oilfield pits & arsenic usage, louisiana

Oilfield Pit Groundwater and 1950sOilfield Pit Groundwater and 1950sArsenic Corrosion Inhibitor Usage, LakeArsenic Corrosion Inhibitor Usage, LakeSt. John Field, LA: Possible Causes &St. John Field, LA: Possible Causes &Models for Arsenic and Iron PatternsModels for Arsenic and Iron Patterns

Mary L. Barrett, Ph.D.Mary L. Barrett, Ph.D.Consulting Geologist & Oilfield HistorianConsulting Geologist & Oilfield Historian

Professor Emeritus of GeologyProfessor Emeritus of GeologyCentenary College of LouisianaCentenary College of Louisiana

Shreveport, LAShreveport, [email protected]@centenary.edu

1010thth Annual Louisiana Groundwater, Surface Water and Water ResourcesAnnual Louisiana Groundwater, Surface Water and Water ResourcesSymposiumSymposium

Louisiana State UniversityLouisiana State UniversityMarch 24March 24--25, 201625, 2016

Oilfield pit groundwater and 1950s arsenic corrosion inhibitorusage, Lake St. John Field, LA: possible causes and models forarsenic and iron patterns

Mary L. Barrett, Department of Geology & Geography, Centenary College ofLouisiana, Shreveport, LA 71104: [email protected]

EXTENDED ABSTRACT

At the Lake St. John (LSJ) Field, Concordia Parish, LA, dissolved arsenic in shallowgroundwater (8 ft to 22 ft below ground surface) occurs in former emergency pit areas associatedwith tank batteries and with the saltwater injection disposal system. This study uses publically-available geochemical and historic oilfield records to examine the possible origins of elevatedgroundwater arsenic in three oilfield pits. The study area is composed of two leases historicallyknown as the Applegate lease and the Pan American Insurance Company lease. They weredeveloped and produced beginning in 1942 by the California Company (Standard Oil ofCalifornia, later Chevron). Both lease areas, in part, have been involved in modernenvironmental oilfield (legacy) litigation under LA Act 312 legislation initially passed in 2006.This legislative act requires involvement and cleanup oversight (along with the court system) bythe Louisiana Office of Conservation (LA OOC) in legacy environmental lawsuits. Thelegislation has resulted in a large and rapidly-growing public record of high-quality geochemicalmeasurements of various media (groundwater, sediment/soil, solid and liquid wastes) performedby state-certified laboratories. The records (both case files and occasional hearing files) includepaper and digital copies and are available at the LA OOC office in Baton Rouge, LA. The LAOOC collections of Lake St. John field litigation are used extensively in this study. Geochemicaldata were collected by the environmental companies/experts of Pisani & Associates, ICON, andGeosyntec Consultants.

The three studied pits were used in the 1950s – 1980s as emergency pits (periodic usage) andwere initially closed in the mid- to late-1980s. The study area and the field are located on theMississippi River alluvium. The clayey upper section varies from less than 5 ft to over 15 ft inthickness in the study area. The pits were about 6 ft deep. The lowest dissolved arsenic valuesoccur at the Applegate (tank battery) pit area, and values range from non-detect to 0.13 mg/l.Part of this pit’s base was in sand. The highest dissolved arsenic values occur at the PanAmerican (tank battery) pit area, and values range from non-detect to 0.915 mg/l. This pit’s basewas underlain by a few feet of clayey sediment. The Wilcox pit was an emergency pit for thesaltwater disposal (SWD) well system, and its dissolved arsenic values range from non-detect upto 0.517 mg/l. This pit’s base was underlain by clayey sediment, also.

Two models have been put forth in the public record to explain elevated shallow groundwaterarsenic patterns at the LSJ Field. The first model, a reductive-dissolution model, was put forwardby Geosyntec Consultants (2008a, b, c) based on groundwater sampling of one pit six monthsafter pit re-closure (the Applegate pit, first closed about 1984, re-closed 2007). The Geosyntecwork has been submitted to the LA OOC records from 2008 through March of 2015. In thismodel, reducing groundwater conditions related to oily pit wastes or other organics result in

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adsorbed natural arsenic being released into solution when oxidized iron and manganese speciesare dissolved. Expected groundwater model conditions include low oxidation-reduction potential(ORP) measurements, and elevated arsenic and elevated iron wholly due to solids dissolution.

Published Louisiana studies indicate that sediment redox conditions influence solubility ofarsenic and iron, and this is expected to influence dissolved metal amounts in naturalenvironments (Guo and others, 1997; Miao and others, 2006). But, some dissolved groundwaterarsenic below the LSJ field pits is elevated above Pisani & Associates’ interpretation of 0.12mg/l as the highest naturally-occurring dissolved arsenic value, and the pit values are also abovea documented 0.10 mg/l measurement in shallow Mississippi River alluvium groundwater awayfrom the oil field.

The second model was put forward by the author in meeting presentations beginning in Octoberof 2014, and it relies on the geochemical data from the three sampled pits (2006-2015) and thehistoric record of arsenic corrosion inhibitor usage in the LSJ field. W-41, a patented arsenic-based corrosion inhibitor of Standard Oil of California, was added to well brines and circulatedthrough LSJ field’s unit and lease production systems prior to well injection and disposal in the1950s. Organic-based (no metals) corrosion inhibitors were being used by the early 1960s.

Oilfields require consideration of all possible anthropogenic sources for arsenic, especiallyarsenic-based corrosion inhibitors and arsenic-based herbicides. Arsenic was used to inhibitcorrosion in oilfield flow systems in two ways: 1) as a production corrosion inhibitor dissolvedin circulating oilfield waters and used in U.S. fields in the 1950s (Hill and Davie, 1955) and inthe Gulf Coast oilfields from 1949 to at least the late 1950s (Jones, 1955; LA Stream ControlCommission, 1957; Gardner, 1963); and 2) as an acid corrosion inhibitor, used in acid welltreatments from the mid-1930s into the 1970s. Patents held by Standard Oil of California on thearsenic-based production corrosion inhibitor stated a preferred dissolved arsenic concentration inproduced water at 5 ppm after introduction of 10 to 50 ppm at a well, depending on corrosiontreatment requirements (calculated as arsenous oxide) (Rohrback and McCloud, 1953; Frisius,1959).

Examples of forgotten knowledge about arsenic-based corrosion inhibitors are publications ofthe American Petroleum Institute (API)—while a paper published in 1955 described arsenic-based corrosion inhibitor usage in California fields (Hill and Davie, 1955), publications of 1998and 2011 did not list this previous arsenic usage as a possible anthropogenic source (API, 1998,2006). Past arsenic-based herbicide and corrosion usages are also documented in U.S. oilfieldsby veterinary studies of poisoned cows (Edwards and others, 1979; Morgan and others, 1984;Coppock and others, 1996).

