cbe report - dioxins and refineries (scanned)

7/29/2019 CBE Report - Dioxins and Refineries (Scanned)

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Dioxins and Refineries:Analysis in the San Francisco Bay Area.

August 2000

Introduction.In a June 21, 2000 television interview a Bay Area oil refinery official summarized his indus

.try's position on why it is not taking action to prevent its ongoing releases of dioxins. sayingthat: "[O]ver 95 percent of the dioxin that goes out in our effluent to the Bay comes fromsources outside of our control."Dioxins cause serious threats to public health. Bay Area communities and most Bay A.rea elect_ed officials seek dioxins elimination wherever possible, suggesting that oil refiners should dotheir part to stop the pollution. However, public officials charged with protecting environmentalhealth from refinery pollution have declined to require- or even to investigate- pollution prevention for dioxins and refineries. The San Francisco Bay Regional Water Quality ControlBoard explains this inaction by siding with the industry argument. The Water Board saysrefineries cause so little of this pollution that most of the dioxins contamination in refineries iscaused by residential wood fires and vehicle use by people in the community.In fact, no government health agency has ever made a thorough assessment of all the rekases ofdioxins caused by petroleum refineries.Dioxins and Refineries reports the first comprehensive assessment of the total amount of dioxinsreleased from all petroleum refinery sources. It reveals oil refining as an important source ofdioxins in the Bay Area. It shows that existing government analyses drastically underestimaterefinery releases of dioxins. As an immediate matter. it sets forth specific steps for cost-effective elimination of dioxins in refineries.

Communities for a Better Environment ( CBE) Report No. 2000-2


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Author:

Dioxins and Refineries:Analysis in the San Francisco Bay Area.

Communities for a Better Environment (CBE)CBE Report No. 2000-2. August 10, 2000.

Supporting analysis:Greg Karras, Senior ScientistAzibuike Akaba, Staff ScientistAnne Simon, Senior AttorneyKaren Susag, Community Health AdvocateSue Tuddenham, Intern

This report was made possible by thousands of CBE's members, friends andsupporters, and by the generous support of the Richard and Rhoda GoldmanFund, Jenifer Altman Foundation, Patagonia Environmental Grants Program,Mari Mayeda and Albert Kutchins, through the San Francisco Foundation, andof the V-Fund through the Tides Foundation.

In addition, many environmental scientists, researchers, community membersand other experts reviewed, guided and substantially improved the research,analysis and communication of the information. CBE is solely responsible forthe report's content.Thank you all!

Founded in 1978, Communities for a Better Environment (CBE) is anenvironmental health and justice organization that works with urbancommunities directly affected by industrial pollution. CBE providesorganizing skills and legal, technical and scientific resources thatassist these communities in taking control of the decisions that affecttheir quality of life. We believe that fundamental change comes from thegrass roots up, and that environmental solutions can only be sustained inconcert with social and economic justice.Currently CBE's staff are:- Organizing community members and developing their leadership skills to

reduce exposure to environmental hazards.- Training community members who live in heavily industrial areas to use

low-cost and highly accurate air monitoring devices.- Fighting for the elimination of dioxin releases into the San Francisco

Bay and promoting community Right-To-Know about dioxin emissions byindustries.

- Using legal strategies to affect policy change and enforce environmentalhealth protection laws and rules .

Oakland Office1611 Telegraph Ave., Suite 450Oakland, CA 94612510/ 302-0430

Huntington Park Office5610 Pacific Blvd., Suite 203Huntington Park, CA 90255323/ 826-9771


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CONTENTS:IntroductionContentsPurpose, scope and termsApproachFindingsDiscussionRecommendationsPart 1. Multiple sources of preventable dioxin pollution in oil refineries

Confirmed sources:Reforming catalyst regenerationCracking catalyst regenerationOil- and waste-fired process heaters and boilersContamination of diesel fuel in refineriesContamination of motor oil in refineries

Suspected sources:Flares, coking, desalting, distillation and other processesContamination of petroleum coke and other productsProcess upsets and uncontrolled firesContaminated solid waste disposal

page 1page 2page 3page 4page 5page 8page 11page 12page 12

page 16

Part 2. Measurement of the dioxins release rate from all Bay Area oil refinery sources page 17Analysis of dioxins release measurement data quality: page 17

Error and bias related to choice of analytical methodsError and bias related to test frequency and disclosureError and bias when there is no testing of a known or suspected sourceError and bias related to sampling of release pathways

Analysis of source-specific measurements: page 23Reforming catalyst regenerationCracking catalyst regenerationOil- and waste-fired process heaters and boilersContamination of refined products in refineriesContamination of effluent in refineriesOther (suspected) refinery sources

Minimum and maximum bounds of total Bay Area oil refining dioxins release page 27Part 3. Measurements linking dioxins in the Bay Area environment to refinery sources page 28

Analysis of dioxins pollution gradients in sediment, water and fishAnalysis of dioxins profiles at refinery sources and in environmental samplesComparison of releases with fallout to Bay Area refineries from other sources

Literature cited

2

page 28page 33page 35page 38


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Purpose, Scope and Terms.Dioxins are a group of industrial byproducts and among the most toxic chemicals known. Preindustrial dioxin pollution was virtually nonexistent. Today people throughout the general population have dioxins in their tissues at or near concentrations that cause a high risk of cancer, andmay cause diabetes, endometriosis and other effects.l,2,3,4 Studies of humans suggest that dioxins exposures in the womb and through breast feeding cause effects on learning and the immunesystem in 10-20% of children 1 ,2,3.4Citing high exposure for people who rely on San Francisco Bay fish for food, the U.S.Environmental Protection Agency overruled the California Regional Water Quality ControlBoard in 1999 to designate dioxins pollution as a "high priority" cause of water quality standards violations throughout the Bay.5 Nearly ten years earlier, California established a policythat directs the Water Board to eliminate dioxins discharges to the Bay by the year 2000.6The term "dioxins" in this report includes the polychlorinated dibenzo-p-dioxins and dibenzofurans with chlorine atoms in the 2,3,7 and 8 positions ("CDDs" and "CDFs"), and polychlorinated biphenyls (PCBs) that exhibit dioxin-like toxicity. Refinery releases are reported as thecombined toxicity of these chemicals (including dioxin-like PCBs) using the World HealthOrganization consensus (TEQDFP-WH098 ). 16 When measurements include only CDD/Fs thecombined toxicity of these dioxins is noted as TEQ0 F (the "P" is left out of the subscript).Individual dioxins are named using abbreviations (for example: OCDD, OCDF, and PCB-126).When a larger group of chemicals that includes some dioxins is discussed, the larger group isreferred to by a different term, such as "total CDD/Fs" or "PCB homologue groups."Petroleum refining is among the world's largest industries, yet the first published evidencethat oil refining is a dioxins source came only 12 years ago,7 31 years after dioxin was found tocause health problems in 1957.4 As recently as November 1999 EPA admitted that it does notknow the total amount of dioxins released by refineries.8 Importantly, more data exist on refinery dioxin pollution in the Bay Area than in any other region of the country.Underestimating pollution is a recurrent environmental problem. For example, until late1990 the Water Board agreed with oil company managers' claims that refineries are not significant sources of toxic selenium pollution in S.F. Bay.9 However, the Water Board later admittedthat refineries appeared to be the "predominant" source of this pollution 1 until citizen suitsforced clean ups. 11 The Water Board also agreed with refinery management claims that dioxinsdo not violate water quality standards in the Bay 12 before EPA overruled this claim in 1999.Today, oil industry and Water Board managers assert the hypothesis that refineries are insignificant sources of dioxins to S.F. Bay, and claim refineries are dioxin "sinks" that remove moredioxins from the environment than they release.\3.14 Water Board staff say that a focus on refinery dioxin pollution is "really a distraction and a diversion from solving the problem," 14 and theWater Board has increased the amount of dioxins it allows to be released.15This case study attempts a comprehensive review of existing information on petroleum refinery dioxins pollution in the S.F. Bay Area. It allows the first thorough public review of thehypothesis that refineries are "insignificant" dioxins sources. It attempts to quantify releasesfrom refineries themselves. This analysis is specific to the Bay Area, where there are relativelymore refinery dioxins data, but it can be used by communities near refineries everywhere.

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ApproachIn general, there are four ways to investigate a pollution source: 1) by measuringhow pollution is caused and prevented at the source; 2) by measuring the pollution releasedfrom the source and from other similar sources; 3) by measuring the flow of pollution from thesource into the environment where this pollution accumulates; and 4) by measuring healtheffects caused by the pollution source in humans and other organisms. The first three types ofmeasurements are used here to investigate dioxins released from Bay Area petroleum refineries.Part I investigates the ways in which dioxins are created and released by refineries, and howthis can be prevented. This pollution prevention engineering analysis is useful in answering thecentral question of how to improve health protection. It also tells us whether refinery activitiesare sources creating dioxins, or merely pathways carrying them from some other source.Part 2 investigates measurements of the amounts of dioxins released from all refinery sources.It builds on the engineering analysis in part 1 and uncovers the amount of dioxins refineriesrelease to the environment through all pollution pathways, based on a detailed analysis of whatis - and is not - known from existing measurements of each refinery source. This analysis isuseful because despite public debate over the significance of this pollution, there is no government estimate today of overall releases of dioxins from all refinery sources.Part 3 analyzes measurements in the environment to investigate the extent to which environmental accumulations of dioxins can be traced to refinery sources. It builds on CBE's comprehensive inventory of Bay Area sources of dioxins. When other sources are accounted fm;, one canget a more complete picture of the pollution gradients stretching from refineries into the environment. It analyzes new information on how dioxins might (in some cases) be traced to theirsource using the "profile" of the relative amounts of specific dioxin compounds. Informationexplored here links releases to environmental exposures , and provides a "check" on the sourcemeasurements of pollution amounts in part 2.A discussion of findings and recommendations looks at the data as a whole and puts the newfindings in perspective based on what is known now, what we can learn quickly, and what canbe done now to improve environmental health protection from refinery dioxin pollution.Readers should note that despite important new data, few data exist to describe exactly"how much" dioxin is released from most sources. This analysis benefits from a comprehensiveassessment of Bay Area data on all dioxins, sources in refineries, and release pathways fromrefineries into the environment. Further, it looks at releases of these persistent, trans-generationtaxies from the more relevant perspective of long-term release, allowing more data to be considered. Nevertheless, poor monitoring has led to many gaps in scientific information. In order tointerpret the incomplete data accurately, this analysis takes the approach of estimating that BayArea refineries as a group release more than a minimum amount of dioxin pollution, and lessthan a larger maximum amount of this pollution.These region-wide refining estimates should not be applied to an individual source: this couldoverestimate or underestimate the amount ofdioxins released, and the measurement accuracy, depending upon the source. Data and analysis methods are detailed in parts 1, 2 and 3.

