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EO12866_Mercury Emissions from Mercury Cell Chlor‐Alkali Plants 2060‐AN99 NPRM Redline

Preamble and Rule_20101207

6560-50-P

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2002-0017; FRL- ]

RIN 2060-AN99

National Emission Standards for Hazardous Air Pollutants: 

Mercury Emissions from Mercury Cell Chlor-Alkali Plants

AGENCY: Environmental Protection Agency (EPA).

ACTION: Supplemental proposed rule.

SUMMARY: This action proposes amendments to the national 

emission standards for hazardous air pollutants (NESHAP) for 

mercury emissions from mercury cell chlor-alkali plants.

(Mercury Cell NESHAP). On June 11, 2008, EPA proposed 

amendments to this NESHAP in response to a petition for 

reconsideration filed by the Natural Resources Defense Council 

(NRDC). This action is a supplement to the June 11, 2008, 

proposal, and revises certain aspects of the 2008 proposal while 

maintaining others. This . Specifically, this action proposes 

to amendtwo options for amending the NESHAP to prohibitfor 

mercury emissions of mercury from mercury cell chlor-alkali 

production processes within three years from promulgationplants. 

The first option would require the elimination of mercury 

emissions and thus encourage the conversion to non-mercury 
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Page 2 of 2

technology. The second option would require the measures 

proposed in 2008. These measures, which included significant 

improvements in the work practices to reduce fugitive emissions 

from the cell room, would result in near-zero levels of mercury 

emissions while still allowing the mercury cell facilities to 

continue to operate. We are specifically requesting comment on 

which of the final rule. Facilities could meet these limits

byoptions is more appropriate, and may finalize either 

converting to nonmercury technologyoption or by ceasing their 

chlorine production operations. For all mercury recovery units,

the proposed rule also prohibits mercury emissions within three 

yearsa combination of elements from promulgation of the final 

rule. If promulgated, this supplemental proposed rule would 

eliminate approximately 640 pounds of annual mercury emissions, 

and result in reduced energy demand of around 350,000 megawatt 

hours per year, which is approximately equivalent to the energy 

produced in one year by a 40 megawatt power plantthem. In 

addition, this action proposes to amend the several amendments 

that would apply regardless of which option we select. These 

proposed amendments are (1) provisions of the existing NESHAP 

that would apply to periods of startup, shutdown, and 

malfunction. Two amendments proposed on June 11, 2008 to 

correct (SSM), and (2) corrections to compliance errors in the 

rule are being retained. Specifically, these two amendments are 
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Page 3 of 3

related to the detection limit for continuous mercury analyzers 

and the frequency of determining compliance with the emissions 

standard for mercury recovery units. currently effective rule.

DATES: Comments. Comments must be received on or before 

[INSERT DATE 60

DAYS AFTER PUBLICATION OF THIS PROPOSAL IN THE FEDERAL 

REGISTER]. Under the Paperwork Reduction Act, comments on the 

information collection provisions must be received by the Office 

of Management and Budget (OMB) on or before [INSERT DATE 30 DAYS 

AFTER PUBLICATION OF THIS PROPOSAL IN THE FEDERAL REGISTER].

Public Hearing. If anyone contacts EPA by [INSERT DATE 15 

DAYS AFTER PUBLICATION OF THIS PROPOSAL IN THE FEDERAL REGISTER]

requesting to speak at a public hearing, aEPA will hold a public

hearing will be on [INSERT DATE 30 DAYS AFTER PUBLICATION OF 

THIS PROPOSAL IN THE FEDERAL REGISTER]. If a public hearing is 

held on [INSERT DATE 30 DAYS AFTER PUBLICATION IN THE FEDERAL 

REGISTER]. , it will be held at EPA’s Campus located at 109 

T.W. Alexander Drive in Research Triangle Park, NC, or an 

alternate site nearby. Contact Ms. Pamela Garrett at (919) 541-

7966 to request a hearing, to determine if a hearing will be 

held, or to determine the hearing location. If no one contacts 

EPA requesting to speak at a public hearing concerning this 

proposed rule by [INSERT DATE 15 DAYS AFTER PUBLICATION OF THIS 
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PROPOSAL IN THE FEDERAL REGISTER], the hearing will be cancelled 

without further notice.

ADDRESSES: You may submit comments, identified by Docket ID No. 

EPA-HQ-OAR-2002-0017, by any of the following methods:

• Federal eRulemaking Portal: 

http://www.regulations.gov: Follow the instructions 

for submitting comments.

• Agency Web Site: http://www.epa.gov/oar/docket.html. 

Follow the instructions for submitting comments on the 

EPA Air and Radiation Docket Web site.

• E-mail: a-and-r-docket@epa.gov. Include Docket ID 

No. EPA-HQ-OAR-2002-0017 in the subject line of the 

message.

• Fax: (202) 566-9744.

• Mail: National Emission Standards for Hazardous Air 

Pollutants for Mercury Cell Chlor-alkali Plants 

Docket, Environmental Protection Agency, EPA Docket 

Center (EPA/DC), Air and Radiation Docket, Mail Code 

2822T, 1200 Pennsylvania Ave., NW, Washington, DC 

20460. 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 
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Page 5 of 5

Management and Budget (OMB), Attn: Desk Officer for 

EPA, 725 17th St., NW., Washington, DC 20503.

• Hand Delivery: EPA Docket Center, Public Reading 

Room, EPA West, Room 3334, 1301 Constitution Ave., NW, 

Washington, DC 20460. Such deliveries are only 

accepted during the Docket’s normal hours of 

operation, and special arrangements should be made for 

deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. EPAHQ-OAR-2002-0017. 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. 

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 
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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.

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, is not placed on 

the Internet and will be publicly available only in hard copy 

form. Publicly available docket materials are available either 

electronically through www.regulations.gov or in hard copy at 

the National Emission Standards for Hazardous Air Pollutants for 

Mercury Cell Chlor-alkali Plants Docket, EPA/DC, EPA West, 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 Air Docket is (202) 566-1742.
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FOR FURTHER INFORMATION CONTACT: Dr. Donna Lee JonesSharon 

Nizich, Sector Policies and Programs Division, Office of Air 

Quality Planning and Standards (D243-02), Environmental 

Protection Agency, Research Triangle Park, North Carolina 27711, 

telephone number: (919) 541-52512825; fax number: (919) 541-

32075450; e-mail address: jones.donnaleenizich.sharon@epa.gov. 

SUPPLEMENTARY INFORMATION:

The supplementary information in this preamble is organized 

as follows:

I. General Information

A. Does this action 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?

D. When would a public hearing occur?

II. Background Information

A. What is the history of the Mercury Cell NESHAP?

B. What petitions were filed after promulgation of the Mercury

Cell NESHAP in 2003?

C. What were the considered decisions proposed in 2008?

D. What current legislation is related to this effort?

III. Summary of Proposed Amendments

A. What is the non-mercury technology option (Option 1)?

B. What is the enhanced work practices option (Option 2)?

C. What amendments are being proposed that are independent of 

which option is selected?

IV. Request for Comment

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
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I. National Technology Transfer and Advancement Act

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and LowIncome Populations

I. General Information

A. Does this action apply to me?

The regulated categories and entities potentially affected 

by this proposed action include:

Category NAICS code1 Examples of regulated entities

Industry. . . . . 325181 Alkalis and Chlorine 

Manufacturing

Federal government . . . . Not affected.

State/local/tribal 

government

. . . . Not affected.

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 

would be regulated by this action, you should examine the 

applicability criteria in 40 CFR 63.7682 of subpart IIIII,

National Emission Standards for Hazardous Air Pollutants 

(NESHAP): Mercury Emissions from Mercury Cell Chlor-Alkali 

(hereafter called the “2003 Mercury Cell MACTNESHAP”). If you 

have any questions regarding the applicability of this action to 

a particular entity, consult either the air permitting authority 

for the entity or your EPA regional representative as listed in 

40 CFR 63.13 of subpart A (General Provisions).
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B. What should I consider as I prepare my comments to EPA?

Do not submit information containing CBI to EPA through 

www.regulations.gov or e-mail. Send or deliver information 

identified as CBI only to the following address: Roberto 

Morales, OAQPS Document Control Officer (C404-02), Environmental 

Protection Agency, Office of Air Quality Planning and Standards, 

Research Triangle Park, North Carolina 27711, Attention Docket 

ID EPA-HQ-OAR-2002-0017. 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. Information so 

marked will not be disclosed except in accordance with 

procedures set forth in 40 CFR part 2. 

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 

Worldwide Web (WWW) through the Technology Transfer Network 

(TTN). Following signature, a copy of this proposed action will 

be posted on the TTN’s policy and guidance page for newly 
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Page 10 of 10

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.

D. When would a public hearing occur?

If anyone contacts EPA requesting to speak at a public 

hearing concerning the proposed amendments by [INSERT DATE 10 

DAYS AFTER PUBLICATION OF THIS PROPOSAL IN THE FEDERAL 

REGISTER], we will hold a public hearing on [INSERT DATE 30 DAYS 

AFTER PUBLICATION OF THIS PROPOSAL IN THE FEDERAL REGISTER]. If 

you are interested in attending the public hearing, contact Ms. 

Pamela Garrett at (919) 541-7966 to verify that a hearing will 

be held. If a public hearing is held, it will be held at 10 

a.m. at the EPA’s Environmental Research Center Auditorium, 

Research Triangle Park, NC, or an alternate site nearby.

E. How is this document organized?

The supplementary information in this preamble is organized 

as follows:

I. General Information

A. Does this action 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?

D. When would a public hearing occur?

E. How is this document organized?

II. Background Information

III.Summary of Proposed Amendments

A. What are the proposed amendments?

B. How do these proposed amendments relate to the amendments 

proposed on June 11, 2008?

IV. Rationale for Proposed Amendments

A. What is the basis for the proposed zero mercury standard?
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1. Technical information and analyses

2. Rationale for selection of the zero mercury standard 

B. What is the basis for the proposed rule changes related to 

startup, shutdown, and malfunction?

C. What is the basis for the proposed rule corrections?

D. What is our rationale for doing a supplemental proposal?

V. Impacts of Proposed Amendments

A. What are the cost and economic impacts of this proposal?

1. Cost impacts

2. Economic impacts

B. What are the environmental and energy impacts of this 

proposal?

VI. 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 and Advancement Act

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and LowIncome Populations

II. Background Information

A. What is the history of the Mercury Cell NESHAP?

On December 19, 2003, EPA promulgated the 2003 Mercury Cell 

MACTNESHAP (40 CFR part 63, subpart IIIII, 68 FR 70904). This 

rule for mercury cell chlor-alkali plants implements section 

112(d) of the Clean Air Act (CAA), which requires all categories 

and subcategories of major sources listed under section 112(c) 

to meet hazardous air pollutant emission standards reflecting 
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Page 12 of 12

the application of the maximum achievable control technology 

(MACT). Mercury cell chlor-alkali plants are a subcategory of 

the chlorine production source category listed under the 

authority of section 112(c)(1) of the CAA. In addition, mercury 

cell chlor-alkali plants are listed as an area source category 

under section 112(c)(3) and (k)(3)(B) of the CAA. The 2003 

Mercury Cell MACTNESHAP satisfied our requirement to issue 

112(d) regulations under each of these listings (for mercury). 

The 2003 Mercury Cell MACTNESHAP required both existing major 

and area sources to meet mercury emission limits on stack 

emission sources from both chlorine production and from the 

recovery of mercury from wastes and other scrap in mercury 

thermal recovery units. The 2003 Mercury Cell MACTNESHAP also 

required the facilities to monitor and minimize fugitive mercury 

emissions from the cell room by conducting either daily work 

practices or work practices performed in response to high levels 

of mercury emissions determined from continuous mercury 

monitoring. The 2003 rule required facilities to comply with 

applicable emission limitations and work practice requirements 

at all times, except during periods of startup, shutdown, and 

malfunction.SSM. Finally, the 2003 Mercury Cell MACTNESHAP

prohibited mercury emissions from new and reconstructed 

facilities. 
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B. What petitions were filed after promulgation of the Mercury 

Cell NESHAP in 2003?

On February 17, 2004, the Natural Resources Defense Council 

(NRDC) submitted an administrative petition to EPA asking us to 

reconsider several aspects of the 2003 Mercury Cell MACTNESHAP

under CAA section 307(d)(7)(B). InOn the same day as the 

administrative petition, the NRDC and the Sierra Club also filed 

a petition for judicial review of the 2003 Mercury Cell NESHAP 

in the U.S. Court of Appeals for the D.C. Circuit (Civ. No. 04-

1048). requested

By a letter dated April 8, 2004, Jeffrey Holmstead, thenEPA Assistant Administrator for the Office of Air and Radiation, 

notified the NRDC that EPA had granted NRDC’s petition for 

reconsideration of the 2003 Mercury Cell NESHAP. On July 20, 

2004, the Court granted EPA’s motion to hold the case for 

judicial review in abeyance pending EPA’s action on the 

reconsideration of the 2003 Mercury Cell NESHAP. 

C. What were the reconsideration decisions proposed in 2008?

On June 11, 2008 (73 FR 33257), EPA responded to NRDC’s 

petition for reconsideration. In their petition, NRDC asked EPA 

to reconsider: five issues: (1) the decision to develop a set 

of work practice requirements under CAAClean Air Act section 

112(h) in lieu of a numeric emission limitation for cell rooms; 

(2) the decision to make the promulgated work practices optional 
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Page 14 of 14

for sources that choose to undertake continuous monitoring; (3) 

the decision to not require existing facilities to convert to a 

non-mercury-free chlorine manufacturing process; (4) the 

elimination of the previously applicable part 61 rule’s 2,300 

grams/day plant-wide emission limitation; and (5) the decision 

to create a subcategory of mercury cell chlor-alkali plants 

within the chlorine production category. On the same day as the 

administrative petition, NRDC and the Sierra Club also filed a 

petition for judicial review of the 2003 Mercury Cell MACT in 

the U.S. Court of Appeals for the D.C. Circuit (Civ. In the 

2008 proposal, EPA addressed each of these issues and proposed 

amendments where we determined them to be appropriate. 

Following are brief summaries of our reconsideration decisions. 

For a full explanation of these decisions and the rationale 

supporting them, please see the preamble for the June 11, 2008 

proposal (73 FR 33258). The 2008 proposed amendments, which are 

being co-proposed in this action as Option 2, are discussed in 

section III.B of this document. No. 04-1048). 

By In addition, while not specifically listed as a letter 

dated April 8, 2004, Jeffrey Holmstead, then-EPA Assistant 

Administratormajor issue in their petition, the uncertainty 

related to the magnitude of fugitive mercury emissions was 

clearly a basis for the Office of Air much of NRDC’s concern. 

This was also addressed in the 2008 proposal and Radiation, 
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Page 15 of 15

notified the is summarized below after the five specific issues 

cited by NRDC that EPA had granted NRDC’s in the petition. 

1. Emission limitation for cell room

In its petition for reconsideration of the NRDC stated that 

EPA failed to adequately justify that a numeric emission 

limitation was not feasible per the criteria prescribed in 

section 112(h) of the Clean Air Act (CAA). In our 2008 

reconsideration, we concluded that it is not feasible to 

prescribe or enforce an emission limitation for fugitive 

emissions from the cell room. We maintained that fugitive 

emissions from mercury cells and associated equipment are a 

clear example of the type of situation to be addressed by the 

provisions of section 112(h). The various points which led to 

our opinion on the feasibility of establishing an emission 

standard were discussed in detail in the 2008 proposal (73 FR 

33267-33271). In summary, consistent with CAA section 112(h), 

we believe that it is not feasible to prescribe or enforce an 

emission standard in this case. There are two independent bases 

for this conclusion. First, consistent with CAA section 

112(h)(2)(A), we concluded that fugitive mercury emissions from 

a mercury cell chlor-alkali plant cannot be emitted through a 

conveyance designed and constructed to emit or capture such 

pollutant. Second, consistent with CAA section 112(h)(2)(B), we 

established that the application of measurement technology to 
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Page 16 of 16

mercury cell rooms is not practicable due to technological and 

economic limitations. 

2. Optional work practices

The 2003 Mercury Cell NESHAP requires facilities to follow 

a set of detailed work practices. The NESHAP also allows 

facilities to institute a cell room monitoring program to 

continuously monitor the mercury vapor concentration in the 

upper portion of each cell room as an alternative to these work 

practice standards. One of the objections raised by NRDC was 

that this provision backtracked from the Agency’s proposed work 

practice standards. NRDC pointed out that in the development of 

the Mercury Cell NESHAP, EPA concluded that the housekeeping 

activities that facilities in the industry follow to comply with 

the part 61 mercury NESHAP (40 CFR 61, subpart E) represented 

the MACT. On July 20, 2004, the Court granted EPA’s motion to 

hold the case for judicial review in abeyance pending EPA’s 

action on the reconsideration of the floor and that requiring 

practices based upon the most detailed activities in the 

industry (i.e., “beyond-the-floor” practices) was justified. 

But NRDC was concerned because the work practices in the 2003 

Mercury Cell NESHAP were optional if facilities chose to do 

continuous monitoring and, therefore, this option would allow 

sources to avoid conducting activities that represent the MACT. 

On June 11, 2008 (73 FR 33257), EPA floor. NRDC argued that 
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Page 17 of 17

this was a violation of section 112(d)(3) of the CAA, which 

requires all facilities to meet the MACT floor.

As a result of our consideration of NRDC’s point, we 

included proposed amendments in response to NRDC’s petition for 

reconsideration. Comments received on the 2008 2008 that would 

require that all plants institute a cell room monitoring program 

and comply with work practice standards (73 FR 33271-33272). As 

part of today’s action, we are re-proposing the combination of 

work practices and cell room monitoring program as option 2. 

The specific proposed amendments were reviewed and considered by 

EPAare discussed in section III.B of this document.

One3. Requiring conversion to a non-mercury chlorine 

manufacturing process

In its petition NRDC argued that the 2003 Mercury Cell 

NESHAP does nothing to limit the use of mercury cell technology 

by existing chlor-alkali plants, and that the Agency ignored a 

known technique for reducing mercury emissions from this 

industry, namely, conversion to non-mercury processes. 

According to NRDC, requiring the industry to convert to a nonmercury process is cost-justified and would provide significant 

non-air quality benefits. In response to NRDC's concerns that 

we did not evaluate the conversion of mercury cell chlor-alkali 

production plants to non-mercury technology, we performed an 

analysis to estimate the capital and annual costs of this 
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Page 18 of 18

action. In performing the analysis, we used information from 

all readily available sources of information. Based on the 

results of this analysis, we proposed to reject the option of 

requiring conversion to non-mercury technology because of the 

high cost impact this forced conversion would impose on the 

facilities in the industry (73 FR 33274-33275).

Following the 2008 proposal, one commenter provided 

detailed comments on our proposed decision to not require 

existing facilities to convert to a non-mercury-free chlorine 

manufacturing process. In addition to comments on the EPA cost 

analysis described in our 2008 proposal, the commenter provided 

a report to support its comments. We reviewed these comments, 

examined the commenter’s report, and concluded that our cost 

analysis could be improved. Therefore, we incorporated some 

aspects of the commenter’s cost analysis, and gathered 

additional cost information. In addition, we considered The 

results of our revised analyses, and our consideration of the 

policy and legal comments made by the commenter regarding the 

benefits of nonmercurynon-mercury technology to produce 

chlorine. Today’s notice summarizes, provided the comments 

received on these issues, along withimpetus for the non-mercury 

mercury option being proposed today as Option 1. Details of

this supplemental proposal that reflects our consideration of 
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Page 19 of 19

these commentsproposed option are provided in section III.A of 

this document.

4. Elimination of part 61 NESHAP numeric limit

NRDC stated that EPA illegally eliminated the 2,300 g/day 

limit on plant-wide mercury emissions that existed under the 

part 61 Mercury NESHAP. Upon reconsideration, we disagreed with 

NRDC’s argument. We determined that the plant-wide emission 

limit from the part 61 Mercury NESHAP was a standard to which no 

mercury cell facility had ever demonstrated compliance by way of 

emissions testing, that it is not an enforceable standard today, 

and, more importantly, and that it did not reflect the MACT 

level of emissions control required under CAA section 

112(d)(3)(B). Therefore, we concluded that we did not 

unlawfully remove any actual requirement of the part 61 Mercury 

NESHAP. Instead, the 2003 Mercury Cell NESHAP adopted a set of 

MACT-level work practice requirements under section 112(h) that 

are more stringent in terms of controlling fugitive mercury 

emissions than was allowed in the part 61 NESHAP. Details on 

this conclusion were provided on pages 73 FR 33270 and 33271 of 

the June 11, 2008 proposal.

5. Mercury Cell Chlor-Alkali subcategory

As stated in the preamble to the final 2003 Mercury Cell 

NESHAP (68 FR 70905), we divided the chlorine production source 

category into two subcategories: (1) mercury cell chlor-alkali 
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Page 20 of 20

plants and (2) chlorine production plants that do not rely upon 

mercury cells for chlorine production. In December 2003 (68 FR 

70949), we issued our final decision to delete the subcategory 

of the chlorine production source category for chlorine 

production plants that do not utilize mercury cells to produce 

chlorine and caustic. This action was made under our authority 

in CAA section 112(c)(9)(B)(ii), and was not challenged in a 

petition for judicial review. Nor did anyone ask us to 

reconsider that action pursuant to CAA section 307(d)(7)(B). 

