Hunton & Williams LLP •Counsel to UWAG • 1900 K Street, N.W. • Washington, D.C. 20006 Steering/Audit Committee

Angela M. Grooms

,

Chairman C. Richard Bozek Rayburn L. Butts Alan E. Gaulke M. R. (Mick) Greeson David M. Lee James F. Stine John G. Valeri, Esq. Kerry M. Whelan Judson White

March 1 9 , 2010 FILE NO.: 29142.070 312

Mr. R onald P. Jordan U. S. EPA Engineering & Analysis Division (4303T) Ariel Rios Building 1200 Pennsylvania Avenue, N.W. Washington, DC 20460

Mr. Richard W. Reding U.S. EPA Ariel Rios Building (4303T) 1200 Pennsylvania Avenue, N.W. Washington, DC 20460

UW AG Comments on EPA Draft Standard Operating Procedure entitled “Inductively Coupled Plasma Mass Spectrometry for Trace Element Analysis in Flue Gas Desulfurization Wastewaters” dated February 12, 2010

Dear Ron and Dick:

The Utility Water Act Group (UWAG) is pleased to submit comments on the draft standard operating procedure (SOP) entitled “Inductively Coupled Plasma Mass Spectrometry for Trace Element Analysis in Flue Gas Desulfurization Wastewaters” dated February 12, 2010. UWAG’s comments , however, sh ould be considered preliminary because UWAG has not yet had a chance to evaluate the accuracy of any FGD wastewater data produced u sing the draft SOP. Also, UWAG asked several questions at our March 11 meeting concerning the actual instrumental setup and procedures used to develop the draft SOP but we have not yet received specific answers to those significant questions. UWAG is anxious to provide a comprehensive review of the draft SOP but without the appropriate information about fundamental aspects of the draft SOP our ability to provide substantive and validating comments concerning the accuracy of data produced by the draft SOP is limited.

Our comments are organized into two sections. The first section deals with general comments that apply to the dr aft SOP as a whole. The second section includes specific comments on the individual sections of the draft SOP.Mr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 2

A. General Comments/Questions

1. The draft SOP, even though ostensibly developed specifically for FGD wastewater analysis, is quite generic and appears patterned largely after EPA method 200.8 with minimal modifications to accommodate FGD samples. Except for the use of a synthetic FGD wastewater (see note 2), very little information is given in the draft SOP that helps the analyst run FGD sample s in a way that is different from running any other sample type. The draft SOP doesn’t even provide a description of the nature and analytical challenges posed by complex FGD matrices.

2. The primary SOP modification specific to FGD wastewaters appears to be the use of a “synthetic FGD wastewater” (SFGDWW, sections 7.2.7 and 9.4) to confirm the lack of uncontrolled interferences above the various elemental method reporting limits. The SFGDWW is also used to perform an annual matrix specific method detecti on limit study (section 12.1). The use of a SFGDWW is a good approach. However, the use of the SFGDWW should be expanded as follows to more fully evaluate potential enhancement or reduction of “real” element concentrations from a given CRC

- ICP

- MS instrum ental setup:

a. The SFGDWW should be analyzed prior to initiating each FGD sample analysis run and not just once a quarter.

b. Each aliquot of SFGDWW analyzed should first be digested in the same manner as “normal” FGD wastewater samples.

c. Additional SF GDWW performance parameter requirements should be given in the draft SOP. For example, when compared to the dilute acid method blank, the SFGDWW should not cause a reduction or enhancement in either the elemental signals or internal standards counts beyon d some specified window such as 60

- 125%. The exact percentage window should be determined based on method validation data showing at what point the accuracy of the method is impacted. Corrective action(s) should be specified for when the percentage windo w requirement is not met.

d. A single spiked digested SFGDWW aliquot should also be run with spiking levels that are the same as the laboratory fortified blank (section 9.7). An acceptable percent recovery requirement should be specified such as the 70

- 13 0 %R used for MS/MSD (section 9.8). Corrective action(s) should be specified for when the percent recovery requirement is not met for one or more elements. For example, if the spiking shows an uncontrollable matrix interference for a given element then t heMr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 3

element is not appropriate for inclusion in the method. Leaving the element out of the draft SOP method is more appropriate than just flagging every sample as having a “matrix interference” for that element. See also note A.8.

