Oil and Natural Gas Sector: Reconsideration of Additional Provisions of New Source Performance Standa rds

40 CFR Part 60 Response to Public Comments on P roposed Rule (7 9 FR 41752 ; July 1 7, 2014 )

U.S. Environmental Protection Agency Office of A ir Quality Planning and Standards Sector Policies and Programs Division Research Triangle Park, NC 27711

December 1 9 , 201 4i 

### Table of Contents 1.0 Summary
................................ ................................ ................................ ................................ ... 1 1.1 Background
................................ ................................ ................................ ........................... 1 2.0 Response to Comments
................................ ................................ ................................ ............. 9 2.1 Well Completions
................................ ................................ ................................ ................. 9 2.1.1 Initial Flowback Stage
................................ ................................ ................................ ... 9 2.1.2 Production Stage
................................ ................................ ................................ ............ 9 2.1.3 Recordkeeping and Reporting Requirements
................................ .............................. 12 2.1.4 Use of Lower Explosive Limit (LEL) Meters
................................ .............................. 13 2.1.5 Definitions Associated with Well Completions
................................ ........................... 15 2.2 Storage Vessels
................................ ................................ ................................ ................... 17 2.2.1 Applicability and Compliance
................................ ................................ ..................... 17 2.2.2 Storage Vessels Removed from Service
................................ ................................ ...... 21 2.3 Vapor R ecovery Unit (VRU) Provisions
................................ ................................ ............ 21 2.4 Alternative Compliance Option for Reciprocating Compressors
................................ ....... 22 2.5 Pneumatic Controllers
................................ ................................ ................................ ......... 24 2.6 Control Device Operating Requirements
................................ ................................ ............ 25 2.7 Exempti ons to the Equipment Leak Standards
................................ ................................ ... 25 2.8 Responsible Official
................................ ................................ ................................ ............ 26 2.9 Technical Corrections
................................ ................................ ................................ ......... 26ii Acronyms and Abbreviations CAA Clean Air Act CDPHE Colorado Department of Public Hea l th and Environment CFR Co de of Federal Regulations EPA Environmental Protection Agency LEL Lower Explosive Limit NESHAP National Emission Standards for Hazardous Air Pollutants NSPS New Source Performance Standards RTR Residual Risk and Technology Review SCFH Standard Cubic Feet Per Hour SO 2 Sulfur Dioxide SSM Startup, Shutdown and Malfunction TPY Tons P er Year VOC Volatile Organic Comp ounds VRU Vapor Recovery Unit1 

### 1.0 Summary 1.1 Background On January 14, 2009, pursuant to section 304(a)(2) of the Clean Air Act (CAA), WildEarth Guardians and the San Juan Citizens Alliance filed a Complaint alleging that the U.S. Environmental Protect ion Agency (EPA) failed to meet its obligations under CAA sections 111(b)(1)(B), 112(d)(6) and 112(f)(2) to take actions relative to the review/revision of the new source performance standards (NSPS) and the national emissions standards for hazardous air p ollutants (NESHAP) with respect to the Oil and Natural Gas Production source category. On February 4, 2010, a consent decree was entered that, as modified, required the EPA to sign by July 28, 2011, proposed standards and/or determinations not to issue sta ndards pursuant to CAA sections 111(b)(1)(B), 112(d)(6) and 112(f)(2) and to take final action by April 3, 2012. On August 8, 2011, the EPA announced (76 FR 52738) how the Agency proposed to address the reviews of the new source performance standards (NSPS ) for volatile organic compound (VOC) and sulfur dioxide (SO 2 ) emissions from natural gas processing plants. The EPA proposed to add to the source category list any oil and gas operation not covered by the current listing. This action also included propose d amendments to the existing NSPS for VOCs from natural gas processing plants and proposed standards for operations not covered by the existing NSPS. In addition, this action proposed how the EPA would address the residual risk and technology review (RTR) conducted for the oil and natural gas production and natural gas transmission and storage national emission standards for hazardous air pollutants (NESHAP). The EPA further proposed standards for emission sources within these two source categories that wer e not then addressed, as well as amendments to improve aspects of these NESHAP related to applicability and implementation. Finally, the EPA addressed provisions in these NSPS and NESHAP related to emissions during periods of startup, shutdown and malfunct ion (SSM). On August 16, 2012, the EPA published final NSPS and NESHAP for the oil and natural gas sector (77 FR49490) . The Adminis trator received petitions for reconsideration of certain aspects for the standards. On April 12, 2013, the EPA announced the ir proposed amendments to the oil and natural gas sector NSPS as a result of reconsideration of certain issues related to implementation of storage vessel provisions. On September 23, 2013 , the EPA published final NSPS rule revisions for the oil and natura l gas sector ( 78 FR 58416 ) for certain issues related to implementation of storage vessel provisions. On July 17, 2014, the EPA proposed amendments to NSPS for the oil and natural gas sectors related to certain time

- critical issues related to certain stor age vessel provisions and well completion provisions. Over ninety comment letters were received on the proposed amendments and entered into the EPA’s Air and Radiation docket assigned for this rulemaking ( docket2

number EPA

- HQ

- OAR

- 2010

- 0505). The EPA revie wed all of the comment letters entered into the docket. This document presents a summary of the public comments entered into docket EPA

- HQ

OAR

- 2010

- 0505 regarding specific issues and topics related to the development of the proposed subpart OOOO NSPS (40 C FR part 60) amendments and the EPA’s responses to those comments. This document responds to comments not addressed in the preamble to the final rule action. The EPA assigned these comments to specific categories (see Table of Contents) based on an assessme nt of the principal subject of the comment; however, some comments inevitably overlap multiple subject areas. Table 1 provides the list of comments received by docket document ID, the commenter and their affiliation. The last 4 digits of the docket documen t ID are used to identify comments summarized and responded to in this document.3

Table 1 . List of Commenters on the Oil and Natural Gas Sector: Reconsideration of Additional Provisions of

New Source Performance Standards; P ropose d Rule (7 9 FR 41752 ; July 17 , 201 4 )

Document ID Name and Affiliation Date Received
EPA

- HQ

- OAR

- 2010

- 0505

- 46 51 Tim Campbell August 14, 2014
EPA

- HQ

- OAR

- 2010

- 0505

- 4652 Jackie Raesly August 14, 2014
EP A

- HQ

- OAR

- 2010

- 0505

- 4653 Dan Boggs August 14, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4654 Dr. Richard Guldi Christine Guldi August 14, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4655 Andrew Pearce, General Manager, ACL Manufacturing August 14, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4656 John Robitalle, Vice President, Petroleum Association of Wyomin g August 14, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4657 Anonymous Public Comment August 17, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4658 Brian Jefferies, Executive Director, Wyoming Pipeline Authority August 17, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4659 Douglas Jordan, Director Corporate E nvironmental Programs, V+ Resource Development Solutions, Southwestern Energy August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4660 Duplicate of EPA

- HQ

- OAR

- 2010

- 0505

- 4658 August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4661 Veronica Nasser, REM Technologies Inc. August 18, 201 4

