CONSENT DECREE

JAMES G. CARR, District Judge.

WHEREAS, Plaintiff the United States of America ("United States"), by the authority of the Attorney General of the United States and through its undersigned counsel, acting at the request and on behalf of the United States Environmental Protection Agency ("EPA"), has simultaneously filed a complaint under the Clean Air Act ("CAA"), 42 U.S.C. § 7401 et seq. ("the Complaint"), and lodged this Consent Decree against defendants MPLX LP, MarkWest Liberty Midstream & Resources, L.L.C., MarkWest Liberty Bluestone, L.L.C., MarkWest Hydrocarbon, L.L.C., MarkWest Ohio Fractionation Company, L.L.C., MarkWest Utica EMG, L.L.C., Ohio Condensate Company, L.L.C., MarkWest Oklahoma Gas Company, L.L.C., MarkWest Buffalo Creek Gas Company, L.L.C., MarkWest Javelina Company, L.L.C., MarkWest East Texas Gas Company, L.L.C., and MarkWest Energy Texas Gas Company, L.L.C. ("Defendants") for alleged environmental violations at one or more of their natural gas processing plants;

WHEREAS, Defendants have natural gas processing plants located in Washington County, Pennsylvania; Evans City, Pennsylvania; Dallas, West Virginia; Smithfield, West Virginia; West Union, West Virginia; Clendenin, West Virginia; Kenova, West Virginia; South Shore, Kentucky; Langley, Kentucky; Pikeville, Kentucky; Jewett, Ohio; Cadiz, Ohio; Summerfield, Ohio; Butler, Oklahoma; Sayre, Oklahoma; Corpus Christi, Texas; Carthage, Texas; and Orla, Texas (the "Covered Facilities");

WHEREAS, the State of West Virginia, on behalf of the West Virginia Department of Environmental Protection, has joined in this matter alleging violations of applicable state implementation plan ("SIP") provisions and/or other laws, rules, regulations, and permits incorporating and implementing CAA requirements;

WHEREAS, the Pennsylvania Department of Environmental Protection ("PADEP"), the agency of the Commonwealth of Pennsylvania charged with the implementation and enforcement of the Air Pollution Control Act, 35 P.S. § 4001 et seq., has joined in this matter alleging violations of its applicable SIP provisions and/or other laws, rules, regulations, and permits incorporating and implementing CAA requirements;

WHEREAS, the Oklahoma Department of Environmental Quality, an official agency of the State of Oklahoma to which the Oklahoma Legislature has delegated the power and duty to enforce the Oklahoma Statutes, including the authority to bring actions in courts of competent jurisdiction for violations of the Oklahoma Statutes, Oklahoma's SIP, and/or other state rules and regulations incorporating and implementing Clean Air Act requirements (see 27A OKLA. STAT. § 2-3-101(B)(2)), has joined in this matter alleging violations of its applicable SIP provisions and/or other laws, rules, regulations, and permits incorporating and implementing CAA requirements;

WHEREAS, the Complaint alleges that MPLX, LP and MarkWest Liberty Midstream & Resources, L.L.C. violated and/or continues to violate at the gas processing plant at their Houston Facility the New Source Performance Standard ("NSPS") regulations promulgated pursuant to Section 111 of the CAA, 42 U.S.C. § 7411, and found at NSPS General Provisions under 40 C.F.R. Part 60, Subpart A ("Subpart A"); 40 C.F.R. Part 60, Subpart KKK (Standards of Performance for Equipment Leaks of Volatile Organic Compounds From Onshore Natural Gas Processing Plants for which Construction, Reconstruction, or Modification commenced after January 20, 1984, and on or before August 23, 2011) ("Subpart KKK"); Subpart VV (Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for which Construction, Reconstruction, or Modification Commenced After January 5, 1981, and on or Before November 7, 2006) ("Subpart W"); Subpart OOOO (Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution) ("Subpart OOOO"); 40 C.F.R. Part 60, Subpart VVa (Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006) ("Subpart VVa"); and 40 C.F.R. Part 60, Subpart NNN (Standards of Performance for VOC From Synthetic Organic Chemical Manufacturing Industry Distillation Operations) ("Subpart NNN");

WHEREAS, the Complaint alleges that MPLX LP and MarkWest Fractionation Company, L.L.C. violated and/or continue to violate at the gas processing plant at their Hopedale Facility 40 C.F.R. Part 60, Subparts A, OOOO, VVa, NNN, and Kb (Standards of Performance for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After July 23, 1984) ("Subpart Kb"); Condition C.2.b.2.a of the October 14, 2014 Permit to Install and Operate No. P0116897; and Ohio Administrative Code 3745-31;

WHEREAS, the Complaint alleges that MPLX LP and MarkWest Utica EMG, L.L.C. violated and/or continue to violate at their Seneca Facility 40 C.F.R. Part 60, Subparts A, OOOO, and VVa;

WHEREAS, Defendants have allegedly violated and/or continue to violate 40 C.F.R. Part 60, Subparts A, KKK, OOOO, VVa, NNN, Kb and/or VV, at the gas processing plants at one or more of the Covered Facilities;

WHEREAS, Defendants have allegedly violated and/or continue to violate 40 C.F.R. Part 60, Subpart Db, Standards of Performance for Industrial-Commercial-Institutional Steam Generating Units ("Subpart Db"), and 40 C.F.R. Part 60, Subpart Dc, Standards of Performance for Small Industrial-Commercial-Institutional Steam Generating Units ("Subpart Dc"), at heaters located at the gas processing plants at one or more of the Covered Facilities;

WHEREAS, Defendants completed a performance test on November 27 — December 1, 2016, in compliance with 40 C.F.R. Part 60, Subpart OOOO, for their railyard Enclosed Combustion Device located at the Hopedale Facility;

WHEREAS, Defendants have waived any applicable federal or state requirements of statutory notice of the alleged violations;

WHEREAS, Defendants do not admit any liability to the United States, PADEP, the Oklahoma Department of Environmental Quality on behalf of the State of Oklahoma, and the State of West Virginia, on behalf of the West Virginia Department of Environmental Protection ("State Co-Plaintiffs") arising out of the transactions or occurrences alleged in the Complaint or in this Consent Decree; and

WHEREAS, the United States, the State Co-Plaintiffs, and Defendants recognize, and this Court by entering this Consent Decree finds, that this Consent Decree has been negotiated by the Parties in good faith and will avoid litigation between the Parties, and that this Consent Decree is fair, reasonable, and in the public interest;

NOW, THEREFORE, before the taking of any testimony, without the adjudication or admission of any issue of fact or law except as provided in Section I, and with the consent of the Parties, IT IS HEREBY ADJUDGED, ORDERED, AND DECREED as follows:

I. JURISDICTION AND VENUE

1. This Court has jurisdiction over the subject matter of this action and over the Parties, pursuant to 28 U.S.C. §§ 1331, 1345, 1355 and 1367, and Section 113(b) of the CAA, 42 U.S.C. § 7413(b). Venue is proper in this judicial district pursuant to Section 113(b) of the CAA, 42 U.S.C. § 7413(b), and 28 U.S.C. §§ 1391(b) and (c), and 1395(a), because violations alleged in the Complaint are alleged to have occurred, and Defendants conduct business, in this judicial district. Defendants consent to and shall not challenge entry of this Consent Decree or this Court's jurisdiction to enter and enforce this Decree, and further consent to venue in this judicial district solely for the purpose of entering and enforcing this Consent Decree. Authority to bring this suit is vested in the United States Department of Justice by 28 U.S.C. §§ 516 and 519 and Section 305 of the CAA, 42 U.S.C. § 7605, and in State Co-Plaintiffs by Section 304 of the CAA, 42 U.S.C. § 7604, Section 4 of the Pennsylvania Air Pollution Control Act (APCA), 35 P.S. § 4004, 27A OKLA. STAT. § 2-3-101(B)(2)), and West Virginia Code §§ 22-5-6 and 22-5-7.

2. For purposes of this Consent Decree, Defendants agree that the Complaint states claims upon which relief may be granted.

3. Notice of the commencement of this action shall be given to the State of Ohio, Commonwealth of Kentucky, State of West Virginia, State of Texas, State of Oklahoma, and the Commonwealth of Pennsylvania, Pennsylvania Department of Environmental Protection as required by Section 113(b) of the CAA, 42 U.S.C. § 7413(b).

II. APPLICABILITY AND SALES OR TRANSFERS OF OWNERSHIP AND OPERATION INTERESTS

4. The obligations of this Consent Decree apply to and are binding upon the United States, State Co-Plaintiffs, and Defendants, and any of their respective successors or assigns, or other entities or persons otherwise bound by law.

5. In the event that a Defendant proposes to sell or transfer ownership or operation, in whole or in part, of any of the Covered Facilities, to an entity unrelated to a Defendant ("Third Party"), such Defendant shall notify the Third Party in writing of the existence of this Consent Decree prior to the closing of such sale or transfer. Defendant shall send a copy of this written notification to the United States and the Applicable State Co-Plaintiff(s) pursuant to Section IX (Notices) prior to the proposed closing.

6. Defendant shall condition any sale or transfer, in whole or part, of ownership or operation of any of the Covered Facilities upon the execution by the Third Party of a modification to this Consent Decree to make the terms and conditions of this Consent Decree related to the ownership or operation of the transferred Covered Facilities applicable to the Third Party. No earlier than thirty (30) Days after giving notice of a successor in interest pursuant to Paragraph 5, Defendant may file a motion to modify this Consent Decree with the Court to make the terms and conditions of the Consent Decree related to the ownership or operation of the transferred Covered Facilities applicable to the Third Party. Defendant shall be released from the requirements of this Consent Decree with respect to the transferred Covered Facilities unless the Court finds that the Third Party does not have the financial or technical ability to comply with the requirements of this Consent Decree.

7. This Consent Decree shall not be construed to impede the sale or transfer of any asset or interest between Defendant and any Third Party so long as the requirements of this Consent Decree are met.

8. Paragraphs 4-6 shall not be construed to affect or apply to mergers or other corporate transactions in which Defendant is acquired by a Third Party and the surviving entity, by operation of law, assumes all of such Defendant's assets and liabilities pursuant to the Consent Decree relating to the Covered Facilities.

9. Defendants shall: (a) provide a copy of this Consent Decree to all officers of Defendants and managers who will be responsible for implementation of the terms of this Consent Decree, and ensure that any employees and contractors whose duties might reasonably include compliance with any provision of this Consent Decree are made aware of this Consent Decree that fall within such persons' duties; and (b) place an electronic version of the Consent Decree on its internal environmental website. Defendants shall be responsible for ensuring that all employees and contractors involved in performing any work pursuant to this Consent Decree perform such work in compliance with the requirements of this Consent Decree.

10. In any action to enforce this Consent Decree, a Defendant shall not raise as a defense to liability or stipulated penalty the failure by any of its officers, directors, employees, agents, or contractors to take any actions necessary to comply with the provisions of this Consent Decree. This Section does not preclude a Defendant from holding any employee, agent, or contractor who is alleged to have not complied with this Consent Decree liable for their actions. Nor does this Section preclude a Defendant in an action to enforce this Consent Decree pursuant to Paragraph 146, from raising the failure of any contractor to take any actions necessary to comply with the provisions of this Consent Decree as a mitigating factor with regard to any non-injunctive relief sought.

11. Defendants Responsible for Compliance. The following table identifies the Defendants responsible for each Covered Facility.

III. DEFINITIONS

12. The terms used in this Consent Decree that are defined in the CAA or in federal and state regulations promulgated pursuant to the CAA shall have the meaning assigned to them in the CAA or such regulations, unless otherwise provided in this Decree. Whenever the terms set forth below are used in this Consent Decree, the following definitions shall apply:

IV. CIVIL PENALTY

13. By no later than 30 Days after the Effective Date of this Consent Decree, Defendants shall pay civil penalties totaling $925,000 as follows: (i) $693,751 to the United States; (ii) $77,083 to the State of Oklahoma; (iii) $77,083 to PADEP; and (iv) $77,083 to the State of West Virginia.

14. Payment of the civil penalty to the United States shall be made by Electronic Funds Transfer ("EFT") to the U.S. Department of Justice in accordance with written instructions to be provided to Defendants by the Financial Litigation Unit of the U.S. Attorney's Office for the Northern District of Ohio following lodging of the Consent Decree. At the time of payment, Defendants shall send a copy of the EFT authorization form, the EFT transaction record, and a transmittal letter: (i) to the United States in the manner set forth in Section IX of this Decree (Notices), (ii) by email to acctsreceivable.CINWD@epa.gov; and (iii) by mail to:

The transmittal letter shall state that the payment is for the civil penalty owed pursuant to the Consent Decree in United States, et al. v. MPLX LP, et al., and shall reference the civil action number, and DOJ case number 90-5-2-1-11374/1.

15. State Payment Instructions.

16. If any portion of the civil penalty due to the United States is not paid when due, Defendants shall pay interest on the amount past due, accruing from the Effective Date through the date of payment, at the rate specified in 28 U.S.C. § 1961. Interest payment under this Paragraph shall be in addition to any stipulated penalty due.

17. Not Tax Deductible. Defendants shall not deduct any penalties paid under this Section or Section XI (Stipulated Penalties) in calculating their federal, state, or local income tax.

18. Upon the Effective Date, this Consent Decree shall constitute an enforceable judgment for purposes of post-judgment collection in accordance with Federal Rule of Civil Procedure 69, the Federal Debt Collection Procedure Act, 28 U.S.C. §§ 3001-3308, and other applicable federal authority. The United States and State Co-Plaintiffs shall be deemed judgment creditors for purposes of collecting any unpaid amounts of the civil and stipulated penalties and Interest.

V. INJUNCTIVE RELIEF

A. Subpart KKK and Subpart OOOO Applicability to Process Units

19. NSPS and Covered Process Units Applicability.

20. Connector Monitoring at Subpart KKK Process Units. This Paragraph applies to connectors in gas/vapor service and in light liquid service for all Covered Process Units located at the Cobb, Kenova, Siloam, Langley, Boldman, Arapaho, Majorsville, Javelina, and Carthage Facilities at the time of the lodging of this Consent Decree.

B. LDAR Program

21. Applicability.

22. LDAR Document. By no later than 180 Days after the Effective Date, Defendants shall develop, for each Covered Facility, a facility-wide document that describes: (i) the LDAR program (e.g., applicability of regulations to process units and/or specific equipment; leak definitions; monitoring frequencies) that includes the flowchart set forth in Appendix C; (ii) a tracking program (e.g., Management of Change as provided in Paragraph 46) that ensures that new pieces of equipment added to the Covered Facility for any reason are integrated into the LDAR program and that pieces of equipment that are taken out of service are removed from the LDAR program; (iii) the roles and responsibilities of all employee and contractor personnel assigned to LDAR functions at the Facility; (iv) how the number of personnel dedicated to LDAR functions is sufficient to satisfy the requirements of the LDAR program; and (v) how the Covered Facility plans to implement this LDAR Program under this Consent Decree. Once developed, Defendants shall review the LDAR Document annually and update it by no later than March 31 of each year.

23. Monitoring Frequency. Beginning no later than 180 Days after the Effective Date, for all Covered Equipment, Defendants shall comply with the following periodic monitoring frequencies, unless: (i) more frequent monitoring is required by federal, state, or local laws or regulations; or (ii) the relevant Covered Process Unit has been permanently shut down:

Compliance with the monitoring frequencies in this Paragraph is not required when an applicable LDAR regulation excludes or exempts, fully or partially, monitoring at a periodic frequency (e.g., an exemption for equipment that is designated as unsafe-to-monitor or difficult-to-monitor or an exemption for pumps that have no externally actuated shaft), provided that Defendants satisfy all applicable conditions and requirements for the exclusion or exemption set forth in the regulation.

24. Method 21 Data Logging. Beginning no later than 180 Days after the Effective Date, for all Covered Equipment, Defendants shall comply with Method 21 in performing LDAR monitoring, using an instrument attached to a data logger (or an equivalent instrument) which directly records electronically the Screening Value detected at each piece of Covered Equipment, the date and time that each Screening Value is taken, and the identification numbers of the monitoring instrument and the technician. Defendants shall transfer this monitoring data to an electronic database on at least a weekly basis for recordkeeping purposes.

25. If, during monitoring in the field, a piece of Covered Equipment is discovered that is not listed in the data logger, Defendants are permitted to monitor the piece of Covered Equipment and record, by any means available, the Screening Value, the date and time of the Screening Value, and the identification numbers of the monitoring instrument and technician. In such an instance, the failure to initially record the information electronically, in the data logger, does not constitute a violation of this Paragraph's requirement to record the required information electronically, provided that Defendants thereafter promptly add the piece of Covered Equipment and the information regarding the monitoring event to the LDAR database.

26. Covered Facilities that are complying with the alternative work practice ("AWP") as provided in 40 C.F.R. § 60.18(g) at the Date of Lodging may continue to comply with the AWP for purposes of complying with "LDAR Monitoring Frequency and Equipment" provisions of this Consent Decree.

27. Action Levels.

Table 1: Leak Definitions for Covered Types of Equipment

28. Repairs. Except as provided in Subparagraph 38.d.i., by no later than five Days after detecting a leak, Defendants shall perform a first attempt at repair. By no later than 15 Days after detection, Defendants shall perform a final attempt at repair of the leaking piece of Covered Equipment or may place the piece of Covered Equipment on the DOR list provided that Defendants have complied with all applicable LDAR regulations and with the requirements of Paragraphs 29-33, 34 (valve replacement and improvement), and Paragraphs 44 and 45 (connector replacement).

29. Repair Verification Monitoring. Except as provided in Subparagraph 38.d.i., beginning no later than 180 Days after the Effective Date of this Consent Decree and continuing until termination of this Consent Decree, Defendants shall perform Repair Verification Monitoring.

30. Drill and Tap for Valves (other than Control Valves).

31. Except as provided in Subparagraph 38.d.i., for each leak, Defendants shall record the following information: the date of all repair attempts; the repair methods used during each repair attempt; the date, time and Screening Values for all re-monitoring events; and, if applicable, documentation of compliance with Paragraphs 30 and 33 for Covered Equipment placed on the DOR list.

32. Nothing in Paragraphs 28-31 is intended to prevent Defendants from taking a leaking piece of Covered Equipment out of service; provided, however, that prior to placing the leaking piece of Covered Equipment back in service, Defendants must repair the leak or must comply with the requirements of Paragraph 33 to place the piece of Covered Equipment on the DOR list.

33. Delay of Repair. Beginning no later than the Effective Date of this Consent Decree for the requirements in Subparagraphs 33.b and c.i., and beginning no later than 180 after the Effective Date of this Consent Decree for the other requirements set forth below in this Paragraph, for all Covered Equipment placed on the DOR list, Defendants shall:

Valve Replacement and Improvement Program

34. Valve Replacement and Improvement Program. Commencing no later than 180 Days after the Effective Date for Covered Process Units subject to Subpart OOOO as of the Date of Lodging of this Consent Decree, and commencing no later than 365 Days after the Effective Date of this Consent Decree for Covered Process Units subject to Subpart KKK as of the Date of Lodging of this Consent Decree, and continuing until termination of this Consent Decree, Defendants shall implement the program set forth in Paragraphs 34-43 to improve the emissions performance of the valves that are Covered Equipment in each Covered Process Unit. All references to "valves" in Paragraphs 34-43 exclude pressure relief valves.

35. List of all Existing Valves in the Covered Process Units. In the first compliance status report required under Paragraph 58, Defendants shall include a list of the tag numbers of all valves subject to this LDAR Program, broken down by Covered Process Unit, that are in existence as of the Effective Date. The valves on this list shall be the "Existing Valves" for purposes of Paragraphs 36-38.

36. Proactive Initial Valve Tightening Work Practices Relating to each New Valve that Is Installed and each Existing Valve that Is Repacked. Defendants shall undertake the work practices specified in this Paragraph with respect to each new valve that is subject to LDAR that is installed (whether the new valve replaces an Existing Valve or is newly added to a Covered Process Unit) and each Existing Valve that is repacked. Upon installation (or re-installation in the case of repacking), Defendants shall tighten the valve's packing gland nuts or their equivalent (e.g., pushers) to: (i) the manufacturer's recommended gland nut or packing torque; or (ii) any appropriate tightness that will minimize the potential for fugitive emission leaks of any magnitude. This practice shall be implemented prior to the valve's exposure (or re-exposure, in the case of repacking) to process fluids.

