1 

### MEMORANDUM | 2 4 March 2009

TO 

### Cho

- Yi Kwan and Timothy Roberts, EPA

FROM 

### Cynthia Manson

, Todd Chamoy

, and Mark Ewen, Industrial Economics , Inc.

SUBJECT 

### Detailed Assessment of UST Universe by Tank Purpose and Design

( WA 1

- 25, Task 6 )

EPA’s Office of Underground Storage Tanks (OUST) is currently exploring the possibility of revising existing regulations associated with certain types of underground storage tank (UST) systems and equipment. Under Executive Order 12866, U nder the requirements of the Regulatory Flexibility Act (RFA) of 1980, as amended by the Small Business Regulatory Enforcement Fairness Act of 1996 ( SBREFA) and Executive Order (EO) 13272, entitled “ Proper Consideration of Small Entities in Agency Rulemaking, ” agencies must consider the potential impact of regulations on small businesses, small governmental jurisdictions, and small organizations during the development of their rules.

This memo randum describes the underground storage tank universe with estimates of the

number of facilities and tanks

, and the purposes of those tanks

, in order to inform future

small business and other regulatory analyses

.

This memo classif

ies the universe of USTs into the following categories of tank purpose and design :

Retail motor fuel (i.e., s ervice station ) tanks;

Airport hydrant systems;

Emergency generator tanks;

Field

- constructed tanks;

Non

- retail f

uel and other petr oleum product tanks; and

Tanks storing used oil and non

- petroleum substances (e.g., hazardous chemicals)

.

We will also include a discussion of USTs found on Tribal lands, including privately

owned USTs as well as those owned by Tribal governments.

This section describes the regulated universe of USTs

. W e first distribute the known USTs by type or purpose of tank using two possible methodologies that provide a range

of values

. Next, we examine whether data on the contents of the tanks will help further refine these estimates. Finally, we conclude with a discussion of the industries using tanks

on Tribal lands. INTRODUCTION AND

BACKGROUND

THE UST UNIVERSE2 TYPES AND PURPOSES O F UST S 

### Potential OUST regulatory revisions may affect one or more of s ix general categories of

USTs according to the design and/or purpose of the tank :

Tanks storing motor fuel for retail sale at service (i.e., gas) stations;

Tanks (both storage tanks and hydrants) that are part of stationary airport h ydrant refueling systems;

Field

- constructed tanks (large scale storage for various purposes) ;

Tanks storing fuel to provide emergency generator support, including emergenc y generator tanks at nuclear power plants;

T anks storin g non

- retail motor fuel for ve hicles and fleets, and petroleum for other

non

- emergency purposes (e.g., lubricating or motor oil) ; and

Tanks storing used oil and non

- petroleum s ubstances (e.g., petroleum additives,

hazardous substances ).

According to EPA data, 6 23

, 319 active undergrou nd storage tanks were reported in the 50

states and on Tribal lands at the end of fiscal year 200 8

. 1 

### To distribute this total across the six categories of tank purpose we build on two previous research efforts. In the first analysis, IEc and PCCI estimated the distribution of USTs by state based on data from the Energy Information Administration (EIA), the EPA, and other sources

. 2 

### Separately, E 2


### Incorporated (E 2 

### ) analyzed state databases to determine the national distribution of tanks by industry sector

. 3 

### We refine both of these analyses to include more specific data on the number of tanks from EPA, and more recent data on the number of motor fuel retailers (service stations) from National Petroleum News (NPN)

, and to distribute other tanks

among their various uses. 4



### Exhibit 1 list s our two best estimates of tanks distributed by purpose , based on the

refined PCCI and E 2 

### methodologies. Both of these estimates indicate that motor fuel retailers account for the majority of underground storage tanks in the United States, although the e stimates of the number of retail motor fuel tanks differ significantly

.

We extrapolate data from a set of state databases to estimate the number o f emergency generator tanks and tanks storing used oil and non

- pet roleum products , and assume that the remaining tanks are used to provide non

- retail fuel for vehicles and fleets (e.g.,
government

- owned vehicles, car dealerships, school bus operators) and other large

- scale,

non

- emergency petroleum product storage

.
We hav e reliable estimates of t he number of field

- constructed tanks , nuclear emergency generator tanks, and airport hydr ant refueling systems from the Federal Aviation Administration (FAA) and the Defense Energy Support Center (DESC). 5 

### It appears that

1 EPA, “FY200 8 End

- of

- Year Activity Report,” November 20, 2008 , as viewed at
http://www.epa.gov/swerust1/cat/ca_08_34.pdf on February 12, 2009

. This number includes tanks designated as
“temporarily closed.”

2 See Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST
Regulations ; Tasks 2

- 4, Work Assignment 1

- 25,” November 20, 2008, and appendices.

3 See E 2 , Incorporated, “Delivery Prohibition

- Draft Preliminary Analyses,” December 18, 2006.

