### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY SECTOR POLICIES AND PROGRAMS DIVISION OFFICE OF AIR QUALITY PLANNING AND STANDARDS

OFFICE OF AIR AND RADIATION



### DATE: February 28

, 2014

SUBJECT: Updated Review of the Continuous Emission Monitoring and Continuous Opacity

Monitoring Data from the Pulp and Paper ICR Responses for NSPS Sources

FROM: Kelley Spence (EPA/OAR/OAQPS/SPPD/NRG)

TO: EPA

- HQ

- OAR

- 2012

- 0640

The purpose of this memorandum is to present the results of a n updated review of the Continuous Emission Monitoring System (CEM S ) and Continuous Opacity Monitoring System (COM S ) data provided by the pulp and paper industry in response to the 201 1 Information Collection R equest (ICR). This analysis is part of the U.S. Environmental Protection Agency’s (EPA) effort to review the New Source Performance Standards (NSPS) for kraft pulp mills (40 CFR part 60, subpart BB) in accordance with section 111(b)(1)(B) of the Clean Air Act (CAA).

S ection 111 (b)(1)(B) of the CAA mandates that the EPA review and, if appropriate, revise the existing NSPS at least every 8 years. The kraft pulp mills NSPS w ere promulgated in 197 8 and reviewed in 1986. The NSPS regulate opacity and emissions of particulate matter (PM) from new, modified, and reconstructed recovery furnaces, smelt dissolving tanks, and lime kilns at kraft pulp mills. The NSPS also regulate emissions of total reduce d sulfur (TRS) compounds from new, modified, and reco nstructed digesters, brown stock washers, multiple

- effect evaporators, condensate strippers, recovery furnaces, smelt dissolving tanks, and lime kilns at kraft pulp mills. On December 6, 2011, the Center for Biological Diversity, Greenpeace, and the Port T ownsend Air W atchers filed a complaint (Clean Air Act c itizen s uit) against the EPA to review the NSPS. This complaint resulted in a consent decree that requir ed the EPA to review the NSPS by May 15, 2013 for proposal and requires promulgation by March 1 4, 2014 for promulgation. See docket ID number EPA

- HQ

- OGC

- 2012

- 0730 for a copy of the consent decree.

As part of the NSPS review, t he EPA reviewed the CEMS and COMS data and presented the results of the review in a memorandum to the docket , which included recommendations for proposed emission limits and associated monitoring allowances

. 1 

### T he proposed new standards (40 CFR part 60, subpart BBa) were published in the Federal Register on May 23, 2013

. Once promulgated

, t he new standards will apply to affected sources at kraft pulp mills for which construction, modification or reconstruction commences on or after May 23, 2013. A number of public comments were received after the proposal that raised questions about the CEMS and COMS data pres ented at proposal

, which prompted further review and documentation of the data prior to promulgation of the rule

. This memorandum presents the results of the updated CEMS/COMS review.2



### Section I of this memorandum provides a summary of the t abulation and quality

assurance / quality control ( QA/ QC) analysis of the CEMS/COMS data provided by industry in response to the ICR survey. Section II of this memorandum discusses the analysis of the QA/QC ’d data

.

I. Data Assembly and QA/QC

The CEMS and COMS d ata w ere co llected from the pulp and paper industry in 201 1 in
response to a C A A section 114 ICR

. The three

- part survey was distributed by the EPA in February 201 1 and request ed information needed to perform various regulatory reviews, including the subpart BB NSPS review. This section of the memo discusses the pre

- proposal QA/QC of the CEM S and COM S data that were provided in response to the ICR.

The general approach for proce ssing the CEMS and COMS data was to extract the data, as received, from individual ICR responses into a tabulation spreadsheet. Separate tabulation spreadsheets were developed for recovery furna ce opacity

, lime kiln opacity, recovery furnace TRS

, lime kiln TRS , and TRS from other pulping process emission units . Tabs within each tabulation spreadsheet were labeled in the format of RTI facility code followed by emission unit ID with a period as a separator for the two values. If data were provided for multipl e stacks for a given unit, they were also extracted into separate worksheets with the same naming convention, followed by an indication of stack location in parentheses. For example, the unit R401 at RTI f acility 243 has two stacks and wa s represented by d ata in two separate worksheets with tabs labeled as follows: 243.R401 (N) and 243.R401 (S). A summary worksheet was included in each tabulation spreadsheet to link and tabulate the data provided for each emission unit. Emission unit ID, RTI facility ID, an d NEI site ID were provided to characterize the emission units; the “tab name ” of each worksheet from which the data are linked wa s provided ; and summary information such as annual average emissions, 99 th 

### percentiles , and maximum values were calculated. Th e count and percent of averaging periods exceeding limits under consideration were also calculated on both an annual and semiannual basis. The data from each summary worksheet were used for the data analys e s discussed in Section II in this document.

Spreadsheet templates for COMS and CEMS data were provided with part III of the ICR (P&P CEMS_PIII.xls). The ICR template requested 6

- minute average opacity values for a period of one year (87,600 opacity averages), as well as 1

- hour average and 12

- hour av erage TRS values for a period of one year. Alternative formats were also accepted. To some extent, the data extracted into the COMS and CEMS tabulation spreadsheets varied in format and type, depending on the facility and the unit, likely due to other stat e reporting and compliance requirements

. In some cases, respondents did not provide COMS or TRS CEMS data , or provided the data in an alternative format ( i.e

. , .pdf or .doc or .txt) that would have required extensive manipulation or re

- entry of data. Given the abundance of data sets provided in spreadsheet form that were “analysis

- ready

, ” it was elected not to tabulate data provided in an alternative form

. Mills that did not provide data in spreadsheet form were excluded from the quantitative analysis of the o pacity and TRS emission limit s , but the information these mills3



### provided was reviewed qualitatively to confirm that it was comparable to the “analysis

- ready” information provided by other mills

. All data provided were reviewed for erroneous CO MS or CEMS readings prior to proposal, and again following proposal based on comments questioning certain aspects of the proposal data sets

. The follo wing types of data were removed:

 Negative opacity and negative TRS concentration measurements which 

### were d eemed suspect and were removed to prevent artificial lowering of a unit’s annual average performance

.

 Measurements (including abnormally large values) corresponding with periods of zero (or negative) production values or periods labeled as “process down time” because emissions of opacity or TRS would not be expected when the process is down. These were removed to prevent the artificial increase in the annual average emissions associated with the unit.

 Measurements recorded during monitoring system malfunctions, out

- of

- control periods or repairs, and monitor QA/QC checks, calibration checks, or zero or span adjustments to the extent that these time periods were labeled in the data sets. These were removed to be consistent with the proposed rule requi rements that these data be excluded from compliance calculations

. The cells containing these values were highlighted to indicate removal of data . Large values reported during other periods were not deleted from the data set s

. Facilities were asked to indic ate in the ICR if any data were affected by periods of startup, shut down, and malfunction (SSM). Opacity and TRS emissions occurring during periods of SSM were retained in the continuous monitoring data averages analyzed in order to evaluate whether the up dated NSPS should distinguish betw een periods of startup and shutdown and normal operation as revised emission limits were considered. 1 

### In response to comments on the proposal analysis of the CEMS and COMS data, EPA also resolved double oxygen ( O 2 

### ) corrections for units pointed out by commenters, rechecked calculation references, ensured any O 2 

### correction calculations added to the data sets were based on the 12

- hour average TRS concentration and 12

- hour average O 2 

### concentration (consisten t with the r ule), and updated other information as needed. The resultant “cleaned” data sets after removal of the erroneous/inappropriate data described above were used for further analysis of the promulgated standards. The cleaned data sets replace and supersede the pre

- proposal data sets

. Based on the part III survey responses, there were 1 51 recovery furnaces and 13 1 lime kilns at 98 kraft pulp mills in 2009. Of these, two recovery furnaces were indicated as non

operational during the year of the ICR, resulting in 149 operating recovery furnaces. These two units were the following: RF18 at Longview Fiber and Packaging (RTI 156, NEI42338) and EU445A at International Paper in Springfield (RTI 105, NEI45182).

1 Although malfunction data were not removed from the data sets, malfunction data were noted as invalid in analyses where these data would have been inappropriate for use (e.g., when setting the upper TRS concentration limits).4



### A summary of the type of recovery furnace COMS and TRS CEM S data received and the comments from our QA/QC are listed in Appendix A. Similarly, a summary of the type of lime kiln COMS and TRS CEMS data and our QA/QC comments are listed in Appendix B.

A. Recovery Furnace Opacity Data

C ontinuous opacity monitoring system data were provided for 13 7 of the 149 operating recovery furnaces . Of the 13 7 units with data provided, 13 5 were extracted into a comp i led recovery furnace COM S spreadsheet containing individual worksheets for each unit

. Th ere were 2 5 units with multiple

- stack opacity data. The two units with data that were not extracted into the
sp readsheet were not provided in E xcel format. The data for 117.B21 were provided as

. pdf and the data for 155.RECOVERY FURNACE were provided in W ord format (.doc). Recovery furnace design ( direct contact evaporator [ DCE ] or non

- direct contact evaporator [ NDCE ] ) and air pollution control device ( APCD ) type were added to the spreadsheet from the part III database. In all, adding in emis sion units with COMS on multiple stacks, 160 COMS data sets were available for analysis.

The order of preference for opacity averaging period extracted into the opacity tabulation spreadsheet was 6

- minute averages followed by 1

- hour average s . Of the data provided, 5 units were extracted in the 1

- hour format (1 unit with multiple stacks) and the remaining units were extracted in the 6

- minute average format.

T he recovery furnace COMS summary worksheet summarizes the data type as “ 6

- minute averages, ” “ hourly averages, ” “ data not provided, ” or indicates if data are provided in alternate format. For each COMS, the summary spreadsheet contains the maximum opacity, the
average ( including and excluding exceedances )

, the standard deviation, the 99 th 

### percentile, the median, and the number (and percentage) of opacity 6

- minute average values over 20 percent and 35 percent

. The number of averaging periods in which valid opacity data were provided is also indicated along with the percent of periods that exceeded the limits under consideration

.

B. Recovery Furnace Total Reduced Sulfur (TRS) CEMS Data

Total r educed s ulfur CEM S data were provided for 13 5 of the 149 operating recovery furnaces

. Of the 13 5 units with data provided, 1 31 were extracted into a comp i led recovery furnace TRS CEMs spreadsheet containing individual worksheets for each unit

. There were 1 0 recovery furnaces with multiple stack TRS data. The four units with data that were not extract ed into the sp readsheet were not provided in E xcel format. The data for three of these units were provided in W ord format and one unit was provided as a PDF document

. In all, adding emission units with multiple stacks, 141 TRS CEMS data sets were available for analysis.

As noted previously, s eparate TRS CEMS spreadsheet templates requesting 12

- hour and 1

- hour average TRS data for a perio d of one year were provided with p art III of the ICR . The 1

- hour average data were requested in addition to the 12

- hour average data in order for EPA to explore shorter averaging times should there be a prevalence of shorter TRS averaging times required by s tate r egulations . However, based on a review of permit limits and of the CEMS data provided

, it appears that a 12

- hour averaging time is most consistently used for compliance.5



### Therefore, t he order of preference for TRS averaging time extracted into the tabulatio n spreadsheet used was 12

- hour averages, followed by 12

- hour averages manually calculated based

on 1

- hour averages, with 24

- hour averages being least desirable . Of the TRS data provided, 11 4 recovery furnaces were extracted in the 12

- hour average format (9 units with multiple stacks) , 1 0 units in the 12

- hour average calculated based on 1

- hour averages , and 7 units in the 24

- hour format (1 unit with multiple stacks)

.

