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MEMORANDUM 

Date: November 2011 

To: Brian Shrager, US EPA 

From: Eastern Research Group, Inc. 

Subject: Summary of Test Report Data Review from Best Performing Units at Industrial, 

Commercial, and Institutional Boilers and Process Heaters National Emission Standards for 

Hazardous Air Pollutants – Major Source 

This memorandum describes the procedures used to review test reports from best 

performing units in each subcategory for consistency in reporting stack test and laboratory data. 

The memorandum is organized as follows: 

1.0 Introduction 

2.0 Particulate Matter Data Review 

3.0 Mercury Data Review 

4.0 Dioxin/Furan Data Review 

5.0 HCl Data Review 

6.0 References 

Appendix A: Particulate Matter Data Review 

Appendix B: Mercury Data Review 

Appendix C: Dioxin/Furan Data Review 

 Appendix D: HCl Data Review 

1.0 INTRODUCTION 

With a large pool of emission data and with stack tests performed over a period of twenty 

years a more thorough look at the data was undertaken. Petitioners were concerned about the 
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quality of the data, specifically that the tests were not always representative of a boiler’s 

characteristics, that ICR stack test protocols were not followed, and that a wide range in 

variability was seen in the boiler data. See the emissions database for all boiler data available.1 

Although some test reports were available to conduct an audit, they had not been properly vetted 

at the time of the March 2011 promulgation for the NESHAP at Industrial, Commercial, and 

Institutional Boilers and Process Heaters (Boiler MACT). Additionally, after promulgation of 

the Boiler MACT in March 2011, and in support of the reconsideration, EPA requested industry 

to submit additional test reports from best performers identified in the March 2011 promulgation 

in order to conduct a more complete review. The review focused on screening the reports of best 

performing boilers which were used in MACT floor calculations for the March 2011 

promulgation since these reports are the most likely to have an impact on the emission limits for 

the reconsideration proposal. 

 For each pollutant, the applicable EPA test method (e.g. Method 5 or Method 29) was 

examined and main points from the protocol were selected to create a review template specific to 

each. In addition, reports were reviewed at a test run level to ensure each run was properly 

reported. If revisions were necessary individual test runs could be updated on a case by case 

basis. This memorandum discusses the results for PM, mercury, dioxin/furan, and HCl test 

reports reviews. A related test report review was also performed for CO and is presented in a 

separate memorandum. 2

2.0 PARTICULATE MATTER DATA REVIEW 

 Stack test reports for best performing boilers for filterable particulate matter were 

reviewed for consistency in reporting the measured mass values from the particulate on the filter 

and in the rinse. According to Method 5 the filterable particulate matter weight is recorded 

twice; the mass of particulate matter which is caught in the filter and the mass of the particulate 

matter which is measured in the rinse. The filter mass and rinse mass are added together to 

calculate the total mass of particulate matter. When reporting the mass values in the stack test 

reports which were then used to complete the Boiler survey, however, there were inconsistencies 

in what was reported. 

Three major changes were implemented to correct for low PM values: 
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1. The total filterable PM mass was adjusted to remove negative filter weights. When 

reporting data, some facilities reported the filter weight as a negative value and 

actually subtracted this value from the rinse weight when providing the total 

particulate matter. When this occurred, the filter value was changed to zero and the 

total particulate matter would then be equal to just the rinse weight. This was done 

because the vast majority of the PM tests did not subtract a negative filter weight and 

this adjustment put all of the reviewed test results on the same basis. 

2. The total filterable PM mass was adjusted to correct values which were less than 1 

mg. In cases where the total PM was reported to be less than 1 mg, this value was 

adjusted to 1 mg. This is per guidance provided in 64 FR 53028 which stated that 

EPA conducted a systematic laboratory study to define what is the method detection 

limit (MDL) for Method 5 and determined the Method to have a calculated MDL of 1 

mg. 

3. The total filterable PM mass was adjusted for weights reported as “<” an amount 

which were not included in the total. For example, a report would provide a filter 

mass of <0.3 mg and rinse mass of 4.0 mg, and would then show the total mass as 4.0 

mg. In instances where a “<” value was reported, the total particulate mass was 

corrected to include both weight values. 

Two additional miscellaneous corrections were also made as a result of the review of the 

remaining best performing PM tests: 

1. The total filterable PM mass was corrected due to an over-subtraction of the blank. 

When determining the rinse weight Method 10 allows subtraction of .001% of the 

mass of the acetone used. For one boiler’s test report, however, when correcting for 

the acetone too large a value was subtracted from the result which biased it low. In 

this instance, 3.0 mg was added to the total mass to correct. 

2. The total filterable PM mass was corrected to adjust for a discrepancy between the 

summary page and the laboratory data sheets in the report. In this instance the 

calculated value shown in the laboratory data was used. 

In addition to correcting data, whether or not a stack test followed Method 10 protocol 

was determined. Based on this, data from one facility was removed from the PM analysis. 
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For each test run that was corrected, we used the sample volume, O2 concentration in the 

sample, and the F-factor which were provided in the test report to update the lb/mmBtu values. 

For sites where an F-factor was not available we used a ratio of the old mg of the PM catch to the 

corrected PM catch to adjust the old lb/mmBtu value proportionally. 

In total, there were 147 test reports reviewed for consistency in PM data. Not all best 

performing boilers had test reports available, but a majority of the units were covered. See 

Appendix A-1 for the PM test report review template with results for all reviewed test reports 

and Appendix A-2 for results on test reports where PM data was modified or removed. 

