### Page 1 700 2nd Street NE, W ashington, DC 20002 | (202) 249. 7000

Via CDX and Electronic Mail
January 20, 2015 Mr. Jeff Morris Deputy Director for Programs Office of Pollution Prevention and Toxics USEPA Headquarters Wi lliam Jefferson Clinton Building 1200 Penns yl vania Avenue, N. W. Mail Code: 7401M Wa shington, DC 20460

Re: Request for Schedule Modification

– Change in Deadline to Submit Study Plan Testing Consent Order for Octamethylc yc lotetrasiloxane (D4) CASRN: 556

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- 2 40 C.F.R. 799.5000 EPA

- HQ

- OPPT

- 2012

- 0209 Dear Mr. Morris: The Silicones Environmental, Health and Safety Center (SEHSC), in its role as Principal Test Sponsor for the Signatory Companies to the Enforceable Consent Agreement for Environmental Testing for Octamethylcyclotetrasiloxane (D4) CASRN: 556

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- 2 (ECA), is submitting this written request for modification in the schedule for delivery of the Study Plan to the U.S. Environmental Protection Ag ency (EPA or Agency) under the ECA. This submission follows on our prior communications with EPA regarding this matter and is being made pursuant to Section IX of the ECA and 40 C.F.R. 790.68. By this letter, SEHSC is formally requesting that the deadl ine for submission of the Study Plan specified in Section IX.A of the ECA be changed from “no more than one hundred twenty (120) day s after the effective date of the ECA” to “no later than February 2, 2015.” 1 As explained further below, we do not believe the requested modification would significantly change the overall schedule for completing the ECA Testing Program. **Background** In June 2014, SEHSC notified EPA of the challenges it was experiencing in identifying and securing the cooperation of third par ty wastewater treatment plants (WW TPs) to participate in the Testing Program set out in the ECA. At that time, SEHSC formally requested that the deadline for submission of the draft Study Plan be extended to April 2, 2015. 2 SEHSC and representatives of t he Signatory Companies met with EPA on July 15, 2014 to discuss the extension request, SEHSC’s progress on completing ECA tasks, and opportunities for collaboration between SEHSC and EPA to facilitate completion of the Testing Program. During the meeting, SEHSC presented data and other information regarding the length of time it had been taking to secure qualified sites. Following the me eting, SEHSC submitted letters to EPA on July 23, 2014 and on August 1, 2014 which reiterated the extension

1 February 1, 2015, which was the submission date referenced during the November 17, 2014 meeting and in our November 25, 2014 lette r falls on a Sunday; hence, this formal extension request references the submission date as Monday, February 2, 2015. 2 See June 27, 2014 Letter from Karluss Thomas (SEHSC) to Jim Jones (EPA). As noted in the letter, the proposed duration of the extensi on was based on the amount of time it had been taking to identify and secure written cooperation of third party WWTP locations meeting the criteria specified in Appendices 2 and 3 of the ECA.Page 2 700 2nd Street NE, W ashington, DC 20002 | (202) 249. 7000

request. 3 A nd, in the interest of keeping the Testing Program moving forward, SEHSC submitted a partial Draft Stud y Plan to EPA on August 8, 2014 that addressed monitoring at the four direct discharge sites specified in the ECA which are locations controlled by the S ignator y Com panies. EPA notified SEHSC of the Agency’s denial of the extension request by letter dated August 18, 2014, which stated that from the Agency’s perspective, “SEHSC and the ECA Signatory Companies have had many months to secure WWTP cooperati on and it is not clear that a six month delay will, by itself, result in obtaining such cooperation.” 4 Notwithstanding this denial, SEHSC continued its good faith efforts to secure the cooperation of WWTPs and to mo ve the ECA Testing Program forward. On October 1, 2014, SEHSC submitted a timely draft Quality Assurance Project Plan (QAPP) and 6

- mo nth Interim Progress Report to EPA. And, it continued to work on securing qualified WWTP s, preparing the pertinent portion of the Study Plan for those sites, an d completing other tasks related to the ECA ( e.g. , laboratory certification, field training, etc. ). On November 17, 2014, SEHSC and representatives of the ECA Signatory Companies met with EPA to discuss im plem entation of the ECA. During the meeting , SEHSC reported that it had been able to secure the cooperation of nine (of the required ten) third party WW TPs. 5 Based on this progress, SEHSC indicated that it anticipated being able to provide a complete Study Plan and updated QAPP for all sites by Fe bruary 1 , 2015 6 . In the meeting, EPA expressed a willingness to modify the ECA schedule to accommodate the proposed change in submission date for the complete Study Plan and QAPP. As follow up to the November 17, 2014 meeting, SEHSC submitted a letter to EPA summarizing the discussions. 7 This letter reiterated SEHSC’s intent to submit a complete Study Plan and update QAPP for ECA sites by February 1 , 2015 8 and noted that SEHSC would be submitting a formal request for a letter of approval from EPA for the schedule change consistent with 40 C.F.R. 790.68. Importantly, in late December, SEHSC secured the cooperation of a tenth WWTP to meet the requirements of the Testing Program. This present letter constitutes SEHSC’s request for a schedule modification a nd is based on this progress and the proposed schedule discussed during our November 17 meeting with the Agenc y. **Rationale** As detailed in our prior correspondence and meetings with the Agency, the process of identifying and securing the cooperation of t hird party WWTPs to participate in the ECA Testing Program has been challenging and has taken mu ch longer than what was contemplated at the time the ECA was agreed upon. 9 Many W WT P operators expressed a reluctance to participate and it has been a time

