Date: October 14, 2014

To: Brenda Shine, EPA/OAQPS/SPPD

From: Jeff Coburn

Subject: Meeting Minutes for October 7, 2014, Meeting Between the U.S. EPA and

Representatives of Marathon Petroleum Company

On October 7, 2014, representatives of the U.S. Environmental Protection Agency (EPA) 

and their contractor (RTI International) participated in a meeting with representatives of the

Marathon Petroleum Company LP (MPC). The names and affiliations of the participants are 

included in Attachment 1. The purpose of the meeting was to discuss MPC’s concerns over

various requirements in the refinery sector rule proposal. The agenda focused on the following 

sections of the proposed rule: atmospheric pressure relief devices (PRDs), halogenated vent 

streams, reformer standard revisions, fenceline monitoring, startup, shutdown and malfunction 

(SSM) provisions, as well as the proposed revisions to NSPS Ja. The memorandum is organized 

by these areas of concern. The MPC representatives provided a presentation summarizing their

concerns; the presentation is included as Attachment 2 to this memorandum. Additional

supporting information related to fenceline monitoring provided by the MPC representatives is 

included as Attachment 3 to this memorandum.

Atmospheric Pressure Relief Devices:

The MPC representatives expressed their concerns over the equipment monitoring and 

emissions control requirements as well as the compliance date for atmospheric PRDs in the 

EPA’s current sector rule proposal. MPC representatives asserted that the frequency and 

emissions related to PRD releases in HAP service are small. Based on their company records,

MPC had only 5 PRD releases (in HAP service) considering all 7 of its refineries over the most 

recent 5 year period; 2 of these 5 releases exceeded the reportable quantity (RQ) for hydrogen 

sulfide (H2S). 

The MPC representatives presented an alternate work practice based compliance 

approach and alternate compliance dates for atmospheric PRDs. The work practice based 

approach would require atmospheric PRDs to have 3 layers of prevention as described on page 5 

of Attachment 2. In addition to requiring 3 layers of prevention, the work practice based 

compliance approach would require the operator to perform root cause analysis and corrective 

action for each release. MPC representatives also presented several different examples of the 3 

layers of prevention on pages 6-9 of Attachment 2. During the discussion of the layers of 

prevention, the EPA representatives asked why a rupture disk would be considered a prevention 

method. MPC representatives explained that these devices were not prone to leaking or 
“chattering” when the pressure is near, but not necessarily exceeding the pressure set point of the 

PRD.

MPC representatives also stated that more time would be needed to bring these devices 

into compliance, even under the work practice based compliance approach. MPC proposed an 

alternate compliance date of 3 years after rule promulgation or the first plant TAR, whichever is 

longer.

MPC representatives indicated that they follow rigorous design standards governed by 

EPA’s Risk Management Program (RMP) and Occupational Safety and Health Administration 

(OSHA) Process Safety Management (PSM) standards for ensuring the safety of their employees 

and minimizing releases from atmospheric PRDs. The EPA representatives requested a copy of 

one of MPC’s RMP plans to review the existing design standards. 

MPC representatives also pointed out that release reporting is currently governed by the 

requirements of the Comprehensive Environmental Response, Compensation, and Liability Act

(CERCLA) and Emergency Planning and Community Right-to-Know Act (EPCRA) programs.

MPC representatives described the reporting requirements of these two programs and requested 

that the reporting requirements in the refinery sector rule proposal be adjusted to coincide with 

the semiannual MACT report rather than another separate reporting scheme. The EPA 

representatives noted that there are community concerns about the availability of the information

reported through the CERCLA/EPCRA programs, and that some stakeholders want an 

immediate, publicly available resource (such as a website, or twitter feed) to receive notifications 

of releases.

Halogenated Vent Streams:

The MPC representatives noted that the provisions for halogenated vent streams in the 

refinery sector rule proposal do not provide details on the method for demonstrating compliance.

Additionally, MPC requested clarity on the 1 lb/hr limit by asking if this limit is per stream or 

per the total volume of gas to the flare at a given time. MPC also requested clarification on the 

averaging period for the emissions related to this limit (i.e., hourly or annual averaging). The 

EPA representatives stated that their intent was to allow process knowledge and engineering 

estimate to assess compliance with the limit and that the limit was expected to be evaluated on an 

annual averaging period.

