United States Office of Enforcement EPA 300-N-00-014 Environmental Protection and Compliance (revised) Agency Assurance (2248A) EEnfnfororcementcement AAlerlertt Volume 3, Number 9 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

laring is an engineering practice device (a flare) where they Fthat provides for process equip­ can be quickly and safely in­ ment to immediately release gases to a cinerated. The proper use of flares is a good engineering practice because flares can prevent About damages, fires and Enforcement Alert explo­ “Enforcement Alert” is sions, published periodically by the and inju­ Office of Regulatory ries to Enforcement to inform and employ­ educate the public and regulated community of ees. Flar­ important environmental ing also enforcement issues, recent converts trends and significant noxious and odorous gases re- enforcement actions. leased in emergencies to less hazardous and objectionable This information should help the regulated community emissions by the burning of anticipate and prevent the gases. violations of federal But EPA investigations sug­ environmental law that could otherwise lead to enforcement gest that flaring frequently action. Reproduction and wide occurs in routine, dissemination of this nonemergency situations or is publication are encouraged. used to bypass pollution con­ trol equipment. This results For information on obtaining in unacceptably high releases additional copies of this Frequent and routine use of flares publication, contact the editor of sulfur dioxide and other noxious pol­ may not be good air pollution control listed below. lutants and may violate the requirement practice for reducing emissions. that companies operate their facilities (Photograph courtesy of Kaldair Inc.) Eric V. Schaeffer Director, Office of Editor’s Note: To clarify sulfur dioxide re- Regulatory Enforcement porting requirements, this issue contains in a manner consistent with good air slight revisions to the sections, “Diagnos­ pollution practices for minimizing emis­ Editor: Virginia Bueno ing, Preventing Excess Flaring,” located sions. New “clean fuels” requirements (202) 564-8684 on page 3 and “EPCRA Reporting Re­ will lead to the removal of even greater [email protected] quirements for Flaring Incidents” on (Please Email all address and name changes or subscription page 4. Please disregard the earlier is- requests for this newsletter.) sue. Continued on page 2

This publication is found on the Internet at http://www.epa.gov/oeca/ore/enfalert Enforcement Alert Continued from page 1 Flares, however, are also used to com­ and odoriferous hydrogen sulfide dur­ bust acid gas—a highly concentrated ing malfunctions at the SRP, EPA has waste stream of hydrogen sulfide gas documented situations of regular or rou­ amounts of sulfur from feed stocks. (up to 90 percent pure)—and sour wa­ tine use of flares for acid gas incinera­ Companies should ensure they have ad- ter stripper gas (about 30 percent pure). tion instead of the expected reliance on equate capacity to treat these pollut­ the flare only for emergencies. Sulfur Recovery Plants (SRPs) nor­ ants without resorting to excess flar­ mally process hydrogen sulfide gas and One day of acid gas flaring can eas­ ing. sour water stripper gas. A sulfur re­ ily release more SO2 than is released in Good pollution control practices in­ covery plant is a refinery process for a single year of permitted SRP activity. clude: producing elemental sulfur for sale but On numerous occasions, EPA has un­ is also a part of the refinery’s air pollu­ covered information on acid gas flar­ 1. Procedures to diagnose and ing incidents that shows that 100 tons prevent malfunctions; and tion control systems. The process con­ verts 95 percent or more of these hy­ or more of SO2 can be released in 2. Adequate capacity at the back drogen sulfide gases into elemental sul­ such flaring within a 24-hour period. end of the refinery to process acid gas. fur while reducing emissions to insig­ A moderately sized Claus sulfur recov­ ery plant (approximately 100 long tons At petroleum refineries, flares are nificant levels. Use of a flare for com­ of sulfur recovered per day capacity) used in a variety of process areas to busting acid gas instead of processing that is subject to the New Source Per­ prevent hydrocarbons and waste gases it in the SRP produces very large un­ formance Standards and properly op­ from being released directly to the at­ controlled releases of sulfur dioxide (SO ) and effectively bypasses the per­ erated with its pollution control device mosphere. Since hydrocarbons are the 2 should emit no more than 250 parts per primary product at refineries, compa­ mitted and monitored SRP emission million of SO , a rate that corre­ nies should make every effort to avoid point. While the flare is designed to pre- 2 sponds to a little less than 100 tons sending their products up in flames. vent the direct release of the very toxic annually.

