National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2002-0037; FRL-9298-7]

RIN 2060-AN33

National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

EPA is proposing National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production. The proposed rule would establish emission standards for hazardous air pollutants from polyvinyl chloride and copolymers production located at major and area sources. The proposed rule includes requirements to demonstrate initial and continuous compliance with the proposed emission standards. EPA is proposing standards that would apply at all times, including during periods of startup, shutdown, and malfunctions. The proposed standards also include continuous monitoring provisions and recordkeeping and reporting requirements.

DATES:

Comments.

Comments must be received on or before July 19, 2011. Under the Paperwork Reduction Act, comments on the information collection provisions are best assured of having full effect if the Office of Management and Budget (OMB) receives a copy of your comments on or before June 20, 2011.

Public Hearing.

We

1

will hold two public hearings concerning the proposed polyvinyl chloride and copolymers (PVC) production rules in the Houston, Texas area, and in Baton Rouge, Louisiana. Persons interested in presenting oral testimony at either public hearing should contact Ms. Teresa Clemons at (919) 541-0252 or at

clemons.teresa@epa.gov

by May 31, 2011. If no one requests to speak at the public hearings by May 31, 2011, then the public hearings will be cancelled without further notice. We will specify the date and time of the public hearings on

http://www.epa.gov/ttn/atw/pvc/pvcpg.html.

1

Throughout this preamble, “we” refers to EPA.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2002-0037 by one of the following methods:

•

http://www.regulations.gov.

Follow the on-line instructions for submitting comments.

•

http://www.epa.gov/oar/docket.html.

Follow the instructions for submitting comments.

•

E-mail: a-and-r-Docket@epa.gov

. Attn: Docket ID No. EPA-HQ-OAR-2002-0037.

•

Fax:

(202) 566-9744. Attn: Docket ID No. EPA-HQ-OAR-2002-0037.

•

Mail:

By U.S. Postal Service, send your comments to: EPA Docket Center, EPA West Building (Air Docket), U.S. Environmental Protection Agency, Mail Code: 2822T, 1200 Pennsylvania Ave., NW., Washington, DC 20460, Attn: Docket ID No. EPA-HQ-OAR-2002-0037. Please include a total of two copies. In addition, please mail a copy of your comments on the information collection provisions to the Office of Information and Regulatory Affairs, Office of Management and Budget, Attn: Desk Officer for EPA, 725 17th St., NW., Washington, DC 20503.

•

Hand Delivery

: By courier, deliver your comments to: U.S. Environmental Protection Agency, EPA Docket Center, EPA West Building (Air Docket), Room 3334, 1301 Constitution Ave., NW., Washington, DC 20004, Attn: Docket ID No. EPA-HQ-OAR-2002-0037. Such deliveries are only accepted during the normal hours of operation (8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays), and special arrangements should be made for deliveries of boxed information.

Instructions

: All submissions must include agency name and docket number or Regulatory Information Number (RIN) for this rulemaking. Direct your comments to Docket ID No. EPA-HQ-OAR-2002-0037. EPA's policy is that all comments received will be included in the public docket and may be made available online at

http://www.regulations.gov

, including any personal information provided, unless the comment includes information claimed to be confidential business information (CBI), or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI, or otherwise protected through

http://www.regulations.gov

or E-mail. The

http://www.regulations.gov

Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an E-mail comment directly to EPA without going through

http://www.regulations.gov

, your E-mail address will be automatically captured and included as part of the comment that is placed in the public docket, and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment, and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties, and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket, visit the EPA Docket Center homepage at

http://www.regulations.gov

.

Docket:

EPA has established a docket for this action under Docket ID No. EPA-HQ-OAR-2002-0037. All documents in the docket are listed in the

http://www.regulations.gov

index. Although listed in the index, some information is not publicly available,

e.g.,

CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy form. Publicly available docket materials are available either electronically at

http://www.regulations.gov

, or in hard copy at the EPA Docket Center, EPA West Building (Air Docket), Room 3334, 1301 Constitution Ave., NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the EPA Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT:

Ms. Jodi Howard, Sector Policies and Programs Division (E143-01), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; Telephone number: (919) 541-4607; Fax number: (919) 541-0246; E-mail address:

howard.jodi@epa.gov

.

SUPPLEMENTARY INFORMATION:

Acronyms and Abbreviations.

Several acronyms and terms are used in this preamble. While this may not be an exhaustive list, to ease the reading of this preamble and for reference purposes, the following terms and acronyms are defined here:

CAA—Clean Air Act

CBI—confidential business information

CDD/CDF—chlorinated dibenzo-dioxins and furans

CDX—Central Data Exchange

CEMS—continuous emission monitoring system

CPMS—continuous parameter monitoring system

ERT—Emissions Reporting Tool

Fe—fraction emitted

GACT—generally available control technologies or management practices

HAP—hazardous air pollutants

HCl—hydrogen chloride

HON—Hazardous Organic NESHAP

ICR—information collection request

K—kurtosis

lbs/yr—pounds per year

l/min—liters per minute

MACT—maximum achievable control technology

NESHAP—national emission standards for hazardous air pollutants

ng/dscm—nanograms per dry standard cubic meter

NTTAA—National Technology Transfer and Advancement Act

OP—Office of Policy

ppbv—parts per billion by volume

ppbw—parts per billion by weight

ppmv—parts per million by volume

ppmw—parts per million by weight

PRD—pressure relief device

psia—pounds per square inch absolute

PVC—polyvinyl chloride and copolymers

PVCPU—PVC production process unit

RFA—Regulatory Flexibility Act

RIN—Regulatory Information Number

S—skewness

SEK—standard error of kurtosis

SES—standard error of skewness

TCEQ—Texas Commission on Environmental Quality

TEF—toxic equivalency factor

TEQ—toxic equivalent

THC—total hydrocarbons

TTN—Technology Transfer Network

UMRA—Unfunded Mandates Reform Act

UPL—upper prediction limit

VCM—vinyl chloride monomer

WWW—World Wide Web

Organization of This Document

. The following outline is provided to aid in locating information in this preamble.

I. General Information

A. Do these rules apply to me?

B. What should I consider as I prepare my comments to EPA?

C. Where can I get a copy of this document?

II. Background Information for these Proposed Rules

A. What is the statutory authority for the proposed PVC rule?

B. What is the history of the PVC Production source category?

C. Summary of Related Court Decisions

D. What are the emission sources at PVC production facilities?

E. What HAP are emitted from PVC production facilities?

F. How did we gather information for the proposed PVC rule?

III. Summary of the Proposed Rule

A. What is the affected source for the proposed rule?

B. What is the relationship between this proposed rule and the existing 40 CFR part 61 standards for PVCPU?

C. How have we used subcategories in the proposed rule?

D. What proposed emission limitations and work practice standards must I meet?

E. When must I comply with the proposed standards?

F. What are the initial and continuous compliance requirements?

G. What are the performance testing requirements for batch process operations?

H. What are the notification, recordkeeping, and reporting requirements?

I. What are the electronic data submittal requirements?

J. What revisions are proposed for the area source rule (40 CFR part 63, subpart DDDDDD)?

IV. Rationale for the Proposed PVC Rule for Major and Area Sources (40 CFR part 63, subpart HHHHHHH)

A. How did EPA subcategorize PVC production?

B. How did EPA select the emission points, format, and pollutants for the proposed rule?

C. How did EPA determine the proposed emission standards for area sources?

D. How did EPA determine the MACT floors for existing major sources?

E. How did EPA determine the MACT floors for new major sources?

F. How did EPA analyze beyond-the-floor options and determine MACT?

G. How did EPA select the compliance and monitoring requirements for the proposed rule?

H. How did EPA determine compliance times for the proposed rule?

I. How did EPA determine the required records and reports for this proposed rule?

J. What are the startup, shutdown, and malfunction provisions?

V. Impacts of the Proposed PVC Rule

A. What are the air impacts?

B. What are the cost impacts?

C. What are the non-air quality health, environmental, and energy impacts?

D. What are the economic impacts of the proposed standards?

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act of 1995 (UMRA)

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments

G. Executive Order 13045: Protection of Children from Environmental Health Risks and Safety Risks

H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer and Advancement Act

J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations

A redline version of the regulatory language that incorporates the changes in this proposed action to 40 CFR 63, subpart DDDDDD is available in the docket.

I. General Information

A. Do these rules apply to me?

The proposed rules establish national emission standards for hazardous air pollutants (NESHAP) for PVC production.

The regulated categories and entities potentially affected by the proposed PVC production standards include the following:

Category

NAICS

1

Code

Examples of potentially regulated entities

Polyvinyl chloride resins manufacturing

325211

Facilities that polymerize vinyl chloride monomer to produce polyvinyl chloride and/or copolymers products.

1

North American Industry Classification System.

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be affected by this action. To determine whether your facility, company, business, organization,

etc.,

would be affected by this proposed action, you should examine the applicability criteria in the proposed 40 CFR part 63, subpart HHHHHHH (National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production), and in 40 CFR part 63, subpart DDDDDD (National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production Area Sources).

Your PVC production process unit (PVCPU) is not subject to this subpart if it is a research and development facility, as defined in section 112(c)(7) of the Clean Air Act (CAA). If you have any questions regarding the applicability of the proposed action to a particular entity, contact the person listed in the

preceding

FOR FURTHER INFORMATION CONTACT

section.

B. What should I consider as I prepare my comments to EPA?

Submitting CBI.

Do not submit information that you consider to be CBI electronically through

http://www.regulations.gov

or E-mail. Send or deliver information identified as CBI to only the following address: Ms. Jodi Howard, c/o OAQPS Document Control Officer (Room C404-02), U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, Attn: Docket ID No. EPA-HQ-OAR-2002-0037.

Clearly mark the part or all of the information that you claim to be CBI. For CBI information in a disk or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as CBI and then identify electronically within the disk or CD-ROM the specific information that is claimed as CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. If you submit a disk or CD-ROM that does not contain CBI, mark the outside of the disk or CD-ROM clearly that it does not contain CBI. Information marked as CBI will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.

If you have any questions about CBI or the procedures for claiming CBI, please consult the person identified in the

FOR FURTHER INFORMATION CONTACT

section.

C. Where can I get a copy of this document?

In addition to being available in the docket, an electronic copy of this proposed action will also be available on the World Wide Web (WWW) through the Technology Transfer Network (TTN). Following signature, a copy of the proposed action will be posted on the TTN's policy and guidance page for newly proposed or promulgated rules at the following address:

http://www.epa.gov/ttn/oarpg/.

The TTN provides information and technology exchange in various areas of air pollution control.

II. Background Information for These Proposed Rules

A. What is the statutory authority for the proposed PVC rule?

Section 112(d) of the CAA requires us to establish NESHAP for source categories and subcategories of both major and area sources of hazardous air pollutants (HAP) that are listed for regulation under CAA section 112(c). A major source emits or has the potential to emit 10 tons per year (tpy) or more of any single HAP or 25 tpy or more of any combination of HAP. An area source is a HAP-emitting stationary source that is not a major source.

Section 112(d) of the CAA requires EPA to set emissions standards for HAP emitted by major stationary sources based on performance of the maximum achievable control technology (MACT). The MACT standards for existing sources must be at least as stringent as the average emissions limitation achieved by the best performing 12 percent of existing sources (for which the Administrator has emissions information) or the best performing five sources for source categories or subcategories with fewer than 30 sources (CAA section 112(d)(3)(A) and (B)). This minimum level of stringency is called the MACT floor. For new sources, MACT standards must be at least as stringent as the control level achieved in practice by the best controlled similar source (CAA section 112(d)(3)). EPA also must consider more stringent “beyond-the-floor” control options. When considering beyond-the-floor options, EPA must consider not only the maximum degree of reduction in emissions of HAP, but must take into account costs, energy, and non-air quality health and environmental impacts when doing so.

Section 112(k)(3)(B) of the CAA requires EPA to identify at least 30 HAP which, as a result of emissions from area sources, pose the greatest threat to public health in the largest number of urban areas. EPA implemented this provision in 1999 in the Integrated Urban Air Toxics Strategy (Strategy), (64 FR 38715, July 19, 1999). Specifically, in the Strategy, EPA identified 30 HAP that pose the greatest potential health threat in urban areas, and these HAP are referred to as the “30 urban HAP.” CAA section 112(c)(3) requires EPA to list sufficient categories or subcategories of area sources to ensure that area sources representing 90 percent of the emissions of the 30 urban HAP are subject to regulation. A primary goal of the Strategy is to achieve a 75-percent reduction in cancer incidence attributable to HAP emitted from stationary sources.

EPA can set MACT standards for area sources. Section 112(d)(2). Alternatively, under CAA section 112(d)(5), EPA can promulgate standards or requirements for area sources “which provide for the use of generally available control technologies [“GACT”] or management practices by such sources to reduce emissions of hazardous air pollutants.” Additional information on GACT is found in the Senate report on the legislation (Senate Report Number 101-228, December 20, 1989), which describes GACT as:

* * * methods, practices and techniques which are commercially available and appropriate for application by the sources in the category considering economic impacts and the technical capabilities of the firms to operate and maintain the emissions control systems. Consistent with the legislative history, we can consider costs and economic impacts in determining GACT.

Determining what constitutes GACT involves considering the control technologies and management practices that are generally available to the area sources in the source category. We also consider the standards applicable to major sources in the analogous source category to determine if the control technologies and management practices are transferable and generally available to area sources. In appropriate circumstances, we may also consider technologies and practices at area and major sources in similar categories to determine whether such technologies and practices could be considered generally available for the area source categories at issue. Finally, as noted above, in determining GACT for a particular area source category, we consider the costs and economic impacts of available control technologies and management practices on that category.

Under CAA section 112(d)(6), we are required to “review, and revise as necessary (taking into account developments in practices, processes, and control technologies), emission standards promulgated under this section no less often than every 8 years.”

We are proposing revised standards for vinyl chloride emissions from area sources under the authority of CAA section 112(d)(6). We are also proposing standards for dioxin, hydrogen chloride (HCl), and total HAP under CAA section 112(d)(5).

B. What is the history of the PVC Production source category?

On July 16, 1992, PVC Production was listed as a major source category for regulation pursuant to section 112(c) of the CAA (57 FR 31576). A major source of HAP is a stationary source that has the potential to emit 10 tpy or more of any one HAP or 25 tpy or more of any combination of HAP.

On June 26, 2002, PVC Production was listed as an area source category for regulation pursuant to sections 112(c)(3) and 112(k)(3)(B)(ii) of the CAA (67 FR

43112). An area source is a stationary source of HAP that is not a major source.

On July 10, 2002, EPA promulgated NESHAP for new and existing PVC production facilities that are major sources in 40 CFR part 63, subpart J (67 FR 45886, July 10, 2002) (referred to as the “part 63 NESHAP”). In that rulemaking, EPA determined that compliance with the existing Vinyl Chloride NESHAP (40 CFR part 61, subpart F) (referred to as the “part 61 NESHAP”) reflected the application of MACT; thus, satisfying CAA section 112(d), with the exception of adding requirements for equipment leaks at new sources. In the part 61 NESHAP and the associated part 63 NESHAP, EPA regulated vinyl chloride emissions as a surrogate for all HAP emitted from PVC production. For equipment leaks, the part 63 NESHAP required that new sources comply with 40 CFR part 63, subpart UU, National Emission Standards for Equipment Leaks—Control Level 2 Standards.