Reformer Standard Revisions:

The MPC representatives expressed concern that the removal of the exemption from 

active purging going to the atmosphere during de-pressurization of the unit prevents the ability to 

vent nitrogen gas during catalyst dumping or air freeing the system during periods of startup or 

shutdown. MPC representatives stated that little to no HAP emissions are expected during these 

events and requested clarification that the proposed rule provisions were not intended to regulate 

these types of purges.

2
Fenceline Monitoring:

The MPC representatives presented the results of ambient monitoring performed at some 

of their refineries. MPC representatives requested that, in cases where existing monitoring 

systems exist, the rule should provide some flexibility to utilize those systems. The EPA

representatives expressed concerns with relying solely on the existing monitoring sites as they do 

not provide full coverage around the facility. The MPC representatives asserted that sampling 

stations should only be required on borders sharing sensitive areas such as schools, residential, 

hospitals, etc. The historical readings at the MPC monitors were all below the EPA’s proposed

action level; however, the MPC representatives expressed concerns regarding the proposed 

action level, particularly for facilities in more industrialized areas where background and other 

emission sources may contribute to the total ambient concentrations measured by the monitors.

SSM Provisions:

MPC representatives discussed the use of Safety Instruments Systems (SIS) on the fluid 

catalytic cracking unit (FCCU). This system automatically shuts the unit down based on predefined criteria. MPC representatives presented a list of examples of times when the SIS initiated 

a system shutdown to demonstrate that these occurrences are not always caused by an equipment 

malfunction. MPC representatives stated that there have been 40 SIS activations in a 19 month 

timespan (January 2013 to July 2014) at MPC refineries. The MPC representatives asserted that 

the shutdown and subsequent startup related to the SIS activation meets the definition of startup 

and shutdown in the MACT general provisions and, therefore, the EPA should revise the 

proposed rule to allow the alternate emissions standards for startup and shutdown to apply during 

these events.

Monitoring Requirements of FCCU:

The refinery sector rule proposal removes the provision for existing FCCUs to comply 

with the provisions in NSPS J for PM control and, according to the MPC representatives, will 

force existing FCCU to comply with the monitoring requirements in NSPS Ja. MPC operates one 

FCCU with a tertiary cyclone control device in Canton, OH and one FCCU with a baghouse for 

emissions control in Catlettsburg, KY. MPC representatives provided test data from the Canton, 

OH FCCU to support their assertion that there is a poor correlation between opacity and PM for 

this emissions source. Based on their emissions data, MPC representatives recommended

removing the site-specific opacity limit in the MACT rule and replacing it with an annual stack 

test requirement for cyclone control devices. The EPA representatives requested that the full test 

report be submitted. MPC also stated that there would be significant challenges with installing a 

baghouse leak detection system (BLDS) because of the design of their baghouse and requested 

that EPA add an option for an alternate monitoring plan for baghouses in the MACT and NSPS 

to include pressure drop monitoring and annual emissions testing in lieu of the BLDS. The EPA 

representatives noted that the general provisions in 40 CFR parts 60 and 63 allow facilities to 

request the use of an alternative monitoring plan.

3
Attachment 1

Participants in October 7, 2014 EPA/MPC Meeting

MPC Representatives

Charles Bennett

Nicole Brien

Ruth Cade

Jacob Fournier

Joe Stevens

U.S. EPA Representatives

Andrew Bouchard

Eric Goehl

Penny Lassiter

Brenda Shine

RTI International (EPA contractor)

Jeff Coburn

Leslie Pearce
Attachment 2

Presentation Slides

Proposed Refinery Sector Rule

Marathon Petroleum Company LP
Proposed Refinery Sector Rule

October 7, 2014
Agenda

 Atmospheric Pressure Relief Devices

 Work Practice and Equipment Standard

 Refinery Release Reporting

 Halogenated Vent Streams

 Reformer Standard Revisions

 Fence Line Monitoring

 Overview of data

 Discussion of alternative monitoring

 Startup and Shutdown

 SIS systems discussion

 Other concerns

 NSPS Ja Revisions

2
Atmospheric Pressure Relief Devices

3
Atmospheric Pressure Relief Devices

EPA Proposal

 Prohibition of relief to atmosphere from gas/vapor pressure relief devices in HAP 

service

 Installation of monitoring system to detect reliefs to the atmosphere

 Effective at promulgation

MPC Concerns

 Relief valves are safety devices to protect equipment from significant damage during 

malfunctions

 Emissions from atmospheric relief events are minimal and existing reporting 

requirements are in place to capture the events

 Technical reasons why certain atmospheric relief valves can not be connected to a flare 

system (or other control device).

