UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20 460

Mr. Karluss Thomas Senior Director 

### AUG 18 Z014

Silicones Environmental , Health , and Safety Center American Chemistry Council 700 2nd Street N.E. Washington, D.C. 20002 OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

Re: Testing Consent Order for Octamet hylcyclotetrasiloxane CD4) (CASRN: 556

- 67

-2; 40 C.P.R. 799.5000; EPA-HQ-OPPT- 2012-0209) Dear Mr. T homas: This letter is in response to your June 27 , July 23, and August 1, 2014, let ters requesting a modification in the schedule for delivery of the Study Plan to the U.S. E nvironmental Protection Agency (EPA) for the Testing Program set out in the April4 , 2014, Enforceable Consent Agreement (ECA) for Environmental Testing for Octamethylcyclotetrasiloxane (D4) between EPA and five manufacturers ofthe chemical (the ECA Signatory Companies). As you know, the Study Plan was due to the EPA by August 2 , 2014, (as per the ECA, § IX.A
... no more than 120 days after the effective date), w ith subsequent Qua lity Assurance Project Plans (QAPP) due to the EPA by October I , 2014 (as per the ECA, § IX.A
...no more than 180 days after the effective date). The S ili cones Environmental, Health, and Safety Center (SEHSC), in its role as Principal Tes t Sponsor for the ECA Signatory Companies, requested by the letters noted above , that the deadli ne for submission of the Study P lan be extended to April 2 , 2015, based on the amount of time needed to identify and secure the cooperation of the requisite wastewater treatment plants (WWTP) that meet the criteria specified in the ECA
. These chall enges were discussed during a July 15 , 2014 , meeting between the EPA , the SEHSC , and the ECA S ignatory Companies. At the meeting, and in your letters, the SEHSC and the ECA Signatory Companies acknowledged that site access agreements and Study Plans have been completed for four direct discharge sites
. On August 8 , 20 I 4 , the SEHSC and the E CA Signatory Companies submitted a Study Plan address ing sampling at the four d irect discharge sites
. The SEHSC has asked that the ECA schedule be modified to allow an amended Study Plan addressing the remaining ten third party WWTPs to be monitored and amended QAPP be submitted by April2, 2015
.

Internet Address (URLJ • hrtp.//www epa gov Recycled/Recyclable • Prmted With Vegetable Otl Based Inks on 100% Postconsumer Process Chlorine Free Recycled PaperThe EPA has carefully reviewed your propos ed modification to the schedule. The SEHSC and the ECA Signatory Companies have had many months to secure WWTP cooperation and it is not clear that a six month delay will, by itself, resu lt in obtaining such cooperation. Therefore, the EPA is denying your request. The EPA expects the SEHSC and the EPA Signatory Companies to continue to make a good faith effort to secure the cooperation of third party WWTP operators, or to propose an alternative approach that will achieve the objectives of the ECA. If you have any questions, please contact Heather Njo of my staff at 202-564-2574 or at njo.heather@epa
.gov . Sincerely,

# WVvt~~ ' / V
.... Wendy Cleland-I-Iamnett, Director**~** Office of Polluti on Prevention and Toxics