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Proposed Rule

National Emission Standards for Hazardous Air Pollutants for Semiconductor Manufacturing

Document Details

Information about this document as published in the Federal Register.

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Start Preamble

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

EPA is proposing amendments to the national emission standards for hazardous air pollutants (NESHAP) for Semiconductor Manufacturing, published on May 22, 2003. We are proposing amendments to the final rule to clarify the emission requirements for process vents by establishing a new maximum achievable control technology (MACT) floor level of control for combined hazardous air pollutants (HAP) process vent streams containing inorganic and organic HAP and adding new source requirements for combined HAP process vents. Requirements for existing combined HAP process vents would be no control, which is the MACT floor. The new source combined HAP process vent limit would be the same level of control as is currently required for new inorganic and organic HAP process vents.

DATES:

Comments must be received on or before December 4, 2006.

Public Hearing. If anyone contacts EPA by November 8, 2006 requesting to speak at a public hearing, EPA will hold a public hearing on November 20, 2006. If you are interested in attending the public hearing, contact Lala Alston at (919) 541-5545 to verify that a hearing will be held.

ADDRESSES:

Comments. Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2002-0086, by one of the following methods:

  • http://www.regulations.gov: Follow the on-line instructions for submitting comments.
  • E-mail: a-and-r-docket@epa.gov, Attention Docket ID No. EPA-HQ-OAR-2002-0086.
  • Mail: U.S. Postal Service, send comments to: EPA Docket Center (6102T), Attention Docket ID No. EPA7-HQ-OAR-2002-0086, 1200 Pennsylvania Avenue, NW., Washington, DC 20460. Please include a total of two copies.
  • Hand Delivery: In person or by courier, deliver comments to: EPA Docket Center (6102T), Attention Docket ID No. EPA-HQ-OAR-2002-0086, 1301 Constitution Avenue, NW., Room B-108, Washington, DC 20004. Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information. Please include a total of two copies.

Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-2002-0086. EPA's policy is that all comments received will be included in the public docket without change 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 www.regulations.gov or e-mail. Send or deliver information identified as CBI to only the following address: Mr. Roberto Morales, OAQPS Document Control Officer, EPA (C404-02), Attention Docket ID No. EPA-HQ-OAR-2002-0086, Research Triangle Park, NC 27711. Clearly mark the part or all of the information that you claim to be CBI. The 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 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.epa.gov/​epahome/​dockets.htm.

Docket. All documents in the docket are listed in the 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. Publicly available docket materials are available either electronically in http://www.regulations.gov or in hard copy at the EPA Docket Center, Docket ID No. EPA-HQ-OAR-2002-0086, EPA West Building, Room B-102, 1301 Constitution Ave., NW., Washington, DC. The EPA Docket Center 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. A reasonable fee may be charged for copying docket materials.

Note:

The EPA Docket Center suffered damage due to flooding during the last week of June 2006. The Docket Center is continuing to operate. However, during the cleanup, there will be temporary changes to Docket Center telephone numbers, addresses, and hours of operation for people who wish to visit the Public Reading Room to view documents. Consult EPA's Federal Register notice at 71 FR 38147 (July 5, 2006) or the EPA Web site at http://www.epa.gov/​epahome/​dockets.htm for current information on docket status, locations, and telephone numbers.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Mr. John Schaefer, EPA, Office of Air Quality Planning and Standards, Sector Policies and Programs Division, Measurement Policy Group (D-243-05), Research Triangle Park, NC 27711; telephone number (919) 541-0296; fax number (919) 541-1039; e-mail address schaefer.john@epa.gov.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

Regulated Entities. Entities potentially affected by the direct final amendments to the national emission standards for hazardous air pollutants for semiconductor manufacturing are those semiconductor manufacturing facilities. Regulated categories and entities include: Start Printed Page 61702

