B-1

Appendix B: Methodology for Extrapolation from State Databases

I. State Database Survey

 Using EPA’s State and Territorial UST Program Directory as a guide,1E

2 Inc. 

investigated the UST program Web sites for all 50 states. State UST programs 

are typically administered through the state’s environmental management 

department, though in some cases the programs are a service of the state fire 

marshal’s office or fire department. The purpose of the investigation was to 

ascertain if the Web site contained a publicly available downloadable database of 

regulated USTs with facility, tank, and industry sector information. 

 E

2 Inc. also obtained datasets from Abt Associates Inc. (Abt) that provided 

information on USTs for 11 states (AL, DE, FL, KS, MA, MD, MN, NY, PA, 

VA, WI). Abt obtained these data from state agencies in 2005 in order to estimate 

the SPCC-regulated universe of facilities to support the SPCC rulemaking 

activities for EPA’s Office of Emergency Management. 

 E

2 Inc. summarized its findings for each state in a spreadsheet, which identifies 

the following information: state name, data source, database name, the state’s 

UST regulatory requirements, industry sectors used (if available), data elements 

included (e.g., tank capacity, contents), the program’s contact details, and a Web 

link to the database. 

II. Thirteen States Identified for Analysis

 E

2 Inc. identified thirteen states as having accessible databases (either through Abt 

or state Web sites) that included industry sector breakdowns. Exhibit B-1 shows 

the states that met these criteria.

Exhibit B-1. Summary of State Databases Used for Industry Sector Profile Analysis

State Data Source Database Name Regulatory Requirement Industry Sectors

Alabama Abt Data for 

Alabama (one of 

the four states not 

used in SPCC 

analysis)

"Owners" and 

"Utanks" Microsoft 

Excel spreadsheets 

Alabama Department of 

Environmental Management regulates 

tanks that are more than 110 gallons in 

capacity with the exception of farm or 

residential tanks of 1,100 gallons or 

less capacity used for storing motor 

fuel for noncommercial purposes; and 

tanks used for storing heating oil for 

consumptive use on the premises 

where stored.

Retail; Bulk Facility; Industrial; 

Local Government; 

State/Federal Government; 

Farm/Residential

 

1 EPA’s State and Territorial UST Program Directory is available at 

http://www.epa.gov/OUST/states/statcon1.htm
B-2

State Data Source Database Name Regulatory Requirement Industry Sectors

Alaska Alaska 

Department of 

Environmental 

Conservation 

Alaska UST 

Database

An underground storage tank or 

underground storage tank system 

means one or more stationary devices, 

including any connected underground 

pipes, designed to contain an 

accumulation of petroleum, of which 

the volume, including the volume of 

underground pipes, is 10% or more 

beneath the surface of the grade. 

DEC's definition is essentially the 

same as EPA's.

State Government; Federal 

Military; Commercial; Aircraft 

Owner; Gas Station; 

Contractor; Petroleum 

Distributor; Truck/Transporter; 

Auto Dealership; Farm; 

Utilities; Local Government; 

Residential; Industrial; Federal 

Non-Military; Railroad; 

Unlisted

Delaware Delaware 

Department of 

Natural 

Resources and 

Environmental 

Control 

Listing of Recent 

Facility, Owner, 

and Tank 

Information

Delaware's Department of Natural 

Resources and Environmental Control 

regulates all USTs with the following 

exceptions: any UST system whose 

capacity is 110 gallons or less; 

Agricultural/Farm and residential UST 

systems of 1,100 gallons or less used 

for storing motor fuels for noncommercial purposes; UST systems 

containing heating oils of 1,100 

gallons or less used for consumptive 

purposes on the premises where 

stored.