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Findings.Multiple sources create oil refineries' releases of dioxins.Six San Francisco Bay Area oil refineries use many process units that create dioxins.Reformers, crackers, and oil-fired heaters and boilers that process a total of more than 25 million gallons of petrochemicals each day in Bay Area refineries are confirmed sources of dioxins.This is based on measurements of CDD/Fs in the initial releases from these processes at BayArea refineries, and the presence of chlorine inputs and process conditions that create dioxins inthese processes. Measurements of PCBs homologue groups also confirm the creation andrelease of newly-formed PCBs in Bay Area refineries' reforming and oil-fired processes.In addition to these known sources, there is suggestive evidence that flares, cokers, desalters,distillation towers, and/or uncontrolled fires in refineries create and release dioxins, although notests of these suspected sources for dioxins have been reported publicly.Releases of dioxins from refineries are confirmed by direct measurements of smoke stacks,waste water discharges, and rain storm runoff discharges at Bay Area refineries and by directmeasurements of newly-refined diesel fuel and motor oil at southern California refineries.Newly-refined diesel also contains chlorine, which could cause more dioxins to form in vehicles. Although the diesel pollution pathway to the environment is through vehicle exhaust pipes,it is important to recognize the refinery source because - regardless of how much of the dioxinsemitting from the tailpipe form in the refinery and how much form in the vehicle - getting thedioxins and the chlorine out at the refinery may be the most practical way to stop this pollution.Refineries are poorly monitored for releases of dioxins.Despite relatively better monitoring of dioxins at S.F. Bay Area oil refineries than at refinerieselsewhere, many refinery sources, pollution pathways to the environment, chemicals in the"dioxins" group, and pollution-causing events have not been measured at Bay Area refineries.Direct measurements for dioxins are not reported in releases from flares, cokers, desalters, distillation towers, or uncontrolled fires at any Bay Area refinery. None of the major Bay Arearefineries reports measurements of dioxins from every one of the confirmed source types it uses.No Bay Area refinery reports these measurements for most of its smoke stacks, or for any of thediesel, motor oil and other products it refines . Despite direct measurements confirming releaseof PCB homologue groups that contain dioxin-like PCBs, no Bay Area refinery reports directmeasurements that isolate dioxin-like PCBs from other PCBs it releases. Further, most of themeasurements that have been done were not planned to be sensitive enough to fully quantifymany of the individual CDD/F chemicals above analytical detection limits.Finally, even monitored releases are measured only a small fraction (one-ten thousandth) of thetime that the releases are occurring, and these tests are announced in advance, raising the possibility that only the low end of the highly variable releases from refineries is measured directly.Because of this poor monitoring, the true rate of dioxins release from refineries is only knownwithin a wide range (of minimum to maximum release).

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Bay Area oil refineries release more than 1.8 billion picograms ofdioxins perday, and up to a maximum of 171 billion picograms ofdioxins/day, on average.This is measured as the toxicity of CDD/Fs and dioxin-like PCBs (TEQDFP-WH098 ).The minimum rate of dioxins release (1.8 billion pg/day) is based on direct measurements ofconfirmed refinery sources and release pathways, and the minimum plausible amount ofCDD/Fs and dioxin-like PCB compounds that were present but not fully quantified in confirmedreleases due to analytical problems. However, Bay Area refineries actually release an amount aslow as this minimum amount of dioxins only if all the following conditions exist:- none of the many suspected, but unconfirmed sources in refineries release dioxins;- dioxins known to be released that are not fully quantified in releases due to analytical prob-

lems are released at only the lowest rate that measurements show is possible;- on-road diesel is the only refined product causing environmental release of dioxins; and- releases are not larger during refinery fires or when refiners know "they are not being tested.While it is possible that all these conditions exist in reality, the detailed analysis in this reportshows that the probability of this is very low.It is equally possible (and equally unlikely) that all of the opposite conditions exist: one ormore suspected refinery sources release dioxins; dioxins present but not fully quantified inreleases are released at only the highest rate existing measurements indicate is possible; otherrefined products release dioxins; and releases are much larger when refineries are not tested. Ifall these conditions exist, refineries could release up to a maximum of 171 billion pg/day ofdioxins TEQ.Of course, the most likely situation is that some of these conditions exist (for example, anunconfirmed source releases dioxins), and some other conditions exist in between the minimumand maximum possible extremes (for example, dioxins below detection are released at ratesbetween the lowest and highest possible rates defined by analytical detection limits).Thus, Bay Area oil refineries release more than 1.8 billion pg/day and less than 171 billionpg/day of dioxins TEQ, and their true release rate is likely to be closer to the middle than theextremes of this 1.8 - 171 billion pg/day range.Environmental measurements support the finding that Bay Area refineriesrelease more than 1.8 billion picograms per day ofdioxins toxicity.Average concentrations of dioxins (TEQDFP-WH098 ) in San Francisco Bay fish are 30 to 250times larger than those in fish from a comparable location in northern California that shouldreceive similar amounts of dioxins from distant sources. The greater fish contamination in theBay Area suggests that there are important Bay Area sources of dioxins.The average concentration of CDD/Fs (TEQ0F-WH098) in aquatic sediment of a Bay Arearefinery discharge canal is 20 to 140 times larger than the concentrations of TEQDFP-WH098 inthe northern reach of the S.F. Bay/Delta and two of its tributary rivers, and 600 times larger thanthe concentrations of TEQ 0F-WH098 in sediment of two of its other tributary rivers. The relative levels of different individual CDD/F chemicals in the refinery's canal sediment and one ofits process releases (the "profiles" of dioxins within each homologue group) are similar, supporting the conclusion that refinery caused the accumulation of dioxins in its discharge canal.

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Maximum concentrations of CDD/Fs (TEQ0F-WH094 ) in changing rain storm runoff are up to70 times greater at refineries than at sites 15 to 25 kilometers from refineries and other industrialsources of dioxins, and these maximum levels taper off for at least six miles from the sources.Further, particulate pollution follows this same pollution gradient from refineries: This is important because dioxins often attach to particulate pollutants from refineries and other sources, andthis enhances their fallout near sources and their movement into this storm water runoff.Finally, a disproportionate number of runoff tests at refineries have high dioxins levels that cannot be explained by the suspended solids levels in the runoff: This provides another indicationthat refinery sources are contributing to the dioxins gradient observed in the runoff.All these measurements indicate a gradient of pollution with higher levels of dioxins nearrefineries and other industrial sources, and gradually decreasing levels as the pollution dispersesfar into the Bay Area environment. These measurements show that oil refineries contributeimportant amounts of the dioxins found in the Bay Area environment.The pollution gradient in runoff is also of interest with respect to another type of dioxins release.According to the Bay Area Air Quality Management District, residential wood burning releasesas much dioxins as any Bay Area source : an estimated 2.2 billion pg/day of TEQ0 F-WH094.14However, the levels of dioxins at runoff sites near residential wood burning but far from industrial sources are among the lowest found in the Bay Area, and these sites are at the low end ofthe pollution gradient, while refineries are at the high end of the pollution gradient. This indicates that refinery releases could not be significantly smaller than residential wood burningreleases (2.2 billion pg/day), and it suggests that refinery releases are larger.The comparison in Figure ES-1 shows that the minimum refinery release discussed above is atleast 30 times the amount of dioxins from other sources that is estimated to fall out to a landarea of the size used by Bay Area refineries. This is consistent with the much greater dioxinslevels in sediment and runoff at refineries than those at sites far from industrial sources.Environmental measurements support the source measurements that indicate Bay Area refineriesrelease more than 1.8 billion pg/day of dioxins TEQ. Indeed, if refinery releases were muchsmaller than those from residential fireplaces (estimated at 2.2 billion pg/day) and much lessthan 30 times fallout from other sources, the 20-600 times greater concentrations of dioxinsTEQ found at refineries than at other Bay Area sites would be very difficult to explain.Oil refineries can prevent dioxin pollution now.Chlorinated dioxins cannot be created without chlorine. Refiners can block the chemical reactions that create dioxins by removing chlorine from their processes. They can also trace thechlorine entering their processes to its sources and prevent chlorine from entering the processes.One small refiner in the South Bay community of Newark has committed to do this - and thusvirtually eliminate dioxins from a process heater- within two years. Dioxins have no industrialuse, and chlorine has no use in cracking or heater or boiler processes. Thus, dioxins can beeliminated in these refinery processes immediately.Refiners do use chlorine to regenerate reforming catalyst; but even here, the creation of dioxinscan be eliminated by a concerted effort to find and install methods that protect, clean and repairthis catalyst without burning chlorine. Thus, at every process that is a known source of dioxinsand in every Bay Area oil refinery, steps can be taken today to eliminate the creation of dioxins.

