United States Office of Air Quality EPA-45013-91-022a 

Environmental Protection Planning and Standards November 1991 

Agency Research Triangle Park NC 2771 1 

Air 

Technical Guidance - Stage II Vapor Recovery 

Systems for Control of 

Vehicle Refueling 

Emissions at Gasoline 

Dispensing Facilities 

Volume I: Chapters 
Technical Guidance -

Stage II Vapor Recovery Systems 

for Control of Vehicle Refueling 

Emissions at Gasoline 

Dispensing Facilities 

Volume I: Chapters 

Emission Standards Division 

U.S. ENVIRONMENTAL PROTECTION AGENCY 

Office of Air and Radiation 

Office of Air Quality Pbmlng and Standards 

ResearchTriangle Park, North Carolina 27711 

November 1891 
This report has been reviewed by the Emission Standards 


Division of the Office of Air Quality Planning and 


Standards, EPA, and approved for publication. Mention 


of trade names or commercial products is not intended 


to constitute endorsement or recommendation for use. 


Copies of this report are available, as supplies permit 


through the Library Services Office (MD-35), U.S. 


Environmental Protection Agency, Research Triangle Park 


NC 27711, (919) 541-2777, or for a nominal fee, from 


National Technical Information Services, 5285 Port 


Royal Road, Springfield VA 22161, (703) 487-4650. 

TABLE OF CONTENTS 

CHAPTER 1.0 INTRODUCTION 

1.1 Background 

1.2 Clean Air Act Requirements 

1.3 Organization of Report 

1.4 References 

CHAPTER 2.0 INDUSTRY DESCRIPTION 

2.1 Industry Description 

2.2 Industry Population and Size 

Distribution 

2.3 Model Plants 

2.4 Summary 

2.5 References 

CHAPTER 3.0 SOURCES OF EMISSIONS 

3.1 General 

3.2 Emission Sources 

3.3 Factors Influencing Emissions 

3.4 Emission Factor Calculations 

3.5 Model Plant Emission Estimates 

3.6 References 

CHAPTER 4.0 CONTROL TECHNOWY 4-1 

4.1 Types of Stage I1 Systems 4-2 

4.2 System Components 4-11 

4.3 California Certification Program 4-33 

4.4 In-Use Effectiveness 4-46 

4.5 References 4-56 

iii 
CHAPTER 5.0 


CHAPTER 6.0 


APPENDIX A 


APPENDIX B 


APPENDIX C 


APPENDIX D 


APPENDIX E 


APPENDIX F 


APPENDIX G 


APPENDIX H 


APPENDIX I 


APPENDIX J 


APPENDIX K 


TABLE OF CONTENTS (Concluded) 


STAGE 11 COSTS 


5.1 Equipment, Installation 


and Annual Costs 


5.2 Model Plant Costs 


5.3 Comparison of Recent Cost Studies 


5.4 Current Costs of Stage I1 Systems 


5.5 References 


PROGRAM IMPLEMENTATION 


6.1 


6.2 


6.3 


6.4 


6.5 


6.6 


Planning 


Regulations 


Permitting 


Inspections 


Summary 


References 


LUNDBERG SURVEY INCORPORATED INDIVIDUAL 


COUNTY SIZE DISTRIBUTION A-1 


STAGE I1 FACILITY COSTS B-1 


CALIFORNIA AIR RESOURCES BOARD 


STAGE 11 (PHASE 11) CERTIFICATION 


TEST PROCEDURES C-1 


CALIFORNIA AIR RESOURCES BOARD 


EXECUTIVE ORDERS D-1 


ILLUSTRATIVE EXAMPLE OF IN-USE 


EFFICIENCY CALCULATION PROCEDURES E-1 


STAGE 11 PROGRAM SUMMARIES F-1 


PUBLIC AWARENESS INFORMATION G-1 


STAGE I1 REGULATIONS H-1 

PERMITTING INFORMATION 1-1 

STAGE I1 TEST WETHODS J-1 

INSPECTION INFORMATION K-1 
LIST OF FIGURES 


Gasoline Marketing in the United States 


Comparison of Ins Angeles Average Service 


Station Size to MPSI Data 


Comparison of EPA Nationwide, Sierra Ins 


Angeles, and Lundberg Retail Service 


Station Size Distributions 


Uncontrolled Service Station Operations 


Controlled Service Station Operations 


(Stage I and Stage 11) 


Region Boundaries 


Vapor Balance System 


Hasstech Assist System 


Hirt Assist System 


Healy Assist System 


Amoco Bellowless Nozzle System 


Example Balance Nozzles 


Example Assist Nozzle 


Example Bellowless Nozzle 


High Hang Hose Configurations 


Example Liquid Removal Device 


Example Emergency Breakaway 


Individual Vapor Balance System 


Underground Piping 


Manifolded Balance System Underground 


Piping 


Relationship of Inspection Frequency to 


Program In-Use Efficiency 


Relationship of Inspection Frequency to 


Program In-Use Efficiency with Exemptions 


Comparison of Installed Capital Costs 


Lines Based on Data Point Averages 


Comparison of Installed Capital Costs 


Lines Based on Linear Regression 


Comparison of Annual Costs Lines Based on 


Data Point Averages 


Comparison of Normalized Annual Costs 


Lines Based on Linear Regression 

LIST OF TABLES 


OZONE NONATTAINMENT AREAS CLASSIFIED 


MODERATE OR ABOVE 


MONTHLY STATE GASOLINE CONSUHPTION FOR 


1990 


GASOLINE THROUGHPUT PERCENTAGES OF 


NATIONAL TOTAL FOR OZONE NONATTAINMENT 


AREAS CLASSIFIED MODERATE OR ABOVE 


ESTIMATED GASOLINE CONSUMPTION BY STATE 


FOR MODERATE AND ABOVE OZONE 


NONATTAINMENT AREAS 


ESTIMATED 1990 RETAIL SERVICE STATION 


POPULATION 


ESTIMATED PRIVATE SERVICE STATION 


POPULATION 


NATIONWIDE RETAIL SERVICE STATION 


DISTRIBUTION ESTIMATED BY EPA 


1990 MPSI MARKET SHARE BREAKDOWN 


IAS ANGELES RETAIL SERVICE STATION 


DISTRIBUTION REPORTED BY SIERRA RESEARCH 


RETAIL SERVICE STATION DISTRIBUTION BASED 


ON MTNDBERG DATA FROM 16 METROPOLITAN 


AREAS 


CONSUMPTION DISTRIBUTION FOR NATIONWIDE 


AND METROPOLITAN AREA SCENARIOS 


ESTIMATED PERCENTAGE OF RETAIL STATIONS 


THAT ARE INDEPENDENTS BY THROUGHPUT 


CLASSIFICATION 


SERVICE STATION MODEL PLANTS AND 


NATIONWIDE POPULATIONS 


EXAMPLE COMPOSITION OF GASOLINE VAPORS 


GASOLINE HAZARDOUS AIR POLLUTANT 


VAPOR PROFILE 


1992 AND BEYOND RVP LIMITS BY MONTH AND 


BY GEOGRAPHIC IBCATION 


MONTHLY AVERAGE DISPENSED LIQUID 


TEMPERATURE 


SEASONAL VARIATION FOR TEMPERATURE 


DIFFERENCE BETWEEN DISPENSED FUEL 


AND VEHICLE FUEL TANK (AT) , 'F 
LIST OF TABLES (Concluded) 


MONTHLY AND GEOGRAPHIC VARIATIONS IN 


REFUELING EMISSION FACTOR 


SUMMARY OF STAGEII/CONVENTIONAL REFUELING 


SPILLAGE DATA 


VOC EMISSIONS FROM REFWELING OPERATIONS 


FOR SERVICE STATION MODEL PLANTS 


SUMMARY OF CARB EXECUTIVE ORDERS CERTIFYING 

SYSTEMS TO BE AT LEAST 


95 PERCENT EFFICIENT 


EFFICIENCY DECREASES ASSOCIATED WITH STAGE 


I1 BALANCE SYSTEM DEFECTS 


PERCENT CONSUMPTION EXCWDED WITH VARIOUS 


STAGE I1 EXEMPTION SCENARIOS 


PURCHASE COSTS FOR VAPOR RECOVERY NOZZLES 


AND REPLACEMENT PARTS (May 1991 Dollars) 


TYPICAL VAPOR RECOVERY HOSE COSTS (May 


1991 Dollars) 


TYPICAL COSTS OF OTHER VAPOR RECOVERY 


COMPONENTS (May 1991 Dollars) 


PIPING COMPONENT DIFFERENCES BETWEEN 


INDIVIDUAL AND MANIFOLDED BALAWCE 


SYSTEM 


TYPICAL VAPOR PIPING COSTS FOR 65,000 


GALLON PER MONTH SERVICE STATION 


ACTIONS TAKEN IN RESPONSE TO FINDING A 


LEAK IN AN UNDERGROUND TANK SYSTEM 


SUMMARY OF STAGE I1 SYSTEM CAPITAL COST 


ESTIMATES FROM ALL SOURCES 


SUMMARY OF NORMALIZED STAGE I1 SYSTEM 


ANNUAL COST ESTIMATES FROM ALL SOURCES 


SUMMARY OF COST ITEMS CHANGED IN APPENDIX 


B COST MODEL TO OBTAIN 1991 COSTS 


1991 STAGE I1 BALANCE SYSTEM CAPITAL COST 


1991 STAGE I1 BALANCE SYSTEM ANNUAL COST 


COST EFFECTIVENESS OF 1991 STAGE I1 BALANCE 


SYSTEMS 


PROGRAM COST EFFECTIVENESS COMPARED TO 


EXEMPTION LEVEL 


SUMWUXY OF STAGE I1 PROGRAM EXEMPTION 


LEVELS AND COMPLIANCE SCHEDULES 


PHASE I1 INSPECTION PROCEDURES 


MASSACHUSETTS STAGE 11 VIOLATIONS 


vii 
1.0 INTRODUCTION 


The Clean Air Act Amendments (CAM) of 1990 require the 


installation of Stage I1 vapor recovery systems in many 


ozone nonattainment areas and direct EPA to issue guidance 


as appropriate on the effectiveness of Stage I1 systems. 


This document provides guidance on the effectiveness of 


Stage I1 systems and other Stage I1 technical information. 


Stage I1 vapor recovery on vehicle refueling is an 


effective control technology to reduce gasoline vapor 


emissions that contain volatile organic compounds (VOC) and 


hazardous air pollutants. Vehicle refueling emissions 


consist of the gasoline vapors displaced from the automobile 


tank by dispensed liquid gasoline. The Stage I1 system 


collects these vapors at the vehicle fillpipe and returns 


them to the underground storage tank. Without vapor 


recovery, the dispensing of gasoline causes the introduction 


of fresh air into the storage tank. Liquid gasoline then 


evaporates until liquid/vapor equilibrium is attained. 


Stage I1 systems return saturated vapors to the storage tank 


thus preventing this evaporation and actually saving 


gasoline. 


The purpose of this document is to provide information 


and guidance to State and local agencies related to the 


planning, permitting, and implementation of Stage I1 vapor 


recovery programs. While the subject of enforcement is 


introduced in this document, more detailed information and 


guidance for enforcement programs are provided under 


separate cover in the EPAts nnEnforcement Guidance for Stage 


I1 Programsnt to be issued concurrently with this document. 

The information and guidance provided in this technical 


document is not intended to establish a binding norm or a 


final determination of issues or policies. Decisions on 


issues and policies will be made during the development, 


submittal, and review process on each individual State 


Implementation Plan. 


1.1 BACKGROUND 


Stage 11 vapor recovery has been a part of VOC emission 


control in California for some time. Since the introduction 


of Stage I1 in California in the early 1970s, this program 


has become one of California's major VOC control strategies. 


Seventeen districts in California contain areas which are 


classified nonattainment for ozone and have Stage 11 


programs that have been in effect for over a decade. It is 


estimated that in California, Stage 11 vapor recovery 


systems reduce hydrocarbon emissions by 48,000-56,000 tons 


annually, and save 15-18 million gallons of gasoline.ln2 The 


remaining districts in California have also recently adopted 


hazardous air pollutant regulations requiring Stage 11 vapor 


recovery for control of benzene emissions. 


Other areas of the country have also established Stage 


11 vapor recovery programs. The District of Columbia 


implemented a Stage 11 program in the early 1980s and 


Missouri adopted vehicle refueling regulations in the St. 


Louis area in the late 1980s. In the late 1980s and early 


19908, several other States and local agencies adopted Stage 


11 programs. These agencies currently include New Jersey, 


New York (New York city metropolitan area), Massachusetts, 


Philadelphia, Washington, Oregon, and Dade County, Florida. 


These programs range from ones that are well into the 


implementation and enforcement period to those in the 


initial stages. A number of additional areas are also 


considering Stage I1 regulations. 

1.2 CLEAN AIR ACT REQUIREMENTS 


The requirements in the CAAA of 1990 regarding Stage I1 


vapor recovery are contained in Title I: Provisions for 


Attainment and Maintenance of National Ambient Air Quality 


Standards. A key element of this title is that it 


wclassifiesw areas with similar pollution levels. The 


purpose of this classification system is to match pollution 


control requirements with the severity of an area's air 


quality problem. For ozone, there are five classes: . 

marginal, moderate, serious, severe, and extreme. Marginal 


areas are subject to the least stringent requirements and 


each subsequent classification is subject to more stringent 


requirements. Areas in the higher classes must meet 


requirements of all the areas in lower classifications plus 


the additional requirements of their class. 


Subject to the provisions of Section 202, Stage I1 


vapor recovery is required for moderate areas, and thus is 


required for all areas classified as serious, severe, or 


extreme. Section 182(b) of the CAAA of 1990 contains 


requirements for moderate areas and section 182(b)(3) 


specifically addresses gasoline vapor recovery. 


(3) GASOLINE VAPOR RECOVERY. 


(A) GENERAL RULE.-Not later than 2 years 


after the date of the enactment of the Clean 


Air Act Amendments of 1990, the State shall 


submit a revision to the applicable 


implementation plan to require all owners or 


operators of gasoline dispensing systems to 


install and operate, by the date prescribed 


under subparagraph (B), a system for gasoline 


vapor recovery of emissions from the fueling 


of motor vehicles. The Administrator shall 


issue guidance as appropriate as to the 


effectiveness of such system. This 


subparagraph shall apply only to facilities 


which sell more than 10,000 gallons of 


gasoline per month (50,000 gallons per month 


in the case of an independent small business 


marketer of gasoline as defined in section 


325). 


(B) EFFECTIVE DATE - The date required 

under subparagraph (A) shall be- 

ti) 6 months after the ado~tion 


date; in the case of gasoline &spensing 


facilities for which construction 


commenced after the date of the 


enactment of the Clean Air Act 


Amendments of 1990; 


(ii) one year after the adoption 


date, in the case of gasoline dispensing 


facilities which dispense at least 


100,000 gallons of gasoline per month, 


based on average monthly sales for the 


2-year period before the adoption date; 


or 


(iii) 2 years after the adoption 


date, in the case of all other gasoline 


dispensing facilities. 


Any gasoline dispensing facility described 


under both clause (i) and clause (ii) shall 


meet the requirements of clause (i). 


(C) REFERENCE TO TERMS - For purposes of 

this paragraph, any reference to the term 


'adoption date' shall be considered a 


reference to the date of adoption by the 


State of requirements for the installation 


and operation of a system for gasoline vapor 


recovery of emissions from the fueling of 


motor vehicles. 


Using nonattainment designations based on 1987-1989 design 


values or a few areas based on 1988-90 design values, these 


requirements would affect 56 metropolitan areas in the 


United States. A breakdown of these areas by classification 


is 32 moderate, 14 serious, 9 severe, and 1 extreme. The 


areas are shown in Table 1-1. 


In addition, Title 1, section 184, Control of 


Interstate Ozone Air Pollution, creates an ozone transport 


region comprised of the States of Connecticut, Delaware, 


Maine, Maryland, Massachusetts, New Hampshire, New Jersey, 


New York, Pennsylvania, Rhode Island, and Vermont, and the 


CMSA that includes the District of Columbia. 

TABLE 1-1. OZONE NONATTAINMENT AREAS 


CLASSIFIED MODERATE OR ABOVE 


Extreme 


Los Angeles-South Coast Air Basin, CA 


Severe 


Baltimore, MD Philadelphia-Wilm-Trent, 


Chicago-Gary-Lake County, IL-IN PA-NJ-DE-MD 


ousto on-~alveston-~razoria, TX San Diego, CA 

Milwaukee-Racine, WI Southeast Desert Modified 


New York-N New Jer-Long Is., AQMA, CA 


NY-NJ-CT Ventura Co, CA 


Serious 


Atlanta, GA Portsmouth-Dover-Rochester, 


Baton Rouge, LA NH 


Beaumont-Port Arthur, TX Providence (All RI) , RI 

Boston-Lawrence-Worcester Sacramento Metro, CA 


(E .MA) , MA-NH San Joaquin Valley, CA 

El Paso, TX Sheboygan, WI 


Greater Connecticut Springfield (Western MA) , MA 

Muskegon, MI Washington, DC-MD-VA 


Moderate 


Atlantic City, NJ Miami-Fort Lauderdale-W. Palm 


Charleston, WV Beach, FL 


Charlotte-Gastonia, NC Monterey Bay, CA 


Cincinnati-Hamilton, OH-KY Nashville, TN 


Cleveland-Akron-Lorain, OH Parkersburg, WV 


Dallas-Fort Worth, TX Phoenix, AZ 


Dayton-Springfield, OH Pittsburgh-Beaver Valley, PA 


Detroit-Ann Arbor, MI Portland, ME 


Grand Rapids, MI Raleigh-Durham, NC 


Greensboro-Winston Salem-High Reading, PA 


Point, NC Richmond-Petersburg, VA 


Huntington-Ashland, WV-KY Salt Lake City, UT 


Kewaunee Co, WI San Francisco-Bay Area, CA 


Knox & Lincoln Cos, ME Santa Barbara-Santa 

Lewiston-Auburn, ME Maria-Lompoc, CA 


Louisville, KY-IN St Louis, MO-IL 


Manitowoc Co, WI Toledo, OH 


Source: 56 Federal Reaister 56692, 40 CFR 81, Air Quality 


Designations; Final Rule. November 6, 1991. 


1-5 

The requirements for this region also include provisions 


related to Stage 11, in section 184(b)(2). 


(2) Within 3 years after the date of the 


enactment of the Clean Air Act amendments of 


1990, the Administrator shall complete a 


study identifying control measures capable of 


achieving emission reductions comparable to 


those achievable through vehicle refueling 


controls contained in section 182(b)(3), and 


such measures or such vehicle refueling 


controls shall be implemented in accordance 


with the provisions of this section. 


Notwithstanding other deadlines in this 


section, the applicable implementation plan 


shall be revised to reflect such measures 


within 1 year of completion of the study. 


In summary, all of the States in the transport region will 


be required to implement Stage 11 controls or controls 


determined by EPA to achieve comparable emission reductions. 


Another portion of the Amendments with potential 


impacts on the implementation of Stage I1 in moderate areas 


is contained in Title 2: Provisions Relating to Mobile 


Sources. Section 202, Control of Vehicle Refueling 


Emissions, deals with the control of vehicle refueling 


emissions using "onboard" systems. Onboard vapor control 


systems consist of activated carbon canisters installed on 


the vehicle to control refueling emissions. The carbon 


canister system adsorbs the vapors that are displaced from 


the vehicle fuel tank by the incoming liquid gasoline, and 


subsequently purges these vapors from the carbon to the 


engine when the engine is operating. 


....The requirements of section 182(b)(3) 

(relating to Stage I1 gasoline vapor 


recovery) for areas classified under section 


181 as moderate for ozone shall not apply 


after promulgation of such standards and the 


Administrator may, by rule, revise or waive 


the application of the requirements of such 


section 182(b)(3) for areas classified under 


section 181 as Serious, Severe, or Extreme 


for ozone, as appropriate, after such time as 


the Administrator determines that onboard 


emissions control systems required under this 


paragraph are in widespread use throughout 


the motor vehicle fleet. 

This section has the effect of removing Stage I1 


requirements for moderate areas once onboard controls are 


promulgated, and for the higher classified areas by EPA 


rule, once onboard is in "widespread usem. 


The 1990 CAAA exempt, in section 182(b)(3), facilities 

with gasoline throughputs of 10,000 gallons per month or 


less and independent small business marketers (independents, 


as defined in section 325 of the Clean Air Act as amended in 


August 1977) with throughputs less than 50,000 gallons per 


month. Section 325 has now been redesignated as section 326 


by PL 98-213 and reads as follows: 


Sec. 326. (a) The regulations under this 


Act applicable to vapor recovery from fueling 


of motor vehicles at retail outlets.of 


gasoline shall not apply to any outlet owned 


by an independent small business marketer of 


gasoline having monthly sales of less than 


50,000 gallons. In the case of any outlet 


owned by an independent small business 


marketer, such regulations shall provide, 


with respect to independent small business 


marketers of gasoline, for a three-year 


phase-in period for the installation of such 


vapor recovery equipment at such outlets 


under which such marketers shall have- 


(1) 33 percent of such outlets in 


compliance at the end of the first year 


during which such regulations apply to such 


marketers. 


(2) 66 percent at the end of such second 


year, and 


(3) 100 percent at the end of the third 


year. 


(b) Nothing in subsection (a) shall be 


construed to prohibit any State from adopting 


or enforcing, with respect to independent 


small business marketers of gasoline having 


monthly sales of less than 50,000 gallons, 


any vapor recovery requirements for mobile 


source fuels at retail outlets. Any vapor 


recovery requirement which is adopted by a 


State and submitted to the Administrator as 


part of its implementation plan may be 


approved and enforced by the Administrator as 


part of the applicable implementation plan 


for that State. 


(c) For purposes of this section, an 


independent small business marketer of 

gasoline is a person engaged in the 


marketing of gasoline who would be required 


to pay for procurement and installation of 


vapor recovery equipment under section 324 of 


this Act or under regulations of the 


Administrator, unless such person- 


(1)(A) is a refiner, or 


(B) controls, is controlled by, or is 


under common control with, a refiner, 


(C) is otherwise directly or indirectly 


affiliated (as determined under the 


regulations of the Administrator) with a 


refiner or with a person who controls, is 


controlled by, or is under a common control 


with a refiner (unless the sole affiliation 


referred to herein is by means of a supply 


contract or an agreement or contract to use 


as a trademark, trade name, service mark, or 


other identifying symbol or name owned by 


such refiner or any such person), or 


(2) receives less than 50 percent of his 


annual income from refining or marketing of 


gasoline. 


For the purpose of this section, the term 


"refinerw shall not include any refiner whose 


total refinery capacity (including the 


refinery capacity of any person who controls, 


is controlled by, or is under common control 


with, such refiner) does not exceed 65,000 


barrels per day. For purposes of this 


section, llcontrolw of a corporation means 


ownership of more than 50 percent of its 


stock. 


While this defines an independent marketer, it allows a 


State or local agency to select an exemption level less than 


50,000 gallons per month. A single exemption level approach 


is currently taken by many regulatory agencies in their 


Stage I1 programs. 


There is another direct reference to Stage 11 vapor 


recovery contained in the CAAA of 1977. This is section 324 


regarding Cost of Emission Control for Vapor Recovery. 


Sec. 324. (a) The regulations under this 


Act applicable to vapor recovery with respect 


to mobile source fuels at retail outlets of 


such fuels shall provide that the cost of 


procurement and installation of such vapor 


recovery shall be borne by the owner of such 


outlet (as determined under such 


regulations). Except as provided in 

subsection (b), such regulations shall 


provide that no lease of a retail outlet by 


the owner thereof which is entered into or 


renewed after the date of enactment of the 


Clean Air Act Amendments of 1977 may provide 


for a payment by the lessee of the cost of 


procurement and installation of vapor 


recovery equipment. Such regulations shall 


also provide that the cost of procurement and 


installation of vapor recovery equipment may 


be recovered by the owner of such outlet by 


means of price increases in the cost of any 


product sold by such owner, notwithstanding 


any provision of law. 


(b) The regulations of the Administrator 


referred to in subsection (a) shall permit a 


lease of a retail outlet to provide for 


payment by the lessee of the cost of 


procurement and installation of vapor 


recovery equipment over a reasonable period 


(as determined in accordance with such 


regulations), if the owner of such outlet 


does not sell, trade in, or otherwise 


dispense any product at wholesale or retail 


at such outlet. 


In summary, the Clean Air Act and its 1990 Amendments 


impose several direct requirements regarding Stage I1 vapor 


recovery. The provisions in Title 1 will require that Stage 


I1 controls be installed at all gasoline dispensing 


facilities with throughputs above specified levels in 


moderate, serious, severe, and extreme ozone nonattainment 


areas, and Title I1 contains provisions which may relieve 


the requirement for moderate and above areas if onboard 


vehicle controls are promulgated. There are also direct 


references that define independent marketers and describe 


the party responsible for incurring the costs of vapor 


recovery. 


1.3 ORGANIZATION OF REPORT 


The chief objective of this document is to provide 


information pertaining to Stage I1 vapor recovery and 


guidance to State and local agencies in the planning and 


implementation of Stage I1 programs. Therefore, the report 

is organized in a manner that first provides an introduction 


to Stage I1 vapor recovery and then emphasizes 


implementation issues and potential problems. 


Chapter 2 profiles the gasoline marketing industry, 


with special consideration given to gasoline dispensing 


facilities. Nationwide populations and size distributions 


of these facilities are discussed as well as size 


distributions representative of metropolitan areas. In 


addition, model facilities are provided. 


Chapter 3 discusses the sources of emissions at vehicle 


refueling facilities, including the calculation of refueling 


emission factors. This chapter also provides a discussion 


of factors which influence refueling emissions. Emissions 


are calculated for the model facilities described in 


Chapter 2. Finally, emission factors are calculated on a 


State basis taking into consideration RVP and temperature 


differences across the nation. 


Chapter 4 discusses vehicle refueling control 


technology, both from a current and an historical basis. In 


addition, a description of the California Air Resources 


Board's (CARB) vapor recovery equipment certification 


program is given which includes details of the certification 


process and the certified equipment. Finally, the 


effectiveness of the equipment is discussed, along with 


program in-use efficiency . Chapter 5 addresses the costs associated with Stage I1 


control. Equipment, installation, and maintenance costs are 


discussed. Also, studies conducted in the St. Louis area 


which Lnclude actual costs of Stage I1 installations are 


presented. 


The final chapter is a guidance-oriented chapter which 


uses the infornation presented in the earlier chapters. The 


chapter discusses regulations and approaches to planning, 


permitting, and enforcement, and is based on areas of the 


country that have experience with Stage I1 vapor recovery 


programs. It also addresses problems experienced by these 

agencies and suggested methods for others to use in avoiding 


similar difficulties. 


1.4 REFERENCES 


1. McKinney, Laura. California Air Resources Board. 


Gasoline Vapor Recovery Certification. (Presented 


at the Air and Waste Management Association 83rd 


Annual Meeting. Pittsburgh, PA. June 24-29, 


1990). 


2. Letter from Kunaniec, K., Bay Area Air Quality 


Management District, to Shedd, S., U.S. 


Environmental Protection Agency, Chemicals and 


Petroleum Branch. July 31, 1991. Comments on 


Preliminary technical guidance document. 

2.0 INDUSTRY DESCRIPTION 


The purpose of this chapter is to define the industry 


and facilities affected by a Stage I1 vapor recovery 


program. The entire gasoline marketing industry is first 


discussed, with special emphasis placed on the facilities 


where gasoline is dispensed into vehicle fuel tanks (service 


stations). Population and characteristics of the service 


station industry are then addressed, including a discussion 


of model dispensing facilities which may be used to 


summarize the service station size distribution and 


facilitate the estimation of environmental and economic 


impacts. 


2.1 INDUSTRY DESCRIPTION 


The gasoline marketing industry includes many 


components that move gasoline, from the refinery to the bulk 


terminal and on to service stations. Gasoline produced by 


refineries is distributed by a complex system comprised of 


wholesale and retail outlets. Figure 2-1 depicts the main 


elements in the marketing network. The flow of gasoline 


through the marketing system is shown from the point of 


production, (the refinery), through bulk storage facilities 


(bulk terminals), and finally to retail service stations or 


private facilities where it is dispensed into vehicle fuel 


tanks. Gasoline is often carried directly to the dispensing 


facility from the bulk terminal; however, some gasoline 


passes through intermediate storage and loading facilities 


called bulk plants. The wholesale operations of storing and 


transporting gasoline, including delivery toand storage in 

t 
 @ 

7 

t 

Service Station BulkPlant 1 


Consumer 

Figure 2-1. Gasoline Marketing In The United States 

a service station underground tank, are commonly called 


Stage I operations. Vehicle refueling operations are 


commonly termed Stage 11. 


Bulk gasoline terminals serve as the major distribution 


point for the gasoline after it leaves the refinery. 


Gasoline is most commonly delivered to terminals by 


pipeline, but may also be transferred by ship or barge. 


Gasoline is stored in large aboveground tanks and later 


pumped through metered loading areas, called loading racks, 


into delivery tank trucks. These tank trucks, in turn, 


deliver product to various wholesale and retail accounts in 


the marketing network. 


Bulk gasoline plants are secondary distribution 


facilities that typically receive gasoline from bulk 


terminals transported by tank trucks, store it in 


aboveground storage tanks, and subsequently dispense it into 


smaller account trucks for delivery. Only a small portion 


of the total gasoline is routed through bulk plants and much 


of this eventually is delivered to private accounts and 


small service stations. 


Gasoline tank trucks are normally divided into 


compartments with a hatchway at the top of each compartment. 


Loading can be accomplished by top splash loading or 


submerged fill through the hatch, or by bottom loading. 


Either top or bottom loading can be adapted for vapor 


collection. However, almost all gasoline is transferred 


using bottom loading because of State vapor recovery 


regulations and operating and safety advantages. The vapor 


collection equipment on the truck is basically composed of 


enclosed valves and piping that enable the vapors from the 


compartment being filled to be transferred to the storage 


tank being emptied (vapor balance) or to a vapor control 


system. 


Although the terms @@service stationt@, or @@dispensing 


facilityt@, may be used to describe various types of 


facilities, the term is used in this document to mean any 

site where gasoline is dispensed to motor vehicle fuel tanks 


from stationary storage vessels. This includes both public 


(retail) and private facilities. Miscellaneous retail 


outlets that are considered service stations include 


conventional service stations, convenience stores, and mass 


merchandisers or wlpumpers.w Other facilities that may be 


considered in this classification are marinas, parking 


garages, and other similar facilities which sell gasoline to 


the public. 


Private facilities include those locations where 


gasoline is dispensed into government agency (Federal, 


military, State, and local) vehicles, fleet (auto rental, 


utility companies, taxis, school buses, etc.) vehicles, and 


trucking and local service vehicles. Other private 


facilities include those that refuel farm equipment. 


2.2 INDUSTRY POPULATION AND SIZE DISTRIBUTION 


The volume of gasoline consumed and the number of 


service stations in an area are important considerations in 


assessing refueling emissions as well the potential emission 


reductions, the economic impact, and even the overall 


viability of a Stage I1 vapor recovery program. Also, 


current and future trends are important in understanding the 


industry and possible impacts. For example, the present 


trend toward larger stations means that fewer stations and a 


greater portion of the throughput would be subject to Stage 


I1 controls. Also, the emergence of single nozzle multi- 


product dispensers could greatly lessen the costs of Stage 


I1 equipment and maintenance. 


2.2.1 Gasoline Consumwtioq 


It is estimated by the Federal Highway Administration 


that approximately 116 billion gallons of gasoline were 


consumed in the United States in 1990.' One can assume that 


essentially this entire volume was eventually loaded into 


vehicle fuel tanks, resulting in refueling VOC emissions. 


Therefore, nationwide emissions from this source could have 

been almost 700,000 Mg of VOC/year, using a typical 


uncontrolled refueling emission factor of 1,450 mg of 


VOC/liter of gasoline dispensed (discussed in Chapter 3). 


As one would expect, gasoline consumption is directly 


related to population. Therefore, States and areas with 


high population density tend to show the highest gasoline 


consumption figures. Monthly gasoline consumption by State 


for 1990 is shown in Table 2-1. 


It is estimated that over 40 percent of the gasoline in 


the United States is consumed in ozone nonattainment areas 


classified as moderate and above. This is due to the large 


population density and vehicle traffic centered around the 


metropolitan areas that traditionally have ozone attainment 


problems. The percentage of the nationwide throughput for 


each of the nonattainment areas shown in Table 1-1 


represents is shown in Table 2-2. The estimated annual 


gasoline consumption for ozone nonattainment areas by State 


for 1990 is provided in Table 2-3. Ozone nonattainment area 


consumption was estimated using county-to-State consumption 


ratios calculated from EPA1s 1985 NEDS gasoline consumption2 


and the nonattainment counties are the final area 


designations based on 1987-89 design values or 1988-90 


design values for a few areas. These data show close to 


half of the national throughput could be affected by Stage 


I1 programs and that the impacts in serious, severe, 


extreme, and possibly moderate areas could be considerable. 