The objection raised by NRDC in its petition for reconsideration 

of the 2003 Mercury Cell NESHAP was that it was not appropriate 

to create a mercury cell chlor-alkali plants subcategory. 

According to NRDC, if the MACT floor for mercury emissions was 

determined for the chlorine production source category as a 

whole, the best-performing 12 percent of sources in the category 

would be mercury-free. In our 2008 proposal (73 FR 33273-

33274), we explained that EPA has a long history of using 

subcategorization to appropriately differentiate between types 

of emissions and/or types of operations when analyzing whether

air pollution control technology is feasible for groups of 

sources. Upon reconsideration of this situation for mercury 

cell chlor-alkali plants, we concluded that our earlier decision 

to create the mercury cell chlor-alkali plant subcategory was 

sound.
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6. Magnitude of fugitive mercury emissions

Prior to 2008, the uncertainty associated with fugitive 

mercury emissions from mercury cell chlor-alkali plants had long 

been an issue. Few studies had been conducted to measure these 

fugitive mercury emissions, and the studies that had been 

conducted were short-term and did not account for a range of 

operating and maintenance conditions. For around 30 years, 

mercury cell chlor-alkali plants had reported fugitive mercury 

emissions of 1,300 grams per day (g/day), which equates to 

around 0.5 tons per year per plant. These estimates were based 

on two limited studies conducted by EPA in the early 1970’s.

The sensitivity and concern over the actual levels of 

fugitive mercury emissions from the cell rooms was exacerbated 

by the inability of the industry to fully account for all the 

mercury that was added to the cells. In 2000, there were 

approximately 65 tons of mercury unaccounted for at the 12 

mercury cell plants in operation at that time. This discrepancy 

was based on the difference between the amount of mercury used, 

as reported in the Chlorine Institute’s 2001 annual report to 

EPA’s Binational Toxics Strategy Mercury Workgroup,a

 

a Binational Toxics Strategy Mercury Workgroup - Reducing Mercury 

in the Great Lakes Region. U.S. Environmental Protection 

Agency.

http://www.epa.gov/reg5oair/mercury/reducing.html#regulation

and the 

amount of mercury released to all media, as reported in the 2000 
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Toxics Release Inventory. While industry representatives 

provided explanations for this discrepancy, they could not fully 

substantiate their theories. NRDC maintained that this 

“missing” mercury was being emitted as fugitive emissions.

We recognized that the body of fugitive mercury emissions 

data could be improved. Therefore, as part of our 

reconsideration of the 2003 Mercury Cell NESHAP, we collected 

additional information on fugitive mercury emissions from 

mercury cell chlor-alkali plants. The primary purpose of this 

effort was to address whether the fugitive emissions from a 

mercury cell chlor-alkali plant are on the order of magnitude of 

the historical assumption of 1,300 g/day, corresponding to 

0.5 tons per year (tpy) per plant, or an order of magnitude 

higher as estimated by NRDC. 

Consequently, as part of our reconsideration efforts 

leading the 2008 proposal, we sponsored a test program to 

address the issue of the magnitude of the fugitive mercury 

emissions at mercury cell chlor-alkali plants. In addition to 

this EPA test program, we also collected mercury emissions data 

from the continuous mercury monitoring systems installed at 

three mercury cell plants.

The daily fugitive mercury emission rates extrapolated from 

these data sets ranged from around 20 to 1,300 g/day per 

facility. The average daily emission rates ranged from around 
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420 g/day to just under 500 g/day per facility, with the mean of 

these average values being slightly less than 450 g/day per 

facility. Therefore, the information we obtained in the almost 

one million dollar study of fugitive emissions from mercury cell 

chlor-alkali plants shows that fugitive emissions are on the 

order of magnitude of the historical assumption of 1,300 g/day 

or less. There was no evidence obtained during any of the 

studies that indicated that fugitive mercury emissions were at 

levels higher than 1,300 g/day. All of the studies that 

produced these data were of sufficient duration to encompass all 

types of maintenance activities. Further, the length of these 

studies was also sufficient to include emissions from a variety 

of process upsets, such as: liquid mercury spills, leaking cells 

and other process equipment, and other process upsets.

We also note that since 2008, the mercury cell plants with 

continuous monitoring systems and methods to estimate the flow 

rates have reported even lower mercury emissions than those 

reported in the 2008 proposal. In 2008, these plants reported 

fugitive mercury emissions averaging around 225 g/day/plant.

D. What current legislation is related to this action?

There is also U.S. legislation, both recently enacted and 

proposed, that has or will have an impact on these mercury 

chlor-alkali facilities. On October 14, 2008, President Bush 

signed the Mercury Export Ban Act of 2008 into law. This law 
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bans U.S. export of elemental mercury (effective in 2013), 

requires the Department of Energy (DOE) to designate and manage 

a long-term storage facility for elemental mercury, and 

prohibits the transfer of elemental mercury by federal agencies.

Both houses of Congress are currently considering 

legislation that, if enacted, would affect this industry (S.1428 

and H.R. 2190). These bills would amend the Toxic Substances 

Control Act to prohibit the use of mercury at chlor-alkali 

facilities. The House bill would require the facilities to 

cease using mercury by 2013 if the plant chooses to close or by 

2015 if the plant chooses to convert to nonmercurynon-mercury. 

If this legislation passes Congress and is signed by the 

President into law, we will evaluate the appropriate action for 

EPA in light of the scope and impact of the law.

III. Summary of Proposed Amendments

A. What are the proposed amendments?

Today we are proposing to amend the 2003 Mercury Cell MACT

In today’s action, we are proposing two options for 

amending the Mercury Cell NESHAP. The first option (non-mercury 

technology option) would encourage the conversion to non-mercury 

technology by requiring the elimination of mercury emissions. 

The second option (enhanced work practices option) would require 

improvements in the work practice standards to reduce fugitive 

emissions from the cell room including the requirement that 
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every facility institute a cell room monitoring program and 

implement detailed work practices. These options, along with 

the estimated impacts of each, are described below in sections 

III.A and III.B. Also included is rationale for the selection 

of each option.

In addition to these options, we are also proposing 

amendments that would apply regardless of which option we 

select. These amendments are described in section III.C.

A. What is the non-mercury technology option (Option 1)?

1. Summary of non-mercury technology option

This proposed option would amend the 2003 Mercury Cell

NESHAP by prohibiting mercury emissions from existing mercury 

cell chlor-alkali plants. This would make the standard for 

existing sources the same as the current standard for new and 

reconstructed sources, which is codified at 40 CFR 

63.8190(a)(1). 

Since we believe it is impossible to operateimprobable that

a mercury cell chlor-alkali plant with zerocan be operated 

without mercury emissions, we believe that this proposal would 

effectively require existing mercury cell chlor-alkali plants 

either to convert to a nonmercurynon-mercury technology or to 

cease production of chlorine with their current mercury cell 

production methods. If promulgated, this supplemental proposed 

rule would eliminate approximately 640 pounds of annual mercury 
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emissions, and result in reduced energy demand of around 350,000 

megawatt hours per year, which is approximately equivalent to 

the energy produced by a 40 megawatt power plant. However, if 

there are circumstances where the elimination of mercury 

emissions from an operating mercury cell plant could be 

achieved, we are interested in data and supporting information 

regarding technologies that would eliminate mercury emissions 

from an operating mercury cell facility.

TheThis proposed ruleoption would provide a three-year 

period from the date the final rule is published in the Federal 

Register to achieve zero mercury emissions from mercury cell 

chlor-alkali manufacturing and from mercury recovery 

units.comply. To demonstrate compliance, each owner or operator 

would have to submit a report certifying that all mercuryemitting processes emissions have ceased operationbeen 

eliminated permanently. This report would have to be submitted 

no later than 120 days following the applicable compliance date.

In addition, this proposed action would amend the 

provisions of the existing NESHAP that apply to periods of 

startup, shutdown, and malfunction. The revisions of these 

provisions is the result of a Court decision that invalidated 

certain regulations related to startup, shutdown, and 

malfunction in the General Provisions of 40 CFR part 63 (Sierra 

Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008)). Consequently, 
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the proposed revised rule would require that affected sources 

comply with the emission limitations and work practices at all 

times, including during periods of startup, shutdown, and 

malfunction. These changes would go into effect upon the 

effective date of promulgation of the final rule.

Finally, this proposed rule would correct errors and 

improve the compliance provisions of the rule. These changes, 

which are described below, were included in the June 2008 

proposal (73 FR 33275).

• The detection limit for continuous mercury monitor analyzers 

would be changed to a capability to detect a mercury 

concentration at or below 0.5 times the mercury concentration 

measured during the test or 0.1 μg/m3; and 

• The frequency of determining continuous compliance with the 

emissions standard for mercury recovery units would be 

corrected to specify a daily average (rather than hourly) in

paragraph (b) of §63.8246 “How do I demonstrate continuous 

compliance with the emission limitations and work practice 

standards?” in the 2003 Mercury Cell MACT.

B. How do these proposed amendments relate to the amendments 

proposed on June 11, 2008?

On June 11, 2008 (73 FR 33257), we published the results of 

our reconsideration of the 2003 Mercury Cell MACT. One result 

of this re-consideration was that we proposed modifications to 
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the work practice standards that apply to fugitive emissions, 

primarily those fugitive emissions from cell rooms. The 

proposed modifications to these work practices included 

requiring mercury monitoring in the cell room for all

facilities, along with daily work practices, with weekly 

certification of the performance of these work practices. 

Establishment of the “action level” for investigating and 

correcting high mercury concentration levels revealed by the 

continuous monitors would be done for a minimum of 14 days and 

up to 30 days, at least every six months, and the action level

would be set at the 90th percentile of the data acquired during 

the re-setting time period(s). We also proposed to require 

mercury thermal recovery units that continue to operate at 

closed or converted plants to remain subject to the applicable 

requirements as long as they are in operation. Finally, we 

proposed to correct typographical errors and to make technical 

corrections in the rule related to the compliance requirements.

Five comments were received on the proposed amendments. 

These commenters represent one environmental organization, one 

industry trade organization, and two companies that own and 

operate mercury cell chlor-alkali plants. The fifth comment was 

anonymously submitted in support of environmental organizations.

We have reviewed and considered these comments. As 

discussed in section IV of this preamble, the consideration of 
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one of the issues raised in the comments has caused us to 

publish this supplemental proposal today.

If, after consideration of comments on this proposal, we 

decide to promulgate the amendments proposed in today’s notice 

prohibiting mercury emissions, we would not finalize the 

amendments proposed on June 11, 2008, related to cell room 

operation, since the 2008 proposed amendments presupposed that 

mercury cell chlorine production processes would continue to be 

permitted to emit mercury and would become moot if we promulgate 

today’s proposed amendments. As noted above, two minor 

amendments which were proposed on June 11, 2008, are repeated in 

this proposal. In addition, amendments are being proposed 

related to the requirements which apply during startup, 

shutdown, and malfunction events. If comments received on this 

proposal result in the withdrawal of the proposed prohibition of 

mercury emissions, we then might promulgate the amendments to 

the rule proposed on June 11, 2008, and may incorporate

additional changes to the rule based on public comments. We may 

also promulgate the amendments proposed today related to 

startup, shutdown, and malfunction, even if this proposal is 

withdrawn.

IV. Rationale for Proposed Amendments

A. What is the basis for the proposed zero mercury standard?
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12. Technical information and analyses. for the non-mercury 

technology option

a. Background on the 2008 proposal and costs analysis

Section 112(d)(2) of the CAA provides that emission 

standards for new or existing sources of hazardous air 

pollutants (HAP) shall require the maximum degree of reduction 

in emissions (including a prohibition on such emissions, where 

achievable) that EPA, taking into consideration the cost of 

achieving such emission reduction, and any non-air quality 

health and environmental impacts and energy requirements, 

determines is achievable through application of measures, 

processes, methods, systems or techniques. These may include, 

but are not limited to, measures which (A) reduce the volume of 

or eliminate emissions through process changes, substitution of 

materials or other modifications; (B) enclose systems or 

processes to eliminate emissions; (C) collect, capture or treat 

such pollutants when released from a process, stack, storage or 

fugitive emission point; (D) are design, equipment, work 

practice, or operational standards; or (E) are a combination of 

the above. 

One of the claims presented in NRDC’s petition for 

reconsideration of the 2003 Mercury Cell MACTNESHAP was that EPA 

had not adequately considered nonmercurynon-mercury technology 

as a “beyond-the-floor” MACT control measure for existing 
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sources in the original rulemaking for the Mercury Cell 

MACT.NESHAP (see section II.D.3). Further, NRDC claimed that 

the cost-effectiveness of such a requirement, in terms of the 

annualized costs of control per pound of mercury eliminated, 

would be less than the $9,000 per pound of mercury emission 

reduction that EPAEPA previously indicated was warranted for 

mercury emissions from this source category in the original 2002 

proposal (67 FR 44683, July 3, 2002).the mercury cell 

subcategory. 

In response to this comment, we performed an analysis in 

2008 to determine the capital and annual costs of requiring 

nonmercurynon-mercury technology (Docket Item EPA-HQ-OAR-2002-

0017-0088), as a beyond-the-floor MACT control determination.). 

Specifically, this analysis estimated the costs and the costeffectiveness of converting the existing mercury cell chloralkali plants to membrane cells. 

In a chlor-alkali process, an electric current is passed 

through a salt solution or brine (sodium chloride or potassium 

chloride), causing the dissociation of salt to produce chlorine 

gas and an alkaline solution (sodium hydroxide or potassium 

hydroxide). Hydrogen gas is also produced as a by-product. 

This dissociation occurs in chlor-alkali “cells,” where the 

chloride ions stripped from the brine flow to the anode to form 

the chlorine product, and the sodium/potassium ions flow to the 
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cathode, where they form the hydroxide product and hydrogen. In 

a mercury cell, the cathode is a flowing layer of liquid 

mercury. The sodium/potassium ions form an amalgam with the 

mercury, which is routed to a decomposer. In the decomposer, 

the amalgam is reacted with water to form the hydroxide product 

and hydrogen. The mercury is then recycled. In the membrane 

process, the chloride ions (at the anode) and the hydrogen (at 

the cathode) are kept apart by a selective polymer membrane that 

allows the sodium ions to pass into the cathodic compartment and 

react to form the hydroxide.

In a membrane process, a polymer membrane is used to 

separate the anode products from the cathode products. The 

chloride ions (at the anode) and the hydrogen (at the cathode) 

are kept apart by this membrane, which allows the sodium ions to 

pass into the cathodic compartment and react to form the 

hydroxide.

Conversion from mercury cells to membrane cells is 

technically possible at all existing mercury cell chlor-alkali 

plants, although the amount of significant changes will vary for 

each individual situation. There are parts of the mercury cell 

plant that could be re-used after conversion to the membrane 

cells. It could be possible to use the existing cell room 

building for the new membrane cells, provided that the building 

is in good condition. However, constructing a new membrane cell 
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room building would reduce the production losses as the mercury 

cells could continue to operate longer throughout the conversion 

process. Other equipment and processes that possibly could be 

retained include the rectifiers, the hydrogen treatment system, 

and the chlorine compression and liquefaction process.

Obviously, the The mercury cells themselves (and associated 

decomposers) would have to be replaced by membrane cells. 

Membrane cells need purer brine than mercury cells, so a 

completely new brine purification system would likely be needed. 

Other equipment that would commonly need to be totally replaced 

include the sodium/potassium hydroxide concentration unit and 

evaporation system, the chlorine gas drying and chlorine gas 

absorption units, the power supply unit (excluding the 

rectifiers), pumps, instruments, and much of the piping.

In performing the cost analysis, we used data from readilyavailable sources of information. In our 2008 proposal, we 

estimated that the average cost-effectiveness associated with 

conversion to nonmercurynon-mercury technology would be 

approximately $14,000 per pound of mercury emissions eliminated, 

as opposed to $9,000 per pound.. Further, our 2008 analysis 

predictedestimated the average capital cost of conversion for 

one mercury cell chlor-alkali facility in the U.S. to be 

approximately $68 million per plant. The average annualized 

facility costs for this conversion were estimated to be 
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approximately $7.5 million per plant. Nationwide, the capital 

cost was estimated to be nearly $340 million and the annual 

costs around $38 million for the five facilities in operation at 

the time. We estimated that this cost impact would be 

approximately 11 percent of revenues. As a result of these 

analyses, we proposed in 2008 to reject conversion to 

nonmercurynon-mercury technology as a beyond-the-floor control 

requirement. 

b. Summary of comments received on the 2008 cost analysis

One environmental commenterorganization disagreed with both 

our technical analysis and resulting conclusions in the 2008 

proposal, and claimed that the switch to nonmercury technology 

would be economical. The commenter maintained that conversion

could save millions of dollars annually per plant, with the 

majority of these savings being related to energy costs alone. 

The commenter argued that our 2008 proposal failed to recognize 

or take advantage of these savings, instead allowing a small 

number of plants to operate to the end of their useful lives 

while emitting mercury into the environment.

The commenter said thatnon-mercury technology would be 

economical. The commenter said that, in the 2008 analysis, EPA 

considered only the costs associated with the conversion, 

without considering the net cost or economic benefit. The 

commenter maintained that it is likely that any plant that 
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converts will experience substantial benefits, including an 

increase in energy efficiency between 25 and 35 percent per ton 

of chlorine produced.. The commenter claimed that this 

increased energy efficiency could amount to substantial savings

of more than $98.6 million over five years. Furthermore, the 

commenter pointed out that membrane cells are smaller than 

mercury cells, which would allow plants to increase their 

chlorine capacity as much as 25 percent, leading to increased 

sales and additional energy savings due to the additional 

capacity. The commenter submitted a report that it prepared 

which provided individualized cost analyses for each of the 

remaining mercury cell chlor-alkali plants (Docket Item EPA-HQOAR-2002-0017-0094.3). According to the commenter, its report 

proves that conversion would pay for the majority of its cost in 

five years. Thus, the commenter concluded that EPA’s proposal 

was incorrect to suppose a “high cost impact” of conversion to 

nonmercurynon-mercury technology, and claimed that EPA should 

heed the evidence that conversion is not only economically 

feasible but beneficial and mandate conversion to nonmercurynonmercury technology as a beyond-the-floor control requirement.

c. Revised 2009 revised cost analyses

In the second quarter of 2009, in anticipation of this 

supplemental proposal, we performed a revised beyond-the-floor 

cost analysis to address comments received on the 2008 proposed 
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amendments described above. While we agree with many of the 

comments in favor of a conversion to mercury-free technology,

the The impacts, particularly the savings and benefits, of a 

forced conversion to membrane cells might not be universally 

applicable since the conditions and benefits are not the same at 

every facility. We do agree, however, that these facilities 

would achieve some savings associated with lower electricity and 

the elimination of environmental compliance costs for water 

treatment, waste disposal, and mercury monitoring, and that 

these items should be added to the EPA cost analyses. 

Therefore, without assuming that a uniform energy savings would 

accrue to every facility currently operating, we updated our 

analysis to consider the energy costs savings. We also amended 

our analysis to include savings from the elimination of waste 

treatment, waste disposal, and mercury monitoring. On June 5, 

2009, we developed a revised and updated analysis of conversion 

costs for the industry. This analysis was posted as a 

memorandum in the docket (Docket Item EPA-HQ-OAR-2002-0017-

0098). 

Subsequent to the posting of the June 5, 2009, memorandum, 

industry representatives provided comments on the revised 

analysis (Docket Items EPA-HQ-OAR-2002-0017-0100, 0101, 0102, 

and 0103). One of the major comments raised by industry 

representatives on our revised analysis regarded the 2006 
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mercury emission levels used to estimate the cost-effectiveness 

of conversion to nonmercurynon-mercury technology. The industry 

representatives stated that these data werereflected emission 

levels considerably higher than their more recently reported 

emissions. In addition, the industry representatives stated 

that the capital and annual costs in our 2008 analysis were 

underestimated. The industry representatives also believed that 

the annual energy savings were overstated because these savings

did not take into account the additional energy and fuel that 

would be needed to concentrate the caustic by-product obtained 

using membrane cells, which is produced at 33 percent purity, to 

the 50 percent purity obtained using the mercury cell process. 

The industry representatives also commented that the June 2009

cost analysis: (1) underestimated the mercury storage costs;

(2) used an interest rate that was in practicality too low for 

calculating the capital recovery factor; (3) erroneously used 

information from a European study to estimate the savings due to 

the elimination of the mercury process that were not applicable

to the U.S.; and (4) did not consider decommissioning costs.

Consequently, we considered the industry comments and, in 

instances where specific relevant data were provided or 

available, we incorporated the information into another revised 

cost analysis dated September 15, 2009, which was placed in the 

docket (Docket Item EPA-HQ-OAR-2002-0017-0105). The September 
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2009 updated cost analysis for conversion to membrane technology 

estimated that the costs to convert the four remaining mercury 

cell plants to be nearly $336 million in total capital costs and 

almost $36 million per year in total annual costs, considering 

electricity and other savings. The cost-effectiveness of 

conversion based on this September 2009 analysis was about 

$66,000 per pound of mercury. 

