG enough to cut through
275 phone lines out of a bundle of 300.
The phone company trucks
showed up about six hours after the
-------
March 2005 • LUSTLine Bulletin 49
hole was drilled, and when I left the
site, they were setting up tents for a
long repair session. I'm sure that
someone eventually got a hefty bill
for that repair. When I'm drilling, I
like to avoid the utility mark-outs by
at least five feet, but that would have
put the hole in the pavement instead
of in the grass.
Marching Orders
Of course, the sampling report didn't
make the 90-day deadline, and it V;
came with absolutely no conclusions
or recommendations, even though
the first round of samples from the
temporary wells showed 380 ppm
MtBE at the top of the water table at
20 feet, and 16 ppm MtBE at 40 feet,
on the downgradient property
boundary.
The next letter to the RP from
DNREC provided a detailed set of
marching orders with an equally long
list of deadlines for getting additional
tasks completed, such as installing
permanent onsite wells, doing off site
plume delineation, and their taking
over the sampling and filter mainte-
nance for wells in the second
impacted neighborhood.
One thing we learned from the
temporary wells on the site is that
there is still a diverging groundwater
flow pattern, just as there had been
previously when the station was a
LUST site. One component of
groundwater flow is toward the first
station and the first neighborhood of
impacted wells. The other compo-
nent of flow is toward the second
neighborhood of impacted wells.
Unfortunately, a six-lane high-
way runs between the two stations.
Between overhead and underground
utilities and the highway, it is
extremely difficult to find any loca-
tions where holes can be drilled
between the two stations that would
show whether the plume of the
"recalcitrant RP" has crossed the
highway. Of course, any plume
crossing the highway is doing it on a
diagonal, so without multiple sam-
pling points on both sides of the
highway, it is hard to determine
whether the two plumes may be
merging in the vicinity of the first sta-
tion.
Sixteen months after the original
letter went out requiring the RP to
"determine the full extent of contami-
nation, both laterally and vertically, a
workplan was just submitted. It
includes several permanent monitor-
ing wells, all onsite, and nothing
more. Even though the first round of
samples from the temporary wells
showed elevated MtBE on the down-
gradient property boundary, no off-
site wells were proposed.
Darn
Cloud!
We have two
LUST projects,
both started at
the same time.
One of the sites has identified a 1,200-
foot long plume and will have a cor-
rective action plan in any day now.
The RP at other site is doing every-
thing the hard way—kicking,
screaming, protesting, foot-dragging.
He has only just figured out that he
has had some sort of a release, proba-
bly coming from the vicinity of the
tank field. In the meantime, another
neighborhood's domestic wells have
been impacted since the first request
to do an investigation.
At the same time, DNREC has
been working toward extending a
public water line into the first neigh-
borhood. Sixteen wells were
impacted, and about 30 homes will
be connected to the water line. Some
residents aren't very happy about
having a water bill in the future. Four
people in the neighborhood have
been opposed to the water line solu-
tion, and of course, it is through one
of their properties that we need an
easement to extend the line! After
five months of negotiations, we have
our signed easements and can com-
plete the engineering work needed to
bid out the installation.
No end in sight any time soon for
this project. Unfortunately, I have
two other projects that are about the
same scale, one with 25 well impacts
and one with 21 impacts, so far, and I
am also the project officer for about
70 more LUST projects. •
• Isotopic Fingerprints from page 9
Both laboratory and field data indi-
cate that water-soluble gasoline con-
stituents carry the lead isotopic
signature of the source of a leaded or
unleaded gasoline release into
groundwater, making the lead-iso-
topic system a viable method to iden-
tify the source as well as trace the fate
and transport of MtBE/BTEX in
groundwater systems.
Are Other Fuel Releases
Datable via the ALAS Model?
Although developed to estimate the
age of leaded gasoline releases, the
ALAS Model has been successfully
applied to age-dating releases of jet-
A, diesel, kerosene, motor oil, and
heating oil. The condition under
which the ALAS Model can be
applied to middle/heavy petroleum
distillate releases includes situations
where fuels are suspected of acciden-
tally acquiring small, yet significant
quantities of alkylleads during refin-
ing. The condition is recognized
when lead in a middle/heavy petro-
leum distillate exceeds normal con-
centrations (< few hundred ppb
lead). As with unleaded gasoline,
lead-isotopic ratios may be used to
correlate environmental releases of
these products to their source. •
Richard W. Hurst, Ph.D., is the Presi-
dent of Hurst & Associates, Inc. and
has been a Professor of Geology/Geo-
chemistry since 1978 at California
State University, Los Angeles. He can
be reached at (805) 492-7764 or
Alasrwh@aol.com. Check out his Web
site at www.hurstforensics.com.
References
Hurst, R.W., 2000, Applications of Anthropogenic
Lead ArchaeoStratigraphy (ALAS Model) to
Hydrocarbon Remediation, Journal of Environmental
Forensics 1, pp. 11-23.
Hurst, R.W., Barren, D. Washington, M. and
Bowring, S.A., 2001, Lead Isotopes as Age Sensitive,
Genetic Markers in Hydrocarbons: 1. Co-Partition-
ing of Lead with MTBE into Water and Implications
for MTBE-Source Correlations, Environmental Geo-
science 8, pp. 242-250.
Hurst, R.W., 2002a, Lead Isotopes as Age Sensitive,
Genetic Markers in Hydrocarbons: 2. Kerogens,
Crude Oils, and Unleaded Gasoline, Environmental
Geoscience 9, pp. 1-7.
Hurst, R.W., 2002b, Lead Isotopes as Age Sensitive,
Genetic Markers in Hydrocarbons: 3. Leaded Gaso-
line, 1923-1990, Environmental Geoscience 9, pp. 43-
50.
