RULE 4624 TRANSFER OF ORGANIC LIQUID (Adopted April 11, 1991; Amended 

September 19, 1991; Amended May 21, 1992; Amended December 17, 1992; 

Amended December 20, 2007) 

1.0 Purpose 

The purpose of this rule is to limit VOC emissions from the transfer of organic liquids. 

 

2.0 Applicability 

This rule shall apply to organic liquid transfer facilities as defined in this rule. 

3.0 Definitions 

3.1 APCO: as defined in Rule 1020 (Definitions). 

3.2 API: American Petroleum Institute. 

3.3 ARB: The California Air Resource Board. 

3.4 ASTM: American Society for Testing and Materials. 

3.5 Background: the ambient concentration of organic compounds determined at 

least two (2) meters upwind from any valve or flange to be inspected and which 

is uninfluenced by any specific emission permit unit. 

3.6 Bottom Loading: a type of organic liquid loading operation where the discharge 

opening into the container is completely submerged below the level of the 

organic liquid in the container. 

3.7 CFR: Code of Federal Regulations. 

3.8 Class 1 Organic Liquid Transfer Facility: any location transferring 20,000 

gallons or more on any one day of organic liquids with a TVP of 1.5 psia or 

greater to or from tank trucks, trailers, or railroad tank cars. 

3.9 Class 2 Organic Liquid Transfer Facility: any location transferring 4,000 

gallons or more but less than 20,000 gallons on any one day of organic liquids 

with a TVP of 1.5 psia or greater to or from tank trucks, trailers, or railroad 

tank cars. 

3.10 Closed VOC Emission Control System: an APCO-approved VOC emission 

control system that is not open to the atmosphere and that is composed of hardpiping, ductwork connections, and, if necessary, flow inducing devices that 

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transport collected gases or vapors from a piece or pieces of equipment to a 

vapor return system or condensation system that connects to a process stream, a 

gas processing plant, a gas pipeline recovery and distribution system (sales gas 

system), a fuel gas system, or an injection well for disposal of vapors as 

approved by the California Department of Resources, Division of Oil, Gas, and 

Geothermal Resources. 

3.11 Container: any stationary tank, reservoir, or vessel in which any organic liquid 

is placed, held, or stored. 

3.12 EPA: United States Environmental Protection Agency. 

3.13 Excess Organic Liquid Drainage: more than ten (10) milliliters liquid drainage. 

Such liquid drainage for disconnect operations shall be determined by computing 

the average drainage from three consecutive disconnects at any one permit unit. 

3.14 Gasoline: any petroleum distillate, petroleum distillate/alcohol blend or alcohol 

having a Reid vapor pressure of four (4) pounds per square inch absolute or 

greater, which is used as a motor vehicle fuel, or any fuel which is commonly or 

commercially known or sold as gasoline. 

3.15 Gasoline Bulk Plant: any loading facility and associated unloading facilities, 

storage tanks and vapor recovery system(s) used to load less than 20,000 gallons 

in any one (1) day of gasoline to delivery vessels (i.e., tank trucks or trailers). 

3.16 IBP: Initial Boiling Point. 

3.17 Leak: the dripping of VOC-containing liquid at a rate of more than three (3) 

drops per minute; or 

3.17.1 For organic liquids other than gasoline, the detection of any gaseous or 

vapor emissions with a concentration of VOC greater than 1,000 ppmv 

above a background as methane when measured in accordance with the 

test method in Section 6.3.7 shall constitute a leak 

3.17.2 For gasoline, a concentration of VOC greater than 10,000 ppmv, as 

methane, above background when measured in accordance with the test 

method in Section 6.3.7 shall constitute a leak. 

3.17.3 Any liquid or gas coming from a component undergoing repair or 

replacement, or during sampling of process fluid from equipment into a 

container is not considered a leak provided such activities are 

accomplished as expeditiously as possible and with minimal spillage of 

material and VOC emissions to the atmosphere. 

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3.18 Location: any single site at a building, structure, facility, or installation.

3.19 Normal Business Hours: Monday through Friday, 8:00 am to 5:00 pm. 

3.20 Organic Liquid: any liquid which contains VOCs and has a TVP of 1.5 psia or 

greater at the storage container’s maximum organic liquid storage temperature. 

Clean produced water, as defined by Rule 1020, and other types of liquids that 

contain no more than 35 milligrams of VOC per liter, shall not be considered to 

be an organic liquid. 

