UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

for

EPA’s Direct Final Rulemaking

for the

California State Implementation Plan

South Coast Air Quality Management District Rule 463 

Organic Liquid Storage

Prepared by: Cara Peck

Reviewed by: Andrew Steckel

December 28, 2012
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Rule Agency: South Coast Air Quality Management District (SCAQMD)

SIP Approved Rule: Rule 463 - Organic Liquid Storage

Amended – May 6, 2005

Submitted – October 20, 2005

EPA Approved on January 04, 2007

Subject of this TSD: Rule 463, Organic Liquid Storage

Amended – November 4, 2011

Submitted – February 23, 2012

RULE SUMMARY

SCAQMD Rule 463 controls emissions of volatile organic compounds (VOCs) from 

above-ground storage tanks used for storage of organic liquids. Organic liquid storage 

tanks are classified into three types: fixed roof tanks, fixed roof tanks with internal 

floating covers, and external floating roof tanks. 

RULE BACKGROUND

Rule 463 was originally adopted on August 15, 1977. It was later amended on June 1, 

1984, December 7, 1990, March 11, 1994 and May 6, 2005. The May 6, 2005 rule was 

approved by the Environmental Protection Agency (EPA) into the California State 

Implementation Plan (SIP) on January 04, 2007. The SCAQMD amended Rule 463 

again on November 04, 2011, and submitted it to EPA on February 23, 2012.

RULE CHANGES

The February 23, 2012 SIP submitted version of Rule 463 mainly differs from the current 

SIP rule (approved into the SIP on January 4, 2007) due to updated testing methods, 

aligning the rule with Rule 1178 used in determining vapor pressure for heavier 

petroleum products.

1. Definitions: 

 “Ambient temperature” is added, consistent with the definition of Rule 1178.

 “Certified Person” is defined rather than “Certified”, consistent with the 

proposed amended rule language usage. 

 “Drain-Dry Breakout Tank” is defined to support a limited exemption from 

the vapor headspace limitation requirements for such tanks that are primarily 

used to receive product from pipelines and to distribute product back into 

pipelines and that are subject to the vapor control requirements of Rule 1149-

Storage Tank and Pipeline Cleaning Degassing. 

 “Vapor-Tight” is updated to reflect current detecting methods and limits (from 

1,000 to 500 ppm). 

 “Volatile Organic Compound” is updated to refer to Rule 102 - Definitions.
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 “Working Day” is defined as Monday through Friday and includes holidays 

that fall on any of the days Monday through Friday. 

2. Requirements: 

 Language was added stating that vapor recovery systems shall have an efficiency 

of at least 95 percent by weight, or vent tank emissions to a fuel gas system. 

 A requirement for the Inspection and Maintenance Plan was changed and now 

states that the owner or operator shall maintain, rather than submit, a current or 

revised Inspection and Maintenance Plan approved by the Executive Officer.

3. Reporting and Recordkeeping: 

 All compliance and inspection reports and documents submitted to the Executive 

Officer can now be submitted electronically rather than just via hard copy, within 

5 working days of completion of the self-inspection. 

 An exemption was added stating that the provisions of (d)(2) shall not apply to 

drain-dry breakout tanks that are subject to the provisions of Rule 1149 - Storage 

Tank and Pipeline Cleaning and Degassing. 

4. Test Methods: 

 Language was added stating that the Reid vapor pressure used in determining the 

true vapor pressure limit shall be determined according to ASTM D-323-82-

Vapor Pressure of Petroleum Products (Reid Method) or California Code of 

Regulations, Title 13, Section 2297, and converted to true vapor pressure using 

applicable nomographs in U.S. EPA AP-42, Fifth Edition, Volume 1, Chapter 7, 

or nomographs approved by the Executive Officer and U.S. EPA. 