 

3.0 MERCURY DATA REVIEW 

 Stack test reports for mercury best performing boilers were reviewed for consistency in 

reporting mercury fractions. According to Method 29, five fractions of mercury shall be 

recorded, and this request was specified in the phase II ICR test program for the Boiler MACT. 

However, not all laboratories reported each fraction in the stack test report. When conducting 

the review, first, the mass of each Hg fraction available in the laboratory section was recorded. 

The sum of the five fractions from the laboratory section was then compared to the total Hg 

value provided in the report. If there was a large discrepancy between the two values the Hg 

value was further investigated, otherwise it was determined to be correct. If the Hg fractions 

were not in agreement one of two actions was taken: 

1. The Hg value was revised using the sum of the five reported fractions, or the sum of 

the reported fractions and the detection limits for certain fractions, when appropriate. 

The Hg values were updated by taking a ratio of the revised computed sum of all five 

fractions and the reported sum in the test reports, see equation 1. This update was 

made for 52 test runs at 19 boilers. 

ܪ݃ோ௘௩ ൌ ܪ݃ோ௘௣ כ ு௚ ௙௥௔௖௧௜௢௡ೃ೐ೡ

ு௚ ௙௥௔௖௧௜௢௡ೃ೐೛

 (Equation 1) 

Where: 

HgRev = Revised Hg value to be used in floor calculations (lb/mmBtu) 

HgRep = Hg value provided in stack test report (lb/mmBtu) 
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Hg fractionRev = Sum of five Hg mercury fractions from laboratory section review 

(μg) 

Hg fractionRep = Sum of the Hg fractions provided in stack test report (μg) 

2. Where insufficient laboratory data was available to calculate a sum of all five 

fractions and it could not be determined if proper Method 29 protocol was followed, 

the boiler’s Hg data was removed from the MACT floor rankings. With Method 29 

requiring five mercury fractions, in order to create a representative MACT floor it 

was necessary to ensure five fractions were reported. If data were based on fewer 

fractions the resultant Hg emissions could be biased low. Mercury data was removed 

for 38 test runs at 13 boilers. 

Before revising or removing Hg values, one final check was performed. In some cases, 

although the laboratory data review indicated that certain mercury data were based on less than 

five fractions, we did not edit the data because separate notes were provided in ERT or a later 

data submittal provided explanation or correction of the data that was not reflected in the 

laboratory section of the test reports. In total, 52 test reports were reviewed for mercury. See 

Appendix B for the mercury review template with results and the rationale for each mercury data 

point which was revised or removed. 

4.0 DIOXIN/FURAN DATA REVIEW 

 Stack test reports for dioxin/furan best performing boilers were reviewed for accuracy of 

individual congener values and individual congener non-detect flags. According to EPA Method 

23, the nanogram (ng) and sample volume in cubic meters (dscm) for each dioxin/furan 

congener is to be recorded and the corresponding ng/dscm value calculated. Each congener also 

shall be appropriately flagged if data is non-detect. Upon review of the dataset, it was found that 

several dioxin/furan data were incorrectly reported or calculated, so for this review an in depth 

look at the test report data was conducted. For each report, the individual congener values and 

non-detect flags were extracted from the laboratory data into a spreadsheet. Then, the nanogram 

values from the laboratory section of the test report were used to calculate ng/dscm @ 7% O2

values. The calculated dioxin/furan values were then compared to the values in the database to 

determine which congeners were incorrect. If there was a large discrepancy between the 
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calculated value and the database value then the database value was replaced with the calculated 

value. In the laboratory section of the test report, each congener non-detect value flag was also 

reviewed and compared to the database flag. Where differences were present in the database flag 

and the flag from the review, the database flag was replaced with the flag from the review. Test 

reports from 18 best performers from the March 2011 promulgation were reviewed for 

dioxin/furan data. Dioxin/furan congener values were revised for 4 boilers and non-detect flags 

were updated for 10 boilers. See Appendix C for the dioxin/furan review template with results. 

Additional review of dioxin/furan congener data were made as a result of a separate analysis. 

Those edits are discussed in another memorandum.3 

5.0 HCL DATA REVIEW 

 Stack test reports for HCl were reviewed for reported mass values, detection limits, and 

method protocol checks. Based on the test report review, no major errors were found which 

would warrant the removal of data although some concerns with certain reports were noted in the 

review. It is noted that although test reports were provided for many of the best performing units 

for HCl, there was a lack of detailed laboratory data available to conduct a complete review of all 

the details of each test. 

In one instance (WAGraysHarborPaper, No. 6 Boiler (EU2)), the results were reported 

separately for two portions of the gas stream and the database was corrected to reflect the total 

emissions from both the duct and stack portions. One of the tests for FLUSSugarCorp, Boiler 

No. 4 will be investigated further before promulgation of the final rule. All of the reviewed HCl 

data was used for MACT floor calculations. In total, 65 boilers were reviewed for HCl. See 

Appendix D for the HCl review template with findings during the review. 

 
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6.0 REFERENCES 

1. Emissions Database for Boilers and Process Heaters Containing Stack Test, CEM, & Fuel 

Analysis Date Reported under ICR No. 2286.01 & ICR No. 2286.03 (version 6) 

2. Eastern Research Group, Inc.. Incorporating Measurement Error in Reported Carbon 

Monoxide (CO) Data – Updated for Reconsideration Proposal. November 2011. 

3. Eastern Research Group, Inc.. Analysis of Dioxin/Furan Data and Minimum Detection 

Levels from Industrial, Commercial, and Institutional Boilers and Process Heaters National 

Emission Standards for hazardous Air Pollutants – Major Sources. November 2011.