The CEM S spreadsheet template that was sent to industry with part III of the survey (P& P CEMS_PIII.xls) requested that a facility report the “ 12

- hour average emission value for TRS (ppmdv corrected for % O 2 

### ) ” in column I with the instructions “ p lease enter concentration (ppmdv) corrected for % O 2 

### as required by subpart BB (8% O 2 

### for recovery furnaces; 10% O 2 

### for other equipment for which data are requested).” The spreadsheet template also requested that a facility report the “ % O 2 

### correction (by volume, dry basis) ” in column J with the instructions to enter “t he % O 2 

### correction by volume (dry basis) (e.g

. , 8% or 10%). ” For the recovery furnace TRS CEM S , it was expected that the O 2 

### correction would be reported as 8 percent in column J

. The oxygen correction data for 7 units (127.REC1, 171.02, 171.03, 171.04, 183.002, 207.038, and 340.005) repor ted in column J appeared to be raw O 2 

### data instead of the requeste d corrected O 2 

### value of 8 percent

. It was assumed

, because raw O 2 

### data were reported instead of the correction value

, that the TRS data provided in column I w ere also raw data. The raw TRS and O 2 

### values were used to determine the corrected TRS value using Eqn. 1 shown below from 40 CFR 60.284(c)(3)

. 2 

### The new TRS column was highlighted in yellow for the 7 units reported for which values were calculated. Unit 163.RF1901 had d ata reported as corrected to 10 percent O 2 

### and unit 242.AA

- 011 had data as corrected to 5 percent O 2


### . These units were corrected to 8 percent O 2


### . The data for two units (100.037A, 143.7000) were indicated as raw data. These values were also corrected using Eqn. 1 and the corrected TRS value column was highlighted in yellow.

Corrected TRS value = Raw TRS concentration value * ((21

- 8)/(21

- O 2 

### value)) ( Eqn. 1 )

Data provided for five units (179.RF3, 240.RF04, 240.RF01, 163.RF1901, and 163.RF2904 ) may slightly skew the performance values ( e.g. , annual average, median, 99 th 

### percentile) for those units high because data w ere reported as “<1” instead of decimal values. These values were not removed or edited ; therefore

, they did not contrib ute to the performance values

, but the reporting of the data was considered in the analys is

. 3



### The summary worksheet in the recovery furnace TRS CEM S spreadsheet indicated the data type as “ 12

- hr average, ” “ 12

- hr calculated from 1

- hr averages ,” “ 24

- hr average, ” “ not

2 Commenters expressed conc ern about the potential for double correction for oxygen in the pre

- proposal analysis. Upon further examination of the data sets following proposal , we determined that the impact of the potential double correction on our conclusions relative to the propos ed emissions limits and monitoring allowances is insignificant because the number of exceedances of the proposed standard was similar in the original TRS concentration column and the potentially double

- corrected TRS concentration column of each CEMS data s heet. Therefore, we did not burden ICR respondents with follow

- up questions on the TRS CEM S data, nor did we remove the 7 potentially double

- corrected data sets from the analysis.
3 Upon further examination of these units following proposal, these values h ad no significant effect on any conclusions presented in this memorandum.6



### provided, ” or indicated whether data are provided in alternative format. The annual average and standard deviation of the corrected TRS parts per million (ppm) 4 

### values were calculated for each unit (to determine 99 th 

### percentiles) , as well as the maximum reported average and the n umber of exceedances over 5 ppm

. Because most DCE recovery furnaces are not currently subject to the NSPS, the 20 ppm emission guideline for DCEs was also used for comparison. The emission guideline for ND CEs is 5 ppm (the same as the NSPS , though permitting approaches vary by
state ). Additional details such as APCD type, NSPS applicability, and whether or not the recovery furnace burns non

- condensable gases (NCG) were imported into the CEMS tabulation
spre adsheet for analysis.

C. Lime Kiln TRS CEMS Data

Total r educe d s ulfur CEMS data were provided for 11 5 of the 131 operating lime kilns

. Of the 11 5 units with data provided, 11 0 units were extracted into a comp i led lime kiln TRS CEMS spreadsheet containing individual worksheets for each unit

. Data for one kiln was not used based on public comment that the respondent provided uncorrected data (and did not provide the actual O 2 

### percent to correct it with). The four kilns with data that were not extracted into the sp readsheet were not provided in E xcel format. The data for two of these kilns were provided in text format (.txt), one kiln was provided in W ord format

, and one kiln was provided

as a PDF document

. In all, 11 0 T RS CEMS data sets were available for analysis.

Similar to recovery furnaces, the order of preference for TRS averaging period for lime kilns was 12

- hour averages, followed by 12

- hour averages calculated based on 1

- hour averages, with 24

- hour averages being least desirable . Of the data provided, 90 kiln s were extracted in the 12

- hour average format, 1 2 kiln s were extracted in the 1

- hour average format, and 8 were extracted in the 24

- hour format. The 1

- hour average TRS data sets were converted to 12

- hour average format for comparison purposes.

T he O 2 

### correction data for 7 lime kilns (127.LK1, 127.LK2, 164.P12, 171.009, 171.010, 183.004, and 340.008) reported in column J of the ICR template appeared to be raw O 2 

### data instead of the requested corrected O 2 

### value of 10 percent . The raw TRS and O 2 

### values were used to determine the corrected TRS value using Eqn. 1 above. 5 

### Units 119.EQT006, 103.G

- 65, and 105.EU455 had data reported as corrected to 8 percent O 2 

### ; therefore

, a new column was added (highlighted yellow) with the data c orrected to 10 percent . Raw data were reported for unit 143.6063, which w ere used to calculate the corrected TRS values.

4 All parts

- per

- million values reported in this document represent ppm by volume on a dry basis (ppmdv)

. 5 Commenters expressed concern about the potential for double correction for oxygen in the pre

- proposal analysis. Upon further examination of the data sets following proposal , we determined that the impact of the potential double correction on our conclusions relative to the proposed emissions limits and monitoring allowances is insignificant because the number of exceedances of the proposed standard was similar in the original TRS concentration column and the potentially double

- corrected TRS concentration column of each CEMS data sheet. Therefore, we did not burden ICR respond ents with follow

- up questions on the TRS CEM S data, nor did we remove the 7 potentially double

- corrected data sets from the analysis.7



### Data provided for four units (163.LK1501, 163.LK2502, 179.LK3, 240.CA81) may skew the annual performance values (e.g., annual average, 99 th 

### percentile) for those units because data were reported as “<1” instead of decimal values. These values were not removed or edited ; therefore

, they did not contribute to the performance values

, but t he reporting of the data

was considered in the analysis. 6



### A summary worksheet was added to the lime kil n TRS CEMS spreadsheet to characterize the data provided. Emission unit ID , RTI facility ID, and NEI site ID were provided to characterize the emission units. The name of the worksheet for which the data were calculated for each row of data was provided as “tab name

, ” and data type was indicated as “ 12

- hr
average, ” “ 24

- hr average, ” “ not provided, ” or if provided in alternative format. The ann ual average and standard deviation of the corrected TRS ppm values were calculated for each unit (to determine 99 th 

### percentile) , as well as the maximum

, average and the number of exceedances over 8 ppm

. Because some lime kilns are not currently subject to NSPS, the 20 ppm emission guideline was also used for comparison. Additional lime kiln details such as APCD type, NSPS applicability, whether or not the lime kiln burns non

- condensable gases (NCG), or us es a white

liquor NCG pre

- scrubber were imported into the CEMS tabulation spreadsheet for analysis.

D. Lime Kiln Opacity Data

Lime kiln opacity data were compiled in order to establish a limit for lime kilns with electrostatic precipitators ( ESPs ) under the NSPS. Continuous opacity monitoring system data were provided for 27 lime kilns that utilize ESPs or ESP/scrubber combinations as pollution control devices. These were extracted into a compiled lime kiln COMs spreadsheet containing individual wo rksheets for each unit. T here were 2 units with multiple stack opacity data. The order of preference for opacity averaging period extracted into the opacity tabulation spreadsheet was 6

- minute averages and 1

- hour average. There were 25 units extracted in t he 6

- minute average format and 2 extracted in the 1

- hour format. Including kilns with dual stacks, 29 data sets were available for analysis.

The lime kiln COMS summary worksheet summarizes the data type as “6

- minute averages” and “hourly averages.” The ma ximum opacity, the average, the standard deviation, the 99 th 

### percentile, the median, and the number (and percentage) of opacity average values over 20 percent were calculated

.

II. Data Analysis

The updated s ummary data from the recovery furnace and lime kiln COMS and TRS CEMS spreadsheets described in Section I were plotted and compared to the current NSPS limits in order to evaluate the accuracy of the proposed regulatory options and finalize the regulatory options for the NSPS review. A nnual average measurements and the 99 th 

### percentile of the

6 Upon further examination of these units following proposal, these values had no significant effect on any conclusions pr esented in this memorandum.8



### averaging periods were plotted for each emission unit and used to evaluate each opacity or TRS emission limit

. The 99 th 

### percentile was used as an indicator of the emission limitation consistently met by each emission unit. The percent of averaging periods exceeding the opacity or TRS limit under consideration was calculated and plotted on both an annual basis (as was d one for proposal) and on an semiannual basis (in response to comments on the proposal) to evaluate appropri ate monitoring allowances to be coupled with each opacity or TRS emission limit. Distinctions in furnace design and control systems , and current emissions allowances in the NSPS, were considered in the CEMS and COMS analyse s as described in more detail in the following sections. In addition, emission units were identified as either NSPS units (currently subject to subpart BB) or non

- NSPS units (uni ts that have not triggered subpart BB) when appropriate. Emission units that have previously triggered NSPS subpart BB were further subdivided into new units and modified units in some cases.

A. Recovery Furnace COMS Analysis

Opacity limit evaluation

. The subpart BB kraft pulp mill NSPS contain a 35 percent limit for opacity from recovery furnaces and do not distinguish between recovery furnace design (DCE or NDCE). The NSPS require opacity to be recorded as 6

- minute averages, and allow 6 percent of the 6

- m inute averages per quarter recorded to be in exceedance of the 35 percent limit. Ap pendix C contains graphs of the updated recovery furnace opacity data

. The horizontal axis represents each emission unit , but is not labeled with emission unit IDs because this would make the figures too difficult to read. A total of 160 COMS data sets were graphed (including multiple data sets for furnaces with separate COMS for dual stacks). The majority (15 4 ) o f the COMS data sets graphed were 6

- minute averag e data

. S ix data sets were based on hourly average. The hourly data sets were generally within the range of the 6

- minute average data

. Figure 1 in Appendix C presents the annual average of the opacity readings for each recovery furnace COMS data set (160 data sets)

. Based on this figure, it does not appear that

r ecovery furnace design affect s opacity

. The highest annual average opacity was 17 percent, well bel ow the 35 percent NSPS limit. Figures 2 and 3 show annual average opacity by control type (within DCE and NDCE groupings in Figure 2). The primary control types are wet

- bottom ESP (WBESP), dry

- bottom ESP with a dry PM return system (DBESP), and dry

- bottom ESP with a wet PM return system (DBESP

- WPR). Figures 2 and 3 reveal no clear distinction between recovery furnace control system and opacity.

