October 4 , 200 6

Sent via E

- Mail McDonald.Rand y@epa.com

Regarding : **Vapor Balancing Provisions of the National Emission Standards for Hazardous Air pollutants from the Synthetic Organic Chemical Manufacturing Industry and Other**  **Processes Subject to th e Negotiated Regulation for Equipment Leaks**  Related to: Docket ID Number EPA

- HQ

- OAR

- 2005

- 0475 ; National Emission Standard for Hazardous Air Pollutants for Organic Hazardous Air Pollutants from the Synthetic Organic Chemical Manufacturing Industry

Dear Mr . McDonald :
On December 23, 2004 , EPA issued direct final rule amendments to the National Emission Standards for Hazardous Air pollutants from the Sy nthetic Organic Chemical Manufacturing Industry (HON) and Other Processes Subject to the Negotiated Regulation for Equipment Leaks. Specificall y, EPA adopted amendments that allowed the use of vapor balancing as a control technique for storage tanks. In doing so, EPA also required that certain actions were required of facilities that are neither subject to the HON nor any other Maximum Achievable Control Technology

standard. The Dow Chemical Company (Dow) , as an owner and operator of numerous sy nthetic organic chemical facilities throughout the United States (US) , is hereb y submitting comments concerning th e vapor balancing provisions of the HON. Although not directly related to the HON Residual Risk Rule proposal, the timing for making changes to the HON regulation is appropriate while the rule is being addressed. If EPA cannot address these comments as p art of the residual risk amendments , it may

be feasible and acceptable for EPA to address the se vapor balancing comments as a direct final rule as was done when the vapor balancing provisions were first promulgated in the December 23, 2004 amendments

. Dow believes that vapor balancing emis sions generated during storage tank filling operations back to the delivery

vehicle (rail car, tank truck, marine vessel) is an effective “control technology ” for controlling storage tank working loss emissions . There ar e v irtually no emissions generated at the source during vapor balancing

. The owner or operator of s torage tanks in which working loss emissions are controlled via vapor balancing should be exempt from any further control, recordkeeping or reporting requir ements in the rule applicable to that storage tank

. Inaddition, EPA should not impose any further emission reduction , recordkeeping or reporting requirements on reloading / cleaning facilit ies

. For this reason, Dow recommends that EPA eliminate the vap or balancing provisions in 63.119(g) all together and not impose any additional requirements on the vapors remaining in the delivery vehicle, either at the time of transfer or when the vehicle leaves the HON process unit to be returned to the reloading / c leaning facility

.The Dow Chemical Company Page 2 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 The attached comments further explain Dow’s position on this issue. Should EPA choose to keep the vapor balancing provisions in HON, Dow is suggesting alternative language to improve the usability and flexibility of these provisions. T hank y ou in advance for y our consideration of our comments. If you have questions, concerning the following comments, please contact me at (225) 353

- 8844 or email me at b a lexius@dow.com

.

Sincerel y,

Bruce J. Alexius EH&S Operations Regulatory Management The Dow Chemical Company P. O. Box 150 , Building 3502 Plaquemine, LA 70765

- 0150The Dow Chemical Company Page 3 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 **Vapor Balancing Provisions of the National Emission Standard for Hazardous Air**  **Pollutants for Organic Hazardous Air Pollutants from the Synthetic Organic Chemical Manufacturi**  **ng Industry**
The Dow Chemical Company ( Dow ) thanks EPA for consideration of comments relative to the vapor balancing provisions of the National Emission Standard for Hazardous Air Pollutants for Organic Hazardous Air Pollutants from the Sy nthetic Organic C hemical Manufacturing Industry

. Dow strongl y believes that reducing regulatory burden or eliminating regulatory hurdles associated with emission controls is a highl y effective way of promoting the employment of emission reduction strategies. In addressi ng the vapor balancing requirements of the HON , Dow maintains that : 1. Vapor balancing during tank filling operations creates virtually no emissions to the atmosphere at the source . Storage tanks using vapor balancing for tank filling operations should be ex empt from the storage tank provisions in the rule and an y associated recordkeeping and reporting requirements