Table 1.—Regulated Entities Table

CategoryNAICS 1Examples of regulated entities
Industry334413Semiconductor crystal growing facilities, semiconductor wafer fabrication facilities, semiconductor test and assembly facilities.
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 regulated by this action. This table lists the types of entities that may potentially be affected by this action. To determine whether your facility is regulated by this action, you should carefully examine the applicability criteria in 40 CFR 63.7181 of the rule. If you have questions regarding the applicability of the direct final amendments to a particular entity, consult the person listed in the preceding FOR FURTHER INFORMATION CONTACT section. Submitting CBI. Do not submit this information through www.regulations.gov or e-mail. Send or deliver information identified as CBI only to the following address listed in the ADDRESSES section of this document. Clearly mark the part or all the information you claim to be CBI. For CBI information submitted on 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. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.

Worldwide Web (WWW). In addition to being available in the docket, an electronic copy of today's proposal will also be available through the WWW. Following the Administrator's signature, a copy of this action will be posted on EPA's Technology Transfer Network (TTN) policy and guidance page for newly proposed or promulgated rules at http://www.epa.gov/​ttn/​oarpg/​. The TTN at EPA's Web site provides information and technology exchange in various areas of air pollution control.

How can I get copies of the proposed amendments and other related information?

EPA has established the official public docket for the proposed rulemaking under docket ID No. EPA-HQ-OAR-2002-0086. Information on how to access the docket is presented above in the ADDRESSES section. In addition, information may be obtained from the Webpage for the proposed rulemaking at: http://www.epa.gov/​ttn/​atw/​pcem/​pcempg.html.

Outline. The information presented in this preamble is organized as follows:

I. Background

II. Summary of the Proposed Amendments

III. Rationale for the Proposed Amendments

IV. Impacts of the Proposed Amendments

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act

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 and Safety Risks

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

I. National Technology Transfer Advancement Act

I. Background

On May 22, 2003 (68 FR 27913), we issued the NESHAP for Semiconductor Manufacturing (40 CFR part 63, subpart BBBBB). The NESHAP implement section 112(d) of the Clean Air Act (CAA) by requiring all major sources to meet emission standards for HAP reflecting application of the maximum achievable control technology (MACT). The NESHAP establish emission limitations for emission sources at operations used to manufacture p-type and n-type semiconductors and active solid-state devices from a wafer substrate.

After promulgation of the NESHAP, it was brought to our attention that while the NESHAP established separate emission standards for organic and inorganic HAP from process vents, some plants combine inorganic and organic vent streams into a single atmospheric process vent. This situation was quite different from the process vents examined during the development phase of the rule, which were segregated into strictly organic or inorganic HAP constituents. Therefore, we believe the promulgated rule failed to adequately account for the existence of combined organic and inorganic HAP process vents, and we are proposing to revise the standards to reflect the actual existing source MACT floor for these process vents.

II. Summary of the Proposed Amendments

The proposed revisions would establish separate process vent definitions for organic HAP, inorganic HAP, and combined HAP process vents. We have not changed the MACT floors calculated in the final rule for inorganic or organic HAP. We have simply added new definitions to clarify the applicability of the rule to inorganic, organic, and combined HAP process vents. Therefore, inorganic HAP process vents will retain the control requirements set for process vents containing inorganic HAP in the promulgated rule. This means that existing and new source requirements for these vents would effectively remain the same. Similarly, organic process vents will retain the control requirements set for process vents containing organic HAP in the promulgated rule and control requirements for these vents will remain unchanged.

However, we have developed a new MACT floor for combined HAP process vents. The MACT floor for these vents was determined to be no reduction in emissions from existing sources, and the final rule is being amended to reflect this. For new and reconstructed combined HAP process vents, however, the requirement for inorganic HAP is the same as the requirement for inorganic HAP process vents and the requirement for organic HAP is the same as the requirement for the organic HAP process vents.