Airport/Aircraft Owner; 

Apts/Senior Ctr; Auto 

Dealership; Auto Parts/Service; 

Bank; Church/Synagogue; 

Commercial; Contractor; 

Entertainment; Farm; Federal 

Military; Federal Non-Military; 

Gas Station/Mini-Market; 

Health Care Operations; 

Hotel/Motel; Industrial; 

Laundry/Garment; Local 

Government; Manufacturing; 

Marina; Mom & Pop/General 

Store; Not Listed; Other; 

Petroleum Distributor; Post 

Office; Private School; 

Railroad; Recreation/Clubs; 

Recreational; Retail; Shopping 

Mall/Ctr; State Government; 

Truck/Bus/Transporter; Utilities

Florida Abt Data -

Florida 

Department of 

Environmental 

Protection

Storage Tank 

Facility 

Information

Florida Department of Environmental 

Protection regulates all non-residential 

USTs whose capacity exceeds 110 

gallons with the exception of storage 

tank systems used solely for 

temporary storage of mixtures of 

pesticides and diluents for 

reapplication as pesticides; storage 

tank systems with a storage capacity 

of less than 30,000 gallons used for 

the sole purpose of storing heating oil 

for consumptive use on the premises 

where stored; and agricultural storage 

tank systems of 550 gallons capacity 

or less. 

Agricultural; Chemical User; 

Collection Station; Condo 

Residential; Contamination 

Site; County Government; Fuel 

user/Non-retail; Indian Land; 

Local Government; 

Marine/Coastal Fueling 

Location; Other Regulated 

Facility; Residential; Retail 

Station; State Government; 

Terminal/NonReg Tanks; 

Waterfront Fueling Location
B-3

State Data Source Database Name Regulatory Requirement Industry Sectors

Georgia Georgia 

Environmental 

Protection 

Division of the 

Department of 

Natural 

Resources

List of Georgia 

Underground 

Storage Tanks, 

Facilities/Owner 

Data; List of 

Georgia 

Underground 

Storage Tanks, 

Tank Data

The GA DNR regulates all USTs 

whose capacity exceeds 110 gallons 

with the exception of farm or 

residential tanks of 1,100 gallons or 

less capacity used for storing motor 

fuel for noncommercial purposes; and 

tanks used for storing heating oil for 

consumptive use on the premises 

where stored.

Gas Station; Petroleum 

Distributor; Federal Military; 

Truck/Transport; State; County; 

City; Local; Other; Not marked; 

Commercial; Industrial; 

Airline; Aircraft Owner; 

Contractor; Auto Dealership; 

Educational; Farm; Federal 

Non-Military; Hospital; 

Railroad; Residential; Utilities

Maryland Abt Data -

Maryland 

Department of 

Environment

UST Oil 

Operations 

Database

Maryland Department of 

Environment's Oil Control Program 

regulates all petroleum USTs with the 

exception of tanks that are 1,100-

gallon capacity or less and used to 

store petroleum products at a private 

residence or farm.

Air Taxi (Airline); Auto 

Dealership; Commercial; 

Contractor; Educational; Farm; 

Federal Military; Federal NonMilitary; 

Fire/Rescue/Ambulance; Gas 

Station; Industrial; Local 

Government; Marina; Not 

Listed; Office; Other; 

Petroleum Distributor; 

Railroad; Residential; State 

Government; Store; 

Truck/Transporter; Utilities

Massachusetts Abt Data for 

Massachusetts 

(one of the four 

states not used in 

SPCC analysis), 

which is same 

data as found 

through 

Massachusetts 

Department of 

Fire Services 

Web site

UST Database The UST program regulates all USTs 

with the exception of farm or 

residential tanks of 1,100 gallons 

capacity or less used for storing motor 

fuel for noncommercial purposes, and 

residential or commercial tanks 

storing or having stored heating oil 

(fuel oil) for consumptive use on the 

premises.

Gas Station; Municipal; 

Industrial; Vehicle Dealer; 

Truck/Transport; Utilities; 

Other; Farm; Petr. Distr; 

Contractor; Federal/Military; 

Aircraft Owner; Hotel; State; 

Country Club/Golf Course; 

Marina; etc. (There are about 

100 categories in all)

Minnesota Abt Data -

Minnesota 

Pollution Control 

Agency (MPCA)

Tanks Database Petroleum and “Other.” Registration 

is required for petroleum USTs 

covered by EPA's UST program.

Landfill/Rubbish, State 

Government, Family Farm, 

Refinery, Food Processing, 

Utility, Agricultural, 

Construction, 

Autocare/Autoparts

Missouri Missouri 

Department of 

Natural 

Resources

UST Summary 

Database

Any UST containing regulated 

substance excluding farm or 

residential tanks less than 1,100 

gallons containing fuel for noncommercial purposes. 

