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Retooling the Vapor Recovery System: Part 2 - Will New Rules Evade Old Concerns?

In part 2, vapor recovery expert Wolf Koch, PhD, analyzes the California Air Resources Board’s new Enhanced Vapor Recovery program and explains his concerns about the program’s foundation, direction and impact.



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Author: Koch Wolf H. , PhD
Last month’s issue of PE&T revisited our past coverage of vapor recovery developments and activities to reacquaint readers with vapor recovery legislation and technologies and the critical issues concerning their effectiveness (“Retooling the Vapor Recovery System, Part 1: Looking Back with PE&T,” by Joe Totten, Jun. 2000, p. 6).For this article, Wolf Koch provides an analysis of the California Air Resources Board’s (CARB’s) new Enhanced Vapor Recovery (EVR) program, and he voices his concerns about the program’s foundation, direction and impact. He also discusses plans and actions by California air pollution district officials related to the new rules and their enforcement. The tables in the article were derived from CARB materials at CARB’s website.

On March 23, CARB passed its EVR program, which brings major changes to equipment testing and certification requirements. Prior to that action, CARB held vapor recovery workshops (November and January) and CAPCOA met (February) to discuss the subject.

Before the February CAPCOA meeting, CARB released a draft of its proposed rules, as mandated by California’s 45-day notice requirement. The draft was the primary discussion topic at the CAPCOA meeting. The topic was revisited at CAPCOA’s May meeting—after CARB passed the new program. The final proposal to the Board in March was revised significantly from the one released in February.

It was distributed at the Board meeting as “Resolution 00-9, Enhanced Vapor Recovery.” CARB staff is assembling the responses to the proposal and will publish additional revisions in late summer, allowing for another 15-day comment period.

In my view, CARB’s actions will not resolve some basic issues concerning (1) the total amount of refueling emissions that need to be addressed in the vapor recovery effort, (2) the need for improved enforcement to ensure that vapor recovery equipment works efficiently and meets requirements and (3) the potential for local jurisdictions’ enforcement procedures to create non-uniform testing requirements that gasoline marketers must meet.

Events evoking changes
From my perspective, CARB’s motivation to change the testing and certification requirements came from the following:

• Stage II assist systems that cause fugitive emissions when fueling vehicles equipped with and Onboard Refueling Vapor Recovery (ORVR) systems have been recognized for some time. Beginning in 1994, CARB sponsored a series of workshops on defining the Stage II/ORVR problem and a potential safety issue with ORVR systems. Since 1998, CARB has hosted ten workshops on various aspects of proposed new standards related to those issues.

• Poor results from efficiency testing of many balance and assist Stage II systems in operation have provided additional reasons for new standards. During the last year, CARB staff and CAPCOA have tested many assist and balance systems at perating stations. A just-released report on balance system performance estimates that the San Diego and South Coast Air Quality Management Districts (AQMDs) experience an average collection efficiency of about 70 percent. The report (B. McEntire, Performance of Balance Vapor Recovery Systems At Gasoline Dispensing Facilities, May 18, 2000) projects that efficiencies between 85 and 90 percent are possible with increased enforcement through recurring testing, an idea which has been adopted in the form of quarterly testing requirements by the Monterey AQMD.

•The settlement requirements of a lawsuit for failure to attain air quality emissions improvements have forced the timing for new rules. While CARB sets statewide requirements for California, the implementation and enforcement rests with the individual AQMDs. In 1997, the Coalition for Clean Air filed suit against the South Coast AQMD for not having attained air quality goals outlined in California’s state implementation plan (SIP). Last year, CARB entered into a settlement agreement, committing the Board to achieving additional reductions of 5 to 10 tons of Reactive Organic Gases (ROG) or Volatile Organic Compounds (VOC) by 2010.

To meet the requirements of the settlement agreement, CARB combined previous ideas for requiring Stage II-ORVR compatibility with other actions to form an EVR program. The new program is to be implemented over the next eight years. In my view, CARB’s response to the events overlooked the obvious: fixing what is wrong with current systems now, instead of phasing in a new program over the next eight years. I will elaborate on this after explaining the specific requirements of the EVR program.