In this analysis, we did not add certain highly variable 

costs mentioned by the industry commenter that the commenter 

stated could potentially be incurred by a plant when making a 

change to nonmercurynon-mercury technology. These variable 

costs include losses in production, building replacement, plant 

decommissioning, and many others that are likely to be highly 

variable from facility to facility. We believe that the 

magnitude of these costs, although very likely to occur for most 

facilities, would depend on factors such as the condition of the 

existing buildings, available space on the facility site to 

erect a new cell room building to avoid production losses, and 

possibly other unknown factors. We also received comments from 

an environmental group on the revised 2009 cost analyses from 

the same environmental organization that provided comments on 

the 2008 cost analysis. The complete comments can be found in 

the docket (Docket EPA-HQ-OAR-2002-0017). TheThe environmental 

organization commenter stated that the capital costs estimated 
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by EPA are too high and the EPA analysis doesdid not uniformly 

account for expansion during conversion. In addition, the 

commenter stated that the regression formula of cost vs. 

capacity used to establish an equation is incorrect since there 

is no relationship between capital costs and capacity when 

considering the full set of relevant data rather than just 

recent U.S. facilities. Also, the commenter stated that the 

capital costs should be annualized over a longer period than the 

15 years used in the analysis since 30 years is a more likely 

useful life.

The environmental commenter also made the following points: 

the energy savings estimated by EPA are too low, since higher 

reductions in electricity consumption are common place; the EPA 

cost estimate for producing steam double-counted the cost 

associated with concentrating caustic and did not account for 

the fact the steam could be obtained on-site without expense; 

the cost savings for environmental compliance avoided are 

underestimated; and the decommissioning costs are already 

included in estimates of conversion since many factories include 

the cost of dismantling and decommission in the reported cost of 

conversion.

In addition, the commenter recommended that in evaluating 

the costs, EPA should use the average sales per establishment 

instead of the average sales per ton of chlorine capacity 
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because the commenter believes that the latter term grossly 

underestimates sales. The commenter also stated that societal 

costs of conversion to nonmercurynon-mercury technology could 

result in a savings of $4.6 billion in economic productivity 

and, within 30 years, could result in an average of $28 million 

in societal benefits from each facility.should be considered 

(Docket Item EPA-HQ-OAR-2002-0017-0104). The commenter also 

believed that the industry-supplied emission estimates are not 

reliable and are likely underestimated, thus overestimating the 

costs per pound of mercury emissions prevented. 

Finally, the commenter stated that EPA’s overall conclusion does 

not reflect the real world since over 100 plants have made the 

conversion globally and at least five chlor-alkali facilities 

expected or received a complete repayment from their investment 

within five years. d. Revised cost analysis for this proposal

d. Cost Analysis for Supplemental Proposal

Many of the comments we received on the September 2009 cost 

analysis were considered and used to estimate costs that 

represent the outcome of a potential conversion to 

nonmercurynon-mercury technology. In this revised analysis, we 

recognize that there are significant uncertainties in estimating 

these costs, and consider ranges of the potential costs (and 

savings) associated with each cost element. For each element, 

we do select a “best estimate” to allow the estimation of 
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capital and annual costs of conversion for each facility. The 

results of this analysis are summarized below in section 

III.A.2.a of this document, and a memorandum that documents the 

details of this cost analysis can be found in the docket. We 

are specifically requesting comment on our analysis, along with 

additional facility-specific data, to allow a refinement of the 

analysis.

3. Estimated impacts of the non-mercury technology option

a. Environmental and energy impacts

We estimate that the total mercury emissions from the four 

mercury cell operating facilities to be around 640 pounds per 

year. The non-mercury technology option would reduce mercury 

emissions by this amount. These four facilities reported almost 

2,000 additional pounds per year of on-site and off-site mercury 

releases to non-air media. These releases, which are primarily 

in the form of hazardous wastes, would be eliminated in the 

longer term, with consequential benefits for non-air quality 

related health and environmental values. The potential problems 

associated with the handling and continuous management of over 

1,200 tons of virgin mercury that is used in the cells at these 

four chlor-alkali plants would also be eliminated. In addition, 

approximately two tons of this mercury was reported by the 

industry as “unaccounted” in 2008. This non-mercury technology 

option would eliminate the unaccounted mercury as well. 
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The membrane cell chlor-alkali process requires less energy 

than the mercury cell process. Therefore, assuming that all 

four existing mercury cell chlor-alkali plants convert to 

membrane cells, there would be a savings in energy. We estimate 

that this savings would be around 350,000 megawatt hours per 

year, which is approximately equivalent to the energy produced 

annually by a 40 megawatt power plant. The emission reductions 

associated with this reduced electricity generation are 

estimated to be 68 tons per year of fine particulate matter 

(PM2.5), 5 tons per year of volatile organic compounds (VOC), 0.1 

tons per year of ammonia (NH3) 0.008 tons per year of mercury, 

and 287,000 tons per year of carbon dioxide (CO2). Since NOx and 

SO2 are covered by capped emissions trading programs, we are only 

estimating PM2.5 emission reductions from reduced electricity 

demand.

In the short term, the conversion of these facilities would 

result in the need to dispose of mercury-contaminated wastes. 

While there is considerable uncertainty in quantifying the 

amount of these wastes, we estimate that there could be around 

7,000 cubic meters of mercury contaminated waste generated that 

could contain around 6 tons of mercury. 

As stated above, over 1,200 tons of virgin or process 

mercury from the facilities would need to be dealt with whether 

the facilities close or convert to non-mercury technology. The 
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Mercury Export Ban Act of 2008, discussed earlier, would 

prohibit this mercury from being exported. Therefore, this 

mercury would need to be stored or sold domestically. Since 

mercury is a hazardous substance, it cannot be stored without a 

permit; hence, Department of Energy (DOE) is planning to build a 

federal facility to accommodate the excess mercury that results 

from the export ban.

b. Cost impacts

The estimated costs for this proposed rulethe non-mercury 

technology option, assuming that all four currently operating 

mercury cell chlor-alkali plants convert to membrane cell 

technology, include total U.S. capital costs of approximately 

$300 million dollars, with individual plant capital costs 

ranging from a low of $28 million to a high of approximately 

$160 million. Our analysis does show that, in the hypothetical 

situation that a single plant could incur the lowest possible 

costs while also realizing the highest possible energy and other 

savings, there could be an overall cost savings in the 

conversion from mercury cells to membrane cells. However, we do 

not believe that this scenario is realistic. Using more 

conservative assumptions, our best estimate is that the average 

annual costs would be between $800,000 and $6.67 million per 

year per plant. The total U.S. annual costs are estimated to be 

$13 million per year. Based on these costs and the estimated
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mercury emissions for each facility, the cost-effectiveness, in 

terms of annualized costs per pound of mercury eliminated, is

approximately $20,000 per pound for the industry, with a range 

of around $13,000 to $31,000 per pound for the individual 

facilities. This is within the range of cost-effectiveness 

impacts that we have previously found to be reasonable. 

c. Economic impacts

In addition to cost analyses, we also conducted an economic 

analysis of the impacts of the zero option to require nonmercury beyond-the-floor option. Antechnology. A regulatory

impact analysis (RIA) was performed for this non-mercury 

technology option. A report that documents the EIA methods and 

results can be found in the docket (EPA-HQ-OAR-2002-0017). 

Although individual plant information would be the best 

method to assess the true economic impacts of the non-mercury 

technology option, detailed information for this industry was 

not publicly available. As a result, we relied on parent 

company information provided in company annual reports (e.g., 

form 10-K), local press and industry trade publications, and 

company Web sites. 

There are many aspects of the cost estimate for conversion 

that are unknown or difficult to assess. While we believe that 

we have evaluated the conversion cost information available to 

us at the time of this action, the true costs may vary 
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considerably. However, variation in engineering costs is not 

expected to cause a significant difference in the general 

conclusions of the RIA.

We performed an analysis that compared the annual

conversion costs to sales showed that the one small entity’s 

(cost- to- sales ratio (, or CSR). We estimated that the CSR of 

ASHTA, the one small business in this industry, would range from 

one to two percent using the costs presented in this proposal. 

The other three plants are owned by large parent companies with 

significant company-wide sales. As a result, the CSRs for these 

large parent companies are below one percent. When single plant 

sales were considered, the CSRs for the mercury cell chloralkali plants owned by large parent companies ranged from 4 to 

9 percent.) would range from 1 to 2 percent, which suggests a 

significant economic impact. The CSRs for the three other 

parent companies are below 1 percent. A 

We also analyzed industry profitability effects analysis 

suggested thatby comparing the annual conversion costs could 

reduce theto reported industry margins for a representative 

electrochemical unit. This analysis confirms the results of the 

sales comparisons that plant conversion costs will likely have 

an economically significant effect. Conversion costs could 

reduce the margins by 10 to 20 percent.
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by 10 to 20 percent. Each of the four facilitiesThis nonmercury technology option would force owners of mercury chloralkali plants to make an investment decision based on the costs 

of conversion as opposed to the future benefits of the 

conversion. This non-mercury technology option could elect to 

close rather than convert to nonmercury technology. Since 2003, 

six mercury cell facilities have ceased operation. Three of 

these plants have elected to close, and three have elected to 

convert. Although EPA does not have sufficient data to 

definitively determine whether individual companies would choose 

to convert or closelead to plant shutdowns that would involve 

adjustment costs for people working at the affected plants. 

Affected plants may also have strong links with other firms or 

downstream markets; as a result, secondary consequences of the 

regulation are important to consider. We are interested in 

receiving comments related to the downstream impacts of 

potential mercury cell plant shutdowns. In particular, we are 

interested in the impact on the potassium carbonate market and 

the potential impact on the competitiveness of the potassium 

hydroxide market. 

Many owners have converted from mercury cell chlor-alkali 

technologies in Europe and the U.S., while other mercury cell 

chlor-alkali plant owners have concluded the investment decision 

was currently not in their company’s interest given their 
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Page 47 of 47

assessment of future economic conditions, and have shutdown 

their mercury cell chlor-alkali plants instead. Since 2003, 

three U.S. mercury cell chlor-alkali facilities have closed and 

three have converted. Specifically, the Occidental Chemical 

mercury cell chlor-alkali facilities in Delaware City, Delaware, 

Muscle Shoals, Alabama, and Deer Park, Texas, have closed; while 

the PPG facility in Lake Charles, Louisiana, the ERCO facility 

in Port Edwards, Wisconsin, and the Pioneer chlor-alkali 

facility (now owned by Olin) in St. Gabriel, Louisiana, have 

converted to membrane cells.

We do not have sufficient data to predict whether 

individual companies would choose to convert or close the 

affected mercury cell chlor-alkali plants. However, the data 

obtained in this study suggests that plant closure may be a 

preferred alternative to meet the requirements of the , the data 

suggest that plant closure may be the owner’s preferred 

alternative to meet the requirements of the proposed rule. If 

all four plants elected to close rather than convert, we 

estimate that over 1,000 jobsnon-mercury technology option for 

one or more of the mercury cell chlor-alkali plants.

As noted above, individual plant information was not 

available to perform a refined analysis of whether these mercury 

cell plants would likely convert to non-mercury technology or 

close. We are specifically requesting comment on our analysis, 
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along with facility-specific data, to allow a refinement of the 

analysis for this non-mercury technology option.

Mercury is a highly neurotoxic contaminant that enters the 

food web as a methylated compound, methylmercury (U.S. EPA, 

2008c). The contaminant is concentrated in higher trophic 

levels, including fish eaten by humans. Mercury is emitted to 

the air from various man-made and natural sources. These 

emissions transport through the atmosphere and eventually 

deposit to land or water bodies. This deposition can occur 

locally, regionally, or globally, depending on the form of 

mercury emitted and other factors such as the weather. The form 

of mercury emitted from these sources is estimated to be about 

98 percent elemental and two percent divalent mercury. Gaseous 

elemental mercury can be transported very long distances, even 

globally, to regions far from the emissions source (becoming 

part of the global “pool”) before deposition occurs. Inorganic 

ionic (divalent) mercury has a shorter atmospheric lifetime and 

can deposit to land or water bodies closer to the emissions 

source. Furthermore, elemental mercury in the atmosphere can 

undergo transformation into ionic mercury, providing over $50 million 

in wages could be a significant pathway for deposition of emitted 

elemental mercury.

d. Benefits
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This source category emitted about 640 pounds of mercury in 

the air in 2008 in the U.S. Based on the EPA’s National Emission 

Inventory, about 103 tons of mercury were emitted from all 

anthropogenic sources in the U.S. in 2005. Moreover, the United 

Nations has estimated that about 2,100 tons of mercury were 

emitted worldwide by anthropogenic sources in 2005. We believe 

that total mercury emissions in the U.S. and globally in 2008 

were about the same magnitude in 2005. Therefore, we estimate 

that in 2008, these sources emitted about 0.3 percent of the 

total anthropogenic mercury emissions in the U.S. and about 0.02

percent of the global emissions. Overall, the non-mercury 

technology option (Option 1) would directly affected by closure of all four 

plants. Details of the economic analysis are discussed below in section V.A.2reduce 

mercury emissions by about 640 pounds per year from current 

levels as well as an estimated 16 pounds per year indirectly 

through reduced electricity generation, and therefore, 

contribute to reductions in mercury exposures and health 

effects. Due to data, time, and resource limitations, we were 

unable to model mercury dispersion, deposition, methylation, 

bioaccumulation in fish tissue, and human consumption of

mercury-contaminated fish that would be needed in order to 

estimate the human health benefits from reducing mercury 

emissions.

e. Effects of Potential exposure routes to mercury
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Mercury is a naturally occurring element that is found in 

air, water, and soil in various forms. In general, industrial 

sources emit different combinations of three different species: 

elemental mercury, inorganic mercury compounds (e.g., mercuric 

chloride), and particulate mercury. The deposition of these

emissions could, under circumstances described below, lead to 

formation of an organic form,include both direct inhalation and 

consumption of fish containing methylmercury. 

The majority of mercury emitted from mercury cell chloralkali plants is elemental, with a small fraction being 

inorganic mercury.

In general, for For elemental mercury, inhalation is the 

primarymost direct exposure route of potential concern. Effects 

on the nervous system appear to be the most sensitive 

toxicological endpoint and can include tremors, nervousness, 

insomnia, neuromuscular changes (such as weakness, muscle 

atrophy, and muscle twitching), headaches, polyneuropathy, and memory loss. 

and headaches.b

 

b Integrated Risk Information System (IRIS). U.S. Environmental 

Protection Agency. http://www.epa.gov/ncea/iris/subst/0370.htm

In the U.S., the primary route of human exposure 

to mercury emissions from industrial sources is generally 

indirectly through the consumption of fish containing 

methylmercury. As described above, mercury that has been emitted 

to the air eventually settles into water bodies or onto land 
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where it can either move directly or be leached into 

waterbodies. Once deposited, certain microorganisms can change 

it into methylmercury, a highly toxic form that builds up in 

fish, shellfish and animals that eat fish. Consumption of fish 

and shellfish are the main sources of methylmercury exposure to 

humans. Methylmercury builds up more in some types of fish and 

shellfish than in others. The levels of methylmercury in fish 

and shellfish vary widely depending on what they eat, how long 

they live, and how high they are in the food chain. Most fish, 

including ocean species and local freshwater fish, contain some 

methylmercury. For example, in recent studies by EPA and the 

U.S. Geological Survey (USGS) of fish tissues, every fish 

sampled from 291 streams across the country contained some 

methylmercury (Scudder, 2009).c

In general, for inorganic mercury compounds, both 

inhalation and ingestion exposure routes are of potential 

interest. Effects associated with high exposures to inorganic 

mercury compounds include damage to the gastrointestinal tract, 

the nervous system, and the kidneys. The most sensitive general 

systemic adverse effect due to exposure to inorganic mercury 

compounds is the formation of autoimmune glomerulonephritis 

 

c Scudder, B.C., Chasar, L.C., Wentz, D.A., Bauch, N.J., Brigham, 

M.E., Moran, P.W., and Krabbenhoft, D.P. 2009. Mercury in fish, 

bed sediment, and water from streams across the United States, 

1998–2005: U.S. Geological Survey Scientific Investigations 

Report 2009–5109, 74 p.
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(that is, inflammation of the kidney). Specific symptoms of 

high exposures to inorganic mercury can include skin rashes and 

dermatitis; mood swings; memory loss; mental disturbances; and 

muscle weakness. 

Mercury that is emitted can be atmospherically transported 

different distances depending on the species. While inorganic 

mercury is generally transported relatively short distances 

before depositing, elemental mercury, barring any topographical 

interferences, can enter the global pool and remain in 

circulation up to 12 months prior to deposition. Once 

deposited, natural processes, particularly in water bodies, can 

transform some of the mercury into methylmercury, which is a 

highly toxic, more bioavailable form that bioaccumulates in 

organisms and then biomagnifies in the aquatic food chain (such 

as in fish). Thus, the ingestion route via fish consumption 

dominates the pathway for human and wildlife exposure to 

methylmercury. Symptoms of methylmercury poisoning may include:

impairment of the peripheral vision; disturbances in sensations; 

lack of coordination of movements; impairment of speech, 

hearing, walking; and muscle weakness. In general, while adults

can experience effects from high ingestion exposure to 

methylmercury, exposures to developing fetuses, infants, and 

children can pose the highest concerns. For fetuses, infants, 

and children, the primary health effect of methylmercury is 
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Page 53 of 53

impaired neurological development. Methylmercury exposure in the 

womb can adversely affect a baby's growing brain and nervous 

system. Impacts on cognitive thinking, memory, attention, 

language, and fine motor and visual spatial skills, all of which 

can result in learning disabilities, have been seen in children 

exposed to methylmercury.

In general, avoidance of any potential for these severe 

health effects can result from reducing the amount of mercury 

released to the air, water, and other media. The four existing 

mercury cell chlor-alkali plants emit around 640 pounds of 

mercury each year to the air, based on recent estimates. They 

also release a total of just under 1 ton of mercury per year to 

other media, including around 50 pounds per year to water. The 

proposed amendments would result in the elimination of these 

releases in the future, and therefore could have beneficial nonair quality health and environmental impacts.

In addition, mercury cell chlor-alkali plants are commonly 

identified as contaminated sites and designated for correction 

action under the EPA Superfund or Resource Conservation and 

Recovery Act (RCRA) corrective action programs. In fact, three 

of the four currently operating mercury cell plants have been

identified under the RCRA corrective action program. The 

shutdown of the mercury cell processes would accelerate the 
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clean-up of these sites, again resulting in beneficial non-air 

quality health and environmental impacts.

2The majority of fish consumed in the U.S. are ocean 

species. The methylmercury concentrations in ocean fish species 

are primarily influenced by the global mercury pool. However, 

the methylmercury found in local fish can be due, at least 

partly, to mercury emissions from local sources. Research shows 

that most people’s fish consumption does not cause a mercuryrelated health concern. However, certain people may be at higher 

risk because of their routinely high consumption of fish (e.g., 

tribal and other subsistence fishers and their families who rely 

heavily on fish for a substantial part of their diet). It has 

been demonstrated that high levels of methylmercury in the 

bloodstream of unborn babies and young children may harm the 

developing nervous system, making the child less able to think 

and learn. Moreover, mercury exposure at high levels can harm 

the brain, heart, kidneys, lungs, and immune system of people of 

all ages. 

Several studies suggest that the methylmercury content of 

fish may reduce these cardio-protective effects of fish 

consumption. Some of these studies also suggest that 

methylmercury may cause adverse effects to the cardiovascular 

system. For example, the NRC (2000) review of the literature 

concerning methylmercury health effects took note of two 
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epidemiological studies that found an association between 

dietary exposure to methylmercury and adverse cardiovascular 

effects.d Moreover, in a study of 1,833 males in Finland aged 42 

to 60 years, Solonen et al. (1995) observed a relationship 

between methylmercury exposure via fish consumption and acute 

myocardial infarction (AMI or heart attacks), coronary heart 

disease, cardiovascular disease, and all-cause mortality.e The 

NRC also noted a study of 917 seven year old children in the 

Faroe Islands, whose initial exposure to methylmercury was in 

utero although post natal exposures may have occurred as well. 

At seven years of age, these children exhibited an increase in 

blood pressure and a decrease in heart rate variability.f

 

d National Research Council (NRC). 2000. Toxicological Effects of 

Methylmercury. Committee on the Toxicological Effects of 

Methylmercury, Board on Environmental Studies and Toxicology. 

National Academies Press. Washington, DC. pp. 168-173.

Based 

on these and other studies, NRC concluded in 2000 that, while 

“the data base is not as extensive for cardiovascular effects as 

it is for other end points (i.e., neurologic effects) the 

e Salonen, J.T., Seppanen, K. Nyyssonen et al. 1995. “Intake of 

mercury from fish lipid peroxidation, and the risk of 

myocardial infarction and coronary, cardiovascular and any 

death in Eastern Finnish men.” Circulation, 91 (3):645-655.

f Sorensen, N, K. Murata, E. Budtz-Jorgensen, P. Weihe, and 

Grandjean, P., 1999. “Prenatal Methylmercury Exposure As A 

Cardiovascular Risk Factor At Seven Years of Age”, 

Epidemiology, pp370-375.
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cardiovascular system appears to be a target for methylmercury 

toxicity.”g

Since publication of the NRC report there have been some 30 

published papers presenting the findings of studies that have 

examined the possible cardiovascular effects of methylmercury 

exposure. These studies include epidemiological, toxicological, 

and toxicokinetic investigations. Over a dozen review papers 

have also been published. If there is a causal relationship 

between methylmercury exposure and adverse cardiovascular 

effects, then reducing exposure to methylmercury would result in 

public health benefits from reduced cardiovascular effects.

