Page 1 700 2nd Street NE, Washington, DC 20002 | (202) 249. 7000 Via E lectronic M ail

June 2 7 , 2014

Mr. Jim Jones

Assistant Administrator Office of Chemical Safety and Pollution Prevention USEPA Headquarters 1200 Pennsylvania Avenue, N.W.

Mail Code: 7101M Washington, DC 20460

Re: Proposed Modification to Schedule to Submit Study Plan Testing Consent Order for Octamethylcyclotetrasiloxane (D4) CASRN: 556

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- 2 40 C.F.R. 799.5000; EPA

- HQ

- OPPT

- 2012

- 0209

Dear Mr. Jones:

The Silicones Environmental, Health and Safety Center (SEHSC), in its role as Principal Test Spo nsor 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 request for modification in the schedule for delivery of the Study Plan to the U.S. Environmental Protection Agency (EPA or Agency) for the Testing Program set out in the ECA. This follows on my recent discussions with Paul Lewis. In particular, SEHSC is requesting that the deadline for submission of the draft Study Plan be

extende d to April 2, 2015. 1 Although SEHSC, the Signatory Companies and their contractors are and have been working diligently to meet the existing August 2, 2014 deadline, additional time will be required to secure the cooperation of the requisite number of qua lified wastewater treatment plant (WWTP) locations to participate in the Testing Program.

Appendices 2 and 3 of the ECA state that “ [p]rior to including a specific location in the Study Plan, the Signatory Companies shall secure, as necessary and appro priate, a letter of cooperation/access from the person with control of the location. These letters will be included in the Study Plan. ” The dual tasks of identifying, and of obtaining a signed letter of cooperation from WWTP locations that meet the eligi bility criteria specified in the ECA is proving quite challenging. It has been very difficult to identify WWTPs that meet all of the criteria: they receive effluent from D4 processing sites; use only activated sludge but no other tertiary treatment besid es secondary clarification or disinfectant (unless agreed to by EPA); meet all other criteria specified in Appendix 2; and are also willing to participate in the Testing Program. Thus far, when we have successfully identified a qualified site, the owners/ operators of the WWTPs have often

1 SEHSC provides this written request for a modification of the schedule in accordance with Sec tion IX of the ECA and 40
C.F.R. § 790.68. Section IX.A of the ECA specifies that a Study Plan prepared pursuant to the ECA must be submitted within 120 days of the effective date of the ECA and at least 45 days prior to the initiation of testing. The ef fective date of the ECA is April 4, 2014, which means the Study Plan is due to EPA August 2, 2014. With the proposed modification, the due date would be extended by 8 months to April 2 , 201 5. The proposed extension is based on the amount of time it has b een taking to identify and secure in writing the cooperation of the third party wastewater treatment plant locations that meet the criteria specified in Appendices 2 and 3 of the ECA.Page 2 700 2nd Street NE, Washington, DC 20002 | (202) 249. 7000 declined to participate in the Testing Program. Further, based on informal vetting of candidate sites with EPA, the Agency, to date, has expressed an unwillingness to accept any sites with tertiary treatment

other than di sinfection.

Notwithstanding these challenges, aggressive efforts are continuing to identify qualifying WWTPs that are willing to participate in the Testing Program. However, given the progress to date and the need to negotiate access agreements/letters of cooperation with the owner/operators of the WWTPs, meeting the August 2 nd deadline for Study Plan submission will be impossible absent a dramatic change in affairs.

We are mov ing forward with the preparation of the Study Plan, including detailed Samp ling Plans, for the four direct discharge sites specified in Appendix 1 of the ECA. Importantly, for the ten WWTPs locations described in Appendices 2 and 3 of the ECA, it is not practical or, with respect to certain information, even possible to prepare the detailed Sampling Plans required to be included for each site in the Study Plan until they have agreed to participate in the Testing Program.

SEHSC has been communicating regularly with Paul Lewis and Heather Njo at the EPA to keep the Agency info rmed of progress and challenges in carrying out the Testing Program. A face

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- face meeting has been scheduled with EPA staff on July 15 th to discuss in greater detail the Testing Program challenges and opportunities to facilitate the development of the S tudy Plan and Quality Assurance Project Plan (QAPP). We are optimistic that this meeting may lead to progress in identifying and securing the cooperation of WWTPs so that the referenced documents can be completed. In the meantime, we are submitting this letter to provide the Agency with formal, written notice of the extension
request.

Should you have any questions or desire further information, please do not hesitate to contact me. We look forward to continuing to work with your staff to effecti vely implement the ECA and achieve the goals of the Testing Program.

Sincerely,

Karluss Thomas

Sr. Director

cc: Paul Lewis (EPA) Heather Njo (EPA)