Apart from the monitoring allowance discussed below, c ompliance is based on each individual averaging period and not the annual average . T herefore, the 99 th 

### percentile and percent of averaging periods exceeding 35 percent were graphed in order to understand how opacity varies

. Figure 4 in Appendix C presents the 99 th 

### percentile values from e ach of the 160 COMS data s ets. From Figure 4

, it is apparent that the majority of mi lls are consistently meeting the NSPS limit of 35 percent opacity. The s ubpart MM NESHAP contains a 20 percent opacity monitoring action level for new and existing recovery furnaces (40 CFR 63.864(k) (1) (i))

. For new recovery furnaces equipped with an ESP, subpart MM considers opacity greater than 20 percent for more than 6 percent of quarterly operating time to be a violation of the subpart MM standards (40 CFR 63.864(k)(2)(i))

. Figu re 4 shows that most ( 136 of 160 data sets ) recovery furnac e COMS had 99 th 

### percentiles below the 20 percent level regardless of recovery furnace9



### design

. Figures 5 and 6 break out 99 th 

### percentile opacity by control type (within design groupings in Figure 5). Figures 5 and 6 show that most control types are capable of meeting 20 percent opacity consistently , and that all control types are meeting 35 percent consistently. Two unique control systems (a parallel DBES P

- WPR/DBESP/DBESP syste m and a two

- sided dry and wet bottom ESP) had 99 th 

### percentiles around 25 and 27 percent, respectively

. The annual averages for these two unique systems were around 14 and 10 percent, respectively.

Based on Figures 1 through 6 in Appendix C

, 20 percent opacity was proposed and remains an acceptable regulatory option for the final NSPS review because: (1) 20 percent is already a benchmark under subpart MM, (2) all mills had annual average opacity o f 17 percent or less, and (3) the majority of recovery fur naces are consistently achieving 20 percent opacity

. The EPA could have consider ed hi gher or lower options (e.g., 25 percent or 15 percent )

, but these do not have the benefit of relating to subpart MM. A n opacity limit of 20 percent is still considered ade quately demonstrated for recovery furnaces.

Monitoring allowance evaluation

. In the pre

- proposal analysis of the COMS data, monitoring allowance calculations for opacity were conducted on an annual basis. Commenters on the proposal requested that EPA evaluate the monitoring allowances on the same time period as will be used for compliance instead of evaluating the allowance on an annual basis and then using a shorter quarterly or semiannual timeframe for compliance calculations of the monitoring allowa nce. A semiannual timeframe was selected for the final rule consistent with the semiannual reporting frequency in 40 CFR 60.288a(a). EPA revised the annual monitoring allowance calculations presented at proposal using the updated data sets, and added analy sis of the monitoring allowance on a semiannual basis in response to comments.

Figures 7 through 9 in Appendix C review the percentage of averaging periods (on an annual basis) exceeding the current 35 percent NSPS opacity limit, as compared to the current 6 percent monitoring exceedance allowance

. Similarly, Figures 10 through 12 in Appendix C show the percentage of averaging p eriods exceeding 20 percent opacity

. Figures 7 through 9 show that the overwhelming majority of mills are performing far better than the 6 percent monitoring allowance for opacity above 35 percent regardless of recovery furnace design or APCD type

. These figures show that a 1 to 2 percent mon itoring allowance more accurately represent s the number of exceed a n ces mills are incurring under a 35 percent opacity limit

. Twenty

- eight recovery furnace COMS had zero exceedances of the 35 percent limit.

As to be expected, the percent of averaging periods that are exceedances increases when an opacity limit of 20 percent is considered (instead of 35 percent). Nevertheless, Figures 10 through 12 show that a 2 percent monitor ing allowance coupled with a 20 p ercent limit is achieved by many recovery furnaces regardless of design or control system

. One of the unique control systems mentioned above (the parallel DBESP

- WPR/DBESP/DBESP system) would be challenged to remain under a 2 percent monitoring allowance b ut because alternative control designs are both available and adequately demonstrated, it is not clear if th is unique system would continue to be used if this furnace were to be replaced, modified, or reconstructed. A 6 percent monitoring allowance would c over nearly all exceedances of the 20 percent opacit y limit and is consistent with subpart MM (but a 6 percent allowance would not provide much incentive for improvement compared to a 2 percent allowance)

. A 2 percent monitoring allowance more10



### accurately represents the number of exceed a n ces the best performing recovery furnaces were incurring on opacity limits ranging from 20 to 35 percent

. Only 8 of 160 recovery furnaces COMS had zero exceedances of the 20 percent opacity limit which supports the need for having a monitoring allowance

.

As mentioned above , the EPA repeated monitoring allowance calculations based on a semiannual reporting period instead of the annual basis used for the proposal. Table 1 summarize s the number of COMS data sets analyzed for new, modified (or reconstructed), and existing recovery furnaces. The number of COMS data sets in compliance with the proposed opacity standard and monitoring allowance before proposal and in the final data sets i s indicated. The values presented from the proposal analysis represent calculation of the opacity monitoring allowance on an annual basis, while the values from the final analysis reflect the revised data sets and calculation of the opacity monitoring allo wance on a semiannual basis. Use of a semiannual basis for calculating the opacity allowance resulted in only minor differences in the number of emission units that would not be in compliance with the proposed opacity standard and monitoring allowance. The semiannual allowance calculation would ch ange the compliance outcome for only 3 out of 160 recovery furnace COMS data sets

.

Table 1. Summary of Recovery Furnace COMS Data Sets Analyzed

Unit NSPS Classification 1 Proposal data set 2 Final data

set 3 Notes No. of COMS data sets 160 New 52 Modified 32 Existing (not subject to NSPS) 76 No. of COMS meeting 20% opacity with a 2% allowance 144 141

New 45 44 Modified 30 30 Existing (not subject to NSPS) 69 67 No. of COMS not meeting 20% opacity with a 2% allowance 16 19

New 7 8 Installation dates ranged from 1978 to 1991. The semiannual percentage of periods exceeding 20% opacity ranged from 0.59 to 8.05%. Four of the 8 units in the final data s et achieved a 4% allowance in both semiannual basis. Modified 2 2 Two stacks having separate COMS on a furnace that became subject to the NSPS in 1990. The semiannual percentage of periods exceeding 20% opacity ranged from 1.26 to 7.72%. Neither of these COMS achieved a 4% allowance in both semiannual periods. Existing (not subject to NSPS) 7 9 5 of the 9 units in the final data set achieved a 4% allowance on a semiannual basis. The semiannual percentage of periods exceeding 20% opacity ranged from 0.39 to 35.2%. 1. New and modified units are defined in terms of the subpart BB NSPS 1976 applicability date (not the more recent subpart MM applicability date). 2. The monitoring allowance was calculated on an annual basis in the proposal data set ( Reference 1). 3. This column refers to the monitoring allowance calculated on a semiannual basis using the final updated data set presented in this memorandum.11



### Figures 13 through 15 in Appendix C show the percentage of averaging p eriods exceeding 20 percent opacity on a semiannual basis and indicate that that a 2 percent monitor ing allowance (on a semiannual basis) coupled with a 20 percent limit is achieved by most recovery furnaces regardless of design or control system.

Figures 16 through 18 in Appendix C depict semiannual monitoring allowance calculations for only those recovery furnaces that triggered the subpart BB NSPS as new or modified units after the 1976 subpart BB applicability date . Figure s 16 through 18 show that the 2 percent monitori ng allowance for recovery furnace opacity is achieved by most recovery furnaces regardless of their control system or their prior NSPS classification as new or modified units

. While a few recovery furnaces that became subject to the NSPS when they were installed new or were modified did not achieve 20 percent opacity with a 2 percent allowance for one or more semiannual periods

, it is notable that these units all became subject to the NSPS over 20 years ago. Recovery furnaces that have come online as new units or been upgraded over the past decade showed compliance with the proposed 20 percent opacity limit with a 2 percent monitoring allowance.

One commenter on the proposal su ggested a 4 percent monitoring allowance for recovery furnace opacity. Based on the data in Figures 13 through 18, although a 4 percent allowance would provide some additional flexibility, it would not resolve the issues noted for all of the new and modifi ed NSPS units in Table 1 that did not meet 20 percent opacity with a 2 percent allowance. The two modified recovery furnaces that did not meet th e 2 percent allowance also did not meet a 4 percent allowance in both semiannual periods

.

Recommendation

. The figures in Appendix C support the proposed regulatory decision to reduce the subpart BB opacity limit from 35 percent to 20 percent and to reduce the monitoring allowance from 6 percent to 2 percent for new, modified, and reconstructed recovery furnace s

. Overall, 141 of 160 total recovery furnace COMS data sets demonstrated that the 20 percent opacity limit with a 2 percent monitoring allowance proposed for subpart BBa was achieved with a semiannual monitoring allowance calculation

. Consequently, it i s recommended that the 20 percent opacity limit and 2 percent monitoring allowance for new, modified, and reconstructed recovery furnaces be finalized as proposed.

Startup and shutdown periods were included in the data sets used to evaluate the revised
op acity limit. Therefore, a revised limit of 20 percent opacity with a 2 percent monitoring allowance accounts for startup and shutdown periods (as well as normal operation)

, supporting the conclusion that separate opacity limits for startup and shutdown are unnecessary. Continuous compliance with the NSPS opacity limit can be demonstrated through monitoring of control device operating parameters (e.g.

, ESP secondary voltage and current or power) during tim es when the 2 percent monitoring allowance is invoked.

B. Recovery Furnace TRS CEMS Analysis

TRS limit evaluation

. The subpart BB kraft pulp mill NSPS limit TRS emissions from straight recovery furnaces to 5 ppm at 8 percent O 2 

### and from cross recovery furnaces to 25 ppm at 8 percent O 2 

### . Review of the part III ICR data indicate s that no cross recovery furnaces are12



### currently subject to the NSPS. Likewise, there are no TRS emissions data to analyze for th ese units. M aintain ing the current cross recovery fu rnace TRS limit is recommended for three technical reasons. First, the sulfur content of the semichemical liquor is higher than traditional kraft liquor. Second, the heat content of the liquor is lower because it contains less organic material than kraft p ulping liquor because of higher pulping yields. Lastly, the heavier sulfur loading and the lower operating temperature puts a restriction on the amount of excess oxygen available to oxidize sulfur compounds. W e do not project any modified, reconstructed

, o r new cross recovery furnaces being constructed in our analysis

. The remainder of this section will focus on TRS emissions from straight recovery furnaces.

The subpart BB NSPS require TRS to be recorded as 12

- hour averages and allow 1 percent of the 12 hour averages recorded per quarter to be in exceedance of the 5 ppm limit without constituting a violation. As noted previously, t he EPA is finalizing a semiannual period for the monitoring allowance calculation consistent with the semian nual reporting frequency in 40 CFR 60.288a(a). EPA revised the annual monitoring allowance calculations presented in this section using the post

- proposal updated data sets, and added an analysis of the monitoring allowance on a semiannual basis in response to comments.

Appendix D contains graphs of the updated recovery furnace TRS data. A total of 1 31 recovery furnaces are represented by these graphs (including 1 0 recovery furnaces with multiple TRS CEMS for a total of 14 1 TRS data sets) , with the majority reported as 12

- hour averages. The TRS emission guidelines require a limit of 5 ppm for exi s ting NDCE and 20 ppm for existing DCE recovery furnaces. All of the recovery furnace TRS ppm values discussed in this section reflect conversion to 8 percent O 2


### . The plots in Appendix D present t he recovery furnace TRS summary data from the summary spreadsheet described in Section I. Most of the TRS values shown on the plots are based on 12

- hour averaging periods ; h owever, seven of the TRS data sets (for non

- NSPS f urnaces) are ba sed on 24

- hour average values. T he graphs distinguish between NSPS and non

NSPS recovery furnaces because there are separate Federal TRS limits for existing and new sources under the emission guidelines and NSPS, respectively. Recovery furna ce design and NSPS applicability appear to be more relevant than control device type in distinguishing between the best performing recovery furnaces for TRS. Process control factors (e.g., good combustion practices ) are expected to play a large role in recovery furnace TRS emissions.