EPA

- HQ

- OAR

- 2010

- 050 5

- 4662 William Addison, Director, Air Pollution Control Division, Colorado Department of Public Health and Environment August 18, 20144 Document ID Name and Affiliation Date Received

EPA

- HQ

- OAR

- 2010

- 0505

- 4663 Todd Parfitt, Director, Wyoming Department of Environmental Quality Augu st 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4664 Jeff Applekamp, Vice President of Government Affairs, Gas Processors Association August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4665 Nicholas DeMarco, President, West Virginia Oil and Natural Gas Association August 18, 2014

E PA

- HQ

- OAR

- 2010

- 0505

- 4666 Gretchen Kern, Sr. Regulatory and Environmental Policy Advisor, Sustainable Development, Pioneer Natural Resources USA, Inc. August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4667 Anonymous Public Comment August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4668 Darin Schroeder and David McCabe, Clean Air Task Force et al. August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4669 Alice Edwards, Director, Division of Air Quality, Alaska Department of Environmental Conservation August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4670 Senat or Eli Bebout and Representative Tim Stubson, Select Committee on Federal Natural Resource Management of the Wyoming Legislature August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4671 Cory Pomeroy, General Counsel, Texas Oil & Gas Association August 18, 2014

EPA

- HQ

- O AR

- 2010

- 0505

- 4672 Andrew McNeill, Executive Director, Kentucky Oil & Gas Association, Inc. August 18, 20145 Document ID Name and Affiliation Date Received

EPA

- HQ

- OAR

- 2010

- 0505

- 4673 Jimmy Carlile, HSE and Regulatory Supervisor, Fasken Oil and Ranch, Ltd., on behalf of the Permian Basin Petroleum Associa tion August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4674 Ursula Rick, Manager of Regulatory Affairs, Western Energy Alliance August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4675 Duplicate of EPA

- HQ

- OAR

- 2010

- 0505

- 4665
EPA

- HQ

- OAR

- 2010

- 0505

- 4676 Duplicate of EPA

- HQ

- OAR

- 2010

- 0 505

- 4669 August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 46 77 Matthew Todd, American Petroleum Association August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 46 78 V. Bruce Thompson, President, American Exploration and Production Council August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 46 79 Jenny Y ang, Director, Environmental Regulatory Issues, ConocoPhillips Company August 18, 2014

EPA

- HQ

- OAR

- 2010

- 0505

- 4680 Duplicate of EPA

- HQ

- OAR

- 2010

- 0505

- 4656 EPA

- HQ

- OAR

- 2010

- 0505

- 4681 Larry Schweiger August 17, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4682 Bill Fe rullo August 17, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4683 Olivia Themudo August 17, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4684 Daniel Chaplain August 17, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4685 Dean Marshall August 17, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4686 Tom Blackwell August 17, 2014 EP A

- HQ

- OAR

- 2010

- 0505

- 4687 Darryl Sullivan August 17, 20146 Document ID Name and Affiliation Date Received EPA

- HQ

- OAR

- 2010

- 0505

- 4688 Patti Rogers August 16, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4689 Tom Damura August 15, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4690 Anonymous Public Comment August 15, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4691 Don Young August 15, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4692 Laura Sessions August 15, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4693 Benjamin Ketchum, Marketing Director, Greenbelt Events August 15, 2014
EPA

- HQ

- OAR

- 2010

- 0505

- 4694 Diane Hume August 15, 2014 EPA

- HQ

- OAR

- 201 0

- 0505

- 4695 Brenda Allen August 15, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4696 Robert West August 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4697 Vera Scroggins August 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4698 Fred Gustafson August 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4699 Angela Spotts Aug ust 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4700 Barbara VanHanken, Chair Sierra Club Oklahoma Chapter August 14, 2014
EPA

- HQ

- OAR

- 2010

- 0505

- 4701 Anonymous Public Comment August 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4702 Marisa Soliz August 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4703 Anne White August 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4704 Hobie Hukill August 14, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4705 Lynne and Paul Binner August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4706 Susan Tyler August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4707 Renee Nielsen August 13, 20147 Document ID Name and Affiliation Date Received EPA

- HQ

- OAR

- 2010

- 0505

- 4708 Mike Dean August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4709 Duplicate of EPA

- HQ

- OAR

- 2010

- 0505

- 4708 EPA

- HQ

- OAR

- 2010

- 0505

- 4710 Mary Cato August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4711 Rebecca Williams August 13, 2014 EPA

- HQ

- OAR

- 20 10

- 0505

- 4712 Connie Triolo August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4713 Dick Schoech August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4714 Cindy Caudle

- Dean August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4715 Eileen Barziloski August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4716 Kit Jone s, Organizer Fort Worth MoveOn Council August 13, 2014
EPA

- HQ

- OAR

- 2010

- 0505

- 4717 Audrey Gozdiskowski August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4718 Gail Neustadt August 13, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4719 Christine Guldi August 12, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4720 Sheila Purdy Native American Industries, Inc. August 18, 2014
EPA

- HQ

- OAR

- 2010

- 0505

- 4721 Peter Smith July 9, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4722 Alyssa Tharp August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4723 Chris Guldi August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4724 Tamera J. Bounds , President Woodland Estates HOA August 18, 2014
EPA

- HQ

- OAR

- 2010

- 0505

- 4725 Gary Hogan August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4726 Gerard Farias Associate Professor of Management August 18, 20148 Document ID Name and Affiliation Date Received Silberman College of Business EPA

- HQ

- OAR

- 201 0

- 0505

- 4727 Ramona Saldana

- Flores August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4728 Daniel Tartaglia August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4729 Sandra DenBraber August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4730 Becky Bornhorst August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4731 Todd Harshman August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4732 Leonard Seiler August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4733 Sinikka Di ckerson August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4734 Jerry Lobdill August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4735 Jenny Lisak August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4736 Ann Mai August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4737 Jacqueline Lansford August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4738 John Fischer October 15, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4739 Anonymous Public Comment August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4740 Susan Waskey August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4741 Tim Campbell August 18, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4742 Shelly McAllister August 17, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4743 Martha Hand August 17, 2014 EPA

