[Federal Register Volume 82, Number 247 (Wednesday, December 27, 2017)]
[Notices]
[Page 61281]
[FR Doc No: 2017-27907]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. ER18-472-000]

Supplemental Notice That Initial Market-Based Rate Filing
Includes Request for Blanket Section 204 Authorization; States Edge
Wind I Holding LLC

    This is a supplemental notice in the above-referenced proceeding of
States Edge Wind I Holding LLC`s application for market-based rate
authority, with an accompanying rate tariff, noting that such
application includes a request for blanket authorization, under 18 CFR
part 34, of future issuances of securities and assumptions of
liability.
    Any person desiring to intervene or to protest should file with the
Federal Energy Regulatory Commission, 888 First Street NE, Washington,
DC 20426, in accordance with Rules 211 and 214 of the Commission's
Rules of Practice and Procedure (18 CFR 385.211 and 385.214). Anyone
filing a motion to intervene or protest must serve a copy of that
document on the Applicant.
    Notice is hereby given that the deadline for filing protests with
regard to the applicant's request for blanket authorization, under 18
CFR part 34, of future issuances of securities and assumptions of
liability, is January 9, 2018.
    The Commission encourages electronic submission of protests and
interventions in lieu of paper, using the FERC Online links at http://www.ferc.gov. To facilitate electronic service, persons with internet
access who will eFile a document and/or be listed as a contact for an
intervenor must create and validate an eRegistration account using the
eRegistration link. Select the eFiling link to log on and submit the
intervention or protests.
    Persons unable to file electronically should submit an original and
5 copies of the intervention or protest to the Federal Energy
Regulatory Commission, 888 First Street NE, Washington, DC 20426.
    The filings in the above-referenced proceeding are accessible in
the Commission's eLibrary system by clicking on the appropriate link in
the above list. They are also available for electronic review in the
Commission's Public Reference Room in Washington, DC. There is an
eSubscription link on the website that enables subscribers to receive
email notification when a document is added to a subscribed docket(s).
For assistance with any FERC Online service, please email
[email protected]. or call<PHONE_NUMBER> (toll free). For
TTY, call<PHONE_NUMBER>.

    Dated: December 20, 2017.
Nathaniel J. Davis, Sr.,
Deputy Secretary.
[FR Doc. 2017-27907 Filed 12-26-17; 8:45 am]
 BILLING CODE 6717-01-P


[Federal Register Volume 87, Number 195 (Tuesday, October 11, 2022)]
[Notices]
[Pages 61311-61312]
[FR Doc No: 2022-22032]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. ER23-9-000]

Doc Brown LLC; Supplemental Notice That Initial Market-Based Rate
Filing Includes Request for Blanket Section 204 Authorization

    This is a supplemental notice in the above-referenced proceeding of
Doc Brown LLC's application for market-based rate authority, with an
accompanying rate tariff, noting that such application includes a
request for blanket authorization, under 18 CFR part 34, of future
issuances of securities and assumptions of liability.
    Any person desiring to intervene or to protest should file with the
Federal Energy Regulatory Commission, 888 First Street NE, Washington,
DC 20426, in accordance with Rules 211 and 214 of the Commission's
Rules of Practice and Procedure (18 CFR 385.211 and 385.214). Anyone
filing a motion to intervene or protest must serve a copy of that
document on the Applicant.
    Notice is hereby given that the deadline for filing protests with
regard to the applicant's request for blanket authorization, under 18
CFR part 34, of future issuances of securities and assumptions of
liability, is October 24, 2022.
    The Commission encourages electronic submission of protests and
interventions in lieu of paper, using the FERC Online links at http://www.ferc.gov. To facilitate electronic service, persons with internet
access who will eFile a document and/or be listed as a contact for an
intervenor must create and validate an eRegistration account using the

eRegistration link. Select the eFiling link to log on and submit the
intervention or protests.
    Persons unable to file electronically may mail similar pleadings to
the Federal Energy Regulatory Commission, 888 First Street NE,
Washington, DC 20426. Hand delivered submissions in docketed
proceedings should be delivered to Health and Human Services, 12225
Wilkins Avenue, Rockville, Maryland 20852.
    In addition to publishing the full text of this document in the
Federal Register, the Commission provides all interested persons an
opportunity to view and/or print the contents of this document via the
internet through the Commission's Home Page (http://www.ferc.gov) using
the ``eLibrary'' link. Enter the docket number excluding the last three
digits in the docket number field to access the document. At this time,
the Commission has suspended access to the Commission's Public
Reference Room, due to the proclamation declaring a National Emergency
concerning the Novel Coronavirus Disease (COVID-19), issued by the
President on March 13, 2020. For assistance, contact the Federal Energy
Regulatory Commission at [email protected] or call toll-free,
(886) 208-3676 or TYY,<PHONE_NUMBER>.

    Dated: October 4, 2022.
Debbie-Anne A. Reese,
Deputy Secretary.
[FR Doc. 2022-22032 Filed 10-7-22; 8:45 am]
BILLING CODE 6717-01-P


in Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements) by deleting the example (" e. g., removing bolts from a side panel...") because it is not practicable to remove the electrolyzer side panel bolts until after the electrolyzer has cooled and the mercury removed.

Response: We have reassessed the practicality of removing the bolts from the side panel,

and we agree that it is difficult to remove the electrolyzer side panel bolts before the electrolyzer has cooled and the mercury is removed. Thus, we are deleting the example phrase from Item 2. b.( 1) in Table 1.

Comment: Two commenters ( IV D 04, IV D 07) requested that Items 2. b( 2), 2. c, 2. d, and 2. e in Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements) be modified by adding the words " when possible" at the end of each requirement. The commenters explained that in some cases, these requirements cannot be implemented.

Response: The proposed standards in table 1 ( Items 2. b( 2), 2. c, 2. d, and 2. e would have required facilities to perform several activities when opening electrolyzers to minimize mercury emissions, such as keeping the bottom covered using an aqueous solution. We agree with the commenter that it may not be possible to take the specified actions in all situations. For example,

due to the design of different electrolyzers, it may not be possible to ensure that an aqueous liquid covers or flows over the bottom during a side panel change. Therefore, we have added the phrase " when possible" as suggested by the commenter. However, we think that it is important to 51 document why it is not possible, so we have added an item to Table 9 of the final rule ( Table 8 of the proposed rule) requiring records to document when these actions are not possible.

Comment: One commenter ( IV D 07) stated that EPA should combine Items 4. a and 4. b in Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements) into one Item ( 4. a) as follows:

" a. To prevent mercury buildup after [ DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL REGISTER], equip each new process line and piping system with smooth interiors and adequate low point drains or mercury knock out pots to avoid liquid mercury buildups within the pipe and to facilitate mercury collection and recovery.

Response: We agree with the commenter that Items 4. a and 4. b are redundant and have combined these two items into one item ( 4. a) as suggested by the commenter.

Comment: One commenter ( IV D 07) stated that they believed that EPA intended for Item 5. a in Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements) to apply to concrete floors. Therefore, the commenter recommended the following modification to Item 5. a: " a. Maintain a coating on concrete cell room floors..."