Since the recommended method used to calculate 


refueling emissions is based on gasoline throughput, 


accurate consumption estimates are critical. Gasoline 


consumption data on a county basis are available from EPA8s 


National Air Data Branch. These data are calculated from 


State gasoline consumption data provided by the Bureau of 


the Census and apportioned to the county level using total 


sales data. This approach has come under scrutiny, as the 


relationship between gasoline consumption and total sales 



TABLE 2-2. GASOLINE THROUGHPUT PERCENTAGES OF 


NATIONAL TOTAL FOR OZONE NONATTAINMENT 


AREAS CLASSIFIED MODERATE OR ABOVE 


Percentage Percentage 

of of 

Nonattaimt Areas National Nonattairrmt Areas National 

Throughput Throughput 

Los Angeles-Swth Coast Air Basin, U 

Baltimore, W) 0.99 Phi Ladelphia-Ui Lm-Trent, PA-NJ-DE-W) 

Chicago-Gary-Lake Canty, IL-IN 2.52 Southeast Desert Modified AW, U 

Houston-Galveston-Brazoria, TX 1.64 San Diego, U 

Milwaukee-Racine, UI 0.52 Ventura Co, U 

Ncw York-N New Jer-Long Is, NY-NJ-CT 4.97 

Ser iws 

Atlanta, GA 1 .I8 

Baton Rouge, LA 0.27 Portsmouth-Dover-Rochester, NH 

Beaunont-Port Arthur, TX 0.18 San Jompin Valley, U 

Boston-Lawrence-Uorcester (€.HA), 2.40 Providence (All RI), RI 

HA-NH Sacrmto Metro, CA 

EL Paso, TX 0.17 Sheboygan, UI 

Greater Connecticut 1.26 Springfield Western HA), HA 

Muskegon, MI 0.05 Uashington, DC-W)-VA 

Moderate 

Atlantic City, NJ 0.12 Hieuni-Fort Lauderdale-U. Palm Beach, 

Charleston, W 0.12 FL 

Charlotte-Gastonia, NC 0.25 Honterey Bay, CA 

Cincinnati-Hamilton, OH-KY 0.60 Nashville, TN 

Cleveland-Akron-Lorain, OH 1.10 Parkersburg, W 

Dallas-Fort Uorth, TX 1.63 Phoenix, AZ 

Dayton-Springf ield, OH 0.35 Pittsburgh-Beaver Valley, PA 

Detroi t-Am Arbor, HI 1.76 Portland, HE 

Grand Rapids, HI 0.25 Raleigh-Durham, NC 

Greensboro-Uinston Salcm-H Point, NC 0.30 .Reading, PA 

Hmtington-Ashland, W-KY 0.09 Richmond-Peterskrrg, VA 

Keuaunee co, UI 0.01 Salt Lake City, UT 

Knox 8 Lincoln Cos, HE 0.03 San Francisco-Bay Area, U 

Leuiston-Alkrrn, HE 0.08 Santa Barbara-Santa Maria-Larpoc, U 

Louisville, KY-IN 0.34 St Louis, W-IL 

Hanitowoc Co, UI 0.03 Toledo, OH 

Source: Nonattainwnt desig~tions fran 56 56692 (See Table 1-1) 

Gasoline consurption percentages tstimted using 1985 WEDS fuel use report 

* Gasoline consurption not reported because the consurption for this area and the LA Swth Coast Air Basin 

consurption cited We overlap, and sufficient infomtion is not in the database to allow proportion 

this area's consurption fran the LA consurption. 
STATE 

ALA0AMA 

ALASKA 

ARIZONA 

ARKANSAS 

CALIFORNIA 

C0L0RAOO 

CONNECTICUT 

DELAWARE 

DISTRICT OF COL. 

FLORIDA 

GEORGIA 

HAWAI I 

IDAHO 

ILLINOIS 

INDIANA 

IOWA 

KANSAS 

KENTUCKY 

LOUISIANA 

MAINE 

MARYLAND 

MASSACHUSETTS 

MICHIGAN 

MINNESOTA 

MISSISSIPPI 

M ISSOUR I 

WNTANA 

NEBRASKA 

NEVADA 

NEW HAMPSHIRE 

NEW JERSEY 

NEW MEXICO 

NEW YORK 

NORTH CAROL INA 

NORTH DAKOTA 

OHIO 

OKLAHW 

OREGON 

PENNSYLVANIA 

RHODE ISLAND 

SOUTH CAROLINA 

SOUTH DAKOTA 

TENNESSEE 

TEXAS 

UTAH 

VERmNT 

VIRGINIA 

WASHINGTON 

WEST VIRGINIA 

WISCONSIN 

WYOnl NG 

NATIONWIDE 

------=-1=1--1=1-11--I---I---I---I-I-II---=-~---=--.,---~-----=--------=---=--


SOURCES: (1) Federal Highway Administration, Clonthly Gasoline Reports 

As Reported in 1991 NPN Factbook 

(2) Preliminary estimate based on 1987-89 design values 

or 1988-90 design values for a few areas 
has not been well documented. EPA1s Global Emissions and 


Control Division, Air and Energy Engineering Research 


Laboratory, in Research Triangle Park, NC, is studying this 


issue in detail and plans to develop correlations with 


other data such as population density, vehicle registration, 


number of licensed drivers, highway usage, and many other 


parameters, which will provide accurate estimates of 


gasoline consumption on the county level.3 


EPA1s mobile source emission factor model, MOBILE4.1, 


estimates refueling emission factors that are dependent on 


either gasoline throughput or vehicle use, i.e. vehicle 


miles travelled (VMT). As discussed in more detail in 


Chapter 3, the emission factors are calculated in MOBILE4.1 


using the same equation discussed in Section 3.4.1. 


However, MOBILE4.1 also uses fuel economy information to 


convert the emission factor from mass per gasoline 


throughput to mass per VMT. 


2.2.2 Service Station Po~ulation 


While gasoline throughput, or consumption, is the 


parameter used to calculate emissions, an estimate of the 


number of facilities is necessary to help characterize the 


affected community in more detail and to assess economic 


impacts, both on industry and on regulatory agencies. 


2.2.2.1 Retail Stations. A precise determination of 


the number of retail service stations is very difficult. 


The U.S. Census Bureau is the source usually relied upon for 


information of this type. The Census Bureau provides 


estimates of the number of retail service stations in the 


Census of Retail Trade, but these data have limited 


usefulness in defining the entire retail service station 


industry. These reports are produced every five years and 


have shown a steady and dramatic decrease in the number of 


service stations. The reported service station population 


has gone from 226,459 in 1972 to 114,748 in the most recent 


1987 report.4 However, the definition of service station 


used by the Census Bureau and the changing face of the 

industry make it difficult, if not impossible, to draw 


conclusions from these estimates. 


The Census Bureau defines as retail service stations 


only those outlets that do 50 percent or more of their 


dollar business in petroleum products. In 1972, this 


provided a reasonably representative count of the retail 


gasoline distribution facilities, as traditional service 


stations accounted for the majority of retail outlets. 


Today however, many facilities, such as convenience stores, 


have large gasoline throughputs yet their sales from 


gasoline may not total 50 percent of their sales due to the 


wide variety of products offered. 


An added problem with these census data is that they 


consider only those stations that have payrolls. This 


automatically excludes the privately owned and operated 


family, or "Mom and Popw, facilities. 


Another source of information traditionally used to 


estimate retail service station population in the interim 


period between Census Retail Trade Reports is "Franchising 


in the Economyw, a report formerly generated by the U.S. 


Department of Commerce. This survey was discontinued in 


January 1989, but was resumed by the International 


Franchising Association, a private enterprise. These 


reports also suffer from shortcomings as the definition of 


service station is identical to that used by the Census 


Bureau. The estimates by Franchising in the Economy place 


the number of service stations in 1990 at 111,700.5 


Franchising in the Economy does provide figures on 


convenience store population. The 1988-1990 report accounts 


for 17,000 stores. However, "National Petroleum Newsw (NPN) 


refutes this number by estimating that there are as many as 


80,000 convenience stores in bu~iness.~ 


After determining the need for a more accurate, current 


estimate of retail gasoline dispensing facilities, NPN began 


a vigorous nationwide survey. The results of this effort 


were contained in the April 1991 issue of NPN.7 NPN 

embarked on this study by collecting the information on a 


State basis, and allowing each State to be responsible for 


its own statistics. Official figures for retail gasoline 


station counts were not available for many States. The 


study involved searching through motor vehicle department, 


licensing department, and tax division records in more than 


half of the States. NPN also contacted weights and measures 


departments and key local trade associations. NPN estimated 


that approximately 67 percent of the data obtained were 


"hardw numbers; i.e., based on registration, licensing, and 


tax division compilations. The remaining third were 


obtained from unofficial estimates and, in a few cases, best 


guess type estimates. 


The results of this NPN study are provided in Table 


2-4. As shown, the total retail service station population 


in the nation is estimated to be 210,120. The NPN article 


also discusses various methodologies which may be useful in 


the determination of gasoline station population on a State, 


regional, or local basis. 


EPA has conducted several studies of the gasoline 


marketing industry in connection with the development and 


implementation of emission regulations. These studies 


required estimates of the number of service stations. For 


the most part, EPA has also relied on Census Bureau data as 


the basis for its estimates. However, the Agency has long 


recognized the shortcomings of these data and has attempted 


to locate other sources of accurate information. EPA has 


utilized service station retail population estimates of 


approximately 211,000 in 1982,' and 190,000 in 1984.~ 


In 1991, EPA is studying the hazardous air pollutant 


(HAP) emissions from gasoline marketing sources in 


accordance with Title I11 of the 1990 Clean Air Act 


Amendments, including those from tank truck unloading at 


service stations. During the search for information related 


to nationwide service station population, EPA received 


estimates of the current number of retail gasoline outlets 

TABLE 2-4. ESTIMATED 1990 RETAIL SERVICE STATION POPULATION 


State 


Alabama 


Alaska 


Arizona 


Arkansas 


California 


Colorado 


Connecticut 


Delaware 


Dist. of Columbia 


Florida 


Georgia 


Hawaii 


Idaho 


Illinois 


Indiana 


Iowa 


Kansas 


Kentucky 


Louisi'ana 


Maine 


Maryland 


Massachusetts 


Michigan 


Minnesota 


Mississippi 


Missouri 


Number of 


Stations State 


Montana 


Nebraska 


Nevada 


New Hampshire 


New Jersey 


New Mexico 


New York 


North Carolina 


North Dakota 


Ohio 


Oklahoma 


Oregon 


Pennsylvania 


Rhode Island. 


South Carolina 


South Dakota 


Tennessee 


Texas 


Utah 


Vermont 


Virginia 


Washington 


West Virginia 


Wisconsin 


Wyoming 


NATIONWIDE TOTAL 


Number of 


Stations 


210,120 


Source: National Petroleum News, ggCounting Procedure Shows 


How Retail Outlet Population is Greater Than 


Expected," April 1991. 

from a number of sources. Independent estimates by both the 


American Petroleum Institute (API)" and Lundberg Survey, 


1nc.l' placed the number of retail outlets at approximately 


175,000. 


The NPN estimates discussed earlier were considered. 


However, EPA concluded that NPN article may slightly 


overstate the retail population. Support for these 


conclusions lies in the fact that Lundberg Survey recently 


conducted a detailed survey of service stations in Arizona 


that placed the population at 2,000, while the NPN article 


estimated there are twice that number in the state.'' Also, 


there are other questions raised by some of the NPN data, 


one of which is seen when comparing State service station 


population and gasoline throughput. For example, the NPN 


numbers show that North Carolina has over two times as many 


retail service stations as New York, while the gasoline 


throughput is approximately 50 percent of New York's. 


In lieu of any more precise or better supported number, 


the 175,000 figure is being used for the 1990 nationwide 


population of retail service stations in HAP analysis. This 


is a significant increase in the total number from the 


estimated 111,000 for 1989 in the Franchising in the Economy 


data. This increase is primarily due to the inclusion of 


"otherm gasoline dispensing facilities not included in the 


Census Bureau definition of service station. 


While the nationwide estimate could be a point of 


contention, there are essentially no affects of the 


nationwide population for Stage I1 purposes. Since the 


Stage I1 requirements contained in the 1990 CAM are related 


to ozone nonattainment areas only, the important service 


station population figures are those for these nonattainment 


areas. These nationwide estimates are included here to 


provide States and local agencies with various information 


related to retail service station population. These 


agencies have the alternative to use any of this information 


in estimating the population for their area. 

2.2.2.2 private Stations. All of the estimates 

discussed above are only for public, or retail facilities. 


In addition to "publicw outlets, there are a significant 


number of "privatew facilities. These outlets are 


maintained by governmental, commercial, and industrial 


consumers for their own fleet operations. Government 


agencies with central garages are typically regional 


locations for the postal service, Federal government 


agencies, and State and county agencies. Other 


miscellaneous facilities include utility companies, taxi 


fleets, rental car fleets, school buses, and corporate 


fleets. Estimated national population figures for private 


facilities are shown in Table 2-513 The agricultural sector 

of private outlets, including farms, nurseries, and 


landscaping firms, are not included. In general, 


agricultural outlets have throughputs less than the cutoff 


levels. These private facilities are an important segment 


of the industry and should be considered in population 


estimates. The numbers shown in Table 2-5 were estimated in 

1978. However, no more recent nationwide estimates have 


been identified since this time. 


2.2.2.3 Inde~endents. One issue not addressed in any 

of these estimates is the number of independent service 


stations. As the Clean Air Act contains a different 


exemption level for independents, it would be beneficial to 


describe this segment of the industry. However, as 


discussed in Chapter 1, the definition of "independentw 


provided in the Clean Air Act is difficult to apply on a 


quantitative basis. Also, the complex nature of service 


station ownership and suppliers increases the difficulty of 


a tally of independents. Estimates of relative percentages 


of independent stations are discussed in the following 


section. 


2.2.3 Service Station Size Distribution 

Not only is the number of facilities important to a 


Stage I1 vapor recovery program, but estimates of the 

- - 

TABLE 2-5. ESTIMATED PRIVATE SERVICE STATION POPULATION' 


"Privatew Outlets 


Government (Federal, military, 


state, local) 


Miscellaneous (auto rental, 


utilities, others) 


Trucking and Local Service 


Taxis 


School Buses 


Total 


a Not including about 2.5 million agricultural outlets. 

Source: "The Economic Impact of VaDor Recovery Reaulations 


on the Service Station Industrv," EPA-450/3-78-029, 


July 1978. 

relative sizes of facilities within the population are 


needed for the cost analyses discussed later. The 


parameters most useful to rank service stations are gasoline 


throughput and the number of nozzles. This apportionment is 


important for many reasons, but two principal ones are: (1) 


to estimate the facilities which will be exempted, and (2) 


to estimate the economic impacts of a regulation. 


2.2.3.1 Retail Stations. The size distribution of 


retail service stations according to gasoline throughput 


used in the 1987 EPA Stage I study is given in Table 2-6.14 


This size distribution, based on throughput, was used to 


develop a national profile. The population is skewed toward 


smaller stations, with over 75 percent having throughputs 


less than 25,000 gallons per month. 


Concerns have been raised regarding the applicability 


of these estimates to larger metropolitan areas that are 


typically nonattainment for ozone. In a 1988 report, "An 


Analysis of Stage I1 and Onboard Refueling Emissions 


Controltt (Sierra Report),'' prepared by Sierra Research for 


the Motor Vehicle Manufacturers Association, the 


characteristics of the metropolitan service station 


population are addressed. In this report, it is stated that 


"EPA has ... failed to recognize that the average size of 

gasoline stations in metropolitan nonattainment areas is 


larger than the national average." 


The Sierra Report contained a profile from Los Angeles 


and compared it to the EPA estimates, to demonstrate the 


difference in retail service station distribution for large 


metropolitan areas. The use of Los Angeles data to 


characterize all metropolitan areas in the United States is 


questionable; however, Sierra did provide information 


compiled by MPSI Americas, Inc. that suggests the Los 


Angeles data are only slightly higher than other areas. 


MPSI, Inc. of Tulsa, Oklahoma annually provides statistics 


that are reported in the NPN Factbook. Among the statistics 


are estimates of average facility gasoline consumption on a 

TABLE 2-6. NATIONWIDE RETAIL 


SERVICE STATION DISTRIBUTION ESTIMATED BY EPA 


Gasoline Throughput Range Percentage of Retail 


(gallons/month) Service Stations 


Source: "Draft RIA: Proposed Refueling Emission 


Regulations for Baseline Motor Vehicles - Volume I 

Analysis of Gasoline Marketing Regulatory 


Strategies," EPA-450/3-87-001a. 

category basis. The categories are service stations, 


pumpers, convenience food stores, and others. Overall 


totals are also given. The MPSI summaries for 1990 as 


contained in the 1991 NPN Factbook16 are shown in Table 2-7. 


In order to validate the application of the Los Angeles data 


to other areas of the country, Sierra used 1987 MPSI 


information as reported in the 1988 NPN Factbook. Sierra 


compared the average facility throughput for Los Angeles to 


that reported by MPSI for 1987. The retail service station 


size distribution from the Sierra Report for Los Angeles is 


shown in Table 2-8, and the relationship of the Los Angeles 


data to the 1987 MPSI data is illustrated in Figure 2-2. 


The 1989 MPSI average service station size is also shown for 


comparison in Figure 2-2. 


EPA has obtained service station throughput data for 


several metropolitan areas to verify the application of the 


Los Angeles information presented in the Sierra Report to 


metropolitan areas across the U.S. The data obtained were 


compiled by the Lundberg Survey incorporatedi' and listed 


gasoline stations and their associated gasoline monthly 


volumes in gallons. There were approximately 11,000 


individual service stations in the database which 


represented 16 metropolitan statistical areas across the 


United States. The areas included were: 


Syracuse, NY Houston-Galveston-Brazoria, TX 

Phoenix, AZ St. Louis, MI-IL 

San Diego, CA Portland-Vancouver, OR-WA 

Detroit, MI Milwaukee-Racine, WI 

Lansing, MI New York-Newark-Long Island, NY-NJ-CT 

Grand Rapids, MI Providence-Pawtucket-Fall River, MA-RI 

El Paso, TX Madison, WI 

Orlando, FL Santa Barbara-Santa Maria-Lompoc, CA 

The service stations were placed into seven categories 


according to monthly gasoline throughput. This was done for 

TABLE 2-7. 1990 MPSI MARKET SHARE BREAKDOWN 

Service Convenience 

Stations Purpers Stores Others Tota 1 

Northeastern Region 

X of Outlets 

X of Volw 

Avg. Monthly Volw 

(Gallons) 

Midwestern Region 

X of Outlets 

X of Volw 

Avg. Monthly Volw 

(Gallons) 

Svlbelt Region 

X of Outlets 

X of Volw 

Avg. Monthly Volw 

(Gal Lons) 

Yestern Region 

X of Outlets 

X of Volw 

Avg. Monthly Volw 

(Gallons) 

Total United States 

X of Outlets 

X of Volw 

Ava. Monthly Volw 62.4% 

(~al lons) 

Source: MPSI Inc., Tulsa, Oklahoma, reported in lWl NPN factbook. 
TABLE 2-8. LOS ANGELES RETAIL 


SERVICE STATION DISTRIBUTION REPORTED BY SIERRA RESEARCH 


Gasoline Throughput Range Percentage of Service 


(gallons/month) Stations 


Source: Sierra Research, "An Analysis of Stage I1 and 


Onboard Refueling Emissions Controlw, November 30, 


1988. 


each county as well as an overall distribution for the 


entire database. The overall distribution from these data 


is shown in Table 2-9. As seen in the table, the 


distribution is skewed toward the larger stations, just as 


Sierra reported. More detailed breakdowns of the Lundberg 


data are provided in Appendix A. 


A side-by-side comparison of the EPA nationwide 


distribution, the Sierra Los Angeles distribution, and the 


Lundberg information distribution is provided in Figure 2-3. 


These data indicate that the nationwide EPA distribution, 


while accurate for nationwide analyses, may not be 


appropriate for large metropolitan areas. 


A comparison was also made between the consumption 


distribution of the EPA nationwide facility distribution and 


the metropolitan area distribution. Table 2-10 summarizes 


this comparison. As would be expected from the facility 


distribution, the throughput distribution in metropolitan 


areas is skewed toward the larger throughput stations. 


2.2.3.2 Private Stations. Based on information from 


Arthur D. Little, Inc.18 and the U.S. Census Bureau,19 it was 


previously estimated that approximately 90 percent of 


private outlets have throughputs of less than 10,000 gallons 


per month. In other analy~es,~~#~' 
 EPA has used this figure 


and distributed the remaining 10 percent in proportions 


representative of the public service station distribution. 


2.2.3.3 Jndewendents. Previous EPA analyses have 


also estimated the relative percentages of retail facilities 


that would be classified as "independent marketersw under 


the Clean Air Act definition discussed in Chapter 1. Table 


2-11 shows the relative percentages of retail stations that 


are considered to be independents with the associated 


throughput ranges. 


These percentages were originally estimated during the 


1984 Study based on information contained in EPA's report 


"The Economic Impact of Vapor Recovery Regulations on the 


Service Station This report categorized public 

TABLE 2-9. RETAIL SERVICE STATION DISTRIBUTION 

BASED ON LUNDBERG DATA FROM 16 METROPOLITAN AREAS 

Gasoline Throughput Range Percentage of Service 

(sallons/month) Stations 

Source: Lundberg Survey, Incorporated. 
EPA Nationwide Sierra Los Angeles Lundberg Metropolitan 

....-..- ............... 


Figure 2-3. Comparison of EPA Nationwide, Sierra Los 

Angeles, and Lundberg Retail Service station Size 


Distributions 

TABLE 2-10. CONSUMPTION DISTRIBUTION FOR NATIONWIDE 


AND METROPOLITAN AREA SCENARIOS 


Percent Consum~tion 


Facility Throughput Range Nationwide Metropolitan 


(gallons/month) Distribution Distribution 


TABLE 2-11. ESTIMATED PERCENTAGE OF RETAIL STATIONS THAT 


ARE INDEPENDENTS BY THROUGHPUT CLASSIFICATION 


r - Throughput Range Percentage of 


(gallons/month) Independents -

0 - 9,999 18% 
public service stations by company-controlled/company 


operated, company- controlled/dealer operated, dealer 


controlled/dealer operated, and convenience stores and 


provided throughput distributions for each by direct 


supplier and independent marketer/wholesaler. The 


distributions in the Economic Impact Study were adjusted to 


remove all convenience stores from independent marketers (it 


is not expected that convenience stores obtain greater than 


50 percent of sales from gasoline) and add all dealer- 


controlled/dealer operated stations to independent 


marketer/wholesaler. Based on the Census Bureau definition 


of service station (greater than 50 percent of sales from 


gasoline) and studies that estimate the total number of 


public outlets that sell gasoline, an approximate ratio of 


the Census population tot total population was estimated. 


This ratio was approximately 2/3. The importance of this 


ratio is that it indicates that approximately 1/3 of the 


stations do not obtain over 50 percent of their sales form 


gasoline. Therefore, the percentages obtained for 


independent marketers were reduced by one-third. 


2.2.4 Trends in the Service Station Industry 


There are several trends in the service station 


industry which could have an effect on a Stage 11 program. 


Public acceptance of Stage I1 equipment is an important 


aspect of any Stage I1 program. This is especially true in 


light of the increase in the popularity of self-service type 


stations. NPN reports substantial increases in the 


percentage of self-service outlets across the country from 


under 20 percent in 1975 to over 80 percent in 1989.~~
A 


similar trend is related to unattended gasoline stations. 


This concept seems to be growing faster for commercial 


fleets than for retail facilities. It is anticipated that 


the number of convenience stores selling gasoline will 


continue to increase, as well as the volume of gasoline sold 


by these stores. 

As discussed in the previous section, the size of 


service stations continues to rise. A steady increase in 


the average facility gasoline throughput has been seen in 


the last decade. The widespread popularity of dispensers 


that allow the pumping of two or three gasoline products, or 


ggmultiproduct dispensersw have allowed a station to have 


more nozzles per station. However, the onset of dispensers 


that have only one nozzle that can dispense multiple 


gasoline products may cause a substantial decrease in the 


number of nozzles per station. 


Costs are discussed in Chapter 5, but one trend with 


cost implications should be mentioned in this section. The 


leaking underground storage tank (UST and LUST) programs, 


depending upon the age and condition of the tank, require 


replacement of tanks and/or piping. These programs could 


affect Stage I1 programs in two different ways. First, if 


the underground tanks and piping are replaced concurrently, 


then the cost attributable to Stage 11 could be lessened. 


Second, if these events do not occur simultaneously, then it 


is possible that service station owners may be required to 


initiate relatively major reconstruction more than once. 


This issue is discussed in more detail in Chapter 5. 


2.3 MODEL PLANTS 


The development of typical, or model plants is a 


technique often employed to assist in the determination of 


impacts of a regulation during the planning stages. It is 


preferable to develop several model plants to represent the 


range of sizes of facilities present in the industry. The 


distribution of facilities is applied to the model plants to 


determine the relative percentage of facilities depicted by 


each model plant. 


In previous analyse~,~~~~~ 
 EPA has developed model plants 


for the service station industry. The parameters selected 


for the model plants are shown in Table 2-12. 


2.4 SUBMAFtY 

It is important to develop an accurate characterization 


of the industry that would be affected by a Stage I1 vapor 


recovery regulation. This chapter has provided information 


related to gasoline consumption, service station population, 


size distribution, and model plants that may be useful to 


agencies involved in these planning activities. 

2.5 REFERENCES 


Federal Highway Administration, Monthly Gasoline 


Reports 1990, as reported in 1991 National 


Petroleum News (NPN) Factbook Annual Issue. June 


1990. 


1985 NEDS Fuel Use Report. U.S. Environmental 


Protection Agency National Air Data Branch. 


Research Triangle Park, NC. 


Memorandum from Nowood, P., Pacific Environmental 


Services, Inc., to Shedd, S., U.S. Environmental 


Protection Agency. April 11, 1991. Reporting on a 


meeting with Larry Jones, EPA, AEERL, regarding 


gasoline consumption project. 


1987 Census of Retail Trade. U.S. Department of 


Commerce. 


Franchising in the Economy 1988-1990. International 


Franchising Association, Washington, D.C. 


"Updated Survey Shows Fairly Static Growth In 


Service Station Populationn, National Petroleum 


News (NPN) . April 1990. 

"Counting Procedure Shows How Retail Outlet 


Population Is Greater Than Expectedmm, National 


Petroleum News (NPN). ~pril 1991. 


Evaluation of Air Pollution Regulatory Strategies 


for Gasoline Marketing Industry. U.S. Environ-


mental Protection Agency, Office of Air Quality 


Planning and Standards and Office of Mobile 


Sources. Publication No. EPA-450/4-84-012a. July 


1984. 


Draft Regulatory Impact Analysis: Proposed 


Refueling Emission Regulations for Gasoline-Fueled 


Motor Vehicles -- Volume I - Analysis of Gasoline 

Marketing Regulatory Strategies. U.S. Environ-


mental Protection Agency. Office of Air Quality 


Planning and Standards and Office of Mobile 


Sources. Publication No. EPA-450/3-87-001a. July 


1987. 


Telecon. Thompson, S., Pacific Environmental 


Services, Inc., with Peterson, B., American 


Petroleum Institute. March 27, 1991. Number of 


Service Stations. 

Telecon. Bollman, A., Research Triangle Institute, 


with Keene, B., Lundberg Survey, Inc. April 19, 


1991. Number of Public Service Stations. 


Reference 11. 


The Economic Impact of Vapor Recovery Regulations 


on the Service Station Industry. U.S. Occupational 


Safety and Health Administration, Washington, D.C., 


and U.S. EPA, Research Triangle Park, N.C. 


Publication No. EPA-450/3-78-029. July 1978. 


Reference 9. 


Sierra Research, An Analysis of Stage I1 and 


Onboard Refueling Emissions Control, prepared for 


Motor Vehicle Manufacturers Association, Inc. 


November 30, 1988. 


W.S. Regional and National Market Shares.", MPSI 


Inc., Tulsa Oklahoma, as reported in 1990 National 


Petroleum News (NPN) Factbook Annual Issue. June 


1990. 


Lundberg Survey, Inc. Census Data Gasoline 


Throughput for U.S. EPA, June 28, 1989. 


Reference 13. 


1977 Census of Retail Trade. U.S. Department of 


Commerce. 


Reference 8. 


Reference 9. 


Reference 13. 


1990 National Petroleum News (NPN) Factbook Annual 


Issue. June 1990. 


Reference 8. 


Reference 9. 

3.0 SOURCES OF EMISSIONS 


In this chapter, the emission sources at service 


stations are described along with factors that affect the 


rate at which emissions occur. In addition, emission 


estimates or emission factors are presented that represent 


emissions in different areas of the country. Emission rates 


for different model facilities are presented to show how 


total emissions vary by facility size and to characterize 


rates for facilities throughout the country. 


3.1 GENERAL 


In virtually all cases in the gasoline marketing chain, 


emissions of gasoline vapors are caused by the transfer of 


liquid gasoline from one container (or tank) to another. 


The liquid entering the fixed volume container displaces an 


equal volume of gasoline vapor/air mixture to the 


atmosphere. If the volume of vapor displaced from the 


container equals the volume of liquid loaded into the 


container, the ratio of vapor to liquid volume (V/L ratio) 


is equal to 1. 


However, the volume of vapors displaced often does not 


equal the volume of liquid transferred. Temperature 


variations between the liquid loaded and the vapors in the 


tank can cause an expansion or contraction of the vapors 


causing the V/L ratio to vary from 1. When warm liquid 


enters a cool tank, the temperature in the tank increases 


thereby increasing the volume of vapors in the tank and 


increasing the volume of vapors displaced. This causes the 


volume of displaced vapors to be greater than the volume of 

liquid loaded, resulting in a V/L ratio greater than 1. 


This is called vapor growth. 


The opposite occurs when the liquid entering the fixed 


volume tank is cooler than the tank temperature. The cooler 


temperature reduces the vapor volume displaced and the V/L 


ratio is less than 1. This is called vapor shrinkage. 


Vapor growth or vapor shrinkage can be a common occur- 


rence when transferring liquids from service station 


underground tanks containing liquid of relatively stable 


temperature, insulated by the surrounding earth, into a 


vehicle fuel tank at extreme temperatures caused by over- 


road exposure to ambient conditions (fuel tanks very warm in 


summer, very cold in winter). Because vapor growth and 


vapor shrinkage occur so often, errors in emission estimates 


can easily be encountered by simply assuming the volume of 


vapors displaced equals the volume of liquid entering the 


tank. Testing of these emission sources requires accurate 


measurements of displaced volumes to calculate the mass of 


emissions released. 


Because the amount of emissions that occur is tied so 


closely to the amount of liquid transferred into the tank or 


container, emission factors are often expressed in terms of 


mass emitted per volume of liquid loaded (i.e., pounds of 


VOC per 1,000 gallons of liquid loaded or milligrams of VOC 


per liter of liquid loaded). 


Increased emphasis is being placed on the evaluation of 


the emissions of hazardous air pollutants (HAPs). The CAAA 

of 1990 specify 189 compounds that have been classified as 


HAPs. Several of these HAPs are typically found in gasoline 


vapors. Gasoline vapors are made up of a complex mixture of 


compounds originating from the evaporation of liquid 


gasoline.' Table 3-1 shows an example mixture of compounds 


found in displaced gasoline vapors. Several of these 


compounds correspond with compounds found on the list of 189 

TABLE 3-1. EXAMPLE COMPOSITION OF GASOLINE VAPORS 


Compound Weight Percent 


N-Propane 


Isobutane 


N-Butane 


Isopentane 


N-Pentane 


2-2-Dimethyl Butane 


2-3-Dimethyl Butane 


2-Methyl Pentane 


3-Methyl Pentane 


N-Hexane 


3-3-Dimethyl Pentane 


3-Methyl Hexane 


Methyl Cyclopentane 


Benzene 


Toluene 


Othera 


Other hydrocarbons with individual weight percent less 


than 0.5. 


Source: Furey, Robert and Nagel, Bernard. Composition of 


Vapor Emitted From a Vehicle Gasoline Tank During 


Refueling. SAE Technical Paper Series #860086, 


February 1986. 

HAPS listed in Title I11 of the CAAA. Table 3-2 summarizes 


the HAP compounds found in normal gasoline vapors and 


indicates the percent of total emissions, on a weight basis, 


that each HAP represent^.^ These HAP emission rates were 


calculated using liquid gasoline composition, Raoultls Law, 


and gasoline vapor analyses. These values may not compare 


exactly between Tables 3-1 and 3-2, since Table 3-1 is based 


on one experimental sample group and the normal fuel profile 


in Table 3-2 is based on a wide variety of samples. 