- HQ

- OAR

- 2010

- 0505

- 4744 Dan Ferrell August 17, 20149 

### 2.0 Response to Comments 2.1 Well Completions 2.1.1 Initial Flowback Stage Comment: Several commenters (4651, 4652, 4653, 4654, 4657, and 4667) contend that a mix of fracking water, fracking chemicals, heavy metals, naturally occurri ng radioactive materials, and hydrocarbon compounds such as BTEX are directed into open tanks during the initial flowback stage. The commenters believe the best system of emission reduction for flowback liquids is to direct the liquids into closed, ventles s, pressurized tanks and urge the EPA to amend the proposed rule to require these tanks during flowback. Response: Pressurized tanks perform best where conditions are constant and predictable such that operating parameters for the tanks can be set and mai ntained. Several characteristics of the liquid stream during flowback are highly variable ( e.g., pressure, flow rate, solids content, or slug flow) and render the use of pressurized storage vessels technologically infeasible under most circumstances. Therefore, the EPA does not believe specifying the use of closed, ventless, pressurized tanks as a method to control emissions from these operations is warranted. 2.1. 2 Production Stage 2.1. 2
. 1 Applicability Comment: One commenter (4662) contends that the proposed rule does not distinguish what type of equipment is excluded from venting or combusting gas during the production stage, which results in confusion as to whether the temporary flowback separator or the permanent production separator is prohibi ted from using combustion as a control. Re sponse: In the final rule, we have amended the regulatory language in the well completions provisions of §60.5375 to identify two distinct stages associated with well completion, with each stage having specific r equirements for handling of gases and liquids. As amended, the flowback stage consists of two stages, the “initial flowback stage” and the “separation flowback stage.” As such, the requirements do not apply to a production separator. Comment: Two commen ter s ( 4663 , 4670 ) point out that the title of §60.5375 refers only to gas wells. However, the proposed language regarding the different stages utilizes industry terminology ordinarily associated with oil wells. For example, §60.5375(a)(1)(ii) uses the ter m “crude oil” whereas gas well operators would normally use “hydrocarbon liquid” or “liquid condensate.” The commenter recommends replacing “crude oil” with one of these alternate terms and to specifically clarify that §60.5375 applies only to gas wells. A nother commenter (4670)10

also states that §60.5375 should apply only to wells drilled principally for the production of gas, and no other type of well. Response: We are unsure as to which proposed language the commenter is referring. The language we propos ed for §60.5375, including §60.5375(a)(1)(ii) referred to by the commenter, uses the term “liquids” or “recovered liquids.” We did not use the term “crude oil” in the proposed regulatory text for this section. The only instance where we used the term “crud e oil” in the proposed regulatory text is in the definition of “production stage” in §60.5430. We note that the final rule no longer includes this definition. We did, however, repeatedly use the phrase
“ crude oil, condensate and produced water ” in the prea mble to the proposed rule in the context of storage vessels and liquids in general , regardless of whether a particular well would involve all these liquids. Although we appreciate the commenters’ concerns on the use of proper terminology, we do not believ e any confusion will result from the terminology we used in the preamble or the proposed rule language. Concerning the comment on the applicability of §60.5375, we point out that §60.5 43 0 defines a gas well as “an onshore well drilled principally for prod uction of natural gas.” 2.1. 2
. 2 Prohibition on Venting or Routing Emissions to a Combustion Device Comment: One commenter (4671) claims that the prohibition is in conflict with the storage vessel control requirements. Proposed §60.5375(a)(1)(iii) states that during the production stage, “recovered gas may not be vented or controlled by any combustion device.” Subpart OOOO requires operators to reduce VOC emissions from storage vessels (which are primarily used in production operations) by 95 percent. Con trol of storage vessel emissions is typically achieved through a combustion device. According to the commenter, combusting the gas emitted from storage vessels during production would be in apparent conflict with the prohibition on combustion in the propos ed rule, and controlling only 95 percent of emissions from the storage vessel would be in conflict with the proposed prohibition on venting gas. Response: In the final rule, we have amended the regulatory language in the well completions provisions of §6 0.5375 to identify two distinct stages associated with well completion, with each stage having specific requirements for handling of gases and liquids. As amended, the flowback stage consists of two stages, the “initial flowback stage” and the “separation flowback stage.” Provisions relating to the production stage, including §60.5375(a)(1)(iii), are not included in the final rule. Thus, the issue raised by the commenter is now resolved
. Comment: Two commenters (4665, 4677), believe the EPA’s prohibiti on on venting and combusting emissions during the production stage is related to the concern about possible use of portable frac tanks as substitutes for storage vessels after production has begun, thus delaying the11

time the 60

- day emissions and control ev aluation would begin. The commenters contend that is could be avoided, and the need to regulate production activities eliminated, by revising the definition of "well completion vessel" to add as the third sentence of the definition the following: A vesse l that is skid

- mounted or portable that continues to receive well flow from a hydraulically fractured well after startup of production of the well shall be deemed a new storage vessel for only as long as it continues to receive well flow from that well. The commenters contend that this would treat portable frac tanks as storage vessels if they were used to support production activities, but only as long as they were used in that capacity. Response: As discussed in the previous comment response, the fina l rule no longer includes provisions relating to the production stage. Therefore, the commenters’ concern about the prohibition on venting and combusting emissions during the production stage is now moot. We point out, however, that we have amended the def inition of “storage vessel” in the final rule to include the provision that “a well completion vessel that receives recovered liquids from a well after startup o f production following flowback for a period which exceeds 60 days is considered a storage vess el under this subpart ” The commenters are referred to sections III.A and IV.A of the preamble to the final rule for further discussion of these changes
. 2.1. 2
. 3 Consideration of Costs Comment: One c ommenter (4663) contends that the EPA failed to consider costs associated with the prohibition on venting and flaring, which the commenter believes is required by the CAA when determining the best system of emission reduction. Specifically, the commenter s tated that the EPA failed to consider the costs associated with the prohibition for oil wells. The EPA stated that “there will be no significant change in compliance costs as a result of this proposed rule because our analysis shows that owners and operato rs of affected facilities would install the same or similar control technologies as they would have installed to comply with the previously finalized standards.” The commenter contends that the EPA’s statement is only applicable to gas wells, which by virt ue of their purpose are already connected to sales lines for natural gas. However, there would be substantial compliance costs for oil wells due to a lack of natural gas pipeline infrastructure in areas dominated by oil wells. The commenter adds that if the proposed rule bans all venting and flaring from oil wells during the production stage, then oil well operators would be faced with the choice of installing pipelines to connect to sales lines, utilizing recovered gas as fuel on site or shutting the wel ls in until they could perform one of these options. The commenter urges the EPA to allow venting and flaring during all stages of well completion and production.12

Response: We believe the commenter is referring to the prohibition in §60.5375(a)(1)(iii) of the proposed rule on venting and flaring during the production stage. First, we point out that §60.5375 applies only to gas wells. Insomuch as the commenter is concerned about the effect on oil wells, these concerns are not relevant because §60.5375 doe s not apply to oil wells. Second, we have amended the regulatory language in the well completions provisions of §60.5375 to identify two distinct stages associated with well completion, with each stage having specific requirements for handling of gases and liquids. As amended, the flowback stage consists of two stages, the “initial flowback stage” and the “separation flowback stage.” Provisions relating to the production stage, including §60.5375(a)(1)(iii), are not included in the final rule. 2.1. 3 Rec ordkeeping and Reporting Requirements Comment: One commenter (4668) urge s the EPA to require that producers document each instance in which the infeasibility exception in proposed §60.5375(a)(1)(ii) is invoked, to include the reasons for using this excep tion in annual reports to the EPA in light of the operative regulatory criteria, and to ensure these reports are publicly available. The commenter believes the omission of this recordkeeping and reporting requirement in the current language of s ubpart OOOO is a serious compliance and enforcement deficiency , and c orrecting this deficiency will help ensure basic transparency and accountability in the use of this exception. Response: The EPA agrees with the commenter with respect to the need for operators to document exceptions to the requirements for handling gases from the separator during flowback, which consists of the initial flowback stage and the separation flowback stage
. The NSPS , at §60.5420(c) (1) (iii) , requires records of the date and time of the o nset of flowback following hydraulic fracturing or refracturing; the date and time of each attempt to direct flowback to a separator as required in §60.5375(a)(1)(i); the date and time of each occurrence of returning to the initial flowback stage under §60 .5375 (a)(1)( i) ; and the date and time that either the well was shut in and the flowback equipment was permanently disconnected, or production commenced (i.e., the “startup of production”)

