Clean Air Act, Health Effects and Rule Overview Training for Environmental Justice advocates held in Detroit April 25-26, 2014 Presentation and discussion - EPA / MDEQ / Community EJ advocates

1. Clean Air Act, Health Effects and Rule Overview
Laura McKelvey and Stephanie Karisny

2. Titles of the Clean Air Act
• Title I—National Ambient Air Quality
Standards, Hazardous Air Pollutants
– SIP, NSR and Technology Standards
• Title II—Mobile Sources
• Title III— Emergency Powers and Tribal
Authority, Public Involvement
• Title IV—Acid Deposition
• Title V—Operating Permits
• Title VI—Stratospheric Ozone

3. A Brief Overview of the CAA
• The U.S. Environmental Protection Agency was created in
1970; the Clean Air Act (CAA) was passed in 1970;
amendments were passed in 1990
• The goal of the Clean Air Act was to give the federal
government the authority to address air pollution in the United
States
• Since the inception of the Clean Air Act (in 1970):
– There has been a 50% decrease in the criteria pollutants; criteria
pollutants include particulate matter (PM), ground-level ozone,
carbon monoxide, sulfur oxides, nitrogen oxides and lead
– Air toxics from large industrial plants have been reduced by 70%
– New cars are more than 90% cleaner
– Production of ozone-depleting chemicals has ceased

4. Air Quality Management Process
Implement Control Strategies
Evaluate Air Quality
- Air Quality Assessments
•Emissions Inventory Data
•Ambient Air Monitoring Data
Choose Control Strategies
-Voluntary programs /
Outreach
-Some strategies may be
regulatory
Determine Necessary
Emissions Reductions
Set Air Quality Goals

5. NAAQS
• National Ambient Air Quality Standards (NAAQS)
– Primary standard set to protect public health
– Secondary standard set to protect public and welfare
• State Implementation Plans – State plans to attain or
maintain the NAAQS
• New Source Review and Prevention of Significant
Deterioration (PSD) permits are part of the SIPs
• Title V Permits takes all the requirements from SIPs,
technology standards, new source performance
standards, etc. and combine them in one permit

6. Setting Air Quality Goals for Commonly Found
“Criteria” Pollutants
• EPA sets limits for the amount (concentration) of
pollutant that can be in the air for six commonly found
pollutants:
– Particulate Matter (PM)
– Ground Level Ozone (O3)
– Carbon Monoxide (CO)
– Sulfur Oxides (SOx)
– Nitrogen Oxides (NOx)
– Lead (Pb)
• These six pollutants are generally referred to as “criteria
pollutants”
• These limits are called National Ambient Air Quality
Standards (NAAQS)
• There are two types of NAAQS:
– Primary standards are set at a level to protect public health
– Secondary standards are set at a level to protect
ecosystems, the environment and other values

7. EPA’s Role in Setting Air Quality Goals
• NAAQS set national levels for acceptable concentrations of these six pollutants in outdoor air
• EPA determines/designates all areas in the country as:
– Clean or in “attainment”
– Dirty (above the standard) or contributing to dirty air in a nearby location or “nonattainment”
or
– Not having enough information to determine the air quality status “unclassifiable”
• The CAA sets dates by which these pollution levels must be reached
• EPA provides guidance to the states on how to address air quality and reviews and approves
(where appropriate) state air plans
• EPA and oversees implementation of plans and can enforce state requirements where necessary
• State plan for cleaning the air or keeping it clean to meet the national standards for these six
“criteria pollutants” is called a State Implementation Plan (SIP)
• The criteria pollutants are also regulated through New Source Performance Standards
(issued by EPA) which apply to certain new air pollution sources and SIPs and Permit
requirements for sources must at least be as stringent as the NSPS but States can be more
stringent then the NSPS

8. Ground-level Ozone is
• Primary component of smog
• Sometimes called “bad ozone” to distinguish it from
“good ozone”
– Both types of ozone have the same chemical composition (O3)
– “Good ozone” occurs naturally in the upper portions of the
earth’s atmosphere and forms a layer that protects life on earth
from the sun's harmful rays
– “Bad ozone” at ground level is harmful to breathe

