April 7, 2009

Mr. K. C. Hustvedt

US EPA

Office of Air Quality Planning and Standards

Mail Drop E143-01

Research Triangle Park, NC 27711

Hustvedt.Ken@epamail.epa.gov

Re: Environmental Protection Agency’s (EPA’s) National Emission Standards for 

Hazardous Air Pollutants From Petroleum Refineries: Final Rule.

The American Petroleum Institute (API) and the National Petrochemical and Refiners 

Association (NPRA) submit these suggestions on the Environmental Protection Agency’s 

(EPA’s) “National Emission Standards for Hazardous Air Pollutants From Petroleum Refineries:

Final Rule” as posted on the EPA Office of Air and Radiation Policy and Guidance Website on 

January 16, 2009. We believe there are some clarifications and corrections that could make the 

rule clearer and consistent with the stated intent.

1. Compliance schedule and applicability provisions in §63.640(h).

We believe the following revisions are needed to§63.640(h) in order to clearly and properly 

reflect the intent as indicated in the preamble and to correct editorial errors. 

(h)(1) Changing "and" to "through", which is clearly the intent.

(h)(1)(i) and (iii) Changing "Storage vessels" to "Group 1 storage vessels", for 

correctness and for consistency with (h)(4).

(h)(1)(i) through (iv) Changing the sentence structure to clarify that the date of 

construction/reconstruction is referring to the entire source, rather than to the individual 

storage vessel or heat exchange system.

(h)(1)(i) and (ii) Correcting the date upon which the original new source requirements 

kicked in, from August 18, 1995 to July 14, 1994. As shown in (h)(1), the trigger date 

for new construction under the original rule was July 14, 1994. August 18, 1995 was the 

date of rule promulgation, but applicability was based on the proposal date.

(h)(2) Adding a paragraph return to separate this paragraph from (h)(1)(iv).
(h)(4)(ii) Editing the text for correctness and for consistency with (h)(4)(i).

(h)(1)(i) and (h)(4)(iii) Revising the language to clarify that compliance with §63.646(a) 

through (l) is no longer required once compliance with §63.646(m) is achieved. 

Currently this language could be read to assume both sets of requirements apply, despite 

the language in §63.646(a) on this point. This important point need to be made clear in 

§63.640(h) as well as in §63.646(a).

We suggest the following specific revisions to the text in the posted rule to accomplish these 

changes.

(1) Except as provided in paragraphs (h)(1)(i) andthrough (iv) of this section, new 

sources that commence construction or reconstruction after July 14, 1994, shall be in 

compliance with this subpart upon initial startup or August 18, 1995, whichever is later. 

(i) Storage vessels aAt a new sources that commenced construction or reconstruction 

after July 14, 1994August 18, 1995, but before September 4, 2007, Group 1 storage 

vessels shall comply with the new source requirements for storage vessels specified in 

§63.646(a) through (l) upon startup. and tCompliance with the new source requirements 

for storage vessels specified in §63.646(m) shall be achieved in place of the 

requirements in §63.646(a) through (l) no later than [INSERT DATE 36 MONTHS 

AFTER DATE OF PUBLICATION]. 

(ii) Heat exchange systems aAt a new sources that commenced construction or 

reconstruction after July 14, 1994August 18, 1995, but before September 4, 2007, heat 

exchange systems shall comply with the existing source requirements for heat exchange 

systems specified in §63.654 no later than [INSERT DATE 36 MONTHS AFTER 

DATE OF PUBLICATION] 

(iii) Storage vessels aAt a new sources that commences construction or reconstruction 

after September 4, 2007, Group 1 storage vessels shall be in compliance with the new 

source requirements in §63.646(m) upon initial startup or [INSERT DATE OF 

PUBLICATION], whichever is later. 

(iv) Heat exchange systems aAt a new sources that commences construction or 

reconstruction after September 4, 2007, heat exchange systems shall be in compliance 

with the new source requirements in §63.654 upon initial startup or [INSERT DATE 

OF PUBLICATION], whichever is later.

(2) Except as provided in paragraphs (h)(3) through (h)(6) of this section, existing 

sources shall be in compliance with this subpart no later than August 18, 1998, except 

as provided in §63.6(c)(5) of subpart A of this part, or unless an extension has been 

granted by the Administrator as provided in §63.6(i) of subpart A of this part. 
* * * * * 

(4) A Group 1 storage vessel that is part of an existing source shall be in compliance 

with §63.646 as specified in paragraphs (h)(4)(i) through (h)(4)(iii). 

