November 25, 2014

Paul Lewis Chief, Chemical Information and Testing Branch Office of Pollution Prevention and Toxics USEPA Headquarters William Jefferson Clinton Building 1200 Pennsylvania Avenue, N. W. Washington, DC 20460 Re: Follow up to November 17, 2014 Meeting Testing Consent Orderfor Octamethylcyclotetrasiloxane (D4) CASRN 556
-67
-2 40 C.F.R. 799.5000; EPA
-HQ
-OPPT
-2012
-0209
Dear Paul, The Silicones Environmental, Health, and Safety Center (SEHSC) and the signatory companies to the Enforceable ConsentAgreementforEnvironmental Testing for Octamethylcyclotetrasiloxane (D4) CASRN: 556
-67
-2 (ECA) appreciate the U.S. Environmental Protection Agency’s (EPA)’s collaborative engagement during the November 17, 2014 meeting discussing the implementation of the ECA. We thank you for the opportunity to discuss our progress in moving the monitoring program forward and strategies for meeting program challenges. We look forward to continued dialogue and cooperation throughout the D4 monitoring program to meet our shared goal of collecting a robust data set as well as share and support the implementing concepts expressed in the meeting for effectiveness and efficiency

. We are providing this letter to summarize the key outcomes of the meeting. POTW Identification SEHSC reported that 5 residential and 4 industrial sites have agreed to participate inthe monitoring program and have signed site access agreements. SEHSC noted that at least 3 POTWs have expressed an interest in participating in the program, and might be inclined to formally agree to participate if they received a letter of encouragement from EPA. EPA agreed to use the template letter previously provided by SEHSC to develop an encouragement letter that will be sent to POTWs to encourage their participation in the program. The template encouragement letter is included in Appendix I ofthis letter. The contact information for those POTWs that requested an encouragement letterfrom EPA is included in Appendix II of this letter

. EPA also agreed to send a letter of appreciation to those POTWs that have agreed to participate in the program. The template POTW appreciation letter is included in Appendix III ofthis letter. The contact information for the 9 POTWs that have already agreed to participate in the program is included in Appendix IV ofthis letter

. EPA also expressed a willingness to participate in a phone call or webinar with POTWs to address questions or concerns about the program with the aim of encouraging participation

. We look forward to working with EPA in engaging POTWs to encouragePage 2 of 7

those that have yet to agree to participate, and to thank those POTWs that have agreed to participate in the program. Site Study Plans / Quality Assurance Project Plan (QAPP) EPA reviewed the “initial comments” it provided via letter dated October 31, 2014 on the draft Study Plan submitted by SEHSC on August 8, 2014 for the four direct discharge sites. EPA also provided some initial feedback on the draft QAPP submitted by SEHSC on October 1, 2014 and indicated that written comments would be forthcoming by the end of this month. SEHSC reviewed some of the challenges that were encountered during a field training exercise that was designed to provide the field technicians with practical experience with identifying, securing, handling, tracking, and shipping the field samples for the program. These included such items as identification ofthe mixing zone for surface water and benthic organism sampling, collection of benthic samples, and weather disruptions that caused delays in sampling scheduling. There was agreement that the study plans should include appropriateflexibility to allow field personnel sufficient discretion for sample collection, and include sufficient detail regarding methodological optionsfor sampling for issues such as how far from mixing zone to collect samples and how long to look for samples when they are difficult to locate. It was noted that when challenges are encountered in the field that impact data quality and/or the program schedule, those challenges should be communicated as soon as possible to EPA

. Health Ngo was identified as the primary EPA contact for field sampling issues. Program Quality and Schedule In recognition of the unique challenges that can be associated with environmental monitoring programs, Jeff Morris indicated that the Agency would adopt a change process for the D4 ECA to accommodate potential future challenges regarding data quality and/or the program schedule. The request for a change process must include three elements: 1. Description of incident, 2. Identification ofappropriate remedy, 3. Determination of impact on program timing. EPA agreed that this change process will be used to accommodate the signatory company’s intent to submit a complete Study Plan and updated QAPP for all 14 sites (i.e., 4 direct discharge locations and 10 POTWs) by February 1, 2015. These documents would address and incorporate, as appropriate, the “initial comments” provided by EPA on the draft Study Plan for 4 Direct Discharge Sites and those expected to be provided shortly by EPA on the draft QAPP. EPA expressed a willingness to modify the ECA schedule to accommodatethe proposed change in submission date for the complete Study Plan and QAPP. SEHSC will submit a formal request under separate coverfor a letter of approval from EPA forthis change in schedule consistent with 40 C.F.R. 790.68.