Hurst, R.W., 2005, ALAS, A Model for Estimating the
Age of Gasoline Releases and Tracing Fuel Oxy-
genates (e.g. MtBE): Part I. Model Development,
LLJSrLme#48,p. 7.
23
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LUSTLine Bulletin 49 • March 2005
by W. David McCaskill
David McCaskill is an Environmental Engineer with the Maine Department of
Environmental Protection (DEP). "Tanks Down East" is a regular feature of
LUSTLine. David can be reached at David.Mccaskill@maine.gov.
As always, we welcome your comments.
As with most of Northern New England, Maine has been blessed with abundant water and rocks. Do we have rocks! We've got our
famous rock-bound, wave-lashed coast. We've got our springtime crop of rocks popping up in farmers' fields after the winter frost,
ready to be transformed into sturdy stone watts. And we've got fractured bedrock with water-filled cracks covered by precious little
soil to absorb petroleum-product spills. This generally thin covering of glacially derived soils all too often fails to provide much of a
barrier to petroleum contamination that seems to be inevitably attracted to private water wells. More than 50 percent of Mainers
receive their drinking water from private wells drilled into fractured bedrock. Because petroleum use and groundwater use often occur
in close proximity (think corner store, basement oil tank, lawnmower, and backyard water well), private water wells often serve as
unwitting monitoring wells.
In New England, small petroleum spills count, whether they are from underground tank overfills at the corner mom-and-pop
convenience store, careless home heating oil deliveries, or a homeowner sloshing gasoline between the gas can and the lawnmower in
the backyard. In this edition of "Tanks Downeast" I'm going to discuss some of the strategies that Maine has included in its quiver of
groundwater protection tools to target these "little" spills.
Spillage During Deliveries at
UST Facilities
According to about two-and-a-half
years of Maine DEP's spill records,
underground tank overfills make up
40 percent of spills over 10 gallons.
Once a tank is overfilled, the spill
bucket is the only thing between the
driver and a flood of gasoline across
the pavement! To understand why
this can happen and why it shouldn't
happen (in case you haven't come to
that realization), let's quickly brush
up on the basics of a gravity fuel
delivery at a gas station.
Dropping Fuel at a Gas Station
Before anything else happens, the
driver should gauge the tank to make
sure that the amount of fuel in the
truck will fit into the target UST. To
begin the delivery, the driver clamps
one end of the delivery hose to the
tank fill pipe and the other end to the
fuel outlet on the bottom of the tank
truck. A valve is opened at the truck
and because of gravity, fuel flows
through the hose. If all goes accord-
ing to plan, once a compartment on
the tank truck is empty, the valve
underneath the tank truck is closed,
the hose is disconnected from the
truck's fuel outlet, and "walked"
back to the UST by methodically lift-
24~
ing the hose from the tank truck end
to the underground tank end to drain
the residual fuel in the hose into the
underground tank.
Once a tank is overfilled, the spill
bucket is the only thing between the
driver and a flood of gasoline
across the pavement!
If the overfill prevention device
was ignored or bypassed, and if it
turns out the UST didn't have enough
space to hold all the fuel in the truck
compartment, the driver will have
about 20 feet of a 4-inch hose that is
full of product—about 14 gallons to
dispose of. Hmm, how do you cram
14 gallons of fuel into a 3- to 5-gallon
spill bucket? Well, you don't.
So it occurred to us that our over-
fill prevention efforts were not work-
ing. (See LUSTline #31, "If Only
Overfill Prevention Worked," if you
want to understand why it doesn't
work). We continued to have spills
because drivers were trying to
squeeze too much product into an
UST. We needed to be sure that spill
buckets were large enough to hold
the contents of a typical delivery hose
when overfill prevention equipment
failed.
15-Gallon Spill Buckets
Beginning in March 2004, DEP
upgraded its UST rules, adding a
requirement (among others) that all
new UST installations and all
replacement spill buckets must have
at least a 15-gallon capacity. If, in the
case of a replacement, a 15-gallon
spill bucket does not fit, then the
largest capacity that will fit must be
installed.
During testimony on this rule,
one oil company representative sug-
gested that the larger spill buckets
will encourage delivery drivers to
spill more into the spill buckets and
therefore increase the maintenance
cost for removing and disposing of
the gasoline and water mixture. Now
maybe we're naive, but we don't
believe that tanker drivers go around
surreptitiously filling spill buckets
with fuel with a malicious gleam in
their eye.
The simple truth is that spill
buckets get filled with fuel because
drivers have nowhere else to put the
fuel. For example, when a driver
arrives at a gas station whose owner
has ordered too much fuel, he is
faced with a knotty decision: Does he
refuse to deliver after driving from
Searsport to Stonington? Or does
he fill the tank, hoping that a cus-
-------
March 2005 • LUSTLine Bulletin 49
tomer will have arrived and
pumped enough gas into her SUV to
subtract the difference?
While it may be true that large-
capacity spill buckets will increase
tank owner maintenance costs, it
seems equally true that small-capac-
ity spill buckets increase our cleanup
costs. This makes a pretty strong
argument to us to (a) have the larger-
capacity spill buckets and (b) get all
stakeholders involved in figuring out
how to avoid having spill buckets full
of fuel in the first place. To encourage
stakeholder involvement, DEP has
decided that training of the delivery
drivers by their employers will have
to take place!
As to the issue of spill bucket
replacement—which is frequently
necessary as metal or plastic buckets
rust or degrade—contractors were
concerned that there would be no
room between tank risers to allow
for the installation of larger spill
buckets. To that end, we have devel-
oped a spreadsheet of the dimen-
sions of various makes and models
of 10- and 15-gallon spill buckets to
aid contractors in selecting a replace-
ment (http://www. maine.gov/dep/rwm/
ust/ pdf/spillbucketdimensions.pdf). To
date, very few problems have been
encountered.