Dissolved iron and chlorides are also elevated in the LSJ field pits’ groundwater. Both old LSJfield brine analyses and published general oilfield corrosion studies indicate that elevateddissolved iron is common in produced brines due to corrosion. The observed geochemicalpatterns around the heavily-sampled Pan American pit indicate that relative ion mobility in thegroundwater is chlorides > iron > arsenic. The ORP values below the pit are slightly reduced ascompared to nearby monitoring wells, but elevated pit groundwater arsenic or iron does not varywith ORP. Highest arsenic and iron values are associated with chlorides.

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The Applegate pit, first closed in 1984, was sampled sporadically from 2007 to 2015. The lowestdissolved arsenic measurements at the pit were in 2008, 6 months after the Applegate pit was re-closed. Arsenic values suggest an apparent relationship to not only ORP and iron, but also toconductivity (salinity). The 2008 sampling event is interpreted as impacted by the pit re-closure.The groundwater sampling from 2012-2015 contained elevated arsenic and elevated chlorides bythe pit, similar to what was present in initial 2007 sampling prior to pit re-closure.

The Geosyntec reductive-dissolution model depends on the presence of oily waste or otherorganics in an oilfield setting and no anthropogenic sources of arsenic and iron. Publically-available oilfield geochemical data in Louisiana oilfields do not show a common pattern of oilywastes (in pits or otherwise) to elevated dissolved arsenic. This model may be limited in itsability to explain elevated arsenic in old oilfield pits. However, if the elevated groundwaterarsenic is related to the 1950s usage of arsenic corrosion inhibitors, then prediction of otherpotentially-impacted areas is easier. In the LSJ Field, tank battery pits and saltwater disposalwell pits of the 1950s operated by the California Company will be of interest.

A 1955 document addressing SWD wells at LSJ field stated that W-41 circulation fromproduction wells controlled corrosion for the SWD wells, indicating that both the unit and non-unit (lease) production systems of the California Company circulated W-41. Thus, the 1950stank battery pits and the saltwater well (SWD) pits are expected to have been exposed to wastesaltwater elevated to different amounts with dissolved arsenic corrosion inhibitors. Oilfieldmaps and historic aerial photography of 1955, 1959 and 1960 were used to find and map the tankbattery and SWD well pits. Other pits were also noted (reserve/drilling pits, well/burn pits, high-pressure gas blowdown pits), but these individual well-associated pit types are less-likely tocontain a large saltwater impact. These other pits were not mapped as probably having anelevated arsenic signature related to 1950s production wells producing saltwater.

SELECTED REFERENCES

American Petroleum Institute, 1998, Arsenic: chemistry, fate, toxicity, and wastewater treatmentoptions; API Publ. no. 4676, prepared under contract by EA Engineering, Science, &Technology, Inc., 193 pp.

American Petroleum Institute, 2011, API groundwater arsenic manual: attenuation of naturally-occurring arsenic at petroleum impacted sites; API Publ. no. 4761, prepared under contract byERM, Inc., 98 pp.

Barrett, M. L., 2014, Historic oilfield arsenic sources: implications for pit groundwater models;21st International Petroleum Environmental Conference, Oct. 14-16, Houston, TX, presentation<http://ipec.utulsa.edu/Conf2014/Full_Manuscripts_Presentations_Speech/Barrett.pdf>Accessed March 20, 2015.

California Spray-Chemical Corporation, 1952, Ortho W-41; U. S. Patent Office, trade-markserial no. 71629474, application dated 5-10-1952, registered 12-09-1952.

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Coppock, R. W., M. S. Mostrom, E. L. Stair, and S. S. Semalulu, 1996, Toxicopathology ofoilfield poisoning in cattle: a review; Veterinary and Human Toxicology, v. 38, p. 36-42.

Edwards, V. C., R. W. Cappock, and L. L. Zinn, 1979, Toxicoses related to the petroleumindustry; Veterinary and Human Toxicology, v. 21, p. 328-337.

Frisius, E. N., 1959, Inhibitor solution, and method of inhibiting oil well corrosion therewith; U.S. Patent no. 2885359, filed 10-12-1954, patented 5-5-1959.

Geosyntec Consultants, 2008a, Groundwater characterization work plan, former June Bug(Applegate) pit, Concordia Parish, LA, April 2008; LA Office of Conservation Tensas-Poppadochearing docket no. ENV 2001-L-1, Chevron exhibits v. 12, C202-0001 to -0032.

Geosyntec Consultants, 2008b, Groundwater characterization report, former June Bug(Applegate) pit, Concordia Parish, LA, July 2008; LA Office of Conservation Tensas-Poppadochearing docket no. ENV 2001-L-1, G. Miller reliance documents, v. 28, P-EX-1085, p. 198-424.

Geosyntec Consultants, 2008c, Groundwater characterization report, review and summary,former June Bug (Applegate) pit, presentation slides, July 2008; LA Office of ConservationTensas-Poppadoc hearing docket no. ENV 2001-L-1, Chevron exhibits v. 18, C217-0001 to -0013.

Gardner, G. S., et al., 1963, Inhibitor composition and method of inhibiting acid attack on metalin acidizing of wells; U.S. patent no. 3094490, filed 12-27-1960, patented 6-18-63.

Ghosh, R., et al., 2003, Geochemistry, fate and transport of dissolved arsenic in petroleumhydrocarbon-impacted groundwater; National Groundwater Assoc., Proceedings, 20th Conf.,Costa Mesa, CA, Aug. 19-22, 2003, pg. 266-280.

Guo, T., R. D. DeLaune, and W. H. Patrick, Jr., 1997, The influence of sediment redox chemistryon chemically active forms of arsenic, cadmium, chromium, and zinc in estuarine sediment;Environment International, v. 23, p. 305-316.

Hill, P. W., and F. E. Davie, 1955, Corrosion treatment of pumping wells in California, inDrilling and Production Practice, 1954; New York, American Petroleum Institute, p. 181-186.

Jones, E. N., 1955, The corrosion problem in the Wilcox trend of Texas, in Proceedings, 8th OilRecovery Conference, April 4-5, 1955, Texas Petroleum Research Committee, Bull. no. 44, p.257-269.

Klinchuch, L. A., et al., 1999, Does biodegradation of petroleum hydrocarbons affect theoccurrence or mobility of dissolved arsenic in groundwater? Environmental Geosciences, v. 6, p.9-24.