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DiscussionThis report shows that preventable sources in BayArea oil refineries release at least as much dioxinsas the biggest pollution sources cited by regionalgovernment officials, and contribute significantly tohealth threats affecting subsistence anglers.It also highlights a health concern for the generalfood supply, when one begins to consider the toxicological significance of more than 1.8 billionpg/day of dioxins toxicity release from Bay Arearefineries, and where some of it may be going. Onepicogram of dioxin exposure per day can cause aperson to exceed the lowest lifetime cancer riskthreshold considered "acceptable" by public healthofficials. Most dioxins released will end up in soiland sediment rather than in our food, but prevailingwinds from the Pacific Ocean could carry significant amounts of dioxins emitted by Bay Arearefineries to parts of California that EPA says areamong the major U.S. food producing regions. 4This pollution should be prevented starting nowThis analysis suggests refineries release amounts ofdioxins significantly within the extremes of the 1.8-171 billion pg/day range shown in Figure ES-1.Nevertheless, given the size and scope of this industry, its release rate needs to be known better. I f theindustry's releases nationwide approach the medianof this range, refineries may cause more release ofdioxins than all but one source estimated by EPA.4One might speculate that releases approach the geometric mean of this range (and refineries are the sixthlargest source) but in any case, such speculation really only highlights a need to monitor refineries.A program to organize monitoring of dioxins in theconfirmed and suspected refinery sources andrelease pathways is needed now. This should bedone before Toxics Release Inventory reports ondioxins8 are released nationwide next year.Figure ES-1 shows that even the minimum amountof dioxins released by Bay Area oil refineries is165 times greater than that estimated by the SanFrancisco Bay Regional Water Quality ControlBoard, and 13 times greater than that estimated by

8

Figure ES-1. Lower and upper bounds ofdioxins release from Bay Area oil refineries(pg/day T E Q m ~ p - W H 0 9 g ) , v . other estimates,and fallout on refineries from other sources.

171billionpgldayor less

~ ~(Scale compressed)

tt1.82billionpgldayor more

KeyI IDD

~t

Lower bound of amount

Upper bound of amount

Estimates by others

Arrows point toincreasing likelihoodof true release rate

Bay Area Refineries Refineries Fallout onrefineriesa (Bay Area (Water Bay AreaAQMD)b Board)C refineriesdNOTES: aThis analysis. bBAAQMD refinery (refonning)estimate from reference 34. CRWQCB refinery (effluent)estimate from reference 53 . dEstimated from national datain reference 4. refinery acreage, and methods in part 3.


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the Bay Area Air Quality Management District. The maximum possible release found by thisanalysis exceeds these regional health officials' estimates of refinery release rates by1,200-15,000 times. The Water Board's estimate that Bay Area refineries release an amount ofdioxins equal to 11 million pg/day is documented in its February 1998 staff report entitledDioxins in the Bay Environment, and in its May 25, 1999 and June 21, 2000 staff reports regarding the Tosco Avon Refinery.t3,14,53 The Air District's estimate that these refineries release anamount of dioxins equal to 137 million pg/day is documented in its March 27, 1996 staff reportentitled Air emissions ofdioxins in the Bay Area environment.34However, these Water Board and Air District analyses exclude many considerations that proveimportant based on the evidence in this report:- The Air District estimate does not report any amount of release from known refinery sources

in cracking and oil-fired processes, or from suspected sources in flares, cokers, distillationunits, desalters or fires. The Water Board analyses rely on this Air District estimate.

- The Water Board and Air District estimates do not report any amount of refinery release viastorm water runoff, refinery products, or fugitive emissions from fires.

- The Water Board and Air District estimates do not report dioxin-like PCBs releases.- The Water Board estimate does not report any release of CDD/Fs known to be created and

released by refineries when the chemicals are below detection limits due to poor monitoring.- Refinery releases of dioxins are tested only a small fraction (one-ten thousandth) of the time,

release rates can change by hundreds of times, and advance warning of tests may result insampling when releases are low. However, the Air District and Water Board estimatesassume refineries never release more dioxins when they are not looking (testing the releases).

The cumulative error caused by excluding many refinery sources, release pathways, dioxins, andmeasurements of greater release explains how the Water Board and Air District have drasticallyunderestimated oil refinery releases of dioxins.Amounts of dioxins in the environment near Bay Area refineries provide a second importantmeasurement of this pollution, confirming the refinery release rate from source measurements.The analysis in this report finds links between refineries and pollution in fish, sediment, andrunoff, that were missed by public health officials' earlier assessments.In fish, a 30-250 times greater concentration of dioxins is linked to Bay Area sources by considering a key site-specific factor, and comparing Bay Area fish with other fish near the PacificOcean. These fish are more comparable due to the lower rate of dioxins fallout near the Pacific.In contrast, the Water Board's February 1998 staff report53 does not account for this ocean influence, compares S.F. Bay fish with fish from U.S. waters far from the Pacific that receive falloutfrom many land-based sources to windward, and fails to find the clear difference revealed here.In sediment, a 20-600 times greater concentration of dioxins is linked to refinery sources byconsidering environmental processes that affect dioxins. Dioxins build up in sediment nearsources for a long time, and move back into the water only slowly. The report accounts for this,comparing dioxins in sediment with long-term releases. In contrast, in its June 21, 2000 and June16, 1999 staff presentation reports 14 the Water Board agrees that the dioxins buildup in sedimentcould cause discharges from a refinery canal for years, then contradicts itself by claiming that discharge from the refinery's canal during a five-month plant shutdown was from another source.

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Environmental processes also shift the mix(the "profile") of dioxins so that sediment hashigher levels of dioxins with more chlorineatoms, and lower levels of dioxins with lesschlorines, as compared to sources. The reportaccounts for this factor, and finds that the"profile" of dioxins in sediment of the refinery discharge canal is (not surprisingly) similar to that of the refinery source. In contrast,the Water Board's May 25, 1999 staff reportl3does not account for this factor, and fails tonotice this similarity in the profiles.In storm runoff, dioxins, particulate pollutionassociated with dioxins, and changes in theratio of dioxins to particulates are each linkedto refinery sources when one accounts for allthe nearby industrial sources of this pollution.Figure ES-2 shows the location of sources,illustrating how runoff far from refineriesmight be near other sources of dioxins.Figure ES-3 shows that when the distancefrom all these sources is accounted for,refineries (gray bars) are shown to influenceall three pollution-related factors. As shownin the Figure, this analysis reveals pollutiongradients starting from maximum dioxins andsuspended solids levels at refineries, andinstances of high dioxins at refineries evenwhen suspended solids levels are moderate.Thus, refineries influence a pollution gradientwith 70 times greater maximum runoff levelsthat taper off for miles into the environment.In contrast, the Water Board's June 21, 2000staff reportl3 compares runoff between onlytwo types of sites: refineries and all others(even if other sources are nearby). This doesnot account for the effects of other industrialsources. Thus, the Water Board has missedrefinery effects on this pollution gradient.Most important, this report reveals immediatesteps that can eliminate creation of dioxins inrefineries by blocking chlorine inputs. Thiswill stop this pollution via all routes - including stack and tailpipe discharge to the Bay.Therefore, it is within the Water Board's mandate to address all discharges to water.

Figure ES-2. Oil refineries and other industrialdioxin sources identified in the S.F. Bay Area.

Source key:il refineriesncinerators0scrapfurnaceshemicaldrumfurnaces0foundries0otherindustries

NOTES: Data from references 2 and 47. 0Figure ES-3. Dioxins and suspended solids in Bay Area

runoff v. distance from industrial sources.

7o

so40

Jo

20

IO

- Runoff sample at refineriesI Runoff sample atother sites

7o

~ ~so!-'

...:.

-5Jo ]....!!20-11"'sIo Q

NOTES: 47 s:unples with CDD/F and solids doUI; from references 2. 47. 97 ond 98.

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RECOMMENDATIONS:1. The San Francisco Bay Regional Water Quality Control Board, State Water ResourcesControl Board and U.S. Environmental Protection Agency should reverse their deci

sions to allow ongoing dioxin pollution by Bay Area oil refineries. The agencies should: Reverse the June 21, 2000 decision to weaken the effluent limit on dioxins discharge bythe Tosco Avon Refinery. The Regional Board based this decision on its drastic under

estimate of refinery dioxin pollution, but it did not raise this reason in its proposal untilafter its comment deadline, and it did not accept written comments thereafter.

Revise the permit allowing dioxins discharge by the Chevron Richmond Refinery to S.F.Bay, which expired by its own terms in 1997, to require dioxins elimination.

Conduct a basin planning process with formal public debate on how Federal requirements for total maximum "loads" of all dioxins release to S.F. Bay can best meet theexisting State policy goal to eliminate dioxins discharge to the Bay by the year 2000.

2. The Regional Board, State Board and EPA should require pollution prevent ion auditsof all root sources creating dioxins at the Chevron, Tosco, Equilon (formerly Shell), andValero (formerly Exxon) refineries in the Bay Area, and fund experts hired and directedby the community and workers to ensure independently verifiable results. Within twoyears audits should identify, test and effect options that:

Protect reforming catalyst or repair and clean it without incinerating chlorineIdentify, trace and prevent chlorine inputs to cracking processes .Identify, trace and prevent chlorine inputs to oil/waste-fired process heaters/boilers.Identify, trace and prevent or remove chlorine inputs to other refinery processes .

