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TRANSCRIPT
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PUBLIC WORKSHOP TO DISCUSS:
Overpressure Conditions at Gasoline Dispensing Facilities Equipped with Underground Storage Tanks and Phase II Enhanced Vapor Recovery including In-
Station Diagnostic Systems
December 12, 2017: Diamond Bar, CADecember 13, 2017: Sacramento, CA 1
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Workshop Agenda
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Topic Anticipated DurationIntroductory Remarks 10 minutesCARB Gasoline Vapor Recovery Program Presentation
50 minutes
Break 10 minutesCARB Advanced Clean Cars Program Presentation
50 minutes
Break 10 minutesComments and Questions 50 minutes
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Housekeeping• Participant Sign-In, Emergency Exits, Restrooms• Hold questions and comments until the end• For those joining remotely (via “listen only”
conference line and webinar), email your comments and questions to [email protected]
• Presentation, webinar access, and conference call information is posted at http://www.arb.ca.gov/vapor/vapor.htm
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mailto:[email protected]://www.arb.ca.gov/vapor/vapor.htm
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Prior Workshops on Overpressure• November 2012- First Overpressure Workshop• September 2013- Planning for “Mega Blitz
2013/2014”• March 2014- Results of Mega Blitz and
Preliminary Emission Estimates• November 2015- Results of Mega Blitz, Assist
Nozzle ORVR Recognition Study, Identification of Capless Fill Pipe Designs, Concerns with Balance Systems
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Discussion Topics
1. Refresher on Overpressure2. Activities Since Prior Workshop
November of 20153. Solutions Envisioned by CARB Staff4. Alternatives Considered5. Next Steps
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Discussion Topic #1: Refresher on Overpressure
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California’s Vapor Recovery Program• ~15 billion gallons of gasoline consumed/year• ~240 tons of V.O.C.’s reduced/day• ~10,000 gasoline dispensing facilities (GDFs)
with Phase II Enhanced Vapor Recovery• ~7,400 of these GDF equipped with In-Station
Diagnostic (ISD) systems
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Phase II Enhanced Vapor Recovery Systems: Differences Between Balance and Assist
Assist Balance
% of CA GDF Population ~60% ~40%
Principal of Operation Active, requires vacuum pump for collection of vapors at the nozzle and vehicle interface
Passive, dispensing of gasoline displaces vapors which are captured by the nozzle
Vapor Pathway One way path, breathing losses from UST cannot occur at nozzle
Two way path, allows breathing losses from UST to occur at nozzle
Nozzle(s) Healy Model 900 VST-EVR-NBEMCO-A4005EVR
Processor(s) Healy Clean Air Separator Healy Clean Air SeparatorV-R Vapor PolisherHirt VCS-100VST ECS or Green Machine
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In-Station Diagnostics (ISD) • Continuously monitors important vapor recovery system
parameters and alerts GDF operators of potential equipment failures
• Monitors pressure in the headspace of the underground storage tank (overpressure)
• Beginning in 2009, GDF operators:– Informed CARB of excessive overpressure alarms in the winter–Concerned about expense of responding to such alarms
• Advisory 405 released to provide temporary relief from the expense of alarm response
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https://www.arb.ca.gov/vapor/advisories/adv405.pdf
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ISD Overpressure (OP) Alarm CriteriaAssessment Period
Current ISD OP Alarm Criteria
Weekly 5% of UST pressure data above1.5”WCG(Section 9.2.4 of CP-201)
Monthly 25% of UST pressure data above 0.5”WCG(Section 9.2.4 of CP-201)
Daily Daily assessment to identify vapor processor malfunction(Section 9.2.5 of CP-201)
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http://www.arb.ca.gov/testmeth/vol2/cp201_april2013.pdfhttp://www.arb.ca.gov/testmeth/vol2/cp201_april2013.pdfhttp://www.arb.ca.gov/testmeth/vol2/cp201_april2013.pdf
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Why Are We Concerned?1. Overpressure ISD Alarms
• Cost, no problem found with vapor recovery equipment in winter time
• Disruptive to GDF operations2. Air Quality Impacts
• Potential V.O.C. emission increases• Potential near source health risk issues at worst
case sites due to increased benzene exposure
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• Primary Causes:• High Reid Vapor Pressure
(RVP) winter blend gasoline• Excess air ingested due to poor
nozzle seal or vented vehicle fill pipes
• Other Contributors:• GDF monthly throughput• GDF maintenance practices• GDF operating hours
What Causes Overpressure?