Spillage During Deliveries at
Home Heating Oil Tanks
Maine has over 415,000 fuel-oil cus-
tomers, and Maine heating-oil deal-
ers deliver more than 350 million
gallons of fuel oil to these customers
each year. On average, Maine DEP
responds to one heating-oil spill a
day at single-family residences. Over
the last seven years, we have spent
about $300,000 on public and indus-
try outreach in the form of pam-
phlets, paid television ads, and
newspaper ads. Is that too much? Is it
too little? In that same time frame we
have spent around $9.6 million in
cleanup! You compare the numbers
and decide.
Our latest outreach effort is a 20-
minute training video, Working
Together for Spill Prevention, directed
at fuel-oil delivery drivers and oil-
heat technicians. (See sidebar on page
26.) The video covers everything
from proper delivery techniques to
how to spill-proof basement heating
oil tank installations.
Most times, everything works just
fine. However, sometimes
homeowners move the tank to
another area in the hasement, hut
leave the old, now unattached, fill
pipe in the exterior wall of the house
unbeknownst to the delivery driver!
Dropping Fuel at Home
So, let's go over the anatomy of a resi-
dential fuel-oil delivery. Because of
the small quantities (100 to 200 gal-
lons) delivered, the fuel-oil delivery
operation is very different from the
gas station delivery. It resembles the
typical automobile-fueling operation,
except that the fuel-oil nozzle usually
clamps firmly to the fill pipe.
The driver connects a nozzle
attached to a long hose coiled on the
delivery truck to a fill pipe sticking
out of the basement wall and opens a
valve on the nozzle that allows the
fuel oil to flow. Because the nozzle-
to-fill-pipe connection is airtight, as
fuel flows into the tank, the air inside
the tank is vented out through a sepa-
rate vent pipe.
Inside the tank, where the vent
pipe connects to the tank top, there is
a short tube, called a vent whistle,
that extends into the tank. As air
passes through this whistle tube on
its way out the vent, a whistling
sound is created. The vent pipe
should be located close to the fill pipe
so the delivery person can hear the
whistling sound.
As the tank fills and the oil level
reaches the bottom end of the whistle
tube, air exits exclusively through the
vent and the whistling sound stops.
When the delivery driver doesn't
hear the whistle, it's time to shut the
nozzle valve.
The whistle is, in a sense, a
reverse overfill alarm! The driver
then carefully unhooks the nozzle of
the hose from the fill pipe and coils
the hose back on the reel on the truck.
Because the hose has a valve on the
end of it, the hose remains full of
product between customers, and
there is no need to drain it.
So what can go wrong? Most
times, everything works just fine.
However, sometimes homeowners
move the tank to another area in the
basement, but leave the old, now
unattached, fill pipe in the exterior
wall of the house unbeknownst to the
delivery driver! In this scenerio, the
driver's first clue is that no whistle is
whistling, but not all tanks have the
required whistle—or one that works.
I've been told that even without a
whistle, the old pros can listen to the
sound emitting from the vent and tell
when the tank is almost full. But for
those without such talented ears, the
biggest tip-off to trouble is when 300
gallons have been pumped into the
"phantom" 275-gallon tank!
Other problem scenarios involve
situations where tanks: (a) are over-
pressurized and bursting when the
vent is blocked, (b) have insufficient
capacity, or (c) are overfilled with
product (without a whistle, how can
you tell when a tank is full?)
Those are delivery-related spills,
not to be confused with spills due to
"acts of nature"—used in the broad
sense. For example, snow and ice can
fall from a roof and strike the fuel-
outlet fitting and filter (located on the
bottom the tank), thus releasing all or
some of the contents of the 275-gallon
tank. This scenario is restricted to
tanks installed outside, but basement
tanks can suffer a similar fate—but
with dogs and kids substituted for
the snow and ice! (See LUSTLine #33,
"Those Tanks in America's Back-
yards and Basements.")
Spills During Yard
Equipment Filling
In 2003, Maine passed a law to
require that all gas cans sold in the
state be "spill-proof" as defined by
the California Air Resources Board
(CARB). The purpose of this rule was
to reduce: (a) the amount of volatile
organic compounds (VOC) being
released into the air due to spills dur-
ing fuel transfers, (b) volatilization
resulting from leaving the cap off the
spout while the can is not in use, and
(c) vapor diffusion through the walls
of the plastic cans. These VOCs con-
tribute to ground-level ozone, and
the gas can rule was a component of
a suite of regulations adopted by
Maine and other New England states
to prevent regional ozone problems.
An obvious secondary benefit of
these rules is that they help prevent
small gasoline spills that could
impact homeowner drinking water
wells.
• continued on page 26
~25
-------
LUSTLine Bulletin 49 • March 2005
m The Spill Drill from page 25
Dropping Fuel into a Lawnmower
To prevent overfills while yard
equipment is being filled, the spout
of the gas can is designed to automat-
ically shut off flow when the "target"
container (e.g., your lawnmower's
tank) is full. The spout seals itself off
automatically when it's removed
from the target tank so you never
have to remember to put the cap back
on. Finally, the area around the spout
is designed to seal with the target
container, reducing the release of fuel
vapors but allowing air to vent into
the gas can through an opening in the
spout so gas can flow (sort of like a
balance Stage II vapor-recovery sys-
tem).