In

Mossville Environmental Action Now

v.

EPA,

370 F.3d 1232 (DC Cir. 2004), the petitioners argued that EPA failed to set emission standards for all HAP emitted by PVC plants. EPA had set emission standards for vinyl chloride as a surrogate for the remaining HAP, because it was the predominant HAP used and emitted at PVC plants. The Court ruled that EPA did not adequately explain the basis for its decision to use vinyl chloride as a surrogate for other HAP. The Court “vacated and remanded [the rule in its entirety] to the Agency for it to reconsider or properly explain its methodology for regulating [HAP] emitted in PVC production other than vinyl chloride by use of a surrogate.” 370 F.3d at 1243. This rule proposes NESHAP for PVC production major sources in response to the remand, and in accordance with section 112 of the CAA.

On January 23, 2007 (72 FR 2930), EPA promulgated NESHAP for new and existing PVC production area sources in 40 CFR part 63, subpart DDDDDD. Subpart DDDDDD is based on GACT, and requires area sources to meet the requirements in the existing Vinyl Chloride NESHAP (part 61 NESHAP). The part 61 NESHAP requirements address only vinyl chloride emissions. In this rulemaking, we are fulfilling our obligation under section 112(d)(6) of the CAA to review, and revise, as necessary, the PVC production area source standards. We are coordinating our review of the area source standards with the development of major source MACT standards in response to the Court remand.

C. Summary of Related Court Decisions

In addition to

Mossville Environmental Action Now

v.

EPA,

summarized above, two other court decisions are relevant to this proposal. In March 2007, the District of Columbia Circuit Court issued an opinion (

Sierra Club

v.

EPA,

479 F.3d 875 (DC Cir. 2007) (Brick MACT)) vacating and remanding CAA section 112(d) MACT standards for the Brick and Structural Clay Ceramics source categories. Some key holdings in that case were:

• MACT floors for existing sources must reflect the average emission limitation achieved by the best performing 12 percent of existing sources, not levels EPA considers to be achievable by all sources (479 F.3d at 880-81);

• EPA cannot set floors of “no control.” The Court reiterated its prior holdings, including

National Lime Association

v.

EPA,

233 F.3d 625 (DC Cir. 2000), confirming that EPA must set floor standards for all HAP emitted by the major source, including those HAP that are not controlled by at-the-stack control devices (479 F.3d at 883); and

• EPA cannot ignore non-technology factors that reduce HAP emissions, including when determining which sources are best performers for purposes of ascertaining the MACT floor. Specifically, the Court held that “EPA's decision to base floors exclusively on technology even though non-technology factors affect emissions violates the Act.” (479 F.3d at 883).

In addition, the fact that a specific level of performance is not being intentionally achieved by the source is not a legal basis for excluding the source's performance from consideration.

Sierra Club

v.

EPA,

479 F.3d at 631-34;

National Lime Association

v.

EPA,

233 F.3d at 640.

The Brick MACT decision also stated that EPA may account for variability in setting floors. However, the Court found that EPA erred in assessing variability, because it relied on data from the worst performers to estimate best performers' variability, and held that “EPA may not use emission levels of the worst performers to estimate variability of the best performers without a demonstrated relationship between the two” (479 F.3d at 882).

A second Court opinion of relevance to this proposal is Sierra Club v. EPA, 551 F.3d 1019 (DC Cir. 2008). In that case, the Court vacated portions of two provisions contained in the General Provisions (40 CFR part 63, subpart A). The regulations at issue were 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), which, when incorporated into CAA section 112(d) regulations for specific source categories, exempt sources from the requirement to comply with the otherwise applicable CAA section 112(d) emission standard during periods of startup, shutdown, and malfunction.

D. What are the emission sources at PVC production facilities?

PVC production includes the manufacture of PVC resins. The resins are then used to make a large number of commercial and industrial products. Producing these resins involves batch reactors where vinyl chloride monomer (VCM), along with initiators and inhibitors, is polymerized as a homopolymer, or copolymerized with varying amounts of a co-monomer, such as vinyl acetate. At most facilities, the resulting resins are in a slurry form and are then stripped to recover the unreacted VCM. The stripped resin is then dried into powders or granules. PVC resins are then either shipped offsite, or used to make final products in equipment and unit operations that are not covered under this source category.

PVC is not a HAP, but the manufacture of PVC resin requires VCM, which is a HAP, as a primary feedstock. Unreacted VCM and other organic HAP present in feedstocks or formed during the polymerization process may be present in process components. HAP may be released from an opening or leak in a process component; or the residual HAP (

i.e.,

unreacted VCM, and other organic compounds) in the resin may be released to the atmosphere as a result of drying or handling dry resin. Stripping the polymerized resin to recover unreacted VCM reduces the air emissions of vinyl chloride and other HAP from the resin slurry by reducing the amount of HAP present. Gaseous vent streams containing vinyl chloride and other HAP that originates from process equipment prior to, and including the resin stripper, are sent to a VCM recovery process before being routed to one or more control devices, such as an absorber, or thermal oxidizer, followed by a halogenated compound scrubber. Combustion controls greatly reduce vinyl chloride and other HAP emissions, but may create other HAP, in particular, chlorinated dibenzo-dioxins and furans (CDD/CDF), and HCl.

Emission sources in the PVC production process include process components prior to, and including, the resin stripper(s) (

e.g.,

the reactor, resin stripper, reactor used as a stripper, storage and feed vessels for raw materials, additives, initiators, and

inhibitors); VCM recovery systems (

e.g.,

condenser or other vapor separation devices, holding tanks, gas holders); and process components downstream of the resin stripper(s) (

e.g.,

centrifuges, concentrators, blend tanks, filters, dryers, conveyor air discharges, bagging operations, resin handling and conveyance equipment), and final resin storage tanks or storage silos. Additional emission sources at PVC production facilities include leaking equipment (

e.g.,

pumps, valves, compressors); wastewater collection and treatment systems; heat exchange system components (

e.g.,

cooling towers, heat exchangers, pumps, and other equipment associated with the heat exchange system); and other emission sources, such as opening a reactor and other components for maintenance and cleaning.

E. What HAP are emitted from PVC production facilities?

The HAP emitted from PVC production processes includes a wide variety of HAP. There are no metal HAP emitted from PVC production. In addition, combustion control devices emit HCl and CDD/CDF. Of the HAP emitted from PVC production processes, 1,3-butadiene, benzene, CDD/CDF, and vinyl chloride have been classified as known human carcinogens.

2

Several other compounds that may be emitted from PVC production processes have been classified as probable carcinogens, such as acetaldehyde, bis (2-ethylhexyl) phthalate, chloroform, chloroprene, ethylene dichloride, ethylidene dichloride, formaldehyde, iso-octane, methylene chloride, vinyl bromide, and vinylidene chloride.

3

Hydrogen chloride, along with other non-carcinogenic HAP (

e.g.,

methanol), are also emitted from PVC production processes.

2

U.S. EPA,

Integrated Risk Information System

(IRIS). Available at

http://www.epa.gov/IRIS/index.html.

F. How did we gather information for the proposed PVC rule?

We gathered information on PVC production through review of previously collected information, current literature, data from the

National Emissions Inventory,

meetings and voluntary information submissions by industry and the industry trade association, and formal information collection pursuant to CAA section 114.

There were two components to the information collection. First, we solicited information from eight PVC companies in the United States that manufacture PVC resin. The collection obtained available information on PVC production units at major and area sources (

e.g.,

information on production processes, equipment, emission points, control techniques, operating practices, and emissions based on previous tests or calculations). Companies were also asked to provide data for other emission sources, including process component openings and cleanouts, handling of unstripped resin, filters, and gas holders. Second, we required the same companies to measure the HAP content in their PVC resins (both following stripping, but before drying, and after drying) and measure the HAP emissions at the inlet and outlet to their process vent control devices. The information collection is documented in the memorandum,

Information Collection for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category,

and results of this information collection are available in the docket.

III. Summary of the Proposed Rule

This section summarizes and provides our rationale for the requirements proposed in this action. In section III of this preamble, the term “you” refers to owners and operators of sources affected by the proposed rule.

A. What is the affected source for the proposed rule?

The proposed rule applies to owners or operators of PVC PU located at, or that are part of, a major source or an area source as defined in 40 CFR 63.2. The affected source for this subpart is each individual PVCPU. An existing affected source is a PVCPU that is not a new affected source, as defined in 40 CFR 63.11870 of the proposed rule. A new affected source is a PVCPU for which construction is commenced on or after May 20, 2011 at a major or area source. If components of an existing affected source are replaced such that the replacement meets the definition of reconstruction in 40 CFR 63.2 and the reconstruction commenced on or after May 20, 2011, then the existing source becomes a reconstructed source and is subject to the relevant standards for a new affected source. The reconstructed source must comply with the requirements for a new affected source upon initial startup of the reconstructed source, or by the effective date of publication of the final rule in the

Federal Register

, whichever is later.

A PVCPU is defined as a collection of process components that is assembled and connected by hard-piping or duct work that processes raw materials to manufacture PVC resin. A PVCPU includes, but is not limited to, polymerization reactors; resin strippers; blend tanks; centrifuges; dryers; product separators; recovery devices; feed, intermediate, and product storage vessels; finished product loading operations; heat exchange systems; wastewater strippers; wastewater treatment systems; connected ducts and piping; and equipment in HAP service, including pumps, compressors, agitators, pressure relief devices (PRD), sampling connection systems, open-ended valves or lines, valves, and connectors.

B. What is the relationship between this proposed rule and the existing 40 CFR part 61 standards for PVCPU?

PVCPU are currently subject to requirements in the part 61 NESHAP. This proposed rule includes requirements that are at least as stringent as the requirements in this existing rule. We, therefore, propose that once facilities are in compliance with the final PVCPU MACT, the requirements of the part 61 NESHAP would no longer apply.

C. How have we used subcategories in the proposed rule?

Most of the emissions sources subject to the proposed regulation have the same characteristics, and are addressed consistently, independent of process operations or products produced. We are proposing, however, three subcategories for our limits on the amount of HAP remaining in resins following polymerization and stripping (

i.e.,

the stripped resin). These subcategories are based on the type of resin produced, and include: (1) Bulk resin, (2) dispersion resin, and (3) all other resin (

e.g.,

suspension and solution resin).

D. What proposed emission limitations and work practice standards must I meet?

The proposed rule would establish the same requirements for affected sources located at major and area sources. We explain in section IV.C below our rationale for the standards proposed for area sources.

1. Storage Vessels and Handling Operations

Under 40 CFR 63.11910 and Table 4 of the proposed rule, if you own or operate a storage vessel at a new or existing affected source, we are proposing that material with a maximum true vapor pressure of the stored liquid greater than 11.1 pounds per square inch absolute (psia) be stored in pressure vessels with no emissions to the atmosphere. During those times when purging is required, or when the pressure vessel is being loaded, the

purged stream or the emission stream during loading would be required to be routed to a closed vent system and control device. The closed vent system and control device must meet the requirements specified in 40 CFR 63.11925 of the proposed rule. You would also be required to equip all openings in the pressure vessel with closure devices that are designed to operate with no detectable emissions, as determined using procedures specified in 40 CFR 63.11910(a)(3) of the proposed rule.

For storage vessels with a capacity greater than or equal to 40,000 gallons, storing material with a maximum true vapor pressure greater than or equal to 0.75 psia, or storage vessels with a capacity greater than or equal to 20,000 gallons (but less than 40,000 gallons), storing materials with a maximum true vapor pressure greater than or equal to 4 psia, we are proposing two equivalent compliance options. We are proposing that material be stored in either: (1) A floating roof tank meeting the operating, inspection, and maintenance requirements of 40 CFR part 63, subpart WW, or (2) a fixed roof storage vessel that routes vent streams to a closed vent system and control device (meeting the requirements of 40 CFR 63.11925 of the proposed rule) capable of reducing inlet volatile organic compound (VOC) emissions by 95 or greater.

We are proposing that all other storage vessels meet the operating, inspection, and maintenance requirements for fixed roof vessels of 40 CFR 63.11910(a) of the proposed rule, or comply with either the controlled fixed roof or floating roof requirements discussed previously. 40 CFR 63.11910(a)(1)(ii) and 40 CFR 63.11910(a)(3)(i) of the proposed rule include requirements to equip each opening in the roof with a closure device, and to perform initial and annual inspections, and repair any defects found within the specified time period. Defects include, but are not limited to, visible cracks, holes, gaps, or other open spaces in the closure device or between the perimeter of the opening and the closure device; broken, cracked, or otherwise damaged seals or gaskets on closure devices; and broken or missing hatches, access covers, caps, or other closure devices.

We are not proposing requirements for handling operations (unloading and transfer) for reasons explained in section IV.D of this preamble.

2. Equipment Leaks

In 40 CFR 63.11915 of the proposed rule, we are proposing that existing and new affected sources comply with the leak detection and repair (LDAR) program requirements of the National Emission Standards for Equipment Leaks-Control Level 2 Standards, subpart UU of 40 CFR part 63, except for agitators, and rotating or reciprocating pumps and compressors. For gas and light liquid valves, subpart UU specifies a leak definition of 500 parts per million VOC, and a monitoring frequency that is dependent upon the number of leaking valves. Subpart UU also requires equipment specifications that prevent leaks for other pieces of equipment.

We are proposing that rotating pumps be sealless, equipped with double seals, or equivalent. Reciprocating pumps, reciprocating and rotating compressors, and agitator must be equipped with double seals, or equivalent, as provided in 40 CFR 63.11915 of the proposed rule. If double mechanical seals or double outboard seals are used, HAP emissions must be minimized by maintaining the pressure between the two seals so that the leak occurs into the pump, compressor, or agitator; by ducting any HAP between the two seals through a closed vent system to a control device meeting the process vent emission limits specified in 40 CFR 63.11925 of the proposed rule; or by an equivalent method, as provided in 40 CFR 63.11915 of the proposed rule.

We are proposing that a vinyl chloride monitoring system be operated for detection of major leaks and identification of the general area of the plant where a leak is located. A vinyl chloride monitoring system is a device that obtains air samples from one or more points continuously, and analyzes the samples with gas chromatography, infrared spectrophotometry, flame ion detection, or an equivalent or alternate method.

In 40 CFR 63.11915 of the proposed rule, we are also proposing that, in addition to operating with no detectable emissions, there be no discharge to the atmosphere from any PRD on any equipment in HAP service within the PVCPU. We are proposing that upon a discharge to the atmosphere from the PRD that the monitoring requirements specified in 40 CFR part 63, subpart UU for pressure releases from PRD be followed.

