United States
Environmental Protection
Agency
Office of Enforcement
and Compliance
Assurance (2248A)
EPA 300-N-00-014
(revised)
Enforcement Alert
Volumes, Number9
Office of Regulatory Enforcement
October 2000
Frequent, Routine Flaring May Cause Excessive,
Uncontrolled Sulfur Dioxide Releases
Practice Not Considered 'Good Pollution Control Practice'; May Violate Clean Air Act
Flaring is an engineering practice
that provides for process equip-
ment to immediately release gases to a
About
Enforcement Alert
"Enforcement Alert" \
published periodically by the
Office of Regulatory
Enforcement to inform and
educate the public and
regulated community of
important environmental
enforcement issues, recent
trends and significant
enforcement actions.
This information should help
the regulated community
anticipate and prevent
violations of federal
environmental law that could
otherwise lead to enforcement
action. Reproduction and wide
dissemination of this
publication are encouraged.
For information on obtaining
additional copies of this
publication, contact the editor
listed below.
Eric V. Schaeffer
Director, Office of
Regulatory Enforcement
Editor: Virginia Bueno
(202) 564-8684
bueno.virginia@epamail.epa.gov
(Please Email all address and
name changes or subscription
requests for this newsletter.)
device (a flare) where they
can be quickly and safely in-
cinerated. The proper use of
flares is a good engineering
practice because flares can
prevent
damages,
fires and
explo-
sions,
and inju-
ries to
employ-
ees. Flar-
ing also
converts
noxious and odorous gases re-
leased in emergencies to less
hazardous and objectionable
emissions by the burning of
the gases.
But EPA investigations sug-
gest that flaring frequently
occurs in routine,
nonemergency situations or is
used to bypass pollution con-
trol equipment. This results
in unacceptably high releases
of sulfur dioxide and other noxious pol-
lutants and may violate the requirement
that companies operate their facilities
Editor's Note: To clarify sulfur dioxide re-
porting requirements, this issue contains
slight revisions to the sections, "Diagnos-
ing, Preventing Excess Flaring," located
on page 3 and "EPCRA Reporting Re-
quirements for Flaring Incidents" on
page 4. Please disregard the earlier is-
sue.
Frequent and routine use of flares
may not be good air pollution control
practice for reducing emissions.
(Photograph courtesy of Kaldair
Inc.)
in a manner consistent with good air
pollution practices for minimizing emis-
sions. New "clean fuels" requirements
will lead to the removal of even greater
Continued on page 2
.ation is found on the Internet at http://www.epa.gov/oeca/ore/enfalert
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Enforcement Alert
Continued from page 1
amounts of sulfur from feed stocks.
Companies should ensure they have ad-
equate capacity to treat these pollut-
ants without resorting to excess flar-
ing.
Good pollution control practices in-
clude:
1. Procedures to diagnose and
prevent malfunctions; and
2. Adequate capacity at the back
end of the refinery to process acid gas.
At petroleum refineries, flares are
used in a variety of process areas to
prevent hydrocarbons and waste gases
from being released directly to the at-
mosphere. Since hydrocarbons are the
primary product at refineries, compa-
nies should make every effort to avoid
sending their products up in flames.
Flares, however, are also used to com-
bust acid gas—a highly concentrated
waste stream of hydrogen sulfide gas
(up to 90 percent pure)—and sour wa-
ter stripper gas (about 30 percent pure).
Sulfur Recovery Plants (SRPs) nor-
mally process hydrogen sulfide gas and
sour water stripper gas. A sulfur re-
covery plant is a refinery process for
producing elemental sulfur for sale but
is also a part of the refinery's air pollu-
tion control systems. The process con-
verts 95 percent or more of these hy-
drogen sulfide gases into elemental sul-
fur while reducing emissions to insig-
nificant levels. Use of a flare for com-
busting acid gas instead of processing
it in the SRP produces very large un-
controlled releases of sulfur dioxide
(S02) and effectively bypasses the per-
mitted and monitored SRP emission
point. While the flare is designed to pre-
vent the direct release of the very toxic
Hydrocarbon Flaring Considered Fuel Gas Combustion
Subject to NSPS
The NSPS defines "fuel gas" to be any gas generated and combusted at
a refinery and identifies flares as NSPS affected facilities. EPA's letter to
Koch Petroleum Company (Dec. 2,1999) provides a detailed explanation of
the various types of gases subject that are to NSPS requirements because
they meet the definition of fuel gas (see http://www.epa.gov/oeca/ore/aed).
The NSPS exempts flaring of fuel gas from the standards for sulfur ox-
ides and monitoring requirements only when there is a process upset or an
emergency malfunction. (40 C.F.R.Section 60.104(a)(1)). This "plain En-
glish" exemption applies only to true emergencies, and the Agency ex-
pects other flaring to be monitored and comply with applicable emission
limits.