In early 2010, EPA sponsored a workshop in which a group of 

experts were asked to assess the plausibility of a causal 

relationship between methylmercury exposure and cardiovascular 

health effects and to advise EPA on methodologies for estimating 

population level cardiovascular health impacts of reduced 

methylmercury exposure. The report from that workshop is in 

preparation.

The primary benefit of the non-mercury technology option 

would be the reduction of mercury emissions from these sources, 

as discussed above. Due to data and resource limitations, we 

 

g National Research Council (NRC). 2000. Toxicological Effects of 

Methylmercury. Committee on the Toxicological Effects of 

Methylmercury, Board on Environmental Studies and Toxicology. 

National Academies Press. Washington, DC. p. 229.
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were unable to monetize the benefits associated with reducing 

mercury emissions for this non-mercury technology option. 

However, we estimate the monetized energy co-benefits of the 

non-mercury technology option to be $22 million to $43 million 

(2007$, 3 percent discount rate) in the implementation year 

(2013). The monetized co-benefits of the regulatory action at a 

7 percent discount rate are $14 million to $33 million (2007$). 

Higher or lower co-benefits estimates are plausible using other 

assumptions.h

Table 1. Summary of the Monetized Co-Benefits Estimates for the 

Proposed Non-Mercury Technology Option in 2013 (millions of 

2007$)1

 A summary of the monetized energy co-benefits 

estimates at discount rates of 3 percent and 7 percent is in 

Table 1 of this preamble. 

Pollutant Estimated emission 

reductions 

Monetized cobenefitsMonetized cobenefits

(3% Discount 

Rate)

(7% Discount 

Rate)

Mercury2 656 pounds per year N/A N/A

Direct 

PM2.5

68 tons per year $15 to $37 $14 to $33

CO2

3 287,000 tons per 

year $6.5 $6.5

Grand Total $22 to $43 $21 to $40

1 All estimates are for the implementation year (2013), and are 

rounded to two significant figures so numbers may not sum 

across rows. All fine particles are assumed to have equivalent 

health effects. 2 Includes an estimated 16 pounds per year of mercury emission 

reductions from energy savings. 

 

h Roman et al, 2008. “Expert Judgment Assessment of the 

Mortality Impact of Changes in Ambient Fine Particulate Matter 

in the U.S.” Environ Sci Technol, 42, 7, 2268 – 2274.
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3 CO2-related benefits were calculated using the social cost of 

carbon (SCC), which is discussed further in the RIA. The net 

present value of reduced CO2 emissions is calculated differently 

than other benefits. The same discount rate used to discount 

the value of damages from future emissions (SCC at 5, 3, 2.5 

percent) is used to calculate net present value of SCC for 

internal consistency. This table shows monetized CO2 co-benefits 

at discount rates of 3 and 7 percent that were calculated using 

the global average SCC estimate at a 3% discount rate because 

the interagency workgroup on this topic deemed this marginal 

value to be the central value. In the RIA, we also provide the 

monetized CO2 co-benefits using discount rates of 5 percent 

(average), 2.5 percent (average), and 3 percent (95th 

percentile).

These co-benefits estimates represent the total monetized 

human health benefits for populations exposed to less PM2.5 in 

2013 from emission reductions due to the decreased electricity 

demand. These co-estimates are calculated as the sum of the 

monetized value of avoided premature mortality and morbidity 

associated with reducing a ton of PM2.5 precursor emissions. To 

estimate the human health benefits derived from reducing PM2.5

precursor emissions, we used the general approach and 

methodology laid out in Fann, Fulcher, and Hubbell (2009)i

To generate the benefit-per-ton estimates, we used a model 

to convert emissions of direct PM2.5 and PM2.5 precursors into 

changes in ambient PM2.5 levels and another model to estimate the 

changes in human health associated with that change in air 

. 

 

i Fann, N., C.M. Fulcher, B.J. Hubbell. 2009. “The influence of 

location, source, and emissions type in estimates of the human 

health benefits of reducing a ton of air pollution.” Air Qual 

Atmos Health (2009) 2:169–176.
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quality. The PM2.5 benefit-per-ton estimates used for this rule 

assume a certain geographic distribution of emissions 

reductions, population density, meteorology, exposure and 

baseline health incidence rates. To the extent that these 

attributes differ greatly from those of the Mercury Chlor Alkali 

facilities, the use of these $/ton values in combination with 

emission changes at MCL facilities to estimate PM2.5 co-benefits 

may lead to higher or lower benefit estimates than if these cobenefits were estimated using site-specific data. Finally, the

monetized health co-benefits were divided by the emissions 

reductions to create the benefit-per-ton estimates. These 

models assume that all fine particles, regardless of their 

chemical composition, are equally potent in causing premature 

mortality because there is no clear scientific evidence that 

would support the development of differential effects estimates 

by particle type. 

Direct PM is the only PM2.5 precursor we are estimating for

the non-mercury technology option. For context, it is important 

to note that the magnitude of the PM co-benefits is largely 

driven by the concentration response function for premature 

mortality. Experts have advised EPA to consider a variety of 

assumptions, including estimates based both on empirical 

(epidemiological) studies and judgments elicited from scientific 

experts, to characterize the uncertainty in the relationship 
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between PM2.5 concentrations and premature mortality. For this 

non-mercury technology option we cite two key empirical studies, 

one based on the American Cancer Society cohort studyj and the 

extended Six Cities cohort studyk

EPA strives to use the best available science to support 

our benefits analyses. We recognize that interpretation of the 

science regarding air pollution and health is dynamic and 

evolving. After reviewing the scientific literature and recent 

scientific advice, we have determined that the no-threshold 

model is the most appropriate model for assessing the mortality 

benefits associated with reducing PM2.5 exposure. Consistent with 

this recent advice, we are replacing the previous threshold 

sensitivity analysis with a new “Lowest Measured Level” (LML) 

assessment. While a LML assessment provides some insight into 

the level of uncertainty in the estimated PM mortality benefits, 

EPA does not view the LML as a threshold and continues to 

. In the RIA for this nonmercury technology option, which is available in the docket, we 

also include co-benefits estimates derived from expert judgments 

and other assumptions.

 

j Pope et al, 2002. “Lung Cancer, Cardiopulmonary Mortality, and 

Long-term Exposure to Fine Particulate Air Pollution.” Journal 

of the American Medical Association 287:1132-1141 k Laden et al, 2006. “Reduction in Fine Particulate Air 

Pollution and Mortality.” American Journal of Respiratory and 

Critical Care Medicine. 173: 667-672
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quantify PM-related mortality impacts using a full range of 

modeled air quality concentrations. 

Most of the estimated PM-related benefits in this nonmercury technology option would accrue to populations exposed to 

higher levels of PM2.5. Using the Pope et al. (2002) study, 85 

percent of the population is exposed at or above the LML of 7.5 

μg/m3. Using the Laden et al. (2006) study, 40 percent of the 

population is exposed above the LML of 10 μg/m3. It is important 

to emphasize that we have high confidence in PM2.5-related 

effects down to the lowest LML of the major cohort studies. 

This fact is important, because as we estimate PM-related 

mortality among populations exposed to levels of PM2.5 that are 

successively lower, our confidence in the results diminishes. 

However, our analysis shows that the great majority of the 

impacts occur at higher exposures. This analysis does not 

include the type of detailed uncertainty assessment found in the 

2006 PM2.5 National Ambient Air Quality Standard (NAAQS) RIA 

because we lack the necessary air quality input and monitoring 

data to run the benefits model. In addition, we have not 

conducted any air quality modeling for this rule. The 2006 PM2.5

NAAQS benefits analysisl

 

l U.S. Environmental Protection Agency, 2006. Final Regulatory 

Impact Analysis: PM2.5 NAAQS. Prepared by Office of Air and 

provides an indication of the 

sensitivity of our results to various assumptions. 
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It should be emphasized that the monetized co-benefits 

estimates provided above do not include benefits from several 

important benefit categories, including reducing HAP emissions, 

ecosystem effects, and visibility impairment. The primary 

benefit of this non-mercury technology option is the reduction 

of mercury emissions from these sources. Due to data and 

resource limitations, we were unable to model mercury 

dispersion, deposition, methylation, bioaccumulation in fish 

tissue, and human consumption of mercury-contaminated fish that 

would be needed in order to estimate the human health benefits 

from reducing mercury emissions. Although we do not have 

sufficient information or modeling available to provide 

monetized estimates for this non-mercury technology option, we 

include a qualitative assessment of these other effects in the 

RIA for the non-mercury technology option, which is available in 

the docket.

The annualized social costs of this non-mercury technology 

option are estimated to be $13 million (2007$, 7 percent 

discount rate) in 2013. The combined monetized energy cobenefits are $22 million to $43 million (2007$, 3 percent 

discount rate) and $21 million to $40 million (2007$, 7 percent

discount rate) for 2013. Thus, net benefits of the non-mercury 

 

Radiation. October. Available on the Internet at 

http://www.epa.gov/ttn/ecas/ria.html
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technology option are estimated at $9 million to $30 million 

(2007$, 3 percent discount rate) and $8 million to $27million 

(2007$, 7 percent discount rate) in 2013. EPA believes that the 

non-monetized mercury benefits and the energy co-benefits of the 

non-mercury technology option are likely to exceed the costs 

even when taking into account the uncertainties in the cost and 

benefit estimates.

4. Rationale for selection of the zero non-mercury 

standardtechnology option

While the results of these additional analyses were that 

the costs and cost-effectiveness values decreased from those 

estimated in our 2008 analysis, there is still some uncertainty 

regarding numerous facets of the cost analysis. Since the lower 

estimates of potential costs show that conversion to 

nonmercurynon-mercury technology may be a reasonable investment 

action in the long term, we are proposing this supplemental 

amendment to request a complete set of comments on the costs 

presented here in order to prepare a final cost analysis to 

support or not support a standard for zero the non-mercury 

emissionstechnology option. Once all comments are received, we 

will re-evaluate whether or not these costs constitute an 

unreasonably high cost impact given the benefits of 

zeroeliminating all mercury emissions to public health, the 

environment, and to energy use. 
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We gave serious consideration to the comments we received 

that stated the use of mercury in chlor-alkali plants is 

unnecessary since over 95 percent of the chlorine produced in 

the U.S. is already produced using mercury-free technology. 

Forcing these plants to switch to mercury-free technology would 

eliminate the approximately 0.5 tons of mercury released per 

year.

In the 2008 proposal, we rejected the conversion to 

nonmercurynon-mercury technology as a beyond-the floor option 

because of the high cost impacts. The total annual costs 

estimated at that time were around $38 million, or around $7.5 

million per facility on average for each of the five facilities 

operating at that time. The revised cost analysis described 

above estimates total annual costs of around $13 million, which 

averages to just over $3 million per facility. Therefore, the 

current estimated conversion costs are around 60 percent lower 

than those driving our decision in 2008. 

With regard to cost-effectiveness, we stated in the 

original proposal of the Mercury Cell MACTNESHAP Standard in 

2002 (67 FR 44683) that we considered the additional mercury 

emission reduction achieved by the beyond-the-floor option for 

hydrogen by-product vents and end-box ventilation systems to be 

warranted at an incremental cost-effectiveness of $9,000 per 

pound of mercury emission reduction. We did not indicate that 
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Page 65 of 65

this cost-effectiveness level represented an upper end of 

acceptability, and in other contexts, such as the Clean Air 

Mercury Rule (70 Federal RegisterFR 28606, 05/18/2005),m

Historically, EPA has not established a clear costeffectiveness level for mercury reductions that are considered 

acceptable. In fact, we have rejected regulatory alternatives 

for mercury with cost-effectiveness values of $5,000 per pound, 

and accepted regulatory strategies with estimated costeffectiveness values of $39,000 per pound, in the case of the 

we have 

found even larger cost-effectiveness factors to be reasonable. 

Similarly, in our 2008 proposal of amendments, we did not 

conclude that a cost-effectiveness value of $14,000 per pound of 

mercury emission reduction was unacceptable, as this was one of 

several cost and economic factors considered that led to our 

conclusion regarding the high cost impact of the beyond-thefloor option of forced conversion. 

 

m On March 29, 2005, EPA published a final rule ( 70 FR 15994 ) 

entitled ‘‘Revision of December 2000 Regulatory Finding on the 

Emissions of Hazardous Air Pollutants From Electric Utility 

Steam Generating Units and the Removal of Coal- and Oil-Fired 

Electric Utility Steam Generating Units from the Section 112(c) 

List (Section 112(n) Revision Rule).” Following that final 

action, the Administrator received two petitions for 

reconsideration. In response to those petitions, EPA announced 

(Federal Register, Vol. 70, October 28, 2005, p. 62200) the

reconsideration of certain aspects of the Section 112(n) 

Revision Rule, but these aspects did not include costs related 

to mercury control or cost-effectiveness. 
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Clean Air Mercury Rule.n

We also recognize that the mercury cell technology is an 

outdated technology that has been largely phased out in the U.S. 

even without a zero mercury emissions requirementprohibition and 

even with the high costs of the conversion process. While the 

economic analysis suggests significant adverse economic impacts 

could occur if all four plants closed rather than convert to 

nonmercurynon-mercury technology, we believe that it is possible 

that one potential outcome of this proposed rule is that some 

companies will convert rather than close, if the recent 

incidence of conversion to nonmercurynon-mercury technology by

the U.S. chlor-alkali industry continues. Therefore, the 

negative economic effects described above would be mitigated if 

only some of the four facilities closed.

 Obviously, when making decisions 

regarding regulatory approaches to achieve mercury reductions, 

we have looked at cost in conjunction with many other factors to 

assess the reasonableness of possible control strategies.

 

n The costs of complying with CAMR as a whole are discussed 

briefly in the preamble to the final rule [Federal Register, 

Vol. 70, No. 95, May 18, 2005, pp. 28606 -28700. Standards of 

Performance for New and Existing Stationary Sources: Electric 

Utility Steam Generating Units (40 CFR Parts 60, 72, and 75)], 

and in more detail in two items in the two air dockets for the 

CAMR rule: EPA Office of Research and Development’s White 

Papers ‘‘Control of Mercury Emissions from Coal Fired Electric 

Utility Boilers." Docket ID No. OAR–2002–0056 and Docket ID No. 

A–92–55. 
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We also believe that any near-term negative economic impacts are 

justified given the potential adverse health and environmental 

effects of mercury that will be reduced permanently into the 

future. Therefore, the negative economic effects described 

above would be mitigated if only some of the four facilities 

closed.

We also believe that any near-term negative economic 

impacts are justified given the potential adverse health and 

environmental effects of mercury that will be reduced 

permanently into the future. Therefore, we are proposing this 

amendmentnon-mercury technology option to request comments on 

whether the benefits of achieving zeroeliminating mercury 

emissions from this industry, as a beyond-the-floor control 

alternative, are warranted given the foregoing discussion.

B. What is the basis for the enhanced work practices option 

(Option 2)?

1. Summary of enhanced work practices option

On June 11, 2008 (73 FR 33257), we proposed modifications 

to the work practice standards that apply to fugitive emissions, 

primarily those fugitive emissions from cell rooms. The 

proposed modifications to these work practices included 

requiring mercury monitoring in the cell room for all 

facilities, along with daily work practices and weekly 

certification of the performance of these work practices. 
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Establishment of the “action level” for investigating and 

correcting high mercury concentration levels revealed by the 

continuous monitors would be done for a minimum of 14 days and 

up to 30 days, at least every 6 months, and the action level 

would be set at the 90th percentile of the data acquired during 

the re-setting time period(s). We also proposed to require 

mercury thermal recovery units that continue to operate at 

closed or converted plants to remain subject to the applicable 

requirements as long as they are in operation. These amendments 

are discussed in more detail in the 2008 proposal (73 FR 33271 –

33272 and 33275).

In this action, we are re-proposing these amendments as 

Option 2. We received comments on these proposed amendments in 

2008. In developing our final action for the Mercury Cell 

NESHAP, we will consider these previously submitted comments, 

along with any additional comments received on this option as a 

result of this proposed action.

2. Estimated impacts of the enhanced work practices option

a. Environmental and energy impacts

The mercury emissions reported to the TRI for 2008 for the 

four operating plants represent an 88 percent decrease from the 

pre-MACT levels. While some of this reduction is a result of 

the ability to estimate emission levels using the measured 

concentrations from the cell room continuous mercury monitoring 
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systems and calculated flow rates, they are also a result of 

impacts of the Mercury Cell NESHAP. We do not believe that 

there will initially be substantial emission reductions 

associated with the enhanced work practice option. However, we 

believe that as these plants increase their knowledge of the 

causes of fugitive mercury emissions in the cell room through 

operation of the cell room monitoring program, mercury emissions 

will continue to steadily decrease. This is illustrated by the 

fact that the three plants utilizing these systems reported a 

decrease in mercury emissions of over 20 percent between 2007 

and 2008. While this rate of decrease is not likely to occur 

every year, we believe the fugitive mercury emissions will 

continue to be reduced.

Since the enhanced monitoring option will not change the 

basic operation of the mercury cells, we do not anticipate that 

there will be any energy impacts.

b. Cost and economic impacts

The enhanced monitoring option would make the cell room 

monitoring program mandatory for all mercury cell chlor-alkali 

plants and would potentially impact all currently operating 

plants. However, the level of these impacts will vary depending 

on whether a plant previously elected to purchase and install a 

continuous mercury monitoring system in its cell room to comply 

with the cell room monitoring program alternative of the 2003 
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Mercury Cell NESHAP. For the three plants that are currently 

complying via the cell room monitoring program alternative 

option, we do not predict that there would be any cost impacts. 

For the single plant that has elected not to purchase, install, 

and operate a cell room monitoring system to comply via the cell 

room monitoring program alternative, we estimate that it would 

incur a capital cost for a monitoring system of around $120,000, 

and that the total annual cost (including annualized capital 

cost and operation and maintenance costs) would be slightly more 

than $25,000 per year. We believe that this value is a low 

percentage of the annual revenues for this facility and would 

not cause any adverse economic impacts. The cost and economic 

impacts of the enhanced monitoring option were discussed in more 

detailed in the 2008 proposal (73 FR 33276).

3. Rationale for selection of the enhanced work practices 

option

The evidence is clear that the continuous mercury 

monitoring programs are effective in identifying and correcting 

emission events. It is also evident that they are beneficial in 

identifying emission sources that may have previously been 

undetected. However, we believe that the routine work practices 

also play an important role in reducing emissions, by avoiding 

situations where elevated mercury concentrations are detected by 

the monitoring program. We believe that the cost and economic 
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impacts of requiring both the work practices and the monitoring 

program are justified, given the effectiveness this combination 

has in reducing mercury emissions. Further, we believe that 

selection of this option would lessen the potential near-term 

negative economic impacts associated with the non-mercury 

technology option, since plants would likely continue to 

operate.

C. What amendments are being proposed that are independent of 

which option is selected?

In addition to the co-proposal of the two options discussed 

above in Sections III.A and III.B, we are also proposing 

amendments that would apply regardless of whether we select the 

non-mercury technology option or the enhanced monitoring option. 

Specifically, we are proposing to amend the provisions of the 

existing NESHAP that apply to periods of SSM and to correct 

compliance errors in the rule changes related to .

1. Provisions that apply during periods of startup, shutdown, 

and malfunction?

This proposed action would amend the provisions of the 

existing NESHAP that apply to periods of SSM. The proposed 

revisions of these provisions result from a Court decision that 

vacated portions of two provisions in EPA’s CAA section 112 

regulations governing the emissions of HAP during periods of 

SSM. (Sierra Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008), cert. 
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denied, 130 S. Ct. 1735 (U.S. 2010)). Consequently, this 

proposed revised rule would require that affected sources comply 

with the emission limitations and work practices at all times, 

including during periods of SSM. For reasons discussed below, 

we are also proposing to promulgate an affirmative defense to 

civil penalties for exceedances of emission standards caused by 

malfunctions, as well as criteria for establishing the 

affirmative defense. These changes would go into effect upon 

the effective date of promulgation of the final rule.

The United States Court of Appeals for the District of 

Columbia Circuit vacated portions of two provisions in EPA’s CAA 

Section 112 General Provisions regulations governing the 

emissions of HAP during periods of startup, shutdown, and 

malfunction (SSM).. Sierra Club v. EPA, 551 F.3d 1019 (D.C. 