4 " Market Facts 2008 Overview," NPN Magazine July/August 2008, p.26.

5 P CCI identified 241 hydrant systems; 201 at Department of Defense facilities and 40 at commercial airports. P CCI’s
research could not identify any operating field

- constructed tanks except for 239 operated by the Department of Defense. Of
these, approximately 75 percent (179) are located in states that require notification; these 179 tanks are therefore included

in the non

- retail tanks. The remaining 25 percent of field

- constructed tanks (60 tanks) are located in states that defer this3 

### most comm ercial airport hydrant refueling systems employ aboveground storage tanks, and we assume that any military airport hydrant systems employing underground tanks

are included in the non

- retail fuel tanks. 6 

### Airport hydrant system tanks are not, therefore, identified separately in Exhibit 1 , but are reflected, to the extent that they have underground tanks, in non

- retail fuel and other oil product tanks

.

EXHIBIT 1 DISTRIBUTION OF TANK S BY USE

USE CATEGORY NUMBER OF TANKS (REFINED PCCI METHODOLOGY) PERCENTAGE

OF TOTAL NUMBER OF

TANKS (REFINED
E 2 METHODOLOGY) PERCENTAGE OF TOTAL

Retail Motor Fuel (Service Station) Tanks 437,154 1 70.1% 480,613 2 77.1%

Field

- Constructed Tanks (FCTs) 3 239 0% 239 0%
Nuclear Emergency Generator Tanks (EGTs) 4 104 0% 104 0%

Other Emergency Generator Tanks (EGTs) 5 18,500 3.0% 18,410 3.0%

Other ( Used Oil and Non

- Petroleum Product ) Tanks 6 24,318 3.0% 23,238 3.7%

Non

- Retail Fuel and Other Oil Product Tanks 7 143,004 22.9% 100,71 5 16.2%

Total Active USTs 8 623,319 100% 623,319 100%

Notes: 1. Equal to 2.65 times the 161,768 retail motor fuel locations (service stations) reported by NPN, adjusted downwards in states where that value would exceed the total number of tanks. Also adjusted for more precise state data available in state and Tribal land UST databases. 2. Equal to 3.13 times 161,768 retail motor fuel locations reported by NPN, adjusted downwards in states where that value would exceed the total number of tanks. Also adjusted for more precise state data available in state and Tribal land UST databases. 3. Industrial Economics, “Prelim inary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” November 20, 2008, Appendix A. 4. Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” November 20, 2008, Appendix A. 5. Equal to 3 percent of total tanks, based on weighted average in databases from Florida, Massachusetts, Missouri, and Wisconsin, except in states where not enough t anks remain to account for other documented uses.
6. Equal to E 2 estimate of 4 percent of total tanks, except in states where not enough tanks remain to account for this category, and Alaska, where the state database identified 59 tanks containing used oil

. Estimate based on review of 2006 state data; according to E 2

, Category includes tanks containing used oil, hazardous chemicals, and substances labeled as “unknown” or “other” in state databases. 7. Equal to all unaccounted

- for tanks after calculating ot her values. 8. EPA, “FY2008 End

- of

- Year Activity Report.”



### T he key difference between the refine d PCCI and refine d E 2 

### methodologies is the

estimated number of tanks per retail motor fuel location

. The estimated number of retail

motor fuel tank s under the PCCI methodology assumes that the average number of tanks

per retail location is 2.65 , based on the total national average number of tanks per facility reported in EPA’s June 2000 “Report to Congress on a Compliance Plan for the Underground Sto rage Tank Program.” T he modified E 2 

### methodology extrapolates state

data collected by E 2 

### to that indicate that retail motor fuel locations typically have 3.13 tanks per facility

. T his method results in approximately 43,500 additional tanks (roughly

type of tank from Subpart B state n otification requirements. It is therefore possible that these 60 tanks may not be included
in the 623,319 active tanks reported to EPA. However, due to the small number of tanks and the uncertainty about state
reporting requirements, we do not adjust th e EPA reported totals to include any potentially unaccounted

- for field

constructed tanks



### .
6 See Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST
Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” Novem ber 20 , 2008, Appendix A, p.9.4 

### seven p ercent of total tanks) identified as retail motor fuel tanks under the modified E 2


### methodology ; most of these are assumed to be non

- retail fuel tanks u nder the modified PCCI methodology

. For a breakdown of the distribution of tanks by state under each methodology , see Appendi x A

. 7



### As the results show, a number o f differences exist between the figures, and certain

estimates reflect considerable uncertainty. We discuss these issues below, including: (1)

the number of tanks at motor fuel retailers; (2) th e number of non

- retail fuel tanks; (3) the number of emergency generator tanks; and (4) other non

- fuel tanks.

