MEMORANDUM :

DATE: June 5 , 2014

SUBJECT: Determination of “non

- detect” from EPA Method 29 (multi

- metals) and EP A Method 23

(dioxin/furan) test data when evaluating the setting of MACT floors versus establishing work practice standards.

FROM: Steffan Johnson

Measurement Policy Group, SPPD

TO: SPPD Rule Writers, SPPD Policy and Strategies Group, SPPD Measurement Policy Group,

AQAD Measurement Technology Group , and SPPD management.



## 1. Background

Maximum Achievable Control Technology ( MACT ) floor devel opment at EPA has highlighted the need for more consistent understanding of detection limits from EPA emission testing methods and how they are applied to the rule making process . Detection limits are used both as baseline emission value s where below dete ction limit values are reported and for determination on whether to pursue a MACT floor or a work practice standard

. W he n a pre
- determined majority of emissions test results demonstrate that the pollutant of interest is not generally present in measurabl e quantities a work practice is typically written

. The exception being that work practice standards do not apply for CAA Section 129 rules.
This guidance memo is focused on the use of detection limits as an indicator of the measurable presence of a given pollutant, specifically where multi

- component samples of metals or dioxin/furan emissions are the pollutants of concern. For multicomponent measurement methods there are several variations to the detection limit issue that have not been addressed in guida nce already developed for the use of detection limits in setting standards. Currently, the se variations lack clarity on the criteria used to determine what constitutes a “non

- detect” for any particular set of these multi

- component test method data

. Lacking t he further refinement provided by this memo , “ non
- detection ” variations for multicomponent methods may currently be defined as any of the following : a) A majority of the metals or dioxin/furan congeners being non

- detect

. b) A ny single metal or dioxin/ furan congener reported below detection

. c) Absence of any measurable amount of every metal or congener. d) A non

- detect in any one portion of a sample train.
A reasoned and consistent approach to making this determination is necessary so that we put forth ru le requirements that are scientifically sensible, consistent , appropriate , and defensible

.Caveats:

Understanding terminology and context is paramount to evaluating detection limits. A December 13, 2011 memo from Peter Westlin and Ray Merrill ( EPA Docket item EPA

- HQ

- OAR

- 2011

- 0817

- 0142) titled “Data and procedure for handling below detection level data in analyzing various pollutant emissions databases for MACT and RTR emissions limits” provides guidance on what Representative Detection Limits may be expect ed from the analysis of multi

- metals (Method 29) and dioxin/furan (Method 23) test results. Th is memorandum refers to RDLs (Representative Detection Limits) and these will be our primary grounding rod for making decisions regarding use of metals data. ED L (Estimated Detection Limit) values for dioxin/furan lab results will be our benchmark for reviewing dioxin/furan test data. As th e Westlin/Merrill memo is referenced several times in this document it serves you, the reader, well to read and understand the memo thoroughly. This document contains some screenshots from the Westlin/Merrill memo to enhance your understanding of the process and the overall context of the discussion and how it relates to that memo.

RDL is an EPA

- derived term, and the RDLs i n the Westlin/Merrill memo were determined by averaging the lowest MDL (Method Detection Limit) data submitted for individual tests during the Utility (MATS) NESHAP ICR and the Industrial Boiler NESHAP Rule ICR. The MDL is a key indicator and it is critic al that these individual test and laboratory determined values are determined consistently by each laboratory. The MDL should also be identified in each test/lab report. ICR test requirements now include the reporting of the lab ’ s MDL with their data se ts, even though the reporting of MDL is not a current requirement of many EPA air compliance test methods. MDLs are often inconsistently reported in emission test reports or associated lab data, and some other “quantification value” or “reporting limit”

v alue (RL, PQL, QL, etc.) is often substituted by the lab. Rule writers and their contractors must be vigilant to be sure and use an appropriate MDL and RDL value when evaluating detection limits; the Westlin/Merrill RDL table value is a tool well

- suited f or that purpose. It is important to know that a lab’s “reporting limit” (or PQL, QL, etc.) is not necessarily the MDL we are looking for, especially if they are much higher than the RDLs in the Westlin/Merrill memorandum. Where this is the case such valu es are very likely in the RL/PQL/QL, etc., pool and should not be used as one would use an MDL. With dioxin/furan test results, EDL is an appropriate benchmark to use and EDL data are those referenced on page 8 of the Westlin/Merrill memo.



