Appendix B Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006


*>EPA

United States
Environmental Protection
Agency

The National LUST Cleanup Backlog:

A Study of Opportunities

Printed on Recycled Paper

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oEPA

United States
Environmental Protection
Agency

APPENDIX B:
PHASE 1 ANALYSIS
LUST RELEASES AS

Office of Solid Waste and Emergency Response
Office of Underground Storage Tanks
September 2011

THE BACKLOG OF OPEN
NOVEMBER 2006

B-1

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LIST OF ACRONYMS

ASTSWMO

Association of State and Territorial Solid Waste Management Officials

EPA

U.S. Environmental Protection Agency

FY

Fiscal Year

LUST

Leaking Underground Storage Tank

OUST

Office of Underground Storage Tanks

SDWA

Safe Drinking Water Act

UST

Underground Storage Tank

B-2

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

CONTENTS	

Executive Summary	B-5

Background 	B-6

Number of Cleanups Completed Each Year Has Trended Downward	B-7

Federal LUST Spending Has Trended Downward when Adjusted for Inflation	B-7

Trends Slowing State Cleanups	B-8

A Snapshot of the Cleanup Backlog	B-9

More Than Half of the National Backlog is Concentrated in 10 States	B-9

More Than Half of Releases Are at Least 10 Years Old	 B-10

More Than Half of Releases Contaminate Groundwater	 B-10

Releases that Impact Soil Only Constitute 16 Percent of the Backlog	 B-12

Releases with Unknown Media Contamination Constitute 21 Percent of the Backlog	 B-13

A $2.3 Billion Budget Shortfall for Cleanups May Exist for the 24 States Analyzed	 B-14

Potential Opportunities to Expedite Reduction of the Cleanup Backlog	 B-15

Concentrated Distribution of Releases	 B-15

Releases with Soil-only Contamination	 B-15

Releases with Unknown Media Contamination	 B-15

Potential Constraints on Expediting Backlog Reduction	 B-16

Data Management	 B-16

State Financing Gaps	 B-16

Technological Constraints of Groundwater Cleanup	 B-16

Conclusion	 B-17

Methodology and Data Quality	 B-18

September 2011	B-3

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

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B-4

September 2011

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

EXECUT VE SUMMARY

Many underground storage tank (UST) releases were discovered due to the
implementation of new federal release prevention and detection requirements
and state cleanup programs. The total number of federally-regulated open (i.e.,
incomplete) leaking underground storage tank (LUST) releases is commonly referred
to as the cleanup backlog or the backlog. Although the national backlog has declined
since 2000, a large backlog of open LUST releases continues to exist despite cleanup
efforts, and fewer cleanups are being completed annually by states. Several factors
may have contributed to the decrease in annual cleanups completed by states since
2000, or more broadly, to the persistence of a cleanup backlog. In an effort to better
characterize the composition of the LUST cleanup backlog, the U.S. Environmental
Protection Agency's (EPA's) Office of Underground Storage Tanks (OUST) invited states
to voluntarily share their LUST cleanup data for analysis. Forty-three states, Puerto
Rico, and the District of Columbia volunteered data files.1 The aggregate LUST cleanup
backlog for the 45 states is 104,884 releases which is 92 percent of the 2006 national
backlog of 113,915 releases. In this report, the backlog of 104,884 releases is a proxy
for the "national backlog." These data provided a snapshot of the cleanup backlog as
of November 2006.

Analysis of the state data identified several major characteristics of the backlog:

• Approximately two-thirds (64 percent; 67,147 releases) of releases in the
national backlog are concentrated in 10 states.

• More than half (59 percent; 62,149 releases) of releases involve impacts to
groundwater resources.

• More than half (55 percent; 57,588 releases) of cleanups in the backlog are 10
years of age or older:

o Of releases that impact groundwater, 60 percent are 10 years old or
older;

o Of releases that contaminate soil only, 40 percent are 10 years old or
older; and

o Of releases where the impacted media is unknown, 48 percent are 10
years old or older.

• Approximately 21 percent of cleanups involve "unknown" media
contamination, where the impacted media is not specified in the available
data.

• There is an estimated $2.3 billion budget shortfall for cleanups for the 24
states with relevant data that could be analyzed.