Response: It was not our intent to specify the type of floor on which coatings must be maintained. The intention of this item was to ensure that all cell room floors are coated with a mercury resistant coating to facilitate detection of a liquid mercury spill and accumulation.

Therefore, we have not made any changes to Item 5. a of Table 1.

Comment: One commenter ( IV D 07) stated that Item 5. c in Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements) was not required as long as the requirements specified in Item 5. d of Table 1 are met ( i. e., " maintain a layer of aqueous liquid on liquid mercury in trenches..."). Therefore the commenter recommended that Item 5. c be deleted.

Response: We agree with the commenter that the requirements in Item 5. d of Table 1 are sufficient for preventing or minimizing mercury emissions from mercury contained in troughs or trenches. However, in order to prevent and minimize mercury emissions from mercury spills on a cell room floor, we believe it is necessary to require that the entire cell room floor must be maintained to prevent mercury accumulation in the corners. Therefore, we have modified Item 5. c as follows:

c. Maintain the cell room floor troughs and trenches to prevent mercury accumulation in the corners. 6 A. Hartman, EC/ R to Docket. Cleanup of Mercury Spills. August 12, 1999. ( EPA Air Docket A 2000 32, Item II B 8).

52 Comment: One commenter ( IV D 07) did not agree that the work practice standards need to specify that the aqueous layer be replenished at least once per day as specified in Item 5. d of Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements).

According to the commenter, sufficient control of mercury vapors is achieved as long as a facility is required to maintain a layer of aqueous liquid on liquid mercury contained in trenches or drains.

Therefore, the commenter requested that EPA delete the last part of the sentence in Item 5. d of Table 1 and modify the statement to read: " Maintain a layer of aqueous liquid on liquid mercury contained in trenches or drains."

Response: We disagree with the commenter that simply maintaining an aqueous liquid on liquid mercury contained in trenches or drains would sufficiently control mercury vapors without being replenished. If the pool of water covering the mercury is saturated with mercury vapor and the air above it is well below saturation, the mercury vapor would have a strong tendency to escape the pool. 6 Therefore, we have not removed the requirement to replenish the aqueous liquid on a daily basis.

Comment: Commenter IV D 04 suggested that the words " leak tight" be deleted after the first word in Item 7. b in Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements). In addition, the commenter requested that EPA add " in good condition" after the words " caustic system piping" and end the sentence there ( i. e., delete phrase beginning " except..."). The commenter stated that these changes maintain continuity between section 7. b and all other sections of Table 1. The commenter explained that other sections of Table 1 list work practices which limit leaks or emissions to the extent possible, and other tables mandate actions to be taken in the event of a leak. If prescribed actions are not taken in a timely manner,

then a violation of a work practice has occurred. The commenter argued that only Section 7. b mandates that no leaks ever occur, and the fact of a leak in and of itself would be considered a violation of a work practice. Thus, the commenter's suggested changes would make the requirements for handling a leak in caustic system piping consistent with the requirements for handling leaks in other piping systems. 53 Response: We agree with the commenter that the proposed language could be interpreted to forbid any leaks and that was not our intent. Thus, we are making certain changes to this language. We are deleting the phrase " leak tight" and adding the phrase " in good condition" as suggested by the commenter. However, we are not deleting the phrase beginning with " except,"

instead we are clarifying it's intent.

It was our intent to require that the connections between the decomposer and its corresponding cell components be maintained to minimize leaks to the greatest extent possible.

Therefore, in order to ensure these conditions without completely forbidding leaks, we believe it is necessary to specify that these connections be kept closed or tight unless maintenance activities require opening or loosening of these connections. The commenter's suggestion to delete the phrase " leak tight" and add the phrase " in good condition" by itself will not ensure these that leaks will be minimized to the greatest extent possible. As such, we have modified Item 7. b of Table 1 of the final rule to read as follows:

Maintain connections between the decomposer and the corresponding cell components, hydrogen system piping, and caustic system piping in good condition and keep the connections closed/ tight except when maintenance activities require opening/ loosening these connections.

Comment: One commenter ( IV D 07) stated that the work practice requirement in Item 7. d. 1 of Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements) is confusing. According to the commenter, part of the requirement states "... that meets the requirements listed below for closed containers..." but there does not appear to be any requirements for closed containers " listed below." The commenter assumed that EPA intended to refer to the requirements defined in Items 9 and 10 of Table 1. Therefore, the commenter recommended that EPA clarify the language in Item 7. d.( 1) as follows:

"... fill the decomposer with an aqueous liquid or drain... into a container that meets the requirements listed below for closed containers in Table 1, Items 9 or 10."

Response: We agree with the commenter that the statement "... a container that meets the requirements listed below for closed containers..." in Item 7. d( 1) of Table 1 is confusing.

Furthermore, it was not our intention to specify that the liquid mercury in the decomposer should be drained into a container meeting only the closed container requirements. In fact, because of the short term need for mercury to be removed from the decomposer for maintenance, we believe 54 that it is appropriate to allow open top containers meeting the requirements in Item 9. Therefore we have modified Item 7. d( 1) to refer to Items 9 ( requirements for " Containers holding liquid mercury") and 10 of Table 1 ( requirements for " Containers used to store liquid mercury") as follows:

"... fill the decomposer with an aqueous liquid or drain... into a container that meets the requirements listed below for closed containers in Table 1, Items 9 or 10."

Comment: Two commenters ( IV D 04, IV D 07) requested that the words "... collect the liquid mercury from the container in accordance with the requirements of Table 4 in this subpart..." be deleted from Item 9 in Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements). The commenters stated that there is no good reason to collect small amounts of mercury on a daily basis. The commenters maintained that such daily collections would increase the handling of mercury and hence the potential for emissions.

Response: We believe that the commenters have misunderstood the intent of Item 9 in Table 1. Item 9 does not require the daily collection of liquid mercury. Instead, Item 9 requires that aqueous layer holding liquids be replenished at least once per day. It was our intent that the phrase " and collect liquid mercury from the container in accordance with the requirements in Table 4 to this subpart" would be understood to mean that liquid mercury should be collected from these containers as needed or as required by operating practices. To address the commenters' confusion, we are adding language to Item 9 of Table 1 of the final rule as follows ( see italics):

Maintain a layer of aqueous liquid over liquid mercury containers in each open top container. Replenish the aqueous layer holding liquid at least once per day and, when necessitated by operating procedures or observation, collect the liquid mercury from the container in accordance with the requirements of Table 4 to this subpart.

Comment: Two commenters ( IV D 04, IV D 07) recommended that EPA delete Table 4 ( Work Practice Standards  Requirements for Mercury Liquid Collection), because the goal should be to minimize the handling of mercury. The commenters believe that Table 3 ( Work Practice Standards  Required Actions for Liquid Mercury Spills and Accumulations and Hydrogen and Mercury Vapor Leaks) prescribes the needed actions sufficiently.