. The EPA considers the se recordkeeping requirements to be necessary for enforcement personnel to clearly understand the duration of flowback and how the well completion was c onducted , including how long after the onset of flowback that attempts were made to route flowback to a separator and how many times the operator reverted to the initial flowback stage
. Comment: One commenter (4679) points out that the recordkeeping requirements for gas well affected facilities in §60.5420 (c)(1)(iii)(A) requires records of the duration of venting. According to the commenter, during the initial flowback stage, the well is not routed to any phase separation equipment capable of determining the presence of gas. As indicated by the EPA, any gas generated during the initial flowback stage will be negligible and does not warrant13

applicability under the subpart OOOO green comp letion work practice standards. Accordingly, the commenter states that no gas volumes may be measured and it would not be possible to make accurate representations of “venting” during the initial flowback stage to satisfy the recordkeeping requirement for logging the duration of venting. The commenter requests that the EPA clarify that these recordkeeping requirements apply only during the separation flowback stage. Response: We point out that the proposed language in §60.5375(a)(1)(i) states that “any g as present in flowback prior to the separation flowback stage is not subject to control under this section.” That means that operators are not required to “control” these emissions or capture them. However, any gas in the flowback that is routed to a n uncontrolled well completion vessel or storage vessel during the initial flowback stage in accordance with the requirements of §60.5375(a)(1)(i) is c onsidered to be “vented , ” and the recordkeeping requirements of §60.542 0(c)(1)(iii) to document the duration of venting would apply to the initial flowback stage , since that stage is a part of the flowback period
. As a result the initial flowback stage ( including any occurrences of reverting to that stage) would be con sidered a period of venting to be included in the total duration of venting re quired to be recorded in accordance with §60.5375( b ) and as specified in §60.5420(c) (1)(iii)
. The periods of venting, combustion and collection would account for the entire flowback period, minus any time the well was shut in. 2.1. 4 Use of Lower Explosive Limit (LEL) Meters Comment: Three commenters (4668, 4674, and 4678) support the use of an LEL meter to determine when flowback gas can be diverted to a separator. One commenter (4668) states that a recent study indicates that the methane LEL is a conservative indicator of the feasibility of separating and controlling emissions during a completion, and recommend s that the EPA explicitly define the methane concentration that signifies the end of the initial flowback period. The commenter also urges the EPA to pr ovide clear parameters regarding acceptable technologies for methane monitoring as well as the installation and calibration of such monitors. Two commenters (4674, 4678) stated that the EPA is correct that some operators use LEL meter results a s one piec e of data to determine when fluids can be routed to a separator during flowback, but this practice is not universal throughout the oil and natural gas industry. According to the commenter s , LEL meters can be used as an indication that gas is present but ar e not used as the sole determinant that a separator could operate. The commenter suggest s the EPA allow flowback crews and operators the flexibility in the methods used to determine when it is safe to route fluids to a separator. Several commenters (465 6, 4659, 4671, 4673, 4677, and 4679) oppose the use of an LEL meter. As described by one commenter (4656), LEL meters offer no empirical means from which to make th e determination of when gas can be routed to a separator . A separator requires both14

sufficie nt gas pressure and volume to operate. An LEL meter provides information on neither. Making the determination that the separation stage can begin is an experience

- based decision and flowback characteristics are variable from well to well. Two commenters (4 677, 4679) add that the sand and water content are important factors in this experience

- based decision. Requiring an LEL to make this determination could force the separation stage to occur prematurely which risks flooding the separator and lines with flui ds that need to be cleaned out. This would necessitate shutting in the well and restarting flowback which is not desirable. One commenter (4671) adds that LEL measurements are used by some operators to determine if any gas is present in the flowback, but the measurements do not inform an operator whether sufficient pressure and quantity of gas to operate a separator is present. Further, the gas content in flowback is highly variable over time, and an LEL measurement by itself is not a conclusive indicator of a steady and sufficient gas concentration and pressure. In addition, for certain well site configurations, such as those discharging to a lined earthen pit during initial flowback, the flowback is not contained in a manner where it is practical to coll ect a representative LEL measurement. Another commenter (4679) add s that LEL meter readings can vary depending on location and external influences such as wind. Due to the high variability of well behavior during flowback, including fluctuations in gas con centration and pressure, the commenter states that there is no single objective criterion relied upon by operators to signal when to begin separation. The well completion process is dependent on experienced operators to gauge when sufficient gas is present to operate a separator. The commenter does not believe i t is realistic for the EPA to proscribe objective criteria for this determination when none exist in the field. Response : We appreciate all of the informative comments on the use and function of LEL meters. As discussed in section IV.A of the preamble to the final rule, we believed that some operators used LEL meters to determine when sufficient gas is present in the flowback for the separator to function. However, we were uncertain whether this method could be used effectively in all applications and whether there were other techniques used by operators to make this determination. Based on the comments received, it is apparent that some owners and operators use LEL meters at least as an indicator that the separator can function, but other owners and operators strongly contend that LEL meters do not necessarily indicate in all situations that sufficient gas is present for the separator to function. Because whether a separator can operate may depend on site specific factors other than the amount of gas present in the flowback, we are not finalizing requirements to use a LEL meter to determine when the separator can function.15

2.1. 5 Definitions Associated with Well Completions Comment: One commente r (4677) provides the following explanations for recommended amendments to the proposed definitions. In addition, the commenter provide s revised wording for each of these definitions in their comments. Flowback . The definition of flowback should be revis ed to clarify the conditions indicating the end of the flowback period. The EPA proposed a revision to this definition stating that one condition for the end of flowback is when “the production stage begins,” which is defined as when flowback has declined and stabilized sufficiently to allow continuous recovery of the gas and to allow separation and recovery of any crude oil, condensate and produced water. This is a rather subjective threshold, and should be replaced with more determinative criteria. The ot her condition for the end of flowback in the EPA’s proposed definition is when “the well is shut in.” However, there are circumstances that require a well to be temporarily shut