. There is no basis for regulating an activity that has no associated emissions . Therefore, it is not necessary to include vapor balancing in the regulatory

text to address working loss emissions

. Note: Any breathing losses from the storage tank would still be subject to the storage vessel provisions. 2. Reloading / cleaning operations located at areas sources or outside of the United States should n ot be regulated under MACT rules that apply to U.S. plant sites located at major source s as defined in section 112(a) of the Act

. Reloading / cleaning operations still must comply with state and/or local requirements for reloading and cleaning. In additi on, r eloading facilities in the U.S. that are located at major sources are properl y regulated under the Organic Liquids Distribution source category if reloading an organic liquid containing > 5% Table 1 OHAP , as defined in 40 CFR 63 Subpart EEEE

. 3. If EPA chooses to maintain vapor balancing provisions complete with requirements for reloading / cleaning facilities, then Dow proposes language that will make the HON, Pharma MACT and PAI P MACT more flexible

. Please note that several MACT standards such as P&R I, P&R IV, Poly ether Polyol MACT, etc. reference the HON for storage tank control options. The recommendations outlined in these comments will also improve the flexibility in these rules.The Dow Chemical Company Page 4 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 **Discussion**
**There are virtually**  **n o emissions from vapor balancing**  **itself and no additional emissions**  **from tank**  **cars as compared to unloading without vapor balancing**
**. Dow maintains that**  **whether vapor balancing has been employed or not during an offloading operation, the transport vehicle is left with a saturated vapor s**  **pace that contains the same amount of residual HAP content.**  The following illustrations depict normal unloading operations to further demonstrate the point. In the illustrations below, a ty pical unloading operation is depicted. Rather than draw ident ical pictures, one showing a vapor recovery line and one showing a line to a control device such as a flare from the top of the storage tank, the lines are depicted on one drawing to be concise. Please note that the only

difference between Figure 1 and Fi gure 2 is that the rail car is full in the case of Figure 1 and “empty ’ in the case of Figure 2.Rail Car Storage Tank A Load Li ne Line to Control Device

Vapor Return Line

Pump
**Figure 1** FlareThe Dow Chemical Company Page 6 of 12 Comments Concerning HON Vapor Balancing Requirements

2/15/2012 Rail Car

Storage Tank A Load Li ne Line to Control Device

Vapor Return Lin e

Flare

Pump
**Figure 2**When using a standard pump to unload a transport vehicle such as a rail car, the pump will draw

down the liquid level in the car until the point where the pump no longer has sufficient suction head (level of liquid above the pump suction) to continue pumping. At this stage in time, pumping is discontinued leaving a slight level of liquid in the tr ansport vehicle. The vapor space above the liquid is saturated with the chemical being unloaded and remains saturated unless extraordinary

means are taken to evacuate or wash the car. In fact, even with a “full” car of liquid, there must be a vapor space and this vapor space is saturated with the chemical being unloaded. It does not matter whether vapors from the storage are being returned to the transport vehicle during the unloading process o r whether the vapors from the storage tank are being direct ed to a control device. When liquid transfer is complete, regardless of how the vapors were handled during transfer, the transport vehicle is left with the same amount of residual chemical in the vehicle . The amount in the vapor space is equivalent to ho w much chemical the vapor space can contain at the given pressure and temperature of the vehicle being unloaded. Therefore, there is no technical reason for regulatory differentiation between unloading with vapor recovery and unloading while directing vap ors to a control device. Additional certifications required under the current H ON language for the cases discussed above have no technical basis and only serve to discourage the use of vapor balancing which essentiall y has no emissions during the unload ing process. EPA should remove the requirements that may discourage vapor balancing and actuall y promote the use of this very effective technology

. Should EPA decide to keep the vapor balancing provisions, then the following changes would provide additio nal flexibility to improve the usability

of these provisions.

**(A) The HON should be updated to exclude off** 

**- site**  **reloading / cleaning facilities from**  **additional notification and**  **reporting obligation.**  Section 63.119(g)(7)(ii) of HON requires compliance with §§63.119 through 63.123 of HON. Section 63.122(c) requires submittal of a Notification of Compliance Status and 63.122(g) contains periodic reporting requirements for storage tank s using a closed vent sy stem and control device. Therefore, if the rel oading / cleaning facility chooses to use a closed vent sy stem and control device to reduce emissions of HAP by 95% by weight or greater in accordance with 63.119(g)(6)(i), then Dow assumes that the reloading / cleaning facilit y will be subject to all noti fication and reporting obligations contained or referenced within §§63.119 through 63.123.
Both the MON and the OLD MACT were recentl y amended to exclude the owner or operator of the reloading / cleaning facility from any notification or periodic report ing obligation other than the initial certification.