Response: We disagree with the commenters that Table 3 addresses the same situations as does Table 4, and we are not deleting Table 4. Table 3 addresses spills of liquid mercury, 55 unplanned/ un designed accumulations of liquid mercury, hydrogen vapor leaks, and mercury vapor leaks; all four of these situations involve accidental and/ or unintentional outcomes of operations. Table 4 addresses the collection of liquid mercury from equipment designed to temporarily store, collect, or accumulate liquid mercury. Table 3 assumes that the liquid mercury is where it should not be ( e. g., on the floor), while Table 4 describes the periodic collection of liquid mercury from equipment expected to have accumulations of liquid mercury. Contrary to the commenters' interpretation, we do not believe compliance with the provisions in Table 4 result in any unnecessary handling of mercury. Instead these provisions only address how to collect mercury when such expected accumulations of liquid mercury inevitably occur as a result of the manufacturing process.

Comment: Two commenters ( IV D 04, IV D 07) suggested that EPA replace the word " store" in Item 11. c., Table 1 ( Work Practice Standards  Design, Operation and Maintenance Requirements), with " collect" and delete the word " wastes." In addition, the commenters recommended that after the word " containing," EPA should add the phrase " materials in process vessels or...." The commenters reasoned that the materials are not yet wastes, and in some cases,

process vessels are used.

Response: We agree that the commenters' suggested changes more clearly communicate our intent for caustic systems. Furthermore, since we have deleted Table 5 of the proposed rule ( see later comment), we have added a reference to the applicable RCRA requirements in Table 1.

Therefore, Item 11. c. of Table 1 of the final rule now reads:

Collect solids and liquids from back flushing each primary caustic filter and collect these mercury containing materials in process vessels or in accordance with the requirements in 40 CFR part 265, subpart I and CC.

Comment: Two commenters ( IV D 04, IV D 07) suggested that, where applicable, timing requirements for Table 2 ( Work Practice Standards  Required Inspections) should be changed in from " at least once each 12 hours" to " at least twice daily." Due to operational issues, the commenters reasoned that some inspections might be delayed to be beyond 12 hours apart and that such a delay should not constitute a violation.

Response: We agree with the commenters that our intent would be more clearly communicated if the reference to " at least once each 12 hours" was changed. Our intent was that these inspections occur once each half day or twice daily. A similar confusion does not exist 56 when the terms " month", " 3 months", or " 6 months" are used because it is commonly understood what starting point and ending point are covered by these terms ( e. g., the 1st through the 31st or January through June). Therefore, we are changing the language of Table 2 to use the terms " half day" and " day" to replace the terms " 12 hours" and " 24 hours" respectively, relying on the common understanding that day represents each calendar day beginning at 12: 00 a. m. and ending at 11: 59 p. m.

Comment: Two commenters ( IV D 04, IV D 07) suggested that Table 5 ( Work Practice Standards  Requirements for Handling and Storage of Mercury Containing Wastes) duplicates or modifies practices that are required by RCRA. The commenters recommended that EPA delete the table because RCRA regulations adequately address these issues. The commenters also suggested that Items 6 and 7 of Table 8 ( Required Records for Work Practice Standards)

duplicate or modify practices that are required by RCRA and should be deleted as well to avoid conflicting regulations.

Response: Mercury cell chlor alkali facilities are subject to RCRA requirements under 40 CFR parts 268, subparts C and E; 262, subpart C; 265, subparts I and CC. Under CFR part 265,

subparts I and CC facilities are required to store mercury wastes in containers that are kept closed at all times except when wastes are being added or removed. We agree with the commenters that the requirements contained in Table 5 of the proposed rule duplicate, and do not add to, the requirements already in effect for chlor alkali facilities under RCRA. We will remove Table 5 ( Work Practice Standards   Requirements for Handling and Storage of Mercury Containing Wastes) and strike the requirements of Items 6 and 7 of Table 9 ( Required Records for Work Practice Standards) of the final rule ( Table 8 of the proposed rule).

Comment: Two commenters ( IV D 04, IV D 07) recommended that the term " castings"

should be deleted from Table 6 ( Required Elements of Washdown Plans) of the proposed rule,

because it is a term that is unfamiliar to the industry. In addition, the commenters requested that a new item, " Thermal Treatment Units," be added to the washdown plan.

Response: We agree with the commenters and have removed the term " castings" from Table 7 of the final rule ( Table 6 of the proposed rule). In addition, we have added Thermal Treatment Units as an item of equipment that should be included in Table 7 of the final rule ( Table 57 6 of the proposed rule), since these areas are potential locations where mercury could accumulate on the floor.

Comment: One commenter ( IV D 07) requested modifications to Item 1 of Table 8 ( Required Records for Work Practice Standards) due to the nature of cell room operations and to provide some flexibility in their compliance activities. The commenter requested that the language " Date and time the inspection was conducted" be revised to " Date and shift or time the inspection was conducted." According to the commenter, inspections may occur during the conduct of other activities and the specific time the inspection occurred may not be readily known.

Response: Some of the inspections required under Table 2 must occur twice daily ( e. g., end box inspections). Requiring the time of the inspection, rather than just the shift, allows inspectors to accurately determine whether the required inspections were conducted at the appropriate time.

Inspectors would not be able to determine whether two inspections were in fact conducted between 12: 00 a. m. and 11: 59 p. m. if only the shift was recorded. We believe that it is not overly burdensome to require the specific time to be recorded when an inspection is conducted and therefore, we have not made the suggested modifications to Item 1 of Table 9 of the final rule ( Table 8 of the proposed rule).

Comment: Two commenters ( IV D 04, IV D 07) recommended that EPA replace the word " weight" with the word " amount" in Item 4. b. of Table 8 ( Required Records for Work Practice Standards). The commenters explained that it is not practicable to weigh very small amounts of mercury ( e. g., a few drops).

Response: We agree with the commenters that in some instances weight of the liquid mercury will be difficult to determine. However, since liquid mercury has a high density, the weight of a few drops of mercury is not insignificant. We also believe that it is more clear to require an estimate of weight rather than an estimate of " amount."

2.5.3 Cell room monitoring Comment: Two commenters ( IV D 04, IV D 07) disagreed with EPA's proposal to institute a continuous mercury monitoring program whereby owners and operators would be required to continuously monitor mercury concentration in the upper portion of each cell room and take corrective actions when elevated mercury vapor levels are detected. Under the proposed program, results would be used to determine relative changes in mercury vapor levels rather than 58 compliance with a cell room emission or operating limit. The commenters stated that they believed that the proposed monitoring program was seriously flawed and should be deleted from the final rule. The commenters noted that periodic monitoring done in various areas of the cell room ( as currently practiced to ensure compliance with the Occupational Safety & Health Administration ( OSHA) permissible exposure limits) was an appropriate substitute. The commenters stated that cell room monitoring is redundant to the housekeeping requirements and that the work practices required in Tables 1 5 allow for sufficient opportunity to quickly detect abnormal sources of mercury emissions.

In contrast, one commenter who submitted comments after the close of the comment period ( IV G 1) " enthusiastically" supported the proposed cell room monitoring program. Nonetheless,

the commenters felt that it was unwise for the EPA to allow each owner/ operator to set his/ her own cell room action level. They claimed that this strategy will allow more fugitive releases than necessary and was incompatible with the Clean Air Act.