Owner Class: City, Federal, 

Government Owner, Hospital, 

Local, Marketer, Non-Marketer, 

County, Private Owner, State, 

Unclassified, School

Nevada Nevada Division 

of Environmental 

Protection

Registered 

Underground 

Storage Tank List

Nevada has adopted 40CFR280, the 

Federal UST Regulations. 

Private; Commercial; Federal, 

State; Local Government
B-4

State Data Source Database Name Regulatory Requirement Industry Sectors

Tennessee Tennessee 

Department of 

Environment and 

Conservation

Petroleum 

Underground 

Storage Tank 

Database

Tennessee Department of 

Environment and Conservation 

regulates all petroleum USTs that are 

more than 110 gallons in capacity 

with the exception of farm or 

residential tanks of 1,100 gallons or 

less capacity used for storing motor 

fuel for noncommercial purposes; and 

tanks used for storing heating oil for 

consumptive use on the premises 

where stored. 

Air Taxi (Airline); Aircraft 

Owner; Auto Dealership; 

Commercial; Contractor; Farm; 

Federal Military; Federal NonMilitary; Gas Station; 

Industrial; Local Government; 

Not Listed; Other; Petroleum 

Distributor; Railroad; 

Residential; State Government; 

Truck/Transporter; Utilities

Virginia VA Department 

of Environmental 

Quality

UST & AST 

registered 

petroleum storage 

tanks

The Virginia regulation is very similar to 

the federal regulation, except it requires 

notifications from owners of all regulated 

USTs that remain in the ground.

Commercial; Autodealer; 

Utility; Aircraft; Fuel Station; 

Contractor; Industrial; Local

Wisconsin Wisconsin 

Department of 

Commerce

Storage Tank 

Database

Registration required for all USTs 

larger than 60 gallons and storing 

petroleum or CERCLA hazardous 

substances. 

Assembly; Business; 

Educational; Factory/Industrial; 

Hazardous; Institutional; 

Mercantile/Commercial; 

Residential; Storage; Bulk Plant 

Storage; Retail Fuel Sales; 

Industrial

III. Preparing Databases for Analysis

 E

2 Inc. imported the thirteen databases into Microsoft Excel format. 

 E

2 Inc. refined/filtered the thirteen databases to include only active (designated as 

either currently in use or temporarily out of use), regulated underground storage 

tanks. This process involved removing any aboveground storage tanks; tanks 

with non-active status such as closed, removed, or abandoned; and tanks that are 

not federally regulated. Non-regulated tanks were identified as being either less 

than 110 gallons in capacity, storing heating oil, or storing less than 1,100 gallons 

of motor fuel and being a farm or residential tank. Additional non-regulated tanks 

were identified and removed on a state-specific basis. For example, tanks with 

contents listed as “other non-regulated” were removed from Florida’s database. 

 E

2 Inc. compared the number of active, regulated tanks in the thirteen databases 

and the corresponding numbers from EPA’s End-of-Year Activity Reports as 

shown in Exhibit B-2 below.2 This was performed to ensure that the subsequent 

industry sector analysis was based on the set of tanks affected by the delivery

prohibition regulations. E2Inc. used the FY 2004 End of the Year report for 

databases received from Abt, which had been gathered from state agencies in 

2005, and the FY 2006 report for the databases obtained online.

 

2 The FY 2004 End-of-Year Activity Report is available at http://www.epa.gov/OUST/cat/ca_043_4.pdf; 

and the FY 2006 report is available at http://www.epa.gov/OUST/cat/ca_06_34.pdf 
B-5

