UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

SECTOR POLICIES AND PROGRAMS DIVISION

OFFICE OF AIR QUALITY PLANNING AND STANDARDS

OFFICE OF AIR AND RADIATION

DATE: April 5, 2013

SUBJECT: Review of the Continuous Emission Monitoring and Continuous Opacity 

Monitoring Data from the Pulp and Paper Information Collection Request 

Responses Pertaining to Subpart BB 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 review of the Continuous 

Emission Monitoring System (CEMS) and Continuous Opacity Monitoring System (COMS) data

provided by the pulp and paper industry in response to the 2011 Information Collection Request 

(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). 

Section 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 was promulgated in 1978

and reviewed in 1986. The NSPS regulates 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 regulates emissions of total reduce sulfur (TRS) compounds from 

new, modified, and reconstructed 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 Townsend 

Airwatchers filed a complaint (Clean Air Act citizen suit) against the EPA to review the NSPS. 

This complaint resulted in a consent decree that requires EPA to review the NSPS by May 15, 

2013 for proposal and March 14, 2014 for promulgation. See docket ID number EPA-HQ-OGC2012-0730 for a copy of the consent decree.

Section I of this memorandum provides a summary of the tabulation and quality 

assurance/quality control (QA/QC) analysis of the 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 data were collected from the pulp and paper industry in 2011 in 

response to a CAA §114 ICR. The three-part survey was distributed by the EPA in February 

2011 and requested information needed to perform various regulatory reviews, including the 
2

subpart BB NSPS review. This section of the memo discusses the QA/QC of the CEMS and 

COMS data that were provided in response to the ICR. 

The general approach for processing 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 furnace 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 multiple 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 

facility 243 has two stacks and was represented by data 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, and NEI site ID were provided to characterize the emission units; the 

“tab name” of each worksheet from which the data are linked was provided; and summary 

information such as annual average emissions, 99th percentiles, and maximum values were

calculated. The data from each summary worksheet were used for the data analysis 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 average 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 state 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 opacity and TRS emission limits, but the information these mills 

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 COMS or CEMS readings. These readings 

included negative values and abnormally large values during periods of process downtime. All 

negative readings were deemed suspect and were removed from the data set to prevent artificial 

lowering of a unit’s annual average performance. The cells containing these values were 

highlighted in yellow to indicate removal. Abnormally large values that occurred during periods 

labeled as “process downtime” were removed if the production rate was reported as zero to 

indicate that the unit was non-operational 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. The cells corresponding to the removed 

values were also highlighted in yellow. Large values that were reported during other periods, in 

which the production rate was not zero, were not deleted from the data set. Facilities were asked 
3

to indicate in the ICR if any data were affected by periods of startup, shutdown, 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 updated NSPS 

should distinguish between periods of startup and shutdown and normal operation as revised 

emission limits were considered.

Based on the part III survey responses, there were 151 recovery furnaces and 131 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). 

A summary of the type of recovery furnace COMS and TRS CEMS 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

Continuous opacity monitoring system data were provided for 137 of the 149 operating 

recovery furnaces. Of the 137 units with data provided, 135 were extracted into a compiled 

recovery furnace COMS spreadsheet containing individual worksheets for each unit. There were 

25 units with multiple-stack opacity data. The two units with data that were not extracted into the 

spreadsheet were not provided in Excel format. The data for 117.B21 were provided as .pdf and 

the data for 155.RECOVERY FURNACE were provided in Word 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 emission 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, 1-hour average, and maximum 6-minute average per hour. 

Of the data provided, 128 units were extracted in the 6-minute format (23 units with multiple 

stacks), 5 units in the 1-hour format (1 unit with multiple stacks), and 2 units in the maximum 

hourly 6-minute average format (1 unit with multiple stacks). 

The recovery furnace COMS summary worksheet summarizes the data type as “6-minute 

averages,” “hourly averages,” “highest 6-minute average per hour,” “data not provided,” or “data 

provided in alternate format.” For each COMS, the summary spreadsheet contains the maximum 

opacity, the average (including and excluding exceedances), the standard deviation, the 99th

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 opacity data were not 

provided (e.g., invalid data) is also indicated.
4

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

Total reduced sulfur CEMS data were provided for 135 of the 149 operating recovery 

furnaces. Of the 135 units with data provided, 131 were extracted into a compiled recovery 

furnace TRS CEMs spreadsheet containing individual worksheets for each unit. There were 10

recovery furnaces with multiple stack TRS data. The four units with data that were not extracted 

into the spreadsheet were not provided in Excel format. The data for three of these units were 

provided in Word 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, separate TRS CEMS spreadsheet templates requesting 12-hour and 

1-hour average TRS data for a period of one year were provided with part 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 state regulations. 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. 

Therefore, the order of preference for TRS averaging time extracted into the tabulation 

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, 115

recovery furnaces were extracted in the 12-hour average format (9 units with multiple stacks), 10

units in the 12-hour average calculated based on 1-hour averages, and 6 units in the 24-hour 

format (1 unit with multiple stacks). 

The CEMS 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 % O2)” in column I with the instructions “please enter concentration 

(ppmdv) corrected for % O2 as required by subpart BB (8% O2 for recovery furnaces; 10% O2

for other equipment for which data are requested).” The spreadsheet template also requested that 

a facility report the “% O2 correction (by volume, dry basis)” in column J with the instructions to 

enter “the % O2 correction by volume (dry basis) (e.g., 8% or 10%).” For the recovery furnace 

TRS CEMS, it was expected that the oxygen (O2) correction would be reported as 8 percent in 

column J. The oxygen correction data for 9 units (109.RB3, 109.RB4, 127.REC1, 171.02, 

171.03, 171.04, 183.002, 207.038, and 340.005) reported in column J appeared to be raw O2 data 

instead of the requested corrected O2 value of 8 percent. It was assumed, because raw O2 data 

were reported instead of the correction value, that the TRS data provided in column I were also 

raw data. The raw TRS and O2 values were used to determine the corrected TRS value using 

Eqn. 1 shown below from 40 CFR 60.284(c)(3). The new TRS column was highlighted in yellow 

for the 9 units reported for which values were calculated. Unit 163.RF1901 had data reported as 

corrected to 10 percent O2 and unit 242.AA-011 had data as corrected to 5 percent O2. These 

units were corrected to 8 percent O2. 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-O2 value)) (Eqn. 1)
5

Data provided for six units (179.RF3, 240.RF04, 240.RF01, 163.RF1901, 163.RF2904, and 

151.REC004) may slightly skew the performance values (e.g., annual average, median, 99th

percentile) for those units because data were reported as “<1” instead of decimal values for 

179.RF3, 240.RF04, 240.RF01, 163.RF1901, 163.RF2904, and “0” for values less than 0.5 for 

151.REC004. These values were not removed or edited; therefore, they did not contribute to the 

performance values, but the reporting of the data was considered in the analysis.