37. Installing New Valves. Except as provided in Subparagraphs 37.a., b., c., or Paragraph 40, Defendants shall ensure that each new valve (other than a valve that serves as the closure device on an open-ended line) that it installs in each Covered Process Unit, and that, when installed, will be regulated under applicable LDAR regulations, either is a Low-E Valve or is fitted with Low-E Packing. This requirement applies to entirely new valves that are added to a Covered Process Unit and to Existing Valves that are replaced for any reason in a Covered Process Unit.

38. Replacing or Repacking Existing Valves with Low-E Valves or Low-E Packing.

39. Provisions Related to Low-E Valves and Low-E Packing.

40. Commercial Unavailability of a Low-E Valve or Low-E Packing. Defendants shall not be required to utilize a Low-E Valve or Low-E Packing to replace or repack a valve if a Low-E Valve or Low-E Packing is commercially unavailable. The factors relevant to the question of commercial unavailability and the procedures that Defendants must follow to assert that a Low-E Valve or Low-E Packing is commercially unavailable are set forth in Appendix A.

41. Records of Low-E Valves and Low-E Packing. Prior to installing any Low-E Valves or Low-E Packing, or if not possible before installation, then as soon as possible after installation, Defendants shall secure from each manufacturer documentation that demonstrates that the proposed valve or packing technology meets the definition of "Low-E Valve" and/or "Low-E Packing." Defendants shall make the documentation available upon request by EPA or the Applicable State Co-Plaintiff.

42. Nothing in Paragraphs 37-40 requires Defendants to utilize any valve or valve packing technology that is not appropriate for its intended use in a Covered Process Unit.

43. In each Compliance Status Report due under Paragraph 58 of this Decree, Defendants shall include a separate section in the Report that: (i) describes the actions it took to comply with Paragraphs 34-432 (Valve Replacement and Improvement Program), including identifying each piece of equipment that triggered a requirement under Paragraphs 34-42, the Screening Value for that piece of equipment, the type of action taken (i.e., replacement, repacking, or improvement, and the date when the action was taken); (ii) identifies any required actions that were not taken and explains why; and (iii) identifies the schedule for any known future replacements, repackings, improvements, or eliminations.

44. Connector Replacement and Improvement Descriptions.

For purposes of this Paragraph, "gasket" means a sealing element that includes, but is not limited to, an O-ring, gasket, or D-ring.

45. Replacing or Improving Connectors.

46. Management of Change. To the extent not already done, beginning no later than 180 Days after the Effective Date of this Consent Decree, Defendants shall, for each Covered Facility, implement a "Management of Change Protocol" that shall ensure that each valve, pump, and connector added to the Covered Process Units at the Covered Facility for any reason is evaluated to determine if it is subject to LDAR regulations. Defendants also shall ensure that each valve, pump, and connector that was subject to the LDAR Program is eliminated from the LDAR Program if it is physically removed from a Covered Process Unit. This evaluation shall be a part of Defendants' facility-wide Management of Change Protocol.

47. Training. By no later than 270 Days after the Effective Date, Defendants shall develop, for each Covered Facility, a training protocol (or, as applicable, require its contractor(s) to develop a training protocol for the contractor's employees) and shall ensure that all LDAR Personnel have completed training on all aspects of LDAR, including this LDAR Program, that are relevant to the person's duties. Once per calendar year starting in the calendar year after completion of initial training, Defendants shall ensure that refresher training is performed with respect to each employee and contractor; provided, however, that refresher training is not required if an individual's employment at the Covered Facility ceases prior to the end of the calendar year or no longer involves duties relevant to LDAR. Beginning no later than the Effective Date and continuing until termination of this Consent Decree, Defendants shall ensure (or as applicable, require its contractor to ensure for the contractor's employees) that new LDAR Personnel are sufficiently trained no more than 90 Days prior to any field involvement (other than supervised involvement for purposes of training) with LDAR and/or the LDAR Program.

48. Daily Certification by Monitoring Technicians. Commencing by no later than 30 Days after the Effective Date, on each Day that monitoring occurs, at the end of such monitoring, Defendants shall ensure that each monitoring technician certifies that the data collected accurately represents the monitoring performed for that Day by requiring the monitoring technician to sign a form that includes the following certification:

49. QA/QC. Commencing by no later than the first full calendar Quarter after the Effective Date, at times that are not announced to the LDAR monitoring technicians, an LDAR-trained employee or contractor of Defendants, who does not serve on a routine basis as an LDAR monitoring technician at the Covered Facility, shall undertake the following no less than once per calendar Quarter at such Covered Facility:

Defendants shall promptly correct any deficiencies detected or observed. Defendants shall maintain a log that: (i) records the date and time that the reviews, verifications, and observations required by this Paragraph are undertaken; and (ii) describes the nature and timing of any corrective actions taken.

50. LDAR Audit Schedule.

51. Requirements related to persons conducting LDAR Audits. For the LDAR Audits to be conducted under this Consent Decree, Defendants shall retain a third-party with experience in conducting LDAR Audits, except that, at their discretion, Defendants may conduct the second LDAR Audit at Covered Facilities subject to Paragraph 50.a., b. and c. internally with their own personnel, provided that: the personnel Defendants use are not employed at the Covered Facility being audited but rather are employed centrally at one or more other facilities owned or operated by Defendants; and the personnel are experienced in conducting LDAR Audits at such other facilities that have previously implemented or are currently implementing an LDAR Program. For each third-party LDAR Audit, Defendants shall select a different company than the Facility's regular LDAR contractor to perform the third-party LDAR Audit and Defendants may not hire that company as the Covered Facility's regular LDAR contractor during the life of this Consent Decree.

52. For each Covered Process Unit, each LDAR Audit shall include: (i) reviewing compliance with all applicable LDAR regulations, including LDAR requirements related to valves and pumps in heavy liquid service; (ii) reviewing and/or verifying the same items that are required to be reviewed and/or verified in Paragraph 49; (iii) reviewing whether any pieces of equipment that are required to be in the LDAR program are not included; and (iv) "comparative monitoring" as described in Paragraph 53. LDAR Audits after the first audit at each Covered Facility shall also include reviewing the Covered Facility's compliance with this LDAR Program.

53. Comparative Monitoring. Comparative monitoring during LDAR Audits shall be undertaken as follows:

54. When More Frequent Periodic Monitoring is Required. If a Comparative Monitoring Audit Leak Percentage calculated pursuant to Subparagraph 53.a. triggers a more frequent monitoring schedule under any applicable federal, state, or local law or regulation than the frequencies listed in Paragraph 23 as applicable for the Covered Type of Equipment in that Covered Process Unit, Defendants shall monitor the Covered Type of Equipment at the greater frequency unless and until less frequent monitoring is again allowed under the specific federal, state, or local law or regulation. At no time may Defendants monitor at intervals less frequently than those listed in Paragraph 23.

55. Corrective Action Plan ("CAP").

56. Certification of Compliance. Within 180 Days after the initial LDAR Audit Completion Date, Defendants shall certify to EPA and the Applicable State Co-Plaintiff that, to the signer's best knowledge and belief formed after reasonable inquiry: (i) except as otherwise identified, the Covered Facility is in compliance with all applicable LDAR regulations and this LDAR Program; (ii) Defendant has completed all corrective actions, if applicable, or is in the process of completing all corrective actions pursuant to a CAP; and (iii) all equipment at the Facility that is regulated under LDAR has been identified and included in the LDAR program. To the extent that Defendants cannot make the certification in all respects, it shall specifically identify any deviations from Items (i)-(iii) in this Paragraph.

57. Recordkeeping. Defendants shall keep all records required by this LDAR Program, including each LDAR Audit report, to document compliance with the requirements of this LDAR Program as provided in Paragraph 160. Upon request by EPA, Defendants shall make all such documents available to EPA and the State Co-Plaintiffs, and shall provide, in electronic format if so requested, all LDAR monitoring data generated during the life of this Consent Decree.

58. LDAR Program Compliance Status Reports. On the dates and for the time periods set forth in Section VIII (Reporting Requirements) Defendant shall submit to EPA and the Applicable State Co-Plaintiff, in the manner set forth in Section IX (Notices), a report containing the following information for each Covered Facility:

C. Pilot-Operated Modulating Pressure Relief Valves ("PORVs")

59. As of the Effective Date of this Consent Decree, Defendants shall install and operate Bottom Dome Vent Piping on any new PORV that is or will be subject to the requirements of Subparts KKK or OOOO, with the exception of the PORV categories identified in Subparagraph 59.a or b:

60. Beginning with the first full calendar Quarter after the Effective Date of the Consent Decree, or the alternative work practice in accordance with 40 C.F.R. § 60.18(g)-(i), Defendants shall conduct Method 21 monitoring on PORVs subject to Subparts KKK or Subpart OOOO on a quarterly frequency, unless: (i) more frequent monitoring is required by federal, state, or local laws or regulations; or (ii) the relevant Covered Process Unit has been permanently shut down.

61. Defendants shall repair all leaks of PORVs detected at or above 500 ppm in accordance with this Paragraph:

62. By no later than 180 Days after the Effective Date, Defendants shall install Bottom Dome Vapor Recovery Piping on any existing PORV, that is subject to either Subpart KKK or OOOO, and that has a Pre-existing Tap and Isolation Valve, with the exception of the PORV categories identified in Subparagraph 59.a or b.

63. For the purposes of this Consent Decree, the following PORVs with pressure safety valve (PSV) identification numbers located at the Bluestone Facility are not covered by this Consent Decree: PSV-1003A, PSV-1003B, PSV-V103, and 0-PSV-1001.

64. For the purposes of this Consent Decree, the following PORVs with PSV identification numbers located at the Majorsville Facility are not covered by this Consent Decree: PSV-361, PSV-462, PSV-463, PSV-2462, PSV-2463, PSV-2110, and PSV-2210.

65. For each leak identified under Paragraph 61 above, Defendants shall record the following information: the date the leak was identified and the Screening Value; the date of all repair attempts; the repair methods used during each repair attempt; the date, time, and Screening Values for all re-monitoring events; and, if applicable, documentation of compliance with Subparagraph c. for PORVs placed on the DOR list.

66. Reporting. On the dates and for the time periods set forth in Section VIII (Reporting), Defendants shall submit to EPA Headquarters, the EPA Regional Office(s), and Applicable State-Co-Plaintiffs, for each Covered Facility subject to Paragraphs 59-65 above, the following information for each Covered Facility:

D. Subpart NNN

67. Beginning no later than 90 Days after the Effective Date, the following Covered Facilities shall comply with Subpart NNN as specified in Paragraph 68 at Distillation Units that are "affected facilities" as defined under 40 C.F.R. § 60.660: Houston, Bluestone, Siloam, Hopedale, Javelina, and Utica Condensate.

68. By no later than 180 Days after the Effective Date, Defendants shall comply with 40 C.F.R. § 60.660(d) by complying with the provisions in 40 C.F.R. Part 65, Subpart D, to satisfy the requirements of 40 C.F.R. §§ 60.662 through 60.665 and 60.668.

E. Fin Fan Units

69. By no later than 180 Days after the Effective Date, Defendants shall identify all Fin Fan Units at each Covered Facility that are in light liquid and/or gas/vapor service, as defined in 40 C.F.R. § 60.481a.

70. By no later than 180 Days after the Effective Date, Defendants shall comply, with respect to Covered Facilities that operate Fin Fan Units that are in light liquid and/or gas/vapor service, with Paragraphs 71-73 below.

71. Defendants shall monitor Fin Fan Units as follows:

72. Defendants shall repair all leaks of Fin Fan Unit plugs in accordance with the following requirements:

73. Recordkeeping. Defendants subject to Paragraphs 69-72 above shall maintain the following records:

F. Railyard or any Other Enclosed Combustion Devices (including Portable)

74. By no later than 180 Days after the Effective Date, the following Covered Facilities shall comply with Subpart OOOO with the requirements of 40 C.F.R. § 60.482-10a(c) for each Enclosed Combustion Device: Siloam, Hopedale, and Houston.

75. Beginning no later than 270 Days after the Effective Date, at all times a Covered Facility is operating such that VOC could be sent to an Enclosed Combustion Device subject to Paragraph 74 above, Defendants shall maintain, for each Enclosed Combustion Device, the minimum operating temperature per the table below, to demonstrate continuous compliance with 40 C.F.R. § 60.482-10a(c):

76. Beginning no later than 365 Days after the Effective Date of this Consent Decree, Defendants shall measure and record 15-minute average combustion operating temperature of each Enclosed Combustion Device subject to Paragraph 74 above. These 15-minute averages shall then be used to calculate and record the rolling average period per the table in Paragraph

75. This requirement shall apply at all times during operation of the Enclosed Combustion Devices except during device breakdowns, repairs, periodic accuracy evaluations, calibration checks, and zero span adjustments.

77. Recordkeeping. Defendants must maintain records of the average firebox temperature of each Enclosed Combustion Device subject to Paragraph 74 above, measured at least every 15 minutes, and averaged over the same period used to comply with Paragraph 75 and demonstrating compliance with Paragraph 76.

G. Hose Connections to Railcar/Truck Loading Operations

78. By no later than 180 Days after the Effective Date, Defendants shall identify each railcar loading bay and truck loading bay at each Covered Facility with a unique identifier.

79. By no later than 180 Days after the Effective Date, Defendants shall use either of the following options to monitor for leaks at any hose connections in VOC service during railcar or truck loading operations, or representative of loading conditions, at each railcar or truck loading bay at any Covered Facility:

80. Defendants shall repair all leaks of hose connections identified under Paragraph 79, above, in accordance with the following requirements:

81. Defendants subject to Paragraph 78 above shall maintain the following records:

H. Natural Gasoline Storage Vessels

82. By no later than 180 Days after the Effective Date, Defendants shall install Isolation Valves upstream of all pressure relief devices operating on Natural Gasoline Storage Vessels at the Hopedale Facility, the Houston Facility, and the Siloam Facility.

83. Beginning with the first full calendar Quarter that begins after the Effective Date of the Consent Decree, for Natural Gasoline Storage Vessels operating at Covered Facilities, Defendants shall conduct Method 21 monitoring for any leaks above 500 ppm from pressure relief devices operating on such Natural Gasoline Storage Vessels on a quarterly basis.

84. Except as provided in Paragraph 85 below, Defendants shall repair all leaks of pressure relief devices identified under Paragraph 83 above, in accordance with the following requirements:

85. If Defendants detect leaks of any such pressure relief device above 500 ppm in two consecutive quarterly monitoring periods for the Bluestone Facility, Defendant shall install an Isolation Valve upstream of the pressure relief device within 30 Days, or as soon as reasonably practicable thereafter, of identifying the second leak.

86. Defendants subject to Paragraphs 84 and 85 above shall maintain the following records:

I. Large Hot Oil Heaters Subject to NSPS Db

87. Each steam generating unit at a Covered Facility with a design firing rate greater than 29 Megawatts (100 million British thermal units ("MMBtu/h")) ("Large Hot Oil Heaters"), shall comply with 40 C.F.R. § 60.40b-49b (NSPS Subpart Db) as set forth below.

88. By no later than 180 Days after the Effective Date, Defendants shall submit an initial notification for each Large Hot Oil Heater subject to Paragraph 87, above, in accordance with 40 C.F.R. § 60.49b.

89. Defendants may rely on the results of the initial performance tests and existing developed predictive emission monitoring system ("PEMS") plans of three Large Hot Oil Heaters at the Hopedale and Houston Facilities in accordance with 40 C.F.R. § 60.46b. All other Large Hot Oil Heaters including heaters installed during the life of this Consent Decree, may rely on an existing performance test and use a developed PEMS plan from another heater under this Consent Decree, as long as the performance test results and PEMS plan being applied were conducted and developed for a similar Large Hot Oil Heater with the same burner design. Heaters currently in the MarkWest system can use the following tests and PEMS plans:

90. Beginning no later than 365 Days after the Effective Date of this Consent Decree, Defendants shall continuously comply with the nitrogen oxides ("NOx") limit of 0.10 lb/MM Btu for all Large Hot Oil Heaters as required by 40 C.F.R. § 60.44b(a).

91. To demonstrate compliance with the limit of 0.10 lb/MM Btu for Large Hot Oil Heaters, Defendants shall monitor operating conditions to predict NOx emission rates using a PEMS as required by 40 C.F.R. § 60.48b(g)(2) as follows:

92. Defendants shall calculate a 30-day rolling average from average daily NOx emissions calculated by the PEMS on an hourly basis.

93. Recordkeeping. Defendants must maintain emissions monitoring of all required parameters per 40 C.F.R. § 60.49b(c) for each Large Hot Oil Heater subject to Paragraph 91, above, to demonstrate compliance with Paragraph 91, above.

J. Small Hot Oil Heaters Subject to NSPS Dc

94.

95. Recordkeeping. Beginning no later than 180 Days after the Effective Date of this Consent Decree, Defendants shall measure or estimate and record, in accordance with 40 C.F.R. § 60.48c(g)(2), fuel usage during each calendar month by each Small Hot Oil Heater. The maximum design heat rate may be used to estimate heater fuel flow rate per 40 C.F.R. § 60.46c(g)(3).

K. Compressor Stations Mitigation Projects

96. By no later than 180 Days after the Effective Date, Defendants shall implement and commence operation of the Environmental Mitigation Projects set forth in Paragraph 97 for the purpose of reducing emissions of VOCs from two natural gas compressor stations, one in Pennsylvania and one in Ohio, through installation and operation of VOC emission control measures for truck loading operations ("Compressor Stations Mitigation Projects"). In implementing the Compressor Stations Mitigation Projects, Defendants shall spend no less than $700,000 in Project Dollars, and comply with Paragraphs 97 and 98.

97. By no later than 180 Days of the Effective Date, the Defendants shall purchase and install an Air Defender System at the Carpenter Compressor Station located in Donegal Township, Pennsylvania and the Humphreys Compressor Station located near Barnesville, Ohio.

98. By no later than 90 Days of installing the Air Defender Systems, the Defendants must verify that each system is operating properly in accordance with manufacturer specifications.

99. By signing this Consent Decree, each Defendant certifies that it and any other owners or operators of the natural gas compressor stations affected by these Compressor Stations Mitigation Projects, and each Defendant and any other owners or operators of a Covered Facility with a Fin Fan Unit(s) subject to the monitoring requirements in Paragraphs 69-73, are not required to perform or develop these Environmental Mitigation Projects by any federal, state, or local law or regulation and are not required to perform or develop these Projects by agreement, grant, or as injunctive relief awarded in any other action in any forum; that these Projects are not ones that they were intending to construct, perform, or implement other than in settlement of the claims resolved by this Decree; and that they will not receive any reimbursement for any portion of the costs of these Projects from any other person.

100. Compressor Stations Mitigation Projects Progress and Completion Reports. Defendants shall include in each report required under Section VIII (Reporting), a status update on the Compressor Stations Mitigation Projects required by this Section until the Projects are completed. In addition, the report required by Section VIII for the period in which the Projects are completed shall contain the following information:

VI. INCORPORATION OF CONSENT DECREE REQUIREMENTS INTO FEDERALLY ENFORCEABLE PERMITS

101. Permits Needed to Meet Compliance Obligations.

102. Permits to Ensure Survival of Consent Decree Limits and Standards after Termination of Consent Decree.

103. Modifications to Title V Operating Permits. Prior to termination of this Consent Decree, Defendants shall, for any Covered Facility with a Title V Operating Permit, submit complete applications to applicable permitting authorities to modify, amend or revise such Title V permit to incorporate the applicable limits and standards identified in the preceding Paragraph into the Title V Permit. The Parties agree that the incorporation of these emission limits and standards into Title V Permits shall be done in accordance with applicable state or local Title V rules. The Parties agree that the incorporation may be by "amendment" under 40 C.F.R. § 70.7(d) and analogous state Title V rules, where allowed by state law.

VII. SUPPLEMENTAL ENVIRONMENTAL PROJECTS

104. VOC Fence Line Monitoring System. Defendants shall implement as a Supplemental Environmental Project ("SEP") the installation, operation and maintenance of speciated VOC fence line systems at the Houston Facility, Siloam Facility, Sherwood Facility, and Carthage Facility, to monitor certain pollutants, and to provide the data to EPA and the Applicable State Co-Plaintiff ("Fence Line Monitoring System SEP" or "FLMS SEP"). Defendants shall implement the FLMS SEP in accordance with this Paragraph and the criteria, terms and procedures in Appendix B. Defendants shall spend not less than $2.5 million in Project Dollars to implement the FLMS SEP.

105. Defendants are responsible for the satisfactory completion of the FLMS Monitoring SEP in accordance with the requirements of this Consent Decree. Defendants may use contractors or consultants in planning and implementing the SEP.