9. • Not emitted directly into air; forms when emissions of nitrogen oxides
(NOx) and volatile organic compounds (VOCs) “cook” in sun
– Emissions from industrial facilities, electric utilities, motor vehicle
exhaust, gasoline vapors, and chemical solvents are major man-made
sources of NOx and VOCs
• Mainly a summertime pollutant, because sunlight and hot weather
accelerate its formation
• Ozone levels can be high in both urban and rural areas, often due to
transport of ozone, or the NOx and VOC emissions that form ozone
Ground-level Ozone (cont.)

10. • Ozone can penetrate deep into the lungs and can:
– Make it more difficult for people working or playing outside
to breathe as deeply and vigorously as normal
– Irritate the airways, causing: coughing, sore or scratchy
throat, pain when taking a deep breath, and shortness of
breath
– Increase asthma attacks and use of asthma medication
– Inflame and damage the lining of the lung by injuring the
cells that line the air spaces in the lung
– Increase susceptibility to respiratory infection
– Aggravate chronic lung diseases such as asthma,
emphysema and bronchitis
Ozone and Health
• Repeated exposure may cause permanent changes in the lung,
leading to long-term health effects and a lower quality of life

11. Ozone Health Impacts: “ Pyramid of Effects”
Susceptible and vulnerable
groups include
– People with lung disease
such as asthma
– Children
– Older adults
– People who are more
likely to be exposed, such
as outdoor workers
Proportion of Population AffectedProportion of Population Affected
Severity
of Effects
A large number of scientific studies have
linked ozone exposure to serious health
outcomes such as emergency department
visits, hospitalizations for respiratory
causes, and mortality

12. Particulate Matter: What is It?
A complex mixture of extremely small particles and liquid droplets

14. Fine Particles
Combustion, gases to particles
Sulfates/acids
Nitrate
Ammonium
Organics
Carbon
Metals
Water
Sources:
Coal, oil, gasoline, diesel, wood combustion
Transformation of SOx, NOx, organic gases
including biogenics
High temperature industrial
processes
(smelters, steel mills)
Forest fires
Exposure/Lifetime:
Lifetime days to weeks, regional distribution
over urban scale to 1000s of km
Inhalable Coarse Particles
Crushing, grinding, dust
Resuspended dusts
(soil, street dust)
Coal/oil fly ash
Aluminum, silica,
iron-oxides
Tire and brake wear
Inhalable Biological
Materials
(e.g., from soils,
plant fragments)
Sources:
Resuspension of dust tracked onto roads
Suspension from disturbed soil (farms, mines,
unpaved roads)
Construction/demolition
Industrial fugitives
Biological sources
Exposure/Lifetime:
Coarse fraction (2.5-10) lifetime of hours to
days, distribution up to 100s km
PM Components: fine and coarse

15. • Larger particles (> PM10) deposit in the
upper respiratory tract
• Smaller, inhalable particles (≤ PM10)
penetrate deep into the lungs
• Both coarse PM10-2.5 and fine PM2.5 can
penetrate to lower lung
• Deposited particles may accumulate,
react, be cleared or absorbed
Particulate Matter

16. Heath Effects of Particle Pollution
• Particles can cause both respiratory and cardio-vascular
health problems, including:
– Aggravated asthma
– Increases in respiratory symptoms like coughing and difficult or
painful breathing
– Chronic bronchitis
– Decreased lung function
– Changes in heart rate and heart rate variability
– Cardiac arrhythmias
– Heart attacks
– Premature death
• Types of studies:
– Epidemiology/Field
– Controlled human exposure
– Animal

17. lung function changes, immunecell responses,
heart rateor heart ratevariability responses
Asthmaattacks, medication use,
symptoms
Doctor visits
Hospital
Admissions
Death
PM Health Impacts: “Pyramid of Effects”PM Health Impacts: “Pyramid of Effects”
Some groups are at greater risk
• People with heart or lung diseases
– Diseases make them vulnerable
– May include people with diabetes
• Older adults
– May have undiagnosed disease
• Children
– Bodies still developing