As shown in Figure 1 in Appendix D, m any DCE recovery furnaces that are not s ubject to the NSPS TRS limit exhibit emissions above 5 ppm but belo w the 20 ppm emission guideline on an average basis ( i.e., the average of the block averaging periods provided for the year)

. On average, all but one of the NDCE recovery furnaces met the 5 ppm limit, and most of the NDCEs averaged below 2 ppm.

Apart from the 1 percent monitoring allowance, compliance with the NSPS TRS lim it is based on each 12

- hour block average (rather than the average of all 12

- hour blocks in a year)

. Therefore, we considered the 99 th 

### percentile of the TRS averaging periods in Figure 2 as an indicator of how consistently the block average limit is achiev ed

. Two 99 th 

### percentile outliers were omitted from Figure 2 (a non

- NSPS DCE with 99 th 

### percentile at 126 ppm, and a NDCE13



### subject to the NSPS with 99 th 

### percentile at 43 ppm). When considering the 99 th 

### percentile, nearly all of the DCE furnaces had TRS emissions above 5 ppm while the majority of NDCE furnaces achieved 5 ppm consistently

. Most of the DCE furnaces had 99 th 

### percentile values between 5 ppm and 20 ppm, with a few DCE furnaces exhibiting 99 th 

### percentile values between 20 and 30
ppm.

We also considered the number of averaging periods in excess of 5 ppm for each recovery furnace in Figure 3. Predictably, the DCEs exhibited a high percentage of averaging periods (on an annual basis) above 5 ppm because most DCEs are not r equired to consistently meet the 5 ppm limit. The majority of NDCEs achieved the 5 ppm limit consistently with 1 percent or fewer of the averaging periods (on an annual basis) in excess of 5 ppm. As noted previously, s ubpart BB contains a 1 percent monitoring allowance for recovery furnace TRS

. A few NDCE furnaces had a relatively high percentage of averaging periods (on an annual basis) in excess of 5 ppm, but these were mostly non

- NSPS NDCEs.

Only the recovery furnaces subject to the NSPS were plo tted in Figures 4 through 6 in order to better evaluate the 1 percent TRS monitoring allowance (on an annual basis) and the effect of different types of air pollution controls

. As shown in Figure 4, two of the three DCEs subject to the NSPS exceeded 5 ppm in less than 1 percent of the averaging period s. One of these DCEs had zero exceedances. The third DCE (controlled by a WBESP and scrubber) exceeded the 5 ppm limit in 46 percent of the averaging periods, which again suggests that DCEs are challenged to meet a TRS limit of 5 ppm. Many of the NDCEs ( 44 of 72 ) subject to the NSPS achieved the 5 ppm limit with zero exceedances during the year reported

. An additional 14 NDCEs had some exceedances but remained below the 1 percent monitoring allowance

, and 8

un its exceeded 5 ppm for 1 percent of the reporting periods. Six NDCEs exceeded 5 ppm in up to 8 percent of the averaging periods

. Figure 5 shows that there is little difference in the performance of various control systems used on NSPS recovery furnaces

. All systems achieved the 5 ppm limit on an annual basis , with the exception of the DCE controlled by a WBESP in conjunction with a scrubber. In Figure 6, we observe that control device type does not appear to significantly affect the 99 th 

### percentile TR S value for the NSPS recovery furnaces

. Few recovery furnaces had a 99 th 

### percentile TRS value in excess of 5 ppm, including a unique system with a two

- sided dry

- and wet

- bottom ESP. The 99 th 

### percentile values shown on this figure indicate that most of the NSPS recovery furnaces are achieving 5 ppm 99 percent of the time , regardless of APCD type

. Although the annual average of the TRS averaging periods (shown in Figure 5) seems to suggest that a limit lower than 5 ppm ( e.g., 3 ppm) is achieved, the 99 th 

### percentile TRS value in Figure 6 reflects the variability exhibited in each block average and affirms that a limit of 5 ppm provides for the variability in TRS expected from the best performing sources

. Figure 7 in Appen dix D investigates the e ffect on DCE recovery furnace TRS emissions i f multiple

- stage black liquor oxidation (BLO) is used prior to the DCE. Of the three NSPS DCE recovery furnaces, two units ha d two

- stage BLO systems and one ha d a single

- stage BLO system. A total of 12 recovery furnaces with data were indicated as single stage BLO (3 units with multiple stacks) and 1 4 recovery furnaces with T RS data were indicated to have two

- stage BLO, and four ha d three

- stage BLO systems

. The TRS data in Figure 7 are inconclusive as to14



### whether multiple

- stage BLO systems reduce TRS emissions better than single

- stage systems. Most of the BLO systems did not achieve the 5 ppm NSPS limit.

Figures 8 and 9 explore the impact of burning NCGs. Figure 8 shows the impact of burning NCGs on the annual TRS average

, and Figure 9 shows the impact on the 99 th 

### percentile. B urning NCGs did not appear to significantly increase recovery furnace TRS emission s , but it did indicate an increase in the potential for TRS emissions variability as evidenced by the greater range i n 99 th 

### percentiles for the NCG

- burning NDCE furnaces in Figure 9

. Monitoring allowance evaluation

. In the pre

- proposal analysis of the TRS CEMS data, monitoring allowance calculations for TRS were conducted on an annual basis. The annual

- basis analysis was repeated with updated data sets, and a semiannual monitoring allowance calculation was added as discussed later in this subsection. As shown in Figure 4 of Appendix D , most recovery furnaces subject to the NSPS have achieved a 5 ppm TRS limit with 1 percent or less monitoring deviations (on an annual basis) during normal operations and startup and shutdown periods . The TRS CEMS data shown i n Figure 4 include periods of startup and shutdown , and show that many mills comply with the TRS limit in spite of startup and shutdown periods. The TRS CEMS data were reviewed closely to determine the impact of removal of the SSM exemption in 40 CFR 60.284(e)(1) and continuous application of the 5 ppm limit to startup and shutdown periods in addition to normal operations. Periods of malfunction and process downtime ( i.e., when BLS firing ceases) were excluded from consideration because these are not valid operating periods for rulemaking. The TRS CEMS data reveal that some exceedances of a 5 p pm limit falling within the 1 percent monitoring allowance are associated with periods of startup and shutdown. To ensure that the standard is continuous, an upper limit ( i.e.

, a cap) was determined. Table D

- 1 in Appendix D shows the CEMS data for periods of startup and shutdown. After removing the extreme values for reasons noted in the table

, three recovery furnaces had values associated with startup and shutdown between 25 and 30 ppm. Thus, 30 ppm appears to be a representative cap for the 1 percent monitoring allowance. For any of the recovery furnaces, up to eight of the 12

- hour periods were in excess of the 5 ppm limit. Eight of 730 possible 12

- hour blocks in a year corresponds to about 1 percent of possible averaging periods ( 8 /730 = 1.1 %).

Dur ing periods of startup and shutdown, the EPA observed that corrected TRS concentrations may be grossly inflated as a result of the oxygen correction equation. As the stack gas concentration approaches ambient conditions, the denominator of the oxygen corre ction equation becomes very small, leading to an oxygen corrected concentration that is artificially high, such that an otherwise compliant TRS measurement can exceed the applicable concentration because it is corrected for oxygen. Table D

- 2 in Appendix D shows this inflation. The proposed solution to this issue was to allow uncorrected, actual TRS values to be used during periods of startup and shutdown for compliance for periods when the oxygen concentration is greater than 15 perc ent

.

Table 2 below summarizes the number of TRS CEMS data sets analyzed for new, modified (or reconstructed), and existing recovery furnaces . The number of TRS CEMS data sets in compliance with the proposed TRS standard and monitoring allowance before pr oposal and in the final data sets is indicated. The values presented from the proposal analysis represent15



### calculation of the TRS monitoring allowance on an annual basis, while the values from the final analysis reflect the revised data sets and calculation of the TRS monitoring allowance on a semiannual basis. Use of a semiannual basis for calculating the TRS allowance resulted in only minor differences in the number of emission units that would not be in compliance with the proposed TRS standard and monito ring allowance. The semiannual allowance calculation would change the compliance outcome for only 2 out of 141 recovery furnace TRS CEMS data sets.

Table 2 . Summary of Recovery Furnace TRS CEMS Data Sets Analyzed

Unit NSPS Classification 1 Proposal data set 2 Final

data set 3 Notes No. of TRS CEMS data sets 141 New 51 Modified 28 Existing (not subject to NSPS) 62 No. of CEMS meeting 5 ppm with a 1% allowance 95 93

New 45 45 Modified 26 26 Existing (not subject to NSPS) 24 22 No. of CEMS not meeting 5 ppm with a 1% allowance 46 48

New 6 6 Installation dates range from 1977 to 1992. Modified 2 2 Modified in 1989 and 1990. Existing (not subject to NSPS) 38 40 Includes 33 DCE recovery furnace CEMS. The TRS emission guideline for existing DCE recovery furnaces is 20 ppm.

4 of these existing units were DCE furnaces in the final data set that have since been replaced with or converted to NDCE technology (in 2011

- 2012 after the data were collected). 1. New and modified units are defined in terms of the subpart BB NSPS 1976 applicability date (not the more recent subpart MM applicability date). 2. The m onitoring allowance was calculated on an annual basis in the proposal data set (Reference 1). 3. This column re fers to the m onitoring allowance calculated on a semi annual basis using the final updated data set presented in this memorandum.



### Figure 10 in Appendix D depict s semiannual monitoring allowance calculations for recovery furnaces already subject to the subpart BB NSPS. The monitoring allowance represents the percent of TRS CEMS averaging periods exceeding the limit for each emission unit. Figure 10 show s that the majority of recovery furnaces subject to subpart BB achieved a 1 percent TRS monitoring allowance on a semiannual basis. In fact, the majority of the 79 NSPS CEMS data sets displayed in Figure 10 reflected zero exceedances of the 5 ppm limit (i.e., 59

- 60 of the 79 data sets had zero exceeedances in each semiannual period). T otal reduced sulfu r data for existing sources are not shown in Figure 10 because existing sources are subject to TRS limits less stringent than the NSPS limits. Based on this figure, it appears that a 1 percent monitoring allowance reflects the level of TRS compliance that has been adequately demonstrated and is achieved by the best performing recovery furnaces (on a semiannual basis)

.16



### Recommendation

. Based on the TRS data presented in this section, it can be concluded that DCE recovery furnaces would not be expected to reliably meet the current NSPS limit of 5
ppm . It would also be expected that the current NSPS (at baseline) would require that new recovery furnaces be NDCE furnaces and modified or reconstructed DCE recovery furnaces to convert to NDCE technology. We did not project any new DCE recovery furnaces being constructed in our analysis

. The figures presented i n Appendix D support the proposed regulatory decision to mainta in a TRS limit of 5 ppm with a 1 percent monitoring allowance for recovery furnaces. To ensu re the TRS standard is a continuous standard (consistent with the decision in of the D.C. Circuit Court of Appeals decision in Sierra Club v. EPA

, 551 F.3d 1019 (D.C. Cir. 2008) ), the monitoring allowance was capped a proposal at 30 ppm

, which is representative of the upper limit achieved by most recovery furnaces. Because the TRS CEMS data analyzed include startup and shutdown periods (in addition to normal operational periods), there is no need for a separate standard during periods of startup and shutdown.