Louisiana Office of Conservation, Baton Rouge, oilfield cleanup files, OC Legacy Project no.006-007, Tensas-Poppadoc property (Applegate and Wilcox pits), Lake St. John Field.

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Louisiana Office of Conservation, Baton Rouge, oilfield cleanup files, OC Legacy Project no.007-007, Tillman property (Pan American Life Insurance pit), Lake St. John Field.

Louisiana Office of Conservation, Baton Rouge, Tensas-Poppadoc, Inc., et al., vs. ChevronU.S.A., Inc., et al., hearing and file records of Docket no. ENV 2008-L-01 (hearing of Feb. 9-13,16, 2009).

Louisiana Stream Control Commission, 1957, Proceedings of minutes, June 13, 1957; LDEQ-EDMS Doc. no. 2986904, p. 40-41 (available at edms.deq.louisiana.gov/app/doc/querydef.aspx).

Miao, S., R. D. DeLaune, A. Jugsujinda, 2006, Influence of sediment redox conditions onrelease/solubility of metals and nutrients in a Louisiana Mississippi River deltaic plainfreshwater lake; Science of the Total Environment, v. 371, p. 334-343.

Morgan, S. E., G. L. Morgan, and W. C. Edwards, 1984, Pinpointing the source of arsenicpoisoning in a herd of cattle; Veterinary Medicine, v. 79, p. 1525-1528.

Rohrback, G. H., D. M. McCloud, and W. R. Scott, 1953, Corrosion inhibitor containingarsenous oxide and potassium hydroxide; U. S. patent no. 2636000, filed 12-22-1951, patented 4-21-1953.

Rohrback, G. H., and D. M. McCloud, 1953, Method for inhibiting corrosion; U. S. patent no.2635698, filed 3-16-1951, patented 4-21-1953.

Rohrback, G. H., D. M. McCloud, and W. R. Scott, 1954, Corrosion inhibitor; U. S. patent2684332, filed 12-29-1950, patented 7-20-1954.

Rohrback, G. H., et al., 1954, Corrosion inhibiting composition; U. S. patent 2684333, filed 12-29-1950, patented 7-20-1954.

Shock, D. A., and J. D. Sudbury, 1954, Corrosion control in gas lift wells, part II, evaluation ofinhibitors; Corrosion, v. 10, Sept. 1954, p. 289-294.

U. S. Environmental Protection Agency, 1973, Recommended methods of reduction,neutralization, recovery or disposal of hazardous waste, volume VI; EPA-670/2-73-053-f,August 1973.

Welch, H. L., et al., 2010, Occurrence of phosphorous in groundwater and surface water ofnorthwestern Mississippi; Proceedings, Mississippi Water Resources Conf., Nov. 3-5, 2010, BaySt. Louis, MS, p. 142-155.

Yang, N., et al., 2014, Predicting geogenic arsenic contamination in shallow groundwater ofSouth Louisiana, United States; Environmental Science & Technology, v. 48, p. 5660-5666.

Public Record Usage for InterpretationsPublic Record Usage for Interpretations

The Lake St. John Field, LA, has a large public recordThe Lake St. John Field, LA, has a large public recordavailable due to litigation (four cases settled 9/2014; courtavailable due to litigation (four cases settled 9/2014; court& OOC hearing records in one case)& OOC hearing records in one case)This is primarily due to LA Act 312 (2006+) & LA Office ofThis is primarily due to LA Act 312 (2006+) & LA Office of

Conservation (OOC) cleanup oversight of oilfield litigationConservation (OOC) cleanup oversight of oilfield litigation““legacylegacy”” sites (investigation & closure reports addressingsites (investigation & closure reports addressingOrder 29Order 29--B and RECAP standards; raw data; hearingB and RECAP standards; raw data; hearingrecords w/ historic field records)records w/ historic field records)I was a defense expert retained in two cases thatI was a defense expert retained in two cases thatgenerated public records; geologist, oilfield historiangenerated public records; geologist, oilfield historian(environmental companies responsible for analytical data:(environmental companies responsible for analytical data:ICON;ICON; PisaniPisani & Assoc., some& Assoc., some GeosyntecGeosyntec))Work on the last case ended Feb. 2014; I have pursuedWork on the last case ended Feb. 2014; I have pursuedthis research since then, not retained concerning it, nothis research since then, not retained concerning it, nodiscussions with past litigation experts (my opinions)discussions with past litigation experts (my opinions)

Presentation ObjectivesPresentation ObjectivesLake St. John Field, Concordia/TensasLake St. John Field, Concordia/Tensas

Parishes, LAParishes, LA

Update my IPEC 11/2015 talk with additional public regulatory daUpdate my IPEC 11/2015 talk with additional public regulatory datatafrom two litigation (settled 9/14) lease production sites (Applefrom two litigation (settled 9/14) lease production sites (ApplegategateOOC # 007OOC # 007--006; and Pan American Life Insurance OOC #007006; and Pan American Life Insurance OOC #007--007)007)Consider multiple hypotheses for origin of elevated shallowConsider multiple hypotheses for origin of elevated shallowgroundwater (GW) arsenic (As), iron (Fe) and chlorides (groundwater (GW) arsenic (As), iron (Fe) and chlorides (ClCl) below) belowpitspitsArsenic (as corrosion inhibitor) was used in the 1950s field; cArsenic (as corrosion inhibitor) was used in the 1950s field; consideronsiderhow this knowledge is important as a model of arsenic impact arehow this knowledge is important as a model of arsenic impact areasasConsider if data (as of 9/15) reasonably support a 2008 reductivConsider if data (as of 9/15) reasonably support a 2008 reductivee--dissolution GW pit model to partially or completely explain elevdissolution GW pit model to partially or completely explain elevatedatedarsenic patternsarsenic patternsAdd another litigation (settled 9/14) area (Wagoner OOC # 006Add another litigation (settled 9/14) area (Wagoner OOC # 006--001)001)where no groundwater wells, just soil data within old pits. Compwhere no groundwater wells, just soil data within old pits. Compare toare topreviouslypreviously--studied pits and related LSJ Field arsenic & pit historystudied pits and related LSJ Field arsenic & pit history

Study AreasStudy Areas

(Modified from Pisani & Associates report, 2008;LA OOC file # 006-007)

Lake St. John Field ExamplesLake St. John Field Examples

Discovered in 1942, Tensas & Concordia Parishes, LADiscovered in 1942, Tensas & Concordia Parishes, LA

Major producing field for The California CompanyMajor producing field for The California Company(Standard Oil of CA, later Chevron); lease & unit operator(Standard Oil of CA, later Chevron); lease & unit operator

Lease production impacts (Applegate & Pan AmericanLease production impacts (Applegate & Pan Americanexamples, Wilcox Fm mainly) have the most modern dataexamples, Wilcox Fm mainly) have the most modern data

Unit production example (Wagoner example, CretaceousUnit production example (Wagoner example, Cretaceous& some Tertiary age) has modern soil geochemical data& some Tertiary age) has modern soil geochemical dataonlyonly

Outline of field study interpretationsOutline of field study interpretations–– Public records indicate 1950s arsenic corrosion inhibitor usagePublic records indicate 1950s arsenic corrosion inhibitor usage in leasein lease

and unit systemsand unit systems

–– Examine modern groundwater geochemistry around old lease emergenExamine modern groundwater geochemistry around old lease emergencycypit areas; interpreted as arsenic corrosion inhibitor impactpit areas; interpreted as arsenic corrosion inhibitor impact

–– Look at Wagoner unit example and closure; probable shallowLook at Wagoner unit example and closure; probable shallow gwgw impact?impact?