3. UWAG was pleased to b e asked by the EPA to analyze representative split samples as part of the EPA’s Collision Cell Inductively

- Coupled Plasma Mass Spectrometry (CRC

- ICP

MS) method development and evaluation study. The draft SOP being reviewed here is a result of that study. To support the EPA CRC

- ICP

- MS method development study, UWAG developed a substantial confirming analysis data set based on the analysis of the split samples as summarized below:

a. Confirming analyses were performed on all twenty split samples also analyz ed by the EPA’s contract laboratory to develop the draft SOP.

b. The closed vessel digestion procedure used by UWAG to prepare the split samples for analysis was essentially identical to the digestion method used by EPA’s contract laboratory and described in the draft SOP (section 10.2).

c. Confirming analyses were performed on identical digestion splits data by five independent laboratories, all with experience analyzing FGD wastewaters

.
d. Eighteen elements were measured in the split samples ( i.e.
, Ag, A l, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Se, Tl, V, Zn).

e. Confirming analyses were performed by at least four independent analytical methods including CRC

- ICP

- MS (the same method used by the EPA contract laboratory), high

- resolution

- ICP

- MS, Dy namic Reaction Cell (DRC)

- ICP

- MS and ICP

- Atomic Emission Spectrometry (EPA method 200.7). Selenium was confirmed by a fifth independent analytical method ( i.e.
, hydride generation atomic fluorescence).

f. All confirming analyses were done in the blind. T his is the standard approach used for all intercalibration exercises including those required by EPA and NELAC for laboratory accreditation. With the exception of Albion Environmental (AE) that perform ed the closed vessel digestion and prepared the digest ion splits, none of the UWAG confirming analysis laboratories knew anything about the split samples except a unique sample ID and the estimated total dissolved solids (TDS) level to use in optimizing their analytical procedures. No inter

- confirming analys is laboratoryMr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 4

communications were allowed until after each laboratory had submitted its final data report.

g. Selected split samples were also digested using four other digestion procedures (including the one described in EPA method 200

. 2 and 200.8) and an alyzed to provide additional confirming analysis data.

UWAG believed that our confirming analysis data would be used by EPA to help validate the accuracy and efficacy of the EPA’s draft CRC

- ICP

- MS method. UWAG is anxious to share its confirming analysis d ata with EPA. However, UWAG believes that the appropriate approach is for both EPA and UWAG to share their respective data sets simultaneously at the same meeting. This approach preserves the blind inter

- calibration approach used for UWAG’s confirming an alysis study and insures that all data comparisons will be done without any a priori comparisons by either EPA or UWAG. Without such data comparisons, UWAG has no way of knowing if the draft SOP is capable of producing accurate metals data in FGD wastewat er matrices. Before sharing and comparing data, EPA and UWAG should agree as to what will constitute acceptable agreement between the EPA and UWAG confirming analysis data. Since the draft SOP may be used for compliance monitoring, a relative percent dif ference of 15% would represent acceptable agreement between the two data sets.

4. Both the EPA split sample data and the UWAG confirming analysis data sets should be included as an attachment to the draft SOP to provide labs with examples of results from the analysis of “real world” FGD wastewater samples using the CRC

- ICP

- MS methodology as well as other methods. Use Table 12 in EPA method 200.8 as an example of a possible format.

5. The draft SOP is vague and lacks the completeness and detail required to allow a “normal” analytical laboratory to set up the method for routine use. Examples of the lack of detail are given below. Additional omissions or lack of detail are included in the specific comments section B.

a. Was a “slug type” sample loop discret e sample introduction system ( e.g. , Agilent ISIS

- DS) used to develop the draft SOP (see section 6.1)? If so, an explanation of why this approach was used and how the discrete sampler should be configured is important to include in the SOP. An explanation is also important because such additional cost add

- ons will likely reduce the number of laboratories willing or able to implement the draft SOP.Mr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 5

b. Was a high matrix interface ( e.g. , Agilent HMI aerosol dilution interface) used to develop the draft SOP? If so, an explanation of why this approach was used and how the HMI should be configured is important to include in the SOP. An explanation is also important because such additional cost add

- ons will likely reduce the number of laboratories willing or abl e to implement the draft SOP. HMI systems require the instrument to be cleaned more often.