Three commenters ( IV D 04, IV D 05, IV D 07) stated that they would not be opposed to the continuous mercury monitoring program if the technology were field demonstrated. The commenters argued that the technology to continuously monitor for fugitive mercury emissions is not proven, and in fact, the commenters were aware of only two attempts to continuously monitor cell rooms: at a facility formerly operating in Maine, and a two week testing program performed at a facility in Augusta, Georgia in February 2000. According to the commenters, the State of Maine questioned whether the monitoring program at the Maine facility was representative of cell room emissions and EPA declined to comment on the validity of the program being performed at the facility. With respect to the testing program, the commenters stated that a two week testing program does not show that monitoring on a long term basis is feasible. The commenters noted that the testing program was performed by approximately 30 expert scientists highly knowledgeable in performing such tests and keeping the equipment operational during the test period.

Two commenters ( IV D 04, IV D 07) stated that they would be willing to assist in the development of an appropriate evaluation program for monitoring cell room mercury concentration. Three commenters ( IV D 04, IV D 05, IV D 07) recommended that the regulation should be sufficiently flexible to allow for a variety of ways to implement the 7J. S. Kinsey. Characterization of Mercury Emissions at a Chlor Alkali Plant, Volumes I and II. U. S. Environmental Protection Agency, National Risk Management Research Laboratory. Research Triangle Park, NC. Publication EPA 600/ R 02 007a and EPA 600/ R 02 007b. January 2002..

59 monitoring. Two commenters ( IV D 04, IV D 07) suggested that such flexibility should allow for no, or only partial, implementation of the continuous monitoring program if testing should prove to be less than wholly successful. The commenters noted that if the testing proves to be successful and the monitoring is required, the regulation should allow for a substantial reduction in the frequency of inspections ( Tables 1 5) and the complete elimination of some inspections.

Commenter IV D 05 stated that the rule should either require continuous monitoring or detailed work practice standards but not both. The commenter argued that cell room designs vary greatly. Given this variability, the commenter urged EPA to enable facilities to select the appropriate compliance strategy for individual circumstances.

Response: The issues raised by the commenters can be summarized in two issues. First,

they question the technical feasibility of the cell room monitoring program for all facilities.

Second, they point out that requiring compliance with both the detailed work practices and the cell room monitoring program is redundant.

With regard to technical feasibility, a cell room mercury monitoring system was tested in 2000 at a mercury cell facility in August, Georgia, 7 that demonstrated that the monitoring technology can be effectively installed and operated in mercury cell chlor alkali plant cell rooms,

and this technology, along with other measures, can be an effective mechanism to identify leaking equipment and other problems that result in fugitive mercury emissions from the cell room.

We acknowledge that this success, which occurred in a limited and very controlled situation for a short time period, does not necessarily prove that similar monitoring at every mercury cell room would prove to be an effective long term method to reduce mercury fugitive emissions. In fact, the design and operation of the Augusta facility probably represented the optimum circumstances for a mercury cell room monitoring program to be successful. We are aware that the cell room designs vary greatly and recognize that the design affects the location and number of monitors necessary to accurately monitor each individual cell room. In addition, depending on the 60 design of the roof, it may be possible that installation of monitors that adequately monitor mercury concentration would not even be possible.

Even with these limitations, a well designed and implemented cell room monitoring program can effectively reduce mercury fugitive emissions on a long term basis. Therefore, we included this concept in the final rule.

However, we do agree with the commenters that a comprehensive continuous cell room monitoring program should be sufficient to reduce fugitive mercury emissions from the cell room without imposing the overlapping requirements of the detailed work practices. Therefore, we have concluded that it is appropriate to allow facilities to implement the continuous cell room monitoring program as an alternative to, and not in addition to, the work practice requirements.

In the final rule, facilities are given the option to implement the continuous cell room monitoring program in lieu of the work practice requirements. We do, however, feel there is a need to outline more specifically the elements that must be included in the cell room monitoring program to ensure that it provides at least the same level of control as the work practices and cell room monitoring program would have provided together. Therefore, there are more prescriptive requirements in the final rule for the cell room monitoring plan option. The final rule dictates how the action level is to be established, what measures must be followed when the action level is exceeded, and what records must be kept.

Although the continuous cell room monitoring provisions are optional, some mercury monitoring to detect elevated mercury levels in the cell room is appropriate. Therefore, we have included a periodic monitoring program to be performed throughout the cell room as a substitute for continuous monitoring. The final rule contains a floor level periodic monitoring program as part of the work practice standards.

2.6 TEST METHODS, PROCEDURES, AND REQUIREMENTS Comment: In a previous comment ( see section 2.2 of this document), two commenters (

IVD 04, IV D 07) requested that we remove the title V requirements for mercury cell chlor alkali facilities. Therefore, the commenters requested that § 63.8231 be revised to remove the reference to the title V permit such that subsequent performance testing be required to be conducted no less frequently than every two and a half years. 61 Response: As stated in our response to the comment in section 2.2 of this document, we have retained the requirement to obtain a title V permit in the final rule. The final rule contains two compliance options. The first option is to operate mercury continuous emission monitors that continuously measure mercury emissions and compare them to the units of the standard.

After the initial performance test and CEM performance evaluation, the final rule does not require owners and operators to conduct subsequent performance tests under this option. The second option is to conduct performance tests weekly. Obviously if a plant is conducting performance tests weekly there is no need for subsequent performance tests. Therefore, we have deleted § 63.8231.

Comment: Two commenters ( IV D 04, IV D 07) were concerned that some of the performance tests required by EPA to demonstrate initial compliance with emission limits do not reflect the actual operating conditions of the units. For example, the commenters pointed to § 63.8232( f), which requires operators of mercury thermal recovery unit vents to use, during test runs, only mercury containing wastes that result in the highest mercury concentration in the vent.

The commenters noted that in actual practice there is very little correlation between the type of wastes processed and the mercury in the vent. The commenters recommended that EPA delete § 63.8232( f) from the proposed rule. The commenters also mentioned that there were similar examples of inappropriate test method revisions in § 63.8232( d) and ( e) but did not provide examples.

Response: In the preamble to the proposed rule, we stated that we were unable to develop a correlation between the type of wastes being processed and the outlet mercury concentration ( see III. D. 3, 67 FR 44686). It was our intent to obligate owners and operators to process mercury containing wastes that result in the highest mercury vent concentration during performance testing to present the most challenging control situation during the test. We believed that requiring facilities to determine which mercury waste would provide the highest outlet mercury concentration would have achieved this goal. However, based on the comments received, our evaluation of these comments, and given our decisions regarding continuous and periodic monitoring ( see section 2.7 of this document), we have concluded that it is appropriate for owners and operators to operate their thermal recovery units in such a way that represents normal operation. This is consistent with § 63.7( e) of the General Provisions, and as such, we 62 believe that § 63.8232( f) is unnecessary. Therefore, we have deleted § 63.8232( f) as proposed for the final rule.

Comment: Three commenters ( IV D 04, IV D 05, IV D 07) were concerned that EPA had not subjected the test run procedures and analytical methods proposed in § 63.8232( c)

through ( f) to a separate notice and comment process to assure their validity for chlor alkali producers. The commenters urged EPA to subject these test methods to the full notice and comment procedure that the Agency has typically used to validate new test methods and procedures. Therefore, the commenter suggested that EPA delete proposed § 63.8232( f) and eliminate or modify § 63.8232( c). The commenters indicated that they were willing to work with EPA to assess and validate revisions to test procedures to incorporate into the proposed NESHAP.