3. Heat Exchange Systems

In 40 CFR 63.11920 of the proposed rule, we are proposing that you implement a LDAR program to detect leaks of VOC into cooling water. For existing sources, we are proposing monthly monitoring for both closed loop and once-through heat exchange systems using either the Texas Commission on Environmental Quality (TCEQ) Modified El Paso Method

3

or EPA Method 8021B, Aromatic and Halogenated Volatiles by Gas Chromatography Using Photoionization and/or Electrolytic Conductivity Detectors, with a leak action level of 38 parts per billion by weight (ppbw) of total strippable VOC in the cooling water or 2.9 parts per million by volume (ppmv) of total strippable VOC in the stripping gas. For new sources, we are proposing twice-daily (12 hour intervals) monitoring for both closed loop and once-through heat exchange systems using either the TCEQ's Modified El Paso Method

4

or EPA Method 8021B with a leak action level of 30 ppbw of total strippable VOC in the cooling water or 2.3 ppmv of total strippable VOC in the stripping gas. The delay of repair action level for both new and existing sources is 380 ppbw of total strippable VOC in the cooling water or 29 ppmv of total strippable VOC in the stripping gas. When a leak is identified, additional monitoring must be performed to isolate the source of the leak. If the total strippable VOC concentration remains below the leak action level throughout the period of additional monitoring, then repairs are not required; otherwise, repairs must be completed within 45 days of identifying the leak. Repairs may be delayed if the concentration of total strippable VOC in the cooling water or stripping gas remains below the delay of repair action level and either: (1) It is technically infeasible to repair the leak without a shutdown, or (2) the necessary equipment, parts, or personnel are not available.

3

Air Stripping Method (Modified El Paso Method) for Determination of Volatile Organic Compound Emissions from Water Sources,

Revision Number One, dated January 2003, Sampling Procedures Manual, Appendix P: Cooling Tower Monitoring, prepared by TCEQ, January 31, 2003 (incorporated by reference—see 40 CFR 65.645).

4

Air Stripping Method (Modified El Paso Method) for Determination of Volatile Organic Compound Emissions from Water Sources,

Revision Number One, dated January 2003,

Sampling Procedures Manual

, Appendix P: Cooling Tower Monitoring, prepared by TCEQ, January 31, 2003 (incorporated by reference—see 40 CFR 65.645).

4. Process Vents

In 40 CFR 63.11925 of the proposed rule, we are proposing all the vent streams from: polymerization reactors, resin strippers, other process components prior to the resin stripper, VCM recovery systems, wastewater collection and treatment system, slip gauges, unloading and loading lines, and samples be routed through a closed vent system to a control device. We are proposing the emission limitations presented in Table 1 of this preamble for

the outlet of the control device. These emission limitations apply at all times.

Table 1—Emission Limitations for Process Vents

a

Pollutant

Emission Limitations

b

Existing sources

New sources

Vinyl chloride

0.32 ppmv

3.2 ppbv

Hydrogen chloride

150 ppmv

0.17 ppmv

Total organic HAP

12 ppmv

0.22 ppmv

Dioxin/Furans (TEQ)

0.023 ng/dscm

0.0087 ng/dscm

a

Process vents limits apply at the outlet of the control device which controls closed vent streams from polymerization reactors, resin strippers, other process components prior to the resin stripper(s), VCM recovery systems, certain storage vessels, the wastewater collection and treatment system, slip gauges, unloading and loading lines, and samples.

b

ppbv = parts per billion by volume dry at 3-percent O

2

. ppmv = parts per million by volume dry at 3-percent O

2

. ng/dscm = nanograms per dry standard cubic meter at 3-percent O

2

.

5. Other Emission Sources

Other emission sources include reactor and other component opening losses. When reactors or other components (including pre-polymerization reactors used in the manufacture of bulk resins) are opened for cleaning, we are proposing in 40 CFR 63.11955 of the proposed rule that emissions be minimized prior to opening. We are proposing that emissions from opening a polymerization reactor must not exceed 0.04 pound vinyl chloride/ton of polyvinyl chloride product where the product means the gross product of pre-polymerization and post-polymerization. We are proposing emissions from opening of process components for any reason be minimized by reducing the volume of vinyl chloride to an amount that occupies a volume of no more than 2.0 percent of the component's containment volume or 25 gallons, whichever is larger, at standard temperature and pressure. Any vinyl chloride removed from opening equipment must be ducted through a closed vent system to a control device meeting the requirements in 40 CFR 63.11925 through 40 CFR 63.11950 of the proposed rule. The outlet of the control device must meet the emission limitations for process vents discussed in section III.D.4.

6. Stripped Resin

In 40 CFR 63.11960 of the proposed rule, we are proposing emission limitations for residual vinyl chloride and total HAP in the stripped resin presented in Tables 2 and 3 of this preamble. The limits were developed for new and existing sources for three subcategories of PVC resins: (1) Bulk resins, (2) dispersion resins, and (3) all other resins. These emission limits would apply at all times.

Table 2—Limits for Stripped Resin at Existing Sources

Pollutant

Emission limits (ppmw)

Bulk resins

Dispersion resins

All other resins

Vinyl chloride

7.1

55

0.48

Total HAP

170

110

76

Table 3—Limits for Stripped Resin at New Sources

Pollutant

Emission limitations (ppmw)

Bulk resins

Dispersion resins

All other resins

Vinyl chloride

7.1

41

0.20

Total HAP

170

58

42

7. Wastewater

In 40 CFR 63.11965 of the proposed rule, we are proposing that you must determine the vinyl chloride concentration for each wastewater stream at the point of wastewater generation. Streams with 10 ppmw vinyl chloride, or more, must be treated to reduce the concentration of vinyl chloride to a concentration of 0.11 ppmw for existing sources, and 0.0060 ppmw for new sources. The 10 ppmw determination applies before the wastewater stream is exposed to the atmosphere, stored, mixed with any other wastewater stream, and enters a wastewater treatment process, or is discharged untreated as a wastewater.

We are also proposing that wastewater streams with flow rates greater than or equal to 10 liters per minute (l/min),

and the concentrations of HAP, as determined by Method 305 (as specified in 40 CFR part 63, subpart G, Table 9) greater than or equal to 1,000 ppmw, meet the Hazardous Organic NESHAP (HON) wastewater requirements, as described in the sections of 40 CFR part 63, subpart G, and specified in the proposed rule.

Streams that contain less than 10 ppmw vinyl chloride (at the point of generation), and streams that either contain less than 1,000 ppmw total HAP, or have a flow rate less than the 10 l/min criteria (at the point of determination, as defined by 40 CFR part 63, subpart G), are not required to further reduce emissions, but must remain below these levels.

E. When must I comply with the proposed standards?

Existing affected sources would be required to comply with the proposed 40 CFR part 63, subpart HHHHHHH no later than 3 years after publication of the final rule in the

Federal Register

. New affected sources would be required to comply on the effective date of the final rule, or upon startup, whichever is later.

F. What are the initial and continuous compliance requirements?

In 40 CFR 63.11896 of the proposed rule, we are proposing that, if you make a process change to an existing affected source that does not meet the criteria to become a new affected source in 40 CFR 63.11870(c) of the proposed rule, you must demonstrate that any added emission points are in compliance with the applicable requirements for an existing affected source. If the process change results in a change in the characteristics of any emission point such that a different emission limit, operating parameter limit, or work practice standard applies, we are proposing that you demonstrate that the changed emission point complies with the applicable requirements for an existing affected source. You must demonstrate compliance with any applicable work practice standards upon startup of the changed emission point, and must demonstrate compliance with any emission limits and establish applicable operating limits by 180 days after the date of initial startup of the changed process unit.

We are also proposing that, if you make a process change to a new affected source, you would demonstrate that any added emission point(s) is/are in compliance with the applicable work practice standards for a new affected source by start-up of the changed emission point. You must also demonstrate initial compliance with any emission limits and establish applicable operating limits by 180 days after the date of initial startup of the changed process unit.

If you make a process change that adds or changes emission points, we are proposing that you demonstrate continuous compliance with your emission limits and standards, operating limits, and work practice standards according to the procedures and frequency in 40 CFR 63.11910 through 40 CFR 63.11980 of this proposed rule, and submit a notification report specified in 40 CFR 63.11985 of the proposed rule.

1. What are the initial and continuous compliance requirements for storage vessels?

For each floating roof storage vessel, we are proposing that you meet the operating, inspection, repair, and maintenance requirements of 40 CFR part 63, subpart WW. For each fixed roof storage tank venting through a closed vent system to a control device achieving 95-percent reduction in total HAP emissions, we are proposing that you meet the requirements for closed vent systems and control devices in 40 CFR 63.11925 of the proposed rule, and summarized in section III.D.3 of this preamble.

In 40 CFR 63.11910 of the proposed rule, we are also proposing that, for each fixed roof tank, you install and maintain the tank with no visible cracks, holes, or other open spaces between roof section joints or between the interface of the roof edge and the tank wall. We are also proposing that you must install closure devices that you secure in the closed position except during periods when you need to have access to the interior of the fixed roof tank. The closure device may be opened when needed to provide access. The fixed roof tank and its closure device would be required to be inspected initially, and at least once per year. The inspection requirements would not be applicable to parts of the fixed roof that are determined to be unsafe to inspect if you document and explain why it is unsafe to inspect and develop a plan to conduct inspections when the tank is not in service. A first attempt to repair defects must be made no later than 5 calendar days after detection, and repairs would be required to be completed no later than 45 days after detection, except as specified in 40 CFR 63.11910(a)(4)(ii) of the proposed rule.

In 40 CFR 63.11910 of the proposed rule, for pressure vessels, we are proposing that all potential leak interfaces in the pressure vessel be monitored for leaks annually and repaired following the procedures of 40 CFR 63.11915 of the proposed rule.

2. What are the initial and continuous compliance requirements for equipment leaks?

For each applicable piece of equipment (e.g., valves, connectors) associated with your affected source, we are proposing that you meet the LDAR requirements of 40 CFR part 63, subpart UU. In 40 CFR 63.11915 of the proposed rule, you would also be required to install electronic indicators on each PRD that would be able to identify and record the time and duration of each pressure release and notify operators that a pressure release has occurred.

3. What are the initial and continuous compliance requirements for heat exchange systems?

We are proposing that for each affected source, you must operate an equipment leak program, as specified in the proposed rule. Under the compliance requirements for heat exchange systems in 40 CFR 63.11920 of the proposed rule, an affected source would be required to conduct sampling and analyses using either the TCEQ Modified El Paso Method, Revision Number One, dated January 2003,

5

or EPA Method 8021B, no less frequently than monthly for existing sources and twice-daily (12-hour intervals) for new sources, and fix any leaks detected. We are proposing different sampling locations for once-through and closed loop heat exchange systems as specified in 40 CFR 63.11920 of the proposed rule. For once-through systems only, you may monitor at the cooling tower return line prior to exposure to the air. For once-through systems, you must monitor selected heat exchanger exit line(s) so that each heat exchanger or group of heat exchangers within a system is covered by the selected monitoring location. Monitoring of selected heat exchanger exit lines is also a monitoring option for closed loop systems. Additionally, for once-through systems, you may also monitor the inlet water feed line prior to any heat exchanger. If multiple heat exchange systems use the same water feed (

i.e.

, inlet water from the same primary water source), you may monitor at one representative location and use the monitoring results for that sampling location for all heat exchange systems

that use that same water feed. We are proposing to exempt a heat exchange system from the monitoring requirements in 40 CFR 63.11920 if all heat exchangers within the heat exchange system operate with the minimum pressure on the cooling water side at least 35 kilopascals greater than the maximum pressure on the process side, or the heat exchange system does not contain any heat exchangers.

5

Air Stripping Method (Modified El Paso Method) for Determination of Volatile Organic Compound Emissions from Water Sources

, Revision Number One, dated January 2003,

Sampling Procedures Manual

, Appendix P: Cooling Tower Monitoring, prepared by TCEQ, January 31, 2003 (incorporated by reference—see 40 CFR 65.645).

Identified leaks must be repaired as soon as practicable, but within 45 days after identifying the leak. We are proposing delay of repair action levels as either a total strippable VOC concentration (as methane) in the stripping gas of 29 ppmv or a total strippable VOC concentration in the cooling water of 380 ppbw. Leaking heat exchanger repairs may be delayed if the repair is technically infeasible without a shutdown, or the necessary equipment, parts, or personnel are not available. To delay repairs in either case, the total strippable VOC must initially be, and remain less than, the delay of repair action level for all monitoring periods during the delay of repair.

4. What are the initial and continuous compliance requirements for process vents?

To demonstrate compliance for process vents, you would be required to meet the requirements of proposed 40 CFR 63.11930 for each closed vent system that routes emissions from process vents subject to the HAP emission limits to a control device. You would be required to meet the initial and continuous compliance requirements for process vents specified in 40 CFR 63.11925 and 40 CFR 63.11935, the monitoring requirements for your process vent control device, as specified in proposed 40 CFR 63.11940, and the performance testing requirements for process vents in 40 CFR 60.11945. You may not use a flare to comply with the emission limits of the proposed rule, as specified in 40 CFR 63.11925(b).

Closed vent systems

. In 40 CFR 63.11930 of the proposed rule, for closed vent systems, you would be required to meet specified design requirements and install flow indicators in the bypass lines, or meet other requirements to prevent and detect bypass of the control device. You must also follow the inspection, leak monitoring, and repair requirements in 40 CFR 63.11930 of the proposed rule for closed vent systems. Closed vent systems in vacuum service would be required to install alarms rather than performing leak inspection and monitoring. If you operate a closed vent system in vacuum service, you are not required to comply with the other closed vent system requirements in the proposed rule.

Performance testing, continuous parameter monitoring system (CPMS), and continuous emission monitoring system (CEMS) requirements for process vents and associated control devices

.

Compliance would be demonstrated through a combination of performance testing (as specified in 40 CFR 63.11925 and 40 CFR 63.11945) and/or monitoring using CEMS or CPMS that measure process vent control device operating parameters (as specified in 40 CFR 63.11925, 40 CFR 63.11935, and 40 CFR 63.11940). These sections also refer to Tables 1, 2, 6, and 7 of the proposed rule for emission limits, testing methods, and requirements. Below, we summarize the process vent testing and compliance requirements by pollutant. Each test would consist of three test runs.

We are proposing that existing and new sources would be required to demonstrate initial and annual compliance with the total organic HAP emission limits in Table 1 or 2 of the proposed rule by measuring total hydrocarbon (THC) at the outlet of the control device using EPA Method 25A, as specified in Table 9 of the proposed rule. The minimum test run duration would be 1 hour.

During the initial compliance test, you would be required to establish values for the control device operating parameters specified in 40 CFR 63.11935 and 40 CFR 63.11940 (

e.g.

, incinerator temperature). You would then use a CPMS to continuously monitor that parameter to demonstrate continuous compliance with the total organic HAP limit. New and existing sources could elect to use THC CEMS instead of annual testing and CPMS for total organic HAP. All CEMS must meet the applicable performance specifications, procedures, and other calibration, accuracy, and operating and maintenance requirements, as specified in 40 CFR 63.11935 of the proposed rule. For vinyl chloride, you would demonstrate compliance by conducting initial and annual performance tests using EPA Method 18. You would be required to establish monitoring parameters during the initial performance test, and continuously monitor control device operating parameters.

For CDD/CDF, you would demonstrate compliance by conducting initial and annual performance tests using EPA Method 23. The minimum sampling volume collected would be 5 cubic meters for Method 23. For HCl, you would demonstrate compliance by conducting an initial performance test using EPA Method 26 or 26A. The minimum sampling volumes collected would be 60 liters for EPA Method 26, or 1 cubic meter for EPA Method 26A. You would be required to establish monitoring parameters during the initial performance test, and continuously monitor control device operating parameters (e.g., liquid flow rate and pH for scrubbers, and temperature and carbon injection rate for activated carbon injection). After EPA publishes final performance specifications for CEMS for HCl and CDD/CDF, new sources would be required to use CEMS instead of annual testing for these pollutants, as required in 40 CFR 63.11925 of the proposed rule. Existing sources could elect to use CEMS instead of annual testing and CPMS for these pollutants. All CEMS must meet the applicable performance specifications, procedures, and other calibration, accuracy, and operating and maintenance requirements, as specified in 40 CFR 63.11935 of the proposed rule.

