December 

### 13,z}ll(revised April 5,2012)

Note: Subject: Data and procedure 

### for handling 

### below detection 

### level data 

### in analyzing various 

### pollutant emissions databases

### for 

### MACT and 

### RTR emissions 

### limits To: SPPD management and 

### MACT rulewriters 

### From: Peter 

### Westlin, SPPD, 

### MPG Raymond 

### Merrill, AQAD, 

### MTG This is a note regarding the 

### handling of below detection 

### level 

### (BDL) data and 

### in developing representative detection 

### level 

### (RDL) data 

### in evaluating the

### floor and setting emissions 

### limits for your NSPS, 

### MACT, and 

### RTR rule 

### making 

### projects.At the end 

### of this note is atable 

### which includes several 

### updates. The updates 

### include correctedvalues 

### for metals 

### RDL, aneasier

### to use table (e.g.,

### sample volume versus sampling 

### time) and some 

### pollutants not covered 

### inthe

### initial table (e.g., 

### HCI and 

### filterable PM).
The 

### RDL determination procedure
The revised procedure 

### for determining an 

### RDL starts

### with identifying all of theavailable reported 

### pollutant specific method detection levels 

### for the best 

### performing units regardless 

## of any subcategory (e.g., 

### existing or new, 

### fuel type, 

### etc.). Fromthat combined 

### pool of data,

### we calculate the

### arithmetic mean value. 

### By limiting the data set

### tothose tests used

### to establishthe 

### floor or emissions 

### limit (i.e., best performers), we believe thatthe result is representative 

### of the best 

### performing testing companies and laboratories using the most sensitive 

### analytical procedures.V/e believe that theoutcome should 

### minimize the 

### effect of atest(s) 

### with an 

### inordinately high method detection 

### level (e.g.,the sample 

### volume wastoo small, the 

### laboratory technique was

### insufficiently sensitive, or the procedure 

### for determining the 

### minimum value 

### for reportingwasother thanthedetection 

### level). We then

### call the 

### resulting mean

### of the method detection levels asthe representative detection 

### level 

### (RDL) as characteristic 

### of accepted source emissions measurement performance.
The second step 

### in the process is

### to calculate three times the 

### RDL to compare 

### with the calculated 

### floor or emissions 

### limit. This step is 

### similar towhat we have used before 

### in rulemaking applications. 'We use the

### multiplication factor 

### of three 

### to approximate reduce the 

### imprecision

## of the 

### analytical method 

### until the 

### imprecision inthe

### field sampling reflects the 

### relative method 

### precision asestimated 

### by the

### ASME studyr that also indicates that such 

### relative imprecision, 

### from 10

### to 20 percent, remains constant over the range 

### of the methods. 

### For comparing 

### tothe 

### floor, 

### if three times the 

### RDL were lessthan the calculated 

### floor or emissions 

### limit (e.g., calculated 

### from the 

### UPL), we

### would conclude that measurement 

### variability was adequately addressed. The calculated 

### floor or emissions 

### limitwould need no adjustment. 

# If ontheother hand,thevalue equal 

### tothreetimes the 

### RDL were greater than the 

### UPL, we

### would conclude that

I 1n.MAR¡' PHASE l, Precision of Manual Stâck Emission Measurements; American Society of Mechanical Engineers, Research Committee on Industrial and Municipal Waste, February 2001,thecalculated 