Response: The procedures required in § 63.8232( c) through ( f) are not modifications to the reference test methods in Appendix A of 40 CFR part 61 and therefore are not subject to the separate notice and comment procedure for modifications to test methods. The proposed provisions in § 63.8232( c) through ( f) were requirements for how these reference methods are to be applied for this particular rule, and it is entirely appropriate and necessary for individual rules to contain such provisions. With regard to notice and comment, the proposal provided the public ample opportunity to comment on these requirements on how to apply the reference test methods for subpart IIIII. As discussed below, comments were received on the specific requirements in § 63.8232( c) through ( f) and we have made changes in the final rule in response to these comments. The fact that a number of commenters have suggested modifications and changes to the proposed provisions test methods affirms that adequate notice and opportunity to comment has already been provided.

Comment: Commenters IV D 04, IV D 05, and IV D 07 objected to the proposed requirements in § 63.8232( c), which required facilities to conduct test runs that ( 1) include sample times which last at least two hours and ( 2) generate field samples with mercury concentrations at least two times the limit of detection for the analytical method. According to the commenters, the currently approved test method has no requirement to generate samples with mercury concentrations at least twice the detection limit. The commenters noted that in practice, many operators may not initially detect mercury in their test runs because the stacks and vents typically 63 emit very low amounts of mercury. Therefore, to obtain a sample that contains an amount of mercury at least double the method's limit of detection could require facilities to extend their sampling times by a factor of three to four times with no guarantee of collecting a valid sample until after the analyses have been performed. The commenters stated that there appears to be no technical justification for requiring a sample containing twice the detection limit for the analytical method. In addition, the commenters argued that the cost of conducting such tests could also be several much higher than a regular test, and may have to be performed two or more times to obtain a valid test. The commenters noted that these uncertainties and costs underscore the fact that no chlor alkali facility has used this type of extended testing procedure. The commenters recommended that EPA eliminate or modify Section 63.8232( c).

Response: During the development of the proposed rule, we collected numerous test reports from mercury cell chlor alkali plants. Most of these tests were conducted in a manner that resulted in a quantifiable measurement ( i. e., a measurement above the detection limit of the analytical method), even for those situations where the mercury emissions were very low.

However, there were tests, typically those conducted in the late 1980s, that reported mercury emissions below the detection limit. This alerted us to the possibility that tests conducted using Methods 101, 101A, and 102 could result in " non detects."

We believe that compliance should be determined using actual measured values whenever feasible and reasonable. This was the basis for the proposed requirement to obtain a sample at least twice the detection limit. However, the commenters raise valid points and it is not our desire to include requirements that impose unreasonable testing burdens on the industry. Therefore, we provided an alternatives to the proposed requirement ( at least two hours and twice the detection limit) in the final rule. Specifically, this alternative is that the sampling time and sampling volume for each run must be at least 2 hours and 1.70 dscm ( 60 dscf), respectively. This volumetric requirement, which was developed assuming the volumetric flow for a typical Method 5 sampling train, was added to provide a definitive end point to the test while still helping to ensure that a measurable amount is collected. If these two minimum sampling requirements are met and the results are still below the analytical laboratory's detection limit, the reported analytical detection limit can be used to calculate the sample concentration value and, in turn, the emission rate in the units of the standard. 64 Comment: Two commenters ( IV D 04, IV D 07) indicated that the hydrogen and end box emission limitations should be based on chlorine capacity and not actual production as proposed.

The commenters also proposed that the rule clarify how the annual chlorine capacity is defined.

This commenters suggested that annual chlorine capacity ( tons per year) be defined as follows:

AnnualChlorine Capacity ton per year DailyChlorineCapacity of cell rated electricalcurrent ton Number of cells days yr ( ) @ ( ) * * = maximum 365 According to the commenters, each facility would provide EPA with documentation and updated information concerning its chlorine capacity. The commenters recommended that § 63.8246( a)( 2)

be modified and § 63.8246( a)( 3) should be deleted to address these comments.

Response: When developing the form of the standard, we determined that the large variation within the source category among the plants in terms of production and mercury emissions potential, any equitable assessment of MACT should account for this disparity. We selected chlorine produced by weight as the uniform parameter for our analysis for the following reasons: ( 1) chlorine is the primary product generated; ( 2) chlorine production can be accurately determined; and ( 3) chlorine and hydrogen are generated in the same stoichiometric quantities ( i. e., one molecule of hydrogen is produced for each molecule of chlorine produced). The data provided to us by the industry and used to determine the emission limitations for hydrogen and end box were in terms of actual annual production, not production capacity. Therefore, using production capacity would bias the emissions per mass of chlorine production low, thus not resulting an appropriate measure against the emission limitation as it was developed.

As discussed below in section 2.7, the averaging period for compliance with the emission limitation for by product hydrogen streams and end box ventilation system vents has been changed to 52 weeks. The rule is not specific regarding the method that must be used to determine the chlorine production for the 52 week period. Rather, the rule requires that each source develop a site specific monitoring plan that includes a description of how they will measure or otherwise determine chlorine production. This provision is not meant to impose any additional burden on affected sources, as we believe that all plants accurately determine chlorine production. This simply requires that their methodology be submitted to the designated authority. 65 The final rule does retain the proposed equation on how to calculate short term chlorine production for the initial performance test. This calculation is based on the average cell line current load during the test.

2.7 CONTINUOUS COMPLIANCE DEMONSTRATION Comment: Three commenters ( IV D 04, IV D 05, IV D 07) questioned EPA's intent in establishing emission limitations based on the initial performance test. These commenters felt that the proposed standards amounted to changing the emission limit based on the emissions observed during the performance test which amounted to ignoring the emission limit established through the rulemaking process. Two commenters ( IV D 04, IV D 07) stated that the amount of mercury emissions measured during the initial compliance performance test should be used only to verify compliance with the MACT standards, and not to establish new emission limits. The commenters were concerned that the emission limits would become floating limits based on the most recent performance test, as opposed to being MACT standards. The commenters stated that they were not aware of any other MACT standard that has been written specifically in this manner, and they seriously questioned EPA's rationale relating to this portion of the proposal.

The commenters indicated that variations around the concentrations, above and below,

measured during the performance test can be expected. Treatment systems employed to obtain compliance ( e. g., carbon) would be expected to show some slight deterioration after a period of operation. Therefore, a performance test conducted just after a carbon change would result in an unrealistically low operating limit. Finally, the commenters were concerned that different facilities would have different operating limits, depending on variables like the type of control equipment installed, the operating conditions on the day of the emission test ( i. e., mercury volatility changes significantly with temperature), and other factors.

Commenter IV D 05 was concerned that, given the wide variability in emission constituents, operators would not be able to assure that their facilities will consistently emit within the limits established during an ideally controlled initial performance test.

Two commenters ( IV D 04, IV D 07) acknowledged that other MACT standards require the gathering of data for surrogate parameters ( e. g., scrubber liquor pH, scrubber liquor flow)

when direct measurement of a control parameter is not required or feasible. These surrogate parameters are used to establish performance requirements for the control device. The 66 commenters argued that in these cases, the direct measurement of a specific control parameter may not have been required ( in fact, such is the case with the current Mercury NESHAP). The commenters went on to say that in cases where performance requirements based on surrogate parameters were established during the performance test, the emission limitation was not modified to reflect the actual emissions experience during the test. However, the commenters stated that they felt that this is exactly what is required under the proposed rule.