EPA believes that many affected facilities at petroleum refineries may
not be in compliance with applicable NSPS requirements (fuel gas monitor-
ing and emission limits for fuel gas combustion devices) because of their
routine reliance on flaring to control releases of hydrocarbons. The Agency
also believes that, as with acid gas flaring, good air pollution control prac-
tices include investigating the causes of flaring events and taking corrective
action to avoid or reduce the probability of their recurrence. One way to
address these potential compliance issues may be through the proper de-
sign, operation and maintenance of flare gas recovery systems.
and odoriferous hydrogen sulfide dur-
ing malfunctions at the SRP, EPA has
documented situations of regular or rou-
tine use of flares for acid gas incinera-
tion instead of the expected reliance on
the flare only for emergencies.
One day of acid gas flaring can eas-
ily release more S02 than is released in
a single year of permitted SRP activity.
On numerous occasions, EPA has un-
covered information on acid gas flar-
ing incidents that shows that 100 tons
or more of SO2 can be released in
such flaring within a 24-hour period.
A moderately sized Claus sulfur recov-
ery plant (approximately 100 long tons
of sulfur recovered per day capacity)
that is subject to the New Source Per-
formance Standards and properly op-
erated with its pollution control device
should emit no more than 250 parts per
million of S02, a rate that corre-
sponds to a little less than 100 tons
annually.
Health Dangers From
Sulfur Dioxide
Flaring H2S can produce high am-
bient concentrations of S02. Short-term
exposures to elevated S02 levels while
at moderate exertion may result in re-
duced lung function accompanied by
such symptoms as wheezing, chest
tightness, or shortness of breath in asth-
matic children and adults. Other effects
associated with longer-term exposures
to high concentrations of S02 com-
bined with high levels of particulate mat-
ter, can result in respiratory illness, al-
terations in the lungs' defenses, and ag-
gravation of existing cardiovascular dis-
ease. Those at risk include individuals
with cardiovascular disease or chronic
lung disease, as well as children and
the elderly.
Acid Gas Flaring
Routine or nonemergency "flaring
Continued on page 3
October 2000
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Enforcement Alert
Continued from page 2
of acid gas" is directing that gas away
from the recovery plant, combusting it
at a flare and releasing sulfur dioxide to
the atmosphere. Acid gas flaring is not
a federally permitted operation and
should typically only occur during a
malfunction (a "sudden, infrequent, and
not reasonably preventable failure of
equipment or processes to operate in a
normal or usual manner") (40 C.F.R.
Section 60.2). In EPA's experience, fre-
quent and repetitive acid gas flaring is
often not due to malfunctions. Acid gas
flaring that is routine or preventable vio-
lates the NSPS requirement for operat-
ing consistent with 'Good Air Pollution
Control Practices' to minimize emis-
sions at refineries with NSPS fuel gas
combustion devices and affected facili-
ties including SRPs (40 C.F.R. Section
Chain Reaction: Upstream
Upsets May Result in
Downstream Malfunctions
Properly designed, operated and
maintained SRPs can typically receive
and treat all acid gas produced at the
refinery (most also are designed to treat
sour water stripper gas). These gases
should not be flared except under emer-
gency or malfunction conditions.
Upsets in upstream process equip-
The Agency also believes
that, as with acid gas
flaring, good air pollution
control practices include
investigating the causes
of flaring events and
taking corrective action to
avoid or reduce the
probability of their
recurrence.
ment may result in hydrocarbons or
other contaminants entering the acid gas
stream. Hydrocarbons can be very dis-
ruptive to the short- and long-term op-
eration of the SRP. Historically, not
much effort has been put into investi-
gating and correcting the root cause of
contamination or upsets. Instead, inci-
dents have been simply reported as
"malfunctions." EPA, believes that re-
peated malfunctions for the same cause,
generally, could be predicted and pre-
vented. If flaring results from a pre-
ventable upset, EPA believes that it does
not represent good air pollution control
practices and that it may violate the
CAA.
Diagnosing, Preventing
Excess Flaring
Repeated or regularly occurring in-
cidents of flaring can be anticipated and
should not be classified as 'malfunc-
tions.' For example, regularly switch-
ing between high and low sulfur crude
may cause fluctuations of the acid gas
feed to the SRP. This can create opera-
tional problems for the SRP and/or its
pollution control equipment, resulting
in a perceived need to flare. These up-
sets should be addressed through im-
proved operational control systems, im-
proved and frequent training of opera-
tors, and continued optimal perfor-
mance of the SRP, not by bypassing or
flaring acid gas and sour water strip-
per gas.