### Definitions:
ADL (Above Detection Limit): Results from the lab show measured values above the MDL. (Be sure to distinguish reported values as being above the MDL versus above the RL or other lab ‘confidence’ level).
BDL (Below Detection Limit): A laboratory resul t where detectable amounts of an individual pollutant or congener are not found. Again, evaluate the data to ensure BDL means “below MDL” and not “below RL” or some other ‘confidence’ level.DLL (Detection Limit Limited): A test result where some fracti ons of the analysis return

detectable amounts of a pollutant or congener (above MDL), while other fractions are BDL.
EDL (Estimated Detection Limit): For Dioxin/Furan tests, a commonly reported estimate of the concentration where a given analyte would ha ve to be present to produce a signal with a peak height of at least 2.5x the background noise signal level. The EDL determination is done for each sample set at the time of analysis. This is specific to the analytical technique and is affected by factors such as sample size, dilution, etc., commonly reported for non

- detected analytes instead of other values such as PQL, RL, QL, etc. It is important to note that EDL and MDL are not the same , but EDL is a standard benchmark for determining detection from an isotope dilution analysis, common to dioxin/furan emission testing

. EMPC (Estimated Maximum Potential Concentration): for Dioxin/Furan analysis, a congener value reported by a lab that is meant to flag some uncertainty in the quantitation of the reporte d value, specifically when the signal

- to

- noise ratio is at least 2.5 or higher for both quantitation ions but the ion abundance ratio criteria are not met. In general, EMPC data are considered to be actual emissions until shown otherwise. EMPC values may be below, at, or above the MDL for that congener, and may involve some other analytical interference (or not). EMPC values below the MDL for any congener are treated as BDL for the purposes of this exercise. EMPC values at or above the MDL for any conge ner must be treated as measured values.
LOQ (Level of Quantitation): A value where measurement certainty increases to 95%, generally equivalent to a value ranging from 3x

– 5x the MDL.
MDL (Method Detection Limit): Synonymous with the term LOD (Level of Detection) the MDL is defined as the lowest quantity of a substance that can be distinguished from the absence of that substance (i.e. a blank value) with a stated level of confidence. For the purposes of this document, the process of identifying the MD L of a given substance is defined in EPA Method 301, Section 15

. PQL (Practical Quantitation Limit): Synonymous with the term LOQ (Level of Quantitation).
QL (Quantification limit): A term that is loosely used, sometimes synonymous with MDL, and other times synonymous with RL or PQL. As such, a reported QL requires extra scrutiny during report review to ascertain the context of its usage.
RDL (Representative Detection Limit): Sometimes referred to as the Representative Method Detection Limit (RMDL) t his is the mean MDL value of a specific analyte determined by a n MTG review of l lab analyses represented by labs who provided data for best performing sources , thereby creating a representative value by which to assess detection such that the best perform ing lab handing any particular analytical sample does not drive all detection limit discussion and decision making. By establishing this value as the mean of several labs we allow for the selection of local and cost effective analysis of environmental sam ples while maintaining a balance of quality analyses. The Westlin/Merrill memo defines RDL for dioxin/furans as EDL x 2.RL (Reporting Limit): A value determined by an analytical laboratory to represent the lowest

concentration of an analyte that they are certain they can accurately quantify. This can be some multiple of the MDL or may just be the lowest calibration standard for the Laboratory ’s standard analysis method. Many labs report this value instead of the MDL.



## 2. Discussion

Drivers:
The Westlin/Merrill memorandum provides specific guidance on the determination of a representative method detection limit and the use of that value in deter mination of a MACT floor limit , but setting MACT floor limits is not the only time a rule writer will find detection limit information useful.

D etection limit evaluation is also important to EPA rule writers when determini ng whether to develop a MACT floor limit or, where emissions of a particular pollutant are not demonstrated to exist in measurable quantities , to develop work practice standards for management of emissions potential . The Office of General Council (OGC) has provided SPPD rule writers some guidance on what percentage of data in a data set may be necessary to meet their expectation of when a work practice standard is appropriate

. At the time of this writing , OGC’s guidance states that at least 55% of the test data , including those outside the group of best performing sources, must be non

- detect in order to justify a work practice standard (versus setting a limit). Even with this clear statement from OGC on this policy , there is a need for a consistent approach concerning multi

- component samples to resolve current ambiguity on how to balance the four types of non