18. Sulfur Dioxide Health Effects
• Short-term exposures to SO2, ranging
from 5 minutes to 24 hours
• Respiratory effects including:
– bronchoconstriction
– increased asthma symptoms
• These effects are particularly important
for asthmatics while exercising or
playing.
• Short-term exposure result in:
– increased visits to emergency
departments and hospital
admissions for respiratory
illnesses
– particularly in at-risk populations
including children, the elderly, and
asthmatics
• Emissions that lead to high
concentrations of SO2 generally also
lead to the formation of other Sox.
• SOx can react with other compounds
in the atmosphere to form small
particles or PM2.5 discussed earlier.
• These particles penetrate deeply into
sensitive parts of the lungs and can
cause or worsen respiratory disease,
such as emphysema and bronchitis,
and can aggravate existing heart
disease, leading to increased hospital
admissions and premature death.
• EPA’s NAAQS for particulate matter
(PM) are designed to provide
protection against these health effects.

19. Current National Ambient Air Quality Standards
(NAAQS) as of March 2014
Pollutant Primary/
Secondary
Averaging Time Level Form
CO primary
8-hour 9 ppm
Not to be exceeded more than once per year
1-hour 35 ppm
Lead primary and
secondary
Rolling 3 month
average 0.15 μg/m3 Not to be exceeded
NO2
primary and
secondary Annual 53 ppb Annual mean
primary 1-hour 100 ppb 98th
percentile of 1-hour daily maximum
concentrations, averaged over 3 years
O3
primary and
secondary 8-hour 0.075 ppm Annual fourth-highest daily maximum
8-hr concentration, averaged over 3 years
PM2.5
primary
Annual
12.0 μg/m3
annual mean, averaged over 3 years
secondary 15.0 μg/m3
primary and
secondary 24-hour 35 μg/m3 98th
percentile, averaged over 3 years
PM10
primary and
secondary 24-hour 150 μg/m3 Not to be exceeded more than once per year on
average over 3 years
SO2
primary 1-hour 75 ppb 99th
percentile of 1-hour daily maximum
concentrations, averaged over 3 years
secondary 3-hour 0.5 ppm Not to be exceeded more than once per year
Primary (health-based) and secondary (welfare-based) standards. Units of measure are parts per million (ppm),
parts per billion (ppb) or micrograms per cubic meter of air (μg/m3
). For more information about the standards,
visit http://www.epa.gov/ttn/naaqs/.

20. “Everything is connected”
Permits
MonitoringPlanning
&
Analysis
Statutory
Authority
Resources:
FTEs & $$
$
Compliance
&
Enforcement
Rules &
Regulations
Emissions
Inventory
What is a SIP?

21. What is a SIP?
• Most air pollution control regulations in the US are
found in SIPs (State Implementation Plans)
• States and have great leeway in developing SIPs
• Implementation plans include information to
understand and track air quality like:
– Emissions inventories (what sources are in the area)
– Air quality monitoring
– Modeling to show how the plan will achieve or maintain
good air quality
• Control strategies for all the sources of pollution in
an area which can include
– Voluntary programs to improve air quality, for example,
• Build High Occupancy Vehicle Lanes
• Cash for clunkers
– Regulatory programs, for example
• Impose limits on bus idling
• Require sources to install air pollution control equipment
– Permit programs for new and modified sources
• Development of these components generally
takes 3-4 years
• CAA requires an area move to attainment with in
5-7 years.

