0

dKC de la Torre Klausmeier Consulting

 _____________________________________

1401 Foxtail Cove

Austin, TX 78704

(512) 447-3077

E-mail: delaklaus@aol.com

DRAFT REPORT

ANALYSIS OF FUTURE OPTIONS FOR CONNECTICUT’S GASOLINE 

DISPENSING FACILITY VAPOR CONTROL PROGRAM

December 8, 2011

Prepared for:

Connecticut Department of Energy and Environmental Protection

79 Elm St.

Hartford, CT 06106-5127

Prepared by:

Rob Klausmeier

de la Torre Klausmeier Consulting, Inc.
1

1. INTRODUCTION

Under purchase order # DEPM1-0000031039, de la Torre Klausmeier Consulting, Inc. 

(dKC) is assisting the Connecticut Department of Environmental Protection (DEEP) in 

evaluating the Gasoline Dispensing Facility (GDF) Vapor Control Program. The primary 

objectives of this project are listed below:

Determine when onboard refueling vapor recovery (ORVR) systems in 

Connecticut’s vehicle fleet have met a particular threshold described as 

widespread use (WSU). ORVR systems were phased into the motor 

vehicle fleet beginning with the 1998 model year. After Connecticut 

reaches WSU, EPA will allow it to terminate the Stage II portion of the 

Vapor Recovery program, provided it does not need the emission 

reductions from Stage II. 

Estimate the cost and benefits of terminating or enhancing the Stage II 

program.

Estimate the cost and benefits of enhancing the Stage I program.

Determine the best way to decommission Stage II systems.

This report presents the results of this project.

Summary of Results: Depending on the definition of WSU and assumed effectiveness 

of Stage II systems, Connecticut has passed or will soon pass the WSU threshold. 

Continuing the current program beyond WSU will achieve minimal emission reductions, 

and will in fact increase emissions after 2014. Adopting the Stage II provisions of the 

California Enhanced Vapor Recovery (EVR) program does not appear to be cost 

effective. However, emissions from GDFs can be significantly reduced for a reasonable 

cost by enhancing DEEP’s Stage I program. DEEP should consider regulations to 

terminate the Stage II program and require GDF’s to be equipped with vapor leak

monitoring systems and tank vent control systems. These regulations will increase the 

emission reductions from the GDF Vapor Control Program. They also will help assure 

the State that any leaks that result from removing or capping Stage II systems will be 

promptly identified and repaired. These regulations should exempt GDFs that dispense 

relatively low volumes of gasoline from pressure monitoring and tank vent control 

systems.

2. SUMMARY OF GDF SURVEY

To collect data on the characteristics of GDFs in Connecticut, dKC contracted Eastern 

Research Group (ERG) to conduct a comprehensive survey. ERG designed the survey 

sample from GDF data obtained from the Connecticut DEEP. ERG filtered out facilities 

that were closed or inactive, or only handled non-gasoline materials. 2,033 surveys 

were mailed out on February 17. Of these, 23 were undeliverable. 

Survey responses were received for a total of 908 GDFs located in Connecticut. Based 

on the number of delivered surveys (i.e., 2,010 surveys), the survey response rate was 

43.4%. For purposes of comparison, a survey was conducted for a similar GDF sample 
2

size in Texas in 2008 and the return rate was only 27.4%.1 The high survey response 

rate increases confidence that the findings of this study are applicable to GDFs across 

the entire state of Connecticut. 

ERG designed a Microsoft Access database to house the received survey data. All 

survey returns that were sent in via mail, fax, or PDF format were input into the 

database manually. Significant findings are shown below:

The 96 facilities that do not have Stage II vapor control are limited to the 

smallest throughput classification.

The facilities that did not identify whether or not they have Stage II vapor control 

are primarily limited to the smallest throughput classification (i.e., 73 out of 80 

non-respondents to this question).

Of the facilities that did identify that Stage II vapor control was present, 80 

percent (i.e., 540 out of 675 facilities) had vacuum-assisted systems, while the 

remaining 20 percent (i.e., 135 facilities) had balance systems.

The facilities that had balance Stage II vapor control systems were concentrated 

primarily in the smaller throughput classifications. 

The overall yearly gasoline throughput derived from the survey results was estimated to 

be 745,413,813 gallons, which is about half annual fuel consumption. The 

disaggregation of this based upon Stage II control technology is as follows:

Vacuum-assisted – 696,954,309 gallons (93.5% of total)

Balance – 38,502,475 gallons (5.2% of total)

Do not know – 6,966,505 gallons (0.9% of total)

None – 2,990,523 gallons (0.4% of total)

Another way of interpreting the results is that vacuum assist systems account for 95% of 

the gasoline dispensed at GDFs with Stage II systems.

The survey helps us describe the distribution of GDFs in terms of gasoline throughput. 

This distribution is used later in this report to evaluate the costs and effectiveness of 

enhancements to the State’s Stage I and Stage II programs. We calculated two 

distributions of the GDFs. Results shown in Table 1 are disaggregated into five monthly 

facility throughput classifications that have previously been used in Stage II analyses 

conducted by the California Air Resources Board (ARB).2 Results shown in Table 2 are 

disaggregated into 15 yearly facility throughput classifications that have previously been 

used in Stage I analyses conducted by the New York Department of Environmental 

Conservation (DEC)3. As shown on Tables 1 and 2, 336 out of 908 GDFs (37%) fell into 

the smallest gasoline throughput group, less than 300,000 gallons per year (less than 

25,000 gallons per month).

 

1

Stage I and Stage II Gasoline Dispensing Emissions Inventory. Final. Prepared for the Texas Commission on 

Environmental Quality by Eastern Research Group, Inc. (ERG), Sacramento, CA. August 31, 2008.

2 Enhanced Vapor Recovery Technology Review. Staff Report. Prepared by the California Air Resources Board, 

Monitoring and Laboratory Division. October 2002.

3

Stage I and Stage II Vapor Recovery Analyses. PowerPoint presentation. Prepared by the New York Department 

of Environmental Conservation.
3

Table 1 – Summary of Survey Results – California ARB Classifications

Group

Average 

Monthly 

Throughput by 

Facility (gallons)

Number of 

Facilities

Stage II Present? Type of Stage II System Number of USTs

Yes No

Do Not 

Know Vacuum Assisted Balanced 1 2 3 4 5 Blank

1 0-25,000 336 167 96 73 70 97 221 48 54 4 1 8

2 25,001-50,000 98 95 0 3 78 17 3 45 45 4 0 1

3 50,001-100,000 213 209 0 4 193 16 3 92 110 7 0 1

4 100,001-200,000 127 127 0 0 122 5 1 51 72 3 0 0

5 > 200,000 77 77 0 0 77 0 0 43 31 3 0 0

Table 2 – Summary of Survey Results – New York DEC Classifications

Group 

(gallons)

Yearly Throughput 

by Facility (gallons)

Number 

of 

Facilities

Stage II Present? Type of Stage II System Number of USTs

Yes No

Do Not 

Know

Vacuum 

Assisted Balanced 1 2 3 4 5 Blank

A (120,000) 0-300,000 336 167 96 73 70 97 221 48 54 4 1 8

B (400,000) 300,001-500,000 71 69 0 2 55 14 3 33 30 4 0 1

C (600,000) 500,001-700,000 71 68 0 3 65 3 1 31 36 2 0 1

D (800,000) 700,001-900,000 75 75 0 0 65 10 0 33 40 2 0 0

E (1,000,000) 900,001-1,100,000 60 60 0 0 56 4 2 27 29 2 0 0

F (1,200,000) 1,100,00-1,300,000 51 49 0 2 46 3 1 21 27 2 0 0

G (1,400,000) 1,300,00 -1,500,000 31 31 0 0 29 2 0 14 16 1 0 0

H (1,600,000) 1,500,001-1,700,000 22 22 0 0 21 1 0 10 12 0 0 0

I (1,800,000) 1,700,001-1,900,000 25 25 0 0 24 1 0 9 16 0 0 0

J (2,000,000) 1,900,001-2,100,000 15 15 0 0 15 0 0 5 10 0 0 0

K (2,400,000) 2,100,001-2,700,000 36 36 0 0 36 0 0 13 22 1 0 0

L (3,000,000) 2,700,001-3,300,000 19 19 0 0 19 0 0 12 6 1 0 0

M (3,600,000) 3,300,001-3,900,000 15 15 0 0 15 0 0 11 4 0 0 0

N (4,000,000) 3,900,001-4,100,000 7 7 0 0 7 0 0 3 4 0 0 0

O (5,000,000) >4,100,000 17 17 0 0 17 0 0 9 6 2 0 0
4

3. WIDESPREAD USE (WSU) ANALYSIS

Widespread use (WSU) occurs when on-board refueling vapor recovery (ORVR) 

systems provide the same benefits as Stage II systems. dKC estimated when GDFs in 

Connecticut pass the WSU threshold. Appendix A presents the report dKC provided 

DEEP on the WSU. Results of the WSU analysis are summarized below:

a. Condition of Vapor Recovery Systems – The WSU date is sensitive to 

the assumed effectiveness of Stage II. Data from Connecticut and other 

states indicate that Stage II systems quickly develop leaks and other 

malfunctions that cause them to fail system performance tests. It’s unlikely 

that Stage II systems have the 86% control efficiency that is assumed in 

Connecticut’s State Implementation Plan (SIP). The actual Stage II control 

efficiency is likely to be 60% or less. dKC used two estimates of Stage II 

effectiveness: 86% and 60%. Corrected for rule penetration and rule 

effectiveness, this translates into an overall Stage II effectiveness of 82% 

and 57%.

o Connecticut Test Results – dKC reviewed two sources of

information on the condition of GDFs in Connecticut: results of 

official certification tests and results of additional GDF tests

performed by dKC:

 Table 3 summarizes the initial results of GDF inspections 

that were witnessed by DEEP since December 20, 2010. 

Overall, 70% of the GDFs failed inspection. The most 

common failure reasons were the tank decay test (45%), 

followed by air/liquid test (A/L) (14%). 

 dKC commissioned additional GDF tests to help determine 

when key components of the vapor control system start to 

deteriorate. These tests were performed approximately 2 

months and 4 months after the station received its 

certification test. Two stations participated: one is a 

government station with a balance system; the other is a 

private station with a vacuum assist system. Table 4

summarizes results of these tests. None of the tests had an 

overall result of pass.

Table 3 – Results of Triennial GDF Inspections in Connecticut

Parameter

# and % of Failures

System 

Pass/Fail Decay

Dry 

Blockage

Wet 

Blockage

P/V 

Cap A/L 

6 

Click

# 111 72 5 6 10 23 13

% of Tests 70% 45% 3% 4% 6% 14% 8%
5

Table 4 – Results of Bi-monthly GDF Inspections in Connecticut

Station/Stage II Type Test date Overall Result Failed items

J and A Gas

Vacuum Assist

6/2/11 Fail A/L Test

8/23/11 Fail A/L Test

DOT Newington

Balance

4/25/11 Fail P/V valve

7/14/11 Fail Decay, P/V valve, torn 

hose

11/9/11 Fail Decay, P/V valve

o Massachusetts Test Results – Massachusetts DEP requires 

GDFs to report the initial results of their annual Stage II Certification 

tests. Table 5 summarizes the percent of stations that fail their 

initial Stage II test in Massachusetts. As shown, from 2001 through 

2010, 66% to 82% of the GDFs fail the initial annual Certification 

tests. The primary problem causing test failures were seal caps and 

fittings that needed tightening.

o From May 2002 through October 2003, Massachusetts required 

new GDFs with vacuum assist Stage II systems or significantly 

modified GDFs with vacuum assist systems to receive a 

Certification test 120 days after they were initially certified. Results 

of these tests are shown on Table 6. Results indicate that over half 

(56%) of the recently certified GDFs failed Certification tests 120 

days later. The most common failure was for the pressure decay 

test.