(i) Except for existing floating roof storage vessels, a Group 1 storage vessel that is part 

of an existing source shall be in compliance with §63.646(a) through (l) of this subpart 

no later than August 18, 1998. An owner or operator may elect to comply with 

§63.646(m) of this subpart instead of §63.646(a) through (l) of this subpart. 

(ii) Existing GA group 1 floating roof storage vessels that is part of an existing source 

shall be in compliance with §63.646(a) through (l) of this subpart at the first degassing 

and cleaning activity after August 18, 1998, or August 18, 2005, whichever is first. An 

owner or operator may elect to comply with §63.646(m) of this subpart instead of 

§63.646(a) through (l) of this subpart. 

(iii) All Group 1 storage vessels that are part of an existing source shall complybe in 

compliance with §63.646(m) of this subpart instead of §63.646(a) through (l) of this 

subpart no later than [INSERT DATE 36 MONTHS FROM DATE OF 

PUBLICATION].

2. Overlap provisions for storage vessels in §63.640(n).

We believe the following revisions are needed to§63.640(n) in order to clearly and properly 

reflect the intent as indicated in the preamble and to correct editorial errors. 

(n)(1), (n)(3), & (n)(4) Consolidating the overlap provisions for Group 2 tanks and 

NSPS subpart Kb (Kb) into (n)(3) & (n)(4), and additionally addressing overlap of Group 

2 tanks and Part 61 subpart Y (61 Y) in (n)(3).

(n)(1) & (n)(2) Separating new sources from existing sources in the overlap provisions 

for Group 1 tanks and either Kb or 61 Y, with existing sources addressed in (n)(1) and 

new sources in (n)(2).

(n)(1) Stipulating that, when opting to comply with subpart WW in lieu of Kb or 61 Y 

for an internal floating roof storage vessel at an existing source, the deck fitting 

requirements of §63.1063(a)(2) are required. While §63.646(m)(2) exempts internal 

floating roof storage vessels at existing facilities from these requirements, these controls 

are required by Kb and by 61 Y, and thus should be required in the event of overlap with 

either of those rules.

(n)(3) Adding overlap with 61 Y to this provision for overlap of Group 2 tanks and Kb.

(n)(3) & (n)(4) Deleting the reference to new sources, thereby rendering these provisions 

applicable to both new and existing sources.
We suggest the following specific revisions to the text in the posted rule to accomplish these 

changes. Note that §63.640(n)(3) and (4) were not revised in these amendments.

(n) Overlap of subpart CC with other regulations for storage vessels. As applicable, 

paragraphs (n)(1), (n)(3), (n)(4), (n)(6), and (n)(7) of this section apply for Group 2 

storage vessels and paragraphs (n)(1), (n)(2) and (n)(5) of this section apply for Group 1 

storage vessels. 

(1) After the compliance dates specified in paragraph (h) of this section, a Group 12

storage vessel that is part of an existing source and is also subject to the provisions of 

40 CFR part 60, subpart Kb and/or 40 CFR part 61, subpart Y, is required to comply 

only with the requirements of 40 CFR part 60, subpart Kb, except as provided in 

paragraph (n)(8) of this section; 40 CFR part 61, subpart Y except as provided in 

paragraph (n)(10) of this section; or this subpart except that §63.1063(a)(2) does apply 

to internal floating roof storage vessels. 

(2) After the compliance dates specified in paragraph (h) of this section, a Group 1 

storage vessel that is part of a new source and is also subject to 40 CFR part 60, subpart 

Kb and/or 40 CFR part 61, subpart Y is required to comply only with 40 CFR part 60, 

subpart Kb except as provided in paragraph (n)(8) of this section; 40 CFR part 61, 

subpart Y except as provided in paragraph (n)(10) of this section; or this subpart.

(3) After the compliance dates specified in paragraph (h) of this section, a Group 2 

storage vessel that is part of a new source and isalso subject to the control requirements 

in §60.112b of 40 CFR part 60, subpart Kb and/or §61.271 of 40 CFR part 61, subpart 

Y is required to comply only with 40 CFR part 60, subpart Kb except as provided in 

paragraph (n)(8) of this section or 40 CFR part 61, subpart Y except as provided in 

paragraph (n)(10) of this section.

(4) After the compliance dates specified in paragraph (h) of this section, a Group 2 

storage vessel that is part of a new source and isalso subject to 40 CFR 60.110b, but is 

not required to apply controls by 40 CFR 60.110b or 60.112b is required to comply only 

with this subpart.