We have included specific performance testing requirements, including the process operating conditions under which performance tests should be conducted, for continuous process vents and batch operations, as provided in 40 CFR 63.11945 of the proposed rule, and discussed in section III.F and III.G of this preamble.

All CPMS would be required to have data averaging periods of 3-hour block averages. All CPMS would be required to meet minimum accuracy and calibration frequency requirements, as specified in 40 CFR 63.11935 and Table 8 of the proposed rule. For each monitored parameter, you would establish a minimum, maximum, or a range that indicates proper operation of the control device, as specified in 40 CFR 63.11935(d). The proposed rule specifies the parameters that would be monitored for each type of control device, including each incinerator, absorber, adsorber, condenser, sorbent injection system, fabric filter, or other control device. You must also install a flow indicator at the inlet of the control device to indicate periods of no flow to the control device.

Some control devices would be subject to additional emission point-specific performance testing requirements, as described in 40 CFR 63.11945 of the proposed rule. We have included specific performance testing requirements for continuous process vents and batch operations, as provided in 40 CFR 63.11945 of the proposed

rule, and discussed in section III.F of this preamble.

5. What are the initial and continuous compliance requirements for wastewater?

As specified in 40 CFR 63.11965(a) of the proposed rule, we are proposing that you must conduct an initial test for wastewater streams from the affected source to determine the vinyl chloride concentration, the total HAP concentration (including all HAP listed in Table 9 of 40 CFR part 63, subpart G), and the flow rate. The concentration tests would be conducted using EPA Method 107 in combination with Resource Conservation and Recovery Act (RCRA) Method SW-8260B and EPA Method 305. Prior to testing, you would be required to submit a test plan for EPA approval that includes your proposed method for analysis using these methods. We are proposing that you sample for vinyl chloride by collecting one grab sample at the point of generation. We are also proposing that you sample for total HAP by collecting one grab sample at the point of determination, as specified in 40 CFR part 63, subpart G.

Wastewater streams that contain less than 10 ppmw vinyl chloride (at the point of generation), and wastewater streams that either contain less than 1,000 ppmw total HAP, or have a flow rate less than the 10 l/min criteria (at the point of determination, as defined by 40 CFR part 63, subpart G), must remain below these levels. You would conduct periodic tests at the same locations, and using the same test methods described above to verify that the stream concentration stays below the vinyl chloride and total HAP concentration levels. Wastewater streams would be tested monthly. There are also proposed requirements in 40 CFR 63.11975(e)(2) of the proposed rule, for demonstrating that you remain below the 10 l/min flow rate criterion, based on flow rate measurements.

If your wastewater stream contains vinyl chloride concentrations greater than or equal to 10 ppmw, you would be required to treat the wastewater stream to achieve a concentration of 0.11 ppmw vinyl chloride at the wastewater stripper outlet for existing sources, and 0.0060 ppmw at new sources. You must conduct an initial compliance test and monthly testing to demonstrate compliance with these limits. We are proposing that you measure at the outlet of the wastewater stripper by collecting one grab sample. In addition, during your performance test, you would be required to establish operating ranges for your wastewater steam or vacuum stripper, including steam-to-feed ratios and stripper bottoms temperature, and also the vacuum level measured in the column for vacuum strippers. You would use a CPMS to continuously monitor control device operating parameters to demonstrate that you continuously meet these limits.

If the wastewater stream exceeds the 1,000 ppmw HAP concentration (based on the list of HAP in Table 9 of 40 CFR part 63, subpart G), and the 10-l/min flow rate, then you must comply with the 40 CFR part 63, subpart G, Group 1, wastewater suppression and treatment requirements, and conduct the compliance testing and monitoring required in subpart G.

For more information on the wastewater compliance requirements, see 40 CFR 63.11965, 40 CFR 63.11970, and 40 CFR 63.11975 of the proposed rule.

6. What are the initial and continuous compliance requirements for stripped resins?

In 40 CFR 63.11960 of the proposed rule, we are proposing that you conduct initial performance tests to demonstrate compliance with the proposed vinyl chloride and total HAP limits for stripped resin. We are also proposing that you conduct daily performance testing to demonstrate continuous compliance with the proposed vinyl chloride limit, and monthly performance testing to demonstrate continuous compliance with the proposed total HAP limit. The tests would be conducted at the outlet of the resin stripper for continuous processes and immediately after stripping for batch processes. You would be required to use EPA Method 107 in combination with RCRA Method SW-8260B, and to include in your test plan a proposed method for analysis using these methods. You would be required to submit the test plan for EPA approval. In addition, during your initial performance test, you would be required to establish operating ranges for your resin steam or vacuum stripper, including steam-to-feed ratios, stripping temperature, and the vacuum level measured in the column for vacuum strippers. You would use a CPMS to continuously monitor resin stripper operating parameters. All CPMS would be required to calculate 3-hour block averages for the parameters measured.

To demonstrate initial compliance with the total HAP limits, you would be required to collect one grab sample every 8 hours for a single grade, or one grab sample per grade of PVC resin produced, whichever is more frequent for each resin stripper over a 24-hour period. To determine initial compliance with the vinyl chloride limit, you would be required to collect one grab sample every 8 hours for a single grade, or one grab sample per grade of PVC resin produced, whichever is more frequent, for each resin stripper over a 24-hour period. You would be required to collect samples over a 24-hour period during which you are manufacturing the grade of resin, which you produce the most of, based on total mass of resin produced in the preceding month.

To demonstrate continuous compliance with the vinyl chloride limit for a continuous process, you would be required to collect one grab sample from each resin stripper every 8 hours for a single grade, or one grab sample per grade of PVC resin produced, whichever is more frequent. Grade is defined in 40 CFR 63.12010 of the proposed rule and is unchanged from the definition in the Part 61 NESHAP other than the insertion of the term “PVC.” To demonstrate compliance with the vinyl chloride limit for a batch process, you would be required to collect one grab sample from each batch of resin produced. You must demonstrate compliance on a daily basis using a 24-hour average concentration weighted on production.

To demonstrate continuous compliance with the total HAP limits for a continuous process, on a monthly basis you would be required to collect one grab sample every 8 hours for a single grade, or per grade of PVC resin produced, whichever is more frequent from each resin stripper over a 24-hour period. Individual sampling events may be 3 to 5 weeks apart, but you must conduct a minimum of 12 sampling events per calendar year. The 24-hour arithmetic average total HAP concentration for each stripper for each resin grade produced during the 24-hour sampling period must be calculated using the individual HAP concentrations measured for the grab. Beginning 13 months following your initial demonstration of compliance, you must demonstrate continuous compliance with the total HAP emission limit in Table 1 or 2 to this subpart, based on a 12-month rolling average concentration, calculated as the average of the 12 most recent 24-hour arithmetic average concentrations.

To demonstrate continuous compliance with the total HAP limits for a batch process, on a monthly basis, you would be required to collect one grab sample for each batch of resin produced over a 24-hour period. You would be required to collect samples over a 24-hour period during which you

are producing the grade of resin, which you manufacture for a majority of the time during that month. You must demonstrate compliance on a monthly basis with the average concentration of the most recent 12 months of data.

7. What are the initial and continuous compliance requirements for other emission sources?

To demonstrate compliance with the requirements for other emission sources, we are proposing that for reactors and other components prior to opening, you must follow the initial and continuous compliance requirements in 40 CFR 63.11925. We are requesting comments on this compliance approach.

G. What are the performance testing requirements for batch process operations?

For batch process operations, performance tests would be conducted under the most challenging conditions that you would run your batch process operations to make sure that the control devices are operating at the level needed to demonstrate compliance with the appropriate emission limits. The Agency's intent is to require testing of the performance of the control device under its most challenging conditions. Subsequent to the initial compliance test, continuous monitoring of operating parameters established during the initial test is a reasonable measure of continuous compliance with the efficiency requirement under all conditions. Presumably, the control device should function as well or better under conditions that are not as challenging. You would be required to develop an emission profile that describes the characteristics of the vent stream at the inlet to the control device under either absolute or hypothetical worst-case conditions. The emissions profile may be developed by process, by process component, or by capture and control device limitations, as specified in 40 CFR 63.11945(c)(3) of the proposed rule. We have provided methodologies to develop the emissions profile for each batch processing operation in proposed 40 CFR 63.11950, including methodologies for vapor displacement, gas sweep of a partially filled vessel, heating, depressurization, vacuum systems, gas evolution, air drying, and purging. All other HAP emissions for the emissions profile would be determined through an engineering assessment, or through testing approved by the Administrator. See 40 CFR 63.11945 of the proposed rule.

H. What are the notification, recordkeeping, and reporting requirements?

1. Notifications and Reports

All new and existing sources would be required to comply with certain requirements of the General Provisions (40 CFR part 63, subpart A), which are identified in Table 5 of the proposed 40 CFR part 63, subpart HHHHHHH. The General Provisions include specific requirements for notifications, recordkeeping, and reporting. Reports include notifications of initial startup, initial notification, notification of compliance status, compliance reports, notification of performance test, notification of inspection, batch pre-compliance report, and other notifications and reports specified in proposed 40 CFR 63.11985.

The notification of compliance status report required by 40 CFR 63.9(h) must include certifications of compliance with rule requirements.

The excess emissions and continuous system performance report and summary report required by 40 CFR 63.10(e)(3) of the NESHAP General Provisions (referred to in the rule as a compliance report) would be required to be submitted semi-annually for reporting periods during which there was: An exceedance of any emission limit or a monitored parameter; a deviation from any of the requirements in the rule occurred; or if any process changes occurred and compliance certifications were reevaluated. The proposed rule includes additional requirements for what you must include in these reports for each type of emission point. See 40 CFR 63.11985 of the proposed rule.

2. Recordkeeping

The proposed rule would require compiling and retaining records to demonstrate compliance with each emission limit and work practice standard. These recordkeeping requirements are specified either directly in the proposed rule, in the General Provisions to 40 CFR part 63, and in 40 CFR part 63, subparts UU and WW. Records that we are proposing that you keep include performance tests, records of CPMS and CEMS, records of malfunction, records of deviations, records specific to each emission point, and other records specified in proposed 40 CFR 63.11990. The 40 CFR part 63 General Provisions requirements that apply are listed in Table 5 of the proposed rule. We are proposing that records be kept for 5 years in a form suitable and readily available for EPA review. We are proposing that records be kept on-site for 2 years; you may keep the records off-site for the remaining 3 years. See 40 CFR 63.11990 of the proposed rule.

I. What are the electronic data submittal requirements?

EPA must have performance test data to conduct effective reviews (

e.g.,

risk assessment) of CAA section 112 standards, as well as for many other purposes, including compliance determinations, emission factor development, and annual emission rate determinations. In conducting these reviews, EPA has found it ineffective and time consuming, not only for us, but also for regulatory agencies and source owners and operators to locate, collect, and submit emissions test data in paper form because of varied locations for data storage and varied data storage methods. In recent years, though, stack testing firms have typically collected performance test data in electronic format, making it possible to move to an electronic data submittal system that would increase the ease and efficiency of data submittal and improve data accessibility.

In this action, EPA is proposing a step to increase the ease and efficiency of data submittal and improve data accessibility. Specifically, we are proposing that owners and operators of PVC production facilities would be required to submit electronic copies of reports of certain required performance test reports to EPA's WebFIRE database. The WebFIRE database was constructed to store performance test data for use in developing emission factors. A description of the WebFIRE database is available at

http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main.

EPA solicits comment on the proposed electronic data submittal requirements.

Data entry will be through an electronic emissions test report structure called the

Electronic Reporting Tool

(ERT). The ERT would be able to transmit the electronic report through EPA's

Central Data Exchange

(CDX) network for storage in the WebFIRE database making submittal of data very straightforward and easy. A description of the ERT can be found at

http://www.epa.gov/ttn/chief/ert/ert_tool.html.

The requirement to submit source test data electronically to EPA would only apply to those performance tests conducted using test methods that are supported by the ERT. The ERT contains a specific electronic data entry form for most of the commonly used EPA reference methods. A listing of the pollutants and test methods supported by the ERT is available at

http://www.epa.gov/ttn/chief/ert/ert_tool.html.

We believe that industry would benefit from this proposed approach to electronic data submittal. Having these data, EPA would be able to develop improved emission factors, make fewer information requests, and promulgate better regulations.

One major advantage of submitting source test data through the ERT is that it will provide a standardized method to compile and store much of the documentation required to be reported by the proposed rule. Another advantage is that the ERT clearly states what testing information would be required.

Another important benefit of submitting these data to EPA at the time the source test is conducted is that it should substantially reduce the effort involved in data collection activities in the future. When EPA has performance test data in hand, there will likely be fewer or less substantial data collection requests in conjunction with prospective required residual risk assessments or technology reviews. This would result in a reduced burden on both affected facilities (in terms of reduced manpower to respond to data collection requests) and EPA (in terms of preparing and distributing data collection requests and assessing the results).

State, local, and Tribal agencies may also benefit from a more streamlined and accurate review process rather than a manual data assessment, making review and evaluation of the source provided data and calculations easier and more efficient. Finally, another benefit of the proposed data submittal to WebFIRE electronically is that these data would greatly improve the overall quality of existing and new emissions factors by supplementing the pool of emissions test data for establishing emissions factors, and by ensuring that the factors are more representative of current industry operational procedures. A common complaint heard from industry and regulators is that emission factors are outdated or not representative of a particular source category. With timely receipt and incorporation of data from most performance tests, EPA would be able to ensure that emission factors, when updated, represent the most current range of operational practices. In summary, consistent with Executive Order 13563,

Improving Regulation and Regulatory Review,

issued on January 18, 2011, in addition to supporting regulation development, control strategy development, and other air pollution control activities, having an electronic database populated with performance test data would save industry, State, local, Tribal agencies, and EPA significant time, money, and effort while also improving the quality of emission inventories and, as a result, air quality regulations.

J. What revisions are proposed for the area source rule (40 CFR part 63, subpart DDDDDD)?

We are proposing to revise the existing NESHAP for PVC production area sources (40 CFR part 63, subpart DDDDDD) to require that PVC production area sources comply with the proposed rule. Area sources would be required to continue to comply with the current provisions of subpart DDDDDD until they are in compliance with the proposed rule. After that date, existing and new area sources would no longer be subject to the requirements of subpart DDDDDD.

IV. Rationale for the Proposed PVC Rule for Major and Area Sources (40 CFR part 63, subpart HHHHHHH)

A. How did EPA subcategorize PVC production?

The CAA allows EPA to divide source categories into subcategories, based on differences in class, type, or size. For example, differences between given types of units can lead to corresponding differences in the nature of emissions and the technical feasibility of applying emission control techniques. For the stripped resin limits, we are proposing three subcategories.

In the United States, four different types of polymerization processes have been used to manufacture PVC: dispersion, suspension, solution, and bulk. The type of resin production process used is dictated by the end use of the product and the product's required physical and chemical properties and function, such as the need for flexibility, rigidity, or the ability to be molded. For example, to make dispersion resins (as compared to other types of resins), different reactants, initiators, and surfactants are used in the manufacturing process. The differences in chemicals used for manufacturing, and the properties of the final product, result in products with different compositions.