- con suming and labor

- intensive process to obtain sufficient data to validate that sites willing to participate potentially meet the criteria specified in the ECA. In the face of these challenges, the Signator y Com panies through their Test Sponsor and contract or have worked diligently and expended significant resources to line up the required number of WWTP s. Wi th the requisite number

3 See July 23, 2014 and August 1, 2014 Letters from Karluss Thom as (SEHSC) to Jim Jones (EPA). The August 1 st letter also referenced Section XVI of the ECA which provides that: The Signatory Companies shall make a good faith effort to secure the cooperation of third parties (such as WWTP operators) as needed to complete the Testing Program under this ECA. How ever, the Signatory Companies are not responsible for the action of third parties and shall not be held liable for any inability to secure needed cooperation and/or permission to conduct the environmental te sting specified under this ECA at locations owned, operated, and/or controlled by non

- parties to this ECA.

4 See August 18, 2014 Letter from Wendy Cleland

- Hamnett (EPA) to Karluss Thomas (SEHSC). 5 SEHSC also noted that based on feedback its contractor had been receiving from candidate sites, certain of those sites might be inclined to participate if they were to receive a letter of encouragement from the Agency. 6 See footnote 1 above. 7 See Novem

ber 25, 2014 Letter from Karluss Thomas (SEHSC) to Paul Lewis (EPA). 8 See footnote 1 above. 9 That said, from the outset, EPA, SEHSC, and the Signatory Companies recognized that the w illingness of third parties to participate in the Testing Program was be yo nd the control of the Signatory Companies, and, as reflected in Section XVI of the ECA, the Signatory Companies “are not responsible for the actions of third parties and shall not be held liable for any inabi lity to secure needed cooperation and/or permi ssion” from those parties to conduct the testing set out in the ECA.Page 3 700 2nd Street NE, W ashington, DC 20002 | (202) 249. 7000

of sites now in the fold, efforts are on

- going to finalize the Study Plan (and update the QAPP, as appropriate) to address thos e sites so that the documents can be submitted to the Agenc y for review by Februar y 2, 2015. 10 Importantly, based on our understanding of when targeted sampling conditions will likely exist at the WWTP locations ( e.g. , low flow, acceptable weather/acce ss, etc. ), the requested extension in the deadline for submission of the Study Plan for the ten WWTP locations should not prevent the overall Testing Program from being completed in approximately the same timeframe contemplated by the current ECA. As disc ussed during the November 17, 2014 meeting, it is anticipated that all field sampling ( i.e. , both sampling events required by the ECA) should be com pleted by the end of Fall 2015 as sampling during winter months would likely not be realistic at many sites. 11 The approximate time windows for the two sampling events would be May

– August and September

– November. Because the deadline for submitting the QAPP was October 1, 2014 (and the ECA provides EPA with up to 60 days to review), as a practical matter, th e first sampling event for the program would be the same ( i.e. , during the May

– August 2015 window) under either the original or revised schedule. It follows that the requested modification would not significantly impact the final reporting deadline of t he Testing Program. 12 Rather, it would assure that the ECA ma tches practical reality and reflect the significant effort the Signatory Companies have made to obtain third party WWTP s for the Program. In light of the foregoing, we respectfully request tha t the Agency grant this request and provide written acknowledgment of the same. Should you have any questions or desire further information, please do not hesitate to contact me. Sincerely,

Karluss Thomas Sr. Director

cc: Paul Lewis (EPA) Heather Njo (EPA) ECA Signator y Com panies SEHSC legal counsel

10 See footnote 1 above. 11 Actual timing will, of course, depend on numerous factors, such as weather, operating conditions and Agency approval of Study Plan and QAPP submissions, which ar e beyond the control of SEHSC or the Signatory Companies. 12 In its ECA regulations, EPA defines a significant change in schedule as one that w ould extend the reporting deadline by mo re than 12 months. The regulations provide that EPA may approve such chan ges without asking for public comment. 40 C.F.R. 790.68(b)(2).