The summary worksheet in the recovery furnace TRS CEMS spreadsheet indicated the data 

type as “12-hr average,” “12-hr calculated from 1-hr averages,” “24-hr average,” “not provided,”

or “provided in alternative format.” The annual average and standard deviation of the corrected 

TRS parts per million (ppm)1 values were calculated for each unit (to determine 99th percentiles), 

as well as the maximum reported average and the number 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 NDCEs 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 spreadsheet for analysis.

 

C. Lime Kiln TRS CEMS Data

Total reduced sulfur CEMS data were provided for 116 of the 131 operating lime kilns. Of 

the 116 units with data provided, 111 units were extracted into a compiled lime kiln TRS CEMS

spreadsheet containing individual worksheets for each unit. There was only one lime kiln with 

multiple stack data provided. The four kilns with data that were not extracted into the 

spreadsheet were not provided in Excel format. The data for two of these kilns were provided in 

text format (.txt), one kiln was provided in Word format, and one kiln was provided as a PDF

document. In all, adding emission units with multiple stacks, 112 TRS 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, 91 kilns were extracted in the 12-

hour average format (1 unit with multiple stacks), 14 kilns were extracted in the 1-hour average 

format, and 6 were extracted in the 24-hour format. The 1-hour average TRS data sets were 

converted to 12-hour average format for comparison purposes.

The O2 correction data for 9 lime kilns (109.LK1, 112.AA-11, 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 O2 data instead of the requested corrected O2 value of 10 percent. The raw TRS and O2

values were used to determine the corrected TRS value using Eqn. 1 above. Units 119.EQT006, 

103.G-65, and 105.EU455 had data reported as corrected to 8 percent O2; therefore, a new 

 1 All parts-per-million values reported in this document represent ppm by volume on a dry basis (ppmdv). 
6

column was added (highlighted yellow) with the data corrected to 10 percent. Raw data were

reported for unit 143.6063, which were used to calculate the corrected TRS values. 

Data provided for four units (163.LK1501, 163.LK2502, 179.LK3, 240.CA81) may skew the 

annual performance values (e.g., annual average, 99th 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 the reporting of the data was 

considered in the analysis. 

A summary worksheet was added to the lime kiln 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 “provided in alternative format.” The annual average and standard 

deviation of the corrected TRS ppm values were calculated for each unit (to determine 99th

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 uses 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 worksheets for each unit. There 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 the 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 maximum opacity, the average, the standard deviation, the 99th

percentile, the median, and the number (and percentage) of opacity average values over 20 

percent were calculated. 

II. Data Analysis 

Summary 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 develop 

regulatory options for the NSPS review. The annual average measurements, percent of averaging 

periods exceeding the current standard, and the 99th percentile of the averaging periods were 
7

plotted for each emission unit. The 99th percentile was used as an indicator of the emission 

limitation consistently met by each emission unit. Distinctions in furnace design and control 

systems, and current emissions allowances in the NSPS, were considered in the CEMS and 

COMS analyses as described in more detail in the following sections.

A. Recovery Furnace COMS Analysis

Opacity limit evaluation. The kraft pulping NSPS contain a 35 percent limit for opacity from 

recovery furnaces and does not distinguish between recovery furnace design (DCE or NDCE). 

The NSPS requires opacity to be recorded as 6-minute averages, and allows 6 percent of the 6-

minute averages per quarter recorded to be in exceedance of the 35 percent limit. Appendix C

contains graphs of the 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 (151) of the COMS data sets 

graphed were 6-minute average data. Three data sets represented the highest 6-minute average 

per hour, and six data sets were based on hourly average. The highest 6-minute average per hour 

and hourly data sets were generally within the range of the 6-minute average data (unless 

otherwise noted on the plots).

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 recovery 

furnace design affects opacity. The highest annual average opacity was 16 percent, well below 

the 35 percent NSPS limit. Figures 2 and 3 show annual average opacity by control type (within 

DCE and NDCE groupings in Figure 2). From Figures 2 and 3, it appears that there is no clear 

distinction between recovery furnace control system and opacity.

Compliance is based on each individual averaging period and not the annual average. 

Therefore, the 99th 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 99th

percentile values from each of the 160 COMS data sets. From Figure 4, it is apparent that most 

mills are consistently meeting the NSPS limit of 35 percent opacity. The Subpart 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)). Figure 4 shows that most (129 

of 160 data sets) recovery furnace COMS had 99th percentiles below the 20 percent level

regardless of recovery furnace design. Figures 5 and 6 break out 99th 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 DBESP-WPR/DBESP/DBESP 

system and a two-sided dry and wet bottom ESP) had 99th 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 emerges as a regulatory 

option for investigation under the NSPS review because: (1) 20 percent is already a benchmark 
8

under subpart MM, (2) all mills had annual average opacity of 16 percent or less, and (3) the 

majority of recovery furnaces are consistently achieving 20 percent opacity. The EPA could 

consider higher or lower options (e.g., 25 percent or 15 percent), but these do not have the 

benefit of relating to subpart MM. It appears that an opacity limit of 20 percent has been 

adequately demonstrated for recovery furnaces. 