After the polymerization process is complete, the PVC resin is sent to a resin stripper, or the resin can be stripped directly in the reactor to remove residual HAP such as vinyl chloride. The vent streams from the resin stripper, polymerization reactors, other process components upstream of the resin stripper, and vents from the wastewater stripper are sent to recovery processes to recover unreacted VCM. After recovery, the vent stream containing unrecovered VCM is sent to a control device before being emitted to atmosphere.

Dispersion resins have less porosity, mechanical stability, and heat stability than suspension or solution resins, resulting in more difficulty in stripping vinyl chloride. Consequently, the levels of vinyl chloride in the stripped dispersion resin products are not as low as those in the stripped suspension resin products. At bulk resin production, the product of the polymerization process results in a resin that is more of a solid than a slurry, which is unlike solution, dispersion, and suspension resins, and results in a different emissions profile at the resin stripper for organic HAP and vinyl chloride. We are unaware of any resin that is being manufactured using the solution process, and we do not have emissions data on this type of process.

For purposes of the stripped resin limits, which serve to limit emissions from points downstream of the resin stripper, we are proposing to subcategorize PVCPU into three subcategories: bulk resins, dispersion resins, and all other resin types. In the absence of data on solution resin production facilities, we are incorporating them into the “other resins” subcategory, which also includes suspension resin. We are requesting comment on the proposed subcategorization, and the appropriateness of including suspension and solution resins in the same subcategory.

We are not proposing to establish separate subcategories for any of the other emission points regulated by the proposed rule (process vents, equipment leaks, wastewater, storage vessels, other emission sources, and heat exchange systems by resin type). The same air pollution control devices, wastewater treatment processes, and work practices for these kinds of emission points are applicable and effective regardless of any potential differences in physical and chemical properties of the resin being produced. Therefore, EPA chose not to subcategorize in setting emission limitations and work practice standards for these emission points.

B. How did EPA select the emission points, format, and pollutants for the proposed rule?

1. How did EPA select the emission points covered?

The emission points covered by the proposed rule were selected to ensure control of all sources of HAP emissions within the PVC production process. The

HAP emission points within PVCPU are process vents (e.g., process vents from polymerization reactors, resin strippers, other process components prior to the resin stripper, the VCM recovery system, slip gauges, loading and unloading lines, samples, the wastewater collection and treatment system that routes emissions through a closed vent system to a control device, and emission control devices), stripped resin, equipment leaks (

e.g.,

valves, pumps, connectors, and PRD), wastewater collection and treatment systems, storage vessels, reactor and other process component openings, and heat exchange systems.

EPA solicits comment on the emission points proposed for regulation.

2. How did EPA select the format of the proposed rule?

We are proposing to establish numerical emission limits in the form of concentration limits for process vents, stripped resin, and wastewater. We are establishing the process vent emission limits at the outlet of the control device. The process vent emissions are comprised of emissions from polymerization reactors, resin strippers, other process components prior to the resin stripper, the VCM recovery system, certain pressurized and fixed storage vessels, slip gauges, loading and unloading lines, samples, the wastewater collection and treatment system that routes emissions through a closed vent system to the control device, and emission control devices.

The emission limits in the proposed rule provides flexibility for the regulated community by allowing a regulated source to choose any control technology or technique to meet the emission limits, rather than requiring each unit to use a prescribed control method that may not be appropriate in each case. We are proposing numerical emission rate limits as ppmv dry standardized to 3-percent oxygen for process vents. A concentration limit in units of ppmv is consistent with previous EPA and State regulations for PVC production facilities, and other processes controlled by combustion devices.

We are proposing a concentration limit for HAP in the stripped resin in units of ppmw as a means to control HAP emissions from downstream sources (e.g. dryers, centrifuges, filters). We are proposing a concentration based limit because the HAP emissions from vents associated with processes downstream of the resin stripper are dependent on the concentration of HAP in the stripped resin. That is, the greater the HAP concentration in the stripped resin, the greater the HAP emissions from downstream process components. Similarly, the lower the HAP concentration in the stripped resin, the lower the HAP emissions from downstream process components. Consequently, limiting HAP in the stripped resin is the best means to control HAP emissions from downstream processes. This approach is consistent with current Federal and State regulations that are applicable to PVC production facilities.

For wastewater streams that contain greater than or equal to 10 ppmw vinyl chloride, and, accordingly, require treatment to reduce the vinyl chloride concentration, we are proposing a stripper outlet concentration. Wastewater streams with less than 10 ppmw vinyl chloride must stay below that level. To address HAP emissions other than vinyl chloride, the proposed rule would require compliance with the HON requirements in 40 CFR part 63, subpart G.

We are proposing work practice standards to reduce emissions from storage vessels, equipment leaks, and heat exchange systems.

CAA section 112(h)(1) states that the Administrator may prescribe a work practice standard or other requirements, consistent with the provisions of CAA sections 112(d) or (f), in those cases where, in the judgment of the Administrator, it is not feasible to enforce an emission standard. CAA section 112(h)(2) defines the phrase “not feasible to prescribe or enforce an emission standard” as follows:

[A]ny situation in which the Administrator determines that (A) a hazardous air pollutant or pollutants cannot be emitted through a conveyance designed and constructed to emit or capture such pollutant, or that any requirement for, or use of, such a conveyance would be inconsistent with any Federal, State, or local law, or (B) the application of measurement methodology to a particular class of sources is not practicable due to technological and economic limitations.

The work practice standards in this proposed rule are consistent with CAA section 112(h)(2)(B), because applying a measurement methodology to this class of sources is not technologically feasible due to the number of openings and possible emissions points.

The proposed work standards for emissions from storage tanks are evaporative losses that result from barometric pressure and ambient temperature changes, as well as filling and emptying operations. The flow rate of vent emissions from a tank is very low, except during filling. The concentration of HAP in the vent stream varies with the degree of saturation of HAP in the tank vapor space. The degree of saturation depends on such factors as HAP vapor pressure, tank size, and liquid throughput. Low flow rate and varying concentration make emission measurement impractical.

Emissions from equipment leaks are intermittent and fugitive in nature, so it is, therefore, not feasible to fully measure the mass emission rate from numerous potential leaks at an affected source.

3. How did EPA determine the pollutants for which to set emission limits?

The major HAP emitted from PVC production processes is the raw material, vinyl chloride. This is from the feed material processing prior to the reaction, and from post reaction processing (some of the VCM raw material remains unreacted during the polymerization process). For these reasons, we are setting emission limits for vinyl chloride.

PVC production processes also emit a variety of other HAP that may be contained in initiators or inhibitors of polymerization, additives, copolymer feedstocks, impurities, or formed during the polymerization process. As discussed earlier, these HAP include 1,3-butadiene, benzene, acetaldehyde, bis (2-ethylhexyl) phthalate, chloroform, chloroprene, ethylene dichloride, ethylidene dichloride, formaldehyde, iso-octane, methylene chloride, vinyl bromide, and vinylidene chloride.

3

PVCPU use different processes to produce a variety of resin products. Rather than setting individual emission limits for the wide variety of other HAP that can be found in PVC production processes, we are proposing a total HAP emission limit. A total HAP limit is appropriate because emissions from PVC facilities are comprised of mixtures of these HAP, and the control technologies used to control total HAP such as condensers and thermal oxidizers, achieve control of the individual HAP. Thermal oxidizers combust all organic HAP and convert them to carbon dioxide and water, with only trace amounts of organic compounds remaining. An acid gas scrubber removes any inorganic compounds that remain after combustion. Condensers, as a part of the vinyl chloride recovery system condense out organic compounds that are re-used in the process.

Process vents are often controlled using thermal oxidizers because they are effective at reducing emissions of vinyl chloride and organic HAP. However, the combustion of halogenated organic compounds results in formation of hydrogen chloride, which is a HAP, and

can also result in the formation of CDD/CDF. We are proposing to set emission limits for HCl from process vents.

We are authorized to regulate the CDD/CDF class of HAP. While dibenzofuran and 2,3,7,8-TCDD are identified by name as HAP in CAA section 112, all CDD/CDF are polycyclic organic matter, and, as such, we have the authority to regulate these compounds. Under CAA section 112(d), the MACT floor standards are to be based on the average emissions performance of the best performing units for which the Administrator has emissions information. We received a substantial amount of emissions test data for CDD/CDF emissions through the CAA section 114 information collection, in which we sought CDD/CDF information from sampling runs that lasted about 4 hours each. While reported CDD/CDF emissions were below detectable levels in approximately 46 percent of the individual test runs for all CDD/CDF isomers reported, only 37 percent of three-run test averages were comprised of individual test runs where all runs were below detection limits. Therefore, a majority (63 percent) of the three-run tests detected some level of CDD/CDF. Furthermore, some of the emission tests detected most or all isomers at some level, and CDD/CDF emissions can be precisely measured for most control devices in the PVC production source category. Therefore, the statutory test for establishment of work practice standards—

i.e.,

that measurement of emissions is impracticable due to technological and economic limitations—is not met.

To make sure that the emission limits are set at a level that can be measured, we adjusted for variability using the upper prediction limit (UPL) approach, and we used the “three times MDL” approach (discussed elsewhere in this preamble) as a minimum level at which a CDD/CDF emission limit, on a toxic equivalency (TEQ) basis, is set. Rather than establishing work practice standards, but recognizing that emissions tend to be very low compared to more significant sources of CDD/CDF, such as incinerators, our approach to CDD/CDF requires an initial compliance test to demonstrate that the PVCPU meet the CDD/CDF standard, and additional compliance testing on an annual basis. Initial and continuous compliance requirements for process vents are discussed in section III.F.4 of this preamble. Furthermore, the CDD/CDF test method, EPA Method 23, requires that, for compliance purposes, non-detect values from runs should be reported and calculated as zeroes. Therefore, for purposes of compliance, there should be no concern about being unable to meet the standards because of the contribution of non-detect values. Consequently, we are proposing to set emission limits for CDD/CDF (on a TEQ basis) from process vents.

Cooling towers may emit a variety of VOC, depending on which process components may be leaking into the heat exchange system. The most prevalent HAP that may leak into a heat exchange system is vinyl chloride, which is also a VOC. The proposed compliance method for heat exchange systems measures total VOC and not speciated compounds. A detection of total VOC in the cooling water indicates leakage of organic HAP (including vinyl chloride) into the heat exchange system.

4. Solicitation of Comments

EPA solicits comment on the emission points proposed for regulation and the format of the proposed standards. We also solicit comments on the pollutants that we have proposed for regulation and how we grouped pollutants such as total HAP and dioxin.

C. How did EPA determine the proposed emission standards for area sources?

Under CAA section 112(d)(6), we are required to “* * * review, and revise as necessary (taking into account developments in practices, processes, and control technologies), emission standards promulgated under this section no less often than every 8 years.” With this rulemaking, we are fulfilling our obligation to review, and revise, as necessary, the PVC Production area source standards. The 2007 NESHAP for PVC production area sources (40 CFR, part 63, subpart DDDDDD) are based on GACT. The area source NESHAP only set emission limits for vinyl chloride, which was the pollutant for which we needed the PVC Production area source category to meet our 90-percent obligation in CAA section 112(c)(3) and (k)(3)(B). We are proposing to tighten emission standards for vinyl chloride under CAA section 112(d)(6).

Under CAA section 112(d)(5), we may elect to promulgate standards or requirements for area sources “which provide for the use of generally available control technologies [“GACT”] or management practices by such sources to reduce emissions of hazardous air pollutants.” In this proposed rule, we have determined that area source emission limits should be set for total HAP, CDD/CDF, and HCl, in addition to vinyl chloride, that are emitted from PVC production processes. As explained in other area source rules, the Agency has discretion to set standards for all urban HAP, in this case, CDD/CDF and total HAP, and to not limit standards to only the urban HAP for which the area source category was listed (

i.e.,

vinyl chloride). In addition to vinyl chloride, PVC production processes emit a variety of other HAP that may be contained in initiators or inhibitors of polymerization, additives, copolymer feedstocks, impurities, or formed during the polymerization process. The urban HAP reported to be emitted by the only existing PVC area source include 1,3-butadiene, ethylene dichloride, and methylene chloride. However, PVCPU can produce a variety of resin products over time which can influence the HAP emitted, so there is a potential that the area source could also emit other organic HAP reported at major source PVCPU (such as benzene, acetaldehyde, chloroform, and formaldehyde). Rather than setting individual emission limits for the wide variety of HAP that can be emitted by the area source PVC facility, we are proposing a total HAP emission limit (as we are for major sources). A total HAP limit is appropriate because emissions from the area source PVC facility are comprised of mixtures of these organic HAP, and the control technologies used to control total HAP achieve control of the individual organic HAP.

Although we recognize that we have met the 90-percent requirement of CAA section 112(c)(3), nothing precludes the Agency from regulating beyond the 90 percent with regard to the 30 urban HAP. We also believe it is appropriate to establish area source emission standards for HCl because, although not an urban HAP, it is formed as a product of combustion in controlling vents containing vinyl chloride and HAP. We solicit comment on our proposal to regulate these other HAP, beyond vinyl chloride since the Agency has already met its 90-percent statutory obligation under CAA section 112(c)(3) and 112(k)(3)(B).The 2007 GACT standards (40 CFR part 63, subpart DDDDDD) generally required area sources to continue to comply with the vinyl chloride emission limits, and other requirements in the part 61 NESHAP, which had been promulgated in 1976 (41 FR 46560, October 21, 1976). Therefore, the 2007 GACT standards did not achieve any emissions reductions.

In determining what constitutes GACT for this proposed rule, we considered the control technologies and management practices that are generally available to PVC area sources by examining relevant data and information, including information collected from the only known PVC area

source. We also considered the standards proposed for major sources to determine if the control technologies and management practices are transferable and generally available to area sources. (See section III of this preamble for a summary of the MACT standards and sections IV.D through IV.F for further information on how the proposed MACT standards were determined.) As part of the GACT determination, we considered the costs and economic impacts of available control technologies and management practices on area sources.

As explained in greater detail below, we determined that GACT standards for area sources should be the same as the major source MACT standards, based on the similarity between production processes, emission points, emissions, and control technologies that are characteristic of both major and area source PVC production facilities. Due to the nature of the PVC production process and as reported in the information collected, the one existing area source has the same kinds of emission points (process vents, stripped resin, wastewater, equipment leaks, storage, heat exchangers, and other emission sources) and emits the same types of pollutants (identified in section IV.B of this preamble) as major sources. From the information that we collected during this rule development, which includes stack testing and site visits at both major and area sources, we now know that area sources have the same types of emissions, emission sources, and controls (see control information below) as major sources. Information that we have collected to support development of these proposed standards indicates that the one area source would be major, based on its potential to emit, except that the source has an enforceable requirement to operate its thermal oxidizer, which keeps it below major source levels. We are not aware of any planned new area sources.