Basic Model: Reductive Dissolution of Iron OxidesBasic Model: Reductive Dissolution of Iron Oxides

Fe oxides common in ourFe oxides common in ourLA sedimentLA sediment

As released into GW withAs released into GW with““reductive dissolutionreductive dissolution””when some cause for awhen some cause for areducing environmentreducing environment(organics, oil, clay(organics, oil, clay……))

Fe oxides reFe oxides re--precipitate asprecipitate asGW move into oxidizingGW move into oxidizingzone, rezone, re--absorb Asabsorb As

Model looks for relationsModel looks for relationsbetween ORP, Fe, Asbetween ORP, Fe, As

Does not addressDoes not addressanthopogenicanthopogenic As, FeAs, Fe

Does not address AsDoes not address Asdesorption (phosphates)desorption (phosphates)

(Diagram modified frompetroleum refinery & oil spillexample, Ghosh et al., 2003)

Groundwater Arsenic GeochemicalGroundwater Arsenic GeochemicalModels & Oil Field SitesModels & Oil Field Sites

TheThe GeosyntecGeosyntec 2008 reductive2008 reductive--dissolution model/reportdissolution model/reporthas been submitted to the OOC public record from 2008has been submitted to the OOC public record from 2008--2015 by defendant environmental experts2015 by defendant environmental experts

This and published arsenic models are useful, but mustThis and published arsenic models are useful, but mustconsider Gulf Coast oilfield regions of different geology &consider Gulf Coast oilfield regions of different geology &hydrogeology, and oilfield knowledgehydrogeology, and oilfield knowledge

WasteWaste ““oilfield chemistryoilfield chemistry”” has a history, & pits oftenhas a history, & pits oftenrecord this historyrecord this history

Any oilfield groundwater model which uses naturallyAny oilfield groundwater model which uses naturally--dissolved iron & arsenic must consider their possibledissolved iron & arsenic must consider their possibleanthropogenic sources as wellanthropogenic sources as well

Amorphous Iron Precipitates: Long History of Study inAmorphous Iron Precipitates: Long History of Study inOilfield Chemistry (Hydrous ferric oxidesOilfield Chemistry (Hydrous ferric oxides——HFOsHFOs))

1950s Oilfield Water Treatment (Powell & Johnson, 1952)

Iron Analyses, LSJ Field Produced WaterIron Analyses, LSJ Field Produced Water

1945 analysis, 141945 analysis, 14 ppmppm ((ClCl 13,82013,820 ppmppm))



1995 analysis, 21 mg/l (1995 analysis, 21 mg/l (ClCl 59,44959,449 ppmppm))

GENERAL OBSERVATION: Many oil fields had decades (into1970s, esp.) of elevated dissolved iron in produced water, and thuspotentially into pits

(LA OOC, Tensas Poppadoc hearing files, 2009;

Norman reliance documents, v. 52-53)

Historic Arsenic Uses/Contaminants w/Historic Arsenic Uses/Contaminants w/Potential Environmental SignaturesPotential Environmental Signatures

PesticidesPesticides

–– Concordia Parish cotton, 1910+Concordia Parish cotton, 1910+

–– Vegetable gardens, treesVegetable gardens, trees

–– Cattle dipping vatsCattle dipping vats

HerbicidesHerbicides–– Inorganic & organicInorganic & organic

–– Land & aquatic weed killerLand & aquatic weed killerOilfield usage documented byOilfield usage documented byveterinary studies of cow poisoningveterinary studies of cow poisoning

IndustrialIndustrial

–– Corrosion inhibitorCorrosion inhibitor

–– Oilfield waste (produced water,Oilfield waste (produced water,barite mud sulfide impurities, oil,barite mud sulfide impurities, oil,……))

–– Detergents, fertilizersDetergents, fertilizers(phosphorous)(phosphorous)

–– OtherOther

Griffin presentation onoilfield legacy litigation (2006)

OilFieldOilField Arsenic Corrosion InhibitorsArsenic Corrosion InhibitorsHistoric U. S. SummaryHistoric U. S. Summary

Acid Corrosion InhibitorAcid Corrosion Inhibitor

–– 19321932, Michigan oilfield acid, Michigan oilfield acidjob, limestonejob, limestone

–– 19341934, arsenic is important acid, arsenic is important acidjob inhibitor, but organics nowjob inhibitor, but organics nowavailableavailable

–– Early 1960sEarly 1960s, decrease As, decrease Asusage, but good for highusage, but good for high--TTwellswells

–– In 1970sIn 1970s, arsenic inhibitor, arsenic inhibitorphasephase--out in acid jobsout in acid jobs

Production Corrosion InhibitorProduction Corrosion Inhibitor–– 19491949, Reported first usage in, Reported first usage in

Wilcox of Texas (Jones, 1955)Wilcox of Texas (Jones, 1955)–– 19501950, LSJ Field considers As, LSJ Field considers As

–– 19541954, CA survey, 17 fields;, CA survey, 17 fields;65 % pumping wells used65 % pumping wells usedinorganic inhibitors (arsenicalinorganic inhibitors (arsenicalcompounds and chromates)compounds and chromates)(Hill & Davie, API, 1955)(Hill & Davie, API, 1955)

–– 19551955, LSJ Field using As, LSJ Field using As–– 19571957, LA Stream Control, LA Stream Control

Commission minutes reportCommission minutes reportphasephase--out of oilfield arsenicout of oilfield arseniccorrosion pellets, strippercorrosion pellets, stripperfieldsfields

–– 19601960, general end of U. S., general end of U. S.oilfield arsenic corrosionoilfield arsenic corrosioninhibitors (Gardner, 1963);inhibitors (Gardner, 1963);move to organicsmove to organics

Iron & 1950s Arsenic Inhibitor in ProducedIron & 1950s Arsenic Inhibitor in ProducedWater (Wilcox Trend, Texas)Water (Wilcox Trend, Texas)

Jones (1955)(Jones, 1955)

LSJ Field Public Documents, ArsenicLSJ Field Public Documents, ArsenicCorrosion InhibitorsCorrosion Inhibitors

(LA OOC Tensas Poppadoc hearing, 2009; Miller/ICONreliance documents, v. 28;Tensas/Miller 02469-02470)

WW--41 History41 History

WW--41, an arsenic corrosion inhibitor patented by41, an arsenic corrosion inhibitor patented byStandard Oil of CA, is one example of arsenicStandard Oil of CA, is one example of arseniccorrosion inhibitors used in some 1950s oilfields ofcorrosion inhibitors used in some 1950s oilfields ofthe U.S.the U.S.