### floor or emissions 

### limit does not account

### entirely for measurement 

### variability. 

# If

indicated, we substituted thevalue equalto three times the 

### RDL for the calculated 

### floor or emissions 

### limit which results 

### in aconcentration where the method

### would produce measurement accuracy ontheorder

### of 10to 20 percent 

### similar to other EPA test methods and the results found 

### inthe

### ASME study. V/e determined the 

### RDL for each 

### pollutant using data 

### from tests

### of all the best performers 

### for all of the

### final regulatory subcategories (i.e., pooled test data). 'We applied the same 

### pollutantspecifrc 

### RDL and emissions 

### limit adjustment procedure

### toall subcategories 

### for which we established emissions 

### limits. V/e believe that emissions 

### limits adjusted 

### inthis manner better ensure measurement 

### variability is adequately addressed relative 

### to compliance determinations than

### did the procedure applied 

### for the proposal that may have been basedon data sets smaller than seven tests and as

### few as one

### test. We also believe that theemissions testing procedures and technologies available 

### now and 

### in thefuture 

### will be adequateto 

### provide the measurement 

### certainty sufficient for sources

### to demonstrate compliance atthe levels 

### of the adjusted emissions 

### limits when applied 

### in the manner representative 

### of this 

### protocol. We recommend 

### that rule 

### writers considering emissions 

### limits for these 

### pollutants review the existing data sets

### and compare the 

### RDL values used 

### inearlier analyses

### with the revised 

### RDLs shown 

### inthe attached 

### table.\ile believe

### that these 

### revised values and the procedures described 

### inthe table 

### better reflect representative method 

### capabilities and should be used 

### in data review

### for current rule development 

### projects and Ín setting representative emissions 

### limits.
Results 

### of 

### MDL/RDL data analyses We have collected data used 

### for the 

### boilers rule reconsideration and the proposed 

### utility MACT in light of thecomments to 

### review the

### effect

### of available larger pools 

### of dioxin/furan emissions as measured 

### with Method

### 23 and the 

### Hg emissions as measured 

### with Method 29

### of datafor these sources. The expanded data set represents several hundred emissionstests used 

### inthe

### floor calculations (i.e., best 

### performers)for the 

### boilers and 

### utility rules. We presume that data 

### for the best 

### performing units also 

### reflect thecapabilities 

### of high quality testing companies and 

### laboratories. Further, the method detection levels calculated 

### from larger data are more representative 

### of the inherent measurement 

### variability both

### within and between testing 

### companies. V/e have also 

### included data onthe 

### RDL values

### for the 

### individual metals as measured 

### with Method 29 basedon a

### similar assessment 

### of data collected 

### during method 

### development. The tables attached 

### below express the results 

### in two formats: 1)The mass

### of pollutant sample the method can detect 

### quantitatively and is representative 

### of the method detection 

### level 

### (RDL) for the set

### of data collected 

### for the

### specific rule development; and 

### 2)The lowest concentrations that could be measured 

### quantitatively for a range 

### of sample 

### volumesfor use 

### in comparing 

### to calculated 

### UPL values and 

### in setting applicable emissions 

### limits.The 

### first table represents athorough 

### review of D/F emissions data 

### for both the 

### boilers and 

### utility

data 