3. Deck fitting controls for internal floating roofs.

The rule requires, as it always has, the control of deck fittings for floating roof storage vessels at 

new sources (the rule now refers to Part 63 subpart WW rather than to Part 63 subpart G for the 

specific requirements, but the requirements in these two rules are substantially equivalent). The 

understood intent of the rule is to exempt internal floating roof storage vessels at existing sources 

from the requirement for controlled deck fittings, but to require these controls at new sources. 

The new language, however, inexplicably exempts internal floating roof storage vessels at new 

sources from the requirement to control the deck fittings for slotted and unslotted guidepoles. 
This would seem to be an oversight, which would be corrected by striking the last sentence in 

paragraph §63.646(m)(2).

§63.646(m)(2) For purposes of this subpart, §63.1063(a)(2) does not apply to internal 

floating roof storage vessels at existing sources subject to this subpart. For purposes of 

this subpart, §§63.1063(a)(2)(vii) and (viii) do not apply to internal floating roof storage 

vessels at new sources subject to this subpart.

4. MACT reporting paradigm for overlap with Part 61 subpart Y.

The MACT rule requires reporting of inspection results only if an inspection failure has been 

observed, and allow for these reports to be gathered into semi-annual periodic reports. The 

overlap provisions allow this same reporting paradigm to be applied to other rules that apply to 

the same emission points (consistent with EPA’s Recordkeeping and Reporting Burden 

Reduction Rule of February 12, 1999). The new language, however, applies this paradigm only 

to failed seal gap measurements, and not to other inspection failures. This would seem to be an 

oversight, which would be corrected by editing paragraph §63.640(n)(10) as follows.

§63.640(n)(10) Storage vessels described by paragraphs (n)(1), (n)(2), and (n)(3) electing 

to comply with 40 CFR part 61, subpart Y shall comply with subpart Y except as 

provided for in paragraphs (n)(10)(i) through (n)(10)(vii) of this section. 

* * * * * * 

(v) Owners and operators of storage vessels complying with subpart Y of part 61 may 

submit the inspection reports required by 40 CFR 61.275(a), (b)(1), and (d) as part of the 

periodic reports required by this subpart, rather than within the 60-day period specified in 

40 CFR 61.275(a),and (b)(1) and (d). 

(vi) The reports of rim seal inspections specified in 40 CFR 61.275(a), (b)(1), and (d) are 

not required if noneall of the observed conditions meetmeasured gaps or calculated gap 

areas exceed the requirementslimitations specified in 40 CFR 61.272(a) or (b)(4) as 

applicable. Documentation of the inspections shall be recorded as specified in 40 CFR 

61.276(a). 

5. Clarify the §63.641 definition of heat exchange system.

We believe four clarifications, as follows, are needed to make the definition consistent with the 

way such systems exist in refineries, the monitoring requirements, the proposal and the final 

amendment preamble.

Unlike the proposed definition, the discussion in the preamble to the final amendments, 

and the precedents set in other cooling tower monitoring rules, the second sentence of the 

heat exchange system definition defines “heat exchange system” proscriptively for 

recirculating systems and precludes critical flexibility. According to the preamble to the 

final amendments, “... if the cooling tower or once-through system services multiple heat 

exchangers, the owner or operator may elect to monitor only the heat exchangers “in 
organic HAP service” or monitor at branch points that combine several heat exchanger 

exit lines, or monitor at the combined stream for the entire system.1” However, the final 

definition specifies that for a cooling tower system there is only one heat exchange 

system made up of all exchangers serving that cooling tower. This would preclude 

monitoring at branch points that combine several heat exchanger exit lines. This 

grouping flexibility is critical, since cooling towers often service multiple process units, 

have multiple return lines and service many exchangers that are not “in organic HAP 

service” and would have been provided had the proposed heat exchange definition been 

finalized. Furthermore, the §63.654(b) monitoring exemption language presumes this 

flexibility and is made unusable if there is only a single heat exchange system for each 

cooling tower. Thus, the wording of the second sentence should be revised to allow such 

grouping.

Including the cooling tower in the heat exchange system definition was not proposed and 

is confusing. It further suggests that heat exchangers cannot be subgrouped for 

monitoring purposes. Furthermore, since there may be many heat exchange systems 

associated with a single cooling tower, it is unclear where the cooling tower would be 

assigned. Since including the cooling tower is not critical to the definition or to the 

monitoring requirements, we suggest it be deleted.

The use of the word “series” in the first sentence of the definition could result in the 

mistaken impression that heat exchangers must be arranged in series, as opposed to being 

arranged in parallel. This unintended conclusion would be avoided if the word 

“collection” were used.