 Timing of proposal is inadequate, at least 3 years for implementation would be needed.

 Work practices and equipment standards could be implemented to minimize events
Atmospheric PRD Work Practices & Equipment Standards

 Atmospheric PRD relief standard should be a work practice

 Work practice and equipment standard recommendation:

 Require sufficient prevention methods in a PRD standard

 Require Root Cause Analysis / Corrective Action procedures

 Implementation at 3 years, or at next TAR (whichever is longer)

 Reporting of Atmospheric PRD relief should be done in a semi-annual report

 Prevention methods may include any three of the following:

 Rupture disks

 Level monitoring, alarms, and corrective action at high priority alarms

 Pressure monitoring, alarms, and corrective action at high priority alarms

 Staged venting to flare 

 Automatic SIS system that would initiate heat source removal or shut down feed 

supply to equipment

 Mechanical testing of PRV during TAR and installation

 Operator training

5
ARV Discharge Prevention 

Scenario 1

6

• Rupture Disks are installed under some ATM Relief Valves to prevent malfunctioning relief valves from 

leaking to the atmosphere needlessly

• Level indication with alarm in bottom of Vessels allow operators to have knowledge of normal liquid level 

and trends. Typical installation is a local sight glass and an electronic level signal to the control room

• High pressure alarms to control room trigger differing operator action depending on the level of urgency 

associated with the alarm

ATM

ARV

Set @ 

Vessel 

MAWP

Rupture Disk 

Set @ Vessel 

MAWP

PAH Multiple alarm set 

points with elevating 

sense of urgency

Control 

Room

 Tiered alarm Philosophy

• High Pressure alarm is high 

priority alarm set below MAWP 

that triggers troubleshooting 

guidelines for operators to use 

in an effort to find and fix the 

problem 

• Not to Exceed Alarm is an 

urgent alarm set at MAWP that 

triggers a prescribed set of 

operator actions that must be 

taken to bring the situation 

under control as quickly as 

possible

LI
ARV Discharge Prevention 

Scenario 2

7

• Level Switches are installed on some vessels to prevent over pressure by liquid overfill by stopping flow of 

liquid into the vessel. Corporate standards do not allow discharge of liquid through atmospheric relief 

valves.

• Level indication with alarm in bottom of Vessels allow operators to have knowledge of normal liquid level 

and trends. Typical installation is a local sight glass and an electronic level signal to the control room

• High pressure alarms to control room trigger differing operator action depending on the level of urgency 

associated with the alarm

ATM

Equipment 

Charge

LS

ARV

Set @ 

Vessel 

MAWP

PAH

Control 

Room

 Tiered alarm Philosophy

• High Pressure alarm is high 

priority alarm set below MAWP 

that triggers troubleshooting 

guidelines for operators to use 

in an effort to find and fix the 

problem 

• Not to Exceed Alarm is an 

urgent alarm set at MAWP 

that triggers a prescribed set of 

operator actions that must be 

taken to bring the situation 

under control as quickly as 

possible LI
ARV Discharge Prevention 

Scenario 3

8

• Automated pressure Controlled Vents to the flare allow the refiner to vent over pressure events to the flare 

before the ATM relief valve discharges. Corporate standards require that a relief valve still be present as a last 

line of defense in case instrumentation malfunctions.

• Level indication with alarm in bottom of Vessels allow operators to have knowledge of normal liquid level and 

trends. Typical installation is a local sight glass and an electronic level signal to the control room

• High pressure alarms to control room trigger differing operator action depending on the level of urgency 

associated with the alarm

ATM

PC

Flare

ARV

Set @ 

Vessel 

MAWP

Set Below 

Vessel MAWP

LI

PAH

Control 

Room

 Tiered alarm Philosophy

• High Pressure alarm is high 

priority alarm set below MAWP 

that triggers troubleshooting 

guidelines for operators to use 

in an effort to find and fix the 

problem 

• Not to Exceed Alarm is an 

urgent alarm set at MAWP that 

triggers a prescribed set of 

operator actions that must be 

taken to bring the situation 

under control as quickly as 

possible
ARV Discharge Prevention

Scenario 4

9

ATM

PS

ARV

Set @ 

Vessel 

MAWP

Set Below 

Vessel MAWP

Fuel 

Gas

Control PAH

Room

 Tiered alarm Philosophy

• High Pressure alarm is high 

priority alarm set below MAWP 

that triggers troubleshooting 

guidelines for operators to use 

in an effort to find and fix the 

problem 

• Not to Exceed Alarm is an 

urgent alarm set at MAWP that 

triggers a prescribed set of 

operator actions that must be 

taken to bring the situation 

under control as quickly as 

possible

LI

• Automated Pressure trips will stop the supply of heating medium to some distillation towers to stop pressure 

build before the ATM relief valve discharges. Corporate standards require that a relief valve still be present as a 

last line of defense in case instrumentation malfunctions.