### sets. Not too 

### surprisingly, the 

### resulting values are

### similar but 

### not 

### identical. Our 

### first observation isthat these calculated representative detection levels aregenerally greater 

### in magnitude than those calculated 

### for the

### initial reviews and 

### particularly for establishing new source 

### limits (i.e., 

### for the single best 

### performing 

### unit). The second observation isthat the 

### RDLs determined 

### for the 

### utility ICR data set are 

### lower in magnitude than 

### for the 

### boiler data collected 

### during an earlier 

### ICR 

### project. We believe that the 

### boiler data set includes some data reported 

### incorrectly (e.g., 

### laboratory reporting 

### limits rather than method detection 

### limits) andthatthe 

### utility D/F data set includes fewer 

### of these misreported 

### data. As a result, we believe thatthe 

### RDLs determined 

### from the

### utility D/F data set are more representative 

### of current expected measurement data

### quality. The 

### application procedures described 

### in thetable 

### reflect this conclusion. 

### Also attached to this note is aspreadsheet example 

### of the calculations used

### to develop these values. 

### As rulewriters collect additional data 

### inthe

### future andtest methods and techniques 

### improve, there

### will be a need

### to assess new data

### for representative method detection 

### capabilities. We

### will prepare new procedures 

### for you and 

### your contractors 

### to use as needed 

### in future 

### rule making activities based onthese

### findings. We

### will build on these procedures to 

### reflect greater reliance onthe broadest set

### of measurement data available and 

### provide default values

### to usewhen there are

### only afew (e.g., fewer than seven) performance test results available 

### for a source category.
Peter 

### Westlin Measurement 

### Policy Group Sectors Policies and Programs 

### Division Raymond 

### Merrill Measurement 

### Technology Group 

### Air Quality Assessment 

### Division
Addressees: SPPD management SPPD technical 

### staff

cc: Conniesue Oldham, 

### MTG,

### AQAD Jason Dewees, 

### MTG,

### AQAD Kim Garnett, 

### MTG, 

### AQAD Kristen Benedict, 

### MTG, 

### AQAD Robin Segall, 

### MTG,

### AQAD

### Summary of 

### pollutant emissions 

### representative method detection level analyses 

### and a 

### regulatory emissions 

### limit setting 

### procedure


### RDL (ns) 

## 3x

RDL (ns) 3

### x 

### RDL Concentrations (ng/dscm) 

### I dscm test 2 dscm test 3 dscm test 4 dscm test 6 dscm test 

### I dscm test 

### Ind. Boilers DÆ

### total mass 

### Method 23) 5.6E-01 

### 1.78+00 1.7E+00 8.5E-01 5.7E-01 4.3E-01 2.8E-01 

### 2.tB-0t Ind. Boilers TEQ (Method 23) 

### 8.28-02 2.58-01 

### 2.sB-0t 1.38-01 8.3E-02 

### 6.3F-02 4.28-02 

### 3.tE-02 Utilities DIF total mass 

### (Method 23) 

### 3.lE-01 9.28-0r 9.2F-01 4.6E-01 

### 3.lE-01 

### 2.3F-0t 1.sE-O1 1.2E-01 

### Utilities TEQ 

### Method 23) 

### 3.6F-02 1.1E-01 

### l.lE-01 s.sE-02 

### 3.78-02 2.88-02 l.8E-02 t.4E-02



### RDL (ug) 

## 3xRDL

lusl 3