22. SIPs Must Meet Minimum Requirements
• The Clean Air Act has many requirements for SIPs, including
a requirement that non-attainment areas come into attainment
as soon as possible
• SIPs must have:
– Enforceable emission limits and control measures
– An air monitoring program
– Permit programs to control construction and modification of new
stationary sources
– Measures to prevent one State from significantly contributing
to nonattainment in another State
• SIPs are submitted to EPA for approval
– EPA must publish notice before approving a SIP (typically found
in the Federal Register) and must give the public an opportunity
to request public hearing and at least a 30-day comment period

23. Implementing Control Strategies
• Pre-construction and operating
permits help with compliance and
enforcement of the SIP
– Permits contain requirements and
become enforcement tools
– Before a permit is issued, the public
can request a public hearing and
make comments on the draft permit
• Progress can be tracked through
– Ambient monitoring
– Reporting requirements contained in
permits and regulations
• Enforcement is essential

24. SIP Process and Roles Opportunities for Input
SIP is now federally enforceable
Meet w/State SIP development team, join SIP
stakeholder group, get on mailing list
Work w/Regional Office to provide input and
community or tribal perspective
Attend and speak at public hearing, submit written
comments
Work w/Regional Office to review and provide input
Attend and speak at public hearing, submit written
comments
Work w/EPA and State to ensure controls are in place
and working
State / local agencies start to develop SIP
State holds public hearing and comment period
State revises SIP to respond to public comment
State adopts & officially submits SIP to EPA Regional
Office
EPA performs completeness review (EPA has 6
months)
EPA publishes proposed notice in Federal Register
EPA holds public comment period
EPA publishes final action responding to public
comment
State modifies SIP based on EPA comments
State drafts SIP and submits to EPA for informal
review
The State Implementation Plan Process

25. Stephanie Karisny
Staff Attorney
Great Lakes Environmental Law Center

26. • National Ambient Air Quality Standard
(NAAQS) for SO2
– Primary standard: Protection of human health
including "sensitive" populations such as
asthmatics, children, and the elderly
• One-hour standard, 75 parts per billion (ppb)
• Calculated as the three-year average of the 99th
percentile of the annual distribution of daily maximum
1-hour average concentrations
– Secondary standard: Protection against
environmental and property damage - e.g.,
protection against decreased visibility, damage
to animals, crops, vegetation, buildings
• Three-hour standard, 0.5 parts per million (ppm)
• Not to be exceeded more than once per calendar
year

27. • Wayne is the only county in Michigan
that is a designated nonattainment
area for SO2 under the 2010 standard
– “The area bounded on the east by the
Michigan-Ontario border, on the south by the
Wayne County- Monroe County border, on
the west by Interstate 75 north to Southfield
Road, Southfield Road to Interstate 94, and
Interstate 94 north to Michigan Avenue, and
on the north by Michigan Avenue to
Woodward Avenue and a line on Woodward
Avenue extended to the Michigan-Ontario
border”

31. • States are primarily responsible for ensuring
attainment and maintenance of NAAQS once EPA
has established them
• State needs to create a State Implementation Plan
(SIP) that provides for the attainment and
maintenance of NAAQS through control programs
directed at sources of SO2
• SIP goes through public participation process (state
level)
• USEPA has final say, approves or disapproves SIP
(also public participation)
• SIPs due to USEPA by April 6, 2015
• NAAQS for SO2
must be met by October 4, 2018

32. • General Nonattainment SIP Requirements:
– Section 172 of the Clean Air Act (CAA) addresses
the general requirements for areas designated as
nonattainment
– States with nonattainment areas must submit a SIP
that shows the affected area will attain the standard
by the applicable attainment date (10/4/2018)
– SIP must demonstrate that area will attain the
standard as expeditiously as practicable, and
provide for the implementation of all reasonably
available control measures (RACM) including
reductions in emissions from existing sources
through adoption of additional control technologies

33. • What kinds of SO2
control options
are available?
– Switch to low-sulfur fuel (low sulfur coal)
– Implement flue gas desulfurization
control technology
• Dry FGD technologies
• Wet FGD technologies

34. Overview
• Section 112 of the Clean Air Act
– Overview
– Emission standards
– MACT program
– Risk and technology review (RTR)
• Available Resources
• Status Updates on Rules