Exhibit B-2. Comparison of EPA’s End-of-Year Activity Reports Data with State

Databases

EPA Data from End-of-Year Reports State Databases

States

Number of 

Active Tanks 

in 2004

Number of 

Active Tanks 

in 2005

Number of 

Active Tanks 

in 2006

Number of 

Active Tanks

Source of State 

Data

Year for State 

Data

Alabama 18,153 18,021 19,063 18,144 Abt 2004

Alaska 1,081 1,065 1,142 1,145 State Web site 2006

Delaware 1,566 1,598 1,606 1,585 State Web site 2006

Florida 32,236 31,109 30,051 29,028 Abt 2004

Georgia 38,437 30,320 30,081 29,057 State Web site 2006

Maryland 9,423 9,439 9,317 9,418 Abt 2004

Massachusetts 11,441 11,368 11,211 11,758 State Web site 2006

Minnesota 14,129 14,328 14,414 14,236 Abt 2004

Missouri 10,281 10,305 10,274 9,997 State Web site 2006

Nevada 3,677 3,688 3,721 4,080 State Web site 2006

Tennessee 16,279 16,147 17,575 17,637 State Web site 2006

Virginia 26,994 25,464 22,101 21,824 State Web site 2006

Wisconsin 13,744 13,721 13,757 12,651 State Web site 2006

 After E2Inc. verified the numbers of active regulated tanks, E2Inc. filtered the 

databases further to include only tanks containing petroleum products. E2Inc. 

compiled a separate dataset of all the individual facilities associated with these 

tanks for each state. Both of these datasets are used for the subsequent industry

sector analysis. 

IV. Selection of Industry Sectors for Analysis

 E

2 Inc. examined the particular industry sector breakdowns, which varied from 

state to state, to select seven industry sectors that were most frequently 

represented. These seven industry sectors are: 

o Retail Motor Fuels Sales; 

o Agricultural;

o Institutional (hospitals only); 

o Commercial (includes Wholesale Trade, Retail Trade, Accommodation 

and Food Services, excluding gas stations);

o Industrial/Manufacturing; 

o Transportation (excluding railroads); and 

o Utilities and Phone. 

 E

2 Inc. reviewed the types of companies represented in the state databases for 

each industry sector. E2 Inc. then identified appropriate NAICS codes to represent 

these sub-sectors. For example, the commercial sector included sub-sectors such 

as automobile dealerships, hotels, and restaurants.
B-6

 It is important to note that not all sectors are represented in all state databases. 

Exhibit B-3 shows the states that were used to analyze each industry sector.

Exhibit B-3. States Used to Calculate Industry Sectors

Industry Sector

NAICS 

Codes NAICS Definitions

Number of 

States Used to 

Calculate 

Sector States Used to Calculate Sector

Retail Motor Fuels Sales 447 Gasoline Stations 9 Alaska, Delaware, Florida, Maryland, 

Massachusetts, Minnesota, Tennessee, 

Virginia, Wisconsin

Agriculture 111 Crops Production 9 Delaware, Florida, Georgia, Maryland, 

Massachusetts, Minnesota, Tennessee, 

112 Animal Production Virginia, Wisconsin

Industrial/Manufacturing 31-33 Manufacturing 10 Alabama, Alaska, Delaware, Georgia, 

Maryland, Massachusetts, Minnesota, 

Tennessee, Virginia, Wisconsin

Transportation 481 Air Transportation 8 Alaska, Delaware, Georgia, Maryland, 

Massachusetts, Minnesota, Tennessee, 

Virginia

483 Water Transportation

484 Truck Transportation

485 Transit and Ground Passenger 

Transportation

486 Pipeline Transportation

48811 Airport Operations

Utilities and Phone 2211 Electric Power Generation, 

Transmission, and 

Distribution

9 Alaska, Delaware, Georgia, Maryland, 

Massachusetts, Minnesota, Tennessee, 

Virginia, Wisconsin

5171 Wired Telecommunications 

Carrier

Commercial (excluding 

447)

42 Wholesale Trade 10 Alaska, Delaware, Georgia, Maryland, 

Massachusetts, Minnesota, Nevada, 

Tennessee, Virginia, Wisconsin

44-45 Retail Trade

72 Accommodation and Food 

Services

Institutional (Hospitals) 622 Hospitals 3 Georgia, Massachusetts, Missouri

V. Industry Sector Analysis (Calculations)

 E

2 Inc. calculated the number of individual USTs and facilities associated with 

each industry sector for the set of states relevant to that sector. 

 E

2 Inc. used the total numbers of USTs and facilities to calculate and UST to 

facility ratio for each of the seven industry sectors. 
B-7

 As show in Exhibit B-4 below, the UST to facility ratios were largely consistent 

with those calculated using the results of the 1988 rulemaking for the seven 

sectors. The overall UST to facility ratio calculated from the state data was 2.865, 

and the ratio calculated from the 1988 rulemaking was 2.728.