Tanks at Motor Fuel Retailers 

### The number of tanks at motor fuel retailers is an estimate with considerable uncertainty. According to EPA’s June 20 00 “ Report to Congress on a Compliance Plan for the Underground Storage Tank Program, ” facilities with tanks have an average of 2.65 tanks

per facility

. 8 

### However, a more recent investigation of a subset of state databases by E 2


### shows an average of 2.87 ta nks per facility , with retail motor fuel locations specifically having 3.13 tanks per facility

. 9 

### Finally, a comparison of the state data in EPA’s “ FY2007

End

- of

- Year Activity Report ” and data on the number of motor fuel retailers in each state

from the Ene rgy Information Administration (EIA) shows that in many states there must
be less than 2.65 tanks per location , as the total number of active USTs in all sectors is

less than 2.65 times the number of retail motor fuel locations

. 10



### Note that a prior IEc and PCCI estimate us ing the EPA average of 2.65 tanks per facility ( except in states where the number of tanks per facility must be lower, as discussed

above ) and 2007 retail motor fuel location data identified 427,500 tanks at retail motor

fuel locations

. 11 

### Exhibit 1 refine s this estimate with more precise data from states that publish their UST databases and with 2008 tank population and retail fuel location data

. Applying the same adjustments to the E 2 

### state data

- derived estimate of 3.13 tanks per

retail mo tor fuel location, we estimate that the number of tanks at motor fuel retailers range approximately between 43 7

, 0 00 and 48 1

, 0 00.

Tanks with Non

- Retail Motor Fuel and Other Petroleum Products


### Non

- retail motor fuel tanks typically include tanks used for multiple vehicles and “fleets

, ” as well as other types of fuels (aviation fuel, home heating oil) and non

- fuel petroleum projects such as motor oil and lubricating oil.

7 N ote that under the modified E 2 methodology, two states (Alabama and Nevada) have no tanks in either the non

- retail or

non

- fuel categories

. T wo additional states (South Carolina and Washington)

, have no tanks in the non

- retail fuel category.
Under the modified PCCI methodology, two states (Iowa and North Dakota) have no ta nks in either the non

- retail fuel or non

fuel categories.

8 EPA, “Report to Congress on a Compliance Plan for the Underground Storage Tank Program, ” June 2000, as viewed at
http://www.epa.gov/OUST/pubs/rtc_0600.pdf on December 18, 2008, p.38.

9 E 2 , Incorporated, “Delivery Prohibition

- Draft Preliminary Analyses,” December 18, 2006.

10 Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations;

Tasks 2

- 4, Work Assignment 1

- 25,” November 10, 2008, Appendix A. Note that this memorandum update s the Appendix A

estimates to reflect the number of service stations from NPN Market Facts 2008 an d the number of tanks from EPA’s 2008

End

- of

- Year Activity Report.

11 T he number of service stations is derived from EIA data a nd other sources for non

- state territories. This value is multiplied
by 2.65 and compared to the total number of tanks reported in EPA’ s “FY2008 End

- of

- Year Activity Report.” If the result
exceeds the total number of tanks reported to EPA

, we adjust the number of tanks per facility rate down to either 2.0 or 1.0

until this is corrected . See Industrial Economics, “Preliminary Assessment an d Scoping of Data Related to Potential Revisions
to the UST Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” November 2 0, 2008, Appendix A.5 

### I nformation on t he distribution of some non

- retail motor fuel tanks comes from t he Steel

Tank Institute . I n 2000, the Steel Tank Institute estimated that tanks serving vehicle

fleets accounted for just four percent of new UST installations. 12 

### However, they further

estimate that “ institutions ” (e.g., universities and hospitals) account f or six percent of

installations

, and government account for another six percent. These sectors likely include a mix of refueling stations for vehicles and emergency generator tanks. In general, the Steel Tank Institute observes that, due to EPA regulatio ns and clean

- up costs associated with UST leaks, non

- retail service station facilit ies that need tanks favor

above ground storage tanks. 13 

### Because we do not have reliable estimates of non

- retail

t anks for fueling fleets and other vehicles , and because we be lieve these tanks account for a large portion of tanks not otherwise specified in this analysis, we assign all remaining

tanks reported in EPA’s FY2008 End

- of

- Year Activity Report after calculating the other categories to non

- retail fuel tanks

.

In additi on to tanks used for non

- retail vehicle fueling, a limited number of the tanks in this category support uses other than motor

- vehicle fueling. These include tanks with

non

- transportation fuels such as propane and home heating oil stored for resale , other transportation fuels such as jet fuel (distributed through fueling trucks and no hydrant systems)

, and petroleum products such as lubricating oils and crude oil. A review of 2006 state data collected by E 2 

### indicates that these non

- motor

- vehicle uses repre sent roughly three percent of all tanks.