- detect data for pollutants such as metals and dioxins/furans.
In the previous guidance it was clear w ith a single component test, such as an HCl emissions
measurement , the rule wr iter only need s to evaluate the number of test results that are below the detection limit in relation to the number of test results available and determine the direct percentage of

non
- detect values; this is straightforward enough. The assessment is more complex with a multi

component sample, such as a M ethod 29 multi

- metals test result. Lab analysis from this test can return information on up to on sixteen non

- mercury metals

. E ach metal analy sis may have two separate fractions : front

- half (filter) and ba ck

- half (impinger catch) . Each fraction is analyzed separately at the lab and thus has a separate detection limit, and each metal may have detection from one, both, or neither fraction

. There may be emission sources where a few metals dominate the emission s and the majority of the remaining metals are nearly absent. With three test runs per pollutant, and 2 analytical fractions each having its own detection limit , and sixteen analytes being sampled, there are 96 sample fractions potentially represented in the data set

. W hat then constitutes “non

- detect” in regards to the individual metals tests , much less the combined results of all the metals analyses ? This assessment complexity increases with Dioxin/ F uran emission tests as a result of calculating a Toxi c Equival ents (TEQ) which multiplies different components by a weighting factor and sums the components to yield a single value that is applied as an aid to assessment.In review of n on
- mercury m ulti

- metals data :

EPA Method 29 is capable of measuring 17 me tals, including mercury, with repeatable accuracy and precision. The m ethod uses isokinetic sampling with a filter to separate out particulate matter (including particle bound metals) and acidic absorbing solution behind the filter to oxidize and capture

non
- mercury metals that may be present in vapor forms. When reviewing Method 29 data one must keep in mind that some metals may be present only in a single form (all particulate or all vaporous) or in both particulate and vaporous forms , in varying ratios

. It is also important to understand that while M ethod 29 has a single sampling technique the tester has the option of asking the lab to determine the metal concentrations by one of four different analytical approaches(except for mercury which has a singl e analytical technique). The analytical approach chosen for the sample makes a difference , especially in terms of the method ’ s ability to achieve low detection. These four analytical approaches

are:

I. Atomic Absorption Spectroscopy (AAS) II. Inductively Coupled

- Atomic Emission Spectroscopy (ICP

- AES) III. Inductively Coupled Plasma

- Mass Spectrometry (ICP

- MS) IV. Graphite Furnace Atomic Absorption Analysis (GFAAS)

It is not critical for the reader to understand the intricacies of each of these analytical techniques, but it is important to understand that the first two on the list will result in generally higher detection limits from a ny given lab than the last two will

. While t his is not true for some of the common metal analyte s which are present at rel atively high concentration , it is true for the majority

. For this reason we have started requir ing one of the latter two analytical techniques when asking for M ethod 29 data in recent ICRs.

It is also essential to understand that laboratories often , thoug h not always, report two analytical fractions for each metal ; one representing the front half (filterable) and one representing the back half (vaporous) results . This reporting variability originates from the option in Method 29 to allow a single analytic al fraction (it is easier to achieve detection when the entire sample is rolled into a single analytical fraction). For this reason the Westlin/Merrill memorandum lists a single RDL for each metal , and provides guidance for what that RDL value may be if t he sample volume is increased . It is appropriate to sum the MDL for both halves (when two fractions are reported) for comparison to the RDL in the Westlin/Merrill memorandum , as that document is based on the combined MDL ( see reference image 4

- 1 ). Where a lab report provides a “reporting limit” or “practical quantitation limit” (see above definitions) the sum of these two fractions is likely to differ greatly from the RDL listed in the Westlin/Merri ll memo . Where a lab reports an MDL, the sum sho uld be very close (maybe lower, maybe higher) t o the listed RDL for a 1 dscm sample volume

.
A single metal analyte reported in excess of the M DL listed for the appropriate analytical fraction of Method 29 signifies “ d etection ” of that analyte. Note that th is may include DLL data points as one fraction may show high detection while another fraction of the same sample is below the detection limit

.Method 29 detection , as we discuss it in this memo , should be determined on a per

- analyte basis.

Therefore with any given test run, if any individual metal is detected, there is detection for that metal in that test result

. Detection versus non

- detection must not be based on the entire group of metals; but rather they must be treated individually and on a run

- by

- run basis, though consideration for MACT floor development or work standard development will be made by considering the pool of test run results

.