In reviewing the data collected from major and area sources for development of the proposed rule, it is clear that the one PVC area source, like the major sources, is achieving vinyl chloride emission limits well below those required in the 2007 area source NESHAP (40 CFR part 63, subpart DDDDDD) and the part 61 NESHAP. The data collected from major and area sources are discussed in the memorandum,

Baseline Emission Estimates for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category

, which is available in the docket. The PVC area source uses the same control technologies as the major sources. For example, for process vents, the area source is using the same control technology (a thermal oxidizer in series with an acid gas scrubber) as most major sources. It is also using the same wastewater control (a wastewater stripper) used by major sources, and implementing the same type of equipment LDAR program as most major sources. The achievability of stripped resin HAP limits is a function of the resin-type subcategory (bulk, dispersion, or other) rather than the size of the PVCPU, or its location at a major or area source, and the PVC area source is already meting the proposed stripped resin MACT limits for the bulk PVC subcategory. In addition, the area source PVC plant is already meeting the proposed MACT limits for storage vessels and other emission sources (reactor and other component opening losses). Therefore, the control technologies and management practices used by major sources are generally available for area sources. In addition, the part 61 NESHAP for this industry requires all PVC production facilities to meet the same standards with no major or area source distinction, and because of the similarities between major and area sources, it is reasonable for them to meet the same emission standards under this proposed rule.

As part of the GACT determination, we analyzed the cost and emissions reduction for the area source to meet the proposed GACT standards. The overall annual cost is $332,351, and the annual emission reduction is 17.23 tons of HAP per year. For information on the methodology and more detailed results of this analysis, see the memorandum,

Costs and Emission Reductions of the Proposed Standards for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category,

in the docket. The economic impact analysis (see section V.D of this preamble) showed that there are no significant economic impacts.

For the aforementioned reasons, we have determined, pursuant to CAA sections 112(d)(5) and (6), that the control technologies and management practices necessary to meet the proposed major source emission standards are generally available for area sources in this source category. Accordingly, we are proposing the GACT level of control for area sources is the same as the MACT level of control for major sources, and that these area sources must meet the same standards as proposed in this rule for major sources.

Because the compliance dates in the proposed rule are 3 years after promulgation for existing area sources, and startup or the date of promulgation, whichever is later, for new area sources, area sources must continue to comply with the current provisions of 40 CFR part 63, subpart DDDDDD until they are required to comply with 40 CFR part 63, subpart HHHHHHH. However, on and after the proposed rule's compliance dates, existing and new PVC production area sources would no longer be required to comply with subpart DDDDDD. The proposed amendments to subpart DDDDDD make this clear. Amending subpart DDDDDD in this manner allows for continuous compliance with emission standards for PVC production area sources, while avoiding duplicative or burdensome requirements under more than one subpart.

EPA solicits comment on the proposed approach. We further solicit comment on whether we should issue MACT standards under CAA section 112(d)(2) and (3) in lieu of GACT standards under CAA section 112(d)(5) given the significant amount of additional information on the one area source that was not available to EPA at the time of the 2007 area source GACT promulgation.

D. How did EPA determine the MACT floors for existing major sources?

There are less than 30 sources in this source category. Therefore, EPA has based the MACT floor on the average of the best performing five sources. The determination of the best performing sources is discussed below.

In general, MACT floor analyses involve an assessment of the emissions from the best performing sources in a source category using the available emissions information. For each source category, the assessment involves a review of emissions data with an appropriate accounting for emissions variability. Various methods of estimating emissions can be used if the methods can be shown to provide reasonable estimates of the actual emissions performance of a source or sources.

Process vents and stripped resin.

To develop the MACT floor emission limits for process vents (which includes all the vent streams from polymerization reactors, resin strippers, other process components prior to the resin stripping operation, VCM recovery system, slip gauges, loading and unloading lines, samples, and the wastewater collection and treatment system that are sent to a control device) and stripped resin, we ranked all the available emission concentration or resin concentration data for each pollutant: vinyl chloride, HCl, CDD/CDF, and total HAP for

process vents; and vinyl chloride and total HAP for stripped resin. For this ranking, EPA included all major sources and the one synthetic area source. In previous rulemakings (

e.g.,

Brick NESHAP, 68 FR 26697-26698, May 16, 2003), EPA determined that including synthetic area sources in calculating the MACT floor for major sources is consistent with CAA section 112(d).

Concentration data for each pollutant were ranked from sources within the entire category (for process vents), or each subcategory (for resins) from lowest to highest. Based on information available to EPA, at all existing PVC production facilities, emissions from process vents are routed to a VCM recovery system. The vent stream from the recovery system is controlled either by a thermal oxidizer followed by a scrubber, or by an absorber. Emissions data were collected from emissions tests (consisting of three test runs) conducted at the outlet of the absorber, or the thermal oxidizer/scrubber control system. For each pollutant, the average of the three test runs was calculated for each facility. The average values (for each pollutant) from each facility were then ranked from lowest to highest to identify the best performing sources.

The CAA section 114 information collection required each facility to take samples of the stripped resin being produced daily over a 30-day period at the outlets of the resin stripper(s) and the resin dryer(s). The facilities analyzed the samples for the concentration(s) of HAP present in the resin, and then calculated the corresponding mass of each HAP present in the stripped resin, based on the analysis of the concentration in each of the samples. Facilities were asked to report both the mass of each HAP present in the sampled resin, and also the production rate for that resin. The test results revealed that the methods used to convert the HAP concentration to mass varied across the industry making the emissions information incomparable. For example, some companies used the production rate from the entire plant, while others used the production rate from the production lines being sampled. We did not initially request the HAP concentration values for the analyzed resins, but because of the many discrepancies in the mass of each HAP in the stripped resin, these HAP concentrations values were provided in a subsequent data submittal by the industry trade association. The industry trade association also provided additional detail related to the detection levels and specific test methods used during the sampling and analysis required by our CAA section 114 information collection. The data used to calculate the MACT floors for stripped resin were the HAP concentration data, and not the mass loading data. To determine the stripped resin limits, we calculated the average concentration levels for each pollutant at each facility. They were then ranked from lowest to highest for each facility in the subcategory to identify the best performing sources.

MACT floors were calculated for each pollutant regulated by the proposed rule. Because there are fewer than 30 sources in the source category (for process vents) and each subcategory (for stripped resins), the MACT floor for each pollutant was calculated from the average of the best performing (

i.e.,

lowest emitting) five sources. We took the numerical average of the five best performing sources, and accounted for variability, as discussed later in this section of the preamble.

Wastewater.

All PVC production facilities are currently subject to the part 61 NESHAP inprocess wastewater standards. In the part 61 NESHAP, inprocess wastewater is defined as “* * * water which, during manufacturing or processing, comes into direct contact with vinyl chloride or results from the production or use of any raw material, intermediate product, finished product, by-product, or waste product containing vinyl chloride or polyvinyl chloride, but which has not been discharged to a wastewater treatment process or discharged untreated as wastewater. Gasholder seal water is not wastewater until it is removed from the gasholder.” The part 61 NESHAP requires control of inprocess wastewater streams with a concentration of 10 ppmw or more vinyl chloride at the point of generation, and all facilities achieve this control by using a wastewater steam stripper. The average annual vinyl chloride concentrations at the outlet of the stripper were provided in survey responses for 13 out of 17 facilities. The average values from each facility were then ranked from lowest to highest to identify the best performing sources (that controlled streams with vinyl chloride concentrations greater than 10 ppmw at the point of generation). We took the numerical average of the five best performing sources, and accounted for variability, as discussed later in this section of the preamble. The predominant HAP in wastewater streams generated from this source category is vinyl chloride. All of the stripped wastewater streams contain vinyl chloride, which the survey data show comprises, on average, 95 percent of the HAP concentration in these streams. A review of the streams exiting the wastewater stripper, and streams that do not require control to meet the 10 ppmw vinyl chloride requirements (from the part 61 NESHAP) at the point of generation, does not indicate that additional control is used to reduce those compounds that are not easily removed by the wastewater stripper. We have documented this analysis in the memorandum,

MACT Floor Analysis for the Polyvinyl Chloride and (PVC) Copolymers Production Source Category,

which is available in the docket. However, as explained in section IV.F of this preamble, we are proposing additional control of wastewater streams, based on other HAP (in additional to vinyl chloride as a beyond-the-floor option, and have included total HAP limits in the proposed rule.

Equipment leaks.

For equipment leaks, we ranked the LDAR programs used at each affected PVC source from most stringent to least stringent, based on the leak definitions, monitoring frequencies, control requirements, and repair requirements. We then identified the LDAR programs employed by the best performing five sources. The results of this analysis showed that three out of the best performing five sources comply with 40 CFR part 63, subpart UU level 2 controls. The remaining sources comply with less stringent LDAR programs, such as 40 CFR part 61, subpart V. Additionally, existing sources are complying with the requirements of the part 61 NESHAP, that rotating pumps must be either sealless, equipped with double mechanical seals, or equivalent and all reciprocating pumps, rotating and reciprocating compressors, and agitators must be equipped with double mechanical seals or equivalent. If double mechanical seals or double outboard seals are used, HAP emissions must be minimized by maintaining the pressure between the two seals so that the leak occurs into the pump, compressor, or agitator by ducting any HAP between the two seals through a closed vent system to a control device.

Therefore, we are proposing that existing and new affected sources comply with the LDAR program requirements of the National Emission Standards for Equipment Leaks-Control Level 2 Standards, subpart UU of 40 CFR part 63, except for rotating or reciprocating pumps, compressors, and agitators. We are proposing that rotating pumps be sealless, equipped with double seals, or equivalent. Reciprocating pumps, reciprocating and rotating compressors, and agitator be equipped with double seals, or

equivalent, as provided in 40 CFR 63.11915 of the proposed rule.

The part 61 NESHAP also requires installation of a vinyl chloride monitoring system for detection of major leaks and identification of the general area of the plant where a leak is located. A vinyl chloride monitoring system is a device that obtains air samples from one or more points continuously, and analyzes the samples with gas chromatography, infrared spectrophotometry, flame ion detection, or an equivalent or alternate method. These requirements from the part 61 NESHAP also constitute the MACT floor level of control.

The MACT floor analysis is available in the docket in the memorandum,

MACT Floor Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category.

Storage vessels and handling operations.

Two different types of storage vessels were identified from data collected from the PVC production industry: (1) Storage vessels storing material that are gases at ambient conditions (vapor pressures greater than 14.7 psia), and (2) storage vessels storing all other materials. The information collected showed that materials with vapor pressures greater than 14.7 psia are stored under pressure. A closed vent system that is routed to a control device is used at all facilities when filling the tank or purging the tank. All other materials are stored at all facilities in fixed roof tanks ranging in size from less than 5,000 gallons up to 30,000 gallons. These tanks primarily store methanol. The responses to the CAA section 114 information collection indicated that these tanks are not controlled.

The part 61 NESHAP, which covers ethylene dichloride, vinyl chloride, and PVC plants, has specific emission standards for handling operations (

i.e.,

loading and unloading of liquid products). However, PVC processes do not produce liquid products and do not have transfer rack loading operations. Handling a solid final product is unlikely to emit HAP, and the stripped resins limit already minimizes the HAP content of the final product. Consequently, no emission standards are being proposed for transfer operations. Unloading operations at PVC production facilities are considered part of process vents or storage, because emissions from unloading operations occur when charging storage vessels or reactor vessels, and any emissions are released from reactor vents or from the storage vessels. The emissions from these activities are subject to the process vent emission limits or storage vessel work practices. We are requesting comment on our proposed standards.

Heat exchange systems.

For heat exchange systems, we requested information on each heat exchange system at PVC production facilities, including closed loop and once-through systems, existing programs and procedures to identify leaks of HAP into cooling water, leak action levels, and estimates of emissions from cooling towers. We also requested information on the regulations applicable to PVC production facilities. Leak action levels are the concentration of pollutants in the cooling water that indicates one or more heat exchangers is leaking process fluid, or other HAP-containing fluid into the circulating cooling water. The HAP contained in the cooling water can then be emitted from a cooling tower once the cooling water is exposed to the atmosphere. We received leak action levels for vinyl chloride, ethylene dichloride, vinylidene chloride, VOC, and non-methane hydrocarbons from twelve facilities. From the data submitted by the best performing facilities discussed above, we determined that leak action levels ranged from 30 ppbw to 5,000 ppbw for VOC and non-methane hydrocarbons. The best performers had an average leak action level of 38 ppbw for total VOC, which corresponds to a total strippable VOC concentration of 2.9 ppmv in stripping gas. Therefore, we are proposing a leak action level of 38 ppbw of total strippable VOC in cooling water, or 2.9 ppmv total strippable VOC in stripping gas with monthly monitoring is the MACT floor for existing sources. While the data provided indicate that facilities monitor on a variety of different frequencies, we are proposing monthly monitoring. The majority perform either weekly or monthly monitoring.

Other emission sources.

The requirements from the part 61 NESHAP for reactor opening losses and component openings set numeric limits that must be met. The reactor opening loss from each reactor must not exceed 0.04 pound vinyl chloride/ton of PVC product. This requirement does not apply to pre-polymerization reactors in the bulk process. This requirement does apply to post-polymerization reactors in the bulk process, where the product means the gross product of pre-polymerization and post-polymerization.

The part 61 NESHAP also require that emissions from opening of other components, including pre-polymerization reactors used in the manufacture of bulk resins are to be minimized by reducing the volume of vinyl chloride to an amount which occupies a volume of no more than 2.0 percent of the equipment's containment volume, or 25 gallons, whichever is larger, at standard temperature and pressure. In the case of reactors used as strippers, the standard is based on the sum of allowable reactor opening losses, and the emissions limit for all downstream equipment (

e.g.,

the stripped resin limits). Furthermore, exhaust gasses from reactors and any vinyl chloride removed from process components must be ducted through a control system meeting specified outlet concentration limits. These requirements from the part 61 NESHAP constitute the MACT floor level of control from these emission sources.

1. Variability Calculation for MACT Floor Emission Limits Based on Emissions Test Data

For process vents, facilities measured the concentration of HAP in the vent stream exiting the control device used to control process vent streams. For stripped resin, facilities measured the concentration of HAP in the resin slurry exiting the resin stripper. For wastewater, facilities measured the concentration of vinyl chloride in the wastewater exiting the wastewater stripper. We used the emission concentration, resin concentration, and wastewater concentration data from the best performing sources to determine the MACT floor emission limits, with an accounting for variability. Data were collected from the CAA section 114 information collection, process vent emission testing results, resin sampling and analysis results, and additional data submissions by individual companies and the industry trade association that clarified, and/or corrected initial submissions, or that provided the same data in a different format (

e.g.,

concentration instead of mass in the case of stripped resin analysis results). We account for variability of the best-controlled source in setting floors, not only because variability is an element of performance, but because it is reasonable to assess best performance over time. The District of Columbia Circuit Court of Appeals has recognized that EPA may consider variability in estimating the degree of emission reduction achieved by best performing sources, and in setting MACT floors. See

Mossville Environmental Action Now

v.

EPA,

370 F.3d 1232, 1241-42 (DC Cir. 2004).

In determining the MACT floor limits for process vents, stripped resins, and wastewater, we first determined the MACT floor, which is the level achieved in practice by the average of the best-

performing five sources. We then assessed variability of the best performers by using a statistical formula designed to estimate a MACT floor level that is achieved by the average of the five best performing sources. Specifically, the MACT floor limit is an UPL calculated with the Student's t-test using the TINV function in Microsoft Excel©. The UPL has also been used in other EPA rulemakings (

e.g.

, the final NESHAP for Portland cement manufacturing, and the final NESHAP for industrial/commercial/institutional boilers) in accounting for variability. A prediction interval for a future observation is an interval that will, with a specified degree of confidence, contain the next (or some other pre-specified) randomly selected observation from a population. In other words, the prediction interval estimates what future values will be based upon present or past background samples taken. Given this definition, the UPL represents the value that we can expect the mean of three future observations (three-run average) to fall below, based upon the results of an independent sample from the same population. In other words, if we were to randomly select a future test condition from any of these sources (

i.e.