Table 5 – Results of Annual GDF Certification Tests in Massachusetts

Year % Fail

2001 82%

2002 78%

2003 75%

2004 67%

2005 76%

2006 78%

2007 78%

2008 73%

2009 71%

2010 66%
6

Table 6 – Results of 120 Day GDF Certification Tests in Massachusetts

Failure Reason # % Fail

Air/Liquid Ratio 17 17%

Pressure Decay 45 46%

P/V Cap 2 2%

Any Failure 55 56%

o New Hampshire Test Results -- According to vapor release 

research conducted by New Hampshire, Stage II repairs last an 

average of 58 days. Overall findings of New Hampshire’s research 

found: 

 Inspections and testing failed to fix key leaks.

 Most leaks required the station to upgrade the hardware (i.e. 

hoses, nozzles, breakaways).

 Gasoline deliveries triggered leaks

b. EPA’s WSU Determination – On July 8, 2011, EPA published a 

Proposed Rule on WSU determination for Onboard Refueling Vapor 

Recovery (ORVR) systems. EPA will consider that widespread use (WSU) 

has occurred when emissions with Stage II systems alone equal 

emissions with ORVR alone. In the absence of state specific analysis, 

EPA has set a WSU date of July 1, 2013. 

dKC used EPA’s current emission factor model, MOVES, to determine 

WSU dates for Connecticut. Following are estimates based on MOVES of 

when emissions with Stage II systems alone equal emissions with ORVR 

alone:

82% Stage II efficiency: July 2012

57% Stage II efficiency: 2007-2008

Figure 1 shows g/gal estimates for ORVR alone by model year 

vs. Stage II alone. WSU occurs when g/gal for ORVR alone

drop below the Stage II lines.
7

Figure 1

c. Implications of EPA’s proposed rule – EPA’s proposed WSU rule has 

implications for this analysis and future strategies for controlling emissions 

at GDFs in Connecticut:

o Stage II Effectiveness: EPA lists the effectiveness of Stage II as 

follows:

 Semi-annual inspections: 92%

 Annual inspections: 86%

 Minimal or less frequent inspections: 62%

EPA assumes that 90% of gasoline is dispensed at GDFs with 

Stage II systems. ERG’s GDF survey determined that in 

Connecticut, 99% of gasoline is dispensed at GDFs with Stage II 

systems. Based on GDF tests in Connecticut, Massachusetts, and 

New Hampshire, Stage II effectiveness is likely to be lower than 

EPA’s estimates.

o ORVR/Stage II Incompatibility: The Proposed Rule acknowledges 

the incompatibility between ORVR and vacuum-assist Stage II 

systems, saying that it reduces the effectiveness of Stage II by 1% 

to 10%. Incompatibility was not considered in the widespread use 

determination, but EPA did mention that states should require 

Stage II systems to be upgraded to be ORVR compatible, if they 

opt to continue the requirement. Emissions resulting from the 

incompatibility between ORVR and vacuum-assist Stage II systems 

are termed incompatibility excess emissions (IEE). Published IEE 

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

1.800

2.000

2005 2010 2015 2020

Refueling Emissions: HC -- g/gal

Refueling Emissions: ORVR Alone vs. Stage II Alone 

(MOVES)

ORVR

Stage II -- 82%

Stage II -- 57%
8

rates vary from a low of 0.42 lb/1000 gallons to a high of 2.5 

lb/1000 gallons. dKC used 0.86 (California’s estimate) in its IEE 

calculations.

o Backsliding: The Proposed Rule says that ozone non-attainment 

areas must make up for any emission reductions that are lost due 

to terminating Stage II programs. The Rule does not state if IEE

can be factored into calculations of lost emissions reductions. If IEE 

is considered, continuing the current Stage II program without 

ORVR compatibility provides minimal benefits, and in fact, may 

increase emission in the future. Accounting for IEE, Connecticut 

must make up 0.48 tons/day VOC in 2013. By 2015, emissions 

increase if Stage II is continued due to IEE. Without considering 

IEE, Connecticut must make up 1.8 tons/day in 2013 and 1.3

tons/day in 2015. IEE is discussed in greater detail below.

o Stage I Improvements: EPA has stated that states can make up 

for the shortfall by improving Stage I systems, even if these 

improvements only bring the system up to assumed SIP 

effectiveness.

4. POSSIBLE STAGE II ENHANCEMENTS

If DEEP decides to continue the Stage II program it should consider the following 

enhancements:

a. End ORVR Incompatibility – Currently, vacuum assist Stage II systems 

in Connecticut are not compatible with on-board refueling vapor recovery 

(ORVR). When a vehicle with ORVR is refueled at a GDF with a vacuum 

assist system, ambient air from the vicinity of the GDF nozzle will be 

drawn back into the GDF storage tank. This air dilutes the concentration of 

gasoline vapors in the headspace of the storage tank, causing some of the 

liquid gasoline in the storage tank to evaporate, which increases the 

storage tank pressure. If the tank pressure increases above the positive 

setting of the P/V valve, the storage tank will vent to the atmosphere. As 

mentioned earlier, the increased emissions that occur due to the dilution of 

the storage tank with air from ORVR vehicles is termed incompatibility 

excess emissions (IEE). IEE is limited to vacuum assist systems. Balance 

systems are generally compatible with ORVR systems. Almost all (94%) of 

the gasoline dispensed in Connecticut is dispensed at GDFs with vacuum 

assist systems.

IEE can be mitigated or eliminated by the following measures:

a. Install nozzles that sense ORVR vehicles,

b. Add devices called processors to capture or incinerate 

vapors at the vent, or

c. Convert to balance type systems.
9

b. Other Possible Stage II Enhancements – In addition to addressing IEE 

with vacuum assist systems, other enhancements could be made to Stage 

II systems. These enhancements have been included in California’s 

Enhanced Vapor Recovery (CA EVR) program, and are listed below:

California EVR Module 2 – General Stage II improvements

and tightened performance standards.

California EVR Module 6 – In-Station Diagnostics (ISD): ISD 

require GDFs to install systems that monitor tank pressure 

and air/liquid (A/L) and set alarms when there are problems 

that could lead to excessive emissions. ISD is similar in 

concept to onboard diagnostic (OBD) systems that have 

been on vehicles since 1996. A lot of concerns have been 

raised by industry over the reliability of ISD with regard to 

monitoring A/L. Monitoring GDFs for the presence of vapor 

leaks appears to be reliable. Data from Veeder-Root, which 

installs ISD systems in California, indicate that A/L alarms 

occur much more frequently than alarms for GDF vapor 

leaks.

c. Gasoline Dispensing Improvements – The CA EVR program includes 

two modules that are theoretically applicable to GDFs with and without 

Stage II systems:

California EVR Module 4 – Liquid Retention and Spitting 

California EVR Module 5 – Dripless Nozzles

Based on discussions with OPW, it’s uncertain if dripless nozzles are 

feasible.

Appendix B summarizes the CA EVR program.

5. POSSIBLE STAGE I ENHANCEMENTS

DEEP’s Stage I control program could be improved by implementing measures that go 

beyond current Stage I requirements:

a. Add vapor leak monitoring system – Continuous monitoring of GDF 

tank pressure and other parameters that indicate the presence of vapor 

leaks has the potential for significant emissions reductions. Based on GDF 

inspections, actual Stage I control efficiencies are much lower than the 

96% control efficiency assumed in the SIP. In addition, the control 

efficiencies for breathing losses assumed for Pressure Vacuum (PV) 

valves are likely to be lower than the 90% control efficiency assumed in 

the SIP. This measure could reduce State oversight costs if it were 

coupled with self-certification of compliance. In this case, the requirement 

for State supervised inspections could be dropped, assuming EPA will 

revise its inspection requirements for Stage I systems to allow continuous 

monitoring as an alternative to periodic inspections. Requiring these 

systems also will help assure the State that any leaks that result from 
10

removing or capping Stage II systems will be promptly identified and 

repaired, should the State decide to terminate the Stage II program.

b. Add pressure management system (emissions processors) to 

eliminate vent emissions – Managing the pressure with a vapor processor 

reduces breathing losses and maintains the tank pressure close to 

ambient to avoid fugitive emissions. Losses are proportional to GDF 

gasoline sales volume. New York State is proposing to require stations 

that dispense more than 1,100,000 gallons per year to be equipped with 

pressure management systems.

In addition to the above options, the CA EVR program outlines additional Stage I 

improvements in Module 1. GDFs in Connecticut have most of these improvements. 

Following are additional enhancements included in CA EVR that could be made to 

Connecticut’s Stage I program:

c. Spill Containment Boxes – California requires spill containment boxes to 

meet leak rate limits and prohibit standing fuel. Vendors have developed 

double-wall spill containers that meet CA EVR requirements.

d. Drop tube with Overfill Protection Specification – California requires

drop tubes to be equipped with devices that shut off liquid flow when the 

underground storage tank is being filled. These drop tubes also must meet 

leak rate specifications.

6. EMISSION REDUCTIONS FOR STAGE I AND STAGE II SYSTEM 

IMPROVEMENTS

a. Gasoline Consumption

i. Emissions and emission reductions are proportional to gasoline 

consumption

ii. Statewide consumption is based on Department of Revenue 

reports.

Table 7 – Statewide Gasoline Consumption (2010)

MONTH GALLONS CONSUMED

JAN 119,417,253

FEB 109,313,343

MAR 124,366,769

APR 124,549,371

MAY 132,812,176

JUN 129,606,224

JUL 134,879,449

AUG 130,328,001

SEP 125,097,789

OCT 130,473,564

NOV 124,071,272

DEC 129,706,355

TOTAL 1,514,621,566
11

b. Current Stage II program

i. dKC estimated emissions reductions for:

1. Continuing the current Stage II program

2. Decommissioning the current Stage II program, with ORVR 

solely providing vapor recovery.

ii. Note on Figure 2 that continuing Stage II (without ORVR 

compatible nozzles) increases emissions after 2015 due to IEE.

Figure 2

Table 8 – VOC Emission Reductions (Tons/Day) for Continuing Current Stage II 

Controls (Negative Values mean that keeping Current Systems increase 

emissions due to IEE4)

Year ORVR only Additional Reductions with Stage II

82% Control Efficiency 57% Control Efficiency

2012 11.194 0.833 0.579

2013 11.558 0.485 0.337

2014 11.869 0.189 0.131

2015 12.137 -0.063 -0.044

2016 12.313 -0.233 -0.162

2017 12.500 -0.405 -0.281

c. Making all Stage II systems in CT ORVR compatible. Two Stage II 

control scenarios were evaluated:

 

4

IEE: Incompatibility Excess Emissions (0.86 lb/1000 gallons)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

1.800

2.000

2005 2010 2015 2020

Refueling Emissions: HC -- g/gal

Refueling Emissions: ORVR Alone vs. Stage II + ORVR 

(MOVES, 0.86 lb/1000 gal IEE)

ORVR Alone

ORVR+Stage II -- 82%

ORVR+Stage II -- 57%
12

i. Upgrading nozzles in the current program to be ORVR 

compatible. With this option, the current program will be retained 

with the requirement that stations must upgrade to ORVR 

compatible nozzles. 

1. This option eliminates incompatibility excess emissions (IEE)

2. Control efficiencies are based on current program data

3. Two efficiencies were modeled: 82% and 57%.

Emission estimates were calculated by multiplying g/gal estimates 

without Stage II (derived from MOVES) times annual gasoline 

consumption times estimated control efficiency. 

4. By 2015, ORVR compatible Stage II systems have minimal 

benefits, as shown on Figure 3.

Figure 3

ii. Add California EVR elements that pertain to Stage II, including 

ORVR compatibility and in-station diagnostics (ISD).