Its history is available in public documents.Its history is available in public documents.

WW--41 History41 History

California ResearchCalifornia ResearchCorpCorp (As & oilfield corrosion)(As & oilfield corrosion)

–– Dec 1950, 2 patents,Dec 1950, 2 patents,RohrbackRohrback et al (1954)et al (1954)

–– Mar 1951, 2 patents,Mar 1951, 2 patents,

RohrbackRohrback et al (1953)et al (1953)

–– Dec 1951, patent,Dec 1951, patent,

RohrbackRohrback et al (1953)et al (1953)

–– Oct 1954, patent,Oct 1954, patent,

FrisiusFrisius (1959)(1959)

California SprayCalifornia Spray--Chemical CorpChemical Corp

–– 1952, trademark1952, trademarkapplication granted forapplication granted for““Ortho WOrtho W--41,41,”” also used isalso used is““WW--41,41,”” for arsenicfor arseniccorrosion inhibitor (42 %corrosion inhibitor (42 %sodiumsodium arsenitearsenite) (EPA,) (EPA,1973)1973)

(My Opinion from the public record: W-41 was used in the LSJ Fieldin the 1950s; organic inhibitors were used after that)

The Lease Study Area: TankThe Lease Study Area: Tank BatterysBatterys andandSWD Emergency PitsSWD Emergency Pits

Mississippi RiverMississippi RiverAlluvium & Aquifer atAlluvium & Aquifer at

LSJ FieldLSJ Field

–– Braided stream gravels atBraided stream gravels atbase; cuts into underlyingbase; cuts into underlyingCatahoula Fm sandsCatahoula Fm sands

–– Mostly pointMostly point--bar sandsbar sands

–– FiningFining--up into levee, overbank,up into levee, overbank,floodplain deposits (clay/silt)floodplain deposits (clay/silt)

–– This nearThis near--surface unit issurface unit isaquiferaquifer’’s confining layer, ands confining layer, and

–– It varies from 2It varies from 2 –– 18 ft in18 ft inApplegate/Pan Am areas, (22Applegate/Pan Am areas, (22 ––34 ft in Wagoner area)34 ft in Wagoner area) (Typical near-surface

section from Pisani &Assoc., 2008; LA OOCfile # 006-007)

1968 Pit Descriptions, Study Area1968 Pit Descriptions, Study Area

Applegate PitApplegate Pit (closed ~ 1984; re(closed ~ 1984; re--closed 2007)closed 2007)–– 7070’’ x 150x 150’’ x 8x 8’’ (include 2(include 2’’ levee)levee)

–– UsageUsage ““only in emergencyonly in emergency””

Wilcox PitWilcox Pit (closed 1990)(closed 1990)–– 100100’’ x 100x 100’’ x 8x 8’’ (include 2(include 2’’ levee)levee)

–– UsageUsage ““well backwashingwell backwashing”” (and emergency)(and emergency)

Pan American PitPan American Pit (closed ~ 1984; re(closed ~ 1984; re--closedclosed2010)2010)–– 150150’’ x 200x 200’’ x 8x 8’’ (include 2(include 2’’ levee)levee)

–– UsageUsage ““only in emergencyonly in emergency””

(LA OOC Tensas-Poppadoc hearing; exhibit Tensas/Miller 2455-56)

FineFine--grained Unit Thicknessgrained Unit Thickness

(data from all soil boring descriptions of ICON, Pisani & Assoc., andGeosyntec; meander & swale lines after Saucier, 1967)

Clay & silt

Sand

Shallow Groundwater Data (8Shallow Groundwater Data (8’’ to 22to 22’’ belowbelowsurface) From Lease Study Areassurface) From Lease Study Areas

The analyses fromThe analyses from PisaniPisani & Associates, ICON& Associates, ICON(G. Miller), are numerous and of high(G. Miller), are numerous and of high--qualityquality((GeosyntecGeosyntec data are limited but of highdata are limited but of high--quality)quality)

Shallow groundwater data are most reflective ofShallow groundwater data are most reflective ofpotential old oilfield impacts & possiblepotential old oilfield impacts & possiblecontrolling influences in pit areascontrolling influences in pit areas

Groundwater wells at deeper depths (60Groundwater wells at deeper depths (60’’--8080’’, +, +below surface) do not have total arsenic valuesbelow surface) do not have total arsenic valuesabove natural variability range; deeper alluviumabove natural variability range; deeper alluviumwaters are a variation within the largerwaters are a variation within the largersediment/water geochemical systemsediment/water geochemical system

What is the LSJ Field AreaWhat is the LSJ Field Area’’s Dissolveds DissolvedArsenic Natural Variability?Arsenic Natural Variability?

PisaniPisani & Associates (2012 report; LA OOC file& Associates (2012 report; LA OOC file

# 007# 007--007) interpret the natural range from non007) interpret the natural range from non--detect (ND)detect (ND)up to 0.12 mg/lup to 0.12 mg/l

A study in shallowA study in shallow allluviumallluvium across the River in Mississippiacross the River in Mississippihas an As range of ND to 0.10 mg/l (Welsh et al, 2010; alsohas an As range of ND to 0.10 mg/l (Welsh et al, 2010; alsophosphorous)phosphorous)

ICON data from Tensas Parish landfill, ND up to 0.16 mg/lICON data from Tensas Parish landfill, ND up to 0.16 mg/l(~ 25 mi away, 1994 to 2014 data, LDEQ EDMS # AI 43506)(~ 25 mi away, 1994 to 2014 data, LDEQ EDMS # AI 43506)

The LSJ field study area has localized shallow groundwaterThe LSJ field study area has localized shallow groundwatermeasurements (total arsenic) above these valuesmeasurements (total arsenic) above these values