106. Predictive Leak Monitoring: Predictive leak modeling software ("PLMS") is a modeling software that uses process operations criteria along with stream compositions to predict leak probability of process equipment from fugitive emission leaks. By no later than 365 Days after the Effective Date, Defendants shall perform a leak study using PLMS (PLMS SEP) to identify LDAR leaks at the Seneca Facility. Defendants shall spend not less than $75,000 in Project Dollars to implement the PLMS SEP. Within 180 Days after completion of the leak study, Defendants shall submit a report to EPA that includes the following:

107. With regard to the FLMS SEP and the PLMS SEP, Defendants certify the truth and accuracy of each of the following:

108. SEP Completion Report. Within thirty (30) Days after completion of each FLMS and PLMS SEP, Defendants shall submit a SEP Completion Report to the United States and the Applicable State Co-Plaintiff in accordance with Section IX (Notices) of this Consent Decree. Each SEP Completion Report shall contain the following information:

109. The United States may, in its sole discretion, require Defendants to provide information in addition to that described in Paragraph 108 (SEP Completion Report) in order to evaluate Defendants' SEP Completion Report.

110. After receiving a SEP Completion Report, the United States will notify Defendants whether or not Defendants have satisfactorily completed the SEP. If Defendants have not completed the SEP in accordance with this Consent Decree, stipulated penalties may be assessed under Section XI (Stipulated Penalties) of this Consent Decree.

111. Defendants may invoke dispute resolution under Section XIII of the Decree (Dispute Resolution) regarding EPA's determination of (i) whether Defendants have satisfactorily performed a SEP and (ii) the amount of eligible SEP costs. No other disputes arising under this Section are subject to Dispute Resolution.

112. Defendants shall ensure that each submission required under this Section is signed by a Defendant official with knowledge of the SEP and bears the certification language set forth in Paragraph 120.

113. If Defendants reference the SEPs under this Consent Decree in any press conference, press release, or similar formal public statement, Defendants shall include language in substantially the following form: "This project was undertaken in connection with the settlement of an enforcement action under the Clean Air Act brought by the United States, the State of Oklahoma, PADEP, and the State of West Virginia against certain MarkWest entities."

114. For federal income tax purposes, Defendants agree that they will neither capitalize into inventory or basis nor deduct any costs or expenditures incurred in performing each SEP.

VIII. REPORTING REQUIREMENTS

115. After the Effective Date and until termination of this Decree pursuant to Section XX (Termination), Defendants shall submit periodic reports on the status of the injunctive relief, SEPs, and other reporting required by the Consent Decree to EPA Headquarters, the EPA Regional Office(s), and the Applicable State Co-Plaintiff(s). The initial such status report shall cover the first 365-Day period after the Effective Date and shall be due within thirty (30) Days after the end of the 365-Day period. Each subsequent status report shall cover a one (1) year period and shall be due within thirty (30) Days after the end of the annual period covered. Each status report shall contain the following information:

116. Each report submitted by Defendants under this Section shall also include a description of any noncompliance with the requirements of this Consent Decree and an explanation of the noncompliance's likely cause and of the remedial steps taken, or to be taken, to prevent or minimize such noncompliance. If the cause of a noncompliance cannot be fully explained at the time the report is due, Defendants shall so state in the report. Defendants shall investigate the cause of the violation and shall then submit an amendment to the report, including a full explanation of the cause of the violation, within 30 Days of the Day Defendants become aware of the cause of the violation. Nothing in this Paragraph or the following Paragraph relieves Defendants of their obligation to provide the notice required by Section XII (Force Majeure).

117. All Reports under this Consent Decree shall be submitted to EPA in the manner designated in Section IX (Notices) of this Consent Decree.

118. The reporting requirements of this Consent Decree do not relieve Defendants of any reporting obligations required by the CAA or implementing regulations, or by any other federal, state, or local law, regulation, permit, or other requirement. The reporting requirements of this Section are in addition to any other reports, plans, or submissions required by other Sections of this Consent Decree.

119. Whenever any violation of this Consent Decree or of any applicable permits or any other event affecting a Defendant's performance under this Decree, or the performance of a Covered Facility, may pose an immediate threat to the public health or welfare or the environment, Defendants shall notify EPA and the Applicable State Co-Plaintiff orally or by electronic transmission as soon as possible, but no later than 24 hours after Defendants first knew of the non-compliance or event. This procedure is in addition to the requirements set forth in the preceding Paragraph.

120. Each report submitted by Defendants under this Section shall be signed by a Defendant's official (head of those responsible for environmental management and compliance) and include the following certification:

121. This certification requirement does not apply to emergency or similar notifications where compliance would be impractical.

122. [Reserved]

123. Any information provided pursuant to this Consent Decree may be used by the United States in any proceeding to enforce the provisions of this Consent Decree and as otherwise permitted by law.

IX. NOTICES

124. Each report, study, notification, or other communications between Parties to this Consent Decree shall be submitted as specified in this Paragraph and Paragraphs 127-129 below. Where this Consent Decree requires that notices and submissions are to be made to the "United States" they shall be made to the U.S. Department of Justice, EPA Headquarters, and the EPA Regional Office(s) for the Covered Facility or Facilities the submission concerns. Where this Consent Decree requires that notices and submissions are to be made to an Applicable Co-Plaintiff(s), they shall be made to the Applicable Co-Plaintiff(s) and/or Permitting Authority for the jurisdiction(s) in which the Covered Facility or Facilities are located.

125. Unless otherwise provided herein, notifications to or communications between the Parties shall be deemed submitted on the date they are postmarked and sent by U.S. Mail, postage pre-paid, or shipped by a delivery service with confirmation of delivery, except for notices under Section XII (Force Majeure) and Section XIII (Dispute Resolution) which shall be sent either by overnight mail or by certified or registered mail, return receipt requested.

126. If the date for submission of a report, study, notification, or other communication falls on a Saturday, Sunday, or legal holiday, the report, study, notification, or other communication shall be deemed timely if it is submitted the next Day.

127. Where an e-mail address is provided below, Defendants may submit any reports, notification, certifications, or other communications required by this Consent Decree electronically (other than submission of a permit application required by this Consent Decree, payment of penalties under Section IV or Section XI (Stipulated Penalties) and notices under Section XII (Force Majeure) and Section XIII (Dispute Resolution) in lieu of submission by U.S. Mail. Electronic submissions shall be deemed submitted on the date they are transmitted electronically. Any report, notification, certification, or other communication that cannot be submitted electronically shall be submitted in hard-copy as provided in this Section IX.

128. Except as otherwise provided herein, all reports, notifications, certifications, or other communications required or allowed under this Consent Decree to be submitted or delivered to the United States, EPA, Applicable EPA Regional Office, the State Co-Plaintiffs, and Defendants shall be addressed as follows:

129. Any Party may change either the notice recipient or the address for providing notices to it by serving all other parties with a notice setting forth such new notice recipient or address. In addition, the nature, means of submission (e.g., electronic instead of paper copies), and frequency of reports required by this Consent Decree may be modified by mutual consent of the Parties. The consent of the United States to such modification shall be in the form of a written notification from EPA, but need not be filed with the Court to be effective.

X. APPROVAL OF DELIVERABLES

130. After review of any plan, report, or other item that is required to be submitted pursuant to this Consent Decree, EPA after consultation with the Applicable State Co-Plaintiff shall in writing: (a) approve the submission; (b) approve the submission upon specified conditions; (c) approve part of the submission and disapprove the remainder; or (d) disapprove the submission.

131. If the submission is approved pursuant to Paragraph 130(a), Defendants shall take all actions required by the plan, report, or other document, in accordance with the schedules and requirements of the plan, report, or other document, as approved. If the submission is conditionally approved or approved only in part pursuant to Paragraph 130(b) or (c), Defendants shall, upon written direction from EPA after consultation with the Applicable State Co-Plaintiff, take all actions required by the approved plan, report, or other item that EPA after consultation with the Applicable State Co-Plaintiff determines are technically severable from any disapproved portions, subject to Defendants' right to dispute only the specified conditions or the disapproved portions, under Section XIII (Dispute Resolution).

132. If the submission is disapproved in whole or in part pursuant to Paragraph 130(c) or (d), Defendants shall, within 45 Days or such other time as the EPA and Defendants agree to in writing, correct all deficiencies and resubmit the plan, report, or other item, or disapproved portion thereof, for approval, in accordance with the preceding Paragraphs. If the resubmission is approved in whole or in part, Defendants shall proceed in accordance with the preceding Paragraph.

133. If a resubmitted plan, report, or other item, or portion thereof, is disapproved in whole or in part, EPA after consultation with the Applicable State Co-Plaintiff may again require Defendants to correct any deficiencies, in accordance with the preceding Paragraphs, or may itself correct any deficiencies subject to Defendants' right to invoke Dispute Resolution and the right of EPA after consultation with the Applicable State Co-Plaintiff to seek stipulated penalties.

134. Any stipulated penalties applicable to the original submission, as provided in Section XI (Stipulated Penalties), shall accrue during the 45 Day period or other specified period, but shall not be payable unless the resubmission is untimely or is disapproved in whole or in part; provided that, if the original submission was so deficient as to constitute a material breach of Defendants' obligations under this Decree, the stipulated penalties applicable to the original submission shall be due and payable notwithstanding any subsequent resubmission.

XI. STIPULATED PENALTIES

135. Stipulated penalties shall be paid to the United States and to the Applicable State Co-Plaintiffs for each failure by a Defendant to comply with the terms of this Consent Decree as provided herein at any Covered Facility where the Defendant is responsible for compliance under Paragraph 11 above. These stipulated penalties shall be split 50% to the United States, and 50% to the Applicable State Co-Plaintiff. Where more than one Defendant is responsible for compliance with respect to a Covered Facility, asset, and/or equipment that it owns or operates at a Covered Facility, there shall be only one stipulated penalty assessed per violation against the Defendants responsible for compliance for which they shall be jointly and severally liable. Stipulated penalties shall be calculated in the amounts specified in this Section XI.

136. [Reserved].

137. Demand for Stipulated Penalties. Subject to Section XIII (Dispute Resolution) or any order of the Court, the applicable Defendants shall pay stipulated penalties upon written demand by the United States no later than sixty (60) Days after a Defendant receives such a demand. Demand from the United States shall be deemed a demand from the appropriate Applicable State Co-Plaintiff, but the United States and the appropriate Applicable State Co-Plaintiff shall consult each other prior to making a demand. A demand for the payment of stipulated penalties shall identify the particular violation(s) to which the stipulated penalty relates, the stipulated penalty amount that the United States is demanding for each violation (as can be best estimated), the calculation method underlying the demand, and the grounds upon which the demand is based.

138. Payment of Stipulated Penalties. Any stipulated penalty demand shall identify to which Plaintiff(s) payment shall be made. Stipulated Penalties owing to the United States of under $10,000 shall be paid by check and made payable to "U.S. Department of Justice," referencing DOJ case number 90-5-2-1-11374/1 and delivered to the U.S. Attorney's Office in the Northern District of Ohio. Stipulated penalties owing to the United States of $10,000 or more and stipulated penalties owing to any State Co-Plaintiff shall be paid in the manner set forth in Section IV (Civil Penalty). The transmittal letter required by Paragraph 14 shall specify that the payment is for stipulated penalties.

139. Failure to Pay Civil Penalty. If Defendants fail to pay any portion of the civil penalty required to be paid under Section IV of this Decree (Civil Penalty) when due, Defendants shall pay a stipulated penalty of $5,000 per Day for each Day that the payment is late. Late payment of the civil penalty and any accrued stipulated penalties shall be made in accordance with Paragraph 14 above.

140. Failure to Meet all Other Consent Decree Obligations. Defendants shall be liable for stipulated penalties to the United States and/or the Applicable State Co-Plaintiff for violations of this Consent Decree at any Covered Facility where the Defendant is responsible for compliance under Paragraph 11 above unless excused under Section XII of this Consent Decree (Force Majeure). The payment of stipulated penalties and interest, if any, shall not alter in any way Defendants' obligation to complete the performance of the requirements of this Consent Decree.

141. Stipulated Penalties in Lieu of those in Subparagraphs 140.b.xvi., xvii and xviii.

142. Waiver of Payment. Either the United States or State Co-Plaintiff may, in the unreviewable exercise of their respective discretion, reduce or waive payment of stipulated penalties otherwise due them under this Consent Decree.

143. Stipulated Penalties Payment Due Date. Stipulated Penalties shall be paid no later than 30 Days after receipt of a written demand by the United States or State Co-Plaintiff unless the demand is disputed through compliance with the requirements of the Dispute Resolution (Section XIII) below.

144. Accrual of Stipulated Penalties.

145. Subject to the provisions of Section XV (Effect of Settlement/Reservation of Rights), the stipulated penalties provided for in this Consent Decree shall be in addition to any other rights, remedies, or sanctions available to the United States and the State Co-Plaintiffs for Defendants' violations of this Consent Decree or applicable law. Where a violation of this Decree is also a violation of relevant statutory or regulatory requirements, Defendants shall be allowed a credit for any stipulated penalties paid against any statutory penalties imposed for such violation under the applicable federal or state requirement.

XII. FORCE MAJEURE

146. "Force majeure," for purposes of this Consent Decree, is defined as any event arising from a cause or causes beyond the control of Defendants, of any entity controlled by Defendants, or of Defendants' contractors, that delays or prevents the performance of any obligation under this Decree despite Defendants' best efforts to fulfill the obligation. The requirement that Defendants exercise "best efforts to fulfill the obligation" includes using reasonable efforts to anticipate any potential force majeure event and best efforts to address the effects of any such event (a) as it is occurring and (b) after it has occurred in order to minimize delay and any adverse effects of the delay to the greatest extent possible. Force majeure does not include Defendants' financial inability to perform any obligation under this Decree.

147. If any event occurs or has occurred that may delay the performance of any obligation under this Consent Decree, for which Defendants intend or may intend to assert a claim of force majeure, Defendants shall provide notice orally or by electronic transmission within three (3) Days of when Defendants first knew that the event might cause a delay to the addresses provided in Section IX of this Consent Decree (Notices). Within fifteen (15) Days of this initial notification, Defendants shall provide in writing to EPA and to the Applicable State Co-Plaintiff, to the extent available: an explanation and description of the reasons for the delay; the anticipated duration of the delay; all actions taken or to be taken to prevent or minimize the delay; a schedule for implementation of any measures to be taken to mitigate the delay or the effect of the delay; and Defendants' rationale for attributing such delay to a force majeure event if it intends to assert such a claim. Defendants shall include with any notice all available documentation necessary to support the claim that the delay was attributable to a force majeure. Any material failure to comply with the above requirements that prejudices EPA's ability to assess Defendants' claim of force majeure shall preclude Defendants from asserting any claim of force majeure for that event for the period of time of such failure to comply.

148. If EPA agrees that the delay or anticipated delay is attributable to a force majeure, the time for performance of the obligations under this Consent Decree that are affected by the force majeure event will be extended by EPA for such time as is necessary to complete those obligations. An extension of the time for performance of the obligations affected by the force majeure event shall not, of itself, extend the time for performance of any other obligation. EPA will notify Defendants in writing of the length of the extension, if any, for performance of the obligations affected by the force majeure.

149. If EPA does not agree that the delay or anticipated delay has been or will be caused by a force majeure event, EPA will notify Defendants in writing of its decision.

150. If Defendants elect to invoke the dispute resolution procedures set forth in Section XIII (Dispute Resolution) of this Consent Decree with regard to a force majeure event, it shall do so no later than thirty (30) Days after receipt of EPA's notice. In any such proceeding, Defendants bear the burden of demonstrating by a preponderance of the evidence that the delay or anticipated delay has been or will be caused by a force majeure, that the duration of the delay or the extension sought was or will be warranted under the circumstances, that best efforts were exercised to avoid and mitigate the effects of the delay, and that Defendants complied with the requirements of Paragraphs 146 and 147. If Defendants carry this burden, the delay at issue shall be deemed not to be a violation of the affected obligation of this Decree.

XIII. DISPUTE RESOLUTION

151. Unless otherwise expressly provided for in this Consent Decree, the dispute resolution procedures of this Section shall be the exclusive mechanism to resolve any dispute arising under or with respect to this Consent Decree.

152. Informal Dispute Resolution. Any dispute subject to dispute resolution under this Consent Decree shall first be the subject of informal negotiations. The dispute shall be considered to have arisen when Defendants dispute a decision of the United States and sends the United States and the Applicable State Co-Plaintiff(s) a written Notice of Dispute. Such Notice of Dispute shall state clearly the matter in dispute. The period of informal negotiations shall not exceed ninety (90) Days from the date the dispute arises, unless that period is modified by written agreement. If the Parties cannot resolve a dispute by informal negotiations, then the position advanced by the United States, after consultation with the Applicable State Co-Plaintiff(s) shall be considered binding unless, within ninety (90) Days after the conclusion of the informal negotiation period, Defendants invoke formal dispute resolution procedures as set forth below.

153. Formal Dispute Resolution. Defendants shall invoke formal dispute resolution procedures, within the time period provided in the preceding Paragraph, by serving on the United States and the Applicable State Co-Plaintiff(s) a written Statement of Position regarding the matter in dispute. The Defendants' Statement of Position shall include, but need not be limited to, any factual data, analysis, or opinion supporting Defendants' position and any supporting documentation relied upon by Defendants.

154. The United States, after consultation with the Applicable State Co-Plaintiff(s) shall serve its Statement of Position within forty-five (45) Days of receipt of Defendants' Statement of Position. The United States' Statement of Position shall include, but need not be limited to, any factual data, analysis, or opinion supporting that position and any supporting documentation relied upon by the United States. The United States' Statement of Position shall be binding on Defendants unless Defendants file a motion for judicial review of the dispute in accordance with the following Paragraph.

155. Defendants may seek judicial review of the dispute by filing with the Court and serving on the United States, in accordance with Section IX of this Consent Decree (Notices), a motion requesting judicial resolution of the dispute. The motion must be filed within 30 Days of receipt of the United States' Statement of Position pursuant to the preceding Paragraph. The motion shall contain a written statement of Defendants' position on the matter in dispute, including any supporting factual data, analysis, opinion, or documentation, and shall set forth the relief requested and any schedule within which the dispute must be resolved for orderly implementation of the Consent Decree.

156. The United States shall respond to Defendants' motion within the time period allowed by the Local Rules of this Court for responses to dispositive motions. Defendants may file a reply memorandum to the extent permitted by the Local Rules.

157. Standard of Review.

158. The invocation of dispute resolution procedures under this Section shall not, by itself, extend, postpone, or affect in any way any obligation of Defendants under this Consent Decree, unless and until final resolution of the dispute so provides. Stipulated penalties with respect to the disputed matter shall continue to accrue from the first Day of noncompliance, but payment shall be stayed pending resolution of the dispute as provided in Subparagraph 144.b. above. If Defendants do not prevail on the disputed issue, subject to the Court's order, stipulated penalties shall be assessed and paid as provided in Section XI (Stipulated Penalties).

XIV. INFORMATION COLLECTION AND RETENTION

159. The United States, any Applicable State Co-Plaintiff, and their representatives and employees shall have the right of entry into any Covered Facility, at all reasonable times, upon presentation of credentials and any other documentation required by law, to:

160. Until two years after termination of this Consent Decree, (or for such longer period as may be required under State law), Defendants shall retain, and shall instruct its contractors and agents to preserve, all documents, records, or other information, regardless of storage medium (e.g., paper or electronic) in their or their contractors' or agents' possession or control, or that come into their or their contractors' or agents' possession or control, and that directly relate to Defendants' performance of its obligations under this Consent Decree. This information-retention requirement shall apply regardless of any contrary corporate or institutional policies or procedures. At any time during this information-retention period, the United States and/or any Applicable State Co-Plaintiff may request copies of any documents, records, or other information required to be maintained under this Paragraph.

161. Except for emissions data, including Screening Values, a Defendant may also assert that information required to be provided under this Section is protected as Confidential Business Information ("CBI") under 40 C.F.R. Part 2. As to any information that the Defendant seeks to protect as CBI, the Defendant shall follow the procedures set forth in 40 C.F.R. Part 2, where applicable. Except for emissions data, including Screening Values, the Defendant reserves the right to assert any legal privilege and the United States reserves the right to challenge any claim of privilege.

