### Second e-mail Gomez-Taylor.Maria to: Harry B McCarty 10/04/2011 01:37 PM

----- Forwarded by Maria Gomez-Taylor/DC/USEPA/US on 10/04/2011 01:36 PM

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From: "Tyler Martin" <tyler.martin@ossmaine.com> To: Maria Gomez-Taylor/DC/USEPA/US@EPA, <dean.smith@ossmaine.com> Cc: <carl.tripp@ossmaine.com>, Denis Borum/DC/USEPA/US@EPA, Maryt Smith/DC/USEPA/US@EPA Date: 10/19/2010 11:21 AM Subject: RE: Request for Information

Maria,

Per our conversation of 10-18-2010, I have attached OSS's data for extending the number of matrices for which D7575 has been compared to EPA 1664A. We are quite happy with the results of testing these other matrices, particularly the restaurant samples for which we have received several questions. There are three sets of data in the attached spreadsheet along with charts to aid in visually comparing results. Please contact us with questions regarding this set or any of the other data.

At this point we are done sending data and information unless you get back to us with further requests for information. Please let us know if you still need more details of outlier removal, etc.

Regards, -Tyler

Tyler Martin, Ph. D. Senior Research Engineer OSS - Orono Spectral Solutions 983 Stillwater Ave., Old Town, ME 04468 PHONE: 1-857-277-7843 (direct line) PHONE: 1-866-269-8007 (toll free) FAX: 1-866-660-4759 EMAIL: tyler.martin@ossmaine.com WEB: www.ossmaine.com

------------------------------------------------------- Please be advised that this email may contain confidential information. If you are not the intended recipient, please do not read, copy or re-transmit this email. If you have received this email in error, please notify us by email by replying to the sender and by telephone (call us at +1 866-269-8007) and delete this message and any attachments. Thank you inadvance for your cooperation and assistance

. -----Original Message----- From: Tyler Martin [mailto:tyler.martin@ossmaine.com] Sent: Friday, October 15, 2010 4:24 PM To: 'Gomez-Taylor.Maria@epamail.epa .gov'; 'dean.smith@ossmaine.com' Cc: 'carl.tripp@ossmaine.com'; 'Borum.Denis@epamail.epa.gov'; 'Smith.Maryt@epamail.epa.gov' Subject: RE: Request for Information

Maria,

I have tried to contact you with some questions, but we decided to start sending what information we have ready at this time. This is not the complete data to meet your request of item 1 below. Instead, this is a start to address what you have asked for.

-'SLV_Lab_Sheets_Raw_Data' contains the single laboratory reports directly from the lab that performed the study, as no anonymity was requested or granted for this study. -'MLV_Lab_Sheets_Noteboooks' contain the multi-lab validation raw data,

as requested in item 2 of your email. Names and identifying info are redacted. -'Expanded ASTM D7575 Validation Report - for EPA 10-15-2010' is an expanded version of the D7575 validation report that is in the docket for the recent method update rule. The replicates have been compiled for the MDL, IPR, and QC work in both single and multi lab studies in Appendix C, as requested. Appendix D has only a slight change describing sb in more detail. The main body text and tables did not change at all. -'Comparability - SLV complete' contains a step-by-step walkthrough of the comparability statistics from the single lab validation

Again, we realize that the attachments do not satisfy all of your requests. However, we did not want to take any longer to start providing information, and we are also hoping to get some feedback from you. The Comparability statistics are laid out in great detail, and we would like to know if this is sufficient info in a good format, and if this level of detail is needed for all other calculation steps, as it is quite time consuming. Please let us know your thoughts.

Answers to your other questions:

3. Grubbs test was applied to the difference between log-transformed triplicate means of each method.

4. A single RMSD assessment was applied to all data from the single lab validation simultaneously.5. I found the current guidance on 1664 available online at http://www.epa.gov/waterscience/methods/ method/oil/1664guide.pdf a bit easier to follow. Page 2-4 describes the MSE in detail. It is the mean of the variances of the log-transformed replicates calculated for each sample/matrix/method.