Emergency Generator Tanks 

### We identified a range of estimates of the number of emergency generator tanks from

several states and in conversations with installers. A necdotal evidence from the Hill Company, a large installer of USTs in Texas, suggests that up to 80 percent of tanks that

are not at retail motor fuel locations may be part of emergency generators. 14 

### However, an

examination of several state databases sugge sts that a much smaller portion of the UST universe is emergency generator tanks

. In Massachusetts, only two percent (243 of 11,876) of active USTs in the state database are designated as emergency generator tanks, although over 18 percent do not have a u sage designated. 15 

### Wisconsin identifies a similar percentage of tanks as generators ( 234 of 12,354, or 1.9 percent), and while the state does not have any unidentified tanks, another 6.5 percent of tanks belong to the broad categories “ Industrial ” and “ Mer cantile/Commercial ” and could be used to support emergency generation. 16 

### Missouri identifies approximately 2.5 percent (215 of 8,419) of active tanks as emergency generators. 17 

### Fi nally, while Florida ’s database does not explicitly identify tanks as emergen cy generator tanks, according to the tank contents

12 Geyer, Wayne, “UST History,” 2000, as viewed at
https://www.steeltank.com/LinkClick.aspx?fileticket=GLBrj44tMj0%3D&t abid=108&mid=502 on November 23, 2008, p. 12.
Note the Steel Tank Institute does not define or otherwise specify what types of businesses are included in the category

“fleet” in their statistics.

13 Geyer, Wayne, “UST History,” 2000, as viewed at
https://ww w.steeltank.com/LinkClick.aspx?fileticket=GLBrj44tMj0%3D&tabid=108&mid=502 on November 23, 2008, p. 10.

14 Personal communication with Tommy Dillard, Estimator/Project Coordinator, the Hill Company, on November 24, 2008. It

is not clear whether Mr. Dillard considers fleet refueling and government operations as part of his estimate of retail
establishments. This may account for at least part of the discrepancy between his estimate and the state data.

15 Massachusetts’ UST database is available at http://www.mass.gov/Eeops/docs/dfs/osfm/ust/ust.exe

16 Wisconsin’s UST database is available at http://apps.commerce.state.wi.us/ers/ER

- EN

- TankArchive.zip

17 Missouri’s UST database is available at http://www.dnr.mo.gov/env/hwp/tanks/internet.zip6 

### field

, 3.8 percent (1,130 of 29,028) of tanks have the value “ Emergency Generator

Diesel ” listed as the fuel

. 18



### Based on the weighted average percentage of emergency generator tanks identified in the

four states reporting this distinction, we estimate that up to three percent of the total tanks in a state are emergency generator tanks (Exhibit 1)

. While four states are not enough to provide statistical significance in our national estimates, these states r epresent several regions of the United States, have differences in regulation for emergency generators, and present a tight range of estimates of emergency generator tanks, suggesting that it may be

reasonable to assume that these numbers are representativ e of national patterns

.

Other Tanks: Field

- Constructed Tanks, Nuclear Power Plant Tanks, and Non

- Fuel

Tanks


### Exhibit 1 presents estimates of field

- constructed tanks and emergency generator tanks at nuclear power plants identified in o ur previous research. 19 

### While these estimates do not reflect a comprehensive effort to identify all tanks, the specific estimates are derived from Department of Defense data sources and other published estimates, and tank installation experts contacted asserted that these tank types are not used by other sectors. In addition, the tanks in this population are a small fraction of the total tank universe , suggesting that uncertainty associated with this estimate is not likely to affect regulatory costs.

Finally, up to four percent of tanks are designated as tanks for storage of non

- fuel products

. 20 

### Based on E 2 

### ’s analysis of state databases, approximately 1.8 percent of these tanks hold used oil, 0.3 percent hold hazardous chemicals, and the remaining tanks have

contents labeled as “other” or “unknown” in the state databases.

TANK CONTENTS


### T o further refine and verify the precision of our estimates above, we investigated the types of fuels or other chemicals identified in 13 state databases that provide detail about

tank contents

. Our ability to identify tank purpose by tank content is limited by the multiple uses of

diesel fuel, which is associated with retail motor fuel establishments , non

- retail motor fuel uses (e.g., agriculture, construction, and government) and emergency gener ators. However, a review o f the state data provides some insights into estimates in Exhibit 1, in

that:

Roughly 75 percent of all tanks in the 13 state databases contain gasoline or ethanol; this is generally consistent with the range of retail motor fuel tanks (70.1 percent and 77.1 percent) described in Exhibit 1. While some of these tanks are likely associated with non

- retail establishments, this number does not include the

diesel fuel and other tanks associated with retail motor fuel sales.

Tanks st oring fuels appropriate for emergency generation (i.e., diesel not specified as vehicle fuel, propane, and kerosene) represent 18.5 pe rcent of all tanks in the 13 state databases. A large number of these tanks, however, are likely diesel tanks storing fue l for vehicle use at both retail and non

- retail facilities. Similarly, some

18 Florida’s UST database delivered by email from E 2 via EPA on December 16, 2008.

19 Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations;

Tasks 2

- 4, Work Assignment 1

- 25,” November 20 , 2008, Appendix A.