162. This Consent Decree in no way limits or affects any right of entry and inspection, or any right to obtain information, held by the United States or any Applicable State Co-Plaintiff pursuant to applicable federal laws, state laws, regulations, or permits, nor does it limit or affect any duty or obligation of Defendants to maintain documents, records, or other information imposed by applicable federal or state laws, regulations, or permits.

XV. EFFECT OF SETTLEMENT/RESERVATION OF RIGHTS

163. Entry of this Consent Decree resolves the civil claims of the United States and the State Co-Plaintiffs, from the date those claims accrued through the Date of Lodging, for the violations alleged in the Complaint filed in this action, Region 5's September 20, 2015 Notice and Finding of Violation for the Hopedale Facility (Appendix E), Region 3's April 4, 2016 Notice of Noncompliance for the Houston Facility (Appendix F), Region 5's June 21, 2016 Finding of Violation for the Hopedale Facility (Appendix G), Region 5's September 7, 2016 Finding of Violation for the Seneca Facility (Appendix H), and other alleged violations of the referenced NSPS Subparts at the following Covered Facilities:

Entry of this Consent Decree also resolves the civil claims of the United States and the State Co-Plaintiffs, from the date those claims accrued through the Date of Lodging, for the violations alleged in the Complaint of 40 C.F.R. Part 60, Subpart Db, for the following Large Hot Oil Heaters: Cadiz H-1782; Hopedale H-1741, and Hot Oil #4; Houston 3 Hot Oil and Frac Hot Oil-H-781; De-Ethanizer Hot Oil H-1741; Majorsville De-Ethanizer Hot Oil (H-2782 and 2782); Sherwood De-Ethanizer Hot Oil; and 40 C.F.R. Part 60, Subpart Dc, for the following Small Hot Oil Heaters: Heaters Cadiz B002, B008, and B013; Utica Condensate B001 and B002; Hopedale B001 and B002; Seneca B004, B005, B006, B009, and B011; Bluestone Source 107-4, Source 107-5, Source 107-8, Source 107-12, and Source 107-13; Carthage H8, H-2 and H-6; Mobley 1781, H-2781, H-4781, and H-5781; Majorsville H-781, H-3781, H-4781, H-4782, and H6782; and Sherwood H771 and H-10768.

164. The resolution of liability by the United States and the State Co-Plaintiffs to Defendants as set forth in Paragraph 163, will be rendered void if Defendants materially fail to comply with the obligations and requirements of Sections V through VII of this Consent Decree; provided, however, that the resolution of liability in Paragraph 163 will not be rendered void if Defendants timely remedy such material failure and pay any stipulated penalties due as a result of such material failure.

165. The United States and the State Co-Plaintiffs reserve all legal and equitable remedies available to enforce the provisions of this Consent Decree, except as expressly stated in Paragraphs 145, 163 and 164. This Consent Decree shall not be construed to limit the rights of the United States or the State Co-Plaintiffs to obtain penalties or injunctive relief under the CAA or implementing regulations, or under other federal laws, state laws, regulations, or permit conditions, except as expressly specified in Paragraphs 163 and 164. The United States and the State Co-Plaintiffs further reserve all legal and equitable remedies to address any situation that may present an imminent and substantial endangerment to the public health or welfare or the environment arising at, or posed by, the Covered Facility, whether related to the violations addressed in this Consent Decree or otherwise.

166. In any subsequent administrative or judicial proceeding initiated by the United States and/or the State Co-Plaintiffs for injunctive relief, civil penalties, or other appropriate relief relating to a Covered Facility, Defendants shall not assert, and may not maintain, any defense or claim based upon the principles of waiver, res judicata, collateral estoppel, issue preclusion, claim preclusion, claim-splitting, or other defenses based upon any contention that the claims raised by the United States and/or State Co-Plaintiffs in the subsequent proceeding were or should have been brought in the instant case, except with respect to claims that have been specifically resolved pursuant to Paragraphs 163 and 164 of this Section.

167. This Consent Decree is not a permit, or a modification of any permit, under any federal, state, or local laws or regulations. Defendants are responsible for achieving and maintaining compliance with all applicable federal, state, and local laws, regulations, and permits and a Defendant's compliance with this Consent Decree shall be no defense to any action commenced pursuant to any such laws, regulations, or permits. The United States and the State Co-Plaintiffs do not, by their consent to the entry of this Consent Decree, warrant or aver in any manner that Defendants' compliance with any aspect of this Consent Decree will result in compliance with provisions of the CAA, or with any other provisions of federal, state, or local laws, regulations, or permits.

168. This Consent Decree does not limit or affect the rights of Defendants or of the United States and State Co-Plaintiffs against any third parties, not party to this Consent Decree, nor does it limit the rights of third parties not party to this Consent Decree, against Defendants, except as otherwise provided by law.

169. This Consent Decree shall not be construed to create rights in, or grant any cause of action to, any third party that is not a Party to this Consent Decree.

170. Defendants expressly deny and do not admit any liability to the United States or the State Co-Plaintiffs arising out of the conduct, transactions or occurrences alleged in the Complaint. Nothing in this Consent Decree shall be construed as an admission of Defendants' liability, nor shall Defendants' performance of any obligation under this Decree be considered any admission of liability. This Consent Decree shall not be admissible against Defendants in any administrative or judicial proceeding, except in a proceeding initiated by the Parties to enforce this Decree.

XVI. COSTS

171. The Parties shall bear their own costs of this action, including attorneys' fees, except that the United States and any Applicable State Co-Plaintiffs shall be entitled to collect the costs (including attorneys' fees) against a Defendant incurred in any action necessary to enforce this Consent Decree or to collect any portion of the civil penalty or any stipulated penalties due but not paid by a Defendant.

XVII. EFFECTIVE DATE

172. The Effective Date of this Consent Decree shall be the date upon which this Consent Decree is entered by the Court or a motion to enter the Consent Decree is granted, whichever occurs first, as recorded on the Court's docket. In the event the United States withdraws or withholds consent to this Consent Decree before entry, or the Court declines to enter the Consent Decree, then the preceding requirement to comply with requirements of this Consent Decree upon the Date of Lodging shall terminate.

XVIII. RETENTION OF JURISDICTION

173. The Court shall retain jurisdiction over this case until termination of this Consent Decree for the purposes of resolving disputes arising under this Decree, entering orders modifying this Decree, or effectuating or enforcing compliance with the terms of this Decree.

XIX. MODIFICATION

174. This Consent Decree contains the entire agreement of the Parties and shall not be modified by a prior oral or written agreement, representation, or understanding. Non-material modifications to this Consent Decree shall be effective when signed in writing by the United States, the Defendants responsible for compliance at the Covered Facility or Covered Facilities affected by the modification pursuant to Paragraph 11 above and the Applicable State Co-Plaintiff. The United States shall file non-material modifications with the Court on a periodic basis. Material modifications to this Consent Decree shall be in writing, signed by the United States, the Applicable State Co-Plaintiff, and the Defendants responsible for the compliance at the Covered Facility or Covered Facilities affected by the modification pursuant to Paragraph 11 above, and shall be effective upon approval by the Court.

175. Any disputes concerning modification of this Decree shall be resolved pursuant to Section XIII of this Decree (Dispute Resolution); provided, however, that instead of the burden of proof as provided by Paragraph 157, the Party seeking the modification bears the burden of demonstrating that it is entitled to the requested modification in accordance with Federal Rule of Civil Procedure 60(b).

XX. TERMINATION

176. Termination: Conditions Precedent. Prior to termination, Defendants must have completed all of the following requirements of this Consent Decree:

177. Termination: Procedure.

XXI. PUBLIC PARTICIPATION

178. This Consent Decree shall be lodged with the Court for a period of not less than 30 Days for public notice and comment in accordance with 28 C.F.R. § 50.7. The United States and the State Co-Plaintiffs reserve the right to withdraw or withhold their consent if the comments regarding the Consent Decree disclose facts or considerations indicating that the Consent Decree is inappropriate, improper, or inadequate. Defendants consent to entry of this Consent Decree without further notice.

XXII. SIGNATORIES/SERVICE

179. The undersigned representatives of the Defendants and the Assistant Attorney General for the Environment and Natural Resources Division of the Department of Justice (or his or her designee) and the State Co-Plaintiffs each certify that he or she is fully authorized to enter into the terms and conditions of this Consent Decree and to execute and legally bind the Party he or she represents to this document.

180. This Consent Decree may be signed in counterparts, and its validity shall not be challenged on that basis.

181. Defendants agree not to oppose entry of this Consent Decree by the Court or to challenge any provision of the Decree unless the United States has notified Defendants in writing that it no longer supports entry of the Decree.

182. Defendants agree to accept service of process by mail with respect to all matters arising under or relating to this Consent Decree and to waive the formal service requirements set forth in Rules 4 and 5 of the Federal Rules of Civil Procedure and any applicable Local Rules of this Court including, but not limited to, service of a summons. Defendants need not file an answer to the complaint in this action unless or until the Court expressly declines to enter this Consent Decree.

XXIII. INTEGRATION

183. This Consent Decree and its Appendices constitute the final, complete, and exclusive agreement and understanding between the Parties with respect to the settlement embodied in this Consent Decree and its Appendices, and supersede all prior agreements and understandings, whether oral or written, concerning the settlement embodied herein. No other document, except for any plans or other deliverables that are submitted and approved pursuant to this Decree, nor any representation, inducement, agreement, understanding, or promise, constitutes any part of this Decree or the settlement it represents, and no such extrinsic document or statement of any kind shall be used in construing the terms of this Decree.

XXIV. SECTION 162(f)(2)(A)(ii) IDENTIFICATION

184. For purposes of the identification requirement of Section 162(f)(2)(A)(ii) of the Internal Revenue Code, 26 U.S.C. § 162(f)(2)(A)(ii), performance of Section II (Applicability and Sales or Transfers of Ownership and Operation Interests), Paragraph 9, Section V (Injunctive Relief), Paragraphs 19-100, Section VI (Permits), Paragraphs 101-103, Section VIII (Reporting), Paragraphs 115(a)(i)(1)-(11), (iii), and (b), 116-117 and 120, and Section XIV (Information Collection and Retention), Paragraphs 159-160, is restitution or required to come into compliance with law.

XXV. FINAL JUDGMENT

185. Upon approval and entry of this Consent Decree by the Court, this Consent Decree shall constitute a final judgment of the Court in this action as to the United States, State Co-Plaintiffs, and Defendants. The Court finds that there is no just reason for delay and therefore enters this judgment as a final judgment under Fed. R. Civ. P. 54 and 58.

We hereby consent to the entry of the Consent Decree in the matter of United States, et al. v. MPLX LP., et al., subject to public notice and comment.

We hereby consent to the entry of the Consent Decree in the matter of United States, et al v. MPLX LP. et al., subject to public notice and comment.

We hereby consent to the entry of the Consent Decree in the matter of United States, et al. v. MPLX L.P., et al., subject to public notice and comment.

We hereby consent to the entry of the Consent Decree in the matter of United States, et al. v. MPLX L.P., et al., subject to public notice and comment.

We hereby consent to the entry of the Consent Decree in the matter of United States, et al. v. MPLX L.P., et al., subject to public notice and comment.

APPENDIX A

Factors to be Considered and Procedures to be Followed To Claim Commercial Unavailability

This Appendix outlines the factors to be taken into consideration and the procedures to be followed for Defendants to assert that a Low-E Valve or Low-E Packing is "commercially unavailable" pursuant to Paragraph 40 of the Consent Decree.

I. FACTORS

A. Nothing in this Consent Decree or this Appendix requires Defendants to utilize any valve or packing that is not suitable for its intended use in a Covered Process Unit.

B. The following factors are relevant in determining whether a Low-E Valve or Low-E Packing is commercially available to replace or repack an existing valve:

C. The following factors may also be relevant, depending upon the Process Unit or equipment where the valve is located:

II. PROCEDURES THAT DEFENDANTS SHALL FOLLOW TO ASSERT COMMERCIAL UNAVAILABILITY

A. Defendants shall comply with the following procedures if they seek to assert commercial unavailability under Paragraph 40 of the Consent Decree:

1. Defendants must contact a reasonable number of vendors of valves or valve packing that Defendants, in good faith, believe may have valves or valve packing suitable for the intended use taking into account the relevant factors listed in Section I of this Appendix above.

2. Defendants shall obtain a written representation from each vendor, or equivalent documentation, that a particular valve or valve packing is not available as "Low-Emissions" from that vendor for the intended conditions or use.

a. "Equivalent documentation" may include e-mail or other correspondence or data showing that a valve or valve packing suitable for the intended use does not meet the definition of "Low-E Valve" or "Low-E Packing" in the Consent Decree or that the valve or packing is not suitable for the intended use.

b. If the vendor does not respond or refuses to provide documentation, "equivalent documentation" may consist of records of Defendants' attempts to obtain a response from the vendor.

3. Each LDAR Program Compliance Status Report required by Section V of the Consent Decree shall identify each valve that Defendants otherwise were required to replace or repack, but for which, during the time period covered by the Report, Defendants determined that a Low-E Valve and/or Low-E Packing was not commercially available. Defendants shall provide a complete explanation of the basis for its claim of commercial unavailability, including, as an attachment to the Compliance Status Report, all relevant documentation. This report shall be valid for a period of 365 Days from the date of the report for the specific valve involved and all other similar valves, taking into account the factors listed in Part I.

III. OPTIONAL EPA REVIEW OF DEFENDANT'S ASSERTION OF COMMERCIAL UNAVAILABILITY

A. At its option, EPA may review an assertion by Defendants of commercial unavailability. If EPA disagrees with Defendants' assertion, EPA shall notify Defendants in writing, specifying the Low-E Valve or Low-E Packing that EPA believes to be commercially available and the basis for its view that such valve or packing is appropriate taking into consideration the Factors described in Part I. After Defendants receive EPA's notice, the following shall apply:

1. Defendants shall not be required to retrofit the valve or valve packing for which it asserted commercial unavailability (unless Defendants are otherwise required to do so pursuant to another provision of the Consent Decree).

2. Defendants shall be on notice that EPA will not accept a future assertion of commercial unavailability for: (i) the valve or packing that was the subject of the unavailability assertion; and/or (ii) a valve or packing that is similar to the valve or packing subject to the unavailability assertion, taking into account the Factors described in Part I.

3. If Defendants disagree with EPA's notification, Defendants and EPA shall informally discuss the basis for the claim of commercial unavailability. EPA may thereafter revise its determination, if necessary.

4. If Defendants make a subsequent commercial unavailability claim for the same or similar valve or packing that EPA previously rejected, and the subsequent claim also is rejected by EPA, Defendants shall retrofit the valve or packing with the commercially available valve or packing unless Defendants are successful under Subsection III.B of this Appendix below.

B. Any disputes under this Appendix first shall be subject to informal discussions between Defendants and EPA for a period not to exceed 30 Days before Defendants shall be required to invoke the Dispute Resolution provisions of Section XIII of the Consent Decree. Thereafter, if the dispute remains, Defendants shall invoke the Dispute Resolution provisions.

APPENDIX B

FENCE LINE MONITORING SYSTEM SUPPLEMENTAL ENVIRONMENTAL PROJECT

A. General Requirements

B. Stationary Equipment Requirements

C. Operation of FLMS

APPENDIX C

APPENDIX D

APPENDIX E

Dear Ms. McBurney:

The U.S. Environmental Protection Agency is issuing the enclosed Notice and Finding of Violation (NOV/FOV) to MarkWest Energy Partners L.P. and MarkWest Utica EMG, L.L.C. (collectively MarkWest or you) under Sections 113(a)(1) and (3) of the Clean Air Act, 42 U.S.C. § 7413(a)(1) and (3). We find that you are violating the following at your Hopedale Fractionation Plant in Jewett, Ohio: (1) Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution at 40 C.F.R. §§ 60.5360-5430 (Subpart OOOO); (2) Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 at 40 C.F.R. §§ 60.480a-60.490 (Subpart VVa); (3) Standards of Performance for Volatile Organic Compounds (VOC) From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Distillation Operations at 40 C.F.R. §§ 60.660-60.668 (Subpart NNN); (4) Standards of Performance for VOC From SOCMI Reactor Processes at 40 C.F.R. §§ 60.700-60.708 (Subpart RRR); (5) Standards of Performance for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After July 23, 1984 at 40 C.F.R. §§ 60.110b-117b (Subpart Kb); and (6) Permit to Install and Operate (PTIO) conditions established pursuant to the Ohio State Implementation Plan (SIP) at Ohio Administrative Code (OAC) 3745-31.

Section 113 of the Clean Air Act gives us several enforcement options. These options include issuing an administrative compliance order, issuing an administrative penalty order and bringing a judicial civil or criminal action.

We are offering you an opportunity to confer with us about the violations alleged in the NOV/FOV. The conference will give you an opportunity to present information on the specific findings of violation, any efforts you have taken to comply and the steps you will take to prevent future violations. In addition, in order to make the conference more productive, we encourage you to submit to us information responsive to the NOV/FOV prior to the conference date.

Please plan for your facility's technical and management personnel to attend the conference to discuss compliance measures and commitments. You may have an attorney represent you at this conference. The EPA contact in this matter is Constantinos Loukeris. You may call him at (312) 353-6198 to request a conference. You should make the request within 10 calendar days following receipt of this letter. We should hold any conference within 30 calendar days following receipt of this letter.

NOTICE AND FINDING OF VIOLATION

The U.S. Environmental Protection Agency finds that MarkWest Energy Partners, L.P. and MarkWest Utica EMG, L.L.C. (collectively "MarkWest") is violating the Clean Air Act (CAA) and its implementing regulations at the company's Hopedale Fractionation Facility in Jewett, Ohio. Specifically, MarkWest is violating: (1) Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution at 40 C.F.R. §§ 60.5360-5430 (Subpart OOOO); (2) Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 at 40 C.F.R. §§ 60.480a-60.490 (Subpart VVa); (3) Standards of Performance for Volatile Organic Compounds (VOC) From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Distillation Operations at 40 C.F.R. §§ 60.660-60.668 (Subpart NNN); (4) Standards of Performance for VOC From SOCMI Reactor Processes at 40 C.F.R. §§ 60.700-60.708 (Subpart RRR); (5) Standards of Performance for Volatile Organic Liquid Storage Vessels (Including Petroleum Liquid Storage Vessels) for Which Construction, Reconstruction, or Modification Commenced After July 23, 1984 at 40 C.F.R. §§ 60.110b-117b (Subpart Kb); and (6) Permit to Install and Operate (PTIO) conditions established pursuant to the Ohio State Implementation Plan (SIP) at Ohio Administrative Code (OAC) 3745-31.

Regulatory Authority

New Source Performance Standard Subpart OOOO

1. Section 111 of the CAA, 42 U.S.C. § 7411, authorizes EPA to promulgate regulations establishing New Source Performance Standards (NSPS).

2. Section 111(e) of the CAA, 42 U.S.C. § 7411(e), states that after the effective date of standards of performance promulgated under this section, it shall be unlawful for any owner or operator of any new source to operate such source in violation of any standard of performance applicable to such source.

3. EPA promulgated Subpart OOOO on September 23, 2013. 78 Fed. Reg. 58435.

4. Subpart OOOO at 40 C.F.R. § 60.5365 states that an owner or operator of one or more of the onshore affected facilities listed in paragraphs (a) through (g) of this section for which construction, modification, or reconstruction commenced after August 23, 2011 is subject to the applicable provisions of Subpart OOOO. § 60.5365(f) states that the group of all equipment, except compressors, within a process unit is an affected facility. § 60.5365(f)(3) further provides that the equipment within a process unit of an affected facility located at onshore natural gas process plants and described in paragraph (f) of this section are exempt from Subpart OOOO if they are subject to and controlled according to Subparts VVa, GGG, or GGGa of 40 C.F.R. Part 60.

5. Subpart OOOO at 40 C.F.R. § 60.5430 defines "process unit" to mean components assembled for the extraction of natural gas liquids from field gas, the fractionation of the liquids into natural gas products, or other operations associated with the processing of natural gas products.

6. Subpart OOOO at 40 C.F.R. § 60.5430 defines a "natural gas processing plant (gas plant)" as "any processing site engaged in the extraction of natural gas liquids from field gas, fractionation of mixed natural gas liquids to natural gas products, or both."

7. Subpart OOOO at 40 C.F.R. § 60.5400 sets forth equipment standards that apply to affected facilities at an onshore natural gas processing plant. This section applies to the group of all equipment, except compressors, within a process unit.

8. Subpart OOOO at 40 C.F.R. § 60.5400(a) states a subject owner or operator must comply with the equipment leak standard requirements of specific portions of Subpart VVa at 40 C.F.R. §§ 60.482-1 a(a), (b), and (d), 60.482-2a, and 60.482-4a through 60.482-11a., except as provided in § 60.5401.