3.21 Organic Liquid Loading Operation: the transfer of organic liquid to a tank 

truck, trailer, or railroad car. 

3.22 Organic Liquid Transfer Facility: any aggregate or combination of transfer 

racks and vapor control equipment at a location, including, but not limited to, 

the stationary organic liquid pump, and the hose end connector, and the 

discharge of the vapor control device(s). 

3.23 Portable Hydrocarbon Detection Instrument: a hand-held hydrocarbon analyzer 

that meets the criteria specified in EPA Method 21, 40 CFR Part 60. The 

instrument shall be calibrated with methane. 

3.24 Psia: Pounds per square inch, absolute. 

3.25 Pump: a device used to transport fluids by the addition of energy, and includes 

all associated components used for connecting or sealing purposes. The phrase 

"all associated components used for connecting and sealing purposes" means the 

first VOC leak points (first components) on the body of the pump. For example, 

a valve that is connected to a threaded hole on body of the pump, the first VOC 

leak point is the threaded connection on the body side of the pump, but the valve 

itself is not a "first VOC leak point". Similarly, a pump shaft seal is considered 

as a first “VOC leak point”. 

3.26 Transfer Rack: a loading rack as defined in Rule 1020 (Definitions) or an 

unloading rack as defined in Rule 2020 (Exemptions). This rule applies only to 

racks with stationary pumps. 

3.27 TVP: True Vapor Pressure. 

3.28 VOC: as defined in Rule 1020 (Definitions). 

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4.0 Exemptions 

4.1 The requirements of Section 5.0 of this rule shall not apply to organic liquid 

transfer facilities which transfer less than 4,000 gallons of organic liquids in any 

one day. The operator shall meet the applicable recordkeeping requirements of 

Section 6.1.1. 

4.2 The requirements of this rule shall not apply to transfer operations subject to the 

requirements of Rule 4621 (Gasoline Transfer into Stationary Storage 

Containers, Gasoline Delivery Vessels and Gasoline Bulk Plants) or to transfer 

operations that are subject to Rule 4622 (Gasoline Transfer into Motor Vehicle 

Fuel Tanks). 

4.3 Except for Section 6.1, the requirements of this rule shall not apply to the 

transfer of organic liquids with TVP less than 1.5 psia at the storage container’s 

maximum organic liquid storage temperature. 

4.4 The requirements of Section 5.9 shall not apply to equipment or components 

subject to: 

4.4.1 Rule 4409 (Components at Light Crude Oil Production Facilities, 

Natural Gas Production Facilities, and Natural Gas Processing 

Facilities); 

4.4.2 Rule 4455 (Components at Petroleum Refineries, Gas Liquids Processing 

Facilities, and Chemical Plants); or 

4.4.3 Rule 4623 (Storage of Organic Liquids). 

4.5 Except for the one-time record submission requirement of Section 6.1.5 for 

vacuum truck operators, the requirements of this rule shall not apply to transfer 

operations involving vacuum trucks. 

5.0 Requirements 

5.1 For a Class 1 organic liquid transfer facility, the emission of VOC from the 

transfer operation shall not exceed 0.08 pounds per 1,000 gallons of organic 

liquid transferred and use one of the following systems: 

5.1.1 An organic liquid loading operation shall be bottom loaded. 

5.1.2 The VOC from the transfer operation shall be routed to: 

5.1.2.1 A vapor collection and control system; 

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5.1.2.2 A fixed roof container that meets the control requirements 

specified in Rule 4623 (Storage of Organic Liquids); 

5.1.2.3 A floating roof container that meets the control requirements 

specified in Rule 4623 (Storage of Organic Liquids); or 

5.1.2.4 A pressure vessel equipped with an APCO-approved vapor 

recovery system that meets the control requirements specified in 

Rule 4623 (Storage of Organic Liquids); or 

5.1.2.5 A closed VOC emission control system. 

5.2 A Class 2 organic liquid transfer facility shall prevent the release to the 

atmosphere of at least 95 percent by weight of the VOC displaced during 

organic liquid transfers and use one of the following systems: 