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Discussion Topic #2: Activities Since November 2015 Public
Workshop
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Activities Since November 2015 Public Workshop
Vapor Recovery Related Field Studies:• Mega Blitz of December 2015• Evaluation of Assist Nozzle “EOR” Spout Assembly• Evaluation of Pressure Driven Balance Emissions
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Mega Blitz December 2015
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Data Collected From ~400 Sitesin Six Geographic Regions
Collaborative effort between CARB, Air Pollution Control Districts, and randomly selected GDF operators
ISD Data- All alarm history data available- Available pressure and ullage data- V/L data for recent fueling events
GDF Characteristics- Operating hours, monthly throughput- Gasoline brand and source- Inventory report with UST capacities
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Mega Blitz 2013 vs 2015
DescriptionSouth Coast
Bay AreaSan
Joaquin Valley
San Luis ObispoNorthCoast
MojaveEl Dorado
Placer
San Diego
SacramentoYolo-Solano
Feather River
% of 7,400 GDF w/ ISD
40.3% 17.1% 11.3% 11.1% 8.3% 6.9%
% 395 GDF Used in 2013 Analysis
33.7% 15% 10.6% 9.3% 19.7%* 13%*
% of 329** GDF Used in 2015 Analysis
22% 16% 10.5% 9.4% 10%* 11%*
Statewide ~7,400 GDF are equipped with Phase II EVR with ISD , the 2013 data set represents a 5% sample size*San Diego and Sacramento regions were oversampled**Number of sites was reduced in 2015 largely due to conversion from assist to balance
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Prevalence of OP Alarms Data Set OP Alarms October 2013
October2015
November 2013
November 2015
All Sites Combined (329)
Average Numberof Alarms Per Site 0.11 0.16 1.27 1.50
% of Sites With at Least One Alarm 6.4% 9.4% 50.8% 56.2%
Assist Sites(210)
Average Number of Alarms Per Site 0.16 0.22 1.80 2.18
% of Sites With at Least One Alarm 9.0% 13.3% 68.6% 79.0%
Balance Sites(119)
Average Number of Alarms Per Site 0.03 0.04 0.35 0.32
% of Sites With at Least One Alarm
1.7% 2.5% 19.3% 16.0%
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Vapor to Liquid (V/L) Ratio Effect on Pressure While Dispensing
Observation at Assist Sites
PWDObserved in Dec 2013?
PWD Observed
in Dec 2015?
Site V/L Average 2015
SCAQMD
Site V/L Average 2015
SDCAPCD
No No 0.60 (22 sites) 0.61 (27 sites)
Yes Yes 0.65 (19 sites) 0.64 (8 sites)
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Conclusions From Mega Blitz of 2015• Overpressure remains a winter time phenomena• Overpressure ISD alarm frequency has increased• Assist Sites
– PWD increased from 2013 to 2015 (34% to 44%) – 8% of sites had one or more leak alarm– 18% of assist sites converted to balance
• Balance Sites– Overpressure alarm frequency decreased slightly from 2013
to 2015– Percentage of sites with one or more leak alarms decreased
slightly from 2013 to 2015 (34% to 29%)
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Evaluation of Assist NozzleEnhanced ORVR-Vehicle Recognition
(EOR) Spout Assembly
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Expected “Vapor to Liquid” Ratio for ORVR Vehicles
• Phase II systems are designed to reduce the volume of vapor collected relative to volume of liquid dispensed (V/L) when fueling ORVR vehicles
• V/L ≥ 0.5 on ORVR vehicles results in excess air ingestion which leads to vapor growth inside UST
• Field data indicate GDFs that exhibit overpressure also have elevated V/L
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V/L Ratio
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Conventional vs ORVR Equipped Vehicles
Conventional Vehicle• Saturated vapors exit the vehicle fill pipe
during fueling, captured by the EVR nozzle, and returned to GDF tank
• Collection of saturated vapors do not result in vapor growth in GDF tank
• All vehicles prior to 1998, and certain later vehicles
ORVR Vehicle• Vapors captured by on-board
canister and later burned by the engine
• Phased in starting with 1998 model year
• If poor seal is formed at nozzle, excess air ingestion causes vapor growth in GDF tank
No competition between vehicle and station vapor recovery
Potential competition between vehicle and station vapor recovery