The reformulated and oxygenated fuel requirements 


contained in Title I1 of the CAAA will affect the HAP 


content of gasoline. Also contained in Table 3.2 is an 


estimate of a vapor profile for a reformulated gasoline. 


Taken into account in this profile are the required 


reductions in benzene and total aromatic content, the 


addition of methyl tert butyl ether (MTBE) as an oxygenate, 


and the reduction of all other components due to the 


addition of a large volume of MTBE. HAP emissions from all 


Stage I gasoline marketing sources (pipelines, terminals, 


bulk plants, storage tanks, tank trucks, service station 


underground tank loading) are being evaluated for regulation 


under the National Emission Standards for Hazardous Air 


Pollutant (NESHAP) program. 


An interesting point is with regard to MTBE. MTBE is a 


gasoline additive traditionally used in small amounts as an 


octane booster. However, with oxygenated fuel requirements 


contained in Title I1 of the 1990 Clean Air Amendments, the 


addition of MTBE in gasoline will be widespread. 


Approximately 15 weight percent MTBE in liquid gasoline is 


needed to meet the 2.7 weight percent oxygen requirement for 


carbon monoxide nonattainment areas, and 11 weight percent 


to meet the 2.0 weight percent oxygen requirements for the 


largest ozone nonattainment areas. This means that for 


gasolines containing MTBE, 15 percent or more of gasoline 


vapor could be made up of components listed by EPA as 


hazardous pollutants. 

TABLE 3-2. GASOLINE HAZARDOUS AIR POLLUTANT VAPOR PROFILE 


HAP Content 

HAP/VOC wt percentage ratio 

Hazardous Air Pollutant Arithmetic Estimated 

Average Normal Reformulated 

Fuel Fuel 

Hexane 

Benzene 

Toluene 

2,2,4 Trimethylpentane 

(iso-octane) 

Xylenes 

Ethylbenzene 

Naphthalene 

Cumene 

MTBE 

TOTAL HAPSa 

a Columns do not add to totals. Total HAPS as well as 


individual HAPS were calculated for each data point in 


the normal fuel analysis, and thus the totals are not 


simply sums of the individual components. Adjustments 


were made to this normal fuel based on the reformulated 


gasoline requirements to predict a reformulated profile. 


Source: Preliminary Estimates from EPA Stage I NESHAP 


project on gasoline marketing. 

3.2 EMISSION SOURCES 


Emission sources described in this section are divided 


into service station Stage I emissions (gasoline transfers 


into the station underground storage tanks) and service 


station Stage I1 emissions (automobile refueling emissions). 


3.2.1 Service Station Stacfe I Emissions 


Gasoline vapor or volatile organic compound (VOC) 


emissions occur when gasoline being delivered to the service 


station displaces vapors to the atmosphere (as described 


earlier). Under a typical gasoline delivery, a hose is 


connected from the delivery truck to a ground level fitting 


that is attached to the underground gasoline storage tank 


(see Figure 3-1). The gasoline is allowed to drop from the 


delivery truck into the underground tank. This activity is 


often called "the service station dropw or "dropping a load 


of productw. Displaced vapors are emitted to the atmosphere 


through the underground tank vent. Submerged loading, 


consisting of a tube installed to within 6 inches of the 


bottom of the tank, significantly reduces emissions because 


turbulence caused by the splashing of the delivery product 


in the underground tank is minimized. 


When Stage I emission controls are used, displaced 


vapors are collected and routed back into the delivery truck 


using a combination of pipes and hoses (see Figure 3-2). 


Stage I emissions from service stations and the resulting 


technology are not the subject of this report but have been 


included in the discussion for completeness. These 


emissions have been the subject of several EPA programs and 


further information can be obtained in other EPA 


publications.3*685s6*7 While tank truck unloading (Stage I) 

and vehicle refueling (Stage 11) are separate events, 


defective Stage t equipment (leaking seals, missing caps, 


etc.) can adversely affect the efficiency of a Stage I1 


system. 

Loading of Service Station Underground Storage Tank 

(A) With No Controls. 

(B)Semce Station Vehicle Refueling With No Controls 

Figure 3-1. Uncontrolled Service Station Operations 

Loading of Service Station Underground Storage Tank 

Witb Vapor Balana System (Stage I Controls). (A) 

Coaxial Vaporfiquid Hose 

Service Station Vehicle Refueling Witb Vapor Balance 

(B) System (Stage IIantrob). 

Figure 3-2. Controlled Service Station operations 


(Stage I and Stage 11) 

3.2.2. Vehicle Refuelina Emissions 


3.2.2.1 Vehicle Refuelinq. Gasoline vapor/VOC 


emissions occur when liquid from the underground tank is 


dispensed into the vehicle fuel tank. Vapors contained in 


the fuel tank are displaced back through the vehicle 


fillneck and are emitted to the atmosphere (see Figure 3-1). 


With the installation of Stage I1 vapor recovery equipment, 


displaced vapors are captured at the vehicle fillneck and 


routed back to the underground tank. Figure 3-2 illustrates 


the basic Stage I1 vapor recovery concept. Detailed 


descriptions of the Stage I1 vapor recovery equipment and 


discussions of emission reductions can be found in Chapter 


4. Factors influencing emissions and estimates of emissions 


are presented later in this chapter. 


3.2.2.2. S~illaae. VOC emissions from the vehicle 


refueling operation can also occur when loading the vehicle 


at a rate faster than the displaced vapors can be released. 


When this occurs liquid is forced up the fillneck and can 


cause "spitbacklI of liquid back out of the vehicle fillneck. 


Overfilling of the vehicle can also cause liquid spillage. 


Overfills can occur due to a failure in the nozzle shutoff 


mechanism or can occur due to operator error (repeated 


"topping offgg of the vehicle tank). Small amounts of liquid 


drips can also be spilled due to wetted nozzle tips upon 


removal from the vehicle and vapor condensation on cool 


nozzle surfaces. 


3.2.2.3. Breathina/Em~tvina Losses. Emptying losses 


occur when gasoline is pumped out of the service station 


underground tank to refuel a customerls automobile fuel 


tank. Air is drawn into the underground tank, through the 


underground tank vent pipe, to replace the volume of liquid 


removed. Prior to any gasoline being removed from the tank, 


the liquid and vapors in the underground tank are at 


equilibrium and the vapor space above the liquid is 


essentially saturated. When liquid is pumped from the tank 


and air is drawn in through the vent, the vapor space above 

the liquid is no longer in equilibrium with the liquid. A 


small amount of liquid evaporation takes place in an attempt 


to again saturate the vapor space above the liquid. This 


evaporation causes an increase in volume in the vapor space 


and this excess volume is pushed out the underground tank 


Vent pipe. The portion of vapors pushed out the vent is 


called the emptying loss. 


Stage I1 vapor recovery equipment helps to controls 


this emptying loss by returning essentially saturated vapors 


from the vehicle fuel tank back to the service station 


underground tank to replace the liquid removed. Because the 


return vapors are saturated and equal in volume to the 


liquid removed, equilibrium in the tank is maintained, 


product evaporation does not take place, and emptying loss 


emissions do not occur. 


Breathing loses in fixed volume storage tanks are 


caused by vapor and liquid expansion and contraction due to 


diurnal temperature changes. As temperatures increase, 


vapor volume increases pushing vapor out of the vent pipe 


(out-breathing). When temperatures decrease, vapor volume 


decreases and air is drawn into the tank (in-breathing). 


Breathing loss emissions are minimal at service stations 


since storage tanks are located underground, insulated by 


the earth, and have a very stable temperature profile. 


However, breathing losses from service station storage tanks 


are becoming more prevalent due to the popularity of above 


ground storage tanks and the installation of vaulted 


underground storage tanks. Above ground storage tanks are 


more susceptible to temperature and pressure changes and 


thus are more likely to experience both vapor growth and 


vapor shrinkage. It is also reported that the double wall, 


or Waultedt1 underground storage tanks that are being 


installed to comply with underground storage tank (UST) 


regulations are more susceptible to thermal effect and 


theref ore breathing losses 

3.3 FACTORS INFLUENCING EMISSIONS 


Many studies have been done to evaluate the factors 


that affect refueling emissions. A recent study by EPA1s 


Office of Mobile Sources (OMS) empirically derived an 


equation that predicts the emissions from an automobile 


refueling event.'' This testing consisted of controlled 


vehicle refueling inside a shed with sensors to gather fuel 


tank temperature, liquid dispensed temperature, and 


displaced vapor. Emissions testing was conducted on a 


variety of light-duty vehicles, with varying fillneck 


configurations, and on light-duty trucks. The following 


sections describe the different factors that influence this 


emission factor equation. 


3.3.1 Reid Va~or Pressure (RVP) 


Certainly one of the most important factors affecting 


the emissions from automobile refueling is the volatility of 


the gasoline. A less volatile gasoline will create less 


emissions when transferred than a more volatile gasoline. 


Reid vapor pressure (RVP) is a common measure of fuel 


volatility and represents the vapor pressure of the fuel at 


100°F. RVP is a standard industry measure of fuel 


volatility. Although RVP is a measure of fuel volatility at 


100°F, the empirical emissions equation described below 


(3.4.1) adjusts this volatility to reflect actual 


temperature conditions. 


The RVP of gasoline is adjusted through blending at the 


refinery to account for temperature and pressure different- 


iations across the country. In the summer when warm 


temperatures enhance volatilization, gasolines can be 


blended with a lower RVP and still provide ample vaporiza- 


tion for combustion in the vehicle engine. Reducing RVP in 


the summer, therefore, reduces emissions from gasoline 


transfers without reducing vehicle performance. Too high an 


RVP in the summer can create excess volatilization in the 


engine causing vapor lock. During the winter months when 


cold temperatures inhibit volatilization, gasolines can be 

blended with a higher RVP to ensure sufficient volatiliza- 


tion for engine start-up and operations. This increase in 


RVP when temperatures decrease and decrease in RVP when 


temperatures increase is an attempt to provide a uniform 


fuel volatility for smooth engine performance all year. 


Information on winter/summer actual RVP samples are 


taken throughout the year in selected areas. This 


information is compiled and published by the National 


Institute for Petroleum and Energy Research (NIPER) 


organization. This data is based on fuel surveys and fuel 


analyses conducted throughout the country. 11 


Fuel RVPs can be blended to adjust for certain altitude 


and temperature variations in specific geographical areas. 


On June 11, 1990, EPA promulgated limits for RVP in the 


summer for all States." These limits will reduce fuel RVP 


to 9.0 or below in most States in the summer months. 


However, the RVP requirements proposed in the May 29, 1991, 


Federal ~eaister'~ 
 indicate that RVPs less than 9.0 will 


only be required during the summer months in ozone 


nonattainment areas. The remaining areas in States with 


lower RVP limits need only meet 9.0. Table 3-3 summarizes 


the RVP restrictions by month for each State for the entire 


year.14815 The weighted averages presented are weighted by 


the monthly fuel consumption presented in Table 2-1. In 


addition, the summer weighted average RVP is calculated 


using the values in the table (i.e. values less than 9.0 


RVP) and is therefore representative of nonattainment areas 


for those States. Attainment area RVP would be higher since 


summer RVP is not regulated below 9.0. For those States 


where an RVP restriction less than 9.0 appears in the summer 


months, this more stringent restriction applies only to 



nonattainment areas within the State. RVP in non summer 


months is typically blended to conform to limits suggested 


by ASTM and is not usually regulated by EPA. 


3.3.2 Liauid Tem~erature 


Along with fuel volatility, the temperature of the fuel 


being dispensed and the temperature of the vehicle fuel tank 


affect the rate in which emissions occur. The warmer the 


temperature of the dispensed liquid or the vehicle fuel tank 


the more volatile the liquid becomes and the more emissions 


occur. Also, the temperature difference between the 


dispensed liquid and the liquid in the fuel tank can affect 


emissions. The loading of cool dispensed fuel into a warm 


tank will decrease emissions (like vapor shrinkage) and the 


loading of warm fuel into a cold vehicle tank can increase 


emissions (like vapor growth). The more typical situation 


is where you have cool liquid being dispensed into a warm 


vehicle tank. The empirically derived emission factor 


equation accounts for these temperature differences. 


As with RVP, these key temperature parameters will vary 


with time of year and with geographical location. Table 3-4 


presents dispensed fuel temperature presented by month for 


several regions in the country (Figure 3-3 indicates the 


regional boundaries).16 As would be expected, dispensed 


fuel temperatures increase in the summer when RVPs decrease. 


Table 3-5 presents average annual fuel differentials 


between the dispensed fuel and the fuel in the vehicle tank. 


Data are presented by region for an annual average AT, plus 


values for summer and winter months.17 In addition, data 


are presented for a 5-month (May-September) and 2-month 


(July and August) ozone season. 


3.4 EMISSION FACTOR CALCULATIONS 


3.4.1 Vehicle Refueling 


As discussed in Section 3.3, EPA Office of Mobile 


Sources empirically derived an equation to estimate 




refueling emissions based on test data. This equation is as 


follows: 

E, = 264.21 (-5.909) - 0.0949 (AT) + 0.0884 (T,, 

+ 0.485 (RVP)] 

where : 

E, = Emission rate, milligrams of VOC per 

liter of liquid loaded 

RVP = Reid vapor pressure, psia 

AT = Difference between the temperature of 

the fuel in the automobile tank and the 

temperature of the dispensed fuel, OF 

T, = Dispensed fuel temperature, OF 

Using this emission factor equation, .and the RVP and 


temperatures found in Tables 3-3, 3-4, and 3-5, automobile 


refueling emission factors can be derived for specific 


geographic locations and for different seasons of the year. 


Emission factors calculated using this equation should allow 


the estimation of emissions from automobile refueling for 


any area of the country. This approach is certainly more 


accurate than using the single value provided in EPA's 


Compilation of Emission Factors (AP-42).18 


Table 3-6 illustrates how these emission factors can 


vary from location to location and by time of year for each 


State. Using the emission factor equations indicates 


variations of over 40 percent between summertime emissions 


rates found in Colorado (1,080 mg/L) and Florida (1,550 


mg/liter). This indicates that an error would be introduced 


in emission planning activities if a single factor were 


used. 


While this methodology has been used in prior EPA 


st~diesl~n~~
 to estimate refueling emissions, it should be 


noted that revised State implementation plan (SIP) emission 


inventory guidance issued by EPA in 19912' recommends that 


refueling emissions be calculated using emission factors 



generated by MOBILE 4.1, EPA's mobile source emission factor 


computer model. MOBILE4.1 utilizes the same equation 


presented above to calculate a refueling emission factor. 


User supplied inputs for temperature and RVP are used to 


calculate an emission factor based on gasoline throughput 


(-/gal). MOBILE4.1 also will convert this emission factor 


to one based on VMT by using assumptions for the on-road 


automobile population and the fuel economy for each model 


year. There is uncertainty introduced by using VMT as the 


parameter for calculating refueling emissions. First, the 


fact that a vehicle travels through a certain area does not 


indicate that the vehicle is refueled in the same area, and 


second, the use of fuel economy introduces another layer of 


uncertainty to the calculation. In the absence of accurate 


throughput data, refueling emissions may be estimated using 


VMT. However, it is suggested in MOBILE4.1 guidance that 


refueling emissions be calculated using throughput data 


instead of VMT.22 


3.4.2 S~illaae 


Several recent studies have been conducted comparing 


the occurrences of spillage during refueling events both 


with and without Stage I1 vapor recovery equipment. The 


studies are: (1) a 1989 study by the American Petroleum 


~nstitute~~;
 (2) a 1990 study by the California Air 


Resources ~oard~~; 
 and (3) a 1983 study by the Bay Area Air 


Quality Management ~istrict.~~ 
 A fourth study was conducted 


in 1987 by L~ndberg.~~ 
 The Lundberg study provided some 


simplified frequency information but no quantification of 


spillage or emissions. The survey contained only 


observances of spillage along with other questions and 


observations taken during refueling episodes. Since no 


quantification of spills was contained in the study, it is 


not summarized here. 


The three studies were similar in that they observed 


refueling at both conventional and Stage I1 systems, 


documented spillage frequency, and estimated the quantity of 

spillage that occurred. Spillage quantities were estimated 


by correlating spill area measured on the ground with volume 


quantities of liquid gasoline spilled. Table 3-7 summarizes 


the results of these studies. 


The API study was conducted at 20 "well maintainedw 


Stage I1 systems in the Washington, DC area and 20 


conventional systems in Baltimore. Considerable effort was 


taken to assure that the Stage I1 and conventional stations 


were comparable in throughput, number of nozzles, and 


location (urban inner city). Spills were quantified by 


measuring wetted surface area caused by the drip or spill 


that occurred during the refueling cycle. 


Inspectors/observers were trained by spilling specific 


liquid quantities and measuring the resulting spill area. 


Spill areas were calibrated at each test site to take into 


account differences in surface porosity, fuel character- 


istics, and ambient conditions. The API study found an 


increase in spill frequency with Stage I1 equipment and an 


increase in spill quantity. 


The CARB study was similar to the API study in 


methodology using spill size versus quantity techniques. In 


addition to measurable spills on the ground, CARB included 


spills along the side of the vehicle. The CARB study took 


place at 31 Stage I1 systems in Sacramento and 21 


conventional stations north of Sacramento. Data were 


reported for all spills and adjusted to account for one 


large spill that CARB felt biased the results. API made no 


adjustments to the data collected at the Washington, DC and 


Baltimore stations for any large spills. To convert spill 


size/volume data in the CARB study to quantity data, two 


assumptions had to be used: (1) gasoline density was 0.67 


gm/ml (the same used in the Stage I1 recovery credit 


calculations), and (2) the average volume per refueling 


event was 10 gallons. The CARB study found a lower 

ddd 


S;Bg 
frequency of spills and smaller quantities of spills with Stage 


I1 equipment. It should be noted that spillage determinations 


are part of the certification procedures for Stage I1 equipment 


in California. To pass certification, the Stage I1 equipment 


must have spillage quantities less than conventional equipment. 


The third study was conducted by the Bay Area AQMD. The 


results of this study was obtained from the Bay Area, but no 


narrative was supplied. From the data supplied and a 


conversation with Bay Area AQMD it was determined that the test 


program was similar to that of the CARB and API studies. The 


conventional nozzle study dates back to a 1974 study by Scott 


Environmental. This conventional nozzle study by Scott was the 


basis for the AP-42 emission factor for spillage from automobile 


refueling (80 mg/liter). The Stage I1 data were obtained from 


facilities in the Bay Area. The Bay Area data indicated a slight 


increase in spill frequency with Stage I1 equipment but a 


significantly lower emission rate. 


It is difficult to draw any specific conclusions on the 


relative merit of the studies. Each appeared to incorporate 


similar procedures, however, slightly different results were 


obtained. The results of all studies are in the same order of 


magnitude and in the same approximate range. This further 


complicates the task of evaluating spillage information. It is 


impossible, based on this data, to conclude one way or the other 


on whether Stage I1 or conventional refueling results in higher 


spillage. This difficulty in concluding a definitive spillage 


quantity must be put in perspective. The difference in this 


spillage data represents less than one percent of the emissions 


from the total refueling event. 


3.4.3 Fm~tvina Losses 


Emissions have also been reported at service stations due to 


storage tank emptying and breathing losses. Breathing losses are 


attributable to gasoline evaporation due to barometric pressure 


and temperature changes. Breathing loses in fixed volume storage 


tanks are caused by vapor and liquid expansion and contraction 


due to diurnal temperature changes. As temperatures increase, 

vapor volume increases pushing vapor out of the vent pipe (out- 


breathing). When temperatures decrease, vapor volume decreases 


and air is drawn into the tank (in-breathing). Breathing loss 


emissions have traditionally been minimal at service stations 


since storage tanks have generally been located underground, 


insulated by the earth, with a very stable temperature profile. 


However, breathing losses from service station storage tanks are 


becoming more prevalent due to the popularity of aboveground 


storage tanks and the installation of vaulted underground storage 


tanks. Aboveground storage tanks are more susceptible to 


temperature and pressure changes and thus are more likely to 


experience both vapor growth and vapor shrinkage. It is also 


reported that the double wall, or wvaultedm underground storage 


tanks being installed to comply with underground storage tank 


(UST) regulations are more susceptible to thermal effect and 


theref ore breathing losses. 27s28 


Emptying losses occur when gasoline is withdrawn from the 


tank allowing fresh air to enter. This enhances evaporation 


(i.e., vapor growth) and causes vapors to be vented from the pipe 


as the saturated gasoline vapors tend to occupy a larger volume 


than air. EPAts AP-42 cites an average breathing emission rate 


of 120 milligrams per liter of throughput. 


This original source for this factor was a Journal of the 


Air Pollution Control Association November 1963 article based on 


a study by the Air Pollution Control District of Los Angeles 


County (LAAPCD). This article was. entitled "Emissions from 


Underground Gasoline Storage Tanks", and lists as authors Robert 


Chass, Raymond Holmes, Albert Fudurich, and Ralph Burlin of the 


Los Angeles Di~trict.~~ 
 This article describes emptying losses 


as follows. 


When an automobile is fueled, gasoline is pumped 


from the underground tank, causing air to be inhaled 


through the vent pipe, the volume being approximately 


equal to the volume of gasoline withdrawn. The air 


then becomes saturated with gasoline vapors, tending to 


occupy a larger volume. This in turn, causes the 


vapor-air mixture to exhaust from the underground tank 


until a pressure equilibrium is attained. 

The mg/l emission factor listed in AP-42 was estimated in 


this study by measuring air expelled from the vent pipe after 


vehicle fueling and applying a theoretical gasoline vapor to air 


ratio of 40 percent. They concluded that it was impractical, in 


their study, to collect representative vapor samples for 


analysis. While the emission factor of one pound per thousand 


gallon of throughput (approximately 120 mg/l) was presented in 


this study, it also discussed complexities with estimating these 


emissions. The study concluded: 


Factors affecting the breathing losses are complex 


and interrelated, depending on the service station 


operation, pumping rate, frequency of pumping, ratio of 


liquid surface to vapor volume, diffusion and mixing of 


air and gasoline vapors, vapor pressure and temperature 


of the gasoline, the volume and configuration of the 


tank, and the size and length of the vent pipe. 


Because of these many variables involved, much more 


data from a number of representative retail stations 


would be necessary before an accurate determination of 


overall, basin-wide breathing losses could be made. 


Since the time of this original analysis, several studies 


have been conducted to attempt to account for many of these 


variables. These range from studies that conclude there are no 


VOC emptying losses to those reporting emissions much higher than 


those predicted by the AP-42 emission factor. 


Dr. R.A. Nichols has studied this subject extensively 


throughout the 1970s and 1980s. In a 1987 paper on the 


subject30, the conclusion is that the model used in the LAAPCD 


analysis ignored the effect of the vent line. Dr. Nichols 


states: 


Air enters a nearly underground tank containing 


saturated vapor. Air will spread over a large and 


heavier vapor layer enhancing diffusion into this 


layer. As the surface layer gains vapor, the lighter 


upper vapor, which is essentially air, is vented from 


the tank through the vent line. The air-vapor mixture 


expelled from the tank to the vent line occupy only a 


small fraction of the vent line volume. The air-vapor 


mixture remains in the vent pipe for some time because 


of low diffusion rate. Subsequently, this mixture is 


inhaled back into the tank in the next refueling. 


Consequently, the vent line acts as a buffer to 

effectively ensure that only air enters and leaves the 


vent during intermittent refueling. 


Dr. Nichols indicates that vapor emissions could only occur 


during periods of long refueling inactivity. He concludes that 


high fueling activity followed by long periods of inactivity will 


lead to the highest (and possibly the only) vapor venting 


emissions. This paper did not provide any emission factor for 


these emissions. 


The California Air Resources Board (CARB) conducted a study 


to estimate storage tank breathing losses in 1987.~' Emissions 


were measured at a low throughput (15,000 gallons per month per 


tank) station and a high throughput (50,000 gallons per month per 


tank) station. The study found different results for the two 


stations. The emission factor calculated for the low throughput 


station was 0.92 lbs VOC per 1000 gallon throughput (110 mg/l), 


and 0.21 pounds per 1000 gallon (25 mg/l) for the high throughput 


station. Observations made during the testing indicated that 


mass emissions from the underground storage tanks appeared to 


occur during periods when dispensing of product was the lowest, 


that emissions were at a minimum during conditions of near 


continuous fuelings, and that the highest mass emissions occurred 


during intermittent vehicle fuelings followed by relatively long 


periods of dispensing inactivity. The differences in emission 


factors at the high and low throughput stations are explained in 


these observations. 


The National Institute for Petroleum and Energy Research 


(NIPER) conducted a study and reached conclusions partially in 


agreement with those of both Dr. Nichols and CARB.~~NIPER1s 


study concluded that no vent losses would occur if the dispensing 


frequency were high enough and that vent losses would be markedly 


reduced if the height of the vent was increased. The rationale 


for the origin of emissions agreed with the discussion provided 


in the original LAAPCD study. This was that emissions were due 


to 1) air induction through the vent, 2) dilution of the 


hydrocarbon vapor in the tank, 3) saturation of the diluted vapor 


by evaporation of the liquid fuel, resulting in increased 

pressure in the tank. If this pressure was greater than that 


exerted by the column of vapor in the vent, emissions resulted. 


The emissions measured for a high flow stations were 0.85 and 


1.05 grams per gallons dispensed (225 and 277 mg/l, 


respectively). A comparison of the CARB and NIPER studies shows that the 


NIPER emission factors are much higher than those from CARB. 


Recognizing this discrepancy, CARB and NIPER met on August 21, 


1987 to discuss the differences.== The conclusion reached at 


this meeting was that NIPERts results should be adjusted because 


the dispensing period (8 hours) during NIPERts tests was not 


considered representative of the effective dispensing period at a 


high volume station. Adjustments were made and it was determined 


that a more appropriate emission factor for the NIPER data is 0.6 


lbs/1000 gallons (72 mg/l) for a high throughput station. 


In summary, these studies indicate that the emissions from 


storage tank emptying are affected by several factors, most 


notably the height of the vent pipe and the vehicle fueling 


activity. For the purposes of the analysis in this document, it 


is believed that the AP-42 factor of 120 mg/l represents an 


emission factor that may be very conservative, but is not 


unrealistic. 


3.5 MODEL PLANT EMISSION ESTIMATES 


Model plants, as described in Chapter 2, are used to 


represent the industry for cost and emission estimation purposes. 


The data presented earlier in this chapter and in Chapter 2 were 


used to calculate emissions for each model plant. Table 3-8 


summarizes model plant emissions using an emission factor 


calculated with the overall national annual average RVP of 11.4 


psi, a AT of 4.4'F and a T, of 66.0mF. Using emission factors in 


Table 3-8 and the gasoline throughput associated with each model 


plant allows the calculation of model plant emission estimates 


for any geographical area. The equation for estimating model 


plant emissions is as follows: 

TABLE 3.8. VOC EMISSIONS FROM REFUELING FOR 


SERVICE STATION MODEL PIANTSa 


Average Model 


Service Station Average Emission Plant 


Model plantsb Throughput Factor Emissions 


Liters/Month mg/literc W/Y~ 


Model Plant 1 23,000 1,340 
 0.4 


Model Plant 2 76,000 1,340 1.2 


Model Plant 3 132,000 1,340 2.1 


Model Plant 4 234,000 1,340 3.9 


Model Plant 5 700,000 1,340 11.2 


a Not including emissions associated with spillage and tank 

emptying/breathing. 


Model plants described in Chapter 2. 


Average emission factor based on the following: 


RVP 11.4 


Dispensed fuel temp. 66.0 


Dispensed f uel/f uel 4.4 


tank temp. diff. 

MP, = (E,) (MP,) (12 months/year) / (1o9mg/~g) 

where : 

MP, = Model plant emissions, Mg VOC/yr 

Er = Emission rate, mg VOC/liter 

MP, = Model plant gasoline throughput, liters/month 
3.6. REFERENCES 


1. Furey, Robert and Bernard Nagel. Composition of Vapor 


Emitted from a Vehicle ~asoline Tank During Refueling. 


Society of Automobile Engineers (SAE) Technical Papers 


Series 860086, February 1986, 


2. Gasoline Marketing Industry (Stage I) - Background 

Information for Proposed Standards, Preliminary Draft. 


U.S. Environmental Protection Agency, Research Triangle 


Park, NC. November 1991. 


3. Evaluation of Air Pollution Regulatory Strategies for 


Gasoline Marketing Industry. U.S. Environmental 


Protection Agency, Office of Air Quality Planning and 


Standards and Office of Mobile Sources. Ann Arbor, MI. 


Publication No. EPA-450/4-84-012a. July 1984. 


4. Draft Regulatory Impact Analysis: Proposed Refueling 


Emission Regulations for Gasoline-Fueled Motor Vehicles 
 -- Volume I - Analysis of Gasoline Marketing Regulatory 

Strategies. U.S. Environmental Protection Agency. 


Office of Air Quality Planning and Standards and Office 


of Mobile Sources. Ann Arbor, MI. Publication No. 


EPA-450/3-87-001a. July 1987. 


5. Pacific Environmental Services, Inc. Description of 


Analysis Conducted to Estimate Impacts of Benzene 


Emissions from Stage I Gasoline Marketing Sources. 


Prepared for U.S. Environmental Protection Agency. 


Research Triangle Park, NC 27711. August 1989. 


6. Design Criteria for Stage I Vapor Control Systems 


Gasoline Service Stations. U.S. Environmental 


Protection Agency, Office of Air Quality Planning and 


Standards, Research Triangle Park, NC 27711. November 


1975. 


7, Norton, R.L., R.R. Sakaida, and M.M. Yamada (Pacific 

Environmental Services, Inc.). Hydrocarbon Control 


Strategies for Gasoline Marketing Operations. Prepared 


for U.S. Environmental Protection Agency. State 


Publication No. EPA-450/3-78-017. April 1978. 


8. Telecon. Bowen, E., Pacific Environmental Services, 


Inc. with Bradt, R., Hirt Engineers, U.S. Environmental 


Protection Agency, September 25, 1991. Comments on 


preliminary draft technical guidance document. 


9. Letter, from Kunaniec, K., Bay Area Air Quality 


Management District, to Shedd, S., U.S. Environmental 


Protection Agency. July 31, 1991. Comments on 


preliminary draft technical guidance document. 

Rothman, David, and Robert Johnson. Technical Report - Refueling Emissions from Uncontrolled Vehicles. 


Prepared for U.S. Environmental Protection Agency, 


Office of Mobile Sources. Ann Arbor, MI. Publication 


No. EPA-AA-ADSB-85-6, June 1985. 


Motor Gasolines, Summer 1990 and Winter 1989-1990. 


National Institute for Petroleum and Energy Research. 


Bartlesville, Oklahoma. February 1991 and June 1990. 


Volatility Regulations for Gasoline and Alcohol Blends 


Sold in Calendar Years 1991 and Beyond. Federal 


Reaister, Vol. 55, No. 112, 23658. June 11, 1990. 


Clean fuels rules and guidelines negotiated rulemaking 


advisory committee. Federal, peaister, Vol. 56, No. 


103, 24157. May 29, 1991. 


Fax communication to Norton, Robert, Pacific 


Environmental Services, Inc., from Johnson, Robert, 


U.S. Environmental Protection Agency, Office of Mobile 


Sources. April lo, 1991. 


Reference 12. 


McAnnally, Michael and J.L. Dickerman (Radian 


Corporation). Summary and Analysis of Data from 


Gasoline Temperature Survey Conducted by American 


Petroleum Institute. May 1976. 


Reference 10. 


Compilation of Air Pollutant Emission Factors, Fourth 


Edition (AP-42). Section 4.4 Transportation and 


Marketing of Petroleum Liquids. September 1985. 


Reference 3. 


Reference 4. 


Procedures for the Preparation of Emission Inventories 


for Carbon Monoxide and Precursors of Ozone Volume I: 


General Guidance for Stationary Sources. Prepared for 


U.S. Environmental Protection Agency, Research Triangle 


Park, NC. Publication No. EPA-450/4-91-016. May 1991. 


User's Guide to MOBILE4.1. EPA-AA-TEB-91-01. U.S. 


Environmental Protection Agency. Office of Mobile 


Sources. Ann Arbor, MI. July, 1991. 

A Survey and Analysis of Liquid Gasoline Released to 


the Environment During Vehicle Refueling at Service 


Stations. American Petroleum Institute. API 


Publication No. 4498. June 1989. 


Memorandum from Fricker, Robert L., California Air 


Resources Board to Morgester, James T., California Air 


Resources Board. April 18, 1991. Investigation of 


Gasoline Spillage at Retail Service Stations. 


Fax transmission from Kunaniec, K. Bay Area Air Quality 


Management District, to Norton, R., Pacific 


Environmental Services, Inc. September 19, 1991. Data 


from Bay Area Spillage Study. 