III. Rationale for the Proposed Amendments

Almost all semiconductor manufacturing facilities segregate their process vent emissions into streams containing either inorganic or organic pollutants. This has been common practice in the industry since the early 1980s. Given the prevalence of this practice and the fact that very few semiconductor manufacturing plants pre-dating the mid-1980s were still in operation when we issued the final rule, Start Printed Page 61703the final rule was only intended to regulate emissions from segregated inorganic or organic HAP process vents.

However, there is at least one older semiconductor manufacturing plant in operation that reflects the earlier design philosophy of combining inorganic and organic HAP into a single process vent. This plant combines inorganic and organic process emission streams into four combined HAP atmospheric process vents. In addition, this facility adds process heat into these combined organic/inorganic process vents.

Adding organic HAP streams and process heat into an inorganic HAP emission stream, which is the predominant HAP emission vent type in the industry, increases the difficulty and costs of controlling a semiconductor process vent in two ways. First, wet scrubber technology, which is the typical control technology utilized to control inorganic HAP pollutants by this industry, cannot be used to effectively control organic HAP pollutants at the very low concentrations present in the semiconductor industry. Therefore, a combined HAP vent stream needs a much larger and more expensive scrubber to control a combined HAP process vent than a similar inorganic process vent at a more modern facility. In addition, a wet scrubber is not an effective control option for low volume organic pollutant streams such as those in the semiconductor industry and it would not reduce organic HAP by a significant amount. Combining inorganic and organic HAP streams just increases control costs without providing an additional reduction in pollutant levels.

Second, by adding process heat with combined HAP process vent streams, a facility must cool the process vent air in order to effectively control the inorganic HAP emissions with a wet scrubber. This is a much more significant task than controlling a process vent where the process heat is already separated out and makes a combined HAP process vent with process heat even more difficult and expensive to control. In fact, the most effective way to control an existing combined HAP process vent would be to reconstruct the vent system to segregate the process heat from the inorganic HAP stream, which is the current practice in all semiconductor manufacturing facilities, constructed over the past 20 years.

Based on this information, we believe it is necessary to revise the final rule to separately address combined HAP process vents with process heat. The floor level of control for inorganic process vents and organic process vents is not being changed by this action. However, for the limited number of existing combined process vents with process heat, the rule is being revised to reflect the actual floor level of control for those vents. The floor level of control for combined HAP process vents has been determined to be no reduction in emissions. We are aware of four combined process vents with added process heat located at major semiconductor sources. We do not know of any existing combined HAP process vents that do not add process heat. Our research indicates that none of those vents are currently subject to any controls to reduce HAP emissions and no work practices are employed that reduce emissions. Control options above the floor for the four existing combined HAP process vents with added process heat were examined. However, we rejected these options because the cost was estimated to be in excess of $750,000 per ton of HAP emissions reduction, which is not a reasonable beyond the floor control option. Therefore, the rule is being amended with the intention that no emission control is required for existing combined HAP process vents with added process heat.

For new sources, however, we determined that by utilizing proper design, a combined HAP vent stream could achieve reductions similar to those required for inorganic process vents for inorganic HAP and organic process vents for organic HAP. Therefore, for new and reconstructed combined HAP process vents including those with added process heat, the requirement for inorganic HAP components is the same as the current requirement for inorganic HAP process vents and the requirement for organic HAP is the same as the requirement for organic HAP process vents.

IV. Impacts of the Proposed Amendments

The proposed amendments do not affect the level of emissions control required by the existing NESHAP for the nonair, health, environmental, and energy impacts. In the final rule we estimated that no additional control would be required. These amendments do not change the impacts associated with the final rule. The primary purpose of these amendments is to clarify the final rule requirements. Therefore, a re-evaluation of costs associated with the final rule was not necessary.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

This action is not a “significant regulatory action” under the terms of Executive Order (EO) 12866 (58 FR 51735, October 4, 1993) and is therefore not subject to review under the EO.