Monitoring allowance evaluation. Figures 7 through 9 review the percentage of averaging 

periods exceeding the current 35 percent NSPS opacity limit, as compared to the current 6 

percent monitoring exceedance allowance. Similarly, Figures 10 through 12 show the percentage 

of averaging periods 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 2 percent monitoring allowance would more accurately represent the 

number of exceedances mills are incurring under a 35 percent opacity limit. Twenty-three

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

Figures 10 through 12 show that a 2 percent monitoring allowance coupled with a 20 percent

limit is achieved by many recovery furnaces regardless of design or control system. The two

unique control systems mentioned above would be challenged to remain under a 2 percent

monitoring allowance but because alternative control designs are both available and adequately 

demonstrated, it is not clear if the two unique control types would continue to be used if those 

furnaces were to be replaced, modified, or reconstructed. A 6 percent monitoring allowance 

would cover nearly all exceedances of the 20 percent opacity 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 more accurately represents the number 

of exceedances the best performing recovery furnaces were incurring on opacity limits ranging 

from 20 to 35 percent. Only 12 of 160 recovery furnaces COMS did not exceed the 20 percent

opacity limit.

The proposed Subpart BBa NSPS will not be applicable to any existing unit (unless the unit 

is modified or reconstructed). However, we evaluated the recovery furnaces that, according to 

the data provided, might be challenged to meet a 20 percent limit with a 2 percent allowance in 

order to see if they shared common attributes. Further analysis of the 16 COMS data sets above

the 2 percent exceedance threshold in Figures 10 through 12 revealed that 15 furnaces did not

meet a 20 percent opacity with a 2 percent allowance (1 furnace had 2 stacks). After removal of 

data indicated as malfunctions and process down from the COMS data sets, three additional 

furnaces achieved 20 percent opacity with a 2 percent allowance. Seven of the 12 furnaces that 

did not achieve 20 percent opacity with a 2 percent allowance are NSPS units (NDCEs) and five 

furnaces (4 NDCE and 1 DCE) were not subject to the NSPS. The range of exceedances after 

removing the malfunction and process down data was 2.1 to 7.8 percent (excluding the 27.1

percent unit omitted from the graphs) and the average is 3.7 percent. Some COMS data sets were 

not annotated with process down or malfunction periods and it is thought that labeling and 

removing the affected 6-minute averages would likely result in some of these furnaces achieving 

a 20 percent limit with a 2 percent monitoring allowance. Overall, 123 of 135 recovery furnaces 

with multiple types of control systems (e.g., dry and wet bottom ESPs with and without dry PM 

return) adequately demonstrated the ability to meet a 20 percent opacity limit with a 2 percent 

allowance option, each at numerous facilities in the industry.
9

Recommendation. The figures in Appendix C support a 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 furnaces. Startup and 

shutdown periods were included in the data sets used to evaluate the revised opacity 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 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. 

B. Recovery Furnace TRS CEMS Analysis

TRS limit evaluation. The kraft pulp mill NSPS limit TRS emissions from straight recovery 

furnaces to 5 ppm at 8 percent O2 and from cross recovery furnaces to 25 ppm at 8 percent O2. 

Review of the part III ICR data indicate that no cross recovery furnaces are currently subject to 

the NSPS. Likewise, there is no TRS emissions data to analyze for these units. Maintaining the 

current cross recovery furnace 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 pulping 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. Practically, we do not project any modified, reconstructed, or new cross recovery 

furnaces being constructed in our analysis. The remainder of this section will focus on TRS 

emissions from straight recovery furnaces.

The NSPS require TRS to be recorded as 12-hour averages and allow one percent of the 12 

hour averages recorded per quarter to be in exceedance of the 5 ppm limit without constituting a 

violation. Appendix D contains graphs of the recovery furnace TRS data. A total of 131 recovery 

furnaces are represented by these graphs (including 10 recovery furnaces with multiple TRS 

CEMS for a total of 141 TRS data sets), with the majority reported as 12-hour averages. The 

TRS emission guidelines require a limit of 5 ppm for exiting 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 O2.

The plots in Appendix D present the 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; however, seven of the TRS data sets (for non-NSPS furnaces) are based 

on 24-hour average values. The 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 furnace 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. 
10

As shown in Figure 1 in Appendix D, many DCE recovery furnaces that are not subject to the 

NSPS TRS limit exhibit emissions above 5 ppm but below 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. 

Because compliance with the NSPS TRS limit is based on each 12-hour block average (rather 

than the average of all 12-hour blocks in a year), we considered the 99th percentile of the TRS 

averaging periods in Figure 2 as an indicator of how consistently the block average limit is 

achieved. Two 99th percentile outliers were omitted from Figure 2 (a non-NSPS DCE with 99th

percentile at 126 ppm, and a NDCE subject to the NSPS with 99th percentile at 43 ppm). When 

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

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 

above 5 ppm because most DCEs are not required to consistently meet the 5 ppm limit. The 

majority of NDCEs achieved the 5 ppm limit consistently with one percent or fewer of the

averaging periods in excess of 5 ppm. As noted previously, subpart BB contains a one percent 

monitoring allowance for recovery furnace TRS. A few NDCE furnaces had a relatively high 

percentage of averaging periods in excess of 5 ppm, but these were mostly non-NSPS NDCEs.

Only the recovery furnaces subject to the NSPS were plotted in Figures 4 through 6 in order 

to better evaluate the one percent TRS monitoring allowance 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 one percent of the averaging periods. 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 one percent monitoring allowance, and 8 units exceeded 5 

ppm for 1 percent of the reporting periods. Six NDCEs exceeded 5 ppm in up to 7 percent 

averaging periods. Based on this figure, it appears that a one percent monitoring allowance

reflects the level of TRS compliance that has been adequately demonstrated and is achieved by 

the best performing recovery furnaces.

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 and scrubber. In Figure 6, we observe that 

control device type does not appear to significantly affect the 99th percentile TRS value for the 

NSPS recovery furnaces. Few recovery furnaces had a 99th percentile TRS value in excess of 5 

ppm, including a unique system with a two-sided dry- and wet-bottom ESP. The 99th 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 
11

averaging periods (shown in Figure 5) seems to suggest that a limit lower than 5 ppm (e.g., 3 

ppm) is achieved, the 99th 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 Appendix D investigates the effect on DCE recovery furnace TRS emissions if 

multiple-stage black liquor oxidation (BLO) is used prior to the DCE. Of the three NSPS DCE 

recovery furnaces, two units had two-stage BLO systems and one had 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 14 recovery furnaces with TRS data were indicated to have two-stage 

BLO, and four had three-stage BLO systems. The TRS data in Figure 7 are inconclusive as to 

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 99th percentile. Burning 

NCGs did not appear to significantly increase recovery furnace TRS emissions, but it did

indicate an increase in the potential for TRS emissions variability as evidenced by the greater 

range in 99th percentiles for the NCG-burning NDCE furnaces in Figure 9.