1. This option eliminates IEE

2. Control efficiency based on California EVR corrected for rule 

effectiveness.

3. 90% control efficiency was modeled 

4. This option gets slightly greater emission reductions than 

adding ORVR compatibility to the current Stage II program, 

as shown on Table 9 below.

0

2

4

6

8

10

12

14

16

2005 2012 2015 2017

HC (tons/day)

Incremental Reduction in Refueling Emissions

82% Stage II Control Efficiency (tons/day) 

ORVR Alone Stage II
13

Table 9 – Emission Reductions from Enhancing Stage II Systems to add ORVR 

Compatibility and Other Enhancements (Tons/Day)

Year ORVR Alone

Stage II Efficiency (Increase over ORVR alone)

90% (CA EVR) 82% (ORVR High) 57% (ORVR Low)

2012 11.194 2.252 2.052 1.426

2013 11.558 1.924 1.753 1.219

2014 11.869 1.644 1.498 1.041

2015 12.137 1.403 1.279 0.889

2016 12.313 1.245 1.134 0.788

2017 12.500 1.077 0.981 0.682

d. Stage I Improvements

i. Continuous monitoring for GDF vapor leaks – The emission 

reductions from real-time monitoring for vapor leaks were estimated 

as follows:

1. Estimated improvement in Stage I efficiency was applied to 

emission estimates for GDF tank filling losses. No data has 

been identified on the improvement in Stage I efficiency from 

eliminating leaks; 10% is assumed. As previously 

mentioned, GDF tanks quickly develop leaks that impact 

vapor containment, and increase filling losses.

2. Tank breathing loss estimates for New York State were 

adjusted for Connecticut’s GDF population by gasoline 

volume (see Table 11). The distribution of Connecticut’s 

GDFs is based on the GDF survey.

About 40% of the GDFs dispense less than 300,000 gallons per 

year. As shown on Table 12, exempting these GDFs from these 

requirements has a small impact on estimated benefits.

Table 10 – Assumptions for Determining Reductions in Tank Filling Losses for 

Continuous Monitoring for Vapor Leaks

Parameter Value

Uncontrolled Tank Filling losses (g/gal) 3.314

Stage I Efficiency Improvement 10%
14

Table 11 – Breathing Loss Reductions for Continuous Monitoring for Vapor Leaks

(Containment) and Pressure Management System (PMC)5

Yearly Throughput 

intervals 

# gas 

stations 

CT

Recovery 

factor from 

containment

(tons/GDF/Yr.)

Containment 

recovery 

(tons/year)

Recovery factor 

from 

Containment & 

PMC 

(tons/GDF/Yr.)

Total 

containment 

& PMC 

recovery 

(tons/year)

Additional 

from PMC 

(tons/year)

<300,000 803 0.06 47 0.06 47 0

300,000-500,000 170 0.18 30 0.19 33 2

500,000-700,000 170 0.17 29 0.29 49 20

700,000-900,000 179 0.26 47 0.39 70 23

900,000-1,100,000 143 0.28 41 0.49 70 29

1,100,000-1,300,000 122 0.28 34 0.58 71 37

1,300,000-1,500,000 74 0.27 20 0.68 50 31

1,500,000-1,700,000 53 0.41 22 0.78 41 19

1,700,000-1,900,000 60 0.40 24 0.87 52 28

1,900,000-2,100,000 36 0.40 14 0.97 35 20

2,100,000-2,700,000 86 0.55 47 1.16 100 53

2,700,000-3,300,000 45 0.61 28 1.46 66 39

3,300,000-3,900,000 36 0.58 21 1.75 63 42

3,900,000-4,100,000 17 0.64 11 1.94 32 22

>4,100,000 41 0.68 28 2.43 98 71

TOTAL 2,033 441 435

Table 12 -- Emission Reductions for Continuous Monitoring for Vapor Leaks

(Tons/Day)

Pollution 

Source All GDFs GDFs with 300,000+ gal/year

Filling losses 1.51 1.47

Tank Breathing 1.21 1.08

Total 2.72 2.55

ii. Require pressure management system (emissions processors)

– GDFs will have breathing losses corresponding to the amount of 

air ingested in the tank and the evaporation rate. 

1. Estimated benefits from requiring pressure management 

systems on high volume stations are based on information 

provided by Veeder-Root. Losses are greatest in stations 

that dispense a lot of gasoline (see Figure 4). 

2. Based on available data, exempting stations that dispense 

less than 1,100,000 gal/yr will reduce implementation costs 

by 72% while program benefits are only reduced by 17% 

(from 1.2 to 1.0 tons/day) (see Table 13).

 

5

Personal Communication between Rob Klausmeier, dKC and Kristine Anderson, Veeder Root, 

Vapor Emissions Workbook, November 8, 2011.
15

Figure 4

Table 13 – Breathing Loss Reductions for Pressure Management Controls (PMC)

Scenario Tons/day

All GDFs 1.2

GDFs with 1,100,000+ gal/yr 1.0

iii. Other Stage I Enhancements – Data were not available on the 

emission reductions from CA EVR requirements for spill 

containment boxes and specifications to reduce leaks in drop tubes 

with overfill protection devices installed. These measures are likely 

to reduce tank leaks that would be identified by continuous vapor 

leak monitoring systems, so they are unlikely to result in significant 

additional benefits over tank pressure monitoring systems. This 

does not mean these measures do not have merit. GDFs could 

install CA EVR approved drop tubes and spill containment devices 

to reduce incidents of pressure monitoring alarms.

e. Impact on Air Toxics – The primary air toxic of concern with GDF 

operations is benzene. dKC used MOVES to estimate benzene emissions 

in vehicle refueling vapors. According to MOVES, benzene is 0.54% 

(mass percent) of refueling vapor. Reducing or increasing gasoline vapor 

emissions will have a proportional impact on benzene emissions.

0

0.5

1

1.5

2

0 100,000 200,000 300,000 400,000 500,000

Tons VOC/GDF/yr

GDF Volume (gals/month)

Estimated Benefit of Pressure Management 

System vs. GDF Volume
16

7. IMPLEMENTATION AND OPERATING COSTS FOR CONTROL 

ALTERNATIVES

a. Current Costs

i. Costs to Continue Stage II Systems

1. Annual cost for continuing Stage II. Cost sources:

a. New York State -- $2,000 per GDF.

b. API: $4,410 per GDF.

c. EPA -- $3,277 per GDF.

Table 14 -- Annual Costs to GDFs for Continuing Current Stage II Program

Low: New York State6 High: API7EPA8

Annual Stage II Cost/Station $2,000 $4,410 $3,277

Total Annual Stage II Cost $3,559,728 $7,849,343 $5,832,614

b. Cost to Make all Stage II systems in Connecticut ORVR compatible

i. Costs to make Stage II systems compatible with ORVR systems 

are based on two sources: OPW and the CA EVR spreadsheet for 

modules 2, 3, and 6.

1. OPW’s cost quotes were used as the basis of the costs for 

upgrading equipment to be compatible with ORVR systems.

Upgrade costs are estimated to be $2,000 to $14,000 per 

GDF9.

2. Costs to continue the program (with ORVR compatibility) are 

based on EPA’s cost estimate for continuing the current 

program plus the cost for ORVR upgrades based on OPW’s 

cost quotes.

Table 15 – Annual Costs for ORVR Compatible Stage II Systems

Cost Component Annual Cost

Cost for Continuing Current Program (EPA 

Estimate): Not including DEEP oversight)

$5,832,614

ORVR Upgrade (source OPW) $3,797,338

Total $9,629,951

 

6

Part 230 -- Gasoline Dispensing Sites and Transport Vehicles, Stakeholder Meeting; New York 

Department of Environmental Protection, December 7, 2010.

7 REFUELING EMISSION CONTROLS AT RETAIL GASOLINE DISPENSING STATIONS AND COSTBENEFIT ANALYSIS OF STAGE II IN CONNECTICUT; Tech Environmental, Inc., September 24, 2007

8 Widespread Use for Onboard Refueling Vapor Recovery and Stage II Waiver; USEPA, July 8, 

2011.

9

Personal Communication between Rob Klausmeier, dKC and Jeff Steel, OPW, August 8, 2011
17

c. Costs for Enhanced Stage II Systems: ORVR compatibility plus CA 

EVR enhancements

i. The CA EVR spreadsheet10 was used as the basis for the costs of 

a higher efficiency program that includes all the CA EVR Stage II 

upgrades.

1. California’s costs per GDF in different monthly throughput 

categories were multiplied times the projected number of 

GDFs in Connecticut in these categories to estimate total 

costs.

2. Costs were adjusted for inflation since 2001, when the CA 

EVR spreadsheet was last updated.

Table 16 – Fixed Costs per GDFs for Enhanced Stage II Systems (Source: 

California EVR Spreadsheet)

Group

Average Monthly 

Throughput by Facility 

(gallons)

Vacuum 

Assisted Balance

1 0-25,000 $22,678 $23,360 

2 25,001-50,000 $24,056 $25,086 

3 50,001-100,000 $29,305 $31,365 

4 100,001-200,000 $34,549 $37,638 

5 > 200,000 $39,549 $41,783 

Table 17 -- Total Annual Costs to CT GDFs for Enhanced Stage II Systems

(Source: California EVR Spreadsheet)

Group

Average 

Monthly 

Throughput by 

Facility (gallons)

Total Annual Cost

1 0-25,000 $2,844,983

2 25,001-50,000 $1,723,774

3 50,001-100,000 $5,028,657

4 100,001-200,000 $3,820,741

5 > 200,000 $2,885,281

TOTAL $16,303,440

 

10 EVR Cost Analysis Spreadsheet; California Air Resources Board, October 16, 2002. Results 

adjusted for inflation using Marshall and Swift Equipment Cost Index.
18

d. Costs for Improving DEEP’s Stage I control program by 

implementing measures that go beyond current Stage I requirements

i. Requiring real-time monitoring for GDF vapor leaks

Two sources were used to define the costs for real-time monitoring 

for GDF vapor leaks:

New York State: Supporting data provided by Veeder-Root for 

proposed New York Part 230 Regulation11.

California EVR spreadsheet: Costs for the vapor leak

monitoring portion of the California EVR program.

California’s and New York’s costs per GDF were multiplied times 

the number of GDFs in Connecticut to estimate total costs. Both 

sources yield similar estimates for fixed costs. Subsequent cost 

analysis is based on New York’s estimates.

As discussed above, exempting GDFs that dispense less than 

300,000 gallons per year reduces emission reductions of this 

measure by 7%; as shown on Table 19, exempting these GDFs 

reduces costs of this measure by 39%.

Table 18 -- Fixed Costs for Continuous Monitoring for Vapor Leaks

Parameter

Source

New York California

Cost/GDF $6,000 $6,105 

Total Fixed Cost $12,198,000 $12,410,973 

Table 19 – Annual Costs for Continuous Monitoring for Vapor Leaks

Parameter

Annualized 

Equip Costs

Fuel 

Savings

Net Cost

Annual Cost per GDF $1,476

Costs for installing in all GDFs $3,001,668 $1,310,479 $1,691,190

Costs for installing in GDFs with 300,000+ gal/yr $1,816,521 $1,228,681 $587,839

ii. Requiring GDF Tank Pressure Control Systems

Costs for requiring GDFs to be equipped with tank pressure control

systems are based on estimates prepared by Veeder-Root for New 

York State DEC10. Total costs are reduced by 72% by exempting 

stations that dispense less than 1,100,000 gallons per year. This 

exemption reduces emission benefits by 16%.