There have been problems
encountered in some of the designs
that have forced CARD to review
their specifications. Soon after the
Maine rule went into effect, yours
truly ran out to purchase what
turned out to be (in my opinion) a
less-than-perfectly-designed can. The
problem with the can I bought is that
to dispense fuel the nozzle must be
positioned almost vertically into the
fill on the lawnmower, then the gas
can spout is opened by pressing the
can down onto the target container's
fill opening. Cans with a round
flange around the spout to push
against encourage proper use. Those
with a tab (like the one I bought)
instead of the flange let you cheat by
filling at an angle and splashing gas
on the side of the lawnmower's fill
allowing vapors to escape and
increasing the likelihood of a spill.
Education and Outreach
But the best of tools (or regulations)
will only take us so far toward suc-
cess. We have to get people on board
so they will comply with the rules
rather than resist them. Wth respect
to deliveries at UST facilities, the oil
industry agreed during a public hear-
ing on the rule to work with DEP to
develop some training.
Recognizing that getting drivers
into a state-sponsored training class
is not likely to happen, but that these
folks do get training from their
employers on various matters, DEP is
planning a "Stop the Spill" semi-
nar/panel discussion this summer
for the employers. During this train-
26~
ing we will cover topics ranging
from-how to train both the home
heating oil delivery driver and the
homeowner (tank upkeep and main-
tenanace) to what the transport dri-
ver needs to know about overfill
devices and spill buckets. Weighty
matters for sure.
This training will probably be
built around our home heating oil
delivery video and the still-timely
U.S. EPA video, Keeping It Clean: Mak-
ing Safe and Spill-Free Motor-Fuel
Deliveries. On the home front, we
have already sent out 250 copies of
our home heating oil delivery video
to all the members of the oil industry
trade groups in our state.
Homeowner education is always
problematic. However the DEP has a
weekly newspaper column entitled
"In Our Backyard" that appears in
many weekly papers throughout the
state. We have used this as a vehicle
to reach out to the homeowner on
various environmental issues includ-
ing heating oil tank safety and gaso-
line handling.
Keep on Chipping
The task of reducing the threat posed
by transferring fuel at every level,
from 10,000-gallon transport trucks
to 3-gallon gas cans, is a difficult one
because of the frequency of these
kinds of events, the huge number of
tanks involved, and the large number
of people who carry out the transfers.
But in New England, we have to con-
tinue to chip away at the problem
because small spills count. •
New Training Video for Fuel Oil Delivery
Drivers and Oil Heat Technicians Available
from Maine DEP
The Maine Department of Envi-
ronmental Protection has
developed a 20-minute train-
ing video, entitled Working
Together lor Spill Prevention,
directed at fuel oil delivery drivers
and oil heat technicians The video
instructs the truck drivers of oil
delivery companies on the fine, and
rather detailed, art of making a home heating oil delivery and also instructs
oil-burner technicians (the people who install, service, and repair furnaces and
boilers) on how to spot problems with oil tanks and oil line installations when
they are making service calls.
Using one of Maine DEP's crack oil spill responders, Tom Varney, the talents
of part-time actor/DEP employee, Robert Demkowicz, and the technical assis-
tance and collaboration of a local oil company, the video details all steps the
driver should take to assure a spill-free delivery for both indoor and outdoor
tanks.
These steps include checking the label on the fill pipe with the customer num-
ber on the delivery ticket, "walking" the delivery path first—without the
hose—to assure it is free of obstacles, checking the fill and vent pipe, setting
the meter, pulling the hose and attaching it to the fill pipe of the tank, listening
for the whistle, stopping the flow when the whistle stops, and recoiling the
hose with the nozzle pointing up so no oil drips out.
The finished video was delivered to various oil dealers throughout the state,
primarily by the Maine Oil Dealers Association (MODA), a state industry trade
group that represents oil dealers and gas station (convenience store) owners.
To request a copy of the video or DVD, contact David McCaskill at Maine DEP
at (207) 287-7056. •
-------
March 2005 • LUSTLine Bulletin 49
nically Speaking
by Marcel Moreau
Marcel Moreau is a nationally
recognized petroleum storage specialist
whose column, Tank-nically Speaking,
is a regular feature o/LUSTLine. As
always, we welcome your comments and
questions. If there are technical issues
that you would like to have Marcel
discuss, let him know at
marcel.moreau@juno.com
Maine - The Way!
What's Wrong with
This Picture?
As I sat in a darkened conference
room listening to the groans and
snickers of an audience of UST regu-
lators and industry folk viewing a
series of decidedly ugly looking tank-
top and dispenser sump pictures, I
was thinking that the sumps I typi-
cally saw in Maine were much better
looking than the ones I was seeing in
this presentation. It wasn't until some
time later that it occurred to me to
ask, "Why?" Why is it that contain-
ment sumps in Maine are, generally
speaking, substantially cleaner, drier,
more functional and (presumably)
more effective in performing their
intended functions?
There was a time, some 20 years
ago, when I too used to obtain similar
reactions from audiences upon show-
ing them slides of primitive "do-it-
yourself" UST installations in Maine.
But I would be hard-pressed to find
such pictures in Maine today.
Okay, it's true that Maine's tank
program is two decades old. Indeed, I
would be seriously depressed if, after
all this time, the situation in Maine's
UST world had not improved. But
the federal tank program is only a
few years younger than Maine's, and
a number of states have tank pro-
grams that are as old or older than
Maine's.
Why Is Sump Appearance
Important?
After all, unlike rest rooms, nobody is
grossed out by a gas station because
it has dirty sumps. Sump appearance
is important because a really dirty
sump is generally an indication of the
presence of liquid. Typically, the liq-
uid is mostly water (though some
amount of product together with the
water is not uncommon), and if water
is getting in, then product can likely
get out.