It is recommended that the 5 ppm TRS limit and 1 percent monitoring allowance, capped
at 30 ppm , for new, modified, and reconstructed straight recovery furnaces be finalized as proposed. The monitoring allowance would be calculated on a semiannual basis.

C. Lime Kiln TRS CEMS Analysis

TRS limit evaluation

. Lime kiln TRS emiss ions are limited to 8 ppm at 10 percent O 2 

### by the subpart BB kraft pulp mill NSPS. All of the lime kiln TRS ppm values discussed in this section reflect conditions at 10 percent O 2


### . Figures 1 through 9 in Appendix E present updated TRS C E MS summary data for each lime kiln (1 unit with multiple stacks, for a total of 110 data sets)

. Most of the data points shown in these figures reflect 12

- hour average CEMS data sets

. However, 7 of the 110 lime kiln CEMS data sets were based on 24

- hour averages. The 24

- hour averages are annotated on the graphs where appropriate

. The figures in Appendix E distinguish between lime kilns subject to the NSPS and non

- NSPS kil ns because there were several lime kilns that are not currently subject to the 8 ppm NSPS limit (but are more likely held to the 20 ppm emission guideline) , and

, therefore, exceeded 8 ppm

. Figure 1 shows all of the lime kiln CEMS data sets for NSPS and n on

- NSPS kilns based

on APCD type: ESP, ESP followed by a scrubber (ESP/SCBR), and SCBR

. The 24

- hour average data sets were noted and fe ll within the scatter of the 12

- hour average data sets

. We observe d that control device performance overlaps

, and that ESP/SCBR systems f e ll within the scatter of the ESP

- alone and SCBR

- alone systems

. With no clear distinction in TRS by control device

, it is expected that process factors ( e.g., mud washing, use of uncontaminated scrubber water , and NCG burning) h ave a greater effect on lime kiln TRS emissions tha n control device type

. As shown in Figure 1, m ost of the lime kilns achieved the 8 ppm limit on an annual average basis

. Figure 2 shows the 99 th 

### percentile of the averaging periods for NSPS and non

- NSPS ki lns based on APCD type . As shown in Figure 2, m any of the kilns consistently achieved 8 ppm 99 percent of the time. However, compliance is based on each 12

- hour block averaging period

, so the percentage of averaging periods in excess of 8 ppm was plotted i n Figure 3 . Several scrubbers and one non

- NSPS ESP exceeded 8 ppm for a relatively high percentage of averaging periods

.17



### The non

- NSPS kilns were removed from the remaining figures in Appendix E in order to more clearly examine lime kilns that are required to meet 8 ppm

. In F igure 4

, it can be observed that the overwhelming majority of the NSPS kilns met the 8 ppm limit regardless of control device. Most of the kilns were operating with roughly a 4 ppm compliance margin below the 8 ppm limit based on annual average

. The one scrubber

- controlled kiln with annual average emissions above 8 ppm experienced an uncommon number of startup and shutdown events and considerable downtime during the year.

Fi gure 5 shows the percentage of averaging periods exceeding 8 ppm for the lime kilns subject to NSPS. There is no monitoring allowance for lime kiln TRS CEMS data in the subpart BB NSPS ( e.g., any average that is an exceedance can be considered as a violati on)

. Although some well

- controlled kilns had a few exceedances of the 8 ppm limit (which supports the need for an allowance), several of the NSPS kilns ( 33 of 58 ) achieved zero exceedances of the 8 ppm limit regardless of control device type

. We note that startup and shutdown periods were included in the percentages of averaging periods that exceeded 8 ppm. Startup and shutdown periods would be subject to the 8 ppm emission limit, while malfunctions can be handled with affirmative defense provisions. T he sc rubber

- controlled kilns appear to be the most challenged to remain below 8 ppm

. Figure 6 considers the 99 th 

### percentile of the averaging periods for each kiln subject to the NSPS

. Most of the kilns consistently achieved 8 ppm 99 percent of the time regard less of control system

. Figure 6 shows that most of the kilns use the compliance margin afforded by the 8 ppm limit in order to remain in compliance and that a new source limit more stringent than 8 ppm would be difficult for well

- controlled kilns to meet consistently

. A lower limit would reduce the compliance margin

, and there is no clear technological basis for achieving a lower TRS limit. While ESP/ SCBR

- controlled kilns all remained below the 8 ppm limit, their 99 th 

### percentile performance was within the range of that achieved by the lime kilns with ESP or scrubber control only.

Figure 7 shows the 99 th 

### percentile for NSPS kiln s based on combustion of NCGs. While NCGs can contribute to TRS (if not properly combusted) , there does not appear to be any clear distinction in the TRS emissions of NCG

- burning kilns versus non

- NCG burning kilns. NCG

burning kilns with white liquor pre

- scrubbers have similar TRS emissions to NCG

- burning kilns without pre

- scrubbers. Figure 8 sh ows the percent of periods exceeding the TRS 8 ppm limit for lime kilns based on NCG burning. NCG burning appears to result in the potential for additional
process v ariability.

Monitoring allowance evaluation

. In the pre

- proposal analysis of the TRS CEMS data, monitoring allowance calculations for TRS were conducted on an annual basis. The annual

- basis analysis was repeated with updated data sets, and a semiannual monitoring allowance calculation was added as discu ssed later in this subsection. As shown in Figure 5 of Appendix E

, all but four of the lime kilns subject to the NSPS achieved the 8 ppm TRS limit with 1 percent or less monitoring deviations (on an annual basis) in spite of startup and shutdown period s. The TRS CEMS data were reviewed closely to determine the impact of removal of the SSM exemption in 40 CFR 60.284(e)(1) and continuous application of the 8 ppm limit to startup and shutdown periods in addition to normal operations. Periods of malfunction and process downtime ( i.e.,18



### when lime mud charging ceases) were excluded from consideration because these are not valid operating periods for rulemaking. As shown in Appendix E , 12

- hour average CEMS data sets providing startup and shutdown detail were available for 3 0 lime kilns controlled by ESP and subject to the NSPS. Upon review of these data sets

, we observed that a 12

- hour block can either be partially or completely affect ed by startup or shutdown periods. Up to 113 of a possible 730 annual 12

- hour averaging periods were affected by startup and shutdown in the data sets reviewed for startup and shutdown

. On average it takes a lime kiln 24 hours to start up and 12 hours to s hu t down

. 7 

### Of the 3 0 data sets with startup and shutdown indicated, 2 1 of the data sets contained no exceedances of the 12

- hour 8 ppm limit. Thus, compliance with the 8 ppm limit during startup and shutdown has been demonstrated at several mills

. However, for 9 other kiln s , compliance with the 8 ppm TRS limit during startup and shutdown has not been adequately demonstrated because these kiln s experienced exceedances in up to seven 12

- hour blocks affected by startup and shutdown. Seven of 730 possible 12

- hour blocks in a year corresponds to 1 percent of possible averaging periods ( 7 /730 = 1.0 %)

. This percentage of averaging periods affected by startup and shutdown is consistent with the information in Figure 5

, which shows 5 4 of 58 NSPS kilns in compliance with the 8 ppm TRS limit in all but 1 percent of averaging periods.

Table E

- 1 in Appendix E shows the maximum TRS 12

- hour average ppm values occurring during startup and shutdown where there were exceedances of the 8 ppm standard. Where available for the higher

- end values, 1

- hour TRS data sets corresponding with the 12

- hour averages were reviewed to determine the nature of the TRS emissions during the startup and shutdown events. Most of the high

- end values w ere determined not to be representative for rulemaking purposes. The 12

- hour TRS concentration corrected to 10 percent O 2 

### that appeared to be representative of startup and shutdown events w as 22 ppm. Similarly, for most NSPS kilns, the 99 th 

### percentile 12

- h our average during all time periods (including startup and shutdown) was less than 20 ppm as shown in Figure 6

. Therefore, an upper limit 12

- hour average of 22 ppm appears to be representative of the TRS concentration that has been achieved in practice during startup and shutdown events.

As discussed for recovery furnaces, d uring periods of startup and shutdown, the EPA observed that corrected TRS concentrations may be grossly inflated as a result of the oxygen correction equation. As the stack gas concentration approaches ambient conditions, the denominator of the oxygen cor rection equation becomes very small, leading to an oxygen corrected concentration that is artificially high, such that an otherwise compliant TRS measurement can exceed the applicable concentration because it is corrected for oxygen. See T able D

- 2. Consequ ently, EPA propose d to allow uncorrected, actual TRS values to be used during periods of startup and shutdown for compliance for periods when the oxygen concentration is greater than 15 percent

. As noted previously, t he EPA is finalizing a semiannual per iod for the monitoring allowance calculation consistent with the semiannual reporting frequency in 40 CFR 60.288a(a).

7 Memorandum from K. Hanks, and C. Gooden, RTI International to K. Spence and B. Schrock, EPA. Review of Pulp and Paper Information Collection Request (ICR) Responses Pertaining to Startup and Shutdown of Subpart BB Equipment

. March 22, 2013.19



### In the updated analysis of the TRS C E MS data, the EPA repeated monitoring allowance calculations based on a semiannual reporting period in addition to the annual basis used for the proposal. Table 3 below summarizes the number of TRS CEMS data sets analyzed for new, modified (or reconstructed), and existing lime kilns . The number of TRS CEMS data sets in compliance with the proposed TRS stan dard and monitoring allow ance before proposal and in the final data sets is indicated. The values presented from the proposal analysis represent calculation of the TRS monitoring allowance on an annual basis, while the values from the final analysis reflec t the revised data sets and calculation of the TRS monitoring allowance on a semiannual basis. Use of a semiannual basis for calculating the TRS allowance resulted in only minor differences in the number of emission units that would not be in compliance with the proposed TRS standard and monitoring allowance. The semiannual allowance calculation would ch ange the compliance outcome for only 2 out o f 1 10 lime kiln TRS CEMS data sets.

Table 3. Summary of Lime Kiln TRS CEMS Data Sets Analyzed
Unit NSPS Classification 1 Proposal data set 2 Final

data set 3 Notes No. of TRS CEMS data sets 112 110 2 data sets (for 1 new kiln and 1 existing kiln)

were removed from the final analysis due to data quality issues. New 48 47 Modified 11 11 Existing (not subject to NSPS) 53 52 No. of CEMS meeting 8 ppm with a 1% allowance 68 64 2 data sets (for 1 new kiln and 1 existing kiln) were removed from the final analysis due to data quality issues. New 45 44 Modified 7 7 Existing (not subject to NSPS) 16 13 No. of CEMS not meeting 8 ppm with a 1% allowance 44 46

New 3 3 Installed 1997, 1989, and 1994. Modified 4 4 Modified in pre

- 1990, pre

- 1995, and 2007. Scrubber

- controlled. Some of these kilns were up and down and had data availability issues throughout the year. Existing (not subject to NSPS) 37 39 The TRS emission guideline for existing lime kilns is 20 ppm. 1. New and modified units are defined in terms of the subpart BB NSPS 1976 applicability date (not the more recent subpart MM applicability date). 2. The m onitoring allowance was calculated on an annual basis in the proposal data set (Reference 1). 3. This column re fers to the m onitoring allowance calculated on a semi annual basis using the final updated data set presented in this memorandum.