 

11 Personal Communication between Rob Klausmeier, dKC and Kristine Anderson, Veeder Root, 

Vapor Emissions Workbook, November 8, 2011
19

Table 20 -- Fixed Costs for GDF Tank Pressure Control Systems

Parameter Costs

Fixed Cost per GDF $12,250

Costs for installing in all GDFs $24,904,250

Costs for installing in GDFs with 1,100,000+ gal/yr $6,964,996

Table 21 – Annual Costs for GDF Tank Pressure Control Systems

Parameter

Annualized 

Equip Costs

Fuel 

Savings

Net Cost

Annual Cost per GDF $3,219

Costs for installing in all GDFs $6,543,477 $573,374 $5,970,103 

Costs for installing in GDFs with 1,100,000+ gal/yr $1,830,021 $475,408 $1,354,613 

8. COST PER TON OF POLLUTANT REDUCTIONS FOR CONTROL 

ALTERNATIVES

a. Making current Stage II systems in Connecticut ORVR compatible

Table 22 shows the calculation of the emission reductions from improving 

Stage II systems to make them ORVR compatible. Emission estimates 

were calculated by multiplying g/gal estimates without Stage II (derived 

from MOVES) times annual gasoline consumption times estimated control 

efficiency. Two Stage II control efficiencies were modeled: 82% and 57%. 

Regardless of the assumed control efficiency, by 2015 this option is 

expensive and results in relatively few emission reductions.

Table 22 – Cost Effectiveness of Improving Stage II Systems to make them 

Compatible with ORVR Systems

Annual Cost

(2011$)

Includes DEEP

Oversight

Tons/Yr Reduction Fuel Savings ($/yr.) $/Ton

Year

g/gal 

without 

Stage II 

(MOVES)

82% 57% 82% 57% 82% 57%

2011 0.669 $10,448,781

1

914 636 $1,205,203

3

$837,763

3

$10,108 $15,120

2012 0.547 $10,448,781 749 521 $986,968 $686,063 $12,635 $18,755

2013 0.468 $10,448,781 640 445 $843,418 $586,278 $15,010 $22,171

2014 0.400 $10,448,781 547 380 $720,661 $500,948 $17,791 $26,172

2015 0.341 $10,448,781 467 324 $615,095 $427,566 $21,071 $30,890

2016 0.303 $10,448,781 414 288 $545,486 $379,179 $23,928 $35,000

2017 0.262 $10,448,781 358 249 $471,845 $327,990 $27,868 $40,668

b. Enhanced Stage II Systems: ORVR compatibility plus CA EVR 

enhancements

dKC assumes that Stage II, with all the CA EVR enhancements, has a 

90% control efficiency. This option results in slightly greater emission 
20

reductions than just making Stage II systems compatible with ORVR 

systems, and is more costly in terms of $/ton. 

Table 23 – Cost Effectiveness of Implementing CA EVR Enhancements Including 

ORVR Compatibility – 90% Overall Control Efficiency

Year g/gal

Annual Cost

(2011$)

Includes DEEP

Oversight

Tons/Yr

Reduction Fuel Savings ($/yr.) $/ton

2011 0.669 $17,122,269 1,004 $1,322,784 $15,742

2012 0.547 $17,122,269 822 $1,083,258 $19,514

2013 0.468 $17,122,269 702 $925,702 $23,060

2014 0.400 $17,122,269 600 $790,970 $27,212

2015 0.341 $17,122,269 512 $675,104 $32,109

2016 0.303 $17,122,269 454 $598,704 $36,374

2017 0.262 $17,122,269 393 $517,879 $42,257

c. Enhance Stage I: Requiring real-time monitoring of GDFs for vapor 

leaks

The calculation of the cost-effectiveness of real-time monitoring for vapor 

leaks is shown on Table 24. Cost effectiveness and emission reductions 

are shown graphically on Figure 5. Exempting GDFs that dispense less 

than 300,000 gallons per year reduces $/ton from $1,701 to $631.

As mentioned above, dKC did not have access to data on the reduction in 

filling losses from real-time monitoring for vapor leaks. Emission 

reductions assume a 10% reduction in filling losses. Table 25 presents the 

cost-effectiveness of this measure when the only benefit is reduction in 

breathing loses. This measure still appears to be cost-effective for GDFs 

that dispense more than 300,000 gallons per year.
21

Table 24 – Cost/Ton Estimates for Vapor Leak Monitoring Systems

Yearly Throughput 

intervals

# gas 

stations 

CT

$/Yr 

Pressure 

Monitoring

Cumul 

$/yr 

(%)

Filling Loss 

Reduction 

from 

Pressure 

Monitoring 

tons/year

Breathing 

Loss 

Reduction 

from Pressure 

Monitoring 

tons/year

Emissions 

Reduction 

from 

Pressure 

Monitoring 

tons/year

Cumulative 

Reductions 

from 

Pressure 

Monitoring 

(%)

Fuel Savings from 

Pressure Monitoring

$/ton 

Pressure 

Monitoring

<300,000 803 $1,185,148 39% 15 47 62 7% $81,797 $17,778

300,000-500,000 170 $250,433 48% 21 30 51 12% $67,786 $3,551

500,000-700,000 170 $250,433 56% 32 29 61 19% $80,919 $2,761

700,000-900,000 179 $264,542 65% 45 47 92 27% $120,633 $1,572

900,000-1,100,000 143 $211,633 72% 45 41 85 36% $112,612 $1,159

1,100,000-1,300,000 122 $179,888 78% 45 34 78 45% $103,157 $980

1,300,000-1,500,000 74 $109,344 82% 32 20 52 51% $67,913 $804

1,500,000-1,700,000 53 $77,599 84% 26 22 48 55% $63,322 $297

1,700,000-1,900,000 60 $88,181 87% 33 24 57 61% $75,536 $221

1,900,000-2,100,000 36 $52,908 89% 22 14 37 64% $48,490 $120

2,100,000-2,700,000 86 $126,980 93% 64 47 111 75% $146,338 -$174

2,700,000-3,300,000 45 $67,017 95% 42 28 69 81% $91,524 -$353

3,300,000-3,900,000 36 $52,908 97% 40 21 60 88% $79,736 -$443

3,900,000-4,100,000 17 $24,691 98% 21 11 32 91% $41,536 -$535

>4,100,000 41 $59,963 100% 70 28 98 100% $129,180 -$706

Total All 2,033 $3,001,668 553 441 994 $1,310,479 $1,701

Total 300,000+ 1,230 $1,816,521 538 395 932 $1,160,896 $631
22

Table 25 – Cost/Ton Estimates for Vapor Leak Monitoring Systems Assuming 

Only Benefit is Reduction in Breathing Losses

Yearly Throughput 

intervals

# gas 

stations 

CT

$/Yr 

Pressure 

Monitoring

Breathing 

Loss 

Reduction 

from 

Pressure 

Monitoring 

tons/year

Fuel Savings 

from Pressure 

Monitoring

$/ton Pressure 

Monitoring

<300,000 803 $1,185,148 47 $61,570 $24,051

300,000-500,000 170 $250,433 30 $40,196 $6,893

500,000-700,000 170 $250,433 29 $38,176 $7,328

700,000-900,000 179 $264,542 47 $61,557 $4,346

900,000-1,100,000 143 $211,633 41 $53,769 $3,869

1,100,000-1,300,000 122 $179,888 34 $44,253 $4,040

1,300,000-1,500,000 74 $109,344 20 $26,017 $4,221

1,500,000-1,700,000 53 $77,599 22 $28,634 $2,254

1,700,000-1,900,000 60 $88,181 24 $31,828 $2,334

1,900,000-2,100,000 36 $52,908 14 $19,097 $2,334

2,100,000-2,700,000 86 $126,980 47 $62,475 $1,361

2,700,000-3,300,000 45 $67,017 28 $36,284 $1,116

3,300,000-3,900,000 36 $52,908 21 $27,365 $1,230

3,900,000-4,100,000 17 $24,691 11 $14,189 $975

>4,100,000 41 $59,963 28 $36,454 $850

Total All 2,033 $3,001,668 441 $581,863 $5,481.01

Total 300,000+ 1,230 $1,816,521 395 $480,097 $3,283.48

Figure 5
23

d. Enhance Stage I: Requiring GDF tank pressure control systems

The calculation of the cost-effectiveness of tank pressure control systems 

is shown on Table 26. Cost effectiveness and emission reductions are 

shown graphically on Figure 6. New York’s proposed exemption limit of 

1,100,000 gallons/year makes sense. Exempting GDFs that dispense less 

than 1,100,000 gallons per year reduces costs by about 72% while 

emission reductions are reduced by only 16%, so $/ton is reduced from 

$14,000 to $3,800.

Table 26 -- Cost/Ton Estimates for Tank Pressure Control Systems

Yearly Throughput 

intervals

# gas 

stations 

CT

Additional 

from PMC 

tons/year

Cumulative 

Reductions 

from PMC 

(%)

$/Yr PMC Cumul 

$/yr (%)

Fuel 

Savings 

$/yr

$/ton 

PMC

<300,000 803 0 0% $2,583,558 39% $0 NM

300,000-500,000 170 2 1% $545,931 48% $3,172 $225,517 

500,000-700,000 170 20 5% $545,931 56% $26,876 $25,454 

700,000-900,000 179 23 10% $576,687 65% $30,065 $23,962 

900,000-1,100,000 143 29 17% $461,350 72% $37,853 $14,745 

1,100,000-1,300,000 122 37 26% $392,147 78% $49,202 $9,186 

1,300,000-1,500,000 74 31 33% $238,364 82% $40,257 $6,486 

1,500,000-1,700,000 53 19 37% $169,162 84% $25,118 $7,558 

1,700,000-1,900,000 60 28 44% $192,229 87% $36,889 $5,550 

1,900,000-2,100,000 36 20 48% $115,337 89% $26,715 $4,372 

2,100,000-2,700,000 86 53 60% $276,810 93% $69,462 $3,934 

2,700,000-3,300,000 45 39 69% $146,094 95% $50,758 $2,475 

3,300,000-3,900,000 36 42 79% $115,337 97% $55,096 $1,441 

3,900,000-4,100,000 17 22 84% $53,824 98% $28,568 $1,165 

>4,100,000 41 71 100% $130,716 100% $93,344 $528 

Total All 2,033 435 $6,543,477 $573,374 $13,723 

Total 1,100,000+ 569 361 $1,830,021 $475,408 $3,755 
24

Figure 6
25

9. PROCEDURES FOR DECOMMISSIONING STAGE II SYSTEMS

Following is a summary of how to decommission the major components of Stage II 

vapor recovery systems:

Vapor recovery piping

Hanging hardware for dispenser

Dispenser decals for instructions and proper use

Vacuum pump (only for vacuum-assist systems)

Liquid drop-out tank (if necessary)

The vacuum pump is a component unique to vacuum-assisted systems. Aside from the 

disabling these pumps, the steps to decommission both vacuum-assisted and balance 

systems are congruent. 

Drawn from implemented procedures in Vermont and New York, as well as standard 

protocols from the Petroleum Equipment Institute’s (PEI) Recommend Practices for 

Installation and Testing of Vapor-Recovery Systems at Vehicle-Fueling Sites PEI RP 

300-09, the steps to decommission each component of Stage II vapor recovery systems 

are summarized below.

a. Vapor recovery piping

1. Disconnect piping from dispenser(s). Purge any liquid from piping. Seal 

with vapor-tight cap or plug.

2. If accessible without excavation, disconnect piping from tank and seal. 

Check for liquids and, if necessary, discard properly. Remove piping.

3. If tank is not accessible, leave piping in place (i.e., connected to tank) until 

next excavation.

b. Liquid drop-out tank

1. Some GDFs, where the slope between the dispensers and tanks is not 

sufficient, require a drop-out tank to collect any liquid accumulated in the 

stage II vapor recovery piping.

