i.tì., r.,r:'r,

Katlrleen Hartnett \Nhite, Clta innatt

Larr-y R. Soivard, Commissirtner

Glenn Shankle, Executiue Direclor

Tpxas CorørurrssroN oN ENVIRoNMENTAL QUALITy ?.

Protecting Texas bg Reducittg and Preuenting Pollution'

Docket Nos. 2006-1874-SIP, 2006-17 96-R[IL,r2006-1804-RUL r

June 13,2007

Richard E- Greene, Regional Adnrinistrator

U.S. Environmental Protection Agency - Region 6

1445 Ross Avenue

Dallas. Texas 7 5202-2733

3

Dear Mayor Greene: f

On May 23,2007, the Texas Commission on Environmental Quality (Commission) adopted revisions tõne

Implementation Plan (SlP) for the Houston-Galveston-Brazoriã lHGe) eiglrt-hour ozone nonattainlnenl al'ea.

These revisions include three components- The first component is a revision to the SIP for the HGB eight-hour ozone

nonattainment a¡ea that includes additional Voluntary Mobile Emission Reduction Program (VMEP) commitments. In

addition, the Commission adopted amendments to S 114.6 and $ 114.319 in 30 Tex. Admin. Code Chapter I14, Control of

Ai¡ Pollution frorn Motor Vehicles. These rules amend the definition of diesel fuel to include marine distillate fuels,

requiring thern to be compliant with low emission diesel (LED) standards i¡ the HGB nonattainment area, and amend the

compliance schedule for the infoduction of LED-compliant marine diesel fuels into the HGB area counties.

Lurtty, rhe commission adopred new $ 1l5.ll0 and amendmenrs ro s$ 115.1l2 - ll5.l17, I l5.l19, 115.541 - 1i5.547, andl

115.549 of 30 Tex- Admin. Code Chapter ll'5, Conh'ol of Ai¡Pollution from Volatile Organic Compounds. Specifically, I

the new section and amendúrents reduce emissions of volatile organic conipounds (VOC) û'om VOC storage and degassing I

operations by estabiishing lrore stringent controls for fittings on floating loof storage vessels, establishing control I

requiretnents or operational lirnitations on landing floating roofs, establislring control requirenrents for flash elnissions fi-om I

crude oil and condensate storage tanks, and establishing nore stringent control requirentents for degassing and cleaning ofJ

storage, transpoll, and marine vessels.

Enclosed are tlrese proposed revisions to the SIP, a cornplete record ofthe public hearings. the accompanying orders, and a

public lrearing certification. I look forward to your expeditious approval of these SIP rei,isiots.

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Enclosures 

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cc: The Honorable Rick Perr1,. Govenlor of Texas

Mr. Zal< CovaL- Offìce of Budget, Planning arrd Policy, Offìce of the Covenlor

Mr. Glen¡ Shankle, Executive Dù-ector. Texas Con'lllission on Envir-onrnenta) Quaìit1,

Sincerely,

P.(_).p-oi.':-3()87 6 A_ustirr. Te,.l¿rs 7åì7ìl-3û87 + 5l!,,!,?9-itl(tfl € ilrr.cr.na', ¿rcici.rr,s:: i¡'.r.r,rt.ictr¡.sLate.t:,..us
THE STATE OF TEXAS 

COUNTY OF TRAVIS 

This is to certify that the attached are true and correct copies of documents for revisions to the Texas 

State Implementation Plan, adopted on May 23, 2007, pursuant to 40 Code of Federal Regulations (C.F.R.) 5 

51.104. I am the records administrator for the Office of Chief Engineer of the Texas Commission on 

Environmental Quality (Commission). 

R 

Susana M. Hildebrand, P.E. 

Director, Air Quality Division 

Texas Commission on Environmental Quality 
Texas Commission on Environmental Quality 

Public Hearings 

January 29 and 31, and February 1,6, and 8,2007 

Concerning Revisions to 30 TAC Chapter 11 5 

Control of Air Pollution from Volatile Organic Compounds 

Control of VOC Emissions from Storage 8, Degassing 

Operations in HGB for the Eight-Hour Ozone Standard 

Rule Project No. 2006-038-1 15-EN 
The Texas Commission on Environmental Quality (commission) held public hearings in Houston on 

January 29, 2007; Dallas on January 31, 2007; Arlington and Midlothian on February 1, 2007; 

Longview on February 6, 2007; and Austin on February 8, 2007, to receive testimony regarding 

revisions to 30 TAC Chapter 1 14, Control of Air Pollution from Motor Vehicles; Chapter 1 15, Control 

of Air Pollution from Volatile Organic Compounds; Chapter 117, Control of Air Pollution from 

Nitrogen Compounds; and corresponding revisions to the state implementation plan. 

The comment period closed on February 12, 2007. All testimony and comments have been 

reviewed and seriously considered. This hearing record contains a complete record of the public 

hearings and is divided into the followirrg four sections: 

o Public Notification and Proposal 

o Written and Oral Testimony 

0 Evaluation of Testimony 

o Staff Recommendations/Order 

Additional copies of this hearing record are maintained in the TCEQ central office at 12100 Park 35 

Circle, Austin, Texas 78753. For further information, please contact Teresa Hurley at (51 2) 239- 

531 6. 
STAFF 

RECOMMENDATIONS 
SUBCHAPTER B: GENERAL VOLATILE ORGANIC COMPOUND SOURCES 

DMSION 1: STORAGE OF VOLATILE ORGANIC COMPOUNDS 

$§115.110, 115.112 - 115.117, 115.119 

STATUTORY AUTHORITY 

The amendments and new rule are adopted under Texas Water Code, $5.102, concerning General 

Powers, 55.103, concerning Rules, and 55.105, concerning General Policy, that authorize the 

commission to adopt rules necessary to carry out its powers and duties under the Texas Water Code; and 

under Texas Health and Safety Code, 5382.017, concerning Rules, that authorizes the commission to 

adopt rules consistent with the policy and purposes of the Texas Health and Safety Code, Chapter 382 

(also known as the Texas Clean Air Act). The amendments and new rule are also adopted under Texas 

Health and Safety Code, 5382.002, concerning Policy and Purpose, that establishes the commission's 

purpose to safeguard the state air resources, consistent with the protection of public health, general 

welfare, and physical property; 5382.01 1, concerning General Powers and Duties, that authorizes the 

commission to control the quality of the state's air; 5382.012, concerning State Air Control Plan, that 

authorizes the commission to prepare and develop a general, comprehensive plan for the control of the 

state's air; 5382.014, concerning Emission Inventory, which authorizes the commission to require the 

submission of information concerning the emission of air contaminants; and 5382.016, concerning 

Monitoring Requirements; Examination of Records, which authorizes the commission to require owners 

and operators of emission sources to maintain measuring and monitoring records and make such records 

available to the commission. The rules are adopted under federal mandates contained in 42 USC, 57410, 

that require states to introduce pollution control measures in order to reach specific air quality standards 

in particular areas of the state. 
The adopted amendments and new rule implement Texas Health and Safety Code, 55382.002, 382.01 1, 

382.012, 382.014, and 382.016. 

The following words and terms, when used in this division (relating to Storage of Volatile 

Organic Compounds), have the following meanings, unless the context clearly indicates otherwise. 

Additional definitions for terms used in this division are found in $83.2, 101.1, and 115.10 of this title 

(relating to Definitions). 

(1) Deck cover--A device that covers an opening in a floating roof deck. Some deck 

covers move horizontally relative to the deck (i.e., a sliding cover). 

(2) Flexible enclosure system--A system that includes all of the following: a flexible 

device that completely encloses the slotted guidepole and eliminates the hydrocarbon vapor emission 

pathway from inside the tank through the guidepole slots to the outside air; a guidepole cover at the top 

of the guidepole; and a well cover positioned at the top of the guidepole well that seals any openings 

between the well cover and the guidepole (e.g. pole wiper), any openings between the well cover and 

any other objects that pass through the well cover, and any other openings in the top of the guidepole 

well. 

(3) Incompatible liquid--A liquid that is a different chemical compound, a different 

chemical mixture, a different grade of liquid material, or a fuel with different regulatory specifications 
provided that the chemical compound, chemical mixture, grade of liquid material, or fuel would be 

unusable for its intended purpose due to contamination from the previously stored liquid. 

(4) Internal sleeve emission control system--An emissions control system that includes 

all of the following: an internal guidepole sleeve that eliminates the hydrocarbon vapor emission pathway 

from inside the tank through the guidepole slots to the outside air; a guidepole cover at the top of the 

guidepole; and a well cover positioned at the top of the guidepole well that seals any openings between 

the well cover and the guidepole (e.g. pole wiper), any openings between the well cover and any other 

objects that pass through the well cover, and any other openings in the top of the guidepole well. 

(5) Pipeline breakout station--A facility along a pipeline containing storage vessels used 

to relieve surges or receive and store crude oil or condensate from the pipeline for reinjection into the 

pipeline and continued transportation by pipeline or to other facilities. 

(6) Pole float--A float located inside a guidepole that floats on the surface of the stored 

liquid. The rim of the float has a wiper or seal that extends to the inner surface of the pole. 

(7) Pole sleeve-A device that extends from either the cover or the rim of an opening in 

a floating roof deck to the outer surface of a pole that passes through the opening. The sleeve extends 

into the stored liquid. 

(8) Pole wiper--A seal that extends from either the cover or the rim of an opening in a 

floating roof deck to the outer surface of a pole that passes through the opening. 
(9) Slotted guidepole--A guidepole or gaugepole that has slots or holes through the wall 

of the pole. The slots or holes allow the stored liquid to flow into the pole at liquid levels above the 

lowest operating level. 

(10) Tank battery--A collection of equipment used to separate, treat, store, and 

transfer crude oil, condensate, natural gas, and produced water. A tank battery typically receives crude 

oil, condensate, natural gas, or some combination of these extracted products from several production 

wells for accumulation and separation prior to transmission to a natural gas plant or petroleum refinery. 

A collection of storage tanks at a pipeline breakout station, petroleum refinery, or petrochemical plant is 

not considered to be a tank battery. 

01 15.112. Control Requirements. 

(a) For all persons in the BeaurnontIPort Arthur, DallasIFort Worth, El Paso, and until January 

1, 2009, in the Houston/Galveston/Brazoria areas as defined in $1 15.10 of this title (relating to 

Definitions), the following requirements apply. 

(1) No person shall place, store, or hold in any stationary tank, reservoir, or other 

container any volatile organic compound (VOC) unless such container is capable of maintaining working 

pressure sufficient at all times to prevent any vapor or gas loss to the atmosphere, or is equipped with at 

least the control device specified in Table I(a) of this paragraph for VOC other than crude oil and 

condensate, or Table II(a) of this paragraph for crude oil and condensate. 
Figure: 30 TAC 5 1 15.112(a)(l) 

I " ~ Table I(a) 

REQUIRED CONTROL FOR STORAGE TANKS FOR 

VOC OTHER THAN CRUDE OIL AND CONDENSATE 

I 

True Vapor Pressure Emission Control 

of Compound at Storage Conditions Capacity Requirements 

None 

> 1,000 gal (3,785 L) Submerged fill pipe 

2 1.5 psia (10.3 Pa) 

and 

< 11 psia (75.8 Pa) 

External floating roof with 

> 25 ,000 gal (94,635 L) 

and 

7 

5 40,000 gal (151,416 L) 

I 11 psia (75.8 Pa) 

Internal or external floating 

roof (any type) 

or 

recovery system 

Internal floating roof 

I I *psia= pounds per square inch absolute, *Pa = kilo Pascals, *gal =gallon, *L = Liter 
(2) For floating roof storage tanks subject to the provisions of paragraph (1) of this 

subsection, the following requirements apply. 

Table II(a) 

REQUIRED CONTROL DEVICES FOR STORAGE TANKS FOR 

CRUDE OIL AND CONDENSATE 

(A) All openings in an internal or external floating roof except for automatic 

True Vapor Pressure 

of Compound at Storage Conditions Capacity 

< 1.5 psia* (10.3 kPa*) 1 Any 

Emission Control 

Requirements 

None 

2 1.5 psia (10.3 kPa) Internal floating roof 

< 1 1 psia (75.8 kPa) External floating roof with 

vapor recovery system 

1 I 1,000 gal (3,785 L) I None 

3 1 1 psia (75.8 kPa) 

1 *psia = Pounds per square inch .A absolute, - - *kPa = kilo Pascals, *gal = Gallon, *L = Liter 
bleeder vents (vacuum breaker vents) and rim space vents must provide a projection below the liquid 

surface or be equipped with a cover, seal, or lid. Any cover, seal, or lid must be in a closed (i.e., no 

visible gap) position at all times except when the device is in actual use. 

(B) Automatic bleeder vents (vacuum breaker vents) must be closed at all times 

except when the roof is being floated off or landed on the roof leg supports. 

(C) Rim vents, if provided, must be set to open only when the roof is being 

floated off the roof leg supports or at the manufacturer's recommended setting. 

(D) Any roof drain that empties into the stored liquid must be equipped with a 

slotted membrane fabric cover that covers at least 90% of the area of the opening. 

(E) There must be no visible holes, tears, or other openings in any seal or seal 

fabric. 

(F) For external floating roof storage tanks, secondary seals must be the rimmounted type (the seal must be continuous from the floating roof to the tank wall). The accumulated area 

of gaps that exceed 118 inch (0.32 centimeter) in width between the secondary seal and tank wall must be 

no greater than 1.0 square inch per foot (21 square centimeters permeter) of tank diameter. 

(3) Vapor recovery systems used as a control device on any stationary tank, reservoir, or 

other container must maintain a minimum control efficiency of 90%. 
(b) For all persons in Gregg, Nueces, and Victoria Counties, the following requirements shall 

apply: 

(1) No person shall place, store, or hold in any stationary tank, reservoir, or other 

container any volatile organic compound (VOC), unless such container is capable of maintaining working 

pressure sufficient at all times to prevent any vapor or gas loss to the atmosphere, or is equipped with at 

least the control device specified in Table I(a) for VOC other than crude oil and condensate or Table 

II(a) for crude oil and condensate. 

(2) For floating roof storage tanks subject to the provisions of paragraph (1) of this 

subsection, the following requirements shall apply. 

(A) All openings in an internal or external floating roof, except for automatic 

bleeder vents (vacuum breaker vents) and rim space vents, must provide a projection below the liquid 

surface or be equipped with a cover, seal, or lid. Any cover, seal, or lid must be in a closed (i.e., no 

visible gap) position at all times, except when the device is in actual use. 

(B) Automatic bleeder vents (vacuum breaker vents) are to be closed at all times 

except when the roof is being floated off or landed on the roof leg supports. 

(C) Rim vents, if provided, are to be set to open only when the roof is being 

floated off the roof leg supports or at the manufacturer's recommended setting. 
(D) Any roof drain that empties into the stored liquid shall be equipped with a 

slotted membrane fabric cover that covers at least 90% of the area of the opening. 

(E) There shall be no visible holes, tears, or other openings in any seal or seal 

fabric. 

(F) For external floating roof storage tanks, secondary seals shall be the rimmounted type (the seal shall be continuous from the floating roof to the tank wall). The accumulated area 

of gaps that exceed 118 inch (0.32 centimeter) in width between the secondary seal and tank wall shall be 

no greater than 1.0 square inch per foot (21 square centimeterstmeter) of tank diameter. 

(c) For all persons in Aransas, Bexar, Calhoun, Matagorda, San Patricia, and Travis Counties, 

the following requirements shall apply. 

(1) No person may place, store, or hold in any stationary tank, reservoir, or other 

container any VOC, other than crude oil or condensate, unless such container is capable of maintaining 

working pressure sufficient at all times to prevent any vapor or gas loss to the atmosphere, or is designed 

and equipped with at least the control device specified in Table I@) for VOC other than crude oil and 

condensate. 
Figure: 30 TAC $1 15.112(c)(l) 

Table I(b) 

REQUIRED CONTROL DEVICES FOR STORAGE TANKS FOR 

VOC OTHER THAN CRUDE OIL AND CONDENSATE 

Emission Control 

2 1.5 psia (10.3 Pa) 

and 

< 1 1 psia (75.8 kPa) 

of Compound at storage Conditions I Capacity 

I > 1,000 gal (3,785 L) 1 None 

I > 1,OOO gal (3,785 L) / Submerged fill pipe 

Requirements 

I and I or 

< 1.5 ~sia (10.3 Pa) Anv None 

77 

I 125,000 gal (94,635 L) 1 vapor recovery system 

vapor recovery system 

> 25,000 gal (94,635 L) 

2 1 1 psia (75.8 Pa) 

> 25,000 gal (94,635 L) 

Internal or external floating 

roof (any type) 

or 

(2) For floating roof storage tanks subject to the provisions of paragraph (1) of 'this 

subsection, the following requirements shall apply. 
(A) There shall be no visible holes, tears, or other openings in any seal or seal 

fabric. 

(B) All tank gauging and sampling devices shall be vapor-tight except when 

gauging and sampling is taking place. 

(3) No person in Matagorda or San Patricio Counties shall place, store, or hold crude oil 

or condensate in any stationary tank, reservoir, or other container, unless such tank, reservoir, or other 

container is a pressure tank capable of maintaining working pressures sufficient at all times to prevent 

vapor or gas loss to the atmosphere or is equipped with one of the following vapor-loss control devices, 

properly maintained and operated: 

(A) an internal floating cover or external floating roof as defined in 51 15.10 of 

this title (relating to Definitions). This control equipment shall not be permitted if the VOC has a true 

vapor pressure of 11.0 psia (75.8 kPa) or greater. All tank-gauging and tank-sampling devices shall be 

vapor-tight, except when gauging or sampling is taking place; or 

(B) a vapor recovery system as defined in 51 15.10 of this title (relating to 

Definitions). 

(d) For all persons in the Houston/Galveston/Brazoria area the following requirements apply 

beginning January 1, 2009. 
(1) No person shall place, store, or hold in any stationary tank, reservoir, or other 

container any VOC unless such container is capable of maintaining working pressure sufficient at all 

times to prevent any vapor or gas loss to the atmosphere, or is equipped with at least the control device 

specified in either Table I(a) of subsection (a)(l) of this section for VOC other than crude oil and 

condensate, or Table U(a) of subsection (a)(l) of this section for crude oil and condensate. 

(2) For floating roof storage tanks subject to the provisions of paragraph (1) of this 

subsection, the following requirements apply. 

(A) All openings in an internal floating cover or external floating roof as defined 

in 51 15.10 of this title (relating to Definitions) except for automatic bleeder vents (vacuum breaker 

vents), and rim space vents must provide a projection below the liquid surface. All openings in an 

internal floating cover or external floating roof except for automatic bleeder vents (vacuum breaker 

vents), rim space vents, leg sleeves, and roof drains must be equipped with a deck cover. The deck 

cover must be equipped with a gasket in good operating condition between the cover and the deck. The 

deck cover must be closed (i.e. no gap of more than 118 inch) at all times, except when the cover must 

be open for access. 

(B) Automatic bleeder vents (vacuum breaker vents) and rim space vents must 

be equipped with a gasketed lid, pallet, flapper, or other closure device and must be closed (i.e. no gap 

of more than 118 inch) at all times except when required to be open to relieve excess pressure or 

vacuum, in accordance with the manufacturer's design. 
(C) Each opening into the internal floating cover for a fixed roof support column 

may be equipped with a flexible fabric sleeve seal instead of a deck cover. 

(D) Any roof drain that empties into the stored liquid must be equipped with a 

slotted membrane fabric cover that covers at least 90% of the area of the opening or an equivalent 

control that must be kept in a closed (i.e., no gap of more than 118 inch) position at all times except 

when the drain is in actual use. Stub drains on internal floating roof tanks are not subject to this 

requirement. 

(E) There must be no visible holes, tears, or other openings in any seal or seal 

fabric. 

(F) For external floating roof storage tanks, secondary seals must be the rimmounted type (the seal must be continuous from the floating roof to the tank wall with the exception of 

gaps that do not exceed the following specification). The accumulated area of gaps that exceed 118 inch 

(0.32 centimeter) in width between the secondary seal and tank wall must be no greater than 1.0 square 

inch per foot (21 square centimeters per meter) of tank diameter. 

(G) Each opening for a slotted guidepole in an external floating roof tank must 

be equipped with one of the control device configurations specified in clauses.(i) - (vi) of this 

subparagraph. 
(i) A pole wiper and a pole float. The wiper or seal of the pole float 

must be at or above the height of the pole wiper. 

(ii) A pole wiper and a pole sleeve. 

(iii) An internal sleeve emission control system. 

(iv) Retrofit to a solid guidepole system. 

(v) A flexible enclosure system. 

(vi) A cover on an external floating roof tank. 

(H) The floating roof must be floating on the liquid surface at all times except 

when the floating roof is supported by the leg supports or other support devices (e.g., hangers from the 

fixed roof) during the initial fill (including refill after the tank has been degassed and cleaned in 

accordance with §§115.54.1 - 115.547 of this title (relating to Degassing or Cleaning of Stationary, 

Marine, and Transport Vessels) or as allowed under the following circumstances: 

(i) when necessary for maintenance or inspection; 

(ii) when necessary for supporting a change in service to an 

incompatible liquid); 
(iii) when the storage tank has a capacity of less than 25,000 gallons or 

the vapor pressure of the material stored is less than 1.5 psia; 

(iv) when the vapors are routed to a control device from the time the 

floating roof is landed until the floating roof is within ten percent by volume of being refloated; 

(v) when all emissions from the tank, including emissions from roof 

landings, have been included in a floating roof storage tank emissions limit or cap approved under 

Chapter 116 of this title (relating to Control of Air Pollution by Permits for New Construction or 

Modification); or 

(vi) when all emissions from floating roof landings at the regulated 

entity as defined in $101.1 of this title (relating to Definitions) are less than 25 tons per year. 

(3) Vapor recovery systems used as a control device on any stationary tank, reservoir, or 

other container must maintain a minimum control efficiency of 90%. 

(4) Storage tanks storing condensate prior to custody transfer must route flashed gases to 

a vapor recovery system or control device if the liquid throughput through an individual tank or the 

aggregate of tanks in a tank battery exceeds 1,500 barrels (63,000 gallons) per year. 

(5) Storage tanks storing crude oil or condensate prior to custody transfer or at a pipeline 
breakout station must route flashed gases to a vapor recovery system or control device if the uncontrolled 

VOC emissions from an individual storage tank, or from the aggregate of tanks in a tank battery, have 

the potential to equal or exceed 25 tons per year on a rolling 12-month basis. Uncontrolled emissions 

must be estimated by one of the following methods; however, if emissions determined using direct 

measurements or other methods approved by the executive director under subparagraphs (A) or (D) of 

this paragraph are higher than emissions estimated using the default factors or charts in subparagraphs 

(B) or (C) of this paragraph, the higher values must be used: 

(A) direct measurement using the measuring instruments and methods specified 

in 5 1 15.1 15 of this title (relating to Approved Test Methods); 

(B) using a factor of 33.3 pounds of VOC per barrel (42 gallons) of condensate 

produced or 1.6 pounds of VOC per barrel (42 gallons) of oil produced; 

(C) for crude oil storage only, using the chart in Exhibit 2 of the United States 

Environmental Protection Agency publication Lessons Learnedfrom Natural Gas STAR Partners: 

Installing Vapor Recovery Units on Crude Oil Storage Tanks, October 2003, and assuming that the 

hydrocarbon vapors have a molecular weight of 34 pounds per pound mole and are 48 % by weight 

VOC; or 

(D) other test method or computer simulation approved by the executive 

director. 
51 15.113. Alternate Control Requirements. 

Alternate methods of demonstrating and documenting continuous compliance with the applicable 

control requirements or exemption criteria in this division (relating to Storage of Volatile Organic 

Compounds) may be approved by the executive director in accordance with $1 15.910 of this title 

(relating to Availability of Alternate Means of Control) if emission reductions are demonstrated to be 

substantially equivalent. 

5115.114. Inspection Requirements. 

(a) For all persons in the BeaumontIPort Arthur, DallasIFort Worth, El Paso, and 

Houston/Galveston/Brazoria areas, the following inspection requirements apply. 

(1) For internal floating roof storage tanks, the internal floating roof and the primary 

seal or the secondary seal (if one is in service) must be visually inspected through a fixed roof inspection 

hatch at least once every 12 months. If the internal floating roof is not resting on the surface of the 

volatile organic compounds (VOC) inside the storage tank and is not resting on the leg supports; or 

liquid has accumulated on the internal floating roof; or the seal is detached; or there are holes or tears in 

the seal fabric; or there are visible gaps between the seal and the wall of the storage tank, within 60 days 

of the inspection the owner or operator shall repair the items or shall empty and degas the storage tank in 

accordance with 55115.541 - 115.547 of this title (relating to Degassing or Cleaning of Stationary, 

Marine, and Transport Vessels). If a failure cannot be repaired within 60 days and if the storage tank 

cannot be emptied within 60 days, the owner or operator may submit written requests for up to two 
extensions of up to 30 additional days each to the appropriate regional office. The owner or operator 

shall submit a copy to any local air pollution control program with jurisdiction. Each request for an 

extension must include a statement that alternate storage capacity is unavailable and a schedule that will 

assure that the repairs will be completed as soon as possible. 

(2) For external floating roof storage tanks, the secondary seal gap must be physically 

measured at least once every 12 months to insure compliance with $1 15.112(a)(2)(F) and 

$1 15.112(d)(2)(F) of this title (relating to Control Requirements). If the secondary seal gap exceeds the 

limitations specified by $1 15.112(a)(2)(F) or $1 15.112(d)(2)(F) of this title, within 60 days of the 

inspection the owner or operator shall repair the items or shall empty and degas the storage tank in 

accordance with $81 15.541 - 115.547 of this title. If a failure cannot be repaired within 60 days and if 

the storage tank cannot be emptied within 60 days, the owner or operator may submit written requests 

for up to two extensions of up to 30 additional days each to the appropriate regional office. The owner or 

operator shall submit a copy to any local air pollution control program with jurisdiction. Each request for 

an extension must include a statement that alternate storage capacity is unavailable and a schedule that 

will assure that the repairs will be completed as soon as possible. 

(3) If the tank is equipped with a mechanical shoe or liquid-mounted primary seal, 

compliance with $ 1 15.1 12(a)(2)(F) and $ 1 15.1 12(d)(2)(F) of this title can be determined by visual 

inspection. 

(4) For external floating roof storage tanks, the secondary seal must be visually 

inspected at least once every six months to ensure compliance with $1 15.112(a)(2)(E) and (F) and 
$1 15.112(d)(2)(E) and (F) of this title. If the external floating roof is not resting on the surface of the 

VOC inside the storage tank and is not resting on the leg supports; or liquid has accumulated on the 

external floating roof; or the seal is detached; or there are holes or tears in the seal fabric; or there are 

visible gaps between the seal and the wall of the storage tank, within 60 days of the inspection the owner 

or operator shall repair the items or shall empty and degas the storage tank in accordance with 

$5 1 15.54 1 - 1 15.547 of this title. If a failure cannot be repaired within 60 days and if the storage tank 

cannot be emptied within 60 days, the owner or operator may submit written requests for up to two 

extensions of up to 30 additional days each to the appropriate regional office. The owner or operator 

shall submit a copy to any local air pollution control program with jurisdiction. Each request for an 

extension must include a statement that alternate storage capacity is unavailable and a schedule that will 

assure that the repairs will be completed as soon as possible. 

(b) For all persons in Gregg, Nueces, and Victoria Counties, the following inspection 

requirements shall apply. 

(1) If during an inspection of an internal floating roof storage tank, the internal floating 

roof is not resting on the surface of the VOC inside the storage tank and is not resting on the leg 

supports; or liquid has accumulated on the internal floating roof; or the seal is detached; or there are 

holes or tears in the seal fabric; or there are visible gaps between the seal and the wall of the storage 

tank, within 60 days of the inspection the owner or operator shall repair the items or shall empty and 

degas the storage tank. If a failure cannot be repaired within 60 days and if the storage tank cannot be 

emptied within 60 days, the owner or operator may submit written requests for up to two extensions of 

up to 30 additional days each to the appropriate regional office. The owner or operator shall submit a 
copy to any local air pollution control program with jurisdiction. Each request for an extension shall 

include a statement that alternate storage capacity is unavailable and a schedule that will assure that the 

repairs will be completed as soon as possible. 

(2) For external floating roof storage tanks, the secondary seal gap shall be physically 

measured at least once every 12 months to insure compliance with $115.112@)(2)(F) of this title. If the 

secondary seal gap exceeds the limitations specified by $1 15.112(b)(2)(F) of this title, within 60 days of 

the inspection the owner or operator shall repair the items or shall empty and degas the storage tank. If a 

failure cannot be repaired within 60 days and if the storage tank cannot be emptied within 60 days, the 

owner or operator may submit written requests for up to two extensions of up to 30 additional days each 

to the appropriate regional office. The owner or operator shall submit a copy to any local air pollution 

control program with jurisdiction. Each request for an extension shall include a statement that alternate 

storage capacity is unavailable and a schedule that will assure that the repairs will be completed as soon 

as possible. 

(3) If the tank is equipped with a mechanical shoe or liquid-mounted primary seal, 

compliance with $115.1 12(b)(2)(F) of this title can be determined by visual inspection. 

(4) For external floating roof storage tanks, the secondary seal shall be visually inspected 

at least once every 12 months to insure compliance with $ 1 15.1 12@)(2)(E) - (F) of this title. If the 

external floating roof is not resting on the surface of the VOC inside the storage tank and is not resting 

on the leg supports; or liquid has accumulated on the external floating roof; or the seal is detached; or 

there are holes or tears in the seal fabric; or there are visible gaps between the seal and the wall of the 
storage tank, within 60 days of the inspection the owner or operator shall repair the items or shall empty 

and degas the storage tank. If a failure cannot be repaired within 60 days and if the storage tank cannot 

be emptied within 60 days, the owner or operator may submit written requests for up to two extensions 

of up to 30 additional days each to the appropriate regional office. The owner or operator shall submit a 

copy to any local air pollution control program with jurisdiction. Each request for an extension shall 

include a statement that alternate storage capacity is unavailable and a schedule that will assure that the 

repairs will be completed as soon as possible. 

