MEMORANDUM

Subject: Estimating E0 use in recreational marine engines

From: David Korotney , U.S. EPA, Office of Transportation and Air Quality

To: EPA Air Docket EPA

- HQ

- OAR

- 201 5

- 0111

R ecreational marine engines are used in a water environment where there is a much

greater potential for water contamination of the fuel. For gasoline that contains ethanol, the

water can separate from the gasoline and cause engine damage. As a result, some recreational

marine engine owners seek out gasoline witho ut ethanol ( E0 )

.

We investigated the use of E0 in recreational marine engines using information provided

by stakeholders in response to the June 10, 2015 Notice of Proposed Rulemaking (NPRM) , and

other information. This memorandum is a followup to a p revious memorandum entitled, "

Estimating E0 Volume Sold in the U.S. at marinas " by Lester Wyborny that was released along

with the June 10, 2015 NPRM

.

T otal gasoline consumption by recreational marine engines is currently about 1.55 billion

gallons acco rding to a recent estimate from the EPA's NONROAD model. 1 However, there is

no data available to directly demonstrate the fraction of this volume which is E0 versus that

which is E10. Anecdotal information provided by the National Marine Manufacturers

Association (NMMA) and others suggesting that owners of recreational marine engines

preferentially seek out E0 is insufficient to permit quantitative estimation of the actual volume of

E0 consumed. However, these parties did confirm that the vast majority of recreational marine

engines are refueled at retail service stations rather than at marinas. While the specific fraction

that is refueled at retail rather than marinas was not provided, NMMA did indicate that 95% of

boats are under 2 6 feet in length an d thus are frequently trailered and refue l ed at the same time as

the towing vehicle. For the purposes of this memorandum, therefore, we have assumed that 95%

of recreational marine engines are refu e led at retail stations , while 5% are refueled at marinas.

Data provided by NMMA on the number of registered boats in each state does suggest a

weak correlation with the number of retail stations offering E0 in each state as provided by Pure

gas.org.

1 "NONROAD estimate of fuel use in recreational marine," EPA docket EPA

- HQ

- OAR

- 2015

- 0111Figure 1

While the scatter in the data is significant, a statistical analysis verified that there is indeed a

trend (i.e. the pattern exhibited in the figure abo v e is highly unlikely to be purely random). This

suggests that some retail stations may offer E0 because they are frequented by customers with

trailere d boats. However, the fact that the correlation is weak is evidence that this is not

consistent among retail stations that offer E0 , and that other factors may be at play

. A state may

have a proportionally larger number of boaters than other states , but this does not necessarily

mean that it will have a correspondingly larger number of retail stations offering E0. Moreover,

any correlation between the number of boaters in a state and the number of retail stations

offering E0 in that state is indicative o nly of the opportunity for the boat owner to refuel on E0,

not the actual refueling choice boat owner s make. Thus , th e weak correlation shown in Figure 1

provides no straightforward mechanism to quantitatively determine the volume of E0 consumed

by recrea tional marine engines.

Given the paucity of data, w e considered several different approaches to estimating the

volume of E0 consumed by recreational marine engines. Each of these is summarized below.

We have insufficient information at this time to determine which of these three methods provides

a more accurate estimate of E0 used in recreational marine engines.



### Method 1

Marinas

 Assume that all m arinas offer both E0 and E10, and boaters are twice as likely to buy E0 as

E10

1.55 bill gal × 5% = 78 mill gal E0 + E10

1/3 of boat owners buy E10

2/3 of boat owners buy E0

78 × (2/3) = 52 mill gal E0Retail stations

 Assume that t he 10,300 locations offering E0 ( according to Pure

- gas.org ) includes 6300

marinas (according to M arinas.com) , so the number of retail stations offering E0 is 4000

10,300

- 6300 = 4000

 2. 6 % of all non

- marina retail service stations nationwide offer E0

4000 stations offering E0 / 152,000 total retail stations = 2. 6 %

 Assume that all r ecreational marine engines refueling at retail stations that offer E0 will always

refuel on E0

1.55 bill gal × 95% × 2. 6 % = 3 8 mill gal

 Total consumption of E0 by recreational marine engines = 90 mill gal

52 + 3 8 = 90



### Method 2

Marinas

 Assu m e th at a ll marinas offer E0 exclusively

1 .55 bill gal × 5% = 78 mill gal E0

Retail stations

 Assume that t he 10,300 locations offering E0 (according to Pure

- gas.org) do not include any

marinas, so the number of retail stations offering E0 is 10,300

 6. 8 % of all non

- marina retail service stations nationwide offer E0

10,300 stations offering E0 / 152,000 total retail station s = 6. 8 %

 Assume that all r ecreational marine engines refueling at retail stations offering E0 will always

refuel on E0

1.55 bill gal × 95% × 6. 8 % = 100 mill gal

 Total consumption of E0 by recreational marine engines = 17 8 mill gal

78 + 100 = 17 8



### Method 3

Marinas

 Assume that a ll marinas offer E0 exclusively

1.55 bill gal × 5% = 78 mill gal

Retail stations

 Assume that t he 10,300 locations offering E0 (according to Pure

- gas.org) do not include any

marinas, so the number of retail stations offering E0 is 10,300 While 6. 8 % of all non

- marina retail service stations nationwide offer E0, Figure 1 above

suggests that the geographic concentration of stations offering E0 may be slightly higher in areas

frequented by boaters than in areas not frequented by boaters

 Assume that 10% of non

- marina retail service stations in areas frequented by boaters offer E0

(as opposed to the 6.8% assumed in Method 2)

 Assume that all r ecreational marine engines refueling at non

- marina retail stations that offer E0

will always refuel on E0

1.55 bill gal × 95% × 10 % = 147 mill gal

 Total consumption of E0 by recreational marine engines = 2 25 mill gal

78 + 200 = 2 25Estimated number of Marinas by State from Marinas.com *

State # of

Marinas State # of

Marinas

Alabama 35 Montana UC

Alaska UC Nebraska UC

Arizona 1 Nevada UC

Arkansas 2 New Hampshire 15

California 468 New Jersey 438

Colorado 1 New Mexico UC

Connecticut 255 New York 900

Delaware 21 North Carolina 128

Dist. of Columbia 6 North Dakota UC

Florida 970 Ohio 243

Georgia 33 Oklahoma 1

Hawaii 19 Oregon 57

Idaho 1 Pennsylvania 33

Illinois 74 Rhode Island 153

Indiana 12 South Carolina 65

Iowa UC South Dakota UC

Kansas UC Tennessee 27

Kentucky 34 Texas 67

Louisiana 19 Utah UC

Maine 277 Vermont 34

Maryland 428 Virginia 185

Massachusetts 394 Washington 303

Michigan 414 West Virginia UC

Minnesota 11 Wisconsin 151

Mississippi 18 Wyoming UC

Missouri 8

*The term UC means “under construction” meaning that data collection is incomplete

Total number of marinas = 6,300