Cir. 2008), cert. denied, 130 S. Ct. 1735 (2010). Specifically, 

the Court vacated the SSM exemption contained in 40 CFR 

63.6(f)(1) and 40 CFR 63.6(h)(1).), that is part of a regulation 

commonly known as the “General Provisions Rule,” That EPA had 

promulgated under section 112 of the CAA. When incorporated 

into CAA Section 112(d) regulations for specific source 

categories, these two provisions exempted sources from the 

requirement to comply with the otherwise applicable CAA section 

112(d) emission standard during periods of SSM. The 2003 

Mercury Cell MACTNESHAP Subpart included a reference to 40 CFR 
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63.6(f)(1), as well as regulatory text unique to the 2003 

Mercury Cell MACTNESHAP that exempted compliance with standards 

during SSM events. It did not include a reference to 40 CFR 

63.6 (h)(1), since the rule does not have opacity and visible 

emission standards. In light of Sierra Club v. EPA, we are 

proposing to reviseeliminate the SSM exemption in the Mercury 

Cell NESHAP, by revising Table 10, which addresses the 

applicability of the Part 63 General Provisions to mercury cell 

chlor-alkali plants, to state that 40 CFR 63.6(f)(1) does not 

apply. As such, all emission standards and work practices would 

apply at all times. We are also proposing to remove other 

references in subpart IIIII and Table 10 related to SSM, 

including provisions that exempted compliance with standards 

during SSM periods. First, regarding the references We are also 

proposing to the vacated portions of remove the General 

Provisions,Provisions’ requirement that the source develop an 

SSM plan, and to remove certain recordkeeping and reporting 

requirements related to the SSM exemption, but we are retaining 

the recordkeeping and related requirements for malfunctions and 

request public comment on the requirements. EPA believes that 

deleting those references is a ministerial actionhas attempted 

to ensure that is compelled by the Court’s 2008 ruling in Sierra 

Club. Regarding the regulatory language relating to the SSM 

exemption has been removed. We solicit comment on whether we 
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have overlooked any regulatory provisions in the 2003 Mercury 

Cell MACT that independently (without merely referring to might 

be inappropriate, unnecessary, or redundant based on our 

proposal to remove the vacated portions of the General 

Provisions) exemptexemption from compliance with emission 

standards during SSM periods, EPA does not believe it is 

appropriate to propose rule revisions that leave in place 

existing provisions that are inconsistent with the decision of 

the D.C. Circuit. of SSM.

Regarding startup and shutdown modes of operation at

mercury cell plants, based on available information EPA does not 

consider emissions during these periods to be significantly 

different than emissions during normal operation, and therefore 

is not proposing separate limits that would apply during these 

periods. We do not have any information that shows emissions at 

mercury cell plants would be significantly different during 

startup or shutdown than during normal operation. Nor do we 

have information suggesting that the emissions control measures 

required by the 2003 rule would be less effective during startup 

or shutdown periods. We request public comment on whether 

emissions during startup and shutdown are instead significantly 

different compared to other normal operation, such that a 

different standard for startup and shutdown periods would be 

warranted. 
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In addition, EPA does not view malfunction as a distinct 

operating mode and, therefore, any emissions that occur at such 

times do not need to be taken into account in setting CAA 

section 112(d) standards. Malfunctions are distinguishable from 

Periods of startup, shutdown and normal operations, whichand 

shutdown are all predictable and routine aspects of a source’s 

operations. ByIn contrast, malfunction is defined as a “sudden, 

infrequent, and not reasonably preventable failure of air 

pollution control and monitoring equipment, process equipment, 

or a process to operate in a normal or useful manner [. . .]” 

(40 CFR 63.2). We* * * ” (40 CFR 63.2). EPA believes that a 

malfunction should not be viewed as a distinct operating mode 

and, therefore, any emissions that occur during malfunctions do 

not need to be factored into development of CAA section 112(d) 

standards, which, once promulgated, apply at all times. In 

Mossville Environmental Action Now v. EPA, 370 F.3d 1232, 1242 

(D.C. Cir. 2004), the court upheld as reasonable standards that 

had factored in variability of emissions under all operating 

conditions. However, nothing in section 112(d) or in caselaw 

requires that EPA anticipate and account for the innumerable 

types of potential malfunction events in setting emission 

standards. See, Weyerhaeuser v Costle, 590 F.2d 1011, 1058 (D.C. 

Cir. 1978)(“ In the nature of things, no general limit, 

individual permit, or even any upset provision can anticipate 
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all upset situations. After a certain point, the transgression 

of regulatory limits caused by "uncontrollable acts of third 

parties," such as strikes, sabotage, operator intoxication or 

insanity, and a variety of other eventualities, must be a matter

for the administrative exercise of case-by-case enforcement 

discretion, not for specification in advance by regulation.”) 

Further, it is reasonable to interpret CAA section 112(d) as not 

requiring EPA to account for malfunctions in setting emission 

standards. For example, we note that CAA section 112 uses the 

concept of “best performing” sources to define MACT, the level 

of stringency that major source standards must meet. It is 

reasonable to interpret section 112(d) as not requiring EPA to 

account for malfunctions in setting emission standards. 

Applying the concept of “best performing” to a source that is 

malfunctioning presents significant difficulties. The goal of 

best performing sources is to operate in such as way as to avoid 

malfunctions of their units. Consequently, MACT should not be 

based on periods in which there is a failure to operate. 

Moreover, even if malfunctions were considered a distinct 

operating mode, we believe it would be impracticable to take 

into account malfunctions in setting CAA section 112(d) 

standards. As noted above, by definition malfunctions are 

sudden and unexpected events, and it would be difficult to set a 

standard that takes into account the myriad different types of 
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malfunctions that can occur across all sources. in each source 

category. Moreover, malfunctions can vary in frequency, degree, 

and duration, further complicating standard setting. 

This approach will encourage shutdowns as soon as 

practicable when a malfunction that affects emissions occurs. 

InUnder this proposal, in the event that a source fails to 

comply with the applicable CAA section 112(d) standards as a 

result of a malfunction event, EPA would determine an 

appropriate response based on, among other things, the good 

faith efforts of the source to minimize emissions during 

malfunction periods, including preventative and corrective 

actions, as well as root cause analyses to ascertain and rectify 

excess emissions. EPA would also consider whether the source’s 

failure to comply with the CAA section 112(d) standard was, in 

fact, “sudden, infrequent, not reasonably preventable” and was 

not instead “caused in part by poor maintenance or careless 

operation.” 40 CFR 63.2 (definition of malfunction). 

C. What is the basis for the proposed rule corrections?

1Finally, EPA recognizes that even equipment that is 

properly designed and maintained can sometimes fail and that 

such failure can sometimes cause or contribute to an exceedance 

of the relevant emission standard. (See, e.g., State 

Implementation Plans: Policy Regarding Excessive Emissions 

During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); 
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Policy on Excess Emissions During Startup, Shutdown, 

Maintenance, and Malfunctions (Feb. 15, 1983)). Therefore, 

consistent with our recently promulgated final amendments to 

regulations addressing the Portland Cement category (75 FR 

54970, Sept. 9, 2010), we are proposing to add regulatory 

language providing an affirmative defense against civil 

penalties for exceedances of emission limits that are caused by 

malfunctions. See proposed amendment to 40 C.F.R. 63.8266

(defining “affirmative defense” to mean, in the context of an 

enforcement proceeding, a response or defense put forward by a 

defendant, regarding which the defendant has the burden of 

proof, and the merits of which are independently and objectively 

evaluated in a judicial or administrative proceeding). We are 

also proposing regulatory provisions to specify the elements 

that are necessary to establish this affirmative defense; the 

source would have to prove by a preponderance of the evidence 

that it has met all of the elements set forth in sections. (See 

proposed amendment to 40 C.F.R. 63.8226(b); see also 40 C.F.R. 

22.24). The proposed criteria would ensure that the affirmative 

defense is available only where the event that causes an 

exceedance of the emission limit meets the narrow definition of 

malfunction in 40 C.F.R. 63.2 (sudden, infrequent, not 

reasonable preventable and not caused by poor maintenance and/or 

careless operation). The proposed criteria also are designed to 
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ensure that steps are taken to correct the malfunction, to 

minimize emissions, and to prevent future malfunctions. In any 

judicial or administrative proceeding, the Administrator would 

be able to challenge the assertion of the affirmative defense 

and, if the respondent has not met its burden of proving all of 

the requirements in the affirmative defense, appropriate 

penalties could be assessed in accordance with Section 113 of 

the Clean Air Act (see also 40 CFR Part 22.77). 

2. Compliance provisions rule corrections

We are proposing amendments to correct errors and improve 

the compliance provisions of the rule. These changes, which are 

described below, were included in the June 2008 proposal (73 FR 

33275).

a. Detection limit for mercury monitor analyzers. 

Paragraph (a)(2) of §63.8242, “What are the installation, 

operation, and maintenance requirements for my continuous 

monitoring systems?” requires that mercury continuous monitor 

analyzers have a detector with the capability to detect a 

mercury concentration at or below 0.5 times the mercury 

concentration level measured during the performance test. Since 

promulgation of the 2003 Mercury Cell MACTNESHAP, we determined 

that setting the analyzer detection capability in reference to 

the concentration level during the performance test could be 

problematic. We realized that a concentration of 0.5 times the 
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mercury concentration could, in cases of low mercury 

concentrations, be infeasible for the monitoring devices on the 

market. Information available to us at this time shows that 0.1 

micrograms per cubic meter (μg/m3) is the detection limit of 

commonly commercially available analyzers. We believe that 

analyzers with detection limits at this level are more than 

sufficient to determine compliance with the limitations in the 

2003 Mercury Cell MACTNESHAP. Therefore, we are proposing to 

revise this paragraph to require a detector with the capability

to detect a mercury concentration at or below 0.5 times the 

mercury concentration measured during the test or 0.1 μg/m3.

2b. Averaging period for mercury recovery unit compliance. 

The 2003 Mercury Cell MACTNESHAP is inconsistent as to 

whether the rule requires a daily average or an hourly average 

to determine continuous compliance with the emissions standard 

for mercury recovery units found at §63.8190(a)(3)of §63.8190 

“What emission limitations must I meet?” Paragraph (b) of 

§63.8243 “What equations and procedures must I use to 

demonstrate continuous compliance?” clearly indicates that this 

averaging period is daily: “you must calculate the daily

average mercury concentration using Equation 2 . . .” However, 

paragraph (b) of §63.8246 “How do I demonstrate continuous 

compliance with the emission limitations and work practice 

standards?” states that for each mercury thermal recovery unit 
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vent, “you must demonstrate continuous compliance with the 

applicable emission limit specified in §63.8190(a)(3) by 

maintaining the outlet mercury hourly-average concentration no 

higher than the applicable limit.”

It was our intention for compliance to be based on a daily

average, as detailed below, and the inclusion of “hourly” in 

paragraph (b) of §63.8246 “How do I demonstrate continuous 

compliance with the emission limitations and work practice 

standards?” was a drafting error. Therefore, we are proposing 

to correct this error by replacing “hourly” in §63.8246(b) with 

“daily.” In the proposal Federal Register notice for the 2003 

Mercury cell MACTCell NESHAP (67 FR 44678, July 3, 2002), we 

clearly stated our intention when we summarized the requirements 

as follows:

“To continuously comply with the emission limit for 

each by-product hydrogen stream, end-box ventilation system 

vent, and mercury thermal recovery unit, we are proposing 

that each owner and operator would continuously monitor 

outlet elemental mercury concentration and compare the 

daily average results with a mercury concentration 

operating limit for the vent . . . .”

“Continuous compliance would be demonstrated by 

collecting outlet elemental mercury concentration data 

using continuous mercury vapor monitor, calculating daily 

averages, and documenting that the calculated daily average 

values are no higher than established operating limits. 

Each daily average vent elemental mercury concentration 

greater than the established operating limit would be 

considered a deviation. 

IV. Request for Comment
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We request comment on all aspects of the proposed action. 

All significant comments received during the comment period will 

be considered.

Five comments were received on the amendments proposed in June 

2008. These commenters represent one environmental 

organization, one industry trade organization, and two companies 

that own and operate mercury cell chlor-alkali plants. The 

fifth comment was anonymously submitted in support of 

environmental organizations.D. What is our rationale for doing 

a supplemental proposal?

The prohibition of mercury emission requirement that we are 

proposing today is a result of comments received on the 

amendments proposed on June 11, 2008. We will examine and 

analyze all comments received on today’s proposal and then we 

will take final action that may either: (1) promulgate today’s 

proposed prohibition of mercury emissions, (2) promulgate the

amendments proposed on June 11, 2008, or (3) respond to comments 

we receive and promulgate other amendments that are supported by 

the data. However, the compliance errors that we proposed to 

correct in our 2008 amendments likely will be promulgated in 

either pathway since the facilities will need to comply with the 

Mercury Chlor-alkali MACT for at least a few more years even if 

we promulgate a beyond-floor zero mercury standard. The 

amendments to SSM provisions will also likely be promulgated 
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under either pathway. We also will likely require mercury 

thermal recovery units that continue to operate at closed or 

converted plants to remain subject to the applicable 

requirements of the Mercury Cell MACT as long as they are in 

operation.

V. Impacts of Proposed Amendments

A. What are the cost and economic impacts of this proposal?

1. Cost Impacts

The estimated costs for the proposed rule, assuming that 

all four currently operating mercury cell chlor-alkali plants 

convert to membrane cell technology, include total U.S. capital 

costs of approximately $300 million dollars, with individual 

plant capital costs ranging from a low of $28 million to a high 

of approximately $160 million. The total U.S. annual costs are 

estimated to be around $13 million per year, ranging from a low 

of $800,000 per plant per year to almost $7 million per plant. 

Based on these costs and the reported mercury emissions for 2008 

for each facility,o

 

o For the purpose of this analysis, we assumed that the mercury emissions 

from the ASHTA facility were 100 pounds per year.

the cost-effectiveness, in terms of 

annualized costs per pound of mercury eliminated, is estimated 

to be approximately $20,000 per pound, which is less than the 

$39,000 per pound level we found reasonable in the Clean Air 

Mercury Rule. A memorandum that documents the details of this 

cost analysis can be found in the docket. We are specifically 
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requesting comment on our analysis, along with facility-specific 

data, to allow a refinement of the analysis for this proposed 

rule.

2. Economic Impacts

An economic impact analysis (EIA) and small business 

screening analysis was performed for this proposed rule that 

would amend the NESHAP to prohibit emissions of mercury from the 

mercury cell chlor-alkali process. A report that documents the 

EIA methods and results can be found in the docket (EPA-HQ-OAR2002-0017). 

Although individual plant information would be the best 

method to assess the true economic impacts of the rule, detailed 

information for this industry was not publicly available. As a 

result, we relied on parent company information provided in 

company annual reports (e.g., form 10-K), local press and 

industry trade publications, and company Web sites. 

There are many aspects of the cost estimate for conversion 

that are unknown or difficult to assess. While we believe that 

we have evaluated the conversion cost information available to 

us at the time of this action, the true costs may vary 

considerably. However, variation in engineering costs is not 

expected to cause a significant difference in the general 

conclusions of the EIA.
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We performed an analysis that compared the annual 

conversion costs to sales. We estimated that the CSR of ASHTA, 

the one small business in this industry, would range from one to 

two percent using the costs presented in this proposal. The 

other three plants are owned by large parent companies with 

significant company-wide sales. As a result, the CSRs for these 

large parent companies are below one percent. When single plant 

sales were considered, the CSRs for the mercury cell chloralkali plants owned by large parent companies ranged from 4 to 

9 percent. 

We also analyzed industry profitability effects by 

comparing the annual conversion costs to reported industry 

margins for a representative electrochemical unit (ECU). This 

analysis confirms the results of the sales comparisons that 

plant conversion costs will likely have an economically 

significant effect. Conversion costs could reduce the margins 

by 10 to 20 percent.

This proposed rule would force owners of mercury chloralkali plants to make an investment decision based on the costs 

of conversion as opposed to the future benefits of the 

conversion. This proposed rule could lead to plant shutdowns 

that would involve adjustment costs for people working at the 

affected plants. Affected plants may also have strong links 
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with other firms or downstream markets; as a result, secondary 

consequences of the regulation are important to consider. 

Many owners have converted from mercury cell chlor-alkali 

technologies in Europe and the U.S., while other mercury cell 

chlor-alkali plant owners have concluded the investment decision 

was currently not in their company’s interest given their 

assessment of future economic conditions, and have shutdown 

their mercury cell chlor-alkali plants instead. Since 2003, 

three U.S. mercury cell chlor-alkali facilities have closed and 

three have converted. Specifically, the Occidental Chemical 

mercury cell chlor-alkali facilities in Delaware City, Delaware, 

Muscle Shoals, Alabama, and Deer Park, Texas, have closed; while 

the PPG facility in Lake Charles, Louisiana, the ERCO facility 

in Port Edwards, Wisconsin, and the Pioneer chlor-alkali 

facility (now owned by Olin) in St. Gabriel, Louisiana, have 

converted to membrane cells.

We do not have sufficient data to predict whether 

individual companies would choose to convert or close the 

affected mercury cell chlor-alkali plants. However, the data 

obtained in this study suggests that plant closure may be a 

preferred alternative to meet the requirements of the proposed 

rule for one or more of the mercury cell chlor-alkali plants. 

If all four plants elected to close rather than convert, 

approximately 1,000 jobs providing over $50 million in wages 
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could be directly affected. Whether plants convert or close, 

however, there is the possibility of temporary jobs created for 

the conversion or decommissioning of the plants. 

As noted above, individual plant information was not 

available to perform a refined analysis of whether these mercury 

cell plants would likely convert to nonmercury technology or 

close. We are specifically requesting comment on our analysis, 

along with facility-specific data, to allow a refinement of the 

analysis for this proposed rule.

B. What are the environmental and energy impacts of this 

proposal?

 We reviewed and considered these comments. As discussed 

above in section II.C.3 of this preamble, the consideration of 

one of the issues raised in the comments has caused us to 

publish this supplemental proposal today proposing the nonmercury technology option. In developing our final action, we 

will consider all previously-submitted relevant comments in 

addition to any comments submitted in response to today’s 

proposal.

Comments are requested on several aspects of this proposed 

action. First, we are soliciting comments on which of the two 

options (Option 1: Non-Mercury Technology or Option 2: Enhanced 

Work Practices) is most appropriate. In providing comments on 

the selection of one of these options, please provide detailed 
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rationale and additional technical information that supports 

your recommendation.

Second, we are requesting comments on the specific 

amendments being proposed under both options. After making a 

decision on which option we will select for promulgation, we 

will consider and address all significant comments received on 

the amendments related to that option. We received comments on 

the enhanced work practices option following the proposal in 

June 2008. If that is option selected, we will consider and 

address those comments along with any new comments received.

Third, we are specifically requesting comments on the 

potential for the elimination of mercury emissions without 

converting to membrane cells or plant closure. We are also 

requesting comment on any measures beyond those included in the 

enhanced monitoring option that might be employed at mercury 

cell facilities which could achieve even greater reductions such 

that mercury emissions are at “near zero” levels without 

conversion to a non-mercury process or closure.

As noted earlier, we believe that it is improbable that a 

mercury cell chlor-alkali plant can be operated without mercury 

emissions. Therefore, we have assumed that requiring the 

elimination of mercury emissions would effectively require 

existing mercury cell chlor-alkali plants either to convert to a 

non-mercury technology or to cease production of chlorine with 
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their current mercury cell production methods. However, if 

there are circumstances where the elimination of mercury 

emissions from an operating mercury cell plant could be 

achieved, we are specifically interested in data and supporting 

information regarding technologies that would eliminate mercury 

emissions from an operating mercury cell facility. 

We are also interested in the possibility of other emission 

reduction technologies, process modifications, or practices not 

included in the enhanced work practices option that could reduce 

mercury emissions to “near-zero” levels. We are aware of the 

significant efforts that have been made by the four currently 

operating mercury cell facilities to reduce mercury emissions. 

As some of these efforts have been developed more fully in 

recent years, we have seen significant and consistent reductions 

in emissions to the current levels. We believe that the further 

refinement of these methods would continue to steadily decrease 

mercury emissions. We are requesting comment on a realistic 

lower bound level that could be achieved.

In addition, a near-zero emission standard alternative 

would need to include appropriate testing and monitoring 

provisions. Therefore, in addition to information regarding a 

realistic lower-bound emissions level, we are also requesting 

comment on methods to overcome the difficulty of accurately 

measuring cell room fugitive emissions.
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Fourth, we are requesting comments on the proposed 

amendments related to provisions that apply during periods of 

SSM and the compliance provisions rule corrections. These 

amendments would apply regardless of which option we select. 

The compliance provisions rule corrections were also proposed in 

June 2008, and any comments received on the prior proposal 

related to these amendments will also be considered and 

addressed.

Finally, comments were provided in 2008 on all the 

reconsideration decisions discussed in our June 2008 proposal 

(and summarized in section II.C of this preamble). We will 

accept additional comments on these decisions and consider them, 

along with the previous comments, in making our final decisions.

VII We estimate that the total mercury emissions from the four 

mercury cell operating facilities to be around 640 pounds per 

year. This proposed rule would reduce mercury emissions by this 

amount. These four facilities reported almost 2,000 additional 

pounds of on-site and off-site mercury releases to media other 

than air per year. These releases would be eliminated in the 

longer term, with consequential benefits for non-air quality 

related health and environmental values. The potential problems 

associated with the handling and continuous management of over 

1,200 tons of virgin mercury that is used in the cells at these 

four chlor-alkali plants would also be eliminated. In addition, 
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approximately two tons of this mercury was reported by the 

industry as “unaccounted” in 2008. This proposed rule would 

eliminate the unaccounted mercury as well. 