EVR requirements
The new EVR requirements are broken down into six modules in the CARB Staff Report (Hearing Notice and Staff Report: Enhanced Vapor Recovery, February 4, 2000) and in Resolution 00-9, dated March 23, 2000. The following descriptions are summarized from the Resolution:

Module 1: Stage I Vapor Recovery
Stage I vapor recovery is applied to the transfer of gasoline from the cargo tanker truck to the gasoline dispensing facility. Currently, Stage I systems are certified to be at least 95 percent efficient in returning vapors from the underground storage tank (UST) vapor space to the cargo tank. CARB will increase the certification standard to require Stage I systems to be certified at a minimum of 98 percent efficiency. This corresponds to an emission limit of 0.15 lb./1,000 gallons using a summer uncontrolled emission factor of 7.6 lb./1,000 gallons. All currently used Stage I equipment will be decertified as of April 2001 and must be recertified to the new standards (see Table 1).

Performance Type

RequirementStd. or Spec.Test Procedure

Stage I efficiency

98.0% minimum

Std.

TP-201.1
TP-201.1A

Stage I emission limit

0.15 pounds HC per 1,000 gallons

Std.

TP-201.1A

Static pressure performance

Compliance as specified in TP-201.3

Std

TP-201.3

Pressure integrity of drop-tube with overfill protection

<=0.17 CFH at 2.0 inches H2O

Spec.

TP-201.2B

Stage I product adapter/ delivery elbow connection

Rotatable 360° or equivalent

Spec.

Engineering evaluation

Stage I vapor adapter/delivery elbow connection

Rotatable 360° or equivalent

Spec

Engineering evaluation

Stage I vapor adapter

Poppetted

Spec.

Engineering evaluation

Stage I vapor adapter

No indication of leaks using liquid leak detection solution or bagging

--

Leak detection solution

Stage I vapor adapter dynamic pressure drop

Pressure drop at 300, 400, and 500 gpm: specification to be established during certification process

Spec.

TP-201.2B

UST vent pipe pressure/ vacuum relief valves

Pressure Settings:
3.0 <= 0.5 inches H2O positive pressure
8.0 <= 2.0 inches H2O negative pressure
Leak rate at +2.0 inches H2O <=0.17 CFH
Leak rate at -4.0 inches H2O <=0.21 CFH
Total additive leak rate from all P/V valves: <= 0.17 CFH at 2.0 inches H2O

Std.

TP-201.2B

Containment boxes

Leak rate at +2.0 inches H2O: <=0.17 CFH
No standing fuel in box

Std.

TP-201.2O Visual

Connectors and fittings

No indication of leaks using liquid leak detection solution or bagging

Spec.

LDS or bagging

Compatibility with fuel blends

Materials shall be compatible with approved fuel blends

Spec.

Engineering evaluation

 
Table 1: Stage I Performance standards and specifications for all vapor recovery systems

 

Module 2: Stage II Vapor Recovery
CARB will substitute an emissions limit of 0.38 lb./1,000 gallons (corresponds to 95 percent efficiency using an uncontrolled summer emission factor of 7.6 lb./1,000 gallons) for the 95 percent efficiency requirement. The old requirement was for 95 percent efficiency based on an emissions factor of 8.4 lb./1000 gallons. In addition, the required certification testing will be increased from a 90-day operational period to a 180-day period and from 100 cars to 200 cars. The new emissions factor and the requirements for nozzles with internal vapor valves and unihose dispensers will be effective in April 2001, while the new performance standards and specifications for Stage II equipment, as shown in Tables 2, 3 and 4, will be effective in April 2003.