(c) For all persons in Aransas, Bexar, Calhoun, Matagorda, San Patricia, and Travis Counties, 

the .following inspection requirements shall apply. 

(1) If during an inspection of an internal floating roof storage tank, the internal floating 

roof is not resting on the surface of the VOC inside the storage tank and is not resting on the leg 

supports; or liquid has accumulated on the internal floating roof; or the seal is detached; or there are 

holes or tears in the seal fabric; or there are visible gaps between the seal and the wall of the storage 

tank, within 60 days of the inspection the owner or operator shall repair the items or shall empty and 

degas the storage tank. If a failure cannot be repaired within 60 days and if the storage tank cannot be 

emptied within 60 days, the owner or operator may submit written requests for up to two extensions of 

up to 30 additional days each to the appropriate regional office. The owner or operator shall submit a 

copy to any local air pollution control program with jurisdiction. Each request for an extension shall 

include a statement that alternate storage capacity is unavailable and a schedule that will assure that the 

repairs will be completed as soon as possible. 
(2) If during an inspection of an external floating roof storage tank, the external floating 

roof is not resting on the surface of the VOC inside the storage tank and is not resting on the leg 

supports; or liquid has accumulated on the external floating roof; or the seal is detached; or there are 

holes or tears in the seal fabric; or there are visible gaps between the seal and the wall of the storage 

tank, within 60 days of the inspection the owner or operator shall repair the items or shall empty and 

degas the storage tank. If a failure cannot be repaired within 60 days and if the storage tank cannot be 

emptied within 60 days, the owner or operator may submit written requests for up to two extensions of 

up to 30 additional days each to the appropriate regional office. The owner or operator shall submit a 

copy to any local air pollution control program with jurisdiction. Each request for an extension shall 

include a statement that alternate storage capacity is unavailable and a schedule that will assure that the 

repairs will be completed as soon as possible. 

$115.115. Approved Test Methods. 

(a) For the Beaumont/Port Arthur, DallasIFort Worth, El Paso, and Houston/Galveston/Brazoria 

areas, compliance with $115.112(a) and (d) of this title (relating to Control Requirements) must be 

determined by applying the following test methods, as appropriate: 

(1) Test Methods 1-4 (40 Code of Federal Regulations (CFR) Part 60, Appendix A) for 

determining flow rates, as necessary; 

(2) Test Method 18 (40 CFR Part 60, Appendix A) for determining gaseous organic 

compound emissions by gas chromatography; 
(3) Test Method 22 (40 CFR Part 60, Appendix A) for visual determination of fugitive 

emissions from material sources and smoke emissions from flares; 

(4) Test Method 25 (40 CFR Part 60, Appendix A) for determining total gaseous 

nonrnethane organic emissions as carbon; 

(5) Test Methods 25A or 25B (40 CFR Part 60, Appendix A) for determining total 

gaseous organic concentrations using flame ionization or nondispersive infrared analysis; 

(6) test method described in 40 CFR $60.113a(a)(l)(ii) (effective April 8, 1987) for 

measurement of storage tank seal gap; 

(7) determination of true vapor pressure using American Society for Testing and 

Materials (ASTM) Test Methods D323-89, D2879, D4953, D5 190, or D5 191 for the measurement of 

Reid vapor pressure; or. 

(8) minor modifications to these test methods approved by the executive director. 

(b) For Gregg, Nueces, and Victoria Counties, compliance with $1 15.112@) of this title shall be 

determined by applying the following test methods, as appropriate: 

(1) Test Methods 14 (40 Code of Federal Regulations 60, Appendix A) for determining 

flow rates, as necessary; 
(2) Test Method 18 (40 Code of Federal Regulations 60, Appendix A) for determining 

gaseous organic compound emissions by gas chromatography; 

(3) Test Method 22 (40 Code of Federal Regulations 60, Appendix A) for visual 

determination of fugitive emissions from material sources and smoke emissions from flares; 

(4) Test Method 25 (40 Code of Federal Regulations 60, Appendix A) for determining 

total gaseous nonrnethane organic emissions as carbon; 

(5) Test Methods 25A or 25B (40 Code of Federal Regulations 60, Appendix A) for 

determining total gaseous organic concentrations using flame ionization or nondispersive infrared 

analysis; 

(6) test method described in 40 CFR 60.113a(a)(l)(ii) (effective April 8, 1987) for 

measurement of storage tank seal gap; 

(7) determination of true vapor pressure using ASTM Test Methods D323-89, D2879, 

D4953, D5190, or D5191 for the measurement of Reid vapor pressure; or 

(8) minor modifications to these test methods approved by the executive director. 
(c) For the Houston~GalvestonlBrazoria area, compliance with $1 15.1 12(d)(5) of this title may 

be determined by using the following measurement instruments or applying the following test methods, 

as appropriate: 

(1) mass flow meter, positive displacement meter, or similar device over a 24-hour 

period representative of normal operation for flow measurements of flash gases. For crude oil and 

natural gas production sites, the flow measurements must be made while the producing wells are 

operational; and 

(2) test methods referenced in subsection (a)(2), (4), and (5) of this section or Gas 

Processors Association Method 2286, Tentative Method of Extended Analysis for Natural Gas and 

Similar Mixtures by Temperature Programmed Gas Chromatography, to measure the concentration of 

VOC in the flashed gases; or 

(3) minor modifications to these test methods approved by the executive director. 

$115.116. Monitoring and Recordkeeping Requirements. 

(a) For all persons in the BeaumontIPort Arthur, DallasIFort Worth, El Paso, and 

Houston/Galveston/Brazoria areas, the following recordkeeping requirements apply. 

(1) The owner or operator of any storage vessel with an external floating roof that is 

exempted from the requirement for a secondary seal as specified in $1 15.117(a)(l), (6), and (7) of this 
title (relating to Exemptions) and is used to store volatile organic compounds (VOC) with a true vapor 

pressure greater than 1.0 pounds per square inch absolute (psia) (6.9 kilo Pascals (kPa)) at storage 

conditions shall maintain records of the type of VOC stored and the average monthly true vapor pressure 

of the stored liquid. 

(2) The results of inspections required by 81 15.1 14(a) of this title (relating to Inspection 

Requirements) must be recorded. For secondary seal gaps that are required to be physically measured 

during inspection, these records must include a calculation of emissions for all secondary seal gaps that 

exceed 118 inch (0.32 centimeter) where the accumulated area of such gaps is greater than 1.0 square 

inch per foot (21 square centimeters per meter) of tank diameter. These calculated emissions inventory 

reportable emissions (Tr) must be reported in the annual emissions inventory submittal required by 

§101.10 of this title (relating to Emissions Inventory Requirements). The emissions must be calculated 

using the following methodology: 

(A) Allowable Seal Gap (greater than 118 inch wide): As (square inches) = 1 

square inch per tank diameter foot x tank diameter. 

(B) Measured Seal Gap: Ms (square inches). 

(C) Reportable Seal Gap Area: Rs = Ms - As in square inches. 

(D) Reportable Seal GapIAllowable Ratio: RRs = Rs divided by As. 
(E) Tank Circumference: Tc (feet). 

(F) Reportable Seal Gap Length (total linear feet of seal gap greater than 118 

inch gap width): Rl. 

(G) Reportable Seal Gap Length1Tan.k Circumference Ratio: RRI = RllTc. 

(H) Tank Emissions (with good single seal): Ts = Compilation of Air Pollutant 

Emission Factors (AP-42) Calculation (convert to poundslday). 

(I) Tank Emissions (with two good seals): Tss = AP-42 Calculation (convert to 

poundslday). Note: Use maximum local monthly average ambient temperature as reported by the 

National Weather Service to calculate true vapor pressure. 

(J) Emissions Inventory Reportable emissions: Tr (pounds) = (Ts - Tss) x RRs 

x RRI x 90 days. Note: In no case should Tr be greater than (Ts - Tss). 

(3) Affected persons shall install and maintain monitors to continuously measure and 

record operational parameters of any of the following emission control devices installed to meet 

applicable control requirements. Such records must be sufficient to demonstrate proper functioning of 

those devices to design specifications, including: 
(A) the exhaust gas temperature immediately downstream of a direct-flame 

incinerator; 

(B) the inlet and outlet gas temperature of a chiller or catalytic incinerator; and 

(C) the exhaust gas VOC concentration of any carbon adsorption system, as 

defined in $1 15.10 of this title (relating to Definitions), to determine if breakthrough has occurred. 

(4) The results of any testing conducted in accordance with the provisions specified in 

$ 1 15.1 15(a) of this title (relating to Approved Test Methods) must be maintained at an affected facility. 

(5) All records must be maintained for two years and be made available for review upon 

request by authorized representatives of the executive director, the United States Environmental 

Protection Agency (EPA), or local air pollution control agencies with jurisdiction. 

(b) For all persons in Gregg, Nueces, and Victoria Counties, the following recordkeeping 

requirements shall apply. 

(1) The owner or operator of any storage vessel with an external floating roof which is 

exempted from the requirement for a secondary seal as specified in $1 15.117(b)(l), (6), and (7) of this 

title and used to store VOC with a true vapor pressure greater than 1.0 psia (6.9 kPa) at storage 

conditions shall maintain records of the type of VOC stored and the average monthly true vapor pressure 

of the stored liquid. 
(2) The results of inspections required by $1 15.114(b) of this title shall be recorded. 

(3) In Victoria County, affected persons shall install and maintain monitors to 

continuously measure and record operational parameters of any of the following emission control devices 

installed to meet applicable control requirements. Such records must be sufficient to demonstrate proper 

functioning of those devices to design specifications, including: 

(A) the exhaust gas temperature immediately downstream of a direct-flame 

incinerator; 

(B) the inlet and outlet gas temperature of a chiller or catalytic incinerator; and 

(C) the exhaust gas VOC concentration of any carbon adsorption system, as 

defined in $ 115.10 of this title, to determine if breakthrough has occurred. 

(4) The results of any testing conducted in accordance with the provisions specified in 

$1 15.115(b) of this title shall be maintained at an affected facility. 

(5) All records shall be maintained for two years and be made available for review upon 

request by authorized representatives of the executive director, EPA, or local air pollution control 

agencies. 
(c) For all persons in the Houston/Galveston/Brazoria area, the following recordkeeping 

requirements apply in addition to those specified in subsection (a) of this section. 

(1) The owner or operator of any stationay tank, reservoir, or container with a fixed 

roof that is not required to be equipped with a floating roof or vapor recovery system, as specified in 

either Table I(a) or Table II(a) of 51 15.112(a)(l) of this title (relating to Control Requirements), shall 

maintain records of the type of VOC stored, the starting and ending dates when the material is stored, 

and the true vapor pressure at the average monthly storage temperature of the stored liquid. This 

requirement does not apply to storage tanks with nominal storage capacity of 25,000 gallons or less 

storing volatile organic liquids other than crude oil or condensate, or to storage tanks with nominal 

storage capacity of 40,000 gallons or less storing crude oil or condensate. 

(2) The owner or operator of any storage tank that stores crude oil or condensate prior to 

custody transfer or at a pipeline breakout station and is not equipped with vapor recovery shall maintain 

records of the estimated annual emissions from the storage tank to document that the uncontrolled 

emissions are less than 25 tons per year. The records must be updated annually and must be made 

available for review within 72 hours upon request by authorized representatives of the executive director, 

the EPA, or local air pollution control agencies with jurisdiction. 

6115.117. Exemptions. 

(a) For all persons in the BeaumontIPort Arthur, DallasIFort Worth, El Paso, and 

Houston/Galveston/Brazoria areas, the following exemptions apply. 
(1) Except as provided in $1 15.116 of this title (relating to Monitoring and 

Recordkeeping Requirements), any volatile organic compound (VOC) with a true vapor pressure less 

than 1.5 pounds per square inch absolute (psia) (10.3 kilo Pascals @Pa)) at storage conditions is exempt 

from the requirements of this division (relating to Storage of Volatile Organic Compounds). 

(2) Crude oil and condensate stored in tanks with a nominal capacity less than 210,000 

gallons (794,850 liters), prior to custody transfer, is exempt from the requirements of this division. After 

January 1, 2009, this exemption no longer applies in the HoustonlGalveston/Brazoria area. 

(3) Storage containers that have a capacity of less than 25,000 gallons (94,625 liters) 

located at motor vehicle fuel dispensing facilities are exempt from the requirements of this division. 

(4) A welded tank with a mechanical shoe primary seal that has a secondary seal from 

the top of the shoe seal to the tank wall (a shoe-mounted secondary seal) is exempt from the requirement 

for retrofitting with a rim-mounted secondary seal if the shoe-mounted secondary seal was installed or 

scheduled for installation before August 22, 1980. 

(5) External floating roof tanks storing waxy, high pour point crude oils are exempt 

from any secondary seal requirements of $1 15.112(a) of this title (relating to Control Requirements). 

(6) Any welded tank storing VOC having a true vapor pressure less than 4.0 psia (27.6 

kPa) is exempt from any external floating roof secondary seal requirement if any of the following types 

of primary seals have been installed before August 22, 1980: 
(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(7) Any welded tank storing crude oil having a true vapor pressure equal to or greater 

than 4.0 psia (27.6 kPa) and less than 6.0 psia (41.4 kPa) at storage conditions is exempt from any 

external floating roof secondary seal requirement if any of the following types of primary seals have 

been installed before December 10, 1982: 

(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(8) Storage containers that have a capacity of no more than 1,000 gallons are exempt 

from the requirements of this division. 

(9) Condensate storage tanks or tank batteries with a throughput exceeding 1,500 barrels 

(63,000 gallons) per year are exempt from the requirement in $1 15.112(d)(4) of this title to route flashed 

gases to a vapor recovery system or control device if the owner or operator demonstrates using test 
methods specified in $1 15.115(c) of this title, that uncontrolled VOC emissions from the individual tank, 

or from the aggregate of storage tanks in a tank battery, are less than 25 tons per year on a rolling 12- 

month basis. 

(b) For all persons in Gregg, Nueces, and Victoria Counties, the following exemptions apply. 

(1) Except as provided in $1 15.116 of this title, any VOC with a true vapor pressure less 

than 1.5 psia (10.3 kPa) at storage conditions is exempt from the requirements of this division. 

(2) Crude oil and condensate stored in tanks with a nominal capacity less than 210,000 

gallons (794,850 liters), prior to custody transfer, is exempt from the requirements of this division. 

(3) Storage containers which have a capacity of less than 25,000 gallons (94,625 liters) 

located at motor vehicle fuel dispensing facilities are exempt from the requirements of this division. 

(4) A welded tank with a mechanical shoe primary seal which has a secondary seal from 

the top of the shoe seal to the tank wall (a shoe-mounted secondary seal) is exempt from the requirement 

for retrofitting with a rim-mounted secondary seal if the shoe-mounted secondary seal was installed or 

scheduled for installation before August 22, 1980. 

(5) External floating roof tanks storing waxy, high pour point crude oils are exempt 

from any secondary seal requirements of 81 15.1 12(b) of this title. 
(6) Any welded tank storing VOC having a true vapor pressure less than 4.0 psia (27.6 

kPa) is exempt from any external secondary seal requirement if any of the following types of primary 

seals have been installed before August 22, 1980: 

(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(7) Any welded tank storing crude oil having a true vapor pressure equal to or greater 

than 4.0 psia (27.6 kPa) and less than 6.0 psia (41.4 kPa) at storage conditions is exempt from any 

external secondary seal requirement if any of the following types of primary seals have been installed 

before December 10, 1982: 

(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(8) Storage containers which have a capacity of no more than 1,000 gallons are exempt 

from the requirements of this division. 
(c) For all persons in Aransas, Bexar, Calhoun, Matagorda, San Patricio, and Travis Counties, 

the following exemptions apply. 

(1) Any VOC with a true vapor pressure less than 1.5 psia (10.3 kPa) at storage 

conditions is exempt from the requirements of this division. 

(2) Slotted sampling and gauge pipes installed in any floating roof storage tank are 

exempt from the provisions of $1 15.112(c) of this title. 

(3) Storage tanks with nominal capacities between 1,000 gallons (3,785 liters) and 

25,000 gallons (94,625 liters) are exempt from the requirements of $1 15.112(c)(l) of this title if 

construction began before May 12, 1973. 

(4) Storage tanks with a nominal capacity of 420,000 gallons (1,589,700 liters) or less 

are exempt from the requirements of $1 15.112(~)(3) of this title. 

(5) Storage containers which have a capacity of no more than 1,000 gallons are exempt 

from the requirements of this division. 

§115.119. Counties and CompLiance Schedules. 

(a) The owner or operator of each stationary tank, reservoir, or other container in which any 

volatile organic compound (VOC) is placed, stored, or held in Brazoria, Chambers, Collin, Dallas, 

Denton, El Paso, Fort Bend, Galveston, Hardin, Harris, Jefferson, Liberty, Montgomery, Orange, 
Tarrant, and Waller Counties shall continue to comply with this division (relating to Storage of Volatile 

Organic Compounds) as required by $115.930 of this title (relating to Compliance Dates). 

(b) The owner or operator of each stationary tank, reservoir, or other container in which any 

VOC is placed, stored, or held in Ellis, Johnson, Kaufman, Parker, and Rockwall Counties shall comply 

with this division as soon as practicable, but no later than March 1, 2009. 

(c) The owner or operator of each stationary tank, reservoir, or other container in which any 

VOC is placed, stored, or held in Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, 

Montgomery, and Waller Counties shall comply with the requirements of $5 1 15.1 12(d), 1 15.1 15(c), and 

115.116(c) of this title (relating to Control Requirements; Approved Test Methods; and Monitoring and 

Recordkeeping Requirements) as soon as practicable, but no later than January 1, 2009. If compliance 

with these requirements would require emptying and degassing of the stationary tank, reservoir, or 

container, compliance is not required until the next time the stationary tank, reservoir, or container is 

emptied or degassed but no later than January 1,2017. The owner or operator of each stationary tank, 

reservoir, or container with a nominal capacity less than 210,000 gallons (794,850 liters) storing crude 

oil and condensate prior to custody transfer in Brazoria, Chambers, Fort Bend, Galveston, Harris, 

Liberty, Montgomery, and Waller Counties shall comply with the requirements of this division as soon 

as practicable but no later than January 1, 2009, regardless if compliance with these requirements would 

require emptying and degassing of the stationary tank, reservoir, or container. 
SUBCHAPTER F: MISCELLANEOUS INDUSTRIAL SOURCES 

DIVISION 3: DEGASSING OR CLEANING OF STATIONARY, MARINE, AND TRANSPORT 

VEssns 

§§115.541 - 115.547,115.549 

STATUTORY AUTHORITY 

The amendments are adopted under Texas Water Code, $5.102, concerning General Powers, $5.103, 

concerning Rules, and 55.105, concerning General Policy, that authorize the commission to adopt rules 

necessary to carry out its powers and duties under the Texas Water Code; and under Texas Health and 

Safety Code, $382.017, concerning Rules, that authorizes the commission to adopt rules consistent with 

the policy and purposes of the Texas Health and Safety Code, Chapter 382 (also known as the Texas 

Clean Air Act). The amendments are also adopted under Texas Health and Safety Code, $382.002, 

concerning Policy and Purpose, that establishes the commission's purpose to safeguard the state air 

resources, consistent with the protection of public health, general welfare, and physical property; 

$382.01 1, concerning General Powers and Duties, that authorizes the commission to control the quality 

of the state's air; $382.012, concerning State Air Control Plan, that authorizes the commission to 

prepare and develop a general, comprehensive plan for the control of the state's air; 5382.014, 

concerning Emission Inventory, which authorizes the commission to require the submission of 

information concerning the emission of air contaminants; and $382.016, concerning Monitoring 

Requirements; Examination of Records, which authorizes the commission to require owners and 

operators of emission sources to maintain measuring and monitoring records and make such records 

available to the commission. The rules are adopted under federal mandates contained in 42 USC, $7410, 

that require states to introduce pollution control measures in order to reach specific air quality standards 
in particular areas of the state. 

The adopted amendments implement Texas Health and Safety Code, 55382.002, 382.01 1, 382.012, 

382.014, and 382.016. 

5115.541. Emission Specifications. 

(a) For all persons in the Beaurnont/Port Arthur, DallasIFort Worth, El Paso, and 

Houston/Galveston/Brazoria areas as defined in 51 15.10 of this title (relating to Definitions), the 

following emission specifications apply to degassing during or in preparation of cleaning. 

(1) F& all stationary volatile organic compound (VOC) storage tanks with a nominal 

storage capacity of one million gallons or more and after January 1, 2009, storage tanks in the 

Houston/Galveston/Brazoria area with a nominal storage capacity of 250,000 gallons or greater or with a 

nominal storage capacity of 75,000 gallons or greater storing materials with a true vapor pressure greater 

than 2.6 pounds per square inch absolute (psia). 

(A) No person shall pennit VOC emissions with a vapor space partial pressure 

greater than or equal to 0.5 psia (3.4 kilo Pascals (kPa)) under actual storage conditions unless the 

vapors are processed by a vapor control system. 

(B) The vapor control system must maintain a control efficiency of at least 90%. 
(C) When conducting degassing or cleaning operations, no avoidable liquid or 

gaseous leaks, as detected by sight or sound, may originate from the degassing or cleaning operations. 

(D) The intentional bypassing of a vapor control device used during degassing or 

cleaning is prohibited. Any visible VOC leak originating from the vapor control device or other 

associated product recovery device must be repaired as soon as practical. 

(2) For all transport vessels, as defined in $1 15.10 of this title, with a nominal storage 

capacity of 8,000 gallons or more. 

(A) No person shall pennit VOC emissions with a vapor space partial pressure 

greater than or equal to 0.5 psia (3.4 @a) under actual storage conditions unless the vapors are 

processed by a vapor control system. 

(B) The vapor control system must maintain a control efficiency of at least 90%. 

(C) When conducting degassing or cleaning operations, no avoidable liquid or 

gaseous leaks, as detected by sight or sound, may originate from the degassing or cleaning operations. 

(D) The intentional bypassing of a vapor control device used during degassing or 

cleaning is prohibited. Any visible VOC leak originating from the vapor control device or other 

associated product recovery device must be repaired as soon as practical. 
(E) All transport vessels, as defined in $1 15.10 of this title, must be kept vaportight at all times until the VOC vapors remaining in the vessel are discharged to a vapor control system. 

(b) For all persons in the Beaumont/Port Arthur and Houston/Galveston/Brazoria areas, the 

following emission specifications apply to degassing during or in preparation of cleaning for all marine 

vessels, as defined in $101.1 of this title (relating to Definitions), that have a nominal storage capacity of 

10,000 barrels (420,000 gallons) or more and contain VOC. 

(1) No person shall degas or clean a tank that carried a VOC with a vapor partial 

pressure greater than or equal to 0.5 psia (3.4 kPa) unless the vapors are processed by a vapor control 

system. 

(2) The vapor control system must maintain a control efficiency of at least 90%. 

(3) When conducting degassing or cleaning operations, no avoidable liquid or gaseous 

leaks, as detected by sight or sound, may originate from the degassing or cleaning operations. 

(4) The intentional bypassing of a vapor control device used during degassing or 

cleaning is prohibited. Any visible VOC leak originating from the vapor control device or other 

associated product recovery device must be repaired as soon as possible. 

(5) All marine vessels, as defined in $101.1 of this title, containing VOC must have all 

cargo tank closures properly secured, or maintain a negative pressure within the tank when a closure is 
opened, and must have all pressurefvacuum relief valves operating within certified limits as specified by 

classification society or flag state until the vapors are discharged to a vapor control system if the vessel is 

degassed or cleaned. 

5115.542. Control Requirements. 

(a) For all persons in the Beaumont/Port Arthur, DallasIFort Worth, El Paso, and 

Houston/Galveston/Brazoria areas as defined in $1 15.10 of this title (relating to Definitions), the 

following control requirements apply to stationary storage tanks and transport vessels. 

(1) No person shall permit the degassing or cleaning of volatile organic compounds 

(VOC) from a stationary storage tank or transport vessel unless the vapors are processed by a vapor 

control system. 

(2) When degassing or cleaning is effected through the hatches of a transport vessel with 

a loading arm equipped with a vapor collection adapter, then pneumatic, hydraulic, or other mechanical 

means must be provided to force a vapor-tight seal between the adapter and the hatch. A means must be 

provided to minimize liquid drainage from the degassing or cleaning device when it is removed from the 

hatch of any transport vessel or to accomplish drainage before such removal. 

(3) When degassing or cleaning is effected through the hatches or manways of stationary 

VOC storage tanks, all lines must be equipped with fittings that make vapor-tight connections and that 
are closed when disconnected; or equipped to permit residual VOC in the line to discharge into a 

recovery or disposal system after degassing or cleaning is complete. 

(4) Degassing and cleaning equipment must be designed and operated to prevent 

avoidable VOC leaks. 

(5) In the Beaumont/Port Arthur, DallasIFort Worth, El Paso, and until January 1, 

2009, in the Houston/Galveston/l3razoria areas, vapors must be routed to the control device until a 

turnover of at least four vapor space volumes has occurred, or four turnovers of the vapor space under a 

floating roof, or the partial vapor pressure is less than 0.5 pounds per square inch absolute (psia) (19,000 

parts per million by weight (ppmw), or 34,000 parts per million by volume (ppmv) expressed as 

methane). After one of these conditions has been satisfied, the storage tank or transport vessel may be 

vented to the atmosphere for the remainder of the degassing or cleaning process. 

(6) After January 1, 2009, in the Houston/Galveston/Brazoria area, vapors must be 

routed to the control device until the VOC measured concentration before the inlet to the control device 

is less than 34,000 ppmv as methane or less than 50% of the lower explosive limit (LEL). After this 

condition has been satisfied, the storage tank or transport vessel may be vented to the atmosphere for the 

remainder of the degassing or cleaning process provided that the VOC concentration remains below 

34,000 ppmv as methane or less than 50% of the LEL. The VOC concentration must be measured once 

every 12 hours if the storage tank or transport vessel is vented continuously to the atmosphere, and upon 

restart of the degassing and cleaning operation if venting to the atmosphere has been suspended for more 

than four hours. If any measurements of the VOC concentration equal or exceed 34,000 ppmv as 
methane or are equal to or greater than 50% of the LEL, the storage tank or transport vessel must be 

routed to the control device until the concentration is below 34,000 ppmv as methane or less than 50% of 

the LEL. While venting to the atmosphere, measurements must continue until five consecutive readings 

of VOC concentrations collected at 12 hour intervals are measured to be less than 34,000 ppmv or less 

than 50% of the LEL. 

(b) For all persons in the BeaumontIPort Arthur and Houston/Galveston/Brazoria areas, the 

following control requirements apply to marine vessels. 

(1) No person shall permit the degassing or cleaning of a marine vessel containing VOC 

unless the vapors are processed by a vapor control system. 

(2) When degassing or cleaning is effected through the hatches of a marine vessel 

containing VOC with a loading arm equipped with a vapor collection adapter, then pneumatic, hydraulic, 

or other mechanical means must be provided to force a vapor-tight seal between the adapter and the 

hatch, or a negative pressure inside the cargo tank must be maintained. A means must be provided to 

minimize liquid drainage from the degassing or cleaning device and line when they are removed from the 

hatch of any marine vessel containing VOC or to accomplish drainage before such removal. 

(3) Degassing and cleaning equipment must be designed and operated to prevent 

avoidable VOC leaks. 

(4) In the Beaumont/Port Arthur area and until January 1, 2009, in the 
Houston/Galveston/Brazoria area, vapors must be routed to the control device until the marine vessel is 

stripped VOC liquid-free and a turnover of at least four vapor space volumes has occurred, the partial 

vapor pressure is less than 0.5 psia (19,000 ppmw, or 34,000 ppmv expressed as methane), or the 

concentration of VOC is less than 20% of the LEL. After one of these conditions has been satisfied, the 

marine vessel may be vented to the atmosphere for the remainder of the degassing or cleaning process. 

(5) After January 1, 2009, in the Houston/Galveston/Brazoria area, vapors must be 

routed to the control device until the VOC measured concentration before the inlet to the control device 

is less than 34,000 ppmv as methane or less than 50% of the LEL. After this condition has been 

satisfied, the marine vessel may be vented to the atmosphere for the remainder of the degassing or 

cleaning process provided that the VOC concentration remains below 34,000 ppmv as methane or less 

than 50% of the LEL. The VOC concentration must be measured once every 12 hours if the marine 

vessel is vented continuously to the atmosphere, and upon restart of the degassing and cleaning operation 

if venting to the atmosphere has been suspended for more than four hours. If any measurements of the 

VOC concentration equal or exceed 34,000 ppmv as methane or are equal to or greater than 50% of the 

LEL, the marine vessel must be routed to the control device until the concentration is below 34,000 

ppmv as methane or less than 50% of the LEL. While venting to the atmosphere, measurements must 

continue until five consecutive readings of VOC concentrations collected at 12-hour intervals are 

measured to be less than 34,000 ppmv or less than 50% of the LEL. 
0115.543. Alternate Control Requirements. 

For all persons in the BeaumontIPort Arthur, DallasIFort Worth, El Paso, and 

Houston/Galves todBrazoria areas as defined in $ 1 15.10 of this title (relating to Definitions), alternate 

methods of demonstrating and documenting continuous compliance with the applicable control 

requirements or exemption criteria in this division (relating to Degassing or Cleaning of Stationary, 

Marine, and Transport Vessels) may be approved by the executive director in accordance with $ 1 15.910 

of this title (relating to Availability of Alternate Means of Control) if emission reductions are 

demonstrated to be substantially equivalent. 

0 115.544. Inspection Requirements. 

For all persons in the BeaumonttPort Arthur, Dallas/Fort Worth, El Paso, and 

Houston/Galveston/Brazoria areas as defined in $1 15.10 of this title (relating to Definitions), the 

following inspection requirements apply. 