• Level indication with alarms in bottom of Vessels allow operators to have knowledge of normal liquid level and 

trends. Typical installation is a local sight glass and an electronic level signal to the control room

• High pressure alarms to control room trigger differing operator action depending on the level of urgency 

associated with the alarm
Atmospheric PRDs Summary

 MPC has existing systems in place that adequately address HAP reliefs to 

atmosphere and believes these should not be addressed as violations in the 

refinery sector rule

 MPC follows rigorous existing design standards governed by EPA’s RMP and 

OSHA PSM regulations.

– MPC already has a policy in place that incorporates API 521 for safe relief of atmospheric 

PRDs

– This includes appropriate dispersion modeling to ensure community and plant individuals 

will not be harmed by release when installing new PSVs

 Equipment standards and work practices should be implemented

 Work practice and equipment standard recommendation:

 Require at least 3 defined prevention methods in a PRD standard

 Require RCA/CA analysis

 Implementation at 3 years, or at next TAR (whichever is longer)

 Reporting of atmospheric PRD relief should be done in a semi-annual MACT report

10
EPA Release Reporting Flow Chart

11
MPC Notification Process

 A release occurs

 Refinery personnel evaluate what has been released and make estimates on 

the quantities

 At the same time personnel are working to mitigate the release if it has not yet 

been secured

 Refinery personnel make calls to proper agencies (local, state, federal) within 

15 minutes of discovery

 Once event has been secured, an investigation occurs to determine the cause 

of the release

 Written follow-up notifications are submitted and include the final emissions 

estimate from the event and often a cause

12
Halogenated Vent Streams

13
Halogens 

 The proposed refinery sector rule includes a ban on halogenated streams 

going to the flare

 Compliance demonstration not included in the proposed rule

 MPC has reviewed our systems and identified some streams that may be 

above the 1 lb/hr limit on a short-term basis during Startup, Shutdown, or 

Malfunction activities.

 Halogenated streams in a refinery are corrosive. Refineries have incentives to 

minimize concentrations due to metallurgy and corrosion concerns.

 Due to moisture in flare header, believe that these drop out with water in the flare 

knock-out drum.

 Monitoring for some of these streams may be unsafe and systems may be 

costly to install

 Location of 1 lb/hr limit compliance point is not defined

14
Sources at a Refinery: CRUs and Isom Units

 Catalytic Reforming Units and Isomerization Units

 CRUs and Isomerization units use perchloroethylene

 Use in reactors results in chlorinated compounds that meet the definition of 

halogenated streams in the proposed rule

 Streams identified:

 Recycle hydrogen

 Turnaround and maintenance activities

 Current controls for chlorides:

 Chloride guard beds

 Current monitoring for hydrogen:

 Dragger testing for HCl

 Levels monitored for breakthrough

 May not be measurable in total flare gas volume in the flare header

15
General Reformer 

16

Flare
Sources at a Refinery: HF Alkylation

 HF Alky

 HF Alky units have hydrocarbon streams that contain amounts of HF 

 Streams that have a potential to have HF are scrubbed

 Scrubbers are monitored using based on caustic strength

 Keeping HF out of the flare is in a refineries best interest

– HF service piping is much more expensive that piping used for normal flare systems

– HF will cause damage to piping and quickly lead to leaks in the lines if not scrubbed 

adequately

– HF will also destroy columns in the GCs for the flare systems at fairly low concentrations 

fairly quickly if they get to the system

 Monitoring for HF specifically requires multiple safety precautions

17
General Alky 

18

Flare
Compliance Recommendations

 Provide exemptions if scrubbers or chloride guard beds are used on stream 

prior to flare.

 Establish a 1 lb/hr compliance standard on an annual basis.