### x 

### RDL Concentrations (us/dscm)



### I dscm test 2 dscm test 3 dscmtest 4 dscm test 

### HCVCI2 CMethod

### 264) 6.0E+1 1.8E+2 1.88+02 9.0E+01 6.0E+01 4.58+01 

### PM filterable (Method 5) 

### 2.08+3 6.08+3 6.0E+03 

### 3.08+03 2.0E+03 1.5E+03 

### Ind. 

### Boiler He fMethod 29) 8.3E-01 

### 2.58+00 

### 2.lE+00 l.0E+00 7.tE-01 

### 6.28-0r

120L test 240L test 360L test 

### HCVCL? 

### Method 26) 

### l.0E+01 3.0E'+01 

### 2.58+02 I.3E+02 8.3E+01

### Summary of 

### pollutant emissions 

### representative method detection level analyses 

### and 

### regulatory emissions 

### limit setting

procedure 

### for Method'29Metals usÍng 

### Inductively CoupledAtomic Emission Spectroscopy 

### or

### AtomicAbsorption Analysis

Method 29 

### Metal RDL

ICP/AES or

### AA fus) 

## 3XRDL ICP/AES 

### or AA fus) 3

### x 

### RDL Concentrations (us/dscm)



### I dscm tesl 2 dscm test 3 dscm test 4 dscm test 

### Antimony l.2E+01 3.5E+01 3.5E+01 1.7E+01 1.2E+01 8.6E+00 

### Arsenic 1.9E+01 5.7E+01 5.7E+01 

### 2.98+0t 1.98+01 1.4E+01 

### Barium 8.0E-01 

### 2.48+00 2.48+00 1.2E+00 8.0E-01 6.0E-01 

### Beryllium 1.1E-01 3.38-01 3.3E-01 1.7E-01 1.18-01 

### 8.38-02 Cadmium 1.5E+00 4.5E+00 4.5E+00 

### 2.38+00 

### l.5E+00 1.1E+00 

### Chromium 2.5E+00 

### 7.58+00 7.5E+00 3.8E+00 2.5E+00 1.9E+00 

### Cobalt 2.5E+00 7.5E+00 7.5E+00 

### 3.88+00 2.5E+00 1.9E+00 Copper 2.1E+00 6.3E+00 6.3E+00 3.2E+00 2.1E+00 1.6E+00 Lead 1.5E+01 

### 4.58+01 4.58+01 2.38+Ol 1.5E+01 1.1E+01 Manganese 7.0E-01 

### 2.18+00 2.18+00 1.1E+00 7.0E-01 5.3E-01 

### Mercury* 5.6E-01 

### t.7E+00 1.7E+00 8.4E-01 s.6E-01 

### 4.2E-01 

### Nickel 5.48+00 1.6E+01 1.6E+01 8.1E+00 5.4E+00 4.1E+00 Phosphorus 

### 2.7F+0t 8.1E+01 8.1E+01 

### 4.lE+01 2.78+01 2.0E+01 Selenium 2.78+01 8.1E+01 8.1E+01 4.1E+01 2.78+01 2.08+01 

### Silver 2.6E+00 

### 7.88+00 7.8E+00 3.9E+00 

### 2.6F+00 2.0E+00 

### Thallium 1.4E+01 

### 4.38+01 4.38+01 2.28+01 

### l.4E+01 1.lE+01 

### Zinc 8.0E-01 

### 2.48+00 2.4F+00 1.2E+00 8.0E-01 6.08-01 

### *Mercury analyzedby Cold Vapor 

### AA RDL = 

### Method derived 

### regulatory detection 

### limit based. 

### ICP/AES

# : Inductively Coupled 

### Argon Plasma/Atomic Emission Spectroscopy 

### AA

## - Atomic Absorption Spectroscopy 

## GFAA: Graphite Fumace

### Atomic Absorption spectroscopy

### Summary of 

### pollutant emissions 

### representative method detection level analyses 

### and 

### regulatory emissÍons 

### lÍmit setting



### procedure for Method 29 

### Metals using 

### Inductively Coupled Plasma/lVlass 

### Spectrometry 

### or Graphite Furnace 

### Atomic Absorption Analysis

Method 29 

### Metal 

### RDL

ICP/]US 

### or GFAA (us/dscm) 

## 3XRDL

ICPNúS 

### or GFAA (us/dscm) Concentrations (¡tg/ds c

### m)



### I dscm test 2 dscm test 3 dscm test 4 dscm test 5 dscm test 

### Antimony 1.lE+00 3.3E+00 3.3E+00 1.7E+00 

### l.tE+00 8.3E-01 6.6E-01 

### Arsenic 4.0E-01 1.2E+00 

### t.2E+00 6.0E-01 4.0E-01 3.08-01 

### 2.48-01 Barium** 8.0E-01 

### 2.4F+00 2.48+00 1.2E+00 8.0E-01 6.0E-01 4.8E-01 

### Bervllium 8.0E-02 

### 2.48-0t 2.48-01 t.2E-01 8.0E-02 

### 6.0F-02 

### 4.8F-02 Cadmium 3.0F-02 9.0E-02 

### 9.08-02 4.5F-02 3.0E-02 

### 2.38-02 1.8E-02 

### Chromium 3.0E-01 9.08-01 9.0E-01 4.58-01 3.0E-01 

### 2.3F-Or l.8E-01 Cobalt 3.0E-01 9.08-01 9.08-01 4.5E-01 3.0E-01 

### 2.38-Or l.8E-01 Copper** 

### 2.lE+00 6.3E+00 6.3E+00 3.28+OO 

### 2.lE+00 1.6E+00 1.3E+00 Lead 3.0E-01 9.0E-01 9.0E-01 4.5E-01 3.0E-01 

### 2.38-01 l.8E-01 Manganese 3.0E-01 9.0E-01 

### 