(1) Inspection for visible liquid leaks, visible fumes, or significant odors resulting from 

volatile organic compound (VOC) transfer operations must be conducted during each degassing or 

cleaning operation by the owner or operator of the VOC degassing and cleaning facility. 

(2) VOC degassing or cleaning through the affected transfer lines must be discontinued 

when a leak is observed and the leak cannot be repaired within a reasonable length of time. The 

intentional bypassing of a vapor control device during cleaning or degassing is prohibited. 
5115.545. Approved Test Methods. 

For the BeaumontIPort Arthur, DallasIFort Worth, El Paso, and HoustonlGalvestonIBrazoria 

areas as defined in 5 115.10 of this title (relating to Definitions), compliance with 5 1 15.541 and 5 1 15.542 

of this title (relating to Emission Specifications and Control Requirements) must be determined by 

applying the following test methods, as appropriate: 

(1) Test Methods 1-4 (40 Code of Federal Regulations (CFR) Part 60, Appendix A) for 

determining flow rates; 

(2) Test Method 18 (40 CFR Part 60, Appendix A) for determining gaseous organic 

compound emissions by gas chromatography; 

(3) Test Method 25 (40 CFR Part 60, Appendix A) for determining total gaseous 

nonrnethane organic edssions as carbon; 

(4) Test Methods 25A or 25B (40 CFR Part 60, Appendix A) for determining total 

gaseous organic concentrations using flame ionization or nondispersive infrared analysis; 

(5) additional test procedures described in 40 CFR 560.503(b), (c), and (d) (effective 

February 14, 1989) for determining compliance for bulk gasoline terminals; 
(6) Test Method 21 (40 CFR Part 60, Appendix A) for determining volatile organic 

compound (VOC) leaks; 

(7) determination of true vapor pressure using American Society for Testing and 

Materials (ASTM) Test Method D323-89, D2879, D4953, D5190, or D5191 for the measurement of 

Reid vapor pressure, adjusted for actual storage temperature in accordance with API Publication 25 17, 

Third Edition, 1989; 

(8) Test Method 27 (40 CFR Part 60, Appendix A) for determining tank-truck leaks; 

(9) 40 CFR §63.565(c) (effective September 19, 1995) or 40 CFR §61.304(f) (effective 

October 17, 2000) for determination of marine vessel vapor tightness; 

(10) minor modifications to these test methods approved by the executive director; or 

(11) VOC concentration measurements required by $1 15.542(a)(6) and (b)(5) of this title 

(relating to Control Requirements) must be performed using one of the methods or measurement 

instruments listed in subparagraphs (A) - (F) of this paragraph. 

(A) Test Method 21 (40 CFR Part 60, Appendix A). The instrument response 

factor criteria in $8.1 of the United States Environmental Protection Agency Method 21 may be 

determined using the average composition of the liquid in the tank rather than for each individual liquid. 
(B) Test Method 18 (40 CFR Part 60, Appendix A) except that only one bag 

sample needs to be collected for each concentration measurement. 

(C) Bag samples, provided the means of collecting the sample and the type of 

bag used are appropriate and representative of the type of space being sampled and the analytical method 

used to evaluate bag contents are appropriate for the concentration levels and compound types. 

(D) Test Method 25A (40 CFR Part 60, Appendix A). 

(E) Portable hydrocarbon gas analyzer using an appropriate detector that is 

effective in the concentration range being measured and calibrated with compounds of interest in each 

case. Analyzers must be calibrated and maintained according to manufacturer's specifications. 

(F) Lower explosive limit detector. The detector must be calibrated and 

maintained according to manufacturer's specifications. 

$1 15.546. Monitoring and Recordkeeping Requirements. 

For facilities in the BeaumontlPort Arthur, DallasJFort Worth, El Paso, and 

Houston/Galveston/Brazoria areas as defined in $1 15.10 of this title (relating to Definitions) affected by 

$1 15.541 and $1 15.542 of this title (relating to Emission Specifications and Control Requirements), the 

owner or operator of any volatile organic compound (VOC) degassing or cleaning facility shall maintain 

the following information at the facility for at least two years and shall make such information available 
upon request to representatives of the executive director, the United States Environmental Protection 

Agency, or any local air pollution control agency having jurisdiction in the area: 

(1) for storage tank, transport vessel, or marine vessel degassing or cleaning operations: 

(A) a record of the type and number of all transport vessels, stationary VOC 

storage tanks, and marine vessels that are degassed or cleaned at the affected facility; 

(B) the chemical name and estimated liquid quantity of VOC contained in each 

vessel prior to degassing or cleaning; 

(C) the chemical name and estimated liquid quantity of VOC removed from each 

storage tank, transport vessel, or marine vessel; and 

. (D) after January 1, 2009, in the Houston/Galveston/Brazoria area, a record of 

the measurements of VOC concentration or percent of lower explosive limit from the storage tank, 

transport vessel, or marine vessel being degassed while the tank or vessel is vented to the atmosphere; 

(2) for vapor control systems: 

(A) continuous monitoring and recording of the exhaust gas temperature 

immediately downstream of a direct-flame incinerator; 
(B) continuous monitoring and recording of the inlet and outlet gas temperature 

of a catalytic incinerator; and 

(C) continuous monitoring and recording of the exhaust gas VOC concentration 

for carbon adsorption systems that contain facilities to regenerate the carbon bed directly, as defined in 

$1 15.10 of this title (relating to Definitions); or periodic monitoring of the exhaust gas VOC as specified 

by 40 Code of Federal Regulations $61.354(d) (effective October 17, 2000), of any carbon adsorption 

system that does not regenerate the carbon bed directly, to determine breakthrough; 

(3) the results of any leak inspection and repair conducted in accordance with the 

provisions specified in $1 15.544 of this title (relating to Inspection Requirements); and 

(4) the results of any testing conducted in accordance with the provisions specified in 

$ 115.545 of this title (relating to Approved Test Methods). 

5115.547. Exemptions. 

For all persons in the Beaumont/Port Arthur, DallasIFort Worth, El Paso, and 

Houston/Galveston/Brazoria areas as defined in $1 15.10 of this title (relating to Definitions), the 

following exemptions apply. 

(1) Degassing or cleaning any storage tank, transport vessel, or marine vessel with a 

vapor space partial pressure less than 0.5 pounds per square inch absolute (psia) (3.4 kilo Pascals) of 
volatile organic compound (VOC) under actual storage conditions is exempt from the requirements of 

this division (relating to Degassing or Cleaning of Stationary, Marine, and Transport Vessels). 

(2) Degassing or cleaning any transport vessel with a nominal storage capacity of less 

than 8,000 gallons, or any stationary VOC storage tank with a nominal storage capacity of less than 1 

million gallons, or any marine vessel with a nominal storage capacity of less than 10,000 barrels 

(420,000 gallons), is exempt from the requirements of this division. After January 1, 2009, stationary 

VOC storage tanks in the Houston/Galveston/Brazoria area with a nominal storage capacity and vapor 

pressure of stored liquid as listed in subparagraphs (A) and (B) of this paragraph are no longer exempt 

from the requirements of this division. 

(A) Storage tanks with nominal storage capacity greater than or equal to 250,000 

gallons but less than 1 million gallons. 

(B) Storage tanks with nominal storage capacity greater than or equal to 75,000 

gallons but less than 250,000 gallons storing materials with true vapor pressure greater than 2.6 psia. 

(3) Any stationary VOC storage tank during preventative maintenance, roof repair, 

primary seal inspection, or removal and installation of a secondary seal, if product is not moved in or out 

of the storage tank, emissions are minimized, and the repair is completed within seven calendar days, is 

exempt from the requirements of this division. 
(4) Any marine vessel that has sustained damage that prevents a cargo tank's opening 

from being properly secured, causes the onboard vapor recovery system to be inoperative, or prevents 

the pressure/vacuum relief valves from operating within certified limits as specified by classification 

society or flag state is exempt from 81 15.541(b) and §115.542(b) of this title (relating to Emission 

Specifications and Control Requirements); however, all reasonable measures must be taken to minimize 

VOC emissions. 

(5) Any oceangoing, self-propelled marine vessel is exempt from the degassing or 

cleaning requirements of this division. 

5115.549. Counties and Compliance Schedules. 

(a) All affected persons in the Brazoria, Chambers, Fort Bend, Galveston, Hardin, Harris, 

Jefferson, Liberty, Montgomery, Orange, and Waller Counties shall continue to comply with this 

division (relating to Degassing or Cleaning of Stationary, Marine, and Transport Vessels) as required by 

8 1 15.930 of this title (relating to Compliance Dates). 

(b) All affected persons in Collin, Dallas, Denton, and Tarrant Counties shall be in compliance 

with this division as soon as practicable, but no later than one year, after the commission publishes 

notification in the Texas Register of its determination that this contingency rule is necessary as a result of 

failure to attain the national ambient air quality standard (NAAQS) for ozone by the attainment deadline 

or failure to demonstrate reasonable further progress as set forth in the 1990 Amendments to the Federal 

Clean Air Act (FCAA), 8 172(c)(9). 
(c) All affected persons in El Paso County shall be in compliance with this division as soon as 

practicable, but no later than one year, after the commission publishes notification in the Texas Register 

of its determination that this contingency rule is necessary as a result of failure to attain the NAAQS for 

ozone by the attainment deadline or failure to demonstrate reasonable further progress as set forth in the 

1990 Amendments to the FCAA, $172(c)(9). 

(d) All affected persons in Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, 

Montgomery, and Waller Counties shall comply with the requirements in $1 15.542(a)(6) and @)(5), and 

$1 15.546(1)(D) of this title (relating to Control Requirements and Monitoring and Recordkeeping 

Requirements) as soon as practicable but no later January 1, 2009. 
~&UW Castanuela, Chief Clerk 

Comm' ' on Environmental ~uality ORDER ADOPTING NEW AND AMENDED RULES ~m 

REVISIONS TO THE STATE IMPLEMENTATION PLAN 

Docket No. 2006-1804-RUL 

On May 23, 2007, the Texas Commission on Environmental Quality (Commission), during a public 

meeting, considered adoption of new $ 115.110 and amendments to $8 115.112 - 115.117, 115.1 19, 115.541 

- 115.547, and 115.549 of 30 TAC Chapter 115, Control of Air Pollution from Volatile Organic Compounds, 

and corresponding revisions to the State Implementation Plan (SIP). The Commission adopts these 

amendments and corresponding revisions to. the SIP. The adopted rulemaking reduces emissions of volatile 

organic compounds (VOC) from VOC storage and degassing operations by establishing more stringent 

controls for fittings on floating roof storage vessels, establishing control requirements or operational 

limitations on landing floating roofs, establishing control requirements for flash emissions from crude oil and 

condensate storage tanks, and establishing more stringent control requirements for degassing and cleaning of 

storage, transport, and marine vessels. Under Texas Health & Safety Code $$ 382.011, 382.012, and 

382.023, the Commission has the authority to control the quality of the state's air and to issue orders 

consistent with the policies and purposes of the Texas Clean Air Act, Chapter 382 of the Texas Health & 

Safety Code. The proposed rules were published for comment in the December 29, 2006, issue of the Texas 

Register (31 TexReg 10525). 

Pursuant to Texas Health & Safety Code 382.017, Texas Gov't Code Chapter 2001, and 40 Code 

of Federal Regulations $ 51.102 and after proper notice, the Commission coilducted public hearings to 

consider the amendments and corresponding revisions to the SIP. Proper notice included prominent 

advertisement in the areas affected at least 30 days prior to the date of the hearings. Public hearings were 

held at the following times and locations: January 29, 2007, 2:00 p.m. and 6:00 p.m., Houston-Galveston 

Area Council, 3555 Timmons Lane, Houston; January 31, 2007, 7:00 p.m., J. Erik Jonsson Central 

Library Auditorium, 1515 Young Street, Dallas; February 1, 2007, 2:00 p.m., Arlington City Hall Council 

Chambers, 101 W. Abrams Street, Arlington; February 1, 2007, 6:00 p.m., Midlothian Conference Center, 

1 Co~nmunity Circle, Midlothian; February 6, 2007, 2:00 p.m., Longview Public Library, 222 W. Cotton 

Street, Longview; and February 8, 2007, 2:00 p.m., Texas Commission on Environmental Quality, 

Building E, Rooin 201S, 12100 Park 35 Circle, Austin. 

The Commission circulated hearing notices of its intended action to the public, including interested 

persons, the Regional Administrator of the EPA, and all applicable local air pollution coi~trol agencies. The 

public was invited to submit data, views, and recommendations on the proposed amendments and 

corresponding revisions to the SIP at each hearing or during the comment period. Prior to the scheduled 

hearings, copies of the proposed ainendments and corresponding revisions to the SIP were available for 

public inspection at the Commission's central office and on the Commission's Web site. 
Data, views, and reco~nme~~clations of interested persons regarding the proposed amendments and 

corresponding revisions to the SIP were submitted to tlle Commission during the coinlnent period, and were 

considered by the Colnmission as reflected in the analysis of testilllony incorporated by reference to this 

Order. The Cominission finds that the analysis of testimony includes the names of all interested groups or 

associations offering comment on the ainendinents and corresponding revisions to the SIP and their position 

concerning the same. 

IT IS THEREFORE .ORDERED BY THE COMMISSION that the ameildinellts and corresponding 

revisions to the SIP incorporated by reference to this Order are hereby adopted. The Commissioll further 

authorizes staff to make any non-substantive revisions to the rules necessary to coinply with Texas Register 

requirements. The adopted rules and the preamble to the adopted rules and the revisions to the SIP are 

incorporated by reference in this Order as if set forth at length verbatim in this Order. 

IT IS FURTHER ORDERED BY THE COMMISSION that on behalf of the Cominission, the 

Chairman should transinit a copy of this Order, together with the adopted rules and revisions to the SIP, to 

the Regional Administrator of EPA as a proposed revision to the Texas SIP pursuant to the Federal Clean 

Air Act, 5 110, codified at 42 U.S. Code Ann. 65 7410 - 7671q' as amended. 

This Order constitutes the Order of the Co~nmission required by the Administrative Procedure Act, 

Texas Gov't Code, $2001.033: 

If any portion of this Order is for any reason held to be invalid by a court of competent jurisdiction, 

the invalidity of any portion shall not affect the validity of the remaining portions. 

Date issued: 3 0 2007 TEXAS COMMISSION ON 

ENVIRONMENTAL QUALITY 

1 P 

Ifhieen Hartnett White, Chairman 
The adopted amendment imple ents Texas Water Code, 55.103 

and 55.105, and Texas Health and Safety Code. 55382.002, 

382.011, 382.012, 382.017, an 1 382.202. 

legal authority. 

TRD-200702033 

Robert Martinez 

Effective date: June 14, 2007 

+ + 

CHAPTER 11 5. CONTROL OF AIR 

POLLUTION FROM VOLATILE ORGANIC 

COMPOUNDS 

The Texas Commission on Environmental Quality (TCEQ 

or commission) adopts new §115.110 and amendments to 

55115.112 - 115.117, 115.119, 115.541 - 115.547, and 115.549. 

New §115.110 and amendments to 55115.112, 115.115 - 

115.117, 115.119, and 115.541 - 115.547 are adopted with 

changes to the proposed text as published in the December 

29, 2006, issue of the Texas Register (31 TexReg 10525). 

Amendments to 5511 5.113, 115.114, and 11 5.549 are adopted 

without changes and will not be republished. 

The amendments will be submitted to the United States Environmental Protection Agency (EPA) as a revision to the state implementation plan (SIP). 

BACKGROUND AND SUMMARY OF THE FACTUAL BASIS 

FOR THE ADOPTED RULES 

On June 15, 2004, the Houston-Galveston-Brazoria (HGB) 

ozone nonattainment area was classified as a moderate nonattainment area under the eight-hour national ambient air quality 

standard (NAAQS) under the Federal Clean Air Act (FCAA) 

Amendments of 1990 (42 United States Code (USC), 557401 

et seq.). For the HGB area, defined by Brazoria, Chambers, 

Fort Bend, Galveston, Hanis, Liberty, Montgomery, and Waller 

Counties, the TCEQ has developed this eight-hour ozone 

SIP revision in accordance with 42 USC, 57410. Hence, this 

rulemaking and HGB SIP revision is part of the first step in 

addressing the eight-hour ozone standard for the area. 

The one-hour ozone NAAQS, which preceded the eight-hour 

ozone standard, was revoked June 15, 2005(69 FR 23951). 

However, the one-hour ozone control strategies in the HGB area 

will remain in place. This set of strategies will continue to reduce 

the amount of ozone precursors and ozone in the HGB airshed. 

On September 6,2006 (71 FR 52656), EPA published approval 

of the HGB nonattainment area's one-hour ozone attainment 

demonstration and associated rules. The approval was pub 

lished in six parts, covering the rules for the control of highly-reactive volatile organic compounds (HRVOC), the HRVOC emission cap and trade (HECT) program, the mass emission cap and 

trade (MECT) program for nitrogen oxides (NO,), the one-hour 

ozone attainment plan, the emissions credit banking and trading program, and the discrete emission credit banking and trading program. For a more complete background on the one-hour 

ozone SIP revisions please refer to Chapter 1 of the eight-hour 

SIP revision that has been submitted for adoption concurrent 

with this rule package (Project Number 2006-027-SIP-NR). 

The rulemaking subjects owners or operators of volatile organic 

compound (VOC) storage tanks, transport vessels, and marine 

vessels located in the HGB eiaht-hour ozone nonattainment 

area to more stringent control, monitoring, testing, recordkeepina, and reportina requirements. The revised requirements have 

been deveiopedto reduce VOC emissions that have previously 

been underreported in emissions inventories (El). 

The first Texas Air Quality Study (TexAQS 2000) measured ambient VOC concentrations in the Houston Ship Channel to be in 

greater proportions to NO, emissions than what would be expected based on the reported point source emissions inventories. Therefore, when TCEQ and its research partners began 

TexAQS II in May 2005, one of the study's primary goals was to 

identify VOC emission sources that have been historically unreported or underreported in the El and could potentially be contributing to the discrepancy between measured ambient concentrations and reported point source emissions. 

TexAQS II remote sensing VOC project results indicate that certain types of storage tank emissions, including degassing, flash, 

and floating roof landing loss emissions, generally have been 

unreported in the El. Recent data analysis, a floating roof landing loss emissions survey, and other TCEQ studies indicate that 

these unreported emissions could total several thousand tons 

per year (tpy); unreported or underreported floating roof landing loss emissions alone in the HGB area totaled approximately 

7,250 tons in 2003. The rulemaking will help reduce emissions 

from these sources as well as other sources of potentially unreported tank emissions, such as slotted guidepoles and other 

tank fittings. 

SECTION BY SECTION DISCUSSION 

Grammatical, style, and other non-substantive corrections are 

made throughout the rulemaking to be consistent with Texas 

Register requirements, to improve readability, and to conform 

to the drafting standards in the Texas Legislative Drafting Manual, August 2006. Such changes include appropriate and consistent use of acronyms, section references, and certain terminology such as "that" and "which" and "shall" and "must." These 

changes are not discussed further. 

Subchapter B, General Volatile Organic Compound Sources 

Division 1, Storage of Volatile Organic Compounds 

Adopted §115.110 adds ten definitions used in regulatory text. 

Adopted 51 1 5.11 O(3) defines Incompatible liquid as the term is 

used in §115.112(d)(2)(H)(ii). The definition is intended to allow 

tank landings when necessary for change of service to a material that would be contaminated by the previously stored material. For example, a change in service to gasoline with a lower 

Reid vapor pressure (RVP) that must be performed to comply 

with applicable fuel requirements is considered an incompatible 

liquid. The definition has been revised in response to comments 

to specify that different chemical mixtures and different grades 

of liquid material would also be considered incompatible liquids 

if the liquid being introduced into the tank would be made unus32 TexReg 31 78 June 8,2007 Texas Register 
able for its intended purpose due to contamination from the previously stored liquid. Adopted $1 15.1 lO(10) defines Tank battery 

as the term is used in §115.112(d)(4) and (d)(5). In response 

to comments, the definition has been modified to clarify that a 

collection of tanks at a pipeline breakout station, petroleum refinery, or petrochemical plant is not considered to be a tank battery. In response to comments, definitions have been added for 

the terms deck cover, pole float, pole sleeve, pole wiper, slotted guidepole, internal sleeve emission control system, and flexible enclosure system. These definitions have been added to 

clarify additional options for controlling emissions from slotted 

guidepoles that have been incorporated into $115.1 12(d)(2)(G). 

The commission has also added a definition for pipeline breakout station because the term is used in clarifying the applicability 

of requirements for control of flash emissions in §115.112(d)(4) 

and (5). 

Adopted changes to §115.112 amend §115.112(a) to specify that 

the existing requirements apply to the HGB area until January 1, 

2009. Adopted changes also add subsection (d) to specify additional requirements for storage vessels in the HGB area that 

will take effect on January I, 2009. In response to comment, the 

phrase "beginning January 1, 2009," has been added to clarify 

when the new requirements take effect. Adopted gll5.112(d)(l) 

specifies the tank size and vapor pressure criteria that determine control requirements for tanks. These are the same criteria 

and control requirements that are now effective in the HGB area. 

These requirements are being moved to subsection (d) to be at 

the same location as new provisions that will apply to tanks in 

the HGB area. 

Adopted §115.112(d)(2) changes the control requirements for 

tank fMings. In response to comments, rule language has been 

changed to be more consistent with language in the EPA regulations in 40 CFR Part 63, Subpart WW, National Emission Standards for Storage Vessels (Tanks) Control Level 2. 

The proposed requirement in §115.112(d)(2)(A) that all openings in an internal or external floating roof except for automatic 

bleeder vents, rim space vents, and roof drains must provide a 

projection below the liquid surface and be equipped with a cover, 

seal, or lid has been modified. The requirements for all openings except automatic bleeder vents (vacuum breaker vents) and 

rim space vents to provide a projection below the liquid surface 

is separate from the requirement for all openings except automatic bleeder vents (vacuum breaker vents), rim space vents. 

leg sleeves, and roof drains to be equipped with a cover. The 

proposed wording would have incorrectly required the use of 

covers on fixed roof support columns. The proposed wording 

that the cover, seal, or lid must be equipped with a working gasket and kept in a closed position (with no visible gaps) at all times 

except when the opening is in actual use has been revised in response to comments to specify that required deck covers must 

be closed (with no gap of more than 118 inch) at all time, except 

when they must be opened for access. 

Adopted 511 5.1 12(d)(2)(B) specifies that automatic bleeder 

vents (also known as vacuum breaker vents) and rim space 

vents must be equipped with a gasketed lid, pallet, flapper, or 

other closure device and must be closed at all times except 

when required.to be open to relieve excess pressure or vacuum. 

in accordance with the manufacturer's design. The current rule 

requires only that the automatic bleeder vents and rim space 

vents be closed. In response to comments, the language has 

been changed to allow use of a gasketed lid, pallet, flapper, 

or other closure device instead of a working gasket. Also in 

response to comments, language allowing automatic bleeder 

vents to open in accordance with the manufacturer's design has 

been added. For convenience, the requirements for automatic 

bleeder vents and rim space vents have been combined in 

5 11 5. I1 2(d)(2)(B). 

Section 11 5.112(d)(2)(C) has been revised in response to comments to allow openings for fixed roof support columns to be 

equipped with flexible fabric sleeve seals instead of deck covers. 

Adopted 511 5.11 2(d)(2)(D) requires that any roof drain that empties into the stored liquid must be equipped with a slotted membrane fabric cover or equivalent control. The current rule specifies the use of the slotted membrane fabric cover; the adopted 

rule allows the use of other controls. EPA regulations allow cantrols other than slotted membrane fabric covers. Other controls 

can provide equivalent or superior emission reduction performance. Examples include weighted ball or ball in cage type 

controls. The adopted rule also specifies that the requirement 

does not apply to stub drains on internal floating roof tanks. Stub 

drains are found on internal floating roof tanks that have bolted 

decks. Their purpose is to allow stored liquid that collects on 

the roof to drain back into the tank. Covers or other controls 

on these stub drains would provide minimal, if any. reduction in 

VOC emissions. In response to comments, the phrase "no visible gap" has been changed to "no gap of more than 118 inch." 

Adopted §115.112(d)(2)(E) states that there must be no visible 

holes, tears, or other openings in any seal or seal fabric. Adopted 

§115.112(d)(2)(F) states that secondary seals on external floating roof tanks must be rim-mounted and specifies a maximum 

allowable area of gaps between the secondary seal and the tank 

wall. In response to comments, the phrase "with the exception 

of gaps that do not exceed the following specificationn has been 

added to clarify that a limited gap area is allowed. 

Adopted $1 15.1 12(d)(2)(G) requires each slotted guidepole well 

to be controlled. The quantities of emissions reduced would 

depend on various factors including the tank size and material 

stored. As an example, a 100-foot diameter external floating roof 

tank with 4,000,000-gallon capacity that stores gasoline with an 

RVP of 9 pounds per square inch absolute (psia) and has 25 

turnovers per year with an uncontrolled slotted guidepole would 

emit 11.85 tpy VOC from the guidepole alone and 14 tpy total 

VOC from the tank. The same tank with a controlled slotted 

guidepole would have 4.5 tpy VOC from the guidepole alone 

and 6.6 tons tpy total VOC emissions. For this case, controlling 

the slotted guidepole would result in a 62% decrease in annual 

VOC emissions from the guidepole and a 53% decrease in total annual tank VOC emissions. In response to comments, the 

wording has been changed to allow additional control optionsfor 

slotted guidepoles consistent with the EPA regulations for tanks 

in 40 CFR Part 63, Subpart WW, and the Storage Tank Emissions Reduction Partnership Program (STERPP). These additional controls include a pole wiper and a pole float, a pole wiper 

and a pole sleeve, an internal sleeve emission control system, 

retrotit to a solid guidepole system, a flexible enclosure system, 

and a cover over the external tbating roof. Emission calculations 

using the EPA TANKS program indicate that emissions from a 

slotted guidepole in a tank storing gasoline with an RVP of 10 

psia could be reduced from 13.5 tpy down to 0.2 tpy by installing 

a cover over the roof. The language in §115.112(d)(2)(G) has 

also been revised to qualify that the controls for slotted guidepoles are only required for external floating roof tanks. Based on 

the emission calculations, emissions from slotted guidepoles in 

internal floating roof tanks or domed external floating roof tanks 

ADOPTED RULES June 8,2007 32 TexReg 31 79 
would be equivalent to emissions expected by installing slotted 

guidepole controls on external floating roof tanks. 

Adopted §115.112(d)(2)(H) specifies that a floating roof must be 

kept floating on the liquid surface at all times except when it 

must be supported by leg supports during initial fill and other 

limited circumstances. Instances when the roof is supported by 

its legs are referred to as "landings." Adopted §115.112(d)(2)(H) 

limits the circumstances under which tank landings are allowed 

to times when the landing is necessary either to carry out inspections or maintenance, or to support a change in service 

to a liquid that is incompatible with the previously stored liquid. 

Change in service to gasoline with a lower RVP that must be 

performed to comply with applicable fuel requirements is considered a change to a liquid that is incompatible with the previously stored liquid and would be allowed. Different chemical 

mixtures and different grades of liquid material would also be 

considered incompatible liquids if the liquid being introduced into 

the tank would be made unusable for its intended purpose due 

to contamination from the previously stored liquid. Tank landings for the purposes of inventory control (also known as convenience landings) would not be allowed unless vapors are routed 

to a control device during the time that the roof is landed, or 

landing emissions are within an emissions limit or cap established under a 30 TAC Chapter 116 permit. Convenience landings would also be allowed if sitewide landing emissions are less 

than 25 tpy. Emissions from tank landings are higher than those 

that would occur while the roof is floating and have generally 

not been included in El. A recent survey by the Air Quality Division's Industrial Emissions Assessment Section indicates that 

an additional 7,250 tons from tank landings should have been 

reported in 2003. The adopted rule helps to reduce these previously unreported emissions. Storage tanks with a capacity less 

than 25,000 gallons and those storing material with a vapor pressure less than 1.5 psia are not subject to the control requirements because such tanks are not required to be equipped with 

floating roofs. As an alternative to the adopted requirements of 

§115.112(d)(2)(H)(i) - (iv), §115.112(d)(2)(H)(v) provides a compliance option where a floating roof storage tank emissions limit 

or cap could be established in permits issued under 30 TAC 

Chapter 116 to control floating roof tank landing emissions along 

with standing and working loss emissions from the tank. The 

commission has recently established enforceable storage tank 

emission caps with several independent, for-hire petroleum and 

bulk liquid terminals in the HGB region and will allow operation under these caps to demonstrate compliance with the rules 

for reducing emissions from tank landings. The emission limits or caps enable these terminals to reduce landing emissions 

through a combination of measures, including operational roof 

landing restrictions where feasible, lowering of leg position to 

minimize vapor space, restricting landed tank refill rates, degassing with controls following landings, and new and emerging control techniques. In response to comments, the proposed 

restriction specifying the cap could not include any increase in 

emissions due to tank landings that would otherwise be prohibited under §115.112(d)(2)(H)(i) - (iv) has been deleted. Also in 

response to comments, 511 5.1 12(d)(2)(H)(vi) has been added to 

allow facilities with sitewide landing emissions less than 25 tpy 

to be exempt from the restrictions on tank landings. The meaning of "initial fill' in §115.112(d)(2)(H) has been clarified in response to comments to indicate that refilling a tank that has been 

emptied, degassed, and deaned according to the provisions of 

Chapter 115. Subchapter F, Division 3. is allowed. The word "required" has been deleted from $1 15.1 12(d)(2)(H)(i) in response 

to comments to clarify that landings are allowed for maintenance 

performed according to company or site maintenance plans and 

not just in response to regulatory requirements. The wording in 

§115.112(d)(2)(H)(ii) has been revised in response to comments 

to use the term "incompatible liquid" in §115.110. Also in response to comments, §115.112(d)(2)(H)(iv) has been changed 

to require control of VOC emissions until the roof is within 10% 

by volume of being refloated, instead of until the roof is completely refloated. Commenters expressed concern that requiring 

control until the roof was completely refloated could result in liquids being drawn into the control device and causing damage. 