 Clarify compliance determined by 

1. Engineering estimate and process knowledge

2. Monitor on a unit by unit basis where treatment beds are already found

– Compliance at the flare tip would require additional monitoring

19
Reformer Standard Revisions

20
Reformer Standard Revision

 The proposed rule removes the exemption from active purging going to 

atmosphere during de-pressuring of the unit

 The proposed rule also removes the maintenance vent exemption under the 

miscellaneous process vents section

 Concerns with shutdown of continuous catalytic reformers (CCRs)

 Catalyst dumping

 Air freeing the system on startup

21
Reformer Standard Proposed Revisions

 Continuous nitrogen purge needed for safety while catalyst dumping from 

reactor

 Pyrophoric material in reactors could cause unsafe conditions in the reactor

 Routing to flare could potentially cause the same issue in the flare line

 Nitrogen purge is also needed to air-free the unit on startup

 Whole system purged with nitrogen to atmosphere to remove air

 Routing this purge to flare could cause safety issues in the flare lines

 Issue when catalyst change out has not occurred

22
CCR Shutdown Process

 Regenerator shutdown

 Feed Pulled from Unit

 Hot hydrogen sweep

 De-pressure reactor to flare

 Nitrogen purge to flare

 Blind Reactor

 Open reactor to atmosphere with purge

 Begin catalyst dump

23

Feed

N2

H2

Catalyst

Flare

Regen

Reactor
Recommendations

 Nitrogen purges to atmosphere are needed during shutdown activities to 

prevent pyrophoric ignition and little to no HAP expected

 Use engineering knowledge to exempt from MPV standard during unit catalyst 

dumping and initial air freeing of the unit

 MPC wants to ensure periods of catalyst dumping and initial air freeing of the 

unit are still permitted to go to atmosphere as they are not part of the normal 

operation of the unit and fall after the initial depressuring of the unit

 MPC also wants to ensure maintenance venting events such as this remain to 

be allowed under the miscellaneous process vents section

 If these are not correct assumptions, MPC would suggest language be added to 

the rule to allow for these events

24
Fenceline Monitoring

25
Diffusion Tube Fenceline Monitoring Systems

 MPC has collaborated with EPA with diffusion tube studies at our Texas City 

Refinery. We have also implemented studies at Robinson Refinery, as well as 

developing plans to collect additional diffusion tube samples in late 2014/2015 

system-wide.

 In general, we support API & AFPM; however, our concerns & comments will 

focus on the technical aspects of implementation

 Ability to utilize existing fence-line monitors in lieu of diffusion tubes

 Protocol for diffusion tubes located on common fence-lines between 2 industrial 

sources

 Investigation procedures that tie diffusion tube results back to a regulated MACT 

source and underlying standard

 Cost-effectiveness demonstration and thresholds for implementing corrective 

actions

26
Fenceline Monitoring Discussion

 MPC passive monitoring

 Results similar to EPA NATTS national ambient air monitoring

 Need for alternative monitoring

 Texas City industrial area

 Garyville

 Detroit

 Need for work practice

27
28

Refinery Passive Monitoring Results – Robinson 

Results are below EPA’s 

proposed levels of concern.
29

Follow-up Monitoring Results
Refinery Fenceline Monitoring Results

 Results are below EPA levels of concern

 Permitted tank cleaning operation during initial monitoring

 Lower results in follow-up monitoring when tank cleaning was 

complete

 Benzene loading rack may be influenced by idling train engines 

spotting railcars

 Monitoring at property line can result in lower concentrations 

(concentration is an inverse cubic relation: double the distance 

and concentration goes down by about 1/8).

30
Need for Alternative Monitoring

 States have implemented ambient air monitoring that meets the 

needs of the local community

 History of monitoring below action level should qualify for 

alternative compliance demonstration

 MPC’s existing systems use either continuous GC monitoring, 

summa canisters or trigger sample analysis

31
Texas City Area 2011 Benzene Concentrations

32

MPC Galveston Bay Refinery

11th St 0.8 

31st St 0.3

Logan St 0.5

Ball Park 0.5 2nd Ave 0.4 

34th St 0.2

Avenue A 0.2

GBR On-site 0.8

Monitoring Meets State and Source: TCEQ March 11, 2013 Air Pollutant Watch List Proposed Change

Community Needs
33

MPC Monitoring at Garyville

(7 VOC trigger samples; 1.7 ppb 24-hour maximum)

0.27 ppb

Monitoring Meets State and 

Community Needs
MPC Monitoring Results at Detroit 

annual ppb canister samples

34

0.68 ppb @ 4-E

0.47 @ 2A-N

0.46 ppb @ 1-N

0.48 ppb @ Mark Twain 

Middle School

Monitoring Meets State and 

Community Needs
Need for Work Practice

 EPA proposed: 

 “... a HAP concentration to be monitored in the ambient air around a 

refinery, that if exceeded, would trigger corrective action to minimize 

fugitive emissions”

 “... may need to take some corrective action to minimize fugitive 

emissions.”