Also, if water is getting in to a
sump, then chances are (a) alarms are
going off and being ignored or (b)
sensors are being "adjusted" to
ensure that these "nuisance" alarms
don't happen. Thus, while sump
appearance is not the real issue, it is
frequently an indication that a sump
is not tight, which in turn compro-
mises the ability of a sump to contain
a release and/or the effectiveness of
the leak warning mechanism.
What Accounts for the
Difference in Sump
Appearance?
Why do sumps in some states look
like slimy swamp scenes from a B-
grade Creature from the Black Lagoon
movie, while sumps in Maine would
be quite at home in a movie nomi-
nated for an Oscar? Brands of equip-
ment used? The brands are generally
the same, so I don't believe this is a
factor. Climate? In other parts of the
United States, the amount of precipi-
tation may be greater, water tables
may be higher, the compaction and
weight-bearing properties of the soils
may be different, but none of these
factors seems very persuasive to me
in explaining the difference.
Is the sample of Maine sumps
that I have viewed representative of
the population? I think so. My obser-
vations are based primarily on a
study of the conditions of tank-top
and dispenser sumps conducted on
behalf of the Maine Department of
Environmental Protection in 2002-
2003 (http://www.maine.gov/dep/rwm/
ust/pdf/sumpstudyreport.pdf.) Facilities
included in the study were randomly
selected and geographically dis-
persed across the state. A total of
>
Waterlogged tank-top sump with disabled
sump sensor.
A caved-in, waterlogged tank-top sump.
some 125 dispenser sumps and 87
tank top sumps were inspected.
Ninety percent of the dispenser
sumps and 85 percent of the tank-top
sumps were found to be completely
free of product. Where product was
observed, it was typically no more
than a puddle in a small area of the
sump bottom. Seventy-seven percent
of dispenser sumps and 43 percent of
tank-top sumps were found to be
completely free of water. Where water
was observed, it was again usually no
more than a puddle. The general con-
dition of the sumps was also remark-
ably better than what was shown in
the presentation referenced above.
What's Right with the
Maine Picture?
So, what does account for this differ-
ence? Based on my knowledge and
• continued on page 28
~27
-------
LUSTLine Bulletin 49 • March 2005
• Maine Sumps from page 27
experience (and not any rigid scien-
tific analysis) I would cite the follow-
ing factors:
• Workmanship
Proper installation, sealing, and back-
filling of sumps are very important to
long-term performance. Maine insti-
tuted the first state-level UST-
installer certification program in the
nation in 1986.1 believe this program
has significantly improved the qual-
ity of UST system installations in the
state.
What distinguishes Maine's certi-
fication program from most others is
effective enforcement. Maine estab-
lished a volunteer board to oversee
the installer certification program.
The board is empowered to draft and
sign consent agreements with certi-
fied installers who are found to be in
violation of state regulations. Im-
properly installed sumps and sumps
in no condition to act as secondary
containment represent violations for
which an installer can be held
accountable and be required to fix.
The board meets monthly and
nearly always has several enforce-
ment cases on its agenda. Sometimes
the cases involve paper violations for
failure to obtain required education
credits, but often enough they are
infractions of installation standards,
manufacturers requirements, or
industry practices. Typically, these
infractions result in a requirement to
redo the work properly, significant
fines, certification suspensions, and,
in a few severe cases, revocations of
certification.
Because storage system installa-
tion is still very much a business
where low bidders get the lion's
share of the work, the temptation to
cut corners is always very strong.
Knowledge that cutting these corners
can lead to significant financial and
career consequences helps keep the
players in Maine in line.
• Requirement to Report Evidence
of a Leak
Maine regulations define any amount
of liquid (water or product) in a
sump as "evidence of a leak," which
must be reported to the state. Both
owner/operators and certified in-
stallers are required to independently
report the discovery of such evidence
28~
Tank-top sump at an Environmental Leader facil-
ity in Maine. Believe it or not, this sump was six
years old at the time the picture was taken.
Fairly typical Maine tank-top sump. There is
some staining, most likely due to water intrusion,
but the sump is now dry. This picture was taken
during a random, unannounced inspection.
of a leak to the state. I don't believe
for a moment that this requirement
results in every incident of liquid in a
sump being reported to the state, but
it does provide a substantial incen-
tive for installers and owners to
remove this "evidence of a leak"
when it is discovered to stay out of
regulatory trouble. This requirement
also provides owners/operators with
an incentive to fix sumps where
water intrusion is a perennial prob-
lem.
Liquid, especially product re-
maining in sumps for extended peri-
ods, has been frequently cited as a
cause for failure of certain piping and
containment systems. To my knowl-
edge, Maine has yet to experience a
failure of a piping system attributed
to exposure to petroleum product.
• Annual Inspections
Maine regulations require annual
inspection of leak-detection equip-
ment by third-party certified
installers or inspectors. As a result,
most sumps are inspected at least
once a year, and any liquid found
(whether or not reported as "evi-
dence of a leak") is likely removed to
save the storage system owner as
well as the installer potential regula-
tory aggravation resulting from a
state inspector discovering "evidence
of a leak" that has not been reported.
I believe this annual mopping up of
sumps contributes to their relatively
clean appearance, even after they
have been installed for quite a num-
ber of years.
• Environmental Leader Program
Maine's Environmental Leader Pro-
gram provides recognition to owners
of UST systems who successfully
pass a regulatory compliance inspec-
tion, where every "i" must be dotted
and every "t" crossed. While only a
small percentage of Maine's facilities
participate in this program, those that
do invariably have such good-look-
ing sumps that I expect the sump
manufacturers would be delighted to
feature them in their sales literature.
While not responsible for the
overall good condition of Maine's
sump population because of the small
number of facilities participating in
this program, I believe these sumps
demonstrate that when someone
bothers to make the effort, sumps can
be maintained in pristine condition.