5.2.1 An organic liquid loading operation shall be bottom loaded, equipped 

with a vapor collection and control system and the vapors from loading 

the tank truck, trailer, or railroad tank car shall be routed to the vapor 

collection and control system; or 

5.2.2 The VOC from the transfer operation shall be routed to: 

5.2.2.1 A vapor collection and control system; or 

5.2.2.2 A fixed roof container that meets the control requirements 

specified in Rule 4623 (Storage of Organic Liquids); or 

5.2.2.3 A floating roof container that meets the control requirements 

specified in Rule 4623 (Storage of Organic Liquids); or 

5.2.2.4 A pressure vessel equipped with an APCO-approved vapor 

recovery system that meets the control requirements specified in 

Rule 4623 (Storage of Organic Liquids); or 

5.2.2.5 A closed VOC emission control system. 

5.3 A transfer operation utilizing a closed VOC emission control system or utilizing 

a container that meets the control requirements of Rule 4623 (Storage of 

Organic Liquids) to meet the emission control requirements of this rule shall 

demonstrate compliance with Sections 5.1 and 5.2 by complying with the leak 

inspection requirements of Section 5.9. 

5.4 The vapor collection and control system shall operate such that the pressure in 

the delivery tank being loaded does not exceed 18 inches water column pressure 

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and six (6) inches water column vacuum. This section shall not apply to the 

transfer of liquefied petroleum gas. 

5.5 All delivery tanks which previously contained organic liquids with a TVP of 1.5 

psia or greater at the storage container’s maximum organic liquid storage 

temperature shall be filled only at transfer facilities satisfying Sections 5.1, 5.2, 

or 5.4, as applicable. 

5.6 The transfer rack and vapor collection equipment shall be designed, installed, 

maintained and operated such that there are no leaks and no excess organic 

liquid drainage at disconnections. 

5.7 The construction of any new top loading facility or the reconstruction, as 

defined in 40 CFR 60.15, or the expansion of any existing top loading facility 

with top loading equipment shall not be allowed. 

5.8 Notwithstanding any other provision of this rule, organic liquid transfer facilities 

exclusively handling liquefied petroleum gas need not comply with the bottom 

loading provisions of Sections 5.1, 5.2 or 5.7, provided the operator complies 

with the emission limit of Section 5.1, 5.2 and the provisions of Section 5.6. 

5.9 Leak Inspection Requirements 

5.9.1 The operator of an organic liquid transfer facility shall inspect the vapor 

collection system, the vapor disposal system, and each transfer rack 

handling organic liquids for leaks during transfer at least once every 

calendar quarter using the test method prescribed in Section 6.3.8. 

5.9.2 A floating roof container that meets the applicable control requirements 

of Section 5.0 of Rule 4623 (Storage of Organic Liquids) shall be 

considered not leaking for the purposes of this section. 

5.9.3. All equipment that are found leaking shall be repaired or replaced within 

72 hours. If the leaking component cannot be repaired or replaced 

within 72 hours, the component shall be taken out of service until such 

time the component is repaired or replaced. The repaired or replacement 

equipment shall be reinspected the first time the equipment is in 

operation after the repair or replacement. 

5.9.4 An operator may apply for a written approval from the APCO to change 

the inspection frequency from quarterly to annually provided no leaks 

were found during the inspections required under provisions of Sections 

5.9.1 and 5.9.2 during five consecutive quarterly inspections. Upon 

identification of any leak during an annual inspection the frequency 

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would revert back to quarterly and the operator shall contact the APCO 

in writing within 14 days. 

6.0 Administrative Requirements 

6.1 Recordkeeping 

6.1.1 An operator claiming exemption under Section 4.1 shall keep records of 

daily liquid throughput. 

6.1.2 An operator claiming exemption under Section 4.3 of this rule shall 

maintain accurate daily records of liquid TVP. 

6.1.2.1 Liquid TVP shall be determined using Appendix A or the 

applicable test method in Section 6.3. 

6.1.2.2 The TVP shall be determined whenever there is a change in the 

type of liquid being transferred. 

6.1.2.3 An operator may use a material safety data sheet (MSDS) in 

place of TVP testing if the transferred organic liquid is not 

crude oil or a petroleum distillate. 

6.1.3 An operator subject to any part of Section 5.0 shall keep records of daily 

liquid throughput and the results of any required leak inspections. 

6.1.4 Records required under Sections 6.1.1, 6.1.2, 6.1.3 shall be retained for 

a minimum of five years and shall be made readily available to the 

APCO, ARB, or EPA during normal business hours and submitted upon 

request to the APCO, ARB, or EPA. 