The 16,856 releases in the backlog that contaminate soil only could potentially offer
an opportunity to reduce the cleanup backlog. More time will be needed to complete
the 62,149 releases impacting groundwater. There are an additional 4,274 releases
that impact other media. The true classification of the 21,605 releases where the
contaminated media is unknown needs to be addressed to make a fully informed
decision about how best to proceed with reducing the backlog. Closer tracking of
impacted media and of older stalled cleanups would be very helpful to target and
reduce the backlog of open LUST releases.

1. Arizona, Connecticut, Massachusetts, Maine, Vermont, Georgia, and South Dakota did not send in a data file. Ohio did not provide the release date necessary for
the age calculation but did provide the number of backlogged cleanups and the type of media impacted.

September 2011

B-5

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

BACKGROUND

In 1984, Congress passed Subtitle I of the Solid Waste Disposal Act (SWDA), which
required EPA to develop a comprehensive program for regulation of underground
tanks and underground tank systems and led to the promulgation of the federal
UST regulations in 1988. The widespread implementation of new state release
prevention, leak detection, and cleanup programs identified many additional open
releases requiring cleanup. As states enforced regulations for UST release cleanups,

the number of open LUST releases began increasing. This trend continued until
Fiscal Year (FY) 1999, after which the number of open LUST releases began to decline
(Figure 1 below). This decline illustrates that from 1999 to 2007, state programs were
successfully reducing the national backlog by completing cleanups faster than new
releases were being reported.

Figure 1. LUST National Backlog FY89 - FY07*

200,000
-£> 180,000

OJ

£ 160,000

bo

o 01 140,000
cc

ro = 120,000

CO £

ro O 100,000
£

O O
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3

80,000
60,000
40,000
20,000
0

V

* rP? rft* rPft

N? N? N? ^ N? ^

^ ^ ^ ^ ^ ^ ^	^ ^ n<£

T T y "V "V T

V V T

Fiscal Year

* Year 2000 dollars were calculated using the Bureau of Labor Statistics' Consumer Price Index inflation calculator.

B-6

September 2011

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

NUMBER OF CLEANUPS COMPLETED EACH
YEAR HAS TRENDED DOWNWARD

Despite this reduction in the cleanup backlog (Figure 1, page 6), since 2000, fewer
cleanups are being completed annually by state UST programs (Figure 2 below). With
the exception of 2003, the number of cleanups completed annually by state UST
programs has gradually decreased from 20,834 in 2000 to 13,862 in 2007.

FEDERAL LUST SPENDING HAS TRENDED
DOWNWARD WHEN ADJUSTED FOR
INFLATION

During this same timeframe, annual federal LUST Trust Fund appropriations have
declined when adjusted for inflation, although they have remained level in terms of
current year dollars (Figure 3 below). These federal LUST dollars represent only a small
portion of state cleanup funding and leverage much larger amounts of state resources
that finance and oversee the large majority of LUST cleanups.

Figure 2. Annual Cleanups Completed FY00 - FY07*

25,000

"ro
c

20,000

cS^ cv cv

,# j§> „<$>

0/ v 1/
Fiscal Year

v n>

* Year 2000 dollars were calculated using the Bureau of
Labor Statistics' Consumer Price Index inflation calculator.

Figure 3. FY00-FY07 Cleanups Completed and LUST Appropriations (Actual and Year 2000
Dollars*)

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

TRENDS SLOWING STATE CLEANUPS

State cleanup funds have financed most active and completed cleanups in the backlog.
In 2006, 36 states maintained active state cleanup funds for LUSTs. The Association of
State and Territorial Solid Waste Management Officials (ASTSWMO) State Fund Task
Force reports from these states illustrate some state-level trends that likely affect the
remaining backlog.2 According to these reports, from 1994 to 2008 the 36 states with
active cleanup funds processed more claims per year (Figure 4 top left), experienced

Figure 4. Number of New Claims per Year

increased caseloads per staff worker (Figure 5 top right), and incurred higher average
cleanup cost at closure (Figure 6 bottom left). Figures 4-6 include fitted lines (orange)
to better illustrate the increasing trends. In addition, the aggregate dollar value of
unpaid claims against state funds often exceeds the funds' balance (Figure 7 bottom
right).