6. The Comparability file shows in detail: for j=number of samples, i=number of test methods, and k=number of replicates; df1=j, df2=i*j*(k-1). These exact values varied a bit as outliers were excluded.

7. The true values were determined by OSS personnel, who were the experts in the method D7575. As approved by the relevant ASTM committees and agreed to by Mr. Redding and Mr. Walker, EPA 1664 was not performed on these samples.

We hope this is a good start, and look forward to hearing from you. Regards, -Tyler

Tyler Martin, Ph. D. Senior Research Engineer OSS - Orono Spectral Solutions 983 Stillwater Ave., Old Town, ME 04468 PHONE: 1-857-277-7843 (direct line) PHONE: 1-866-269-8007 (toll free) FAX: 1-866-660-4759 EMAIL: tyler.martin@ossmaine.com WEB: www.ossmaine.com

------------------------------------------------------- Please be advised that this email may contain confidential information. If you are not the intended recipient, please do not read, copy or re-transmit this email. If you have received this email in error, please notify us by email by replying to the sender and by telephone (call us at +1 866-269-8007) and delete this message and any attachments. Thank you in advance for your cooperation and assistance.

-----Original Message----- From: Gomez-Taylor.Maria@epamail.epa.gov [mailto:Gomez-Taylor.Maria@epamail.epa.gov] Sent: Friday, October 08, 2010 11:27 AM To: dean.smith@ossmaine.com Cc: carl.tripp@ossmaine.com; tyler.martin@ossmaine.com; Borum.Denis@epamail.epa.gov; Smith.Maryt@epamail.epa.gov Subject: Request for Information

Hello Mr. Smith,

We asked our contractor to start reviewing the single-laboratory and multi-laboratory validation studies for ASTM Method D-7575-10. After preliminary review of the reports, the contractor is requesting thefollowing information. I know that you are already assembling information I requested earlier this week. The specific information requested below would help expedite the contractor's review.

1. An Excel spreadsheet or spreadsheets containing data from the single-and multi-laboratory studies with cell formulas for calculations of the intermediate and final statistics presented in the report. Examples of intermediate and final statistics being requested are: a. Details on any data transformations and outlier removal, b. Step-by-step calculations of the RMSD and RMSDmax, c. Calculation of the variance components, including sb, used in the calculation of the multi-lab acceptance criteria.

This information will allow the contractor to mathematically trace conclusions and statements in the report to the data.

2. Copies of the completed reporting forms in Appendix A with the laboratory name and other identifying information redacted.

Specific questions regarding single-laboratory validation:

3. In the description of the method comparability calculations in Appendix D, it is stated that "outliers in deviation between the methods are removed. Two Grubbs outliers were found: Day 1 of the seven day POTW study failed at the 97.5% significance level and subsequently Day 5 failed at the 95% significance level." What specific values were the outlier tests applied to; i.e., were the tests applied to individual results, the replicate means, the difference between the means of the log-transformed values, the square of the difference between the means of the log-transformed values, or a different set of values?

4. Was a single RMSD assessment performed using all data shown in Tables C-1 to C-3 (other than those that were removed as outliers, or removed due to being below the ML), or were the data in Table C-3 assessed separately?

5. How was the value of s2 (as given in the formulas for the RMSD assessment shown in Appendix C of the 1995 Freon Replacement study report) calculated; e.g., as the Mean Squared Error calculated by fitting an ANOVA model, the mean of the variances of the replicates calculated for each sample/matrix/method, or following some other calculation?

6. What were the numerator and denominator degrees of freedom used for the F-statistic in the RMSD assessment?

Specific question regarding the multi-laboratory validation report:

7. In Tables C7 and C8, how were the true values known?

_______________________ Please let me know if you have any questions.

Regards,

Maria Gomez-Taylor, Ph.D. 1200 Pennsylvania Avenue N.W. Washington, D.C. 20460 Phone: 202-566-1005E-mail: gomez-taylor.maria@epa

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