Health Dangers From Hydrocarbon Flaring Considered Fuel Gas Combustion Sulfur Dioxide Subject to NSPS Flaring H2S can produce high am­ The NSPS defines “fuel gas” to be any gas generated and combusted at bient concentrations of SO2. Short-term a refinery and identifies flares as NSPS affected facilities. EPA’s letter to exposures to elevated SO2 levels while Koch Petroleum Company (Dec. 2, 1999) provides a detailed explanation of at moderate exertion may result in re­ the various types of gases subject that are to NSPS requirements because duced lung function accompanied by they meet the definition of fuel gas (see http://www.epa.gov/oeca/ore/aed). such symptoms as wheezing, chest The NSPS exempts flaring of fuel gas from the standards for sulfur ox- tightness, or shortness of breath in asth­ ides and monitoring requirements only when there is a process upset or an matic children and adults. Other effects emergency malfunction. (40 C.F.R.Section 60.104(a)(1)). This “plain En­ associated with longer-term exposures

glish” exemption applies only to true emergencies, and the Agency ex­ to high concentrations of SO2, com­ pects other flaring to be monitored and comply with applicable emission bined with high levels of particulate mat­ limits. ter, can result in respiratory illness, al­ terations in the lungs’ defenses, and ag­ EPA believes that many affected facilities at petroleum refineries may gravation of existing cardiovascular dis­ not be in compliance with applicable NSPS requirements (fuel gas monitor­ ease. Those at risk include individuals ing and emission limits for fuel gas combustion devices) because of their with cardiovascular disease or chronic routine reliance on flaring to control releases of hydrocarbons. The Agency lung disease, as well as children and also believes that, as with acid gas flaring, good air pollution control prac­ tices include investigating the causes of flaring events and taking corrective the elderly. action to avoid or reduce the probability of their recurrence. One way to address these potential compliance issues may be through the proper de- Acid Gas Flaring sign, operation and maintenance of flare gas recovery systems. Routine or nonemergency “flaring Continued on page 3

October 2000 2 Enforcement Alert Continued from page 2 ment may result in hydrocarbons or other contaminants entering the acid gas stream. Hydrocarbons can be very dis­ of acid gas” is directing that gas away ruptive to the short- and long-term op­ BP Amoco Reduces from the recovery plant, combusting it eration of the SRP. Historically, not SO Emissions from at a flare and releasing sulfur dioxide to much effort has been put into investi­ 2 the atmosphere. Acid gas flaring is not gating and correcting the root cause of Flaring Nearly 75% a federally permitted operation and contamination or upsets. Instead, inci­ should typically only occur during a rom 1993 to 1995, the BP dents have been simply reported as Amoco facility in Oregon, malfunction (a “sudden, infrequent, and F “malfunctions.” EPA, believes that re­ Ohio, experienced an annual av­ not reasonably preventable failure of peated malfunctions for the same cause, erage of 16 flaring incidents and equipment or processes to operate in a generally, could be predicted and pre- released approximately 180 tons normal or usual manner”) (40 C.F.R. vented. If flaring results from a pre­ of SO2 . Under the procedures out- Section 60.2). In EPA’s experience, fre­ ventable upset, EPA believes that it does lined in a Consent Decree with quent and repetitive acid gas flaring is not represent good air pollution control EPA, BP Amoco has been able to often not due to malfunctions. Acid gas practices and that it may violate the reduce that amount to an insignifi­ flaring that is routine or preventable vio­ CAA. cant number (three flaring events lates the NSPS requirement for operat­ in 1999 released a total of 49 tons ing consistent with ‘Good Air Pollution of SO2) and each event was attrib­ Control Practices’ to minimize emis­ Diagnosing, Preventing utable to a true “malfunction” as sions at refineries with NSPS fuel gas Excess Flaring defined in NSPS. This was accom­ combustion devices and affected facili­ plished through equipment and op­ Repeated or regularly occurring in­ ties including SRPs (40 C.F.R.Section erational changes that eliminated cidents of flaring can be anticipated and 60.11(d)). the root causes of such flaring. The should not be classified as ‘malfunc­ protocol in the consent decree tions.’ For example, regularly switch­ (http://www.epa.gov/oeca/ore/aed) Chain Reaction: Upstream ing between high and low sulfur crude serves as a model in balancing the Upsets May Result in may cause fluctuations of the acid gas concerns of Good Engineering feed to the SRP. This can create opera­ Practice and good Pollution Con­ Downstream Malfunctions tional problems for the SRP and/or its trol Practices for any flaring of acid Properly designed, operated and pollution control equipment, resulting gas or sour water stripper gas. maintained SRPs can typically receive in a perceived need to flare. These up- and treat all acid gas produced at the sets should be addressed through im­ refinery (most also are designed to treat proved operational control systems, im­ � sour water stripper gas). These gases proved and frequent training of opera- Conduct a root-cause analysis should not be flared except under emer­ tors, and continued optimal perfor­ of each flaring incident to identify if any gency or malfunction conditions. mance of the SRP, not by bypassing or equipment and/or operational changes are necessary to eliminate or minimize Upsets in upstream process equip- flaring acid gas and sour water strip- per gas. that cause so as to reduce or avoid fu­ ture flaring events. As appropriate, cor­ Another cause of flaring is inad­ rective measures should be taken and equate capacity of the SRP and its as­ The Agency also believes implemented. If the analysis shows that sociated tail gas unit (TGU) to process that, as with acid gas the same cause has happened before, all the acid gas at the refinery. Refiner­ the incident should not be considered a flaring, good air pollution ies should ensure that their units have malfunction and corrective measures control practices include the capacity and can handle variable vol­ should be taken to prevent future oc­ investigating the causes umes that may occur during different currences; of flaring events and production levels. taking corrective action to � Ensure there is adequate ca­ Refineries should implement the fol­ avoid or reduce the pacity at the SRP and TGU. Redun­ probability of their lowing procedures to ensure that flar­ dant units can prevent flaring by allow- recurrence. ing results only from a true emergency or malfunction: Continued on page 4