2. Either remove or decommission the tank (i.e., remove any liquid, 

disconnect the line, and seal).

c. Vacuum pump

1. For systems with pumps for each dispenser:

i. Disconnect all electronic wiring for pump.

ii. Reprogram dispenser electronics to deactivate stage II vapor 

recovery.
26

iii. Drain any liquids from pump. If no gasoline remains in the pump, it 

can be left in place. Otherwise, remove pump.

2. For systems with a central pump:

i. Remove the vacuum pump.

ii. Seal vapor piping previously attached to pump.

d. Hanging hardware

1. Drain liquid from hardware.

2. Replace stage II hanging hardware with conventional hardware and adjust 

adaptors.

e. Dispenser decals -- Remove stage II operating instructions from dispenser.

f. Final checks and tests

1. Confirm overfill protection device is fully functional. If the stage II vapor 

piping is still connected to the tank and the protection device is not 

operating correctly, gasoline may be released. If the device is found faulty, 

it must be reinstalled.

2. Complete pressure decay and P/V valve test to ensure all components are 

vapor-tight.

3. Once passed, complete a tie-tank test per ARB procedure TP-201.3C to 

confirm all vents are functional.

g. Checklist and documentation

1. Complete form with GDF information and checklist.

2. Submit to necessary authorities.

The above procedures should only be administered by trained technicians. Though 

represented in the summary, we recommend Connecticut refer to PEI RP 300 for 

detailed steps on decommissioning stage II systems.

Next Steps – dKC recommends that the following steps be taken if the State adopts 

regulations to remove the requirement for Stage II:

1. Immediately exempt new or significantly modified GDFs from Stage II 

requirements.

2. Give priority to decommissioning Stage II in stations with vacuum-assist systems.

Decommission Stage II in GDFs with balance systems after vacuum-assist 

systems are decommissioned.

3. Require stations that dispense more than 300,000 gallons per year to implement 

continuous vapor leak monitoring systems. Require stations below this volume 

level to continue periodic inspections for tank decay and P/V valve function.
27

10.CONCLUSIONS/RECOMMENDATIONS

Table 27 summarizes estimates of the emission reductions and cost effectiveness of 

Stage I and Stage II options for calendar year 2015. 

Table 27 – Estimates of Emission Reductions and Cost Effectiveness of Stage I 

and Stage II Options (2015)

Control Measure Emission Reductions (T/D) Cost/Ton

Decommission Stage II Program 0.04 to 0.06 Cost Savings

Make Current Stage II ORVR 

Compatible

0.9 to 1.3 $21,000 to 

$31,000

Upgrade Stage II to CA EVR 

Requirements

1.4 $32,000

Enhance Stage I: GDF Vapor Leak

Monitoring System (exempt GDFs 

<300,000gal/yr)

1.1 to 2.6 $630 to $3,300

Enhance Stage I: GDF Tank Pressure 

Control System (exempt GDFs 

<1,100,000gal/yr)

1.0 $3,800

Following are the primary conclusions of this project:

Widespread use (WSU) will take place by at least summer 2012. The State 

could argue that WSU has already occurred. There are minimal benefits and 

in fact after 2014 there will be increases in emissions if GDFs must keep 

current Stage II systems beyond the WSU date.

Enhancing Stage II systems to make them compatible with ORVR systems is 

expensive. This measure is estimated to result in 0.9 to 1.3 tons per day 

emission reductions in 2014 at a cost of $21,000 to $31,000 per ton. Adopting 

Stage II improvements that are included in the California EVR program 

increases benefits by 0.1 to 0.5 tons/day at a cost of $32,000 per ton.

Enhancing Stage I systems to require continuous monitoring of GDFs for 

vapor leaks appears to be effective and relatively inexpensive. This measure 

is estimated to result in 1.1 to 2.6 tons per day emission reductions in 2015 at 

a cost of $630 to $3,300 per ton. Exempting GDFs that dispense less than 

300,000 gallons/year significantly improves the cost-effectiveness of this 

measure, while decreasing emissions reductions by only 7%. Requiring these 

systems will help assure the State that any leaks that result from removing or 

capping Stage II systems will be promptly identified and repaired, should the 

State decide to terminate the Stage II program.

Adding GDF tank pressure control systems also appears to be cost effective. 

This measure is estimated to result in 1.0 tons per day emission reductions in 

2015 at a cost of $3,800 per ton. Exempting GDFs that dispense less than 

1,100,000 gallons/year significantly improves the cost-effectiveness of this 

measure, while decreasing emissions reductions by 14%.
28

APPENDIX A

REPORT ON ANALYSIS OF WIDESPREAD USE (WSU) IN CONNECTICUT

INTRODUCTION

As part of a task to assist the Connecticut Department of Energy and Environmental 

Protection (DEEP) in evaluating the Gasoline Dispensing Facility (GDF) Vapor Control 

Program., dKC determined when onboard refueling vapor recovery (ORVR) systems in 

Connecticut’s vehicle fleet have met a particular threshold described as widespread use 

(WSU). ORVR systems were phased into the motor vehicle fleet beginning with the 

1998 model year. After Connecticut reaches WSU, EPA will allow it to terminate the 

Stage II portion of the Vapor Recovery program, provided it does not need the emission 

reductions from Stage II.

Results of the WSU analysis are summarized below:

a. Vacuum assist systems are used in 80% of the gasoline dispensing facilities 

(GDFs) with Stage II systems. From a gasoline throughput standpoint, vacuum 

assist systems account for 95% of the gasoline dispensed at GDFs with Stage II 

systems.

b. Data from Connecticut and other states indicate that Stage II systems quickly 

develop leaks and other malfunctions that cause them to fail system performance 

tests. It’s unlikely that Stage II systems have the 86% control efficiency that is 

assumed in Connecticut’s State Implementation Plan. The actual control 

efficiency is likely to be 60% or less.

c. Recent correspondence between EPA and other states indicate that EPA will 

consider that widespread use (WSU) has occurred when emissions with Stage II 

systems alone equal emissions with ORVR alone. dKC used EPA’s current 

emission factor model, MOVES, and the NESCAUM WSU spreadsheet to 

determine WSU dates using this and other WSU criteria. Following are estimates 

of when emissions with Stage II systems alone equal emissions with ORVR 

alone:

o MOVES:

 86% Stage II efficiency: 2012

 60% Stage II efficiency: 2007-2008

o NESCAUM SPREADSHEET:

 86% Stage II efficiency: 2011

 60% Stage II efficiency: 2007

This report presents the results of the WSU analysis. First, we summarize the results of 

a survey of GDFs in Connecticut. The survey provides key inputs into the WSU 

analysis. Next, we review information on the condition of vapor recovery systems in 

GDF’s in Connecticut and nearby states. We then use different methods to assess if or 

when WSU has occurred.
29

RESULTS OF GDF SURVEY

Eastern Research Group (ERG) conducted a comprehensive survey of GDFs located in 

Connecticut. ERG designed the survey sample from GDF data obtained from the 

Connecticut DEEP. ERG filtered out facilities that were closed or inactive, or that were 

only handling non-gasoline materials. 2,033 surveys were mailed out on February 17. 

Of these, 23 were undeliverable. 

Survey responses were received for a total of 908 GDFs located in Connecticut. Based 

on the number of delivered surveys (i.e., 2,010 surveys), the survey response rate was 

43.4%. For purposes of comparison, a comparable survey was conducted for a similar 

GDF sample size in Texas in 2008 and the return rate was only 27.4%.12 The high 

survey response rate increases confidence that the findings of this study are applicable 

to GDFs across the entire state of Connecticut. 

ERG designed a Microsoft Access database to house the received survey data. All 

survey returns that were sent in via mail, fax, or PDF format were input into the 

database manually. Significant findings are shown below:

The 96 facilities that do not have Stage II vapor control are limited to the 

smallest throughput classification.

The facilities that did not identify whether or not they have Stage II vapor control 

are primarily limited to the smallest throughput classification (i.e., 73 out of 80 

non-respondents to this question).

Of the facilities that did identify that Stage II vapor control was present, 80 

percent (i.e., 540 out of 675 facilities) had vacuum-assisted systems, while the 

remaining 20 percent (i.e., 135 facilities) had balance systems.

The facilities that had balance Stage II vapor control systems were concentrated 

primarily in the smaller throughput classifications. 

The overall yearly gasoline throughput derived from the survey results was estimated to 

be 745,413,813 gallons. The disaggregation of this based upon Stage II control 

technology is as follows:

Vacuum-assisted – 696,954,309 gallons (93.5% of total)

Balance – 38,502,475 gallons (5.2% of total)

Do not know – 6,966,505 gallons (0.9% of total)

None – 2,990,523 gallons (0.4% of total)

Another way of interpreting the results is that vacuum assist systems account for 95% of 

the gasoline dispensed at GDFs with Stage II systems.

CONDITION OF VAPOR CONTROL SYSTEMS

As part of this project, dKC is collecting information on the condition of Stage I/II vapor 

control systems in Connecticut. DEEP is providing dKC with the initial results of the 

triennial GDF inspections. In addition, dKC is commissioning additional GDF tests to 

 

12 Stage I and Stage II Gasoline Dispensing Emissions Inventory. Final. Prepared for the Texas Commission on 

Environmental Quality by Eastern Research Group, Inc. (ERG), Sacramento, CA. August 31, 2008.
30

help determine when key components of the vapor control system start to deteriorate. 

dKC also has compiled information from other states on vapor control system 

deterioration rates.

Connecticut Test Results – Table 1a summarizes the initial results of GDF inspections 

that were witnessed by DEEP since December 20, 2010. Overall, 79% of the GDFs 

failed inspection. The most common failure reasons were the tank decay test (50%), 

followed by A/L (25%) and P/V Cap test (21%). 

Table 1a – Results of Triennial GDF Inspections in Connecticut

Parameter

# and % of Failures

System 

Pass/Fail Decay

Dry 

Blockage

Wet 

Blockage

P/V 

Cap A/L 

6 

Click

# 111 72 5 6 10 23 13

% of Tests 70% 45% 3% 4% 6% 14% 8%

dKC commissioned additional GDF tests to help determine when key components of the 

vapor control system start to deteriorate. These tests were performed approximately 2 

months and 4 months after the station received its certification test. Two stations 

participated: one is a government station with a balance system; the other is a private 

station with a vacuum assist system. Table 1b summarizes results of these tests. None 

of the tests had an overall result of pass.

Table 1b – Results of Bi-monthly GDF Inspections in Connecticut

Station/Stage II Type Test date Overall Result Failed items

J and A Gas

Vacuum Assist

6/2/11 Fail A/L Test

8/23/11 Fail A/L Test

DOT Newington

Balance

4/25/11 Fail P/V valve

7/14/11 Fail Decay, P/V valve, torn 

hose

11/9/11 Fail Decay, P/V valve

Massachusetts Test Results – Other states and organizations have reported on the 

reliability of vapor control systems. Massachusetts DEP requires GDFs to report the 

initial results of their annual Stage II Certification tests. Table 2 summarizes the percent 

of stations that fail their initial Stage II tests in Massachusetts. As shown, from 2001 

through 2010, 66% to 82% of the GDFs fail the initial annual Certification tests. The 

primary problem causing test failures were seal caps and fittings that needed tightening. 

Note that Massachusetts required GDFs with vacuum assist systems to implement by 

July 2004 enhancements to improve the integrity of Stage I/II systems, e.g., product and 

vapor swivel adaptors. It’s hard to tell if these enhancements have lowered the failure 

rate.
31

Table 2 – Results of Annual GDF Certification Tests in Massachusetts

Year % Fail

2001 82%

2002 78%

2003 75%

2004 67%

2005 76%

2006 78%

2007 78%

2008 73%

2009 71%

2010 66%

From May 2002 through October 2003, Massachusetts required new GDFs with 

vacuum assist Stage II systems or significantly modified GDFs with vacuum assist 

systems to receive a Certification test 120 days after they were initially certified. Results 

of these tests are shown on Table 3. Results indicate that over half (56%) of the 

recently certified GDFs failed Certification tests 120 days later. The most common 

failure was for the pressure decay test. 