B. Paperwork Reduction Act

This action does not impose any new information collection burden. The information collection requirements in the final rule have not been changed by these proposed amendments. However, OMB has previously approved the information collection requirements contained in the existing regulations 40 CFR part 63, subpart BBBBB under the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. and has assigned OMB control number 2060-0382, EPA ICR number 2042.03. A copy of the OMB approved Information Collection Request (ICR) may be obtained from Susan Auby, Collection Strategies Division; U.S. Environmental Protection Agency (2822T); 1200 Pennsylvania Ave., NW., Washington, DC 20460 or by calling (202) 566-1672.

Burden means the total time, effort, or financial resources expended by persons to generate, maintain, retain, or disclose or provide information to or for a Federal agency. This includes the time needed to review instructions; develop, acquire, install, and utilize technology and systems for the purposes of collecting, validating, and verifying information, processing and maintaining information, and disclosing and providing information; adjust the existing ways to comply with any previously applicable instructions and requirements; train personnel to be able to respond to a collection of information; search data sources; complete and review the collection information; and transmit or otherwise disclose the information.

An agency may not conduct or sponsor, and a person is not required to respond to a collection of information unless it displays a currently valid OMB control number. The OMB control numbers for EPA's regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an agency to prepare a regulatory flexibility analysis of any rule subject to notice and comment rulemaking requirements under the Administrative Procedure Act or any other statute unless the agency certifies that the rule will not have a significant Start Printed Page 61704economic impact on a substantial number of small entities. Small entities include small businesses, small organizations, and small governmental jurisdictions.

For purposes of assessing the impacts of today's rule on small entities, small entity is defined as: (1) A small business as defined by the Small Business Administrations' regulations at 13 CFR 121.201; (2) a small governmental jurisdiction that is a government of a city, county, town, school district or special district with a population of less than 50,000; and (3) a small organization that is any not-for-profit enterprise which is independently owned and operated and is not dominant in its field.

After considering the economic impacts of today's amendments on small entities, I certify that this action will not have a significant economic impact on a substantial number of small entities. The proposed amendments would not impose any requirements on small entities. We continue to be interested in the potential impacts of the proposed rule on small entities and welcome comments on issues related to such impacts.

D. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public Law 104-4, establishes requirements for Federal agencies to assess the effects of their regulatory actions on State, local, and tribal governments and the private sector. Under section 202 of the UMRA, EPA generally must prepare a written statement, including a cost-benefit analysis, for proposed and final rules with “Federal mandates” that may result in expenditures to State, local, and tribal governments, in the aggregate, or to the private sector, of $100 million or more in any 1 year. Before promulgating an EPA rule for which a written statement is needed, section 205 of the UMRA generally requires EPA to identify and consider a reasonable number of regulatory alternatives and adopt the least costly, most cost-effective, or least burdensome alternative that achieves the objectives of the rule. The provisions of section 205 do not apply when they are inconsistent with applicable law. Moreover, section 205 allows EPA to adopt an alternative other than the least costly, most cost-effective, or least burdensome alternative if the Administrator publishes with the final rule an explanation why that alternative was not adopted. Before EPA establishes any regulatory requirements that may significantly or uniquely affect small governments, including tribal governments, it must have developed under section 203 of the UMRA a small government agency plan. The plan must provide for notifying potentially affected small governments, enabling officials of affected small governments to have meaningful and timely input in the development of EPA regulatory proposals with significant Federal intergovernmental mandates, and informing, educating, and advising small governments on compliance with the regulatory requirements.

We have determined that the proposed rule does not contain a Federal mandate that may result in expenditures of $100 million or more for State, local, and tribal governments, in the aggregate, or to the private sector in any 1 year. Thus, the proposed rule is not subject to the requirements of sections 202 and 205 of the UMRA. In addition, EPA has determined that today's proposed rule contains no regulatory requirements that might significantly or uniquely affect small governments because it contains no requirements that apply to such governments or impose obligations upon them. Therefore, the proposed rule is not subject to section 203 of the UMRA.