9.0E-0r 4.5E-01 3.0E-01 

### 2.38-01 r.8E-01 

### Mercury* 5.6E-01 1.7E+00 1.7E+00 8.48-01 5.68-01 

### 4.28-0t 3.4E-0r 

### Nickel** 5.4E+00 

### l.6E+01 l.6E+01 8.1E+00 5.4E+00 

### 4.tE+00 3.2E+00 Phosphorus** 2.78+01 

### 8.lE+01 8.lE+01 4.lE+01 2.78+0t 2.0E+01 

### l.6E+01 Selenium 8.0E-01 

### 2.48+00 2.48+OO 

### l.2E+00 8.0E-01 6.0E-01 4.88-01 

### Silver** 2.68+00 7.8E+00 7.8E+00 

### 3.98+00 2.6E+00 2.0E+00 1.6E+00 

### Thallium 3.0E-01 9.08-01 9.0E-01 4.58-01 3.08-01 

### 2.38-01 1.8E-01 

### Zinc 8.0E-01 2.48+OO 

### 2.4F+00 l.2E+00 8.0E-01 

### 6.0E-0r 4.8E-01 

### *Mercury analyzedby Cold

### VaporAA 

## ** Common 

### metalsanalyzedby 

### Inductively Coupled Plasma/AES or Flame

### Atomic Absorption Spectroscopy 

### RDL:Methodderivedregulatorydetectionlimitbased onl.25 dscmcollectedin 

### I hour. 

### ICP/I{S 

# : Inductively Coupled 

### Argon Plasma/\4ass Spectrometry

## GFAA: Graphite Fumace

### Atomic Absorption spectroscopy

Except 

### for assessing 

### boiler and 

### CISWI data,we recommend that

### you select 

### D/F data calculated 

### from the 

### utilities' data set rather than 

### for the 

### industrial boilers 

### in conducting the

### following analyses. 

## 1. Calculate the 

### UPLfor your respective data set 

### in unitsof pollutant mass Ítssampled by thetest method (e.g., 

### total ng 

### of D/F, totalTEQ of DlF, ug 

### of Hg). 

## 2. Compare the

### 3xRDL massvalue (shown 

### in 

### bold) tothecalculated 

### UPL. If 3xRDL mass

### < UPL mass, use the 

### UPL value 

### for rulemaking. 

### If 3XRDL 

### > UPL, usethe

### 3xRDL value 

### for 

### rulemaking. For source categories other than 

### boilers, use the

### 3xRDL D/F values shown above 

### for 

### Utilities. 

## 3. Alternatively, you may calculate the 

### UPLforyour data set 

### in units of pollutant concentration 

### (ngldscmfor D/F, ug/dscm 

### for 

### Hg). If so, repeat steps 

## I and2 selecting the concentration associated 

### with the sample 

### volume appropriate 

### for your ICR 

### or regulatory 

### decision. You may also determine 

### to convert the values 

### inthetable

### to other emissions formats (e.g.,

### lbilvfMBtu or lb/lvtwh) for these comparisons.Example spreadsheet: (ng/dscm@Tpercent02) mass(average TEQ(averageof ofall 

### congener all TEQ per data in set) 2.79E-02
6.728-03 2.958-03 6.10E-03 1.16E-03 8.24E-03 3.08E-03 1.33E-03 9.64E-04 4.40E-03 1.82E-03 3.37E-03 7.8L8-04 2.3sE-03 1.61E-03 3.38E-03 2.24843

2.L98-O2 7.81E-04 4.26E-03

7.24E-02 1.45E-01 4.35E-01 congener in set)

6.24E-06
1.89E-06 2.70E-05 6.02E-05 1.06E-04 8.10E-04 3.00E-05 L.238-04 8.83E-05 4.33E-03 5.26E-0s 3.26E-04 6.93E-05 2.27E-04 4.6LE-O4 3.34E-03 2.18E-04

4.33E-03 1.89E-06 6.05E-04

1.03E-02 2.068-02 6.L78-O2 ng

lab mass 8.778-02
2.698-02 1.18E-02 2.448-02 4.63E-03 3.30E-02 1.238.0.2 5.32E-03 3.86E-03 L.76E-O2 7.298-03 1.35E-02 3.128-03 9.40E-03 6.438-03 1.35E-02 8.98E-03 ng

TEQ 2.s0E-05
7.55E-06 1.08E-04 2.4tE-O4 4.258-04 3.248-03 L.20E-O4 4.93E-04 3.53E-04 L.73842 2.toB-o4 1.30E-03 2.77E-04 9.09E-04 1.85E-03 t.348-02 8.73E-04 Total OCDD Total OCDF L,2,3,4,6,7,9 HpCDD 7,2,3,4,6,7,8HpCDF I,2,3,4,7,8HxCÐD L,2,3,4,7,8HxCDF L,2,3,4,7,g,g HpCDF 7,2,3,6,7,9HxCùD L,2,3,6,7,8HxCùF L,2,3,7,8PeCDD l,2,3,7,8PeCDF L,2,3,7,g,gHxCDD L,2,3,7,g,gHxCDF 2,3,4,6,'l,8HxCDF 2,3,4,7,8PeCDF 2,3,7,8:ICDD 2,3,7,8--lCùt

max DL

min DL mean DL

sum RDL=EDLx2 RDLx3>floor? 

### 8.778-02 L.73842 

### 3.12E-03 7.55E-06 

### t.70E-02 2.42E-03 2.90E-01 4.ttÊ-02 5.80E-01 8.22E-02 L.74E+OO 2.478-OL