3. The Regional and State water boards, State Air Resources Board and EPA shoulddesign a monitoring program that is capable of confirming oil refinery dioxins re leaserates within 25% of the true rates, and implement this program so that dioxins reportsto the Toxics Release Inventory, which are required for the first time in 2001, will provide useful information. This program should include:

Identification, direct measurement, and ongoing monitoring of all sources of dioxins .Monitoring of all dioxins (CDD/Fs and PCBs) and all release pathways from refineriesAdequate sensitivity (design for quantitation) and greatly increased sample frequencyComprehensive measurement of dioxins release during and after upsets and fires .

4. To improve health pro tection against refinery dioxin pollution, the public needs to takeaction. Community members joining with CBE can demand actions by our public officials and engage refinery managers who still refuse to cooperate in open investigationsof ways to eliminate dioxins at the source. Elected officials should organize and conduct hearings to investigate the ongoing problems in public health officials' responses tooil refinery dioxin pollution, and hold the Water Board, Air District and EPA accountable for actions to prevent this pollution and protect our health.

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Part 1. Multiple sources of preventable dioxin pollution in oil refineries .From years of direct measurements in laboratories, industrial processes and the environment it isnow known that the primary cause of dioxins pollution involves the introduction of chlorine intovarious high-energy (usually high-heat) industrial processes. Sources of chlorine in the highheat processes of petroleum refineries cause some of this dioxin pollution.U.S. refineries process approximately 5.5 billion barrels- 700 million metric tons assuming 45API crude - of crude petroleum annually. This production rate far exceeds that of any otherindustry believed to cause major dioxins releases.2-17.18 One of the three largest oil refining centers on the U.S. west coast surrounds San Francisco Bay and refines nearly 300 million barrelsper year.I7.I9 Major refineries are run by San Francisco-based Chevron Corp. in the communityof Richmond, Tosco (in Avon and Rodeo), Equilon (Martinez), and Valero (Benicia). A sixthplant run by Evergreen Oil, Inc. in Newark (near Hayward) is classified as a "lube" refinery.Generally, refiners remove unwanted chemicals, distill the crude, "crack" the distillate intosmaller fuel-size molecules, "reform" the shapes of these molecules to boost octane, and sell thefuels , lubricants, and side products such as petroleum coke that result. These steps are done byapplying massive amounts of energy in dozens of different hot process units (distillation towers.catalytic crackers, reformers, etc.). Part of the output stream from many process units is fedback into other processes. This is why refineries look like a maze of interconnected pipes- andwhy putting chlorine into one refining process can lead to dioxins formation in other processes.CONFIRMED SOURCES:Catalytic reforming boosts fuel octane by reshapingpetrochemical molecules . Six reformers process170,000 barrels/day at the Chevron, Tosco, Equilon(formerly Shell) and Valero (formerly Exxon) plants.The reforming reaction is aided by a catalyst that contains platinum and/or rhenium. The catalyst becomesless effective with carbon deposits and wear. Therefiner cleans the catalyst in a "regeneration" processthat involves incinerating the carbon deposits.The chlorine source for dioxins formation in thisprocess is the addition of chlorine to aid during cleaning and reactivation of the catalyst . When dioxinswere discovered in refinery sludge in 1988, this wasthe first refinery process tested for dioxins.?Tests of waste water directly exiting reformer catalystregenerators find high concentrations of 17 CDD/Fsfrom reformers at the Chevron, Tosco (Avon andRodeo) and Valero refineries.20.2I Three days of stacktests at the Tosco Avon No.3 Reformer measuredhigh levels of CDD/Fs and high levels of newlyformed PCBs.22 (See tables 1 and 2.)

12

I. Reformer stack tests (Tosco Avon Refinery )picogrnmslharrcl reformed Day I Day 2 Dayj

2,3,7,KTCDD 7 12 221,2,3,7.K-PcCDD


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The mechanism that creates dioxins starts when chlorine is added. Some of the chlorine reacts with thehot carbon atoms and compounds in the reactionchamber and its exhaust piping to form dioxins.Dioxin formation is catalyzed by combustion-inducedchanges in oxygen chemistry, by metals, and by theash/soot/carbon buildup (which on a micro-scale hasa high surface area that aids the reactions). Carbonskeletons of the CDD, CDF and PCB molecules formby slightly differing trace chemistries, and chlorineatoms attach to these molecules. These side-reactionstake seconds in the primary reactor and the downstream sections of the process_2,7,23-30In other words, the chemistry that governs the kindsand amounts of dioxins formed is dynamic and complex, but it is clear that because chlorine is put intothis process that burns waste carbon off metal catalyst, dioxins form in the process and emit into theenvironment. These chlorinated dioxins cannot form,however, if the chlorine source to these reactions isblocked.Immediate next steps toward zero dioxin: Dioxinshave no useful purpose in refining. Since a primarychlorine source causing dioxins creation in reformersis already identified, an immediate next stepinvolves blocking the chlorine source to the chemical side-reaction that creates dioxins. Options toprotect reforming catalyst, or repair and clean itwithout putting chlorine into an incineration process,can be tested for their effectiveness starting today.Steps toward zero dioxin in refinery reformers aresummarized in Figure 1.

2. Reformer water tests (3 Bay Area refineries)picogramslliler Chevron Tosco ToscoRichmond A\on Rodeo

2,3,7,8-TCDD 170 BD 221,2,3,7,8-PeCDD 730 BD 85

1.2,3,4,7,8-HxCDD 740 8700 901,1,3,6,7,8-HxCDD 910 15700 90I 2.3.7,8,9-HxCDD 440 16900 190

1,2,3,4,6,7 ,8-HpCOD 2640 55900 890OCDD 11 70 63400 1400

2,3,7,8-TCDF 3350 5300 1501,2,3.7,8-PeCDF 9150 -14000 1202,3,4,7,8-PeCDF 4600 111500 180

1,2,3,4,7,8-HxCDF 14700 128500 340I 2,3,6,7 8-HxCDF 5800 131000 2402,3,4,6,7 8-HxCDF 1320 2.5000 1901,2,3,7,8,9-HxCDF 1700 177000 230

1,2,3,4 ,6,7 ,8-HpCDF 17100 599000 9701.2,3.4.7,8,9-HpCDF 7500 566000 520

OC DF 10250 279500 1900NOTES: Average c o n c e n t r : ~ u o n s BD=below detecuonlimit. Data from reference 20.

I. Reforming Unit Pollution Prevention.Spent Re fo rmer Catalyst_t_

Remove carbon buildup &regenerate metal catalystwithout forming dioxin

"''rocess gases for recovery Idisposal without liquid (dry "rocess)NOTES : Figure from reference 2.

#1: How to regenerate catalyst withoutchlorinated solvents?#2: How to confirmdioxin elimination &safety of new option?

Catalytic cracking breaks large petroleum molecules into smaller, fuel-sized molecules inorder to make more gasoline, diesel and je t fuel out of each barrel of cnide oil. Including catalytic hydrocracking, at least seven crackers process more than 500,000 barrels/day at theChevron, Tosco, Equilon, and Valero refineries.l7-J9 This process uses a silica-alumina catalystthat is cleaned of carbon deposits by incineration in cracking catalyst regenerators.In the first dioxins tests of this process ever reported, dioxins were detected in three tests ofstack exhaust from the Chevron Richmond Refinery catalyst regenerator.232 See Table 3.Measurements confirm chlorine in partially refined materials fed into cracking processes.231Incinerating cracking catalyst with this chlorine creates dioxins in side-reactions that are catalyzed by high surface area and metals of the silica-alumina catalyst, the carbon deposited on(and burned from) the catalyst and the process unit interior structures_2.23-30.33

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Immediate next steps toward zero dioxin: The dioxinforming reactions in this process can be blocked by getting the chlorine out of the cracker feed stream. Chlorinecan be removed from oil before processing (see oil-firedheaters below). Since methods to measure chlorine in oilare readily available,31 testing in refineries can tracecracker chlorine inputs to their sources and prevent chlorine inputs to all refining processes. (See Figure 2.)

2. Cracking Unit Pollution Prevention.Spent Cruc ker C;ualyst'emove carbon buildupfrom silica-alumina catalyst

without forming dioxin 1'-yBlock the chlorine source tothe dioxin-forming reactionin the process

NOTES: Figure from reference 2.

#1: Chlorine soun:escan be traced by inplant testing.#2: Chlorine can beremoved from inputs,before dioxins fonn.