20 E 2 , Incorporated, “Delivery Prohibition

- Draft Preliminary Analyses,” December 18, 2006.7 

### of the kerosene and propane storage tanks could support other applications such as heating fuel.

Tanks storing petroleum products and fuels other than gasoline and diesel (e.g.,

c rude oil, aviation fuel, and motor oil) represent roughly three percent of all tanks

in the 13 states.

Other tanks (including those storing chemicals, used oil, and unidentified substances) represent 3.2 percent of the tanks in the 13 states. This numbe r is roughly consistent with the four percent estimate provided by E 2 

### and used in Exhibit 1. We rely on the E 2 

### estimate in Exhibit 1 because it was based on a more thorough examination of state data and definitions than we used in this screening

level rev iew.

Overall, however, our review of tank by content suggests that the basic distribution of tanks across purpose is not likely to change significantly based on additional tank content data, though more information about the uses of diesel fuel (e.g., the number of retail motor fuel establishments selling diesel) could help refine the estimate of the number of tanks used for emergency generation. In addition, a detailed review of state data matching content to specific facility name could potentially help refine estimates of retail,

non

- retail, and emergency uses of gasoline, diesel, and other fuels.

In addition to our general review of state data, we used data from Alaska to refine

estimates in Exhibit 1. Alaska ’s tank content data showed a high er number of tanks storing used oil than the four percent estimate from E 2



### . After excluding the 564 tanks positively

- identified as gas station tanks in Alaska, we distribute the remaining tanks by content, shown in Exhibit 2

. Exhibit 2 also presents, for compariso n purposes, the values for tank purpose estimated above.

EXHIBIT 2 NON

- SERVICE STATION TANK S BY CONTENTS IN ALA SKA

TANK CONTENTS TANKS COMMENTS

Diesel 319 Subset of the 524 emergency generator tanks and non

retail f uel tanks.

Gasoline 188 Subset of the 489 non

- retail fuel tanks.

Kerosene 8 Used for jet fuel; included in non

- retail fuel and other petroleum product tank category

. Other 7 Unknown.

Used Oil 59 Exceeds four percent of total tanks; Exhibits 1 and 2 adjusted accordingly.
Source: Alaska state UST database provided by E 2 via EPA.



### Gasoline accounts for 188 tanks, well below the 489 tanks identified earlier. D iesel tanks

could be distributed as either non

- retail fuel tanks or emergency generator tanks such that

this does not conflict with our earlier estimates. The used oil tanks, however, exceed four percent of tanks in Alaska . We therefore adjusted our Exhibit 1 estimates to account for this higher number. This is the only case where the tank contents reported in the 13 sta te
databases directly altered our initial estimates.8 UST S ON TRIBAL LANDS 

### In general, OUST delegates UST activities to state

- level environmental agencies.
However, EPA is the agency responsible for implementing regulations on Tribal lands. Therefore, EPA i s interested in specifically characterizing USTs located on Tribal lands. In addition, Tribal governme nts are typically small entities, so Tribal government

- owned businesses must be considered under RFA/SBREFA. This section provides an estimate of

the numb er of tanks on Tribal lands and a discussion of the industries and sectors to which these tanks belong.

In 2007, OUST produced a report to Congress entitled, “ Report to Congress on Implementing and Enforcing the Underground Storage Tank Program in Indian C ountry. ” In the report, they established that 2,658 active tanks existed on Tribal lands at that

time. 21 

### This estimate differs only slightly from the 2,6 56 tanks estimated in the “ FY2 00 8

End

- of

- Year Activity Report ”

. Exhibit 3 lists the number of tanks in each industry sector as reported in an EPA database documenting tanks in seven of the ten EPA regions, and 2,112 total tanks on Tribal lands

.

EXHIBIT 3 DISTRIBUTION OF TANK S BY SECTOR ON TRIBA L LANDS

SECTOR NUMBER OF TANKS

Airlines & Aircraft Owners 7

Auto Dealership 6

Commercial 47

Contractor 2

Farm 18

Federal Military 18

Federal Non

- Military 54
Retail Motor Fuel Sales (gas station) 1

, 653

Industrial 15

State/ Local Government 120

Other/Unknown 1 29

Petroleum Distributor 9

Private 9

Residential 2

School 14

Truck/Transporter 6

Utilities 3

Total 2

, 112
Source: Database of USTs on Tribal lands provided by EPA.



### T he distribution of tanks by sector in Exhibit 3 is similar to the types of industries that use USTs in the rest of the United States, although there appear to more government

- owned

tanks than elsewhere. In addition, only 35 tanks are identified as emergency generator tanks, and only 724 tanks are iden tified as tribal

- owned.