Table 3 – Results of 120 Day GDF Certification Tests in Massachusetts

Failure Reason # % Fail

Air/Liquid Ratio 17 17%

Pressure Decay 45 46%

P/V Cap 2 2%

Any Failure 55 56%

New Hampshire Test Results – According to vapor release research conducted by 

New Hampshire, Stage II repairs last an average of 58 days. Overall findings of New 

Hampshire’s research found: 

1. Inspections and testing failed to fix key leaks

2. Most leaks required the station to upgrade the hardware (i.e. hoses, nozzles, 

breakaways)

3. Gasoline deliveries triggered leaks

Summary – Based on available data, it’s unlikely that Stage II systems in Connecticut 

are achieving the 86% control efficiency assumed in Connecticut’s State 

Implementation Plan (SIP). Data were not available that relate specific failure modes to 

a reduction in control efficiency. Assuming that stations that fail GDF inspections see a 

50% drop in control efficiency, the actual control efficiency is less than 60%. The WSU 

analysis uses a range between 60% and 86% for control efficiency.
32

PREDICTIONS OF WHEN WSU OCCURS

Definition of Widespread Use

Four general definitions have been proposed to determine when widespread use (WSU) 

has occurred:

a. When “x” percent of the vehicles in service are ORVR-equipped. 75% and 85% 

have been proposed for “x”.

b. When “x” percent of the vehicle miles traveled (VMT) are from ORVR-equipped 

vehicles.

c. When total VOC emissions with ORVR-equipped vehicles are equal to total VOC 

emissions with Stage II VRS programs:

1. When emissions with Stage II alone equal emissions with ORVR 

alone.

2. When emissions with Stage II and ORVR combined including 

Incompatibility Excess Emissions (IEE) equal emissions with ORVR 

alone.

d. When “x” percent of gasoline sold is dispensed to ORVR-equipped vehicles.

EPA’s recent WSU analysis is based on definition c. 1 (When emissions with Stage II 

alone equal emissions with ORVR alone). dKC calculated WSU using all of the above 

methods.

Incompatibility Excess Emissions (IEE) Factors -- The assumed incompatibility 

excess emissions (IEE) factor is a key parameter in estimating when WSU occurs using 

method c.2. (When emissions with Stage II and ORVR combined including IEE equal 

emissions with ORVR alone). IEE refers to the increase in GDF emissions from using 

vacuum assist systems to refuel vehicles with on-board refueling vapor recovery 

(ORVR) systems. When a vehicle with ORVR is refueled at a GDF with a vacuum assist 

system, ambient air from the vicinity of the GDF nozzle will be drawn back into the GDF 

storage tank. This air dilutes the concentration of gasoline vapors in the headspace of 

the storage tank, causing some of the liquid gasoline in the storage tank to evaporate, 

which increases the storage tank pressure. If the tank pressure increases above the 

positive setting of the P/V valve, the storage tank will vent to the atmosphere. Almost all 

(94%) of the gasoline dispensed in Connecticut is dispensed at GDFs with vacuum 

assist systems.

Table 4 documents different estimates of IEE. Based on their research, California Air 

Resources Board uses an IEE factor for vacuum assist systems of 0.86 lb/1000 gallons 

of fuel dispensed. The American Petroleum Institute (API) believes that the IEE factor 

should be lower based on their studies. Recent tests by Veeder-Root place the IEE

factor between 1.5 and 2.5 lb/1000 gallons. dKC analyzed WSU using two IEE factors: 

0.42 lb/1000 gallons and 0.86 lb/gallons.
33

Table 4 – IEE Factors13

Data Collected by Nozzle Type Excess Emissions (lb/1000 

gallons)

CARB Standard (no boot) 0.86

CARB Mini-booted 0.43

API Standard (no boot) 0.72

API Standard (no boot) 0.42*

API Mini-booted 0

Veeder-Root Not-specified 1.5-2.5 (2.0 most likely)

*Rate is for total incompatibility emissions. Total incompatibility emissions are the difference between all 

refueling emissions (pressure-related fugitives, P/V valve and fill pipe emissions) for an ORVR vehicle 

versus a non-ORVR vehicle.

Estimating When WSU Occurs

dKC took two approaches to estimate when WSU occurs:

1. Modify and run the NESCAUM widespread use (WSU) spreadsheet.

2. Use EPA’s latest vehicle emissions model, MOVES, to determine refueling 

emissions with and without Stage II.

WSU Spreadsheet – The Northeast States for Coordinated Air Use Management 

(NESCAUM) developed a spreadsheet model for calculating when WSU occurs. 

NESCAUM modified a model that was initially developed by Todd Tamura who was a 

consultant for the American Petroleum Institute (API). The model calculates refueling 

emissions using algorithms from EPA’s MOBILE6 model. It also calculates 

Incompatibility Excess Emissions (IEE). The model calculates composite refueling 

emissions in g/gal and total emissions in tons/day. The spreadsheet model has been 

used by NESCAUM and other organizations for ORVR WSU analyses. In 2007, Ariel 

Garcia updated the spreadsheet with Connecticut specific parameters. These 

parameters include Stage II effectiveness and vehicle registration distributions. The 

vehicle registration distribution was based on 2007 Connecticut vehicle registration data 

from the Department of Motor Vehicles (DMV). 

dKC has updated the spreadsheet model using 2009 vehicle registration data and the 

fraction of gasoline dispensed at vacuum assist stations, based on results of the 

recently completed survey of GDFs in Connecticut. 

MOVES -- dKC also used EPA’s latest emission factor model, MOVES, to estimate 

when WSU occurs based on Definition c): When total VOC emissions with ORVRequipped vehicles are equal to total VOC emissions with Stage II VRS programs. EPA 

is now requiring states to use MOVES to estimate vehicle emissions and the impact of 

controls such as Stage II and Inspection/Maintenance (I/M) programs. MOVES is much 

 

13 Reference: REFUELING EMISSION CONTROLS AT RETAIL GASOLINE DISPENSING STATIONS

AND COST-BENEFIT ANALYSIS OF STAGE II IN CONNECTICUT, Tech Environmental, Inc., September 

24, 2007.
34

different than EPA’s past “MOBILE” models, and requires complex data input files. 

DEEP provided dKC with MOVES input files by county for years 2007, 2013, 2017 and 

2020. For this analysis, dKC modified 2013 input files for Fairfield County for all the 

years evaluated. Using information outputted by MOVES, dKC calculated composite 

refueling emissions in g/gal.

WSU Predictions based on NESCAUM spreadsheet

dKC used the NESCAUM spreadsheet to determine WSU dates based on the percent 

of vehicles with ORVR and emissions with and without Stage II.

WSU based on the percent of vehicles with ORVR -- Table 5 presents the WSU 

dates (in calendar year) based on the WSU spreadsheet for definitions:

a) percent of vehicles, 

b) percent of VMT, and 

d) percent of gasoline consumed. 

Table 6 shows the ORVR percentages by calendar year.

Table 5 – Widespread Use (WSU) Dates Based on % of Vehicles, VMT, and 

Gasoline Sales

Method Calendar Year

a. When “x” percent of the vehicles in service are ORVR-equipped

75% 2012-2013

85% 2015-2016

b. When “x” percent of the vehicle miles traveled (VMT) are from ORVR-equipped vehicles

75% 2009-2010

85% 2012

d. When “x” percent of gasoline sold is dispensed to ORVR-equipped vehicles

75% 2010-2011

85% 2012-2012

Table 6 -- Fraction of Fleet with ORVR

Calendar 

Year

Vehicle Basis, 

Definition a

VMT Basis, 

Definition b

Fuel Usage Basis, 

Definition d

2001 13% 17% 14%

2002 18% 22% 19%

2003 23% 28% 25%

2004 29% 35% 31%

2005 35% 43% 39%

2006 42% 51% 47%
35

Calendar 

Year

Vehicle Basis, 

Definition a

VMT Basis, 

Definition b

Fuel Usage Basis, 

Definition d

2007 49% 58% 55%

2008 55% 65% 62%

2009 61% 71% 69%

2010 66% 77% 74%

2011 70% 81% 79%

2012 74% 85% 83%

2013 78% 88% 87%

2014 81% 91% 89%

2015 83% 93% 92%

2016 85% 94% 93%

2017 87% 96% 95%

2018 88% 96% 96%

2019 89% 97% 96%

2020 90% 97% 97%

WSU Based on Emissions with and without Stage II -- In addition to the three 

methods based on the percent of vehicles, VMT or gasoline consumption for ORVR 

equipped vehicles, a fourth method has been proposed for WSU determination. With 

this method, WSU is said to occur when total VOC emissions with ORVR-equipped 

vehicles are equal to total VOC emissions with Stage II vapor recovery programs. Two 

ways of doing this calculation have been proposed:

1. When emissions with Stage II alone equal emissions with ORVR alone.

2. When emissions with Stage II and ORVR including Incompatibility Excess 

Emissions (IEE) equal emissions with ORVR alone.

As mentioned earlier, EPA appears to be leaning towards definition 1 for WSU 

determination. 

The WSU spreadsheet allows users to input Stage II control efficiencies. Connecticut’s 

State Implementation Plan (SIP) assumes that the Stage II systems have 86% control 

efficiency. The SIP also assumes that Rule Penetration for Stage II is 99% and that 

Rule Effectiveness is 96.8%. Based on information on the condition of the Stage II 

systems at representative GDFs, dKC believes that the Stage II effectiveness factor for 

Connecticut should be lower than 86%. For the WSU analysis, dKC used two control 

efficiency factors: 86% and 60%. When these factors are adjusted for Rule 

Effectiveness and Rule Penetration, the overall control efficiencies for the two scenarios 

are 82% and 57%.

Table 7 presents the calculated WSU dates when WSU is defined as when emissions 

with Stage II systems alone equal emissions with ORVR alone. This calculation is not 

affected by the assumed IEE factor. As shown, with 86% Stage II effectiveness, the 
36

WSU date is 2011; with 60% effectiveness the WSU date is 2007. Figure 1 shows 

refueling emissions in g/gal for ORVR alone and Stage II alone.

Table 7 – WSU Date When Emissions with Stage II Systems Alone Equal 

Emissions with ORVR Systems Alone (Definition c.1) – Spreadsheet Results

Assumed Stage II Effectiveness WSU Date

82% (86% Adjusted for Rule Penetration and Effectiveness) 2011

57% (60% Adjusted for Rule Penetration and Effectiveness) 2007

Figure 1

Table 8 presents the calculated WSU dates when WSU is defined as when emissions 

with Stage II and ORVR combined (including IEE) equal emissions with ORVR alone. 

This definition determines the time when overall VOC emissions will increase due to 

IEE. It assumes that ORVR compatible Stage II systems are not used in Connecticut. 

Total IEE are sensitive to the assumed percentage of balance vs. vacuum assist 

systems. Based on ERG’s survey of GDFs, dKC assumes that 94% of the gasoline is 

dispensed at stations using vacuum assist systems and 5% is dispensed at stations 

using balance systems. dKC analyzed WSU using two IEE factors: 0.42 lb/1000 gallons 

and 0.86 lb/gallons, and two Stage II effectiveness factors, 82% and 57%. As shown on 

Table 8, the WSU date by this definition is effected by the IEE factor, but not the 

assumed Stage II effectiveness factor. 

Figure 2 shows refueling emissions in g/gal for ORVR alone and Stage II plus ORVR 

(including IEE) when an IEE factor of 0.86 lbs/1000 gal is input into the spreadsheet. 