Stage I1 Survey Statistical Data Report. Lundberg 

Reports Corporation. Fredericksburg, VA. August 1987. 

Reference 8. 

Reference 9. 

Burlin, R., and A. Fudiruch. Air Pollution From 


Filling Underground Gasoline Storage Tanks. Los 


Angeles Air Pollution Control District. December 1962. 


Nichols, R.A. Service Station Underground Tank 


Breathing Emissions. R.A. Nichols Engineering. 


October 13, 1987. 


Memorandum. Simeroth, D.C., California Air Resources 


Board, to Cackette, T., California Air Resources Board, 


September 15, 1987. Determination of Mass Emissions 


from Underground Storage Tanks. 


National Institute for Petroleum and Energy Research. 


Evaporative Losses from a Vented Underground Gasoline 


Storage Tank (with addendum discussing August 24, 1987 


meeting with CARB). Undated. 


Reference 32. 

4.0 CONTROL TECHNOLOGY 


This Chapter provides a basic technical discussion of 


Stage I1 technology and equipment. Phase I1 vapor recovery 


is also used to describe this technology. However, this 


document uses the terminology, nStage 11". While the 


fundamental concept of Stage I1 vapor recovery is simple, 


the practical application becomes quite complex. There are 


many components that have small but important roles in Stage 


I1 systems. The initial sections of this chapter discuss 


the types of Stage I1 systems and the system components. 


Excessive equipment malfunctions and user 


dissatisfaction have been traditional stumbling blocks to 


Stage I1 program implementation. Where there were problems 


with earlier generations of equipment a discussion of 


corrections or improvements has been included. 


Stage I1 originated in California and this State has 


continued to be at the center of developing Stage I1 


technology. Fundamental to the Stage I1 program in 


California (as well as the rest of the country) is the 


equipment certification program conducted by the CARB. This 


program is also discussed in the chapter. Much of the 


information regarding system components and CARB 


certification is taken from a paper presented at the 83rd 


annual meeting of the Air and Waste Management Association 


in June, 1990, entitled "Gasoline Vapor Recovery 


Certif icationM , by Laura McKinney of CARB.' 

Finally, the chapter discusses the effectiveness of 


Stage I1 systems. Results of studies of in-use 


effectiveness and methodologies for determining program 


effectiveness are provided. 

4.1.1 

4.1 TYPES OF STAGE I1 SYSTEMS 


Loading losses due to the refueling of motor vehicles 


can be significantly reduced by Stage I1 systems. There are 


currently two basic types of Stage I1 systems in use in the 


United States. These are the vapor balance system and the 


vacuum assist system. 


The balance type vapor recovery system operates on the 


principle of positive displacement during gasoline transfer 


operations. Balance systems use pressure created in the 


vehicle fuel tank by the incoming liquid gasoline and the 


slight negative pressure created in the storage tank by the 


departing liquid to transfer the vapors through the 


combination fuel dispensing/vapor collection nozzle, through 


the vapor passage, and into the service station underground 


storage tank. Because a slight pressure is generally 


created at the nozzle/fillpipe interface, effective 


operation requires that a tight seal be made at the 


interface during vehicle fuelings to minimize vapor leakage 


into the atmosphere. Also, it is very important that the 


vapor path remain unobstructed. 


The basic design of a balance system is shown in Figure 


4-1. As illustrated, the vapors and liquid are simply 


"balancedn between the vehicle and underground storage 


tanks. 


4.1.2 Vacuum Assist Svstem 


An assist system is designed to enhance vapor recovery 


at the nozzle/fillpipe interface by drawing in vapors using 


a vacuum. Because of this design, assist systems can 


recover vapors effectively without a tight seal at the 


nozzle/fillpipe interface. There are four assist systems 


that are currently available and certified by the California 


Air Resources Board (CARB): the Hasstech, the Healy, the 


Hirt, and the Amoco Bellowless Nozzle Systems. The Hirt and 


Hasstech Systems have a vacuum-generating device, such as a 


compressor or turbine that creates a vacuum such that vapors 


are pulled from the vehicle tank into the storage tank. 


They utilize a processing unit for combustion of the excess 


vapor, while the Healy system creates a vacuum by spraying 


liquid gasoline through saturated vapor by way of a jet, or 


multi-jet pump, and the vapor is driven back to the 


underground storage tank. A vacuum is created in the 


bellowless system by a hydraulic pump driven by the 


dispensed gasoline. The excess vapors are drawn through a 


coaxial spout on the nozzle. The Red Jacket aspirator assist 


,system was one of the first true aspirator assist systems to 


be certified, but is no longer produced. It was fully 


equipped with an aspirator, a modulating valve, and a check 


valve; but it has not been sold since the early 1980's. 


The Hasstech System, shown in Figure 4-2, uses a blower 


as a vacuum generating device that is activated whenever 


gasoline is dispensed. As product is dispensed, the vapors 


are drawn through the vapor hose until they encounter a 


valve that is located inside the dispenser. The purpose of 


this valve is to prevent ambient air flow into the vapor 


recovery line while other nozzles are in use. Vapors pass 


through the valve, then through the blower located between 


the dispensers and the storage tanks. This blower is 


capable of a pressure differential of 20 inches water column 


(in wc), which means that the blower readily pushes the 


vapor into the tanks. When there is an excess volume of 


vapor from either Stage I1 or Stage I, the tank pressure 


rises. When the pressure reaches approximately 1 in wc, a 


switch within the processor is activated and this initiates 


processor operation. The processor incinerates the excess, 


then automatically turns off when pressure equilibrium is 


restored. This system is closed with a pressure/vacuum 


relief valve on the tank vents. There is also a pressure 


gauge located on the vent line that allows the 


owner/operator to monitor the pressure of the system. 


The Hirt System is a vacuum assisted, vapor processing 


Stage I-Stage I1 control system, shown in Figure 4-3. The 


system is piped as a balance system, returning vapor from 


nozzles to storage tank free space through unobstructed 


vapor piping. An assisting vacuum is held in the storage 


tanks by a vapor processor. The processor is piped into the 


top of the storage tank vents which are manifold together 


and closed from the atmosphere. The processor contains a 


regenerative vapor turbine which prevents pressurizing by 


removing excess vapor to the balancing forces, and a thermal 


oxidizer which destroys only that vapor. If for any reason 


the processor should shut down, the system will function as 


a normal vapor balance system. The processor is 


automatically activated if the vacuum degenerates to neat 


atmospheric and remains activated until the vacuum reaches 


about 0.5 in wc. 


Another example of an assist system is the Healy System 


as shown in Figure 4-4. This system operates under negative 


pressure derived from a gasoline driven jet pump. 


Originally the jet pumps were located in the dispensers, 


however, the newer system pumps may be in the vapor return 


piping at the storage tank. The unit located at the tank is 


called a multi-jet or mini-jet, depending on the number of 


jet pumps it contains. The jet pump draws a strong vacuum 


that creates enough suction to draw any excess liquid that 


may be present in the vapor passage. When the pump switch 


is activated, gasoline under pressure is provided to the jet 


pump. At this point an internal pressure sensing valve 


opens and a small stream of gasoline flows through the jet 


pump back to the underground storage tank. Vacuum produced 


by the mini-jet is immediately produced at a controlled 


maximum level (15 to 70" wc). When the nozzle is in use the 


vapors are recovered through the jet pump and returned to 


the gasoline storage tank, A vacuum regulatory, which has a 



0.17 inch diameter orifice, is located within the nozzle and 


monitors this pressure. This opens into a pressure 


regulated chamber that adjusts the flow of vapors and air 


through the vapor recovery line. The regulator in the 


nozzle is designed to open the vapor path when pressure 


inside the nozzle is slightly above atmospheric pressure. 


It also closes the vapor path when the pressure becomes 


slightly negative; and this prevents excess air from 


entering the system. This also keeps a slight vacuum (0 to 


.25 in wc) at the nozzle/fillpipe interface and a tight seal 


is not necessary between the vehicle tank and the nozzle 


fillpipe. Because of this pressure regulator, the high 


vacuum in the vapor return line is not at the 


nozzle/fillpipe interface. There is no need for an 


incineration device with this system, because the amount of 


ambient air drawn into the system is kept at a minimum. 


Healy Systems which have the mini-jet or multi-jet unit are 


required to have a pressure/vacuum (P/V) valve on the vent 


pipes. The pressure setting of this valve is 1" wc. 


Another type of vacuum system, the bellowless nozzle 


system shown in Figure 4-5, develops suction by a dual 


chamber gasoline driven vacuum pump. Currently, the only 


certification for a bellowless nozzle has been issued to 


Amoco Oil Company. A vacuum is created by a hydraulic pump 


driven by the dispensed gasoline. The vapors are drawn 


through spout openings in a bellowless nozzle into the 


underground tank. The vacuum is regulated by the flow of 


fuel, and the ratio of gasoline dispensed to vapors 


collected is approximately one-to-one. Because the vapors 


are drawn into the tank at this "one-to-onew ratio, excess 


vapors are not generated, and incineration is not necessary. 


In addition, the vapor does not contact the liquid driving 


the pump, thus not creating additional evaporation or 


misting into the air-vapor mixture. The bellowless system 


also has a P/V valve on the vent pipes. The current 


settings are 8 oz. and -1/2 oz. The system is under 


additional testing and may be certified by CARB with 


different settings but a P/V valve will be required. 


4.2 SYSTEM COMPONENTS 


A more complete understanding of the technology of 


Stage I1 vapor recovery may be gained by considering the 


equipment on an individual component basis. In this 


section, the function and operation of components are 


discussed as well as a presentation of traditional problems 


and improvements made to Stage I1 equipment. 


4.2.1 Va~or Recoverv Nozzles 


The collection of gasoline vapors at the vehicle- 


fillpipe interface is the starting point for a Stage I1 


vapor recovery system. The component vital to this step is 


the combination fuel dispensing/vapor collection nozzle. 


The nozzle is responsible for dispensing gasoline into the 


vehicle fuel tank while simultaneously collecting the vapors 


being forced from the tank and routing them through the 


vapor recovery hose and the underground piping to the 


storage tank. Due to differences in Stage I1 vapor recovery 


systems and the manner in which the vapors are collected, 


the nozzles vary from vapor balance nozzles that require a 


tight seal at the fillpipe interface to the f bellow less^ 


nozzle, which differs only slightly in appearance from 


conventional nozzles. Figures 4-6 (balance), 4-7 (assist), 


and 4-8 (bellowless) show various types of nozzles. 


Many past problems with Stage I1 vapor recovery have 


been associated with the vapor recovery nozzle. A survey 


conducted in California in the late 1970's during the early 


period of Stage I1 indicated that torn nozzle bellows and 


faceplates, loose or missing latching lugs on balance 


nozzles, loose or unwound latch springs on assist nozzles, 


and fuel recirculation were among the most significant 


problem^.^ Also, a 1983 report to the California 


legislature listed four major consumer complaints all of 

Vapor Check 

Secondary Shutoff Valve 

-.\ '. '. I be1 lows 

Photos Courtesy of Dover Corporation/oPW Division cincinnati, 0 

and Emco Wheaton, Inc. Research Triangle Park, NC 

Figure 4-6. Example Balance Nozzles 

\ LATCHINO DEVICE SPOUT 

Photo Courtesy of Emco Wheaton, Inc. Research Triangle Park, NC 


Figure 4-7. Example As8ist Noztle 
Figure 4-8. Example Bellowless Nozzle 

which were nozzle related: (1) spillage of liquid gasoline 


during refueling, (2) equipment defects, (3) nozzle 


operation and handling difficulty, and (4) gasoline 


recir~ulation.~ 


Stage I1 equipment, especially nozzles, are far more 


reliable and user friendly today than in the past. New 


nozzles are shorter, narrower, and lighter than their 


predecessors. Originally weighing over six pounds, newer 


nozzle designs have reduced the weight by 2 to 3 pounds, 4 


rendering vapor recovery nozzles only slightly heavier than 


conventional ones. 


A major problem that occurred during the initial phase 


of Stage I1 was the compatibility of Stage I1 nozzles and 


vehicle fillpipes. There were many vehicles that had 


fillpipes that simply would not accept the Stage I1 nozzles. 


The State of California quickly recognized this problem and 


passed legislation that required the standardization of all 


vehicle fillpipes for 1977 and subsequent model years 


(California Administrative Code, Title 17, Section 2290, 


Chapter 7, page 267). Due to the difficulty of producing 


cars with different fillpipes and to provide allow motorists 


to fuel vehicles in all areas without difficulty, automakers 


responded by standardizing vehicle fillpipes for vehicles 


sold throughout the country.' Therefore, newer model cars 


should not have a problem using Stage I1 equipment, although 


there will probably be a very small percentage of vehicles 


still in use that have fillpipe configurations that will 


make it difficult to use Stage 11. 


There are several parts of the nozzle which are 


fundamental to the function of the nozzle and the recovery 


of gasoline vapors. These parts are the bellows, the 


primary and secondary shutoffs, the insertion interlock, the 


latch assembly, the hold-open latch, and the vapor check 


valve. Each of these units is discussed in detail in the 


following. 

4.2.1.1 pozzle Bellows. The nozzle bellows, or 


l1bootw, is the device that captures the displaced gasoline 


vapors at the vehicle fillpipe. Bellows were originally 


composed of rubber-like materials over a shape-retaining 


inner spring. The most recent generation of bellows are 


made from shape-holding more durable materials (see Figures 


4-6 and 4-7). 


For balance systems, the tight fit at the vehicle 


fillpipe interface is critical, so the bellows must be 


compressed to create this seal. The faceplate and insertion 


interlock (discussed later) are other components that assist 


in assuring a tight fit. The tension of the bellows and the 


difficulty of compression have been a source of consumer 


complaints during the history of Stage I1 vapor recovery. 


Also, the durability of bellows has been an often cited 


problem. 


The durability of bellows material has also been 


significantly improved since the introduction of Stage 11. 


This is largely responsible for an increased 1-ife expectancy 


of bellows for all systems and the improvements in the user- 


friendliness of balance systems. The high spring-tension of 


early balance bellows was responsible for much of the "hard- 


to-usew reputation of vapor recovery nozzles. The tension 


the bellows exerts on balance-type faceplates is 


substantially less now than it was years ago, and the 


nozzles are consequently much.easier to use. 


The early popularity of assist systems was in part due 


to the difference in the type of bellows necessary for 


proper system operation. Because the vapors are drawn into 


the bellows using a slight vacuum, a tight seal at the 


vehicle fillpipe interface is not necessary. In fact, the 


existence of a tight fit could cause removal problems and a 


chance of pulling a vacuum on the vehicle tank. This less 


stringent demand on the bellows allowed the use of lighter, 


more pliable bellows material for assist systems. 


Therefore, assist systems were attractive due to their 

increased user friendliness over the early designs of 


balance nozzles. Improved technology has resulted in 


lighter and more durable assist bellows, but the gap in user 


friendliness has been closed by the improvements to balance 


systems bellows. 


Despite these improvements, the importance of the 


bellows and the desire to avoid bellows maintenance continue 


to interest the industry. This is evident in the excitement 


and anticipation created by the bellowless nozzle (see 


Figure 4-7). While the bellows improvements have lessened 


many problems, the bellowless nozzle, in theory, will 


eliminate the maintenance associated with nozzle bellows. 


However, this bellowless nozzle has not been installed on a 


wide scale basis at this point. 


Part of the reason that this system is not currently 


more prevalent is due to the fact that the system design was 


developed by Amoco Oil company, and Amoco does not market 


their gasoline products in California. Therefore, the 


incentive to develop and fully market this product in the 


past has not been great. However,, due to the onset of Stage 


I1 regulations in other areas marketed by Amoco, these 


systems have been installed at approximately 100 stations in 


St. Louis, D.C., and Philadelphia, with some "experimentalm 


sites in Maryland. There has been one bellowless nozzle 


system certified by CARB for limited application with 


certification testing for a second generation nozzle planned 


for the near future. It is expected that with the 


regulation in Dade County, the number of operating Amoco 


bellowless nozzle systems could double due to the numerous 


affiliated stations in this county. An Amoco representative 


indicated that the initial plans are to limit the 


availability of these systems to Amoco stations, although 


there is the possibility that market rights will be sold to 


other distributors in areas not marketed by Amoco (such as 


California).6 
4.2.1.2 Face~late or Facecone. Balance nozzles have a 


tight-fitting soft donut-type faceplate, while assist 


nozzles are often equipped with loose-fitting facecones. 


The faceplates are designed to achieve the close seal 


between the nozzle and vehicle fillpipe on which the balance 


system depends. Assist facecones are loose-fitting and 


often contain grooves to prevent a tight seal so that a 


dangerous vacuum in the vehicle tank will be avoided. The 


differences between balance faceplates and assist facecones 


are apparent in Figures 4-6 and 4-7. There are exceptions 


to this generic characterization. For example, one vacuum 


assist system was originally designed and still can be used 


with normal balance nozzles. 


Difficulties have also been noted regarding the 


durability of faceplates and facecones. New materials have 


been developed which make these components stronger and much 


more durable than their predecessors. 


Conventional 

4.2.1.3 

and 

1

vapor recovery nozzles have a primary 


overfill shutoff mechanism, sometimes called the liquid 


shutoff. This causes the nozzle to stop dispensing, thus 


preventing overfills, when a sensing mechanism in the tip of 


the spout (see Figure 4-6) detects that the spout tip is 


submerged. A small tube inside the spout provides a path 


for vapors from a small hole in the tip of the spout to a 


chamber at the base of the spout. As gasoline flows through 


the nozzle, vapor is sucked through this tube and fed 


through tiny holes in the base of the spout back into the 


gasoline. The suction that causes this is created by the 


venturi effect of gasoline flowing through the spout. As 


long as the flow of vapor is uninterrupted, the nozzle 


continues to dispense gasoline. When the tip of the spout 


becomes covered with liquid, however, the flow of vapors 


stops and a vacuum is created. This vacuum pulls a thin, 


rubber-like diaphragm and triggers a mechanical shutoff 


mechanism to stop the flow of gasoline in the nozzle. The 

location of the diaphragm and the way it triggers the 


shutoff differ with nozzle design. 


Some nozzles have a three-ball latch mechanism that 


causes the nozzle to shut off when the tip of the spout is 


in liquid. Another type of shutoff mechanism uses the 


vacuum to pull the diaphragm and two metal rollers away from 


the shaft, which activates the shutoff. 


If the primary shutoff fails on a conventional nozzle 


the customer or attendant can easily recognize an overfill 


situation as gasoline rises in the fillpipe or spills on the 


ground. However, since vapor balance nozzles form a tight 


fit at the fillpipe, it is difficult to determine if the 


primary shutoff is malfunctioning. The nozzle may collect 


the liquid, thus preventing a spill but allowing liquid to 


collect in the vapor passage of the hose. Another common 


problem for vapor balance and assist systems is "topping 


off1#. Customers or attendants wish to fill the vehicle tank 


as full as possible so they attempt to add more gasoline 


once the primary shutoff has been activated. This provides 


the opportunity for liquid to be introduced into the vapor 


passage of the hose. 


Because the balance system depends on a tight 


nozzle/fillneck connection, there is a potential for 


building up pressure in the vehicle tank if the vapor return 


becomes blocked. This was a problem with the early designed 


nozzles as pressure caused forcible ejection of liquid 


product when the nozzle was removed at the end of the 


fueling. To prevent this from occurring, a pressure sensing 


shutoff mechanism (secondary shutoff) was required. The 


pressure shutoff will be triggered if the primary shutoff 


fails and the vapor line becomes blocked with fuel. 


The secondary, or high-pressure, shutoff is required to 


ensure that high pressure in the vehicle tank will not occur 


when the vapor passage is blocked. The first vapor recovery 


nozzles were required to shut off at about 20 inches water 


column. This was later changed and nozzles are now required 

to shut off at or below 10 inches. The current industry 


standard is 6 to 10 inches water for the pressure shutoff. 


Blockage of the vapor return path because of liquid, a 


kinked or flattened hose or other obstruction, can cause the 


nozzles to repeatedly shut off as pressure in the vehicle 


tank builds up. 


The secondary shutoff also acts as a guard against 


recirculation of gasoline through the vapor passage. In the 


event of a failure by the primary shutoff system, the build 


up of liquid in the vapor passage will activate the 


secondary shut-off and turn off the nozzle so that no 


gasoline could be recirculated into the underground storage 


tank. California Weights and Measures conducts stringent 


testing of the secondary shutoff during nozzle 


certification. 


These secondary shutoffs have also contributed to the 


hard-to-use reputation of balance nozzles. In most 


instances continued shut offs occur when problems, 


especially liquid blockage, exist in other parts of the 


system, such as the vapor hose or the underground piping. 


The certification process in California contains stringent 


tests conducted by California Weights and Measures which 


verify the delivery accuracy of nozzles and specifically 


test the primary and secondary shutoffs (see Section 


4.3.3.1). 


4.2.1.4 Insertion Interlock Mechanism. As noted 


previously, balance systems must maintain a tight fit at the 


nozzle/fillpipe interface while assist and hybrid systems do 


not. To achieve this tight fit, balance nozzles employ a 


soft faceplate discussed above and an interlocking 


mechanism. The insertion interlock, or "no seal-no flow" 


device ensures that gasoline cannot be dispensed unless the 


bellows of the balance nozzle are compressed to ensure a 


tight fit at the nozzle/fillpipe interface. In some balance 


nozzles, compression of the bellows opens a valve which 


permits the flow of air from the spout-tip to the primary 

shutoff chamber. Attempting to dispense without compressing 


the bellows therefore triggers the primary shutoff 


mechanism. Other balance nozzles have a mechanical 


interlock which prevents rollers from contacting the shaft 


unless the bellows is compressed. The nozzle trigger is 


loose and @@floppy1@ 
 until the bellows is compressed. This is 


the type of interlock shown in Figure 4-6. 


The difficulty in compressing the bellows so that the 


insertion interlock will allow gasoline flow has been 


another contributing factor to the complaints relating to 


Stage I1 equipment. The earlier generation nozzles required 


a pressure of up to twenty-four pounds to deactivate the 


interlock. This, combined with the weight of the nozzle and 


the tension of the springs in the bellows, made nozzle 


operation difficult for many customers. However, the 


improvement of each of these components has greatly reduced 


this problem. The pressure required to deactivate insertion 


interlocks has been decreased to as low as five pounds on 


some nozzles. 8 

A lack of understanding of the interlock and latch 


mechanisms can frustrate customers. This problem is one 


that can be corrected with public awareness programs and 


proper operating instructions at the pump. 


4.2.1.5 Latch Assemblv. The purpose of the latch 


assembly is to allow the customer or operator to lock the 


nozzle into the vehicle fillpipe by hooking the latch on the 


lip of the fillpipe. The latch assembly may be a spring 


wound around the spout, a ring around the spout (see Figure 


4-7) or a bar riveted or screwed onto the spout (see Figure 


4-6). This device is more critical to balance-type nozzles 


because of the interlock and the greater tension exerted by 


the bellows. Therefore, it is required on balance nozzles 


and is optional for conventional nozzles and some assist 


nozzles. 


This simple device created problems specified in the 


earlier surveys. The difficulties were mainly due to the 

latch assembly coming off the spout. Design and 


manufacturing improvements have been made and complaints in 


this area are now practically nonexistent. 


4.2.1.6 Hold-Oven Latch. This latch allows the nozzle 


trigger to be mlockedw in operating position, freeing the 


operator to move away from the nozzle. Some establishments 


elect to remove hold open latches for business reasons. 


They prefer to keep customers at the nozzle so that they 


will not leave vehicles unattended or drive off with the 


nozzle still in the car. Hold open latches are not critical 


to the actual recovery of vapors and nozzles are allowed 


with and without them. The decision whether hold open 


latches may be used is often decided by local fire marshals. 


4.2.2 Vapor Check Valve 


The vapor check valve opens and closes the vapor 


passage between the underground tank and the atmosphere 


(through the nozzle bellows). This valve closes when the 


nozzle is not in use to prevent vapors from escaping. This 


also prevents air leakage into the Stage I1 system and vapor 


leakage out of it during vehicle refueling at another nozzle 


or tank truck unloading. With the exception of a few 


nozzles which have remotely-located flow-activated vapor 


check valves, balance nozzles generally have vapor check 


valves located in the nozzle at the base of the bellows 


which are opened by compression of the bellows. Most assist 


systems have vapor check valves located in the vapor passage 


but not in the nozzle. For example, one assist system 


nozzle has a ball-check valve (a very simple mechanism 


involving a larger ball-bearing which blocks the vapor 


passage when the nozzle spout points upward). Another has a 


flow-control valve in the dispenser. Another system employs 


a regulating diaphragm inside the nozzle designed to open or 


close the vapor passage as necessary to minimize the 


pressure difference inside and outside the nozzle. 

4.2.4 Hoses and Hose Confiauration Svstems 


4.2.4.1 fisses. Vapor recovery hoses may be coaxial or 


dual hose. Coaxial hoses contain two passages, configured 


as a hose within a hose. One of the passages dispenses 


liquid gasoline. The other passage, the vapor hose, 


receives the gasoline vapors and carries them back through 


the underground piping to the underground storage tank. 


Most coaxial systems employ a 1/2 or 5/8 inch product hose 


inside l-f to 1-# inch vapor hose. The single exception is 


The Healy system which has the vapor hose inside the product 


hose. Dual hose systems have separate hoses for the liquid 


and vapor. Since 1986, all new or modified balance systems 


installed in California must be coaxial. Other areas with 


recently implemented Stage I1 programs only allow coaxial 


hoses. 


Historically, hoses have been a source of problems, 


specifically with regard to their weight, durability, and 


propensity to kink. Also, hoses often touched the ground 


which made them susceptible to damage due to vehicles 


running over them. Also, since Stage I1 was a technology 


originally developed in central and southern California, the 


durability of hoses in colder climates has been a concern. 


The original two hose system was heavy and proved to be 


awkward (due to hose twisting, etc.) for consumers and gas 


pump attendants to use. To overcome this problem, 


manufacturers developed a more manageable coaxial hose. 


However, these were still hardwalled and continue to have a 


weight problem. A second generation of coaxial hoses was 


then developed that is much lighter and even more 


manageable. The swivels that were necessary with the dual 


hose systems and the hardwall coaxial hoses are not required 


with these newer coaxial hoses. This further reduces the 


weight of the hose and makes them easier to handle. Due to 


improvements in thermal plastic materials, new coaxial hoses 


will weight only about five pounds, which is comparable to 


the weight of conventional gasoline dispensing hoses. 

Also, the durability of early model hoses under extreme 


winter temperatures has been questioned. Fifth generation 


coaxial hoses and bellows are designed to withstand 


temperatures as low as -60' F.~Stage I1 systems have been 


installed in New Jersey and New York and no significant 


increase in weather related defects has been observed. lo*'' 

4.2.4.2 piah Hana and Hose Retractor Svstems. Another 


hardware improvement is the development of high-hang hose 


dispensers and hose retractor systems. A major advantage of 


these configurations is that they minimize hose kinks and 


the possibility of the hose being flattened and help to 


lessen the weight of the nozzle for the customer. This 


helps to eliminate these situations which interfere with the 


flow of gasoline vapors to the underground storage tank. 


The hose retractor configurations also are designed to allow 


any liquid gasoline trapped in the vapor portion of the hose 


to drain into the fuel tank during normal fueling. The 


exception to this are systems required to have liquid 


removal devices. Figure 4-9 shows high hang hose and hose 


retractor configurations. 


4.2.4.3 Liuuid Removal Svstems. As stated above, one 


major reason for the advent of the hose retractor systems 


was to allow any gasoline trapped in the vapor passage of 


the hose to drain into the fuel tank. However, the 


structure of multiproduct dispensers does not contain the 


loop that allows this drainage to the vehicle fuel tank. 


Therefore, a method for removing liquid trapped in the vapor 


passage of the hose was developed. Liquid removal systems 


are designed to evacuate trapped liquid from the vapor 


passages in coaxial hoses. They operate using the venturi 


principle. A slight vacuum is created by the fuel flowing 


in the interior hose that draws the liquid out of the vapor 


passage and into the liquid gasoline stream. The venturi 


device can be located at the dispenser end of the hose or 


the nozzle end, depending on the type. Figure 4-10 shows an 


example liquid removal device and illustrates its operation. 

---- -- 

---- 

Overhead Hose 


Retractor 


=' Hose Assemblies r 
 Sloped To Permit 


/ Natural Drainage 

coaxial Hose ,' Into Vapor Return 

/' Piping When 

Retractor fa In 

Retracted Pos istic 


Nozzle 
 1

Vent 


Here 


Separate Liquid 


Pick 


Designed So That During 
 Liquid Pick-Up Or F'ueling Hose Is Sloped 
 Venturi Placed To Vehicle To Allow Any
 Here 
 F'uel In Vapor Line To 


Drain Into Vehicle F'uel 


Tank 


Figure 4-9. High Hang Hose Configurations 

-*
4.2.4.4
 Ern-. An addition to Stage I1 


systems is the emergency breakaway valve. These breakaways 


separate and close the product hose when a customer drives 


off with the nozzle in the fillpipe, thereby preventing 


damage to the equipment and reducing the danger of fire. 


Figure 4-11 shows an example emergency breakaway. 


4.2.5 u
Un q 


The underground vapor piping is an often ignored, but 


important component of Stage I1 systems. In fact, CARB 


certification includes not only the nozzles, hoses, and 


other above ground equipment, but the underground piping as 


well. Therefore, a CARB certified system must have the 


correct underground piping configuration as specified in the 


Executive Order. 


The vapor piping begins with the riser pipe that is 


located either inside the dispenser or on the pump island. 


In many instances, this is a 3/4 inch galvanized riser pipe. 


All vapor return and vent piping should be provided with 


swing joints at the base of the riser to each dispenser, at 


each tank connection, and at the base of the vent pipe riser 


where it fastens to a building or other structure. 


The underground vapor piping system can be made up of 


individual return lines or a manifolded system. In either 


instance, the minimum vapor pipe diameter is commonly 2 or 3 


inches. The underground piping was originally all made of 


steel, but fiberglass vapor piping has now become popular. 


The individual return line system shown in Figure 4-12 


is the simplest design and has one pipe for each underground 


storage tank. If there are multiple dispensers of a 


particular product or grade of gasoline, the vapor lines are 


tied together into one line going to the appropriate tank. 


Therefore, the vapors from the vehicle tank must be 


transferred to the same tank from which liquid gasoline is 


being drawn, The piping should slope towards the 


underground storage tank with sufficient drop so that any 

Photo Courtesy of Goodyear Tire & Rubber, Co. Akron, OH. 

Product 

Vapor 

Product 6 Vapor 

Product 

Photo Courtesy of Themid/HBD Industries, Inc. Be1 lefontaine, OH. 

Figure 4-10 Example Liquid Removal Device 
Photo courtesy of Husky Corporation Pacific, MO 

Figure 4-11. Example Emergency Breakaway 

Figure 4-12. Individual Vapor Balance System 

Underground Piping 
condensate or liquid in the vapor piping will drain to the 


underground storage tank. Each tank also has a vent line 


that is usually required to be at least 2 inches in 


diameter. Therefore, there would be multiple vent lines 


equal to the number of underground storage tanks. The vent 


lines should also slope toward the tanks so that any 


condensate will drain back into the tank. 


In a manifold system, shown in Figure 4-13, all of the 


vapor lines from the dispensers are linked to a common 


manifold. This manifold can be run into a manifold box with 


vapor connections to all of the tanks. More commonly, the 


manifold is connected directly to the storage tank with 


leaded gasoline, or the lowest grade of unleaded (in the 


absence of leaded). This is to avoid contamination of the 


higher grade gasolines. Again, the manifold must be sloped 


adequately to allow any liquid present in the pipe to drain 


to the liquid trap or storage tank. During vehicle fueling, 


the vapors are returned to the appropriate tank due to the 


slight vacuum created in the tank by the removal of the 


liquid. As in the individual vapor return system, each 


underground tank typically has a vent pipe. 


The minimum height of the vent pipe off the ground is 


usually determined by the Fire Marshal. A typical minimum 


height is 12 feet above the adjacent ground level and should 


vent upward or horizontally. Some areas allow pressure 


vacuum vents on service station vent pipes. Pressure Vacuum 


vents are required for some assist systems. 


Problems can occur with the underground piping that 


decrease the efficiency of the vapor recovery to very low 


levels. These problems can take many forms from incorrect 


piping size, to improper plumbing configurations where some 


tanks are not even connected to the vapor piping system. 


The most common problem associated with the underground 


piping is the presence of low points in the line which allow 


the build-up of liquid gasoline. Low points often occur due 

Figure 4-13. Manifolded Balance System Underground 

Piping 
to inadequate backfilling of the piping or from running over 


the piping by construction equipment prior to paving or 


surfacing. Liquid blockage causes pressure build up which 


either forces the vapors out at the nozzle/fillpipe 


interface or causes the secondary shutoff mechanism to stop 


the pumping of gasoline. 