, average of three runs), we can be 99-percent confident that the reported level will fall at or below the UPL value. To calculate the UPL, we used the average (or sample mean) and sample standard deviation, which are two statistical measures calculated from the sample data. The average is the central value of a data set, and the standard deviation is the common measure of the dispersion of the data set around the average for a normally distributed data set.

We first determined the distribution of the emissions data for the best performing five sources within the source category for process vents, and within each subcategory for resins prior to calculating UPL values. To evaluate the distribution of the best performing dataset, we first computed the skewness and kurtosis statistics, and then conducted the appropriate small-sample hypothesis tests.

The skewness statistic (S) characterizes the degree of asymmetry of a given data distribution. Normally, distributed data have a skewness of 0. A skewness statistic that is greater (or less) than 0 indicates that the data are asymmetrically distributed with a right (or left) tail extending towards positive (or negative) values. Further, the standard error of the skewness statistic (SES) is given by SES = SQRT(6/N), where N is the sample size. According to the small sample skewness hypothesis test, if the skewness statistic (S) is greater than 2 times the SES, the data distribution can be considered non-normal.

The kurtosis statistic (K) characterizes the degree of peakedness or flatness of a given data distribution in comparison to a normal distribution. Normally, distributed data have a kurtosis of 0. A kurtosis statistic that is greater (or less) than 0 indicates a relatively peaked (or flat) distribution. Further, the standard error of the kurtosis statistic (SEK) is calculated by SEK = SQRT(24/N) where N is the sample size. According to the small sample kurtosis hypothesis test, if the kurtosis statistic (K) is greater than 2 times the SEK, the data distribution is typically considered to be non-normal.

We applied the skewness and kurtosis hypothesis tests to both the reported test values and the lognormal values of the reported test values. If the skewness (S) and kurtosis (K) statistics of the reported data set were both less than twice the SES and SEK, respectively, we classified the dataset as normally distributed. If neither of the skewness (S) and kurtosis (K) statistics, or only one of these statistics were less than twice the SES or SEK, respectively, then we conducted the skewness and kurtosis hypothesis tests for the natural log-transformed data. Then, we selected the distribution most similar to a log-normal distribution as the basis for calculating the UPL, based on EPA guidance documents. If both the reported values and the natural log-transformed reported values had skewness (S) and kurtosis (K) statistics that were greater than twice the SES or SEK, respectively, we selected the normally distributed dataset as the basis of the MACT floor to be conservative. If the results of the skewness and kurtosis hypothesis tests were mixed for the reported values, and the natural log-transformed reported values, we also chose the log-normal distribution to comply with EPA guidance. We believe this approach is more accurate and obtained more representative results than a more simplistic normal distribution assumption.

Because compliance with the MACT floor emission limit is based on the average of a three-run test, the UPL is calculated by:

EP20MY11.044

Where:

n = Number of test runs.

m = Number of test runs in the compliance average.

s = Standard deviation.

x bar = Mean

t (0.99,n−1) = T-statistic for 99-percent significance, and a sample size of n.

This calculation was performed using the following two Microsoft Excel© functions:

Normal distribution:

99-percent UPL = AVERAGE(Test Runs in Top 5) + [STDEV(Test Runs in Top 5)x TINV(2 x probability, n−1 degrees of freedom)*SQRT((1/n)+(

1/3

))], for a one-tailed t-value (with 2 x probability), probability of 0.01, and sample size of n.

Lognormal distribution

: 99-percent UPL = EXP{AVERAGE(Natural Log Values of Test Runs in Top 5) + [STDEV(Natural Log Values of Test Runs in Top 5) × TINV(2 × probability, n-1 degrees of freedom)* SQRT((1/n) + (

1/3

))]}, for a one-tailed t-value (with 2 x probability), probability of 0.01, and sample size of n.

We followed these procedures for determining the variability of process vent emission limits (for vent streams from polymerization reactors, resin strippers, other process components prior to the resin stripper, VCM recovery system, and wastewater collection and treatment system). For the stripped resin variability analysis, the same procedures were followed with one change. The variability calculation for stripped resins uses the average of the sampling results for each day of the 30-day sampling period (

e.g.

, essentially 30 runs instead of three runs for process vents). As a result, the 99-percent UPL equation uses a compliance average value of 30 instead of 3.

For wastewater, we followed the same procedures for determining variability. A variability analysis was performed on the top five facilities. The skewness and kurtosis statistics were calculated (following the same procedure as for process vents and resins) to determine the top 5 data set distribution. The 99-percent UPL value was calculated for both the normal and log-normal distribution using the same formula as

process vents and resins, except that the number of samples in the data set was set to 5 (the top 5 fraction remaining values), and the number of samples in the compliance average was set to 1 (because the data provided by facilities only included one value for any wastewater concentration).

2. Incorporation of Non-Detect Data

Non-detect values constitute more than 50 percent of the process vent emissions data for CDD/CDF and HCl, and approximately 42 percent of the stripped resin data for all reported HAP. For these pollutants, we developed a methodology to account for the imprecision introduced by incorporating non-detect data into the MACT floor calculation.

At very low emission levels for which emissions tests result in non-detect values, the inherent imprecision in the pollutant measurement method has a large influence on the reliability of the data underlying the MACT floor emission limit. Because of resin sample and emission matrix effects, laboratory techniques, sample size, and other factors, method detection levels normally vary from test to test for any specific test method and pollutant measurement. The confidence level that a value measured at the detection level is greater than zero is about 99 percent. The expected measurement imprecision for an emissions value occurring at or near the method detection level is about 40 to 50 percent. Pollutant measurement imprecision decreases to a consistent level of 10 to 15 percent for values measured at a level about 3 times the method detection level.

6

6

American Society of Mechanical Engineers,

Reference Method Accuracy and Precision (ReMAPJ: Phase 1, Precision of Manual Stack).

We are using an approach to account for measurement variability when significant numbers of non-detect measurements are included in the dataset that starts with defining a method detection level that is representative of the data used in the data pool.

The first step in this approach is to identify the highest test-specific method detection level reported in a data set that is also equal to or less than the average emission calculated for the data set. This approach has the advantage of relying on the data collected to develop the MACT floor emission limit, while, to some degree, minimizing the effect of a test(s) with an inordinately high method detection level (

e.g.,

the sample volume was too small, the laboratory technique was insufficiently sensitive, or the procedure for determining the detection level was other than that specified).

The second step is to determine the value equal to 3 times the representative method detection level, and compare it to the calculated MACT floor emission limit. If 3 times the representative method detection level is less than the calculated MACT floor emission limit, we would conclude that measurement variability is adequately addressed, and we would not adjust the calculated MACT floor emission limit. If, on the other hand, the value equal to 3 times the representative method detection level is greater than the calculated MACT floor emission limit, we would conclude that the calculated MACT floor emission limit does not account entirely for measurement variability. We, therefore, use the value equal to 3 times the method detection level, in place of the calculated MACT floor emission limit, to ensure that the MACT floor emission limit accounts for measurement variability and imprecision. The same procedures were followed for non-detect values for the resin information, but the analysis was done for 30 days worth of samples from each facility rather than three test runs. We request comment on this approach to incorporation of non-detect data in the MACT floor.

We followed the following additional procedures for CDD/CDF TEQ basis limits. To calculate a limit on a TEQ basis, first, we identified non-detect values on an individual CDD/CDF congener basis. There are 17 CDD/CDF congeners used to calculate TEQ values. For facilities that reported some, but not all CDD/CDF congeners as non-detect, we calculated the mean of the non-detect values for each CDD/CDF congener. Then we multiplied the toxic equivalency factor (TEF) for each congener by the mean to determine the TEQ detection level for each CDD/CDF congener. For facilities that reported all CDD/CDF congeners as non-detect, we multiplied each non-detect value by the respective TEF factor. We used the sum of the detection level toxic equivalencies for each of the 17 CDD/CDF congeners of interest to calculate a TEQ detection level sum value. The TEQ sum was then used as the detection limit for the test run. We used the second step discussed above to set the limit. The methodology is described in detail in the memorandum MACT Floor

Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category

, and is available in the docket. We solicit comment on these procedures. For wastewater, non-detect values were not incorporated into the variability analysis because they were not included with the facility submitted survey information.

3. Existing Source MACT Floor Results for Process Vents, Stripped Resins, and Wastewater

We identified the best performing five sources in the category (for process vents and wastewater), or each subcategory (for stripped resins), and each pollutant (

e.g.

, vinyl chloride, total HAP, HCl, and CDD/CDF). We then compiled the individual test run and sampling concentration data for these sources, and conducted a statistical analysis to calculate the average and account for variability, and, thereby, determine the MACT floor emission limit.

Table 4 of this preamble summarizes results of the UPL analysis and the MACT floor emission limits for existing process vents for each pollutant. Table 5 of this preamble presents the results for stripped resins. A detailed discussion of the MACT floor methodology is presented in the memorandum,

MACT Floor Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category

, and is available in the docket.

Table 4—Summary of MACT Floor Emission Limits for PVC Process Vents at Existing Sources

c,d

Pollutant (and units of measure)

99% UPL

MACT floor emission limit

a

Vinyl chloride (ppmv)

0.319

0.32

Hydrogen chloride (ppmv)

140.17

150

Total HAP (ppmv)

11.3

12

b

CDD/CDF (TEQ) (ng/dscm)

0.0183

0.023

b

a

Limits were rounded up to two significant figures.

b

Limit result of detection limit variability analysis.

c

ppmv = parts per million by volume dry at 3-percent oxygen. ng/dscm = nanograms per dry standard cubic meter at 3-percent oxygen.

d

Process vents limits apply at the outlet of the control device which controls closed vent streams from polymerization reactors, resin strippers, other process components prior to the resin stripper(s), certain storage vessels, VCM recovery systems, wastewater collection and treatment system, slip gauges, unloading and loading lines, and samples.

Table 5—Summary of MACT Floor Emission Limits for PVC Stripped Resins at Existing Sources (ppmw)

Pollutant

Bulk resins

99% UPL

MACT floor emission limit

a

Dispersion resins

99% UPL

MACT floor emission limit

a

All other resins

99% UPL

MACT floor emission limit

a

Vinyl chloride

7.1

7.1

54.8

55

0.471

0.48

Total HAP

167.3

170

100.1

110

33.3

76

b

a

Limits were rounded up to two significant figures.

b

Limit result of detection limit variability analysis.

For wastewater that exceeds the 10 ppmw vinyl chloride limit at the point of generation, we determined that the 99-percent UPL is 0.109 ppmw at the outlet of the wastewater stripper and the MACT floor level of control rounded up to two significant figures is 0.11 ppmw. The analysis is documented in the memorandum,

MACT Floor Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category

, and is available in the docket. Wastewater streams below the 10 ppmw vinyl chloride limit at the point of generation, must remain below the 10 ppmw limit.

Results of the MACT floor analysis for heat exchange systems, storage vessels, equipment leaks, and other emission sources are discussed in section IV.D of this preamble.

E. How did EPA determine the MACT floors for new major sources?

Similar to the MACT floor process used for existing sources, the approach for determining the MACT floor for new sources is based on available emissions information. Using such an approach to develop the MACT floor emission limits for process vents and stripped resins for each pollutant, we ranked all the available emission concentration, stripped resin concentration, or wastewater concentration data for each pollutant from sources within the entire category (for process vents and wastewater), or each subcategory (for stripped resin) from lowest to highest. As discussed in section IV.D of this preamble, data from all major sources and the one synthetic area source were included in this ranking. See section IV.D of this preamble for more information about the emission concentration and resin concentration data. Based on this ranking, we calculated the MACT floor limits for each pollutant, and for the summation of pollutants making up the total HAP value, based on the performance (of the lowest emitting (best controlled)) source for each pollutant in the category or subcategory.

We calculated the MACT floor limits accounting for variability for new sources using the same formula that we used for existing sources. As discussed in section IV.D of this preamble, we account for variability of the best-controlled source in setting floors, not only because variability is an element of performance, but also because it is reasonable to assess best performance over time. If we do not account for this variability, we would expect that even the best-controlled similar source would potentially exceed the floor emission levels part of the time, which would mean that their variability was not properly accounted for when setting the MACT floor. We calculated the MACT floor based on the UPL (upper 99th percentile), as described in section IV.D from the average performance, based on emission testing and resin sampling of the best controlled similar source, Students t-factor, the total variability of the best controlled source, and incorporating the non-detect procedures.

This approach reasonably ensures that the emission limit selected as the MACT floor adequately represents the level of control actually achieved by the best controlled similar source, considering ordinary operational variability. Tables 6 and 7 of this preamble present the analysis summaries, and the new source MACT floor limits for PVC process vents and stripped resins, respectively.

A detailed discussion of the MACT floor methodology is presented in the memorandum,

MACT Floor Analysis for the Polyvinyl Chloride and Copolymer (PVC) Production Source Category

, and is available in the docket.

Table 6—Summary of MACT Floor Emission Limits for PVC Process Vents at New Sources

c,d

Pollutant (and unit of measure)

99% UPL

MACT floor emission limit

a

Vinyl chloride (ppbv)

1.53

3.2

b

Hydrogen chloride (ppmv)

0.162

0.17

Total HAP (ppmv)

0.217

0.22

CDD/CDF (TEQ)(ng/dscm)

0.00428

0.0087

b

a

Limits were rounded up to two significant figures.

b

Limit result of detection limit variability analysis.

c

ppbv = parts per billion by volume dry at 3-percent oxygen. ppmv = parts per million by volume dry at 3-percent oxygen. ng/dscm = nanograms per dry standard cubic meter at 3-percent oxygen.

d

Process vents limits apply at the outlet of the control device which controls closed vent streams from polymerization reactors, resin strippers, other process components prior to the resin stripper(s), VCM recovery systems, certain storage vessels, slip gauges, loading and unloading lines, samples, and the wastewater collection and treatment system.

Table 7—Summary of MACT Floor Emission Limits for PVC Stripped Resins at New Sources (ppmw)

Pollutant

Bulk resins

99% UPL

MACT floor emission limit

a

Dispersion resins

99% UPL

MACT floor emission limit

a

All other resins

99% UPL

MACT floor emission limit

a

Vinyl chloride

7.1

7.1

40.3

41

0.191

0.20

Total HAP

167.3

170

57.8

58

25.1

42

b

a

Limits were rounded up to two significant figures.

b

Limit result of detection limit variability analysis.

The best performing wastewater source is complying with the part 61 NESHAP wastewater standards. The part 61 NESHAP requires that inprocess wastewater streams that exceed a vinyl chloride concentration limit of 10 ppmw, at the point of generation, be controlled. The best-performing source achieves this control by using a wastewater steam stripper and achieves a vinyl chloride concentration at the outlet of the wastewater stripper of 0.0060 ppmw. The analysis is documented in the memorandum,

MACT Floor Analysis for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category

, and is available in the docket. We are proposing that all new wastewater streams meet a vinyl chloride limit of 10 ppmw, at the point of generation. We are also proposing that new wastewater streams that exceed the 10 ppmw vinyl chloride limit at the point of generation, reduce vinyl chloride to a wastewater stripper outlet concentration of 0.0060 ppmw.