35. Section 112 of the Clean Air Act
Overview
• Establishes requirements for setting national emission standards for
hazardous air pollutants (NESHAP)
• A hazardous air pollutant is defined as “any air pollutant listed pursuant to
subsection (b) of this section [CAA section 112]”
– There are currently 189 pollutants on the HAP list (the complete list is available online
at: http://www.epa.gov/ttn/atw/overview.html)
• Stationary sources are broken down into two categories: major and area
– A major source “means any stationary source or group of stationary sources located
within a contiguous area and under common control that emits or has the potential to
emit considering controls, in the aggregate, 10 tons per year or more of any
hazardous air pollutant or 25 tons per year or more of any combination of hazardous
air pollutants”
– An area source “means any stationary source of hazardous air pollutants that is not a
major source”

36. Regulation of Toxic Pollutants
• The Clean Air Act listed 189 (now 183) toxic air
pollutants (that may cause cancer or serious health
problems)
• There are literally thousands of sources of toxic air
pollutants (also called hazardous air pollutants or HAPs)
• Sources range from gigantic oil refineries to the dry
cleaner on the corner, as well as mobile sources (cars,
trucks, planes, trains)
• Clean Air Act requires EPA to set standards for specific
source types

37. Section 112 of the Clean Air Act
Emission Standards
• Per section 112(d), “the Administrator shall promulgate regulations
establishing emission standards for each category or subcategory of
major sources and area sources of hazardous air pollutants listed
for regulation pursuant to subsection (c) of this section in
accordance with the schedules provided in subsection (c) and (e) of
this section”
• Emission standards “require the maximum degree of reduction in
emissions of the hazardous air pollutants…the maximum degree of
reduction in emissions that is deemed achievable for new sources in
a category or subcategory shall not be less stringent than the
emission control that is achieved in practice by the best controlled
similar source, as determined by the Administrator”
– The above is speaking to the maximum achievable control
technology or MACT program

38. Section 112 of the Clean Air Act
MACT Program
• Under the MACT program emission limits for existing sources are
established by:
– Examining “the average emission limitation achieved by the best
performing 12 percent of the existing sources (for which the
Administrator has emissions information)… or by examining “the
average emission limitation achieved by the best performing 5 sources
(for which the Administrator has or could reasonably obtain emission
information) in the category or subcategory for categories or
subcategories with fewer than 30 sources)
• For area sources the Administrator may “elect to promulgate
standards or requirements applicable to sources in such categories
or subcategories which provide for the use of generally available
control technologies or management practices by such sources to
reduce emissions of hazardous air pollutants”

39. Section 112 of the Clean Air Act
Risk and Technology Review (RTR)
• Residual risk review and technology review required within 8 years of
promulgation of MACT standards
• 2-step risk analysis
1. Determine if risk is acceptable considering health information only, and if not
acceptable, tighten standards so risks are acceptable
2. Determine if standards provide an ample margin of safety, which considers
health info, costs and feasibility
• Risk review includes inhalation risk assessment (cancer and non-
cancer) and screens to assess multipathway, whole facility, acute and
environmental risks
– Can perform refined multipathway assessments in limited cases if screens
show potential multipathway human health risk
• Technology review takes into account new developments in practices,
processes and control technologies considering cost and feasibility
• We also consider previously unregulated processes and HAP, and we
make technical corrections

40. Available Resources
• Overview of section 112 (this includes the list of HAPs):
http://www.epa.gov/ttn/atw/overview.html
• For further explanation of major and area sources and a list of source
categories please visit:
http://www.epa.gov/ttn/atw/pollsour.html
• For a listing of all of the NESHAP/MACT final rules please visit:
http://www.epa.gov/ttn/atw/mactfnlalph.html
• For an overview of the risk and technology review program please visit:
http://www.epa.gov/ttn/atw/rrisk/rtrpg.html
• Plain English guide to Clean Air Act: http://www.epa.gov/air/caa/peg/
• State, local, tribal and federal partnerships:
http://www.epa.gov/ttn/atw/stprogs.html