Monitoring allowance evaluation. As shown in Figure 4, most recovery furnaces subject to 

the NSPS have achieved a 5 ppm TRS limit with one percent or less monitoring deviations

during normal operations and startup and shutdown periods. The TRS CEMS data shown in 

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 ppm limit falling within the one 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) should be 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, 30 ppm appears to be a representative cap for the one percent

monitoring allowance. 

During 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 correction 

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. 

One solution to this issue would be 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. 
12

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 in Appendix D support a regulatory decision to maintain a TRS 

limit of 5 ppm with a one percent monitoring allowance for recovery furnaces. To ensure 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 can be capped 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. 

C. Lime Kiln TRS CEMS Analysis

TRS limit evaluation. Lime kiln TRS emissions are limited to 8 ppm at 10 percent O2 by the 

kraft pulp mills NSPS. All of the lime kiln TRS ppm values discussed in this section reflect 

conditions at 10 percent O2. Figures 1 through 7 in Appendix E present TRS CEMS summary 

data for each lime kiln (1 unit with multiple stacks, for a total of 112 data sets). Most of the data 

points shown in these figures reflect 12-hour average CEMS data sets. However, 6 of the 112 

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 kilns 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 non-NSPS kilns based on 

air pollution control device type: ESP, ESP followed by a scrubber (ESP/SCBR), and SCBR. 

The 24-hour average data sets were noted and fell within the scatter of the 12-hour average data 

sets. We observed that control device performance overlaps, and that ESP/SCBR systems fell 

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) have a greater effect on lime kiln TRS emissions than control 

device type. Most of the lime kilns achieved the 8 ppm limit on an annual average basis. 

However, compliance is based on each 12-hour block averaging period so the percentage of 

averaging periods in excess of 8 ppm was plotted in Figure 2. Several scrubbers and two nonNSPS ESPs exceeded 8 ppm for a relatively high percentage of averaging periods.

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 Figure 3, it can be observed 

that 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. Figure 4 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 NSPS 

(e.g., any average that is an exceedance can be considered as a violation). Many of the NSPS 
13

kilns (32 of 60) achieved zero exceedances of the 8 ppm limit regardless of control device type. 

Even some well-controlled kilns had a few exceedances of the 8 ppm limit. 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. The scrubber-controlled kilns 

appear to be the most challenged to remain below 8 ppm. 

Figure 5 considers the 99th 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 regardless of control 

system. Figure 5 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 99th percentile 

performance was within the range of that achieved by the lime kilns with ESP or scrubber 

control only. 

Figure 6 shows the 99th percentile for NSPS kilns 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 performance of NCG-burning kilns versus non-NCG burning kilns. NCGburning kilns with white liquor pre-scrubbers have similar TRS emissions to NCG-burning kilns 

without pre-scrubbers. Figure 7 shows 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 variability.

Monitoring allowance evaluation. As shown in Figure 4, most lime kilns subject to the NSPS 

have achieved the 8 ppm TRS limit with one percent or less monitoring deviations 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 8 ppm limit to startup and shutdown periods in addition to normal operations. Periods of 

malfunction and process downtime (i.e., 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 31 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 affected by startup or 

shutdown periods. Up to 113 of a possible 730 annual 12-hour averaging periods were affected 

by startup and shutdown. On average it takes a lime kiln 24 hours to startup and 12 hours to 

shutdown.

2 Of the 31 data sets with startup and shutdown indicated, 20 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 some mills. However, for 11 other kilns compliance with 

the 8 ppm TRS limit during startup and shutdown has not been adequately demonstrated because 

these kilns experienced exceedances in up to eight 12-hour blocks affected by startup and 

 2

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.
14

shutdown. Eight of 730 possible 12-hour blocks in a year corresponds to 1.1 percent of possible 

averaging periods (8/730 = 1.1%). This percentage of averaging periods affected by startup and 

shutdown is consistent with the information in Figure 4 which shows 51 of 60 NSPS kilns in

compliance with the 8 ppm TRS limit in all but one 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 were determined not to be representative for 

rulemaking purposes. The two 12-hour TRS concentrations corrected to 10 percent O2 that 

appeared to be representative of startup and shutdown events were both 22 ppm. Similarly, for 

most NSPS kilns, the 99th percentile 12-hour average during all time periods (including startup 

and shutdown) was less than 20 ppm as shown in Figure 5. 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, during 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 correction 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 

Table D-2. It is recommended that EPA propose 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. 

Recommendation. To summarize, the current 8 ppm TRS limit based on a 12-hour average 

with a one percent monitoring allowance during which time emissions must not exceed 22 ppm 

is recommended as the continuous lime kiln TRS standard. This has been achieved in practice. 

The one percent monitoring allowance (not to exceed 22 ppm) is recommended to adjust the 

current 8 ppm limit (with no allowance) for 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 conditions. It is 

also recommended that periods of zero kiln throughput (zero lime production) be clarified as 

non-operational periods, and that a provision be added to the rule to state that the uncorrected 

TRS concentration can be considered when O2 is near ambient conditions during startup or 

shutdown.

D. Lime Kiln COMS Analysis

Opacity limit evaluation. The kraft pulp mills NSPS does not set 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 had installed ESPs and were required to monitor opacity under subpart MM. 
15

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 graphed (including multiple data sets for two kilns with 

separate COMS for duel stacks) and are provided in Appendix F. The majority (25) of the 

COMS data sets graphed were 6-minute averages. Two data sets represented hourly averages.

Figure 1 in 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 99th

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. Two units exceeded 

the 20 percent opacity, but further investigation shows they did not exceed 20 percent for more 

than the 6 percent monitoring allowance.