Figure 5. Average Staff Member Caseload

200

I uu,uuu

A7-419

812 / 51,^7 A

V v

20,429

26,750

Figure 6. Average Cleanup Cost at Closure

$120,000

$104,776

£ $80,000

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

A SNAPSHOT OF THE CLEANUP BACKLOG

In order to better characterize the composition of the LUST cleanup backlog, OUST
invited states to voluntarily share data on their LUST releases as of November 2006.
Forty-three states, Puerto Rico, and the District of Columbia volunteered data files.3
For convenience, Puerto Rico and the District of Columbia will be considered as states
throughout this report and data will be described as coming from 45 states.

Backlog data from these 45 states were analyzed by geographic distribution, age,
and type of media impacted. For 24 states with available data, FY 2006 LUST cleanup
funding was also analyzed. Data from 15 of the 45 states were used to identify the
brand name associated with cleanup sites. These analyses identified several major
characteristics of the backlog.

MORE THAN HALF OF THE NATIONAL
BACKLOG IS CONCENTRATED IN 10 STATES

There are a total of 104,884 releases in the November 2006 data from the 45 states.
The majority of the cleanup backlog is concentrated in relatively few states. More than
64 percent (67,157 releases) of the national backlog is concentrated in 10 states, and
more than 48 percent (49,935 releases) is within five states. Figure 8 below displays

the number of releases per state from highest (14,063 releases in Florida) to lowest
(37 releases in North Dakota).

The 10 states that have the largest backlogs include Florida, California, Michigan,
Illinois, North Carolina, New Jersey, Texas, Ohio, South Carolina, and Pennsylvania.
Among these states, Florida and California have over 10,000 releases each, followed
by Michigan and Illinois with over 8,500 releases each, and North Carolina with
approximately 6,500 releases. The remaining five states each have approximately
3,000 releases.

However, the majority (32 states) of the 45 states analyzed has a relatively small
backlog, each reporting less than 2,000 releases in November 2006. The states with
the largest backlogs are located in six of the ten EPA Regions, with Regions 4 and 5
having the largest backlogs.

Figure 8. Cleanup Backlogs, by State

16,000
a) 14,000

in 00

S 2 12,000

CC <2 10,000

4—

° 8,000
aj rc

ja in 6,000
| •- 4,000
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3. Arizona, Connecticut, Massachusetts, Maine, Vermont, Georgia, and South Dakota did not send in a data file. Ohio did not provide the release date necessary for
the age calculation but did provide the number of backlogged cleanups and the type of media impacted.

September 2011 B-9

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

MORE THAN HALF OF RELEASES ARE AT
LEAST 10 YEARS OLD

The majority of the cleanup backlog is composed of relatively older releases.
Considering releases affecting all types of media, 55 percent (57,588 releases) of
releases are 10 years old or older (Figure 9 below).

Figure 9. Release Age Distribution

3,313

2,453

2% \ 18,792

18%

~ 0-4.9 Years

0 5-9.9 Years
n 10-14.9 Years

~ 15-19.9 Years

1 I More Than 20 Years
I Unknown Age

Figure 10. Percentage of National Backlog by Media
Contaminated

I I Groundwater
| | Soil
62,149 | Other

¦ Unknown

MORE THAN HALF OF RELEASES
CONTAMINATE GROUNDWATER

With all age classes combined, releases impacting groundwater constitute more than
59 percent (62,149 releases) of the national backlog.4 Soil-only releases constitute
16 percent (16,856 releases) of the national backlog, and a substantial portion (21
percent; 21,605 releases), have unknown media contamination. Additional releases
impacting "Other" media (e.g., vapor or surface water) constitute the remaining four
percent of the national backlog (Figure 10, to the left and below).

The November 2006 data suggest that among older releases, releases that impact
groundwater are more common than releases that impact soil only (Figure 11, page 11).
The larger number of older releases with groundwater impacts is expected because
groundwater cleanups tend to be slower and more costly than soil-only cleanups.

As of November 2006, there were 62,149 releases impacting groundwater across
the 45 states, constituting more than half of the national backlog (Figure 10). These
releases with groundwater contamination tend to be older, with approximately 60
percent (37,642 releases) that are 10 years old or older (Figure 12, page 11). Because
most national backlog releases affect groundwater and most groundwater cleanups
are older, these releases are driving the age distribution pattern of the national backlog
(Figures 9 and 12).