c. No expected method detection limits (MDL) or reporting limits (RL) are given in the draft SOP. EPA method 200.8 includes this information in Table 7 and method 1638 includes this information in T able 1. Since both MDL (once a year) and instrument detection limit (IDL) studies are required in the SOP, expected MDL/RLs should be included to provide labs with an indication of what they should expect to achieve when the instrument is properly configured.

d. No setup parameters are given for the collision cell ( e.g. , cell gas flows, etc.), plasma ( e.g. , power setting, gas flows) or spectrometer data acquisition ( e.g. , dwell times, etc.). Complete setup parameters s hould be provided in easy

- to

- read summary tables (as are provided in EPA method 200.8 Table 6) to facilitate a laboratory properly configuring the instrument for analyses using the draft SOP. As done in method 200.8, it would be helpful to give specific i nformation on the actual CRC

- ICP

- MS instrument used to develop the draft SOP.

e. The draft SOP lacks clean sampling and analysis procedures to allow a “normal” analytical laboratory to more easily adopt procedures needed to consistently obtain accurate dat a at the low concentrations of which DRC

- ICP

- MS is generally capable. Use EPA method 1669 sections 4.1, 4.2 and 8 as an example of the necessary sampling contamination procedures. Use EPA method 1638 sections 4.1, 4.2 and 4.3 as an example of the necessar y analytical contamination control procedures.

6. It appears from the draft SOP that all split sample FGD wastewaters were analyzed undiluted by the EPA contract laboratory

. If so

, an explanation of why this approach was used should be given. Alternative l y, perhaps such a dilution is accomplished through the use of a combination of the ISIS/HMI add

- ons (if used). EPA method 200.8 (sections 1.3 and 4.1.4) recommends that elevated TDS samples be diluted to a TDS level of < 2,000 ppm prior to analysis.

7. T he draft SOP (section 12.4) suggests that FGD wastewater samples may be quantified based on Linear Dynamic Range (LDR) and not the high calibration standard of 100 ppbMr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 6

(Attachment 8). Is this true? If so

, then such an extrapolation with FGD matrices woul d appear to be non

- optimal because the LDR is determined using single element ideal matrix standards (section 9.5). For example, EPA method 200.8 (section 1.1) states that “ ... linear working ranges will be dependent on the sample matrix, ...”. Using a LDR determined using dilute acid standards to extrapolate concentrations above the high calibration standard for undiluted high TDS matrices such as FGD wastewater could be problematic. The draft SOP wording should be changed to require sample dilution so that quantification occurs only at or below the highest calibration standard.

8. It appears from the draft SOP (section 9.8) that failed MS/MSD’s are only R

- Flagged as matrix specific interference suspected if all other QC criteria are acceptable. T here was some confusion during our March 11 meeting on this point

. More effort to resolve such matrix specific interferences ( e.g. , dilution and re

- analysis) should be incorporated into the draft SOP. Also

, with such highly variable matrices as FGD wastewater s, a matrix specific MS/MSD requirement ( i.e.
, perform a MS/MSD on each unique FGD wastewater matrix as is used in EPA method 1631E section 9.3 and EPA method 1631E implementation guidance chapter 5) should be added to the draft SOP. UWAG’s split sample c onfirming analysis data showed the presence of matrix specific interferences for selenium. The matrix specific MS/MSD requirement would be an addition to the 10% batch specific requirement currently in the draft SOP (section 9.8). If this is not done the n one can envision the case where a failed batch specific MS/MSD would invalidate all affected data in the batch ( i.e.
, the other 9 unspiked samples). Finally, a statement should be incorporated into the draft SOP (as is present in EPA method 1631E sectio n 9.3.4.2) that data associated with a failed MS/MSD “may not be reported or used for permitting or regulatory compliance purposes

. ”

9. The draft SOP specifies fixed concentration (40 ppb) pre

- digestion spikes (Attachment 8) for all elements except alumin um. This approach is patterned after EPA method 200.8 and works for aqueous samples with low metal concentrations. However, this approach needs to be modified for FGD wastewaters which often contain elevated concentrations (> 200 ppb) of several elements including selenium, manganese, nickel and zinc. For example, for most FGD wastewaters with elevated selenium concentrations, the 40 ppb spiking level will be too low and the spike signal will be buried in the unspiked sample signal. For example, the ave rage selenium concentration from this 20 split sample study is 1,240 parts per billion (ppb). If the FGD wastewaters are run undiluted (see note 4)