 Additional language was added stating that if demonstration of true vapor 

pressure of less than 5mm Hg (0.1 psi) absolute is required, either of the 

following test methods may be used:

o Organic liquids stored at ambient temperature with a true vapor pressure 

of greater than 5mm HG (0.1 psi) under actual storage conditions shall be 

determined as those with a flash point of less than 100°F as determined by 

ASTM Method D-93-10a- Flash Point by Pensky Martens Closed Cup 

Tester.

o Organic liquids stored at above ambient temperatures with a true vapor 

pressure greater than 5 mm Hg (0.1 psi) shall be determined by ASTM 

Method D-86-11a-Distillation of Petroleum Products at Atmospheric 

Pressure. 

 Language was added stating that vapor tight conditions specified in subparagraphs 

(c)(3)(B) shall be determined according to U.S. EPA’s Reference Method 21 

using an appropriate analyzer calibrated with methane. 
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EPA EVALUATION 

The following criteria were used to evaluate the submitted rule:

1. Enforceability: The Bluebook (Issues Relating to VOC Regulation Cutpoints, 

Deficiencies, and Deviations, EPA, May 25, 1988) and the Little Bluebook 

(Guidance Document for Correcting Common VOC & Other Rule Deficiencies,

EPA Region 9, August 21, 2001) were used to help evaluate compliance with the 

Clean Air Act (CAA) §110(a)(2)(A) requirement for enforceability. 

2. Stringency: EPA’s Control Technique Guideline (CTG) documents titled, “Control 

of Volatile Organic Emissions from Petroleum Liquid Storage in External Floating 

Roof Tanks” (EPA-450/2-78-047) and “Control of Volatile Organic Emissions 

from Storage of Petroleum Liquid in Fixed-Roof Tanks” (EPA-450/2-77-036), and 

other state and local rules for this category were used to help evaluate the RACT 

requirements of CAA §182(b)(2) and §182(f). 

3. SIP Relaxation: CAA §110(l) prohibits EPA from approving any SIP revision that 

would interfere with any applicable requirement concerning attainment and 

reasonable further progress (RFP) or any other applicable requirement of the CAA. 

In addition, CAA §193 prohibits the modification of any SIP-approved control 

requirement in effect before November 15, 1990, in a nonattainment area.

The rule requirements and applicability are clear, and the monitoring, recordkeeping, 

reporting and other provisions sufficiently ensure that affected sources and regulators 

can evaluate and determine compliance with Rule 463 consistently. 

The submitted rule is as stringent as CARB’s RACT guidance and other California 

District rules for this category, including BAAQMD Rule 8-5 and SJVUAPCD Rule 

4623 and it is more stringent than EPA’s 1977 CTG. As a result, we have determined 

that this rule fulfils RACT requirements. 

We propose to determine that our approval of the submittal would comply with CAA 

§§110(l) and 193 because the proposed SIP revision would not interfere with the ongoing process for ensuring that requirements for RFP and attainment of the NAAQS are 

met.

ADDITIONAL RECOMMENDATIONS FOR THE NEXT RULE REVISION 

There are no additional recommendations for the next rule revision. 
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EPA ACTION

The submitted Rule 463 would strengthen the SIP by improving enforceability of certain 

rule requirements. The changes are primarily administrative in nature and are not 

expected to have any adverse effect on emission reductions. EPA staff recommends 

approval of SCAQMD Rule 463 pursuant to CAA §110(k)(3) and §301(a). 

REFERENCES

1. SCAQMD Rule 463, Organic Liquid Storage, as submitted on February 23, 2012.

2. SCAQMD Rule 463, Organic Liquid Storage, as approved into the SIP on 

January 04, 2007

3. Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations, 

(a.k.a., Bluebook) EPA OAQPS, May 25, 1988.

4. Guidance Document for Correcting Common VOC & Other Rule Deficiencies, 

(a.k.a., Little Bluebook), EPA Region 9, August 21, 2001.

5. “Control of Volatile Organic Emissions from Petroleum Liquid Storage in External 

Floating Roof Tanks,” EPA-450/2-78-047.

6. “Control of Volatile Organic Emissions from Storage of Petroleum Liquid in 

Fixed-Roof Tanks,” EPA-450/2-77-036.

7. SJVUAPCD Rule 4623, Organic Liquid Storage, as approved into the SIP on May 

19, 2005

8. BAAQMD Rule 8-5- Storage of Organic Liquids, as approved into the SIP of 

November 27, 2002