### Figure 9 in Appendix E depict s semiannual monitoring allowance calculations for lime kilns already subject to the subpart BB NSPS. The monitoring allowance represents the percent of TRS CEMS averaging periods exceeding the limit for each emission unit. Figure 9 show s that the majority of lime kilns subject to subpart BB achieved a 1 percent TRS monitoring allowanc e on a semiannual basis. In fact, the majority of the 58 CEMS data sets displayed in Figure 9 reflected zero exceedances of the 8 ppm limit (i.e., i n each semiannual period there were 40 CEMS showing zero exceedances ). T otal reduced sulfur data for existin g sources are not shown20



### in Figure 9 because existing sources are subject to TRS limits less stringent than the NSPS limits. Based on this figure, it appears that a 1 percent monitoring allowance reflects the level of TRS compliance that has been adequately demonstrated and is achieved by the best performing lime kilns (on a semiannual basis)

.

Recommendation

. To summarize, the current 8 ppm TRS limit based on a 12

- h ou r average with a 1 percent monitoring allowance during which time emissions must not exceed 22 ppm is recommended to be finalized as proposed as the continuous lime kiln TRS standard

. T h is has been achieved in practice

. The 1 percent monitoring allowance (not to exceed 22 pp m) is recommended to adjust the current 8 ppm limit (with no allowance) f or removal of the startup and shutdown exemption. This option balances the requirement for a continuous emission standard while providing for the operational variability expected from mills under normal, startup, and shutdown condition s. It is also recommended that the proposed provision stat ing that the uncorrected TRS concentration can be considered when O 2 

### is near ambient conditions during startup or shutdown be finalized

.

D. Lime Kiln COMS Analysis

Opacity limit evaluation

. The kraft pulp mills NSPS do not contain an opacity limit for lime kilns because scrubbers were the dominant technology in 1978 and 1986 when the NSPS were originally promulgated and revised, respectively

. However, the EPA received COMS data for lime kilns that ha d installed ESPs and a re required to monitor opacity under subpart MM. Subpart MM requires continuous opacity monitoring for lime kilns and specifies 20 percent as the opacity limit for both new and existing kilns. Subpart MM contains an opacity monitoring allowance where 6 percent of the 6

- minute opacity averages per quarter may exceed the 20 percent limit without being considered an exceedance.

A total of 29 COMS data sets were gr aphed (including multiple data sets for two kilns with separate COMS for du a l stacks)

, and the graphs are provided in Appendix F

. The majority ( 27 ) of the COMS data sets graphed were 6

- minute averages. Two data sets represented hourly
averages.

Figure 1 i n Appendix F presents the annual average of the opacity readings for each lime kiln. The highest annual average observed was 8 percent, well below the 20 percent MACT limit ; however, compliance is based on each averaging period and not the annual average. The 99 th 

### percentile of opacity is shown in Figure 2 based on APCD type. Lime kilns controlled with ESP and ESP/scrubber systems consistently achieved 20 percent opacity . The COMS for ESP/scrubber systems were usually placed between the ESP and scrubber . Tw o units exceeded the 20 percent opacity, but further investigation shows they did not exceed 20 percent for more than the subpart MM 6 percent monitoring allowance.

Monitoring allowance evaluation

. In the pre

- proposal analysis of the COMS data, monitoring allowance calculations for opacity were conducted on an annual basis. Figure 3 in Appendix F shows the percent of averaging periods (on an annual basis) in excess of 20 percent opacity . A ll but t wo kilns consistently achieved 20 percent opacity

, with less than 1 percent of averaging periods in exceedance of 20 percent

.21



### As noted previously, t he EPA is finalizing a semiannual period for the monitoring allowance calculation consistent with the semiannual reporting frequency in 40 CFR 60.288a( a). In the updated analysis of the COMS data, the EPA repeated monitoring allowance calculations based on a semiannual reporting period in addition to the annual basis used for the proposal. Table 4 below summarize s the number of COMS data sets analyzed fo r new, modified (or reconstructed), and existing lime kilns . The number of COMS data sets in compliance with the proposed opacity standard and monitoring allowance before proposal and in the final data sets is indicated. The values presented from the propo sal analysis represent calculation of the opacity monitoring allowance on an annual basis, while the values from the final analysis reflect the revised data sets and calculation of the opacity monitoring allowance on a semiannual basis. Use of a semiannual basis for calculating the opacity allowance resulted in no difference in the number of emission units that would not be in compliance with the proposed opacity standard and monitoring allowance. The semiannual allowance calculation woul d not ch ange the compliance outcome for any of the 29 lime kiln COMS data sets

.

Table 4 . Summary of Lime Kiln COMS Data Sets Analyzed

Unit NSPS Classification 1 Proposal data set 2 Final

data set 3 Notes No. of COMS data sets 29 New 23 Modified 2 Existing (not subject to NSPS) 4 No. of COMS meeting 20% opacity with a 1% allowance 27 27

New 21 21 Modified 2 2 Existing (not subject to NSPS) 4 4 No. of COMS not meeting 20% opacity with a 1% allowance 2 2

New 2 2 Exceedances of the 1% allowance were 1.84% and 2.19% on a semiannual basis. These ESP

controlled kilns became subject to the NSPS in 1997 and 1994, respectively (prior to establishment of the subpart MM opacity monitoring requirements). Modified 0 0 Existing (not subject to NSPS) 0 0 1. New and modified units are defined in terms of the subpart BB NSPS 1976 applicability date (not the more recent subpart MM applicability date). 2. The m onitoring allowance was calculated on an annual basis in the proposal data set (Reference 1). 3. This column refers to the m onitoring allowance calculated on a semi annual basis using the final updated data set presented in this memorandum.



### Figure 3 in Appendix F show s the percentage of averaging p eriods exc eeding 20 percent opacity on a semiannual basis and indicates that a 1 percent monitor ing allowance (on a semiannual basis) coupled with a 20 percent limit is ac hieved by most ESP

- controlled lime kilns. Figure 4 in Appendix F depict s semiannual monitoring allowance calculations for lime kilns that triggered the subpart BB NSPS as new or modified units. Figure 4 shows that the 1 percent22



### monitoring allowance for lime kiln opacity is achieved by nearly all lime kilns regardless of their prior NSPS classificati on as new or modified units

.

Recommendation

. In summary, a 20 percent opacity limit with a 1 percent monitoring allowance has been adequately demonstrated

, and it is recommended that it be finalized as proposed as the lime kiln opacity standard

. Continuous compliance with the NSPS PM standards can be demonstrated through monitoring of control device operating parameters (e.g.

, ESP secondary voltage and current or power) during times when the 2 percent monitoring allowance is invoked. Because the d ata analyzed in arriving at the recommendation included startup and shutdown periods, there is no need for a separate standard for startup and shutdown periods.

E. Analysis of TRS CEMS Data for Other Emission Units

TRS limit evaluation

. As shown in Table 5

, TRS CEMS data were submitted with the ICR for four kraft mill processes emitting non

- condensable gas es

. The 12

- hour average TRS CEMS data sets were reviewed for these systems

. As with the lime kiln and recovery furnace TRS CEMS data sets, zero emissions va lues measured during process downtime and negative emissions were removed

. Emissions measured during startup and shutdown were retained.

The NCG source CEMS data sets were analyzed for maximum and 99 th 

### percentile TRS
averages . These units included a pulp washer, a boiler, and two thermal ox idizers. The pulp washer data were provided as actual (uncorrected) TRS emissions because the oxygen correction is not required for non

- combustion sources. The boiler was characterized as backup control for low

- volume hi gh

- concentration ( LVHC ) and high

- volume low

- concentration i ncineration that

wa s used when the recovery fu rnace (primary control device) wa s not operational. The two thermal oxidizers were used to burn LVHC and stripper off gas streams. These units exhibited 99 th 

### percentile TRS values from 1.33 ppm to 3.88 ppm , but also exhibited maximum values of approximately 5 ppm (4.4, 4.8, and 4.9 ppm ) up to 16 ppm

.

Recommendation

. Based on this limited amount of data, it appears that the current NSPS limit of 5 ppm is the appropriate limit for each of these operations , and no changes are recommended

.

III. References

1. Spence, K., U.S. Environmental Protection Agency. Review of the Continuous Emission Monitoring and Continuous Opacity Monitorin g Data from the Pulp and Paper Information Collection Request Responses Pertaining to Subpart BB Sources. Memorandum to Docket ID No. EPA

- HQ

- OAR

- 2012

- 0640. April 5, 2013.23 

### Table 5

. TRS CEMS Data for Kraft Pulping Processes Emitting NCGs

RTI Code NEI ID Emission

Unit ID Process

Type APCD Type APCD ID NCG S ources C ontrolled Notes Max TRS ppmdv @ 10% O 2 99 th

Percentile TRS ppmdv @ 10% O 2 1
186 NEI18334 HWCHEM Pulp Washer Hardwood

Chemiwasher Scrubber FL34 and

HWCHME Washer Because this is a non

combustion control, the ppmdv is provided at the actual oxygen content of the untreated (undiluted) gas stream

. 4.4 3.29

198 NEI41565 016 Boiler unspecified 016_CD Backup control for digester and washer (NSPS units); also O 2 delig and decker According to Part I,

Boiler 016 serves as the backup control device for HVLC control when the primary control device (recovery furnace) is not operation al. 4.8 1.61

242 NEI34066 AA

- 016 TO Scrubber

- packed bed RC

- 22 condensate stripper, evaporator, turpentine, and digester LVHC 4.9 1.33

112 NEI34064 LVHC01,

LVHC02, LVHC03 TO Scrubber

- packed bed AA

- 113 Digester, evaporator, turpentine, and condensate stripper 16 3.88

1. Calculated as the average of the 12

- hr aver a g e va lues provided including startup and shutdown

.A

- 1



## APPENDIX A: Summary of Recovery Furnace Data Received

### A

- 2 S ummary of Recovery Furnace Data Received

RTI + Emission Unit ID Opacity Data

Type TRS Data Type Comments on Data 100.037A 6

- min averages 1 2

- hr averages Provided raw TRS data

- corrected to 8% O 2 . Calculated 12

- hr average TRS from 1

- hour data. 102.RB10 6

- min averages 12

- hr averages
103.G

- 158 6

- min averages 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 104.EUG D6 data not provided not provided
105.EU445C 6

- min averages 12

- hr averages
105.EU445A unit down unit down
107.08

- P1 6

- min averages 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 108.RB3 6

- min averages 12

- hr averages
109.RB4 6

- min averages 12

- hr averages Commenter confirmed TRS data were corrected to 8%.

109.RB3 6

- min averages 12

- hr averages Commenter confirmed TRS data were corrected to 8%.