A relatively large number of releases contaminating groundwater resources are
concentrated in a few states (Figure 13, page 11). In addition, seven of the 10 states
with the largest backlogs have over 1,000 releases that impact groundwater and are
10 years old or older.

16,856
16%

4. This percentage is based on the classification of all releases with unknown impacts in Florida as releases with groundwater contamination. According to state staff, Florida has a shallow
depth to groundwater and, therefore, those releases where it was not possible to identify the media contaminated based on available data are most likely releases with groundwater
contamination. When calculated without this assumption, 46 percent of releases contaminate groundwater.

B-10

September 2011

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

Figure 11. Age of Releases by Media Contaminated

Figure 12. Age Distribution of Releases that Impact Groundwater

0-4.9
Years

5-9.9
Years

10-14.9
Years

15-19.9
Years

More Than
20 Years

] Groundwater Q Soil Only

| Other

H Unknown

Unknown
Age

1,779

1,908

17,708
28%

~ 0-4.9 Years

~ 5-9.9 Years
n 10-14.9 Years

~ 15-19.9 Years

I I More Than 20 Years
I Unknown Age

Figure 13. Releases 10 Years Old or Older that Impact Groundwater, by State

12,000
10,000
8,000
6,000
4,000
2,000
0

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September 2011

B-11

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

RELEASES THAT IMPACT SOIL ONLY
CONSTITUTE 16 PERCENT OF THE BACKLOG

Although releases contaminating soil only would be expected to be cleaned up
relatively quickly, many older releases that contaminate soil only remain in the
backlog. Compared to releases that affect groundwater resources (Figure 12, page
11), releases that impact soil only were more concentrated in the age classes of zero
to 10 years (Figure 14, to the right). However, there are still 6,886 releases impacting
soil only that were 10 years old or older, consisting of nearly half (41 percent) of the
soil-only cleanups.

The number of open releases that contaminate soil only that are at least 10 years old
is shown in Figure 15 below. The largest numbers of older releases impacting soil only
are found in Washington, California, and North Carolina.

Figure 14. Age Distribution of Releases that Impact Soil Only

243 856

2% 5% 4,163

I I 0-4.9 Years

~ 5-9.9 Years

~ 10 -14.9 Years

~ 15 -19.9 Years
I I More Than 20 Years
H Unknown Age

Figure 15. Releases 10 Years Old or Older that Impact Soil Only, by State

1,400

1,200
1,000
800
600
400
200
0

T~T1 I I I

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B-12

September 2011

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

RELEASES WITH UNKNOWN MEDIA
CONTAMINATION CONSTITUTE 21 PERCENT
OF THE BACKLOG

In 2006, 21 percent (21,605 releases) of the cleanup backlog consisted of releases
where the type of media contaminated was not specified in the states' data. Therefore,
these releases are considered to have unknown media contamination.5 The 21,605
releases with unknown media contamination are evenly distributed across the age
classes between zero and 20 years (Figure 16, to the right).

The 10,411 releases with unknown-media impacts that were 10 years old or older are
distributed evenly across many states, with the exception of Illinois (Figure 17 below).
Illinois' data showed that the media contaminated was unknown for all of its large
number of releases. Thus, Illinois' cleanup backlog contributed to the substantial
portion of the releases with unknown-media impacts in the national backlog.

Figure 16. Age Distribution of Releases that Impact Unknown Media

177 549

I I 0-4.9 Years

0 5-9.9 Years
G 10-14.9 Years
~ 15-19.9 Years

1 I More Than 20 Years
I Unknown Age

Figure 17. Releases 10 Years Old or Older that Impact Unknown Media, by State

6,000

euo

5,000

< <
2 — >

5 >

° £
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^ a.

on <

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State

5. This percentage is based on the classification of all releases with unknown media impacts in Florida as releases with groundwater contamination. When calculated
without this assumption, 34 percent of releases contaminate unknown media.

September 2011

B-13

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

A $2.3 BILLION BUDGET SHORTFALL FOR
CLEANUPS MAY EXIST FOR THE 24 STATES
ANALYZED

A gap in cleanup funding is indicated in data provided by 24 states that used state funds
for 2006 cleanups. These 24 states reported 38,780 open LUST releases as of November
2006, of which only 13,254 cleanups were receiving state financing (Table 1). This left
an estimated 25,526 remaining cleanups not financed by state LUST cleanup funds.
Multiplying the number of unfinanced cleanups by each state's average cleanup cost
at closure estimates that approximately $2.3 billion dollars would be needed to fund
the unfinanced cleanups. Data from California were unavailable for this analysis, but if
included would likely increase the estimated funding gap significantly.