Monitoring allowance evaluation. Figure 3 in Appendix F shows the percent of averaging 

periods in excess of 20 percent opacity. All but three kilns consistently achieved 20 percent 

opacity with less than 1 percent of averaging periods in exceedance of 20 percent. Further 

investigation into these three units show that removal of data labeled as process downtime and 

malfunction resulted in two of the units achieving 20 percent opacity with a 1 percent monitoring 

allowance. In summary, it is recommended that a 20 percent opacity limit with a 1 percent 

monitoring allowance is adequately demonstrated. 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 data 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 1, TRS CEMS data were submitted with the ICR 

for four kraft mill processes emitting non-condensable gases. The 12-hour average TRS CEMS 

data sets were reviewed for these systems. As for the lime kiln and recovery furnace TRS CEMS 

data sets, zero emissions values 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 99th percentile TRS 

averages. These units included a pulp washer, a boiler, and two thermal oxidizers. 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 high-concentration (LVHC) and high-volume low-concentration incineration that
16

was used when the recovery furnace (primary control device) was not operational. The two 

thermal oxidizers were used to burn LVHC and stripper off gas streams. These units exhibited 

99th 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. 
17

Table 1. TRS CEMS Data for Kraft Pulping Processes Emitting NCGs

RTI 

Code NEI ID

Emission 

Unit ID

Process 

Type APCD Type APCD ID

NCG sources 

controlled Notes

Max TRS 

ppmdv @ 

10% O2

99th

Percentile 

TRS 

ppmdv @ 

10% O2

1

186 NEI18334 HWCHEM

Pulp 

Washer

Hardwood 

Chemiwasher 

Scrubber

FL34 and 

HWCHME Washer

Because this is a noncombustion 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 O2

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 

operational. 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 average values provided including startup and shutdown.
A-1

APPENDIX A: Summary of Recovery Furnace Data Received
A-2

Summary of Recovery Furnace Data Received

RTI + Emission 

Unit ID

Opacity Data 

Type TRS Data Type Comments on Data

100.037A 6-min averages 12-hr averages

Provided raw TRS data - corrected to 8% 

O2. Calculated 12-hr average TRS from 1-

hour data.

102.RB10 6-min averages 12-hr averages

103.G-158 6-min averages 12-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 12-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 O2 correction values were not 8%, assumed 

TRS values were raw data and corrected

109.RB3 6-min averages 12-hr averages O2 correction values were not 8%, assumed 

TRS values were raw data and corrected

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 12-hr averages

Unit has opacity data for 2 stacks. O2

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 12-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 12-hr averages

TRS raw data reported - corrected to 8%. 

Calculated 12-hr average TRS from 1-hour 

data.

143.7010 hourly average 12-hr averages Calculated 12-hr average TRS from 1-hour 

data.

143.7020 hourly average 12-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 12-hr averages Calculated 12-hr average TRS from 1-hour 

data.

148.007 6-min averages 12-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 TRS data contained "<1" instead of 

decimal values

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
A-4

RTI + Emission 

Unit ID

Opacity Data 

Type TRS Data Type Comments on Data

154.P37 6-min averages 12-hr averages

P39 and P37 have own WBESP but vent to 

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, O2 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 O2 correction not reported as 8%, assumed 

raw TRS data and corrected

171.003 6-min averages 12-hr averages O2 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, 

O2 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 12-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 O2 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 

DBESP that vent through a comment stack 

(opacity represents combined total)

190.R401 6-min averages 12-hr averages

R400 and R401 appear to each have a 

DBESP that vent through a comment 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 highest 6-min 

average per hour 12-hr averages Calculated 12-hr average TRS from 1-hour data.

199.002 6-min averages 12-hr averages

200.007RF2 highest 6-min 

average per hour 12-hr averages Unit has opacity data for 2 stacks

200.007RF3 highest 6-min 

average per hour 12-hr averages Unit has opacity data for 2 stacks
A-6

RTI + Emission 

Unit ID

Opacity Data 

Type TRS Data Type Comments on Data

201.SR0001 6-min averages not provided

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

Unit has opacity data for 2 stacks. O2

correction 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 O2 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 O2 correction 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 averages
B-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

103.G-165 NA 12-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.

107.11-P14 6-min averages 12-hr average

108.LK1 NA not provided

109.LK1 6-min averages 12-hr average TRS O2 correction not reported as 10%. Assumed 

data were raw and corrected to 10%.

111.G-35 not provided 12-hr average Calculated 12-hr average TRS from 1-hour data.

112.AA-110 not provided 12-hr average

114.U800 6-min averages 12-hr average

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-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 12-hr average Unit has TRS data for 2 stacks

127.LK1 6-min averages 12-hr average

TRS O2 correction not reported as 10%. Assumed 

data were raw and corrected to 10%. Calculated 

12-hr average TRS from 1-hour data.

127.LK2 6-min averages 12-hr average

TRS O2 correction not reported as 10%. Assumed 

data were raw and corrected to 10%. Calculated 

12-hr average TRS from 1-hour 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
B-3

RTI + 

Emission Unit 

ID

Opacity Data 

Type

TRS Data 

Type Comments On Data

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 12-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 12-hr average Calculated 12-hr average TRS from 1-hour data.

148.003 NA 12-hr average Calculated 12-hr average TRS from 1-hour data.

148.009 6-min averages 12-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

156.145000 NA 12-hr average

156.LK5 6-min averages 12-hr average

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 O2 correction not reported as 10%. Assumed 

data were raw and corrected to 10%.

165.000019 NA 12-hr average
B-4

RTI + 

Emission Unit 

ID

Opacity Data 

Type

TRS Data 

Type Comments On Data

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 O2 correction not reported as 10%. Assumed 

data were raw and corrected to 10%.

171.009 NA 12-hr average TRS O2 correction not reported 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-hr average Calculated 12-hr average TRS from 1-hour data.

180.L002 NA 1-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 O2 correction not reported 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

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 CEMS reported to be from all 3 kilns, repeated 

values for the 3 units.

188.003LK3 NA 24-hr average CEMS 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
B-5

RTI + 

Emission Unit 

ID

Opacity Data 

Type

TRS Data 

Type Comments On Data

196.SN-09 NA 12-hr average

196.SN-02 6-min averages 12-hr average

197.1 NA not provided

198.004 NA 12-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 data 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 O2 correction not reported 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

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
C-1

APPENDIX C: Recovery Furnace Opacity Data
C-2

0

2

4

6

8

10

12

14

16

18

Annual Average Opacity (including exceedances)

Figure 1. Annual Average Opacity - DCE vs. NDCE

Calculated as the average of the 6-min averaging periods.* Note that compliance is based on each 12-hour average, not the annual average.