6.1.5 By July 1, 2008, operators of vacuum trucks claiming exemption under 

Section 4.5 shall submit to the District records covering 12 consecutive 

months of operation. The records shall indicate all of the following: 

6.1.5.1 The number of vacuum trucks in operation; 

6.1.5.2 The capacity of each vacuum truck storage container; 

6.1.5.3 The average monthly throughput per vehicle; 

6.1.5.4 The type of organic liquid transferred; and 

6.1.5.5 The VOC capture and control equipment utilized. 

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6.2 Compliance Testing 

6.2.1 By July 20, 2009, the operator of any Class 1 or Class 2 organic liquid 

transfer facility shall perform an initial source test of the VOC emission 

control system in accordance with the method prescribed in Section 6.3.2 

to determine compliance with Section 5.1 and 5.2, as applicable. 

6.2.1.1 Facilities in existence prior to December 20, 2007 that have 

performed the test specified in Section 6.3.2 within the 60 

month period preceding December 20, 2007 need not perform 

an initial source test. 

6.2.1.2 The source testing requirements of Section 6.2.1 shall not apply 

to any Class 1 or Class 2 organic liquid transfer facility 

equipped with a closed VOC control system. 

6.2.1.3 The source testing requirements of Section 6.2.1 shall not apply 

to any Class 1 or Class 2 organic liquid transfer facility 

controlling VOC by routing vapors to: 

6.2.1.3.1 A fixed roof container that meets the control 

requirements specified in Rule 4623 (Storage of 

Organic Liquids); or 

6.2.1.3.2 A floating roof container that meets the control 

requirements specified in Rule 4623 (Storage of 

Organic Liquids); or 

6.2.1.3.3 A pressure vessel equipped with an APCO-approved 

vapor recovery system that meets the control 

requirements specified in Rule 4623 (Storage of 

Organic Liquids). 

6.2.2 The operator of any Class 1 or Class 2 organic liquid transfer facility 

shall perform the source test specified in Section 6.3.2 once every 60 

months, but no more than 30 days before or after initial source test 

anniversary date. 

6.3 Test Methods 

6.3.1 Analysis of halogenated exempt compounds shall be by ARB Method 

432. 

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6.3.2 Compliance with Sections 5.1 and 5.2 shall be determined using 40 CFR 

60.503 "Test Methods and Procedures" and EPA Methods 2A, 2B, 25A 

and 25B and ARB Method 422, or ARB Test Procedure TP-203.1. 

6.3.3 The TVP of any organic liquid shall be determined by measuring the 

Reid Vapor Pressure (RVP) using ASTM D 323 (Test Method for Vapor 

Pressure for Petroleum Products), and converting the RVP to TVP at the 

storage container’s maximum organic liquid storage temperature. The 

conversion of RVP to TVP shall be done in accordance with the 

procedures in Appendix B. Appendix B is an excerpt from the oil and 

gas section of “ARB Technical Guidance Document to the Criteria and 

Guidelines Regulation for AB 2588”, dated August 1989. 

6.3.4 As an alternative to using ASTM D 323, the TVP of crude oil with an 

API gravity range of greater than 26 degrees up to 30 degrees may be 

determined by using other equivalent test methods approved by APCO 

and EPA. 

6.3.5 The latest version of the Lawrence Berkeley National Laboratory “Test 

Method for Vapor Pressure of Reactive Organic Compounds in Heavy 

Crude Oil Using Gas Chromatograph”, as approved by ARB and EPA, 

shall be used to determine the TVP of crude oil with an API gravity of 

26 degrees or less, or for any API gravity that is specified in this test 

method. 

6.3.6 An operator may use the information in Appendix A to determine the 

TVP of the stored organic liquid in a tank provided the storage 

temperature listed in Appendix A is not exceeded at any time. 

6.3.7 The API gravity of crude oil or petroleum distillate shall be determined 

using ASTM Method D 287 (Standard Test Method for API Gravity of 

Crude Petroleum and Petroleum Products (Hydrometer Method)). 

Sampling for API gravity shall be performed in accordance with ASTM 

Method D 4057 (Standard Practices for Manual Sampling of Petroleum 

and Petroleum Products). 

6.3.8 Compliance with facility leaks as defined in Section 3.0 shall be 

determined using a portable hydrocarbon detection instrument in 

accordance with EPA Method 21. 

6.3.9 An alternative test method may be used if the alternative is approved in 

writing by the APCO and EPA. 