- in before flowback is complete, and thus we suggest clarifying language be add ed to explain the intent of this condition. Recovered gas . While the EPA has attempted to clarify the distinction between gas recovered from the separator and gas flashed from a storage vessel or well completion vessel, there is still room for this disti nction to be misconstrued. It should be clarified that recovered gas is gas recovered from the gas outlet of the separator during flowback. Reduced emissions completion . This definition should be deleted as the term is not used in the rule. Salable qua lity gas . Certain of the requirements in §60.5375 hinge on the definition of salable quality gas . This term as defined requires that gas meet “composition, moisture, or other limits set by the purchaser of the natural gas.” This could be construed as exemp ting gas that is suitable for routing to a flow line at the well site if the gas does not meet pipeline specifications, in that the processing to meet composition and moisture limits is often done at a central facility rather than at the individual well si te. The commenter suggests this definition should be expanded so as to include all gas suitable for routing to a flow line or a collection system ( i.e. , meeting the flow line operator specifications and having sufficient pressure), and not to limit it to o nly the gas that meets gas pipeline specifications. Separation flowback stage . The revisions suggested above to clarify the end of flowback in the definition of flowback should be mirrored in the definition of separation flowback stage .16

Well completio n vessel
. The EPA has expressed a concern that liquids from a well which has been hydraulically fractured may continue to be routed to a well completion vessel after startup of production. The most direct and effective way to address this concern may be to declare a well completion vessel to be a storage vessel if it continues to receive well flow from a hydraulically fractured well after startup of production of the well, regardless of the characteristics of the vessel. This would effectively subject the v essel to the applicability determination of §60.5365(e) within 30 days after startup of production, and if determined to be an affected facility, the control requirements of §60.5395(d) within 60 days after startup of production. Response: In the final r ule, we have amended the definition of flowback to include the following provision : “ The flowback period ends when either the well is shut in and permanently disconnected from the flowback equipment or at the startup of production. ” We believe this provision provides the clarity sought by the commenter. Similar changes are also included in the definition of “separation flowback stage.” We agree with the commenter’s suggestion concerning the definition of “recovered gas” and have made the suggested amendment in the final rule , as follows : “ Recovered gas means gas recovered through the separation process during flowback. ” As suggested by the commenter, we have removed the definition of “reduced emissions completion” from the final rule because that term is not used in the rule. We agree that the proposed definition of “salable quality gas” was overly restrictive, and the changes suggeste d by the commenter would allow more gas to be routed to a flowline, which is a beneficial result. Therefore the definition of “salable quality gas” in the final rule incorporates the commenter’s suggestions as follows: “ Salable quality gas means natural g as that meets the flow line or collection system operator specifications, regardless of whether such gas is sold.” We agree with the commenter’s suggestion concerning the treatment of well completion vessels after startup of production. See section s IV.A and V.A of the preamble to the final rule for further discussion of this topic.17



### 2.2 Storage Vessels 2.2.1 Applicability and Compliance 2.2.1. 1 Initial Compliance Period for Modified or Reconstructed Storage Vessels Comment: One commenter (4664) stat es that i f a storage vessel is not an affected source due to emissions of less than 6 tpy of VOC emissions as defined and calculated under §60.5365(e), but then is modified or reconstructed such that emissions increase to 6 tpy or greater, it is unclear wh en the storage vessel must comply with the §60.5395 standards. Currently, §60.5395(d)(1)(i) allows 60 days from startup to achieve the required emissions reductions. As such, the rule should also allow 60 days from the date on which a storage vessel become s an affected facility since there may be some situations where a source becomes an affected facility long after startup occurs. The commenter suggests adding “or within 60 days of the date on which a storage vessel becomes an affected facility” to §60.539 5(d)(1)(i)
. Response : While the comment is so mewhat unclear, we read the comment as requesting that we provide that a tank that is initially determined under § 60.5365(e) to have less than 6 tpy of potential VOC emissions not be given less time than other tanks to come into compliance if circumstance s change. We are not adopting the requested language both because (1) the rule already provides for equivalent treatment in these circumstances; and (2) the requested addition would actually provide 90 days for a tank to come into compliance. To the exten t that the commenter is requesting this longer timeframe , they have not provided information to support such a deviation. Comment: Several commenters (4665, 4666, 4671, 4677, 4679) express concern that §60.5365(e) requires a redetermination of VOC emissions each time a well is connected to a given storage vessel after production has commen ced. The commenter s state that the VOC emissions analysis should only be required for new, modified or reconstructed storage vessels
. The commenters request that the EPA modify §§60.5365(e) and 60.5395(d)(1)(i) accordingly. One commenter adds that in orde r to avoid inadvertent application of the rule to tanks that receive liquids pursuant to §60.5375 but which are not new, modified or reconstructed, §60.5365(e) should be revised to clarify that applicability is triggered by construction, modification or re construction of the storage vessel. Response: In response to these and other comments on § 60.5365(e), the EPA has made several ame n dments to this paragraph (see sections III and IV of the preamble to the final rule for further discussion of these changes). In particular with regards to these com me nts, we agree that the language suggested by the commenters would add clarity and have incorporated the commenters ’ suggestion by adding § 60.5365(e)(1) as follows: “ For each new, modified or18

reconstructed storage vessel receiving liquids pursuant to the standards for gas well affected facilities in §60.5375, including wells subject to §60.5375(f), you must determine the potential f or VOC emissions within 30 days after startup of production. ” 2.2.1. 2 What Constitutes a Modification or Reconstruction for Storage Vessel s Comment: Two commenter s (4666 , 4671 ) express concern that the proposed rule is unclear as what constitutes a modification or reconstruction for a storage vessel. Th e commenter s believe that it was the EPA’s intent to require evaluati on of a storage vessel’s emissions only if it is an affected facility. The rule specifies that a storage vessel affected facility is a storage vessel with the potential for VOC emissions greater than 6 tpy and for which construction, modification or recon struction commenced after August 23, 2011. Thus, according to the commenter s , the NSPS General Provisions dictate the type of change (i.e., modification) that would subject a storage vessel to subpart OOOO because subpart OOOO does not contain a subpart

- sp ecific definition of modification. The General Provisions define modification as “any physical change or change in the method of operation of an existing facility which increases the amount of any air pollutant...or which results in the emissions of any air pollutant...not previously emitted.” The commenter s point out that the General Provisions requires both a physical change and an increase in emissions for the change to be considered a modification. Also, the General Provisions provide that an increase in p roduction rate is not a modification if it can be accomplished without a capital expenditure. The commenter s contend that existing storage vessels may experience an emissions increase from increased throughput due to fracturing, refracturing, addition of n ew wells or rerouting of existing wells; however, none of these actions will change the affected facility status of the storage vessel because of the increased production rate exempti on of the General Provisions. On e commenter (4671) adds that §60.14(e) of the General Provisions provides that an existing facility is not modified by the use of an alternative fuel or raw material if the facility was designed to accommodate the alternative fuel or raw material prior to the effective date of the rule. Existin g storage vessels, the commenter contends, are designed to accommodate recovered liquids of varying compositions. Thus, even when the liquids from new or re

- routed wells are of a different composition than what is currently routed to an existing storage ve ssel, this would not constitute a physical change or change in the method of operation. The commenter provides further support for this view by referencing a general guidance letter from OECA dated August 19, 2003 stating that a change in the liquids store d in a storage vessel does not constitute a modification (in reference to 40 CFR part 60, subparts Ka and Kb). Response: The General Provisions to 40 CFR part 60 govern what constitutes a modificatio n or reconstruction since s ubpart OOOO does not override the General Provisions in this regard. Thus, s ection 60.14 (a) of the General Provisions states that :19