DCE NDCE

*Three mills provided maximum 6-min average for each hour, and 5 mills provided 

hourly averages. These averages are all within the range of the 6-minute averages 

provided.
C-3

0

2

4

6

8

10

12

14

16

18

Annual Average Opacity (including exceedances)

Figure 2. Annual Average Opacity - DCE vs. NDCE (Showing APCD)

Note that compliance is based on each 12-hour average, not the annual average.

DCE - DBESP DCE - DBESP-WPR

DCE - WBESP NDCE - DBESP

NDCE - DBESP-WPR NDCE - DBESP-WPR/DBESP/DBESP

NDCE - DB-WBESP [2-sided dry and wet] NDCE - WBESP
C-4

0

2

4

6

8

10

12

14

16

18

Annual Average Opacity (including exceedances)

Figure 3. Annual Average Opacity - APCD

Note that compliance is based on each 12-hour average, not the annual average.

DBESP DBESP-WPR

DBESP-WPR/DBESP/DBESP DB-WBESP [2-sided dry and wet]

WBESP
C-5

0

5

10

15

20

25

30

35

40

45

50

99th Percentile of Opacity (%)

Figure 4. 99th Percentile of Opacity - DCE vs. NDCE

DCE NDCE

Current NSPS opacity limit = 35%

MM action level= 20%
C-6

0

5

10

15

20

25

30

35

40

45

50

99th Percentile of Opacity (%)

Figure 5. 99th Percentile of Opacity - DCE vs. NDCE (Showing APCD)

DCE - DBESP DCE - DBESP-WPR

DCE - WBESP NDCE - DBESP

NDCE - DBESP-WPR NDCE - DBESP-WPR/DBESP/DBESP

NDCE - DB-WBESP [2-sided dry and wet] NDCE - WBESP

Current NSPS opacity limit = 35%

MM action level= 20%

Highest 6-min average 

provided for each 
C-7

0

5

10

15

20

25

30

35

40

45

50

99th Percentile of Opacity (%)

Figure 6. 99th Percentile of Opacity - APCD

DBESP DBESP-WPR

DBESP-WPR/DBESP/DBESP DB-WBESP [2-sided dry and wet]

WBESP

Current NSPS opacity limit = 35%

MM action level= 20%
C-8

0%

1%

2%

3%

4%

5%

6%

7%

Percent of Averaging Periods Exceeding 35%

Figure 7. Percent of Averaging Periods Exceeding 35%

- DCE vs. NDCE

DCE NDCE

Current NSPS Monitoring Allowance = 6% of averages exceeding 35% opacity
C-9

0%

1%

2%

3%

4%

5%

6%

7%

Percent of Averaging Periods Exceeding 35%

Figure 8. Percent of Averaging Periods Exceeding 35%

- DCE vs. NDCE (Showing APCD)

DCE - DBESP DCE - DBESP-WPR

DCE - WBESP NDCE - DBESP

NDCE - DBESP-WPR NDCE - DBESP-WPR/DBESP/DBESP

NDCE - DB-WBESP [2-sided dry and wet] NDCE - WBESP

Current NSPS Monitoring Allowance = 6% of averages exceeding 35% opacity

Highest 6-min average 

provided for each 

hour
C-10

0%

1%

2%

3%

4%

5%

6%

7%

Percent of Averaging Periods Exceeding 35%

Figure 9. Percent of Averaging Periods Exceeding 35%

- APCD

DBESP DBESP-WPR

DBESP-WPR/DBESP/DBESP DB-WBESP [2-sided dry and wet]

WBESP

Current NSPS Monitoring Allowance = 6% of averages exceeding 35% opacity

Highest 6-min average 

provided for each 

hour
C-11

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

Percent of Averaging Periods Exceeding 20%

Figure 10. Percent of Averaging Periods Exceeding 20%

- DCE vs. NDCE

DCE NDCE

Note: One non-NSPS NDCE with DBESP exceeding 20% 

opacity for 27.6% of time omitted from chart. 
C-12

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

Percent of Averaging Periods Exceeding 20%

Figure 11. Percent of Averaging Periods Exceeding 20%

- DCE vs. NDCE (Showing APCD)

DCE - DBESP DCE - DBESP-WPR

DCE - WBESP NDCE - DBESP

NDCE - DBESP-WPR NDCE - DBESP-WPR/DBESP/DBESP

NDCE - DB-WBESP [2-sided dry and wet] NDCE - WBESP

Note: One non-NSPS NDCE with DBESP exceeding 20% 

opacity for 27.6% of time omitted from chart. 
C-13

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

Percent of Averaging Periods Exceeding 20%

Figure 12. Percent of Averaging Periods Exceeding 20%

- APCD

DBESP DBESP-WPR

DBESP-WPR/DBESP/DBESP DB-WBESP [2-sided dry and wet]

WBESP

Note: One non-NSPS NDCE with DBESP exceeding 20% 

opacity for 27.6% of time omitted from chart. 
D-1

APPENDIX D: Recovery Furnace TRS Data
D-2

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

TRS, ppmdv @ 8% O2

Figure 1. Annual Average of the TRS Averaging Periods (NSPS and Non-NSPS Furnaces)

Values are mostly 12-hr averages, with some 24-hr averages for non-NSPS units. 

Note that compliance is based on each 12-hr average, not the annual average.

DCE NDCE

Current NSPS limit for straight RF (DCE and NDCE) = 5 ppm @ 8%O2

Emission guidelines (8% O2) = 5 ppm for NDCE and 20 ppm for DCE
D-3

0

5

10

15

20

25

30

TRS, ppmdv @ 8% O2

Figure 2. 99th Percentile of the TRS Averaging Periods (NSPS and Non-NSPS Furnaces)

Values are mostly 12-hr averages, with some 24-hr averages for non-NSPS units. 