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Development of EOR Spout Assembly• ORVR Recognition Study 2015-San Diego (VR-OP-A3)• Controlled Fueling Evaluation 2015-Sacramento (VR-OP-A4)• EOR Nozzle Evaluation 2015/2016-Limited to three test
sites, “tail end” of winter fuel period (VR-OP-A5)• EOR Nozzle Evaluation 2016/2017-Expanded to seven test
sites, full winter fuel period (VR-OP-A6)
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https://www.arb.ca.gov/vapor/op/op.htmhttps://www.arb.ca.gov/vapor/op/op.htmhttps://www.arb.ca.gov/vapor/op/op.htmhttps://www.arb.ca.gov/vapor/op/op.htm
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In Addition to EOR Spout Assembly:Assist System Optimization
• Each test site optimized as follows:• Nozzle V/L ratio setting “dialed down”
between 0.95 to 1.0 (allowable range is 0.95-1.15)
• Dispenser leak integrity, fuel dispensing rate, and alignment of nozzle vapor boot verified
• ISD operability and PV vent valve verified• EOR Spout Assembly Configurations
• Field retrofit –can be installed onto existing nozzle body, if existing nozzle did not respond to V/L adjustment, must be replaced
• Factory assembled- brand new nozzle25
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Results of EOR Spout Assembly Evaluation (seven site average)
Parameter/BenchmarkBefore
EOR(Blitz Data)
AfterEOR
(Continuous)Average UST Headspace Pressure (“WCG) +2.2 -1.6
Percentage of Time UST Pressure Exceeds the Gross ISD OP Alarm Threshold
71% 15%
Site Average Vapor to liquid Ratio 0.65 0.55
Percentage of Fueling Events with V/L Ratio Less Than 0.5
50% 64%
Percentage of Days GDF Exhibited Pressure Increase While Dispensing
100% 22%
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EOR Spout Assembly Conclusions• Effective in lowering UST pressure, site average V/L
ratio, OP alarm frequency, and PWD, but did not fully eliminate the occurrence of alarms and PWD
• Optimization of Phase II vapor recovery system also contributed to improved performance
• Field retrofit and factory assembled configurations both performed well, but factory is superior
• EOR spout assembly certified by CARB in August of 2017 via EO VR-201-V and VR-202-V
• Informational Bulletin released on December 4, 2017
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https://www.arb.ca.gov/vapor/eos/eo-vr201/eo-vr201.htmhttps://www.arb.ca.gov/vapor/eos/eo-vr202/eo-vr202.htmhttps://www.arb.ca.gov/vapor/vapor.htm
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Evaluation of Pressure Driven Balance Emissions
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Questions Prompting Investigation of Balance System Pressure Driven Emissions
• GDF equipped with balance systems do not experience a high frequency of overpressure alarms
• Operate at slightly positive pressure for ~ 25% of time with winter fuel and ~ 13% of the time with summer fuel
• Unlike the assist nozzle, the balance nozzles allow both inward and outward flow of gasoline vapors
• Does slight positive pressure and outward flow at the nozzle significantly impact balance system vapor collection efficiency? (VR-OP-B1)
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https://www.arb.ca.gov/vapor/op/op.htm
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2015 CARB Emission Testing of Balance Systems at Slightly Positive UST Pressure
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Baseline Testing at Vacuum Testing at Slight UST Pressure
VST EMCO VST EMCO
ORVR Non-ORVR
ORVR Non-ORVR
ORVR Non-ORVR
ORVR Non-ORVR
Balance NozzleEmission Factorlbs./1,000 gallons
0.03 0.13 0.06 0.16 0.27 1.33 1.34 2.55
Efficiency Loss Due to Nozzle Emissions
0.5% 2.1% 0.8% 2.1% 4.2% 21.0% 19.1% 36.2%
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Application of 2015 Balance System Emission Test Data
• Prior emission estimates assumed percentage of time at positive pressure was equal to the volume of gasoline dispensed at positive pressure
• Further refinement of emission techniques:– Emissions should only include the volume of fuel
dispensed at positive pressure (VDAPP)– Include volume of reverse flow released through
the nozzle when positive pressure exists (RIFE)
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Why is VDAPP Important?• Phase II Vapor Recovery Systems are certified to be at least 95%