41. Status Updates on Rules
Startup Shutdown and Malfunctions
• Historically, EPA’s air pollution rules require compliance with
standards at all times, but most rules allowed an exemption of
the standard if it occurred during a malfunction or during
periods of startup or shutdown
• In 2008, the D.C. Circuit Court ruled that such exemptions
were not permitted
• EPA is addressing the court decision in its rules by removing
the exemption for malfunctions; for start up and shutdown
provisions, EPA considers whether it is viable for sources to
comply at all times, or whether a separate provision is
necessary to address start up and shutdown

42. Status Update on Rules (cont.)
Steel Sector
• Steel mills are regulated under three different rulemakings
• Electric Arc Furnaces (EAF) – steel from recycled steel scrap
– 88 facilities; mostly area sources (80 facilities)
– 5 major stand-alone; 3 major co-located at integrated iron and steel facilities
– Rule promulgated in 2007, included standards for mercury and PM limits
• Integrated Iron and Steel Plants – steel from taconite ore, coke
– 16 facilities: 4 with sinter plants, 3 with EAF
– 5 facilities with co-located coke plants
– MACT rule promulgated in 2003, included PM and opacity limits
• Coke Plants – produces coke, a high-energy fuel used in steel production
– 19 facilities; 5 co-located at integrated iron and steel facilities
– Most have multiple coke oven batteries
– MACT rules were promulgated in 1993 and 2003 for various plant processes
– RTR will be conducted for pushing, quenching and battery stacks
– Coke oven rules include requirements for opacity and PM

43. Status Update on Rules (cont.)
43
Pollutant Limit
PM 27 milligrams per dry standard cubic meter (dscm)
Opacity 10 percent
Cadmium 0.040 milligrams per dscm
Lead 0.44 milligrams per dscm
Mercury 0.080 milligrams per dscm or 15 percent of the potential mercury emission
concentration, whichever is less stringent
Sulfur dioxide 29 parts per million by volume (ppmv) or 25 percent of the potential sulfur dioxide
emission concentration, whichever is less stringent
Hydrogen chloride 29 ppmv or 5 percent of the potential hydrogen chloride emission, whichever is
less stringent
Dioxins/furans If facility uses ESP: 60 nanograms per dscm
If no ESP: 30 nanograms per dscm
Nitrogen oxides 205 ppmv (mass burn waterwall)
Carbon monoxide 100 ppmv (mass burn waterwall)
Federal plan emission limits for large MWCs constructed on or before 9/20/1994 (40 CFR Part 62 Subpart
FFF)
Existing Large Municipal Waste Combustors

44. Status Update on Rules (cont.)
Carbon Pollution Standards for Existing and Modified Power Plants
• The President in his directive to EPA under the Climate Action Plan stated
that the agency should:
– Set flexible carbon pollution standards, regulations or guidelines, as appropriate,
for power plants under section 111 of the Clean Air Act
– Focus on these elements when developing the standards:
• Stakeholder engagement on program design
– States
– Leaders in the power sector
– Labor leaders
– Non-governmental organizations
– Tribal officials
– Members of the public
• Flexibilities in program design
– Market-based instruments, performance standards, others
• Costs
– Tailor regulations and guidelines to reduce costs
• Continued importance of relying on a range of energy sources
• Other regulations that affect the power sector

45. Status Update on Rules (cont.)
Carbon Pollution Standards for Existing and Modified Power Plants
• EPA’s Task:
– Develop carbon pollution standards, regulations or guidelines, as
appropriate, for:
• New power plants
• Modified and reconstructed power plants
• Existing power plants
• Per the President’s Directive, EPA will issue proposed carbon
pollution standards, regulations or guidelines, as appropriate, for
modified, reconstructed and existing power plants, by no later than
June 2014
– EPA will issue final standards, regulations or guidelines as appropriate
by no later than June 2015
– EPA will include in the guidelines addressing existing power plants a
requirement that States submit to EPA the implementation plans by no
later than June 2016