0.000

0.500

1.000

1.500

2.000

2.500

2005 2010 2015 2020

Refueling HC -- g/gal

ORVR Alone vs. Stage II Alone 

(WSU Spreadsheet)

ORVR

Stage II -- 82%

Stage II -- 57%
37

After approximately 2013, emissions for the ORVR + Stage II scenarios are greater than 

for the ORVR only scenario.

Table 8 – WSU Date When Emissions with Stage II Systems plus ORVR Equal 

Emissions with ORVR Systems Alone (Definition c.2)

Assumed Stage II 

Effectiveness

Assumed Incompatibility Excess Emissions (IEE)

(#/1000 gallons)

0.86 0.42

82% 2013 2015

57% 2013 2015

Figure 2

WSU Predictions Based on MOVES

MOVES can be used to determine when WSU occurs according to definition c, when 

emissions with Stage II equal emissions with ORVR alone. To use MOVES to estimate 

emissions for the different WSU scenarios, dKC did the following:

1. Developed input files. DEEP provided input files for different counties and 

calendar years. dKC used the 2013 Fairfield County file with appropriate 

calendar year modifications for all the MOVES runs. Fairfield County has the 

most vehicles miles traveled (VMT) in Connecticut. All runs were made for July.

2. Ran MOVES for the following scenarios:

0.000

0.500

1.000

1.500

2.000

2.500

2005 2010 2015 2020

Refueling HC -- g/gal

ORVR Alone vs. Stage II+ORVR 

(WSU Spreadsheet) 0.86#/1000 gal IEE

ORVR Alone

ORVR+Stage II -- 82%

ORVR+Stage II -- 57%
38

a. On-board vapor recovery (ORVR) only: Compared refueling emissions 

estimates in g/gal with uncontrolled estimates. 

i. Uncontrolled estimates in g/gal were derived by running MOVES for 

calendar year 1990 without vapor controls.

ii. Emissions with ORVR only (no Stage II) were estimated for 

calendar years 2005, 2011, 2012, 2012, 2013, 2014, 2015, 2016 

and 2017. dKC edited the CountyYear file in the MOVES database 

to set the vapor control program effectiveness to 0%.

b. ORVR + Stage II with appropriate effectiveness inputs. dKC ran the same 

years using the following Stage II effectiveness factors:

i. 57% Stage II effectiveness (60% adjusted for Rule Penetration and 

Effectiveness)

ii. 82% Stage II effectiveness (86% adjusted for Rule Penetration and 

Effectiveness)

3. Using the following procedure based on energy consumption estimates outputted 

by MOVES, dKC calculated incompatibility excess emissions (IEE). 

a. Calculate gasoline consumption (1 gallon=115,000 MMBtu).

b. Calculate IEE for a range of IEE factors:

i. 0.42 #/1000 gal

ii. 0.86 #/1000 gal

c. Add IEE to the estimates for the ORVR + Stage II scenario.

Predictions of when ORVR alone provides the same emission reductions as 

Stage II – MOVES provides a means of calculating when ORVR alone will provide the 

same emission reductions as Stage II alone. The user can set the effectiveness of a 

region’s vapor control program to 0% and calculate refueling emissions. The drop in 

refueling emissions will be due to phase-in of vehicles with ORVR.

Table 9 shows the WSU date for this definition based on MOVES. Table 10 presents 

MOVES estimates for refueling emissions in g/gal for the non-Stage II scenarios. The 

percent control column can be directly compared to Stage II control efficiency. For 

example, in 2012, ORVR alone provides 82% control efficiency, which is equivalent to 

applying 82% efficient Stage II controls to a non-ORVR fleet. Results for the ORVR 

alone case are compared with the two Stage II effectiveness scenarios on Figure 3.

Table 9 – WSU Date When Emissions with Stage II Systems Alone Equal 

Emissions with ORVR Systems Alone (Definition c.1) – MOVES Results

Assumed Stage II Effectiveness WSU Date

82% (86% Adjusted for Rule Penetration and Effectiveness) 2012

57% (60% Adjusted for Rule Penetration and Effectiveness) 2007-2008
39

Table 10 – MOVES Refueling Emission Estimates – ORVR Alone

Year Refueling 

Vapor

Distance

(miles)

g/mi Gallons MPG g/gal % 

Control

1990 328,677 696,461,824 0.2143 49,790,737 13.988 2.997 0%

2005 158,985 695,594,368 0.1038 40,254,445 17.280 1.793 40%

2011 58,217 695,284,544 0.0380 39,534,749 17.587 0.669 78%

2012 46,982 695,322,688 0.0307 38,959,823 17.847 0.547 82%

2013 39,571 695,322,688 0.0258 38,399,333 18.108 0.468 84%

2014 33,168 695,334,432 0.0217 37,668,001 18.460 0.400 87%

2015 27,780 695,346,176 0.0181 36,964,029 18.811 0.341 89%

2016 24,048 695,301,600 0.0157 36,081,156 19.270 0.303 90%

2017 20,316 695,257,024 0.0133 35,239,367 19.73 0.262 91%

As shown on Table 9 and Figure 3, the WSU date is between 2007 and 2008 for the 

57% Stage II effectiveness case, and 2012 for the 82% Stage II effectiveness case. 

These are about one year higher than the WSU dates derived from the WSU 

spreadsheet. Note that the WSU spreadsheet uses 2009 registration data, while the 

MOVES files provided by DEEP appear to use 2007 registration data. In December 

2010, when dKC investigated the sensitivity of the WSU dates to the registration data, 

we found that using 2009 data lowered WSU dates by about one year, because the 

2009 data projected a younger light-truck fleet.

Figure 3

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

1.800

2.000

2005 2010 2015 2020

Refueling HC -- g/gal

ORVR Alone vs. Stage II Alone (MOVES)

ORVR

Stage II -- 82%

Stage II -- 57%
40

Predictions of when ORVR alone provides the same emission reductions as 

Stage II plus ORVR – In order to use MOVES to determine when emissions with ORVR 

alone are lower than emissions with ORVR plus Stage II, it is necessary to separately 

calculate incompatibility excess emissions (IEE). MOVES estimates petroleum energy 

consumption from which we derive estimated gasoline consumption. Then, IEE factors 

are applied to gasoline consumption estimates to estimate total IEE. Total IEE is then 

added to MOVES estimates of refueling emissions with Stage II controls.

Table 11 shows WSU dates for the scenario where emissions with Stage II begin to 

increase over the ORVR scenario alone. Table 12 shows the calculation of total 

refueling emissions for the Stage II plus ORVR scenario, accounting for IEE. Results 

are shown graphically on Figure 4. The WSU date using an IEE factor of 0.86 lb/1000 

gal is between 2014 and 2015. The WSU date using an IEE factor of 0.42 lb/1000 gal is 

estimated to be 2018. The WSU date by this definition is not sensitive to the assumed 

Stage II effectiveness factor.

Table 11 – WSU Date Based on MOVES When Emissions with Stage II Systems 

plus ORVR Exceed Emissions with ORVR Systems Alone (Definition c.2)

Assumed Stage II 

Effectiveness

Assumed Incompatibility Excess Emissions (IEE)

(#/1000 gallons)

0.86 0.42

82% 2014-2015 2018

57% 2014-2015 2018

Table 12 – MOVES Refueling Emission Estimates – ORVR Alone vs. Stage II + 

ORVR -- With Incompatibility Excess Emissions (IEE)

Scenario Year

Refueling 

Vapor 

ORVR 

only (#)

Refueling 

Vapor 

ORVR 

only 

(g/gal)

Refueling 

Vapor ORVR + 

Stage II (g/gal)

No IEE

gallons % 

ORVR

IEE (g/gal)

Total Refueling 

Stage II w/IEE 

(g/gal)

0.42 0.86 0.42 0.86

82% 

Control

2005 158,985 1.793 0.323 40,254,445 39% 0.061 0.125 0.3837 0.4476

2011 58,217 0.669 0.120 39,534,749 79% 0.124 0.253 0.2441 0.3738

2012 46,982 0.547 0.099 38,959,823 83% 0.130 0.267 0.2288 0.3653

2013 39,571 0.468 0.084 38,399,333 87% 0.136 0.278 0.2198 0.3618

2014 33,168 0.400 0.072 37,668,001 89% 0.140 0.286 0.2119 0.3584

2015 27,780 0.341 0.061 36,964,029 92% 0.143 0.294 0.2048 0.3550

2016 24,048 0.303 0.054 36,081,156 93% 0.146 0.299 0.2006 0.3536

2017 20,316 0.262 0.047 35,239,367 95% 0.148 0.303 0.1952 0.3503

57% 

Control

2005 158,985 1.793 0.771 40,254,445 39% 0.042 0.087 0.8134 0.8578

2011 58,217 0.669 0.287 39,534,749 79% 0.086 0.176 0.3735 0.4637
41

Scenario Year

Refueling 

Vapor 

ORVR 

only (#)

Refueling 

Vapor 

ORVR 

only 

(g/gal)

Refueling 

Vapor ORVR + 

Stage II (g/gal)

No IEE

gallons % 

ORVR

IEE (g/gal)

Total Refueling 

Stage II w/IEE 

(g/gal)

0.42 0.86 0.42 0.86

2012 46,982 0.547 0.235 38,959,823 83% 0.091 0.185 0.3260 0.4208

2013 39,571 0.468 0.201 38,399,333 87% 0.094 0.193 0.2954 0.3941

2014 33,168 0.400 0.172 37,668,001 89% 0.097 0.199 0.2691 0.3710

2015 27,780 0.341 0.147 36,964,029 92% 0.100 0.204 0.2464 0.3508

2016 24,048 0.303 0.130 36,081,156 93% 0.102 0.208 0.2317 0.3380

2017 20,316 0.262 0.113 35,239,367 95% 0.103 0.211 0.2155 0.3233

Figure 4

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

1.600

1.800

2.000

2005 2010 2015 2020

Refueling HC -- g/gal

ORVR Alone vs. Stage II + ORVR (MOVES)

0.86#/1000 gal IEE

ORVR Alone

ORVR+Stage II -- 82%

ORVR+Stage II -- 57%
42

APPENDIX B

DESCRIPTION OF CALIFORNIA ENHANCED VAPOR RECOVERY PROGRAM

(CA EVR)

Module 1: Phase I Vapor Recovery

ARB Staff proposes to increase efficiency requirements to gain additional emission reductions 

as well as require more stringent leak requirements for Phase I components to ensure these 

efficiencies are achievable at all installations. The proposed certification requirements for Phase 

1 vapor recovery system certification are set forth in CP-201, “Certification Procedure for Vapor 

Recovery Systems for Gasoline Dispensing Facilities.” Proposed changes to Phase I 

certification consist of an increase in the efficiency requirement from 95% to 98%, a new

specification for Phase I couplers to reduce leaks, new performance specifications for drain 

valves in spill containment boxes and other improved Phase I equipment specifications.

A. Increase from 95% Efficiency to 98% Efficiency Standard

B. Phase I Adaptor Specifications: Phase I adaptors are the connection points for the cargo 

tank truck to the service station underground storage tank. The adaptors tend to become loose 

during the bulk drop as the cargo tank driver connects and disconnects the hoses for the fuel 

transfer. This is one of the commonly identified causes of leaks from vapor recovery systems, 

as well as a contributing factor to reduced effectiveness of the Phase I system. Staff has added 

a requirement for 360 degree rotatable Phase I vapor and product adaptors. 

C. Drop tube with Overfill Protection Specification: A new specification is proposed to 

reduce leaks in drop tubes with overfill protection devices installed. These devices are installed 

in the Phase I drop tube and use a valve to shut off liquid flow when the underground storage 

tank is being filled. The moving parts and the fasteners, which connect the flapper valve to the 

drop tube, can result in holes that can lead to air ingestion during the bulk drop. All drop tubes 

with overfill protection will be required to meet a pressure vs. flow specification of < 0.17 CFH at 

2 inches water column.