The membrane cell chlor-alkali process requires less energy 

than the mercury cell process. Therefore, assuming that all 

four existing mercury cell chlor-alkali plants convert to 

membrane cells, there would be a savings in energy. We estimate 

that this savings would be around 350,000 megawatt hours per 

year, which is approximately equivalent to the energy produced 

annually by a 40 megawatt power plant. 

In the short term, the conversion of these facilities would 

result in the need to dispose of mercury-contaminated wastes. 

While there is considerable uncertainty in quantifying the 

amount of these wastes, we estimate that there could be around 

7,000 cubic meters of mercury contaminated waste generated that 

could contain around six tons of mercury. 

As stated above, over 1,200 tons of virgin or process 

mercury from the facilities would need to be dealt with whether 

the facilities close or convert to nonmercury technology. The 

Mercury Export Ban Act of 2008, discussed earlier, would 

prohibit this mercury from being exported. Therefore, this 

mercury would need to be stored or sold domestically. Since 

mercury is a hazardous substance, it cannot be stored without a 

permit; hence, DOE is planning to build a federal facility to 
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accommodate the excess mercury that results from the export ban. 

We are specifically requesting comment on our analysis, along 

with any facility-specific data, to allow a refinement of the 

analysis for this proposed rule.

VI. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory Planning and Review

This action is a “significant regulatory action” under 

the termsUnder section 3(f)(1) of Executive Order 12866 (58 FR 

7173551735, October 34, 1993) ), this action is an “economically 

significant regulatory action” because it may raise novel 

legal(Option 1) is likely to have an annual effect on the 

economy of $100 million or policy issuesmore. Accordingly, EPA

submitted this action to the Office of Management and Budget 

(OMB) for review under EO 12866 and any changes made in response 

to OMB recommendations have been documented in the docket for 

this action. In addition, EPA prepared a RIA of the potential 

costs and benefits associated with this action. 

In addition, EPA prepared an analysis of When estimating the potential costs and 

PM2.5-related human health benefits associated with and compliance 

costs in Table 2 of this action. A copy of the preamble, EPA applied 

methods and assumptions consistent with the state-of-the-science 

for human health impact assessment, economics and air quality 

analysis. EPA applied its best professional judgment in 

performing this analysis is and believes that these estimates 
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provide a reasonable indication of the expected benefits and 

costs to the nation of this rulemaking. The RIA available in 

the docket for this action and the describes in detail the empirical basis 

for EPA's assumptions and characterizes the various sources of 

uncertainties affecting the estimates below. 

When characterizing uncertainty in the PM-mortality 

relationship, EPA has historically presented a sensitivity 

analysis is briefly summarizedapplying alternate assumed 

thresholds in the PM concentration-response relationship. In 

its synthesis of the current state of the PM science, EPA’s 2009 

Integrated Science Assessment for Particulate Matter concluded 

that a no-threshold log-linear model most adequately portrays 

the PM-mortality concentration-response relationship. In the 

RIA accompanying this rulemaking, rather than segmenting out 

impacts predicted to be associated levels above in section 

V.Aand below a ‘bright line’ threshold, EPA includes a LML that 

illustrates the increasing uncertainty that characterizes 

exposure attributed to levels of PM2.5 below the LML for each 

study. Figures provided in the RIA show the distribution of 

baseline exposure to PM2.5, as well as the lowest air quality 

levels measured in each of the epidemiology cohort studies. 

This information provides a context for considering the likely 

portion of PM-related mortality benefits occurring above or 

below the LML of each study; in general, our confidence in the 
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size of the estimated reduction PM2.5-related premature mortality 

diminishes as baseline concentrations of PM2.5 are lowered. Using 

the Pope et al. (2002) study, the 85 percent of the population 

is exposed at or above the LML of 7.5 μg/m3. Using the Laden et 

al. (2006) study, 40 percent of the population is exposed above 

the LML of 10 μg/m3. While the LML analysis provides some 

insight into the level of uncertainty in the estimated PM 

mortality benefits, EPA does not view the LML as a threshold and 

continues to quantify PM-related mortality impacts using a full 

range of modeled air quality concentrations. 

The cost analysis is also subject to uncertainties. 

Estimating the cost conversion from one process to another is 

more difficult than estimating the cost of adding control 

equipment because it is more dependent on plant specific 

information. The estimation of cost savings from environmental 

compliance cost savings elimination of the mercury process is 

also uncertain. The numbers were based on the savings reported 

by one US facility and some studies from outside the US. The 

savings might be greater or smaller than estimated. Likewise, 

since the electricity savings are dependent on many of the same 

factors, they are also uncertain and may be greater or smaller 

than estimated.
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A summary of the monetized benefits, social costs, and net 

benefits for the two options at discount rates of 3 percent and 

7 percent is in Table 2 of this preamble. 

Table 2. Summary of the Monetized Benefits, Social Costs, and 

Net Benefits for the Proposed Mercury Chlor Alkali NESHAP in 

2013 (thousands of 2007$)1

3% Discount Rate 7% Discount Rate

Option 1: Non-mercury Technology Option

Total Monetized Benefitsb $22,00

0

to $43,000 $21,00

0

to $40,000

Total Social Costsc $13,000 $13,000

Net Benefits $9,000 to $30,000 $8,000 to $27,000

Non-monetized Benefits 656 pounds of mercury (including energy cobenefits)

Health effects from NO2 and SO2 exposure

Ecosystem effects 

Visibility impairment 

Option 2: Enhanced Work Practice Standards

Total Monetized Benefitsb $0 $0

Total Social Costsc $25 $25

Net Benefits $-25 $-25

1

All estimates are for the implementation year (2013), and are 

rounded to two significant figures. 
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2 The total monetized benefits reflect the human health benefits 

associated with reducing exposure to PM2.5. It is important to 

note that the monetized benefits include many but not all health 

effects associated with PM2.5 exposure. Benefits are shown as a 

range from Pope et al. (2002) to Laden et al. (2006). These 

models assume that all fine particles, regardless of their 

chemical composition, are equally potent in causing premature 

mortality because there is no clear scientific evidence that 

would support the development of differential effects estimates 

by particle type. The monetized benefits include CO2-related 

benefits calculated using the social cost of carbon, which is 

discussed further in the RIA. The net present value of reduced 

CO2 emissions is calculated differently than other benefits. The 

same discount rate used to discount the value of damages from 

future emissions (SCC at 5, 3, 2.5 percent) is used to calculate 

net present value of SCC for internal consistency. This table 

shows monetized CO2 co-benefits at discount rates of 3 and 7 

percent that were calculated using the global average SCC 

estimate at a 3% discount rate because the interagency workgroup 

on this topic deemed this marginal value to be the central 

value. In the RIA, we also provide the monetized CO2 co-benefits 

using discount rates of 5 percent (average), 2.5 percent 

(average), and 3 percent (95th percentile).

3 The annual compliance costs serve as a proxy for the annual 

social costs of this rulemaking.

For more information on the benefits analysis, please refer 

to the RIA for this rulemaking, which is available in the 

docket.

B. Paperwork Reduction Act

The information collection requirements in this proposed 

rule, have been submitted for approval to OMB under the 

Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The information 

collection request (ICR) document prepared by EPA has been 

assigned an EPA ICR number 2046.06.

The OMB has previously approved the information collection 

requirements in the existing regulation (40 CFR 63, subpart 
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IIIII) under the provisions of the Paperwork Reduction Act, 44 

U.S.C. 3501 et seq. and has assigned OMB control number 2060-

0542. The OMB control numbers for EPA’s regulations in 40 CFR 

are listed in 40 CFR part 9.

TheseThe proposed amendments under Option 1 would result in 

changes to the information collection requirements in the 

regulation. This information is being collected to assure that 

mercury emissions have been eliminated. The required 

notifications, reports, and records are essential in determining 

compliance, and are required of all affected facilities. The 

recordkeeping and reporting requirements in this proposed rule 

are based on the requirements in EPA’s NESHAP General Provisions 

(40 CFR part 63, subpart A). The recordkeeping and reporting 

requirements in the General Provisions are mandatory pursuant to 

section 114 of the CAA (42 U.S.C 7414). All information other 

than emissions data submitted to EPA pursuant to the information 

collection requirements for which a claim of confidentiality is 

made is safeguarded according to CAA section 114(c) and the 

Agency’s implementing regulations at 40 CFR part 2, subpart B.

The only information collection associated with the 

proposed amendments under Option 1 is a one-time certification 

that must be submitted 60 days after the compliance date. It is 

estimated that the burden for this information collection is 3 

labor hours per response per facility, for a total of 12 labor 
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hours for all four facilities. This burden will occur during 

the first year after promulgation, but the annual burden for 

this information collection averaged over the three3 years 

following the compliance date of these amendments is estimated 

to be a total of 4 labor hours per year. Burden is defined at 

5 CFR 1320.3(b).

These proposed amendments under Option 2 would result in 

changes to the information collection requirements in the 

regulation. This information is being collected to assure 

compliance with the regulation. The required notifications, 

reports, and records are essential in determining compliance, 

and are required of all affected facilities. The recordkeeping 

and reporting requirements in proposed option 2 are based on the 

requirements in EPA’s NESHAP General Provisions (40 CFR part 63, 

subpart A). The recordkeeping and reporting requirements in the 

General Provisions are mandatory pursuant to section 114 of the 

CAA (42 U.S.C 7414). All information other than emissions data 

submitted to EPA pursuant to the information collection 

requirements for which a claim of confidentiality is made is 

safeguarded according to CAA section 114(c) and the Agency’s 

implementing regulations at 40 CFR part 2, subpart B.

The annual burden for this information collection averaged 

over the three years following promulgation of these amendments 

is estimated to be a total of 3,800 labor hours per year. The 
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average annual reporting burden is 16 hours per response, with 

approximately 3 responses per facility for 5 respondents. The 

only capital/startup costs are associated with the installation 

of a cell room monitoring system at one facility, since we know 

that these systems are already in place at the other four 

facilities. The total capital/startup cost annualized over its 

expected useful life is $13,000. The total operation and 

maintenance is $60,000 per year. There are no estimated costs 

associated with purchase of services. Burden is defined at 

5 CFR 1320.3(b).

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.

To comment on the Agency’s need for this information, the 

accuracy of the provided burden estimates, and any suggested 

methods for minimizing respondent burden, EPA has established a 

public docket for this action, which includes this ICR, under 

Docket ID number EPA-HQ-OAR-2002-0017. Submit any comments 

related to the ICR for this proposed rulesrule to EPA and OMB. 

See “Addresses” section at the beginning of this notice for 

where to submit comments to EPA. Send comments to OMB at the 

Office of Information and Regulatory Affairs, Office of 
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Management and Budget, 725 17th Street NW, Washington, DC 20503, 

Attention: Desk Office for EPA. Since OMB is required to make 

a decision concerning the ICR between 30 and 60 days after 

[INSERT DATE OF PUBLICATION OF THIS PROPOSAL IN THE FEDERAL 

REGISTER], a comment to OMB is best assured of having its full 

effect if OMB receives it by [INSERT DATE 30 DAYS AFTER 

PUBLICATION OF THIS PROPOSAL IN THE FEDERAL REGISTER]. The 

final rule will respond to any OMB or public comments on the 

information collection requirements contained in these proposed 

amendments.

C. Regulatory Flexibility Act

The Regulatory Flexibility Act 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 would not have a significant 

economic impact on a substantial number of small entities. 

Small entities include small businesses, small not-for-profit 

enterprises, and small governmental jurisdictions. 

For the purposes of assessing the impacts of this proposed 

rule on small entities, small entity is defined as: (1) a small 

business that meets the Small Business Administration size 

standards for small businesses, as defined by the Small Business 

Administration's (SBA) regulations at 13 CFR 121.201; (2) a 
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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 this proposed 

rule on small entities, I certify that this action will not have 

a significant economic impact on a substantial number of small 

entities. This proposed rule is estimated to impact a total of 

four sources, with one of the four facilities estimated to be a 

small entity. We have estimated that small entity compliance 

costs, as assessed by the facilities’ CSR, are expected to be 

just over 1 percent of revenues. New sources are already 

prohibited from using the mercury technology in the chlor-alkali 

production process by virtue of the 2003 Mercury Cell 

MACT’sNESHAP’s provisions; consequently, we did not estimate any 

impacts for new sources since this rulemaking would not impose 

any new requirements on them. 

This proposed rule will not have a significant economic 

impact on a substantial number of small entities, since there is 

only one small entity in the group of four facilities and 

compliance costs for this small entity are expected to be just 

over 1 percent of revenues. However, we continue to be 

interested in the potential impacts of this proposed action on 
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small entities and welcome comments on issues related to such

impacts.

D. Unfunded Mandates Reform Act

This action contains no Federal mandates under the 

regulatory provisions of Title II of the Unfunded Mandates 

Reform Act of 1995 (UMRA), 2 U.S.C. 1531-1538 for State, local, 

or tribal governments or the private sector. The action imposes 

no enforceable duty on any State, local or tribal governments or 

the private sector. (Note: The term “enforceable duty” does not 

include duties and conditions in voluntary federal contracts for 

goods and services.) Therefore, this action is not subject to 

the requirements of sections 202 and 205 of the UMRA. This 

action also is not subject to the requirements of section 203 of 

UMRA because it contains no regulatory requirements that might 

significantly or uniquely affect small governments. 

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 
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distribution of power and responsibilities among the various 

levels of government.” 

This action 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. This proposed rule does not impose any requirements on 

State and local governments. Thus, Executive Order 13132 does 

not apply to this action. 

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

This action does not have tribal implications, as specified 

in Executive Order 13175 (65 FR 67249, November 9, 2000). This 

proposed rule imposes no requirements on tribal governments. 

Thus, Executive Order 13175 does not apply to this 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
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EPA interprets Executive Order 13045 (62 F.R. 19885, 

April 23, 1997) as applying to those regulatory actions that 

concern health or safety risks, such that the analysis required 

under section 5-501 of the Order has the potential to influence 

the regulation. This action is not subject to Executive Order 

13045 because it is based solely on technology performance. 

However, given the potential health effects of mercury on 

children, the elimination in mercury emissions from these four 

facilities could result in additional protection of children 

from environmental health risks.

H. Executive Order 13211: Actions Concerning Regulations That 

Significantly Affect Energy Supply, Distribution, or Use

This action is not a “significant energy action” as 

defined in Executive Order 13211, “Actions Concerning 

Regulations That Significantly Affect Energy Supply, 

Distribution, or Use” (66 FR 28355, May 22, 2001) because it is 

not likely to have a significant adverse effect on the supply, 

distribution, or use of energy. We have concluded that this 

action is not likely to have any adverse energy effects because 

no additional requirements are contained in this proposed rule 

that consume energy. In fact, as discussed previously in this 

preamble, this action would result in decreased energy usage.

I. National Technology Transfer and Advancement Act
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Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 (“NTTAA”), Public Law No. 104-113 (15 

U.S.C. 272 note) directs EPA to use voluntary consensus 

standards in its regulatory activities unless to do so would be 

inconsistent with applicable law or otherwise impractical. 

Voluntary consensus standards are technical standards (e.g., 

materials specifications, test methods, sampling procedures, and 

business practices) that are developed or adopted by voluntary 

consensus standards bodies. NTTAA directs EPA to provide 

Congress, through OMB, explanations when the Agency decides not 

to use available and applicable voluntary consensus standards.

This proposed rulemaking does not involve technical 

standards. Therefore, EPA is not considering the use of any 

voluntary consensus standards.

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations

Executive Order 12898 (59 FR 7629, February 16, 1994) 

establishes Federal executive policy on environmental justice. 

Its main provision directs Federal agencies, to the greatest 

extent practicable and permitted by law, to make environmental 

justice part of their mission by identifying and addressing, as 

appropriate, disproportionately high and adverse human health or 

environmental effects of their programs, policies, and 
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activities on minority populations and low-income populations in 

the U.S.

EPA has determined that this proposed rule will not have 

disproportionately high and adverse human health or 

environmental effects on minority or low-income populations 

because it increases the level of environmental protection for 

all affected populations without having any disproportionately 

high and adverse human health or environmental effects on any 
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population, including any minority or low-income population. 

The nationwide standards would totally eliminate mercury 

emissions from sources affected by this proposed rule and thus 

decrease the amount of emissions to whicheliminate all affected 

adverse human health or environmental effects on all 

populations, including minority or low-income populations.

An analysis of demographic data showed that the average 

percentages of the population below the poverty level and the 

percentages of the population 17 years old and younger in 

populations in close proximity to the sources are exposedsimilar 

to the national averages. The percentage of minorities in 

populations in close proximity to the sources is lower than the 

national average.

In determining the aggregate demographic makeup of the 

communities near affected sources, EPA used census data at the 

block group level to identify demographics of the populations 

considered to be living near affected sources, such that they 

have notable exposures to current emissions from these sources. 

In this approach, EPA reviewed the distributions of different 

socio-demographic groups in the locations of the expected 

emission reductions from this proposed rule. The review 

identified those census block groups with centroids within a 

circular distance of a 0.5, 3, and 5 miles of affected sources 
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and determined the demographic and socio-economic composition 

(e.g. race, income, education, etc) of these census block 

groups. The radius of 3 miles (or approximately 5 kilometers) 

has been used in other demographic analyses focused on areas 

around potential sources.p,q,r,s There were no census block 

groups with centroids within 0.5 miles of any of the sources 

affected by this proposed rule. EPA’s demographic analysis has 

shown that these areas in aggregate have lower proportions of 

American Indians, African-Americans, Hispanics, and “Other and 

Multi-racial” populations than the national average. The 

analysis showed that these areas in aggregated had similar 

proportions of families with incomes below the poverty level as 

the national average.t

EPA defines “Environmental Justice” to include meaningful 

involvement of all people regardless of race, color, national 

origin, or income with respect to the development, 

 

 

p U.S. GAO (Government Accountability Office). Demographics of 

People Living Near Waste Facilities. Washington DC: Government 

Printing Office; 1995. q Mohai P, Saha R. “Reassessing Racial and Socio-economic 

Disparities in Environmental Justice Research”. Demography. 

2006;43(2): 383–399. r Mennis J. “Using Geographic Information Systems to Create and 

Analyze Statistical Surfaces of Populations and Risk for 

Environmental Justice Analysis”. Social Science Quarterly, 

2002;83(1):281-297. s Bullard RD, Mohai P, Wright B, Saha R, et al. Toxic Waste and 

Race at Twenty 1987-2007. United Church of Christ. March, 2007. t The results of the demographic analysis are presented in 

“Review of Environmental Justice Impacts”, August 2010, a copy 

of which is available in the docket.
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implementation, and enforcement of environmental laws, 

regulations, and polices. To promote meaningful involvement, 

EPA has developed a communication and outreach strategy to 

ensure that interested communities have access to this proposed 

rule, are aware of its content, and have an opportunity to 

comment during the comment period. During the comment period, 

EPA will publicize the rulemaking via EJ newsletters, Tribal 

newsletters, EJ listservs, and the internet, including the 

Office of Policy, Economics, and Innovation’s (OPEI) Rulemaking 

Gateway web site (http://yosemite.epa.gov/opei/RuleGate.nsf/). 

EPA will also provide general rulemaking fact sheets (e.g., why 

is this important for my community) for EJ community groups and 

conduct conference calls with interested communities. In 

addition, state and federal permitting requirements will provide 

state and local governments and members of affected communities 

the opportunity to provide comments on the permit conditions 

associated with permitting the sources affected by this 

rulemaking.
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National Emission Standards for Hazardous Air Pollutants: 

Mercury Emissions from Mercury Cell Chlor-Alkali Plants

Page 58100 of 77142

List of Subjects in 40 CFR Part 63 

Environmental protection, Air pollution control, Hazardous 

substances, Incorporation by reference, Reporting and 

recordkeeping requirements.

Dated:

Lisa P. Jackson,

Administrator.
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For the reasons set out in the preamble, title 40, chapter I of 

the Code of Federal Regulations is proposed to be amended as 

follows:

PART 63 - [Amended]

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

follows:

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

[OPTION 1 FOR SUBPART IIIII - AMENDED]

Subpart IIIII - [Amended]

2. Section 63.8184 is amended by revising paragraphs (a) 

and (c) to read as follows:

§ 63.8184 What parts of my plant does this subpart cover? 

(a) This subpart applies to two types of affected sources 

at a mercury cell chlor-alkali plant: the mercury cell chloralkali production facility, as defined in paragraph (a)(1) of 

this section and § 63.8266; and the mercury recovery facility, 

as defined in paragraph (a)(2) of this section and § 63.8266.

(1) The mercury cell chlor-alkali production facility 

affected source consists of all cell rooms and ancillary 

operations used in the manufacture of product chlorine, product 

caustic, and by-product hydrogen at a mercury cell chlor-alkali 

plant. This subpart covers mercury emissions from by-product 

hydrogen streams, end box ventilation system vents, and fugitive 
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emission sources associated with cell rooms, hydrogen systems, 

caustic systems, and storage areas for mercury-containing 

wastes.