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6.4 Version of Test Methods 

All ASTM test methods referenced in Section 6.0 are the most recently EPAapproved version that appears in the CFR as Materials Approved for 

Incorporation by Reference. 

7.0 Compliance Schedule 

7.1 Operators of transfer facility subject to this rule on or before December 20, 

2007 shall be in full compliance with all applicable rule requirements on and 

after December 20, 2008, unless otherwise specified in the rule. 

7.2 The owner or operator of any transfer facility which is subject to the 

requirements of this rule and which was installed or constructed after December 

20, 2007, shall be in full compliance with the requirements of this rule upon 

initial operation. 

7.3 Any organic liquid transfer facility that is exempt pursuant to Section 4.1, 4.2, 

and 4.3 that becomes subject to the requirements of this rule through loss of 

exemption shall not be operated until such time that it is in full compliance with 

the requirements of this rule. 

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Appendix A 

STORAGE TEMPERATURE VERSUS VAPOR PRESSURE 

ORGANIC LIQUID Reference Properties Maximum Temp °F 

Not to Exceed 

Gravity 

°API 

IBP 

°F 

1.5 (psia) 

Middle Distillates 

Kerosene 42.5 350 250 

Diesel 36.4 372 290 

Gas Oil 26.2 390 310 

Stove Oil 23 421 340 

Jet Fuels 

JP-1 43.1 330 230 

JP-3 54.7 110 25 

JP-4 51.5 150 68 

JP-5 39.6 355 260 

JP-7 44-50 360 260 

Fuel Oil 

No. 1 42.5 350 250 

No. 2 36.4 372 290 

No. 3 26.2 390 310 

No. 4 23 421 340 

No. 5 19.9 560 465 

Residual 19.27 --- --- 

No. 6 16.2 625 --- 

Asphalts 

60-100 pen. --- --- 550 

120-150 pen. --- --- 500 

200-300 pen. --- --- 420 

IBP = Initial Boiling Point 

SJVUAPCD 4624-11 12/20/2007
Appendix B 

California Air Resources Board Technical Guidance 

to the Criteria and Guidelines Regulation for AB 2588 

(Partial Excerpt from pages 102, 103 and 104) 

True Vapor Pressure (TVP) 

RVP is the absolute pressure of volatile crude oil and nonviscous petroleum liquids. 

Numerically, the relationship between TVP, RVP and temperature can be expressed by the 

following equation: 

 TVP = (RVP) e[Co(IRTEMP - ITEMP)]

Where: Co = Constant dependent upon the value of RVP 

ITEMP = (1/559.69oR) 

IRTEMP = (1/(Ts + 459.69oR)) 

Ts = Temperature of the stored fluid in oF 

The value of the constant term Co depends upon the given value of RVP. 

Values of Co for different RVP numbers are tabulated in Table C-3. It should be noted, 

however, that an error was discovered in the API nomograph calculated values of TVP so 

that the RVP was not equal to TVP at 100oF as was expected given the general definition 

of RVP. Using linear regression techniques, correction factors (CF) were developed and 

should be added to the calculated values of TVP in order to obtain reasonable TVP 

numbers. The relationship between the three values is given as follows: 

Corrected TVP = Calculated TVP + CF

The correction factor was found to be dependent upon RVP according to the following 

equations: 

If RVP < 3, 

CF = (0.04) x (RVP) + 0.1 

If RVP > 3, 

CF = e[(2.3452061 log (RVP)) - 4.132622]

SJVUAPCD 4624-12 12/20/2007
Appendix B (Continued) 

Table C-3 VALUES OF Co FOR DIFFERENT RVP NUMBERS 

RVP Co

0<RVP<2 -6622.5 

2<RVP<3 -6439.2 

RVP = 3 -6255.9 

3<RVP<4 -6212.1 

RVP = 4 -6169.2 

4<RVP<5 -6177.9 

RVP = 5 -6186.5 

5<RVP<6 -6220.4 

RVP = 6 -6254.3 

6<RVP<7 -6182.1 

RVP = 7 -6109.8 

7<RVP<8 -6238.9 

RVP = 8 -6367.9 

8<RVP<9 -6477.5 

RVP = 9 -6587.9 

9<RVP<10 -6910.5 

RVP = 10 -7234.0 

10<RVP<15 -8178.0 

RVP > 15 -9123.2 

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