Table 1. Estimated FY06 Funding Gap in 24 States6

State

Number of
Backlogged
Cleanups as
of Nov 2006

Ongoing LUST

Cleanups
Receiving State
Funding In FY06

Unfinanced
Cleanups

Average
Cleanup Cost At
Closure (FY06)

Estimated
Funding Gap

8,734

1,047

7,687

$108,000

$830,196,000

3,313

300

3,013

$62,346

$187,848,498

3,284

1,111

2,173

$34,742

$75,494,366

3,266

1,980

1,286

$162,743

$209,287,498

2,811

782

2,029

$174,754

$354,575,866

1,896

384

1,512

$42,000

$63,504,000

1,856

215

1,641

$100,000

$164,100,000

1,767

1,213

554

$51,786

$28,689,444

1,534

964

570

$89,559

$51,048,630

1,265

376

889

$63,756

$56,679,084

1,227

575

652

$350,000

$228,200,000

1,123

625

498

$92,698

$46,163,604

984

220

764

$99,450

$75,979,800

938

674

264

$89,000

$23,496,000

791

719

$39,492

$2,843,424

745

391

354

$93,141

$32,971,914

724

443

281

$59,342

$16,675,102

682

$90,431

$61,673,942

643

560

$350,000

$29,050,000

454

298

156

$19,711

$3,074,916

315

246

$126,537

$8,731,053

274

$125,572

$34,406,728

117

115

$189,908

$379,816

$27,852

$584,892

Total

38,780

13,254

25,526

$2,300,169,469

6. Compilation of State Fund Soundness Data forms returned to OUST for state fiscal year 2006.

B-14

September 2011

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

OPPORTUNITIES TO EXPEDITE
OF THE CLEANUP BACKLOG

POTENTIAL
REDUCTION

Based on the Phase 1 data, EPA identified three areas with potential opportunities
to reduce the backlog of open releases. To further explore whether these and other
areas of the backlog might benefit from backlog reduction strategies, EPA embarked
on a rigorous Phase 2 study to obtain a greater level of detail about open releases
in the backlog. EPA plans to work collaboratively with states to further characterize
the backlog and explore the merits or disadvantages of potential opportunities and
associated backlog reduction strategies.

CONCENTRATED DISTRIBUTION OF
RELEASES

Approximately two-thirds (64 percent; 67,157 releases) of the releases in the national
backlog are concentrated in 10 states. A large concentration in such a small number of
states presents an opportunity to effectively reduce the national backlog by focusing
resources and efforts on the few states with the largest share of the national backlog.

RELEASES WITH SOIL-ONLY
CONTAMINATION

The November 2006 data show that many older releases with soil-only impacts
remain in the backlog, including more than 6,800 releases that are at least 10 years
old. Conventional wisdom holds that soil-only cleanups could be dealt with more
expeditiously than groundwater cleanups. Therefore, these soil-only cleanups may
present an opportunity to quickly reduce the national backlog.

RELEASES WITH UNKNOWN MEDIA
CONTAMINATION

The high numbers of releases contaminating unknown media in every age group make
it difficult to fully characterize the cleanup backlog. Specifying the media contaminated
by these releases with unknown-media impacts could change the character of the
November 2006 backlog and imply significantly different strategies to reduce the
backlog.

For example, if a high percentage of releases with unknown-media contamination
impact soil only, these releases could be targeted to accelerate reduction of the backlog.
In contrast, if most of the releases where the contaminated media is unknown were
releases where groundwater is contaminated, the backlog would likely take longer to
reduce.

Regardless of their nature, the presence of large numbers of releases where the
media contaminated is unknown indicates that many states' LUST data management
can be improved in order to provide data for the media impacted for future backlog
assessments and for developing strategies to reduce the cleanup backlog.