Many people with a great deal of experience with Stage 


I1 systems believe that single most important element to a 


Stage I1 program is to ensure that the systems are initially 


installed correctly. Systems plumbed incorrectly reduce the 


emission reduction potential of Stage I1 vapor recovery 


substantially. Representatives in the San Diego Air 


Pollution Control District of California estimate that the 


underground piping at over 50 percent of the stations will 


be installed improperly without an installation testing 


program (these tests are discussed in Chapter 6 and 


contained in Appendix I) and inspections to identify 


improper systems. l2 


4.2.6 E b m 

With the problems associated with leaking underground 


storage tanks and the resulting stringent UST and LUST 


regulations, the interest in placing service station 


gasoline storage tanks above ground is gaining attention. 


In California there are a small number of service stations 


that have Stage I1 systems on above ground storage tanks.13 


For the most part, these are private card lock stations 


serving fleets and small vaulted, tanks. Balance systems 


have generally been installed for small tanks and vacuum 


assist systems have been installed at these stations with 


large bulk plant type tanks. The certification of above- 


ground Stage XI systems in ~alifornia is discussed in 


Section 4.3,s. 
4.3 CALIFORNIA CERTIFICATION PROGRAM 


It is widely recognized and accepted that Stage I1 


technology originated in California and has developed 


largely due to the regulations and requirements of the CARB 


and local California air pollution agencies such as the Bay 


Area Air Pollution Management District in San Francisco (Bay 


Area), the South Coast Air Pollution Management District in 


the Los Angeles area (South Coast), and the San Diego Air 


Pollution Control District (San Diego). Many States and 


local agencies in other parts of the country rely on 


California for Stage I1 guidance due to their experience and 


expertise. 


California State law requires that the State Air 


Resources Board adopt procedures for determining the compli- 


ance of any system designed for the control of gasoline 


vapor emissions during gasoline marketing operations. l4 1n 


response to this legislative mandate, CARB developed proce- 


dures and test methods which describe the requirements for 


certification for all gasoline marketing emission sources. 


Appendix C.l contains the requirements for certification. 


Because it is not practical to test the efficiency of 


the vapor recovery system in each service station, CARB 


developed a "genericw equipment certification approach. In 


this program a prototype Stage I1 vapor system is evaluated 


and specifications developed. Systems that meet these 


"certifiedgg specifications may be installed without 


individual efficiency tests. 


CARB will accept applications for certification of 


vapor recovery systems from any manufacturer, but there are 


conditions which must be met by the manufacturer before 


certification testing is initiated.15 The manufacturer is 


required to demonstrate the ability to pay the costs of 


testing prior to the commencement of CARB certification 


testing. This demonstration may take the form of posting a 


bond of not less than $20,000. In order to protect the 


purchaser, CARB is also required to evaluate the adequacy of 

the planned methods of distribution and replacement parts 


program, the financial responsibility of the applicant, and 


other factors affecting the economic interests of the 


eventual system purchaser. The manufacturer must also 


provide a three-year warranty for the system. The only 


exception to the warranty requirement is for those 


components that the maintenance manual identifies as having 


expected useful lives of less than three years, such as 


vapor recovery nozzles. The warranty in these cases is 


allowed to specify the expected life of the component. 


Specifically, it is required that the application be in 


writing, signed by an authorized representative of the 


manufacturer, and include the following information: 


A detailed description of the configuration of the 


vapor recovery system which includes the 


underground piping configuration and 


specifications, the gasoline dispensing nozzle to 


be used, engineering parameters for pumps and 


vapor processing units, and allowable pressure 


drops through the system. 


Evidence demonstrating the vapor recovery 


reliability of the system or device for 90 days. 


The procedures by which this is determined are 


discussed below in section 4.3.1. 


A description of tests performed to determine 


compliance with the general standards and the 


results. 


A statement of recommended maintenance procedures, 


equipment performance checkout procedures, and 


equipment necessary to assure that the vapor 


recovery system, in operation, conforms to the 


regulations, plus a description of the program for 


training personnel for such maintenance, and the 


proposed replacement parts program. 


Six copies of the service and operating manuals 


that will be supplied to the purchaser. 


A statement that a vapor recovery system, 


installed at an operating facility, will be 


available for certification testing no later than 


one month after submission of the application for 


certification. The certification testing 


procedure is discussed in detail in Section 4.3.2. 

The retail price of the system and an estimate of 


the installation and yearly maintenance costs. 


A copy of the warranty or warranties provided with 


the system. 


If the application is for a system previously 


tested, but not certified, the application must 


include identification of the system components 


which have been changed, and any new test results 


obtained by the applicant. 


Any other information reasonably required by CARB. 


While this list shows many requirements for certification, 


the major portions of CARB requirements are the 


operational/durability, or "90 dayu test, and the 


certification or "100 carw test. 


4.3.1 O~erational/Durabilitv Test. "90 Day Testw 


As stated above and contained in Appendix C.l, the 


applicant must demonstrate the reliability of the system. 


This demonstration is conducted by installing a system at an 


operating station and observing the durability for at least 


90 days. l6 The facility utilized for certification testing 

must have a minimum throughput of 100,000 gallons per month 


and include at least six nozzles of each type submitted for 


approval. No more than two types of nozzles can be present 


at any one test facility. During this "operationalw test, 


replacement of components or alteration of the control 


system is not allowed, except replacement or modification of 


a component if it has been damaged due to an accident or 


vandalism. No maintenance or adjustments to the system are 


allowed during the test unless specifically called for in 


the system's maintenance manual. The entire system is 


sealed so that unauthorized maintenance or adjustment may be 


detected. If detected, this can be reason for immediate 


failure of the test. CARB observes the station frequently 


during the testing period and evaluates the durability of 


the system or components after this period. 

4.3.2 Certification Testina, "100 Car TestB1 


After meeting all other CARB requirements and 


successful completion of the 90 day test, the efficiency of 


the system is tested1? during at least 100 vehicle fuelings. 


The test method is contained in Appendix C.2. The test 


procedures provide for the fueling to occur during the 


normal operation of the service station, but all CARB 


efficiency testing is conducted in a self-service mode. 


Before the 100 vehicle efficiency test can be conducted, the 


entire vapor recovery system must be tested for leaks. 


Each vehicle tank that is refueled is tested to 


identify those which are leak tight. Vehicles that pass the 


leak tight test may be included in the baseline population 


if other measurements indicate that no vapors were lost 


during the fueling operation. 


Vehicle fuelings are observed until matrix requirements 


are satisfied and at least forty baseline vehicles have been 


identified. This matrix identifies vehicles by manufacturer 


and year and ensures that the vehicles used during the test 


are representative of the on-the-road vehicle population in 


terms of vehicle miles travelled. 


The test procedures for determining the efficiency of 


systems to control gasoline vapors displaced during vehicle 


fueling require that the weight of vapors collected at the 


vehicle, corrected for vent losses, be compared to the 


potential mass emission calculated for that vehicle. A 


standard test sample of the vehicle population is tested and 


an average efficiency calculated. 


The potential mass emissions are determined during the 


fueling of vehicles by measuring the mass of hydrocarbons 


collected from vehicles from which no leak occurred 


(baseline vehicles). Potential emissions are expressed as a 


function of the vapor pressures of the dispensed fuel and 


the temperature of the gasoline in the test vehicle tank. 


The relationship is used as the baseline or reference from 

which the efficiency of a vehicle fueling vapor control 


system is evaluated. 


During these fuelings, spillage and spitback from the 


system are also evaluated. Spillage is defined as "a loss of 


more than one milliliter of liquid gasoline from the 


gasoline nozzle as a result of preparing to fuel a vehicle 


or at the end of a fueling operation in returning the nozzle 


to the dispenserw and spitback defined as "a loss of more 


than one milliliter of liquid gasoline during the dispensing 


of gasoline." In order to pass this portion of the test, no 


more than ten spitbacks or twenty instances of spillage per 


100 vehicle fuelings can occur during the testing. 


4.3.3 FDDr0val of Other Aaencies 


The approval of three other State agencies is also 


required as a precondition to CARB certification. State law 


provides that the State Fire Marshal determine whether any 


component of system creates a fire hazard.18 The Department 


of Food and Agriculture, Division of Measurement Standards, 


is given sole responsibility for the measurement accuracy 


aspects, including gasoline recirculation, of any component 


or system. Finally, the Division of Occupational Safety and 


Health is designated the agency responsible for determining 


whether any gasoline vapor control system or component 


creates a safety hazard other than a fire hazard.19 


Appendix C also contains regulations, requirements, and test 


procedures for these other agencies. 


4.3.3.1 California Measurement Standards Division. 


Prior to Air Resources Board certification, the system must 


be submitted for type approval to the California Department 


of Food and Agriculture, Division of Measurement Standards 


and certified by this division (see Appendix C.3). 


The California Department of Food and Agriculture, 


Division of Measurement Standards, issue certificates of 


approval based on California Administrative Code Article 2, 


Procedures for Twe A~~roval 
 Certification Evaluation and 


Field Com~liance Testinu of Va~or Recoverv Svstems. This 

code establishes regulations to govern some design 


characteristics of Stage I1 vapor recovery systems and their 


operation to ensure liquid recirculation is prevented. 


There are several steps involved in order for 


certification. It is the responsibility of the manufacturer 


to request an application for the National Type Evaluation 


Program (NTEP). Information regarding the design of the 


system, including schematics, blueprints, instruction 


manuals, brochures, and all other pertinent facts are sent 


to the Director of the Measurement Division for a prelimi- 


nary review. 


Once the Director reviews the preliminary application 


and approves, the applicant is authorized to install the 


system in a prescribed location for use in the type approval 


certification testing. 


The Director, in conjunction with the County Sealer of 


Weight and Measures for the designated location observe and 


examine the system in operation normally within 30 to 90 


days. During that time, one or more inspections will be 


conducted which specifically relate the system components, 


their performance, and their accuracy. 


There are system installation specifications. There 


must be a minimum of six nozzles installed on hoses of both 


leaded and unleaded fuels, each tested a minimum of three 


times during an examination. Prior to the field 


examination, the dispenser meters for the test nozzles are 


tested and adjusted accordingly. 


Field compliance tests are conducted to examine: (1) 


the proper operation of primary shut-off and secondary shut- 


off devices, (2) the delivery accuracy of the system, and 


(3) the performance accuracy of assist system evaporation 


and volume change. 


The test procedure for primary shut-off devices 


involves filling the test unit with fuel dispensed from the 


nozzle until the test unit becomes full. This should 


activate the primary shut-off device. Ten consecutive 

override attempts are made which should result in automatic 


nozzle shut-off before the dispenser volume indicator 


increases more than 1/10 gallon limit. The 10 override 


attempts are performed a minimum of three times for each 


nozzle. 


The secondary shut-off device is tested by introducing 


sufficient fuel into the vapor return line to block the 


return of vapors through the line. The nozzle and hose is 


then held in a configuration so the liquid is concentrated 


in the vapor section of the hose. Ten attempts are made to 


dispense fuel into an empty test unit. The volume shown on 


the dispenser indicator is recorded before and after each 


attempt. The nozzle must shut off automatically before the 


dispenser volume indicator increases more than 3/10 gallon 


for each attempt. This procedure must be performed on a 


minimum of 6 nozzles. 


Compliance with delivery accuracy requirements is based 


upon data recorded for at least 150 vehicles (formerly 300 


vehicles) while observing customers fueling with the test 


nozzles under normal field conditions. The 150 or more 


vehicles should be representative of California vehicles. 


The assist system evaporation and volume change 


performance accuracy test is conducted because excessive 


vacuum may result in artificial evaporation of customer 


fuel. This would decrease the measured volume and also 


cause possible implosion of vehicle fuel tanks. 


In addition to all of these tests which are conducted 


by Measurement Division personnel, type approval 


certification is not issued until the applicant submits a 


report of evaluation by an independent, pre-approved testing 


laboratory. It is after review of all of the test data and 


other information that the Division grants certification of 


a vapor recovery system. 


4.3.3.2 California Fire Marshal. Prior to Air 


Resources Board certification of the vapor recovery system, 


plans and specifications for the system must be submitted to 

the State Fire Marshal's Office for review to determine 


whether the system creates a hazardous condition or is 


contrary to adopted fire safety regulations (see Appendix 


C.4). Final determination by the State Fire Marshal may be 


contingent upon a review of each pilot installation of the 


proposed system. The California Fire Marshall has 


regulations, whose purpose is to establish minimum standards 


of fire safety for vapor recovery systems or components. 


Any manufacturer desiring certification and listing of 


a gasoline vapor recovery system or component must submit a 


completed application for evaluation and certification to 


the State Fire Marshall. This form must be accompanied by 


the proper fee. In addition, a test evaluation from a pre- 


approved testing organization, as well as technical data and 


black-line drawings suitable for reproduction must also be 


submitted. 


The final report should include failure analysis 


engineering data, writing diagrams, operating and 


maintenance manuals and photographs, together with a 


description of the tests performed and the results. The 


catalog number, the laboratory test report number, and date 


should also be included. 


After review and approval of the material, the Fire 


Marshal issues a certification of the Stage I1 system. Each 


vapor recovery system or component which is certified by the 


California Fire Marshall must bear a label placed in a 


conspicuous location and must be attached by the 


manufacturer during production or fabrication. 


4.3.3.3 California OSHA. Prior to certification of 


the system, the manufacturer of the system must submit the 


system to the California Occupational Safety and Health 


Administration (Cal OSHA) for determining compliance with 


appropriate safety regulations (see Appendix C.5). The 


Division of Occupational Safety and Health of the Department 


of Industrial Relations is the only agency responsible for 

determining whether a gasoline vapor control system or 


component creates a safety hazard other than a fire hazard. 


The General Industry Safety Orders (GISO) is the 


guideline used in helping to make a determination. Each 


section of the GISO relates to a different part of the 


service station, ranging from the location of the storage 


tanks to the safe operation of electrical equipment. All 


electrical equipment and wiring must be installed in 


accordance with the provisions of the California Electrical 


Safety Orders. All electrical equipment integral with the 


dispensing hose or nozzle must be suitable for use in the 


proper locations. 


They do not necessarily run tests, but assure that the 


GISO guidelines and requirements and are met. The equipment 


is tested by an outside lab which submits a report to 


California OSHA. 


The final determination is made when all of the 


requirements have been met. A letter is sent to CARB 


stating that the system in question has satisfied the 


requirements of California OSHA. 


4.3.4 Cost of Phase I1 Certification 


The certification of equipment is not an inexpensive 


venture for equipment manufacturers. There are application 


fees, government charges for testing, private laboratory 


testing costs, as well as the manpower costs involved with 


the oversight of the certification process. A fee not to 


exceed the actual cost of certification is charged by the 


Air Resources Board to each applicant who submits a system 


for certification. A conservative estimate of the fees 


charged by CARB is placed at around $5,000,20 excluding the 


$20,000 bond discussed earlier. The contractor fee to 


conduct the 100 car certification efficiency test has been 


estimated at about $20,000.~' This puts the cost for only 


the CARB portion of certification at approximately $25,000. 


California State law allows the State Fire Marshal, the 


Division of Measurement Standards, and the ~ivision of 

Industrial Safety to charge reasonable fees for 


certification of gasoline vapor systems not to exceed their 


respective estimated costs. Payment of the fee is a 


condition of certification. Representatives of major 


equipment manufacturers estimate that the total cost for 


obtaining CARB certification can range from $50,000 - $~OO,OOO
 .22J3 


4.3.5 Certification of Abovearound storaae tank systems 


Stage I1 systems have also been installed at gasoline 


dispensing facilities with aboveground storage tanks. CARB 

has certified several balance systems for small aboveground 


vaulted tanks, as well as a Hirt assist system for similar 


tanks. There are also Hirt and Hasstech assist systems 


installed at bulk plant type card lock facilities, but no 


certifications have been issued at this time. CARB 

officials indicate that the certification of such systems on 


a generic basis is expected in the future.24 


Since most of these applications in California are at 


private facilities, the conditions of the 100 car matrix 


could never be met. Therefore, the certifications are based 


on a combination of emissions monitoring, equipment testing, 


and engineering analysis. Appendix D also contains examples 


of executive orders for the small vaulted aboveground tanks. 


4.3.6 Executive Orders 


If the Executive Officer of CARB determines that a 

vapor recovery system conforms to all requirements, an order 


of certification, or Executive Order is issued. The Order 


specifies the conditions which must be met by any system 


installed under the certification. These specifications may 


include the plumbing system, an equipment list, the vapor 


hose configuration, and the maximum allowable pressure drop 


through the system. 


The interpretation of CARB executive orders can be both 

confusing and frustrating. This is in part due to the fact 


that many system updates and subsequent recertification of 


the equipment occur. It is also due to the large number of 

components and manufacturers of these components. The 


understanding of exactly what is "CARB certifiedtt is not an 


easy task, and areas with vapor recovery regulations which 


rely on CARB certification should take the necessary time to 


study and understand the Executive Orders. More discussion 


on the determination of "approved systemsw is given in 


Chapter 6. Table 4-1 presents a list of current Stage I1 


CARB certifications and executive orders. 


Appendix D contains a list of all Stage I1 CARB 


executive orders issued since the initiation of the program. 


This differs from Table 4-1 because some orders have been 


updated, rescinded, etc.. Also included in the appendix are 


summaries of the requirements for the most recent generation 


of equipment. And finally, the appendix contains actual 


executive orders. The executive orders provided include G- 


70-52-AL that gives a summary of all above ground equipment 


for Red Jacket, Hirt, and Balance systems; G-70-70-AB that 


addresses the Healy aspirator assist system; G-70-7-AB that 


addresses the Hasstech vacuum assist system; G-70-118 that 


addresses the Amoco bellowless nozzle system; G-70-36-AC and 


G-70-17-AB that have detailed descriptions of underground 


piping requirements; and G-70-132 and G-70-133 that address 


above ground tank systems. 


If after certification of a system the manufacturer 


wishes to modify the system, the proposed modifications must 


be submitted again for approval. Such modifications may 


include substitution of components, elimination of 


components and modification of the system configuration and 


may not require the full scale testing effort. If after 


certification of a system, CARB finds the system to no 


longer meet the specified certification specifications, they 


may revoke or modify the prior certification. 


4.3.7 Fffectiveness of Svstems 


The test method for certifying Stage I1 systems states 


that such a system Itshall prevent emission to the atmosphere 


of at least 90 percent or that percentage by weight of the 

TABLE 4-1. SUMMARY OF CARB EXECUTIVE ORDERS CERTIFYING 


SYSTEMS TO BE AT LEAST 95 PERCENT EFFICIENT 


-

Executive Order Title CARB Number 


Certification of the Hasstech Model VCP-2 


and VCP-2A Phase I1 Vapor Recovery Systems 


Relating to Modification of Certification of 


the Emco Wheaton Balance Phase I1 Vapor 


Recovery System 


Recertification of the Exxon Balance Phase 


11 Vapor Recovery System 


Recertification of the Atlantic Richfield 


Balance Phase 11 Vapor Recovery System 


Certification of the Modified Hirt VCS-200 


Vacuum Assist Phase 11 Vapor Recovery System 


Relating to Modification of Certification of 


the OPW Balance Phase 11 Vapor Recovery 


Recertification of the Texaco Balance Phase 


I1 Vapor Recovery System 


Recertification of the Mobile Oil Balance 


Phase I Vapor Recovery System 


Recertification of the Union Balance Phase 


11 Vapor Recovery System 


Certification of components for Red Jacket, 


Hirt, and Balance Phase I1 Vapor Recovery 


Recertification of the Chevron Balance Phase 


I1 Vapor Recovery System 


Relating to the Certification of the Healy 


Phase I1 Vapor Recovery System for Service 


Stations 


Certification of EZ-Flo Nozzle Company 


Rebuilt Vapor Recovery Nozzles and Vapor 


Recovery Nozzle Components 


Certification of EZ-Flo Nozzle Model 3006 


and Model 3007 Vapor Recovery Nozzles and 


Use of E-Z Flo Components with OPW Models 


llVC and llVE Vapor Recovery Nozzles 

TABLE 4-1 (CONTINUED). SUMMARY OF CARB EXECUTIVE ORDERS 


CERTIFYING SYSTEMS TO BE AT LEAST 95 PERCENT EFFICIENT 


Executive Order Title 


Certification of Rainbow Petroleum Products 


Model RA3003, RA3005, RA3006 and RA3007 


Vapor Recovery Nozzles and Vapor Recovery 


Components 


Certification of ConVault Incorporated 


Aboveground Tank Filling/Dispensing Vapor 


Recovery System 


Certification of Amoco V-1 Vapor Recovery 


System 


Certification of the Husky Model V Phase I1 


Balance Vapor Recovery Nozzles 


Certification of the OPW Model Ill-V Phase 


I1 Balance Vapor Recovery Nozzle 


Certification of the Bryant Fuel Systems 


Aboveground Tank Filling/Dispensing Vapor 


Recovery System 


Certification of the BRE Products, Inc. 


Enviro-Vault Aboveground Tank 


Filling/Dispensing Vapor Recovery System 


Certification of Sannipoli Corporation Petro 


Vault Aboveground Tank Filling/Dispensing 


Vapor Recovery System 


Certification of Hallmark Industries Tank 


Vault Aboveground Tank Filling/Dispensing 


Vapor Recovery System 


Certification of Trusco Tank, Inc. 


Supervault Aboveground Storage Tank Filling/ 


Dispensing Vapor Recovery System 


Certification of LRS, Inc. Fuelmaster 


Aboveground Storage Tank Filling/Dispensing 


Vapor Recovery System 


Certification of the EZ-Flo Rebuilt A4000- 


* Series and 11V-Series Vapor Recovery Nozzles 

CARB Number 


G-70-107 


G-70-116-A 


G-70-118 


G-70-125 


G-70-127 


G-70-128 


G-70-129 


G-70-130 


G-70-131 


G-70-132 


G-70-133 


G-70-134 


Source: May 17, 1991 letter with attachments from James 


Morgester, CARB, to Stephen Shedd, EPA.= 

gasoline vapors displaced during the filling of the 


stationary storage tank as required by applicable air 


pollution control district rules and regulations.~~~ 


Although this provides an efficiency of 90 percent, all of 


the air pollution districts in California contain 


regulations which require Stage I1 systems which achieve 95 


percent effi~iency.~' Therefore, CARB certifies systems as 


95 percent efficient. In other words, a CARB certified 


system has been tested and can be expected to achieved 95 


percent or greater effectiveness in the removal of VOCs. 


The systems shown in Table 4-1 have all been documented to 


achieve 95 percent efficiency or better. 


4.4 IN-USE EFFECTIVENESS 


As stated previously, all Stage I1 systems certified in 


California have been shown to operate with at least 95 


percent removal efficiency. This efficiency is established 


during the 100-car test segment of the certification 


procedures. This 95 percent emission reduction is the 


minimum required by districts in California and is required 


by ether States. However, after the equipment is installed 


and normal operation begins, associated wear and tear, 


malfunctions or system problems can result in reduction of 


certified efficiency. 


4-4.1 In-Use Efficiencv 


The term in-use efficiency is used to reflect the 


actual average operating efficiency of the system. The in- 


use efficiency takes into account system downtime, 


malfunctions, and defects that can occur relating to 


specific pieces of equipment. The in-use efficiency is 


calculated by determining the frequency of specific 


malfunctions and defects and assuming a specific efficiency 


decrease associated with each malfunction or defect. 


Factors affecting the in-use efficiency of a Stage I1 


system include: 

misinstallation of aboveground or underground 

equipment ; 

specific nozzle defects or malfunctions; 

hoses tears, kinks, or liquid blockage; 

vacuum vapor processor malfunctions; 

generally poor maintenance. 

Many defects or malfunctions to equipment are as a result of 

the equipment being operated by the general public. As a 

result, proper installation and maintenance of the equipment 

is a crucial factor in keeping the in-use effectiveness as 

close to 95 percent as possible. 

Most of the discussion in this section describes the 

affect on efficiency of defects in aboveground equipment. 

Misinstallation of underground equipment can also cause 

significant decreases in efficiency. One person interviewed 

in California indicated that as much as 50 percent of the 

facilities could have problems in underground piping 

 installation^.^^ This emphasizes the importance of 

conducting the underground piping tests (liquid blockage, 

backpressure, and pressure decay) to determine proper 

installation. Chapter 6 discusses these tests in more 

detail. Malfunctions or defective equipment left in 

operation can significantly reduce the vapor capture and 

hence the actual vapor reduction. Studies have shown that 

the frequency of inspections made by enforcement personnel 

can affect the in-use efficiency . 29*30*3'*32 More frequent 

inspections will identify defective equipment, require 

replacement of the equipment, and, as a result, improve 

overall in-use efficiency. 

4.4.2 In-Use Efficiency Calculations 

Several pieces of data are necessary to calculate inuse efficiency for a Stage I1 program. First is a database 

of system malfunction and defects. This database is 

necessary to establish the frequency of occurrence for 

specific defects. Secondly, an efficiency decrease must be 
assigned to each malfunction or defect. This efficiency 


decrease is an estimate .of system efficiency decrease that 


occurs with each malfunction or defect found. The overall 


in-use efficiency is then the product of the individual 


defect frequency and the efficiency decrease. The following 


equation is used to calculate in-use efficiency. 


El = ET [100-(F,) (ED,) ] [(loo-(F,) (ED,) I---[ 

F,) (ED,) I 

(100-

where: 

E, = In-use efficiency, % 

E, = Theoretical or certification efficiency, 3 

(typically 95 percent) 

F, = Frequency of occurrence of defect x, 3 

ED, = Efficiency decrease assigned to defect x, 3 

Table 4-2 lists common defects for vapor balance systems and 


the efficiency decrease associated with each defect. These 


efficiency reductions have been developed and used by EPA in 


previous in-use efficiency The efficiency 


decrease assumptions were in some cases obvious (i.e., no 


vapor recovery installed resulted in 100 percent reduction 


in efficiency), while in other cases based on engineering 


calculations (i.e., tears in nozzle boots). Appendix E of 


this document contains an illustrative example of how to use 


this data to generate an in-use efficiency estimate. 


The example provided in Appendix E illustrates how 


State or local agencies can use a database of defects to 


estimate in-use efficiency. As new data becomes available, 


efficiency decrease estimates in Table 4-2 can be refined to 


better approximate efficiency reductions associated with 


each defect, and a detailed database of malfunctions can be 


obtained to estimate area specific in-use efficiencies. It 


should be noted that the example calculations do not include 


efficiency decreases due to underground piping problems. 


For vacuum assist systems, malfunctions associated with 

TABLE 4-2. EFFICIENCY DECREASES ASSOCIATED WITH STAGE I1 


BALANCE SYSTEM DEFECTS 


Defect 


No Vapor Recovery Equipment Installed 


(non-compliance) 


- Facilities with no equipment on 

any nozzle 


- Facilities with at least some 

vapor recovery 


Nozzle Damage 


Retractor Not Installed (all other V.R. 


equipment installed) 


Retractor Broken 


Boot and Face Seal, or Boot Only, Not 


Installed (V.R. nozzle installed) 


Torn Boot 


Face Seal Only Not Installed (remainder 


of V.R. equipment installed) 


Torn Seal 


Vapor Hose Not Installed 


Torn Vapor Hose 


No Seal-No Flow Broken 


Insufficient Hose Drainaqe 


Source: 1987 RIA, Volume I, Appendix A. 


Efficiency 


Decrease 


Assigned 


(percent) 

100 


100 


22 


5 


30 


22 


10 


100 


10 

vacuum blowers and vapor processors would have to be 

included. 

4.4.3 P R 

The in-use efficiency of a Stage I1 program is directly 

proportional to proper installation, operation and 

maintenance of the control equipment. Control agencies 

where Stage I1 has been installed have asserted different 

levels and frequencies of compliance inspections and 

monitoring, and used public participation by complaint toll 

free numbers to assure Stage I1 compliance. This section of 

the document will focus on the end results of in-use 

effectiveness estimates of Stage I1 systems and programs. 

As discussed and described in the previous section, 

surveys of installed equipment in areas with known levels of 

compliance monitoring, and assumptions on the effect of 

damaged or missing equipment, will allow the calculation of 

the effectiveness of a Stage I1 program in a given area. 

EPA has used this approach to calculate the effectiveness of 

Stage I1 in previous studies for supporting an analysis of 

Stage I1 versus onboard controls .35a36 These studies 

calculated in-use efficiencies of 92 percent with semiannual inspections, 86 percent with annual inspections and 

62 percent with minimal or less frequent inspections. 

Figure 4-14 illustrates the relationship between inspection 

frequency and in-use effectiveness. The range of inspection 

frequencies shown on the graph is a simplification of actual 

inspection frequencies and in most cases actual inspection 

frequencies will fall between the data points. 

EPA received a number of comments during the public 

comment periods on the estimates shown in Figure 4-14. 

Comments were received from auto manufacturers, control 

agencies, equipment manufacturers, and oil company trade 

associations that suggested both upward and downward 

adjustments to the Stage I1 in-use effi~iency.~' 

The EPA evaluated new data in an effort to update the 

in-use efficiency estimates and included this as Appendix A 

to the 1987 Draft RIA. As discussed previously in this 


chapter, EPA also examined a recent report on inspection of 


all Stage I1 service station installations in the 


Washington, D.C. area, and revisions were subsequently made 


to the estimates for the frequency and types of defects 


affecting Stage I1 systems. Using this information, the 


Agency's estimate for the lower end of the Stage I1 


efficiency range was adjusted from 56 to 62 percent. 


The EPA also evaluated California Air Resources Board 


data, which were presented in the 1983 Report to the 


~egislature.~~
 An attempt was made to cull inspection data 


dealing with only the newest Stage I1 systems. However, the 


data were insufficient to differentiate between system type, 


so no refinement of their 80-92 in-use efficiency rate could 


be obtained. The analysis used the average of this range. 


Additional data were obtained from randomly selected service 


stations in the Bay Area of California, which indicated an 


in-use efficiency of 90 to 92 percent; however, the data 


were considered inadequate to update the in-use figure for 


the entire State of California. Therefore, the upper end of 


the in-use efficiency range used in the 1987 RIA was 


maintained at 86 percent. 


Since publication of 1987 RIA, additional data were 


obtained that included inspection results about 12,000 


nozzles in ~alifornia.~~ 
 These inspections took place in 


1986 and 1987 in San Diego, San Francisco Bay Area, and in 


the South Coast (Los Angeles) areas of ~alifornia. Based on 


discussions with personnel in each of these areas, semi- 


annual inspections would best represent their inspection 


program (See Chapter 6). The data available allowed 


comparison between older and newer nozzle equipment. The 


results of these inspections indicated an overall in-use 


efficiency of 92.5 percent for all nozzles, 92 percent for 


older nozzles, and 94 percent for newer nozzle equipment. 


The data from these inspections is used in Appendix E for 


the illustrative example. 

Not taken in account in any of these in-use efficiency 


calculations is misinstallation of underground vapor piping. 


Figure 4-14 assumes 100 percent proper installation, 


operation, and maintenance of belowground vapor piping 


system. 


In addition, Figure 4-14 presents only in-use 


efficiency of controls if they are installed at 100 percent 


of the dispensing facilities. Many areas may use size 


exemptions. Table 4-3 summarizes the gasoline consumption 


that would be exempted under different throughput level 


cutoffs. These gasoline consumption levels were calculated 


based on the size distribution information presented in 


Chapter 2. Figure 4-15 presents in-use efficiency for the 


different levels of exemptions. The curves are compared to 


the information in Figure 4-14, that represented essentially 


no exemptions. 


In conclusion Figure 4-15 presents the range of in-use 


effectiveness of Stage I1 programs and its relationship to 


frequency of inspection and exemption levels. While it is 


well documented that Stage I1 systems can achieve 95 percent 


or better control efficiency, in-use efficiency is 


demonstrated to drop significantly without proper 


installation, operation, and maintenance by the owners and 


operators. 


TABLE 4-3. PERCENT CONSUMPTION EXCLUDED WITH VARIOUS 


STAGE I1 EXEMPTION SCENARIOS 


PERCENT CONSUMPTION 


EXCLUDED FROM 


EXEMPTION SCENARIO REGULATION 


EXEMPT STATIONS 2,000 GAL/MON 2.4% 


EXEMPT STATIONS < 10,000 GAL/MON 2.8% 

EXEMPT STATIONS < 10,000 GAL/MON AND 

INDEPENDENTS < 50,000 GAL/MON 10.0% 

+ 

Exemption values based on metropolitan area throughput by 


model plant shown in Table 2-9, since most, if not all, 


nonattainment areas are.metropolitan areas. Table 2-10 was 


used to estimate exemptions for independents. The following 


assumptions were used: 


< 2,000 gal/mon = Model Plant la 

< 10,000 gal/mon = Model Plant 1 

< 10,000 gal/mon non-independents, < 50,000 gal/mon 

independents = Model Plant 1 plus independents in 

Model Plants 2 and 3 

4.5 REFERENCES 


McKinney, L. California Air Resources Board. 