9. Subpart OOOO at 40 C.F.R. § 60.5400(d) states that a subject owner or operator must comply with the provisions of § 60.485a of Subpart VVa except as provided in § 60.5400(f).

10. Subpart OOOO at 40 C.F.R. § 60.5400(e) states that a subject owner or operator must comply with the provisions of §§ 60.486a and 60.487a of Subpart VVa except as provided in §§ 60.5401, 60.5421, and 60.5422 of Subpart OOOO.

11. Subpart OOOO at 40 C.F.R. § 60.5400(f) states that a subject owner or operator must use the following provision instead of § 60.485a(d)(1): "Each piece of equipment is presumed to be in VOC service or in wet gas service unless an owner or operator demonstrates that the piece of equipment is not in VOC service or in wet gas service."

NSPS Subpart VVa

12. EPA promulgated NSPS Subpart VVa on November 16, 2007. See 72 Fed. Reg. 64883. (Subpart VVa)

13. Subpart VVa at 40 C.F.R. § 60.482-1a(a) states "[e]ach owner or operator subject to the provisions of this subpart shall demonstrate compliance with the requirements of §§ 60.482-1a through 60.482-10a or § 60.480a(e) for all equipment within 180 days of initial startup."

14. Subpart VVa at 40 C.F.R. § 60.482-1a(b) states "[c]ompliance with §§ 60.482-1a to 60.482-10a will be determined by review of records and reports, review of performance test results, and inspection using the methods and procedures specified in § 60.485a."

15. Subpart VVa at 40 C.F.R. § 60.482-2a(a)(1) states "[e]ach pump in light liquid service shall be monitored monthly to detect leaks by the methods specified in § 60.485a(b), except as provided in § 60.482-1a(c) and (f) and paragraphs (d), (e), and (f) of this section. A pump that begins operation in light liquid service after the initial startup date for the process unit must be monitored for the first time within 30 days after the end of its startup period."

16. Subpart VVa at 40 C.F.R. § 60.482-2a(a)(1) states that "each pump in light liquid service shall be checked by visual inspection each calendar week for indications of liquids dripping from the pump seal, except as provided in § 60.482-1a(f)."

17. Subpart VVa at 40 C.F.R. § 60.482-11a(a) states "[t]he owner or operator shall initially monitor all connectors in the process unit for leaks by the later of either 12 months after the compliance date or 12 months after initial startup."

18. Subpart VVa at 40 C.F.R. § 60.481a defines "connector" as meaning flanged, screwed, or other joined fittings used to connect two pipe lines or a pipe line and a piece of process equipment or that close an opening in a pipe that could be connected to another pipe.

19. Subpart VVa at 40 C.F.R. § 60.482-11a(d) states that "when a leak is detected pursuant to paragraphs (a) and (b) of this section, it shall be repaired as soon as practicable, but not later than 15 calendar days after it is detected, except as provided in § 60.482-9a. A first attempt at repair as defined in this subpart shall be made no later than 5 calendar days after the leak is detected" from a connector.

20. Subpart VVa at 40 C.F.R. § 60.482-7a(d)(2) states that "a first attempt at repair shall be made no later than 5 calendar days after each leak is detected" from a valve.

21. Subpart VVa at 40 C.F.R. § 60.482-6a(a)(1) states that "each open-ended valve or line shall be equipped with a cap, blind flange, plug, or a second valve, except as provided in § 60.482-1a(c) and paragraphs (d) and (e) of this section."

22. Subpart VVa at 40 C.F.R. § 60.482-6a(a)(2) states that "the cap, blind flange, plug, or second valve shall seal the open end at all times except during operations requiring process fluid flow through the open-ended valve or line."

23. Subpart VVa at 40 C.F.R. § 60.482-7a(a)(1) states that "each valve shall be monitored monthly to detect leaks by the methods specified in § 60.485a(b) and shall comply with paragraphs (b) through (e) of this section."

24. Subpart VVa at 40 C.F.R. § 60.482-7a(a)(2) states that "a valve that begins operation in gas/vapor service or light liquid service after the initial startup date for the process unit must be monitored according to paragraphs (a)(2)(i) or (ii)."

25. Subpart VVa at 40 C.F.R. § 60.482-7a(a)(2)(i) states that a facility must "monitor the valve as in paragraph (a)(1) of this section. The valve must be monitored for the first time within 30 days after the end of its startup period to ensure proper installation."

26. Subpart VVa at 40 C.F.R. § 60.485a (b) states "[t]he owner or operator shall determine compliance with the standards in §§ 60.482-1a through 60.482-11a, 60.483a, and 60.484a as follows: (1) Method 21 shall be used to determine the presence of leaking sources. The instrument shall be calibrated before use each day of its use by the procedures specified in Method 21 of Appendix A-7 of this part."

27. Subpart VVa at 40 C.F.R. § 60.482-4a provides standards for pressure relief devices in gas/vapor service. § 60.482-4a(c) provides that any pressure relief device that is routed to a process or fuel gas system or equipped with a closed vent system capable of capturing and transporting leakage through the pressure relief device to a control device as described in § 60.482-10a is exempted from the requirements of paragraphs (a) and (b) of this section. § 60.482-10a establishes standards for closed vent systems and control devices used to comply with the provisions of Subpart VVa.

28. The NSPS Appendix A-7, at 40 C.F.R. Part 60, Method 21 §§ 8.3.1 and 8.3.1.1, sets forth the technique which must be used to determine if there is a leak from a valve.

NSPS Subparts NNN/RRR

29. On June 29, 1990, EPA promulgated Subpart NNN. See 55 Fed. Reg. 26,942.

30. Subpart NNN at 40 C.F.R. § 60.660(a) states that Subpart NNN applies to each affected facility designated in paragraph (b) of this section that is part of a process unit that produces any of the chemicals listed in 40 C.F.R. § 60.667 as a product, co-product, by-product, or intermediate, except as provided in paragraph (c).

31. Subpart NNN at 40 C.F.R. § 60.660(b) states the affected facility is any of the following for which construction, modification, or reconstruction commenced after December 30, 1983:

32. Subpart NNN at 40 C.F.R. § 60.661 defines "Distillation operation" as an operation separating one or more feed stream(s) into two or more exit stream(s), each exit stream having component concentrations different from those in the feed stream(s). The separation is achieved by the redistribution of the components between the liquid and vapor-phase as they approach equilibrium within the distillation unit.

33. Subpart NNN at 40 C.F.R. § 60.661 defines "Distillation unit" as a device or vessel in which distillation operations occur, including all associated internals (such as trays or packing) and accessories (such as reboiler, condenser, vacuum pump, steam jet, etc.), plus any associated recovery system.

34. Subpart NNN at 40 C.F.R. § 60.662 states that each owner or operator of any affected facility shall comply with paragraph (a), (b), or (c) of this section for each vent stream on and after the date on which the initial performance test required by 40 C.F.R. § 60.8 and 40 C.F.R. § 60.664 is completed, but not later than 60 days after achieving the maximum production rate at which the affected facility will be operated, or 180 days after the initial start-up, whichever date comes first. Each owner or operator shall either:

35. Subpart NNN at 40 C.F.R. § 60.663 sets forth the monitoring of emissions and operations for control devices including flares, boilers or process heaters, and condensers used as a final recovery device in a recovery system.

36. Subpart NNN at 40 C.F.R. § 60.665(a) states that each owner or operator subject to § 60.662 shall notify the Administrator of the specific provisions of 40 C.F.R. § 60.662 with which the owner or operator has elected to comply. Notification shall be submitted with the notification of initial start-up required by 40 C.F.R. § 60.7(a)(3). If an owner or operator elects at a later date to use an alternative provision of 40 C.F.R. § 60.662 with which he or she will comply, then the Administrator shall be notified by the owner or operator 90 days before implementing a change, and upon implementing the change, a performance test shall be performed as specified by 40 C.F.R. § 60.664 within 180 days.

37. Subpart NNN at 40 C.F.R. § 60.665(b) states that each owner or operator subject to the provisions of this subpart shall keep an up-to-date, readily accessible record of the following data measured during each performance test, and also include the following data in the report of the initial performance test required under 40 C.F.R. § 60.8. Where a boiler or process heater with a design heat input capacity of 44 megawatts (MW) (150 million Btu/hour) or greater is used to comply with 40 C.F.R. § 60.662(a), a report containing performance test data need not be submitted, but a report containing the information in 40 C.F.R. § 60.665(b)(2)(i) is required. The same data specified in this section shall be submitted in the reports of all subsequently required performance tests where either the emission control efficiency of a control device, outlet concentration of TOC, or the TRE index value of a vent stream from a recovery system is determined.

38. On August 31, 1993, EPA promulgated Subpart RRR. See 58 Fed. Reg. 45,962.

39. Subpart RRR at 40 C.F.R. § 60.700(a) provides that Subpart RRR applies to each affected facility designated in 40 C.F.R. § 60.700(b) that is part of a process unit that produces any of the chemicals listed in 40 C.F.R. § 60.707 as a product, co-product, by-product, or intermediate, except as provided in 40 C.F.R. § 60.700(c).

40. Subpart RRR, at 40 C.F.R. § 60.700(b) states that the affected facility is any of the following for which construction, modification, or reconstruction commenced after June 29, 1990:

41. Subpart RRR at 40 C.F.R. § 60.701 defines "Reactor processes" as unit operations in which one or more chemicals, or reactants other than air, are combined or decomposed in such a way that their molecular structures are altered and one or more new organic compounds are formed.

42. Subpart RRR at 40 C.F.R. § 60.702 states that each owner or operator of any affected facility shall comply with paragraph (a), (b). or (c) of this section for each vent stream on and after the date on which the initial performance test required by 40 C.F.R. § 60.8 and 40 C.F.R. § 60.704 is completed, but not later than 60 days after achieving the maximum production rate at which the affected facility will be operated, or 180 days after the initial start-up, whichever date comes first. Each owner or operator shall either:

43. Subpart RRR at 40 C.F.R. § 60.703 sets forth the requirements for the monitoring of emissions and operations for control devices including flares, boilers or process heaters, and condensers used as a final recovery device in a recovery system.

44. Subpart RRR, at 40 C.F.R. § 60.705(a), states that each owner or operator subject to 40 C.F.R. § 60.702 shall notify the Administrator of the specific provisions of 40 C.F.R. § 60.702 with which the owner or operator has elected to comply. Notification shall be submitted with the notification of initial start-up required by 40 C.F.R. § 60.7(a)(3). If an owner or operator elects at a later date to use an alternative provision of 40 C.F.R. § 60.702 with which he or she will comply, then the Administrator shall be notified by the owner or operator 90 days before implementing a change and, upon implementing the change, a performance test shall be performed as specified by 40 C.F.R. § 60.704 no later than 180 days from initial start-up.

45. Subpart RRR at 40 C.F.R. § 60.705(b) states that each owner or operator subject to the provisions of this subpart shall keep an up-to-date, readily accessible record of the following data measured during each performance test, and also include the following data in the report of the initial performance test required under 40 C.F.R. § 60.8. Where a boiler or process heater with a design heat input capacity of 44 MW (150 million Btu/hour) or greater is used or where the reactor process vent stream is introduced as the primary fuel to any size boiler or process heater to comply with 40 C.F.R. § 60.702(a), a report containing performance test data need not be submitted, but a report containing the information in 40 C.F.R. § 60.705(b)(2)(i) is required. The same data specified in this section shall be submitted in the reports of all subsequently required performance tests where either the emission control efficiency of a combustion device, outlet concentration of TOC, or the TRE index value of a vent stream from a recovery system is determined.

NSPS Subpart Kb

46. On April 8, 1987, EPA promulgated Subpart Kb. See 52 Fed. Reg. 11,429.

47. Subpart Kb at 40 C.F.R. § 60.110b(a) states that except as provided in paragraph (b) of this section, the affected facility to which this subpart applies is each storage vessel with a capacity greater than or equal to 75 cubic meters (m3) that is used to store volatile organic liquids (VOL) for which construction, reconstruction, or modification is commenced after July 23, 1984.

48. Subpart Kb at 40 C.F.R. § 60.112b(a) states that the owner or operator of each storage vessel either with a design capacity greater than or equal to 151 m3 containing a VOL that, as stored, has a maximum true vapor pressure equal to or greater than 5.2 kPa but less than 76.6 kPa or with a design capacity greater than or equal to 75 m3 but less than 151 m3 containing a VOL that, as stored, has a maximum true vapor pressure equal to or greater than 27.6 kPa but less than 76.6 kPa, shall equip each storage vessel with one of four compliance options, including, at § 60.112b(a)(3), the following option:

PTIO Permit P0116897

49. Section 110(a)(1) of the CAA, 42 U.S.C. § 7410(a)(1), requires each state to adopt and submit to EPA for approval a SIP that provides for the implementation, maintenance, and enforcement of the National Ambient Air Quality Standards (NAAQS). Under Section 110(a) of the CAA, 42 U.S.C. § 7410(a), each SIP must include a permit program to regulate the modification and construction of any stationary source of air pollution as necessary to assure that NAAQS are achieved. Pursuant to Section 113(a) and (b) of the CAA, 42 U.S.C. § 7413(a) and (b), upon EPA approval, SIP requirements are federally enforceable under Section 113. Under 40 C.F.R. § 52.23, any permit limitation or condition contained within a permit issued under an EPA-approved program that is incorporated in a SIP, is a requirement of the SIP, and is federally enforceable under Section 113.

50. On February 20, 2013, EPA approved revisions to OAC 3745-31, the regulations governing the Ohio PTIO program, as part of the federally enforceable SIP for the State of Ohio. See 78 Fed. Reg. 11,748.

51. On October 14, 2014, Ohio EPA issued to the Hopedale Fractionation Plant PTIO Permit No. P0116897. Condition C.2.b.2.a of the PTIO provides that for any transfer of natural gas liquids from a pressurized storage tank to a railcar, the displaced vapors shall be collected from a vapor recovery system. The vapor recovery system shall be equipped with a vapor tight vapor line from the pressurized storage tanks to the rail vessels and a means to ensure that the vapor line is connected before natural gas liquids are transferred. The vapor recovery system shall be designed and operated to route at least 98.7 percent of displaced vapors from the loading process back to the pressurized storage tanks.

Findings of Fact

52. MarkWest owns and operates an onshore natural gas processing plant, at 6155 E. US Route 6, Jewett, Ohio, called the Hopedale Fractionating Plant (HFP), which removes natural gas liquids from field gas and fractionates the natural gas liquids.

53. On December 12, 2013, MarkWest notified Ohio EPA that the HFP is subject to Subpart OOOO (and by reference Subpart VVa) and Subpart Kb.

54. EPA conducted an inspection of the HFP on May 26-28, 2015 (May 2015 inspection).

55. During the May 2015 inspection, EPA identified at least 24 fin fan assemblies, containing approximately 510 connectors per assembly, which are not included in MarkWest's LDAR program and have not been monitored in accordance with Subpart VVa.

56. Since January 2014, MarkWest produces propane, listed in 40 C.F.R. §§ 60.667 and 60.707, as a product, co-product, by-product, or intermediate from the two depropranizers (one in the FRAC1 process unit and one in the FRAC2 process unit).

57. Since January 2014, MarkWest produces n-butane, butanes, mixed, and/or isobutane, all listed in 40 C.F.R. §§ 60.667 and 60.707, as a product, co-product, by-product, or intermediate from the debutanizer and deisobutanizer in the FRAC2 process unit.

58. MarkWest operates distillation units in the FRAC1 and FRAC2 process units at the HFP.

59. MarkWest operates reactor processes in the FRAC1 and FRAC2 process units at the HEP.

60. MarkWest's distillation units and reactor processes in the FRAC1 and FRAC2 process units are affected facilities subject to Subparts NNN and RRR, respectively.

61. MarkWest has not submitted a notification that the HFP's distillation units and reactor processes are subject to Subparts NNN and RRR, respectively.

62. MarkWest operates two 6,360 m3 (~40,000 barrels) natural gasoline storage tanks that are subject to Subpart Kb.

63. During the May 2015 inspection, EPA observed the pressure relief devices on each of the natural gasoline storage tanks to be venting to atmosphere using a FLIR® GF-320, as confirmed by MarkWest using a portable VOC instrument with the following readings:

64. In reviewing MarkWest's leak history, EPA discovered the following leaks that did not have a first attempt at repair within 5 days:

65. For the three quarterly monitoring events since July 2015. MarkWest reported an average of 0.98% as the percentage of valves leaking in the FRAC1, Railroad, and Truck Loading process units whereas EPA found a 2.89% leaking rate during the May 2015 inspection.

66. MarkWest utilizes a flare to control emissions from pressure relief devices at the HFP to comply with requirements for pressure relief devices under Subparts OOOO and VVa.

67. MarkWest operates approximately 75 pilot designed pressure relief devices throughout the HFP. These pilot pressure relief devices are designed to release gas directly to atmosphere from the pilot vents with any overpressure greater than 1 percent and up to 15 percent prior to actuating the main pressure-relief valve to the flare.

68. During the May 2015 inspection, EPA identified a pressure relief device (Tag #000829) at the FRAC1 process unit venting to atmosphere using a portable VOC instrument (2.800 ppm), and confirmed by MarkWest tagging the pressure relief device as leaking.

69. During the May 2015 inspection, EPA observed several connections between the loading arm and the top of the railcar to not be vapor tight or capturing all the material being loaded, based upon identifying vented VOC emissions using a FLIR® GF-320 and portable VOC instrument with the following readings:

Violations

70. MarkWest failed to perform Method 21 properly on 5 insulated valves (4 valves in FRAC1 and 1 valve in FRAC2), in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-7a(a)(1) (and by reference § 60.485(b)) and 40 C.F.R. Part 60, Method 21 §§ 8.3.1 and 8.3.1.1.

71. MarkWest failed to identify and monitor 10 valves (8 bleeder valves in FRAC1 and 2 bleeder valves in FRAC2) subject to the standards set forth at 40 C.F.R. §§ 60.5400(a) and 60.482-1a to 60.482-11a, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-7a(a)(1).

72. MarkWest failed to perform Method 21 properly on valves per paragraph 65, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-7a(a)(1), and 40 C.F.R. Part 60 Method 21, §§ 8.3.1 and 8.3.1.1, from at least July 2014 until May 2015.

73. MarkWest failed to perform the initial monthly monitoring of all pumps in each process unit at the HFP within 30 days after the end of the startup period in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-2a(a)(1).

74. MarkWest failed to perform annual monitoring on all connectors (specifically all fin fans in VOC service) in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-11a(a).

75. MarkWest failed to perform initial monthly monitoring of all valves within 30 days in process unit at the HFP after the initial startup date in violation of 40 C.F.R. §§ 60.5400(a), 60.482-7a(a)(2), and 60.482-7a(a)(1).

76. MarkWest failed to equip each open-ended valve or line (Tag# 3092, the Butane 3A hose in Truck Loading process unit, and vapor recovery hose for Natural Gasoline West line in Truck Loading process unit) with a cap, blind flange, plug, or a second valve in violation of 40 C.F.R. §§ 60.54.00(a) and 60.482-6a(a)(1).

77. MarkWest failed to seal each open-ended valve or line (closure devices associated with Tag #'s: 001438, 000890, 3224, 3460, 4313, 3926A) with a cap, blind flange, plug, or a second valve in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-6a(a)(2).

78. MarkWest failed to perform weekly visual inspections on pumps in each of the process units at the HFP for the period of January 2014 through February 2015 in violation of 40 C.F.R. §§ 60.5400(a) and 60.482a(a)(2).

79. MarkWest failed to make timely first attempts at repairs within 5 days on the valve listed in paragraph 64 in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-7a(d)(2).

80. MarkWest failed to make timely first attempts at repairs within 5 days on the connector listed in paragraph 64 in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-11a(d).

81. MarkWest failed to demonstrate compliance with the provisions of Subpart NNN for its distillation operations and meet Subpart NNN's various monitoring, recordkeeping, and reporting requirements, in violation of 40 C.F.R. §§ 60.662, 60.663, 60.665(a), and 60.665(b).

82. MarkWest failed to demonstrate compliance with the provisions of Subpart RRR for its reactor processes and meet Subpart RRR's various monitoring, recordkeeping, and reporting requirements, in violation of 40 C.F.R. § 60.702, 60.703, 60.705(a), and 60.705(b).