October 2000 3 United States Environmental Protection Agency Office of Regulatory Enforcement (2248A) 1200 Pennsylvania Avenue, NW Washington, DC 20460

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Continued from page 3 ity to assess whether the flaring inci- E-mail: [email protected]; and dent was caused by a true malfunction, regarding federally permitted release which is considered acceptable engi- questions, contact Ginny Phillips, Of- ing one unit to operate if the other needs neering practices. fice of Regulatory Enforcement, to be shut down for maintenance or an Toxics and Pesticides Enforcement A reference procedure for evaluat- upset; and Division at (202) 564-6139,Email: ing if good air pollution practices are � [email protected]. Prepare an accurate estimate being used when future acid gas flar- of the total SO released (using clear 2 ing events occur can be found in the calculation procedures) for each acid Consent Decree, C.A. No. 3:97CV7790 gas flaring incident. N.D. Ohio, entered May 5, 1999 (see Identifying the root cause of the flar- http://www.epa.gov/oeca/ore/aed). Useful Compliance ing incident gives the refinery the op- For more information, contact Assistance Resources portunity to fix the problem before it Patric McCoy at U.S. EPA’s Region 5 happens again. It also enables the facil- office in Chicago at (312) 886-6869, CAA Applicability Determination Index: http://www.epa.gov/oeca/eptdd/adi.html

Technology Transfer Network EPCRA Reporting Requirements for Flaring Incidents http://www.epa.gov/ttn/

EPCRA Section 304 requires that unpermitted releases of extremely haz- Office of Regulatory Enforcement: ardous substances in excess of their reportable quantity be reported immedi- http://www.epa.gov/oeca/ore/ ately to the State Emergency Response Commission and Local Emergency Planning Committee.The flaring of hydrogen sulfide may require reporting if RCRA Online: http://www.epa.gov/rcraonline/ more than 500 pounds (the reportable quantity) of SO2 are released within a 24-hour period. The Clean Air Act recognizes that accidents, malfunctions, Compliance Assistance Centers: start ups and shut downs may cause excess emissions even when the facil- http://www.epa.gov/oeca/mfcac.html ity has implemented reasonable measures to avoid them. However, it is still important to alert emergency response personnel when these releases occur, Audit Policy Information: http://www.epa.gov/oeca/ore/ as even short periods of flaring can emit large quantities of SO2. For example, apolguid.html a medium-sized refinery with an SRP that processes 500 tons of acid gas Small Business Gateway: 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. http://www.epa.gov/smallbusiness/

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