Limited arsenic species measurements at LSJ field; bothLimited arsenic species measurements at LSJ field; botharsenic species were present (As III and As V) in similararsenic species were present (As III and As V) in similaramountsamounts

Arsenic in Pit Soils, Sediment, & WatersArsenic in Pit Soils, Sediment, & Waters

55 years after alleged As usage, modern pit solids of usually ha55 years after alleged As usage, modern pit solids of usually havevearsenic ranges within Parish soil ranges (from 1 to 10 mg/kg)arsenic ranges within Parish soil ranges (from 1 to 10 mg/kg)–– Pits modified, rebuilt 2Pits modified, rebuilt 2--3 times during usage3 times during usage–– Pan Am & Applegate pit closure ~1984; both rePan Am & Applegate pit closure ~1984; both re--closed (Applegate 2007;closed (Applegate 2007;

Pan Am 2010); Wilcox pit closed in 1990; Wagoner pits closed ~19Pan Am 2010); Wilcox pit closed in 1990; Wagoner pits closed ~198484–– One Wilcox pit sample (Applegate lease) at 16.9 mg/kg; three samOne Wilcox pit sample (Applegate lease) at 16.9 mg/kg; three samplesples

from Wagoner pit areas at 12.3from Wagoner pit areas at 12.3--16.9 mg/kg, and two samples at 55.1 and16.9 mg/kg, and two samples at 55.1 and35.9 mg/kg35.9 mg/kg

A 1984 G & E study found dissolved arsenic in brackish pit waterA 1984 G & E study found dissolved arsenic in brackish pit watersswithin the Applegate (0.04 mg/l) and Pan Am (0.05 mg/l) pits. Awithin the Applegate (0.04 mg/l) and Pan Am (0.05 mg/l) pits. A““central battery #1central battery #1”” pit, possibly a Wagoner pit, was at 0.19 mg/l. Thepit, possibly a Wagoner pit, was at 0.19 mg/l. The2 ft of bottom sludge ranged from 3 to 4.5 mg/kg As2 ft of bottom sludge ranged from 3 to 4.5 mg/kg As

The use of soil analyses alone does not predict whether pitThe use of soil analyses alone does not predict whether pitgroundwater arsenic will be elevated above background valuesgroundwater arsenic will be elevated above background values

(LA OOC Tensas(LA OOC Tensas PoppadocPoppadoc hearing, exhibits Tensas/Miller 00152hearing, exhibits Tensas/Miller 00152--00510;00510;LA OOC file # 006LA OOC file # 006--007, reports of ICON 2008,007, reports of ICON 2008, PisaniPisani & Assoc., 2008 & 2012;& Assoc., 2008 & 2012;LA OOC file # 007LA OOC file # 007--007, reports of007, reports of PisaniPisani & Assoc., 2010 & 2015& Assoc., 2010 & 2015LA OOC file # 006LA OOC file # 006--001,001, PisaniPisani & Associates, 1& Associates, 1--55--2015 report)2015 report)

Wilcox & Pan Am Pit Areas, 1974Wilcox & Pan Am Pit Areas, 1974

Wilcoxpit

PA pit

(oil wells in green, SWD wells in blue)(oil wells in green, SWD wells in blue)

Pan Am Pit Area, GW Data Ranges (in mg/l)Pan Am Pit Area, GW Data Ranges (in mg/l)from Jan. 2010from Jan. 2010-- Sept. 2015Sept. 2015

(data from LA OOC, Tillman file #007-007, Pisani & Assoc. reports 2012-2015)

Pan Am Pit Area, ORP & GW ElevationPan Am Pit Area, ORP & GW Elevation

2010 – 2015 data

Pan Am Pit GWPan Am Pit GW

20102010--20142014

–– Higher iron w/Higher iron w/chlorides under pit;chlorides under pit;probable oilfield waterprobable oilfield watersource impactsource impact

–– Higher arsenic w/Higher arsenic w/

chlorides under pit,chlorides under pit,probable oilfield waterprobable oilfield watersource impactsource impact

Pan Am Pit GWPan Am Pit GW

20102010--20142014

–– As vs. FeAs vs. Fe

varies in relation to pitvaries in relation to pit

proximityproximity

–– ORP v. FeORP v. Fe

There is not an obviousThere is not an obviousrelationship betweenrelationship betweenORP variability and FeORP variability and Fe

Pan Am Pit, Iron & ChloridePan Am Pit, Iron & ChlorideBoundaries if Related to PitBoundaries if Related to Pit

Applegate LeaseApplegate Lease

PisaniPisani (2008, 2015)(2008, 2015)contours 250 mg/lcontours 250 mg/lchloride (yellow line)chloride (yellow line)

–– I labeled highestI labeled highestdissolved arsenicdissolved arsenic(total) hits over 0.10(total) hits over 0.10mg/l (2006mg/l (2006--2015 data)2015 data)

–– Occurs In SWD &Occurs In SWD &

tank battery pit areas;tank battery pit areas;in limited nonin limited non--pit areaspit areas

(Pisani 2008, 2015 chloride contour mapsFrom reports in LA OOC file #006-007)

Applegate Pit Area, GW AnalysesApplegate Pit Area, GW Analyses

(in mg/l) from 2006(in mg/l) from 2006--0707

(ICON analyses plotted on ICON base map, 1974 aerial; LA OOCTensas-Poppadoc hearing, ICON 2008 report)

Applegate PitApplegate Pit

–– GeosyntecGeosyntec GW data, AprilGW data, Aprilof 2008 (only ORP dataof 2008 (only ORP dataever acquired)ever acquired)

–– Sampled six months afterSampled six months afterpartial pitpartial pit digoutdigout/new fill/new fill

–– and during high GWand during high GWelevation, reverse GWelevation, reverse GWmovement towards the lakemovement towards the lake

–– If apparent As relationshipsIf apparent As relationshipswith ORP and Fewith ORP and Fe……..

–– Then apparent relationshipThen apparent relationshipof ORP and conductivityof ORP and conductivity(salinity) ?(salinity) ?

Applegate Pit Area, GW Data Ranges (inApplegate Pit Area, GW Data Ranges (inmg/l) from 2008mg/l) from 2008--20152015

Data from OOC Poppadoc file # 006-007; Geosyntec Report, 2008, Pisani 2012-2015

Applegate PitApplegate Pit

–– All data, 2007All data, 2007--15 (no15 (noORP except 2008)ORP except 2008)

–– TheThe GeosyntecGeosyntec 2008 data2008 dataare generally lower valuesare generally lower valuescompared to 2007 andcompared to 2007 and20122012--1515

–– The April 2008 samplingThe April 2008 samplingwas 6 months after pit rewas 6 months after pit re--closureclosure

–– MWMW--3 has elevated Fe,3 has elevated Fe,why?why?