Gasoline Vapor Recovery Certification. (Presented 


at the Air and Waste Management Association 83rd 


Annual Meeting. Pittsburgh, PA. June 24-29, 


1990). 


South Coast Air Quality Management District, 


"Phase I1 Vapor Recovery Evaluation Program@@, 


1979. 


California Air Resources Board. A Report to the 


Legislature on Gasoline Vapor Recovery systems for 


Vehicle Refueling at Service Stations. 1983. 


Massachusetts Division of Air Quality Control. 


Stage I1 Gasoline Vapor Recovery Program 


Background Information and Technical Support 


Document. January 1989. 


Telecon. Bowen, E., Pacific Environmental 


Services, Inc., with Walker, G., Motor Vehicles 


Manufacturers Association, and Brooks, D., 


Chrysler Corporation. October 31, 1991. Fillpipe 


standardization. 


Telecon. Norwood, P., Pacific Environmental 


Services, Inc., to Strock, D., Amoco Research. 


April 30, 1991. Amoco bellowless nozzle. 


Reference 1. 


Reference 1. 


Reference 1. 


Memorandum from Norwood, P., Pacific Environmental 


Services, Inc. to Shedd, S., U.S. Environmental 


Protection Agency, Chemicals and Petroleum Branch. 


February 22, 1991. Trip Report to New Jersey 


Department of Environmental Protection. 


Memorandum from Norton, R., Pacific Environmental 


Services, Inc. to Shedd, S., U.S. Environmental 


Protection Agency, April 29, 1991. Trip Report to 


New York Department of Environmental Conservation. 


Memorandum from Norwood, P., Pacific Environmental 


Services, Inc. to Shedd, S., U.S. Environmental 


Protection Agency, April 30, 1991. Trip Report to 


California Agencies to Discuss Stage 11. 


Reference 12. 


_I 
California Administrative Code, Section 41954. 


State of California Air Resources Board, 


Certification Procedures for Gasoline Vapor 


Recovery at Service Stations, Method 2-2. 


Reference 15. 


State of California Air Resources Board, Test 


procedures for determining the efficiency of 


Gasoline Vapor Recovery systems at Service 


Stations, Method 2-1. 


California Administrative Code, Section 41955. 


California Administrative Code, Section 41957. 


California Air Resources Board Compliance 


Division, Gasoline Vapor Recovery Certification 


Program, Schedule of Test Fees. March 1991. 


Reference 12. 


Telecon. Norwood, P., Pacific Environmental 


Services, Inc. to Parrish, D.! Emco Wheaton. 


February 15, 1991. CARB Certification program. 


Telecon. Norwood, P., Pacific Environmental 


Services, Inc. to Brown, B., OPW. April 13, 1991. 


CARB Certification Procedures. 


Telecon. Norwood, P., Pacific Environmental 


Services, Inc. to Zimmerman, G., California Air 


Resources Board. October 17, 1991. Aboveground 


tank certifications. 


Letter with attachments from Morgester, J., 


California Air Resources Board, to Shedd, S., U.S. 


Environmental Protection Agency. May 17, 1991. 


Information related to CARB Stage I1 program. 


Reference 15. 


Telecon. Norwood, P.! Pacific Environmental 


Services, Inc. to McKlnney, L., California Air 


Resources Board. May 13, 1991. Requirements of 


CARB Efficiency Test. 


Reference 12. 

Evaluation of Air Pollution Regulatory Strategies 


for Gasoline Marketing Industry. U.S. Environ-


mental Protection Agency, Office of Air Quality 


Planning and Standards and Office of Mobile 


Sources. EPA-450/4-84-012a. July 1984. 


Draft Regulatory Impact Analysis: Proposed 


Refueling Emission Regulations for Gasoline-Fueled 


Motor Vehicles -- Volume I - Analysis of Gasoline 

Marketing Regulatory Strategies. U.S. Environ-


mental Protection Agency. Office of Air Quality 


Planning and Standards and Office of Mobile 


Sources. EPA-450/3-87-001a. July 1987. 


Reference 3. 


Sierra Research, An Analysis of Stage I1 and 


Onboard Refueling Emissions Control, prepared for 


Motor Vehicle Manufacturers Association, Inc. 


November 30, 1988. 


Reference 29. 


Reference 30. 


Reference 29. 


Reference 30. 


Evaluation of Air Pollution Regulatory Strategies 


for Gasoline Marketing Industry - Response to 

Public Comments. U.S. Environmental Protection 


Agency. Office of Air Quality Planning and 


Standards and Office of Mobile Sources. EPA-


450/3-87-012c. July 1987. 


Reference 3. 


Inspection Summaries of California Air Resources 


Board Phase I1 Vapor Recovery Inspections. August 


1986 through October 1987. Received from 


McKinney, L., CARB. October 1991. 

5.0 STAGE I1 COSTS 


The purpose of this chapter is to present the costs 


associated with the purchase, installation, and operation of 


Stage I1 equipment. This cost information is useful to 


State and local regulatory authorities when evaluating the 


cost impacts or burdens of a proposed Stage I1 vapor 


recovery program, and to weigh these cost impacts against 


the emission reduction benefits achieved. In addition, this 


information is useful when reviewing cost burdens presented 


by commenters when implementing a Stage I1 program. 


Developing and evaluating cost estimates for Stage I1 


systems has been a difficult task. 'EPA and industry have 


evaluated unit costs using unit cost estimate approaches as 


well as total cost estimate approaches from quotes from 


stations that have recently installed and purchased Stage I1 


systems. In addition, these studies came at a time when 


each study was trying to influence a decision between Stage 


I1 and onboard refueling controls. These cost methods were 


used and issued in a number of recent Stage I1 cost studies 


by industry and EPA. 


The unit cost estimate approach was based on model 


station sizes and equipment specifications for all 


components in a Stage I1 system. The cost of each piece of 


necessary equipment was obtained, along with its 


installation and maintenance costs. These costs were then 


summed to produce a "ground-upw estimate of Stage I1 costs. 


The total cost estimate approach, using cost quotes 


surveyed from stations that have installed Stage I1 


equipment, is a simpler approach to obtaining Stage I1 


costs, but has many drawbacks. Some stations keep detailed 

cost records on Stage I1 installation while others will have 


only the total cost. This makes comparison of costs very 


difficult. Compounding this problem is most stations re- 


model or replace storage tanks or dispensers at the same 


time they are installing Stage I1 systems. These non-Stage 


I1 costs can, in many cases, be much higher than Stage I1 


installations costs. Trying to compare a mixture of 


detailed and non-detailed cost quotes, and attempting to 


subtract out non-stage I1 costs, can not only be difficult 


and some times impossible to perform, but can add multiple 


assumptions and uncertainties into what were once "actualw 


Stage I1 costs. Without detailed costs it is also 


impossible to analyze the reasons associated with any 


outlier costs obtained from a total cost survey. This 


chapter discusses and presents results of both cost 


approaches, and compares all of the recent cost studies 


performed or provided to EPA to provide the user with a 


range of costs to use in their own assessment. 


The costs presented in this chapter are divided into 


aboveground and below-ground components. Aboveground 


equipment consists of all the nozzles, hoses, swivels, check 


valves, and other related components needed at the 


dispensers to capture the vapors displaced during refueling. 


The costs presented are limited only to equipment that has 


been certified by the California Air Resources Board (CARB) 


and is currently being marketed for Stage I1 systems. The 


below-ground equipment consists of the piping needed to 


route the vapors back to the underground tank. The 


aboveground costs at a facility are driven by the number of 


nozzles present at the service station, while underground 


costs are driven by the physical layout of the facility. 


Many times commenters will present Stage I1 costs on a 


dollar per nozzle basis. But because underground costs are 


not dependent on the number of nozzles, and because 


underground costs can represent more than half of the Stage 


I1 costs, reporting costs on a dollar per nozzle basis is 

not very useful. This report presents costs for the entire 


vapor recovery system, broken down into aboveground and 


below-ground components. Because.there can be an infinite 


number of service station configurations, costs are only 


presented for model facilities (discussed in Chapter 2), 

chosen to represent a cross section of the service station 


industry. 


Cost for key components (those having the biggest cost 


impact and those requiring the most replacements) will be 


discussed. Because most areas implementing Stage I1 have 


been taking advantage of the California certification 


efforts by allowing only systems certified in California, 


component costs are presented only for certified components. 


In this chapter discussions of current equipment costs 


for above and below ground components are presented. Also 


presented is a discussion of capital and annual costs for 


model facilities, a comparison of model plant costs with 


several cost surveys conducted in St. Louis, and a 


presentation of the latest 1991 Stage I1 cost estimates. 


5.1 EQUIPMENT, INSTALLATION, AND ANNUAL COSTS 


As discussed above, the costs are presented separately 


for aboveground components and underground components. Also 


presented in this section is a discussion of the impacts the 


underground storage tank (UST) program could have on Stage 


I1 implementation costs. 


5.1.1 Abovesround Costs 


The aboveground costs are associated with the hardware 


necessary to capture the vapors displaced at the vehicle 


fillneck during vehicle refueling. The discussions of unit 


costs will be limited to certified components. Appendix D 


contains a list of CARB's certified systems and a list of 


the equipment specific to those systems. Most maintenance 


items and replacement components are associated with the 


aboveground equipment. The discussion in this section will 


be more detailed for the higher cost, more maintenance 

intensive equipment (i.e., nozzles and hoses), and less 


detailed for the lower cost, less maintenance intensive 


equipment (i.e., swivels, check valves, etc.). 


Costs presented in this chapter do not include costs 


for the Amoco bellowless nozzle system. As discussed in 


Chapter 4, full scale production of this system has not 


occurred. An Amoco representative stated that the actual 


installed costs once a wide spread production began could 


not be estimated at this point. 


5.1.1.1 pozzles. The vapor recovery nozzles discussed 


in Chapter 4 are the key to the vapor recovery capture. 


Without a proper functioning and well maintained nozzle, 


emissions capture can be almost zero. Appendix D lists the 


nozzles approved for use for the balance, hybrid, and vacuum 


assist systems. Information is presented for all configura- 


tions and generations of nozzles, however the costs in this 


section will be presented only for the latest equipment on 


the market today. California maintains certification lists 


for older generation equipment since many of these systems 


are still being used. New Stage I1 programs, however, are 


excluding most older equipment and are limiting acceptable 


Stage I1 systems to those of the latest design. For 


example, New York will allow only fourth generation or newer 


vapor recovery components1 and St. Louis will allow only 


coaxial nozzles and hoses and will not allow twin hose 


configurations. The newest of the certified balance nozzles are the 


A4005 from EMCO Wheaton, the lllV from OPW and the Model V 


from Husky. These are the only certified balance system 


nozzles being offered by the original equipment 


manufacturers. The cost for these nozzles and for vacuum 


assist nozzles are comparable at about 


Individually these cost seem small, but the costs can mount 


up quickly when there a large number of nozzles, especially 


if the station uses multi-product dispensers (the multi- 


product dispenser for this document refers to a dispenser 

providing three products on each side of the dispenser, one 


nozzle per product, resulting in six nozzles per dispenser). 


The portions of the nozzle most susceptible to wear are 


the nozzle faceplate and bellows. These are also key items 


in the vapor capture system. These components cost about 


$15 for the fa~eplate,~ 
 and about $30-50 for a bellows 


replacement kit.7#8 The life of the equipment will vary, but 


a service station can expect, on average, to replace bellows 


and faceplates about three times per year for balance 


systems and two times per year for vacuum assisted systems. 9 

Other components in the nozzle (i.e., shutoff 


mechanisms, no seal/no flow check valves, etc.) are more 


difficult to repair. If these components fail, the nozzle 


usually has to be replaced. The station operator can 


replace the nozzles with new equipment at the cost stated 


above or can reduce his costs by purchasing "rebuiltm 


nozzles. Rebuilt nozzles use the same core but with new 


components built inside. Nozzle manufacturers will rebuild 


nozzles and sell them back at a reduced price. The 


manufacturers buy back the cores of the used nozzles, repair 


and resell them as certified nozzles. Core credits given by 


the manufacturers are typically around $50. Rebuilt nozzle 


costs range from $145" to about $190." 


The State of New York only allows rebuilt nozzles 


repaired by the original equipment manufacturer. 


California, on the other hand, has certified rebuilt nozzles 


by two rebuilding companies, Rainbow and EZ-flo. These 


nozzles have been certified for use in balance system 


installations. The cost of these nozzles are about $190.'~ 


Table 5-1 summarizes the costs associated with purchase and 


maintenance of Stage I1 vapor recovery nozzles. 


5.1.1.2 oses. The original Stage I1 systems 


incorporated a twin hose approach to vapor recovery. One 


hose transferred the liquid, as in conventional vehicle 


refueling, and an identical hose was used as a vapor return 


hose. These hoses were relatively inexpensive at about 

TABLE 5-1. PURCHASE COSTS FOR VAPOR RECOVERY NOZZLES 


AND REPLACEMENT PARTS~~~~' 


(May 1991 Dollars) 


Item Cost 


Nozzle Costs 


New Nozzle 


Core Return Credit 


Rebuilt Nozzle 


Component Costs 


Nozzle Boot 


Boot Kit 


Face Seal Kit 


Clamp Kit 


Boot Assembly Kit 

$30.'~ However, the twin hose systems were very hard to 


operate. Coaxial vapor return hoses eliminated the 


difficulties caused by twin hoses but cost considerably 


more. Coaxial systems represent the latest technology in 


use in California and are required on all new installations. 


They also are the only systems allowed in St.Louis, New 


York, New Jersey and Dade County, FL. A wide variety of 


materials and manufacturers are being offered for new Stage 


I1 coaxial hose systems. Manufacturers of certified coaxial 


vapor recovery hoses include Goodrich, Goodyear, Dayco, 


Gates and Thermoid. New hose materials make the latest 


hoses more durable and, at the same time, more lightweight 


and flexible. The costs for the coaxial hose range from 


$140 to $230.'~~'~~'~ 
 (See Table 5-2. ) 

Hose life has been extended greatly because of the new 


material, and because of the requirement for high hang hose 


retractors or high hang dispensers. These requirements 


force the hoses up off the ground and minimize or eliminate 


hose problems such as collapsed hoses from being run over by 


a vehicle, or hose tears and wearing from being constantly 


scuffed on the ground. With the use of high hang hose 


retractors or high hang dispensers, it is conservatively 


assumed that vapor hose replacement would occur only on an 


annual basis. 


High hang hose retractors and high hang dispensers also 


minimize vapor path blockage in the vapor hose caused by 


spitback or by liquid condensation. For high-hang 


multiproduct dispensers, venturi trap are required. These 


liquid removal systems consist of a small tube inserted in 


the vapor line extending to the low point of the hose. A 

venturi is placed in the liquid delivery hose and dispensed 


liquid passing through the venturi creates a vacuum in the 


tube. This vacuum draws the liquid from the low point in 


the hose into the liquid delivery hose. Liquid removal 


systems can be purchased separately or in conjunction with a 


coaxial hose assembly. These systems cost $200 if purchased 

separately17 or $240-$430 if purchased with a coaxial hose 


a~sembly.'~ Table 5-2 summarizes the costs associated with 


vapor recovery hose purchase and replacement. 


5.1.1.3 Other Com~onents. Other components that must 


be purchased with the aboveground equipment could include 


high-retractor hose assemblies, hose breakaway fittings, 


vapor check valves, swivels (nozzle, island, dispenser, 


retractor), flow limiters, and hose splitters. Table 5-3 


illustrates typical costs associated with these components. 


These pieces of equipment are not expected to wear or fail 


at the same rate as nozzles, bellows, faceplates, or hoses, 


and are expected to operate relatively maintenance free. 


5.1.1.4 Pis~enser Modifications. Product dispensers 


at existing service stations will have to be converted to 


allow the installation of vapor return piping. Conventional 


dispensers will typically have room within the dispenser to 


allow the vapor piping riser to extend into the dispenser 


and exit out the side. Newer dispensers, such as multi- 


product dispensers, may have to be converted to allow the 


installation of the vapor piping through the dispenser 


housing and back into the underground piping. California 


has included such dispenser modifications as part of a 


certified system since the manner in which the piping is 


plumbed through the dispenser could affect the backpressure 


experienced in the vapor line at the nozzle, thereby 


affecting the system's ability to recover the vapors. 


Typical costs to modify an existing dispenser is about 


$50-60. l9 


5.1.1.5 Va~or Processors. The Hirt and Hasstech CARB 


certified vacuum assist systems use a thermal oxidizer as 


the vapor destruction device. The thermal oxidizer system 


necessary to transport vapors from the underground tank to 


the vapor processor consist of a pilot/ignition system, 


vapor pump, PV vents, etc. The cost of a vapor processing 


system is about $4, 000.20 

TABLE 5-2. TYPICAL VAPOR RECOVERY HOSE COSTS'~~'~~'~ 

(May 1991 Dollars) 


Itema Costs 


Coaxial Hose 


Liquid Removal System 


Coaxial Hose with Removal System 


a Costs presented for a typical 10 foot hose system. 

TABLE 5-3. TYPICAL COSTS OF OTHER VAPOR 


RECOVERY COMPONENTS'~~'~~'~ 


(May 1991 Dollars) 


Item Costs 


High hang hose assembly 


Hose break away fittings 


Vapor check valves 


Swivels 


Nozzle 


Island 


Dispenser 


Retractor 


Flow limiters 


Hose splitters 

The vapor pump and the vapor processor will require 


additional adjustments and repairs. It has been estimated 


that annual maintenance costs would be as much as $400-600 


21
 per year. 


5.1.1.6 Jnstallatioq. Installation of the aboveground 


equipment consists of assembling the hoses, nozzles, 


swivels, check valves, etc., and attaching the nozzle/hose 


assembly to the vapor piping exiting the dispenser. It has 


been estimated that installation would cost about $80 per 


nozzle. If a vacuum assist unit is being installed an 


additional $1,300 would be necessary to take care of the 


thermal oxidizer and vapor pump in~tallation.~' The Healy 


System requires the installation of the jet pump used to 


create the vacuum in the vapor return line. It has been 


estimated that the installation of the jet pump would cost 


$535.23 


5.1.2 Underaround Pi~inq 


The underground portion of the vapor recovery system 


consists of all the underground piping and fittings 


necessary to allow the captured vapors to be returned to the 


underground storage tank. Costs of the underground 


components are directly affected by the service station 


configuration (i.e., the number of islands, the distance 


between islands, the distance from the islands to the 


underground tank), the type of system (individual balance 


system, manifolded balance system, hybrid system, or vacuum 


assist system) and other station physical characteristics 


(amount of concrete over underground tanks, amount of 


backfill material required, or whether the storage tanks are 


located above the islands). The following subsections 


discuss some of these costs in more detail. 


5.1.2.1 Va~or Pi~inq. Most vapor recovery piping 


being used in recent installations consists of fiberglass 


pipe. Reasons usually cited for using this type of piping 


is that it is leak resistant, easy to work with, and easy to 


install (i.e., glued not threaded). Typical vapor piping 

consists of 2 inch or 3 inch pipe laid in a trench, sloping 


down to the underground tank. The amount of piping required 


is certainly affected by specific facility distances, but 


also whether individual or manifolded vapor piping is 


used.24 Table 5-4 summarizes the piping differences between 


a manifolded vapor balance system and an individual vapor 


balance system. Vacuum assist systems can either be 


manifolded or individual. Table 5-5 summarizes the piping 


costs for different certified systems assumed for a typical 


9 nozzle, 65,000 gallon per month service station. 


5.1.2.2 Trenchins and Backfillinq. The majority of 


the costs associated with the underground piping tied to the 


costs of digging the trenches. The trenches must be dug 


from the dispensers to the underground tanks to allow the 


laying in of the vapor piping, assuring proper slope from 


the dispensers down to the underground tanks . Further 

costs are involved with backfilling the trenches and 


repairing the pavement. Digging the trenches requires 


cutting through the concrete pad over the storage tanks and 


at the islands, probably shutting down the station, and 


using a backhoe to dig the trench back to the underground 


tanks. Costs associated with trenching are difficult to 


obtain since it is not hardware related, but consists of 


labor and heavy equipment charges. From a previous 


analysis, EPA derived trenching and backfill costs based 


upon an estimate obtained from a Stage I1 system installer. 


This cost averaged about $30 per foot of trench.25 


A great deal of importance is given to the proper 


installation of the underground piping. Improper slope, 


poor backfilling, and ground settling all can cause breaks 


or low points in the vapor piping system. Breaks in the 


vapor piping can cause vapor leaks in the system, and low 


points in the piping can provide the potential for liquid 


accumulation resulting in liquid blockage. Some areas of 


California have indicated that as many as 50 percent of the 


underground systems are incorrectly installed.26 

TABLE 5-4. PIPING COMPONENT DIFFERENCES BETWEEN INDIVIDUAL 


AND MANIFOLDED BALANCE SYSTEM'^ 


Number of Components 

Individual Manifolded 

Underground Components Balance System Balance System 

Galvanized Pipe for Vapor 

Risers 

1" Pipe (FT) 

211 Pipe (FT) 

3" Pipe (FT) 

3/411 Close Nipple 

1" Close Nipple 

211 Close Nipple 

3" Close Nipple 

1" Elbow 

211 Elbow 

3" Elbow 

1" x 3/411 Reducer 

2" x 1" Reducer 

311 x 2" Reducer 

411 x 211 Bushing 

Fiberglass Pipe for Vapor 

Return Piping 

211 Pipe (FT) 

311 Pipe (FT) 

2" Threaded adapter 

3l1 Threaded adapter 

2" Elbow 

311 Elbow 

2" Tee 

311 Tee 

211 Coupling 

3" Coupling 

3" x 211 Reducer 

Glued Junctions 

Additional Items 

411 x 3" Tank Bushing 

211 Float Check Valve 

Vent Manifold Drum 

Bungs 
TABLE 5-5. TYPICAL VAPOR PIPING COSTS FOR 65,000 GALLON 


PER MONTH SERVICE STATION" 


Vapor Pi~inq Costs 


Individual Balance System 


Manifolded Balance System 


Healy Assist System 


Vacuum Assist Systema 


a Average of both the Hirt and Hasstech certified vacuum 

assist systems. 

California, New York and several other Stage I1 areas 


in the country now require tests to be conducted on the 


underground piping. These tests, discussed in Chapter 6, 


consist of the liquid blockage, pressure decay, and 


backpressure tests. It is estimated that the costs to 


perform these tests is a total of $670.'~ 


A common occurrence over the last several years is that 


station owners across the country have been installing Stage 


I1 underground piping whenever modifications were undertaken 


that required excavation. This will reduce installation 


costs for a great number of stations. 


5.1.3 Affects of the UST Proaram 


Stage I1 installation costs can be affected by a 


simultaneous Stage II/UST program implementation by 


considering the cost savings of installing Stage I1 at the 


time underground tanks are being repaired or replaced. The 


potential cost savings are realized in reduced trenching and 


paving costs that would have been attributed to the Stage I1 


installation in the absence of any UST activity. 


The key items for determining the impacts of a 


simultaneous Stage II/UST program on installation costs is 


to determine how many tank system leaks will occur and what 


equipment will be excavated during repairs or replacement. 


Several assumptions had to be made concerning the number and 


type of repairs required under an UST program. These 


assumptions on number or frequency of repair are drawn from 


a previous analysis and are presented in Table 5-6. 


Table 5-6 further summarizes the possible actions taken 


in response to finding a leak in either the underground 


piping or underground tank. For each remedy action, the 


percent of all tank systems assumed to use that remedy is 


listed. A description is added that summarizes the 


resulting savings in Stage I1 trenching associated with each 


remedy. For example, both Actions 1 and 4 (dig up all 


piping, and dig up all piping and tanks) result in the 

TABLE 5-6. ACTIOWS TAKEN IN RESPOllSE TO FINDING A 

LEAK IN AN UNDERGROUND TANK SYSTEM^ 

Percent of Costs ~avd 

Percent Dercr ipt ion of Savings Undcrgrwnd Total 

of all in Stage I1 Piping Installation Capital . Capital Anrnu~l 

Action Systems Costs Costs Costs 

1. Dig up all piping 4.5% All trenching costs 65% 40% 25% 

2. ~igup md of tanks only 11.8% Trenching costs over md of al l tanks 10% n 5% 

3. Dig up md of tanks end vdcr 1.3% Trenching costs wer all tmks and vdcr 30% 20% 15% 

di spmser s all dispensers 

4. Dig ~pall piping and tanks 12.5% All trenching costs 65% 40% 25% 

5. Dig up only one tank 1.OX Trenching costs over one tank 8% 5% 3% 

6. Repair one leaking tank -3.1% Trenching costs over one tank 8% 5% 3% 

Total 35.0% 

Cost percentages for a typical 65,000 gallon/month station. 
savings of all trenching costs. Also presented in Table 5-6 

is the resulting percentage savings in total Stage 11 costs 

that would occur under each action. 

A further discussion of cost savings associated with 

simultaneous Stage II/UST programs can be found in Appendix 

K of the 1987 Regulatory Impact Analysis (RIA), Volume I 

concerning gasoline marketing strategies. 28 

5.1.4 Pecoverv Credits 

Another aspect of the annual costs for Stage 11 systems 

is recovery credits. As discussed in Chapter 2, the return 

of saturated vapors to the storage tank during vehicle 

fueling eliminates the inbreathing of fresh air and 

subsequent evaporation of liquid gasoline. Each gallon of 

gasoline that is prevented from evaporating represents a 

gallon of product the station owner can sell that would not 

be present in the absence of Stage I1 controls. The 

earnings generated from this gasoline that would have 

otherwise have evaporated are counted as recovery credits. 

Recovery credits may be calculated as follows. 

Assuming 95 percent recovery of both displacement and 

emptying losses, 

recovered vapor = ((1,340 mg/liter)(.%)) + ((120 rg/liter)(.%)) = 1,387 mg/liter. 

Example of recovery credit: 

1,387 mg/liter x 75,700 liters x ax liter x 12 mo. x W.275/liter = S5Wyear. 

ID. 10 mg 0.67kg yr 

5.2 MODEL PLANT COSTS 

Costs in this section are presented for the model 

plants described in Chapter 2 of this report. Because of 

the infinite variations in service station layout and 

design, model plants were developed to represent the 

industry and to fix the physical parameters of each 

facility. In addition to the items specified in Table 2-5, 

such as throughput and number of nozzles, the physical 

design of each model station was developed. This included 
distances from the dispensers to the tank to fix trenching 


lengths, and designs of piping scenarios to fix piping 


costs. 


A detailed cost model was developed by EPA, in the 1987 


Draft Regulatory Impact Analysis (RIA), that created 


"ground-upw costs for each model plant.a This model used 


the piping layouts described above and detailed component 


costs for aboveground equipment. Costs were obtained for 


all certified equipment and averaged to estimate capital and 


installed costs for each component. Costs were also 


obtained for fiberglass pipe and fitting costs, installation 


labor, and trenching costs. For convenience, a detailed 


discussion of this model is reproduced in Appendix B of this 


document. 


5.3 COMPARISON OF RECENT COST STUDIES 


EPA solicited and received public comments on the 1987 


RIA associated with the proposal of onboard controls for 


vehicle refueling. EPA received public comments concerning 


Stage I1 costs from many sources including oil companies, 


service station dealers, and auto manufacturers. Of 


particular interest to EPA were comments received from the 


American Petroleum Institute (API) 30 and from Multinational 


Business Services, Inc. (MBS)~' (under contract to the Motor 


Vehicle Manufacturers Association and the Auto Importers of 


America). These comments were of interest because these two 


groups conducted their own cost analyses of Stage I1 


equipment installed in St. Louis and attempted a comparison 


with the EPA cost analysis found in the Draft RIA on the 


onboard proposal, (see Appendix B). The majority of the 


remaining comments provided little or no cost breakdown, 


making cost comparisons impossible. In addition to comments 


received on Stage I1 costs, Pacific Environmental Services, 


Inc. (PES), under EPA contract, conducted an independent 


analysis of Stage I1 installation costs in St. Louis, 


Missouri and compared the costs they obtained with the 

industry studies and with the Draft RIA.^^ Stage I1 costs 


in St. Louis were considered important at that time because 


Stage I1 installations were recently completed in this 


metropolitan area, and conflicting cost information was 


received during the public comment period. 


As stated before, the Draft RIA used a "ground-upw 


model of Stage I1 costs, whereas, the API, MBS, and PES 


studies were all surveys of Stage I1 costs in St. Louis. As 


discussed earlier in this chapter, direct comparison of cost 


surveys conducted by different groups is often difficult 


especially if cost breakdowns are not available. Cost 


breakdowns allow an analysis of the make-up of the costs, 


and ensures that like costs are being compared (i.e., only 


Stage I1 related costs were included in the reported costs). 


Cost breakdowns and raw data for all industry surveys were 


not available to allow direct comparison to EPA cost models. 


5.3.1 Ca~ital Cost Com~arison 


Stage I1 system installed capital cost estimates from 


all data sources are shown in Table 5-7. These average 


Stage I1 system costs are graphically depicted by model 


plant category in Figure 5-1. This plot is useful in making 


"snapshotu comparisons among the data sources for each of 


the model plant categories. In order to determine a trend 


or relationship among each of the subject data sets, a 


linear regression method was used. The linear function was 


determined as most representative, based on the use of 


correlation coefficient (R-squared) values as criteria for 


best fit. Figure 5-2 illustrates the relationship of 


capital cost versus model plant category after the 


application of the "best fitw line. No information was 


presented in the API Report to explain why the "majorw costs 


were so much higher than the "Jobberw costs. Because of the 


large differences these costs are depicted separately on 


these figures. 


Capital cost data submitted by API suggested that EPA 


had, on average, understated costs by about 40 percent. 

TABLE 5-7. SUMMARY OF STAGE I1 SYSTEM CAPITAL COST 


ESTIMATES FROM ALL SOURCES~~~~~~~~~~' 

Model 

Plant Total System 

No. Cost Estimate Source Capital Costs 

a No data reported. 



Capital costs submitted by MBS suggested EPA had, on 


average, overstated costs by about 20 percent. Stage I1 


costs published in the Draft RIA with the onboard proposal 


fell between the costs submitted by these commenters. In 


addition, the St. Louis data obtained by PES also fell 


between the API and MBS costs and compared favorably (within 


5 percent) with the Draft RIA costs. The fitted curves of 


Figure 5-2 illustrate that PESa costs were close to the 


Draft RIA costs for the smaller model plants and between the 


Draft RIA and API costs for the larger model plants. 


5.3.2 Annual Cost Conmarison 


The commenters supplied annual costs associated with 


the estimated capital costs of the Stage I1 systems on a 


model plant basis. However, difficulties arose in 


summarizing and comparing these costs because each commenter 


used different cost assumptions for: (1) annualized cost of 


capital, (2).maintenance costs, (3) recovery credits, and 


(4) thenumber of nozzles assigned to each model plant. In 


an effort to normalize these variations, each~capital cost 


estimate presented in Section 5.3.1 was converted to 


annualized costs using EPA1s cost methodology from the Draft 


RIA and using the same assumptions for equipment life 


(8 years aboveground equipment, 35 years below-ground 


equipment), interest rate (10 percent), taxes and insurance 


(4 percent), and calculation and costs dealing with recovery 


credits.33 Maintenance costs'were considered the same for 


each annual cost estimate. 


Table 5-8 summarizes the annual cost estimates 


normalized using the assumptions above. These estimates are 


graphically depicted in Figures 5-3 and 5-4. 


5.4 CURRENT COSTS OF STAGE I1 SYSTEMS 


Based on the comparisons discussed in Section 5.3, it 


can be concluded that the ground-up model from the Draft RIA 


(reproduced and presented in Appendix B) provided a 


reasonable estimate of actual Stage I1 installations. This 

TABLE 5-8. SUMMARY OF NORMALIZED STAGE I1 SYSTEM ANNUAL 


COST ESTIMATES FROM ALL SOURCES 


Model 


Plant Normalized Annual 


No. Cost Estimate Source Costs 


1 
 Draft RIA $1,270 


API-Jobber $2,045 


API -Maj or NAa 


MBS $1,288 


PES $1,244
 ......................................................... 


Draft RIA $1,280 


API-Jobber $1,953 


API-Maj or NAB 


MBS $1,195 


PES $1,515
 ....................................................................... 