 Fugitive emissions include: tank seals, water seals from wastewater 

equipment, equipment leaks

 Purpose of passive monitoring is to enhance MACT standards

35
Monitoring is Influenced by non-Refining Sources

Reported Levels of Benzene (μg/m3)

EPA proposed annual RCA/CA trigger: 9 

 EPA Ambient 1994: 1.5 to 5.0 

 EPA Ambient 2010: 0.3 to 2.0 

 EPA Near roadway: 2.0 @ 40 meters to 1.0 @ 100 meters

 World Health Organization (WHO) Background indoor air (non-smoker): 7.0+

 WHO Background indoor air (smoker): 10.5+

 Municipal fires: 11.0

 AWMA Agricultural burning: 11.2

 WHO Inside cars while driving: 12+

36
No

Yes

Yes RCA/CA 

Analysis

EPA list of 

possible impacts

Annual 

Monitoring

> Trigger level 

μg/m3: Check 

Fugitives

Check 

Perimeter

• Violation if no 

RCA/CA Analysis

• Possible fugitives 

violation

• Transportation: rail, auto, 

truck or marine

• Agricultural burning

• Retail operation

• Wood burning fireplaces

• Other

Fenceline Monitoring Process Flow Chart

Fugitives include: 

tanks, LDAR, and 

wastewater 

components
Fenceline Monitoring Process

 Fenceline results include non-refinery emissions (agricultural 

burning, wood burning fireplaces, transportation sources, nearby 

facilities, etc.) 

 Enhanced monitoring can help identify areas of concern in existing 

programs (LDAR, Tanks, etc.)

 RCA/CA Analysis may be triggered by exceedance of annual threshold

 Work practice standard

38
Fenceline Monitoring Recommendations

 Fenceline monitoring has the potential to detect non-refining sources of 

benzene; therefore, it should be limited to only shared borders of sensitive 

areas, such as:

 Residential areas

 Schools, daycares, hospitals

 Churches, temples, synagogues

 Retail businesses

 Existing ambient air monitoring systems should be allowed as alternative 

monitoring to the proposed standard

 Exceedances of “action levels” at the fenceline should only result in 

investigations of the underlying MACT programs (tanks, fugitives, etc.)

 Corrective action analysis, performed once an action level is triggered, should 

include a cost–effectiveness and threshold determination

 Refineries with low benzene monitoring results should be permitted to have a 

reduced fenceline monitoring schedule, similar to LDAR regulations
Startup and Shutdown

40
FCCU Safety Instrumented Systems

 Safety Instruments Systems (SIS) are automatic shutdown systems that engage based upon a pre- defined set of conditions to minimize potential impact to process equipment, employee safety, or 

environmental impact.

 FCCUs are very complex, relying upon maintaining heat & pressure balance.

 Operates between 1000 – 1400 F & 25 – 35 psig.

 Oxygen & hydrocarbon atmospheres separated by only catalyst standpipes and differential pressure. 

 For example, SIS will engage upon the following:

 Wet Gas Compressor shutdown

 Main air blower shutdown

 Slide valve differential pressure

 Loss of feed to the unit

 18 variables are a prescribed set of triggers, set via a thorough technical analysis by subject matter 

experts & industry best practices. 

 The goal is to automatically shutdown in a safe, controlled manner than to leave the decision in the hands of 

an operator.

 Stop energy inputs into Reactor/Regenerator like feed, recycles, and quenches; closed slide valves; and 

introduce quenching steam to the Riser/Reactor.

 Not all SIS activations will be caused by malfunctions. 

 Experienced 40 SIS activations from January 2013 – July 2014 for a variety of reasons.

 The alternative emission standards need to apply during the shutdown or re-start period following 

the SIS activation.

41
Safety Instrumented Systems (Cont’d)

Refinery Cause Potential Impact the SIS Prevented

Robinson Wet gas compressor variable frequency drive 

electronics failure caused the compressor to 

shutdown

Extended flaring of fractionator 

offgases

Garyville Wet gas compressor shutdown on due to high 

vibrations.

Extended flaring of fractionator 

offgases

Robinson Light feed from Gas Oil Hydrotreater caused feed 

pump to cavitate and lose flow to unit.