Module 3: ORVR Compatibility
CARB’s new rules will not allow excess emissions due to refueling of ORVR-equipped vehicles. The new standard requires that refueling ORVR vehicles shall not cause the Stage II vapor recovery system to exceed the emission limit of 0.38 lb./1,000 gallons, and that the pressure-related fugitive emissions shall not exceed 50 percent of the emission factor. The phase-in requirements for ORVR vehicles and their projected impact on California’s vehicle population are shown in Tables 5 and 7. ORVR compatibility will be effective in 2001 and must be operational in 2003. Differences between effective and operational dates will be discussed under “EVR Implementation.”

Module 4: Liquid Retention and Spitting
Emissions occur between vehicle fueling episodes when gasoline retained in the hanging hardware (nozzles and hoses) on the dispenser evaporates into the atmosphere. The gasoline may also be spilled into the fillpipe well or the dispenser housing or otherwise find its way to the atmosphere without being counted as spillage. The liquid product and vapor lines are already required to have valves that separate the underground vapor space from the atmosphere. However, retention emissions occur from the atmospheric side of the valves and at least one vapor recovery system has vapor valves in the dispenser rather than the nozzles. Reduction of liquid retention will be phased in in two stages between 2001 and 2003 as shown in Table 6.

Another new rule addresses “nozzle spitting,” defined as the release of liquid when the nozzle trigger is depressed with the dispenser not actuated. This can happen when the nozzle is lifted from the dispenser and the trigger is accidentally depressed before the dispenser is activated. Nozzle spitting shall not exceed 1.0 ml/nozzle. Spitting conditions usually occur in warm weather when a nozzle has been idle and the gasoline in the hose expands due to warming. The new standard for nozzle spitting will minimize accidental liquid gasoline releases, which occur while moving the nozzle from the dispenser to the vehicle and releasing the trigger before fueling. Implementation will be required in 2004.

Module 5: Spillage and Dripless Nozzle
Spillage is recognized as a significant source of gasoline vapor emissions and includes spitting as well as any other gasoline losses during the fueling process. CARB has reduced the spillage limit from 0.42 lb./1,000 gallons to 0.24 lb./1,000 gallons. CARB also limits post-fueling losses to one drop per fueling event: after the nozzle has shut off, no more than one drop may be discharged while placing it into the dispenser boot. Implementation will be required in 2004.

Performance Type

RequirementStd. or Spec.Test Procedure

Stage II emission limit (includes refueling, vent pipe and pressure-related fugitive emissions)

<=0.38 lb. HC per 1,000 gallons

Std.

TP-201.2
TP-201.2A

Static pressure performance

As specified in TP-201.3

Std.

TP-201.3

Spillage, including drips from spout

<=0.24 pounds/1,000 gallons

Std

TP-201.2C TP-201.2E

ORVR Compatibility

Interaction of refueling ORVR vehicles shall not cause the system to exceed 0.38 lb/1,000 standard, including ORVR penetrations to 80%

Std.

Approved procedure developed by manufacturer

Stage I compatibility

Stage II system shall not cause excess emissions from Stage I operations

Std.

Engineering evaluation

UST pressure criteria (30 day rolling average)

Daily average pressure:<=+0.25 in. H2O Daily high pressure: <=+1.50 in. H2O Non-excluded hours/day = 0 <=0.05 in. H2O

Std

Engineering evaluation and ISD

Nozzle criteria

Post-refueling drips: <=1 drop/refueling Fuel any vehicle that can be fueled with a conventional nozzle

Std

TP-201.2D, engineering evaluation

Liquid retention Nozzle “spitting”

<=100 ml/1,000 gallons
<=1.0 ml per nozzle per test

Std.

TP-201.2E

Liquid removal systems

Capable of removing 5 ml/ gal. (average)

Std.

TP-202.6

Nozzle/dispenser compatibility

Vapor check valve closed when hung; hold-open latch disengaged when hung

Std.

Engineering evaluation

Unihose MPD configuration

One hose/nozzle per dispenser side

Std.

Engineering evaluation

Stage II vapor riser

Min. 1” Nominal ID

Std.