83. Based on pressure relief device design information and VOC monitoring conducted during the May 2015 inspection, MarkWest has failed to comply with closed vent and control device requirements for pilot-designed pressure relief devices at the HFP, in violation of 40 C.F.R. §§ 60.5400(a) and § 60.482-4a(c). Further, MarkWest has failed to comply with the emission control requirements of Subpart NNN and Subpart RRR with respect to uncontrolled vented emissions from the pilot designed pressure relief devices associated with subject distillation operations and reactor processes, in violation of 40 C.F.R. §§ 60.662 and 60.702, respectively.

84. Based on observations of uncontrolled vented emissions from pressure relief devices on the two natural gasoline storage tanks at the inspection of the HFP, MarkWest failed to design a closed-vent system on each natural gasoline storage vessel that collects all VOC vapors and gases discharged from the storage vessel and operated with no detectable emissions as indicated by an instrument reading of less than 500 ppm above background in violation of 40 C.F.R. § 60.112b(a)(3)(i). Moreover, MarkWest failed to reduce inlet VOC emissions by 95 percent or greater for each natural gasoline storage vessel in violation of 40 C.F.R. § 60.112b(a)(3)(ii).

84. MarkWest failed to operate a vapor tight vapor line on transfers of natural gas liquids from a pressurized storage tank to a railcar in violation of Condition C.2.b.2.a of PTIO Permit No. P0116897.

Enforcement Authority

85. Sections 113(a)(1) and (3) of the CAA, 42 U.S.C. § 7413(a)(1) and (3), provide that whenever, on the basis of any information available to the Administrator, the Administrator finds that any person has violated, or is in violation of, any requirement or prohibition of, inter alia, an applicable SIP or permit, any rule promulgated under the NSPS requirements of Section 111(e) of the CAA, 42 U.S.C. § 7411(e), Title V of the CAA, 42 U.S.C. §§ 7661-7661f, or any rule or permit issued thereunder, the Administrator may issue an administrative penalty order under Section 113(d), issue an order requiring compliance with such requirement or prohibition, or bring a civil action pursuant to Section 113(b) for injunctive relief and/or civil penalties.

Environmental Impact of Violations

86. MarkWest's above-referenced violations have caused excess emissions of VOC.

87. Excess VOC emissions can cause eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to the liver, kidney, and central nervous system. Some organics can cause cancer in animals and some are suspected or known to cause cancer in humans.

88. VOC emissions are a precursor to ground-level ozone. Breathing ozone contributes to a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame lung tissue. Repeated exposure may permanently scar lung tissue.

CERTIFICATE OF MAILING

I, Loretta Shaffer, certify that I sent a Finding of Violation, No. EPA-5-15-OH-21, by Certified Mail, Return Receipt Requested, to:

I also certify that I sent copies of the Finding of Violation by first-class mail to:

On the 8th day of October 2015.

CERTIFIED MAIL RECEIPT NUMBER: 7014 2870 0001 9581 4403

CERTIFICATE OF MAILING

I, Loretta Shaffer, certify that I sent a Finding of Violation, No. EPA-5-15-OH-21, by Certified Mail, Return Receipt Requested, to:

I also certify that I sent copies of the Finding of Violation by first-class mail to:

On the 21st day of September 2015.

CERTIFIED MAIL RECEIPT NUMBER: 7014 2870 0001 9581 4236

APPENDIX F

Dear Mr. Ettore:

Enclosed is a Notice of Noncompliance ("NON") alleging violations of the Clean Air Act ("CAA") at MarkWest Liberty Midstream's natural gas processing plant, located in Houston, PA. Specifically, the NON alleges violation of 40 C.F.R. Part 60 Subparts KKK, NNN, and OOOO.

The NON stipulates that MarkWest may request a conference with EPA to discuss the violations within fourteen (14) calendar days of the receipt of this letter. To request a conference, or if you have any questions regarding this NON, you may contact Bruce Augustine, of the Air Protection Division, at (215) 814-2131 or Mr. Dennis Abraham, Senior Assistant Regional Counsel, at (215) 814-5214.

STATUTORY AUTHORITY

This Notice of Noncompliance and Finding of Violation is issued pursuant to Section 113(a)(3) of the Clean Air Act ("CAA" or the "Act"), as amended on November 15, 1990 by P.L. 101-549, 42 U.S.C. § 7413(a)(3), to MarkWest Liberty Midstream & Resources, LLC ("Respondent") for violations of the CAA and its implementing regulations at the company's onshore natural gas process plant, located at 800 Western Avenue, Chartiers Township, Washington County, Pennsylvania 15317 (the "Facility"). Specifically, the United States Environmental Protection Agency, Region III ("EPA" or the "Agency") finds that Respondent is violating: 1) Standards of Performance for Crude Oil and Natural Gas Production. Transmission and Distribution at 40 C.F.R. §§ 60.5360-5430 ("Subpart OOOO"); (2) Standards of Performance for Equipment Leaks of VOC from Onshore Natural Gas Processing Plants for Which Construction, Reconstruction, or Modification Commenced After January 20, 1984, and on or Before August 23, 2011 at 40 C.F.R. Part 60, Subpart KKK ("Subpart KKK"); and (3) Standards of Performance for Volatile Organic Compounds (VOC) From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Distillation Operations at 40 C.F.R. §§ 60.660-60.668 ("Subpart NNN").

Section 113(a)(3) of the Act provides that except for a requirement or prohibition enforceable under Sections 113(a)(1) and (2) of the Act, 42 U.S.C. §§ 7413(a)(1) and (2), whenever, on the basis of any information available to the Administrator, the Administrator finds that any person has violated, or is in violation of, any other requirement or prohibition of this subchapter, including, but not limited to, a requirement or prohibition of any rule, plan, order, waiver, or permit promulgated, issued, or approved under those provisions, the Administrator may (A) issue an administrative penalty order; (B) issue an order requiring such person to comply with such requirement or prohibition; (C) bring a civil action for enforcement; or (D) request that the Attorney General commence a criminal action for criminal penalties. A description of the regulatory background, the relevant facts, and a list of the specific violations identified by EPA are outlined below. The geographical jurisdiction of EPA Region III includes the Commonwealth of Pennsylvania.

Regulatory Authority

New Source Performance Standards-Subpart OOOO (Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution)

1. Section 111 of the CAA, 42 U.S.C. § 7411, authorizes EPA to promulgate regulations establishing New Source Performance Standards ("NSPS").

2. Section 111(e) of the CAA, 42 U.S.C. § 7411(e), states that after the effective date of standards of performance promulgated under this section, it shall be unlawful for any owner or operator of any new source to operate such source in violation of any standard of performance applicable to such source.

3. EPA promulgated Subpart OOOO on August 16, 2012. 77 Fed. Reg. 49,490.

4. Subpart OOOO at 40 C.F.R. § 60.5365 states that an owner or operator of one or more of the onshore affected facilities listed in paragraphs (a) through (g) of this section for which construction, modification, or reconstruction commenced after August 23, 2011 is subject to the applicable provisions of Subpart OOOO. 40 C.F.R. § 60.5365(f) states that the group of all equipment, except compressors, within a process unit is an affected facility. 40 C.F.R. § 60.5365(f)(3) further provides that the equipment within a process unit of an affected facility located at onshore natural gas process plants and described in paragraph (f) of this section are exempt from Subpart OOOO if they are subject to and controlled according to Subparts VVa, GGG, or GGGa of 40 C.F.R. Part 60.

5. Subpart OOOO at 40 C.F.R. § 60.5430 defines "onshore" to mean all facilities except those that are located in the territorial seas or the outer continental shelf.

6. Subpart OOOO at 40 C.F.R. § 60.5430 defines "process unit" to mean components assembled for the extraction of natural gas liquids from field gas, the fractionation of the liquids into natural gas products, or other operations associated with the processing of natural gas products.

7. Subpart OOOO at 40 C.F.R. § 60.5430 defines a "natural gas processing plant (gas plant)" as "any processing site engaged in the extraction of natural gas liquids from field gas, fractionation of mixed natural gas liquids to natural gas products, or both."

8. Subpart OOOO at 40 C.F.R. § 60.5400 sets forth equipment standards that apply to affected facilities at an onshore natural gas processing plant. This section applies to the group of all equipment, except compressors, within a process unit.

9. Subpart OOOO at 40 C.F.R. § 60.5400(a) identifies what equipment standards apply to affected facilities at an onshore natural gas processing plants. Subpart OOOO references 40 C.F.R. Part 60, Subpart VVa (Standards of Performance for Equipment Leaks of VOC in Synthetic Organic Chemical Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006) and states that a subject owner or operator must comply with the equipment leak standard requirements of specific portions of Subpart VVa at 40 C.F.R. §§ 60.482-1a(a), (b), and (d), 60.482-2a, and 60.482-4a through 60.482-11a., except as provided in § 60.5401.

10. Subpart OOOO at 40 C.F.R. § 60.5400(d) states that a subject owner or operator must comply with the provisions of § 60.485a of Subpart VVa except as provided in § 60.5400(f).

11. Subpart OOOO at 40 C.F.R. § 60.5400(e) states that a subject owner or operator must comply with the provisions of §§ 60.486a and 60.487a of Subpart VVa except as provided in §§ 60.5401, 60.5421, and 60.5422 of Subpart OOOO.

12. Subpart OOOO at 40 C.F.R. § 60.5400(f) states that a subject owner or operator must use the following provision instead of § 60.485a(d)(1): "Each piece of equipment is presumed to be in VOC service or in wet gas service unless an owner or operator demonstrates that the piece of equipment is not in VOC service or in wet gas service."

13. The NSPS Appendix A-7, at 40 C.F.R. Part 60, Method 21 §§ 8.3.1 and 8.3.1.1, sets forth the technique which must be used to determine if there is a leak from a valve.

NSPS Subpart NNN (Standards of Performance for VOC From Synthetic Organic Chemical Manufacturing Industry Distillation Operations)

14. On June 29, 1990, EPA promulgated Subpart NNN. See 55 Fed. Reg. 26,942.

15. Subpart NNN at 40 C.F.R. § 60.660(a) states that Subpart NNN applies to each affected facility designated in paragraph (b) of this section that is part of a process unit that produces any of the chemicals listed in 40 C.F.R. § 60.667 as a product, co-product, by-product, or intermediate, except as provided in paragraph (c).

16. Subpart NNN at 40 C.F.R. § 60.660(b) states the affected facility is any of the following for which construction, modification, or reconstruction commenced after December 30, 1983:

17. Subpart NNN at 40 C.F.R. § 60.661 defines "Distillation operation" as an operation separating one or more feed stream(s) into two or more exit stream(s), each exit stream having component concentrations different from those in the feed stream(s). The separation is achieved by the redistribution of the components between the liquid and vapor-phase as they approach equilibrium within the distillation unit.

18. Subpart NNN at 40 C.F.R. § 60.661 defines "Distillation unit" as a device or vessel in which distillation operations occur, including all associated internals (such as trays or packing) and accessories (such as reboiler, condenser, vacuum pump, steam jet, etc.), plus any associated recovery system.

19. Subpart NNN at 40 C.F.R. § 60.662 states that each owner or operator of any affected facility shall comply with paragraph (a), (b), or (c) of this section for each vent stream on and after the date on which the initial performance test required by 40 C.F.R. § 60.8 and 40 C.F.R. § 60.664 is completed, but not later than 60 days after achieving the maximum production rate at which the affected facility will be operated, or 180 days after the initial start-up, whichever date comes first. Each owner or operator shall either:

20. Subpart NNN at 40 C.F.R. § 60.663 sets forth the monitoring of emissions and operations for control devices including flares, boilers or process heaters, and condensers used as a final recovery device in a recovery system.

21. Subpart NNN at 40 C.F.R. § 60.665(a) states that each owner or operator subject to § 60.662 shall notify the Administrator of the specific provisions of 40 C.F.R. § 60.662 with which the owner or operator has elected to comply. Notification shall be submitted with the notification of initial start-up required by 40 C.F.R. § 60.7(a)(3). If an owner or operator elects at a later date to use an alternative provision of 40 C.F.R. § 60.662 with which he or she will comply, then the Administrator shall be notified by the owner or operator 90 days before implementing a change, and upon implementing the change, a performance test shall be performed as specified by 40 C.F.R. § 60.664 within 180 days.

22. Subpart NNN at 40 C.F.R. § 60.665(b) states that each owner or operator subject to the provisions of this subpart shall keep an up-to-date, readily accessible record of the following data measured during each performance test, and also include the following data in the report of the initial performance test required under 40 C.F.R. § 60.8. Where a boiler or process heater with a design heat input capacity of 44 megawatts ("MW") (150 million Btu/hour) or greater is used to comply with 40 C.F.R. § 60.662(a), a report containing performance test data need not be submitted, but a report containing the information in 40 C.F.R. § 60.665(b)(2)(i) is required. The same data specified in this section shall be submitted in the reports of all subsequently required performance tests where either the emission control efficiency of a control device, outlet concentration of TOC, or the TRE index value of a vent stream from a recovery system is determined.

NSPS Subpart KKK (Standards of Performance for Equipment Leaks of VOC from Onshore Natural Gas Processing Plants for Which Construction, Reconstruction, or Modification Commenced After January 20, 1984, and on or Before August 23, 2011)

22. EPA promulgated Subpart KKK on June 24, 1985. 50 FR 26124.

23. Subpart KKK at 40 C.F.R. § 60.630(a)(1) states that the provisions of this subpart apply to affected facilities in onshore natural gas processing plants.

24. Subpart KKK at 40 C.F.R. § 60.630(a)(3) states that the group of all equipment except compressors within a process unit is an affected facility.

25. Subpart KKK at 40 C.F.R. § 60.630(b) states that any affected facility under paragraph (a) of this section that commences construction, reconstruction, or modification after January 20, 1984, and on or before August 23, 2011, is subject to the requirements of this subpart.

26. Subpart KKK at 40 C.F.R. § 60.631 defines "equipment" as "each pump, pressure relief device, open-ended valve or line, valve, compressor, and flange or other connector that is in VOC service, and any device or system required by this subpart."

27. Subpart KKK at 40 C.F.R. § 60.631 defines "field gas" as "feedstock gas entering the natural gas processing plant."

28. Subpart KKK at 40 C.F.R. § 60.631 defines "in light liquid service" to mean "the piece of equipment [that] contains a liquid that meets the conditions specified in § 60.485(e) or § 60.633(h)(2)."

29. Subpart KKK at 40 C.F.R. § 60.631 defines "natural gas liquids" as the hydrocarbons, such as ethane, propane, butane, and pentane, that are extracted from field gas."

30. Subpart KKK at 40 C.F.R. § 60.631 "natural gas processing plant (gas plant) as "any processing site engaged in the extraction of natural gas liquids from field gas, fractionation of mixed natural gas liquids to natural gas products, or both."

31. Subpart KKK at 40 C.F.R. § 60.631 defines "onshore" as "all facilities except those that are located in the territorial seas or on the outer continental shelf."

32. Subpart KKK at 40 C.F.R. § 60.631 defines "process unit" as equipment assembled for the extraction of natural gas liquids from field gas, the fractionation of the liquids into natural gas products, or other operations associated with the processing of natural gas products. A process unit can operate independently if supplied with sufficient feed or raw materials and sufficient storage facilities for the products."

33. Subpart KKK at 40 C.F.R. § 60.632 states that each owner or operator subject to the provisions of this subpart shall comply with the requirements of §§ 60.482-1(a), (b), and (d) and 60.482-2 through 60.482-10, except as provided in § 60.633, as soon as practicable, but no later than 180 days after initial startup."

FINDINGS OF FACT

34. Respondent, MarkWest Liberty Midstream & Resources, LLC, is a subsidiary of MarkWest Energy Partners, L.P.

35. On December 4, 2015, a merger was completed between MarkWest Energy Partners, L.P. and MPLX Energy Logistics ("MPLX"), a subsidiary of Marathon Petroleum Corporation. The deal creates one of the nation's largest natural gas processing companies. MarkWest Energy Partners, L.P. is now a wholly owned subsidiary of MPLX.

36. Respondent, MarkWest Liberty Midstream & Resources, LLC, is incorporated and registered to do business in the state of Delaware.

37. Respondent is the present owner and operator of the Facility and has been the owner and operator of the Facility at all times relevant to this Notice of Noncompliance/Finding of Violation.

38. Respondent is a "person" as that term is defined in Section 302(e) of the Act, 42 U.S.C. § 7602(e).

39. The Facility is an onshore natural gas processing plant (as that term is defined at 40 C.F.R. §§ 60.631 and 60.5430), because it is engaged in operations associated with the processing of natural gas products, including the gathering, processing and transportation of natural gas and natural gas liquids.

40. The Facility was initially constructed and commenced operation in or around October of 2008 (after January 20, 1984 and before August 23, 2011 — the applicability date for NSPS Subpart KKK, related to equipment within process units at onshore natural gas process units constructed during that time period).

41. Portions of the Facility that were constructed, modified or reconstructed before August 23, 2011 are subject to Subpart KKK (and by reference, the equipment leak standard requirements set forth in the provisions of Subpart VV). Other portions of the Facility that were constructed, modified or reconstructed on or after August 23, 2011 are subject to Subpart OOOO (and by reference, the equipment leak standard requirements set forth in the provisions of Subpart VVa), because those portions are located at an onshore natural gas processing plant which is engaged in the extraction of natural gas liquids from field gas, the fractionation of mixed natural gas liquids to natural gas products or both, and portions of the Facility have equipment located in affected process units that were constructed or modified after August 23, 2011.

42. The Facility receives raw field gas from natural gas wells and separates the natural gas from the remaining constituents of the gas (ethane, butane, propane and natural gasoline). There are currently four (4) "plants" operating at the Facility which contain a combination of deethanizers, de-propopanizers, and de-butanizers, which are used to separate the different constituents of the natural gas. "Plant 4" was under construction at the time of EPA's April 28-30, 2015 compliance inspection. Plant 4 has the capacity to process an additional 200 million standard cubic feet per day ("MMscf/day") of natural gas. The Facility currently processes an average of 325-330 MMscf/day of natural gas, while the total capacity of the Facility to process natural gas is 550MMscf/day. There are two (2) flares located at the Facility, which are used to control process upsets and process blowdowns from the various plants and truck loadout. There is also a portable flare located within the railcar area of the Facility. The rail yard is considered part of the MarkWest Houston Gas Plant for emission inventory purposes.

43. The Facility is identified in a Plan Approval issued on October 4, 2012 by the Pennsylvania Department of Environmental Protection ("PADEP") (Plan Approval No. 63-00936F) to the owner, "MarkWest Liberty Midstream & Resources/Houston Gas PLT", located in Chartiers Township, Washington County, PA. The Plan Approval was issued as an extension of previous plan approvals, beginning in July 2008 (See, Plan Approval GP5-63-00936).

44. The Plan Approval terms and conditions provide that Respondent must comply with the applicable requirements of Subparts KKK and OOOO for equipment leaks of VOC from onshore natural gas processing plants, including the implementation of a leak detection and repair ("LDAR") program performed to minimize VOC emissions.

45. The Facility is currently permitted as a minor source for all criteria pollutants and hazardous air pollutants ("HAPs"). The Facility is located in an area that is designated as attainment for nitrogen Oxide ("NOx"), sulfur dioxide ("SO2") and particulate matter ("PM"), and marginal non-attainment for ozone.

46. On the dates of April 28-30, 2015, duly authorized representatives from EPA Region 3 and PADEP conducted an air compliance inspection of the Facility, as part of EPA's national enforcement initiative pertaining to the oil and gas industry (the "April 2015 Air Compliance Inspection"). The scope of the April 2015 Air Compliance Inspection included on-site LDAR monitoring over a period of three (3) days, with the use of a digital camera for documentation photographs. EPA inspectors also utilized a forward looking infrared radiation ("FLIR") thermal imaging camera to observe and obtain video documentation of emission leaks at the Facility. The Respondent was notified of the inspection in advance on April 27, 2015.