Reactor pressure loss could have 

caused reversal from Regen to 

Reactor, allowing air to enter a 

hydrocarbon rich environment.

Detroit Reactor thermocouple read false high, causing slide 

valve to close and lower the differential pressure 

across the slide valve to < 3%.

Low dP across slide valve could have 

caused reversal from Regen to 

Reactor, allowing air to enter a 

hydrocarbon rich environment.

Texas City Feed pump developed a seal leak during period 

that the spare was out for maintenance.

Loss of flow could have caused 

reactor pressure loss could have 

caused reversal from Regen to 

Reactor, allowing air to enter a 

hydrocarbon rich environment.

Texas City Power blip caused main air blower and wet gas 

compressor to shutdown.

Extended flaring of fractionator 

offgases; reactor/regenerator 

pressure imbalance.

42
Safety Instrumented Systems (Cont’d)

 MPC believes that the automatic shutdown and ensuing startup caused by an 

SIS activation meets the definition of startup and shutdown within the MACT 

general provisions.

 Startup means the setting in operation of an affected source or portion of an 

affected source for any purpose.

 Shutdown means the cessation of operation of an affected source or portion of an 

affected source for any purpose.

 Malfunction means any sudden, infrequent, and not reasonably preventable failure 

of air pollution control and monitoring equipment, process equipment, or a process 

to operate in a normal or usual manner which causes, or has the potential to cause, 

the emission limitations in an applicable standard to be exceeded. Failures that are 

caused in part by poor maintenance or careless operation are not malfunctions.

43
Revisions to NSPS Ja

44
NSPS Ja Revisions – FCCU PM Monitoring

 EPA is proposing to require existing FCCUs apply the NSPS Subpart Ja PM 

monitoring requirements to all FCCUs regardless of whether Ja has been 

triggered.

 Cyclones – Utilize opacity monitor & a site specific opacity limit via last stack test

 Baghouses – Utilize a Bag Leak Detection System 

 MPC operates one TSS (Cyclone) FCCU at Canton, Oh, and the only FCCU with a 

Baghouse at Catlettsburg, Ky.

 For these two systems, MPC recommends changes be made to the monitoring 

requirements in both the MACT RTR proposal and the NSPS Subpart Ja to 

address:

 Opacity is a poor correlation to PM emission rates. Opacity correlations to stack test 

data poorly reflect impact of fine particle size distribution to opacity values.

 Sophisticated baghouse leak detection systems as written will be problematic for 

installation on this baghouse design.

45
2004 Study at Canton comparing opacity and PM Emissions

46

y = 0.0791x

R2 = 0.0684

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0

Particulate Matter (#/M#coke)

Opacity (%)

PM vs Opacity - No Correlation
2004 Study at Canton comparing opacity and PM Emissions

47

R2 = 0.0488

R2 = 0.1402

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0

PM Mass Emission Rate (lbs/hr)

Opacity (%)

Opacity vs. PM - No Correlation

Pre-TSS Data

Post-TSS Data
NSPS Ja Revisions – FCCU PM Monitoring (Cont’d)

 Cyclones

 10% opacity limit will force installation of add-on control device 

 Canton currently meets standard – 0.63 lb/Mlb coke burn (2/4/14 stack test)

 Not cost-effective – Addition of an ESP at Canton would result in a ~32 TPY 

reduction in PM and a cost-effectiveness of $121,000/ton

MPC recommends for TSS (Cyclone Systems):

 Removing the stack test correlation to opacity limit in both MACT RTR & NSPS 

Subpart Ja.

 Replacing it with an annual stack test requirement.

48
NSPS Ja Revisions – FCCU PM Monitoring (Cont’d)

 MPC operates the only bag house used for PM control subject to NSPS J 

in the US and has very low emissions

 0.025 lbs/Mlbs cokeburn (July 2014)

 Baghouse unit was originally designed to control PM emissions from a fluidized 

limestone bed boiler on old RCC. MPC converted the RCC to an FCC and 

removed limestone injection in 2004. 

 MACT RTR Proposal requires installation of baghouse leak detection (BLD) 

system within 18 months after promulgation. A BLD consists of:

 A baghouse leak detection sensor & alarm on each baghouse

 Site specific monitoring plan with alarm set-point justification.

 Corrective action to an alarm within 3 hours, or explanation of why action is not 

feasible.

 Monitoring of pressure drop across baghouse cells.