Except as provided under paragraphs (e) and (f) of this section, any physical or operational change to an existing facility which results in an increase in the emission rate to the atmosphere of any pollutant to which a standard applies shall be considered a modification wi thin the meaning of section 111 of the Act. Similarly, §60.15 (b) of the General Provisions states that : Reconstruction means the replacement of components of an existing facility to such an extent that: (1) The fixed capital cost of the new components exceeds 50 percent of the fixed capital cost that would be req uired to construct a comparable entirely new facility, and (2) It is technologically and economically feasible to meet the applicable standards set forth in this part
. It is beyond the scope of this document to address whether a specific situation may constitute modification or reconstruction. Comment : One commenter (4671) states that i f the in tent of the emissions determination requirem ent of §60.5365(e) is to regulate existing storage vessels when a fractured well is connected, this significant new requirement is beyond the scope of the p roposed r ule. The existing regulation regulates storage vessels that are constructed, modified, or r econstructed after August 23, 2011. In the p roposed r ule, the commenter points out that the EPA lists four issues related to storage vessels that the Agency is addressing

– PTE determinations, thief hatches, storage vessels removed from service, and electr onic spark ignition

– but does not provide notice that it is changing the rule to regulate existing storage vessels when a new well is connected. Thus, the commenter contends that regulation of existing storage vessels, under any circumstances, is beyond t he scope of this rulemaking because the EPA did not provide adequate notice to the public of this proposed significant change. In addition, the costs and economic impacts of installing control devices on existing storage vessels, if the rule was changed t o regulate these facilities, were not considered
. Response: The introductory text to §60.5365 reads " You are subject to the applicable provisions of this subpart if you are the owner or operator of one or more of the onshore affected facilities listed in paragraphs (a) through (g) of this section for which you commence construction, modification or reconstruction after August 23, 2011. " Section 60.5365(e) applies only to facilities constructed, modified or reconstructed after August 23, 2011. Th erefore, the commenter has misinterpreted the applicability requirements and the EPA is not expanding coverage of the rule requirements to existing storage vessels
.20

2.2.1. 3 Compliance Period for Storage Vessels Comment : One commenter (4668) states t hat t he proposed amendments allow storage vessels that receive liquids from gas well affected facilities pursuant to §60.5375(a) 60 days after the beginning of the production stage to comply with the 95 percent emissions reduction requirement. Th e commente r finds this to be particularly troubling because the emissions from these storage vessels are likely to be highest during the beginning of the production stage. The commenter points out that r ecent state
- level precedent on this issue shows it is possibl e to require controls during the period that the EPA proposes to exempt. The Colorado Department of Public Health and Environment’s (CDPHE) recent revisions to Regulation 7 require controls on all storage vessels that have a PTE of 1.5 tons or more during the first 90 days of production (roughly the equivalent of 6 tpy). The CDPHE recognized that “[b]ecause production is typically at its highest during this initial period, significant emissions [occurred] before controls [were] installed.” According to the CDPHE, the tanks that would have a PTE of less than 6 tpy would still be able to control VOC emissions at a very reasonable rate of $176 per ton of VOC reduction. The regulations further allow the control to be removed at any time after the first 90 days o f production if the source demonstrates that the uncontrolled actual emissions are below 6 tpy. Based on Colorado’s precedent, the commenter request s that the EPA remove the 60

- day post production phase exclusion period for compliance with the storage ve ssel emission reduction requirements and require all storage vessels, including those that receive liquids from gas well affected facilities, to comply with the 95% VOC reduction requirement during the first 60 days of the production stage. After that time , the commenter recommends that the source could be allowed to remove the pollution control only if it is able to show that its uncontrolled actual emissions would fall below the affected source threshold. Response: As explained in the 2012 NSPS rulemaking, a 30

- day period is provided to allow the throughput to stabi lize and determine a storage vessel’s potential emissions. 77 FR 49526. For storage vessels that require control, because time is needed to acquire and install control, an additional 30 days is provided for these storage vessels to come in compliance. I d. The commenter did not dispute or otherwise comment on the EPA’s rationales for the 60

- day period but requested that the EPA eliminated this period because it is not provided in CDPHE’s regulation. While the CDPHE regulation strives to quickly implement co ntrol on larger sources of emissions , there may be c onditions and factors that may not be an issue in Colorado but are en countered in other states, which we need to consider in establishing the NSPS. For example, Wyoming requires that storage vessels be controlled within 30

- 90 days (depending on the area of the state) to allow owners and operators time to procure and installing controls. In light of the above, we reject the commenter’s request to eliminate the 60 day period.21

2.2.2 Storage Vessels Removed from Service Comment: One commenter (4665) requests that the EPA provide clarification as to what is meant by “physically isolated” as that term is used in the definition of removed from service. In particular, the commenter requests clarification on whether the term is intended to differ from “di sconnected.” Response: The definition of “removed from service” includes both “physically isolated” and “disconnected.” Therefore, the two terms were meant to convey two different criteria otherwise one of the terms would have been redundant. As used in the definition of “removed from service,” the term “disconnected” means that piping used to direct fluid into and out of the storage vessel has been physically detached from the storage vessel. The term “physically isolated” means that the storage vessel h as been moved from its former location and placed where it cannot be readily reconnected for use as a storage vessel. Further, as provided in §60.5395(f)(1) of the final rule , for a storage vessel affected facility to be considered “removed from service , ” the owner or operator must empty and degas the storage vessel and include a notification of the date of its removal from service in the next annual report. 

### 2. 3 V apor R ecovery U nit (VRU) Provisions Comment: Two commenters (4673, 4678) believe that the propose d language in §60.5365(e) is not clear and could be interpreted to state that only vessels that do not have legally and practically enforceable limitations can take into account emission reductions from the VRU when determining applicability. The commenter s request confirmation that, as stated in the preamble, it was the EPA’s intent that storage vessels with a legally and practically enforceable limitation incorporating a VRU may take the reductions into account when determining applicability, and also nee d only comply with the existing enforceable limitation and not the requirements in 60.5365(e). Response: We disagree that our intent wa s not clearly stated in the proposed language of §60.5365(e). In the proposal, the EPA clarified the language to indica te that t he potential to emit determination may exclude emissions that are controlled under a legally and practically enforceable limit in an operating permit or other requirement established under a f ederal , s tate , local or tribal authority. T he proposed rule also states that for storage vessels not subject to a legally and practically enforceable limit in an operating permit or other requirement established under a f ederal, s tate, local or tribal authority, any vapor from the storage vessel th at is recovered and routed to a process through a VRU designed and operated as specified in § 60.5365(e)( 3 ) (i) through (iv) is not required to be included in the determination of VOC potential to emit. In other words, potentially affected fac ilities have two ways to exclude potential emissions from the PTE calculation: by having a legally and practically enforceable limit in an operating permit or22

other requirement established under a f ederal, s tate, local or tribal authority; or by using a VR U operated according to the criteria in 60.5365(e)( 3 ) (i) through (iv)
. The EPA has made both these alternatives available in order to maximize incentives to capture emissions that would otherwise be emitted and use those captured emission s for a useful purpose
. 

