October 4, 2006

	Sent via E-Mail

McDonald.Randy@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 the 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
Synthetic Organic Chemical Manufacturing Industry (HON) and Other
Processes Subject to the Negotiated Regulation for Equipment Leaks. 
Specifically, 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
synthetic organic chemical facilities throughout the United States (US),
is hereby submitting comments concerning the 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 part of the residual risk amendments, it may be
feasible and acceptable for EPA to address these 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 emissions 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 are virtually no
emissions generated at the source during vapor balancing.  The owner or
operator of storage tanks in which working loss emissions are controlled
via vapor balancing should be exempt from any further control,
recordkeeping or reporting requirements in the rule applicable to that
storage tank.  In addition, EPA should not impose any further emission
reduction, recordkeeping or reporting requirements on reloading /
cleaning facilities.  

For this reason, Dow recommends that EPA eliminate the vapor 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 / cleaning facility.

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.  

Thank you in advance for your consideration of our comments. If you have
questions, concerning the following comments, please contact me at (225)
353-8844 or email me at balexius@dow.com.

Sincerely,

Bruce J. Alexius

EH&S Operations Regulatory Management

The Dow Chemical Company

P. O. Box 150, Building 3502

Plaquemine, LA 70765-0150



Vapor Balancing Provisions of the National Emission Standard for
Hazardous Air Pollutants for Organic Hazardous Air Pollutants from the
Synthetic Organic Chemical Manufacturing 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 Synthetic Organic Chemical Manufacturing Industry. 
Dow strongly believes that reducing regulatory burden or eliminating
regulatory hurdles associated with emission controls is a highly
effective way of promoting the employment of emission reduction
strategies.  

In addressing the vapor balancing requirements of the HON, Dow maintains
that:

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 exempt from the storage
tank provisions in the rule and any 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.

Reloading / cleaning operations located at areas sources or outside of
the United States should not be regulated under MACT rules that apply to
U.S. plant sites located at major sources 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
addition, reloading facilities in the U.S. that are located at major
sources are properly 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.  

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 PAIP MACT more
flexible. Please note that several MACT standards such as P&R I, P&R IV,
Polyether 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.

Discussion

There are virtually no 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 space 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 typical
unloading operation is depicted.  Rather than draw identical 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 Figure 2 is that the rail car is full in
the case of Figure 1 and “empty’ in the case of 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
transport 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 or whether the vapors
from the storage tank are being directed 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 how 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 vapors to a
control device.  

Additional certifications required under the current HON language for
the cases discussed above have no technical basis and only serve to
discourage the use of vapor balancing which essentially has no emissions
during the unloading process.  EPA should remove the requirements that
may discourage vapor balancing and actually promote the use of this very
effective technology.

Should EPA decide to keep the vapor balancing provisions, then the
following changes would provide additional 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 tanks using a closed vent system and
control device.  Therefore, if the reloading / cleaning facility chooses
to use a closed vent system 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 facility will be subject to
all notification and reporting obligations contained or referenced
within §§63.119 through 63.123.  

Both the MON and the OLD MACT were recently amended to exclude the owner
or operator of the reloading / cleaning facility from any notification
or periodic reporting 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 that “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 recently 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
notification requirements and the reporting requirements.  Section
63.2346(a)(4)(vii)(B) states:  “(B) If complying with paragraph
(a)(4)(vi)(A) of this section, comply with the requirements for a closed
vent system 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
obligations 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 comply with paragraphs
(g)(7)(i) through (iii) of this section.

(i)…

(ii) If complying with paragraph (g)(6)(i) of this section, comply with
the requirements for a closed vent system 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 updated 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 comply 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 are used in vapor
balancing for storage tanks at the affected source. For an offsite
cleaning or reloading facility that is subject to any other NESHAP under
40 CFR part 63, the final amendments specify that compliance with the
monitoring, recordkeeping, and 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 reloading 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 the
monitoring, recordkeeping, and reporting provisions of
§63.1253(f)(7)(ii) or §63.1253(f)(7)(iii). You must identify in your
notification of compliance status report required by §63.2520(d) the
subpart of this part 63 with which the owner or operator of the offsite
reloading or cleaning facility 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 any other subpart
of this part 63 that has monitoring, recordkeeping, and reporting
provisions constitutes compliance with the monitoring, recordkeeping and
reporting provisions of §63.2346(a)(4)(vii)(B) or
§63.2346(a)(4)(vii)(C). You must identify in your 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 requests 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 in
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 provisions 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 your
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 accordance with 40 CFR 63.565.

Section 63.123(i)(1) further requires that:  “

(i) An owner or operator who elects to comply 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. Department 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 into 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 by 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
pressurized 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 log sheet; a list of DOT serial numbers or Method 27 data; or a
position description for gate security, showing that the security 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 especially 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 comply 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
description for gate security, showing that the security guard will not
allow any trucks on site that do not have the appropriate documentation.

(D)  EPA 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 type of facilities
under other NESHAPs where vapor balancing is a control option.  Imposing
MACT requirements on these sources is outside of EPA’s authority under
the Clean Air Act (CAA) for three reasons.

First, the majority of these cleaning or reloading facilities are area
sources and EPA doesn’t have the authority to impose 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 achieved in practice by the best controlled
similar source.  This type of emission control technology is the MACT. 
However, for area sources MACT doesn’t apply.  EPA only has authority
under § 112(d)(5) of the CAA to promulgate emission standards for area
sources which provide for the use of generally available control
technologies (GACT) or management practices.  Applying MACT standards
for area sources is outside of EPA CAA authority.

Second, EPA has the authority only to promulgate emission standards
under § 112(d) of the CAA for sources listed in each category or
subcategory identified under § 112(c).  Further, EPA cannot apply the
emissions standards promulgated for one source category to another
category of sources without performing an additional MACT analysis 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 standards to cleaning or reloading facilities which
generally don’t manufacture anything much less SOCMI chemicals. 
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 properly regulate area
sources that are cleaning and reloading facilities, must perform a GACT
analysis and propose the rule for public comment.  EPA has done neither.


Third, some of the cleaning and reloading 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 and protect
the quality 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 has 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 to the vapor
balancing provisions of a Part 63 NESHAP 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.  However, 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 part of the
source category being regulated.  

EPA has stated that vapor balancing increases 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 / cleaning
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 by a part 63 NESHAP and further inappropriate that the
reloading / cleaning facility include any such provisions in their Title
V permit.

The Dow Chemical Company	Page   PAGE  12  of   NUMPAGES  12 	           
        Comments Concerning HON Vapor Balancing Requirements

  DATE \@ "M/d/yyyy"  10/4/2006 	                                	

		

Figure 1

Flare

Pump

Rail Car

Storage Tank A

Load Line

Line to Control Device

Vapor Return Line

Rail Car

Storage Tank A

Load Line

Line to Control Device

Vapor Return Line

Flare

Pump

Figure 2