Is Maine Alone?
I cite Maine in this article because it is
the state with which I am most famil-
iar, not because I believe Maine is
unique. Pat Rounds, President and
CEO of the Petroleum Marketers
Mutual Insurance Company in Iowa,
also believes that sumps covered by
his insurance program are in better
condition than most. Inspectors
working for the Iowa insurance pro-
gram inspect each sump at each facil-
ity each year. Facilities with
improperly maintained sumps are
required to correct the deficiency or
lose their insurance coverage.
According to Pat, "if proper
installation, repair, maintenance, and
operation of tank systems isn't
expected by someone who can
enforce that expectation, then as an
industry we will get exactly what is
expected...which, by the way, isn't a
good-looking, dry sump."
• continued on page 31
-------
March 2005 • LUSTLine Bulletin 49
FAQs from the NWGLDE
...All you ever wanted to know about leak detection, but were afraid to ask.
What's All the Fuss about Equivalency?
This installment of the National Work Group on Leak
Detection Evaluations' (NWGLDE's) FAQs focuses on contin-
uing questions about automatic line-leak detectors and line-
tightness tests. Please note: the views expressed in this column
represent those of the workgroup and not necessarily those of
any implementing agency.
Q.
Some of the automatic electronic line-leak-detec-
tor listings in the List of Leak Detection Systems
(the List) talk about "equivalent leak rates." What
does that mean?
A "Equivalent leak rates" are explained and
demonstrated in Standard Test Procedures for Eval-
uating Leak Detection Methods: Pipeline Leak Detec-
tion Methods, EPA/530/UST-90/010, September,
1990. This protocol is one of a series of test proce-
dures that cover most of the methods commonly
used for UST system leak detection. According to
the protocol, "Since leak rate varies as a function
of pressure, the leak-detection test can be con-
ducted at different pressures provided that the
determinable leak rate at the specified test pres-
sure is equivalent to or more stringent than the
one mandated in the regulation."
For example, the automatic line-leak-detection
hourly performance standard requires that a leak of 3
gal/h or larger at 10 psi must be detected within one
hour with a probability of detection (PD) of 95 percent
and a probability of false alarm (PFA) of 5 percent.
Using Table 1.1 on page 4 of the protocol, the equiva-
lent leak rate for an evaluation of an automatic line-
leak detector at 20 psi would be 4.25 gal/h. This could
also be calculated using the formula in Section 4.2 of
the protocol.
Using this process correctly means that the third-
party evaluator establishes a known equivalent leak
rate at a known pressure, such as 4.25 gal/h at 20 psi,
and performs the evaluation. If the evaluation results
show that the equipment is capable of finding the
equivalent leak rate with a PD of 95 percent and a PFA
of 5 percent, then the protocol says that this equipment
will be able to detect the hourly performance standard
leak of 3 gal/h leak at 10 psi.
Another example is the annual line-test perfor-
mance standard, which requires that a leak of 0.1
gal/h be detected at 1.5 times the operating pressure
(which we will assume to be 45 psi). The measured
equivalent leak rate would be 0.07 gal/h at 20 psi as
shown in Table 1.1 of the protocol. If the results of the
evaluation show that the equipment can find a leak
this size 95 percent of the time with a false alarm rate
of no more than 5 percent, then the protocol says that
this equipment will detect the annual line-test perfor-
mance standard leak rate.
Whether or not a third-party test used equivalent
leak rates may be a crucial issue for implementing
agencies as they determine if a specific piece of equip-
ment satisfies the regulatory performance requirement
for hourly, monthly, or annual release detection.
Implementing agencies can often determine whether
or not the evaluation used equivalent leak rates by
reviewing the "Overview of Evaluation Method" sec-
tion of the final report of a given third-party evalua-
tion. Statements in the report that talk about "rates
equivalent to 3 gal/h at 10 psi, 0.20 gal/h at 30 psi, and
0.10 gal/h at 45 psi" validate that the testing used
equivalent leak rates. Another place to look is in the
summary of the testing procedure where similar
wording can be found.
Only recently did the work group begin to use
the "equivalent leak rate" terminology in its list. We
are at present reviewing the reports for previously
listed line-leak detectors to make sure the language for
each listing is appropriate. We anticipate the review
will be complete by this summer. In the interim, each
regulator should be able to make an accurate determi-
nation by referring to the third-party evaluation docu-
ment discussed above.
About NWGLDE
NWGLDE is an independent work group comprising 10
members, including (8) state and (2) U.S. EPA members.
This column provides answers to frequently asked ques-
tions (FAQs) NWGLDE receives from regulators and
people in the industry on leak detection. If you have
questions for the group, please contact them at
questions@nwglde.org.
NWGLDE's mission:
• Review leak detection system third-party evaluations
to determine if each evaluation was performed in
accordance with an acceptable leak detection test
method protocol and ensure that the leak detection
system meets EPA and/or other applicable regula-
tory performance standards
• Review only draft and final leak detection test
method protocols submitted to the work group by a
peer review committee to ensure they meet equiva-
lency standards stated in the U.S. EPA standard test
procedures
• Make the results of such reviews available to inter-
ested parties •
29
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LUSTLine Bulletin 49 • March 2005
from Robert N. Renkes, Executive Vice President, Petroleum Equipment Institute (PEI)
PEI is currently involved with four projects that should be of interest to LUSTLine readers. All of the following projects are
scheduled for completion within the first eight months of'2005 and include recommended practices, checklists, and training
videos offered over the Internet.