### 2. 4 Alternative Compliance Option for Reciprocating Compressors Comment: One commenter (4668) states that while the EPA apparently intends this alternative compliance option to require beneficial use of gas escaping from rod pack ing, the commenter is concerned that the text of the proposed rule text is confusing or perhaps ambiguous and may be read to allow the emissions from rod packing to be sent to a combustion device, instead of “to a process” ( i.e., to be used beneficially). The commenter points out that the proposed regulation would require operators to “[r]oute the rod packing emissions to a process through a closed vent system and cover that meet the requirements of § 60.5411(a) and (b)”, and includes a definition for “ro ute to process
. ” However, the commenter believes that the proposed language is general and some may not realize that the specific definition of “route to process” applies, and does not allow routing to a flare. As currently worded, the proposed definition of “route to a process” includes a broadly stated provision that the commenter contends can be misinterpreted to include combustion in a flare. This confusion is more likely , according to the commenter, because the proposed rule would require operators to “design the closed vent system to route all gases, vapors, and fumes emitted from the material in the reciprocating compressor or the wet seal fluid degassing system to a control device or to a process that meets the requirements specified in § 60.5412(a) through (c).” The commenter points out that a control device can refer to a combustion device or flare. The commenter adds that s ince the alternative that the EPA proposes would not require regular rod packing replacement, the volume of gas escaping thro ugh the rod packing may become quite large if operators choose not to replace the rod packing for several years past the 26,000 hour working period required by §60.5385(a)(1). If all of these emissions are sent to a combustor or flare instead of used in a beneficial manner , the commenter believes that significant unnecessary emissions of CO 2 and combustion pollutants could result. The commenter urge s the EPA to modify the text of §60.5411 to clarify the definition of “route to a process” and provide appro priate preamble language so that it is clear that emissions must be routed to a process that involves beneficial use
. The commenter suggest s separate paragraphs for reciprocating compressor closed vent systems
. Response: The EPA disagrees that this is a possible interpretation of §§ 60.5385(a)(3) and 60.5411(a)(1). While § 60.5411(a)(1) is more general with respect to closed vent systems23

and does describe requirements for closed vent systems that route to a control device, the specific standard applicable to closed vent systems routing rod packing emissions from reciprocating compressors precludes routing to a flare, because the language directly says “to a process” without further options. The EPA considers the current definition of “route to a process” t o be sufficient as well. Comment: One commenter (4668) states that inspecting closed vent systems to ensure that emissions are contained within the closed vent system is critical. While the specific system that the EPA describes for routing rod packing emissions to process is designed to put suction on the closed vent system, the commenter contends that the proposed rule language does not require that the system operate under negative pressure, and conceivably other systems will be invented which operate under positive pressure. I f operators choose not to replace rod packing under the alternative compliance option, the commenter contends that the quantity of gas passing through the closed vent system could become large, making it essential that operators ensure it does not leak. The commenter urge s the EPA to require instrument

- based inspections at intervals more often than annually (quarterly or monthly, for example) for all systems subject to §60.5416 (closed vent systems for wet seal centrifugal compres sors, reciprocating compressors, and storage tanks) and to allow operators to perform such inspections using optical gas imaging technology. Response : The commenter is correct that the decision to add a third alternative for controlling emissions from reciprocating compressor rod packing was based, in part, on the concept of having the rod packing emissions routed to a process under negative pressure. Although the proposed rule did not include requirements for negative pressure, we agree with the comme nter and have included language that requires that the emissions must be conveyed from the rod packing to the process under negative pressure. However, we disagree that more freq uent monitoring is required . Closed vent systems are subject to the closed vent system inspection and monitoring requirements and the no detectable emissions test methods and procedures. The potential examples cited by the commenter are not compelling, g iven that the owner or operator must continuously comply with the negative pressure and no detectable emissions requirements
. With regard to the other emission sources the commenter mentioned, such as wet seal centrifugal compressors and storage vessels, we discussed in detail the monitoring provisions for those units in the September 23, 2013, storage vessel implementation amendments final rule. Comment: Several commenters (4673, 4674, and 4678) expressed support for the provisions in the prop osed rule that allow for control of rod packing vents through the use of combustion devices. However, the commenters do not support the provisions requiring the same testing and monitoring of these control devices as that required for centrifugal wet seal control devices. The commenters contend that r eciprocating compressors have far less emissions than24

centrifugal compressors, and the testing and monitoring requirements are quite onerous for such a small amount of VOC emissions , which could discourage the use of control devices to reduce these emissions
. The commenters suggest the EPA allow the use of the same streamlined monitoring required for storage vessels for reciprocating compressors
. Response: The EPA points out that the proposed requirements for routing rod packing emissions do not allow these emissions to be routed to a control device. Rather, the allowable route for a closed vent system under § 60.5385(a)(3) is to a process, with “route to a process” defined under § 6 0
. 5430 . While clo sed vent systems in general may be routed to combustion devices, this specifically is not the case for reciprocating compressors under § 60.5385(a)(3). We note that , in the final rule, such closed vent system for routing rod packing emissions to a process m ust operate under negative pressure. 

### 2. 5 Pneumatic Controllers Comment: One commenter (4664) appreciates the EPA’s modification to §60.5390(c)(2) which corrects one contradictory requirement. However, the commenter believes there are still significant i ssues with consistency between the pneumatic controller affected facility d escriptions in §60.5365(d) and the rule requirements. As written, the commenter contends that the proposed rule contains requirements for a pneumatic controller whose bleed rate is below 6 scfh. However, if the pneumatic controller bleed rate is below 6 scfh, then it is not an affected facility, and is not subject to this rule. For example, §60.5390(c)(2) references a requirement in §60.5420(c)(4)(iii) to maintain records of the manu facturer's specifications indicating that the controller is designed such that natural gas bleed rate is less than or equal to 6 scfh. There is no circumstance under which §60.5420(c)(4)(iii) will be an applicable requirement, and it should be deleted. Als o, the commenter states that there does not appear to be a scenario under which §60.5390(c)(2) would be an applicable requirement, and it should be deleted as well. The commenter also contends that §60.5390(c)(2) still contains language that is not consist ent with the affected facility descriptions provided in §60.5365(d)(1) and (2). Response: I n this case, an affected facility is defined by a threshold (i.e., 6 scfh)
. In order for both the owner/operator and the regulatory agency to determine whether th e facility is an affected facility, the bleed rate of each pneumatic controller must be determined . In the case of pneumatic controllers, the NSPS provides that manufacturer documentation presenting the controller ’s bleed rate is an acceptable basis for th is determination . Records of these determinations must be maintained in order for the regulatory agency to know which pneumatic controllers are affected facilities. The affected facility determination , in this case, for the non