DCE NDCE

Current NSPS limit for straight RF (DCE and NDCE) = 5 ppm @ 8%O2

Emission guidelines (8% O2) = 5 ppm 

for NDCE and 20 ppm for DCE

Two 99th percentile outliers omitted: non-NSPS DCE (126 ppm), 

and NSPS NDCE (43 ppm)

1
D-4

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Percent of Averaging Periods, %

Figure 3. Percent of TRS Averaging Periods in Excess of 5 ppmdv @ 8% O2 (NSPS and Non-NSPS Furnaces)

Values are mostly 12-hr averages, with some 24-hr averages for non-NSPS units. 

DCE NDCE

Emission guidelines (8% O2) = 5 ppm 

for NDCE and 20 ppm for DCE

Current monitoring allowance forrecovery furnace TRS is 1%.

Non-NSPS

Non-NSPS

Non-NSPS

Non-NSPS
D-5

0%

0.3%

0%

0.3%

0%0%0%

1%

1%

0.3%

1%

1%

0%0%

7%

0.1%

0%0%

3%

0%

2%

0%

0.3%

2%

0%

0.1%

0%

0.1%

0%

0.3%

0.3%

0%0%0%0%0%0%0%0%0%0%

0.1%

0%0%0%0%0%0%0%

1%

0%0%0%0%0%

0.3%

2%

0%0%0%0%0%

1%

3%

0%

1%

0.3%

0.5%

0.4%

0.1%

1%

0%0%

0.3%

0%0%0%0%

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

Percent of Averaging Periods, %

Figure 4. Percent of TRS 12-hour Averaging Periods in Excess of 5 ppmdv @ 8% O2 (NSPS Furnaces)

DCE NDCE

Current monitoring allowance 

forrecovery furnace TRS is 1%.

One NSPS DCE with 46% of averaging periods exceeding 5 ppmdv is omitted from the graph.
D-6

0

1

2

3

4

5

6

7

TRS, ppmdv @ 8% O2

Figure 5. Annual Average of the 12-hour TRS Averaging Periods by APCD (NSPS Furnaces)

Note that compliance is based on each 12-hr average , not the annual average.

DCE WBESP DCE WBESP/SCBR NDCE DBESP NDCE DBESP-WPR NDCE DB-WBESP NDCE WBESP

Current NSPS limit for straight RF (DCE and NDCE) = 5 ppm @ 8%O2

Emission guidelines (8% O2) = 5 ppm 

for NDCE and 20 ppm for DCE
D-7

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

TRS, ppmdv @ 8% O2

Figure 6. 99th Percentile of the 12-hour TRS Averaging Periods by APCD (NSPS Furnaces)

DCE WBESP DCE WBESP/SCBR NDCE DBESP NDCE DBESP-WPR NDCE DB-WBESP NDCE WBESP

Current NSPS limit for straight RF (DCE and NDCE) = 5 ppm @ 8%O2

One 99th percentile omitted: NSPS NDCE (43 ppm)
D-8

0

5

10

15

20

25

TRS, ppmdv @ 8% O2

Figure 7. Comparison of the 99th Percentile of the TRS Averaging Periods for DCE 

Recovery Furnaces with Multiple Stages of Black Liquor Oxidation

1 stage 2 stage 3 stage *NSPS units are indicated by the hollow data points.
D-9

0

1

2

3

4

5

6

7

TRS, ppmdv @ 8% O2

Figure 8. Annual Average of the 12-hour TRS Averaging Periods for NSPS Furnaces With and Without NCG Burning 

Note that compliance is based on each 12-hr average , not the annual average.

DCE (No NCG) NDCE (No NCG) NDCE Burning NCG

Current NSPS limit for straight RF (DCE and NDCE) = 5 ppm @ 8%O2
D-10

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

TRS, ppmdv @ 8% O2

Figure 9. 99th Percentile of the 12-hour TRS Averaging Periods for NSPS Furnaces With and Without NCG Burning 

DCE (No NCG) NDCE (No NCG) NDCE Burning NCG

Current NSPS limit for straight RF (DCE and NDCE) = 5 ppm @ 8%O2
D-11

Table D-1: TRS CEMS Data Sets for Recovery Furnaces with Exceedances of the 5 ppm Limit During Startup and Shutdown 

(based on a 12-hour average)1 

RF type ID

Highest TRS 

ppm during S/S Note Control NSPS

NDCE 119.EQT010 45.22* Could not recreate with 1 hour data DBESP Yes

NDCE 127.REC1 102.84*

Uncorrected for O2; associated with 0 production at 19.15% O2. 

No other valid values reported during startup/shutdown WBESP Yes

DCE 130.2 16.66 WBESP No

NDCE 132.5RB 25.57 DBESP-WPR Yes

DCE 145.55 16.3 WBESP No

NDCE 148.001 18.92 DBESP No

NDCE 149.B011 29.62 Production was CBI; labeled as startup/shutdown DBESP Yes

DCE 151.REC007 39 DBESP No

NDCE 157.RB2

72.6*

15.3

Corresponded to 0 production. 

Highest not associated with 0 production was 15.3 WBESP No

NDCE 186.RB15

48.2 (malf)*

15.9

48.2 was “startup malfunction.”

Next highest startup was 15.9 DBESP Yes

NDCE 189.SN26 27.34 WBESP Yes

DCE 205.009 17.61 WBESP No

DCE 600.G0803 16 WBESP Yes

*This value was disregarded for the reason provided in the “Note” column. The value was not considered as representative for rulemaking purposes.
D-12

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 raw 

data

O2 reading

Recovery 

Furnace TRS 

Corrected to 

8% O2

Lime Kiln 

TRS 

Corrected to 

10% O2

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

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

TRS, ppm at 10% O2

Figure 1. Annual Average TRS CEMS Data for Lime Kilns (Including non-NSPS Kilns) -Calculated as the average of the values for each 12- or 24-hr averaging period

-Note that compliance is based on each individual averaging period, not the annual average. 

ESP ESP/SCBR SCBR

Current NSPS Limit = 8 ppm at 10% O2

24-hr average points have orange outline.
E-3

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Percent of averageing periods exceeding 8 ppm

Figure 2. Percent of Periods Exceeding TRS 8 ppm Limit for Lime Kilns (Including non-NSPS Kilns)

Note: The NSPS has no allowance for lime kiln TRS (e.g., any average that is an exceedance is a violation).