111.G

- 44 6

- min averages 1

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 112.AA

- 100 6

- min averages 12

- hr averages
114.U500 6

- min averages 12

- hr averages
115.RE01 6

- min averages 12

- hr averages Unit has opacity data for 2 stacks
116.003 6

- min averages 12

- hr averages
117.B21 data in pdf form not provided Opacity data not tabulated 119.EQT010 6

- min averages 12

- hr averages 119.EQT008 data not provided not provided
120.F7 6

- min averages 12

- hr averages 121.000013 6

- min averages 12

- hr averages
121.000014 6

- min averages 12

- hr averages
124.001 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
124.019 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
126.RECOV 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
127.REC1 6

- min averages 1 2

- hr averages Unit has opacity data for 2 stacks

. O 2 correction values were not 8%, assumed TRS values were raw data and corrected

. Calculated 12

- hr average TRS from 1

- hour data. 130.1 6

- min averages 12

- hr averages
130.2 6

- min averages 12

- hr averages
130.3 6

- min averages 12

- hr averages
131.5 6

- min averages 24

- hr averages

### A

- 3

RTI + Emission Unit ID Opacity Data

Type TRS Data Type Comments on Data 131.6 6

- min averages 12

- hr averages
132.4RB hourly average 12

- hr averages
132.5RB hourly average 12

- hr averages Unit has opacity data for 2 stacks
133.10 6

- min averages 12

- hr averages
135.003

- 1 6

- min averages 12

- hr averages
136.EU 005 6

- min averages 12

- hr averages
137.189 data not provided provided as .doc TRS data not tabulated
137.721 data not provided provided as .doc TRS data not tabulated
138.002 6

- min averages 12

- hr averages
139.02 6

- min averages 12

- hr averages
140.55 6

- min averages 24

- hr averages
142.CU7216 6

- min averages 12

- hr averages
142.CU7214 6

- min averages 12

- hr averages
142.CU7215 6

- min averages 12

- hr averages
143.7000 hourly average 1 2

- hr averages TRS raw data reported

- corrected to 8%

. Calculated 12

- hr average TRS from 1

- hour data. 143.7010 hourly average 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 143.7020 hourly average 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 145.55 6

- min averages 12

- hr averages
145.54 6

- min averages not provided
146.16 6

- min averages 12

- hr averages 146.8 data not provided 12

- hr averages
147.14 6

- min averages 12

- hr averages Unit has opacity data for 2 stacks
147.5 6

- min averages 12

- hr averages
148.001 6

- min averages 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 148.007 6

- min averages 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 149.B011 6

- min averages 12

- hr averages
150.CREC

- 1 6

- min averages 12

- hr averages
151.REC004 6

- min averages 12

- hr averages
151.REC007 6

- min averages 12

- hr averages
152.03 data not provided 12

- hr averages 153.EQT 0065 not surveyed not surveyed Mill was closed during the development of the survey (reopened in 2010) 154.P36 6

- min averages 12

- hr averages
154.P37 6

- min averages 12

- hr averages P39 and P37 have own WBESP but vent to

### A

- 4

RTI + Emission Unit ID Opacity Data

Type TRS Data Type Comments on Data combined stack with single COMS (2 TRS CEMS) 154.P39 6

- min averages 12

- hr averages P39 and P37 have own WBESP but vent to combined stack with single COMS (2 TRS CEMS) 155.RECOVERY FURNACE provided as .doc provided as .doc Not tabulated.

156.RF18 unit down unit down
156.RF19 6

- min averages 12

- hr averages
156.RF22 6

- min averages 12

- hr averages
157.RB2 6

- min averages 12

- hr averages
159.F3 data not provided provided as .pdf Not tabulated.
162.381A 6

- min averages 12

- hr averages
162.382A 6

- min averages 12

- hr averages
163.RF2904 6

- min averages 12

- hr averages TRS data contained "<1" instead of decimal values 163.RF1901 6

- min averages 12

- hr averages TRS data contained "<1" instead of decimal values, O 2 correct was reported as 10%, corrected to 8% 164.B08 6

- min averages not provided Flue gases from B08 and B10 combine and then split into 2 ESPs 164.B10 6

- min averages not provided Flue gases from B08 and B10 combine and then split into 2 ESPs 165.000013 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
165.000006 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
166.RB01 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
166.RB02 data not provided 12

- hr averages
167.005RB 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
169.04 6

- min averages 12

- hr averages
169.05 6

- min averages 12

- hr averages
171.002 6

- min averages 12

- hr averages O 2 correction not reported as 8%, assumed raw TRS data and corrected

171.003 6

- min averages 12

- hr averages O 2 correction not reported as 8%, assumed raw TRS data and corrected

171.004 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks, O 2 correction not reported as 8%, assumed raw TRS data and corrected 172.RB01 6

- min averages 12

- hr averages
172.RB02 6

- min averages 12

- hr averages
173.RECOVB 6

- min averages not provided Unit has opacity data for 2 stacks
174.G

- 32 6

- min averages 12

- hr averages

### A

- 5

RTI + Emission Unit ID Opacity Data

Type TRS Data Type Comments on Data 174.G

- 92 6

- min averages not provided Unit has opacity data for 2 stacks
175.RB3A 6

- min averages 12

- hr averages
175.RB2A 6

- min averages 24

- hr averages
176.RB7 6

- min averages 12

- hr averages
177.EU0804 6

- min averages 12

- hr averages 178.08P012 6

- min averages 12

- hr averages
178.08P013 6

- min averages 12

- hr averages
179.RF3 6

- min averages 12

- hr averages TRS data contained "<1" instead of decimal values 180.D001 6

- min averages 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 181.50 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
181.10 6

- min averages not provided Unit has opacity data for 2 stacks
182.037 6

- min averages 12

- hr averages
183.002 6

- min averages 12

- hr averages O 2 correction not reported as 8%, assumed TRS raw data and corrected

184.72 6

- min averages 12

- hr averages
184.73 6

- min averages 12

- hr averages
185.02 data not provided 12

- hr averages
186.RB15 6

- min averages 12

- hr averages
188.014RB1 6

- min averages 24

- hr averages
188.016RB2 6

- min averages 24

- hr averages
189.SN26 6

- min averages 12

- hr averages
190.R400 6

- min averages 12

- hr averages R400 and R401 appear to each have a D BESP that vent through a common stack (opacity represents combined total) 190.R401 6

- min averages 12

- hr averages R400 and R401 appear to each have a D BESP that vent through a common stack (opacity represents combined total) 190.R402 6

- min averages 12

- hr averages Unit has opacity and TRS data for 2 stacks
195.003 6

- min averages 12

- hr averages
196.SN

- 06 6

- min averages 12

- hr averages
196.SN

- 14 6

- min averages 12

- hr averages
197.2 data not provided not provided
198.019 6

- min average s 1 2

- hr averages Calculated 12

- hr average TRS from 1

- hour data. 199.002 6

- min averages 12

- hr averages 200.007RF2 6

- min average s 12

- hr averages Unit has opacity data for 2 stacks
200.007RF3 6

- min average s 12

- hr averages Unit has opacity data for 2 stacks
201.SR0001 6

- min averages not provided

### A

- 6

RTI + Emission Unit ID Opacity Data

Type TRS Data Type Comments on Data 202.Recovery Furnace EU320 6

- min averages 12

- hr averages

203.RF#2 6

- min averages 12

- hr averages
203.RF#3 6

- min averages 12

- hr averages
205.009 6

- min averages 12

- hr averages Unit has opacity data for 2 stacks
206.G

- 32 6

- min averages 12

- hr averages
206.G

- 31 6

- min averages 12

- hr averages
207.038 6

- min averages 12

- hr averages Uni t has opacity data for 2 stacks. O 2
co r rection was not reported as 8%, assumed to be raw TRS data and corrected 226.RECB2 6

- min averages 12

- hr averages
226.RECB1 6

- min averages not provided Unit has opacity data for 2 stacks
240.RF04 6

- min averages 12

- hr averages TRS data contained "<1" instead of decimal values 240.RF01 6

- min averages 24

- hr averages TRS data contained "<1" instead of decimal values 242.AA

- 011 6

- min averages 12

- hr averages O 2 correction reported as 5%

- corrected to 8% 243.R407 6

- min averages 12

- hr averages
243.R401 6

- min averages 24

- hr averages Unit has opacity and TRS data for 2 stacks
340.005 6

- min averages 12

- hr averages O 2 cor r ection was not reported as 8%, assumed to be raw TRS data and corrected

525.EU18 6

- min averages 12

- hr averages
531.RF15 6

- min averages 12

- hr averages
600.G0803 6

- min averages 12

- hr averages
600.G0806 6

- min averages 12

- hr averages
606.RB2 6

- min averages 12

- hr averages
606.RB3 6

- min averages 12

- hr averages
606.RB4 6

- min averages 12

- hr averages
610.4 6

- min averages 12

- hr averages Units 4 and 5 utilize a single stack with 1 COMS 610.5 6

- min averages 12

- hr averages Units 4 and 5 utilize a single stack with 1 COMS 613.001 6

- min averages not provided Unit has opacity data for 2 stacks
613.002 6

- min averages not provided Unit has opacity data for 2 stacks
615.24 6

- min averages 12

- hr averages Unit has opacity data for 2 stacks
617.B14 6

- min averages 12

- hr averages
208228535.001 6

- min averages 12

- hr averages
208228535.007 6

- min averages 12

- hr averagesB

- 1



## APPENDIX B: Summary of Lime Kiln Data Received

### B

- 2 Summary of Lime Kiln Data Received RTI + Emission Unit ID Opacity Data

Type TRS Data

Type Comments On Data 100.115 6

- min averages 12

- hr average
102.LK 6

- min averages 12

- hr average Separate stacks. A portion of the ESP exhaust gas is withdrawn from each stack for use by SMI (a PCC plant). This lowers the stack gas flow and reduces pollutant mass emissions (though opacity remains the same). 103.G

- 165 NA 1 2

- hr average TRS values reported as corrected to 8%. Converted values to 10% correction. Calculated 12

- hr average TRS from 1

- hour data. 104.EUG E7 not provided not provided
105.EU455 6

- min averages 12

- hr average TRS values reported as corrected to 8%. Converted values to 10% correction. Lime Kilns #2 and #3 vent through same stack (though LK2 is usually only operated as a backup to LK3) 107.11

- P14 6

- min averages 12

- hr average
108.LK1 NA not provided
109.LK1 6

- min averages 12

- hr average Commenter confirmed TRS data were corrected
to 10%. 111.G

- 35 not provided 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
112.AA

- 110 not provided 12

- hr average Commenter confirmed TRS data were corrected to 10%. 114.U800 6

- min averages See note Did not use 12

- hour average TRS data in final analysis based on public comment that respondent provided uncorrected data (and did not provide the actual O 2 percent to correct with). 115.LK01 6

- min averages 12

- hr average
116.001 NA 12

- hr average
117.P36 NA not provided 119.EQT006 NA 12

- hr average TRS values reported as corrected to 8%. Converted values to 10% correction. 120.M18 NA 12

- hr average
120.M19 NA 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
121.000011 NA 12

- hr average
124.004

- 1 NA 12

- hr average
126.LK not provided 24

- hr average
127.LK1 6

- min averages 1 2

- hr average TRS O 2 correction not r eported as 10%. Assumed data were raw and corrected to 10%. Calculated 12

- hr average TRS from 1

- hour data. 127.LK2 6

- min averages 1 2

- hr average TRS O 2 correction not r eported as 10%. Assumed data were raw and corrected to 10%

. Calculated 12

- hr average TRS from 1

- hour data.