efficient when refueling non ORVR equipped vehicles• As VDAPP increases, overall system efficiency is diminished.• The following table assumes an ORVR penetration of 80% and
uses emission factors presented in prior slide:Percentage of Volume Dispensed at Positive Pressure
Phase II Vapor Recovery System EfficiencyGDF Equipped with VST Nozzles
GDF Equipped with EMCO Nozzles
5% 96% 94%10% 95% 92%15% 94% 90%20% 93% 87%25% 92% 85%
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Why is RIFE Important? • Pressure driven emissions that occur outside of time periods
identified by ISD as dispensing events• Typical GDF which dispenses 150,000 gallons per month (37,500
gallons per week), a relatively small volume of vapor released via reverse flow can also diminish system efficiency:
Gallons of Vapor Released Per Week
EfficiencyLoss
Emission Factor Attributed to ReverseIdle Flow
50 0.1% 0.01 lbs./1,000 gallons
200 0.5% 0.05 lbs./1,000 gallons
500 1.3% 0.13 lbs./1,000 gallons
1,000 2.7% 0.25 lbs./1,000 gallons
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Data Used to Estimate Balance System Pressure Driven Emissions
• VDAPP based on 2013 and 2015 Mega Blitz data • RIFE required establishment of new study sites• 11 new study sites were established with
continuous data collection of ISD information during winter 2016-2017– Sites varied by throughput and geographic location– Nine sites with Healy CAS processor– One site with Hirt VCS 100 processor– One site Veeder-Root Vapor Polisher processor
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85 Mega Blitz Sites(20-CAS, 65 Canister)
10 Study Sites(9-CAS, 1 Canister)
Time Period of Data Collection 30 hours 10 to 15 Weeks
Dates of Data CollectionDec 7 - 17, 2015 Nov 13, 2016 –Feb 26, 2017
Average VDAPP for Sites 280,000 gallons/month 3.5% 4.7%
RIFE Analysis No Yes
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VDAPP – 10 Study Sites vs 85 Blitz Sites*
*An eleventh study site was equipped with the Hirt VCS 100 vapor processor which maintains a slight vacuum within the UST, results are discussed later in presentation.
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Comparison of VDAPP
Distributions
8.8%
14.7%
7.4%
16.2%
27.9%
17.6%
4.4%1.5% 0.0% 1.5% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0%
0%
5%
10%
15%
20%
25%
30%
0 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40% VDAPP
68 Days from 10 Sites Collected Dec 11-17, 2016; 91 kgal/mo < TP < 524 kgal/moAve 2.85% Std Dev 1.80%
2.4% 3.5%
10.6% 9.4%7.1%
11.8%
5.9%3.5%
7.1%
27.1%
3.5% 3.5%1.2% 2.4% 0.0% 1.2%
0%
5%
10%
15%
20%
25%
30%
0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40% VDAPP
30 Hr Data from 85 sites collected Dec 7-17, 2015; 76 kgal/mo < TP < 508 kgal/moAve 9.08% Std Dev 7.39%
Mega Blitz 2015
5.2%3.1%
5.2%
10.4% 11.5% 9.4% 8.3% 7.3% 6.3%9.4%
14.6%
6.3%
2.1% 1.0% 0.0% 0.0% 0.0%0%
5%
10%
15%
20%
25%
30%
0 0-1 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-10 10-15 15-20 20-25 25-30 30-35 35-40 >40%VDAPP
30 Hr Data from 96 sites collected Dec 3-17, 2013; 50 kgal/mo < TP < 425 kgal/moAve VDAPP 7.95% Std Dev 5.42%
Mega Blitz 2013
Study Sites 2016
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Effect of VDAPP & RIFE on Balance SystemWinter Season Emissions
Source of Data Percent VDAPP RIFE
Emission Factor
Efficiency Emission Factor
VST EMCO VST EMCO
10 Study Sites - Average (Hirt not included) 2.9% 0.04 96.4% 95.3% 0.35 0.44
10 Study Sites - Worst Case(Hirt not included) 5.0% 0.09 95.4% 93.8% 0.44 0.59
Hirt Study Site 0.4% 0.08 96.5% 96.1% 0.33 0.37
Blitz Sites - Average 9.1% 0.04 95.0% 92.4% 0.48 0.73
VDAPP from Highest 10 Blitz SitesRIFE from Highest Study Site
30.4% 0.09 89.8% 81.6% 0.97 1.75
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Emission Factor is expressed at pounds per thousand gallons of gasoline dispensed
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Observations Mega Blitz vs Study Sites• Statistical analysis shows study sites represent a
subset of the overall GDF population and are not appropriate for a statewide emission estimate
• Average VDAPP and variation in VDAPP is significantly higher for Mega Blitz vs Study Sites
• Study sites provide the only estimate for RIFE• A low bias is likely in the RIFE emission estimate.