(note that the 9/15 values were not(note that the 9/15 values were notplotted in time, but show slightplotted in time, but show slightincrease in MWincrease in MW--1 arsenic (0.15)1 arsenic (0.15)

Interpretation of PatternsInterpretation of Patterns

GW under the Pan Am pit moderately reduced, but no clearGW under the Pan Am pit moderately reduced, but no clearrelation of ORP & Asrelation of ORP & AsAreas of oily waste impacts do not always have elevated AsAreas of oily waste impacts do not always have elevated AsHighest Fe values (interpreted as added) have elevatedHighest Fe values (interpreted as added) have elevatedarsenic, and associatedarsenic, and associated ClCl indicate oilfield impactsindicate oilfield impactsOther Fe sources besides soil available (produced water,Other Fe sources besides soil available (produced water,rusty oldrusty old flowlinesflowlines, etc), etc)WW--41 arsenic corrosion inhibitor usage in the 1950s likely41 arsenic corrosion inhibitor usage in the 1950s likelysource of elevated dissolved arsenic in pits at LSJ fieldsource of elevated dissolved arsenic in pits at LSJ fieldIn addition, arsenicIn addition, arsenic--based herbicides & rust inhibitors possiblybased herbicides & rust inhibitors possiblyused in the past around oilfield facilitiesused in the past around oilfield facilities——this usage and itsthis usage and itsmodern impacts usually not consideredmodern impacts usually not consideredTheThe GeosyntecGeosyntec 2008 interpretation of a reductive2008 interpretation of a reductive--dissolutiondissolutionmodel to explain elevated GW arsenic & iron is not supportedmodel to explain elevated GW arsenic & iron is not supportedby the additional data; plus, no followby the additional data; plus, no follow--up ORP data acquired,up ORP data acquired,Fe measurements ended 2014Fe measurements ended 2014

A Possible ModelA Possible Model

Observed ion mobility in GW from PA pit:Observed ion mobility in GW from PA pit: ClCl > Fe > As> Fe > As

HFOsHFOs added to emergency pits from produced wateradded to emergency pits from produced waterover decades; As usage in 1950s, strongly absorbed byover decades; As usage in 1950s, strongly absorbed byHFOsHFOs when presentwhen present

In pit bottom, oily sludge and sometimes stagnantIn pit bottom, oily sludge and sometimes stagnantsaltwater above this, reducing; GW below reducingsaltwater above this, reducing; GW below reducing

Movement of reducing water withMovement of reducing water with ClCl, Fe (, Fe (++ As) where pitAs) where pitseepage, into sediment with Fe grain coatingsseepage, into sediment with Fe grain coatings

GW away from pit more oxidizing, see Fe frontGW away from pit more oxidizing, see Fe front

Added As stays within or close to pit or source originsAdded As stays within or close to pit or source origins

One monitor well (MWOne monitor well (MW--3) in Applegate area has elevated3) in Applegate area has elevatedFe (and possibly As) that is not related to the pit; the FeFe (and possibly As) that is not related to the pit; the Feis a clue that another source is responsibleis a clue that another source is responsible

Wagoner Pits are part of LSJ UnitWagoner Pits are part of LSJ Unit

* Aerial photoof 1959; yellowproperty outline

* Site remediation

rpt (2015; OOCfile # 006-001)stated no SWDwell on property(p. 3)

* No anthropogenicarsenic sourcesconsidered inremediation rpt

* Pit soil borings to15 ft; scattered oilyimpacts; a few highAs values

+Boring of 24’:clay then wetsilt @ 22.5’

Wagoner PitsWagoner Pits

22 soil samples; composite22 soil samples; compositeintervals of 0intervals of 0--3 ft, 33 ft, 3--6 ft, 66 ft, 6--9 ft, 99 ft, 9--12 ft12 ft

LeachateLeachate chlorides rangechlorides rangeof 106 to 532 mg/l (oneof 106 to 532 mg/l (onesample over 500 mg/l)sample over 500 mg/l)

No GW monitor wellsNo GW monitor wells

About 16 ft of clay belowAbout 16 ft of clay beloworiginal pits; closure ~1984original pits; closure ~1984

LA OOC, 10/2015,LA OOC, 10/2015, ““NoNofurther action at this timefurther action at this time””(NFA(NFA--ATT)ATT)

20 soil samples;20 soil samples;composite intervals samecomposite intervals same

LeachateLeachate chlorides rangechlorides rangeof 71 to 568 mg/l (oneof 71 to 568 mg/l (onesample over 500 mg/l)sample over 500 mg/l)

GW monitor wells,GW monitor wells,elevated arsenic to 0.915elevated arsenic to 0.915

A few ft of clay belowA few ft of clay beloworiginal pit base; closuresoriginal pit base; closures

~ 1984 and July 2010~ 1984 and July 2010

Pan American Pit

ConclusionsConclusionsA reductive dissolution model for elevated arsenic and iron beloA reductive dissolution model for elevated arsenic and iron belowwoilfield pits must consider all anthropogenic sources to be viaboilfield pits must consider all anthropogenic sources to be viableleTheThe ClCl association is critical, althoughassociation is critical, although ClCl mobility is greater and thusmobility is greater and thusrelatively reducedrelatively reducedShallow pit soils and their geochemical measurements do notShallow pit soils and their geochemical measurements do notappear reflective of shallow GW impacts which occurred from pitappear reflective of shallow GW impacts which occurred from pitleakage waters with chlorides,leakage waters with chlorides, ++ As (Pan Am pit, probably WagonerAs (Pan Am pit, probably Wagonerpits)pits)Lease pit modern excavations/closings may affect oily and saltyLease pit modern excavations/closings may affect oily and saltyimpacts of shallow GW, but apparently not arsenicimpacts of shallow GW, but apparently not arsenicHowever, historic knowledge concerning SWD well and tank batteryHowever, historic knowledge concerning SWD well and tank batterypits, and arsenic usage, should be publically recorded (in Fieldpits, and arsenic usage, should be publically recorded (in Field pitpitclosure plans ?). Does such knowledge play a part in RECAPclosure plans ?). Does such knowledge play a part in RECAPwork?work?Next Steps of 2016+: extrapolate this knowledge to field, find tNext Steps of 2016+: extrapolate this knowledge to field, find the oldhe oldtank battery and SWD pits of the 1950s. Give the map to the LAtank battery and SWD pits of the 1950s. Give the map to the LAOOC and get knowledge to the landownersOOC and get knowledge to the landowners

DATE: April 1, 2016

TO: See Attached List

CC: See Attached List

FROM: Mary L. Barrett, Ph.D.