Adopted §115.112(d)(3) specifies that vapor recovery systems 

used as a control device must maintain a minimum control efficiency of 90%. This is the same requirement that currently applies. 

Adopted 511 5.1 12(d)(4) specifies that flash emissions from 

condensate storage tanks must be controlled if condensate 

throughput for an individual tank or the collection of tanks in 

a tank battery prior to custody transfer is greater than 1,500 

barrels (63,000 gallons) per year, unless the owner or operator 

demonstrates that the emissions from the individual tank or 

the collection of tanks in the tank battery are less than 25 

tpy. Adopted §115.112(d)(5) specifies that flash emissions 

from crude oil or condensate storage tanks must be controlled 

if uncontrolled VOC emissions from an individual tank at an 

upstream oil or gas production site or a midstream pipeline 

breakout station. or collectively from a tank battery at an upstream oil or gas production site, would be greater ihan 25 tpy. 

This limit was proposed as §115.112(d)(4). The throughput limit 

for condensate was added to the adopted rule as §115.112(d)(4) 

for ease of enforcement. Using default emission factors described later in this preamble, a throughput of 1,500 barrels 

per year of condensate would be expected to have 25 tpy of 

VOC emissions. If an owner or operator can demonstrate that 

a condensate tank with throughput greater than 1.500 barrels 

per year would have emissions less than 25 tpy, the tank would 

not be subject to the flash emission controls, as allowed under 

the new exemption in §115.117(a)(9). Crude oil and condensate 

typically contain dissolved gases that flash as the pressure on 

the liquid is reduced. For example. flashing occurs when the 

liquids are routed from a separator or other pressurized vessel 

to an atmospheric storage tank. The flashed gases may contain 

VOC in addition to methane and ethane, and may also entrain 

VOC from the stored liquid. In many cases, these gases can 

be economically routed to a vapor recovery device so that the 

energy content can be recovered for use at the production site 

or the gas can be compressed and routed to the sales line. If 

the volume of gas is sufficient, the capital cost for these vapor 

recovery devices can be repaid in a short time because of the 

high economic value of the recovered gas. The 25 tpy threshold 

for control was chosen because it defines the major source 

level for severe nonattainment areas. The HGB area was classified as severe under the one-hour ozone standard before the 

one-hour standard was replaced with the eight-hour standard. 

The adopted 25 tpy threshold also represents the maximum 

emission rate that a site would be authorized to operate under 

a permit by rule (PBR). The 25 tpy threshold applies to an 

individual tank or to an aggregation of tanks in a tank battery at 

an oil and gas exploration and production site. Because flash 

emissions could occur from any of the connected tanks, the 

adopted rule requires that the total emissions from all connected 

tanks be considered in determining whether the 25 tpy threshold 

is met. In response to comments, the commission has specified 

that the requirements for controlling flash emissions apply only 

32 TexReg 3180 June 8,2007 Texas Register 
to tanks and tank batteries storing crude oil and condensate 

prior to custody transfer at exploration and production sites 

and to individual tanks at midstream pipeline breakout stations. 

Crude oil and condensate stored at downstream sites such 

as pipeline terminals, refineries, or petrochemical plants may 

be a source of flash emissions, but in response to comments, 

the commission has decided not to subject these downstream 

sites to the new rule at this time because the test data and test 

methods in support of the rule were designed to be used at oil 

and gas production sites. The commission will continue to evaluate the extent of flash emissions at downstream sites and may 

regulate such emissions in the future. The adopted rule gives 

several options for estimating the uncontrolled flash emissions. 

The methods are based on estimating an emission factor in 

terms of pounds of VOC emitted per barrel (Iblbbl) of crude oil 

or condensate produced. Railroad Commission regulations in 

16 TAC §3.58(b) require producers to file a monthly report of the 

amount of oil, casing head gas, natural gas, and condensate 

produced during the month. Owners or operators can use these 

production records for the previous 12 months (rolling) along 

with the emission factor to estimate the total VOC emissions. 

The emission factor can be determined by direct measurement 

of the gas over a 24-hour period. Gas volume can be measured 

by manifolding all of the tanks together and using a device such 

as a mass flow meter or positive displacement meter. A sample 

of the gas can be analyzed using Gas Processors Association 

Method 2286, Tentative Method of Extended Analysis for Natural Gas and Similar Mixtures by Temperature Programmed 

Gas Chromatography, or accepted EPA methods to measure 

the composition of the flashed vapors. These measurements 

can be used to calculate the pounds of VOC emitted over the 

24-hour measurement period. The pounds of VOC can then 

be divided by the oil or condensate production rate in barrels 

to determine the emission rate in pounds of VOC per barrel. 

Instead of making direct measurements, the owner or operator 

can use default emission factors of 33.3 Iblbbl of condensate or 

1.6 Iblbbl of crude. These factors were determined in a study 

titled VOC Emissions from Oil and Condensate Storage Tanks. 

This study, conducted in 2006, was sponsored by the TCEQ 

and the Houston Advanced Research Center (HARC) and is 

identified as project H51C. For crude oil, owners or operators 

can use a chart found as Exhibit 2 of the EPA publication 

Lessons Learned from Natural Gas STAR Partners: Installing 

Vapor Recovery Units on Crude Oil Storage Tanks, October 

2003. to estimate the volume of flash gas per barrel of oil. The 

VOC mass emission rate can then be determined by assuming 

that the hydrocarbon vapors have a molecular weight of 34 

pounds per pound mole and are 48% by weight VOC. These 

values came from the HARC H51C study. Finally, the owner 

or operator can use a computer simulation or other method 

approved by the executive director to estimate flash emissions. 

These options are specified to minimize the burden on owners and operators to make direct measurements or complex 

calculations. If the regulated entity chooses to make direct mea 

surements and they yield emission rates that are higher than 

those determined by the default emission, factors, EPA chart, or 

simulation, or if computer simulation yields results higher than 

the default emission factors or chart, the higher rates must be 

used. In response to comments, rule language has been added 

to §115.112(d)(5) to specify that the higher rates must be used. 

The proposed rule only noted this restriction in the preamble. 

The commission has deleted the proposed 51 15.1 12(d)(4)(E) 

and combined the option to use a computer simulation with 

the option to use another method approved by the executive 

director. This language was previously in §115.112(d)(4)(F). 

The accuracy of computer simulations is entirely dependent on 

the accuracy of the inputs and the use of appropriate model 

parameters. Regulated entities will still have the option to use 

a computer simulation to estimate flash emissions, but the use 

must be pre-approved by the executive director to ensure that 

the results are accurate. Staff of the Industrial Emissions Assessment Section who review such calculations for El reporting 

will review the simulation use. 

Nothing in the adopted rule implies authorization of flash emissions. All emissions must be authorized according to a permit 

or other authorization under 30 TAC Chapters 106 or 116. The 

adopted rule regulates flash emissions from crude oil and condensate storage at oil or gas production sites and pipeline terminals. Flash emissions may also occur at storage terminals, refineries, and petrochemical plants, and crude oil and condensate 

are not the only sources of flash emissions. Processes in petroleum refineries and chemical plants can generate liquids containing dissolved gases that will flash when the liquid is routed 

from higher pressure equipment to an atmospheric storage tank. 

Althouah flash emissions from these other liauids are not reaulated under the adopted rule, the commission is not implying Gat 

these emissions are authorized. Methods specified in the EPA 

Compilation of Air Pollutant Emission Factors (AP-42) to calculate emissions from storage tanks do not include emissions from 

flash. Unless these flash emissions have been separately estimated and included in best available control technology (BACT) 

and health effects reviews during permitting, the emissions are 

not authorized even if they are not expressly prohibited by regulation in Chapter 115. 

Adopted 51 15.115(c) specifies appropriate measuring instruments and test methods for determining flash emissions if the 

owner or operator chooses to demonstrate compliance with the 

25 tpy limit by direct measurement. The use of a mass flow meter, positive displacement meter, or similar device must be used 

for determining flash gas flow rate. Conventional pitot tube or 

orifm plate techniques may not be appropriate for the relatively 

low flow rates from oil and condensate storage tanks. Flow 

measurements must be made over a 24-hour period representative of normal operation to make sure that the measurements 

capture emissions during a typical working cycle including 

pumping into and out of the tanks. The language in §115.115(c) 

has been changed to specify that at oil and gas production sites, 

flow measurements must be made while the producing wells 

are operational. The proposed rule listed this requirement, but 

the adopted language has been changed to clarify that it applies 

to measurements made at oil and gas production sites and not 

to measurements made at pipeline breakout stations that could 

be at some distance from the producing wells. Gas composition 

must be determined using Gas Processors Association Method 

2286, Tentative Method of Extended Analysis for Natural Gas 

and Similar Mixtures by Temperature Programmed Gas Chromatography, or approved EPA test methods. The listed test 

methods have been changed since proposal to include standard 

EPA test methods for the determination of VOC composition in 

addition to the Gas Processors Association Method 2286. 

In response to comments, the term "reportable emissions' in 

91 15.1 16(a) has been replaced with the term "emissions inventory reportable emissions" to avoid confusion with the use of the 

term "reportable emissions" as used in the general air quality 

rules in 30 TAC Chapter 101. 

ADOPTED RULES June 8,2007 32 TaReg 3181 
Adopted §115.116(c)(l) specifies that owners or operators of less if compliance would require emptying and degassing the 

storage tanks that are not required to be equipped with a float- tank. 

ing roof or vapor recovery system because the vapor pressure Subchapter F; Miscellaneous industrial Sources of the stored material - - is less than 1.5 ~sia shall kee~ records of 

the material stored and the vapor ~hese'records are Division 3, Degassing or Cleaning of Stationary, Marine, and 

necessarv to document that material stored in fixed roof tanks Transport Vessels 

meets the criteria for exemption from control requirements. In 

response to comments, the wording "length of time material is 

stored" has been replaced with the more precise wording "starting and ending dates when the material is stored." Commenters 

had expressed confusion over the meaning of the phrase. 

Adopted §115.116(~)(2) specifies that owners or operators of 

crude oil or condensate storage tanks with flash emissions shall 

keep records to verify that emissions from these tanks are below the 25 tpy criteria for exemption from control requirements. 

Records must be sufficient to allow investigators to determine 

whether flash emissions have been calculated by an appropriate method. If a computer simulation is used, records of the input and output must be retained. In response to comments, the 

wording has been changed to clarify that the requirements apply only to tanks or tank batteries at exploration and production 

sites or to tanks at pipeline breakout stations. Also in response 

to comments, the requirement to project emissions for the next 

year upon request has been deleted. 

The adopted amendment to 51 15.1 17(a)(2) specifies that in the 

HGB area, the storage of crude oil and condensate prior to custody transfer in tanks with capacity less than 210,000 gallons 

will no longer be exempt from the control requirements of Subchapter B, Division 1 after January I, 2009. The VOC emissions 

from such tanks at oil and gas production sites (especially emissions arising from flashed gases) have been found to be a significant source of VOC emissions and have previously not been 

reported. 

A new exemption §115.117(a)(9) has been added to specify that 

if an owner or operator can demonstrate that a condensate tank 

with throughput greater than 1,500 barrels per year would have 

emissions less than 25 tpy, then the tank would not be subject 

to the flash emission controls in $1 15.11 2(d)(4). 

Adopted §115.119(c) specifies that compliance with the requirements of §§115.112(d), 115.115(c), and 115.116(c) must occur 

by January 1. 2009, as part of the effort to address the eighthour ozone standard for the HGB area. However, if compliance 

with the new requirements would necessitate emptying and degassing the tank, compliance would not be required until the next 

time the tank is emptied or degassed but not later than January 

1, 2017. Additional emissions that would arise from emptying 

and degassing a tank could negate the benefit of the emission 

controls and so would not be required solely for the purpose of 

installing controls. Because tanks are generally taken out of service at least once every ten years, the controls must be installed 

no later than ten years from the date these rules are adopted. 

The delay in compliance would apply only to the installation of 

equipment; monitoring and recordkeeping requirements must be 

observed beginning January 1,2009. Regulated entities that use 

the delay of compliance provision should be prepared to justify 

why tank emptying and degassing was necessary to comply with 

the rules. Tanks with a nominal capacity less than 210,000 gallons (794,850 liters) storing crude oil and condensate prior to 

custody transfer that were previously exempt must comply by 

January 1, 2009. Since proposal, wording has been added to 

clarify that these tanks must comply by January 1,2009, regardThe adopted change to §115.541(a)(l) specifies that after January 1, 2009, the degassing control requirements will apply to 

storage tanks in the HGB area with a nominal capacity of 75,000 

gallons or greater storing materials with a true vapor pressure 

greater than 2.6 psia or to storage tanks with a nominal capacity of 250,000 gallons or more storing material with a true vapor 

pressure of 0.5 psia or greater. The current rule mandates degassing controls only to storage tanks with a nominal capacity 

of one million gallons or more. The El database has records of 

more than 950 floating roof storage tanks with capacity between 

75.000 and one million gallon capacity that could be required to 

employ vapor recovery during tank degassing under the adopted 

rule. There are also more than. 3,000 fixed roof storage tanks in 

this size range, but an unknown number of these storage tanks 

store materials with a vapor pressure less than 2.6 or 0.5 psia 

and will not be subject to the adopted degassing requirement. 

Degassing emissions from these smaller storage tanks can be 

abated with technology similar to that used for larger tanks. The 

size and vapor pressure criteria for determining which storage 

tanks are subject to the degassing control requirements were 

changed since proposal in response to comments and subsequent cost effectiveness calculations by staff. 

The adopted change to 511 5.542(a)(5) specifies that the current 

control requirements apply in the HGB area only until January 1, 

2009. Adopted 51 15.542(a)(6) specifies new criieria for control 

of degassing vapors from storage tanks and transport vessels 

in the HGB area. The change requires that vapors be vented to 

a control device until the VOC concentration of the vapors is reduced to less than 34,000 ppm by volume (ppmv) as methane or 

to less than 50% of the lower explosive limit (LEL). The current 

rules specify the 34,000 ppmv concentration as one criterion for 

determining when vapors can be vented to the atmosphere but 

also allow venting after a turnover of four vapor space volumes 

has occurred. If the storage tanks are drained dry and if the 

flow of displacement gases is measured properly, four turnovers 

would generally be sufficient to reduce VOC concentrations to 

less than 34,000 ppmv. If liquid remains in the bottom of the storage tank or transport vessel, as commonly occurs due to irregularities in the vessel surface, the remaining liquid would continue 

to be a source of VOC emissions after the four turnover criterion 

has been satisfied. The adopted rules remove the option to vent 

to atmosphere after a turnover of four vapor space volumes has 

occurred. Dilution from ventilation gas used to sweep the vapor 

space within the vessel could also cause a reading of 34,000 

ppmv VOC to be reached temporarily, but if liquid remains in the 

storage tank the concentration could again rise when the flow of 

ventilation gas ceases. The adopted revision requires continued 

control of the vapors until the VOC concentration decreases to 

below 34,000 ppmv or a reading of less than 50% is obtained 

on an LEL meter. The concentration must be rechecked periodically while the tank is vented to the atmosphere to ensure that it 

remains below 34,000 ppmv or 50% LEL. If ventilation is continuous, the concentration must be measured at least once every 12 

hours. If ventilation ceases for more than four hours, the concentration must be rechecked before the tank is reopened. The 50% 

LEL criterion was added in response to comments. The VOC 

concentration equivalent to 50% LEL is less than 34.000 ppmv 

32 TexReg 3I82 June 8,2007 Texas Register 
and therefore is an acceptable criterion to determine when degassing vapors can be emitted to atmosphere. Also in response 

to comments, language has been added to specify that the concentration measurements are no longer required after five consecutive readings less than 34,000 ppmv or less than 50% LEL 

have been obtained. 

The adopted change to §115.542(b)(4) specifies that the stated 

control requirements apply in the HGB area only until January 

1. 2009. Adopted 51 15.542(b)(5) specifies new criteria for control of degassing vapors from marine vessels in the HGB area. 

The change requires vapors to be vented to a control device until the VOC concentration of the vapors is reduced to less than 

34.000 ppmv as methane or 50% LEL. The current rules speo 

ify this concentration as one criterion for determining when vapors may be vented to the atmosphere but also allow venting 

after a turnover of four vapor space volumes has occurred. The 

adopted rules remove the option to vent to atmosphere after a 

turnover of four vapor space volumes has occurred. This change 

is being adopted for degassing vapors from marine vessels for 

the same reasons discussed for the adopted 91 15.542(a)(6) for 

storage tanks and transport vessels. The 50% LEL criterion has 

been added to the rule because the commission has specified 

that an equivalent LEL percentage can be used to determine 

when degassing need no longer be controlled for storage tanks. 

The current rule in §115.542(b)(4) uses 20% of the LEL as one 

of the criteria for when marine vessels may be vented to the atmosphere. This requirement was not changed because it applies to sources in the Beaumont-Port Arthur area as well as 

(until January 1, 2009) sources in the HGB area. The revised 

§115.542(b)(5) specifies 50% of the LEL to be consistent with 

the value used in §115.542(a)(6) for storage tanks and transport 

vessels. Because the LEL criterion is an option to allow flexibility in measurement methods, using 50% instead of 20% in 

§115.142(b)(5) will not allow an increase in VOC emissions over 

those allowed under §115.542(b)(4). 

Adopted §115.545(11) specifies the methods that must be used 

to measure the VOC concentration of the storage vessels, transport vessels, or marine vessels to determine when the vapors 

can be vented to the atmosphere instead of to a control device. 

In response to comments, several additional analytical methods have been specified to allow flexibility for the concentration 

measurements. However, the large potential variability in chemical composition of stored liquids necessitates carefully selecting 

and implementing the analytical method according to the precise' 

chemical and physical circumstances occurring at the time of 

the measurement. Thus, the commission requires that sufficient 

records and other information be maintained to show that the alternative method used completely meet the needs of the specific 

instance. Examples of such records are maintenance and calibration records of all equipment, training records of equipment 

operators, and a written sampling plan for each instance complete with data quality objectives and QAIQC measurement parameters. The measurement should be made at the head space 

of the vessel, as close as possible to the tank bottom to ensure 

that the concentration measurement is representative of actual 

conditions, but the measurements should be made at a safe location. 

Adopted §115.546(1)(D) specifies that records of the VOC concentration measurements required by §115.542(a)(6) and (b)(5) 

must be maintained. The records are necessary to document 

that degassing vapors are muted to a control device until they 

reach the criteria to be released to the atmosphere. 

A change to §115.547(2) is adopted to state that after January 1, 

2009, storage tanks in the HGB area with a nominal capacity of 

less than one million gallons but greater than or equal to 250,000 

gallons or with a nominal capacity of greater than or equal to 

75,000 gallons storing material with vapor pressure greater than 

2.6 psia will no longer be exempt from the requirements to control degassing emissions. As discussed earlier in this preamble, 

degassing emissions from these smaller tanks can be controlled 

with technology similar to that used to control degassing emissions from the largertanks. The commission revised the exemption level in response to public comments. 

The words "causes" and "prevents" are added to §l15.547(4) so 

that the text more clearly expresses the intended meaning of the 

exemption. 

Adopted §115.549(d) specifies that compliance with the new and 

revised requirements must occur by January 1.2009, as part of 

the effort to address the eight-hour ozone standard for the HGB 

area. 

FINAL REGULATORY IMPACT ANALYSIS DETERMINATION 

The commission reviewed the adopted rulemaking action in light 

of the regulatory analysis requirements of Texas Govemment 

Code, §2001.0225, and determined that the rulemaking action 

does not meet the definition of a "major environmental rule" as 

defined in that statute. A "major environmental rule" is a rule 

the specific intent of which is to protect the environment or reduce risks to human health from environmental exposure and 

that may adversely affect in a material way the economy, productivity, competition, jobs, the environment, or the public health 

and safety of the state or a sector of the state. The primary purpose of this adopted rulemaking action is to require owners or 

operators of VOC storage tanks, transport vessels, and marine 

vessels located in the HGB eight-hour ozone nonattainment area 

to better control their storage and degassing operations, thereby 

reducing VOC emissions. The adopted rules assist in identifying 

previously unreported emissions, and reducing them appropriatelv. It is antici~ated that this ado~ted rulemakina will ~ositivelv 

affek human health and the envirbnment, and n2 adversely affect the economy or productivity in any material manner. Moreover, the adopted rules will improve air quality and make positive 

progress towards attainment of the HGB eight-hour ozone standard. Therefore, the adopted rulemaking does not constitute a 

major environmental rule, and thus is not subject to a formal regulatory analysis. 

In addition, this adopted rulemaking does not meet any of the 

four applicability criteria of a "major environmental rule" as defined in the Texas Government Code. Texas Government Code, 

52001.0225 applies only to a major environmental rule the result 

of which is to: 1) exceed a standard set by federal law, unless the 

rule is specifically requiredby state law; 2) exceed an express requirement of state law, unless the rule is specifically required by 

federal law; 3) exceed a requirement of a delegation agreement 

or contract between the state and an agency or representative 

of the federal government to implement a state and federal program; or 4) adopt a rule solely under the general powers of the 

agency instead of under a specific state law. 

The rulemaking action, which is designed to reduce VOC emissions that have previously been underreported in El, does not 

exceed an express requirement under federal or state law. Furthermore, there is no contract or delegation agreement that cwers the topic that is the subject of this action. Finally, this rulemaking action was not developed solely under the general powADOPTED RULES June 8,2007 32 TexReg 3183 

The commission acknowledges Celanese's endorsement of the 

comments provided by the TCC. 

The AECT and EOSIPC expressed support for the process the 

agency has used to select the proposed control strategies and 

the conclusions reached. The EOSIPC and TxOGA also expressed support for the proposal with the technical corrections 

submitted by its members comments, and AECT, Dow. EOSIPC, 

and TCC stated that these control strategies will result in additional progress towards attainment of the eight-hour ozone standard in the HGB area. 

The commission appreciates the support. 

The EPA and RSI expressed support for the agency's efforts 

to expand controls and reduce VOC emissions within the HGB 

area. EBI stated that accounting for storage and transport emissions sources is "very good stewardship." 

The commission appreciates the support. 

The EOSIPC expressed support for the commission's ongoing 

work to incorporate the findings of the TexAQS I1 field study 

into the development of new modeling episodes that occurred 

in 2005 and 2006. 

Both the TCC and Dow support the development of a new modeling episode that incorporates the TexAQS I1 field study results. 

Dow additionally suggested that the TCEQ should consider information resulting from industry-sponsored research projects that 

show point source emissions from the HGB perimeter counties 

have rile effect on key air quality monitors in Harris County. 

The commission appreciates the support for the technical work 

completed to date. The TCEQ has, and will continue, to review 

and analyze other technical studies as it moves forward with development of a new modeling episode and development of ap 

propriate control strategies for the HGB area. 

Both the AECT and COMAQ encouraged the agency to consider the primary reason the HGB area cannot attain the eighthour ozone standard by the deadline is due to NO, and VOC 

emissions from on-road and off-road mobile sources, marine 

vessels, and other federally regulated sources. The COMAQ 

stated that NO, emissions from such sources are estimated to 

comprise about 54% of the 2009 NO, emissions inventory for 

the HGB area. The EOSIPC asserted that agency photochemical modeling demonstrates that on-road and non-road mobile 

source emissions reductions constitute the most effective path 

toward the HGB area achieving attainment. The COMAQ and 

EOSIPC stated that significant progress towards attainment in 

the HGB area cannot be realized before substantial reductions 

are made in mobile source emissions. COMAQ further noted the 

TCEQ does not have the authority to regulate emissions from 

federally regulated sources. The TCC and Dow encouraged 

the commission to continue promoting voluntary programs like 

TERP to accelerate mobile source emission reductions. AECT 

and COMAQ expressed support for additional legislative funding for the TERP program. COMAQ additionally commented 

that the agency should emphasize that TERP has resulted in 

about 22 tpd of NO, and VOC emission reductions from on-road 

and non-road sources in the HGB area. The AECT suggested 

the commission continue to encourage the EPA to take all appropriate measures to accelerate reductions of NO, and VOC 

emissions from on-road and non-road mobile sources, marine 

vessels, and other federally regulated emission sources in the 

HGB area. The AECT suggested the commission encourage 

and support programs and initiatives that will reduce NO, and 

VOC emissions from on-road and non-road mobile sources in 

the HGB area even if the measures cannot be used for emission 

reduction credits in the SIP. 

The issues brought up in these comments are beyond the scope 

of this rulemaking. The purpose of this rule project is to decrease 

VOC emissions from industrial point sources that have been previously unreported or underreported to the TCEQ and to provide 

better recordkeeping and reporting to formulate a more accurate 

inventory and enable more accurate modeling for future SIP development. 

The COMAQ encouraged the TCEQ to continue to emphasize 

the following facts and to use these facts in the development 

of the HGB eight-hour ozone SIP rules: (1) emissions of NO, 

and VOC (including HRVOC) from industrial point sources have 

been significantly reduced since 2001; and (2) TCEQ photochemical modeling indicates additional NO, and VOC (including HRVOC) emissions reductions from point and area sources 

in the HGB area will not bring the area into attainment with the 

eight-hour ozone standard. The EOSIPC stated that since 2001, 

its member companies have invested over two billion dollars in 

state-of-the-art emissions controls that have reduced ozone precursor emissions; the results of these investments are evident in 

the ambient air. Additionally, the EOSIPC asserts that independent scientific studies show that the current control strategies 

are reducing ozone. These decreases have occurred before the 

full implementation of the current point source NO, and HRVOC 

emissions control strategy that was adopted in 2004 and will be 

fully implemented in 2007. 

The commission acknowledges the efforts that have been made 

by industrial point sources in the HGB area to reduce emissions. 

The purpose of this rule package is to reduce emissions of VOC 

that have been previously unreported or underreported in the El 

and therefore not considered in modeling exercises to determine 

the most effective control measures to reduce ozone. Additional 

emission reductions from across the broad spectrum of sources 

may be needed to reduce ozone levels enough to meet the eighthour standard. 

The TO requested that the commission make changes to the 

proposed rule to address market realities that for-hire terminals 

face. HSC noted that under "Potentially Controversial Matters" 

in the Executive Summary for the HGB VOC rules TCEQ stated, 

'Representatives of terminal operators oppose the prohibition 

of convenience tank landings." HSC expressed objection that 

TCEQ was allowing the regulated community to "call the shots" 

about rule development. 

The commission has made some changes to the proposed 

rule as a result of the TO comments, as discussed in the 

Response to Comments section of this rulemaking. The reference to the opposition of terminal owners and operators to the 

prohibition of convenience landings was intended only to alert 

the commissioners to communications that had been received 

before the formal rule proposal. The prohibition was included 

in the proposed rule, but after further discussion and research, 

$1 15.1 12(d)(2)(H)(v) and (vi) allow for convenience landings if 

emissions are authorized under a permit limit or emission cap 

in a permit issued under 30 TAC Chapter 116 or if site-wide 

emissions from tank roof landings are less than 25 tpy. 

Both GHASP and HSC requested that the VOC rules be made 

more stringent because TCEQ has not been able to document 

sufficient VOC emission reductions to show attainment of the 

ozone standard by 2010. Similarly, an individual commenter enADOPTED RULES June 8,200 7 32 TexReg 31 85 
couraged the commission to place more stringent controls on 

storage tank emissions. 

Photochemical modeling has shown that VOC reductions alone 

would not be sufficient to allow the HGB area to attain the eighthour ozone standard by 2010. The commission's responses to 

the commenters' specific suggestions for making the VOC rules 

more stringent are detailed elsewhere in this document. 

GHASP asserted that the only new control measures in the 

Shour ozone SIP are enhancements to on-road and non-road 

NO, emissions controls and encouraged the agency to adopt additional control measures. GHASP specifically encouraged the 

agency to consider measures that would expand the monitoring 

network, track emissions events and predict future emissions 

event impacts, incorporate reactivity based strategies such as 

trading of HRVOC andlor other VOC emissions, and control 

wastewater and other industrial VOC sources. GHASP stated 

that the HGB area needs every possible emissions reduction to 

achieve attainment and generally favors industrial controls first, 

followed by diesel source controls. 

The commission appreciates the comment but the suggestions 

are outside the scope of this rulemaking and therefore no 

changes were made to the Chapter 115 rules as a result of 

this comment. The commission considered developing rules 

to require more stringent controls for wastewater facilities, but 

concluded that more information is needed to quantify potentially underreported emissions before effective rules can be 

developed. 

MFCA specifically suggested increasing VOC reductions from 

large industrial sources in the HGB area by 95% or more, and 

both MFCA and GHASP suggested establishing controls on 

other VOC in addition to HRVOC in the HGB area. Additionally, 

GHASP encouraged the agency to consider measures that 

concomitantly reduce pollutants that pose additional risks, such 

as air toxics and particulates. 

The commission appreciates the comments but the suggestions 

are outside the scope of this rulemaking and therefore no 

changes were made to the Chapter 115 rules as a result of 

these comments. 

HCPHES expressed support forthe amendments to Chapter 11 5 

to reduce VOC emissions from storage and degassing operations in the HGB area. The HCPHES suggested adopting andlor 

implementing various rules adopted by other states to reduce 

VOC content in solvents, paints, and various household and cosmetic products. The HCPHES also suggested expanding the 

HRVOC regulations beyond Harris County and adding to the list 

of chemicals subject to the HRVOC rules. 

The commission appreciates the comment in support of the 

Chapter 115 rules and the suggestions for additional control 

measures to reduce VOC emissions. The rule sections associated with the HCPHES suggestions are beyond the scope 

of this rulemaking and therefore no changes have been made 

to the rule based on the comments. Furthermore, the EPA is 

scheduled to adopt more stringent VOC content limits in paints 

and various household and cosmetic products in November 

2007. 