, then the pre

digestion spiking level of 40 ppb would be only ~ 3% of the unspiked concentration and would be lost in the analytical noise. Based on EPA method 200.8 (section 9.4.3) thisMr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 7

invalid (low) spike would just be ignored and the ability to identify any matrix specific interferences would be lost. This approach is inappropriate for an SOP specifically aimed at FGD wastewater analyses where selenium is an element of special interest. The draft SOP MS/MSD approach should be modified to require pre

- screening analysis of FGD samples so that the spiking levels can be adjusted to allow valid spikes ( i.e.
, 1

- 5 times the unspiked concentration) for higher concentration elements such as selenium.

10. Most laboratories with experience using CRC

- ICP

- MS for FGD wastewater analysis prefer the use of hydrogen as the cell gas for selenium analysis. The draft SOP re commends the use of He although the SOP mentions H2 as an optional gas. The draft SOP should explain why He is used over H2

, and should also provide information on the procedures used to optimize cell configuration ( e.g. , gas flow rates, etc.) for FGD was tewaters.

11. Even though CRC

- ICP

- MS is capable of detecting sub

- ppb metal concentrations, both the draft SOP and method 200.8 (upon which the draft SOP appears to be based) are essentially silent on the need for clean metals sampling and analysis procedur es to support such low MDL’s. Method 200.8 mentions the need for field blanks (section 8.5) but only in passing with no specific instructions on collection or evaluation. The draft SOP should be modified to include the following clean metals information to make labs explicitly aware of what is required to consistently achieve low MDL’s without significant contamination bias. The draft SOP should make it clear that clean metals procedures are needed during both sample collection and sample analysis to con sistently produce accurate data:

a. Clean sampling contamination control procedures patterned after sections 4.1, 4.2 and 8 in EPA method 1669.

b. Clean analysis contamination control procedures patterned after sections 4.1, 4.2 and 4.3 in EPA method 1638. The use of pre

- cleaned sample tubes and pump tubing are especially important to maintaining low method blanks.

12. There are inconsistencies throughout the draft SOP concerning matching the acid matrix of samples and standards. EPA methods, including 2 00.8, typically use the same acid strength in the calibration standards and the samples. The draft SOP uses 2% nitric acid in the calibration standards, spiking stock solution, blank matrix, tuning solution, etc. However, the samples are digested (sectio n 10.3) using 1% nitric acid. The strength of hydrochloric acid (0.5%) is consistent throughout the draft SOP. Was this difference for nitric acid intentional? If so an explanation of the decision not to matrix match nitric acid in standards and samples should be given.Mr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 8

B. Specific Comments/Questions

Sec. # Comment/Question

2.2 The w ording is awkward. Ions are not sorted, they are separated from one another. What is a “ channel” electron multiplier?

2.3 A brief description of how the collision cell actually removes molecular ion and other interferences should be added here for clarity. For example, the use of kinetic energy discrimination should be described.

3.3, 3.4 Definitions for “total metals” and “total recoverable metals ” seem redundant. Th e digestion procedure described in the draft SOP ( section 10.2) is basically the closed vessel, in

- bottle dilute acid alternate digestion procedure described in EPA method 1638. The method 1638 digestion procedure is a “total recoverable” digestion. The definition of “total metals” should be deleted or revised to show more clearly why it is different than the total recoverable digestion and how and why the total metals definition applies to the draft SOP.

3.5 Should point to section 12.3, not 12.2. Also a definition of IDL should be given here and not just a reference. For example, EPA method 1638 defines Instrument Detection Limit (IDL) as “The concentration equivalent to the analyte signal which is equal to three times the standard deviation of a seri es of ten replicate measurements of the calibration blank signal at the selected analytical mass(es).”

3.7 Remove the underscore after “Solution”. On most ICP

- MS’s the tuning solution is used to calibrate the mass filter. Perhaps the tuning solution is used differently on the CRC

- ICP

MS instrument used to develop the draft SOP ( e.g. , HP/Agilent 7XXX). For example, is the tuning solution used to calibrate the complex lens system on the Agilent and also optimize the torch position? A better description i s needed so the end user laboratory knows what’s being adjusted.