September 2011

B-15

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

POTENTIAL CONSTRAINTS ON EXPEDITING BACKLOG
REDUCTION

DATA MANAGEMENT

The fact that 21 percent (21,605 releases) of the backlog involves unknown media
contamination suggests potential widespread information gaps in state cleanup data
management systems. Additional improvements to database management could
allow for easier overall program management as well as provide an improved tool for
developing strategies to reduce the cleanup backlog.

STATE FINANCING GAPS

Of states with available state funding data, the four with the largest backlogs accounted
for more than $1.3 billion of the estimated $2.3 billion state funding gap (see Table
1). Because these four states (Illinois, Ohio, South Carolina, and Pennsylvania) rely
primarily on state funds, their lack of adequate state funding could be contributing to
the persistence of their backlogs.

TECHNOLOGICAL CONSTRAINTS OF
GROUNDWATER CLEANUP

The longer timeframe needed to clean up a release affecting groundwater likely
accounts for the continued persistence of releases that impact groundwater in the
backlog. A systematic evaluation of cleanup progress and consideration of alternative
cleanup technologies or other strategies might be necessary to reduce the time to
closure for these releases. With 59 percent (62,149 releases) of the backlog consisting
of releases where groundwater resources are impacted, it could be challenging to
accelerate the reduction of the backlog.

B-16

September 2011

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

CONCLUSION

The persistence of the cleanup backlog is likely the result of many factors, making
it challenging to develop successful backlog reduction strategies. However, this
snapshot of the November 2006 cleanups describes specific states, release age classes,
and media impacted that constitute the majority of the national backlog and reveals
potential opportunities to expedite cleanups. Use of these data will help EPA and the
states work together to reduce the national backlog and to improve national and state
LUST cleanup strategies.

September 2011

B-17

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

METHODOLOGY AND DATA QUALITY

MISSING DATA

The majority of the records excluded from these analyses were removed due to invalid
or missing confirmed release dates, without which release age could not be calculated.
The frequency of these data gaps suggests that data entry errors and missing data
might be a common issue in state LUST data management.

UNUSABLE RECORDS

Initial review of the data led to the exclusion of 5.4 percent of the records in the original
state data files (5,765 records were excluded from the original 110,649 records). The
majority of the records were excluded because they did not have a confirmed release
date (4,734 records, or 4.4 percent of the total records). A smaller portion of the
records were excluded because they are likely duplicates (1,031 records, or 1 percent
of the total records).

Many of the records in states' data files shared the same identifier data fields, indicating
potential duplicates. In addition, some of the records with the same identifier data
fields also shared the same confirmed release dates and media impacted, further
suggesting potential data management issues in these data files. In order to evaluate
the magnitude of potential duplicates counted as separate records, records that shared
the same identifier data fields and the same confirmed release dates were flagged and
treated as separate data records. Records that shared the same identifier data fields,
the same confirmed release dates, and the same media impacted were treated as the
same record (one from each duplicate set was retained while others were excluded).

INTERPRETATIONS OF AMBIGUOUS FIELDS
AND VALUES

In order to perform comparisons among states based on the media impacted,
the contaminated media were categorized into one of the following four types:
"Groundwater," "Soil Only," "Unknown," and "Other." Several states use more detailed
category systems with media impacted that are not commonly tracked by most states,
such as "Drinking Water," "Spring," "Free Product," "Air," and "Bedrock." These data
entries were considered "Other" media. For example, California tracks additional
media impacted other than those discussed in this report (i.e., "Drinking Water" and
"Surface Water") in its LUST database. For this report, 3,929 releases in California that
are listed as impacting "Drinking Water" or "Surface Water" are counted in the "Other"

media category. In addition, there are high percentages of releases with unknown
media impacts in the November 2006 data, some of which may actually contaminate a
known media type that was not specified or pulled into the data files.

The reclassification of all releases with unknown-media impacts in Florida as releases
contaminating groundwater was considered a safe assumption on the basis of
conversation with state staff. Florida alone accounts for 13 percent of the national
backlog, and this reclassification substantially alters the distribution of the type
of media impacted, but the resulting data are likely a better representation of the
national backlog.

B-18

September 2011

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Appendix B: Phase 1 Analysis of the Backlog of Open LUST Releases as of November 2006

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September 2011

B-19

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United States
Environmental
Protection Agency

Solid Waste And
Emergency Response
5401P

EPA 510-R-11-003
September 2011
www.epa.gov/oust

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