### B

- 3

RTI + Emission Unit ID Opacity Data

Type TRS Data

Type Comments On Data 130.4 NA 12

- hr average
130.5 NA 12

- hr average
131.18 NA 24

- hr average
131.16 NA 12

- hr average
132.21LK4 1

- hour average 12

- hr average
133.14 NA 12

- hr average
133.15 NA 12

- hr average
135.004

- 1 NA 12

- hr average
136.EU 033 6

- min averages 12

- hr average
137.511 not provided provided as .txt Did not tabulate
137.512 not provided provided as .txt Did not tabulate
138.001 NA 12

- hr average
139.04 NA 12

- hr average
140.32 NA 24

- hr average
142.P6025 NA 12

- hr average
142.P6009 NA 12

- hr average
143.6063 hourly average 1 2

- hr average Raw TRS was provided, corrected data to 10%

. Calculated 12

- hr average TRS from 1

- hour data. 145.001 NA not provided
146.6 NA 12

- hr average
146.30 6

- min averages 12

- hr average
147.3 NA 12

- hr average
147.55 not provided 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
148.003 NA 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
148.009 6

- min averages 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
149.P001 NA 12

- hr average
150.CAU

- 12 NA 12

- hr average
151.CP002 NA 12

- hr average
151.CP001 NA 12

- hr average
152.08 NA not provided 153.EQT 0053 NA not surveyed Mill was not surveyed
154.P30 6

- min averages 12

- hr average
155.LIME KILN NA provided as .doc Did not tabulate

156.143100 NA 12

- hr average Lime kiln 3
156.145000 NA 12

- hr average Lime kiln 4
156.LK5 6

- min averages 12

- hr average Lime kiln 5; has 2 separate COMS (north and south stacks) but one TRS CEMS

### B

- 4

RTI + Emission Unit ID Opacity Data

Type TRS Data

Type Comments On Data 157.KILN NA 12

- hr average
159.F4 NA provided as .pdf Did not tabulate

162.371A NA 12

- hr average
162.372A 6

- min averages 12

- hr average
163.LK1501 NA 12

- hr average Data contained "<1" instead of decimal values
163.LK2502 NA 12

- hr average Data contained "<1" instead of decimal values
164.P12 NA 12

- hr average TRS O 2 correction not r eported as 10%. Assumed data were raw and corrected to 10%

. 165.000019 NA 12

- hr average
165.000002 NA 12

- hr average
166.LK01 NA 12

- hr average
166.LK02 NA 12

- hr average
167.004LK NA 12

- hr average 169.03 NA 12

- hr average
171.010 NA 12

- hr average TRS O 2 correction not r eported as 10%. Assumed data were raw and corrected to 10%

. 171.009 NA 12

- hr average TRS O 2 correction not r eported as 10%. Assumed data were raw and corrected to 10%

. 172.LK03 NA 12

- hr average
173.LK1 NA not provided
174.G

- 18 6

- min averages 12

- hr average
174.G

- 95 NA not provided
175.LK1A NA 24

- hr average
175.LK2A NA 12

- hr average
176.G

- 5 NA 24

- hr average
177.EU0905 NA 12

- hr average
178.09P037 6

- min averages 12

- hr average
179.LK3 6

- min averages 12

- hr average Data contained "<1" instead of decimal values
180.L001 NA 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
180.L002 NA 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
181.01 NA not provided
181.14 NA not provided
183.004 NA 12

- hr average TRS O 2 correction not r eported as 10%. Assumed data were raw and corrected to 10%. 184.LK1 NA 12

- hr average
184.LK2 not provided 12

- hr average
185.07 NA 12

- hr average
186.LK 6

- min averages 12

- hr average

### B

- 5

RTI + Emission Unit ID Opacity Data

Type TRS Data

Type Comments On Data 188.001LK1 NA 24

- hr average CEMS reported to be from all 3 kilns, repeated values for the 3 units. 188.002LK2 NA 24

- hr average CEM S reported to be from all 3 kilns, repeated values for the 3 units. 188.003LK3 NA 24

- hr average CEM S reported to be from all 3 kilns, repeated values for the 3 units. 189.SN25 NA 12

- hr average
190.L600 NA 12

- hr average
190.L601 NA 12

- hr average
195.002 NA 12

- hr average
196.SN

- 09 NA 12

- hr average
196.SN

- 02 6

- min averages 12

- hr average 197.1 NA not provided
198.004 NA 1 2

- hr average Calculated 12

- hr average TRS from 1

- hour data.
199.011 NA 12

- hr average 200.007_10 6

- min averages 12

- hr average
201.SR0003 NA not provided
202.Lime Kiln EU340 NA 12

- hr average

203.LKScr NA 12

- hr average
205.008 NA 12

- hr average
206.G

- 37 NA 12

- hr average
206.G

- 38 NA 12

- hr average
207.103A NA not provided
226.LK1 NA not provided
226.LK2 NA not provided
240.CA81 6

- min averages 12

- hr average TRS d ata contained "<1" instead of decimal values 242.AA

- 013 not provided 12

- hr average
243.LG07 not provided 12

- hr average
340.008 NA 12

- hr average TRS O 2 correction not r eported as 10%. Assumed data were raw and corrected to 10%

. 525.EU17 NA 12

- hr average
531.LK7 not provided 12

- hr average
600.G0903 NA 12

- hr average
600.G0905 NA 12

- hr average
600.G0908 NA 12

- hr average
606.LK4 6

- min averages 12

- hr average
610.7 NA 12

- hr average

### B

- 6

RTI + Emission Unit ID Opacity Data

Type TRS Data

Type Comments On Data 610.8 NA 12

- hr average
613.009 NA 12

- hr average
615.21 NA 12

- hr average
617.P22 6

- min averages 12

- hr average
208228535.003 NA 12

- hr average
208228535.009 6

- min averages 12

- hr average

NA

– Not applicable (for kilns with wet scrubbers)

### C

- 1



## APPENDIX C: Recovery Furnace Opacity Data

### C

- 2

### C

- 3

### C

- 4

### C

- 5

### C

- 6

### C

- 7

### C

- 8

### C

- 9

### C

- 10

### C

- 11

### C

- 12

### C

- 13

### C

- 14

### C

- 15

### C

- 16

### C

- 17

### C

- 18

### C

- 19

### D

- 1



## APPENDIX D: Recovery Furnace TRS Data

### D

- 2

### D

- 3

### D

- 4

### D

- 5

### D

- 6

### D

- 7

### D

- 8

### D

- 9

### D

- 10

### D

- 11

### D

- 12 Table D

- 1: TRS CEMS Data Sets for Recovery Furnaces Subject to NSPS with Exceedances of the 5 ppm Li mit During Startup and Shutdown (B ased on a 12

- Hour A verage)

RF type ID No. of S/S Periods No. of 12

- hr Periods Exceeding 5 ppm During S/S Highest 12

- hr TRS

ppm during S/S N ote Control NDCE 119.EQT010 13 5 45.22 * 38.58* 23.22* 20.29* 10.44* Could not recreate 12

- hr averages with 1 hour

data DBESP

NDCE 127.REC1 1 1 102.84 * U ncorrected for O 2 ; associated with 0 production at 19.15% O 2 . No other valid values reported during startup/shutdown . Unclear if the O 2 correction near ambient conditions was already applied, and could not recreate 12

- hour average with 1 hour data. WBESP

NDCE 132.5RB 25 6 25.57 12.54 10.83 9.27 9.04 7.61 DBESP

WPR

NDCE 149.B011 15 1 29.62 Production was CBI; labeled as

“ startup/shutdown ” DBESP

NDCE 186.RB15 1 1 15.9 DBESP
NDCE 189.SN26 12 8 27.34 25.78 15.21 11.19 7.49 6.64 6.49 6.23 WBESP

DCE 600.G0803 2 1 16 WBESP *This value was disregarded for the reason provided in the “Note” column. The value was not considered as representative for rulemaking purposes. Note: Not shown in the table are 53 recovery furnaces currently subject to NSPS subpart BB that had no exceedances of the 5 ppm limit at any time (including normal operations or startup/shutdown).

### D

- 13 Table D

- 2: TRS CEMS Data Corrected Based on Various Oxygen Levels

for Lime Kilns and Recovery Furnaces
Recovery Furnace TRS Raw Data Lime Kiln

TRS R aw D ata O 2 R eading Recovery Furnace TRS Corrected to 8% O 2 Lime Kiln

TRS Corrected to 10% O 2 5 8 0 3.1 5.0
5 8 5 4.1 6.5
5 8 6 4.3 6.9
5 8 7 4.6 7.4
5 8 8 5.0 8.0
5 8 9 5.4 8.7
5 8 10 5.9 9.5
5 8 11 6.5 10.4
5 8 12 7.2 11.6
5 8 13 8.1 13.0
5 8 14 9.3 14.9
5 8 15 10.8 17.3
5 8 16 13.0 20.8
5 8 17 16.3 26.0
5 8 18 21.7 34.7
5 8 19 32.5 52.0
5 8 20 65.0 104.0
5 8 20.5 130.0 208.0
5 8 20.999 65000.0 104000.0

### E

- 1 

## APPENDIX E: Lime Kiln TRS Data

### E

- 2

### E

- 3

### E

- 4

### E

- 5

### E

- 6

### E

- 7

### E

- 8

### E

- 9

### E

- 10

### E

- 11

Table E

- 1. TRS CEMS Data Sets for Lime Kilns Subject to NSPS Subpart BB with Exceedances of the 8 ppm Limi t During Startup and Shutdown (Based on a 12

- Hour A verage) 1

Emission Unit ID APCD Type No. of S/S Periods No. of 12

- hr

Periods Exceeding 8
ppm During S/S Max 12

- hr ppm

TRS D uring S/S Events at 10% O 2 unless otherwise noted Comments 107.11

- P14 ESP 8 2 67.9* 10.8  Likely invalid data. 12

- hour block contained one 899 ppm spike followed

by negative 1

- hour readings. Actual O 2 data unavailable; unclear if O 2 correction inflated the ppm

.

 Next highest 12

- hr value was 10.8 ppm. 109.LK1 ESP 20 3 167 @ 20.4% O 2 48.8 @ 19.6% O 2 8.8 @ 15.7% O 2  Mill had two consecutive high O 2 - corrected TRS 12

- hr averages ( 167 and

4 8.8 ppm ) and one unrelated 12

- hr average in excess of 8 ppm. All three of these values would be below 8 ppm after invoking the proposed provision to consider uncorrected values when O 2 exceeds 15%. The uncorrected values would be 9.8, 6 .0, and 4.2 ppm). 147.3 SCBR 9 2 17.8 Next highest 12

- hr value was 8.1 ppm. 148.009 ESP 1 1 8.035 151.CP002 SCBR (NCG

scrubbers pre

kiln + LK ESP] 7 2 37.0* 13 * Although 12

- hr data set indicated 37 ppm (with next highest of 13 ppm), the

corresponding 1

- hr data do not show 37 ppm

. It is unclear how the 37

- ppm 12

- hr average reported was derived because the highest 1

- hr value for that block was 10.9 ppm

. Similarly, all hourly values associated with the 13 ppm 12

- hour average were less than 1 ppm. Data se t not considered further. 151.CP001 14 7 57.0* 43.0* 22 20 17 12 10  Data anomaly. Only one hourly value of 57 ppm was included in the 12

- hr

average because process down time for the other 11 hours is excluded

.

 The 2 nd highest value of 43 ppm was associated with 0 production.

 The 3 rd highest value was 22 ppm

 Actual O 2 data unavailable; unclear if O 2 correction inflated the ppm.

180.L002 SCBR 85 2 10.2 8.5 186.LK ESP/SCBR 18 1 8.1 240.CA81 ESP 10 1 9.0 1. Not shown in the table are 2 1 additional lime kilns that clearly had no exceedances of the 8 ppm TRS standard during startup or shutdown. A total of 33 lime kilns had no exceedances during any time (normal operation or startup/shutdown)

. *Not considered representative for rulemaking purposes.

### F

- 1 

## APPENDIX F: Lime Kiln Opacity Data

### F

- 2

### F

- 3

### F

- 4

### F

- 5