* * *Page 3 of 7

Please do not hesitate to contact me directly ifyou have questions or ifany por tions of this summary are not consistent with your view of the meeting. We look forward to continue to work with the Agency throughout completion of the D4 ECA monitoring program.
Sincerely,

Karluss Thomas Sr. Director, SEHSCPage 4 of 7 Appendix I Template POTW Encouragement Letter Dear [Wasterwater Treatment Plant Owner/Operator], In partnership with the U.S. Environmental Protection Agency (EPA), members of the silicones industry have agreed to conduct environmental monitoring for a silicone material known as Octamethylcyclotetrasiloxane (D4). Ultimately, EPA intends to use this data in an ecological risk assessment for D4. To obtain sound, accurate, and representative data for the D4 assessment, we would encourage you to allow your wastewater treatment plant (WWTP) to serve as a monitoring location for this study. Under the agreement between EPA and the silicones industry, environmental monitoring will be performed at select locations throughout the U.S., including atWWTPs that primarily serve residential customers as well as atWWTPs that serve industrial dischargers that process or formulate with D4. Industry already has received a participation commitment from severalWWTPs. In an effort to secure the additional plants required to meet the program testing requirements, your WWTP has been identified as a candidate to be a monitoring location. To be clear, this testing is narrowly focused, minimally intrusive, and should not interfere with your plant’s normal operations. This program will focus exclusively on the fate of D4 in wastewater. The silicones industry has hired a consultant with extensive experience in this field to perform the monitoring. They should only need access to your site three times: once for an initial site visit to confirm sampling locations/logistics and twice to conduct the actual sampling (two events at least 3 months apart during normalWWTP operations). During the two sampling events, they would sample influent, effluent (at the compliance point), and biosolids at the WWTP and biota, surface water, and sediment in the receiving waters (i.e., where the effluent and river are well mixed). D4 will be the one target analyte (no other chemical speciation will be performed). In order for EPA and industry to gain a fuller understanding of the environmental fate of D4, we are depending on the cooperation ofWWTPs like yourfacility. The success of this D4 monitoring program hinges upon the voluntary participation ofwastewater treatment plants. Without you, the silicones industry simply cannot produce the data needed for EPA to conduct a complete assessment of D4. Therefore, your role in this undertaking cannot be overstated. EPA will formally recognize WWTPs participation at the conclusion of sampling. More broadly, health and environmental safety are a shared responsibility. In our agency’s efforts to be better informed about the safety profile ofa variety of substances, we depend on voluntary partnerships. I hope you will agree to participate in this process and help EPA and industry generate additional data to better protect our environment. I hope yourfacility will agree to participate in this program when contacted by the consultant. Should you have any questions or concerns, please do not hesitate to contact________. Thank you for your support. Sincerely, Gina McCarthy Administrator USEPAPage 5 of 7 Appendix II Contact Information for POTWs Requesting Encouragement Letter

Site Contact & Address Southport WWTP Jamie Dillard 3880W Southport Indianapolis, IN 46217 317
- 927
- 6431 City ofWinston
-Salem Frank Crump 2801 Griffith Rd Winston Salem, NC 27103 336
-727
-8000 HopewellWWTP Jeanie Grindstaff 231 Hummel Ross Road Hopewell, VA 23860 P: (804) 541
-2210Page 6 of 7 Appendix III Template POTW Appreciation Letter
POTW Operator 5 Sunshine Lane Clearwater, FL 23456

Dear POTW Owner/Operator: On behalf of the United States Environmental Protection Agency (USEPA), I would like to thank you for participating in the environmental monitoring program for Octamethylcyclotetrasiloxane (D4). The data generated as part ofthis program will support the development of a risk assessment for D4 which USEPA will use to assess its safety. The risk assessment is part of the EPA’sWork Plan Chemical program which is an essential element of the Agency’s priority work programs. The Agency very much appreciates your willingness to be a part of this program, and I am personally grateful for your cooperation and willingness to engage with USEPA and industry to ensure national efforts to reduce environmental risk are based on the best available scientific information

. Sincerely,

Gina McCarthy Administrator USEPAPage 7 of 7 Appendix IV POTWs that Agreed to Participate and Require Appreciation Letters

Site Name Location (Address) Contact Information Name, Phone# and Email The City of Gresham Wastewater Services 20015 NE Sandy Boulevard Portland, OR 97230 Alan Johnston (503
-618
-3450) Boulder, COWWTP 4049 N. 75th Street Boulder, CO 80301 Chris Douville (303
-413
-7341; douvillec@bouldercolorado.gov) Lexington, KY (Town BranchWWTP) 301 Lisle Industrial Avenue Lexington, Fayette County, KY 40511 Mark Stager (859
-425
-2413; mstager@lexingtonky.gov) Anthony Ragnone Treatment Plant (ARTP), Genesee County, MI 9290 Farrand Road Montrose, Michigan 48457 Joe Goergen (810
-232
-7662 ext.2222;jgoergen@gcdcwws.com) Steamboat Springs WWTP 39565 Routt County Road #33 Steamboat Springs, CO 80477 Gilbert Anderson (970
-879
-7700; wwtp@steamboatsprings.net) City of ElmhurstWWTP 625 South Route 83 Elmhurst, IL 60126 Dan Rosenwinkel (630
-530
-3099; Dan.Rosenwinkel@elmhurst.org) South Iowa CityWWTP 4366 Napoleon Street SE Iowa City, IA 52240 Al Figueroa (319
-356
-5170 ext 6103; albert
-figueroa@iowa
-city.org) WichitaWWTP 2305 E 57th Street Wichita, Kansas 67216 Mark Bradshaw (316
-303
-8703; mbradshaw@wichita.gov) Jackson PikeWWTP 2104 Jackson Pike Columbus, OH 43223 Jeff Hall (614
-645
-3248 ext 2211; JAHall@columbus.gov)