ESP ESP/SCBR SCBR
E-4

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

TRS, ppm at 10% O2

Figure 3. Annual Average TRS CEMS Data for Lime Kilns (NSPS Kilns Only) -Calculated as the average of the values for each 12- or 24-hr averaging period

-Note that compliance is based on each individual averaging period, not the annual average. 

ESP ESP/SCBR SCBR

Current NSPS Limit = 8 ppm at 10% O2

All are based on 12-hr averaging period except for first scrubber.
E-5

0%

0%0%

0.29%

0%0%

0.42%

1.2%

0%0%

1.7%

0%

1.0%

0%

4.0%

0.0%

0.15%

0%0%

1.0%

0.22%

0%

0%0%0%0%

0.15%

0.14%0.14%

0.0%0.0%

11.1% 0.41% 2.8%

5.6%

0.32%

0%

0.58%

4.1%

0%0%

22.8% 0% 0.27%

0%

0.14%

0%0%

0%0%0%

0.28%

0%0%

0.14%

0%

0.27%

0.15%

0%

0%

5%

10%

15%

20%

25%

Percent of averageing periods exceeding 8 ppm

Figure 4. Percent of Periods Exceeding TRS 8 ppm Limit for Lime Kilns (NSPS Kilns Only)

Note: The NSPS has no allowance for lime kiln TRS (e.g., any average that is an exceedance is a violation).

ESP ESP/SCBR SCBR All are based on 12-hr averaging period except for first scrubber.
E-6

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

TRS, ppm at 10% O2

Figure 5. 99th Percentile of TRS CEMS Data Averaging Periods for Lime Kilns (NSPS Kilns Only)

ESP ESP/SCBR SCBR

Current NSPS Limit = 8 ppm at 10% O2

2 NSPS kilns with 99th percentile exceeding 100 

are omitted from this chart (1 ESP and 1 SCBR) .

All are based on 12-hr averaging period except for first scrubber.
E-7

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

TRS, ppm at 10% O2

Figure 6. 99th Percentile of TRS CEMS Data Averaging Periods for Lime Kilns Burning NCGs 

(NSPS Kilns Only)

No NCG NCG Pre-scrubbed NCG

Current NSPS Limit = 8 ppm at 10% O2

All are based on 12-hr averaging period except for first value.

2 NCG-burning kilns with 99th percentile 

exceeding 100 are omitted from this chart.
E-8

0.0%

0.41%

0%0%0%

0.0%

0%

0.15%

0%0%0%

0%

1.0%

0.0%

0%

0%0%0%

11.1% 0.29% 2.8%

5.6%

0%

4.1%

0%

0.42%

1.2%

0%

1.7%

0%0%

22.8%

1.0%

0%0%

0.14%

0%0%0%0%

0.28%

0.14%

0.14%

0%

0.27%

0.14%

0.15%

0%0%0%

4.0%

0.27%

0%

0.22%

0%0%

0.15%

0.58%

0.32%

0%

5%

10%

15%

20%

25%

Percent of averageing periods exceeding 8 ppm

Figure 7. Percent of Periods Exceeding TRS 8 ppm Limit for Lime Kilns (NSPS Kilns Only)

Note: The NSPS has no allowance for lime kiln TRS (e.g., any average that is an exceedance is a violation).

All are based on 12-hr averaging period except for first value. No NCG NCG Pre-scrubbed NCG
E-9

Table E-1. TRS CEMS Data Sets for Lime Kilns Subject to NSPS Subpart BB with Exceedances 

of the 8 ppm Limit During Startup and Shutdown (based on a 12-hour average)1

Emission 

Unit ID

APCD 

Type

No. of 

S/S 

Periods

No. of 

Periods 

Exceeding 8 

ppm

During S/S

Max ppm 

TRS during 

S/S Events 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 O2 

data unavailable; unclear if O2 

correction inflated the ppm. 

• Next highest 12-hr value was 10.8 

ppm.

109.LK1 ESP 20 5

2,853*

397*

21.7

• Mill had two consecutive high TRS 12-

hr averages. The raw 12-hr values were 

167 and 49 ppm which inflated to 

2,853 and 397 with the O2 correction. 

Uncorrected 12-hr averages this high 

were not considered representative for 

rulemaking.

• Next highest 12-hr value was 21.7 

ppm.

146.6 SCBR 1 1 10.0

147.3 SCBR 9 2 17.8

148.009 ESP 1 3 7.4

151.CP002

SCBR 

(NCG 

scrubbers 

pre-kiln 

+ LK 

ESP]

7 2 37.0*

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. 

Data set not considered further.

151.CP001 14 8

57.0*

43.0*

22

• 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 2nd highest value of 43 ppm was 

associated with 0 production.

• The 3rd highest value was 22 ppm

• Actual O2 data unavailable; unclear if 

O2 correction inflated the ppm.

180.L002 SCBR 85 2 10.2

186.LK

ESP/SCB

R 68 1 8.1

203.LKScr SCBR 83 2 10.4

240.CA81 ESP 10 1 9.0

1. Not shown in the table are 20 additional lime kilns that had no exceedances of the 8 ppm TRS standard 

during startup or shutdown.

*Not considered representative for rulemaking purposes.
F-1

APPENDIX F: Lime Kiln Opacity Data
F-2

0

1

2

3

4

5

6

7

8

9

Annual Average Opacity, %

Figure 1. Lime Kiln Annual Average Opacity

Calculated as the average of the 6-min averaging periods for all COMS data sets (except one hourly average set).

ESP ESP/SCBR
F-3

0

5

10

15

20

25

30

99th Percentile Opacity, %

Figure 2. 99th Percentile of Lime Kiln COMS Data Sets

Calculated as the 99th percentile of the 6-min averaging periods for all COMS data sets (except one hourly average set).

ESP ESP/SCBR

MACT violation level = 20% opacity for more than 6% of quarterly operating time
F-4

0%

1%

2%

3%

4%

5%

6%

Averaging Periods Exceeding Opacity Level, %

Figure 3. Percent of Lime Kiln COMS Averaging Periods Exceeding Various Levels

Calculated as the 99th percentile of the 6-min averaging periods 

ESP ESP/SCBR

MACT allowance = 6% of quarterly operating