In review of d ioxin/furan data :

EPA Method 23 measures 10 furan congeners and 7 dioxin congeners , for a to tal of seventeen reported
congeners

. Dioxin and furan sampling is unlike metals testing in that they are not a class of compounds containing a unique periodic element with an established toxicity but rather individual compounds (congeners) that are represe ntative of a class of compounds with varying degrees of toxicity. Another distinguishing difference is that dioxin/furan measurements are reported in units of picograms , making them at least a thousand times less concentrated in samples than metals ; mercury for example

. The detected congener mass, corrected to 7% oxygen concentration is typically used in regulatory limits as the sum of all the individual compounds or as a toxicity weighted sum of those compounds. Method 23 includes procedures for dev eloping an Estimated Detection Limit (EDL) and this memo uses the data derived from that procedure for decision making.
To aid in the understanding of the health impact of dioxin/furans with their small concentration and widely varying toxicity, the World Health Organization developed and EPA has adopted a “Toxic Equivalency Factor” (TEF) multiplier for each dioxin/furan congener. By making use of the TEF multipliers to produce the toxicity weighted sum and the resulting single value Toxic Equivalency (TE Q) , emissions, we can make an informed decision about the detection level of the compiled group of
congeners. Some important points of TEF’s and TEQ’s are:

 Toxic equivalency factor (TEF) expresses the toxicity in terms of the most toxic dioxin, 2,3,7,8

- TC DD

 Toxic equivalency (TEQ) expresses the toxicity

- weighted masses of D/Fs : TEQ = ∑[C i ]*TEF i , Where : Ci is the concentration of individual compounds and TEFi is the toxic equivalency factor for that individual compound

. Page 8 of t he Westlin/Merrill memorandum contains an example spreadsheet ( see Reference Image 4

- 2 ) that displays each congener and an RDL for mass of that congener in nanograms, as well as the equivalent TEQ for that congener at that mass. The Toxic Equivalency Factor (TEF) is a value used for developing the TEQ amounts. The TEF values are based on the values for mammals from the World Health Organization 2006 tables located on page 13 of this report: http://www.epa.gov/raf/files/tefs

for

- dioxin

- epa
- 00

- r
- 10

- 005

- final.pdf

. When and w here more recent World Health Organization ( WHO ) mammalian values are available, those would be deemed more appropriate for this purpose. The Westlin/Merrill memo discuses RDL as (EDL x 2), and the EDL values are those listed in the table on page8 of the memo, whereas the line third from the bottom labeled “sum” is the sum of EDL values; or the

overall m ethod EDL

.
For MACT calculations, w hen determining detection versus non

- detection, for a Method 23 data set the steps are as follows:

1. Ensure that the D /F data are reported in terms of nanograms . If the data are reported in some other mass unit, you will need to convert them to nanograms. If you have values that

are corrected to 7% oxygen look through the test report to find the uncorrected mass values

. 2. Ascertain that the correct WHO TEF factors (outlined above) were used to generate a congener specific TEQ

. If only D/F mass was reported, the TEQ value must be calculated from these factors. 3. Where a lab reports EMPC (Estimated Maximum Potential Concentration) values , use care to make certain that these are reported a s dioxin/furan emissions. EMPC values below the corresponding congener specific EDL (estimated detection limit) value from the Westlin/Merrill memo are counted as BDL for the purposes of this evaluation. 4. S um the TEQ values of all detected (ADL) values from the test run (include EMPC values above EDL values)

. If an indiv id ual congener is listed as non

- detect or otherwise reported below the corresponding E DL of the Westlin/Merrill memo , use the value of zero to represent that congener in this summation. 1 5. Next, compare that sum to the Sum TEQ value (sum of EDL’s as TEQ) in the table on the final page of the Westlin/Merr i ll memo ( this valu e is currently liste d as 4.11E

- 02 for I ndustrial B oilers /CISWI and 1. 8E

- 02 for all other sectors , but be sure to use the most recent version of the memo as the December 2011 version is expected to change in the future ). 6. If the sum of the TEQ from the detected congeners is at or above the sum of congener TEQ value s from the Westlin/Merrill memo, there is detection of dioxin/furans in that sample

. If the sum of the TEQ from the detected congeners is below the sum of congener TEQ value in the Westlin/Merrill memo, the test ru n is considered to be non