PEI/RP100
FBI's Recommended Practices for the Installation of Under-
ground Liquid Storage Systems (PEI/ RP100-2000) is being
revised and updated for the fifth time. The document has
been widely accepted over the 18 years it has been in
existence, with over 75,000 copies distributed world-
wide. It is referenced in the federal UST rules and in the
latest (2003) edition of the National Fire Protection Asso-
ciation's Flammable and Combustible Liquids Code (NFPA
30). The document is also required reading for the Inter-
national Code Council's UST certification program. Of
the 110 proposals PEI received to revise RP100, over half
came from state and federal UST regulators.
Checklist for UST Owners/Operators
The same committee responsible for writing PEI/RP100
is also in the midst of preparing a checklist of proper and
routine maintenance procedures that tank owners/oper-
ators, regulators, and service companies can use to mini-
mize the risk of releases from UST systems. The checklist
will also include recommended inspection frequency.
Recognizing that properly installed UST systems are
often not maintained properly once the contractor leaves
the job site, the PEI Board of Directors assigned this task
to the Tank Installation Committee.
The checklist is designed so the owner/operator of
the facility can easily inspect three specific areas of the
UST system to ensure the UST components are function-
ing properly: (a) under the dispenser (i.e., sumps, piping,
product and vapor shear valves, flex connectors); (b)
around the tank itself (i.e., corrosion protection, monitor-
ing wells, vents, spill- and sump-containment manholes,
sump sensors, flex connectors, overfill prevention
devices); and (c) leak detection (i.e., automatic tank
gauges, interstitial monitoring, inventory control, auto-
matic line-leak detection).
The checklist will be made available to all PEI mem-
bers and their customers free of charge in May 2005. The
checklist will not be copyrighted and photocopying will
be permitted. State and local UST regulators are encour-
aged to use it as well. Check with any PEI member for a
copy or visit www.pei.org. to download a PDF file.
PEI/RP500
A draft of a new recommended practice on fuel-dispens-
ing equipment inspection and maintenance (PEI/ RP500)
is available for public input and comment through April
7, 2005. The purpose of the document is to provide a
basic reference that consolidates published and unpub-
lished information from equipment manufacturers,
installers, and end users concerning the proper inspec-
tion and maintenance of motor vehicle fuel-dispensing
equipment. The recommended practice is intended to
minimize the possibility of fuel-dispensing-equipment
failure, reduce fire hazards, promote fueling safety, and
minimize environmental hazards. Equipment covered
includes all above-grade, liquid- and vapor-handling
components, from the base of the dispenser to the noz-
zle spout. Go to www.pei.org if you wish to receive a
copy of the draft document. All LUST Line readers are
encouraged to submit comments.
Owner/Operator Training on the Internet
The fourth project, approved by the PEI Board of Direc-
tors January 6, 2005, involves the development of a
complement of convenient, cost-effective, and relevant
training opportunities to facility owners and operators
in the petroleum marketing industry using distance
learning via the Internet. PEI members involved in the
petroleum marketing and UST system industries will
benefit from the training, because each person/com-
pany taking the course will better understand how to
use the equipment manufactured, distributed, installed,
and serviced by PEI members. The topics will include:
• The ABCs of ATGs: Tanks
• The ABCs of ATGs: Tanks and Piping
• Double-Walled Piping and Associated Leak
Detection
• Single-walled Piping and Associated Leak
Detection
• Spill Containment and Overfill Prevention
The ATG courses will be available in April 2005.
The others will be available in summer 2005. We pre-
viewed the first course at the LUST/UST Annual Con-
ference in Seattle. Although pricing has not yet been
determined, we envision that discounts will be offered
to PEI members and endorsing organizations, including
state UST agencies. Remember to check www.pei.org for
the latest updates. We invite you to take a course or
two. We think you will be impressed with the material
and presentation and find it worth recommending to
tank owners. •
30
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March 2005 • LUSTLine Bulletin 49
• Maine Sumps from page 28
The Secret to Clean Sumps
So the common thread linking clean
sumps in Maine, Iowa, and other
places somewhere out there, I
believe, is frequent inspection and
effective enforcement of standards.
After all, tank owners are only
human—they will rise (or sink) to the
level of our expectations (to borrow a
phrase from Pat Rounds).
That said, many states are hob-
bled in their inspection efforts by a
lack of inspectors, and many states'
enforcement mechanisms are too
labor-intensive to be effective in pur-
suing what are perceived as house-
keeping-type violations. In addition,
federal rules, which serve as a model
for most state rules, do not describe
specific maintenance requirements
for UST systems.
Sumps merely serve as a very
visible barometer of a storage system
owner's overall maintenance efforts.
If the pictures that prompted this
essay are more representative of the
status of the nation's sumps than the
pictures of Maine sumps in my files,
we have a long way to go before a
satisfactory level of UST maintenance
is achieved.
P.S.
Okay, I admit it, this essay is my decid-
edly unscientific (and undoubtedly
biased) view of what may be responsible
for the quality of installation and mainte-
nance practices for UST-piping sumps in
Maine. My intent is not to toot anyone's
horn or gore anyone's ox but to stimulate
discussion. •
• European MtBE Conference
from page 20
changes in Europe will shape the
future of those countries and whether
they can learn from the environmen-
tal mistakes we have made in the
U.S.—or if they will knowingly
repeat some of them, such as our
decision to protect air quality with-
out carefully examining potential
impacts to groundwater quality. For
now, I'm optimistic and look forward
to future discussions on oxygenates
with my European colleagues.