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Balance System Emission Evaluation Conclusions
• Information collected to date is inconclusive• Need for additional studies in 2017/2018:
– Establish study sites at the upper end of the VDAPP distribution shown by the Blitz data
– Measure evaporation rate at balance & assist sites• Accurate estimates of vapor processor
emissions may not be possible using ISD data alone
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Discussion Topic #3:Solutions Envisioned by CARB Staff
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Goal: Provide GDF Operators With “Menu of Options”
Low Cost & Complexity
Moderate Cost & Complexity
High Cost &
Complexity
ExamplesAssist Balance
EOR Nozzle &
Optimize
One WayCheck
Valves?
ISD Software/
PV Zero
ISD Software?
High Capacity
VaporProcessor
VaporProcessor?
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Non ISD Equipped;; 26%
ISD & Balance Equipped; 27%
ISD & Assist Equipped; 47%
Statewide GDF Population: 10,000
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Non ISD Equipped; 26%
Balance No OP Alarms; 22%
Assist No OP Alarms; 10%
Balance With OP Alarms; 4%
Assist With OP Alarms; 17%
Assist With OP Alarms & PWD;
21%
Statewide GDF Population: 10,000
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Balance Equipped Sites*
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Balance With OP Alarms; 4%
Description of Vapor Recovery Equipment Upgrade
One way check valves?Emission Based ISD Software?
Estimated CostPer Facility
TBD?
*Solutions envisioned by CARB staff for balance equipped sites are currently uncertain, pending results of additional winter 2017/2018 field studies.
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Assist Equipped Sites with OP Alarms
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Assist With OP Alarms; 17%
Description of Vapor Recovery Equipment Upgrade
• EOR Nozzle • ISD Software
Upgrade • PV Zero
Estimated CostPer Facility
• EOR Nozzle ~$4,000
• ISD Software and PV Zero ~$5,500
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Assist Equipped Sites with OP Alarms & PWD
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Assist With OP Alarms & PWD; 21%Description of Vapor Recovery Equipment Upgrade
• EOR Nozzle • ISD Software
Upgrade • PV Zero• High Capacity
Processor Estimated CostPer Facility
• EOR Nozzle: ~$4,000
• ISD Software and PV Zero ~$5,500
• High Capacity Processor: TBD
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Proposed Emission-Based ISD Overpressure Alarm Criteria
Current ISD Threshold Proposed ISD Threshold
Percentage of time at pressure:• 5% of time greater
than 1.5 ”WCG over seven days
• 25% of time greater than 0.5 ”WCG over 30 days
• Set at an efficiency loss threshold due to pressure driven losses
• Provide information to assess site specific health risk impacts
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Preliminary Cost Estimate
Potential SolutionEstimatedCost Per Site*
Estimated Assist Site Population
EstimatedBalance Site Population
Install EOR Nozzles and Optimize Vapor Recovery System(10 nozzles/site)
$4,000 ~3,700 Not Applicable
Install Revised ISD Software and PV Zero Vent Valve
$5,500 ~2,000 TBD**
Install High Capacity Vapor Processor
$15,000 -$50,000
TBD TBD**
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*Cost information is based on surveys conducted by CARB staff in 2014, numbers will be updated at a later date**Additional studies in 2017/2018 are needed to make determination
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Discussion Topic #4: Alternatives Considered
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Alternatives Considered
• Limit RVP of winter blend gasoline• Decommission Phase II Vapor Recovery
including ISD• Extend Advisory 405-D indefinitely• Retain current ISD requirements and require