- detect for dioxin/furan. 7. The data may now be used in the decisions about whether to set a work practice standard

versus an emission limit for dioxin/furans

. ( See examples later in this memo )

.
NOTE: Of particular interest is t he table on pag e 4 of the Westlin/Merrill memorandum that lists one Method 23 RDL for D/F congeners for industrial boilers and another RDL for utility boilers and all other

sources. The memorandum states on page 3 why this is the case and prescribes that it is the RDL developed from utility boiler data that is most representative of achievable detection limits , so we point to that value as our benchmark for sources other than Industrial B oilers

. As of this writing, AQAD/MTG is looking into developme nt of a non

- sector based RDL for dioxin/furan, and this procedure is expected

1 While BDL congeners may be considered as zero for the purposes of this memo it is important to understand that some test methods and ICR’s will request that these same values be reported at the EDL value, even if they are BDL, and different TEQ values wou ld be calculated in those instances.to be revised to incorporate those non

- sector based RDLs after they are published and will be updated,

as necessary, at that later date

. Dioxin/furan detection, as we discuss it in this memo, should be determined as the TEQ sum (sum of EDL as TEQ) of detected congeners. E DL for each congener is defined by the equation in section 9.8 of Method 23.



## 3. Detection Limit Versus Work Practice Determination

The following procedures will b e used w hen making a determination of “Detection” from multi analyte samples, specifically multi

- metals tests and dioxin/furan tests :

Mercury and n on
- mercury metals from EPA Method 29 :

1. Method 29 should be evaluated on an analyte by analyte basis. 2. Care must be taken to use the correct chart for RDL comparison (pages 5

- 6 of Westlin/Merrill memo) , based on the analytical method used by the laboratory. 3. Where t est results for any single analyte are d etection l evel l imited (DLL) or above detection level (ADL) , we assume detection for that test run data, for that specific analyte. See example 1 below. 4. If an analyte is below detection level ( reported as BDL ) (no fraction DLL or ADL) and the reported detection level is at or below the Westlin/Merrill noted RDL ( not the 3x RDL value) , the test run result is below detection for that analyte. See example 2 below. 5. If an analyte is reported as BDL and the reported MDL detection level is above the Westlin/Merrill noted RDL ( not the 3x RDL value) the test result is sai d to be below detection

. 6. If an analyte is reported using an RL, PQL, etc. (not an MDL) and is reported as being below that level (not detected) , t he data must be set aside and not used for this purpose. See example 3 below. (Note: Method 23, section 9.8 requires the development and reporting of an MDL). 7. The percentage criteria for determining whether to write a work practice standard or to write an emission limit for specific combined metal HAPs or for selected individual metals would be based upon the percentage of individual test runs.

Example 1: Nickel results from a test where the metals analysis was done by ICP

- MS show 7.1E+00
ug /dscm of nickel from the front half fraction of a Method 29 test, and <2.1E+00 ug/dscm f rom the back half fraction. The sum of these is 9.2E+00 micrograms/dscm which is above the listed RDL of 5.4E+00 ug/dscm in the third table in the Westlin/Merrill memorandum ( see Reference Image 4

- 1 ). Because nickel was detected in the front half fractio n, t his test run shows detection of nickel.Example 2: Chromium results from a test where the metals analysis was done by ICP

- MS show <1.2E

- 01

ug/dscm of chromium from the front half fraction of a Method 29 test, and <1.2E

- 01 ug/dscm from the back half fr action. The sum of these is 2. 4 E

- 01 ug/dscm which is below the listed RDL of 3.0E

- 01 ug/dscm in the third table in the Westlin/Merrill memorandum ( see Reference Image 4

- 1 ) . This test run is a non

- detect for chromium.
Example 3: Chromium results from a t est where the metals analysis was done by ICP

- MS are reported at <5.2 E

- 01 ug/dscm from the front half fraction of a Method 29 test, and < 5.2 E

- 01 ug/dscm from the back half fraction

. C hromium is reported at a total of <10.4E

- 01 ug/dscm. This result displays the use of a “Reporting Limit” or “Practical Quantitation Limit” or other construct used by the lab, because the reported “detection” values are far greater than the listed RDL (in this case 3.46 times above the RDL of 3.0E

- 01). In su ch a case , we are not informed enough to determine if values of the analyte were detected between the reported value and the RDL, and so this data must be set aside and not used for the purposes of determining the appropriateness of setting a work practice standard. Note: This case applies to BDL data only. Were any fraction ADL (meaning the test run is DLL for this metal) , this data would be appropriate to use for this purpose.