Oil- and waste-fired process heaters and boilersprovide some of the enormous amount of heat used in oilrefining, and can also reduce the amount of "leftover"material that refiners must pay to dispose of as liquid orsolid wastes. Generally, all refineries bum some of thefuels they are refining, ranging from No. 2 fuel oil(diesel) to tank-bottom sludge. A cumulat ive total ofmore than 2.6 million barrels/day of crude and partiallyrefined oil is put through heated distillation, cracking,coking, reforming, hydrotreating and other processes inthe Bay Area. 17 A conservative estimate (that only 1.5-6% of this cumulative throughput is burned with naturalgas and other energy to heat the rest) puts oil burning byBay Area refineries at 40,000-160,000 barrels/day.The chlorine source for dioxins formation in this processis the same as that for catalytic cracking, except thatsome refinery residuals contain relatively high chlorinecontent due to process chemistry or contamination.31,35Oil-fired boilers and heaters are known dioxins sourcesfrom testing elsewhere.2 Table 4 shows results fromthree tests that found dioxins and PCBs in stack exhaustfrom an oil-fired process heater at the Evergreen Oil. Inc.used oil refinery in Newark.36 An old stack test at theShell (Martinez) CO boilers failed to detect dioxins(though the Air District presumed it is a source).3 4

14

3 Cracker stack tests (Chevron Refinery)picogrnms per second Test I Test 2 Tcst3

2.3,7,8-TCOO 80!110) 80( 130) 80(96)I ,2,3,7.8-0eCDO 80{110) 80(801 80 (42)

1,2.3.4.7,8-HxCOO 8[)(130) 80(95) 80(81)1,2,3 ,6,7 8-HxCOD 80(120) 80(98) 80(76)1.2.3.7.8,9-HxCDD 80 (110) 80-CBs ( 190001 110000 (20000)

Octa-CBs (48000) (260001 (24000)Nonachlor


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The mechanism of dioxin formation in oil-fired boilers and process heaters is generally similarto that in other combustion or incineration sources, as described above.223-30 However, the relative amounts of CDDs, CDFs and PCBs produced may differ from these other sources due todifferences in the material burned, the substances that catalyze dioxins formation, and combustion conditions. The mix of dioxins produced by oil/waste-fired boilers tested elsewhere differsfrom the mix of dioxins produced by incinerators.4Immediate next steps toward zero dioxin:Dioxins formation in this process can beblocked by getting the chlorine out of the material burned. In fact, the steps to virtually eliminate dioxins from this process source are starting now at one Bay Area refinery. In a March,2000 settlement agreement with CBE, theEvergreen Oil Inc. refinery committed toremove at least 99% of chlorine from the feedburned in its process heater within two years.Evergreen will measure the effect of its processchange and the data will be independently verifiable. In the event that the process change isnot effective, Evergreen will use a differentenergy source for heat.37 See Figure 3.

3. Oil-fired Heater/boiler Pollution Prevention.Material burned to heat processt

Block the chlorine source tothe dioxin-forming reactionin the process

..

Verify the effectiveness ofprocess/production systemchange with direct testing

f'. #1: Get chlorine outof oil through prevention or removal.#2: Use other zerochlorine energysource to heat theprocess if necessary.

Contamination ofdiesel fuel in refineries is a contributing source to dioxins release frommotor vehicles and a pathway by which dioxins created in refineries enter the environment. Onaverage, from December 1999 through June 2000 California refineries processed 1,680,000 barrels/day of crude and, in addition to other products, produced 290,000 bbl/day of distillates, ofwhich 170,000 bbl/day was diesel for on-road use. IS Bay Area refineries process an average of779,400 bbl/day of crude.I7,19 Thus, based on proportionate production Bay Area refineries produce an estimated 80,000 bbl/day of on-road diesel and 136,000 bbl/day of total distillates.Tests of diesel taken directly from southern California refineries found CDD/F TEQ in on-roadand off-road diesel at concentrations ranging from 0.07 to 300 picograms per liter (detectionlimit problems contribute to the range).38 These diesel fuels were sampled before use in anyvehicle: thus; dioxins measured in the fuel were not created by combustion in vehicles. Instead,diesel and the partially refined oil it is made from accumulate some of the dioxins formed inrefining processes that produce it. Indeed, this accumulation is expected, because dioxins havehigh affinity for lipids (fats and oils) and extremely low volatility and solubility in water.The known sources of chlorine for the dioxins found in diesel are described for reforming,cracking and oil-fired processes above. In addition, diesel as it leaves the refinery containschlorine and other dioxin precursors from refinery processes.31.3 8 Dioxin releases are measuredfrom diesel vehicles.2.34 .38,39.40.41 Dioxins formation in the vehicle is widely suspected, but it isalso possible that dioxins "present in the fuel may be detected in the exhaust because some ofthe fuel is not burned during combustion."38 In either case, refinery sources of dioxins, chlorine and dioxins precursors are preventable sources of dioxins released from vehicle tailpipes.Contamination ofmotor oil in refineries is shown by a test of new oil that found one dioxincompound at 2000 picograms per liter,38 and occurs by similar mechanisms as those for diesel.

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SUSPECTED SOURCES:Flares, coking, desalting, distillation and other processes that were not tested for dioxinsrun a total throughput of 1.9 million barrels of crude and partially refined petroleumin the BayArea daily. These processes appear to create conditions that favor dioxin formation: chlorineinputs (in partially refined materials as shown for cracking and oil-fired processes above); carbon precursors in the feed; soot or ash that catalyzes formation; and combustion or high heat.Tests that detected dibenzofuran as a combustion product of oil-field flaring strongly suggestthat CDFs can be created from refinery flares. 42 Findings that reformer materials containingchlorine may enter cokers,4 and that dioxins are present in a Bay Area refinery's coke pile43 further suggest that coking may form and emit dioxins. The desalting process uses technology similar to that used in chlorine production from brine, which is a known dioxins source. 2 Finally,distillation subjects large quantities of material to temperatures that favor dioxins formation:incomplete desalting might introduce chlorine to crude distillation; and other distillationprocesses are susceptible to the same chlorine sources that affect the cracking and oil-firedprocess sources discussed above.Catalytic cracking catalyst regeneration was an undiscovered dioxins source until this sourcewas tested for the first time - as recently as 1997 - at the Chevron Richmond Refinery. Takentogether, the evidence strongly suggests that additional dioxins sources may exist in refineries.This likelihood can be confirmed or ruled out only by further investigation.Contamination ofpetroleum coke and other products with dioxins has not been confirmedby testing of these refined materials, yet this contamination is likely. Dioxins are found in therefined products that have been tested,38 and in runoff from a refinery coke pile.43 The combustion of petroleum coke after it leaves the refinery (in Bay Area power plants, metal foundriesand smelters, and a cement kiln) is associated with dioxins release.234 The extremely lowvolatility and water solubility of dioxins can result in their accumulation in coke and ash just asthey accumulate in diesel and motor oil. Ash from other combustion sources is known to contain dioxins,44 and refinery furnace ash may be used in clinker by cement kilns - which releasedioxins. Dioxins are probably released from refineries in petroleum coke and furnace ash ..Process upsets and uncontrolled fires that result from such upsets have obvious potential togenerate dioxins from the chlorine and petrochemicals that are present with metals and otherdioxin formation catalysts throughout refineries. Dioxins formation is confirmed in combustionof oil (see above), and during fires in buildings.2.4.34 At least 19 major incidents involvinguncontrolled fires occurred in Contra Costa County oil refineries between March 1989 and April1997.45 .46 In 1999 major fires killed workers at the Avon plant and damaged the Chevron refinery's cracker. Yet despite the clear potential for dioxins creation in some of these major events,no properly designed testing of Bay Area refinery fires for dioxins has been conducted.Contaminated solid waste disposal almost certainly transports dioxins from refineries, however, EPA has excluded disposal of dioxins in landfills from its estimate of release to the environment.4 EPA's approach is open to criticism because landfills sometimes leak, and as EPAadmits, dioxins emit from landfills to the air. 4.34 While supporting this valid criticism, thisanalysis uses a release estimate that excludes landfill releases in order to avoid the potential forinaccuracies as communities compare the results reported here with EPA's estimates.

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Part 2. Measurement of the dioxins release rate from refinery sources.RELEASE MEASUREMENT DATA QUALITY:Error and bias related to choice ofanalyticalmethods: The quality of dioxins data is often limitedby two analytical choices: one about the volume ofsample collected; and one about the dioxins to analyze.Some effects of small sample volume are shown inTable 5. For example, Bay Area refinery effluent teststhat collected one liter samples failed to detect TCDDat levels below about one picogram per liter, but testselsewhere that collected more than 1,000 liters of waterper sample measured TCDD at concentrations morethan a thousand times smaller. The smaller samplevolumes collected in these refinery tests did not allowfor concentrating enough dioxins for the lab instrumentto detect and quantify.51,52 In air samples, tests at aBay Area refinery failed to detect TCDD below aboutone pg per cubic meter of emission, but tests that collected more air detected 50 times smaller levels.Figure 4 shows the potential for error caused by thechoice of small sample volume. In a typical test of arefinery's final effluent discharge to San FranciscoBay, the amount of CDD/Fs toxicity that could be present at the detection limits of the analysis is 50 timesthe amount detected by this analysis. In stack tests ofa Bay Area refinery cracker, the amount of TEQ thatcould be present at the detection limits of the analysisis 370 times the amount detected. In diesel as it leavesrefineries (before use as a fuel), the amount of TEQthat could be present at the detection limits of theanalysis is 900 times the amount detected.When a chemical is measured below the detection limitof the sample-specific analysis, this test really onlymeasured this chemical at a concentration betweenzero and the sample-specific detection limit. The exactlevel is not measured. Assuming the true level is zerocould underestimate this release, but assuming it equalsthe detection limit could overestimate this release.Unless other data suggest that releases approximatehalf the detection limit, this analysis reports theamounts of undetected dioxins in the test as the laboratory reports them: at a level between zero and the sample-specific detection limit of the analysis.

17

5. Effect of sample volume collected on sensitivityof the analysis: examples for 2,3,7,8-TCDD.

Sample Amount Detectionvolume detected limit

WATER TESTS Li ters pg!L pg!LTosco effluent l - 1.3

Baltic Sea 1.500-2.200 0.00025 o.ooosAIR TESTS Cubic m e t ~ r s pgfm3 pgtm3

Chevron stack 112-162 - 1.16So. Cal. ambient 350-540 0.021 0.022

NOTES: average of sample-specific results; averagedetection limits exceed amounts detected due to higherdetection limits for some samples. m3=cubic meter.pg=picogram. L=liter. Data from references 32.48.49.50

4. Effect of sample v9lume collected on thepossible dioxins release that is not measured:examples from measurements of refineries.

TEQdetected0.13 pg!L

6.55 pg/LPossibleTEQreleased

Typical refinery effluent test: 88% of CDD/Fsbelow detection due to small sample volume.