HSC commented that the rule changes for storage tanks, degassing, and flash emissions should be applied statewide. 

Extending coverage of these rules to the entire state is beyond 

the scope of this rulemaking. Because the proposal only applied 

the rule changes tothe HGB area, affected parties in other areas 

of the state have not received proper notice of the changes and 

would not have an opportunity to comment. The commission 

may consider extending coverage of the rule amendments in a 

future rulemaking. 

EBI objected to the adoption of the rule language prior to 

determining the resolution of the Texas Petrochemical situation 

with the city of Houston. EBI recommended the commission 

expressly notify the city of Houston of the intended purpose 

of the regulations and suggested adding a qualifier to the rule 

language specifying the rule does not apply to the foregoing 

situation. 

The city of Houston is aware of the proposed rule language, as 

evidenced by comments made by the mayor of Houston on the 

SIP proposal. The commission has made no changes to the rule 

as a result of this comment. 

HSC expressed disagreement with the statements in the Executive Summary for the HGB VOC rules concerning enforcement 

responsibilities. HSC further expressed concern that new TCEQ 

regulations in the past have created greatly increased workloads 

for investigators and requested that the commission document 

how many more investigations and investigator hours will be required to implement these rules. EBI expressed concerns about 

the commission's lackof enforcement of the regulations the commission promulgates. 

The proposed increased stringency of rules for tanks does not 

require additional inspections, just changes in compliance criteria. The changes to the degassing rules would affect additional 

sources, but degassing is done infrequently. The requirements 

for control of flash emissions would impose new requirements at 

sites that are already subject to other commission rules for permitting and emissions inventory reporting but may not be complying with these requirements due to underestimation of flash 

emissions. The recordkeeping requirements of the new rules 

could aid investigators in determining whether facilities are in 

compliance with existing rules. 

GEM suggested clarifying whether the term "storage vessel" 

used in the proposed rule text refers to "storage tanks." 

The term "storage vessel" as used in the rule includes "storage tanks." Most instances of the term "storage vessel" in the 

adopted rule have been changed to "storage tank." 

EBI suggested the Chapter 115 rule language be revised to distinguish between VOC and NMVOC. EBI recommended clarifying that the rule applies to storage for VOC and NMVOC or limit 

the rule solely to crude and natural gas tanks and then propose 

a separate rule for NMVOC. 

The definition of VOC in 30 TAC 5101 .I (relating to Definitions) 

excludes methane and other compounds determined by the EPA 

to have a negligible contribution to tropospheric ozone formation. 

Therefore, the suggested change is not necessary. 

COMAQ, TCC, TO, and Dow suggested including in ~115.110 

definitions of the following terms as they are defined by the EPA 

in 40 CFR 563.1061: pole float, pole sleeve, pole wiper, and 

slotted guidepole. The lT0 suggested also adding the following 

definitions: deck cover, external floating roof tank cover, flexible 

enclosure system, internal sleeve emission control system. 

The commission has added definitions for the terms deck cover, 

pole float, pole sleeve, pole wiper, slotted guidepole, flexible enclosure system, and internal sleeve emission control system as 

32 TaReg 3186 June 8, 2007 Tpxas Register 
requested. A definition for external floating roof tank cover was 

not added because it was not necessary. 

Dow suggested the TCEQ expand the definition of "incompatible liquid" in §115.110 to include (1) liquids that have different 

chemical mixtures and cannot be mixed due to product quality specifications and (2) different grades of liquid materials that 

cannot be mixed due to product quality specifications. In addition, Dow suggested that theses definition changes should be 

considered acceptable in 51 15.112(d)(2)(H)(ii). Dow also suggested that any liquid or fuel with a different specification should 

be considered as an incompatible liquid for the purposes of the 

rule. The lTO suggested the rule language in g115.110(1) be 

revised to read "incompatible liquid-a liquid that is a different 

chemical compound, a fuel with different regulatory specifcations, or any liquid that is otherwise compatible but for commercia1 contractual reasons." The TCC suggested the term "incompatiblew should recognize the following additional scenarios: a 

liquid material that would contaminate or significantly change the 

quality of a future stored material, any liquid or fuel with different 

product specifications. 

The commission has revised the definition to include different 

chemical mixtures or different grades of liquid material that would 

be unusable for its intended purpose due to contamination from 

the previously stored liquid. Minor differences in product quality 

specifications or materials owned by different customers are not 

intended to be covered under the definition, or the definition of 

incompatible liquid would be so broad as to be practically unenforceable. The cornrnission notes that facilities have the option 

to authorize landing emissions under a cap or emissions limit 

under a Chapter 116 permit or a 25 tpy exemption as allowed in 

g 1 1 5.11 2(d)(2)(H)(v) and (vi). 

The TxOGA expressed support for the definition of "incompatible liquid" in g115.110(1). The TCC agreed with the concept of 

allowing floating roof landings to support a change in service to 

a liquid that is incompatible with the previously stored liquid. 

The commission appreciates the support. 

The TxOGA and TCC suggested the definition of "tank battery" 

in §115.110(2) be changed to read "Exploration and Production 

Tank Battery-A collection of equipment at an exploration and 

production site used to separate, treat store, and transfer crude 

oil, condensate, natural gas, and produced water." 

Instead of making the change as suggested, the commission is 

changing the definition to specify that a collection of tanks at a 

pipeline breakout station, petroleum refinery, or petrochemical 

plant is not considered to be a tank battery. The commission 

has also changed §115.112(d)(4) and (5) to specify that control 

of flash emissions is required only for crude oil or condensate 

storage prior to custody transfer or at a pipeline breakout station. With these changes, the flash emission control requirements would apply to individual tanks or the collection of tanks 

at an oil and gas exploration and production site and to individual tanks at a pipeline breakout station. The requirements 

would apply to upstream and midstream operations but not to 

downstream operations such as crude oil and condensate storage at pipeline terminals, petroleum refineries, or petrochemical 

plants. The commission will continue to evaluate the extent of 

flash emissions at the downstream operations and may take action to regulate these sources at a later time. 

HSC requested that the minimum control efficiency in 

51 15.11 2(a)(3) and (d)(3) be increased from 90% to 95%. 

The commission made no changes to the rule as a result of this 

comment. The focus of the rulernaking project was to effect real 

reductions in VOC emissions. Although the rule only requires a 

control efficiency of 90%, many of the control devices in use in 

fact reduce emissions by 95% or more. 

HSC requested that the rules in §115.112(b) and (c) for Gregg. 

Nueces, Victoria, Aransas. Bexar, Calhoun, Matagorda, San 

Patricio, and Travis Counties be changed to be as stringent as 

those for the HGB area. HSC also requested that all references 

in §115.112(c)(l), Table I(b), to 1.5 psia be changed to 0.5 psia 

and that all references to 25.000 gallons be changed to 10,000 

gallons. 

Revising the rules for the listed counties is beyond the scope of 

this rulemaking. Because no changes were proposed to the referenced subsections, affected parties in these counties have not 

received proper notice of the changes and would not have an opportunity to comment. The cornrnission may consider extending 

coverage of the rule amendments in a future rulemaking. 

HSC commented that rules in §115.112(d) should apply 

statewide. 

Extending coverage to the entire state is beyond the scope of 

this rulernaking. Because the proposed rule only applied the 

rule changes to the HGB area, affected parties in other areas 

of the state have not received proper notice of the changes and 

would not have an opportunity to comment. The commission 

may consider extending coverage of the rule amendments in a 

future rulernaking. 

MFCA suggested requiring the installation of control measures 

for storage tanks with VOC vapor pressure equal to or greater 

than 0.5 pounds per square inch absolute. GHASP commented 

that the Chapter 115 rules should be changed to reflect the best 

available control technology requirements that dictate storage 

tanks operating with a vapor pressure greater than 0.5 psia and 

a capacity of more than 25,000 gallons have a floating roof or 

vent to control device. HSC commented that all references to 

1.5 psia in Tables I(a) and Il(a) should be changed to 0.5 psia 

and that all references to 25,000 gallons and 40,000 gallons in 

Tables I(a) and Il(a) should be changed to 10,000 gallons. 

The commission considered lowering the vapor pressure that 

would trigger control requirements during the development of the 

rule proposal. After reviewing data available in the El, the commission concluded that emissions from fixed-roof tanks storing 

materials with vapor pressures between 0.5 and 1.5 psia represented a small portion of the total VOC emissions from fixed roof 

tanks and that requiring additional controls for these tanks would 

not provide a meaningful reduction in VOC emissions. 

Controls for smaller tanks are less cost effective than controls 

for larger tanks. According to data in the El, there are a total of 

3,451 fixed roof tanks with a total capacity of 52.8 million gallons 

that have capacities greater than or equal to 10,000 gallons but 

less than 25,000 gallons in the HGB area. There are 1,073 tanks 

with total capacity of 32.6 million gallons that have capacities 

between 25,000 and 40,000 gallons. For comparison, there are 

5,498 fixed roof tanks with a total capacity of over 14 billion gallons that have capacities of 40,000 gallons or more. There are 

an additional 2,259 floating roof tanks with combined capacity 

over 24 billion gallons. The relative capacity of tanks that would 

be affected by the requested change represent less than 1 % of 

the total fixed roof tank capacity in the HGB and less than 0.3% 

of the total fixed and floating roof capacity. The commission decided not to pursue additional controls for tanks that represent 

DOPTED RULES June 8,200 7 32 TexReg 318 7 
such a small percentage of the total tank capacity. Controls for 

these small tanks would not result in meaningful emission reductions. 

The €PA requested confirmation that §115.112(d) specifying additional requirements for storage vessels in the HGB area will 

begin January I, 2009. The EPA also noted that although the 

preamble makes this clear, a start date of January 1,2009, may 

need to be added to the rule. 

The commission has added the start date of January I, 2009, to 

§115.112(d) as suggested. 

The TCC suggested incorporating the language in 40 CFR 

§63.1063(b)(I), (2), (3), and (5) into §115.112(d)(2) to address 

the operational requirements of floating roof tanks. 

The commission has revised §115.112(d)(2)(H) to include the 

language in 40 CFR §63.1063(b)(l) regarding support of a floating roof by other devices (e.g.. hangers from the fixed roof). 

Language in 40 CFR §63.1063(b)(3) requiring that covers be 

closed at all times except when they must be opened for access has been incorporated into §115.112(d)(2)(A). The commission declines to add the language in 40 CFR §63.1063(b)(2) and 

(5). The language in 40 CFR 963.1063(b)(2) would require that 

when the liquid depth is insufficient to float the floating roof, the 

process of filling to refloat the roof must be continuous and be 

performed as soon as practical. The restrictions on tank landings 

in 51 15.112(d)(2)(H) adequately address emissions from landed 

floating roofs. The requirement in 40 CFR §63.1063(b)(5) for 

each unslotted guidepole cap to be closed at all times except 

when gauging the liquid level or taking liquid samples is addressed in 511 5.112(d)(2)(A). 

The COMAQ and TCC suggested the rule language in 

§115.112(d)(2)(A) be revised to replace the phrase "no visible gap" with the phrase "no gap of more than 118 inch." The 

requested change would make the TCEQ language consistent with the language in the EPA MACT standard 40 CFR 

§63.1063(d)(l)(v). 

The commission has made the suggested change. 

The TCC encouraged the agency to incorporate the language used in 40 CFR Part 63, Subpart WW and revise 

5115.112(d)(2)(A) to allow exemption for leg sleeves from the 

requirement to have a cover. 

The commission has made the suggested changes. 

TxOGA suggested the word "emergency" be added before "roof 

drains" in 511 5.112(d)(2)(A) and (D). 

The commission has not made the suggested change. The 

wording of §115.112(d)(2)(D) specifies that the requirement 

applies to roof drains that empty into the stored liquid. A roof 

drain system that uses a hose or piping to drain water from the 

roof to the side of the tank shell does not empty into the stored 

liquid and so would not be subject to the control requirement. 

Dow, COMAQ, and the TCC suggested replacing the phrase 

"working gasket" in §115.112(d)(2)(A) - (C) (and elsewhere in 

the proposed document) with the phrase "gasket in good operating condition" for clarity. Additionally, the TCC and COMAQ 

suggested revising §115.112(d)(2)(A) and (C) by changing the 

term "rim vent" to "rim space vent." 

The commission has made the suggested changes. 

TO suggested the rule language in 51 15.1 12(d)(2)(A) 

be deleted and replaced with language from 40 CFR 

§63.1063(a)(2)(i) and (ii) to read "each opening except for 

those for automatic bleeder vents (vacuum breaker vents) and 

rim space vents shall have its lower edge below the surface of 

the stored liquid. Each opening except for automatic bleeder 

vents (vacuum breaker vents), rim space vents, leg sleeves, 

and deck (roo9 drains shall be equipped with a deck cover. The 

deck cover shall be equipped with a gasket between the cover 

and the deck." 

The commission has made the suggested changes, with slight 

differences in wording to correspond to the format of the existing 

rule as well as agency guidelines. Texas Registerguidelines, and 

Texas Legislative Draffing Manual, August 2006. 

lT0 suggested the rule language in §115.112(d)(2)(B) be 

deleted and replaced with language from 40 CFR §63.1063(b)(4) 

to read "each automatic bleeder vent (vacuum breaker vent) 

and rim space vent shall be closed at all times, except when 

required to be open to relieve excess pressure or vacuum, in 

accordance with the manufacturer's design." TCC suggested 

revising §115.112(d)(2)(B) by adding the phrase "or at the 

manufacturer's recommended setting" so that 511 5.11 2(d)(2)(B) 

will be consistent with 5115.112(d)(2)(C) and with 40 CFR 

363.1 063(b)(4). 

The commission has made the suggested changes. 

TxOGA suggested the rule language in §115.112(d)(2)(C) be 

clarified concerning the placement of gaskets on rim vents. 

TxOGA suggested that the language read "rim vent valves, if 

flanged, must be equipped with a working gasket and the valve 

be set to open only when the roof is being floated off the roof 

leg supports or at the manufacturer's recommended setting." 

The commission has revised the language in 5115.112(d)(2) to 

be consistent with language in 40 CFR §63.1063(a)(2)(iii). The 

new language applicable to rim vents is in §115.112(d)(2)(B). It 

specifies that rim space vents must be equipped with a gasketed 

lid, pallet, flapper, or other closure device instead of specifying 

that each rim vent be equipped with a gasket. 

lT0 expressed support for exempting stub drains from the requirements of §115.112(d)(2)(D) and agreed with the commission's assessment that controls on stub drains would provide 

minimal VOC reductions. 

The commission appreciates the support. 

TxOGA suggested the rule language in §115.112(d)(2)(E) be 

clarified to read "there must be no visible holes, tears, or other 

openings in a primary or secondary seal or seal fabric." TxOGA 

expressed the opinion that the envelope on a mechanical shoe 

seal system is not part of the primary or secondary seal, and that 

the "no tear or hole" requirement should not be construed to apply to the envelope on a mechanical shoe seal system. 

The commission has not made the suggested change in the rule 

language because the language applies to fabrics used to seal 

deck fittings as well as primary and secondary seals. The commission acknowledges that inspecting the envelope would be difficult in a tank equipped with a secondary seal. The inspection 

requirements in 5115.114 do not require moving the secondary 

seal to inspect the primary seal. If a hole or tear in the envelope of a mechanical shoe seal is found, it must be repaired if it 

would cause an increase in VOC emissions. Information available to commission staff indicates that the envelope is part of the 

vapor barrier and thus any holes or tears found in the envelope 

must be repaired. 

32 TexReg 3188 June 8,200 7 Taas Register 
TxOGA suggested the rule language in $115.112(d)(2)(F) be 

clarified to read "for external floating roof storage tanks, secondary seals must be the rim-mounted type (the seal must 

be continuous from the floating roof to the tank wall with the 

exception of gaps that do not exceed the following specifications). The accumulated area of gaps that exceed 118 inch (0.32 

centimeters) in width between the secondary seal and the tank 

wall must be no greater than 1.0 square inch per foot (21 square 

centimeters per meter) of tank diameter." 

The cornmission has made the requested change. 

COMAQ, Dow. MPL, and TxOGA suggested that the TCEQ aC 

low the use of a pole sleeve option, similar to the EPA option 

in 40 CFR $60.1063(a)(2)(viii), to control VOC emissions from 

slotted guidepoles as an alternative to a gasketed float as specified in $115.112(d)(2)(G). lT0 suggested the rule language in 

§115.112(d)(2)(G) be deleted and replaced with language from 

both the EPA StorageTank Emission Reduction Partnership Pm 

gram (STERPP) (65 FR 19891, April 13, 2000) and 40 CFR 

§63.1063(a)(2)(viii) to read "each opening for a slotted guidepole 

shall be equipped with one of the following control device configurations: (i) a pole wiper and a pole float. The wiper or seal of 

the pole float shall be at or above the height of the pole wiper, (ii) 

a pole wiper and a pole sleeve, (iii) an internal sleeve emission 

control system, (iv) a flexible enclosure system, or (v) an external floating roof tank cover." TCC and TxOGA suggested revising 

$115.1 12(d)(2)(G) to adopt the language of 40 CFR $63.1063 as 

well as all other control options provided in the EPA STERPP (65 

FR 19891, April 13, 2000). 

The commission has revised $115.112(d)(2)(G) to include the 

suggested options. 

lT0 suggested the language in $1 15.11 2(d)(2)(H) be revised 

to read "the floating roof must be floating on the liquid surface 

at all times except when the floating roof is supported by the 

leg supports during the initial fill of a new floating roof storage 

tank or an existing floating roof storage tank that has been degassed andlor cleaned pursuant to Subchapter F of this chapter. 

or as allowed under the following circumstances." lTO additionally requested darification in preamble language concerning under which. if any, circumstances uncontrolled landing emissions 

would not-be required to be routed to a control device in order to 

comply with proposed 30 TAC $115.112(d)(2)(H). 

The commission has revised the language in $115.112(d)(2)(H) 

to allow refill of a tank that has been degassed and cleaned ao 

cording to the requirements of Chapter 115, Subchapter F, Division 3. The commission has also modified preamble language 

to clarify that uncontrolled landing emissions would be allowed 

under an emissions cap as specified in $115.112(d)(2)(H)(v) or 

when total landing emissions at a site are less than 25 tpy as 

specified in the new $1 15.112(d)(2)(H)(vi). 

Dow suggested that $1 15.112(d)(2)(H)(i) be clarified so that the 

phrase "when necessary for required maintenance or inspeo 

tion" includes maintenance and inspection activities required by 

both environmental regulations and by companylindividual site 

programs. COMAQ and TCC suggested removing the term "required" from $1 15.1 12(d)(2)(H)(i) since the term could be interpreted to mean the maintenance that is required by a particular 

rule. 

The commission has deleted the word "required" as requested. 

The intent of the rule language is to allow landings when 

needed for maintenance and inspection whether the activities 

are needed in order to comply with environmental regulations 

or to satisfy company or individual site programs. 

COMAQ, TCC, and lTO suggested adding the phrase "but not 

limited to" after "including" in $1 15.1 12(d)(2)(H)(ii). 

The commission has not made the requested change. Legally, 

the term "including" is understood to mean "but not limited to." 

The commission has changed the wording to use the definition 

of incompatible liquid in $115.110, so the wording no longer contains the word "including." 

lT0 requested that $115.112(d)(2)(H)(ii) be revised to read 

"when necessary for supporting a change in service to a liquid 

that is not compatible with the previously stored liquid, including 

but not limited to gasoline with a different RVP to comply with 

applicable requirements; a termination of a contract for the 

storage of a liquid; a new customer or owner of a liquid coming 

into a storage tank; or off-spec products." 

The commission has revised the definition of "incompatible liquid" in $115.110 and has changed the wording of 

$115.112(d)(2)(H)(ii) to use the definition. Landings to replace 

off-spec products could be allowed under the revised definition 

if the product to be loaded into the tank would be contaminated 

with the previously stored off-spec product to the extent that 

the newly-loaded product would be unusable for its intended 

purpose. The commission declines to allow landings for commercial reasons such as termination of a contract or a new 

customer or owner of a liquid but notes that facilities have the 

option to authorize landing emissions under an emission limit or 

cap or a 25 tpy exemption as specified in $115.112(d)(2)(H)(v) 

and (vi). 

HSC requested that the proposed §115.112(d)(2)(H)(iii) be revised to change the reference to 25,000 gallons to 10,000 gallons and from l .5 psia to 0.5 psia. 

The purpose of the proposed §115.112(d)(2)(H)(iii) was to exempt floating roof tanks that store materials that could be stored 

in fixed-roof tanks without controls under $115.112(d)(l) from 

the prohibition on tank landings. When a floating roof is landed, 

the tank functions essentially as a fixed roof tank, negating 

the emission reduction benelits of the floating roof. Because 

$1 15.1 12(d)(l) allows materials with a vapor pressure less than 

1.5 psia to be stored in fixed roof tanks, restricting landings 

when the materials are stored in floating roof tanks would hold 

owners and operators who go beyond the requirements of 

the rule by storing such materials in floating roof tanks to an 

unnecessarily restrictive standard. As discussed in response 

to other comments, the commission has chosen not to require 

materials with a vapor pressure of less than 1.5 psia to be stored 

in a floating roof tank or a fixed roof tank with controls. 

TxOGA and lTO suggested the rule language in 

$115.112(d)(2)(H)(iv) be clarified to read "(H) The floating roof 

must be floating on the liquid surface at all times except when 

the floating roof is supported by the leg supports during the 

initial fill or as allowed under the following circumstances: (iv) 

when the vapors are routed to a control device from the time 

the roof is landed until it is within 10% of being refloated." 

The commenters expressed concern that vapor abatement 

equipment may experience problems if liquids are accidentally 

injected. 

The commission has made the requested change. 

Dow expressed support for a floating roof storage tank emissions 

cap in $115.1 12(d)(2)(H)(v) and suggested that the cap does not 

DOPTED RULES June 8,2007 32 TexReg 3189 
have to be sitewide in order to be effective. Dow suggested 

a structure similar to the TCEQ flexible air permitting program, 

where the regulated entity defines the universe of the storage 

tanks at a oiven site that can be included in the emissions cap. 

D~W also Ggiested allowing a single plant site to have multipie 

caps to address floating roof tanks in different geographical areas of the site. 

The commission has removed the term "sitewide" from 

$115.112(d)(2)(H)(v) as requested. 

COMAQ suggested clarifying $1 15.1 12(d)(2)(H)(v) to indicate 

that emissions from the landing of floating roof tanks can be 

authorized by an emission limit in a permit or permit by rule 

(PBR), or included in an emissions cap approved under 30 TAC 

Chapter 116. TCC suggested removing the term "sitewide" from 

the preamble language and from §115.112(d)(2)(H)(v) and revising the rule language to read "tank landings that comply with 

established Chapter 116 emission limits or caps." Both Dow and 

TCC suggested the rule include PBR $106.263 (which can be 

used for tank landings due to scheduled maintenance, startups, 

or shutdowns) as an authorization option for the landing of the 

floating roof tanks for a single tank. 

The commission has removed the term "sitewide" from 

$115.112(d)(2)(H)(v) and added language to clarify that landing 

emissions can be authorized by an emission limit or a cap 

, under a Chapter 116 permit, as long as the limit expressly 

includes landing loss emissions. The commission does not 

agree to allow the use of a PBR to comply with the provisions of 

$115.112(d)(2)(H). Allowing use of PBR 5106.263 to authorize 

emissions from convenience landings could allow a site to 

add up to 25 tpy of VOC emissions in addition to landing loss 

emissions that have been authorized under an express permit 

limit or permit cap. 'The provisions of $115.112(d)(2)(H) would 

not prevent an owner or operator from authorizing a new tank or 

change of service to an existing tank under an applicable PBR, 

but floating roof tank landings from any such tanks would have 

to either meet the requirements of $115.112(d)(2)(H)(i) - (iv) or 

(vi) or be incorporated into an emission cap as referenced in 

$1 15.11 5(d)(2)(H)(v). 

lTO expressed support for the ajmpliance option authorizing 

the approval of sitewide floating roof storage tank emission caps 

in permits issued under Chapter 116 but objected to the language that excludes an increase in caps from "otherwise prohibited roof landing emissions. lTO stated the language was 

vague, could be read to conflict with several existing cap agreements with the Executive Director, and the cap is more appropriately left to the commission's permitting staff. lTO suggested 

the language "and the cap value is not increased to account for 

emission from landings that would otherwise be prohibited" be 

deleted from 511 5.1 12(d)(2)(H)(v). 

The purpose of rules in Chapter 115 requiring emission reductions or controls from specific tvDes of sources is to reduce emissions of VOC that are 'contrib;iing to ozone formation in ozone 

nonattainment areas. Requirements in Chapter 115 may thus 

be more stringent than would be required by the commission's 

permitting staff. The requirements for monitoring and control of 

HRVOC in Chapter 115, Subchapter H, are an example. Forthe 

current rulemaking, however, the commission has deleted the 

suggested language. 

HSC requested that $1 15.1 12(d)(2)(H)(v) be deleted. HSC objects to the use of an emission cap in lieu of a prohibition on 

convenience landings. 

For-hire terminals may have difficulty complying with a strict prohibition on convenience landings, since the terminals do not own 

the liquid in the tanks. Complying with individual emission limits 

or caps will require tank owners and operators to minimize landing loss emissions while allowing them operational flexibility. 

lT0 suggested adding a new $115.112(d)(2)(H)(vi) and (vii) to 

read "(vi) when aggregate sitewide uncontrolled VOC emissions 

from all floating roof tank landings are less than 25 tons per year 

on a rolling 12-month basis using the methodology for landing 

emissions in the United Stated Environmental Protection Agency 

AP-42 "Compilation of Air Pollutant Emission Factors" (revised 

November 2006); (vii) when landing emissions are authorized 

under an applicable permit by rule in Chapter 106 of this title." 

The commission agrees that an exemption from the prohibition 

on roof landings is appropriate for facilities with low landing loss 

emissions and has therefore added $115.112(d)(2)(H)(vi) to provide an exemption for facilities with sitewide emissions less than 

25 tpy. As noted in response to a previous comment, the commission does not agree to allow the use of a PBR to comply with 

the provisions of $11 5.11 2(d)(2)(H). 

GHASP suggested that the vapor recovery system control effk 

ciency requirements in $115.112(d)(3) be changed from 90% to 

95% citing that the New Source Performance Standards specify 

a minimum control efficiency of 95%. 

The commission made no changes to the rule in response to this 

comment. The focus of the rulemaking project was to effect real 

reductions in VOC emissions. Although the rule only requires a 

control efficiency of 90%, many of the control devices in use in 

fact reduce emissions by 95% or more. 

HSC requested that $115.112(d)(4) be made more stringent by 

requiring control of flash emissions for tanks with emissions of 

greater than or equal to 10 tpy instead of the proposed level of 

25 tpy. 

The cost effectiveness of controls decreases proportionally to 

a source's emissions rate. If no pipeline is available to transport recovered vapors, emissions and energy use from tanker 

trucks would counter some of the benefits from vapor recovery. 

Other states that explicitly require control of flash emissions include Wyoming and Colorado. Wyoming requires control if uncontrolled emissions are greater than or equal to 40 tpy. The 

state-wide Colorado rule requires control if uncontrolled emissions are greater than or equal to 20 tpy. The commenter gave 

no specific justification for the proposed level of 10 tpy. Furthermore, the EPA expressed support for the 25 tpy threshold. 

EPA endorsed the 25 tpy threshold for control because it defines 

the major source level for severe ozone nonattainment areas. 

The commission appreciates the support. 

The TCC commented that the vapor pressure of certain liquid 

streams at oil and gas exploration and production sites may be 

greater than 11 psia because of the presence of entrained gas. 

TCC further requested the commission clarify that tanks containing crude oil and condensate streams that have a true vapor 

pressure less than 11 psia and meet the control requirements of 

§115.112 Table 1 (a), including storage in an external floating roof 

with a primary and secondary seal, are adequately controlled for 

the purposes of this rule. 

The commission do& not agree that crude oil and condensate 

streams with a reported true vapor pressure less than 11 psia do 

not have flash emissions nor that storage in an external floating 

32 TexReg 31 90 June 8,2007 Texas Register 
roof tank with primary and secondary seals provides adequate 

control if flash emissions are occurring. The commission acknowledges that the highest flash emissions would be expected 

to occur at upstream oil and gas exploration and production sites 

when the stream is first exposed to atmospheric pressure. Tanks 

at midstream pipeline breakout stations would also be expected 

to have higher potential for flash emissions than tanks at downstream petroleum refineries or petrochemical plants. For these 

reasons, the commission has revised the rule to require control of flash emissions only at the upstream oil and gas exploration and production sites and at midstream pipeline breakout 

stations. 

The TCC suggested the preamble (specifically pages 17 and 18) 

be revised to remove references to crude oil and condensate 

storage at all locations other than exploration and production facilities. Additionally, the TCC requested the commission clarify 

that the term "condensate" applies to the liquids produced from 

natural gas rather than those tanks at a petroleum plant that may 

receive condensate from a natural gas production site. TxOGA 

requested that the term Tanks" in §115.112(d)(4) be revised to 

the phrase "exploration and production tanks.' 

The commission has changed §115.112(d)(4) and (5) to spee 

ify that control of flash emissions is required only for crude oil 

or condensate storage at upstream oil and gas exploration and 

production sites prior to custody transfer or at pipeline breakout 

stations. The requirements would not apply to downstream op 

erations such as crude oil and condensate storage at petroleum 

refineries or petrochemical plants. Remote sensing projects carried out under TexAQS II found plumes from crude oil storage 

tanks at refineries. Crude oil and condensate transferred downstream may still contain dissolved gases; thus, flash emissions 

could still be occurring at these downstream locations. However, the H5IC study that was used to determine default emission factors for crude oil and condensate storage tested tanks 

at upstream sites only, and the test methods that were used to 

measure the emissions would not be a~~licable to larae external 

floating roof storage tanks such as tho& typically usd at refineries. Tanks at midstream ~i~eline breakout stations are also rea- 

"lated under the rule as adbpted. Crude oil and condensate thit 

have been transferred through pressurized pipelines are likely to 

flash when transferred to atmospheric storage tanks. The commission will continue to evaluate the extent of flash emissions 

at the downstream operations and may take action to regulate 

these sources at a later time. 