21 EPA Office of Underground Storage Tanks, “Report to Congress on Implementing and Enforcing the Underground Storage
Tank Program in Indian Country,” August 2007 , p.28.9 

### Of the 35 emergency generator tanks, only 9 are identified as owned by entities other than the Federal government. C onversations with two EPA regional inspecto rs representing Regions 8 and 9 (Lisa Luebke and Mary Keil, respectivel y) suggest that the estimates of emergency generator tanks may be low.

Region 9 includes the Navajo Nation, the largest tribe in the United States , which accordingly accounts for the largest number and variety of tanks

. Ms. Keil identified

several tank use s supporting the Tribe, including bus depots at schools, emergency generators at hospitals, and Tribal government fleet refueling sites. In addition, she noted

that casinos and minin g companies likely have a stronger representation on Tr ibal lands

than el sewhere

. In addition, i n her experience, all casinos have emergency generator

facilities , and many also operate their own retail gas stations. While the database

identified numerous casino

- operated gas stations, it contains only three casino

- owned emergency generator tanks. Unless the remaining casinos use aboveground storage tanks, she believes that the emergency generator estimate for Region 9 may be low

. Ms. Luebke had less detailed information on potential discrepancies in Tribal data, but confirmed that retail motor fuel establishments represent the majority of UST locations.

O ther than the existence of casinos and natural resource extraction industries, we have not

identified substantial differences between the types o f businesses owning USTs on Tribal

lands and businesses in the rest of the United States. However, it is noteworthy that a approximately one

- third of tanks on Tribal lands appear to be owned by Tribal governments, most of which are small entities.

The number and uses of tanks described in this memo are based on various sources. While the total number of active, regulated USTs is relatively precise, we have encountered several conflicting estimates of how those USTs are distributed among

industries and uses. Therefore, we present two estimates of these distributions, with roughly seven percent of the tanks redistributed between the estimates . However, the actual number of tanks of a particular type could be high er or lower than the figures presented in this memo. The greatest source of uncertainty is the distribution of uses for tanks with diesel fuel across emergency generation, retail motor fuel, and non

- retail fuel

uses.
The data presented in this m emo on tan ks on Tribal lands have several areas of uncertainty as well . Most significantly, three of the EPA regions representing 14 states and two territories are not included in this analysis

.

NEXT STEPS 

### This analysis provides a general estimate of the number and type of USTs currently in use, and the general distribution of UST use by purpose and design

. While the priorities for refining this analysis will be determined in part by the specific regulatory options under consideration, the following may provide usef ul insights:

Additional data on Tribal ownership patterns: The data collected to date do not address all tanks on Tribal lands and rely on limited contacts with EPA regional

staff. If Tribal ownership or sector distribution of tanks on tribal lands is cent ral to EPA’s rulemaking effort, collection of additional data on tank ownership and use from remaining regions and Tribes, as well as supplemental data from the regions already contacted, could be useful. KEY SOURCES OF

UNCERTAINTY AND NEXT

STEPS10 

### Detailed analysis of specific sectors or tank appli cations: This analysis provides general information on the uses of USTs , but uses extrapolation from a limited set of data to identify emergency generator tanks. If a detailed assessment of tanks used for emergency generation is central to the evaluation of regulatory options, a more detailed investigation of additional states that track emergency generator tanks, coupled with an investigation of the distribution of different uses
for diesel fuel, would be useful.

Refinement of estimate of retail gasoline establishments and tank use: This analysis identifies discrepancies in the number of tanks and establishments

associated with the retail sale of motor fuel. If EPA determines that the uncertainty associated with retail motor fuel tank usage would have a significant impact on estimates of total regulatory cost, then refining this set of estimates , or undertaking a more detailed analysis of the distribution of ownership in this sector may be

useful to support either a regulatory cost or small business analy sis or both

.11 APPENDIX A

EXHIBIT A

- 1 DISTRIBUTION OF TANK S BY STATE AND USE (MODIF IED PCCI METHODOLOGY )