TEQdetected0.78 pg/second

289 pg/secondPo ssibleTEQreleased

Refinery cracker stack tests: 90% of CDD/Fsbelow detection due to small sample volume.

TEQdetected0.07 pg!L

65.6 pg/LPossibleTEQreleased

Test of Cal. reformulated diesel directly fromrefineries: 94% of CDD/Fs below detection.NOTES: Data from references 32.38.48.


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A second problem stems from the choice to measure PCBs homologue groups (PCBs with thesame number of chlorine atoms), but not to measure individual dioxin-like PCBs. Refmeriescreate relatively large amounts of newly-formed PCBs, and some of these are dioxin-like PCBs.Assuming none of these PCBs are dioxin-like will underestimate TEQ0 FP released, and assuming all these PCBs are dioxin-like will overestimate releases. A better measurement is needed.Laboratory and field studies confirm the formationand release of dioxin-like PCBs from incinerators,cement kilns, and other sources.2,44,54,56,57Refinery sources create similar conditions for formation of dioxin-like PCBs as incinerators andcement kilns_7.22-25 This is reflected in the similarmix of specific CDD/Fs that is measured in thesesource types. Figure 5 shows that in all threesources: HpCDD and especially OCDD dominateamong CDDs; 1,2,3,4,6,7,8-HpCDF dominatesamong HpCDFs; 1,2,3,7,8,9-HxCDF is very low;other HxCDFs exceed HxCDDs; PeCDFs exceedPeCDD; and TCDF exceeds TCDD.In addition to these clear similarities, however, therefinery source produces more PeCDFs, HxCDFs,and HpCDFs than the other sources. Conditionsfavoring formation of CDFs also favor formation ofPCBs.23-25 This suggests that refineries may createmore dioxin-like PCBs than these other sources .In Figure 6, total PCB concentrations at a Bay Arearefinery and a municipal waste incinerator locatedelsewhere are compared. This homologue comparison shows a clear increase in the amount of PCBsrelative to CDD/Fs from the refinery. PeCBsinclude the most toxic dioxin-like PCB and make up13% of the total CDD/Fs and PCBs from the refinery source but only 3% of this total from the incinerator. HxCBs, which include the second most toxicdioxin-like PCB, make up 11% of the total from therefinery source versus 3% from the incinerator.Existing measurements show dioxin-like PCBsrange from 5-25% of total TEQ in municipal incinerators, and 60% of the total TEQ in cement kilnemissions.244,54,56,57 Greater PCBs and CDFs measured at the refinery source suggest PCBs are moreof the total TEQ from refineries than incinerators.This analysis reports the dioxin-like portion of PCBsreleases from refineries as I 0-60% of total TEQ.

18

5. Congener profiles: refineries and other sourcesIndividual CDD or CDF/total CDD+CDF

O.ll2 0.04 0.06 0.08 0.1 0.122.3 .7.8-TCDD

Refinery reformers1.2.3.7.8-PeCDD0 Municipal incinerators1.2.3.4.7 8-HxCDD

1.2.3.6.7.8-HxCDD D Cement kilns

1.2.3.7 .8.9-HxCDD

1.2.3.4 .7.8.9-HpCDF

:-;oTES: Data from references and 55.

6. Total PCBs profiles: refinery and incineratorPCB homologue/total CDD+CDF+PCB'

MonoCBsDiCBs

TriCBsTCBs

PeCBsbHxCBscHpCBs

OCBsNonaCBs

DecaCB

0 0.05 0.1 0.15 0.2 0.25~ Refi nery~ eforme r- - - - - - - ' Munic ipal0 incinerator---- '-'

.....

~~ O T E S : Each PCBs group (mono-chlorinated.etc.) is divided by the sum of total COOs, CDFs.:llld PCBs. CDD/ F portion of profile not shown.blncludes PCB-126. clncludes PCB-169.Dam from references 22 and 54.


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Error and bias related to test frequency and disclosure: On average, the Bay Arearefinery source releases that are tested at all are tested only a small fraction (one-ten thousandth)of the time that the releases are occurring. See Table 6. This is true despite relatively betterdioxins testing of Bay Area refinery releases than those elsewhere.

6. Timing of refinery dioxins releases and release testing in the Bay Area, June 1990-June 2000.Tested Cumulative Testsb Test Cumulative Portion ofsources release-days0 typeC test-days time tested

Effluent 6 21900.0 :!00 grab 0. 139 0.000006Storm runoff 5 912 .5 31 mix 0.354 0.000388Air emission 4 14600.0 12 composite 4.000 0.000274

Refined products - 0 -Totals 37412.5 4.493 0.000120

NOTES: acumulative days of release per source pathway over 10 years. Rain runoff set at 5% per year.bActual test number may be lower. Includes some water tests of combined refinery and non-refinery releases.58CGrab samples set at I minute duration; composite samples set at 8 hours: one runoff sample was a composite.Data from references 17,19,22,32,34,36,48,57,58.

A large variability exists in the concentration of dioxins in emissions. (See Table 7 ) Dioxinsrelease increased by 6.8 times in three consecutive days of testing at one Bay Area reformer. 22At the Chevron cracker, stack emissions detected on all three test days changed by four times. 32These tests on a few days show that releases at single sources change dramatically from day today, but they do not capture the full range of refinery release amounts.On a burn rate basis, releases vary by 20,000 times in two sets of tests at the Shell andEvergreen boiler/heater stacks.2,32,36,59 Emissions varied by 3,000 times between two sets oftests done on two reformer stacks at refineries in Avon and Bakersfield_4,22,55 Tests of othersources confirm similar hundred-fold to thousand-fold changes in dioxins emission rates.24-Z9,44

7. Variability in rate of dioxins release at refinery sources, and similar sourcesChange in Measurements compareddioxins release

6.8 times Stack tests of a Bay Area reformer on three consecutive days224 times Detected emission from three days at one refinery cracker stack32

300 times Average reformer process water at three refineries2020,000 times Emission/kg burned at two Bay Area refinery boiler/heaters_234,36,593,000 times Emissionlbbl from refinery reformers at Avon and Bakersfield4,22.5S

100-2,700 times Full scale tests of similar (non-refinery) processes during differentoperating conditions. grouped by process type27.29,44100-2,000 times Lab & pilot tests of a single boiler or incinerator that measured changesin chlorine, catalyst, heat distribution, & upsets (sooting)24-26,28

Further, the average that is directly measured may not represent the true long-term release, especially for stack tests. This is because existing tests taken during only a small fraction of the timethat releases occur may not measure a representative sample of overall releases. Lab- and pilotscale experiments show that variability in dioxins release (a hundred-fold or greater change, likethose shown in Table 7) can be caused by changes in process or chlorine input, catalyst activity,

19


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heat distribution in the process, and combustion efficiency.23-29 Even a relativelyminor 'upset' in combustion efficiencyincreased dioxins generation greatly forhundreds of hours afterward, because carbon buildup (sooting) continued to catalyze dioxins formation.26These conditions exist in refineries, asshown by the routine regeneration ofreformer and cracking catalyst needed toclean carbon deposits from process materials. In fact, frequent upsets in refineriessuggest that periods when these conditionsdo not exist may be the exception ratherthan the rule.Table 8 lists 41 incidents that were classified as "major" by Contra Costa Countyofficials at five refineries operating in theCounty from March 1989 to April 1997 -nearly one major spill, fire or explosionper refinery each year. In one case whereindependent analysis was performed (thefatal January 21, 1997 cracking unit fire atthe Tosco Avon plant), the process wasoperating inefficiently for much of theyear before the major incident.60.61Closer inspection of Table 8 reveals thatfor each plant, major upsets tend to begrouped around the same time. There wereother upsets that were no t classified as

8. "Major incidents" in Contra Costa refineries 1989-97.Plant County-classified "major" incident

3/25/89 Tosco Fatal lube oil sumo exolosion4/10/89 Chevr lsomax Unit explosion and fire9/5/89 Shell Hvdrotreater explosions and fire9/9/89 Paciti Pioe nioole break. soilJ and fire2/28/90 Shell Tank liner fire1/4/91 Shell LDU Lube Crude heater spill and fare4129/91 Tosco Relief valve hvdroeen sulfide soill to air10n9/91 Chevr Catalytic Cracking Unit fire12/5/91 Chevr Cracking Unit catalyst spill to air3/31/92 Pacifi Heat exchanger tube rupture and fire5/29/92 Pacifi Flare overload spill to air and homes6/23/92 Chevr Cracker pump failure. smoke release8112/92 Tosco Refinery fire trig,eers explosion9/20/92 Tosco Power failure and flarine soark fire12/11/92 Tosco Major flare odor release to air3n/93 Tosco Major butane/hydrocarbons spill to air4/1/93 Shell Sludge storaee tank explosion6/18/93 Tosco Hydrocarbon/hydroeen sulfide soillto air10/5/93 Shell Acid tank exQios ion and fireball

10n/93 Tosco Oil spill to Hastings Slough214/94 Pacifi Fire in crude oil tank seals2/10/94 Chevr Sulfur Recovery Unit spill to air3/30/94 Chevr Instrument & flare failure spill to air8/22194 Unoc 16-dav. I00-ton catacarb so ill to air9115/94 Unoc Compressor failure H2S spill to air619195 Tosco Heat exchaneer fire6116/95 Unoc Tank fire9/25/95 Tosco Boiler malfunction/ bvpass spill to air9/27/95 Pacifi Naotha and sulfur chemicals soill to air2/1196 Shell Hydrogen Unit explosion411/96 Shell Hydrot:reater explosion and fi re5117/96 Unoc Coker fire8/1/96 Pacifi Heavy vacuum eas spill to air8/10/96 Chevr Power outaee causes flare smoke8/16/96 Unoc Compressor malfunction. H2S to air

9/21196 Unoc Malfunction spills H2S to a1r9122196 Unoc Tank leak releases sulfuric acid1/21/97 Tosco Fatal hydrocracker explosion and fire2/17/97 Unoc Odor release traced to refinery4/13/97 Chevr Hydrocarbon and sour eas leak4/16/97 Tosco Hydrogen sulfide and S02 spill to air

"major incidents." Flaring- a sort of NOTES : Data from reference 45."safety valve" for the buildup of explosivegases in refineries62 - is an indirect mea-surement of such process problems.Data from special study of Bay Area refin- 9. Flaring by four Bay Area refineriesery flares are summarized in Table 9.Flaring was reported in all 18 monthsstudied, and the largest refineries flaredvirtually all the time. Major refineryprocesses could be involved in flaring forhours every month (as a per-process grandaverage), based on these data.62Upsets that could increase dioxins may beoccurring on a monthly basis in refineries.