The TCC suggested consistency between the actual rule language in §115.112(d)(4) and the preamble for the rule with regards to estimating flash emissions using the method that yields 

the higher emission rate. 

The commission has moved the requirements that were proposed as §115.112(d)(4) to 91 15.112(d)(5) and has revised the 

language to state that if emissions determined using direct measurements or other methods approved by the executive director 

under §115.112(d)(5)(A) or (D) are higher than emissions estimated using the default factors or charts in §115.112(d)(5)(B) 

or (C), the higher values must be used. The intent of allowing 

the use of default emission factors is to enable regulated entities to avoid the cost of performing measurements or complex 

computer simulations. However, if the regulated enti chooses 

to use one of the more accurate, site-specific emission determination methods. this information should be used in determining 

whether emissions exceed the 25 tpy threshold. 

'The TCC requested clarification that simulation methods acceptable for use to estimate flash emissions include API EBP -. Tank - 

Model and any other model as listed in the TCEQ El guidance 

document (Technical Supplement 6, January, 2007). 

The El guidance document lists a number of methods for estimating flash emissions and ranks them according to expected 

accuracy. These methods are used state-wide. Flash emissions have traditionally been under reported, and one goal of 

the current rulemaking is to obtain a better accounting of these 

emissions in the HGB area. Thus, some of the methods that 

may be acceptable for estimating flash emissions in ozone attainment areas in West Texas may not be accurate for sources 

in the HGB area. The use of any simulation method is problematic, because the model must be run correctly using proper 

input data in order to get accurate results. Because of these 

problems, the commission has revised §115.112(d)(5) to delete 

the proposed §115.112(d)(4)(D) that would have allowed the use 

of computer simulations. The new 91 15.1 12(d)(5)(D) allows the 

use of other test methods or computer simulations preapproved 

by the executive director to estimate flash emissions. Computer 

simulations can still be used, but must be pre-approved by the 

executive director to make sure the simulation is used properly. 

HSC requested that §115.116(a)(l) and (b)(l) be made more 

stringent by changing the referenced vapor pressure from 1.0 

psia to 0.5 psia. 

The requested change would affect tanks in other nonattainment 

areas than HGB. Because notice for the proposed rule indicated 

that the proposed changes would only apply to tanks in the HGB 

area, affected owners and operators in other areas of the state 

have not received proper notice of any changes that would affect their operations. Thus, the requested change is beyond the 

scope of the current rulemaking. 

Dow and COMAQ suggested the removal of the word "reportable" from §115.116(a)(2) since the term "reportable" has 

other meanings in other portions of Texas air pollution regulations. The removal of the word "reportable" will clarify that 

the additional emissions must be included in the emissions 

inventoty report and then either recorded or reported per the 

applicable existing provisions in 30 TAC Chapter 101 (General 

Rules). TCC suggested revising §115.116(a)(2) to change the 

term "reportable" to "emission inventory reportable" to clarify 

that emissions from secondary seal gaps are not necessarily a 

reportable emission event as defined in Chapter 101, Subchapter F. 

The commission has changed the term "reportable" to "emissions inventory reportable" as suggested. 

CEMA suggested that language be added to the rule that 

acknowledges the option for facility operators to use internal 

combustion engine (ICE) based VOC oxidation systems to 

prevent an unfair market advantage for the control technologies 

listed in Chapter 115 despite equal or better performance by 

ICE-based equipment. CEMA suggested revising the rule language in §115.116(a)(3) and (b)(3) and §115.546(2) to include 

a section that reads The output voltage of the engine exhaust 

oxygen sensor and the inlet and outlet gas temperature of the 

catalytic converter on an internal combustion engine." 

The language in the rules does not specify nor exclude the 

use of any particular control technology as long as it achieves 

the required 90% reduction. The referenced rule sections 

do not'list monitoring requirements for all possible types of 

control. Moreover, the suggested monitoring language for ICE 

DOPTED RULES June 8,2007 32 TexReg 3191 
equipment would not be sufiicient to insure that the ICE system 

is functioning properly. For example, PBR §106.533(9)(4) for 

remediation requires that owners or operators of ICE systems 

conduct an evaluation of engine effectiveness initially and at 

least weekly, using a photo ionization detector (PID) or flame 

ionization detector (FID) in conjunction with a flow meter to 

determine the quantity of carbon compounds in the inlet gas 

stream and the engine exhaust. The FID or PID instrument 

chosen must be capable of properly detecting the types of 

contaminants present. For these reasons, no changes have 

been made to the rule language in response to the comment, 

but the absence of specific mention in the rule does not exclude 

the use of ICE-based equipment. 

GHASP suggested that the owners and operators of facilities 

subject to the monitoring and recordkeeping requirements in 

5115.116 be required to report their performance parameters 

and efficiency calculations because the public needs the opportunity to monitor these facilities. 

Facilities with Title V operating permits under 30 TAC Chapter 

122 are required to submit annual reports stating whether they 

are in compliance with all applicable requirements, which would 

include rules in Chapter 115. Owners or operators must also 

submit deviation reports for each six-month period if there have 

been deviations in permit terms or conditions during the period. 

The public can obtain copies of these reports (minus any confidential data) from TCEQ. TCEQ investigators can also request 

that monitored data or calculations be reported. 

EPA recommended that each requirement for a two-year record 

retention time, including those in 51 15.116(a)(5) and (b)(5), be 

changed to require a five-year record retention time, consistent 

with Title V and 30 TAC Chapter 122 requirements. 

The commission has not made the suggested change. Facilities with Title V permits are required to retain records for five 

years under Tttle V and 30 TAC Chapter 122, regardless of the 

specified retention time in a specific rule. The requirements 

in §115.116(a)(5) and (b)(5) apply to sources outside the HGB 

nonattainment area. Thus, no changes can be made to these 

requirements at this time because public notice for the rulemaking indicated that the rule changes would apply only to sources 

in the HGB area. 

HSC requested that §115.116(c)(l) be made more stringent by 

changing 40,000 gallons and 25,000 gallons to 10,000. 

The purpose of the recordkeeping requirement in 9115.1 16(c)(l) 

is to require owners and operators to maintain records documenting that the materials stored in tanks that are not 

equipped with controls as specified in Table I(a) or Table Il(a) of 

§115.112(a)(l) have vapor pressures low enough to be stored 

without controls. As noted in response to other comments, the 

commission has chosen not to change the size threshold at 

which tanks would be subject to controls to 10,000 gallons. 

Dow and TCC suggested deleting the recordkeeping requirements in §115.116(~)(1) since the regulated entity is already required to report this information through the Ttle V Operating 

Permits program. The TCC also suggested that if §115.116(~)(1) 

is not deleted, then the commission should clarify the phrase 

"length of time the material is stored" to indicate if the phrase 

refers to the date the tank is placed into service, the period of 

time it takes the tank to turnover, or the period of time that the 

liquid material lies in the tank while the roof is resting on its legs. 

The commission has maintained the referenced recordkeeping 

requirement to ensure that owners and operators have appropriate, current, readily available records to allow investigators 

to verify that materials stored in uncontrolled tanks have vapor 

pressures low enough to be stored without controls. Records in 

Title V operating permits may only refer to material safety data 

sheets that list a range of vapor pressures for an ill-defined material (such as bunker oil). The actual vapor pressure of such 

materials can vary with different suppliers, different shipments, 

or different production runs. Results of remote sensing studies 

have shown unexpected VOC emissions from fixed-roof storage 

tanks that store materials with reportedly low vapor pressures. 

The commission has revised the language in §115.116(~)(1) to 

specify that the "length of time the material is stored" refers to 

the starting and ending dates that a material is or has been in 

the tank. 

HSC requested that §115.116(~)(2) be made more stringent by 

changing the referenced emission level from 25 tpy to 10 tpy. 

The purpose ofthe recordkeeping requirement in §115.116(~)(2) 

is to document that emissions from tanks not equipped with controls for flash emissions are below the level at which control is 

required. As discussed in response to other comments, the commission has chosen not to change the level from 25 tpy to 10 tpy. 

Since the level has not changed, it would be inappropriate to revise this recordkeeping requirement. 

The TCC suggested revising 51 15.116(~)(2) to read "the owner 

or operator of any Exploration and Production storage vessel . 

. . shall maintain records . . . The records must be updated 

annually and must be made available for review as soon as possible upon request." The TCC suggested the commission use 

the "maximum authorized emission rate" to satisfy the "projected 

emissions" requirement, rather than requiring the owner or operator of an Exploration and Production storage vessel to speculate within the context of the rule on the projected tank emissions 

for the next year of operations. 

The commission has revised §115.116(~)(2) to specify that the 

recordkeeping requirement applies only to crude oil and condensate stored prior to custody transfer or at midstream pipeline 

breakout stations. The commission agrees that the maximum 

authorized emission rate, if calculated to correctly account for 

flash emissions, can be used to document that emissions are 

less than the 25 tpy threshold for control and has deleted the requirement to project emissions for the next year. 

HSC requested that the rule be made more stringent by changing 

1.5 psia to 0.5 psia in §115.117(a)(l) and by changing 25,000 

gallons to 10.000 gallons in §115.117(a)(3). 

As noted in response to earlier comments, the commission has 

decided to maintain the exemption levels at 1.5 psia and 25,000 

gallons. 

HSC requested that the rule be made more stringent by changing 1.5 psia to 0.5 psia in §115.117(b)(l) and (c)(l), by eliminating the exemption in §115.117(b)(2), by changing 25,000 gallons to 10,000 gallons in §115.117(b)(3) and (c)(3). and changing 

420,000 gallons to 10,000 gallons in §115.117(~)(4). 

The requested changes affect subsections that were not opened 

in the current rulemakina. These subsections affect sources outside the HGB eight-hourozone nonattainment area. own& and 

operators of these sources have not been given proper notice of 

proposed changes and would not have an opportunity to com32 TexReg 31 92 June 8,200 7 Texas Register 
ment. Thus, making the suggested changes is beyond the scope 

of the current rulemaking. 

GHASP suggested eliminating the exemptions for tanks constructed prior to 1980 and 1982 and requiring the installation of 

appropriate rim mounted secondary seals for external floating 

roof tanks. In instances where upgrading the tanks is not technologically feasible, GHASP suggested that those tanks should 

be relegated to service with liquids with vapor pressures less 

than 0.5 psia, or service exempt from NSPS Subpart Kb. 

The commission did not propose substantive changes to the referenced exemptions in 51 15.11 7(4). (6), or (7). Making changes 

at this time is thus beyond the scope of the current rulemaking 

because it would impose controls on owners or operators who 

have not received proper notice of additional regulatory requirements and would not have an opportunity to comment. The commission may consider eliminating these exemptions in a future 

rulemaking. 

The EPA requested confirmation that credit for this rule has been 

appropriately prorated to reflect the extended time period allowed for compliance. 

The purpose of the rule was to reduce VOC emissions that have 

been previously unreported or underreported in the El. For this 

reason, the commission has not taken credit for emissions reductions from this rule. 

The EPA requested confirmation that the new rule includes all 

components needed for enforcement purposes. In particular, 

the EPA noted that if cornpliance with the rule would necessitate emptying and degassing the tank, cornpliance would not be 

required until the next time the tank is emptied and degassed 

but not later than January 1, 2017. The EPA asked the commission to consider whether existing reporting requirements are 

sufficient to allow inspectors to verify the most recent date a tank 

was emptied and degassed and to add reporting requirements if 

necessary to provide for enforceability of the rule. 

Commission general air quality rules in 30 TAC §101.20l(b) 

require owners or operators to maintain records of scheduled 

maintenance activities, which would include tank degassing and 

cleaning. No changes were made to the rule as a result of this 

comment. 

COMAQ suggested that TCEQ reconsider its position in 

§115.119(c) that the required control equipment could be put 

into place without tanks having to be taken out of service, citing 

that COMAQ members' experience has been that any significant work on tank roof fittinas and seal systems requires tank 

de-inventory and degassing-in order to prevent unacceptable 

LEL readings and personnel safety concerns. 

The commission maintains that certain types of roof fittings and 

controls for slotted guidepoles can be installed without taking the 

tank out of service. However, the rule language in §115.119(c) 

states that compliance can be delayed beyond January 1,2009, 

until the next time the tank is emptied and degassed if compliant equipment cannot be installed without taking the tank out 

of service. The decision whether equipment can be safely installed without taking the tank out of service will be made by the 

owner or operator. The rule does not give specific requirements 

for proving that the installation cannot be safely performed while 

the tank is in service, but the owner or operator should document 

and maintain for inspection purposes the rationale for delayed 

compliance. 

Dow supports the TCEQ's consideration that storage vessels will 

have to be degassed and emptied to comply with §115.112(d) 

requirements, and suggested editing §115.119(c) to clarify that 

compliance with §§115.112(d), 115.115(c), and 115.116(c) is not 

required until the next scheduled emptying and degassing activity after January 1, 2009. 

The comrnission appreciates the support, but does not agree 

that compliance is not required until the next scheduled emptying 

and degassing activity after January 1,2009. The reason for allowing the delay of cornpliance is to avoid requiring that a tank be 

taken out of service and degassed solely for the purpose of amplying with the new requirements. In some cases, the emissions 

that would occur from the degassing activity (even when complying with the revised requirements for degassing in Chapter 

115, Subchapter F) would be greater than emissions that would 

be reduced by installing compliant equipment. For tanks that will 

be emptied and degassed after the date the rule becomes effective but prior to January 1, 2009, the commission expects that 

equipment required to comply with the revised rules can be installed at that time, even though compliance is not required until 

January 1,2009. Owners and operators who are planning tank 

ernptying and degassing activities should plan ahead to install 

compliant equipment at the next opportunity. 

EPA noted that the preamble discussion for §115.119(c) states. 

"The commission anticipates that most, if not all, of the required 

control equipment can be put into place without taking the tank 

out of service," and requested that the commission consider 

modifying the rule to require that most, if not all, of the components in the rules be met by January 1,2009. 

Industry commenters disagree with the commission's statement 

that most required control equipment can be put into place without taking a tank out of service. The rule language states that 

comoliance must be achieved bv Januarv 1.2009. unless compliance would require emptying and degassing the.storage tank. 

A further reauirement that "most" of the com~onents in the rules 

be met by ~anuary 1,2009, would be unenforceable. 

HSC objected to delayed cornpliance for tanks that must be emptied and degassed to install controls, since degassing is controlled, and stated that exceptions to not ernptying a tank for 

installation of controls should only be allowed based on a petition from a regulated entity that demonstrates that emissions 

from emptying and degassing cannot be controlled and that the 

tank must be emptied to install the controls. GHASP commented 

that the storage tank regulations in Chapter 115 should mandate 

compliance by all affected facilities by January 1.2009. GHASP 

stated that operating practices can be modified to eliminate convenience landings and that if a facility chooses to install controls 

that require emptying the tank, operating practices can be modified until the tank maintenance is undertaken. 

In some cases, the emissions that would occur from the degassing activity (even when complying with the revised requirements for degassing in Chapter 115, Subchapter F) would be 

greater than emissions that would be reduced by installing compliant equipment. Due to the high Cost effectiveness of requiring degassing controls on small tanks, the comrnission has revised the new degassing control requirements to apply only to 

tanks with nominal capacity greater than or equal to 250,000 

gallons or to tanks with nominal capacity greater than or equal 

to 75.000 gallons storing material with vapor pressure greater 

than 2.6 psia. If degassing is not controlled, emissions from taking the tank out of service to install controls could negate the 

environmental benefh of the controls. The provision for delayed 

ADOPTED RULES June 8,2007 32 Tdeg 3193 
compliance is not anticipated to affect the compliance date for 

tank landings, since facilities can comply with the requirements 

by changes in operational practices, as noted by the commenter. 

HSC requested that the control requirements for VOC loading 

operations in 5115.212 be revised to require a control efficiency 

of 95% rather than 90%. 

The requested change is beyond the scope of the current rulemaking, since no changes were proposed to 5115.212. Staff 

considered this change to loading requirements as the rule proposal was being developed. According to available data in the 

El, most of the control devices in use were already reducing 

emissions by 95% or more. Also, emissions from controlled loading operations represent a small fraction of the total VOC from 

point sources in the HGB area. Thus, making this change would 

result in only minimal emissions reductions. 

RSI suggested the commission examine the upcoming South 

Coast Air Quality Management District (SCAQMD) tank degassing regulations. 

The commission has reviewed the existing SCAQMD regulations 

on tank degassing and commission staff has discussed upcoming changes with SCAQMD staff. 

GEM suggested degassing companies be required to provide 

notification of degassing activities if onsite inspections of tank 

degassing is going to be implemented. 

The commission requires notification of scheduled maintenance 

activities such as tank degassing if expected emissions will exceed a reportable quantity as defined in 30 TAC 5101 .I. Aspecific notification requirement may be considered in a future rulemaking. 

The TCC suggested the commission confirm in 5115.541 that if 

a covered tank is flooded with a diluent that has a true vapor 

pressure of less than 0.50 psia then the control requirements of 

this subchapter are no longer applicable. 

The commission does not agree that flooding a tank with a low 

vapor pressure diluent automatically negates the applicability of 

control requirements of Subchapter F. Pockets of material with a 

higher vapor pressure may be present in sludge on the tank bottom and be unaffected by the use of the diluent. Use of a diluent 

would also create a mixture that would presumably be a waste 

that could cause additional VOC emissions when disposed. 

COMAQ suggested the emission specifications and control requirements for the degassing of storage tanks with a nominal 

capacity between 40,000 and 1 million gallons should not be included in 9115.541 (a)(l ) and §115.547(2). COMAQ states that 

the 40,000 gallon threshold was arbitrarily chosen by the commission and does not take into account the quantity of emissions 

from the degassing process or the economic feasibility of installing the controls. TCC commented that the minimum cost for 

complying with the degassing requirements would be $5,000 and 

suggested revising the degassing emission specifications applicability threshold in 5115.541 from 40,000 gallons to 250,000 

gallons. HSC requested that the rule be made more stringent 

by changing 40.000 gallons to 10,000 gallons in §115.541(a)(l) 

and 5115.547(2). 

Emission reductions that can be realized by requiring controlled 

degassing decrease as the size of the tank (and, thus, the 

amount of vapor space saturated with VOC) decreases. Control 

of degassing emissions is generally carried out by outside 

contractors who bring equipment to the site. The charge for 

bringing in and operating the equipment is generally the same 

regardless of the size of the tank to be degassed. Thus, the 

cost effectiveness for controlling degassing emissions for tanks 

as small as 10,000 gallons is much higher than for larger tanks. 

The commission does not believe that the cost for controlling 

degassing emissions from these smaller tanks is justified. As 

noted by TCC, the cost effectiveness for controlling degassing 

emissions from a 40,000 gallon tank storing a material with 

a vapor pressure of 0.5 psia would be greater than $60,000 

per ton of VOC removed. The commission has estimated that 

the cost effectiveness of controlling degassing emissions from 

tanks with capacity of 250.000 gallons storing materials with a 

vapor pressure of 0.5 psia or higher would be less than $12,000 

per ton. The cost effectiveness for requiring degassing controls 

increases for smaller tanks and would exceed the $12,000 per 

ton value that is used in evaluating BACT. Thus, the commission has revised the applicability threshold to 250,000 gallons 

for tanks storing materials with vapor pressures down to 0.5 

psia. However, smaller tanks storing more volatile materials 

would have higher emissions and lower cost effectiveness. 

Regulations applicable in the SCAQMD take the higher emission potential into account by requiring degassing controls for 

tanks as small as 19,815 gallons storing materials with a vapor 

pressure greater than 3.9 psia, and for tanks as small as 39,630 

gallons storing materials with a vapor pressure greater than 

2.6 psia. Commission staff estimated the cost effectiveness to 

control degassing emissions from tanks with a range of sizes 

and vapor pressures of stored liquid, and concluded that the 

cost effectiveness to control degassing emissions from tanks 

75.000 gallons or larger storing materials with vapor pressure 

greater than 2.6 psia was approximately $20,000 per ton or 

less. The commission has revised the rule to require degassing 

control for tanks with a capacity of 250,000 gallons or more. 

and for tanks with capacity of 75.000 gallons to 250,000 gallons 

storing material with vapor pressure greater than 2.6 psia. 

HSC additionally requested that the rule be made more stringent 

by changing 8,000 gallons to 5,000 gallons in 51 15.541 (a)(2) and 

by changing 420,000 gallons to 10.000 gallons in 51 15.541 (b) 

and 5115.547(2). 

The commenter gives no basis to support the requested 

changes. The rule proposal did not include a change in the size 

of transport or marine vessel that would be required to control 

degassing emissions. Thus, the requested change is beyond 

the scope of the current rulemaking. 

HSC requested that the rule be made more stringent by changing 90% to 95% in 5115.541(a)(I)(B) and (a)(2)(B) and in 

5115.541(b)(2). 

The commission made no changes to the rule in response to this 

comment. The focus of the rulemaking project was to effect real 

reductions in VOC emissions. Although the rule only requires a 

control efficiency of 90%, many of the control devices in use in 

fact reduce emissions by 95% or more. 

GEM suggested if the four vapor space turnover requirement 

remains part of the degassing rule then the commission should 

require that approved inlet vapor flow meters be installed at the 

inlet of the control device to help standardize the flow volume 

measurement. 

The commission has deleted the turnover requirement for affected sources in the HGB after January 1, 2009. The four vapor space turnover provision remains in effect for sources in the 

BPA nonattainment area, but changes that would affect sources 

32 TexReg 31 94 June 8,2007 Texas Register 
in this area are beyond the scope of the current rulemaking since 

public notice indicated that rule changes were only being made 

for sources in the HGB area. 

HSC requested that the rule be made more stringent by changing 

34,000 ppmv to 10,000 ppmv in 5115.542(a)(2) and (b)(5). 

The purpose of the proposed rule was to change the method 

for demonstrating when sufficient degassing had occurred, not 

changing the required level. The 34,000 ppmv level is based on 

requiring degassing control down to an equivalent partial pressure of 0.5 psia: 0.5/14.7'1,000.000 = 34,000 ppmv. Because 

no change to this level was proposed, lowering it is beyond the 

scope of this rulemaking. 

HSC requested that the rule be made more stringent by changing 

34.000 ppmv to 10,000 ppmv in 511 5.542(b)(4) and by eliminating the words "a turnover of at least four vapor space volumes 

has occurred, the partial vapor pressure is less than 0.5 psia 

(19,000 ppmw) . . . or the concentration of VOC is less than 

20% of the lower explosive limit." 

The requirements in 5115.542(b)(4) apply to sources in the 

Beaumont-Port Arthur (BPA) and until January 1, 2009, in 

the HGB area. No changes affecting sources in BPA were 

proposed; thus, making the requested change is beyond the 

scope of the current rulemaking. The regulated community 

must have time to implement new rule requirements; thus, the 

current wording is necessary to maintain the applicability of the 

existing requirements in HGB until the compliance date for the 

new requirements. 

COMAQ requests that the TCEQ clarify whether "ventilated," 

"ventilation," and "vented" mean forced ventilation only, or both 

forced and passive ventilation as used in 5115.542(a)(6). In this 

same section, the TCC suggested clarifying the intent of the 

phrase "before dilution." 

The commission has revised the rule language to use the term 

"vented to the atmospherew for clarity. The commission has removed the word "before dilution" from the rule language as requested. The intent of the phrase "before dilution" was to emphasize that vapors are not to be released to the atmosphere untreated because an excessive volume of ventilation gas is used. 

Depending on the type of control technology used to abate the 

degassing emissions, dilution gas is sometimes necessary to 

maintain safe conditions in the abatement device. The concentration measurement should be made before the dilution gas is 

added. 

TxOGA expressed general support for 5115.542 stating that the 

use of vapor concentration rather than turnover volume for determination of sufficient processing of vapors provides operational 

consistency during tank degassing. TxOGA suggested that the 

LEL is a better threshold for determining com~liance than the 

ppmv or ppmw determination and suggeged that 51 15.542(a)(5) 

and (6) be changed to add "50% LELa as a criteria for determining ihen vapors can be released to atmosphere instead of the 

34,000 ppmv concentration limit. 

The commission agrees that a VOC concentration equivalent 

to 50% LEL will be lower than the 34,000 ppmv concentration 

criteria and so has made the requested change in $1 15.542(6). 

The commission has not made the suggested change in 

5115.542(a)(5) because this provision applies to sources in 

the BPA nonattainment area as well as to the HGB area until 

January 1, 2009. Because notice for the current rulemaking 

indicated that changes were being made only for the HGB area, 

changing the provision applicable to BPA is beyond the scope 

of the current rulemaking. 

Dow, TCC, and COMAQ suggested revising the periodic measurements required to confirm that the VOC concentration is 

less that 34,000 ppmv in 5115.542(a)(6) and (b)(5). The commenters suggested that three consecutive readings, each taken 

at a 12-hour interval, with a VOC concentration less than 34.000 

ppmv during ventilation is adequate to confirm that the VOC concentration is not varying significantly and that further checks every 12 hours are not warranted. 

The commission agrees that concentration measurements can 

be ceased at some point in the degassing and cleaning process 

but is concerned that if sludge remains in the tank after the initial degassing, VOC concentrations could decrease to less than 

34.000 ppmv but later increase when the sludge is disturbed during the cleaning process. The commission has changed the rule 

to specify that concentration measurements can be discontinued after five consecutive readings less than 34,000 ppmv. With 

readings taken every 12 hours, the five readings would provide 

that the concentration would remain below 34,000 ppmv for at 

least 48 hours. VOC emissions associated with the removal of 

sludge from the tank may need to be recorded and reported under the maintenance rules in 30 TAC Chapter 101. 

The TCC suggested revising $1 15.541 (a)(l) and $1 15.542(a)(5) 

to allow a delay in compliance until the next time the vessel is 

emptied but no later than January 1. 2017, if compliance would 

require the installation of degassing nozzles or connections. 

However, if appropriate degassing nozzles can be added by 

changing out a manway, the TCC suggested the commission 

should consider revising $115.542(a)(5) to allow a manway to 

be opened for the short period of time necessary to change-out 

the manway to one with the appropriate nozzles. 

The commission does not agree that a delay in compliance is 

necessary for tanks that must have degassing nozzles or connections installed. Hatches with nozzles installed can be obtained for newly-affected tanks. The commission has not revised 

$1 15.542(a)(5) to specifically allow the manway opening. Maintenance activities such as manway opening are subject to an affirmative defense as long as they comply with the general rules 

for maintenance in 30 TAC Chapter 101. 

The TCC suggested that §115.542(b)(5) be revised by adding 

the phrase "of the degassing operation." 

The commission has made the suggested change. 

770 expressed support for the 34.000 ppmv trigger for controlling vapors during tank degassing but requested clarification that 

sampling to obtain VOC concentration measurements during degassing does not require tank entry and VOC concentration measurements can be taken from a tank's manway. TxOGA suggested that the preamble language regarding the frequency aid 

method for measurement of VOC concentrations in $1 15.545(11) 

be modified to read 'the measurement should bemade at'the 

head space of the vessel, as close as possible to the tank bottom 

to ensure that the concentration measurement is representative 

of actual conditions. However, these measurements are to be 

taken at locations that do not endanger the safety of sampling 

personnel." 

The commission did not intend that VOC measurements be 

made inside the tank or other location that would endanger the 

safety of sampling personnel. 

ADOPTED RULES June 8,2007 32 TexReg 3195 
COMAQ, Dow, GEM, TCC, TO, and TxOGA suggested the 

agency allow acceptable alternate test methods for VOC concenbation measurements specified in §115.545(11). The suggested methods include EPA Method 25A; EPA Method 18, adjusted to allow for one bag sample to be collected; bag sampling; 

portable hydrocarbon gas analyzer; PID; chemical specific detection tubes; and LEL meters. COMAQ commented that FlDs 

are not appropriate for testing VOC in nitrogen-rich, oxygen-poor 

atmospheres because the FID will "tlame out." Dow suggested 

that measurement of the total organic carbon (TOC) content of 

the condensate stream be allowed for vessels that are degassed 

and cleaned via steam. 

The commission agrees that additional methods for measuring 

the VOC concentration would be acceptable and has revised the 

rule accordingly. The commission does not agree that chemical 

specific detection tubes are appropriate because they are usually compound specific and could result in false negatives. Also, 

the detection tubes might be difficult to operate in the tank degassing environment. The commission does not agree that measurement of the TOC content of the condensate stream would be 

an appropriate indication of the VOC concentration of the vapor 

space. Even if an accurate correlation between the TOC concentration of the condensate and the VOC in the vapor space could 

be determined, use of this method would require the TCEQ staff 

to review and approve the correlation before it could be used. 

Tank degassing events are episodic and of short duration; approval of a correlation might not be possible in time for it to be 

used. 

Dow and TCC suggested that the TCEQ clarify that the instrument response factor criteria in 58.1 of EPA Method 21 be for the 

average composition of the liquid in the tank, transport vessel, 

or marine vessel and not for each individual VOC in the liquid. 

Dow noted that this approach is consistent with EPA's HON regulation in 40 CFR §63.180(b)(2)(i). 

The commission agrees that use of the average composition of 

the tank contents to determine the instrument response factor is 

appropriate and has revised the rule accordingly. 

RSI suggested that the protocol for sampling and analyzing must 

be clearly defined so that enforcement does not have to merely 

assume that measurements are being done correctly. 

'The commission has listed approved testing methods in 

§115.545(11) in order to ensure that measurements are being 

performed correctly. 