STATE OR TERRITORY SERVICE

STATION TANKS 1 FCT 2 NUCLEAR EGT 3 OTHER

EGT 4 NON

- RETAIL

FLEET REFUELING TANKS 5 OTHER

(NON

- FUEL) TANKS 6 TOTAL

ACTIVE USTS 7

Alabama 16,298 0 5 562 1,115 749 18,728

Alaska 564 4 0 36 535 59 1,198

American Samoa 11 0 0 0 4 1 16

Arizona 5,435 0 3 212 1,129 282 7,061

Arkansas 6,731 0 2 280 1,960 374 9,347

California 27,030 87 4 1,121 7,641 1,495 37,379

Colorado 6,153 0 0 238 1,225 317 7,934

Connecticut 4,055 0 2 292 4,999 389 9,737

Delaware 1,131 0 0 44 218 58 1,450

District of Columbia 313 0 0 21 329 28 690

Florida 24,552 7 5 841 1,515 1,122 28,042

Georgia 23,120 0 4 898 4,709 1,197 29,928

Guam 111 33 0 8 97 10 259

Hawaii 959 24 0 50 571 67 1,671

Idaho 2,536 0 0 105 715 140 3,496

Illinois 11,649 0 11 666 8,978 888 22,192

Indiana 8,104 0 0 411 4,623 547 13,685

Iowa 7,155 0 1 19 0 0 7,175

Kansas 5,600 0 1 210 899 280 6,989

Kentucky 8,790 0 0 365 2,511 486 12,152

Louisiana 9,524 0 2 369 1,907 492 12,294

Maine 2,854 0 0 93 31 124 3,102

Maryland 5,883 0 2 257 2,094 343 8,580

Massachusetts 7,925 0 1 321 2,035 428 10,711

Michigan 12,959 0 4 594 5,449 792 19,797

Minnesota 9,990 0 3 438 3,592 584 14,608

Mississippi 6,738 0 1 262 1,369 349 8,718

Missouri 8,188 0 1 303 1,212 404 10,109

Montana 2,120 0 0 98 912 130 3,260

Nebraska 4,084 0 2 207 2,318 275 6,886

Nevada 3,658 0 0 112 0 0 3,770

New Hampshire 2,422 0 1 93 462 124 3,102

New Jersey 8,326 0 4 484 6,678 646 16,138

New Mexico 3,087 0 0 120 622 160 3,988

New York 17,225 0 6 883 10,129 1,177 29,419

North Carolina 18,227 0 5 851 8,157 1,135 28,375

North Dakota 2,088 0 0 63 0 0 2,15112 STATE OR TERRITORY SERVICE

STATION TANKS 1 FCT 2 NUCLEAR EGT 3 OTHER

EGT 4 NON

- RETAIL

FLEET REFUELING TANKS 5 OTHER

(NON

- FUEL) TANKS 6 TOTAL

ACTIVE USTS 7

Northern Mariana Islands 48 0 0 2 16 3 68

Ohio 13,136 0 2 701 8,607 935 23,382

Oklahoma 10,335 0 0 330 0 338 11,003

Oregon 4,433 0 0 180 1,154 240 6,008

Pennsylvania 12,489 0 9 727 10,040 969 24,235

Puerto Rico 3,146 0 0 136 1,081 182 4,545

Rhode Island 994 0 0 49 512 65 1,619

South Carolina 9,757 5 7 358 1,321 477 11,925

South Dakota 2,761 2 0 92 78 122 3,055

Tennessee 12,104 0 3 509 3,683 679 16,978

Texas 36,191 4 4 1,615 13,870 2,154 53,838

US Virgin Islands 98 0 0 4 36 6 144

Utah 2,981 0 0 120 743 160 4,005

Vermont 1,632 0 1 93 1,238 124 3,088

Virginia 15,189 23 4 599 3,351 799 19,964

Washington 8,178 50 1 302 1,121 402 10,054

West Virginia 3,843 0 0 169 1,383 225 5,619

Wisconsin 10,641 0 3 451 3,347 602 15,044

Wyoming 1,524 0 0 59 292 78 1,952

Tribal Lands 2,079 0 0 80 391 106 2,656

Totals 437,154 239 104 18,500 143,004 24,318 623,319

1. Equal to 2.65 times the 161,768 retail motor fuel locations (service stations) reported by NPN, adjusted downwards in states where that value would exceed the total number of tanks. Also adjusted for more precise state data available in state and Tribal land UST databases.
2 . Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” November 20, 2008, Appe ndix A.
3 . Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” November 20, 2008, Appendix A.

4 . Equal to 3 percent of total tanks, based on weighted average in databases from Florida, Massachusetts, Missouri, and Wisconsin, except in states where not enough tanks remain to account for other documented uses.

5

. Equal to E 2 estimate of 4 percent of total tanks, except in states where not enough tanks remain to account for this category, and Alaska, where the state database identified 59 tanks containing used oil. Estimate based on review of 2006 state data; according to E 2

, Category inc ludes tanks containing used oil, hazardous chemicals, and substances labeled as “unknown” or “other” in state databases.
6 . Equal to all unaccounted

- for tanks after calculating other values.