Exhibit B-4. Comparison of Tank to Facility Ratios from 1988 Rulemaking and 

State Databases

Industry Sector

Tank/Facility Ratio 

from 1988 Rulemaking

Tank/Facility Ratio 

Calculated from State 

Databases

Retail Motor Fuels 3.503 3.131

Agriculture 1.593 1.812

Industrial/Manufacturing 2.500 1.648

Transportation 2.320 1.769

Communication and Utilities 2.053 1.466

Commercial 2.088 2.300

Institutional (Hospitals) N/A 1.636

Total 2.728 2.865

 E

2 Inc. consulted the 2002 Economic Census3

to obtain total numbers of 

establishments for each industry sector. E2 Inc. used these data to extrapolate 

national numbers of facilities and tanks for each sector with the following two 

formulas:

o National number of regulated facilities = 2002 Census national number of 

establishments x (total number of regulated facilities calculated from 

the appropriate state databases/total of 2002 Census number of 

establishments for the same states)

o National number of regulated tanks = National number of regulated 

facilities calculated above x Tank to facility ratio that was calculated 

above for this sector

 As shown in Exhibit B-5 below, E2 Inc. found the extrapolated national number of 

facilities associated with retail motor fuels sales (141,776 facilities) to be in 

between the 2002 Census national number (121,446 facilities) and the national 

number estimated by the American Petroleum Institute (API) (169,000 facilities) 

and the National Association of Convenience Stores (NACS) (168,000 facilities). 

 E

2 Inc. found the total number of facilities associated with retail motor fuels sales 

for the appropriate states (27,302 facilities) to be higher than the 2002 Census 

 

3

2002 Economic Census is available at http://www.census.gov/econ/census02/data/us/US000.HTM. The 

following NAICS codes were used: Retail Motor Fuel Sales - 447; Agriculture - 111,112; Commercial - 42, 

44-45, 72 (excluding 447); Institutional (Hospitals) - 622; Manufacturing/Industrial – 31-33; Transportation 

- 481,483-486, 48811; Utilities and Phone - 2211, 5171.
B-8

total for those same states (23,387), though potentially consistent with a 2003 

NACS survey that reported 19,465 gas stations at convenience stores alone. 

Exhibit B-5. Comparison of State Retail Fuels Sales Facilities Totals

State

Number of Retail 

Motor Fuel Sales 

Facilities Calculated 

from State Databases

2002 Census 

Numbers of Gas 

Station 

Establishments 

(NAICS 447)

Numbers of 

Convenience Stores with 

Gas (from NACS 2003 

Fact Sheet)

Tennessee 4,023 3,339 3,335

Maryland 1,703 1,735 901

Wisconsin 3,232 2,667 2,181

Delaware 314 312 233

Alaska 240 229 163

Florida 8,076 6,544 6,470

Virginia 4,315 3,623 2,945

Minnesota 2,810 2,605 2,162

Massachusetts 2,589 2,333 1,075

Total 27,302 23,387 19,465

National Total 141,776 121,446 101,823

Limitations

 A key limitation of our approach is the fact that we used a small subset of data to 

develop estimates for the entire country, and relied on the assumption that these states 

are in fact representative of the entire country.

 Prior to this analysis E2 Inc. did not cleanse or verify the state databases through any 

sort of quality assurance process investigation. This resulted in erroneous retail 

motor fuels sales facility totals for certain individual states (as compared to 

corresponding 2002 Census numbers). It is possible that in some states multiple 

facility identification numbers (used in this analysis to identify unique facilities) have 

been assigned to individual sites. Facility identification numbers should be further 

refined and clarified as to what exactly they represent.

 Other general drawbacks of the databases include missing records, and the fact that 

industry sector categories used by the states agencies are limited and inconsistent 

across all states. 

 E

2 Inc. could not check the other six industry sectors against the 2002 Census on a 

state-by-state basis. (The Retail Motor Fuels Sales sector can be checked because of 

the fact that virtually all establishments in this sector have one or more underground 

storage tanks. The state database numbers can therefore be compared to the Census 

numbers on a one-to-one basis.)