COMAQ suggested including an exemption from the emissions 

specifications and control requirements if the tank owner oroperator can demonstrate compliance would be economically unreasonable by revising §115.547(2) to read "degassing and cleaning 

. . . any stationary VOC storage tank with a nominal storage capacity of less than one million gallons, or any marine vessel, with 

a nominal storage capacity of less than 10,000 barrels (420,000 

gallons), is exempt from the requirements of this division. In addition, a tank is exempt from the requirements of this division if 

its owner or operator can demonstrate to the satisfaction of the 

executive director that compliance with the requirements of this 

division would be economically unreasonable." 

The commission does not agree that an exemption should be allowed for individual tanks based on whether control is "economically unreasonable." The rules in Chapter 115 must meet the 

standards that the EPA has set for reasonably available control 

technology (RACT). The EPA definition of RACT is "the lowest 

emission limitation that a particular source can meet by applying 

a control technique that is reasonably available considering technological and economic feasibility." The standard is economic 

feasibility, not economic reasonableness. With the revised applicability levels in the adopted rule based on tank size and vapor 

pressure of stored material, the commission maintains that control of degassing emissions from all affected tanks is economically reasonable as well as technically and economically feasible. 

RSI commented that calculating the destruction rate efficiency 

of abatement devices used to control emissions from the tank 

degassing process is not easily defined. Knowing the influent 

concentration in ppmv makes logical sense for determining when 

a tank degassing event is finished but in order to determine the 

allowable emissions it is necessary to also know the flow rate of 

the effluent in cubic feet per minute. 

The degassing rules do not require a calculation of allowable 

emissions from abatement devices. Thus, no changes have 

been made to the rule in response to this comment. 

RSI expressed concern that their ICE technology, with destruction efficiency greater than 99.9%, will be priced out of the market 

in Texas because these rules only require a destruction efficiency 

of 90%. 

The commission has made no change to the rules as a result of 

this comment. Even though the rule only specifies 90% destruction efficiencv. other concerns mav drive reaulated entities to use 

more efficieit control equipment: When &gassing operitions 

are canied out as Dart of maintenance activities. emissions must - - 

be minimized under the requirements of the general air quality 

rules in 30 TAC Chapter 101. Emissions from planned maintenance activities must be authorized under 30 TAC Chapters 106 

or 116 according to the schedule in 30 TAC 5101.222. Authorization will require use of BACT, which could require more stringent 

control than the minimum specified in 30 TAC §115.541. 

TxOGA expressed support for a portable equipment registration or certification program for vendors or contractors who provide degassing equipment that would certify that the vendor degassing equipment meets TCEQ emission standards and ensure 

that contractor providing the portable equipment understands 

TCEQ rules and documentation requirements. 

Establishing a registration or certification program for degassing 

vendors or contractors is beyond the scope of the current rulemaking, but the commission may consider such a program in the 

future. 

HSC requested that the exemption for oceangoing, self-propelled marine vessels in §115.547(5) be removed so that these 

vessels must be degassed and cleaned when they have emptied their VOC cargo. 

The commission did not provide notice of any change to the referenced exemption for oceangoing, self-propelled marine vessels. Thus, proper notice to the owners and operators of such 

vessels has not been given and making the requested change 

is beyond the scope of the current rulemaking. The commission 

may consider a change to this exemption in future rulemaking. 

SUBCHAPTER B. GENERAL VOLATILE 

ORGANIC COMPOUND SOURCES 

DIVISION 1. STORAGE OF VOLATILE 

ORGANIC COMPOUNDS 

30 TAC gg115.110, 115.112 - 115.117,115.119 

32 TexReg 31 96 June 8,2007 Texas Register 
STATUTORY AUTHORITY 

The amendments and new rule are adopted under Texas Water 

Code, 55.102, concerning General Powers, 55.103, concerning 

Rules, and 55.105, concerning General Policy, that authorize 

the commission to adopt rules necessary to carry out its powers and duties under the Texas Water Code; and under Texas 

Health and Safety Code, 5382.017, concerning Rules, that authorizes the commission to adopt rules consistent with the policy and purposes of the Texas Health and Safety Code, Chapter 382 (also known as the Texas Clean Air Act). The amendments and new rule are also adopted under Texas Health and 

Safety Code, 5382.002, concerning Policy and Purpose, that establishes the commission's purpose to safeguard the state air 

resources, consistent with the protection of public health, general welfare, and physical property; 5382.011, concerning General Powers and Duties, that authorizes the commission to control the quality of the state's air; 5382.012, concerning State Air 

Control Plan, that authorizes the commission to prepare and 

develop a general, comprehensive plan for the control of the 

state's air; 5382.a14, concerning Emission Inventory, which authorizes the commission to require the submission of information concerning the emission of air contaminants; and 5382.016, 

concerning Monitoring Requirements; Examination of Records, 

which authorizes the commission to require owners and operators of emission sources to maintain measuring and monitoring records and make such records available to the wrnmission. The rules are adopted under federal mandates contained 

in 42 USC, 57410, that require states to introduce pollution control measures in order to reach specific air quality standards in 

particular areas of the state. 

The adopted amendments and new rule implement Texas Health 

and Safety Code, 55382.002, 382.011, 382.012, 382.014, and 

382.016. 

$11 5.11 0. Definitions. 

The following words and terms, when used in this division (relating 

to Storage of Volatile Organic Compounds), have the following meanings, unless the context clearly indicates otherwise. Additional definitions for terms used in this division are found in $83.2, 101.1, and 

1 15.10 of this title (relating to Definitions). 

(1) Deck cover--A device that covers an opening in a floating roof deck. Some deck covers move horizontally relative to the deck 

(i.e., a sliding cover). 

(2) Flexible enclosure system--A system that includes all 

of the following: a flexible device that completely encloses the slotted guidepole and eliminates the hydrocarbon vapor emission pathway 

from inside the tank through the guidepole slots to the outside air; a 

guidepole cover at the top of the guidepole; and a well cover positioned at the top of the guidepole well that seals any openings between 

the well cover and the guidepole (e.g. pole wiper), any openings between the well cover and any other objects that pass through the well 

cover, and any other openings in the top of the guidepole well. 

(3) Incompatible liquid--A liquid that is a different chemical compound, a different chemical mixture, a different grade of liquid 

material, or a fuel with different regulatory specifications provided that 

the chemical compound, chemical mixture, grade of liquid material, or fuel would be unusable for its intended purpose due to contamination 

from the previously stored liquid. 

(4) Internal sleeve emission control system--An emissions 

control system that includes all of the following: an internal guidepole 

sleeve that eliminates the hydrocarbon vapor emission pathway from 

inside the tank through the guidepole slots to the outside air; a guidepole cover at the top of the guidepole; and a well cover positioned at 

the top of the guidepole well that seals any openings between the well 

cover and the guidepole (e.g. pole wiper), any openings between the 

well cover and any other objects that pass through the well cover, and 

any other openings in the top of the guidepole well. 

(5) Pipeline breakout station--A facility along a pipeline 

containing storage vessels used to relieve surges or receive and store 

crude oil or condensate from the pipeline for reinjection into the 

pipeline and continued transportation by pipeline or to other facilities. 

(6) Pole float-A float located inside a guidepole that floats 

on the surface of the stored liquid. The rim of the float has a wiper or 

seal that extends to the inner surface of the pole. 

(7) Pole sleeve--A device that extends from either the cover or the rim of an opening in a floating roof deck to the outer surface of 

a pole that passes through the opening. The sleeve extends into the 

stored liquid. 

(8) Pole wiper--A seal that extends from either the cover or the rim of an opening in a floating roof deck to the outer surface of a 

pole that passes through the opening. 

(9) Slotted guidepole--A guidepole or gaugepole that has 

slots or holes through the wall of the pole. The slots or holes allow 

the stored liquid to flow into the pole at liquid levels above the lowest 

operating level. 

(10) Tank battery--A collection of equipment used to separate, treat, store, and transfer crude oil, condensate, natural gas, and 

produced water. A tank battery typically receives crude oil, condensate, 

natural gas, or some combination of these extracted products from several production wells for accumulation and separation prior to tmnsmission to a natural gas plant or petroleum refinery. A collection of storage 

tanks at a pipeline breakout station, petroleum refinery, or petrochemical plant is not considered to be a tank battery. 

$115.112. Control Requiremen&. 

(a) For all persons in the BeaurnontPort Arthur, Dallasffort 

Worth, El Paso, and until January 1, 2009, in the HoustonIGalvestoniBrazoria areas as defined in 5115.10 of this title (relating to 

Definitions), the following requirements apply. 

(1) No person shall place, store, or hold in any stationary tank, reservoir, or other container any volatile organic compound 

(VOC) unless such container is capable of maintaining working pressure sufficient at all times to prevent any vapor or gas loss to the atmosphere, or is equipped with at least the control device specified in Table 

I(a) of this paragraph for VOC other than crude oil and condensate, or 

Table II(a) of this paragraph for crude oil and condensate. 

Figure: 30 TAC $1 15.1 12(a)(1) 

(2) For floating roof storage tanks subject to the provisions 

of paragraph (1) of this subsection, the following requirements apply. 

(A) All openings in an internal or external floating roof 

except for automatic bleeder vents (vacuum breaker vents) and rim 

space vents must provide a projection below the liquid surface or be 

equipped with a cover, seal, or lid. Any cover, seal, or lid must be in a 

closed (i.e., no visible gap) position at all times except when the device 

is in actual use. 

(B) Automatic bleeder vents (vacuum breaker vents) 

must be closed at all times except when the roof is being floated off 

or landed on the roof leg supports. 

(C) Rim vents, if provided, must be set to open only 

when the roof is being floated off the roof leg supports or at the manufacturer's recommended setting. 

ADOPTED RULES June 8,2007 32 TexReg 31 9 7 
(D) Any roof drain that empties into the stored liquid 

must be equipped with a slotted membrane fabric cover that covers at 

least 90% of the area of the opening. 

(E) There must be no visible holes, tears, or other openings in any seal or seal fabric. 

(F) For external floating roof storage tanks, secondary 

seals must be the rim-mounted type (the seal must be continuous from 

the floating roof to the tank wall). The accumulated area of gaps that 

exceed 118 inch (0.32 centimeter) in width between the secondary seal 

and tank wall must be no greater than 1.0 square inch per foot (2 1 square 

centimeters permeter) of tank diameter. 

(3) Vapor recovery systems used as a control device on any 

stationary tank, reservoir, or other container must maintain a minimum 

control efficiency of 90%. 

(b) For all persons in Gregg, Nueces, and Victoria Counties, 

the following requirements shall apply: 

(1) No person shall place, store, or hold in any stationary tank, reservoir, or other container any volatile organic compound 

(VOC), unless such container is capable of maintaining working pressure sufficient at all times to prevent any vapor or gas loss to the atmosphere, or is equipped with at least the control device specified in 

Table I(a) for VOC other than crude oil and condensate or Table II(a) 

for crude oil and condensate. 

(2) For floating roof storage tanks subject to the provisions 

of paragraph (1) of this subsection, the following requirements shall 

apply. 

(A) All openings in an internal or external floating roof, 

except for automatic bleeder vents (vacuum breaker vents) and rim 

space vents, must provide a projection below the liquid surface or be 

equipped with a cover, seal, or lid. Any cover, seal, or lid must be in 

a closed (i.e., no visible gap) position at all times, except when the device is in actual use. 

(B) Automatic bleeder vents (vacuum breaker vents) 

are to be closed at all times except when the roof is being floated off 

or landed on the roof leg supports. 

(C) Rim vents, if provided, are to be set to open only 

when the roof is being floated off the roof leg supports or at the manufacturer's recommended setting. 

(D) Any roof drain that empties into the stored liquid 

shall be equipped with a slotted membrane fabric cover that covers at 

least 90% of the area of the opening. 

(E) There shall be no visible holes, tears, or other openings in any seal or seal fabric. 

(F) For external floating roof storage tanks, secondary 

seals shall be the rim-mounted type (the seal shall be continuous from 

the floating roof to the tank wall). The accumulated area of gaps that 

exceed 118 inch (0.32 centimeter) in width between the secondary seal 

and tank wall shall be no greater than 1.0 square inch per foot (21 square 

centimeterslmeter) of tank diameter. 

(c) For all persons in Aransas, Bexar, Calhoun, Matagorda, 

San Patricio, and Travis Counties, the following requirements shall apply. 

(1) No person may place, store, or hold in any stationary 

tank, reservoir, or other container any VOC, other than crude oil or 

condensate, unless such container is capable of maintaining working 

pressure suffcient at all times to prevent any vapor or gas loss to the 

atmosphere, or is designed and equipped with at least the control device 

specified in Table I(b) for VOC other than crude oil and condensate. 

F'igure: 30 TAC $1 i5.112(c)(l) (No change.) 

(2) For floating roof storage tanks subject to the provisions 

of paragraph (1) of this subsection, the following requirements shall 

(A) There shall be no visible holes, tears, or other openings in any seal or seal fabric. 

(B) All tank gauging and sampling devices shall be vapor-tight except when gauging and sampling is taking place. 

(3) No person in Matagorda or San Patricio Counties shall 

place, store, or hold crude oil or condensate in any stationary tank, 

reservoir, or other container, unless such tank, reservoir, or other container is a pressure tank capable of maintaining working pressures sufficient at all times to prevent vapor or gas loss to the atmosphere or is 

equipped with one of the following vapor-loss control devices, properly maintained and operated: 

(A) an internal floating cover or external floating roof 

as defined in $ 11 5.10 of this title (relating to Definitions). This control 

eauipment shall not be permitted if the VOC has a true vapor pressure 

of: l i.0 psia (75.8 kPa) or greater. All tank-gauging and tak-sAmpling 

devices shall be vapor-tight, except when gauging or sampling is taking 

place; or 

(B) a vapor recovery system as defined in $1 15.10 of 

this title (relating to Definitions). 

(d) For all persons in the Houston/Galveston/Brau,ria area the 

following requirements apply beginning January 1, 2009. 

(1) No person shall place, store, or hold in any stationary 

tank, reservoir, or other container any VOC unless such container is capable of maintaining working pressure sufficient at all times to prevent 

any vapor or gas loss to the atmosphere, or is equipped with at least the 

control device specified in either Table I(a) of subsection (a)(]) of this 

section for VOC other than crude oil and condensate, or Table II(a) of 

subsection (a)(l) of this section for crude oil and condensate. 

(2) For floating roof storage tanks subject to the provisions 

of paragraph (1) of this subsection, the following requirements apply. 

(A) All openings in an internal floating cover or external floating roof as defined in $115.10 of this title (relating to Definitions) except for automatic bleeder vents (vacuum breaker vents), and 

rim space vents must provide a projection below the liquid surface. All 

openings in an internal floating cover or external floating roof except 

for automatic bleeder vents (vacuum breaker vents), rim space vents, 

leg sleeves, and roof drains must be equipped with a deck cover. The 

deck cover must be equipped with a gasket in good operating condition 

between the cover and the deck. The deck cover must be closed (i.e. 

no gap of more than 118 inch) at all times, except when the cover must 

be open for access. 

(B) Automatic bleeder vents (vacuum breaker vents) 

and rim space vents must be equipped with a gasketed lid, pallet, 

flapper, or other closure device and must be closed (i.e. no gap of more 

than 118 inch) at all times except when required to be open to relieve 

excess pressure or vacuum, in accordance with the manufacturer's 

design. 

(C) Each opening into the internal floating cover for a 

fixed roof support column may be equipped with a flexible fabric sleeve 

seal instead of a deck cover. 

@) Any roof drain that empties into the stored liquid 

must be equipped with a slotted membrane fabric cover that covers at 

32 TexReg 3198 June 8,2007 Texas Register 
least 90% of the area of the opening or an equivalent control that must 

be kept in a closed (i.e., no gap of more than 118 inch) position at all 

times except when the drain is in actual use. Stub drains on internal 

floating roof tanks are not subject to this requirement. 

(E) There must be no visible holes, tears, or other openings in any seal or seal fabric. 

(F) For external floating roof storage tanks, secondary 

seals must be the rim-mounted type (the seal must be continuous from 

the floating roof to the tank wall with the exception of gaps that do 

not exceed the following specification). The accumulated area of gaps 

that exceed 118 inch (0.32 centimeter) in width between the secondary 

seal and tank wall must be no greater than I .O square inch per foot (2 1 

square centimeters per meter) of tank diameter. 

(G) Each opening for a slotted guidepole in an external 

floating roof tank must be equipped with one of the control device configurations specified in clauses (i) - (vi) of this subparagraph. 

(i) A pole wiper and a pole float. The wiper or seal 

of the pole float must be at or above the height of the pole wiper. 

(ii) A pole wiper and a pole sleeve. 

(iii) An internal sleeve emission control system. 

(iv) Retrofit to a solid guidepole system. 

(v) A flexible enclosure system. 

(vi) A cover on an external floating roof tank. 

(H) The floating roof must be floating on the liquid sur- face at all times except when the floating roof is supported by the leg 

supports or other support devices (e.g., hangers from the fixed roof) 

during the initial fill (including refill after the tank has been degassed 

and cleaned in accordance with $5 115.541 - 115.547 of this title (relating to Degassing or Cleaning of Stationary, Marine, and Transport 

Vessels) or as allowed under the following circumstances: 

(i) when necessary for maintenance or inspection; 

(ii) when necessary for supporting a change in ser- vice to an incompatible liquid); 

(iii) when the storage tank has a capacity of less than 

25,000 gallons or the vapor pressure of the material stored is less than 

1.5 psia; 

(iv) when the vapors are routed to a control device 

from the time the floating roof is landed until the floating roof is within 

ten percent by volume of being refloated; 

(v) when all emissions from the tank, including 

emissions from roof landings, have been included in a floating roof 

storage tank emissions limit or cap approved under Chaptm 116 of 

this title (relating to Control of Air Pollution by Pennits for New 

Construction or Modification); or 

(vi) when all emissions from floating roof landings 

at the regulated entity as defined in $ 101.1 of this title (relating to Definitions) are less than 25 tons per year. 

(3) Vapor recovery systems used as a control device on any 

stationary tank, reservoir, or other container must maintain a minimum 

control efficiency of 90%. 

(4) Storage tanks storing condensate prior to custody transfer must mute flashed gases to a vapor recovery system or control &- 

vice if the liquid throughput through an individual tank or the aggregate of tanks in a tank battery exceeds 1,500 barrels (63,000 gallons) 

per year. 

(5) Storage tanks storing crude oil or condensate prior to 

custody transfer or at a pipeline breakout station must route flashed 

gases to a vapor recovery system or control device if the uncontrolled 

VOC emissions from an individual storage tank, or from the aggregate 

of tanks in a tank battery, have the potential to equal or exceed 25 tons 

per year on a rolling 12-month basis. Uncontrolled emissions must 

be estimated by one of the following methods; however, if emissions 

determined using direct measurements or other methods approved by 

the executive director under subparagraphs (A) or (D) of this paragraph 

are higher than emissions estimated using the default factors or charts 

in subparagraphs (B) or (C) of this paragraph, the higher values must 

be used: 

(A) direct measurement using the measuring instruments and methods specified in $1 15.115 of this title (relating to 

Approved Test Methods); 

(B) using a factor of 33.3 pounds of VOC per barrel (42 

gallons) of condensate produced or 1.6 pounds of VOC per barrel (42 

gallons) of oil produced; 

(C) for crude oil storage only, using the chart in Exhibit 

2 of the United States Environmental Protection Agency publication 

Lessons Learnedfrom Natural Gas STAR Partners: Installing Vapor 

Recovery Units on Crude Oil Storage Tanks, October 2003, and assuming that the hydrocarbon vapors have a molecular weight of 34 pounds 

per pound mole and are 48% by weight VOC; or 

@) other test method or computer simulation approved 

bv the executive director. 

~115.115. Approved Test Methoh. 

(a) For the BeaumontIPort Artj~ur, DallasiFort Worth, El Paso, 

and Houston/Galveston/Brazoria areas, compliance with $115.112(a) 

and (d) of this title (relating to Control Requirements) must be determined by applying the following test methods, as appropriate: 

(1) Test Methods 14 (40 Code of Federal Regulations 

(CFR) Part 60, Appendix A) for determining flow rates, as necessary; 

(2) Test Method 18 (40 CFR Part 60, Appendix A) for determining gaseous organic compound emissions by gas chromatography; 

(3) Test Method 22 (40 CFR Part 60, Appendix A) for visual determination of fugitive emissions from material sources and 

smoke emissions from flares; 

(4) Test Method 25 (40 CFR Part 60, Appendix A) for determining total gaseous nonmethane organic emissions as carbon; 

(5) Test Methods 25A or 25B (40 CFR Part 60, Appendix 

A) for determining total gaseous organic concentrations using flame 

ionization or nondispersive infrared analysis; 

(6) test method described in 40 CFR $60.1 13a(a)(l)(ii) (effective April 8,1987) for measurement of storage tank seal gap; 

(7) determination of true vapor pressure using American 

Society for Testing and Materials (ASTM) Test Methods D323-89, 

D2879, D4953, D5 190, or D5 191 for the measurement of Reid vapor 

pressure; or 

(8) minor modifications to these test methods approved by 

the executive director. 

(b) For Gregg, Nueces, and Victoria Counties, compliance 

with $115.112@) of this title shall be determined by applying the 

following test methods, as appropriate: 

(1) Test Methods 14 (40 Code of Federal Regulations 60, 

Appendix A) for determining flow rates, as necessary; 

ADOPTED RULES June 8,2007 32 TexReg 3199 
(2) Test Method 18 (40 Code of Federal Regulations 60, 

Appendix A) for determining gaseous organic compound emissions by 

gas chromatography; 

(3) Test Method 22 (40 Code of Federal Regulations 60, 

Appendix A) for visual determination of fugitive emissions from material sources and smoke emissions from flares; 

(4) Test Method 25 (40 Code of Federal Regulations 60, 

Appendix A) for determining total gaseous nonmethane organic emissions as carbon; 

(5) Test Methods 25A or 25B (40 Code of Federal Regulations 60, Appendix A) for determining total gaseous organic concentrations using flame ionization or nondispersive infrared analysis; 

(6) test method described in 40 CFR 60.1 13a(a)(l)(ii) (effective April 8, 1987) for measurement of storage tank seal gap; 

(7) determination of true vapor pressure using ASTM Test 

Methods D323-89, D2879, D4953, D5190, or D5191 for the measurement of Reid vapor pressure; or 

(8) minor modifications to these test methods approved by 

the executive director. 

(c) For the Houston/Galveston/Brazoria area, compliance with 

$ 1 15.1 12(d)(5) of this title may be determined by using the following 

measurement instruments or applying the following test methods, as 

appropriate: 

(1) mass flow meter, positive displacement meter, or similar device over a 24-hour period representative of normal operation 

for flow measurements of flash gases. For crude oil and natural gas 

production sites, the flow measurements must be made while the producing wells are operational; and 

(2) test methods referenced in subsection (a)(2), (4), and 

(5) of this section or Gas Processors Association Method 2286, Tentative Method of Extended Analysis for Natural Gas and Similar Mixtures by Temperature Programmed Gas Chromatography, to measure 

the concentration of VOC in the flashed gases; or 

(3) minor modifications to these test methods approved by 

the executive director. 

J115.116. Monitoring and Recordkeeping Requirements. 

(a) For all persons in the Beaumonflort Arthur, Dallas/Fort 

Worth, El Paso, and Houston/Galveston/Brazoria areas, the following 

recordkeeping requirements apply. 

(1) The owner or operator of any storage vessel with an external floating roof that is exempted from the requirement for a secondary seal as specified in 5 115.1 17(a)(l), (6), and (7) of this title (relating to Exemptions) and is used to store volatile organic compounds 

(VOC) with a true vapor pressure greater than 1.0 pounds per square 

inch absolute (psia) (6.9 kilo Pascals @Pa)) at storage conditions shall 

maintain records of the type of VOC stored and the average monthly 

true vapor pressure of the stored liquid. 

(2) The results of inspections required by $ 11 5.114(a) of 

this title (relating to Inspection Requirements) must be recorded. For 

secondary seal gaps that are required to be physically measured during 

inspection, these records must include a calculation of emissions for all 

secondary seal gaps that exceed 118 inch (0.32 centimeter) where the 

accumulated area of such gaps is greater than 1.0 square inch per foot 

(21 square centimeters per meter) of tank diameter. These calculated 

emissions inventory reportable emissions (Tr) must be reported in the 

annual emissions inventory submittal required by 101.10 of this title 

(relating to Emissions Inventory Requirements). The emissions must 

be calculated using the following methodology: 

(A) Allowable Seal Gap (greater than 118 inch wide): 

As (square inches) = 1 square inch per tank diameter foot x tank diameter. 

(B) Measured Seal Gap: Ms (square inches). 

(C) Reportable Seal Gap Area: Rs = Ms - As in square 

inches. 

(D) Reportable Seal GaplAllowable Ratio: RRs = Rs 

divided by As. 

(E) Tank Circumference: Tc (feet). 

(F) Reportable Seal Gap Length (total linear feet of seal 

gap greater than 118 inch gap width): Rl. 

(G) Reportable Seal Gap LengttuTank Circumference 

Ratio: RRI = RVTc. 

(H) Tank Emissions (with good single seal): Ts = Compilation of Air Pollutant Emission Factors (AP-42) Calculation (convert to poundslday). 

(I) Tank Emissions (with two good seals): Tss = AP-42 

Calculation (convert to poundslday). Note: Use maximum local 

monthly average ambient temperature as reported by the National 

Weather Service to calculate true vapor pressure. 

(J) Emissions Inventory Reportable emissions: Tr 

(pounds) = (Ts - Tss) x RRs x RRl x 90 days. Note: In no case should 

Tr be greater than (Ts - Tss). 

(3) Affected persons shall install and maintain monitors to 

continuously measure and record operational parameters of any of the 

following emission control devices installed to meet applicable control 

requirements. Such records must be sufficient to demonstrate proper 

functioning of those devices to design specifications, including: 

(A) the exhaust gas temperature immediately downstream of a direct-flame incinerator; 

(B) the inlet and outlet gas temperature of a chiller or catalytic incinerator; and 

(C) the exhaust gas VOC concentration of any carbon 

adsorption system, as defined in $1 15.10 of this title (relating to Definitions), to determine if breakthrough has occurred. 

(4) The results of any testing conducted in accordance with 

the provisions specified in $ 115.1 15(a) of this title (relating to Approved Test Methods) must be maintained at an affected facility. 

(5) All records must be maintained for two years and be 

made available for review upon request by authorized representatives 

of the executive director, the United States Environmental Protection 

Agency (EPA), or local air pollution control agencies with jurisdiction. 

(b) For all persons in Gregg, Nueces, and Victoria Counties, 

the following recordkeeping requirements shall apply. 

(1) The owner or operator of any storage vessel with an 

external floating roof which is exempted from the requirement for a 

secondary seal as specified in $1 15.1 17(b)(l), (6), and (7) of this title 

and used to store VOC with a true vapor pressure greater than 1.0 psia 

(6.9 kPa) at storage conditions shall maintain records of the type of 

VOC stored and the average monthly true vapor pressure of the stored 

liquid. 

(2) The results of inspections required by $1 15.1 14(b) of 

this title shall be recorded. 

32 Tdeg 3200 June 8,2007 Texas Register 
(3) In Victoria County, affected persons shall install and 

maintain monitors to continuously measure and record operational parameters of any of the following emission control devices installed to 

meet applicable control requirements. Such records must be sufficient 

to demonstrate proper functioning of those devices to design specifications, including: 

(A) the exhaust gas temperature immediately downstream of a direct-flame incinerator; 

(B) the inlet and outlet gas temperature of a chiller or 

catalytic incinerator; and 

(C) the exhaust gas VOC concentration of any carbon 

adsorption system, as defined in $ 11 5.10 of this title, to determine if 

breakthrough has occurred. 

(4) The results of any testing conducted in accordance with 

the provisions specified in $ 115.1 150) ofthis title shall be maintained 

at an affected facility. 

(5) All records shall be maintained for two years and be 

made available for review upon request by authorized representatives 

of the executive director, EPA, or local air pollution control agencies. 

(c) For all persons in the Houston/GalvestoniBrazoria area, the 

following recordkeeping requirements apply in addition to those specified in subsection (a) of this section. 

(1) The owner or operator of any stationary tank, reservoir, or container with a fixed roof that is not required to be equipped with a 

floating roof or vapor recovery system, as specified in either Table I(a) 

or TableII(a) of $ 11 5.112(a)(l)of this title (relating to Control Requirements), shall maintain records of the type of VOC stored, the starting 

and ending dates when the material is stored, and the true vapor pressure at the average monthly storage temperature of the stored liquid. 

This requirement does not apply to storage tanks with nominal storage 

capacity of 25,000 gallons or less storing volatile organic liquids other 

than crude oil or condensate, or to storage tanks with nominal storage 

capacity of 40,000 gallons or less storing crude oil or condensate. 

(2) The owner or operator of any storage tank that stores 

crude oil or condensate prior to custody transfer or at a pipeline breakout station and is not equipped with vapor recovery shall maintain 

records of the estimated annual emissions from the storage tank to document that the uncontrolled emissions are less than 25 tons per year. 

The records must be updated annually and must be made available for 

review within 72 hours upon request by authorized representatives of 

the executive director, the EPA, or local air pollution control agencies 

with jurisdiction. 

(a) For ail persons in the BeaumontPort Arthur, DallasFort 

Worth, El Paso, and Houston/Galveston/Brazoria areas, the following 

exemptions apply. 

(1) Except as provided in $115.116 of this title (relating 

to Monitoring and Recordkeeping Requirements), any volatile organic 

compound (VOC) with a true vapor pressure less than 1.5 pounds per 

square inch absolute (psia) (10.3 kilo Pascals (kF'a)) at storage conditions is exempt from the requirements of this division (relating to Storage of Volatile Organic Compounds). 

(2) Crude oil and condensate stored in tanks with a nominal capacity less than 210,000 gallons (794,850 liters), prior to custody 

transfer, is exempt fiom the requirements of this division. After January 1,2009, this exemption no longer applies in the Houston/Galveston/Brawria area. 

(3) Storage containers that have a capacity of less than 

25,000 gallons (94,625 liters) located at motor vehicle fuel dispensing 

facilities are exempt from the requirements of this division. 