 The MON was amended on July 14, 2006 [71 FR 40316]. In the Preamble on page 40318, EPA states: The final amendments eliminate reporting requirements for offsite cleaning and reloading facilities that control emissions from rail cars and tank trucks that are used in vapor balancing for storage tanks at the affected source. Section 63.2470(e)(2)(i) states thatThe Dow Chemical Company Page 8 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 “The reporting requirements in 63.2520 do not apply to the owner or operator of the offsite cleaning or reloading facility .”

 The vapor balancing option was recentl y added to the OLD MACT as part of the July 28, 2006 amendments [71 FR 42898]. The OLD MACT excludes the owner or operator of the offsite reloading / cleaning facility from the notific ation requirements and the reporting requirements

. Section 63.2346(a)(4)(vii)(B) states: “(B) If compl yi ng with paragraph (a)(4)(vi)(A) of this section, comply with the requirements for a closed vent sy stem and control device as specified in this subpart EEEE. The notification requirements in §63.2382 and the reporting requirements in §63.2386 do not apply to the owner or operator of the offsite cleaning or reloading facility .” Therefore, Dow requests that EPA waive all notification / reporting obligatio ns referenced in § 63.122 imposed on the facilities reloading and/or cleaning transport vehicles that have been vapor balanced at process units subject to HON. Dow recommends that the following language be added to 63.119(g)(7)(ii) that states:

“ (7) The owner or operator of the facility where the railcar, tank truck, or barge is reloaded or cleaned must compl y with paragraphs (g)(7)(i) through (iii) of this section. (i)... (ii) If compl yi ng with paragraph (g)(6)(i) of this section, comply with the requirem ents for a closed vent sy stem and control device specified in §§63.119 through 63.123. **The notification and reporting requirements in §63.122 do not apply to the owner or operator of the offsite cleaning or reloading facility.”** 

(B ) **The HON should be u pdated to allow off** 

**- site**  **reloading / cleaning facilities to comply**  **with other Part 63 standards**
**.** The MON and the OLD MACT also now allow the reloading / cleaning facility to compl y with other applicable Part 63 NESHAPs

- and not just the MON or OLD MACT.

 In the final amendments to the MON promulgated on July 14, 2006, EPA states in the Preamble: “The final amendments eliminate reporting requirements for offsite cleaning and reloading facilities that control emissions from rail cars and tank trucks that a re used in vapor balancing for storage tanks at the affected source. For an offsite cleaning or reloading facility

that is subject to an y other NESHAP under 40 CFR part 63, the final amendments specify

that compliance with the monitoring, recordkeeping, an d reporting requirements in the other rule demonstrates compliance with the requirements in subpart FFFF of 40 CFR part 63. [71 FR 40318] Section 63.2535(a)(2) of the MON states: “2) After the compliance dates specified in §63.2445, at an offsite reload ing or cleaning facility subject to §63.1253(f), as referenced from §63.2470(e), compliance with the monitoring, recordkeeping, and reporting provisions of any

other subpart of this part 63 constitutes compliance with theThe Dow Chemical Company Page 9 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 monitoring, recordkeeping, and rep orting provisions of §63.1253(f)(7)(ii) or §63.1253(f)(7)(iii). You must identify in y our notification of compliance status report required b y §63.2520(d) the subpart of this part 63 with which the owner or operator of the offsite reloading or cleaning fac ility complies.