3.10 The wording is incomplete. The LFB is also used to “... and to verify method performance (control) in an ideal sample matrix.”

3.11 The wording is i ncomplete . There is no mention of th e reason for or use of a reagent blank. Should add something like “are used to determine the concentration of trace metals in the reagents that are used to prepare and analyze the samples. For this Method, reagent blanks are required for each new batch of reagents used.”Mr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 9

Sec. # Comment/Question

3.12 The wording is m isleading

. The calibration blank is not equivalent to the ICB and CCB. They may have the same composition, but they are different and serve different purposes. For example, the calibration blank is used to set the zero point for the calibration curve and the CCB is used to monitor the level of carryover or contamination during an analytical

run.

3.13 The definition given is for a method detection limit not a method reporting limit. A definition for method reporti ng limit should be added to the draft SOP glossary.

4.2 The wording is c onfusing

. It is not correct to say that “isobaric molecular interferences are caused by ions consisting of more than one atom or charge”; more than one atom means molecular, as in Ar Cl. A doubly charged ion can have (can, not must) only one atom, as in Ba++. Should include the description that such interferences “have the same nominal

mass

- to

- charge ratio as the isotope of interest, and which cannot be resolved by the mass spectrome ter in use.”

4.3 For clarity add the units to raw signal intensity ( e.g. , counts per second, total counts, etc.). Also , this section should mention that matching the element and internal standard ionization potential can be an important consideration in addition to the masses.

6.1 A more complete description of the discrete sample introduction system (SIS) used to develop the draft SOP should be given. Is it the Agilent ISIS

- DS? Also detailed setup parameters for the discrete SIS should be included to make it easier for labs to replicate the proper ISIS configuration. Furthermore, if reducing sample analysis time is one of the goals of the method, then more details and emphasis needs to be placed on whether the signal being measured is transient or ha s plateau

- ed and how to confirm and optimize this signal stabilization situation. See also note A.5.a and A.5.b.

6.2 This section s hould specify which gases are needed as liquid (high usage volume) and which gases can be used as compressed cylinders.

7. 2.1 Refers to Attachment 5 not 9.

7.2.3 This section n eed s to provide enough information for a laboratory to easily make up or purchase the calibration standards. Need to clearly identify all custom standard mixes, etc. to avoid any confusion. For examp le, the elemental composition and concentrations (and acid strengths) of the custom multi

- element mixes (presumably ICPMSCal

- 1, ICPMSCal2, ICPMSCal

- 3 and ICPMS

- BRC have to be defined in a table. Remove double period after word “matrix”. Also, there is a r eference to nonexistent Attachment 11. It is p robably referring to attachment 8.Mr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 10

Sec. # Comment/Question

7.2.6 Describe how the individual FGD interference check solutions are prepared (including acid matrix) or if they are purchased individually.

7.2.7 Describe how the synth etic FGD wastewater solution is prepared including acid matrix. Due to the high concentration of some elements is precipitation a problem? If so

, how is precipitation avoided, etc. Why was fluoride added? Has it been quantified in FGD wastewaters?

7.2. 7.1 We a ssume the chloride concentration is 15,000 mg/L not 15.0 mg/L.

7.2.8 Is the reference to ICV standards correct? (Plural ? ) This m ay not be a typo, because the following verb is “are”. Attachment 8 shows three calibration standards but it is not c learly specified. Also see note 7.2.3. The exact elemental composition and concentrations (and acid strengths) of the various mixed standards have to be clearly defined in a table so that a lab can easily recreate the necessary calibration standards. Th e designations here ICPMS

TA, ICV A, etc., are different from those in 7.2.3. Do they refer to a second source of the same custom mixes?

7.2.9 Is 3% nitric acid correct or should it be 2% or 1% ? The b ullet description is incomplete. What is the concen tration? 50 ppb? Refers to a non

- existent attachment 11 which is probably attachment 8.

7.2.10 The section r eference s nonexistent Attachment 11 which is probably attachment 8.

8.0 This section s hould briefly describe the clean sampling procedures and t hen reference method 1669 where more detailed information can be obtained.

9.1 This section r eference s nonexistent Attachment 11 which is probably attachment 8.

9.3 Manganese listed on the draft SOP is also monoisotopic.

9.4 ”P rior to initiating sample analysis” could be a one

- time event or every day. The synthetic FGD wastewater solution should be run each day FGD wastewaters are analyzed. Manganese listed on the draft SOP is also monoisotopic.