(2) The mercury recovery facility affected source consists

of all processes and associated operations needed for mercury 

recovery of wastes generated from a mercury cell chlor-alkali 

plant. This subpart covers mercury emissions from mercury 

thermal recovery unit vents and fugitive emission sources 

associated with storage areas for mercury-containing wastes.

* * * * *

(c) A mercury recovery facility is a new affected source 

if you commence construction or reconstruction of the affected 

source after the dates specified in § 63.8186(c) and (d). An 

affected source is reconstructed if it meets the definition of a 

reconstruction in § 63.2.

3. Section 63.8186 is revised to read as follows:

§ 63.8186 When do I have to comply with this subpart?

(a) Compliance date for the emission limitations in §

63.8190(a)(2), the work practices in § 63.8192, and all the 

associated requirements for existing mercury cell chlor-alkali 

production facility and mercury recovery facility affected 

sources. If you have an existing mercury cell chlor-alkali 

production facility or mercury recovery facility affected 

source, you must comply with the applicable emission limitations 
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in § 63.8190(a)(2), work practices in § 63.8192, and all the 

associated requirements no later than December 19, 2006.

(b) Compliance date for emission limitation in 

§ 63.8190(b) and all the associated requirements for existing 

mercury cell chlor-alkali production facility and mercury 

recovery facility affected sources. If you have an existing 

mercury cell chlor-alkali production facility or mercury 

recovery facility affected source, you must comply with

§ 63.8190(b) by three years after the date that the final rule 

is published in the Federal Register. Prior to compliance with 

§ 63.8190(b), you must comply with the applicable emission 

limitations in § 63.8190(a)(2), work practices in § 63.8192, and 

all the associated requirements. After you have demonstrated 

compliance with § 63.8190(b) and have submitted the 

certification of compliance in accordance with § 63.8252(f), you 

are only subject to § 63.8246(d) of this subpart.

(c) Compliance date for the emission limitations in 

§ 63.8190(a)(3), the work practices in § 63.8192, and all the 

associated requirements for new or reconstructed mercury 

recovery facility affected sources. If you commenced 

construction or reconstruction of your mercury recovery facility 

after July 3, 2002, and before [INSERT DATE OF PUBLICATION OF 

THIS PROPOSAL IN THE FEDERAL REGISTER], you must comply with the 

applicable emission limitation in § 63.8190(a)(3), work 
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practices in § 63.8192, and all the associated requirements by 

either December 19, 2003, or upon initial startup, whichever is 

later.

(d) Compliance date for the emission limitation under

§ 63.8190(b) and all the associated requirements for new or 

reconstructed mercury recovery facility affected sources.

(1) If you commenced construction or reconstruction of 

your mercury recovery facility after July 3, 2002, and before 

[INSERT DATE OF PUBLICATION OF THIS PROPOSAL IN THE FEDERAL 

REGISTER], you must comply with the emission limitation in §

63.8190(b) and all the associated requirements by three years 

after the date that the final rule is published in the Federal 

Register. Prior to compliance with § 63.8190(b), you must 

comply with the applicable emission limitation in §

63.8190(a)(3), work practices in § 63.8192, and all the 

associated requirements. After you have demonstrated compliance 

with § 63.8190(b) and have submitted the certification of 

compliance in accordance with § 63.8252(f), you are you are only 

subject to § 63.8246(d) of this subpart.

(2) If you commenced construction or reconstruction of 

your mercury recovery facility after [INSERT DATE OF PUBLICATION 

OF THIS PROPOSAL IN THE FEDERAL REGISTER], you must comply with 

the emission limitation in § 63.8190(b) and all the associated
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requirements by the date that the final rule is published in the 

Federal Register, or upon initial startup, whichever is later.

4. Section 63.8190 is amended as follows:

a. Revising paragraph (a)(2) introductory text; 

b. Revising paragraph (a)(3) introductory text; and

c. Adding paragraph (b);

The revisions read as follows:

§ 63.8190 What emission limitations must I meet?

(a) * * * 

(2) Emission limits which apply to existing mercury cell 

chlor-alkali production facilities prior to achieving compliance 

with § 63.8190(b). During any consecutive 52-week period, you 

must not discharge to the atmosphere total mercury emissions in 

excess of the applicable limit in paragraph (a)(2)(i) or (ii) of 

this section calculated using the procedures in § 63.8243(a).

* * * * *

(3) Emission limits which apply to existing mercury 

recovery facilities and to new or reconstructed mercury recovery 

facilities that commenced construction or reconstruction after 

July 3, 2002, and before [INSERT DATE OF PUBLICATION OF THIS 

PROPOSAL IN THE FEDERAL REGISTER] prior to achieving compliance 

with paragraph (b) of this section. You must not discharge to 

the atmosphere mercury emissions in excess of the applicable 

limit in paragraph (a)(3)(i) or (ii) of this section.
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* * * * *

(b) Emission limit which applies to each mercury cell 

chlor-alkali production facility and each mercury recovery 

facility after the applicable compliance date specified in 

paragraph § 63.8186(b) or (d). Emissions of mercury are 

prohibited from each existing mercury cell chlor-alkali 

production facility and from each existing, new, or 

reconstructed mercury recovery facility. You must demonstrate 

compliance with this prohibition in accordance with the 

provisions in § 63.8236(e) and § 63.8246(d) and submit the 

certification of compliance required by § 63.8252(f).

5. Section 63.8192 is amended as follows:

a. Revising the introductory text;

b. Revising paragraph (g)(2)(i); and

c. Revising paragraph (g)(3).

The revisions read as follows:

§ 63.8192 What work practice standards must I meet?

Prior to achieving compliance with § 63.8190(b), you must 

meet the work practice requirements specified in paragraphs (a) 

through (f) of this section. As an alternative to the 

requirements specified in paragraphs (a) through (d) of this 

section, you may choose to comply with paragraph (g) of this 

section.

* * * * *
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(g) * * *

(2) * * *

(i) Beginning on the compliance date specified for your 

affected source in § 63.8186(a), measure and record the mercury 

concentration for at least 30 days using a system that meets the 

requirements of paragraph (g)(1) of this section.

* * * * *

(3) Beginning on the compliance date specified for your 

affected source in § 63.8186(a), you must continuously monitor 

the mercury concentration in the cell room. Failure to monitor 

and record the data according to § 63.8256(c)(4)(ii) for 75 

percent of the time in any 6-month period constitutes a 

deviation.

* * * * *

6. Section 63.82268230 is revised to read as follows:

§ 63.8230 By what date must I conduct performance tests or 

other initial compliance demonstrations?

(a) You must conduct a performance test no later than the 

compliance date that is specified in § 63.8186(a) for your 

affected source to demonstrate initial compliance with the 

applicable emission limit in § 63.8190(a)(2) for by-product 

hydrogen streams and end box ventilation system vents and the 

applicable emission limit in § 63.8190(a)(3) for mercury thermal 

recovery unit vents.
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(b) For the applicable work practice standards in 

§ 63.8192 you must demonstrate initial compliance within 30 

calendar days after the compliance date that is specified for 

your affected source in § 63.8186(a).

7. Section 63.8236 is amended by adding paragraph (e) to 

read as follows:

§ 63.8236 How do I demonstrate initial compliance with the 

emission limitations and work practice standards?

* * * * *

(e) For each affected source, you have demonstrated 

initial compliance with the emission limit in § 63.8190(b) if 

you have eliminated mercury emissions and you have submitted the 

compliance certification required by § 63.8252(f).

8. Section 63.8243 is amended by revising paragraphs (a) 

introductory text and (a)(3) introductory text to read as 

follows:

§ 63.8243 What equations and procedures must I use to 

demonstrate continuous compliance?

(a) By-product hydrogen streams and end box ventilation 

system vents. For each consecutive 52-week period, you must 

determine the g Hg/Mg Cl2 produced from all by-product hydrogen 

streams and all end box ventilation system vents, if applicable, 

at a mercury cell chlor-alkali production facility using the 

procedures in paragraphs (a)(1) through (3) of this section. 
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You must begin collecting data on the compliance date that is 

specified in § 63.8186(a) for your affected source and calculate 

your first 52-week average mercury emission rate at the end of 

the 52nd week after the compliance date.

* * * * * 

(3) Beginning 52 weeks after the compliance date specified 

in § 63.8186(a) for your affected source, you must calculate the 

52-week average mercury emission rate from all by-product 

hydrogen steam and all end box ventilation system vents, if 

applicable, using Equation 1 of this section as follows:

* * * * *

9. Section 63.8246 is amended by adding paragraph (d) to 

read as follows:

§ 63.8246 How do I demonstrate continuous compliance with the 

emission limitations and work practice standards?

* * * * *

(d) You must demonstrate continuous compliance with the 

emission limitations in § 63.8190(b) by operating without

mercury emissions.

10. Section 63.8252 is amended by adding paragraph (f) to 

read as follows:

§ 63.8252 What notifications must I submit and when?

* * * * *
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(f) You must submit a compliance certification no later 

than 60 days after the applicable compliance date specified in 

§ 63.8186(b) or (d). This certification must state that you 

have eliminated all mercury emissions and will not use any 

process in the future that will emit mercury. The certification 

should also include a statement as to whether you eliminated 

mercury emissions through conversion to a non-mercury process 

for chlorine production or whether chlorine is no longer 

produced at the site.

11. Section 63.8254 is amended as follows:

a. Revising paragraph (a)(1); 

b. Revising paragraph (a)(2);

The revisions read as follows:

§ 63.8254 What reports must I submit and when?

(a) * * *

(1) The first compliance report must cover the period 

beginning on December 19, 2006, and ending on June 30, 2007.

(2) The first compliance report must be postmarked or 

delivered no later than July 31, 2007.

* * * * *
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[OPTION 2 FOR SUBPART IIIII - AMENDED]

Subpart IIIII—[AMENDED]

12. Section 63.8182 is amended by revising paragraph (a) 

to read as follows:

§ 63.8182 Am I subject to this subpart?

(a) You are subject to this subpart if you own or operate 

a mercury cell chlor-alkali production facility or a mercury 

recovery facility at a mercury cell chlor-alkali plant.

* * * * *

13. Section 63.8184 is amended by revising paragraph (a) 

to read as follows:

§ 63.8184 What parts of my plant does this subpart cover? 

(a) This subpart applies to two types of affected sources 

at a mercury cell chlor-alkali plant: the mercury cell chloralkali production facility, as defined in § 63.8266, “What 

definitions apply to this subpart,” and the mercury recovery 

facility, as also defined in § 63.8266.

* * * * *

14. Section 63.8186 is amended as follows:

a. By revising paragraph (a); and

b. By adding paragraph (e).

§ 63.8186 When do I have to comply with this subpart?

(a) If you have an existing affected source, you must 

comply with the applicable provisions no later than the dates 
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specified in paragraph (a)(1) and in either paragraph (a)(2) or 

(3) of this section.

(1) You must comply with each emission limitation, work 

practice standard, and recordkeeping and reporting requirement 

in this subpart that applies to you no later than December 19, 

2006, with the exception of the requirements listed in (a)(1)(i) 

through (4) of this section.

(i) § 63.8192(h) and (i);

(ii) § 63.8236(e) and (f);

(iii) § 63.8252(f); and

(iv) § 63.8254(e).

(2) If you were complying with the cell room monitoring 

program provisions in § 63.8192(g) on [INSERT DATE OF 

PUBLICATION OF THIS PROPOSAL IN THE FEDERAL REGISTER] as an 

alternative to the work practice standards in § 63.8192(a) 

through (d), you must comply with the provisions in § 63.8192(h) 

and (i) no later than 6 months after publication of the final 

rule in the Federal Register. At the time that you are in 

compliance with § 63.8192(h) and (i), you will no longer be 

subject to the provisions of § 63.8192(g).

(3) If you were complying with the work practice standards 

in § 63.8192(a) through (d) on [INSERT DATE OF PUBLICATION OF 

THIS PROPOSAL IN THE FEDERAL REGISTER], you must comply with the 

provisions in § 63.8192(h) and (i) no later than 2 years after 
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publication of the final rule in the Federal Register. At the 

time that you are in compliance with § 63.8192(h) and (i), you 

will no longer be subject to the provisions of § 63.8192(a) 

through (d).

* * * * *

(e) If you have a mercury recovery facility at a mercury 

cell chlor-alkali plant where the mercury cell chlor-alkali 

production facility ceased production of product chlorine, 

product caustic, and by-product hydrogen prior to the 

publication of the final rule in the Federal Register, you must 

comply with each emission limitation, work practice standard,

and recordkeeping and reporting requirement in this subpart that 

applies to your mercury recovery unit by 1 year after the 

publication of the final rule in the Federal Register.

15. Section 63.8192 is amended as follows:

a. By revising § 63.8192 introductory text; and

b. By adding paragraphs (h) and (i).

§ 63.8192 What work practice standards must I meet?

Prior to the applicable compliance date specified in §

63.8186(a)(2) or (3), you must meet the work practice 

requirements specified in paragraphs (a) through (f) of this 

section. As an alternative to the requirements specified in 

paragraphs (a) through (d) of this section, you may choose to 

comply with paragraph (g) of this section. After the applicable 
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compliance date specified in § 63.8186(a)(2) or (3), you must 

meet the work practice requirements specified in paragraphs (e), 

(f), (h), and (i) of this section.

* * * * *

(h) You must meet the work practice standards in Tables 1 

through 4 to this subpart and the associated recordkeeping 

requirements in Table 12 to this subpart. You must adhere to 

the response intervals specified in Tables 1 through 4 to this 

subpart at all times. Nonadherence to the intervals in Tables 1 

through 4 to this subpart constitutes a deviation and must be 

documented and reported in the compliance report, as required by 

§ 63.8254(b), with the date and time of the deviation, cause of 

the deviation, a description of the conditions, and time actual 

compliance was achieved. As provided in § 63.6(g), you may 

request to use an alternative to the work practice standards in 

Tables 1 through 4 to this subpart.

(i) In addition to the work practice standards in 

paragraph (h) of this section, you must institute a cell room 

monitoring program to continuously monitor the mercury vapor 

concentration in the upper portion of each cell room and to take 

corrective actions as quickly as possible when elevated mercury 

vapor levels are detected. You must prepare and submit to the 

Administrator a cell room monitoring plan containing the 
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elements listed in Table 11 to this subpart and meet the 

requirements in paragraphs (i)(1) through (4) of this section.

(1) You must utilize a mercury monitoring system that meets 

the requirements of Table 8 to this subpart.

(2) You must establish action levels according to the 

requirements in paragraphs (i)(2)(i) through (iii) of this 

section. You must establish an initial action level after the 

compliance date specified in § 63.8186(a)(2) or (3), and you 

must re-establish an action level at least once every six months 

thereafter.

(i) You must measure and record the mercury concentration 

for at least 14 days and no more than 30 days using a system 

that meets the requirements of paragraph (i)(1) of this section. 

For the initial action level, this monitoring must begin on the 

applicable compliance date specified for your affected source in 

§ 63.8186(a)(2) or (3).

(ii) Using the monitoring data collected according to 

paragraph (i)(2)(i) of this section, you must establish your 

action level at the 90th percentile of the data set.

(iii) You must submit your initial action level according 

to § 63.8252(f) and subsequent action levels according to §

63.8252(g).

(3) Beginning on the compliance date specified for your 

affected source in § 63.8186(a)(2) or (3), you must continuously 
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monitor the mercury concentration in the cell room. Failure to 

monitor and record the data according to § 63.8256(e)(4)(iii) 

for 75 percent of the time in any 6-month period constitutes a 

deviation.

(4) If the average mercury concentration for any 1-hour 

period exceeds the currently applicable action level established 

according to paragraph (i)(2) of this section, you must meet the 

requirements in either paragraph (i)(4)(i) or (ii) of this 

section.

(i) If you determine that the cause of the elevated mercury 

concentration is an open electrolyzer, decomposer, or other 

maintenance activity, you must record the information specified 

in paragraphs (i)(4)(i)(A) through (C) of this section.

(A) A description of the maintenance activity resulting in 

elevated mercury concentration;

(B) The time the maintenance activity was initiated and 

completed; and

(C) A detailed explanation how all the applicable 

requirements of Table 1 to this subpart were met during the 

maintenance activity.

(ii) If you determine that the cause of the elevated 

mercury concentration is not an open electrolyzer, decomposer, 

or other maintenance activity, you must follow the procedures 

specified in paragraphs (i)(4)(ii)(A) and (B) of this section 
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until the mercury concentration falls below the action level. 

You must also keep all the associated records for these 

procedures as specified in Table 12 to this subpart. 

Nonadherence to the intervals in paragraphs (i)(4)(ii)(A) and 

(B) of this section constitutes a deviation and must be 

documented and reported in the compliance report, as required by 

§ 63.8254(b).

(A) Within 1 hour of the time the action level was 

exceeded, you must conduct each inspection specified in Table 2 

to this subpart, with the exception of the cell room floor and 

the pillars and beam inspections. You must correct any problem 

identified during these inspections in accordance with the 

requirements in Table 2 and 3 to this subpart.

(B) If the Table 2 inspections and subsequent corrective 

actions do not reduce the mercury concentration below the action 

level, you must inspect all decomposers, hydrogen system piping 

up to the hydrogen header, and other potential locations of 

mercury vapor leaks using a technique specified in Table 6 to 

this subpart. If a mercury vapor leak is identified, you must 

take the appropriate action specified in Table 3 to this 

subpart.

16. Section 63.8230 is amended by revising paragraphs (b) 

and (c) to read as follows:
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§ 63.8230 By what date must I conduct performance tests or 

other initial compliance demonstrations?

* * * * *

(b) For the applicable work practice standards in §

63.8192(a) through (g), you must demonstrate initial compliance 

within 30 calendar days after the compliance date that is 

specified for your affected source in § 63.8186(a)(1).

(c) For the applicable work practice standards in §

63.8192(e), (f), (h), and (i), you must demonstrate initial 

compliance within 60 calendar days after the applicable 

compliance date that is specified for your affected source in §

63.8186(a)(2) or (3).

17. Section 63.8236 is amended by revising paragraph (c) 

introductory text and by adding paragraphs (e) and (f) to read 

as follows:

§ 63.8236 How do I demonstrate initial compliance with the 

emission limitations and work practice standards?

* * * * * 

(c) For each affected source, you have demonstrated 

initial compliance with the applicable work practice standards 

in § 63.8192(a) through (g) if you comply with paragraphs (c)(1) 

through (7) of this section:

* * * * *
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(e) After the date of publication of the final rule in the 

Federal Register, for each affected source, you have 

demonstrated initial compliance with the applicable work 

practice standards in § 63.8192(e), (f), (h), and (i) if you 

comply with paragraphs (e)(1) through (4) of this section:

(1) You certify in your Revised Work Practice Notification 

of Compliance Status that you are operating according to the 

work practice standards in § 63.8192(h).

(2) You have submitted your cell room monitoring plan as 

part of your Revised Work Practice Notification of Compliance 

Status and you certify in your Revised Work Practice 

Notification of Compliance Status that you are operating 

according to the continuous cell room monitoring program under §

63.8192(i) and that you have established your initial action 

level according to § 63.8192(i)(2).

(3) You have re-submitted your washdown plan as part of 

your Revised Work Practice Notification of Compliance Status and 

you re-certify in your Revised Work Practice Notification of 

Compliance Status that you are operating according to your 

washdown plan.

(4) You have re-submitted records of the mass of virgin 

mercury added to cells for the 5 years preceding December 19, 

2006, as part of your Revised Work Practice Notification of 

Compliance Status.
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(f) You must submit the Revised Work Practice Notification 

of Compliance Status containing the results of the initial 

compliance demonstration according to the requirements in §

63.8252(f).

18. Section 63.8246 is amended by revising the first 

sentence of paragraph (b)(1) introductory text to read as 

follows: 

§ 63.8246 How do I demonstrate continuous compliance with the 

emission limitations and work practice standards?

* * * * *

(b) * * *

(1) For each mercury thermal recovery unit vent, you must 

demonstrate continuous compliance with the applicable emission

limit specified in § 63.8190(a)(3) by maintaining the outlet 

mercury daily-average concentration no higher than the 

applicable limit. * * * 

* * * * *

19. Section 63.8252 is amended by adding paragraphs (f) 

and (g) to read as follows:

§ 63.8252 What notifications must I submit and when?

* * * * *

(f) You must submit a Revised Work Practice Notification 

of Compliance Status according to paragraphs (f)(1) and (2) of 

this section.
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(1) You must submit a Revised Work Practice Notification 

of Compliance Status before the close of business on the date 

60 days after the applicable compliance date in date §

63.8186(a)(2) or (3). The Revised Work Practice Notification of 

Compliance Status must contain the items in paragraphs (f)(1)(i) 

through (iii) of this section:

(i) A certification that you are operating according to the 

work practice standards in § 63.8192(h).

(ii) Your cell room monitoring plan, including your initial 

action level determined in accordance with § 63.8192(i)(2), and 

a certification that you are operating according to the 

continuous cell room monitoring program under § 63.8192(i).

(iii) Your washdown plan, and a certification that you are 

operating according to your washdown plan under § 63.8192(e).

(2) Records of the mass of virgin mercury added to cells 

for the 5 years preceding December 19, 2006.

(g) You must submit subsequent action levels determined in 

accordance with § 63.8192(i)(2), along with the supporting data 

used to establish the action level, within 30 calendar days 

after completion of data collection.