For equipment leaks, the best performing source complies with the LDAR requirements for 40 CFR part 63, subpart UU and the existing part 61 NESHAP LDAR requirements for rotating and reciprocating pumps and compressors, and agitators. For storage vessels, the information collected showed that at all sources, including the best performing source, materials with vapor pressures greater than 14.7 psia are stored under pressure; a closed vent system that is routed to a control device is used at all facilities when filling the tank, or purging the tank. All other materials are stored at all facilities in fixed roof tanks.

The current requirements from the part 61 NESHAP, for reactor opening losses and equipment openings, set standards that must be met. In the case of reactors used as strippers, the standard is based on the sum of allowable reactor opening losses, and the standard for all downstream equipment (e.g., the stripped resin limits). All affected sources are required to meet the part 61 NESHAP requirements.

For heat exchange systems, the best performing source has a leak action level of 30 ppbw of total strippable VOC in the cooling water or 2.3 ppmv of total strippable VOC in the stripping gas, with twice-daily monitoring, which is, therefore, the MACT floor for heat exchange systems at new sources.

EPA solicits comment on the proposed MACT floors for new PVC production facilities.

F. How did EPA analyze beyond-the-floor options and determine MACT?

1. Beyond-the-Floor Analysis for Existing Sources

Once the MACT floor determinations were done for each category or subcategory, we considered various regulatory options more stringent than the MACT floor levels of control (

e.g.,

control technologies or work practices that could result in lower emissions). A detailed description of the beyond-the-floor consideration is in the memorandum,

Analysis of Beyond MACT Floor Controls for the Polyvinyl Chloride and Copolymer (PVC) Production Source Category,

and is available in the docket.

We first identified regulatory requirements for each emission point that would be more stringent than the MACT floor level of control, and determined whether they were technically feasible. If the more stringent requirements were technically feasible, a cost and emission impacts analysis was conducted for applying them.

Process Vents.

The control technologies that would be needed to achieve the proposed MACT floor levels for process vents (

e.g.,

enhanced vinyl chloride recovery, activated carbon injection, and fabric filters, in combination with existing controls, such as incinerators and acid gas scrubbers) are generally the most effective controls available for reducing vinyl chloride, HCl, total organic HAP, and dioxins/furans. Therefore, no beyond-the-floor regulatory options were identified for HAP from process vents.

Equipment Leaks.

For equipment leaks, we are proposing to require that

facilities implement the LDAR program from 40 CFR part 63, subpart UU, which is generally equivalent to the HON, and which we identified as the most effective control of emissions from equipment leaks. We are also proposing that facilities implement the equipment requirements for rotating and reciprocating pumps and compressors and agitators from part 61 NESHAP, which are leakless equipment. Therefore, no beyond-the-floor HAP emission reduction approaches were identified for equipment leaks.

Heat Exchange Systems.

For heat exchange systems, the proposed existing source MACT floor level of control is a LDAR program with a leak action level of 38 ppbw of total strippable VOC in the cooling water, or 2.9 ppmv of total strippable VOC in the stripping gas and monthly monitoring. We analyzed a beyond-the-floor option of requiring a lower leak action level for the cooling water of 25 ppbw. Average costs and emission reductions were calculated on a per leak basis. The results of the analysis showed that 5.78 tpy of total VOC would be reduced for an annual cost of $175,630, resulting in a cost of $30,386 per ton of VOC reduced. Consequently, we determined it was not appropriate to go beyond-the-floor considering the cost and emission reductions of this option.

Storage Vessels.

For storage vessels, the CAA section 114 information collection data indicate that methanol is the primary material stored in fixed roof tanks ranging from 5,000 gallons to 30,000 gallons associated with PVCPU. We analyzed a beyond-the-floor option of requiring storage vessels meeting specific vapor pressure and storage capacity parameters specified in 40 CFR part 60, subpart Kb to comply with the control requirements of 40 CFR part 63, subpart WW. The subpart Kb standard in 40 CFR 60.112(b), requires material be stored in controlled tanks if: (1) The material stored has a maximum true vapor pressure greater or equal to 0.75 psia, and the storage vessel has a capacity equal to, or greater than 40,000 gallons, or (2) the material stored has a maximum true vapor pressure greater or equal to 4 psia, and the storage vessel has a capacity equal to, or greater than 20,000 gallons, but less than 40,000 gallons. Subpart Kb also requires materials above 11.1 psia to be stored in pressure tanks. The beyond-the-floor controls include specific sealing mechanisms for internal or external floating roofs or routing streams from a fixed roof vessel through a closed vent system to a control device meeting a 95-percent or greater reduction in volatile organic emissions. We calculated the emission reduction and cost of retrofitting subpart WW controls on model fixed roof tanks meeting subpart Kb vapor pressure and size parameters. The results of the analysis showed that cost-effectiveness ranged from $2,000 to $12,000 per ton of HAP reduced by this option, depending on the number of turnovers assumed. Considering the cost and emissions reduction, we have determined that it is appropriate to propose this beyond-the-floor requirement for storage vessels. Based on information submitted by PVC production facilities, we are not aware of any storage vessels from affected sources that meet the capacity levels (20,000 gallons or 40,000 gallons), and store material that meet the vapor pressure levels. Therefore, we estimate that there are no additional costs and emission reductions for this option for storage vessels currently at PVCPU. However, the proposed beyond-the-floor standards for storage vessels will ensure that, if there are any storage vessels (now or in the future) that meet the capacity and vapor pressure criteria, they will be controlled. This analysis is documented in the memorandum,

Analysis of Beyond MACT Floor Controls for the Polyvinyl Chloride and Copolymer (PVC) Production Source Category,

and is available in the docket.

Five gas holders are currently in use by three facilities, and are a part of the vinyl chloride recovery system. In these recovery systems, process vents originating from polymerization reactors, resin strippers, and wastewater strippers (among others) are routed in closed vent systems to a separate process to recover unreacted VCM from the vent gasses. Gas holders provide intermediate storage of vent gasses which contain VCM before the VCM is recovered, compressed, and recycled back into the process. Gas holders are cylindrical tanks with a floating bell top. The tanks contain water that serves as a seal between the contained gas and the ambient air outside of the tank. The pressure inside the gas holder changes as gasses are fed to, or removed from, the tank. The water inside the gas holder is in constant contact with the vinyl chloride laden gas and can approach saturation. The primary source of emissions from gas holders is from the water seal on the gas holder that is continually exposed to the ambient atmosphere. In addition, as the gas holder bell rises, a thin film of water that contains vinyl chloride remains on the outer surface of the bell. Methods to reduce emissions may include keeping the gas holder water level at the lowest possible level, using either floating objects on the surface of the water seal or using a thin layer of oil, or using a windshield around the gas holder water seal.

We do not have information from emission tests, control information, or cost information on gas holders. We are requesting comment and additional information on emissions, controls, and costs of controls for this emission source.

Wastewater.

For wastewater, EPA has previously determined for the HON that a beyond-the-floor option of treating streams with HAP concentrations greater than 1,000 ppmw (of 40 CFR part 63, subpart G, Table 9 HAP), and annual average flow rates greater than 10 l/min measured at the point of determination (as specified in 40 CFR part 63, subpart G), is cost-effective ($670/ton in 2010 dollars). The analysis previously conducted for the HON is applicable to PVC, because the cost-effectiveness of wastewater treatment depends on the wastewater flow and HAP concentration, not on the type of process unit from which the wastewater stream is generated. The same treatment systems (steam stripping or biotreatment), and the same measures to prevent atmospheric emissions from the systems conveying the wastewater streams to the treatment systems, are applicable to wastewater streams that meet these criteria. Furthermore, 35 percent of PVC production facilities are co-located with chemical manufacturing process units that are subject to the HON, and could potentially route PVC wastewater streams (if any) that meet the total HAP criteria to existing HON wastewater treatment processes to meet these limits. Consequently, we are proposing that streams with HAP concentrations greater than 1,000 ppmw (of 40 CFR part 63, subpart G, Table 9 HAP), and annual average flow rates greater than 10 l/min be treated as specified in the HON requirement as a beyond-the-floor HAP emissions reduction approach. Based on information submitted by PVC production facilities, we are not aware of any wastewater streams from affected sources that are above these flow rate and concentration limits. Therefore, we estimate that there are no additional costs or emission reductions because all facilities are below the 1,000 ppmw total HAP concentration and 10 l/min flow rate limits. However, the limit will ensure that, if there are any wastewater streams meeting the total HAP and flow rate criteria, they will be controlled.

Additionally, wastewater generated during maintenance activities is not currently regulated by 40 CFR part 61, subpart F. We requested and received

limited information on vinyl chloride and HAP concentrations in maintenance wastewater streams. We are requesting comment on whether maintenance wastewater should have separate limits from inprocess wastewater. We are also soliciting additional data relevant to setting a maintenance wastewater MACT standard.

Other Emission Sources.

We did not identify more stringent control requirements than what we are proposing to require at the MACT floor to reduce emissions from reactor and equipment openings. The proposed MACT standard requires that, prior to being opened, emissions from reactor and process component openings must be reduced to a specified level and ducted through a closed vent system and control device that would meet the proposed emission limits for process vents. We did identify an additional work practice that could be used to minimize emissions from all PVC production facilities. One facility identified placing filter bags, strainers, and other removable separation media in closed and sealed containers that remain closed and sealed unless being actively filled or emptied to minimize emissions. However, we do not have information on the costs and emission reductions of this work practice, or the procedures followed. We request comments, and any further information, including cost and performance data, on this practice, and other work practices that are being followed by the industry to minimize emissions from other emission sources.

Stripped Resin.

For stripped resins, we determined that facilities would use additional steam in existing equipment to reduce the concentrations of residual vinyl chloride and total HAP to meet the limits for resins being proposed. We believe that additional stripping in existing equipment beyond what would be required to meet the proposed limits would not be technically feasible as the incremental additional concentration reductions would be either negligible or zero, and existing sources may not be able to further reduce concentrations to the beyond-the-floor levels without degrading product. However, additional HAP emission reductions could be achieved by routing vents from process components downstream of the resin stripper (e.g., resin dryers and centrifuges) to an incinerator. We then determined the cost and emission reductions of applying a 98-percent efficient incinerator to the process vents downstream of the resin stripper (

e.g.

, dryer and centrifuge vents). The results of the analysis are shown in Table 8.

Summary of Beyond the Floor Analysis.

Table 8 of this preamble summarizes the costs of the MACT floor emission level (referred to as option 1), and one beyond-the-floor option for stripped resins (option 2). Option 2 is the same as option 1 plus the installation of a thermal oxidizer on vent streams from processes downstream of the resin stripper.

Table 8—Summary of Costs for PVCPU To Comply With MACT Control Options for Existing Sources (2010$)

Option

Total capital costs

($million)

Total annualized costs

($million/Yr)

a, b

1—MACT Floor

16

20

2—Option 1 + additional control of resin

370

129

a

No beyond-the-floor options were analyzed for costs for process vents, equipment leaks, and other emission sources. The beyond-the-floor options for wastewater and storage vessels do not result in costs, because no sources currently meet the beyond-the-floor applicability requirements for these emission points.

b

Calculated using a 7-percent discount factor.

Table 9 of this preamble summarizes the emission reductions of each pollutant for the MACT control options analyzed.

Table 9—Summary of Emission Reductions for PVCPU To Comply With the MACT Control Options for Existing Sources

Pollutant

Option 1 (MACT floor)

(tpy)

Option 2

(Option 1 + additional control of stripped resin)

(tpy)

a

CDD/CDF TEQ

2.45E-08

2.45E-08

HCl

33

33

Vinyl chloride

135

176

Total HAP

1,570

2,618

a

No beyond-the-floor options were analyzed for process vents, equipment leaks, and other emission sources. The beyond-the-floor options for wastewater and storage vessels do not result in emission reductions, because no sources currently meet the beyond-the-floor applicability requirements for these emission points.

The results provided in Tables 8 and 9 of this preamble were calculated using data gathered for the PVC industry. We estimate that applying additional control to reduce emissions from stripped resins would result in a total annualized cost of $129 million, and would achieve vinyl chloride and total HAP reductions of 176 tpy and 2,618 tpy, respectively. The incremental cost-effectiveness of adding a thermal oxidizer to control emissions from process vents downstream of the resin stripper was estimated to be $2.7 million per ton of vinyl chloride reduced, and over $100,000 per ton of total HAP reduced. Consequently, we determined it was not appropriate to go

beyond the floor, considering the cost and emission reductions of this option. The results of the beyond-the-floor analysis are documented in the memorandum,

Analysis of Beyond MACT Floor Controls for the Polyvinyl Chloride and Copolymers (PVC) Production Source Category,

and is available in the docket. Table 1 in this preamble summarizes the proposed emissions limits for existing PVCPU.

2. Beyond-the-Floor Analysis for New Sources

Except for wastewater and storage vessels, we did not identify any technologies or methods to achieve HAP emission limits more stringent than the MACT floor limits, or work practices for new units, based on the best performing PVC facilities. The control technologies and work practices necessary to achieve the MACT floor levels are generally the most effective controls available.

For wastewater, EPA has previously determined for the HON that a beyond-the-floor option of treating streams with HAP concentrations greater than 1,000 ppmw (of 40 CFR part 63, subpart G, Table 9 HAP), and annual average flow rates greater than 10 l/min is cost-effective for new sources ($1,300/ton in 2010 dollars for new sources). For the same reasons discussed in section IV.F.1 of this preamble, the analysis previously conducted for HON is applicable to PVC because the cost- effectiveness of wastewater treatment depends on the wastewater flow and HAP concentration, not on the type of process unit the wastewater stream is coming from. As discussed in section IV.F.1 of this preamble, we are requesting comment on whether maintenance wastewater should have separate limits from inprocess wastewater, and requesting data relevant to setting a maintenance wastewater MACT standard.

We also concluded, in section IV.F.1 of this preamble, that it was cost-effective ($2,000 to $12,000 per ton of HAP) to require floating roof tanks or fixed roof tanks routed to a closed vent system, and control device for storage vessels that (1) have a storage capacity equal to or greater than 40,000 gallons (151 cubic meters), and store material with maximum true vapor pressures greater or equal to 0.75 psia, or (2) have a storage capacity equal to or greater than 20,000 gallons, and less than 40,000 gallons, and store material with maximum true vapor pressures greater or equal to 4 psia. Consequently, the beyond-the-floor options for wastewater and storage vessels are the only ones being proposed for new sources. Tables 1 and 3 of this preamble summarizes the proposed emissions limits for new PVCPU.

EPA solicits comment on the proposed beyond-the-floor determinations.

G. How did EPA select the compliance and monitoring requirements for the proposed rule?

We are proposing testing, monitoring, notification, recordkeeping, and reporting requirements that are adequate to assure continuous compliance with the requirements of the proposed rule. These requirements are described in detail in various sections in the proposed rule. We solicit comment on the proposed compliance and monitoring requirements. We selected these requirements based upon our examination of the information necessary to ensure that the emission standards and work practices are being followed, and that emission control devices and process components are maintained and operated properly. These proposed requirements impose on facilities the minimum burden that is necessary to ensure compliance with the proposed rule.

1. How did we select the compliance and monitoring requirements for storage vessels?

For storage vessels, we are proposing that you meet the operating, inspection, repair, and maintenance requirements in 40 CFR 63.11910 of the proposed rule, a

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