Flare-hours Percent Hours/pro-per montha of time cesslmonthbChevron 338 46% 8

Shell (Martinez)c 989 100% 25Tosco (Avon)d 730 100% 18

Unocal (Rodeo)e 89 13% 2Totals 2146 100% 13

Notes: aReported for March 1988 through December 198961hAssumes 40 major process units/refinery. CNow Sheli/Equilon. dsale toUltramar announced in June, 2000. eNow Tosco. Data from reference 62.

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The effect of such minor upsets was reported this year from a controlled experiment that measured changes in total CDD/F formation and emission from an industrial boiler.26 Relativelypoor combustion efficiency was created by increasing the feed rate and slightly misaligning aburner nozzle for about 50 hours. This formed carbon deposits contaminated with chlorine anddioxins precursors and catalysts, that in tum created more dioxins with continued source operation long after the upset.26 As shown in Figure 7 stack release increased from 4 to 1,953 pglm3100 hours after the beginning of this upset, increased further (based on deposit testing) untilabout 250 hours after the beginning of the upset, and remained elevated for approximately 300hours after the upset ended. (Due to sampling and analysis considerations noted in the figure,the stack tests provide the best measurement of the extent of dioxins increase while the tests ofcarbon deposits in the unit provide the best measurement of its duration.)7. Timing and extent of dioxins source generation after upset in combustion efficiency.

2000r::: 1800 1600~ 1400~ 1200

10000 800!::::13 6000 400u 200

0

Hours of operation from beginning to end of tests0 100 200 300 400 500 6001,953 pgfm3 . , 1,840 ng/100 mg- , , ~ - Stack releases (pglm3)a- , ~,, , -- Carbon deposits- I ' , , (ng/100 mg)a- I ,,,

I- I- I ......- I ......-0 ng/100 mg I ...... ......- in deposits \ I ...

4pgfm3 . ~ ...... t- ......,in stack 'A .ACombustion Chlorine and metal zeroed out of nputs Chlorine and metalupset begins Combustion upset ends reintroduced

NOTES: as tack measurements analyzed by high resolution GC/MS more accurately reflect extent of emission; depo sit measurement s(measured by low resolution GC/MS in boiler pass 2) more accurately reflect emission duration while chlorine and metals source isinterrupted ( 150-560 hours) because stack measurements were not made during this period. Data from reference 2 6.

There is a clear bias in existing release measurements made only when releases tend to be smaller. The dioxins release tests that were taken were not taken during the major upsets at Bay Arearefineries. Also, the data in Figure 7 show that relatively clean operation for 300-400 hours (2-3weeks) results in a drastic drop in stack emission, and refiners always had this much advancenotice of stack tests. One refiner set up its own test with its contractor.36 The Bay Area AirDistrict began public discussions of the cracking and reforming unit tests that were negotiatedwith the other companies for months before these tests.32,22,34,63,64 Refinery management have astrong and explicit interest in being seen as "insignificant" sources of dioxins, as evidenced bythe energy Bay Area refiners have expended to to assert this point of view.65-72 Thus, there isno scientific basis for concluding that the few measurements taken represent an accurate averageof actual releases over time, because these measurements may instead represent the portion ofthe distribution of highly variable releases that was measured when releases were smaller.In sum, existing tests measure only during a small fraction of the time, and stack releases couldbe much smaller during these tests, because the tests are announced in advance and are taken attimes when the recent history of operating conditions could result in much less dioxins release.

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Therefore, this analysis measures dioxins release rates from Bay Area refinery stacks as follows .To account for the greater magnitude of these releases at times when they were not measuredwithout ignoring source-specif ic data, it applies a variability factor to the existing source-specific measurements. This variabili ty factor integrates (averages) the source-specif ic measurementsof (partial) variability, and the general measurements of the full variability due to minor upsetsshown in Figure 7. To account for the duration of greater releases than source-specific testsmeasured, given frequent process changes that are not distributed evenly over time (as reflectedby the lognormal distribution of industrial releases), this variability factor is calculated as themedian of the log-transformed source-specific and general data. For example:

Example of variability factor derivation for upper bound dioxins stack releases.a. Partial range of release at a Bay Area reformer (Table 7): Log of 6.8 times =b. Full range of release in controlled tests (from Figure 7): Log of 488 times =c. Median of log-transformed source-specific and general data:d. Median of log-transformed data, back-transformed from c above:(58 is the variability factor applied to source-specific release rate data for reforming.)

0.832.69l l i58

To account for the evidence suggesting that a sampling bias may skew the data from direct measurements of stacks toward a false "average" that underestimates releases, this analysis includesthese variability factors in upper bound stack release measurements for Bay Area refineries.Error and bias when there is no testing ofa known or suspected source. Asshown in part 1, there is strong evidence that several major refinery processes which have notbeen tested for dioxins, refinery products such as petroleum coke and furnace ash (used by otherindustries), and uncontrolled fires may cause additional dioxins releases from refineries. Indeed,dioxins releases are likely due to one or more of these suspected sources and products.

The failure of refinery monitoring programs to measure for releases from these sources andproducts results in measurement uncertainty. Though estimating possible dioxins releases fromthese sources is difficult, nevertheless, any assumption that such unmeasured releases do notexist would introduce a bias into release estimates which fails to account for this uncertainty.Since no measurements confirming these releases exist in the Bay Area or elsewhere, and it is atleast possible that these suspected sources are all free of dioxins, this analysis uses zero releasefrom these sources and products as the lower bound measurement of dioxins release from thesesuspected sources.To address the problem of uncertainty (and that of bias when it is assumed that sources whichare ignored do not exist), this analysis estimates possible upper bound dioxins release from suspected process sources and uncontrolled fires at refineries from data on refinery processes thathave been measured, using environmental data as a check on these estimates. The data andmethods are described in the analysis of other (suspected) refinery sources below.For upper bound releases from refined products suspected to contain dioxins (and motor oil aswell) this analysis applies the diesel release factor discussed below to distil late fuel production .

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Error and bias related to sampling of release pathways. No data on dioxins releasescaused by refinery contamination of diesel or motor oil exist from tests in the Bay Area, despitethe fact that both of these products are known to be contaminated with dioxins as they leaverefineries based on direct measurements in southern California. Nor are other products tested.This analysis measures the lower bound of dioxins release in products shipped from Bay Arearefineries using the measurements of diesel reported from southern California refineries and theestimates of Bay Area production of CARE reformulated diesel discussed in part 1. This lowerbound production estimate includes only diesel produced for on-road use in California, and doesnot include motor oil (known to be dioxins contaminated), other distillates, petroleum coke, orash shipped to cement kilns (suspected to contain dioxins). The upper bound of dioxins releaseaccounts for these possible releases in products using the diesel contamination data and the totaldistillate production rate estimated for Bay Area refineries.

ANALYSIS OF SOURCE-SPECIFIC MEASUREMENTS:

Reforming catalyst regeneration.There are six reforming units in Bay Area refineries that process an estimated 170,000 barrelsper day. Releases of dioxins from reformer stacks are estimated here. Since these releasesdeposit to land and water, and a portion of these releases enter rainstorm runoff from refineries,stack estimates include the amounts of refinery dioxin in refinery runoff (to avoid double-counting releases). Other reformer dioxins releases mix with other dioxins released into the combinedeffluent discharge and products from refineries, and are addressed below.Data from tests that measured stack releases from the Tosco Avon Refinery No.3 Reformer in1998 are shown in Table l, part 1 above. All 17 CDD/Fs as well as total PCB homologuegroups were detected in all three tests of this stack release. The CDD/F TEQ measured rangedby 6.8 times, averaged 2.69 ng/barrel and reached 5.51 ng/bbl in these tests. Dioxin-like releases are also reported from a reformer stack test at a Bakersfield refinery,55 but this test was conducted in 1991, did not detect all dioxins analyzed, and did not measure a Bay Area refinery.The partial range of release found in limited source-specific tests and the full range of releasefrom controlled experiments performed elsewhere yield a variability factor of 58 for this source,as shown in the example on the previous page. Thus, the range of release including dioxin-likePCBs (10-60% ofTEQ) is 2.96-770 ng/bbl. However, while the No.3 Reformer at Avon usescontinuous regeneration to process 31,500 bbl/d, the other five units process nearly 140,000bbls/day but may operate only about one week per year.47,17,20 A separate factor to account forreleases only 1/50th of the year must be applied to this portion of the source category.Therefore, the lower bound long-term dioxins release rate from this Bay Area source is 100 million picograms per day, and the upper bound of this release rate is 26.3 billion pg/day.Cracking catalyst regeneration.There are at least seven cracking units in Bay Area refineries that process an estimated 511,740barrels per day. 17 19 Releases of dioxins from cracker stacks are estimated here. These stackestimates include the amounts of dioxin in refinery runoff, to avoid double-counting releases.