 Section 63.2346(a)(4)(vii)(D) of the OLD MACT states: “After the compliance dates specified in §63.2342, at an offsite reloading or cleaning facility subject to §63.2346(a)(4), compliance with the monitoring, recordkeeping, and reporting provisions of an y other subpart of this part 63 that has monitoring, recordkeeping, and reporting provisions constitutes compliance with the monitoring, recordkeeping and reporting provisions of §63.2346(a)(4)(vii)(B) or §63.2346(a)(4)(vii)(C). You must id entify in y our notification of compliance status report required by §63.2382(d) the subpart of this part 63 with which the owner or operator of the offsite reloading or cleaning facility complies.” [Added July

28, 2006, 71 FR 42908]

Therefore, Dow reque sts that EPA add a similar overlap provision to HON to allow the reloading / cleaning facility

to comply

with other Part 63 standards in lieu of the HON or the subpart referencing HON.
Dow recommends that EPA add the following paragraph as a new section i n 63.119(g)(7)(iv) that states:

“ **After the compliance dates specified in §63.100(k) or the referencing Part 63**  **NESHAP at a reloading or cleaning facility subject to §63.**  **119(g )**  **(6)**

**- (g)(7)**  **, compliance with the monitoring, recordkeeping, and reporting provi**  **sions of any other subpart of this part 63 that has monitoring, recordkeeping, and reporting provisions constitutes**  **compliance with the monitoring, recordkeeping and reporting provisions of §63.**  **119(g)(7)(ii) or §63.119(g)(7)(iii). You must identify in you**  **r notification of compliance status report required by §63.**  **152(b) or notification of compliance status report of the Part 63 NESHAP referencing Subpart G,**  **the Part 63**  **subpart with which the owner or operator of the reloading or cleaning facility complies.”** 

**(C) Flexibility should be written into the HON concerning**  **U.S. Department of Transportation**  **certifications of railcars and tank trucks.** The vapor balancing provisions of HON, Section 63.119(g)(2) requires that (2) Tank trucks and railcars must have a current certification in accordance with the U.S. Department of Transportation pressure test requirements of 49 CFR part 180 for tank trucks and 49 CFR 173.31 for railcars. Barges must have a current certification of vapor

- tightness through testing in acco rdance with 40 CFR 63.565.The Dow Chemical Company Page 10 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 Section 63.123(i)(1) further requires that: “ (i) An owner or operator who elects to compl y with §63.119(g) shall keep the records specified in paragraphs (i)(1) through (3) of this section. (1) A record of the U.S. Departme nt of Transportation certification required by §63.119(g)(2).” The transfer rack provisions of HON have a similar requirement related to DOT certification that states: “(e) For each Group 1 transfer rack the owner or operator shall load organic HAP's int o only tank trucks and railcars which: (1) Have a current certification in accordance with the U. S. Department of Transportation pressure test requirements of 49 CFR part 180 for tank trucks and 49 CFR 173.31 for railcars; or (2) Have been demonstrated to be vapor

- tight within the preceding 12 months, as determined b y the procedures in §63.128(f) of this subpart. Vapor

- tight means that the truck or railcar tank will sustain a pressure change of not more than 750 pascals within 5 minutes after it is press urized to a minimum of 4,500 pascals.”

**However, the transfer rack recordkeeping provisions in 63.130(e) provide much greater flexibility on the various methods of verification that can be used. Section 63.130(e)**  **provides that:**

**“** The owner or operator of a Group 1 transfer rack shall record that the verification of DOT tank certification or Method 27 testing, required in §63.126(e) of this subpart, has been performed. Various methods for the record of verification can be used, such as: A check off on a lo g sheet; a list of DOT serial numbers or Method 27 data; or a position description for gate security , showing that the securit y guard will not allow any trucks on site that do not have the appropriate documentation. Obtaining copies of the actual U.S. DOT certifications from suppliers can be very burdensome especiall y if the rail cars or tank trucks are not dedicated to a particular facility. EPA should add flexibility to the vapor balancing provisions of HON in 63.119(g) to allow various methods for the record of verification for DOT tank certification. Dow recommends that amend the language in 63.123(i)(1) as follows: (i) An owner or operator who elects to compl y with §63.119(g) **shall record that the**  **verification of DOT tank certification, required in § 63.119(g)(2) of this subpart, has been**  **performed. Various methods for the record of verification can be used, such as: A check off on a log sheet; a list of DOT serial numbers or Method 27 data; or a position** The Dow Chemical Company Page 11 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 **description for gate security, showing that the security guard will not allow any trucks on**  **site that do not have the appropriate documentation.**