9.5 Since this SOP describes a method optimized for FGD samples, why not use the synthetic FGD wastewater solution as the linear range sample? See also note A.7.

9.6 The acceptance criterion for the method blank appears to be an attempt to estimate the method reporting limit. Why not use the definition of me thod reporting limit used in previous EPA methods: “The ML is calculated by multiplying the MDL by 3.18 and rounding the result to the number nearest to (1, 2, or 5).”Mr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 11

Sec. # Comment/Question

9.7 This section s hould specify that “processed” means carrying the LCS through the en tire sample preparation procedure just like a sample. Why is method 200.8 referred to in this section? Refers to non

- existent attachment 12.

9.8 Simply flagging a failed MS/MSD should not be acceptable for this special method. The analyst should be req uired to dilute and re

- analyze or modify the CRC

- ICP

- MS parameters to resolve the interference. If the failed MS/MSD cannot be resolved then all associated sample data should be rejected and flagged as not usable for compliance reporting purposes. See al so note A.8. Refers to non

- existent attachment 11 which is probably attachment 8.

9.9 Add the corrective procedure to follow if the instrument has drifted

. Presumably , the analyst should stop analyses, recalibrate and re

- analyze all affected samples.

1 0.2.8 Should heat for 2 hrs AFTER the sample temperatures have reached 85 deg. C.

10.3.1 Attachment(s) should be added showing all necessary instrument setup parameters to make it as easy as possible for another lab to implement the draft SOP procedure (s ee also note A.5). Tables 6 in method 200.8 can be used as a starting point. However other tables (attachment) should be added to cover all instrument setup as follows:
Additions to instrument setup parameters not included in Table 6:
Tuning mode = rob ust tuning option
RF matching should be included in the tuning of the instrument
P/A factor should be used at a 100x dilution from stock P/A factor solution (vendor) and the instrument should be rinsed for 10

- min with 2.0% HNO3/0.5% HCl before calibrating the instrument
Spray chamber temperature (2 deg. C?) Carrier gas flow = 0.99 L/min

Table X

- 1: Setup parameters for the ISIS

- DS discrete sample introduction system (if used). Suggested parameters (by no means a complete list) would be sample loop volume, s ample loop flow rate (pump speeds), nebulizer gas flow, flush and read delay (stabilization times) before data acquisition, post acquisition rinse out time (can be combined to next sample flush delay), etc.

Table X

- 2: Setup parameters for the HMI (if used) . Suggested parameters (by no means a complete list) would be mostly related to gas flow rates and inspection orMr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 12

Sec. # Comment/Question cleaning requirements.

Table X

- 3: Setup parameters for the collision cell. Suggested parameters (by no means a complete list) would be cell g as used, cell gas flow rate, QPBias and OctP Bias settings, stabilization time between gas modes, sequence of gas modes ( e.g. , H2 first then he then no gas), etc..

Table X

- 4: Data acquisition parameters for mass spectrometer. Suggested parameters (by

no m eans a complete list) would be integration (dwell) times (seconds per point), number of replicates (typically 3), etc.

10.3.3 This may work for ArCl, but FGD samples have very high calcium (Ca) concentrations. This step should include Ca as well as Cl to ensure that erroneous As counts from CaCl2 can be eliminated as well.

10.3.5 This r eference s nonexistent Attachment 11 which is probably attachment 8. Refers to wrong section (7.2.4); should point to 7.2.8.

10.3.7 The intent of this section is unclear

. This SOP is for CRC

- ICP

- MS analysis. This section seems to have been copied and pasted from EPA method 200.7 where two point calibrations can be used. No RL verification standard is listed in section 7.2.6. This section needs to be clarified or del eted depending on what is intended related to CRC

- ICP

MS analyses. It appears this may be the MDL solution referred to in section 12.