E. Executive Order 13132: Federalism

Executive Order 13132 (64 FR 43255, August 10, 1999) requires EPA to develop an accountable process to ensure “meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications.” “Policies that have federalism implications” is defined in the Executive Order to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.”

The proposed rule does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132. None of the affected Semiconductor facilities are owned or operated by State or local governments. Thus, Executive Order 13132 does not apply to the proposed rule. In the spirit of Executive Order 13132, and consistent with EPA policy to promote communications between EPA and State and local governments, EPA specifically solicits comment on this proposed rule from State and local officials.

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

Executive Order 13175 (65 FR 67249, November 9, 2000) requires EPA to develop an accountable process to ensure “meaningful and timely input by tribal officials in the development of regulatory policies that have tribal implications.” The proposed rule does not have tribal implications as specified in EO 13175. It will not have substantial direct effects on tribal governments, on the relationship between the Federal Government and Indian tribes, or on the distribution of power and responsibilities between the Federal Government and Indian tribes. No tribal governments own semiconductors and are subject to the proposed standards. Thus, EO 13175 does not apply to the proposed rule. EPA specifically solicits additional comment on this proposed rule from tribal officials.

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

Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any rule that: (1) Is determined to be “economically significant” as defined under EO 12866, and (2) concerns an environmental health or safety risk that EPA has reason to believe may have a disproportionate effect on children. If the regulatory action meets both criteria, the Agency must evaluate the environmental health or safety risk of the planned rule on children, and explain why the planned regulation is preferable to other potentially effective and reasonably feasible alternatives considered by the Agency.

The proposed rule is not subject to the EO because it is not economically significant as defined in EO 12866, and because the Agency does not have reason to believe the environmental health or safety risks addressed by this action present a disproportionate risk to children.

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

The proposed rule is not a “significant energy action” as defined in EO 13211 (66 FR 28355, May 22, 2001) because it is not a significant regulatory action under EO 12866. Start Printed Page 61705

I. National Technology Transfer Advancement Act

Section 112(d) of the National Technology Transfer and Advancement Act (NTTAA) of 1995 (Pub. L. 104-113, 12(d) (15 U.S.C. 272 note)), directs EPA to use voluntary consensus standards (VCS) in its regulatory activities unless to do so would be inconsistent with applicable law or otherwise impractical. VCS are technical standards (e.g., materials specifications, test methods, sampling procedures, and business practices) that are developed or adopted by VCS bodies. The NTTAA directs EPA to provide Congress, through OMB, explanations when the Agency decides not to use available and applicable VCS.

The proposed revisions to the NESHAP for Semiconductor Manufacturing do not include requirements for technical standards beyond what the NESHAP requires. Therefore, the requirements of the NTTAA do not apply to this action.

Start List of Subjects

List of Subjects in 40 CFR Part 63

End List of Subjects Start Signature

Dated: October 11, 2006.

Stephen L. Johnson,

Administrator.

End Signature

For the reasons stated in the preamble, title 40, chapter I, part 63, of the Code of the Federal Regulations is proposed to be amended as follows:

Start Part

PART 63—[AMENDED]

1. The authority citation for part 63 continues to read as follows:

Start Authority

Authority: 42 U.S.C. 7401, et seq.

End Authority

2. Section 63.7184 is amended by revising paragraphs (b) through (e) and adding paragraph (f) to read as follows:

What emission limitations, operating limits, and work practice standards must I meet?
* * * * *

(b) Process vents—organic HAP emissions. For each organic HAP process vent, other than process vents from storage tanks, you must limit organic HAP emissions to the level specified in paragraph (b)(1) or (2) of this section. These limitations can be met by venting emissions from your process vent through a closed vent system to any combination of control devices meeting the requirements of § 63.982(a)(2).