**(D) EP**  **A does not have the**  **authority to impose Part 63 NESHAP requirements on a facility that is not a major source of HAP emissions**  **, that is not inclusive in a source category being**  **addressed by a standard, and that is not a facility**  **located in the United States** 
**.** Under 40 CFR § 63.119(g) the owner or an operator of the facility where the railcar or tank truck is reloaded or cleaned after vapor balancing is subject to the Maximum Achievable Control Technology

(“MACT”) requirements under the HON. See 40 CFR §§ 63.119(g)(6) and (7). The EPA is also imposing MACT requirements for the same t ype of facilities under other NESHAPs where vapor balancing is a contr ol option. Imposing MACT requirements on these sources is outside of EPA’s authorit y under the Clean Air Act (CAA) for three r easons. First, the majority

of these cleaning or reloading facilities are area sources and EPA doesn’t have the authority

to imp ose MACT requirements on area sources. Under §112(d) of the CAA, the EPA has the authority

to impose on new and existing major sources the maximum degree of reduction which for new sources may not be less stringent than the emission control that is achiev ed in practice by

the best controlled similar source. This t ype of emission control technology

is the MACT. However, for area sources MACT doesn’t appl y. EPA only has authority under § 112(d)(5) of the CAA to promulgate emission standards for area sourc es which provide for the use of generall y available control technologies (GACT) or management practices. Applying MACT standards for area sources is outside of EPA CAA authority

. Second, EPA has the authority onl y to promulgate emission standards under § 112(d) of the CAA f o r sources listed in each category or subcategory

identified under § 112(c). Further, EPA cannot appl y the emissions standards promulgated for one source category to another category of sources without performing an additional MACT ana ly sis under §§ 112(d)(2) and (3). However, that is exactly

what has occurred with the vapor balancing option under the HON and other NESHAPs. The EPA under the HON vapor balancing option applies the MACT requirements promulgated for HON sources to non

- HON sources. The HON applies to chemical manufacturing process units (CMPUs) that are located at major sources and manufacture as a primary product a SOCMI chemical. See 40 CFR § 63.100(b). Under the vapor balance option, the EPA has applied the HON st andards to cleaning or reloading facilities which generally don’t manufacture an ything much less SOCMIchemicals. Additionally , there is a category for reloading facilities for which EPA chose to regulate only major sources, not area sources, for certain HAPs under the OLD MACT. EPA, if it wishes to properl y regulate area sources that are cleaning and reloading facilities, must perform a GACT anal ys is and propose the rule for public comment. EPA has done neither. Third, some of the cleaning and reloa ding facilities used by Dow are located outside of the United States. EPA is imposing under the vapor balance option , MACT requirements to area sources which are outside of its regulatory reach. The CAA provides a program to enhance andThe Dow Chemical Company Page 12 of 12 Comments Concerning HON Vapor Balancing

Requirements 2/15/2012 protect the quali ty

of the Nation’s air resources. While Congress has adopted and incorporated into the CAA international treaties, such as the Montreal Protocol, it was never Congress’s intent to extend its national air program to international borders. Therefore, EPA h as no authority to require facilities located outside the United States to certify compliance with a § 112(d) emission standard.

**(E) Reloading / cleaning facilities should not**  **have to amend their Title V permits to indicate that they are now subject t**  **o the vapor balancing provisions of a**  **Part 63 NESHA P**  **applicable to their customers.** Many reloading / cleaning facilities will not have Title V permits to amend as they are not major sources of emissions nor or they subject to U. S. based regulations. How ever, should a reloading / cleaning facility

have a Title V permit, it should not be required to amend the permit to indicate that they are now subject to the vapor balancing provisions of a Part 63 NESHAP applicable to their customers. Part 63 standards are applicable to source categories as defined by EPA and driven by section 112 (d) of the Clean Air Act. EPA does not have the authority to regulate sources that are not applicable nor par t of the source category

being regulated

. EPA has stated that v apor balancing increase s the amount of chemical left in the transport and therefore it is appropriate that requirements be added to the reloading / cleaning facilities as the source category

is responsible for increased emissions at the reloading / cleanin g facilities. As illustrated above in the technical discussion , there are no additional emissions from the transport vehicle due to using vapor balancing. Hence, it is inappropriate for these facilities to be governed b y a part 63 NESHAP and further inap propriate that the reloading / cleaning facility include an y such provisions in their Title V permit

.