49
Catlettsburg FCCU Baghouse

50

From Boiler Exhaust

Stack

COMS

 2 Baghouse Systems – North & South

 Each Baghouse Contains 12 Baghouse

Modules.

 Each module is equipped with over 

400 bags.

BAGHOUSE MODULE DIAGRAM
NSPS Ja Revisions – FCCU PM Monitoring (Cont’d)

 Installation of a baghouse leak sensors will be technically challenging and cost 

prohibitive.

 Minimum of at least 24 sensors for both baghouses (1 per module).

 With bag layout configuration, no guarantee that the sensor placement will detect an 

individual bag leak.

 3-hour corrective action is not technically feasible.

 Bag replacement requires module isolation and shutdown of the whole baghouse (either 

North or South).

 Performance of baghouse is exceptional due to it being over-designed for the 

service. Opacity COMS is performing very well in this application.

 Additional bells and whistles for pressure drop and sensor alarms will not reduce PM 

emissions from the baghouse.

 MPC requests EPA add the option to submit an Alternative Monitoring Plan for 

Baghouse systems under both NSPS Ja and MACT RTR proposal.

 Believe existing baghouse pressure drop monitoring is sufficient & identifies issues with 

bag performance well before the emission standard is exceeded.

 Annual stack tests could also be part of AMP.

51
MPC Conclusions

 The requirements for atmospheric pressure relief devices should be changed 

to a work practice standard with an appropriate implementation period.

 Marathon Petroleum recommends that EPA withdraw provisions for the ban 

on halogenated vent streams to the flare. 

 Marathon Petroleum recommends that additional alternative compliance 

standards for MACT units during startup and shutdown be added to fully 

address safety concerns and monitoring (source testing) issues.

 Marathon Petroleum recommends that ambient air monitoring programs 

established to meet state and community needs be determined to be 

acceptable alternative monitoring options to adhere to the proposed 

enhanced monitoring standard.

 Marathon Petroleum recommends that an alternative monitoring plan be an 

acceptable option to the mandatory bag leak detection systems in NSPS Ja.
Attachment 3

Detroit Refinery – VOC Monitoring Data

Marathon Petroleum Company LP
Detroit Refinery

VOC Monitoring Data

April 11, 2014
2

Ambient Air

Monitoring 

Stations

Site 1 “North”

Site 4 “East”

DHOUP Site

Marathon Detroit Refinery”

(Site 3) South

Boynton School

Site 2 “West”
Benzene by Air Monitoring Station 

3

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Benzene Concentration (ppb)

Date

1-North Benzene (ppb) 2-A West Benzene (ppb) 4-East Benzene (ppb) MTMS Benzene (ppb) Benzene ITSL (ppb)
M&P Xylenes by Air Monitoring Station

4

0.00

5.00

10.00

15.00

20.00

25.00

m&p-Xylenes Concentration (ppb)

Date

1-North m&p-xylenes (ppb) 2-A West m&p-xylenes (ppb) 4-East m&p-xylenes (ppb)

MTMS m&p-xylenes (ppb) m&p-Xylenes ITSL (ppb)
O-Xylene by Air Monitoring Station

5

0.00

5.00

10.00

15.00

20.00

25.00

o-Xylene Concentration (ppb)

Date 1-North o-xylene (ppb) 2-A West o-xylene (ppb) 4-East o-xylene (ppb)

MTMS o-xylene (ppb) o-Xylene ITSL (ppb)
Toluene by Air Monitoring Station 

6

0

200

400

600

800

1000

1200

1400

Toluene Concentration (ppb)

Date

Toluene By Station

1-North Toluene (ppb) 2-A West Toluene (ppb) 4-East Toluene (ppb) MTMS Toluene (ppb) Toluene ITSL (ppb)
Hexane by Air Monitoring Station 

7

0.00

50.00

100.00

150.00

200.00

Hexane Concentration (ppb)

Date

1-North Hexane (ppb) 2-A West Hexane (ppb) 4-East Hexane (ppb) MTMS Hexane (ppb) Hexane ITSL (ppb)
Ethylbenzene by Air Monitoring Station 

8

0.00

50.00

100.00

150.00

200.00

250.00

Ethylbenzene Concentration (ppb)

Date

Ethylbenzene By Station

1-North Ethylbenzene (ppb) 2-A West Ethylbenzene (ppb) 4-East Ethylbenzene (ppb)

MTMS Ethylbenzene (ppb) Ethylbenzene ITSL (ppb)
Questions

9