20. Section 63.8254 is amended by revising paragraph 

(b)(7) introductory text to read as follows:

§ 63.8254 What reports must I submit and when?

* * * * *
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(b) * * *

(7) For each deviation from the requirements for work 

practice standards in Tables 1 through 4 to this subpart that 

occurs at an affected source (including deviations where the 

response intervals were not adhered to as described in §

63.8192(b)), each deviation from the cell room monitoring 

program monitoring and data recording requirements in §

63.8192(i)(3), and each deviation from the response intervals 

required by § 63.8192(i)(4) when an action level is exceeded, 

the compliance report must contain the information in paragraphs 

(b)(1) through (4) of this section and the information in 

paragraphs (b)(7)(i) and (ii) of this section. This includes 

periods of startup, shutdown, and malfunction.

* * * * *

21. Section 63.8256 is amended by revising paragraph (c) 

introductory text and adding paragraph (e) to read as follows:

§ 63.8256 What records must I keep?

* * * * * 

(c) Records associated with the work practice standards 

that must be kept prior to the applicable compliance date in §

63.8186(a)(2) or (3).

* * * * *
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(e) Records associated with the work practice standards 

that must be kept after the applicable compliance date in §

63.8186(a)(2) or (3).

(1) You must keep a the records specified in paragraphs 

(e)(1)(i) and (ii) of this section.

(i) A weekly record certifying that you have complied with 

the work practice standards in Tables 1 through 4 to this 

subpart. This record must, at minimum, list each general 

requirement specified in paragraphs (e)(1)(i)(A) through (D) of 

this section. Figure 1 to this subpart provides an example of 

this record.

(A) the design, operation, and maintenance requirements in 

Table 1 to this subpart,

(B) the required inspections in Table 2 to this subpart.

(C) the required actions for liquid mercury spills and 

accumulations and hydrogen and mercury vapor leaks in Table 3 to 

this subpart, and 

(D) the requirements for mercury liquid collection in 

Table 4 to this subpart.

(ii) The records specified in Table 12 to this subpart 

related to mercury and hydrogen leaks.

(2) You must maintain a copy of your current washdown plan 

and records of when each washdown occurs.
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(3) You must maintain records of the mass of virgin mercury 

added to cells for each reporting period.

(4) You must keep your current cell room monitoring plan 

and the records specified in paragraphs (e)(4)(i) through (vi) 

of this section.

(i) Records of the monitoring conducted in accordance with 

§ 63.8192(i)(2)(i) to establish your action levels, and records 

demonstrating the development of these action levels.

(ii) During each period that you are gathering cell room 

monitoring data in accordance with the requirements of §

63.8192(i)(2)(i), records specified in Table 9.

(iii) Records of the cell room mercury concentration 

monitoring data collected.

(iv) Instances when the action level is exceeded.

(v) Records specified in § 63.8192(i)(4)(i) for maintenance 

activities that cause the mercury vapor concentration to exceed 

the action level.

(vi) Records of all inspections and corrective actions 

taken in response to a non-maintenance related situation in 

which the mercury vapor concentration exceeds the action level 

as specified in Table 12 of this subpart.

22. Section 63.8266 is amended by revising the definitions 

of “Mercury cell chlor-alkali plant” and “Mercury recovery 

facility” to read as follows:
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§ 63.8266 What definitions apply to this subpart?

* * * * *

Mercury cell chlor-alkali plant means all contiguous or 

adjoining property that is under common control, where a mercury 

cell chlor-alkali production facility and/or a mercury recovery 

facility is located. A mercury cell chlor-alkali plant includes 

a mercury recovery facility at a plant where the mercury cell 

chlor-alkali production facility ceases production.

* * * * *

Mercury recovery facility means an affected source 

consisting of all processes and associated operations needed for 

mercury recovery from wastes generated by a mercury cell chloralkali plant.

* * * * * 
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23. The tables to subpart IIIII are amended as follows:

a. By revising the title to table 5;

b. By revising the introductory text to table 9;

c. By adding tables 11 and 12; and

d. By adding figure 1:

* * * * *

TABLE 5 TO SUBPART IIIII--REQUIRED ELEMENTS OF FLOOR-LEVEL MERCURY VAPOR MEASUREMENT AND 

CELL ROOM MONITORING PLANS PRIOR TO THE APPLICABLE COMPLIANCE DATE SPECIFIED IN §

63.8186(a)(2) OR (3)

* * * * *

TABLE 9 TO SUBPART IIIII OF PART 63--REQUIRED RECORDS FOR WORK PRACTICE STANDARDS

As stated in § 63.8256(c), you must keep the records (related to the work practice 

standards) specified in the following table prior to the applicable compliance date 

specified in § 63.8186(a)(2) or (3). After the applicable compliance date specified in 

§63.8186(a)(2) or (3), you must keep the records (related to the work practice standards) 

specified in the following table during the period when you are collecting cell room 

monitoring data in accordance with § 63.8192(i)(2)(i) to establish your action level:

* * * * *

TABLE 11 TO SUBPART IIIII--REQUIRED ELEMENTS CELL ROOM MONITORING PLANS AFTER THE 

APPLICABLE COMPLIANCE DATE SPECIFIED IN § 63.8186(a)(2) OR (3)

Your Cell Room Monitoring Plan required by § 63.8192(i) must contain the elements listed 

in the following table:
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You must specify in your cell 

room monitoring plan. . . 

Additional requirements

1. Details of your mercury 

monitoring system

2. How representative 

sampling will be conducted.

Include some pre-plan 

measurements to demonstrate the 

profile of mercury 

concentration in the cell room 

and how the selected sampling 

locations ensure conducted 

representativeness.

3. Quality assurance/quality 

control procedures for your 

mercury monitoring system.

Include a description of how 

you will keep records or other 

means to demonstrate that the 

system is operating properly.

4. Your current action 

level.

Include the background data 

used to establish your current 

level. Records of previous 

action levels must be kept for 

5 years in accordance with 

§63.8258, but are not required 

to be included as part of your 

cell room monitoring plan.

TABLE 12 TO SUBPART IIIII OF PART 63--REQUIRED RECORDS FOR WORK PRACTICE STANDARDS AFTER 

THE APPLICABLE COMPLIANCE DATE SPECIFIED IN § 63.8186(a)(2) OR (3)
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As stated in § 63.8256(e)(1), you must keep the records (related to the work practice 

standards) specified in the following table:

For each . . .

You must record the following

information . . .

1. Liquid mercury spill or accumulation 

identified during an inspection required 

by Table 2 to this subpart or at any 

other time

a. Location of the liquid mercury spill 

or accumulation.

b. Method you use to clean up the liquid 

mercury spill or accumulation.

c. Date and time when you clean up the 

liquid mercury spill or accumulation.

d. Source of the liquid mercury spill or 

accumulation.

e. If the source of the liquid mercury 

spill or accumulation is not identified, 

the time when you reinspect the area.

2. Liquid mercury leak or hydrogen leak 

identified during an inspection required 

by Table 2 to this subpart or at any 

other time

a. Location of the leak.

b. Date and time you identify the leak.

c. If the leak is a liquid mercury leak, 

the date and time that you successfully 

contain the dripping liquid mercury.

d. Date and time you successfully stop 

the leak and repair the leaking 

equipment.
Figure 1. Example Record Certifying Compliance with Work 

Practice Standards

Certification of Compliance with Work Practices Standards

§ 63.8256(e)(1)(i)

I hereby certify, that the [COMPANY NAME] mercury cell chloralkali facility in [LOCATION] has complied with each of the 

following work practice standards for the week of [DATE].

The design, operation, and maintenance requirements in 

Table 1 to 40 CFR part 63, subpart IIIII.

The required inspections in Table 2 to 40 CFR part 63, 

subpart IIIII.

The required actions for liquid mercury spills and 

accumulations and hydrogen and mercury vapor leaks in 

Table 3 to 40 CFR part 63, subpart IIIII.

The requirements for mercury liquid collection in Table 4 to 

40 CFR part 63, subpart IIIII.

COMPANY OFFICIAL DATE
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[AMENDMENTS INDEPENDENT OF WHICH OPTION IS SELECTED]

Subpart IIIII—[AMENDED]

2. Section 63.8226 is revised to read as follows:

§ 63.8226 What are my general requirements for complying with 

this subpart?

(a) You must be in compliance with the applicable emission 

limitations in § 63.8190 at all times. Prior to achieving 

compliance with § 63.8190(b), you must be in compliance with the 

applicable work practice standards in § 63.8192 at all times.

(b) At all times you must operate and maintain any 

affected source, including associated air pollution control 

equipment and monitoring equipment, in a manner consistent with 

safety and good air pollution control practices for minimizing 

emissions. The general duty to minimize emissions does not 

require you to make any further efforts to reduce emissions if 

levels required by this standard have been achieved. 

Determination of whether such operation and maintenance 

procedures are being used will be based on information available 

to the Administrator which may include, but is not limited to, 

monitoring results, review of operation and maintenance 

procedures, review of operation and maintenance records, and 

inspection of the source.

7. Section 63.8230 is revised to read as follows:

§ 63.8230 By what date must I conduct performance tests or 
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other initial compliance demonstrations?

(a) You must conduct a performance test no later than the 

compliance date that is specified in § 63.8186(a) for your 

affected source to demonstrate initial compliance with the 

applicable emission limit in § 63.8190(a)(2) for by-product 

hydrogen streams and end box ventilation system vents and the 

applicable emission limit in § 63.8190(a)(3) for mercury thermal 

recovery unit vents.

(b) For the applicable work practice standards in 

§ 63.8192 you must demonstrate initial compliance within 30 

calendar days after the compliance date that is specified for 

your affected source in § 63.8186(a).

8.3. Section 63.8232 is amended by removing and 

reserving paragraph (a) to read as follows:

§ 63.8232 [Amended]

(a) (a) [Reserved.]

9. Section 63.8236 is amended by adding paragraph (e) to 

read as follows:

§ 63.8236 How do I demonstrate initial compliance with the 

emission limitations and work practice standards?

* * * * *

(e) For each affected source, you have demonstrated 

initial compliance with the emission limit in § 63.8190(b) if 
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you have eliminated mercury emissions and you have submitted the 

compliance certification required by § 63.8252(f).

10* * * * *

4. Section 63.8242 is amended by revising paragraph (a)(2) 

to read as follows:

§ 63.8242 What are the installation, operation, and maintenance 

requirements for my continuous monitoring systems?

(a) * * *

(2) Each mercury continuous emissions monitor analyzer 

must have a detector with the capability to detect a mercury 

concentration of either 0.5 times the mercury concentration 

level measured during the performance test conducted according 

to § 63.8232 or 0.1 μg/m3

.

* * * * *

11. Section 63.8243 is amended by revising paragraphs (a) 

introductory text and (a)(3) introductory text to read as 

follows:

§ 63.8243 What equations and procedures must I use to 

demonstrate continuous compliance?

(a) By-product hydrogen streams and end box ventilation 

system vents. For each consecutive 52-week period, you must 

determine the g Hg/Mg Cl2 produced from all by-product hydrogen 

streams and all end box ventilation system vents, if applicable, 

at a mercury cell chlor-alkali production facility using the 
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procedures in paragraphs (a)(1) through (3) of this section. 

You must begin collecting data on the compliance date that is 

specified in § 63.8186(a) for your affected source and calculate 

your first 52-week average mercury emission rate at the end of 

the 52nd week after the compliance date.

* * * * * 

(3) Beginning 52 weeks after the compliance date specified 

in § 63.8186(a) for your affected source, you must calculate the 

52-week average mercury emission rate from all by-product 

hydrogen steam and all end box ventilation system vents, if 

applicable, using Equation 1 of this section as follows:

* * * * *

125. Section 63.8246 is amended by revising paragraph 

(b)(1) introductory text, and adding paragraph (d) to read as 

follows:

§ 63.8246 How do I demonstrate continuous compliance with the 

emission limitations and work practice standards?

* * * * *

§ 63.8246 How do I demonstrate continuous compliance with the 

emission limitations and work practice standards?

* * * * *

(b) * * * 

(1) For each mercury thermal recovery unit vent, you must 

demonstrate continuous compliance with the applicable emission 
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limit specified in § 63.8190(a)(3) by maintaining the outlet 

mercury daily-average concentration no higher than the 

applicable limit. To determine the outlet mercury 

concentration, you must monitor according to paragraphs 

(b)(1)(i) or (ii) of this section.

* * * * *

(d) You must demonstrate continuous compliance with the 

emission limitations in § 63.8190(b) by operating with zero

mercury emissions.

136. Section 63.8248 is amended as follows:

a. Revising paragraph (a)(1); 

b. Revising paragraph (a)(2); and

c. Removing and reserving paragraph (b).

The revisions read as follows:

§ 63.8248 What other requirements must I meet?

(a) * * *

(1) You must report each instance in which you did not 

meet each emission limitation in § 63.8190 that applies to you. 

(2) You must report each instance in which you did not meet 

each work practice standard in § 63.8192 that applies to you

* * * * *

(b) [Reserved.]

14. Section 63.8252 is amended by adding paragraph (f) to 

read as follows:
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§ 63.8252 What notifications must I submit and when?

* * * * *

(f) You must submit a compliance certification no later 

than 60 days after the applicable compliance date specified in 

§ 63.8186(b) or (d). This certification must state that you 

have eliminated all mercury emissions and will not use any 

process in the future that will emit mercury. The certification 

should also include a statement as to whether you eliminated 

mercury emissions through conversion to a nonmercury process for 

chlorine production or whether chlorine is no longer produced at

the site.

15. Section 63.8254 is amended as follows:

a. Revising paragraph (a)(1); 

b. Revising paragraph (a)(2);

6. Section 63.8254 is amended as follows:

c. Removing and reserving paragraph (b)(4);

d. Revising paragraph (b)(7) introductory text;

e. Revising paragraph (b)(8) introductory text;

f. Revising paragraph (b)(8)(iv);

g. Revising paragraph (b)(8)(vi);

h. Revising paragraph (b)(9) introductory text;

i. Revising paragraph (b)(9)(ii);

j. Revising paragraph (b)(9)(vi); and

k. Removing and reserving paragraph (c).
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The revisions read as follows:

§ 63.8254 What reports must I submit and when?

* * * * *

§ 63.8254 What reports must I submit and when?

(a) * * *

(1) The first compliance report must cover the period 

beginning on December 19, 2006, and ending on June 30, 2007.

(2) The first compliance report must be postmarked or 

delivered no later than July 31, 2007.

* * * * *

(b) * * *

(4) [Reserved.] 

* * * * *

(7) For each deviation from the requirements for work 

practice standards in Tables 1 through 4 to this subpart that 

occurs at an affected source (including deviations where the 

response intervals were not adhered to as described in 

§ 63.8192(b)), the compliance report must contain the 

information in paragraphs (b)(1) through (4) of this section and 

the information in paragraphs (b)(7)(i) and (ii) of this 

section.

* * * * *

(8) For each deviation from an emission limitation 

occurring at an affected source where you are using a mercury 
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continuous emission monitor, according to the site-specific 

monitoring plan required in § 63.8242(a)(3), to comply with the 

emission limitation in this subpart, you must include the 

information in paragraphs (b)(1) through (4) of this section and 

the information in paragraphs (b)(8)(i) through (xii) of this 

section.

* * * * *

(iv) The date and time that each deviation started and 

stopped.

* * * * *

(vi) A breakdown of the total duration of the deviations 

during the reporting period including those that are due to 

control equipment problems, process problems, other known 

causes, and other unknown causes.

* * * * *

(9) For each deviation from an operation and maintenance 

standard occurring at an affected source where you are using the 

periodic monitoring option specified in § 63.8240(b) and your 

final control device is not a nonregenerable carbon adsorber, 

the compliance report must include the information in paragraphs 

(b)(1) through (4) of this section and the information in 

paragraphs (b)(9)(i) through (x) of this section.

* * * * *

(ii) Information on the number, duration, and cause of 
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deviations (including unknown cause, if applicable), as 

applicable, and the corrective action taken.

* * * * *

(vi) A breakdown of the total duration of the deviations 

during the reporting period including those that are due to 

process problems, other known causes, and other unknown causes.

* * * * * 

(c) [Reserved.]

* * * * *

167. Section 63.8256 is amended by removing and reserving 

paragraph (a)(2) to read as follows:

§ 63.8256 What records must I keep?

(a) * * *

(2) [Reserved.]

* * * * *

178. Section 63.8266 is amended by revising the 

definitions of “Deviation;” and “Mercury cell chlor-alkali 

plant” to read as follows:

§ 63.8266 What definitions apply to this subpart?

* * * * *

Deviation means any instance in which an affected source 

subject to this subpart, or an owner or operator of such a 

source:

(1) Fails to meet any requirement or obligation 
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established by this subpart including, but not limited to, any 

emission limitation (including any operating limit) or work 

practice standard;

(2) Fails to meet any term or condition that is adopted to 

implement an applicable requirement in this subpart and that is 

included in the title V operating permit for any affected source 

required to obtain such a permit; or

(3) Fails to take corrective actions within 48 hours that 

result in parameter monitoring values being within range.

* * * * *

Mercury cell chlor-alkali plant means all contiguous or 

adjoining property that is under common control, where a mercury 

cell chlor-alkali production facility and/or a mercury recovery 

facility is located. A property where only a mercury recovery 

facility is operating is considered a mercury cell chlor-alkali 

plant if a mercury cell chlor-alkali production facility had 

operated on that property at any time in the past. 

* * * * *

189. Table 10 to Subpart IIIII of Part 63 is revised to 

read as follows:

TABLE 10 TO SUBPART IIIII OF PART 63--APPLICABILITY OF GENERAL 

PROVISIONS TO SUBPART IIIII

As stated in § 63.8262, you must comply with the applicable 

General Provisions requirements according to the following 

table:
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Citation Subject Applies 

to 

Subpart 

IIIII

Explanation

§ 63.1 Applicability Yes

§ 63.2 Definitions Yes

§ 63.3 Units and Abbreviations Yes

§ 63.4 Prohibited Activities Yes

§ 63.5 Construction/

Reconstruction

Yes

§ 63.6(a) -

(g), (i), (j), 

except for 

(e)(1)(i) and 

(ii), (e)(3), 

and (f)(1)

Compliance with Standards 

and Maintenance 

Requirements

Yes

§ 63.6(e)(1)(i) 

and (ii), 

(e)(3), and 

(f)(1)

SSM Requirements No

§ 63.6(h) Compliance with Opacity 

and Visible Emission 

Standards

No Subpart IIIII 

does not have 

opacity and 

visible emission 

standards.

§ 63.7(a)(1), 

(b)-(h), except 

(e)(1)

Performance Testing 

Requirements

Yes Subpart IIIII 

specifies 

additional 

requirements 

related to sitespecific test 

plans and the 

conduct of 

performance 

tests.

§ 63.7(e)(1) Performance Testing 

Requirements Related to 

SSM

No

§ 63.7(a)(2) Applicability and No Subpart IIIII 
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Performance Test Dates requires the 

performance test 

to be performed 

on the 

compliance date.

§ 63.8(a)(1), 

(a)(3); (b); 

(c)(1)-(4), 

(6)-(8); (d); 

(e); and 

(f)(1)-(5)

Monitoring Requirements Yes

§ 63.8(a)(2) Continuous Monitoring 

System (CMS) Requirements

No Subpart IIIII 

requires a sitespecific 

monitoring plan 

in lieu of a 

promulgated 

performance 

specification 

for a mercury 

concentration 

CMS.

§ 63.8(a)(4) Additional Monitoring 

Requirements for Control 

Devices in ' 63.11

No Subpart IIIII 

does not require 

flares.

§ 63.8(c)(5) COMS Minimum Procedures No Subpart IIIII 

does not have 

opacity and 

visible emission 

standards.

§ 63.8(f)(6) Alternative to

Relative Accuracy Test

No Subpart IIIII 

does not require 

CEMS.

§ 63.8(g) Data Reduction No Subpart IIIII 

specifies 

mercury 

concentration 

CMS data 

reduction 

requirements.

§ 63.9(a)-(e), 

(g)-(j)

Notification

Requirements

Yes
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§ 63.9(f) Notification of VE/Opacity

Test

No Subpart IIIII 

does not have 

opacity and 

visible emission 

standards.

§ 63.10(a); 

(b)(1); 

(b)(2)(vi)-

(xii), (xiv); 

(b)(3); (c); 

(d)(1)-(2), 

(4); (e); (f)

Recordkeeping/Reporting Yes

§ 63.10(b)(2)

(i)- (v), 

(d)(5)

Recordkeeping/ Reporting 

Associated with Startup, 

Shutdown, and Malfunctions

No

§ 63.10(b)(2) 

(xiii)

CMS Records for RATA 

Alternative

No Subpart IIIII 

does not require 

CEMS.

§ 63.10(d)(3) Reporting Opacity or VE

Observations

No Subpart IIIII 

does not have 

opacity and 

visible emission 

standards.

§ 63.11 Flares No Subpart IIIII 

does not require 

flares.

§ 63.12 Delegation Yes

§ 63.13 Addresses Yes

§ 63.14 Incorporation by Reference Yes

§ 63.15 Availability of 

Information

Yes