10.3.8 How many times can the CCV be reanalyzed before analysis is terminated?

10.4.2 The composition of the rinse blan k must be specified probably in section 7.3.

10.4.3 Since this section should be critical in accurately analyzing some of the most challenging samples most labs have seen, there should be guidance and specific detail on what masses should be monitored and how the day to day analyst should decide whether given elements have been affected. As written this important requirement would be very difficult for most labs to implement. A good starting point would be Table 4 from EPA method 200.8. Attachment 4 sho uld be revised to match Table 4 with mass 78 added for selenium, mass 138 added for barium (if desired). All known interferants ( e.g. , calcium, potassium, etc.) for the elements of interest should also be added to Attachment 4 with identification to the

e lement(s) affected. Also

, a description of how to monitor multiple isotope masses by comparing the sample concentrations calculated for each isotope and then using perhaps the spiked synthetic FGD wastewater (see note A.2.d.), reference materials or known interferants, etc. to determine which isotope to use for quantification in a given FGD matrix. This data inspection and evaluation is time consuming in the beginning but will become easier when the most reliable masses for quantifying FGD wastewaters by a givenMr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 13

Sec. # Comment/Question method are determined. However, a caveat must be included that because of the variability of FGD wastewaters no hard and fast rule can be given about the best isotope mass to use for all FGD wastewaters. There is no substitute for continually mon itoring multiple masses and adjusting quantification strategies ( i.e.
, isotope mass and internal standard) for a given batch of FGD wastewaters.

10.4.4 See note A.7. Samples with element concentration greater than the high calibration standard (100 ppb?) should be diluted and re

- analyzed to fall below 100 ppb.

10.4.5 Shows only 1 cal ibration standard, although sections 7.2.4 and 10.3.4 both say that a blank and 3 calibration standards should be run. This section needs to be revised to describe how the c alibration is performed.

11.3 Should specify how the “spike added” is calculated

. 11.4 The RPD equation is incorrect; the denominator should show the sum, not the difference

. 11.5 If the sample digestion is total recoverable as described in the ‘in bott le’ procedure (section 10.2), then the preparation dilution factor is 1 not 1.25.

11.6 Units on the left side of equation are incorrect. The results as calculated will be in terms of micrograms per gram, NOT micrograms per kilogram

. 12.1 How the MDL is calculated needs to be added. Eliminate section 12.2 and add to section 12.1.

12.3 The procedure followed for calculating the IDL is not the one described in either methods 200.8 or 1638, the two methods on which this SOP is based. Was this intended? I f so an explanation of why this approach ( i.e.
, average over three non

- consecutive days multiplied by three) is required should be given.

12.4 This section has a wkward and confus ing wording

. Revise and clarify this section. See also note A.7.

12.5 This section includes an a mbiguous reference to analyst using ICVs from four distinct analytical sequences. Can they all be on the same day? What are the criteria?

16 The a ttachment list shows 1 through 8 , but other a ttachments not included on this list are referenced in the body of the draft SOP.Mr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 14

Sec. # Comment/Question

Attachment 2 The attachment s hould include additional internal standards ( e.g. , Ga, Rh, Bi, Ho, Tb) to provide backups for those internal standard elements that may be present in FGD
wastewaters. It needs a sta tement that internal standards may be present “naturally” in some FGD wastewaters. For example, scandium will be present in some FGD matrices. Need a statement on when and how to substitute (see notes 4.3 and 10.4.3).

Attachment 3 Change footnote 2 to re ad that preservation should NOT be performed in the field. Preservation should be performed by the receiving laboratory under clean room conditions. Change footnote 4 to read within 15 minutes of sample collection as specified in the April 2007 method upd ate rule.

Attachment 4 Revise as per note 10.4.3.

In summary, I would like to emphasize three major points. First, it is essential that EPA validate the data generated using the draft S OP with independent methods that were performed in the blind . We u rge EPA to make this comparison before using the draft SOP for any additional sampling. Second, UWAG has significant concerns that commercial labs will not be able to implement the SOP as written . These comments contain detailed recommendations for impro ving the SOP, and we think it is well worth the time and effort to improve the SOP now, before it is used for any analyses related to the rulemaking. Third, the quality control approach spelled out in the SOP is not robust enough for FGD wastewaters. As we have been emphasizing for several years, FGD wastewaters present a significant analytical challenge that merits additional QC to ensure accurate results.

Please call me if you would like to discuss these comments.

Sincerely,

Donna B. Hill Chair, Ef fluent Guidelines Committee

cc: Mr. Lemuel WalkerMr. Ronald P. Jordan Mr. Richard W. Reding March 19, 2010 Page 15

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