high capacity vapor processors across the board
• Seeking public input on other alternatives
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Discussion Topic #4: Next Steps
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Next Steps1. Additional field studies seek to eliminate
remaining uncertainty on balance system emissions
2. Investigate feasibility of estimating pressure driven emissions at non-ISD equipped sites
3. Implementation of solutions will take several years due to regulatory and certification process
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0%
10%
20%
30%
40%
50%
60%Pe
rcen
tage
of G
DF E
xper
ienc
ing
Win
ter
OP
Alar
ms
Anticipated Timeline For Implementation of Overpressure Solution
OP Alarm Frequency
● Board Hearing
● OAL Adoption of Regulation● Certification of ISD Software & High Capacity Processors
● Rescind Advisory 405-D
● First Year of Implementation
● Second Year of Implementation
● EOR Nozzle Implementation
● Third Year of Implementation
● Full Implementation
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More Information
• General Vapor Recovery Program Inquiries:[email protected]
• Overpressure Related Inquiries:John [email protected]
• Overpressure Webpage:https://www.arb.ca.gov/vapor/op/op.htm
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mailto:[email protected]:[email protected]://www.arb.ca.gov/vapor/op/op.htm
Public workshop to discuss: ��Overpressure Conditions at Gasoline Dispensing Facilities Equipped with Underground Storage Tanks and Phase II Enhanced Vapor Recovery including In-Station Diagnostic Systems������December 12, 2017: Diamond Bar, CA�December 13, 2017: Sacramento, CA�Workshop AgendaHousekeepingPrior Workshops on OverpressureDiscussion TopicsDiscussion Topic #1: �Refresher on OverpressureCalifornia’s Vapor Recovery ProgramPhase II Enhanced Vapor Recovery Systems: Differences Between Balance and AssistIn-Station Diagnostics (ISD) ISD Overpressure (OP) Alarm CriteriaWhy Are We Concerned?What Causes Overpressure?Discussion Topic #2: �Activities Since November 2015 Public WorkshopActivities Since November 2015 Public Workshop Mega Blitz December 2015Data Collected From ~400 Sites� in Six Geographic RegionsMega Blitz 2013 vs 2015Prevalence of OP Alarms Vapor to Liquid (V/L) Ratio Effect on Pressure While Dispensing Observation at Assist SitesConclusions From Mega Blitz of 2015Evaluation of Assist Nozzle� Enhanced ORVR-Vehicle Recognition (EOR) Spout AssemblyExpected “Vapor to Liquid” Ratio for ORVR VehiclesConventional vs ORVR Equipped VehiclesDevelopment of EOR Spout AssemblyIn Addition to EOR Spout Assembly:�Assist System OptimizationResults of EOR Spout Assembly Evaluation (seven site average)EOR Spout Assembly ConclusionsEvaluation of Pressure Driven Balance EmissionsQuestions Prompting Investigation of Balance System Pressure Driven Emissions2015 CARB Emission Testing of Balance Systems at Slightly Positive UST PressureApplication of 2015 Balance System Emission Test DataWhy is VDAPP Important?Why is RIFE Important? Data Used to Estimate Balance System Pressure Driven EmissionsVDAPP – 10 Study Sites vs 85 Blitz Sites*Comparison of VDAPP DistributionsEffect of VDAPP & RIFE on Balance System� Winter Season EmissionsObservations Mega Blitz vs Study SitesBalance System Emission Evaluation ConclusionsDiscussion Topic #3:�Solutions Envisioned by CARB StaffGoal: Provide GDF Operators With �“Menu of Options”Slide Number 42Slide Number 43Balance Equipped Sites*Assist Equipped Sites with OP AlarmsAssist Equipped Sites with OP Alarms & PWDProposed Emission-Based ISD Overpressure Alarm CriteriaPreliminary Cost EstimateDiscussion Topic #4: �Alternatives ConsideredAlternatives ConsideredDiscussion Topic #4: �Next StepsNext StepsSlide Number 53More Information