affected pneumatic controller is t he manufacturer's specification indicating that the pneumatic controller emission rate is less than the threshold. Therefore, the recordkeeping requirement in §60.5390(c)(2) would be an applicable and appropriate requirement
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### 2. 6 Control Device Operating Requirements Comment: Two commenters (4665, 4677) request clarification of the proposed requirements for control devices to be operated at all times that vapors are routed from the storage vessel to the control device. The commenters note that §§60.5412( d)(3) and 60.5417(h)(1)(i) might be interpreted to require operation of control devices at all times, even when the control devices are not needed. The commenters request that the EPA clarify that this requirement applies to all times that vapors are being pushed from the storage vessel by flow from a well, and does not apply to periods when the well is shut in and the only emissions from the storage vessel are breathing losses. Response: We do not agree with the commenters that emissions should be contr olled only when flow is occurring from the well. The re may be periods when liquids containing VOC are present in the storage vessel when there is no flow from the well. There will likely be emissions from these liquids that will be emitted from the tank. T hese emissions should be controlled to the same extent as emissions that occur while liquids are flowing into the storage vessel. T herefore, the requirement to operate the combustion device at all times is appropriate. Comment: One commenter (4664) refe rs to the proposed new requirement in §60.5413(e)(7), which states, “[e]nsure that each enclosed combustion device is maintained in a leak free condition.” The commenter states that s imilar language currently exists at §60.5412(d)(1)(i) , and seeks clarific ation on what this requirement means. According to the commenter, t he terms “ensure” and “leak free” are not described or defined, and specific compliance requirements, if any, are unclear. The commenter also points out that a combustion device must have a vent to atmosphere through which the combustion products are vented to prevent over
- pressurization; therefore, it is unclear how such a device can be “leak free.” Response: This requirement was added to the ongoing compliance demonstration requirement s of §60.5413(e)(7) to be consistent with the initial compliance demonstration requirements of §60.5412 . The EPA does not believe that these provisions are ambiguous and that venting of a combustion device for its normal operation and safety concerns is no t considered a leak. 

### 2. 7 Exemptions to the Equipment Leak Standards Comment: One commenter (4677) points out that the revised wording of §60.5401 appropriately adds connectors to the description of equipment components that are exempt from the standard if located at a small non

- fractionating plant or within a process unit in the Alaskan North Slope, but the language should also include the provision for connectors in the citations at paragraphs §60.5401(d) and (e) to 40 CFR p art 60 , s ubpart VVa. That is, in specifying that there26

is an exemption for connectors, the commenter contends that the language should also cite the provision from which the connectors are exempt. Response: The EPA agrees that the suggested change is appropriate and will add further clarity to the final rule. Therefore, we have added § 60.482

- 11a(a) to the list of exempted equipment in both §60.5401(d) and (e)
. 

### 2. 8 Responsible Off

icial Comment: One commenter (4677) expresses concern with the statement that “the Administrator reserves the right to evaluate such delegation.” The commenter is unsure about w hat this mean s in practice and h ow one would know whether or not their deleg ation is immediately effective . The commenter would also like clarification on how the EPA will ensure that this “evaluation” does not “affect the facilities’ ability to comply with the certification requirement in the event there are delays in approvals o f delegation” as stated in the preamble

. T he commenter recommends that t his sentence be removed or some qualifying language added that allows for use/application of the delegation for certification during evaluation in the event than an agency elects to ex ercise their right to evaluate the delegation. Another option suggested by the commenter might be to establish a period of time within which the evaluation must be completed to allow for unconditional use/application of the delegation in the absence of any agency correspondence to the contrary. Response: In response to the commenter, we note that the final rule does not require the Administrator ’ s approval for delegation. Thus, the delegation is effective upon notification of the delegation as specified in the definition of “certifying official” in §60.5430

. Since approval is not required for delegation, there cannot be a delay of approval , whether by the Administrator’s evaluation or anything else, that would affect a facility’s ability to comply with the certification requirement. 

### 2. 9 Technical Corrections Comment: Two commenter s ( 4664, 4677) note that there are several places in the amendatory regulatory text that appear to exactly match the previous rule language . The amendatory items are numbers 8, 9.f, 12.a, and 15.c. Response: The corrections to which the commenter s refer were changes to spacing and line returns that would not be readily perceivable in compar ison but were deemed important to address clarity.27

Comment: One commenter (4664) points out that i n the preamble, the EPA notes, “[w]e are also proposing to amend §60.5395(f)(1) and (2), and §60.5420(b)(6) to require that the dates that storage ve ssel

- affected facilities are removed from service and returned to service be included when reporting those actions.” (79 Fed. Reg. 41759). However, no changes are proposed to sections §60.5395(f)(1) o r (2). Response: The EPA erroneously noted that changes were made to sections §60.5395(f)(1) o r (2). The on ly proposed changes were to the introductory text of paragraph §60.5395(f)
. Comment: One commenter (4664) suggests the follow change s:

 To improve clarity and consistency in §60.5416(b): §60.5416(b) No d etectable emissions test methods and procedures. If you are required to conduct an inspection of a closed vent system or cover at your centrifugal compressor or reciprocating compressor affected facility as specified in paragraphs (a)(1), (2), or (3) of th is section, you must meet the requirements of paragraphs (b)(1) through (13) of this section.

 §60.5420(c)(8) now applies to reciprocating compressors, so the language that appears in that section should be modified to reflect that (citation path is §60.5 385(a)(3) to §60.5411(a)(3)(i)(A) to §60.54 16(a)(4)(ii) to §60.5420(c)(8)) : §60.5420(c)(8) If you are subject to the bypass requirements of §60.5416(a)(4) for centrifugal compressors or reciprocating compressors or §60.5416(c)(3) for storage vessels, a re cord of each inspection or a record each time the key is checked out or a record of each time the alarm is sounded.

 The title for §60.5415 includes the word “stationary.” This is the only place the phrase “stationary reciprocating compressor affected faci lity” is used in subpart OOOO. The commenter suggests deleting the word “stationary” to avoid unnecessary confusion.

 The EPA is proposing to modify §60.5420(c)(3)(ii). The commenter request s that the requirement to maintain “[r]ecords of the date and tim e of each reciprocating compressor rod packing replacement” should be eliminated. Section 60.5420(c)(3)(i) already requires records of cumulative number of hours of operation or number of months since startup, rule publication, or previous replacement. Thu s, recording the date and time of replacement is duplicative at best but is mostly unnecessary to ensure compliance with the emission reduction28 requirements. The “time,” at minimum, should be eliminated to reduce recordkeeping burden. Response: The EP A appreciates the detailed analysis provided by the commenter. In response to the comments, we agree that the suggested changes to §§ 60.5416(b) and 60.5420(c)(8) are appropriate and add clarity to the rule. Thus, we have incorporated these changes in the f

inal rule. Concerning the use of “stationary” in the title of §60.5415 , we do not believe this wording causes any confusion and have made no changes as a result of the comment. We also disagree that the recordkeeping requirement of §60.5420(c)(3)(ii) a re duplicative or unnecessary. The other records referred to by the commenter track the amount of time or operating hours since the last replacement. Such records would not necessarily indicate when the next replacement occurred. It is important to provide the regulatory authority clear records of when compliance events occurred so that the authority can verify compliance. We do not believe the records of §60.5420(c)(3)(i) are adequate to demonstrate compliance.