Draft RIA $2,380 


API-Jobber 


API-Maj or 


MBS 


PES 


4 Draft RIA $2,960 


API-Jobber 


API-Maj or 


MBS 


PES $2,726 


5 Draft RIA $2,430 


API-Jobber 


API -Ma j or 


MBS 


PES 


a Cannot be calculated since no capital costs reported. 



model was, therefore, used to estimate current 1991 Stage I1 


costs. The model in Appendix B was used, but replacing key 


component costs to reflect 1991. Table 5-9 contains a 


summary of the cost data changed from the Draft RIA analysis 


to generate 1991 costs. As stated earlier in this document, 


multi-product dispensers, offering each of three gasoline 


grades on each side of the dispenser, have increased in 


popularity in recent years. The Draft RIA made an attempt 


to estimate the mix of single and multi-product dispensers 


to calculate a national Stage I1 cost impact. For purposes 


of this document two separate estimates have been made, one 


to represent single dispensers and one to represent multi- 


product dispensers. Table 5-10 summaries 1991 capital costs 


of Stage I1 systems for single dispenser facilities and 1991 


capital costs for multi-product dispensers. Annualized 


costs were also calculated using the approach discussed in 


Appendix B, but using the 1991 capital costs and the 1991 


RVP and gasoline price for recovery credit calculations. 


Table 5-11 summarizes annual costs for single and multi- 


product dispensers, respectively. 


Another important factor to consider when reviewing 


Stage I1 costs is system cost effectiveness. Cost 


effectiveness is the annual operating costs divided by the 


annual emission reduction, yielding a value of dollars spent 


per unit measure of emission reduction. Table 5-12 presents 


the 1991 cost effectiveness of Stage I1 systems, expressed 


as dollars per megagram of emission reduction. Again, 


values are presented for both single and multi-product 


dispensers facilities. 


The program effectiveness or overall emission reduction 


is dependent on the exemption level selected, as indicated 


in Section 4.4.3. The cost effectiveness of the program is 


also dependent on the exemption level imposed. Smaller 


facilities have higher cost effectiveness values (see Table 


5-12). Program cost effectiveness, therefore, improves by 

TABLE 5-9. SUMMARY OF COST ITEMS CHANGED IN APPENDIX B 


COST MODEL TO OBTAIN 1991 COSTS 


Item Cost 


Nozzle Costs (New) 


Emco Wheaton 


OPW 


Husky 


Nozzle (Rebuilt) 


Emco Wheaton 


EZ-f 10 


(OPW or Emco Wheaton) 


Component Costs (Spout kit) 


Emco Wheaton 


Husky 


OPW 


EZ-flo (OPW or Emco wheaton) 


Boot Kit 


EZ-flo 


Husky 


Emco Wheaton 


Hoses (10 ft, w venturi) 


Thermoid 


Goodyear 


Dayco 


Hoses (10 ft., w/o venturi) 


Thermoid 


Goodyear 


Dayco 


Breakaways (one time) 


Dayco 


Husky 


Breakaway (reconnectable) 


Husky 


Petroleum 


EMCO Wheaton 

TABLE 5-9. SUMMARY OF COST ITEMS CHANGED IN APPENDIX B 

COST MODEL TO OBTAIN 1991 COSTS (CONTINUED) 

Item Cost 

Miscellaneous Equipment 

12" whiphose 

Goodyear 42.54 

Themoid 48.76 

Dayco 47.69 

Retractor Clamp 

Goodyear 

Thermoid 

EZ-f low (Dayco) 

(Goodyear, Thermo, and 

Gates) 

High Hang Hose Retractors 

Catlow 

Swivels 50.50 
TABLE 5-10. 1991 STAGE I1 BALANCE SYSTEM CAPITAL COST 


COMPONENT COST OF COMPONENT 

SINGLE MULTIPRODUCT 

MODEL PLANT 1 DISPENSER DISPENSER 

Number of Nozzles 

Dispenser Direct Cost 

Piping Direct Cost 

Total Capital Cost 

MODEL PLANT 2 

Number of Nozzles 

Dispenser Direct Cost 

Piping Direct Cost 

Total Capital Cost 

MODEL PLANT 3 

Number of Nozzles 

Dispenser Direct Cost 

Piping Direct Cost 

Total Capital Cost 

MODEL PLANT 4 

Number of Nozzles 9 

Dispenser Direct Cost 7,120 

Piping Direct Cost 9,690 

Total Capital Cost 16,810 

MODEL PLANT 5 

Number of Nozzles 15 30 

Dispenser Direct Cost 11,860 24,060 

Piping Direct Cost 12,650 12,650 

Total Capital Cost 24,510 36,710 
TABLE 5-11. 1991 STAGE I1 BALANCE SYSTEM ANNUAL COST 


COMPONENT COST OF COMPONENT 

SINGLE MULTIPRODUCT 

MODEL PLANT 1 DISPENSER DISPENSER 

Capital Recovery Cost 

Maintenance Cost 

Other Indirect Costs 

Recovery Credit 

Total Annualized 

Cost 

MODEL PLANT 2 

Capital Recovery Cost 939 

Maintenance Cost 617 

Other Indirect Costs 293 

Recovery Credit 518 

Total Annualized 1,331 

Cost 

MODEL PLANT 3 


Capital Recovery Cost 


Maintenance Cost 


Other Indirect Costs 


Recovery Credit 


Total Annualized 


Cost 


MODEL PLANT 4 


Capital Recovery Cost 


Maintenance Cost 


Other Indirect Costs 


Recovery Credit 


Total Annualized 


Cost 


MODEL PLANT 5 


Capital Recovery Cost 


Maintenance Cost 


Other Indirect Costs 


Recovery Credit 


Total Annualized 


Cost 

TABLE 5-12. COST EFFECTIVENESS OF 1991 STAGE I1 


BALANCE SYSTEMSa 


Single Multiproduct 

Dispenser Dispenser 

MODEL PLANT 1 

Annualized Costs, $ 

Emission Reduction, Mg 

Cost Effectiveness, $/Mg 

MODEL PLANT 2 

Annualized Costs, $ 

Emission Reduction, Mg 

Cost Effectiveness, $/Mg 

MODEL PLANT 3 

Annualized Costs, $ 

Emission Reduction, Mg 

Cost Effectiveness, $/Mg 

MODEL PLANT 4 

~nnualized Costs, $ 

Emission Reduction, Mg 

Cost ~ffectiveness, $/~g 

MODEL PLANT 5 

Annualized Costs, $ 2,735 4,943 

Emission Reduction, Mg 9.7 9.7 

Cost Effectiveness, $/Mg 280 510 

a Emission reduction from Table 3-8, and assuming annual 


enforcement (86 percent in-use efficiency). 

exempting higher cost facilities. Table 5-13 summarizes 


program cost effectiveness when compared to certain 


exemption levels. This table was calculated based upon the 


model plant cost effectiveness values presented in Table 


5-12 and the model plant distribution values contained in 


Tables 2-8 and 2-10. Values are presented for facilities 


with either single dispensers or multiproduct dispensers, as 


in Table 5-12, but also an average cost that assumes equal 


distribution of single and multiproduct dispensers. 

TABLE 5-13. PROGRAM COST EFFECTIVENESS COMPARED 


TO EXEMPTION LEVEL 


Program Cost Effectiveness 


( S/Mg 1 

Program Single Multiproduct 


Exemption Level Dispenser Dispenser Averagea 


No Exemptions 


Ex < 10,000 gal/month 820 1,210 1,020 

Independents 


< 50,000 gal/month 

a Average assumes equal distribution of single and 

multiproduct dispensers. 

5.5 REFERENCES 


Memorandum from Norton, R., Pacific Environmental 


Services, Inc. (PES), to Shedd, S., U.S. 


Environmental Protection Agency. April 29, 1991. 


Trip Report - New York Department of Environmental 

Conservation. 


Telecon. Bowen, Elizabeth, Pacific Environmental 


Services, Inc. (PES) with Pratt, B., State of 


Missouri. May 30, 1991. Stage I1 Program 


Implementation. 


EMCO Wheaton Price List, March 1991. 


Telecon. Bowen, E., Pacific Environmental 


Services, Inc. (PES) with Holcom, C., Husky 


Corporation. April 30, 1991. Stage I1 Nozzle 


Costs. 


Telecon Bowen, E., Pacific Environmental Services, 


Inc. (PES), with Taylor, B., OPW. May 29, 1991. 


Stage I1 Nozzle Costs. 


Reference 3. 


Reference 3. 


Reference 4. 


Draft Regulatory Impact Analysis: Proposed 


Refueling Emission Regulations for Gasoline-Fueled 


Motor Vehicles -- Volume I - Analysis - of Gasoline 

Marketing Regulatory Strategies. U.S. 


Environmental Protection Agency, Office of Air 


Quality Planning and Standards an and Office of 


Mobile Sources. Publication No. EPA-450/3-87- 


001a. July 1987. Appendix B, Table B-15. 


Telecon. Norwood, P., Pacific Environmental 


Services, Inc., with Friedman, G., EZ-flo. 


October 4, 1991. Stage I1 Equipment Costs. 


Reference 3. 


Fax communication to Bowen, E., Pacific 


Environmental Services, Inc. (PES), from Carmack, 


M., Catlow. May 8, 1991. Price List for Stage I1 


Equipment. 


Reference 9, Appendix B, Table B-2. 

Telecon. Bowen, E., Pacific Environmental 


Services, Inc. (PES) with Terlizzi, L., Thermoid. 


April 30, 1991. Stage I1 Equipment Costs. 


Telecon. Bowen, E., Pacific Environmental 


Services, Inc. (PES) with Whittington, G., 


Goodyear. May 6, 1991. Stage I1 Equipment Costs. 


Fax Communication to Bowen, E., Pacific 


Environmental Services, Inc. (PES) from Gelle, B., 


Dayco. May 15, 1991. Stage I1 Equipment Price 


List. 


Reference 12. 


Reference 14, 15, 16. 


Reference 13. 


Reference 9, Appendix B, Table B-5. 


Reference 20. 


Reference 20. 


Reference 2 0. 


Reference 9, Appendix B, Table B-11. 


Reference 24. 


Memorandum from Norwood, P., Pacific Environmental 


Services, Inc. (PES) to Shedd, S., U.S. 


Environmental Protection Agency. April 30, 1991. 


Trip Report to California Agencies to Discuss 


Stage I1 Programs. 


Wakim, Paul, C. J. Sample, K.A. Rooney, and D. 


Clemons (American Petroleum Institute). API 


Survey of Actual Stage I1 Implementation Costs In 


The St. Louis Metropolitan Area. American 


Petroleum Institute. December 2, 1988. 


Reference 9, Appendix K. 


Reference 9, Appendix B. 


Reference 26. 


Responses to Points Raised by EPA Concerning the 


MBS Study "Costs and Cost-Effectiveness of Stage 


I1 and Onboard Refueling Vapor Controlsw (April 


1987). Multinational Business Services, Inc. 


(MBS). October 1987. 
32. Norton, R. and Scott Osbourn (Pacific 


Environmental Services, Inc.). Evaluation of 


Stage I1 Vehicle Refueling Control Equipment 


Installation Costs. Prepared for U.S. 


Environmental Protection Agency. November 28, 


1988. 


33. Reference 9. 

6.0 PROGRAM IMPLEMENTATION 


As discussed in Chapter 1, Stage I1 vapor recovery has 


been a part of VOC emission control in California for some 


time. Since the introduction of Stage I1 vapor recovery 


California in the early 70ts, this program has become one of 


California's major VOC control strategies. Seventeen 


districts in California containing areas that are classified 


nonattainment for ozone have Stage I1 programs that have 


been in effect for over a decade. The remaining districts 


in California have also recently adopted regulations 


requiring Stage I1 vapor recovery for benzene control. 


Other areas of the country have also established Stage 


I1 vapor recovery programs. The District of Columbia 


implemented a Stage I1 program in the early 1980s and 


Missouri adopted vapor recovery regulations in the St. Louis 


area later in the 80s. In the late 1980s and early 1990s 


several other States and local agencies have adopted Stage 


I1 programs. These areas include New Jersey, New York (New 


York City metropolitan area) Massachusetts, Pennsylvania, 


Washington, Oregon, and Dade County, Florida. The CAAA of 


1990 require the installation of Stage I1 vapor recovery 


systems in many ozone nonattainment areas. Based on final 


nonattainment designations, this would affect almost 60 


metropolitan areas in the United States. 


The purpose of this chapter is to provide information 


on the planning, implementation, and enforcement of Stage I1 


programs in other States. Incorporated into this discussion 


are examples of how areas with current Stage I1 programs 


handle certain situations and issues. This ranges from 


experience in areas such as San Diego which has almost 20 


years experience with Stage 11 to areas such as 

Massachusetts and Dade County, Florida with programs only 


recently adopted. Appendix F provides summaries of many of 


the programs in the United States. For each program, 


Appendix F provides a description of the program with 


problems encountered and recommendations for new areas based 


on their experience. In addition, items such as permit 


applications, inspection checklists, etc. are included for 


some of the areas.in Appendices G-K. Specifically, this 


chapter addresses planning elements, regulations, and 


permitting and enforcement considerations. The EPA 


enforcement guidance document should be consulted for 


guidance on enforcement issues. 


6.1 PLANNING 


The planning of a Stage I1 program involves several 


considerations including the characterization of the 


affected industry and the estimation of environmental and 


economic impacts. The information contained in other 


chapters of this document can aid in the determination of 


some of these factors. 


An important consideration from the outset of Stage I1 


program planning is to work closely with other agencies that 


may be affected by the program. For instance, the 


department or agency responsible for the measurement and 


accuracy aspects of gasoline dispensers would probably have 


an interest in such a program. Other agencies that are 


concerned with safety aspects, such as the Occupational 


Safety and Health Administration (OSHA) and the Fire 


Marshal, will also be affected by Stage I1 and should be 


consulted. The significance of working with these types of 


agencies is evident in the California certification process 


discussed in Chapter 4. Before a Stage I1 system is 


certified, it must meet the approval of California Division 


of Measurement Standards, California OSHA, and the 


California Fire Marshal, in addition to meeting the 


requirements of the California Air Resources Board (CARB). 

It may be beneficial to contact these types of agencies at 


the beginning and solicit their involvement with the Stage 


I1 program. 


6.1.1 Characterization of the Affected Industrv 


Chapter 2 characterizes the industry affected by Stage 


I1 regulations. A service station is defined as any site 


where gasoline is dispensed to motor vehicle fuel tanks from 


stationary storage vessels. This includes public (retail) 


and private facilities. Miscellaneous retail outlets that 


are considered service stations include conventional service 


stations, convenience stores, mass merchandisers, marinas, 


parking garages, and other similar facilities which sell 


gasoline to the public. Private facilities include those 


locations where gasoline is dispensed into government agency 


(Federal, military, State, and local) vehicles, fleet (auto 


rental, utility companies, taxis, school buses, etc.) 


vehicles, and trucking and local service vehicles. 


In order to estimate the impacts of a Stage 11 


regulation, it is necessary to identify the number of 


facilities potentially affected and the volume of gasoline 


dispensed at these facilities. 


6.1.1.1 Number of Facilities. The number of 


facilities can be estimated using a variety of techniques. 


Since most areas that will be required to install Stage I1 


have previously been classified as nonattainment for ozone, 


it is likely that Stage I vapor recovery regulations exist 


in these areas. The Stage I permit files can be used to 


supply an estimate of the number of potentially affected 


facilities. Other possible sources of this type of 


information are records pertaining to underground storage 


tanks, Department of Weights and Measures, tax records, 


local fire departments or even phone directories. 


In the absence of actual records or data, local or 


State trade organizations could be contacted. Also, 


information such as the survey completed by NPN discussed in 


Chapter 2 provides retail service station numbers on a State 

basis. These could be used and adjusted to a smaller 


geographic area using a factor such as population or 


gasoline throughput. 


6.1.1.2 Area Gasoline Throuah~ut. The combination of 


the area gasoline throughput and the emission factors 


discussed in Chapter 3 will provide an estimate of the 


uncontrolled emissions from vehicle refueling. If gasoline 


taxes are imposed in the study area, records relating to 


gasoline sales should be available at the tax office. If 


the study area entails an entire State, NPN annually 


estimates gasoline consumption on a State basis. Gasoline 


consumption and methods of estimating gasoline consumption 


on a county level are also discussed in Chapter 2. 


6.1.1.3 Size Distribution of Facilities. The 


distribution of facilities by throughput and according to 


the number of nozzles is important. Ideally, an agency 


could obtain detailed information regarding the number of 


service stations, the associated gasoline throughput, and 


the number of nozzles. However, in the absence of the 


resources necessary to develop such a database, it is 


possible to draw comparisons between the areas covered by 


the Lundberg data discussed in Chapter 2 and summarized in 


Appendix A and the agency's regulated area. The data can be 


used to estimate size distributions for counties in 


designated population ranges or with a known number of 


service stations. For example, if a county's population is 


approximately 50,000, the counties of Union, Hudson, and 


Monmouth, New Jersey could be selected from Appendix A as 


counties with comparable populations. The size 


distributions of these three counties could then be averaged 


to predict a size distribution for the study area county. 


Model plants could then be developed which include the 


number of nozzles and gasoline throughput. Alternatively, 


the model plants provided in Chapter 2 may be used. The 


distribution of facilities could be applied to the model 

plants to estimate the number of facilities represented by 


each model plant. 


6.1.2 E s 


The population and distribution of facilities, gasoline 


consumption, individual facility costs, and planned 


enforcement levels are used to predict environmental and 


economic impacts. 


6.1.2.1 Environmental Im~acts. The emission 


reductions anticipated from the regulation may be estimated 


by calculating the uncontrolled emissions and multiplying 


these emissions by the expected overall effectiveness for 


the program. The uncontrolled emissions can be calculated 


by multiplying the gasoline throughput by the uncontrolled 


emission factor discussed in Chapter 3. The overall, or in- 


use, effectiveness may be estimated according to the 


expected level of effort which the agency plans to have 


available for the program. In-use effectiveness is 


discussed in detail in Chapter 4. 


In order to evaluate the impacts associated with 


exemption levels, the throughput for the number of 


facilities in model plants that fall below the anticipated 


exemption cutoff should not be multiplied by the selected 


control level or use the Stage I1 program efficiencies shown 


in Chapter 4 with exemption levels already assumed. 


6.1.2.2 Economic Im~acts. Costs initially must be 


estimated on a facility basis. The agency may choose to 


gather information specific to their area regarding 


installation, equipment, and maintenance costs for these 


systems. If resources are not available for such a detailed 


analysis, Chapter 5 discussed costs of Stage I1 with model 


plant costs. Model plant costs may then be multiplied by 


the number of facilities assigned for each model plant to 


estimate the total area impacts. 


The overall cost in relation to the emission reduction, 


or cost effectiveness, may then be calculated by dividing 


the overall cost by the overall emission reduction. Since 

the cost effectiveness for smaller facilities is higher due 


to the lower gasoline throughput and resulting lower 


emission reduction and recovery credit, cost effectiveness 


is often used to define exemption levels for these smaller 


facilities. 


6.1.3 public Awareness 


Public acceptance is vital to the success of any Stage 


I1 program. The slight variations in the operation of Stage 


I1 equipment can annoy uninformed customers and lead to 


improper use possibly reducing efficiency and the incorrect 


conclusion that the equipment is faulty. Therefore, an 


agency should consider ways to inform and educate the public 


about the Stage I1 program. Many regulations require that 


operating instructions be placed at the pump. This is 


perhaps the simplest and most straightforward method of 


providing the public information about the operation of 


Stage I1 equipment. 


Another method used, especially in California, is a 


toll free complaint number. The number is placed on the 


pump with the operating instructions and is specifically for 


Stage I1 complaints. California officials have indicated 


that in the earlier periods of Stage 11, these lines were 


used by the public often to express discontent with Stage 


11. However, as the public has become more aware of the 


equipment, the complaint lines have evolved into a form of 


public compliance program, where persons call in with 


reports of faulty or missing equipment. 


In addition to the operating instructions and telephone 


number, the agency can develop a public awareness program. 


The publication and distribution of brochures, pamphlets, 


fact sheets, etc. is a manner of providing information to 


the public. Such a pamphlet from Massachusetts is provided 


in Appendix G-1. The use of the media to describe Stage I1 


has been used successfully in ~alifornia. Television, 


radio, and newspaper spots have described the environmental 

and personal health benefits associated with Stage I1 and an 


explanation of operating procedures. 


While these public awareness measures are important to 


gain acceptance of Stage 11, service station employee 


awareness and education may have a more significant impact 


on reducing emissions. It is extremely helpful if these 


employees are knowledgeable of the operation and maintenance 


requirements of Stage I1 equipment. There are several ways 


that an agency can promote this. They can provide 


workshops, training courses, etc. for service station 


employees that discuss Stage I1 equipment, regulations, and 


inspection procedures. The agency could also promote self- 


inspection programs that encourage station employees to 


conduct periodic equipment inspections to ensure that the 


equipment is in proper condition. Appendix G-2 contains a 

self inspection handbook published by the California Air 


Resources Board that is provided to station owners. An 


informed and conscientious service station employee 


population will decrease the enforcement effort needed and 


the excess emissions from vehicle refueling. 


6.2 REGULATIONS 

Development of appropriate rules is necessary in order 


to satisfy the intent of the program and determine 


individual facility compliance. As with any regulation, 


Stage I1 regulations should be clearly written and specific. 


The rules should contain definitions; requirements for the 


equipment installation, operation, and maintenance; 


exemptions levels; compliance schedules; and testing and 


recordkeeping requirements. Many Stage I1 regulations also 


require that operating instructions be posted at the pumps. 


Copies of many current Stage I1 regulations are contained in 


Appendix H. 


6.2.1 paui~ment Reauirements 

Most current Stage I1 regulations contain a statement 


that prohibits gasoline refueling without a certified or 

approved Stage I1 system. Common language for this 


requirement is IINo owner or operator shall transfer, permit 


the transfer, or provide equipment for the transfer of 


gasoline from a stationary storage tank at a service station 


into a motor vehicle fuel tank unless an approved Stage I1 


vapor recovery system with 95 percent or greater efficiency 


is installed and used during the transfer.I1 


This language brings to light an important point, the 


definition of an napproved Stage I1 vapor recovery system." 


An "approved Stage I1 vapor recovery systemN is defined in 


various ways but in all current situations is directly or 


indirectly linked to certification by the California Air 


Resources Board that the system controls VOC emissions with 


95 percent efficiency. In California, an approved system is 


any CARB certified system. CARB certification and Executive 


Orders are discussed in Chapter 4. In addition, Appendix C 


contains the certification testing procedures and Appendix D 


addresses Executive Orders. Most States and local agencies 


automatically approve, or certify, Stage I1 systems that 


have been certified by CARB. EPA is not aware of any State 


or local agency that has conducted testing and certified 


Stage I1 equipment which has not been previously CARB 


certified. However, most regulations outside of California 


do allow the possibility of non-CARB certification, although 


no specific test methods or procedures are identified. 


While the universe of certified equipment in non- 


California areas has not been broadened to include equipment 


not CARB certified, many areas are limiting the approved 


equipment from the complete list that is currently certified 


by CARB. For instance, both ~assachusetts' and Dade County, 


~lorida~
 allow only coaxial hoses. Dade County permits only 


the most recent generation of nozzles and other equipment. 


These are options available to a beginning program that can 


reduce the confusion as to what is llapprovedll, 
 as well as 


ensuring use of the prevailing technology. In fact, CARB 

representatives have indicated that they feel this is a 


sound approach for new programs.3 


In all circumstances, it is important that both 


industry and inspectors be completely aware of those systems 


and equipment which are approved and acceptable for an area. 


Even if an agency accepts CARB certification to determine 


approvable systems, it can maintain an up-to-date listing 


available to all parties that clearly specifies the 


permissible equipment and combinations of components. This 


is generally the approach being taken by the New York State 


4
 agency. 


6.2.2 Fxem~tion Levels 


The CAM of 1990 require that gasoline dispensing 


facilities with more than 10,000 gallons of gasoline 


throughput per month (50,000 gallons per month in the case 


of an independent small business marketer) install Stage 11. 


Therefore, by legislative mandate, the maximum exemption 


levels which a State or local agency may adopt are clearly 


defined. However, there are several variations that may be 


incorporated. 


Due to the difficulty of determining the stations that 


fall under the definition of "independent small business 


marketerN, many areas choose not to have a separate 


exemption level for this group. This is allowed under the 


Clean Air Act, as discussed in Chapter 1. In fact, 


presently no agency exempts independent marketers at a 


different throughput level from the remainder of the service 


station population. Many areas choose not to have any 


exemption level at all and require that all gasoline 


dispensing facilities install Stage I1 equipment. 


Pennsylvania's Stage I1 regulations contain an 


additional exemption requirement. Initially, all stations 


with monthly throughputs of 10,000 gallons per month or more 


are required to install Stage I1 equipment. In addition, 


whenever a station, regardless of throughput, is constructed 


or modified it is required that Stage I1 equipment be 

installed. Massachusetts' regulations also contain similar 


requirements. This eliminates a large portion of the 


installation cost and lessens the impacts on smaller 


stations. 


It is important that the regulation include specific 


stipulations and procedures to verify exemption status. As 


the CAAA specify exemptions based on gasoline sales, or 


throughput, it is anticipated that most regulatory agencies 


will follow this example, although Missouri's Stage I1 


regulations contain an exemption level related to storage 


tank capacity (2,000 gallons for agricultural usage). 


Agencies with Stage I1 vapor recovery programs have 


indicated that problems exist with the verification of 


facility throughput and, thus, the identification of exempt 


facilities. One approach is to shift the burden of proof 


from the agency to the facility. The Bay Area Air Quality 


Management District (Bay Area) regulations make it apparent 


that the burden of proof lies with the facility. The 


regulation states that "the burden of proof of eligibility 


for exemption from this rule is on the applicant. Persons 


seeking such an exemption shall maintain adequate records 


and furnish them to the Air Pollution Control Officer (APCO) 


upon request." This allows the agency to evaluate not only 


the throughput data but the adequacy of the data provided. 


This situation can also be avoided by specifying 


procedures for keeping records and determining throughput. 


For instance, New York's regulation states, "The sum of all 


gasoline deliveries to a gasoline dispensing site during the 


previous 12 consecutive months will be used to determine 


whether the requirements of section 230.2 of this Part 


apply* Once a gasoline-dispensing site becomes subject to 


the requirements of section 230.2 because its annual 


gasoline throughput exceeds an applicability level, 


subsequent decreases in gasoline deliveries or throughput do 


not excuse a source owner from having to maintain the 


effectiveness of the stage I and/or stage I1 equipment." 

6.2.3 Com~liance Schedules 


The CAAA of 1990 contain specific provisions related to 


compliance dates. Section 182(e)(3) states that within 2 


years from the enactment of the CAAA of 1990, States must 


"submit a revision to the applicable implementation plan to 


require all owners or operators of gasoline dispensing 


systems to install and operate ... a system for gasoline 

vapor recovery of emissions from the fueling of motor 


vehicles." It also designates compliance dates as follows: 


(i) 6 months after the adoption date, in the 


case of gasoline dispensing facilities for which 


construction commenced after the date of the 


enactment of the Clean Air Act Amendments of 1990; 


(ii) one year after the adoption date, in 


the case of gasoline dispensing facilities which 


dispense at least 100,000 gallons of gasoline per 


month, based on average monthly sales for the 2- 


year period before the adoption dater or 


(iii) 2 years after the adoption date, in the 


case of all other gasoline dispensing facilities. 


Any gasoline dispensing facility described under 


both clause (i) and clause (ii) shall meet the 


requirements of clause (i). 


The determination of an appropriate and realistic 


compliance schedule within the CAAA requirements involves 


the study of many factors. The schedule for installation of 


Stage I1 equipment should allow sufficient time for 


facilities to plan for their needs, as well as alleviating 


any contractor shortages and potential premium charges. In 


most instances, the compliance schedule is multi-phase, with 


facilities with larger gasoline throughputs required to 


install the Stage I1 equipment in the initial phase and the 


smaller stations following. This originally would affect 


the larger oil companies and jobbers, and help to avoid 


competition between these facilities and smaller businesses 


for contractors. This method also affects a larger 


percentage of the gasoline throughput in the shortest time 


frame. Under Section 325 of the CAAA, of 1977 a three year 

phase-in for independent small business marketers is 


provided. 


In determining whether a compliance schedule is 


reasonable, the major issues to investigate are: (1) the 


number of contractors in an area; (2) the number of service 


stations in each cutoff classification; and (3) the 


equipment availability due to other areas in the region or 


country that are simultaneously requiring the installation 


of Stage I1 systems. Table 6-1 summarizes the exemption 


levels and compliance schedules of various Stage I1 


programs. 


6.2.4 Recordkee~ina Reauirements 


The most common recordkeeping requirement pertains to 


gasoline sales or throughput. In many instances, throughput 


is determined by keeping records on the amount of gasoline 


delivered to the site, although the CAAA of 1990 specify 

exemptions based on gasoline sales. It is appropriate that 


records be kept for either, or both, deliveries and sales. 


An additional check of gasoline sales could be obtained from 


tax records, or the facility could be required to obtain and 


keep this tax information on-site along with the facility 


generated data. It is also possible that recordkeeping 


requirements could be added as permit conditions. Some 


areas have a recordkeeping requirement that results of 


installation tests be kept on site. These tests are 


discussed in detail in Section 6.3.3. 


6.3 PERMITTING 

Permits are a tool that local air pollution control 


agencies can use in getting Stage I1 vapor recovery control 


systems installed properly. The permits and permit 


conditions should be clearly written to avoid confusion on 


the part of the owner/operator of the facility and to 

enhance enforcement efforts. Several aspects of permitting 


are discussed in more detail in the following sections, 


including the identification of sources, permit forms and 

TABLE 6-1. SUMMARY OF STAGE 11 PROGRAM EXEMPTIOW LEVELS AND COMPLIANCE SCHEDULES 

(Ae of JVK 1991) 

Covered Area 

Bay Area A90 

South Coart AQW) 

Sen Diego APQ) 

Sen Francisco area 

Lor Angeles area 

Sm Diego area 

- Storwe tdr with capocity e 260 The 0.y Area Dirtrict her 

gal. ad used for ~iaplcrrnts of hd Stage 11 rcgrircnantr 

husbandry" since the 1970s 

- Here the Dirtrict cktemim that 

Stage I1 ie not feasible 

- vehicle to vehicle refueling 

- Facilities that excluinly fuel 

motor vehicle taka e 5 gallam 

- Facilities that excluinly fuel 

aircraf t 

- Facilities with 64,000 pr ywr 

throughput where St- I1 un not 

installed before July 1, 1963 

- Fuilitfeswith7Sprcrntof Tho South Cwt Dirtrict 

throughput for fueling irplemnta of hn hd Stage I1 

husbandry rrgrirmtr since the 

1mr 

- Retail rtatiaw wlth storage tdr The Sm Diego Dirtrict hn 

lesr thm 260 gallam had St- I I rcqulrmtr 

since the 19700 

- Wonretail atatid with atorage 

tds lur than 550 gallam 

, - Wonretail stations with lnr th 

2,000 gallon per month throughput 

for the facility 

- Dispensing of ntural g.r or propme 

when not mixed with another Me 

- Into vehicles perfoming eaergmy 

work 

- Storage tm&s wed prinrily for the 

fueling of aircraft or btr 
TABLE 6-1. SWRY OF STAGE 11 PROCRAM EXEMPTION LEVELS AND COMPLIANCE SCHEDULES 

(COUTINUED) 

State/Rcgulatory Agency Covered Area Exqtim Levela C-1 ince Sch&le 

Wcw Jeraty DEP 

I + 

P 

Washington, D.C. 

St. Louie area 

Entire State 

- All dlclpnlng fwllities mildle ln ucordrre wlth the DC 

to the mrrl plblic by virtue of Air Pollutlm Cmtrol Act 

havlng nilltrry status having 3 or of 1% 

less diapenalng nozzles 

- Statlawry atorage taka having 8 Fin1 t-llmm bte for 

capeclty e 2,000 gallonr d used r 1 1 aarrces un Duedm 

for fueling %plcnmta of 31, 1007. 

hwbendryn 

- strtiawry atorage taka having r 

capcity e 2,000 gallonr lnatrlled 

before Septhr 15, 1976 

Dwhr SO, 1908 for 

fwilities 40,000 

gel/mnth d Duhr 29, 

1989 for fuiliticr 

10,000 gal/mnth 

- Dl11pcning devices et a rrin used 

exclusively for rrin vehicles 

Wcw York DEC Wcw York Cl ty area - site qmclflt bteraintim that July 1, 1908 for 

Stage 11 la technically or fuilities 500,000 

uonorlcrlly infeasible gll/ye8r d July 1, 1- 

for fullltlea 250,000 

gll/year 
Floricb/Osde Covlty MP 

TABLE 6-1. SU)URY OF STAGE I1 PROeRAn EKEllPTlOll LEVfLS AM) CO)IPLIAWCE SCHEDULES 

~COWTIWUED) 

Covered Are8 Exaptim Levels 

Rrsauhuret ts DEW Entire State 

Mimi are8 (Dede Covlty) 

- < 20,000 wl/mth cawtructd or April 1, 1991 for 

dified before Novcnkr 1, 1989 fullitia r 1,000,000 

grl/pr; April 1, 1-1 

for fuilitfa P 500,000 

wl/yerr; ad April 1, 

1993 for fuilities > 

20,000 gll/mth 

- Marims servicing boetr 

- Airports rervicing rirplmea 

- < 10,000 wl/mth cawtructd or 

dified before Jvw 25, 1990 

Idirtrly for m 

fuilitia wd Decakr 

14, 1992 for existing 

fuilitia 

hnr 25, 1991 for 

fuilitia % 1,500,000 

wl/pr; Deedor 25, 

1991 for fuilitia . 