Engineering evaluation

Vapor Return Piping

Min. 3” nominal ID after first manifold; Recommended slope 1/4” per foot; Minimum slope 1/8” per foot

Std.

Engineering evaluation

Vapor return pipe runs

Maximum allowable lengths of pipe runs shall be established during the certification process

Spec.

Engineering evaluation

Liquid condensate traps

Shall have automatic evacuation system

Std.

Engineering evaluation

Connectors and Fittings

No indication of vapor leaks using liquid

Spec.

LDS or bagging

 
Table 2: Stage II performance standards and specifications for balance and assist systems

 

Module 6: In-Station Diagnostics (ISD)
In-station diagnostics will require continuous monitoring of important emission-related vapor recovery system parameters and alerting the station operator when a failure mode is detected. It is similar in concept to the current CARB on-board diagnostics regulations for motor vehicles. Many gasoline-dispensing facilities already have a similar diagnostic system for detecting liquid gasoline leaks from USTs. CARB supports integration of the vapor recovery in-station diagnostics with these UST leak detection systems where possible. ISD implementation will be in 2003 or 2004, depending on station throughput.

For balance systems, the rules will require pressure monitoring, as well as checking for liquid blockage at each dispensing point. A high-pressure drop indicates a blockage problem. One solution allowed will be to measure the vapor-to-liquid (V/L) ratio (also referred to as air-to-liquid ratio or A/L) in each dispenser with a flow meter.

For assist systems, monitoring of the V/L ratio—in a way that will detect a failure mode at individual dispensers—will be required. CARB will require that when the monitor detects an A/L ratio of zero (i.e., no vapor flow), the dispenser will be shut down.

Modules 5 and 6 are designed to be technology forcing, because no existing technology has been identified that will meet requirements for dripless nozzles and ISD. CARB plans to monitor industry progress in these areas and will host a technology review in April 2002.

Additional requirements
CARB has also adopted a new four-year certification limit. If, at the end of the four-year period, field problems are minimal, the certification may be extended. Otherwise, the system will be decertified. The agency will no longer certify individual components, but only complete systems. Under the new rules, certifications will expire after the four-year limit for equipment of manufacturers who have merged with other corporations. Manufacturers may make product warranties contingent upon the use of certified installers.

Specific requirements under the new CARB rules, as passed by the Board in March, are summarized in Tables 1-4. New requirements exist for vent processor operations which are not shown in these tables.

EVR implementation
The early proposals for an EVR program called for an April 2001 implementation. At that point, all existing vapor recovery systems were to have been decertified, but would have been allowed to remain in service for an additional four-year period, as provided by California law. After lobbying by the oil industry and comments from equipment suppliers, CARB realized that it would be impossible to recertify all necessary equipment prior to the original April 2001 deadline and changed the implementation schedule to that shown in Table 6.

CARB established effective dates for beginning the four-year grace period, and operative dates by which the new requirements must be implemented. The resulting schedule is an eight-year phase-in of the new requirements. Only Stage I equipment must be recertified by April 2001.

Performance Type

RequirementStd. or Spec.Test Procedure

Nozzle criteria

Insertion interlock device and vapor check valve

Std.

Engineering evaluation

Insertion interlock

Verification of no liquid flow prior to bellows compression

Spec.

Engineering evaluation

Vapor check valve

Leak rate: <=0.07 CFH at 2.0 inches H2O

Std.

TP-201.2B

Bellows insertion force

Pounds (force) to retaining device specified during certification testing

Spec.

Engineering evaluation

Wolf Koch is founder and President of Technology Resources International, Inc. in Sterling, IL. He provides consulting services in technology evaluation, development and testing, and litigation and expert witness support. He managed fuel distribution and service station technology at a major oil company for many years and is an avid motorcyclist and sailor. He is a frequent contributor to Petroleum Equipment & Technology and PE&T online and can be reached at Technology Resources International, Inc. 1314 Mineral Springs Rd. Sterling, IL 61081 Web site: www.t-r-i.com Phone: 815 626 7110 Fax: 815 626 7126

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