The commenters ( IV D 04, IV D 05, IV D 07) stated that they do not believe that the provisions proposed under § 63.8190 are consistent with other MACT standards or the CAA and requested that the Agency delete § 63.8190( b)( 1) and ( 2), as well as all references to this section throughout the proposed regulation, including: deleting § 63.8236( a)( 2) and ( b)( 2)); deleting § 63.8256( b)( 2); and modifying the language in § 63.8254( b)( 8) to eliminate the reference to a sitespecific monitoring plan and to refer to the emission limit.

Commenter IV D 05 argued that EPA's required installation of instruments directly in the vent stream to continuously monitor actual concentration of mercury and, therefore, actual mercury emissions, means that there is no need to rely on operating parameters which have been calculated for only one set of conditions. The commenter acknowledged that EPA may have sought to instill flexibility in the proposed rule, but maintained that this concept of establishing mercury concentration limits during the performance test would impose unrealistic emission limits that would vary widely between facilities.

One commenter ( IV D 07) recommended that EPA allow facilities to propose, in lieu of continuos monitoring, their own periodic monitoring program. The commenter stated that because of the way a nonregenerable carbon adsorption system works, continuous monitoring is not necessary and is impractical.

One commenter ( IV D 04) was concerned about the cost benefits of continuous monitoring systems ( CMS) in the by product hydrogen, end box ventilation system, and mercury thermal recovery unit vent streams. According to the commenter, the types of control devices likely to be used for controlling mercury emissions from these streams ( i. e., carbon or molecular sieve units)

have very good performance characteristics and are not likely to incur short term upsets. The commenter noted that performance is subject to normal variations, and the ability of these systems to absorb mercury does degrade over time. The commenter stated that before emissions reach the 67 permit limits due to reduced performance, the beds must be replaced. The commenter requested that in lieu of CMS, facilities should be allowed to rely on the known capability of the systems to operate reliably. The commenter stated that the Agency could delete the requirement for CMS without any real harm to the environment.

Response: In general, we disagree with the premise of the commenter's argument. The proposed rule would have required that continuous compliance for each vent be determined by monitoring mercury concentration as an operating limit. The measured concentrations would not have been used to compare directly with the emission limitations. Rather, they would have provided an indication that the control device was performing in a manner consistent with the operation during the initial performance test. Therefore, the proposed requirements to establish operating limits would have established emission limitations, or resulted in changing emission limits, based on the initial performance test.

However, we do acknowledge that there is a difference in a mercury concentration operating limit and an operating limit based on surrogate parameters because the mercury concentration is obviously a direct measure of mercury emissions. In fact, we agree with the point made by commenter IV D 05' s that there is no need to rely on operating parameters when a direct measurement of emissions is being required.

As discussed at length in the proposal preamble ( 67 FR 44690), we considered requiring mercury continuous emission monitors ( CEM) that would directly measure in units of the standard. Although monitoring that directly measures compliance is preferred, we decided to propose mercury concentration operating limits based on the uncertainties associated with the cost and reliability of the mercury monitoring devices. Commenters did not provide any information to alleviate these concerns. In fact, as discussed in the subsequent comment, they shared our basic concerns even if the monitoring devices were only used for operating limits.

We weighed the comments related to the mercury concentration operating limits against the concerns associated with using mercury concentration monitors as CEM. Our preference continues to be to require mercury CEM. With sufficient evaluation, analysis, and refinement, the industry will find these devices acceptable. However, we could not require these devices in the final rule without a fallback alternative if sources found that these monitoring devices were not acceptable for use within the industry. 8 Hazardous Air Pollutant Emissions from Mercury Cell Chlor Alkali Plants. Background Information Document for Proposed Standards. EPA 453/ R 02/ 007. U. S. Environmental Protection Agency, Research Triangle Park, North Carolina. February 2002. Page 7 10. [ Air Docket A 2000 32 Item Number II A 02]

68 During the development of the proposed standards, we learned that many mercury cell chlor alkali facilities conducted periodic ( e. g., weekly, monthly) tests to determine the mercury content in vent streams. This is done to assess control device performance or, for the by product hydrogen stream, to ensure product quality. These tests are not typically conducted using EPAapproved test methods, but are usually conducted using modified methods. These methods were discussed in the Background Information Document for the proposed standards. 8 Since this periodic testing is already being conducted at many mercury cell plants, we evaluated whether a continuous compliance option could be included in the final rule based on such periodic testing.

Since such testing directly measures mercury emissions, we concluded that it would be an acceptable alternative to mercury CEM. The only question was how often such testing would be needed to ensure continuous compliance with the emission limitations. Daily testing would certainly be adequate, but we were concerned about the costs and burden associated with 365 tests each year for each process vent.

The most common final control device is ( or will be) nonregenerative carbon adsorption.

These fixed bed carbon devices can operate for long periods of time before a carbon change is needed. The carbon replacement frequency is often more than a year. Weekly testing would be more than sufficient to represent the emissions for the entire week and to indicate when breakthrough ( i. e., the point at which the carbon has become saturated with mercury emissions) is approaching. Because breakthrough does not occur instantaneously, but is slowly approached over time, weekly testing is sufficient to detect the point at which breakthrough is approaching.

However, there is the possibility that non carbon devices such as condensers, absorbers, or regenerative molecular sieves could be used as the final control device to comply with the emission limits in the final rule. Since improper operation of these devices could result in higher emissions for shorter periods, we had concerns about utilizing weekly testing for these devices.

However, we concluded that if parametric monitoring of surrogate parameters ( e. g., condenser 69 temperature) were conducted to ensure consistent and proper operation of these devices, weekly testing would be acceptable.

Therefore, the final rule includes two options for continuous compliance for the by product hydrogen stream, the end box ventilation system vent, and the mercury thermal recovery unit vent. The first option is continuous emissions monitoring using a mercury continuous emissions monitoring system. The second is periodic testing using Method 101, 101A, or 102 or an approved alternative method. Specifically, this second option requires that at least three acceptable test runs be conducted each week. As part of the periodic testing option, if the final control device is not a nonregenerative carbon adsorber, surrogate parameter monitoring is required.

Comment: Two commenters ( IV D 04, IV D 07) were concerned with EPA's proposed requirements for the installation of continuous monitoring systems ( CMS) for monitoring mercury emissions from by product hydrogen, end box ventilation system, and mercury thermal recovery unit vent streams. The commenters were concerned that not only had the technology not been demonstrated, but also that it might not be possible to develop such monitoring systems within the next few years. Furthermore, the commenters were seriously concerned whether such CMS could be installed and operated in hydrogen streams even if the technology could be demonstrated for non flammable streams. The commenters explained that hydrogen is highly flammable and any CMS used in a hydrogen stream would need to be designed to prevent explosions. Therefore,

according to the commenters, the regulation needs to be flexible enough to allow for the possibility that CMS cannot be developed for some or all of these streams.