(1) Reduce the emissions of organic HAP from the process vent stream by 98 percent by weight.

(2) Reduce or maintain the concentration of emitted organic HAP from the process vent to less than or equal to 20 parts per million by volume (ppmv).

(c) Process vents—inorganic HAP emissions. For each inorganic HAP process vent, other than process vents from storage tanks, you must limit inorganic HAP emissions to the level specified in paragraph (c)(1) or (2) of this section. These limitations can be met by venting emissions from your process vent through a closed vent system to a halogen scrubber meeting the requirements of §§ 63.983 (closed vent system requirements) and § 63.994 (halogen scrubber requirements); the applicable general monitoring requirements of § 63.996; the applicable performance test requirements; and the monitoring, recordkeeping and reporting requirements referenced therein.

(1) Reduce the emissions of inorganic HAP from the process vent stream by 95 percent by weight.

(2) Reduce or maintain the concentration of emitted inorganic HAP from the process vent to less than or equal to 0.42 ppmv.

(d) Process vents—combined HAP emissions. For each combined HAP process vent at a new or reconstructed source, other than process vents from storage tanks, you must limit inorganic HAP emissions to the level specified in paragraph (d)(1) or (2) of this section. These limitations can be met by venting emissions from your process vent through a closed vent system to a halogen scrubber meeting the requirements of §§ 63.983 (closed vent system requirements) and 63.994 (halogen scrubber requirements); the applicable general monitoring requirements of § 63.996; the applicable performance test requirements; and the monitoring, recordkeeping and reporting requirements referenced therein. You must limit organic HAP emissions to the level specified in paragraph (d)(3) or (4) of this section. These limitations can be met by venting emissions from your process vent through a closed vent system to any combination of control devices meeting the requirements of § 63.982(a)(2).

(1) Reduce the emissions of inorganic HAP from the process vent stream by 95 percent by weight.

(2) Reduce or maintain the concentration of emitted inorganic HAP from the process vent to less than or equal to 0.42 ppmv.

(3) Reduce the emissions of organic HAP from the process vent stream by 98 percent by weight.

(4) Reduce or maintain the concentration of emitted organic HAP from the process vent to less than or equal to 20 parts ppmv.

(e) Storage tanks. For each storage tank, 1,500 gallons or larger, you must limit total HAP emissions to the level specified in paragraph (e)(1) or (2) of this section if the emissions from the storage tank vent contains greater than 0.42 ppmv inorganic HAP. These limitations can be met by venting emissions from your storage tank through a closed vent system to a halogen scrubber meeting the requirements of §§ 63.983 (closed vent system requirements) and 63.994 (halogen scrubber requirements); the applicable general monitoring requirements of § 63.996; the applicable performance test requirements; and the monitoring, recordkeeping and reporting requirements referenced therein.

(1) Reduce the emissions of inorganic HAP from each storage tank by 95 percent by weight.

(2) Reduce or maintain the concentration of emitted inorganic HAP from the process vent to less than or equal to 0.42 ppmv.

(f) You must comply with the applicable work practice standards and operating limits contained in § 63.982(a)(1) and (2). The closed vent system inspection requirements of § 63.983(c), as referenced by § 63.982(a)(1) and (2), do not apply.

3. Section 63.7195 is amended by adding a definition for “Combined HAP process vents”, “Organic HAP process vents” and “Inorganic HAP process vents” in alphabetical order to read as follows:

What definitions apply to this subpart?
* * * * *

Combined HAP Process Vent means a process vent that emits both inorganic and organic HAP to the atmosphere.

* * * * *

Inorganic HAP Process Vent means a process vent that emits only inorganic HAP to the atmosphere.

Organic HAP Process Vent means a process vent that emits only organic HAP to the atmosphere.

* * * * *
End Part End Supplemental Information

[FR Doc. E6-17224 Filed 10-18-06; 8:45 am]

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