47. During the April 2015 Air Compliance Inspection, David Ettore, Respondent's plant representative or "responsible official" for Facility operations (as that term is used in Subpart OOOO, 40 C.F.R. § 60.5430), confirmed that the Facility was subject to the provisions of Subparts KKK and OOOO. Ettore also specifically identified the following process units within the Facility as being subject to NSPS Subparts KKK and OOOO:

48. At the time of the April 2015 Air Compliance Inspection, several areas of concern or "deviations" (as that term is used in Subpart OOOO, at 40 C.F.R. § 60.5430) were found at the Facility which EPA identified as being not in compliance with the Facility's LDAR monitoring program. Those deviations included:

VIOLATIONS

49. Failure to Identify Applicable Components subject to Subparts KKK and OOOO in Respondent' LDAR Program:

(a) Based on EPA's inspection and review of records kept by the Respondent at the Facility, Respondent failed to keep records of affected equipment subject to Subpart OOOO, 40 C.F.R. § 60.5365(f)(2) (e.g., valves and connectors), along the Mariner East Pipeline (constructed after the August 2011 applicability date for Subpart OOOO). The Mariner East Pipeline is located within the Facility because the pipeline is equipment used for transporting gas from a production plant, gathering system, storage area or other wholesale source of gas to one or more distribution area(s). EPA determined that Respondent failed to monitor affected valves and connectors associated with the Mariner East Pipeline from at least December 2014 through April 2015, in accordance with 40 C.F.R. §§ 60.5365(f)(2) and 60.5400(a), and Subpart VVa §§ 60.482-7a and 60.482-11a. The pipeline carries propane and ethane off-site and then travels east to the PES Refinery in Philadelphia.

(b) Respondent failed to identify, record, and monitor valves and connectors located within the pressurized storage tank area ("Storage Pad 3") of the Facility, in accordance with 40 C.F.R. §§ 60.5365 and 60.5400(a) and Subpart VVa §§ 60.482-7a and 60.482-11a. Pad 3 was constructed or modified after the 2011 applicability date for Subpart OOOO. None of the components within this area were physically tagged or included in Respondent's LDAR program and thus also not monitored from at least July 2012 through April 2015. Respondent began the process of identifying these components during EPA's inspection, and later admitted that 281 valves, 660 connectors, and 18 process safety valves were identified in Storage Pad 3. Respondent stated to EPA that it would henceforth include these components in its LDAR program for Subpart OOOO.

(c) Respondent failed to tag and include several valves located within the truck loading area in its LDAR program and failed to monitor these valves in accordance with Subpart KKK and 40 C.F.R. § 60.632(a) and Subpart VV (§ 60.482-7(a)). The truck loading area was not constructed or modified after August 2011. EPA identified these components to Respondent's personnel during the inspection. In an email dated 6/2/2015 from Respondent's Senior Environmental Manager, David Ettore, to Bruce Augustine of EPA, Ettore indicated that Respondent later addressed the concerns identified by EPA during the April 2015 Air Compliance Inspection regarding missed components in the Respondent's LDAR program in the Storage Pad 3 and truck loading areas, as required under Subparts KKK and OOOO.

50. Failure to Double Block Valve Open-Ended Lines:

During the April 2015 Air Compliance Inspection, EPA inspectors observed the following "open-ended lines" (i.e., valves, except safety relief valves, having one side of the valve seat in contact with process fluid and one side open to the atmosphere, either directly or through open piping):

None of these open-ended lines had a cap, blind flange, plug, or a second valve, in violation of Subparts KKK and OOOO, 40 C.F.R. §§ 60.632(a) and 60.5400(a), and related requirements in Subparts VV and VVa.

51. Failure to Include New Components in LDAR Program.

52. Failure to Operate Pressure Relief Devices with No Detectable Emissions.

53. Failure to Have Access for Monitoring of Values.

54. Failure to Make 1st Attempt at Repair on Leaking Component within 5 Days of Leak Detection.

55. Failure to Properly Implement Method 21.

56. Failure to Comply with NSPS NNN (Standards of Performance for Volatile Organic Compound (VOC) Emissions From Synthetic Organic Chemical Manufacturing Industry (SOCMI) Distillation Operations).

ENFORCEMENT AUTHORITY

57. Section 113(a)(3) of the CAA, 42 U.S.C. § 7413(a)(3), provides that whenever, on the basis of any information available to the Administrator, the Administrator finds that any person has violated, or is in violation of, any requirement or prohibition of, inter alia, any rule promulgated under the NSPS requirements of Section 111 of the CAA, 42 U.S.C. § 7411, Title V of the CAA, 42 U.S.C. §§ 7661-7661f, or any rule or permit issued thereunder, the Administrator may issue an administrative penalty order under Section 113(d), issue an order requiring compliance with such requirement or prohibition, or bring a civil action pursuant to Section 113(b) for injunctive relief and/or civil penalties.

PENALTY ASSESMENT CRITERIA

58. Section 113(e)(1) of the Act, as amended, 42 U.S.C. § 7413(e)(1), states that the court, in an action for assessment of civil or criminal penalties shall as appropriate in determining the amount of penalty to be assessed, take into consideration (in addition to such other factors as justice may require) the size of the business, the economic impact of the penalty on the business, the violator's full compliance history and food faith efforts to comply, the duration of the violation as established by any credible evidence (including evidence other that the applicable test method), payment by the violator of penalties previously assessed for the same violation, the economic benefit of noncompliance, and the seriousness of the violation.

Section 113(e)(2) of the Act, as amended, 42 U.S.C. § 7413(e)(2), allows the court to assess a penalty for each day of the violation. For purposes of determining the number of days of violation, where the plaintiff makes a prima facie showing that the conduct or events giving rise to this violation are likely to have continued or recurred past the date of this notice of noncompliance (or a previously issued air pollution control agency notice of violation for the same violation), the days of the violation shall be presumed to include the date of this notice (or the previous notice of violation) and each and every day thereafter until Respondent establishes that continuous compliance has been achieved, except to the extent that Respondent can prove by the preponderance of the evidence that there were intervening days during which no violation occurred or that the violation was not continuing in nature.

OPPORTUNITY FOR CONFERENCE

59. Respondent may, upon request, confer with EPA to discuss this Notice of Noncompliance and Finding of Violation. If Respondent requests a conference with EPA, Respondent should be prepared to describe the causes of the violation and to describe any actions Respondent may have taken or proposes to take to bring the Facility into compliance. Respondent has the right to be represented by counsel.

Respondent must submit any request for a conference with EPA within fourteen (14) calendar days of receipt of this Notice of Noncompliance and Finding of Violation. A request for a conference with EPA, and/or any inquiries regarding this Notice of Noncompliance and Finding of Violation, should be submitted in writing to:

EFFECTIVE DATE

60. This Notice of Noncompliance and Finding of Violation shall be effective immediately upon receipt.

QUESTIONS REGARDING NOTICE OF NONCOMPLIANCE AND FINDING OF VIOLATION

61. In you have any questions regarding the issuance of this Notice of Noncompliance and Finding of Violation, you may contact Bruce Augustine, Senior Enforcement Officer at (215) 814-2131, or Dennis M. Abraham, Senior Assistant Regional Counsel, at (215) 814-5214.

DISCLOSURE INFORMATION

62. Certain companies may be required to disclose to the Securities and Exchange Commission ("SEC") the existence of certain pending or known to be contemplated environmental legal proceedings (administrative or judicial) arising under Federal, State or Local environmental laws. Please see the attached "Notice of Securities and Exchange Commission Registrants' Duty to Disclose Environmental Legal Proceedings" for more information about this requirement and to aid you in determining whether your company may be subject to the same.

EPA is enclosing an Information Sheet entitled "U.S. EPA Small Business Resources," (EPA 300-F-99-004, September 1999), which identifies a variety of compliance assistance and other tools available to assist small businesses in complying with Federal and State environmental laws.

U.S. EPA Small Business Resources Information Sheet

The United States Environmental Protection Agency provides an array of resources to help small businesses understand and comply with federal and state environmental laws. In addition to helping small businesses understand their environmental obligations and improve compliance, these resources will also help such businesses find cost-effective ways to comply through pollution prevention techniques and innovative technologies.

NOTICE OF SECURITIES AND EXCHANGE COMMISSION REGISTRANTS' DUTY TO DISCLOSE ENVIRONMENTAL LEGAL PROCEEDINGS

Securities and Exchange Commission regulations require companies registered with the SEC (e.g., publicly traded companies) to disclose, on at least a quarterly basis, the existence of certain administrative or judicial proceedings taken against them arising under Federal, State or local provisions that have the primary purpose of protecting the environment. Instruction 5 to Item 103 of the SEC's Regulation S-K (17 CFR 229.103) requires disclosure of these environmental legal proceedings. For those SEC registrants that use the SEC's "small business issuer" reporting system, Instructions 1-4 to Item 103 of the SEC's Regulation S-B (17 CFR 228.103) requires disclosure of these environmental legal proceedings.

If you are an SEC registrant, you have a duty to disclose the existence of pending or known to be contemplated environmental legal proceedings that meet any of the following criteria (17 CFR 229.103(5)(A)-(C)):

Specific information regarding the environmental legal proceedings that must be disclosed is set forth in Item 103 of Regulation S-K or, for registrants using the "small business issuer" reporting system, Item 103(a)-(b) of Regulation S-B. If disclosure is required, it must briefly describe the proceeding, "including the name of the court or agency in which the proceedings are pending, the date instituted, the principal parties thereto, a description of the factual basis alleged to underlie the proceedings and the relief sought."

You have been identified as a party to an environmental legal proceeding to which the United States government is, or was, a party. If you are an SEC registrant, this environmental legal proceeding may trigger, or may already have triggered, the disclosure obligation under the SEC regulations described above.

This notice is being provided to inform you of SEC registrants' duty to disclose any relevant environmental legal proceedings to the SEC. This notice does not create, modify or interpret any existing legal obligations, it is not intended to be an exhaustive description of the legally applicable requirements and it is not a substitute for regulations published in the Code of Federal Regulations. This notice has been issued to you for information purposes only. No determination of the applicability of this reporting requirement to your company has been made by any governmental entity. You should seek competent counsel in determining the applicability of these and other SEC requirements to the environmental legal proceeding at issue, as well as any other proceedings known to be contemplated by governmental authorities.

If you have any questions about the SEC's environmental disclosure requirements, please contact the SEC Office of the Special Senior Counsel for Disclosure Operations at (202) 551-3115.

APPENDIX G

Dear Ms. McBurney:

The U.S. Environmental Protection Agency is issuing the enclosed Finding of Violation (FOV) to MarkWest Energy Partners L.P., MarkWest Utica EMG, L.L.C., and MarkWest Ohio Fractionation Company, L.L.C. (collectively MarkWest or you). We find that you are violating the following at your Hopedale Fractionation Plant in Jewett, Ohio: (1) Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution at 40 C.F.R. §§ 60.5360-5430 (Subpart OOOO);(2) Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 at 40 C.F.R. §§ 60.480a-60.490 (Subpart VVa); and the New Source Performance Standards General Provisions under 40 C.F.R. Part 60, Subpart A.

Section 113 of the Clean Air Act gives us several enforcement options. These options include issuing an administrative compliance order, issuing an administrative penalty order and bringing a judicial civil or criminal action.

We are offering you an opportunity to confer with us about the violations alleged in the FOV. The conference will give you an opportunity to present information on the specific findings of violation, any efforts you have taken to comply and the steps you will take to prevent future violations. In addition, in order to make the conference more productive, we encourage you to submit to us information responsive to the FOV prior to the conference date.

Please plan for your facility's technical and management personnel to attend the conference to discuss compliance measures and commitments. You may have an attorney represent you at this conference. The EPA contact in this matter is Constantinos Loukeris. You may call him at (312) 353-6198 to request a conference. You should make the request within 10 calendar days following receipt of this letter. We should hold any conference within 30 calendar days following receipt of this letter.

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 5

FINDING OF VIOLATION

The U.S. Environmental Protection Agency finds that MarkWest Energy Partners, L.P., MarkWest Utica EMG, L.L.C., and MarkWest Ohio Fractionation Company, L.L.C. (collectively "MarkWest") are violating the Clean Air Act (CAA) and its implementing regulations at the company's Hopedale Fractionation Facility in Jewett, Ohio. Specifically, MarkWest is violating: (1) Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution at 40 C.F.R. §§ 60.5360-5430 (Subpart OOOO);(2) Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 at 40 C.F.R. §§ 60.480a-60.490 (Subpart VVa); and the New Source Performance Standards (NSPS) General Provisions under 40 C.F.R. Part 60, Subpart A. (Subpart A).

Regulatory Authority

NSPS Subpart OOOO

1. Section 111 of the CAA, 42 U.S.C. § 7411, authorizes EPA to promulgate NSPS regulations for certain source categories.

2. Section 111(e) of the CAA, 42 U.S.C. § 7411(e), states that after the effective date of standards of performance promulgated under this section, it shall be unlawful for any owner or operator of any new source to operate such source in violation of any standard of performance applicable to such source.

3. EPA promulgated Subpart OOOO on September 23, 2013. 78 Fed. Reg. 58435.

4. Subpart OOOO at 40 C.F.R. § 60.5365 states that an owner or operator of one or more of the onshore affected facilities listed in paragraphs (a) through (g) of this section for which construction, modification, or reconstruction commenced after August 23, 2011 is subject to the applicable provisions of Subpart OOOO. Section 60.5365(f) states that the group of all equipment, except compressors, within a process unit is an affected facility. Section 60.5365(f)(3) further provides that the equipment within a process unit of an affected facility located at onshore natural gas process plants and described in paragraph (f) of this section are exempt from Subpart OOOO if they are subject to and controlled according to Subparts VVa, GGG, or GGGa of 40 C.F.R. Part 60.

5. Subpart OOOO at 40 C.F.R. § 60.5430 defines "process unit" to mean components assembled for the extraction of natural gas liquids from field gas, the fractionation of the liquids into natural gas products, or other operations associated with the processing of natural gas products.

6. Subpart OOOO at 40 C.F.R. § 60.5430 defines a "natural gas processing plant (gas plant)" as "any processing site engaged in the extraction of natural gas liquids from field gas, fractionation of mixed natural gas liquids to natural gas products, or both."

7. Subpart OOOO at 40 C.F.R. § 60.5400 sets forth equipment standards that apply to affected facilities at an onshore natural gas processing plant. This section applies to the group of all equipment, except compressors, within a process unit.

8. Subpart OOOO at 40 C.F.R. § 60.5400(a) states a subject owner or operator must comply with the equipment leak standard requirements of specific portions of Subpart VVa at 40 C.F.R. §§ 60.482-1a(a), (b), and (d), 60.482-2a, and 60.482-4a through 60.482-11a., except as provided in § 60.5401.

9. Subpart OOOO at 40 C.F.R. § 60.5400(d) states that a subject owner or operator must comply with the provisions of § 60.485a of Subpart VVa except as provided in § 60.5400(f).

10. Subpart OOOO at 40 C.F.R. § 60.5400(e) states that a subject owner or operator must comply with the provisions of 40 C.F.R. §§ 60.486a and 60.487a of Subpart VVa except as provided in 40 C.F.R. §§ 60.5401, 60.5421, and 60.5422 of Subpart OOOO.

11. Subpart OOOO at 40 C.F.R. § 60.5400(f) states that a subject owner or operator must use the following provision instead of 40 C.F.R. § 60.485a(d)(1): "Each piece of equipment is presumed to be in VOC service or in wet gas service unless an owner or operator demonstrates that the piece of equipment is not in VOC service or in wet gas service."

12. Subpart OOOO at 40 C.F.R. § 60.5430 defines "flare" to mean a thermal oxidation system using an open (without enclosure) flame.

13. Subpart OOOO at 40 C.F.R. § 60.5425 and Table 3 of Subpart OOOO provides that certain requirements under the General Provisions of NSPS Subpart A apply to owners and operators subject to Subpart OOOO, including the performance test requirements under 40 C.F.R. § 60.8.

NSPS Subpart VVa

14. EPA promulgated NSPS Subpart VVa on November 16, 2007. See 72 Fed. Reg. 64883. (Subpart VVa)

15. Subpart VVa at 40 C.F.R. § 60.482-1a(a) states "[e]ach owner or operator subject to the provisions of this subpart shall demonstrate compliance with the requirements of §§ 60.482-1a through 60.482-10a or § 60.480a(e) for all equipment within 180 days of initial startup."

16. Subpart VVa at 40 C.F.R. § 60.482-4a establishes emission control requirements for pressure relief devices in gas/vapor services. As an option for compliance with 40 C.F.R. § 60.482-4a, 40 C.F.R. § 60.482-4a(c) provides that owners or operators shall equip subject pressure relief devices with a closed vent system capable of capturing and transporting leakage through the pressure relief device to a control device as described in 40 C.F.R. § 60.482-10a.

17. Subpart VVa at 40 C.F.R. § 60.482-10a(a) states that owners or operators of closed vent systems and control devices used to comply with provisions of this subpart shall comply with the provisions of this section.

18. Subpart VVa at 40 C.F.R. § 60.482-10a(c) states that each enclosed combustion devices shall be designed and operated to reduce the VOC emissions vented to them with an efficiency of 95 percent or greater, or to an exit concentration of 20 ppmv, on a dry basis, corrected to 3 percent oxygen, whichever is less stringent or to provide a minimum residence time of 0.75 seconds at a minimum temperature of 816°C.

19. Subpart VVa at 40 C.F.R. § 60.482-10a(e) provides that owners or operators of control devices used to comply with the provisions of this subpart shall monitor these control devices to ensure that they are operated and maintained in conformance with their designs.

20. Subpart VVa at 40 C.F.R. § 60.482-10a(m) provides that closed vent systems and control devices used to comply with the provisions of this subpart shall be operated at all times when emissions may be vented to them.

NSPS Subpart A

21. Subpart A at 40 C.F.R. § 60.1(a) provides that, except as provided in Subparts B and C, the provisions of this part apply to the owner or operator of any stationary source which contains an affected facility, the construction or modification of which is commenced after the date of publication in this part of any standard (or, if earlier, the date of publication of any proposed standard) applicable to that facility.

22. Subpart A at 40 C.F.R. § 60.8(a) provides that, except as specified in paragraphs (a)(1),(a)(2). (a)(3), and (a)(4) of this section, within 60 days after achieving the maximum production rate at which the affected facility will be operated, but not later than 180 days after initial startup of such facility, or at such other times specified by this part, and at such other times as may be required by the Administrator under Section 114 of the CAA, the owner or operator of such facility shall conduct performance test(s) and furnish the Administrator a written report of the results of such performance test(s).

Findings of Fact

23. MarkWest owns and operates an onshore natural gas processing plant, at 6155 E. US Route 6, Jewett, Ohio, called the Hopedale Fractionating Plant (HFP), which removes natural gas liquids from field gas and fractionates the natural gas liquids.

24. MarkWest also operates a railcar loading operation at the railcar area of the HFP that is used to distribute natural gas liquids (i.e. propane, butane, and natural gasoline) to customers.

25. On December 12, 2013, MarkWest notified Ohio Environmental Protection Agency that the HFP is subject to Subpart OOOO (and by reference Subpart VVa and Subpart A).

26. To control VOC emissions from pressure relief devices at the railcar loading operation, MarkWest operates an enclosed combustion device located at the facility's railcar area. The railcar enclosed combustion device is subject to the Subpart VVa requirement for control devices at 40 C.F.R. § 60.482-10a.

27. EPA conducted an inspection of the HFP on May 26-28, 2015 (May 2015 inspection).

28. During the May 2015 inspection, EPA requested information regarding combustion control temperature data and manufacturer design specifications for the enclosed combustion device located at the site's railcar area.

29. On October 21, 2015 (October 2015 response), MarkWest submitted a response that included daily temperature readings, including daily temperature minimum, average, and maximum for the period of February 15, 2014 through June 15, 2015.

30. In the October 2015 response, MarkWest provided the manufacturer's performance data sheet for the enclosed combustion device that indicated a total hydrocarbon destruction efficiency of 98 percent when operated at a 1,650°F combustion control temperature.

31. On March 29, 2016, EPA issued a Section 114 information requesting additional information regarding enclosed combustion device located at the railcar loading operations.

32. On May 3, 2016, MarkWest submitted a response that included daily temperature readings, including daily temperature minimum, average, and maximum for the period of July 2, 2015 through April 1, 2016.

33. Based on the review of the October 2015 and May 3, 2016 responses, MarkWest did not operate the railcar enclosed combustion device above 816°C (1500.8°F) for 669 days for the period of February 15, 2014 through April 1, 2016. See Attachment 1.

34. Based on May 3, 2016 response to the March 2016 information request, MarkWest has not conducted a performance test for the railcar enclosed combustion device.

Violations

35. MarkWest failed to operate the enclosed combustion device located in the railcar area with a minimum temperature of 816°C and a residence time of 0.75 in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-10a(c). See Attachment 1.

36. MarkWest failed to conduct a performance test of the enclosed combustion device located in the railcar area to demonstrate compliance with 40 C.F.R. § 60.482-10a(c) in violation of 40 C.F.R. § 60.8(a).