46. Status Update on Rules (cont.)
Carbon Pollution Standards for Existing and Modified Power Plants
• EPA has been conducting a robust stakeholder engagement
process
– Participated in meetings with over 300 utility, labor and
environmental groups since June 2013
– Developed video webinar about the Climate Action Plan and
CAA section 111(d); this video has been viewed more than 3,800
times
– Held 11 public listening sessions around the country
• 3,300 people attended
• More than 1,600 people offered oral statements
• Engagement process has given EPA several key insights and
takeaway messages

47. Petroleum Refinery Sector Risk and
Technology Review
Presentation to the U.S. EPA Science Advisory Board
July 19, 2013

48. Developing Exposure Estimates
• We use the EPA Human Exposure Model (HEM) risk modeling
system to estimate exposure, which contains:
– AERMOD dispersion model (EPA’s approved local-scale model)
– 2010 Census data at census block resolution (about 10 households)
– Terrain elevation data
– Meteorological data
• Uses historical (2011) data from weather stations nationwide
• Exposure estimates are conservative
– We assume that there is a person at the centroid of census block who is
continually exposed for 70 years
• If the highest concentration is at residence closer to the facility than the centroid,
we use that concentration as our exposure estimate
– This reflects the Clean Air Act mandate to assess risks to the ‘individual
most exposed’

49. Inhalation Risk Outputs
• Chronic
– Cancer: Maximum Individual Risk (MIR) – highest cancer risk (in a
million) at a location where people live (census block centroid or nearest
residence)
– Noncancer: Hazard Index (HI) – highest noncancer risk at a location
where people live (census block centroid or nearest residence)
– Annual cancer incidence (cases/year)
– Cancer risk bin distributions (>100 in a million, 10 in a million…)
– Source category and facility wide risks
– Process level risk contributions
• Acute
– Maximum off-site impact: pollutant-specific highest 1-hour Hazard
Quotient (HQ) outside estimated facility fenceline
• Default factor of 10x time the annual emissions rate unless source category
specific information is provided
• Can be refined with site-specific boundary conditions

50. Development of Emission Inventories
• The purpose of the risk and technology review is to evaluate the
MACT standards to determine if:
– It is necessary to tighten the standards to protect human health and the
environment with an “ample margin of safety”
– There are advancements in practices, processes or technologies that
warrant tightening the standards
• Risk and technology review requires emission inventory data
• Emission inventories are developed to satisfy state requirements
– EPA provides guidance in the form of AP-42 emission factors, but does
not mandate their use
– Inventories are not consistent among states
– Speciation and completeness of data for air toxic pollutants vary
– EPA houses state inventories in the Emission Inventory System (EIS)

51. Refinery Emissions Inventory
• EPA was petitioned in 2008 under the Data Quality Act to improve emission factors from
refineries
– In response, EPA developed a refinery emissions estimation protocol, which was put through
two rounds of public notice and comment in 2010
• http://www.epa.gov/ttn/chief/efpac/protocol/index.htm
• Refinery Emissions Estimation Protocol
– Provides consistent set of methods for estimating emissions (criteria pollutants and air
toxics)
– Requires speciation of air toxic pollutants
– Describes what refinery emission sources should have pollutant emission estimates
– No new sampling is required
– Ranking of methodologies depending on available data
– More detailed and comprehensive than AP-42 emission factors
• 2011 Refinery ICR required refiners to use the Refinery Emissions Estimation Protocol to develop
their inventory
• Refinery inventory submitted in response to the ICR will be used to perform the risk and
technology review of the MACT standards