D. Pressure/Vacuum Relief Valves (P/V Valves) on Vent Pipes: Vent pipes are required for 

gasoline underground storage tanks to allow venting of vapors if the underground tanks develop 

significant pressure. The EVR proposal requires P/V valves for all systems. 

E. Spill Containment Boxes: Spill containment boxes are required by the State Water 

Resources Control Board (SWRCB) to contain any spills which occur during the bulk drop. ARB 

staff have added product containment box standards which limit the leak rate to < 0.17 CFH at + 

2.0 inches H2O and prohibit any standing fuel in the containment box of product connectors. 

Drain valves would be prohibited in the spill boxes of vapor connectors under this proposal. In 

addition, any application for certification of a drain valve that requires unreasonable 

maintenance shall be deemed unacceptable.

F. Connectors and Fittings: Loose connectors and fittings can also lead to leaks in the 

underground tank vapor. This new specification explicitly states that connectors and fittings shall 

be leak-free as determined by either leak detection solution or by bagging the fittings and 

observing inflation of the bag.
43

G. Fuel Blend Compatibility: Phase I components must be demonstrated to be compatible 

with fuel blends approved for use and commonly used in California, including fuels meeting the 

recently adopted Phase III fuels requirements.

Module 2: Phase II Vapor Recovery

Field inspections conducted jointly by ARB and district staff have uncovered many deficiencies 

in installed Phase II systems. ARB staff is working with the districts and equipment 

manufacturers to resolve these problems, however, it became clear that many reliability 

concerns could be addressed during the certification process. Staff has proposed extending the 

certification tests and expanding on the tests required during certification to thoroughly address 

durability and reliability issues. Staff has also identified new emission points for gasoline vapor 

emissions and proposed new standards to control these emissions.

Fugitive leaks from the underground storage tank are a concern with existing systems. Staff has 

proposed pressure profiles that would limit underground storage tank pressures and assess 

leaks in the vapor space. Increased use of processors is expected to maintain desired 

underground storage tank pressures, but concerns have been raised regarding toxics in the 

exhaust of combustion processors. New limits for selected hazardous air pollutants are included 

in the proposal. Another proposal to address system deficiencies is to limit the certification to 

four years with renewal contingent on successfully addressing any problems that have been 

documented during the four-year period. Currently, certifications have no expiration date.

A. Include Pressure-Related Fugitives in Efficiency Standard Calculation

B. Replace Efficiency Requirement with Emission Limit

C. Compatible with Phase I System: Staff proposes a new standard requiring that Phase II 

vapor recovery systems shall not cause excess emissions from Phase I systems. 

D. Underground Storage Tank Pressure Limits

E. Nozzle/Dispenser Compatibility: Staff proposes a new standard for nozzle/dispenser 

compatibility to verify that the vapor check valve and hold-open latch are closed when the 

nozzle is properly hung on the dispenser.

F. Unihose MPD Configuration: Gasoline dispensers may have three hoses per fueling point, 

one for each grade of gasoline, or just one hose for all grades, which is known as a unihose 

configuration. The unihose configuration reduces the number of hoses, nozzles and other 

hanging hardware by two-thirds. As this equipment has leak sources, such as check valves, the 

less hanging hardware, the less potential for leaks. Staff proposes that all systems have 

unihose dispensers to reduce the potential number of leak sources.

G. Liquid Removal

H. Vapor Return Piping: Staff proposes to

establish the maximum allowable pipe run lengths during the certification process.

I. Liquid Condensate Traps: A new standard is proposed for liquid condensate traps (also 

known as knockout pots). These traps are used to keep the vapor lines clear when it is not 

possible to achieve the minimum slopes for the vapor recovery piping as discussed above. 
44

J. Connections and Fittings: This new specification explicitly states that connectors and 

fittings shall be leak-free as determined by either leak detection solution or by bagging the 

fittings and observing inflation or deflation of the bag when the underground storage tank vapor 

space in under pressure or vacuum. 

Sections K through M: Proposed new standards applicable to balance systems:

K. Balance nozzles: Staff propose that the balance nozzle check valve be located in the nozzle 

to reduce vapor emissions which result if the check valve is present in another location between 

the nozzle and the underground storage tank. A new specification is proposed to determine 

nozzle bellows insertion force. This will allow a check that the production nozzles are consistent 

with the nozzle certified as well as provide an evaluation of nozzle bellows durability. 

L. Dynamic Backpressure: Staff proposes to modify the existing backpressure requirements to 

remove the limit at 40 CFH. 

M. Component Pressure Drop Limits: New standards are proposed for individual balance 

system components to ensure the overall dynamic backpressure requirements discussed above 

are met. This is necessary as certified balance system equipment is currently specified in a 

matrix that allows different combinations of certified balance system components. Staff has 

learned that some combinations of balance system components are not able to meet the 

dynamic backpressure limits described above. A pressure drop budget has been suggested to 

resolve this problem. Staff has developed component pressure drop limits with input from 

several vapor recovery equipment manufacturers. The proposed individual component pressure 

drops are listed below.

N. Assist Nozzles: Staff propose that all “bootless” assist nozzles be equipped with a vapor 

guard. This is a small cup or mini-boot at the base of the nozzle that assists in routing the vapor 

back through the nozzle. Each assist nozzle must have a vapor check valve. The purpose of the 

check valve is to keep vapors from exiting the underground vapor space through the vapor 

return line when the nozzle is not in operation. 

O. Air to Liquid Ratio Limits: Staff proposes a new limit on air to liquid ratio, or A/L, for assist 

systems.

P. Assist Systems with Common Collection Device: Staff proposes new specifications for 

assist systems utilizing a common collection device. This means that there is one vacuum 

source for the entire station rather than a separate vacuum pump in each dispenser. 

Q. Assist Systems with Destructive Processors: New performance standards provide limits 

on criteria (CO, NOx) and hazardous air pollutant (HAP) emissions for destructive processors. 

Module 3 – ORVR Compatibility

The goal of the ORVR compatibility standard is to eliminate the excess emissions which can 

occur during fueling of an ORVR vehicle with a Phase II vapor recovery system. Phase II 

systems must demonstrate during the certification test period that the Phase II system is 

compatible with ORVR vehicles. Compatibility is determined by verifying that the Phase II 

system can refuel ORVR vehicles and that the refueling does not cause the vapor recovery 

system emissions to exceed the 0.38 lbs/1000 gallon standard. The statewide emission 

reductions (in California) for ORVR compatibility were estimated at 6.3 tons/day. 
45

There are at least two certified systems that achieve ORVR compatibility. These are the balance 

system and the Healy system. These systems do not ingest “excess air” when fueling ORVR 

vehicles and thus do not cause excess emissions. No modifications are necessary for the 

balance system to achieve ORVR compatibility, as the passive system design only collects 

vapor actually displaced by fueling of the vehicle. Since the ORVR vehicles collect the vapor in 

the canister, the dispensing facility with a balance system will dispense fuel without replacing it 

with vapor, thus leading to negative pressure in the underground storage tank. Even if the 

balance system station has some leaks, field data shows the underground storage tank tends to 

maintain negative UST pressure. This was demonstrated during an ARB field test of a balance 

system at which 32% of the fuel was dispensed in ORVR simulation.6 The underground storage 

tank pressure was less than 0.10 inches H2O for 99% of the test, including the bulk delivery 

periods. 

The Healy assist-type vapor recovery system recognizes ORVR vehicle fuelings by means of a 

pressure-sensing diaphragm in the nozzle that prevents the ingestion of air when fueling an 

ORVR vehicle. Other system manufacturers are exploring hydrocarbon sensing technology. 

Both of these systems illustrate how differences in the vapor return line can be monitored to 

detect ORVR vehicles and adjust the vapor collection of the system.

Assist systems with processors may be compatible with ORVR, but have not yet been tested to 

confirm that the existing processors can handle the excess air from fueling a significant 

percentage of ORVR vehicles.

Module 4: Liquid Retention and Spitting

Staff is proposing standards for liquid retention and “nozzle spitting”. Liquid detention occurs 

when liquid gasoline contained in the hanging hardware (nozzles, hoses, etc.) on the dispenser 

is allowed to evaporate into the atmosphere between vehicle fuelings while the nozzle is hung 

on the dispenser. Nozzle spitting is defined as the release of liquid when the nozzle trigger is 

depressed with the dispenser not actuated.

Module 5: Spillage and Dripless Nozzle

Staff proposes to reduce the spillage limit from 0.42 lbs/1000 gallons to 0.24 lbs/1000 gallon 

limit. Staff also proposes to limit the number of drops to one drop per fueling event.

Module 6: In-Station Diagnostics (ISD)

The goal of in-station diagnostics is to provide continuous monitoring of important emissionrelated vapor recovery system parameters and to alert the station operator when a failure mode 

is detected so that corrective action can be taken. It is similar in concept to the current ARB onboard diagnostics regulations for motor vehicles,

where every emission-related component or system must be regularly monitored for proper 

operation. 

General requirements for ISD systems include:

a) Diagnostics that alert the owner/operator to potential problems

b) Provide audible and visible alarms upon detection of defect

c) Prohibit dispensing if an identified defect is not repaired within a reasonable period of 

time
46

d) Monitor critical component performance

e) Provide record of system performance

ISD designs are expected to be specific to vapor recovery system type. However,

certain minimum design parameters, such as calibration of monitors, frequency of

data collection, type of data storage and accessibility, criteria for determining

warning and failure conditions and other parameters shall be proposed by the

applicant and will be evaluated and verified during the certification process. Other

criteria proposed for ISD systems are discussed below.

UST pressure monitoring will be required for all vapor recovery systems. These monitors will 

detect leaks in the underground storage space indicated by long periods that the tank remains 

at atmospheric pressure. Pressure monitors can also indicate if the gasoline delivery was 

conducted correctly. For example, connecting the product hose, but failing to connect the vapor 

return hose, would generate a large pressure spike which would lead to escape of the vapors 

out the vent pipe. Stations which remain at high pressures for significant periods would signal 

an investigation to correct system operations so that pressure-related fugitive emissions are 

minimized.

Additional requirements for in-station diagnostics vary depending on the type of vapor recovery 

system. The three system categories are balance, assist, and assist with processor.

A. Balance Systems -- In addition to the pressure monitor, balance systems would be required 

to check for liquid blockage at each dispensing point. A high pressure drop would indicate a 

blockage problem. Another approach is to measure the vapor to liquid ratio, or V/L ratio (also 

referred to as A/L), in each dispenser with a flowmeter. The flowmeter, installed in each 

dispenser, would measure the amount of vapor flow during every fueling episode without 

reducing the vapor recovery system's efficiency. A consistent lack of flow, or low flow, would 

indicate a blockage.

B. Assist Systems -- Assist systems would also be required to monitor the vapor to liquid ratio, 

or V/L ratio in a way that would detect a failure mode at individual dispensers. Recent 

inspections have discovered that vapor pumps were not operating at some dispensers although 

gasoline fueling was normal. Staff proposes that when the monitor detects an A/L of zero, which 

would mean no vapor recovery, that the dispenser be shut down.

C. Assist Systems with a Processor -- In addition to monitoring the V/L ratio, vapor recovery 

systems with processors must have additional ISD sensors to ensure the processors are 

operating correctly. The hydrocarbon concentration, the flowrate, and other parameters unique 

to each processor will need to be continuously monitored. This is already required for current 

systems with thermal processors. For vapor recovery systems certified to operate at a 

continuous vacuum, a pressure switch is used to detect insufficient vacuum. An alarm signals 

the station operator when the system fails to achieve the certified vacuum level after a 

prescribed time interval, indicating insufficient system leak integrity or a system failure.