(4) A welded tank with a mechanical shoe primary seal that 

has a secondary seal from the top of the shoe seal to the tank wall (a 

shoe-mounted secondary seal) is exempt from the requirement for retrofitting with a rim-mounted secondary seal if the shoe-mounted secondary seal was installed or scheduled for installation before August 

22, 1980. 

(5) External floating roof tanks storing waxy, high pour 

point crude oils are exempt from any secondary seal requirements of 

$1 15.1 12(a) of this title (relating to Control Requirements). 

(6) Any welded tank storing VOC having a true vapor pres- sure less than 4.0 psia (27.6 Ha) is exempt from any external floating 

roof secondary seal requirement if any of the following types of primary seals have been installed before August 22, 1980: 

(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(7) Any welded tank storing crude oil having a true vapor 

pressure equal to or greater than 4.0 psia (27.6 Ha) and less than 6.0 

psia (41.4 Ha) at storage conditions is exempt from any external floating roof secondary seal requirement if any of the following types of 

primary seals have been installed before December 10, 1982: 

(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(8) Storage containers that have a capacity of no more than 

1,000 gallons are exempt from the requirements of this division. 

(9) Condensate storage tanks or tank batteries with a 

throughput exceeding 1,500 barrels (63,000 gallons) per year are 

exempt from the requirement in $ 11 5.112(d)(4) of this title to route 

flashed gases to a vapor recovery system or control device if the owner 

or operator demonstrates using~test methods specified in $ 1 15.1 15(c) 

of this title, that uncontrolled VOC emissions from the individual tank, 

or from the aggregate of storage tanks in a tank battery, are less than 

25 tons per year on a rolling 12-month basis. 

(b) For all persons in Gregg, Nueces, and Victoria Counties, 

the following exemptions apply. 

(1) Except as provided in 4 115.1 16 of this title, any VOC 

with a true vapor pressure less than 1.5 psia (10.3 Ha) at storage conditions is exempt from the requirements of this division. 

(2) Crude oil and condensate stored in tanks with a nominal 

capacity less than 210,000 gallons (794,850 liters), prior to custody 

transfer, is exempt from the requirements of this division. 

(3) Storage containers which have a capacity of less than 

25,000 gallons (94,625 liters) located at motor vehicle fuel dispensing 

facilities are exempt from the requirements of this division. 

(4) A welded tank with a mechanical shoe primary seal 

which has a secondary seal from the top of the shoe seal to the tank 

wall (a shoe-mounted secondary seal) is exempt fiom the requirement 

for retrofitting with a rim-mounted secondary seal if the shoe-mounted 

secondary seal was installed or scheduled for installation before August 22, 1980. 

ADOPTED RULES June 8,2007 32 TexReg 3201 
(5) External floating roof tanks storing waxy, high pour 

point crude oils are exempt from any secondary seal requirements of 

4 11 5.1 12(b) of this title. 

(6) Any welded tank storing VOC having a true vapor pressure less than 4.0psia(27.6 kPa) is exempt from any external secondary 

seal requirementif any of the following types of primary seals have 

been installed before August 22, 1980: 

(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(7) Any welded tank storing crude oil having a true vapor 

pressure equal to or greater than 4.0 psia (27.6 kPa) and less than 6.0 

psia (41.4 kPa) at storage conditions is exempt from any external secondary seal requirement if any of the following types of primary seals 

have been installed before December 10, 1982: 

(A) a mechanical shoe seal; 

(B) a liquid-mounted foam seal; or 

(C) a liquid-mounted liquid filled type seal. 

(8) Storage containers which have a capacity of no more 

than 1,000 gallons are exempt from the requirements of this division. 

(c) For all persons in Aransas, Bexar, Calhoun, Matagorda, 

San Patricio, and Travis Counties, the following exemptions apply. 

(1) Any VOC with a true vapor pressure less than 1.5 psia 

(10.3 kPa) at storage conditions is exempt from the requirements of this 

division. 

(2) Slotted sampling and gauge pipes installed in any floating roof storage tank are exempt from the provisions of $1 15.1 12(c) of 

this title. 

(3) Storage tanks with nominal capacities between 1,000 

gallons (3,785 liters) and 25,000 gallons (94,625 liters) are exempt 

from the requirements of 4 115.112(~)(1) of this title if construction began before May 12, 1973. 

(4) Storage tanks with a nominal capacity of 420,000 gallons (1,589,700 liters) or less are exempt from the requirements of 

$ 1 15.11 2(c)(3) of this title. 

(5) Storage containers which have a capacity of no more than 1,000 gallons are exempt from the requirements of this division. 

$11 5.11 9. Counties and Compliance Schedules. 

(a) The owner or operator of each stationary tank, reservoir, or other container in which any volatile organic compound (VOC) is 

placed, stored, or held in Brazoria, Chambers, Collin, Dallas, Denton, El Paso, Fort Bend, Galveston, Hardin, Harris, Jefferson, Liberty, 

Montgomery, Orange, Tarrant, and Waller Counties shall continue to 

comply with this division (relating to Storage of Volatile Organic Compounds) as required by $1 15.930 of this title (relating to Compliance 

Dates). 

(b) The owner or operator of each stationary tank, reservoir, 

or other container in which any VOC is placed, stored, or held in Ellis, 

Johnson, Kaufman, Parker, and Rockwall Counties shall comply with 

this division as soon as practicable, but no later than March 1,2009. 

(c) The owner or operator of each stationary tank, reservoir, or other container in which any VOC is placed, stored, or held in Brazoria, 

Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and 

Waller Counties shall comply with the requirements of $5 11 5.11 2(d), 

115.1 15(c), and 11 5.116(c) of this title (relating to Control Requirements; Approved Test Methods; and Monitoring and Recordkeeping 

Requirements) as soon as practicable, but no later than January 1,2009. 

If compliance with these requirements would require emptying and degassing of the stationary tank, reservoir, or container, compliance is not 

required until the next time the stationary tank, reservoir, or container 

is emptied or degassed but no later than January 1,201 7. The owner 

or operator of each stationary tank, reservoir, or container with a nominal capacity less than 21 0,000 gallons (794,850 liters) storing crude oil 

and condensate prior to custody transfer in Brazoria, Chambers, Fort 

Bend, Galveston, Harris, Liberty, Montgomery, and Waller Counties 

shall comply with the requirements of this division as soon as practicable but no later than January 1,2009, regardless if compliance with 

these requirements would require emptying and degassing of the stationary tank, reservoir, or container. 

This agency hereby certifies thatthe adoption has been reviewed 

by legal counsel and found to be a valid exercise of the agency's 

legal authority. 

Filed with the Office of the Secretary of State on May 25, 2007. 

TRD-200702034 

Robert Martinez 

Director, Environmental Law Division 

Texas Commission on Environmental Quality 

Effective date: June 14, 2007 

Proposal publication date: December 29, 2006 

For further information, please call: (512) 239-6087 

SUBCHAPTER F. MISCELLANEOUS 

INDUSTRIAL SOURCES 

DIVISION 3. DEGASSING OR CLEANING OF 

STATIONARY, MARINE, AND TRANSPORT 

VESSELS 

30 TAC gg115.541- 115.547,115.549 

STATUTORY AUTHORITY 

The amendments are adopted under Texas Water Code, 

55.102, conceming General Powers, 55.103, concerning Rules, 

and s5.105, concerning General Policy, that authorize the 

commission to adopt rules necessary to carry out its powers and 

duties under the Texas Water Code; and under Texas Health 

and Safety Code, s382.017, conceming Rules, that authorizes 

the commission to adopt rules consistent with the policy and 

purposes of the Texas Health and. Safety Code, Chapter 382 

(also known as the Texas Clean Air Act). The amendments are 

also adopted under Texas Health and Safety Code, s382.002. 

conceming Policy and Purpose, that establishes the commission's purpose to safeguard the state air resources, consistent 

with the protection of public health, general welfare, and physical property; s382.011, concerning General Powers and Duties, 

that authorizes the commission to control the quality of the 

state's air; s382.012, conceming State Air Control Plan, that 

authorizes the commission to prepare and develop a general. 

comprehensive plan for the control of the state's air; 5382.014, 

conceming Emission Inventory, which authorizes the commission to require the submission of information concerning the 

emission of air contaminants; and s382.016, concerning Monitoring Requirements; Examination of Records, which authorizes 

the commission to require owners and operators of emission 

sources to maintain measuring and monitoring records and 

32 TexReg 3202 June 8,2007 Texas Register 
make such records available to the commission. The rules are 

adopted under federal mandates contained in 42 USC, 57410, 

that require states to introduce pollution control measures in 

order to reach specific air quality standards in particular areas 

of the state. 

The adopted amendments implement Texas Health and Safety 

Code, §§382.002, 382.011, 382.012, 382.014, and 382.016. 

$11 5.541. Emission Specifications. 

(a) For all persons in the Beaumonflort Arthur, DallasFort 

Worth, El Paso, and HoustodGalveston/Brazoria areas as defined in 

$1 15.10 of this title (relating to Definitions), the following emission 

specifications apply to degassing during or in preparation of cleaning. 

(1) For all stationary volatile organic compound (VOC) 

storage tanks with a nominal storage capacity of one million gallons or 

more and after January 1, 2009, storage tanks in the HoustodGalvestonlBrazoria area with a nominal storage capacity of 250,000 gallons 

or greater or with a nominal storage capacity of 75,000 gallons or 

greater storing materials with a true vapor pressure greater than 2.6 

pounds per square inch absolute (psia). 

(A) No person shall permit VOC emissions with a vapor 

space partial hter than or equal to 0.5 psia (3.4 kilo pascals 

(@a)) under actual storage conditions unless the vapors are processed 

by a vapor control system. 

(B) The vapor control system must maintain a control 

efficiency of at least 90%. 

(C) When conducting degassing or cleaning operations, 

no avoidable liquid or gaseous leaks, as detected by sight or sound, may 

originate from the degassing or cleaning operations. 

@) The intentional bypassing of a vapor control device 

used during degassing or cleaning is prohibited. Any visible VOC leak 

originating from the vapor control device or other associated product 

recovery device must be repaired as soon as practical. 

(2) For all transport vessels, as defined in $ 1 15.10 of this 

title, with a nominal storage capacity of 8,000 gallons or more. 

(A) No person shall permit VOC emissions with a vapor 

space partial pressure greater than or equal to 0.5 psia (3.4 kPa) under 

actual storage conditions unless the vapors are processed by a vapor 

control system. 

(B) The vapor control system must maintain a control 

efficiency of at least 90%. 

(C) When conducting degassing or cleaning operations, no avoidable liquid or gaseous leaks, as detected by sight or sound, may 

originate from the degassing or cleaning operations. 

@) The intentional bypassing of a vapor control device 

used during degassing or cleaning is prohibited. Any visible VOC leak 

originating from the vapor control device or other associated product 

recovery device must be repaired as soon as practical. 

(E) All transport vessels, as defined in $1 15.10 of this 

title, must be kept vapor-tight at all times until the VOC vapors remaining in the vessel are discharged to a vapor control system. 

(b) For all persons in the Beaumonflort Arthur and HoustodGalveston/Brazoria areas, the following emission specifications 

apply to degassing during or in preparation of cleaning for all marine 

vessels, as defined in $ 101.1 of this title (relating to Definitions), that 

have a nominal storage capacity of 10,000 barrels (420,000 gallons) 

or more and contain VOC. 

(1) No person shall degas or clean a tank that carried a VOC 

with a vapor partial pressure greater than or equal to 0.5 psia (3.4 kPa) 

unless the vapors are processed by a vapor control system. 

(2) The vapor control system must maintain a control efficiency of at least 90%. 

(3) When conducting degassing or cleaning operations, no avoidable liquid or gaseous leaks, as detected by sight or sound, may 

originate from the degassing or cleaning operations. 

(4) The intentional bypassing of a vapor control device 

used during degassing or cleaning is prohibited. Any visible VOC leak 

originating from the vapor control device or other associated product 

recovery device must be repaired as soon as possible. 

(5) All marine vessels, as defined in $101.1 of this title, 

containing VOC must have all cargo tank closures properly secured, or 

maintain a negative pressure within the tank when a closure is opened, 

and must have all pressure/vacuum relief valves operating within certified limits as specified by classification society or Rag state until the 

vapors are discharged to a vapor control system if the vessel is degassed 

or cleaned. 

$1 15.542. Control Requirements. 

(a) For all persons in the Beaumonflort Arthur, DallasFort 

Worth, El Paso, and Houston/Galveston/Brazoria areas as defined in 

$1 15.10 of this title (relating to Definitions), the following control requirements apply to stationary storage tanks and tmnsport vessels. 

(1) No person shall permit the degassing or cleaning of 

volatile organic compounds (VOC) from a stationary storage tank or 

transport vessel unless the vapors are processed by a vapor control system. 

(2) When degassing or cleaning is effected through the 

hatches of a transport vessel with a loading arm equipped with a vapor 

collection adapter, then pneumatic, hydraulic, or other mechanical 

means must be provided to force a vapor-tight seal between the adapter 

and the hatch. A means must be provided to minimize liquid drainage 

from the degassing or cleaning device when it is removed from the 

hatch of any transport vessel or to accomplish drainage before such 

removal. 

(3) When degassing or cleaning is effected through the 

hatches or manways of stationary VOC storage tanks, all lines must 

be equipped .with fittings that make vapor-tight connections and that 

are closed when disconnected; or equipped to pennit residual VOC in 

the line to discharge into a recovery or disposal system after degassing 

or cleaning is complete. 

(4) Degassing and cleaning equipment must be designed 

and operated to prevent avoidable VOC leaks. 

(5) In the Beaumonflort Arthur, DallasFort Worth, El 

Paso, and until January 1, 2009, in the Houston/Galveston/Brazoria 

areas, vapors must be routed to the control device until a turnover of 

at least four vapor space volumes has occurred, or four turnovers of 

the vapor space under a floating roof, or the partial vapor pressure 

is less than 0.5 pounds per square inch absolute (psia) (19,000 parts 

per million by weight (ppmw), or 34,000 parts per million by volume 

(ppmv) expressed as methane). After one of these conditions has been 

satisfied, the storage tank or transport vessel may be vented to the 

atmosphere for the remainder of the degassing or cleaning process. 

(6) After January 1, 2009, in the Houston/Galveston/Brazoria area, vapors must be routed to the control device until the VOC 

measuredconcentration before the inlet to the control device is less than 

34,000 ppmv as methane or less than 50% of the lower explosive limit 

(LEL). After this condition has been satisfied,-the storage tank or bansADOPTED RULES June 8,200 7 32 TexReg 3203 
port vessel may be vented to the atmosphere for the remainder of the 

degassing or cleaning process provided that the VOC concentration remains below 34,000 ppmv as methane or less than 50% of the LEL. The 

VOC concentration must be measured once every 12 hours if the storage tank or transport vessel is vented continuously to the atmosphere, 

and upon restart of the degassing and cleaning operation if venting to 

the atmosphere has been suspended for more than four hours. If any 

measurements of the VOC concentration equal or exceed 34,000 ppmv 

as methane or are equal to or greater than 50% of the LEL, the storage 

tank or transport vessel must be routed to the control device until the 

concentration is below 34,000 ppmv as methane or less than 50% of 

the LEL. While venting to the atmosphere, measurements must continue until five consecutive readings of VOC concentrations collected 

at 12 hour intervals are measured to be less than 34,000 ppmv or less 

than 50% of the LEL. 

(b) For all persons in the BeaumontPort Arthur and Houston/Galveston/Brazoria areas, the following control requirements apply to marine vessels. 

(1) No person shall permit the degassing or cleaning of a marine vessel containing VOC unless the vapors are processed by a 

vapor control system. 

(2) When degassing or cleaning is effected through the 

hatches of a marine vessel containing VOC with a loading arm 

equipped with a vapor collection adapter, then pneumatic, hydraulic, 

or other mechanical means must be provided to force a vapor-tight 

seal between the adapter and the hatch, or a negative pressure inside 

the cargo tank must be maintained. A means must be provided to 

minimize liquid drainage from the degassing or cleaning device and 

line when they are removed from the hatch of any marine vessel 

containing VOC or to accomplish drainage before such removal. 

(3) Degassing and cleaning equipment must be designed 

and operated to prevent avoidable VOC leaks. 

(4) In the BeaumontPort Arthur area and until January 1, 

2009, in the Houston/Galveston/Brazoria area, vapors must be routed 

to the control device until the marine vessel is stripped VOC liquid-free 

and a turnover of at least four vapor space volumes has occurred, the 

partial vapor pressure is less than 0.5 psia (19,000 ppmw, or 34,000 

ppmv expressed as methane), or the concentration of VOC is less than 

20% of the LEL. After one of these conditions has been satisfied, the 

marine vessel may be vented to the atmosphere for the remainder of 

the degassing or cleaning process. 

(5) After January 1, 2009, in the HoustoniGalveston/Brazoria area, vapors must be routed to the control device until the VOC 

measured concentration before the inlet to the control device is less than 

34,000 ppmv as methane or less than 50% of the LEL. After this condition has been satisfied, the marine vessel may be vented to the atmosphere for the remainder of the degassing or cleaning process provided 

that the VOC concentration remains below 34,000 ppmv as methane 

or less than 50% of the LEL. The VOC concentration must be measured once every 12 hours if the marine vessel is vented continuously 

to the atmosphere, and upon restart of the degassing and cleaning operation if venting to the atmosphere has been suspended for more than 

four hours. If any measurements of the VOC concentration equal or 

exceed 34,000 ppmv as methane or are equal to or greater than 50% of 

the LEL, the marine vessel must be routed to the control device until 

the concentration is below 34,000 ppmv as methane or less than 50% 

of the LEL. While venting to the atmosphere, measurements must continue until five consecutive readings of VOC concentrations collected 

at 12-hour intervals are measured to be less than 34,000 ppmv or less 

than 50% of the LEL. 

J115.543. Alternote Conml Requirements. 

For all persons in the BeaumontPort Arthur, DallaslFort Worth, El 

Paso, and Houston/Galveston/Brazoria areas as defined in 5 1 15.10 of 

this title (relating to Definitions), alternate methods of demonstrating 

and documenting continuous compliance with the applicable control 

requirements or exemption criteria in this division (relating to Degassing or Cleaning of Stationary, Marine, and Transport Vessels) may 

be approved by the executive director in accordance with 5115.910 

of this title (relating to Availability of Alternate Means of Control) if 

emission reductions are demonstrated to be substantially equivalent. 

J115.544. Inspection Requirements. 

For all persons in the BeaumontPort Arthur, DallaslFort Worth, El 

Paso, and Houston/Galveston/Brazoria areas as defined in 5 115.10 of 

this title (relating to Definitions), the following inspection requirements 

apply. 

(1) Inspection for visible liquid leaks, visible fumes, or significant odors resulting from volatile organic compound (VOC) transfer operations must be conducted during each degassing or cleaning 

operation by the owner or operator of the VOC degassing and cleaning 

facility. 

(2) VOC degassing or cleaning through the affected transfer lines must be discontinued when a leak is observed and the leak 

cannot be repaired within a reasonable length of time. The intentional 

bypassing of a vapor control device during cleaning or degassing is 

prohibited. 

J115.545. Approved Test Methods. 

For the BeaumontTort Arthur, DallaslFort Worth, El Paso, and Houston/Galveston/Brazoria areas as defined in 5 1 15.10 of this title (relating 

to Definitions), compliance with 5115.541 and 5115.542 of this title 

(relating to Emission Specifications and Control Requirements) must 

be determined by applying the following test methods, as appropriate: 

(1) Test Methods 1-4 (40 Code of Federal Regulations 

(CFR) Part 60, Appendix A) for determining flow rates; 

(2) Test Method 18 (40 CFR Part 60, Appendix A) for determining gaseous organic compound emissions by gas chromatography; 

(3) Test Method 25 (40 CFR Part 60, Appendix A) for determining total gaseous nonmethane organic emissions as carbon; 

(4) Test Methods 25A or 25B (40 CFR Part 60, Appendix 

A) for determining total gaseous organic concentrations using flame 

ionization or nondispersive infrared analysis; 

(5) additional test procedures described in 40 CFR 

§60.503@), (c), and (d) (effective February 14, 1989) for determining 

compliance for bulk gasoline terminals; 

(6) Test Method 21 (40 CFR Part 60, Appendix A) for determining volatile organic compound (VOC) leaks; 

(7) determination of true vapor pressure using American 

Society for Testing and Materials (ASTM) Test Method D323-89, 

D2879, D4953, D5190, or D5191 for the measurement of Reid vapor 

pressure, adjusted for actual storage temperature in accordance with 

API Publication 2517, Third Edition, 1989; 

(8) Test Method 27 (40 CFR Part 60, Appendix A) for determining tank-truck leaks; 

(9) 40 CFR §63.565(c) (effective September 19, 1995) or 

40 CFR §61.304(f) (effective October 17,2000) for determination of 

marine vessel vapor tightness; 

(10) minor modifications to these test methods approved 

by the executive director; or 

32 TpxReg 3204 June 8, 2007 Taas Register 
(11) VOC concentration measurements required by 

0 115.542(a)(6) and (b)(5) of this title (relating to Control Requirements) must be performed using one of the methods or measurement 

instruments listed in subparagraphs (A) - (F) of this paragraph. 

(A) Test Method 2 1 (40 CFR Part 60, Appendix A). The 

instrument response factor criteria in $8.1 of the United States Environmental Protection Agency Method 21 may be determined using the 

average composition of the liquid in the tank rather than for each individual liquid. 

(B) Test Method 18 (40 CFR Part 60, Appendix A) except that only one bag sample needs to be collected for each concentration measurement. 

(C) Bag samples, provided the means of collecting the 

sample and the type of bag used are appropriate and representative of 

the type of space being sampled and the analytical method used to evaluate bag contents are appropriate for the concentration levels and cornpound types. 

(D) Test Method 25A (40 CFR Part 60, Appendix A). 

(E) Portable hydrocarbon gas analyzer using an appropriate detector that is effective in the concentration range being measured and calibrated with compounds of interest in each case. Analyzers must be calibrated and maintained according to manufacturer's 

specifications. 

(F) Lower explosive limit detector. The detector must 

be calibrated and maintained according to manufacturer's specifications. 

$115.546. Monitoring and Recordkeeping Requirements. 

For facilities in the Beaumonflort Arthur, DallaslFort Worth, El Paso, 

and Houston/Galveston/Brazoria areas as defined in tj 1 15.1 0 of this title (relating to Definitions) affected by tj1 15.541 and 0115.542 of this 

title (relating to Emission Specifications and Control Requirements), 

the owner or operator of any volatile organic compound (VOC) degassing or cleaning facility shall maintain the following information 

at the facility for at least two years and shall make such information 

available upon request to representatives of the executive director, the 

United States Environmental Protection Agency, or any local air pollution control agency having jurisdiction in the area: 

(1) for storage tank, transport vessel, or marine vessel degassing or cleaning operations: 

(A) a record of the type and number of all transport vessels, stationary VOC storage tanks, and marine vessels that are degassed or cleaned at the affected facility; 

(B) the chemical name and estimated liquid quantity of 

VOC contained in each vessel prior to degassing or cleaning; 

(C) the chemical name and estimated liquid quantity of 

VOC removed from each storage tank, transport vessel, or marine vessel; and 

@) after January 1, 2009, in the HoustodGalveston/Brazoria area, a record of the measurements of VOC concentration or percent of lower explosive limit from the storage tank, transport 

vessel, or marine vessel being degassed while the tank or vessel is 

vented to the atmosphere; 

(2) for vapor control systems: 

(A) continuous monitoring and recording of the exhaust 

gas temperature immediately downstream of a direct-flame incinerator; 

(B) continuous monitoring and recording of the inlet 

and outlet gas temperature of a catalytic incinerator; and 

(C) continuous monitoring and recording of the exhaust 

gas VOC concentration for carbon adsorption systems that contain facilities to regenerate the carbon bed directly, as defined in 01 15.10 of 

this title (relating to Definitions); or periodic monitoring of the exhaust 

gas VOC as specified by 40 Code of Federal Replations $61.354(d) 

(effective October 17,2000), of any carbon adsorption systemthat does 

not regenerate the carbon bed directly, to determine breakthrough; 

(3) the results of any leak inspection and repair conducted 

in accordance with the provisions specified in 81 15.544 of this title 

(relating to Inspection Requirements); and 

(4) the results of any testing conducted in accordance with 

the provisions specified in $ 115.545 of this title (relating to Approved 

Test Methods). 

$115.547. Exemptions. 

For all persons in the Beaumonflort Arthur, DallasEort Worth, El 

Paso, and Houston/Galveston/Brazoria areas as defined in tj115.10 of 

this title (relating to Definitions), the following exemptions apply. 

(1) Degassing or cleaning any storage tank, transport vessel, or marine vessel with a vapor space partial pressure less than 0.5 

pounds per square inch absolute (psia) (3.4 kilo Pascals) of volatile organic compound (VOC) under actual storage conditions is exempt from 

the requirements of this division (relating to Degassing or Cleaning of 

Stationary, Marine, and Transport Vessels). 

(2) Degassing or cleaning any transport vessel with a nom- inal storage capacity of less than 8,000 gallons, or any stationary VOC 

storage tank with a nominal storage capacity of less than 1 million gallons, or any marine vessel with a nominal storage capacity of less than 

10,000 barrels (420,000 gallons), is exempt from the requirements of 

this division. Akr January 1, 2009, stationary VOC storage tanks in 

the Houston/Galveston/Brazoria area with a nominal storage capacity 

and vapor pressure of stored liquid as listed in subparagraphs (A) and 

(B) of this paragraph are no longer exempt from the requirements of 

this division. 

(A) Storage tanks with nominal storage capacity greater 

than or equal to 250,000 gallons but less than 1 million gallons. 

(B) Storage tanks with nominal storage capacity greater 

than or equal to 75,000 gallons but less than 250,000 gallons storing 

materials with true vapor pressure greater than 2.6 psia. 

(3) Any stationary VOC storage tank during preventative 

maintenance, roof repair, primary seal inspection, or removal and installation of a secondary seal, if product is not moved in or out of the 

storage tank, emissions are minimized, and the repair is completed 

within seven calendar days, is exempt from the requirements of this 

division. 

(4) Any marine vessel that has sustained damage that 

prevents a cargo tank's opening from being properly secured, causes 

the onboard vapor recovery system to be inoperative, or prevents 

the pressure/vacuum relief valves fromoperating within certifid 

limits as specified by classification society or flag state is exempt 

from $ 1 15.541 (b) and $1 15.542(b) of this title (relating to Emission 

Specifications and Control Requirements); however, all reasonable 

measures must be taken to minimize VOC emissions. 

(5) Any oceangoing, self-propelled marine vessel is exempt from the degassing or cleaning requirements of this division. 

This agency hereby certif~es that the adoption has been reviewed 

by legal counsel and found to be a valid exercise of the agency's 

legal authority. 

Filed with the Office of the Secretary of State on May 25.2007. 

ADOPTED RULES June 8,200 7 32 TexReg 3205 
TRD-200702035 

Robert Martinez 

Director, Environmental Law Division 

Texas Commission on Environmental Quality 

Effective date: June 14. 2007 

Proposal publication date: December 29,2006 

For further information, please call: (512) 239-6087 

+ + + 

CHAPTER 117. CONT 

POLLUTION FROM NI 

The Texas Commission 

commission) adopts the repeal o 

117.105 - 117.111, 117.113 - 117.119. 117.121. 

117.131, 117.133 - 117.135, 

117.143, 117.145, 117.147, 

117.203, 117.205 - 117.211, 

117.221, 117.223,117.260,117. .265.117.273,117.279, 

117.283, 117.301, 117.305,117. .311.117.313,117.319, 

117.321, 117.401, 117.405,117. .411,117.413,117.419, 

117.421, 117.451, 117.455, 117. .460,117.461,117.463, 

117.465.117.467, 117.469, 117. 

117.479, 117.481,117.510, 1 

117.534, 117.570. and 117. 

new §§117.10, 117.100, 

117.123, 117.125, 117.130, 

117.152,117.154.117.156, 

117.215, 117.223,117.225, 

117.252.117.254,117.256, 

117.315,117.320,117.323, 

117.345, 11 7.350,117.352, 

117.4 10. 11 7.423,117.425, 

11 7.450, 11 7.454, 117.45 

117.1010, 117.1015, 117.1 

117.1045, 117.1052, 117.1 

117.1105, 117.1110, 117 

117.1140, 117.1145, 117 

117.1203, 117.1205, 117 

117.1235, 117.1240, 117 

117.1300, 117.1303, 117.1 

117.1345, 117.1350, 117.1 

117.2010, 117.2025, 117 

117.2103. 117.2110, 117 

117.3000, 117.3003, 117 

117.3035, 117.3040, 117 

117.3101, 117.3103, 117 

117.3140, 117.3142, 117 

117.3205, 117.3210, 117 

117.3325, 117.3330, 117 

11 7.4025, 11 7.4035, 11 7 

117.4105, 117.4125, 117 

117.4200, 117.4205. 117 

117.8110, 117.8120, 117 

11 7.9020, 11 7.9030, 117 

117.9200, 117.9210, 117 

117.9800, and 117.9810. 

117.1210(b), 117.1225, 

117.2025, 117.2110(h), 

117.3123(f), 117.3125, 7.3325. Sections 

117.110(c), 117.125, 11 7.310(c), 117.325, 

117.1010(b), 117.1025, 

117.1225, 117.2010(i), 1 

correspond to portions 

cluded from the EPA-app Sections 11 7.41 0(d), 

.2110(h), 117.2125, 

17.3325 are portions 

that have not previThe commission ad 117.10, 117.101, 

Chapter 117 will be sub- adopted without changes and the t will not be republished. 

BACKGROUND AND SUMMARY THE FACTUAL FO~ THE ADOPTED RLILES 

cept for the following 

GENERAL BACKGROUND 

P 

32 TexReg 3206 June 8,2007 Texas Register