In the third sentence, the definition of heat exchange system describes a once-through 

system as “servicing an individual process unit.” However, if a once-through system 

services more than one process unit, as they often do, it is still a once-through system. 

The definition should be edited so as not to inappropriately limit the definition of a oncethrough system.

We suggest the following specific revisions to the text in the posted rule to accomplish these 

changes.

Heat exchange system means a device or collectionseries of devices used to transfer 

heat from process fluids to water without intentional direct contact of the process fluid 

with the water (i.e., non-contact heat exchanger) and to transport and/or cool the water 

in a closed-loop recirculation system (cooling tower system) or a once-through system 

(e.g., river or pond water). For closed-loop recirculation systems, athe heat exchange 

system consists of a cooling tower, all one or more heat exchangers that are serviced by 

that cooling tower, and all water lines to and from the heat exchanger(s). For once-

 

1

Page 21 of the final rule as posted on the EPA TTN P&G website.
through systems, the heat exchange system consists of one or more heat exchangers 

servicing anone or more individual process units and all water lines to and from the heat 

exchanger(s). Intentional direct contact with process fluids results in the formation of a 

wastewater. 

6. Clarify the intent with respect to monitoring the inlet concentration of once-through 

heat exchange systems.

Paragraph §63.654(c)(1) provides for monitoring the fresh water feed line of once-through heat 

exchange systems in order to determine the total strippable VOC concentration prior to the heat 

exchange system. This is presumably for the purpose of determining how much of the exit 

concentration is attributable to leaks in the heat exchange system as opposed to having already 

been in the feed water. This intent should be clarified by editing paragraph §63.654(c)(2) as 

follows.

(2) For a heat exchange system at an existing source, a leak is a total strippable VOC 

concentration (as methane) in the stripping gas of 6.2 ppmv or greater. For a heat 

exchange system at a new source, a leak is a total strippable VOC concentration (as 

methane) in the stripping gas of 3.1 ppmv or greater. For once-through heat exchange 

systems, the total strippable VOC concentration (as methane) measured in the fresh 

water feed line may be subtracted from the total strippable VOC concentration (as 

methane) measured in the exit line in order to determine the total strippable VOC 

concentration (as methane) for purposes of determining the presence of a leak.

7. Clarify that §63.654(e) is applicable to once-through heat exchange systems.

Paragraph §63.654(e) provides for monitoring individual heat exchangers or groups of heat 

exchangers to verify whether or not there is a leak from a heat exchanger in organic HAP 

service. The intent is undoubtedly to allow this additional monitoring for once-through systems 

as well as for cooling towers. The wording should be revised to clarify this intent, as shown 

below.

(e) If the owner or operator detects a leak when monitoring a cooling tower return line or 

heat exchanger exit line under paragraph (c)(1) of this section, the owner or operator may 

conduct additional monitoring to identify leaks of total strippable VOC emissions using 

Modified El Paso method from each heat exchanger or group of heat exchangers in 

organic HAP service associated with the heat exchange system for which the leak was 

detected. If the additional monitoring shows that the total strippable VOC concentration 

in the stripped air at the heat exchanger exit line for each heat exchanger in organic HAP 

service is less than 6.2 ppmv for existing sources or less than 3.1 ppmv for new sources, 

the heat exchange system is excluded from repair requirements in paragraph (d) of this 

section. 
8. Clarify in §63.654(g) that cooling water flow rate is to be determined by engineering 

analysis.

The preamble expressly states that EPA does not require a continuous flow monitor for 

measuring flow rate, but rather expects the flow rate to be based on “pump curves, heat balance

calculations, or other engineering methods.” The wording in §63.654(g) should be revised to 

clarify this intent.

(g) To delay the repair under paragraph (f) of this section, the owner or operator must 

record the information in paragraphs (g)(1) through (g)(4) of this section. 

...

(4) An estimate of the potential emissions from the leaking heat exchange system or heat 

exchanger following the procedures in paragraphs (g)(4)(i) and (g)(4)(ii) of this section. 

(i) Determine the total strippable VOC concentration in the cooling water, in parts per 

million by weight (ppmw), using equation 7-1 from Modified El Paso method 

(incorporated by reference in §63.14), based on the total strippable concentration in the 

stripped air, ppmv, from monitoring. 

(ii) Calculate the VOC emissions for the leaking heat exchange system or heat exchanger 

by multiplying the VOC concentration in the cooling water, ppmw, by the flow rate of 

the cooling water from the leaking tower or heat exchanger and by the expected duration 

of the delay. The flow rate may be based on pump curves, heat balance calculations, or 

other engineering methods.