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The amounts of cracker dioxins releases contributed to effluent discharge and products fromrefineries are addressed below.Data from tests that measured stack releases from the Chevron Richmond Refinery FluidCatalytic Cracking Unit in 1997 are shown in Table 3, part 1 above. Three CDD/Fs were detected in these tests. One test detected only one of the least toxic CDFs: using this result wouldunderestimate CDD/F TEQ present in that test and overestimate the range during testing.CDDIF TEQ ranged from 0.177 nglbbl when CDD/Fs are assumed present at half the detectionlimits in this test, to 0.535 nglbbl if dioxins are at their detection limits in the test measuring themost release in this refinery's 55,600 bbl/day cracking throughput. (The dioxin detected in alltests exhibits similar variability.) This is the only dioxins test reported for a refinery cracker.The partial range of release found in these limited source-specific tests (0.177 -0.535 nglbbl), andthe full range of release from controlled experiments performed elsewhere, yield a variabilityfactor of 38 for this source. Thus, the range of release including dioxin-like PCBs is 0.19 to50 .8 nglbbl. Applying these factors to the Bay Area production rate for this process source, thelower bound long-term dioxins release rate from this Bay Area source is 97.2 million picogramsper day, and the upper bound of this release rate is 26 billion pg/day.Oil- and waste-fired process heaters and boilers.These processes bum an estimated 40,000 to 160,000 barrels of oil, intermediates, petroleumwastes and/or petroleum fuels ranging from No. 2 fuel oil and heavier in Bay Area refinerieseach day, as discussed in part 1. Releases of dioxins from their stacks are estimated here. Thesestack estimates include the amounts of dioxin in refinery runoff to avoid double-counting thesereleases. Releases into effluent discharge and products are addressed below.Data from 1997 tests of stack releases from a process heater firing about 22.4 barrels of oil perday at the Evergreen Oil refinery in 1997 are shown in Table 4. Fourteen CDD/Fs were detectedin these tests. Analysis of these data suggests that CDD/Fs present below detection limits mayhave been present at half the detection limits, or at greater concentrations in these samples.CDDIF TEQ ranged from 27 to 29.8 pg/test when dioxins present below detection limits are setto half the detection limits in this test. Based on production and release rates, average CDD/FTEQ in these tests was 0.23 ng per liter of oil bumed.2,59 The Air Quality Management Districtestimated CDD/F releases of 0.007 pglkg of waste feed from tests of a boiler at the ShellMartinez plant, but these tests used older methods that did not detect dioxin-like CDD/Fs from aknown source type -waste incineration with electrostatic precipitation treatment234 - so thisresult is suspect. EPA reported dioxins releases ranging from 0.06 to 0.6 ng per liter of oilburned in boilers tested elsewhere.2This analysis uses the Bay Area source data from Evergreen Oil for the CDD/F emission tested(0.23 ng/L burned) and for source-specific variability data (27-29.8 pg/test). Combining thispartial range of release with the full range of release from controlled experiments performedelsewhere yields a variability factor of 23 for this source. However, the resulting release rate isnear the high end of the range reported by EPA, and this test may have been associated with relatively high chlorine in the feed.235 The variability caused by changes in the chlorine contentand rate of feed input at most refinery oil and waste-fired heaters and boilers may be significantly less than that found at the Evergreen process .2 For these reasons , many or most of these

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process sources may release dioxins at the rate measured by these source specific tests ratherthan the greater (upperbound) rate measured by the variability factor.Thus, the range of release rate including PCBs is 0.53-13.23 ng/L burned, but the smaller value(0.53 ng/L) defines the lower bound possible release (sources burning 40,000 bbVday) and 80%of the upper bound of possible release (sources burning 160,000 bbVday) for these processes.Therefore, oil- and waste-fired refinery processes release more than a lower bound of 1.61 billion pg/day, and less than an upper bound of 72.4 billion pg/day in the Bay Area.Contamination of refined products in refineries.Bay Area refineries produce 80,000 bbVday of CARB reformulated diesel and 136,000 bbl/dayof total distillates (which includes diesel and other products).17-19 Some of the dioxins formedby refinery sources leave these refineries in diesel. Dioxins contamination of motor oil inrefineries is confirmed as well, and evidence suggests contamination of petroleum coke, furnaceash, and/or other refined products. Evidence for these conclusions is discussed in part 1 above.Data from tests that measured diesel from southern California refineries in 1998 are shown inTable I 0. OCDD was found in both samples at high concentrations. Other CDD/Fs were belowthe high detection limits of these analyses. The analysis in Table 10 shows that the true concentration of CDDIF TEQ in the diesel was between 0.72 and 302 picograms per liter, however, it isprobably well within this range.Diesel, motor oil and other distillates probably contain all the dioxin compounds produced in refineries, because dioxins have high affinity for fats andoils, and move into the oil content of these products upon contact in refinery sources. This likelypresence of many dioxins means that the relativelyhigh detection limits in the diesel analyses presentan artificially expanded range of possible TEQ inthese samples. The best estimate of the averagedioxins present in this product based on data inTable I 0 is represented by the narrower measurement range of 0.14 to 65 .6 pg/L CDD/F TEQ.Dioxins are confirmed in known amounts of reformulated diesel production, and are confirmed orsuspected in other distillates (including diesel andother products). The lower and upper bounds ofrelease use reformulated diesel, and total distillate,production rates, respectively. Including PCBs,these lower and upper bounds of release in refinedproducts are 1.96 million and 3.5 billion pg/day.

25

I 0. CDD/Fs in diesel leaving California refineries.CARB Pre-

In picograms reformula 1993per liter TEP ted diesel diesel

2.3.7.8-TCDD I sob (26> BD (100)1.2.3,7,8-PeCDO I BO (21) 80(89)

1,2,3,4,7,8-HxCDD 0. 1 BO (21) BD ( 110)1,2,3,6,7,8-HxCDO 0.1 BO (23) BO (120)I 2,3,7 8,9-HxCDD 0.1 BD (20) BO (110)

1.2,3,4,6.7.8- 0.01 BO (47) BO (230)OCDO 0.0001 720 1400

2,3,7.8-TCOF 0.1 BO (II) 80(21)1,2,3,7.8-PeCDF 0.05 80 (8. 1) BD (110)2,3,4,7 8-PeCDF 0.5 BD (II) BO (100)

I 2.3,4,7 8-HxCDF 0.1 BD (6.4) BD (36)l ,2,3,6,7 8-HxCOF 0.1 BD(6.l) BO (34)2,3,4,6,7,8-HxCDF 0.1 BO (17) BD (66)l ,2,3,7 ,8,9-HxCDF 0.1 BD (7.5) BD (36)

1,2,3,4,6,7,8- 0.01 BD (48) BO (92)1.2,3,4,7,8,9- 0.01 BO (50) BO (98)

OCDF 0.0001 BD (4 1) BD (260>TEQ(BD=O) 0.072 0. 14

TEQ(BD=OL) 65.6 302NOTES: aToxicity equivalence factor.bsetow detection (detection limit). Data from reference 38.

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Contamination of effluent in refineriesAt least five Bay Area refineries discharge an average of 77 million liters per day of partiallytreated waste water into San Francisco Bay. Some of the dioxins released by reforming andother refinery dioxins sources are discharged in these effluents.On average, less than 20% of CDD/Fs analyzed were detected in dozens of one-liter grab samples of refinery effluent. The more toxic CDD/Fs were seldom or never detected in final refinery effluents due to the small volumes of samples analyzed, but these dioxins are known to bedischarged below detection limits because they are confirmed by tests of internal waste water inrefineries,20.21 and in discharge canal sediment of one of the plants.73 Analysis of these datasuggests that dioxins below detection limits in these effluents may be present at levels near orbelow one-half the reported detection limits.On the Hook for Zero Dioxin reported average CDD/F TEQ in refinery effluent at 0.88 pg/Lwith below detection results set to zero, and 7.86 pg/L with these results set to hal f the detectionlimits of the analyses.2 Including PCBs this yields a discharge rate of 74.5 million to 1.5 billionpicograms per day. The low end of this range is six times greater the Regional Water Boardstaff estimate of this discharge rate (0.4 grams per year of CDD/F TEQ, or 12.1 million pg/dayincluding PCBs as 10% of TEQ). Expanding the range of this estimate at its lower bound toencompass this analysis, the lower and upper bounds of Bay Area refinery dioxins releases ineffluent are 12.1 million and 1.5 billion pg/day, respectively.Other (suspected) refinery sourcesThe strong evidence suggesting dioxins generation and release due to flaring, coking, distillation, desalting and/or uncontrolled fires in refineries establishes a need to address the uncertaintycaused by failure to measure these suspected sources by estimating some upper bound of theirpossible releases.However, too little data exist for any detailed analysis of any of these individual source types.For example, structure and vehicle fire data are too uncertain for confident release estimates tobe extrapolated to refinery fires,4 and doing so produces a result that is orders of magnitudeabove existing estimates of total dioxins releases in the Bay Area.34 Even though these existingestimates by the regional Air District have been criticized (correctly) for underestimation, therefinery fires estimate extrapolated from these data also approaches an amount that may not besupported by observed dioxins levels in the Bay Area environment. While this suggests a possibility of catastrophic dioxins contamination fromfuture refinery fires, it does not suggest theseextremely high levels of dioxins release are already occurring from refinery sources.Given evidence that one or more of these many suspected sources may form and release dioxins,and evidence suggesting that these releases are unlikely to exceed upper bound releases fromconfirmed sources by orders of magnitude, the best estimate based on existing data would compare possible releas

cbe report - dioxins and refineries (scanned)

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