Another cause of flaring is inad-
equate capacity of the SRP and its as-
sociated tail gas unit (TGU) to process
all the acid gas at the refinery. Refiner-
ies should ensure that their units have
the capacity and can handle variable vol-
umes that may occur during different
production levels.
Refineries should implement the fol-
lowing procedures to ensure that flar-
ing results only from a true emergency
or malfunction:
BP Amoco Reduces
SO2 Emissions from
Flaring Nearly 75%
From 1993 to 1995, the BP
Amoco facility in Oregon,
Ohio, experienced an annual av-
erage of 16 flaring incidents and
released approximately 180 tons
of SO2. Underthe procedures out-
lined in a Consent Decree with
EPA, BP Amoco has been able to
reduce that amount to an insignifi-
cant number (three flaring events
in 1999 released a total of 49 tons
of SO2) and each event was attrib-
utable to a true "malfunction" as
defined in NSPS. This was accom-
plished through equipment and op-
erational changes that eliminated
the root causes of such flaring. The
protocol in the consent decree
(http://www.epa.gov/oeca/ore/aed)
serves as a model in balancing the
concerns of Good Engineering
Practice and good Pollution Con-
trol Practices for any flaring of acid
gas or sour water stripper gas.
October 2000
• Conduct a root-cause analysis
of each flaring incident to identify if any
equipment and/or operational changes
are necessary to eliminate or minimize
that cause so as to reduce or avoid fu-
ture flaring events. As appropriate, cor-
rective measures should be taken and
implemented. If the analysis shows that
the same cause has happened before,
the incident should not be considered a
malfunction and corrective measures
should be taken to prevent future oc-
currences;
• Ensure there is adequate ca-
pacity at the SRP and TGU. Redun-
dant units can prevent flaring by allow-
Continued on page 4
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wEFA
United States
Environmental Protection Agency
Office of Regulatory Enforcement
(2248A)
1200 Pennsylvania Avenue, NW
Washington, DC 20460
Official Business
Penalty for Private Use $300
'Enforcement Alert' newsletter
Continued from page 3
ing one unit to operate if the other needs
to be shut down for maintenance or an
upset; and
• Prepare an accurate estimate
of the total S02 released (using clear
calculation procedures) for each acid
gas flaring incident.
Identifying the root cause of the flar-
ing incident gives the refinery the op-
portunity to fix the problem before it
happens again. It also enables the facil-
ity to assess whether the flaring inci-
dent was caused by a true malfunction,
which is considered acceptable engi-
neering practices.
A reference procedure for evaluat-
ing if good air pollution practices are
being used when future acid gas flar-
ing events occur can be found in the
Consent Decree, C.A. No. 3:97CV7790
N.D. Ohio, entered May 5, 1999 (see
http://www.epa.gov/oeca/ore/aed).
For more information, contact
Patric McCoy at U.S. EPA's Region 5
office in Chicago at (312) 886-6869,
EPCRA Reporting Requirements for Flaring Incidents
EPCRA Section 304 requires that unpermitted releases of extremely haz-
ardous substances in excess of their reportable quantity be reported immedi-
ately to the State Emergency Response Commission and Local Emergency
Planning Committee.The flaring of hydrogen sulfide may require reporting if
more than 500 pounds (the reportable quantity) of SO2are released within a
24-hour period. The Clean Air Act recognizes that accidents, malfunctions,
start ups and shut downs may cause excess emissions even when the facil-
ity has implemented reasonable measures to avoid them. However, it is still
important to alert emergency response personnel when these releases occur,
as even short periods of flaring can emit large quantities of SO2. Forexample,
a medium-sized refinery with an SRP that processes 500 tons of acid gas
each day could release as much as 40 tons of SO2 at the flare in only one
hour, more than 150 times the reportable quantity.
E-mail: mccoy.patric@epa.gov; and
regarding federally permitted release
questions, contact Ginny Phillips, Of-
fice of Regulatory Enforcement,
Toxics and Pesticides Enforcement
Division at (202) 564-6139,Email:
ph illips. ginny@epa. gov.
Useful Corrmliance
Assistance Resources
CAA Applicability Determination
Index:
http://www.epa.gov/oeca/eptdd/adi.html
Technology Transfer Network
http://www.epa.gov/ttn/
Office of Regulatory Enforcement:
http://www.epa.gov/oeca/ore/
RCRA Online:
http://www.epa.gov/rcraonline/
Compliance Assistance Centers:
http://www.epa.gov/oeca/mfcac.html
Audit Policy Information:
http://www.epa.gov/oeca/ore/
apolguid.html
Small Business Gateway:
http://www.epa.gov/smallbusiness/
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