9. Correct the citation in the “reference control technology for storage vessels” definition.

The rim seal requirements for An external floating roof converted to an internal floating roof

incorrectly cite the provisions for an external floating roof. Once converted to an internal 

floating roof, the storage vessel should be subject to the requirements for internal floating roof 

storage vessels. This is corrected by changing the reference to read §63.1063(a)(1)(i) rather than 

§63.1063(a)(1)(ii).

Reference control technology for storage vessels means either: 

(a) For Group 1 storage vessels complying with §63.646(m): 

(1) An internal floating roof meeting the specifications of §§63.1063(a)(1)(i) and (b) of 

subpart WW; 

(2) An external floating roof meeting the specifications of §63.1063(a)(1)(ii), (a)(2), and 

(b) of subpart WW; 

(3) An external floating roof converted to an internal floating roof meeting the 

specifications of §63.1063(a)(1)(i)(ii) and (b); or 
10. Correct the citation to a nonexistent paragraph in §63.654(f).

Paragraph (f) of §63.654 refers to paragraph (f)(3), but there is no paragraph (f)(3). This requires 

two corrections, as follows.

§63.654 Heat exchange systems. 

* * * * * * 

(f) The owner or operator may delay the repair of a leaking heat exchanger when one of 

the conditions in paragraphs (f)(1) and (f)(2)through (3) of this section is met. The 

owner or operator must determine if a delay of repair is necessary as soon as 

practicable, but no later than 45 days after first identifying the leak. 

(1) If the repair is technically infeasible without a shutdown and the total strippable 

VOC concentration (as methane) is initially and remains less than 62 ppmv for all 

monthly monitoring periods during the delay of repair, the owner or operator may delay 

repair until the next scheduled shutdown of the heat exchange system. If, during 

subsequent monthly monitoring, the total strippable VOC concentration (as methane) is 

62 ppmv or greater, the owner or operator must repair the leak within 30 days of the 

monitoring event in which the leak was equal to or exceeded 62 ppmv total strippable 

VOC (as methane), except as provided in paragraph (f)(3) of this section. 

11. Correct the subpart reference in the Table 4 heading.

Table 4 pertains to overlap with the Gasoline Distribution MACT rule, which is part 63 subpart 

R. The heading for the Reference should read “subpart R” rather than “subpart Y.

12. Correct the subscripts in the Table 7 Title.

The subscripts on the variables are shown as upper case in the title, but as lower case in the table 

itself. The title should be corrected as follows.

TABLE 7——FRACTION MEASURED (F

M

)(Fm), FRACTION EMITTED (F

E

)(Fe), AND 

FRACTION REMOVED (FR)(Fr) FOR HAP COMPOUNDS IN WASTEWATER STREAMS 

12. Correct the citation error in §63.655(g)(2)(i)(B).

Paragraph 63.655(g)(2)(i)(B) should reference (g)(2)(i)(B)(1) not (g)(2)(ii)(B)(1).

13. Correct the incomplete and incorrect citations in §63.655(g)(5).

Paragraph 63.655(g)(5) should reference “(g)(5)(i) through (g)(5)(iii), as applicable” instead of

“(g)(4)(i) through (g)(4)(iii), as applicable.”

Paragraph 63.655(g)(5)(i) should reference “(g)(5)(i)(A) and (g)(5)(i)(B)” rather than 

“(g)(4)(i)(A) and (g)(4)(i)(B).”
14. Correct the location of the quotation mark in the note in Table 6 for §63.8(c)(4).

The quotation mark after the word rather in this note appears to be misplaced and should be 

moved to after the word hour, as follows.

Except Subpart CC specifies the monitoring cycle frequency specified in §63.8(c)(4)(ii) 

is “once every hour” rather” than “for each successive 15-minute period.” 

15. Correct the note for §63.10(b)(1) in Table 6.

The note in Table 6 for §63.10(b)(1) mistakenly references §63.644(d) and this should be 

corrected to §63.655(e).

Please let us know if you have any questions or if we can amplify on any of these comments. 

Sincerely,

Matthew Todd

API

toddm@api.org

(202) 682-8319

David Friedman

NPRA

dfriedman@npra.org

(202) 552-8461

cc R. B. Lucas

US EPA

Office of Air Quality Planning and Standards

Mail Drop E143-01

Research Triangle Park, NC 27711

lucas.bob@epa.gov