RE: The Occurrence of Elevated Shallow Groundwater Arsenic Below Old Chevron OilfieldPits, Lake St. John Field, LA, w/ Specific Notes Concerning Remediation/ClosureReport, Wagoner Property, Tensas Parish, LA (LA OOC file # 006-001)

Dear Commissioner of Conservation Ieyoub, Environmental Division Director Snellgrove, andChevron Counsel Ferratt,

I was a defendant (Chevron) expert in two oilfield legacy cases from Lake St. John (LSJ) Field(LA OOC legacy files #007-006 and #007-007) from January 2008 to February 2014 and servedas an expert in oilfield waste history and as a geologist. I was not the defense’s expertenvironmental company, as that is Pisani and Associates and briefly Geosyntec Consultants.There are two other legacy case files (# 006-001 and #003-001) from the LSJ Field, and I did notserve as an expert in those two cases. One of the cases, the Tensas-Poppadoc litigation (OOClegacy file # 007-006), was tried in district court (in which I testified) and then there was also anOOC hearing (docket no. ENV 2008-L-01). The Tensas-Poppadoc case and hearing generatedsubstantial public oilfield records on the LSJ Field. Publically-available paperwork included a1955 Chevron document (attached) that stated that W-41, a Chevron-patented arsenic corrosioninhibitor, was used and circulated in the field’s production system. Since October of 2014, Ihave used the public scientific and LSJ oilfield records to discuss that the reason for elevatedgroundwater arsenic below the sampled old oilfield pits is due to past usage of arsenic-basedcorrosion inhibitors. Generally, the groundwater arsenic in shallow sands has not migrated muchfrom below the clay-based pits.

It is my understanding that a settlement was reached between defendants and plaintiffs on thesefour cases in September 2014. Obviously, you all understand better than I as to the delicatenature of what party, if any, admitted responsibility for particular impacts, versus a settlementwhere this admitted responsibility may not occur. It is not my role to know this.

But as a scientist and citizen of the State, I have a professional and ethical duty to report to youthe fieldwide use (as a possible reasonable 1950s oilfield operator action) of this arseniccorrosion inhibitor in the 1950s LSJ Field operations of Chevron, so that any RECAP analysisconducted on these sites will have knowledge of W-41’s usage and its possible shallowgroundwater impact. I have carried out this duty by presenting my review and on-going findingsat four scientific meetings and providing copies of these presentations and abstracts to: 1) the LAOOC Environmental Division (through Stephen Pennington); and 2) the attorneys representingChevron U.S.A., Inc.

With this letter and the attached presentation (on CD) at last week’s 10th Annual LAGroundwater, Surface Water & Water Resources Symposium (sponsored by the LA GeologicalSurvey and the LA Water Resources Research Institute), this will be the last time that I contactthe OOC Environmental Division and the Chevron attorneys with a copy of meeting powerpointpresentations/abstracts on this subject matter.

The latest presentation of March 24, 2016, caused me to review the LSJ Field public legacyrecords-to-date about 10 days prior, including the Wagoner case file # 006-001. In the file wasthe following: The Site Remediation Plan dated January 6, 2015, by Dave Angle of MichaelPisani & Associates. The OOC correspondence dated October 8, 2015, gave the two Wagoneremergency pits (SWD & tank battery) the closure status of “No further action at this time”(NFA-ATT). However, for your records, the Angle report either incorrectly or incompletelystated some important information which I give below:

1) The report stated (pg. 3) that no saltwater disposal (SWD) well was located on this property.That is incorrect. The first SWD well drilled in LSJ field by Chevron was on this property—it was the Pasternack #2 well, SN #30108, converted to a SWD well in 1947 and P & A’d in1983 (see SONRIS records and OOC records in Baton Rouge);

2) The report considered the underlying clay as protective of groundwater, but the reportdocuments their observation of scattered visible oil within the clay to the bottom of theirborings, indicating that there was past leakage from the pits through clay imperfections;

3) The SWD well (Pasternack #2) on the Wagoner property was listed on the publically-available 1955 Chevron document (attached) that stated that the W-41 corrosion inhibitorwas being used in the field and providing corrosion protection for all the listed SWD wells.This document is the one in my presentations since October 2014;

4) The Angle/Pisani report made no mention of any possible anthropogenic sources of arsenicto the pits, yet there is elevated groundwater arsenic above their background levels at theother case site pits used during the 1950s and which have groundwater monitoring wells;and

5) It is unclear to me whether this significant information would have affected the associatedERM report which gave the RECAP analysis for the Wagoner site. That is for you toconsider and decide, not me. Please see the last few slides of my included presentation formy technical observations concerning the public Wagoner data.

My next steps are as follows. I am, of course, doing this work on my own and am not being paidby anyone to do this. There is little more I can do to help the LA OOC and Chevron in the fourcited cases above, and I wish you the best in determining the next steps in fulfilling yourresponsibilities to protect all affected parties. I know that it is the landowners who areempowered to protect their land, not I. I am probably the most qualified person to identify andlocate the other potentially-impacted Chevron 1950s pits (specifically the SWD and tank batteryemergency pits). This I can do through publically-available data (specifically 1950s aerialphotography and oilfield documents). I have begun this work and to date have found about 7pits; there may be a few more. Once I complete this, I will get the information to the landowners,and then they can take it from there. If you want a copy of this mapping, let me know and I willgive a copy to you. I think it may take the year of 2016 for this to happen.

I have copied this letter and presentation to the following: 1) to Victor Gregoire, the Chevronoutside attorney who requested that I send him my public presentations concerning this, and 2) tothe LA DEQ groundwater team so that they will know of these arsenic occurrences and studies.

Regards,

Mary L. Barrett, Ph.D.Professor Emeritus of Geology, Centenary College of LouisianaConsulting Geologist and Oilfield Historian

Address:639 Stephenson St.Shreveport, LA 71104

Mailing List w/ CD Attachment:

TO: Richard P. Ieyoub Gary SnellgroveCommissioner of Conservation Environmental Division DirectorLA Office of Conservation LA Office of ConservationP. O. Box 94275 P. O. Box 94275Baton Rouge, LA 70804 Baton Rouge, LA 70804

Jennifer L. FerrattCounsel, Litigation Management UnitChevron, U.S.A., Inc.100 Northpark Blvd., Rm N4258Covington, LA

CC: Victor Gregoire LA Dept. of Environmental QualityOutside Senior Counsel for Chevron Office of the SecretaryKean Miller, LLP Aquifer Eval. & Protection UnitP.O. Box 3513 P. O. Box 4301Baton Rouge, LA 70821-3513 Baton Rouge, LA 70821-4301