Dioxins and furans from EPA Method 23 :

1. Method 23 data must be evaluated as the TEQ sum of detected congeners for each test run ( see Reference Image 4

- 2 )

. 2. EMPC values must be consi d ered to be dioxin/furan emissions unless they are below the congener specific E DL listed in the Westlin/Merrill memo . If a reported EMPC is greater tha n the EDL , that congener is considered to be detection level limited ( DLL, ) , not BDL. If the EMPC is below the E DL, then the EMPC must be considered as BDL for the purposes of this exercise

. 3. All congeners reported as, or determined to be BDL must be considered as “zero” and not included in the sum used as the decision point for this exercise

. 2 4. All congeners that are above t he detection limit must be multiplied by the corresponding TEFs from the most recent WHO (mammals) table to determine the individual congener TEQ. 5. The s um of all detected TEQ is compare d to the appropriate Westlin/Merrill TEQ value:

a. For all industry sectors other than Industrial B oilers the Utilities TEQ must be use d , and refer to the corresponding E DL based on the Westlin /Merrill memorandum , page 4 ( see Reference Image 4

- 3 )

. The sum of the TEQ must fall at or below 1.8E

- 02 to be considered non

- detect

. b. For I ndustrial Boilers , the sum of the TEQ must fall at or below 4.11E

- 02 to be considered non

- detect

.

2 While BDL congeners may be considered as zero for the purposes of this memo it is important to understand that some test methods and ICR’s will request that these same values be reported at the R DL value, even if they are BDL, and different TEQ values would be calculated in those instances.6. Complete t his exercise for all collected data , and compare the results on a run

- by

- run basis.

D ecisions about whether to set a work practice standard versus an emission limit for dioxin/furans may now be evaluated . (See examples later in this memo).

Example 1:
The testing of a coal fired facility yields the following Method 23 data. The results are then adjusted to substitute zero values for congeners with BDL values.

Congener Reported TEQ Adjusted TEQ (BDL = 0) OCDD 2.90E

- 05 2.90E

- 05 OCDF 7.99E

- 06 7.99E

- 06 1,2,3,4,6,7,8 HpCDD <1.08E

- 04 0.00E+00 1,2,3,4,6,7,8 HpCDF 3.41E

- 04 3.41E

- 04 1,2,3,4,7,8 HxCDD 4.46E

- 04 4.46E

- 04 1,2,3,4,7,8 HxCDF 3.92E

- 03 3.92E

- 03 1,2,3,4,7,8,9 HpCDF <1.20E

- 04 0.00E+00 1,2,3,6,7,8 HxCDD <4.93E

- 04 0.00E+00 1,2,3,6,7,8 HxCDF 3.93E

- 04 3.93E

- 04 1,2,3,7,8 PeCDD <1.73E

- 02 0.00E+00 1,2,3,7,8 PeCDF 2.50E

- 04 2.50E

- 04 1,2,3,7,8,9 HxCDD <1.30E

- 03 0.00E+00 1,2,3,7,8,9 HxCDF 3.19E

- 04 3.19E

- 04 2,3,4,6,7,8 HxCDF 9.66E

- 04 9.66E

- 04 2,3,4,7,8 PeCDF <1.85E

- 03 0.00E+00 2,3,7,8

- TCDD < 1.34E

- 02 0.00E+00 2,3,7,8

- TCDF 9.55E

- 04 9.55E

- 04

Sum TEQ 4.22E

- 02 7.63E

- 03

Since this data was generated from the Industrial Boiler / CISWI categories, the value we use for comparison is a Sum TEQ of 4.11E

- 02 or the current value displayed on page 4 of the most recent Westlin/Merrill memorandum ( see Reference Image 4

- 3 ). Since 7.63E

- 03 is less than 4.11E

- 02, this test would be considered a non

- detect for dioxin/furan.Example 2:

A test of a brick manufacturing facility returns the following reported data . Again, the reported values are then adjusted to substitute zero values where BDL values were reported.