One commenter ( IV D 04), a trade association, indicated that one of their member companies is working with EPA to determine whether a CMS can operate in the by product hydrogen, end box ventilation system, and mercury thermal recovery unit vent streams. The commenter was concerned that the test plan is insufficient to demonstrate long term plant reliability. In particular, the commenter doubted that the test program could be implemented and assessed sufficiently soon to allow for operation in the two year schedule required by the proposed regulation. The commenter also indicated that they are prepared to participate in a program to assess CMS instrumentation as applied to chlor alkali vent gas streams. In order to ensure that any testing program is comprehensive and reliable, the commenter stated that a 70 minimum of three years would be necessary. Therefore, according to the commenter, the regulation needs to be flexible enough to allow for the possibility that CMS cannot be developed for some or all of these streams.

Response: As discussed in responses to the previous comment and comments in section 2.3,

we believe that changes have been made in the final rule to address these concerns. First, the compliance date has been extended from two to three years from the promulgation date, thus allowing more time for evaluation of mercury continuous emission montitors. Second, an alternative continuous compliance approach based on periodic testing has been added should an owner or operator find that mercury continuous emission monitors are not feasible for their situation.

Comment: Two commenters ( IV D 04, IV D 07) stated that if the CMS technology can be developed and the Agency determines that the cost is reasonable, use of a redundant control system should be allowed in lieu of a CMS. According to the commenters, a redundant system ( e. g., the installation of a second carbon bed downstream of the primary carbon bed) would be more economical than installation and maintenance of a CMS and would minimize mercury emissions better. The commenters stated that in such an arrangement, the mercury concentration leaving the upstream bed would meet the regulatory requirements, and the downstream bed would be the redundant treatment unit. The commenters recommended that by periodically checking the mercury concentration leaving the upstream carbon bed, the facility can ensure compliance with the regulation because the downstream unit would be a protective device.

Response: We would not discourage the use of redundant control to ensure effective control of the mercury emissions. However, given our decision to allow weekly testing on any emission stream, we do not feel that it is necessary to includes provisions for less frequent monitoring if redundant control devices are present.

Comment: One commenter ( IV D 04) stated that the intent of the data collection requirements specified in § 63.8246( a)( 1) are unclear. According to the commenter, it is not feasible to get 90 percent operating time for a proven system, let alone the unproven systems proposed for the vent streams in a mercury cell chlor alkali plant. The commenter argued that for a proven system, achieving a 75 percent on stream time represents good reliability. Therefore,

the commenter proposed that the rule specify a 75 percent operating time instead of 90 percent. 71 Response: We agree with the commenter and have changed the minimum data requirements to 75 percent.

2.8 RECORDKEEPING AND REPORTING Comment: Two commenters ( IV D 04, IV D 07) suggested changes to the startup,

shutdown and malfunction ( SSM) provisions in § 63.8254( c). The commenters stated that they believe the proposed requirement for immediate reporting of startup, shutdown or malfunction events for which actions were taken inconsistent with the written SSM plan is overly burdensome.

The commenters stated that this requirement was removed from previous batch standards,

specifically Subpart JJJ ( Polymer & Resin IV, Table 1) and Subpart PPP ( Polyether Polyol, Table 1). According to the commenters, reporting these events along with the other SSM events on a semi annual basis in the Compliance Report is sufficient.

Response: The commenters are correct that the Polymer & Resin IV and Polyether Polyol rules removed the requirement for immediate reports of SSM events as specified by 63.10( d)( 5)( ii). However, the rationale for removing this requirement for the two cited rules does not apply to this rule, and the requirement for immediate reports of SSM events that do not conform to the SSM plan remains unchanged.

The Polymer & Resin IV and Polyether Polyol rules were patterned after the HON. During promulgation and litigation of the two cited rules, the HON itself was being modified and several changes made to the HON were brought over to these rules to maintain consistency. Dropping the requirement for immediate reports of SSM events as specified by 63.10( d)( 5)( ii) was just such a change. The comment and response document for Polymer & Resin IV cites to an intended consistency with the HON rule as the reason for the change. Since development of the Polymer & Resin IV and Polyether Polyol rules, the EPA has developed rules with the HON in mind, but has not felt obligated to maintain complete consistency. While the requirement for immediate reports of SSM events is not consistent with the HON or the cited rules, it is consistent with the majority of rules developed since those rules. A quick review of promulgated rules spanning 1999 to 2002 shows that requiring immediate reports of SSM events as specified by 63.10( d)( 5)( ii) is the norm. Further, the toxicity of mercury warrants more immediate attention to releases rather than less. 72 Comment: One commenter ( IV D 07) was concerned because a deviation is defined to include SSM events that fail to meet the emission limits or work practice standards. The commenter stated that they believed that EPA is requiring duplicative reporting for SSM events because these events are considered exceedances. Therefore, the commenter requested that EPA make the following revisions to § § 63.8248, 63.8254, and 63.8266:

§ 63.8248 What other requirements must I meet to demonstrate continuous compliance?

( a) Deviations. You must report each instance in which you did not meet each emission limitation in § 63.8190 that applies to you. This includes periods of startup, shutdown, and malfunction. You must also report each instance...

§ 63.8254 What reports must I submit and when? *** ( b) Compliance report contents. *** ( 8) For each deviation from an emission limitation ( emission limit and operating limit) occurring at an affected source... 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. This includes periods of startup, shutdown, and malfunction.

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 established by this subpart including, but not limited to, any emission limitation ( including any operating limit) or work practice standard; or ( 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 A failure to meet any emission limitation ( including any operating limit) or work practice standard in this subpart during startup, shutdown, or malfunction is not considered a deviation for the purposes of this subpart., regardless of whether or not such failure is allowed by this subpart.

Response: We do not agree with the commenter that the rule requires SSM events to be reported twice. The only time SSM events are required to be reported at times other than with the semiannual compliance report is when actions taken during startup, shutdown, or malfunction event are not consistent with the facility's SSM plan. Therefore, we have not made any changes to the final rule in response to this comment. 73 Comment: Two commenters ( IV D 04, IV D 07) suggested that an exception should be made for the records required by § 63.8258( b)( 3). The commenters recommended that to avoid burdensome paperwork, records pertaining to any required CMS need only be retained for the current calendar year plus one year due to the large volume of paper.

Response: We acknowledge the commenters' point that records of continuous monitoring can be voluminous, however, the option to keep these records in electronic format is provided in the proposed rule. Further, we feel that these records are important to our ability to ensure compliance with the rule. Therefore, we are not making any change related to records for continuous monitoring systems. [ Note: the commenters refer to § 63.8258( b)( 3) which does not exist; the proper references are § § 63.8256( b)( 3) and 63.8258( b) which specifies how long the records must be kept.]

2.9 DEFINITIONS Comment: Two commenters ( IV D 04, IV D 07) recommended that the second sentence of the definition for " Hydrogen System" should be modified as follows: " The hydrogen system begins at the decomposer and ends just downstream of the last control device." The commenters maintained that leaks in any systems downstream of the last control device do not matter.

According to the commenters, at this point, it is acceptable to vent the hydrogen stream to the atmosphere and still be in compliance with the permit requirements.