7 . EPA, “FY2008 End

- of

- Year Activity Report.”13 EXHIBIT A

- 2 DIS TRIBUTION OF TANKS B Y STATE AND USE (MODIF IED E 2 METHODOLOGY)

STATE OR TERRITORY SERVICE

STATION TANKS 1 FCT 2 NUCLEAR EGT 3 OTHER

EGT 4 NON

- RETAIL

FLEET REFUELING TANKS 5 OTHER

(NON

- FUEL) TANKS 6 TOTAL

ACTIVE USTS 7

Alabama 18,450 0 5 273 0 0 18,728

Alaska 564 4 0 36 535 59 1,198

American Samoa 13 0 0 0 2 1 16

Arizona 6,420 0 3 212 144 282 7,061

Arkansas 7,950 0 2 280 741 374 9,347

California 31,926 87 4 1,121 2,745 1,495 37,379

Colorado 7,268 0 0 238 111 317 7,934

Connecticut 4,789 0 2 292 4,265 389 9,737

Delaware 1,131 0 0 44 218 58 1,450

District of Columbia 369 0 0 21 272 28 690

Florida 24,552 7 5 841 1,515 1,122 28,042

Georgia 23,120 0 4 898 4,709 1,197 29,928

Guam 131 33 0 8 76 10 259

Hawaii 1,133 24 0 50 397 67 1,671

Idaho 2,995 0 0 105 256 140 3,496

Illinois 13,759 0 11 666 6,868 888 22,192

Indiana 9,572 0 0 411 3,156 547 13,685

Iowa 5,400 0 1 215 1,272 287 7,175

Kansas 5,600 0 1 210 899 280 6,989

Kentucky 10,382 0 0 365 919 486 12,152

Louisiana 11,249 0 2 369 182 492 12,294

Maine 2,854 0 0 93 31 124 3,102

Maryland 5,883 0 2 257 2,094 343 8,580

Massachusetts 7,925 0 1 321 2,035 428 10,711

Michigan 15,306 0 4 594 3,102 792 19,797

Minnesota 9,990 0 3 438 3,592 584 14,608

Mississippi 6,738 0 1 262 1,369 349 8,718

Missouri 8,188 0 1 303 1,212 404 10,109

Montana 2,504 0 0 98 528 130 3,260

Nebraska 4,823 0 2 207 1,579 275 6,886

Nevada 3,658 0 0 112 0 0 3,770

New Hampshire 2,861 0 1 93 23 124 3,102

New Jersey 9,834 0 4 484 5,170 646 16,138

New Mexico 3,646 0 0 120 62 160 3,988

New York 20,345 0 6 883 7,009 1,177 29,419

North Carolina 21,528 0 5 851 4,856 1,135 28,375

North Dakota 1,576 0 0 65 424 86 2,15114 STATE OR TERRITORY SERVICE

STATION TANKS 1 FCT 2 NUCLEAR EGT 3 OTHER

EGT 4 NON

- RETAIL

FLEET REFUELING TANKS 5 OTHER

(NON

- FUEL) TANKS 6 TOTAL

ACTIVE USTS 7

Northern Mariana Islands 56 0 0 2 7 3 68

Ohio 15,515 0 2 701 6,228 935 23,382

Oklahoma 7,800 0 0 330 2,433 440 11,003

Oregon 5,236 0 0 180 351 240 6,008

Pennsylvania 14,752 0 9 727 7,778 969 24,235

Puerto Rico 3,715 0 0 136 512 182 4,545

Rhode Island 1,174 0 0 49 332 65 1,619

South Carolina 11,525 5 7 358 0 31 11,925

South Dakota 2,084 2 0 92 755 122 3,055

Tennessee 12,104 0 3 509 3,683 679 16,978

Texas 42,746 4 4 1,615 7,315 2,154 53,838

US Virgin Islands 116 0 0 4 18 6 144

Utah 3,521 0 0 120 203 160 4,005

Vermont 1,928 0 1 93 943 124 3,088

Virginia 15,189 23 4 599 3,351 799 19,964

Washington 9,659 50 1 302 0 42 10,054

West Virginia 4,539 0 0 169 687 225 5,619

Wisconsin 10,641 0 3 451 3,347 602 15,044

Wyoming 1,800 0 0 59 16 78 1,952

Tribal Lands 2,079 0 0 80 391 106 2,656

Totals 480,613 239 104 18,410 100,716 23,238 623,319

1. Equal to 3.13 times the 161,768 retail motor fuel locations (service stations) reported by NPN, adjusted downwards in states where that value would exceed the total number of tanks. Also adjusted for more precise state data available in state and Tribal land UST databases.
2 . Ind ustrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” November 20, 2008, Appendix A.
3 . Industrial Economics, “Preliminary Assessment and Scoping of Data Related to Potential Revisions to the UST Regulations; Tasks 2

- 4, Work Assignment 1

- 25,” November 20, 2008, Appendix A.

4 . Equal to 3 percent of total tanks, based on weighted average in databases from Florida, Massachusetts, Missouri, and Wisconsin, excep t in states where not enough tanks remain to account for other documented uses.
5

. Equal to E 2 estimate of 4 percent of total tanks, except in states where not enough tanks remain to account for this category, and Alaska, where the state database identifie d 59 tanks containing used oil. Estimate based on review of 2006 state data; according to E 2

, Category includes tanks containing used oil, hazardous chemicals, and substances labeled as “unknown” or “other” in state databases.
6 . Equal to all unaccounted

- for tanks after calculating other values.

7 . EPA, “FY2008 End

- of

- Year Activity Report.”