37. By not appropriately monitoring to ensure the enclosed combustion device located in the railcar area met the standards set forth in 40 C.F.R. § 60.482-10a(c), MarkWest failed to monitor the enclosed combustion device to ensure that it is operated and maintained in conformance with its design, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-10a(e).

Enforcement Authority

38. Sections 113(a)(3) of the CAA, 42 U.S.C. § 7413(a)(3), provide that whenever, on the basis of any information available to the Administrator, the Administrator finds that any person has violated, or is in violation of, any requirement or prohibition of, inter alia, any rule promulgated under the NSPS of Section 111(e) of the CAA, 42 U.S.C. § 7411(e), the Administrator may issue an administrative penalty order under Section 113(d), issue an order requiring compliance with such requirement or prohibition, or bring a civil action pursuant to Section 113(b) for injunctive relief and/or civil penalties.

Environmental Impact of Violations

39. MarkWest's above-referenced violations have caused excess emissions of VOC.

40. Excess VOC emissions can cause eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to the liver, kidney, and central nervous system. Some organics can cause cancer in animals and some are suspected or known to cause cancer in humans.

41. VOC emissions are a precursor to ground-level ozone. Breathing ozone contributes to a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame lung tissue. Repeated exposure may permanently scar lung tissue.

Attachment 1

CERTIFICATE OF MAILING

I, Loretta Shaffer, certify that I sent a Finding of Violation, No. EPA-5-16-OH-09, by Certified Mail, Return Receipt Requested, to:

I also certify that I sent copies of the Finding of Violation by first-class mail to:

On the 23 day of June 2016.

CERTIFIED MAIL RECEIPT NUMBER: 70111150000026408329

APPENDIX H

Dear Ms. McBurney:

The U.S. Environmental Protection Agency is issuing the enclosed Finding of Violation (FOV) to MarkWest Energy Partners L.P. and MarkWest Utica EMG, L.L.C. (collectively MarkWest or you) under Sections 113(a)(3) of the Clean Air Act, 42 U.S.C. § 7413(a)(3). We find that you are violating the following at your Seneca Gas Plant in Summerfield, Ohio: (1) Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution at 40 C.F.R. §§ 60.5360-5430 (Subpart OOOO); and (2) Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 at 40 C.F.R. §§ 60.480a-60.490 (Subpart VVa).

Section 113 of the Clean Air Act gives us several enforcement options. These options include issuing an administrative compliance order, issuing an administrative penalty order, and bringing a judicial civil or criminal action.

We are offering you an opportunity to confer with us about the violations alleged in the FOV. The conference will give you an opportunity to present information on the specific findings of violation, any efforts you have taken to comply, and the steps you will take to prevent future violations. In addition, in order to make the conference more productive, we encourage you to submit to us information responsive to the FOV prior to the conference date.

Please plan for your facility's technical and management personnel to attend the conference to discuss compliance measures and commitments. You may have an attorney represent you at this conference. The EPA contact in this matter is Constantinos Loukeris. You may call him at (312) 353-6198 to request a conference. You should make the request within 10 calendar days following receipt of this letter. We should hold any conference within 30 calendar days following receipt of this letter.

FINDING OF VIOLATION

The U.S. Environmental Protection Agency finds that MarkWest Energy Partners, L.P. and MarkWest Utica EMG, L.L.C. (collectively "MarkWest") is violating the Clean Air Act (CAA) and its implementing regulations at the company's Seneca Facility in Summerfield, Ohio. Specifically, MarkWest is violating: (1) Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution at 40 C.F.R. §§ 60.5360-5430 (Subpart OOOO); and (2) Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemicals Manufacturing Industry for Which Construction, Reconstruction, or Modification Commenced After November 7, 2006 at 40 C.F.R. §§ 60.480a-60.490 (Subpart VVa).

Regulatory Authority

New Source Performance Standard Subpart OOOO

1. Section 111 of the CAA, 42 U.S.C. § 7411, authorizes EPA to promulgate regulations establishing New Source Performance Standards (NSPS).

2. Section 111(e) of the CAA, 42 U.S.C. § 7411(e), states that after the effective date of standards of performance promulgated under this section, it shall be unlawful for any owner or operator of any new source to operate such source in violation of any standard of performance applicable to such source.

3. EPA promulgated Subpart OOOO on September 23, 2013. 78 Fed. Reg. 58435.

4. Subpart OOOO at 40 C.F.R. § 60.5365 states that an owner or operator of one or more of the onshore affected facilities listed in paragraphs (a) through (g) of this section for which construction, modification, or reconstruction commenced after August 23, 2011 is subject to the applicable provisions of Subpart OOOO. Section 60.5365(f) states that the group of all equipment, except compressors, within a process unit is an affected facility. Section 60.5365(f)(3) further provides that the equipment within a process unit of an affected facility located at onshore natural gas process plants and described in paragraph (f) of this section are exempt from Subpart OOOO if they are subject to and controlled according to Subparts VVa, GGG, or GGGa of 40 C.F.R. Part 60.

5. Subpart OOOO at 40 C.F.R. § 60.5430 defines "process unit" to mean "components assembled for the extraction of natural gas liquids from field gas, the fractionation of the liquids into natural gas products, or other operations associated with the processing of natural gas products."

6. Subpart OOOO at 40 C.F.R. § 60.5430 defines a "natural gas processing plant (gas plant)" as "any processing site engaged in the extraction of natural gas liquids from field gas, fractionation of mixed natural gas liquids to natural gas products, or both."

7. Subpart OOOO at 40 C.F.R. § 60.5400 sets forth equipment standards that apply to affected facilities at an onshore natural gas processing plant. This section applies to the group of all equipment, except compressors, within a process unit.

8. Subpart OOOO at 40 C.F.R. § 60.5400(a) states a subject owner or operator must comply with the equipment leak standard requirements of specific portions of Subpart VVa at 40 C.F.R. §§ 60.482-1a(a), (b), and (d), 60.482-2a, and 60.482-4a through 60.482-11a., except as provided in § 60.5401.

9. Subpart OOOO at 40 C.F.R. § 60.5400(d) states that a subject owner or operator must comply with the provisions of 40 C.F.R. § 60.485a of Subpart VVa except as provided in § 60.5400(f).

10. Subpart OOOO at 40 C.F.R. § 60.5400(e) states that a subject owner or operator must comply with the provisions of §§ 60.486a and 60.487a of Subpart VVa except as provided in §§ 60.5401, 60.5421, and 60.5422 of Subpart OOOO.

11. Subpart OOOO at 40 C.F.R. § 60.5400(f) states that a subject owner or operator must use the following provision instead of 40 C.F.R. § 60.485a(d)(1): "Each piece of equipment is presumed to be in VOC service or in wet gas service unless an owner or operator demonstrates that the piece of equipment is not in VOC service or in wet gas service."

12. Subpart OOOO at 40 C.F.R. § 60.5401(b) states that each pressure relief device in gas/vapor service may be monitored quarterly and within 5 days after each pressure release to detect leaks by the methods specified in 40 C.F.R. § 60.485a(b) except as provided in 40 C.F.R. § 60.5400(c) and in paragraph (b)(4) of this section, and 40 C.F.R. § 60.482-4a(a) through (c) of subpart VVa.

13. Subpart OOOO at 40 C.F.R. § 60.5401(b) further provides that if an instrument reading of 500 ppm or greater is measured, a leak is detected, and when a leak is detected, it must be repaired as soon as practicable, but not later than 15 days after it is detected, except as provided in § 60.482-9a. In addition, § 60.5401(b) provides that a first attempt at repair must be made no later than 5 calendar days after each leak is detected. Section 60.5401(b)(4)(i) provides that any pressure relief device that is located in a nonfractionating plant that is monitored only by non-plant personnel may be monitored after a pressure release the next time the monitoring personnel are on-site, instead of within 5 days as specified in paragraph (b)(1) of this section and § 60.482-4a(b)(1) of Subpart VVa; however, no pressure relief device described in paragraph (b)(4)(i) of this section must be allowed to operate for more than 30 days after a pressure release without monitoring.

NSPS Subpart VVa

14. EPA promulgated NSPS Subpart VVa on November 16, 2007 (Subpart VVa). See 72 Fed. Reg. 64883.

15. Subpart VVa at 40 C.F.R. § 60.482-1a(a) states "[e]ach owner or operator subject to the provisions of this subpart shall demonstrate compliance with the requirements of §§ 60.482-1a through 60.482-10a or § 60.480a(e) for all equipment within 180 days of initial startup."

16. Subpart VVa at 40 C.F.R. § 60.482-1a(b) states "[c]ompliance with §§ 60.482-1a to 60.482-10a will be determined by review of records and reports, review of performance test results, and inspection using the methods and procedures specified in § 60.485a."

17. Subpart VVa at 40 C.F.R. § 60.482-2a(a)(1) states "[e]ach pump in light liquid service shall be monitored monthly to detect leaks by the methods specified in § 60.485a(b), except as provided in § 60.482-1a(c) and (f) and paragraphs (d), (e), and (f) of this section. A pump that begins operation in light liquid service after the initial startup date for the process unit must be monitored for the first time within 30 days after the end of its startup period."

18. Subpart VVa at 40 C.F.R. § 60.482-2a(a)(2) states that "[e]ach pump in light liquid service shall be checked by visual inspection each calendar week for indications of liquids dripping from the pump seal, except as provided in § 60.482-1a(f)."

19. Subpart VVa at 40 C.F.R. § 60.482-11a(a) states "[t]he owner or operator shall initially monitor all connectors in the process unit for leaks by the later of either 12 months after the compliance date or 12 months after initial startup."

20. Subpart VVa at 40 C.F.R. § 60.482-11a(d) states that "[w]hen a leak is detected pursuant to paragraphs (a) and (b) of this section, it shall be repaired as soon as practicable, but not later than 15 calendar days after it is detected, except as provided in § 60.482-9a. A first attempt at repair as defined in this subpart shall be made no later than 5 calendar days after the leak is detected" from a connector.

21. Subpart VVa at 40 C.F.R. § 60.482-7a(d)(2) states that "[a] first attempt at repair shall be made no later than 5 calendar days after each leak is detected" from a valve.

22. Subpart VVa at 40 C.F.R. § 60.482-6a(a)(1) states that "[e]ach open-ended valve or line shall be equipped with a cap, blind flange, plug, or a second valve, except as provided in § 60.482-1a(c) and paragraphs (d) and (e) of this section.

23. Subpart VVa at 40 C.F.R. § 60.482-6a(a)(2) states that "[t]he cap, blind flange, plug, or second valve shall seal the open end at all times except during operations requiring process fluid flow through the open-ended valve or line."

24. Subpart VVa at 40 C.F.R. § 60.482-7a(a)(1) states that "[e]ach valve shall be monitored monthly to detect leaks by the methods specified in § 60.485a(b) and shall comply with paragraphs (b) through (e) of this section."

25. Subpart VVa at 40 C.F.R. § 60.482-7a(a)(2) states that "[a] valve that begins operation in gas/vapor service or light liquid service after the initial startup date for the process unit must be monitored according to paragraphs (a)(2)(i) or (ii)."

26. Subpart VVa at 40 C.F.R. § 60.482-7a(a)(2)(i) states that a facility must "[m]onitor the valve as in paragraph (a)(1) of this section. The valve must be monitored for the first time within 30 days after the end of its startup period to ensure proper installation."

27. Subpart VVa at 40 C.F.R. § 60.485a(b) states "[t]he owner or operator shall determine compliance with the standards in §§ 60.482-1a through 60.482-11 a, 60.483a, and 60.484a as follows: (1) Method 21 shall be used to determine the presence of leaking sources. The instrument shall be calibrated before use each day of its use by the procedures specified in Method 21 of Appendix A-7 of this part."

28. Subpart VVa at 40 C.F.R. § 60.482-4a(a) states that "[e]xcept during pressure releases, each pressure relief device in gas/vapor service shall be operated with no detectable emissions, as indicated by an instrument reading of less than 500 ppm above background, as determined by the methods specified in § 60.485a(c)."

29. Subpart VVa at 40 C.F.R. § 60.482-4a(b) states that "[a]fter each pressure release, the pressure relief device shall be returned to a condition of no detectable emissions, as indicated by an instrument reading of less than 500 ppm above background, as soon as practicable, but no later than 5 calendar days after the pressure release, except as provided in § 60.482-9a." Further, 40 C.F.R. § 60.482-4a(b) provides that "[n]o later than 5 calendar days after the pressure release, the pressure relief device shall be monitored to confirm the conditions of no detectable emissions, as indicated by an instrument reading of less than 500 ppm above background, by the methods specified in § 60.485a(c)."

30. Subpart VVa at 40 C.F.R. § 60.482-4a(c) provides that "[a]ny pressure relief device that is routed to a process or fuel gas system or equipped with a closed vent system capable of capturing and transporting leakage through the pressure relief device to a control device as described in 40 C.F.R. § 60.482-10a is exempted from the requirements of paragraphs (a) and (b) of [§ 60.482-4a]."

31. Subpart VVa at 40 C.F.R. § 60.482-10a(a) states that "[o]wners or operators of closed vent systems and control devices used to comply with provisions of this subpart shall comply with the provisions of this section." § 60.482-10a(m) provides that "[c]losed vent systems and control devices used to comply with this subpart shall be operated at all times when emissions may be vented to them."

32. The NSPS Appendix A-7, at 40 C.F.R. Part 60, Method 21 §§ 8.3.1 and 8.3.1.1, sets forth the technique which must be used to determine if there is a leak from a valve.

Findings of Fact

33. MarkWest owns and operates an onshore natural gas processing plant, at 26645 Zep Road East, Summerfield, Ohio, called the Seneca Gas Plant (SGP), which removes natural gas liquids from field gas.

34. On November 4, 2013, MarkWest notified Ohio EPA that the SGP is subject to Subpart OOOO (and by reference Subpart VVa).

35. EPA conducted an inspection of the SGP on April 25-28, 2016 (April 2016 inspection).

36. During the April 2016 inspection, EPA reviewed records indicating that MarkWest did not calibrate their portable volatile organic compound (VOC) monitor with the appropriate calibration gas prior to performing Method 21 monitoring of pumps for the following months:

37. During the April 2016 inspection, EPA observed greater than 10,000 parts per million (ppm) of VOC from an open-ended valve or line not properly connected into a dew point analyzer in the Seneca 3 process unit. In addition, EPA imaged significant hydrocarbons from this sample line using a FLIR® infrared camera.

38. During the April 2016 inspection, EPA observed the following valves that were insulated such that Method 21 could not be performed at the surface of the valve where leakage could occur: Tag# 179EE in Inlet; Tag# 909, 910, 925, 924, 939, 1013, 1009, and 868 in Seneca 1; Tag# 2157, 1620, 1618 in Seneca 2; and Tag# 2850, 2755, and 2756 in Seneca 3.

39. During the April 2016 inspection, EPA reviewed records indicating MarkWest did complete a weekly visual inspection for four pumps for three weeks in August 2015.

40. During the April 2016 inspection, EPA observed pressure relief devices that are routed through a vent system to a flare.

41. On May 19, 2016 (May 2016 Letter), MarkWest submitted follow-up information requested during the April 2016 inspection.

42. In the May 2016 Letter, MarkWest indicated that they were unable to retrieve any records of weekly visual pump inspections for February 2014.

43. During the April 2016 inspection, EPA observed three open-ended valves or lines, with Tag# 758, 759, and 1038 that did not have sealed closure devices.

44. From MarkWest's leak detection and repair (LDAR) database provided during the April 2016 inspection, EPA identified the following number of connectors that were not monitored initially within 12 months:

45. From MarkWest's LDAR database provided during the April 2016 inspection, EPA identified the following number of valves that were not monitored initially within 30 days:

46. From MarkWest's LDAR database provided during the April 2016 inspection, EPA identified the follow pressure relief valves that leaked above 500 ppm:

47. In reviewing MarkWest's leak history, EPA discovered the following leaks that did not have a first attempt at repair within 5 days:

48. For the monthly and quarterly monitoring events since March 2014, MarkWest reported an average of 2.39 as the percentage of valves leaking in the Seneca 1, Seneca 2, and Seneca 3 process units, whereas EPA found a 4.66% leaking rate during the April 2016 inspection.

49. MarkWest operates pilot designed pressure relief devices throughout the SGP. These pilot pressure relief devices are designed to release gas directly to the atmosphere from the pilot vents with any overpressure greater than 1 percent and up to 15 percent prior to actuating the main pressure-relief valve to the flare.

50. During the April 2016 inspection, EPA identified a pilot designed pressure relief device (Tag # 00689) at the Seneca 1 process unit venting to the atmosphere instead of the flare header using a portable VOC instrument (1,900 ppm), and confirmed by MarkWest tagging the pressure relief device as leaking.

Violations

51. MarkWest failed to perform Method 21 properly on 14 insulated valves listed in paragraph 38, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-7a(a)(1) (and by reference § 60.485(b)) and 40 C.F.R. Part 60, Method 21 §§ 8.3.1 and 8.3.1.1.

52. MarkWest failed to perform initial monthly monitoring of all valves, including bleeder valves from 5-way assemblies, listed in paragraph 45 within 30 days for each process unit at the SGP after the initial startup date, in violation of 40 C.F.R. §§ 60.5400(a), 60.482-7a(a)(2), and 60.482-7a(a)(1).

53. MarkWest failed to perform the initial monthly monitoring of all pumps in each process unit at the SGP within 30 days after the end of the startup period, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-2a(a)(1).

54. MarkWest failed to perform annual monitoring on all connectors identified paragraph 44, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-11a(a).

55. MarkWest failed to seal each closure device associated with an open-ended valve or line per paragraph 43 with a cap, blind flange, plug, or a second valve, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-6a(a)(2).

56. MarkWest failed to perform weekly visual inspections on pumps in each of the process units at the SGP for the period of October 2013 through February 2014, and for 4 pumps over 3 weeks in August 2015, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482a(a)(2).

57. MarkWest failed to make timely first attempts at repairs within 5 days on the valve listed in paragraph 47 in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-7a(d)(2).

58. MarkWest failed to make timely first attempts at repairs within 5 days on the connectors listed in paragraph 47 in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-11a(d).

59. Based on pressure relief device design information and VOC monitoring conducted during the April 2016 inspection and per paragraph 46, MarkWest has failed to comply with closed vent and control device requirements for pressure relief devices at the SGP, in violation of 40 C.F.R. §§ 60.5400(a), § 60.482-4a(c), § 60.482-10a(a).

60. For the open-ended valve or line venting to the atmosphere per paragraph 37, MarkWest has failed to place a cap, a blind flange, a plug, or a second valve at the open-ended valve or line, in violation of 40 C.F.R. §§ 60.5400(a) and § 60.482-6a(a)(1).

61. MarkWest failed to perform Method 21 properly on valves per paragraph 48, in violation of 40 C.F.R. §§ 60.5400(a) and 60.482-7a(a)(1), and 40 C.F.R. Part 60 Method 21, §§ 8.3.1 and 8.3.1.1, from at least March 2014 through March 2016.

Enforcement Authority

62. Sections 113(a)(3) of the CAA, 42 U.S.C. § 7413(a)(3), provide that whenever, on the basis of any information available to the Administrator, the Administrator finds that any person has violated, or is in violation of, any requirement or prohibition of, inter alia, an applicable SIP or permit, any rule promulgated under the NSPS requirements of Section 111(e) of the CAA, 42 U.S.C. § 7411(e), Title V of the CAA, 42 U.S.C. §§ 7661-7661f, or any rule or permit issued thereunder, the Administrator may issue an administrative penalty order under Section 113(d), issue an order requiring compliance with such requirement or prohibition, or bring a civil action pursuant to Section 113(b) for injunctive relief and/or civil penalties.

Environmental Impact of Violations

63. MarkWest's above-referenced violations have caused excess emissions of VOC.

64. Excess VOC emissions can cause eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to the liver, kidney, and central nervous system. Some organics can cause cancer in animals and some are suspected or known to cause cancer in humans.

65. VOC emissions are a precursor to ground-level ozone. Breathing ozone contributes to a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame lung tissue. Repeated exposure may permanently scar lung tissue.

CERTIFICATE OF MAILING

I, Loretta Shaffer, certify that I sent a Finding of Violation, No. EPA-5-16-OH-16, by Certified Mail, Return Receipt Requested, to:

I also certify that I sent copies of the Finding of Violation by first-class mail to:

On the 8 day of September 2016.

CERTIFIED MAIL RECEIPT NUMBER: 70091680000076740838