And while I'm hopeful for a
return to more normal winter condi-
tions in Montana, I don't want to go
back in time to Cold War Europe. In
Montana, the Continental Divide will
always separate weather systems
between east and west along the
Rocky Mountains. But the divide that
separated Eastern Europe from West-
ern Europe is gone and in its place is
a new and relatively uncharted
world for science and technology to
grow. I hope the new Europe
embraces the opportunity and tears
down many of the other walls that
exist between researchers, regulators,
and industry—walls that represent
obstacles to future advancement. •
JeffKuhn is a hydrogeologist and man-
ages the Montana DEQ Petroleum
Release Section. Information regarding
the 2nd European Conference on
MTBE can be found at conference web-
site: http://www.iiqab.csic.es/
mtbe/. The 3rd European Conference
on MTBE will be held in Copenhagen,
Denmark in 2005.
Hejp
Celebrate
LUSTLino's ?0th
Ann(
Believe it not,
/^\^^l LUSTLine is about to
/[ J7 mark its 20th year of
^A .^service to the UST/LUST
^^^By community of regulators,
^^X consultants, industry repre-
sentatives, and owners and
operators—our first issue hit the
streets in August 1985. Over the
years we have had the privilege of
providing you with articles written by
a host of contributors who have
helped us keep you informed about
the many-faceted issues associated
with UST systems. So now it would
be really special if you, our readers,
would help us celebrate this auspi-
cious anniversary by sending us
your anecdotal short (paragraph or
two) and (hopefully) sweet "noth-
ings" that we can use to spice up
our summer issue—which will also
be our 50th issue. We realize that
we could be opening up the ever
problematic can of worms, opening
ourselves up to attack from all
sides. But, hey, we're adults now,
we can deal with it.
If you wish to join in the "roast,"
just write to Ellen Frye at
lustline@neiwpcc.org. Please get
you comments to us by May 1,
2005. Tanks.
V, /
L«U*S/I*LINI Subscription Form
Name
Company/Agency.
Mailing Address _
E-mail Address
U One-year subscription. $18.00.
Q Federal, state, or local government. Exempt from fee. (For home delivery,
include request on agency letterhead.)
Please enclose a check or money order (drawn on a U.S. bank) made payable to NEIWPCC.
Send to: New England Interstate Water Pollution Control Commission
Boott Mills South, 100 Foot of John Street, Lowell, MA 01852-1124
Phone: (978) 323-7929 • Fax: (978) 323-7919 • lustline@neiwpcc.org • www.neiwpcc.org
31
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The Phoenix Awards:
Know a Good Candidate?
June 30, 2005 is the deadline for get-
ting Phoenix Awards applications to
the Phoenix Awards Institute, Inc.
The Phoenix Awards were created in 1997
to recognize individuals, groups, compa-
nies, organizations, or government bod-
ies that are working together to solve the
critical environmental problems of trans-
forming old, contaminated areas into pro-
ductive new uses. The awards are
presented each year at the U.S. National
Brownfields Conference held at a different
city each fall. One winner will be selected
from each of the 10 U.S. EPA Regions,
and one project from outside the United
States, as an international winner.
The brownfield redevelopment pro-
jects are broadly defined under this award
program to include properties impacted
by all types of contamination, and reme-
diated under a variety of regulatory pro-
grams (e.g., Superfund, Resource
Conservation and Recovery Act, brown-
fields, and voluntary cleanup programs).
Projects that emphasize public policy ini-
tiatives associated with governmental
programs are encouraged to apply. These
initiatives may include abandoned petro-
leum sites without viable responsible par-
ties (petroleum brownfields).
Applications may be submitted by an
individual involved in the project or by a
third party, with the primary project coor-
dinator (e.g., property owner, environ-
mental engineering firm, or project
developer) or the entire project team
listed as the applicant. To be considered,
the brownfield redevelopment project
must have been completed by the date
the application is submitted. Projects are
deemed "complete" if the end-use enter-
prise is presently conducting business at
the site. Past Phoenix Award winners are
not eligible for the same project in subse-
quent years. However, all previous non-
winning applications will be considered in
the following year's review process.
Criteria
Successful applications must demon-
strate measurable results and/or impact
on environmental improvement and long-
term community economic benefits and
emphasize five topics: (a) magnitude of
the problems and project, (b) use of inno-
vative techniques, (c) cooperative efforts
of multiple parties to undertake the pro-
ject, including financing solutions, (d)
positive impact on the environmental
(e.g., green buildings, greenways, energy
use), and (e) the project's general and
long-term economic impacts on the com-
munity. An independent panel of state,
regional, and federal government leaders,
along with environmental, business, and
academic professionals will select the
winners. •
For more information contact Denise
Chamberlain by e-mail at
dchamberlain@arcadis-us. com,
or by phone at (717) 761-0554
Citing Too Many Abandoned
Gas Stations, Detroit Places
Moratorium on New Stations
Detroit Mayor Kwame Kilpatrick
placed a two-year hold on applica-
tions for new locations for service
stations. "Too many stations have
been abandoned. Many that
remain have become eyesores in
our neighborhoods," said the
mayor. Amru Meah, director of
Buildings and Safety Engineering,
which oversees licensing and
inspection of service stations,
believes the moratorium is neces-
sary for the city to bring existing
stations into compliance. "Under-
ground storage tanks are danger-
ous," said Sarah Lile, Director of
Environmental Affairs. "Across the
city we're still digging out tanks
that were buried decades ago."
The mayor's press release was
issued on October 6,2004, and
can be seen in full at http://www.
ci. detroit.mi. us/mayor/releases/200
4%20Releases/Moratorium%20on
%20New%20Gas%20Stations.htm.
[LU.ST.LINE INDEX
I August 1985/Bullettn # 1 - November 2OO4/Bullettn #48
The LUSTLine Index—is
ONLY available online.
To download the
LUSTLine Index, go to
www.neiwpcc.org/lust-
line.htm, and then click
on LUSTLine Index.
LUST.UNE
New England Interstate Water
Pollution Control Commission
Boott Mills South
100 Foot of John Street
Lowell, MA 01852-1124
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