Response: We thank the commenters for this suggested clarification and have changed the definition of " hydrogen system" to read as follows:

Hydrogen system means all vessels, piping, and equipment that convey a by product hydrogen stream. The hydrogen system begins at the decomposer and ends at the point just downstream of the last control device. The hydrogen system includes all control devices.

Comment: Two commenters ( IV D 04, IV D 07) requested that the definition of "

byproduct hydrogen stream" be deleted because it is the same as " hydrogen system".

Response: The commenters did not offer any technical reasons for deleting the definition of " by product hydrogen stream." We do not see any possible reason for deleting this definition, as we see them as very different concepts. Therefore, we are not making any change related to the definition of these two terms.

2.10 ECONOMIC AND BENEFITS ANALYSIS 74 Comment: Two commenters ( IV D 04, IV D 05) stated that the Agency's estimation of the costs required to comply with both the floor standard and the " beyond the floor" standard are inaccurate. According to one commenter ( IV D 04), EPA estimated that it will cost the industry approximately $ 660,000 in total to install controls to comply with the MACT floor. Total annual operating costs for all the affected facilities ( which includes debt service on the capital cost value)

were estimated to be $ 570,000. However, the commenter noted that EPA did not present the cost bases for these estimates in the preamble. The commenter estimated that it will cost the industry millions of dollars to meet the required floor limitations. Furthermore, the commenter stated that EPA's estimate of the cost to meet the beyond the floor limitation, an additional $ 210,000 in capital costs ($ 150,000 in operating costs) for the nine affected facilities, is inaccurate. Again, EPA did not present a cost basis in the preamble for this estimate. The commenter maintained that the costs to meet the " beyond the floor" value are likely to be in excess of the $ 15 20,000 per plant value presented by EPA. Concluding that EPA had not adequately justified setting the standards at beyond the floor levels, Commenter IV D 04 stated that the standard should be set at the floor levels.

Response: The commenter has not provided any specific data or rationale to refute our economic analysis. Therefore we stand by our original analysis and are not proposing any changes to the economic analysis. We believe we have justified setting the standards at beyondthe floor levels and, with the exception of the hydrogen by product stream and end box ventilation system vents, we are not changing the proposed emission limits. In response to the commenter's statement that the basis for the cost estimates were not presented in the preamble, it has been EPA policy for some time to save Federal Register printing costs by presenting the bulk of the rationale and basis for different analyses in the Background Information Document ( BID).

The basis for all costs included in the economic evaluation are presented in Section 6.0 of the BID. The BID can be obtained from the EPA.

Comment: One commenter ( IV D 05) felt that the proposed NESHAP drastically understates the costs that facilities will likely incur to comply. The commenter has already committed to spend $ 2.3 million dollars to change out hydrogen coolers, seal less mercury pumps, and upgrading and sealing the concrete cell support beams. Additional projects to change the design of the cell end boxes and nickel lining the decomposer will cost approximately 75 $ 780,000. These costs do not account for the additional manpower needed to provide documentation or to buy the types of sophisticated instruments and monitors needed to meet many of the proposed NESHAP's recordkeeping and monitoring requirements. The commenter is anticipating the need to hire 5 additional staff at a cost of $ 375,000 annually to fully comply with the inspection, recordkeeping and leak response requirements in the NESHAP proposal.

The commenter also anticipates approximately $ 100,000 in capital costs for the purchase and installation of continuous monitors for cell point sources, and approximately $ 200,000 for the cell room monitor system. Maintenance and calibration costs will be an additional cost, which the commenter could not accurately predict at this time.

Response: We believe the commenter is making three points   capital costs are higher than estimated by the EPA; manpower costs for ongoing compliance activities are higher than estimated; and costs for the cell room continuous mercury monitoring system is higher than estimated.

The EPA commends the commenter for updating their facility with the purchase of new hydrogen coolers, seal less mercury pumps, and the upgrading and sealing of the concrete cell support beams. However, while these actions will improve the overall environmental performance of this facility, we do not believe that these actions are specifically required for compliance with the proposed standards, and therefore did not include them in our estimates of costs for the standards.

Addressing the commenter's estimated costs for compliance activities related to recordkeeping and monitoring activities, we provided rationale for our estimates of manpower and the cost of that manpower. The commenter did not provide rationale for the projected cost of 5 additional staff at an annual cost of $ 375,000. Nor did the commenter refute our rationale or estimates for manpower costs. Therefore, we do not see the need to reevaluate our original estimates of manpower costs.

Again, the commenter provided costs for a mercury cell room monitoring system but did not provide rationale or the basis for the provided cost estimate, and the commenter did not refute the rationale or costs we provided as part of proposing the standards. Therefore, we do not see the need to reevaluate our original estimates for the mercury cell room continuous monitoring system. 9Memorandum, from Bhatia, K., EC/ R Incorporated, to Rosario, I., EPA/ OAQPS/ ESD// MG. September 26, 2001. Background on Vent Control System Enhancements to Meet Regulatory Alternatives for Existing Mercury Emission Sources at Mercury Cell Chlor Alkali Plants. EPA Air Docket A 2000 02, Number II B 22.

76 Comment: One commenter ( IV D 04) called EPA's claim that 168 lb/ year ( 0.46 lb/ day) of mercury would be collectively reduced from the nine affected plants " speculative." The commenter noted that EPA's statement that a 168 lb/ year reduction would be a 48 percent incremental reduction from the floor reductions is erroneous. If the floor option results in an actual reduction of 1,225 lb/ year mercury emissions, than reducing another 168 lb/ year is only an incremental reduction of 14 percent, not 48 percent.

Response: We feel the commenter's primary point is that our estimation of expected emission reductions is speculative. We strongly disagree. The estimation of emission reductions is based on allowable emissions under the Part 61 Mercury NESHAP, actual emissions reported by industry, and calculated emission rates expressed as mass mercury emitted per mass chlorine produced. Calculating the various emission reductions is a simple math exercise. The portion of our evaluation that is subject to judgment and a proper understanding of technical points is the determination of what controls will be required for each plant in order to achieve the specified emission limits. The selection of controls for each plant and their performance is documented in the BID and in a memorandum in the docket. 9 The commenter did not provide comments on the selection of controls or their performance, therefore we are not persuaded to reevaluate this portion of our analysis.

Addressing the comment about incremental emission reduction, the commenter has misunderstood our calculation. Incremental emission reduction represents the emission reduction achieved in moving from the floor to beyond the floor level of control divided by the emissions allowed at the floor level of control or:

Incremental Emission Reduction s Floor Emis sions * 100 168 lb / yr 350 lb / yr * 100 48 %

       = 77 When this calculation is performed, the result is an incremental emission reduction of 48 percent.

The commenter has taken the incremental emission reduction of 168 lb/ year and divided it by the emission reductions achieved by the floor level of control; this is not the calculation we were representing.

As a point of clarification, the 168 lb/ year represents the emission reduction for hydrogen streams and end box ventilation system vents only. The total point source emission reductions achieved in moving from the floor level of control to beyond the floor levels is 194 lb/ year; this total ( considering rounding errors) includes the cited 168 lb/ year, 14 lb/ year for plants without end box ventilation systems, and 13 lb/ year for mercury thermal recovery unit vents.