1,000,000 981/~8t; Jvrs 

25, 1992 for fuilities % 

500,000 @ml/pr; nd Jvrs 

2s. 1993 for fullities + 

All local districts in califmi8 hm rempomibility for St- I1 (Phre 11) proerr. The By Am, South Cow, ud kn Dim districts 

rhacn in the table ud 14 other districts that are mnrttrimt for orom have hd St- 11 rtgulrtiaw for onr r doc*. the rrrining 

districts raq~ired St- I1 k instrlld for hzem cmtrol by 1991. Ilhile the model regulrtim prwifhd by CARD (see Appendix F.l) 

rumgmtd r thraqhput cutoff of 480,000 wllar par year (40.000 grllaw pr mth), the Districts irplawntd 8 nriety of cutoffs rrrping 

fraa no exmiaw to this 480,000 wl/yerr Level. These Districts are discussed in Appendix E 8s thy are thore with the mt experience 

with Stnee 11. 
applications, the issuance of operating permits, and testing 


requirements. Appendix I contains information related to 


permitting. 


6.3.1 Identification of Sources 


While estimates of the number of facilities may be 


obtained from a variety of sources as discussed in Section 


6.1, the actual identification of sources to be contacted 


for permitting purposes can be difficult. An analysis of 


the methods used for this identification process by agencies 


with the newest Stage I1 programs reveals several 


approaches. 


Stage I permit records can be of great assistance in 


this identification. New ~ersey~ 
 and Dade County, ~lorida~ 


relied on these files. New Jersey sent a letter to all 


facilities in the Stage I permit system and informed them 


that they were required to obtain a Stage 11 permit and 


install the equipment. Dade County also used information 


from their underground storage tank permitting program to 


complement the Stage I data. 


Pennsylvania identified sources by contacting major oil 


companies and obtaining information from the State 


Department of Licensing and In~pection.~ Massachusetts used 


tax records to identify sources. Each source was then sent 


a Registration and Classification form which was returned to 


the Agency, who contacted the facilities which needed a 


permit. 


6.3.2 Permit Forms and A~~lications 


The permit form and application is the best means of 


obtaining information regarding a facility and the type of 


equipment to be installed. The forms should be designed to 


allow the department to easily obtain the important 


information without requiring a great deal of excess data. 


An obvious requirement for the permit application is the 


name and address of the facility. However, in addition to 


this information it is beneficial to include the name and 


address of the business owner, the operator/lessee, and a 

site contact. The nature and purpose of.the application 


should be stated. Station characteristics such as the 


operating schedule, monthly and annual throughput, and 


number of nozzles, hoses, and dispensers should be provided. 


Information pertaining to the type of Stage I1 system to be 


installed should also be included. Specifically, this 


should consist of the equipment to be installed; a 


preliminary site plan of all tanks, dispensers, and 


underground piping. Most current Stage I1 permit forms 


require that the CARB Executive Order number be identified 


for the system to be installed, regardless of the area of 


the country. 


While most of the permit forms and application 


requirements are similar, the procedures vary immensely 


after the submission of the application. Due to resource 


restraints, each air pollution agency must determine the 


focus of their Stage I1 program. Invariably, programs are 


concentrated either on permitting or inspections. 


Therefore, the criteria for the issuance of operating 


permits can range from a paperwork type exercise, with 


emphasis on inspections, to permitting requirements based on 


stringent testing. 


The New Jersey DEP receives the application; checks to 


confirm that all information is complete and that the 


facility has designated a certified system for installation, 


and mails out a permit. The permit contains standard 


conditions that leak and pressure decay/liquid blockage 


tests must be performed on the system after installation and 


that the facility must maintain verification of the tests. 


The existence of this documentation is checked during 


facility inspections. 9 


Massachusetts has developed a two-phase compliance 


approach. The first phase involves verification that the 


appropriate equipment has been installed. This initial 


field inspection is described as a "drive bym screening that 


defines a minimum level of inspection required to assure 

that installation has occurred. The second phase is the 


more detailed verification that the equipment is operational 


and is being maintained." 


The San Diego Air Pollution Control District has 


perhaps the most stringent permitting and testing program 


observed in the country. The program is based on the 


experience and knowledge that most emissions from Stage I1 


equipment are a result of improperly installed systems. The 


following is a description of the permitting and testing 


program in San ~ie~o. 
 l1 


An applicant submits an application for a Stage I1 


permit that contains a preliminary site plan of all tanks, 


dispensers, and underground piping. The application is 


reviewed in detail by a member of the engineering staff to 


confirm that the planned system is in accordance with CARB 


certification and San Diego regulations. If all the 


preliminary requirements are met, the District grants 


Authority to Construct. This Authority to Construct is 


issued subject to several requirements. An example is the 


applicant must notify the District within 10 working days 


after the Stage I1 installation that construction has been 


completed. Temporary authorization to operate begins only 


after receipt by the District of this notice of completion 


and an "as builtvv site plan. 


The applicant must also have several tests performed 


and provide the District with the results. The District 


must be contacted within 10 working days of completion of 


construction to establish a mutually agreeable test date. 


Normally, the tests are witnessed by a District 


representative. If the District is not notified of a test, 


then this test may be declared invalid, in which case a 


retest is required. The required tests are: (1) a pressure 


decay/leak test of vapor control system; (2) a pressure drop 


vs. flow test from each nozzle to its associated underground 


tank; (3) a liquid test of all vapor piping to ensure 


adequate line slope and liquid drainage; (4) a tank vapor 

space tie test to verify the existence of a tank 


interconnect vapor pipe; and (5) a maximum dispensing flow 


rate determination for at least one nozzle. Each of these 


tests is discussed in the following section. 


The temporary authorization to operate remains in 


effect, unless canceled, until the facility is inspected by 


the District for a Permit to Operate. If the facility 


passes inspection, written authorization is given for 


continued operation, which is followed by issuance of the 


Permit to Operate. The above tests are required to be 


repeated if the Stage I1 piping or equipment is changed in 


any way. 


6.3.3 Testina Reauirements 


While efficiency testing is not practical for each 


service station, there are tests that indicate improper 


installation of underground Stage I1 vapor piping. These 


tests are the pressure decay/leak test, the dynamic back- 


pressure test, and the liquid blockage test. Testing 


requirements are usually included as a permit condition but 


could be specified in the regulation. Various test methods 


are contained in Appendix J. 


6.3.3.1 pressure Decav/Leak Test. This test procedure 


is used to quantify the vapor tightness of any vapor 


recovery system installed at a gasoline dispensing facility. 


Leaks in a balance system can cause excessive vapor 


emissions. Leaks in an assist system can decrease the 


efficiency of the vapor collection or processing system, or 


cause the pumps and the incinerator to operate continuously 


while attempting to maintain pressure or vacuum. 


The test is conducted by capping the vent pipe(s) and 


pressurizing the vapor piping system with nitrogen. This 


pressurization can be accomplished by introducing nitrogen 


into the vapor passage at one nozzle but is commonly done at 


the riser in the dispenser. An initial pressure of 10 


inches water column is obtained and the final pressure in 


the system is recorded after a period of 5 minutes. The 

final pressure is compared to minimum requirements linked to 


the ullage space in the tank. Example test procedures of 


this type are contained in Appendix J, Sections J.l and J.5. 


6.3.3.2 Pvnamic Pressure Dro~ Test. This test is used 


to determine the pressure drop (flow resistance) through 


balance vapor recovery systems (including nozzles, vapor 


hose, swivels, dispenser piping, and underground piping) at 


prescribed flow rates. The test method consists of flowing 


gaseous nitrogen through a calibrated test panel into the 


vapor recovery system at different flow rates to simulate 


the back pressure created during vehicle refueling. The 


resulting backpressures are measured near the nozzle 


faceplate using a pressure gauge, and compared with CARB 


certification criteria. The system passes this test if, at 


the nitrogen flow rates of 20, 60, and 100 SCFH, the flow 


resistance measured does not exceed 0.15, 0.45, and 0.95 


inches of water, respectively. This test should be run on 


every nozzle because nozzles, hoses, and dispenser 


connections can cause excessive backpressure. However, in 


the event of limited resources to run this number of tests, 


the proper approach would be to run this test at a minimum 


of the farthest dispenser from the underground tanks for 


each product grade. The test procedures in Appendices J.2 


and 5.4 are for this test. 

6.3.3.3 Liuuid Blockase Test. This test is used for 


balance and assist systems to determine if the piping 


configuration is correct and to detect low points in the 


piping where the accumulation of liquid condensate may cause 


blockages which restrict the flow of vapors and thus 


decrease the system's vapor collection efficiency. The test 


method consists of introducing gasoline into the vapor 


piping at any point up to and including the riser. When 


adequate time has been allowed for the gasoline to flow back 


to the underground tank, gaseous nitrogen is introduced into 


the vapor piping at the three flow rates of 20, 60, and 100 


SCFH. A liquid blockage is indicated either by the needle 
pegging on the pressure gauge and/or wild pulsing of the 


needle, or a reading in excess of the limits discussed above 


using the dynamic pressure drop test apparatus. This test 


is conducted using the same test methods contained in 


Appendices J.2 and J.4. 

6.3.3.4 Va~or S~ace Tie Test. An addition to the leak 


test/pressure decay procedure discussed above allows the 


determination of whether all underground tanks are plumbed 


into the system. After the pressure drop has been measured 


for the specified time period, the dry break on each 


underground tank fillpipe is depressed. If the tank is 


properly tied to the vapor system, a release of pressure 


will occur. The absence of pressure in the tank indicates 


that the tank is not connected to the vapor piping. 


6.3.3.5 paximum DiSDensina Flow Rate Determination. 


The dispensing flow rate may be checked by simply noting the 


volume of gasoline pumped in a specific time interval. This 


can be done during the fueling of any vehicle. This test 


procedure is contained in Appendix J.3. 


6.3.3.6 Liauid Removal Device Test. In addition to 


the tests required in San Diego, there is also a mass draft 


test method to check liquid removal devices in the hoses. 


This test can be performed to check the operation of this 


device. It is conducted by introducing sufficient gasoline 


into the vapor passage of the coaxial hose to produce a 


dynamic back-pressure between 2.0 and 6.0 inches water 

column. This is accomplished with approximately 150 ml of 

gasoline. Then approximately 10 gallons of gasoline are 

dispensed into a vehicle fuel tank. The liquid remaining in 


the vapor passage is then drained and the volume is 


measured. If the device is operating properly, most of the 


gasoline should be removed from the vapor passage during 


this fuel dispensing. 

6.4 INSPECTIONS 


The emphasis of most Stage I1 programs is on the 


inspection program. The utilization of approved or 


certified equipment and the maintenance of this equipment is 


essential to the effectiveness of a Stage I1 vapor recovery 


program. Therefore inspection procedures and frequency, 


inspector training, and the method of handling violations 


are enforcement related matters that need serious 


consideration. Unfortunately, most inspection programs 


concentrate on the above ground portion of Stage I1 systems, 


with little or no attention given to the underground piping. 


Testing procedures can also be incorporated into the 


inspection program. 


6.4.1 Ins~ection Checklists and Procedures 


Detailed inspection procedures and checklists are 


helpful in the development and implementation of a 


consistent and equitable enforcement program. All of the 


standard agency pre- and post-inspection procedures such as 


identification of the purpose of the inspection and 


consultation with the owner/operator after the inspection 


should be followed. In addition, procedures specific to the 


inspection of Stage I1 equipment can be developed. The 


Compliance Assistance Program of CARB publishes a Technical 


Manual for Inspectors of Gasoline Vapor Recovery systems. 12 

The inspection procedures shown in Table 6-2 are taken from 


this document, and describe step-by-step instructions for 


inspecting Stage I1 equipment at a gasoline dispensing 


facility. Also, Appendix K contains various inspection 


checklists and inspection procedures from other areas. 


6.4.2 Jns~ection FreauencY 


The inspection frequency also varies among different 


agencies. The inspection frequency is a direct reflection 


of the resources allocated for a Stage I1 program. The 


frequency ranges from one inspection per facility every 5 


years to two or three annual inspections per facility. 


There is a correlation between inspection frequency and the 

Fueling instructions: 


a. See that fueling instructions are clearly displayed with 


the appropriate toll free number. 


2. Nozzles: 


a. Check each nozzle to verify that it is a current CARB 


certified model. 


b. Verify that each nozzle is ins'talled in accordance with 


ARB Executive Orders. 


c. Check to see that required nozzle components are in 


place and in good condition. Check: 


1) required nozzle components (See 401.3.1). 


2) automatic shut-off mechanism (observe the filling of 


vehicles look for signs of spillage. 


3) trigger (is it leaking or broken) 


4) spout for damage or looseness (wiggle the spout) 


5) leaded nozzle or spout to ensure that it has not been 


replaced an unleaded nozzle or spout (check the 


diameter). 


6) nozzle for leaking gasoline or vapor (tip the nozzle 


down into a container and look for vapors). 


3. Faceplate: 


a. Make sure that the faceplate is smooth, uniform, and 


capable of forming a tight seal for balance system and 


in good working order for assist systems. 


4. Bellows: 


a. Stretch the bellows to check for holes, rips, or tears. 


b. Check to see that the bellows is securely attached to 


the nozzle. 


c. Check to see that the shape of the bellows is normal and 


that there are no deformities. 


5. Spring: 


a. Check to see that the internal bellows spring is not 


missing, broken, distorted, welded, or homemade. Many 


of the newer balance systems do not require the internal 


spring. 

TABLE 6-2. PHASE I1 INSPECTION PROCEDURES (CONTINUED) 

6. Latch: 

a. Check to see that the latching device is not missing, 

broken, distorted, welded, or homemade. 

NOTE 

Neither the spring nor the latching device is required on 

the Hasstech system, but either may be present. Both the 

spring and latching device are required on the Hirt systen. 

The Amoco bellowless nozzle incorporates a tightly wound 

spring around the spout as a latching device. 

7. Check valve: 

a. See that the check valve is in place (inspect the n0zz.e 

for sign of tampering) 

8. Hoses: 

a. Only coaxial vapor recovery nozzles and hoses may be 

installed on balance systems after February 20, 1986. 

Hose configurations must be in compliance with the 

exhibits in the most current version of executive order 

G-70-52. 

b. Check to see that product and vapor hoses with the 

overhead retractor are long enough to permit natural 

drainage into vapor return piping when the retractor is 

in the retracted position, but still avoid kinking whe~ 

fully extended. 

c. Check to see that hoses with retractors are adjusted t> 

maintain a proper loop, and that the bottom of the loc? 

is within the distance from the island surface certified 

by the ARB Executive Order for that particular dispenser 

configuration. 

d. Check to see that hoses are not torn, flattened or 

crimped. 

e. See that the vapor recovery hoses are of the required 

size and length. 

f. If liquid removal device is required, check to see thzt 

it is properly installed. 
Flow Limiter: 


a. If required, open the dispenser (get the key from the 


owner or operator) and check to see that the flow 


limiter indicator arrow is pointing in the same 


direction as the flow of gasoline and that the flow 


limiter is not missing. 


Swivels: 


a. Nozzle and dispenser swivels are optional with the 


lightweight coaxial hoses for many configurations. 


Check the appropriate executive order to see what 


swivels are required. 


b. Check to see that swivels are lubricated to maintain 


power movement (look for full movement). 


c. Check to see that swivels are not missing, defective, or 


leaking. 


d. Check to see that the dispenser end swivels are Fire 


Marshal approved. (look for the Fire Marshal sticker). 


Vent Pipes Pressure Relief Valve 


a. Observe to see that the valve is in place if required 


for a vacuum assist system. 


Vacuum Pump (Amoco Bellowless System Only) 


a. Wait for a vehicle to fuel. 


b. Verify that fuel is being dispensed into the vehicle by 


checking the flow meter on the dispenser. Listen toward 


the top of the dispenser for a rapid "clickingw sound of 


the vapor pump. The mclickingM is caused by the 


movement of the pump seals as they rotate within the 


pump housings. Clicking sounds indicate that the pump 


is working properly. 


Collection Unit (Hasstech Only): 


a. Wait for a vehicle to fuel. 

TABLE 6-2. PHASE I1 INSPECTION PROCEDURES (CONTINUED) 

b. Go to the collection unit and listen for the sound of 


the vacuum/blower inside the collection unit. If the 


collection unit does not appear to be operating, check 


to see that the power switch is ON. If the switch is Cg 

and the collection unit is still operating, check the 


control panel. 


14. Control Panel (Hirt system only) 


a. Check to see that the power switch is in the on 


position. 


b. Check to see that both the power and vacuum lamps are 


illuminated. 


If power lamp is out: 


1) Check to see that the on/off switch if on. 


2) Check to see that the circuit breakers in the main 


electrical panel box are on. 


If the vacuum lamp is out: 


1) switch the vacuum and power lamp bulbs to verify that 


the vacuum lamp is not burned out. 


2) check to see that all fill caps and Phase I vapor 


recovery connections are on and are tightly sealed. 


15. Processing Unit: 


a. Look for convection currents coming out of the burner 


stack on top of the processing unit, indicating that tie 


burner is operating (the burner will not be operating 3t 


all times). You may be able to see these currents mor2 


easily by standing back and observing the top of the 


stack against a background (such as power lines) or by 


looking for the shadows on the ground. 


16. Vacuum gauge (Hirt Only) : 

If the vacuum pump is illuminated, there is no need to chzck 


the vacuum gauge. If the vacuum lamp is not illuminated, a 


check of the vacuum gauge is needed. 

TABLE 6-2. PHASE I1 INSPECTION PROCEDURES (CONTINUED) 


The vacuum gauge may be found inside the base of the 


dispenser furthest from the vent risers. 


a. If the gauge reads zero or negative during dispensing 

and non-dispensing, the system is operating okay. 

b. If the gauge reads positive during non-dispensing or 

pegs to positive during dispensing, the system needs 

attention. 

Source: CARB Technical Manual for Gasoline Facilities; Phase I 


and 11, CARB Compliance Assistance Program. 

number of defects found, although there are other relevant 


factors. 


San Diego inspects private facilities once per year and two 


or three times per year for retail service stations.'= The 


retail facilities in the Bay Area are inspected twice per year 


and the private facilities once per year.'& In the South Coast 


District, they strive to average two inspections per year per 


facility. However, their inspection program is not geared to 


inspect each station twice annually, but rather is a priority 


inspection program. Stations which have exhibited recurrent 


problems in the past are inspected three times per year, average 


situations twice per year, and very conscientious stations are 


inspected only once per year. Also, South Coast is experimenting 


with a "self inspectionw program in which larger companies 


implement their own inspection program and report to the 


District- Preliminary assessments are encouraging, but an 


overall evaluation of this program has not been condu~ted.'~ 


6.4.3 Jns~ector Training 


The level of training for Stage I1 inspectors also varies 


widely. It is critical that inspectors understand Stage I1 


technology fully to be able to recognize violations and potentizl 


problems. While segments of the inspection procedures are 


relatively simple, such as the identification of torn bellows ald 


hoses, items such as proper check valve function and the 


identification of properly certified equipment cannot be graspec 


in a short training program. 


Inspector training ranges from agencies that provide a 2-4 


hour discussion which includes a video of inspection procedures 


to those which have a training program that lasts up to 7 weeks 


The Evaluation and Training Section of CARB has a series of 


training courses for inspectors. Generally, inspectors attend 


2-day training course that includes detailed discussion of 


equipment technology, CARB certification procedures and Executkre 


Orders, inspection techniques, test procedures, and a hands-on 


section in the field. CARB believes that this 2-day 


workshop/training event could easily be 3 or more days to 


1 
I 

adequately cover the necessary material. l6 The South Coast 


District has a 7-week district training program which includes 


working with an experienced inspector for 2 weeks. They also 


have training videos on inspection techniques.17 


There are currently two videos used most often by State and 


local agencies. These are "Stage I1 control^^^, by Multinational 


Business Services (MBS) in Washington D.C. and IvFor Cleaner Air: 


Vapor Recoveryv1 by CARB. 


6.4.4 Testina Durina Ins~ection 


As mentioned previously, Stage I1 inspections often focus 


entirely on the above ground portion of the system. The 


inspection procedures taken from the CARB technical manual that 


are cited above include no mention of underground piping testing. 


However, the pressure vs. flow and liquid blockage tests can be 


conducted by inspectors in the field with minimal time and 


effort, and they can provide an idea of the condition of the 


underground piping. As discussed in Chapter 4, liquid blockages 


can severely inhibit the emission reduction from Stage I1 systems 


even when all nozzles, hoses, and above ground equipment are well 


maintained. This testing during inspections is especially 


critical for programs that do not require testing during the 


permitting process. 


The Bay Area District has testing units available for use by 


their inspectors. Tests are conducted on a random type basis 


during normal inspections and in response to complaints that seem 


to indicate liquid blockage type problem^.'^ Without exception, 


every California official with knowledge and experience in Stage 


I1 technology interviewed by EPA indicated that the testing of 


the underground piping for leakage and liquid blockage is 


possibly the most important aspect of the functioning of Stage I1 


systems.l9 

6.4.5 Violations 


There are two basic methods used for handling Stage I1 


violations. These are removing (i.e., tagging out) defective 


equipment from service and administrative penalties for 

violations. Following is a summary of the mandated procedure 


that must be followed by all agencies in Calif~rnia.~' 


When a district inspector determines that a component 


contains a defect which substantially impairs the effectiveness 


of the system in reducing air contaminants, the district marks 


the component "Out of Orderw. The use of the component is then 


prohibited until the component has been repaired, replaced, or 


adjusted, as necessary, and the district has reinspected the 


component or has authorized use of the component pending 


reinspection. 


Equipment defects which are considered in California to 


ggsubstantially impair the effectiveness of the systems in 


air contaminantsgg are: 


Absence or disconnection of any component required to 


be used in the Executive Order(s) that certified the 


system. 


A vapor hose which is crimped or flattened such that 


the vapor passage is blocked, or the pressure drop 


through the vapor hose exceeds by a factor of two or 


more the requirements in the system certified in the 


Executive Order(s) applicable to the system. 


A nozzle boot which is torn in one or more of the 


following manners: 


1. Triangular-shaped or similar tear 1/2 inch or more :o 


a side, or hole 1/2 inch or more in length. 


Slit 1 inch more length. 


(d) Faceplate or flexible cone which is damaged in the 


following manner: 


1. For balance nozzles and for nozzles for aspirator a~d 


educator assist type systems, damage shall be such 


that the capability to achieve a seal with a fill 


pipe interface is affected for 1/4 of the 


circumference of the faceplate (accumulated). 


2, For nozzles for vacuum assist-type systems, more ttm 

1/4 of the flexible cone missing. 


(e) Nozzle shutoff mechanisms which malfunction in any 


manner. 

Vapor return lines, including such components as 


swivels, antirecirculation valves and underground 


piping, which malfunction or are blocked, or restricted 


such that pressure drop through the lines exceeds by a 


factor of two or more requirements specified in the 


Executive Order(s) that certified the system. 


Vapor processing unit which is inoperative. 


Vacuum producing device which is inoperative. 


Pressure/vacuum relief valves, vapor check valves, or 


dry beaks which are inoperative. 


Any equipment defect which is identified in an 


Executive Order certifying a system pursuant to the 


Certification Procedures incorporated in Section 94001 


of Title 17, California Code of regulations, as 


substantially impairing the effectiveness of the system 


in reducing air contaminants. 


Where a district inspector determines that a component is 


not in good working order but does not contain a defect listed 


above, the district provides the operator with a notice 


specifying the defect. The owner/operator then must correct the 


defect within 7 days or be subject to further action. 


Each district in California follows this procedure, although 


the imposition of administrative penalties, or fines, varies from 


district to district. San Diego assesses a fine for all defects 


detected, while other districts impose fines if a certain 


percentage of defects is found relative to the number of nozzles, 


or if a set number of violations is found.*' 


California officials note that in some situations this tag 


out program has tended to be abused by industry. An extreme 


example is the station owner that recognizes equipment is 


defective but waits until the inspector tags it out of service, 


then immediately replaces it with a new component. A suggestion 


from California officials is that any inspection program should 


be evaluated carefully to avoid creating the situation where the 


inspectors are in effect performing the maintenance program for 


the service stations. This can be avoided by making the 


penalties substantial enough to ensure that the owner will want 

to find these defects instead of waiting for the inspector to 


locate them. 22 

Other areas impose rather severe fines for any violation 


noted by the inspector. In New Jersey, no definition of 


malfunctioning or defective equipment is given and much is left 


to the discretion of the inspector in this regard. Any defect 


noted by an inspector is subject to a fine.a 


A mixture of these approaches is being implemented by 


Massachusetts. The State requires that the facility tag out 


their own equipment if it is found to be defective. If an 


inspector visits a site and equipment is tagged and not being 


used, then no violation occurs. However, the identification ol 


defective equipment by an inspector that has not been tagged o~t 


and is being used results in a violation and administrative 


penalty.24 

Massachusetts also has its own list of violations that 


allows an inspector to positively write violations due to the 


clarity of this list. In order to set some priority between tle 


different types of violations which could be detected, 


Massachusetts separates the kinds of possible violations into 


"potentially emittingw and "non-emittingw .25 The description of 

these violations, with examples, are shown in Table 6-3. 


6.5 SUMMARY 


In summary, there are many issues to consider in the 


implementation of a Stage I1 program. The information containzd 


in this chapter, as well as that provided in Appendix El will 


assist an agency in the initial stages in understanding the 


various aspects of planning, permitting, and enforcement that 


need attention. In addition, the EPA enforcement guidance 


document should be consulted for enforcement guidance and 


requirements. 

TABLE 6-3 MASSACHUSETTS STAGE I1 VIOLATIONS 


Title of Violation 


PRIORITY, .OR "EMITTING" 


VIOLATIONS 


1. Dispensing motor vehicle 


fuel without vapor 


recovery equipment 


2. Vapor recovery system is 


not operating properly 


3. Vapor recovery equipment 


is damaged 


4. Failing to prohibit use of 


a dispenser with an 


inoperative (or 


nonexistent) vapor 


recovery system 


5. Failing to install signs 


to show how to properly 


use the vapor recovery 


system 


6. Failing to install 


certified equipment 


7. Failing to perform or misperforming a requested 


compliance test 


Example 


Station is not equipped with 


Stage I1 vapor recovery 


equipment but is continuing to 


dispense fuel. 


Bellows has been "tied backw, 


latch system bypassed, 


aspirator not turned on, 


processor not turned on. 


Could also include a non-spec 


configuration (hoses too long 


or not assembled correctly) 


Tears or holes in the boot, 


kinks in the hose, hose is 


flattened. 


Equipment is damaged but 


dispenser is still operational 


and could be used. 


Signs are supposed to be 


conspicuous (outside) and 


readable, they must say DO NOT 


TOP OFF 


Installed equipment is not on 


the list of CARB certified 


equipment or equipment has 


been installed which, although 


each piece may be certified, 


the components are assembled 


in an uncertified 


configuration. 


Not an immediate concern since 


a compliance test would 


initially be required only as 


a condition of a UAO. 


However, if such a request is 


made and the facility does not 


conduct the test properly, or 


ignores the requirement, a 


violation would be triggered. 

TABLE 6-3 MASSACHUSETTS STAGE I1 VIOLATIONS (CONTINUED) 


Title of Violation Example 


8. Failing to install and So as to differentiate this 


operate vapor recovery violation from the first 


equipment after the violation type listed above, 


appropriate deadline the finding of this violation 


should be limited to 


facilities who have made no 


effort to comply with the 


requirements of the regulation 


(have not filed ICC or RCC 


forms) or facilities who are 


not listed but still have the 


fuel throughput that would 


trigger applicability to the 


regulation. 


OTHER OR "NON-EMITTING" 


VIOLATIONS 


1. Failing to submit 


Installation and 


Certification forms 


2. Failing to train station 


operators 


3. Failing to place an I1Out 


of OrderN sign on a 


disabled dispenser 


4. Failing to maintain 


N

continuous records 


Source: Massachusetts Department of Air Quality Control, 


Compliance and Enforcement Manual. 

6.6 REFERENCES 


Stage I1 Background Information and Technical Support 


Document. Massachusetts Department of Environmental 


Quality Engineering. January 1989. 


Telecon. Norwood, P., Pacific Environmental Services, 


InC. (PES) with Wong, R., Dade County Air Pollution 


Control. Hay 14, 1991. Dade County Stage I1 Program. 


Memorandum from Norwood, P., Pacific Environmental 


Services, Inc. to Shedd, S., U.S. Environmental 


Protection Agency. April 30, 1991. Trip Report to 


California Agencies to Discuss Stage 11. 


Memorandum from Norton, R. Pacific Environmental 


Services, Inc. to Shedd,S., Environmental Protection 


Agency. April 29, 1991. Trip Report to New York 


Department of Environmental Conservation. 


Memorandum from Norwood, P., Pacific Environmental 


Services, Inc., to Shedd, S., Environmental Protection 


Agency. February 22, 1991. Trip Report to New Jersey 


Department of Environmental Protection. 


Telecon. Bowen, E., Pacific Environmental Services, 


Inc. (PES) with Wong, P., Dade County Air Pollution 


Control. April 15, 1991. Dade County Stage I1 


Program. 


Telecon. Bowen, E., Pacific Environmental Services, 


Inc. (PES) with Estrusky, B., Pennsylvania DER. April 


11, 1991. Philadelphia Stage I1 Program. 


Telecon. Bowen, E., Pacific Environmental Services, 


Inc. (PES) with Carlson, L., Massachusetts DAQC. April 


1, 1991. Massachusetts Stage I1 Program. 


9. Reference 5. 


10. Stage I1 Compliance and Enforcement Manual. 


Massachusetts Department of Environmental Quality 


Engineering. January 1989. 


11. Reference 3. 


12. Gasoline Facilities Phase I & 11. California Air 

Resources Board, Compliance Assistance Program. 


Revised March 1991. 


13. Reference 3. 


14. Reference 3. 

Reference 3. 


Uemorandum from Norwood, P., Pacific Environmental 


Services, Inc. to Shedd, S., U.S. Environmental 


Protection Agency. April 22, 1991. Trip Report to 


Uonterey, CA, for CARB Stage I1 Inspection Workshop. 

Reference 3. 


Reference 3. 


Reference 3. 


California Code of Regulations, Title 17, Section 


94006. 


Reference 3. 


Reference 3. 


Reference 5. 

Reference 10. 


Reference 10. 

I 


TECHNICAL REPORT DATA -

1. RECOnT NO. IAkJemd laacnw athe revcrcc &fwCompIe,,IId, 

1. 

EPA-450/3-91-OZ~a 3.IWC!P~€NT.S
 ACCESSIO~ 


1. TftLEAN0 SUlfIT Lf 

Technical Guidance - Stage 11 Vapor Recovery systems s nCPOnT OAT€ 

for Control of Vehicle Refueling Emissions at Gasoline November 1991 


.Dispensing Facilities, Vol. I - Chapters 6. rtn.O~wl*G ~ ~ ~ A N COO. I
 Z A ~ ~ ~ 

7. AUTHORIS) 

8 PEAFORMING OCIGANIZ~TIONREPOR? kO 

f 

S. PEIICORMtNG ORGANIZATION NAME Ah0 AOORESS : 

US Environmental Protection Agency 


Office of Air Quality Planning and Standards 


Emission Standards Division (KD-13) 


Research Triangle Park, NC 27721 


It. SPONSORING AGENCY NAME &NO AOORESS 

I

US Environmental Protection Agency 

Office of Air and Radiation 


Washington, DC 20460 


I 

15. SUPPLEMENTARY NOTES 

c. 


is. AUSTRACT 

The Clean Air Act Amendments (CrULA) of 1990 require the installation of Stage 

.par recovery Systems in m+ ozone nonattainment areas and direct EPA his to dosment 
 issue


as appropriate on the effectiveness of Stage 11 systems. 


provides guidance on the effectiveness of Stage I1 systems and other Stage IT tech-


nical infomation on emissions, controls, costs, and program implementation. Stage 


11 vapor recovery on vehicle refueling is an effective control technology to reduce 


vapor emissions that concain volatile organic compounds (VOC) and hazardous 

air pollutants. Vehicle refueling emissions consist of the gasoline vapors displaced au~onobil~
 tank by dispensed liquid gasoline. The Stage I1 system collects 


frm the the v&(cle fillpipe and returns them to the undergmund storage tank. 

these