52. Air Toxics Emissions From
Refineries

53. Refinery Emission Sources
• Point sources (vents or stacks)
– Emissions generally well understood and well characterized, and some test data available where pollutants were
directly measured
– Examples include vents at catalytic cracking, fluid coking, delayed coking, catalytic reforming, sulfur recovery,
hydrogen plants
– As part of risk and technology review, EPA is amending rules to require electronic submission of performance test
data; will be used to periodically update emission factors
• Flares
– Destruction of pollutants in an open flame
– Difficult to directly measure pollutants
– Flare studies available to develop correlations for parameters that affect flare destruction efficiencies (2012 peer
review)
– September 2012 NSPS flare amendments will require all flares to eventually have monitors to measure waste gas
flow
– Flare operational requirements ensure good combustion and provide information (waste gas composition and
flare destruction efficiency) that can be used to estimate emissions from flares
• Fugitive emission sources
– Tend to be open sources or not emitted through a stack or vent, thus difficult to directly measure pollutants
– Examples include equipment leaks and pressure relief devices, tanks and transfer operations and wastewater
handling and treatment
– Emission models and estimates are used to predict pollutant emissions
– An emission standard at the fenceline can help ensure fugitive emission standards are being met

54. Fenceline Monitoring
• Fugitive emission sources may not be well characterized in the inventories but are likely
significant contributors to overall emissions
• Fugitives from process piping
• Wastewater sources
• Pressure relief events
• Tanks
• Highest concentrations of these fugitive emission sources outside the facility likely occur
by the property boundary near ground level
• Air monitoring at the property boundary can provide a direct measure of the annual
average concentrations of air toxics directly surrounding the refinery
• Benzene is a refinery risk driver and also primarily emitted from fugitive sources; 85% of
benzene emissions from refineries is from fugitive, ground-level sources, so reducing
emissions of benzene from fugitive sources will reduce emissions of other toxic pollutants
• Perimeter or fenceline monitoring provides an indicator of the level of emissions at
refineries and is a way to ground-truth fugitive emission estimates

55. Low-cost
sensor
networks
Low-cost
sensor
networks
Different technologies and approaches to detect and measure
pollutants over extended areas and time
Mobile
inspection
systems
Mobile
inspection
systems
Monitoring for Assessment of Fugitives
Leak detection power and feasibility of widespread deployment
Analyticalpowerandimplementationcost
Current open-
path and auto
GC systems
Current open-
path and auto
GC systems
Lower cost
optical
systems
Lower cost
optical
systems

56. 0.2 0.5 2 5 10 (µm)0.2 0.5 2 5 10 (µm)
UV DOAS FTIRTDL FLIR
UV Diff. Optical
Absorption
Spectroscopy
Tunable Diode
Laser (scanning)
Forward-Looking
InfraRed
(leak imaging)
Fourier Transform
InfraRed
(scanning)
Open-path
optical
systems
Open-path
optical
systems
Open-Path Instruments

57. N
Low-Cost Sensors Can Provide 24-7 Observation & Enable
New Regulatory Approaches
Facility fenceline monitoringPassive sampling
Low-cost
sensor
networks
Low-cost
sensor
networks
• Locate passive samplers around the
perimeter of each refinery
• Calculate annual average concentration
• If rolling average concentration exceeds
benzene concentration standard (the
action level), initiate tiered approach to
positively identify facility contribution and
conduct corrective action to reduce
emissions

58. Developments in Lower-Cost Time-Resolved Monitoring to Support
Time-Integrated Passive Sampler Fenceline Measurements
Mobile inspection
systems
Mobile inspection
systems
SECONDARY
MIRROR
PRIMARY
MIRROR
SEALED UV
WINDOW
BEAM
SPLITTER
DETECTORS
FOCUSING
LENS
Lower cost
open-path
optical systems
Lower cost
open-path
optical systems
Deep UV optical sensor
Drive-by leak inspection
Drop-in-place sensor packages
Prototype PID sensor package
(pres. temp. , RH., VOC)
Combining
senor and
wind data
Combining
senor and
wind data
New leak-location algorithms
Low-cost
stand-alone
sensors
Low-cost
stand-alone
sensors

59. Wind
April 2013 passive sampler and GMAP demo with a cooperating refinery
Mobile inspection detected benzene leak at location of the highest passive sampler
reading
Passive
sampler
Geospatial measurement
(GMAP) mobile benzene
survey
Passive sampler fenceline and mobile inspection demonstration