Congener Reported TEQ Adjusted TEQ (BDL = 0) OCDD 1.29E

- 04 1.29E

- 04 OCDF 1.85E

- 05 1.85E

- 05 1,2,3,4,6,7,8 HpCDD 1.48E

- 04 1.48E

- 04 1,2,3,4,6,7,8 HpCDF 4.41E

- 04 4.41E

- 04 1,2,3,4,7,8 HxCDD <2.21E

- 04 0.00E+00 1,2,3,4,7,8 HxCDF <1.74E

- 03 0.00E+00 1,2,3,4,7,8,9 HpCDF 1.12E

- 03 1.12E

- 03 1,2,3,6,7,8 HxCDD 9.93E

- 04 9.93E

- 04 1,2,3,6,7,8 HxCDF <1.55E

- 04 0.00E+00 1,2,3,7,8 PeCDD 1.31E

- 02 1.31E

- 02 1,2,3,7,8 PeCDF <1.20E

- 04 0.00E+00 1,2,3,7,8,9 HxCDD <8.00E

- 04 0.00E+00 1,2,3,7,8,9 HxCDF 3.62E

- 04 3.62E

- 04 2,3,4,6,7,8 HxCDF 1.15E

- 03 1.15E

- 03 2,3,4,7,8 PeCDF 1.65E

- 03 1.65E

- 03 2,3,7,8

- TCDD 1.11E

- 02 1.11E

- 02 2,3,7,8

- TCDF <3.04E

- 04 0.00E+00

Sum TEQ 3.36E

- 02 3.02E

- 02

This test run demonstrates detection for dioxin/furan because the sum is greater than the 1.8E

- 02. Recall 1.8E

- 02 is the Sum TEQ to be compared against for utility boilers and all other industry sectors ( See Reference Image 4

- 3 )

.

## 4. Reference Images

The following are screenshot images taken from specific pages in the Westlin/Merrill Memo and are included here to add clarity to the discussion and findings above . Please refer to the most recent copy of the Westlin/Merri ll memo for actual values used in your determinations, as these values are subject to change with time; the screenshots below may be outdated

. 

## Reference Image 4

- 1 :

Reference Image 4

- 1 (above) : RDL values for Method 29 Multi

- Metals sampling taken from page 6 of the December 2013 Westlin/Merrill memo. Note that RDL decreases for each compound proportional to increased sample volume. The circled values above illustrate the ‘standard RDL’ for chromium from a 1 dscm sample volume (left) and the reduced R DL that could be obtained by collecting a 3 dscm sample volume (right) that is generally achieved by extending the test duration . It is worth noting that the lab reported MDL should be close to the 1 dscm value shown, no matter what sample volume was coll ected. Also note that this image is for ICP/MS and GFAAS analysis. Page 5 of the Westlin/Merrill memo outlines a different set of RDL values for ICP/AES and AA analytical techniques; be sure to refer to the correct table appropriate to your data set.

## Reference Image 4

- 2 :

Reference Image 4

- 2 (above) : TEQ and EDL values taken from Page 8 of the December 2013 Westlin/Merrill

memo and represent dioxin/furan detection limit values from Industrial Boiler testing . Note that the line labeled “sum” (third from the bottom) is synonymous with the term EDL and the value in the red oval is the sum TEQ value we use for evaluation with a dioxin/furan data set from an Industrial Boiler emission test

. The RDL value (green rectangle) is appropriate for use when set ting a MACT floor with this data set ( see Reference Image 4

- 3 ), should your test data indicate sufficient detection.

## Reference Image 4

- 3:

Reference Image 4

- 3 (above) : TEQ and Total Mass values representing data collected either from Industrial Boil ers, or from Utilities and all other sources. This image is from Page 4 of the Westlin/Merrill memo and provides MACT floor setting guidance where detection is shown for a given data set; that detection decided by following the process described in Sectio n 3 of this memo). Note that both the sum mass (ng) and sum TEQ are represented for each category; be sure to refer to the correct table appropriate to your data set. The value in the green rectangle correlates to the sum TEQ value indicated in Reference Image 4

- 2 on the previous page. The value in the blue diamond represents the same sum TEQ value were the data set derived from Utility boiler or other industrial source category test data.



### Steffan Johnson Measurement Policy Group Sector Policy and P rograms Division



### Addressees: SPPD management SPPD technical staff

Cc:
Group Leader, MTG, AQAD Ray Merrill, MTG, AQAD Kristen Benedict, MTG, AQAD Robin Segall, MTG, AQAD Jason DeWees, MTG, AQAD