73 %U ;,\rch 1995 STATE DOCUMENTS COLLECTIOI PROGRESS MR ? 2 1395 MONTANA STATE LIBRARY 1515 E. 6th AVE. HELENA, MONTANA 59620 Streamside Tailings Superfund Report By the Montana Department of Health and Environmental Sciences and the U.S. Environmental Protection Agency Introduction TheMontanaDepartmentofHealthandEnvironmental existingandpotentialimpactstotheenvironmentatthesite,but Sciences (MDHES) hasrecentlycompletedtheDraft Baseline is generally less quantitative than the human health risk RiskAssessmentReportfortheStreamsideTailingsportion of assessment Thebaselineriskassessment will guideMDHES the Silver Bow Creek/Butte Area Superfund site. The risk andtheU.S.EnvironmentalProtectionAgency(EPA)inreaching assessmentidentifiesexistingandpotentialriskstobothhuman a final decision aboutsitecleanup. MDHES healthandtheenvironment. has released the Draft Baseline Risk The human health risk assessment uses site-specific Assessment for public comment and will accept comments concentrations ofcontaminants andassumptions abouthuman throughMonday,April 10, 1995. MDHESandEPAencourage exposuretositecontaminantstodeterminetheriskthesiteposes thepublictoreadthedocumentandsubmitcomments. (Please to public health. The ecological risk assessment evaluates refertothe "GetInvolved" section ofthisprogressreport.) Get involved MDHESisquicklyapproachingacleanupdecisionfor April10,1995.Writtencommentsandcorrespondenceregarding the Streamside Tailings site. A feasibility study outlining thesitemaybesenttoJimFord,MDHES SiteProjectOfficer, cleanup alternatives and the agencies' proposed plan for site Montana Department of Health and Environmental Sciences, cleanupshouldbereleasedthisSpring. Followingpublicreview P.O. Box200901,Helena, MT59620-0901. andcommenton thesedocuments,MDHES and theU.S.EPA expecttochoosearemedyforthesitebyAugust1995. MDHES Learn about the site encouragesthepublictobecomeinvolvedinsiteissuesandthe MDHES has establisheddocumentrepositoriesatthe decision-making process. There are a variety of ways to get followinglocations.Therepositoriescontainthesitedocuments involved: which thepublic isallowedtoborrow forreview. ROUNDTABLE MEETINGS Anaconda MDHES has been hosting regular "roundtable" HearstFreeLibrary meetings. These open, public meetings are held about once everymonth forpeopletovoicetheiropinionsandtodiscussa Bozeman variety of topics such as land use, institutional controls, the MontanaStateUniversityRenneLibrary remedial investigation, feasibility study, etc. To get on the mailinglisttoreceivemeetingnoticespleasecontactJimFord, Sate MDHES SiteProjectOfficer,at 1-800-246-8198or(406)444- SilverBowLibrary 1420. MontanaTechLibrary EPAofficein basementofCourthouse Public comment CTECofficeatMontanaTech ThepubliccommentperiodfortheStreamsideTailings § i I BaselineRiskAssessmenthasbeenextendedthroughMonday, CONT. ON PAGE 2 w Printed on RECYCLED PAPER Progress Get involved (from page 1) SUPERFUND HOTLINE DeerLodge NationalParte Service-Grant-KohrsRanchoffice MDHESoperatesatoll-freephonelineformembersof DeerLodgePublicLibrary the public who have questions, comments or concerns about Superfundissues. ThelineisansweredbyMDHES Superfund Helena staffinHelena. Pleasefeelfreetomakeuseofthehotline. The MDHES officeat2209Phoenix Ave. numberis 1-800-246-8198. EPAofficein theFederal Building StateLibrary Back issues of progress reports MontanaHistorical Society Library MDHES has back issues ofsite progress reports like thisoneavailableuponrequest. Toobtainprogressreportsabout Missoula other Streamside Tailings topics such as: site background, MissoulaPublicLibrary community involvement, the remedial investigation, etc. or JniversityofMontanaMansfieldLibrary , aboutanyotherMontanaSuperfundsite,pleasecallMDHES at ClarkFork-PendOreilleCoalitionOffice 1-800-246-8198or(406)444-1420in Helena. How was the Risk Assessment conducted? The Human Health Risk Assessment noncarcinogenthatthehumanbodycantoleratewithoutshowing MDHES conducted the Streamside Tailings Baseline signs of illness. The reference dose is an estimate of the Risk Assessment at the same time the potentially responsible maximum quantity ofacontaminantto which aperson can be party, Atlantic Richfield Company (ARCO) conducted the exposed overa long period of time and still show no adverse Remedial Investigation. MDHES relied on technical reports, healtheffects. Forexample,studiesindicatethattoomuchofthe healthstudies,andsitespecificinformation. Thehumanhealth metal copper can cause respiratory disorders in children. riskassessmenthadfourprimarysteps: However,usingtoxicitystudiesandanalyticalmodels,EPAhas 1) identificationofcontaminantsofconcern (COCs), estimatedthatanindividualcouldeatordrinkupto2.5milligrams 2) toxicityassessment, ofcoppereachdayfor70yearswithoutexperiencingarespiratory 3) exposureassessment, and disorder, even taking into account the extra sensitivity during 4)riskcharacterization. childhoodyears. Thisamountisknownasthe"referencedose" Identificationofcontaminantsofconcernistheprocess (RfD) for copper. Since the exact amount of a contaminant ofdetermining which contaminants at the site shouldbe fully peoplecan toleratedepends on thespecific characteristicsofa MDHES evaluated in the risk assessment. conducted this contaminant,referencedosesdifferforvariouscontaminants. screening process based upon site-specific contaminant The exposure assessment evaluates how people may concentrations and other information including health studies comeincontactwithcontaminantsandpredictstheamountsof and laboratory investigations. contaminantsenteringthebody. AttheStreamsideTailingssite, Thetoxicityassessmentexaminesthepotentialforeach potential exposure to site contaminants- includes ingestion, contaminant of concern to cause adverse health effects and inhalation, and/or direct contact with contaminated soil, MDHES providesanestimateofthe"dose-response"relationship. "Dose- groundwater,surfacewater,and/orstreamsediments. response"relationshipreferstotheamountofcontaminationto usedEPAguidanceandsomesite-specific information tomake whichapersonmustbeexposedbeforesufferingadversehealth assumptions about how people can be exposed to site effects. Adverse health effects can be either carcinogenic contamination. Actual site data was used to calculate (cancer-causing) or non-carcinogenic (adverse health effects concentrationsofcontaminantsonsitetowhichpeoplemightbe otherthancancer)withdifferenttechniquesusedforevaluating exposed. each. The exposure assessment alsoconsidered that people Forcarcinogens,a"cancerpotencyfactor"isestablished usethesitedifferentlybothnowandinthefuture. Thus,different thatrelatestheprobabilityofdevelopingcancerforagivendose exposureestimatesweremadeforpeoplethatmightworkatthe ofacontaminant. Toxicity studiesassume thatany amountof site, recreate along the creek, use railroad bed trails if such a exposuretoacarcinogencarriessomeriskofdevelopingcancer. conversion is made in the future,and/orlivewithin oradjacent The amount of risk associated with a given exposure to a to the site. By usingavarietyofdifferent potential exposures, contaminantmeasuresthestrength(orpotency)ofacarcinogen. theriskassessmentprovidesaspectrumofriskestimatesthatcan Themeasureofacarcinogen'sstrengthiscalleda"slopefactor." beemployedwhendifferentlandusesareconsideredindecisions For non-carcinogens, a "reference dose" (RfD) is on remedial alternatives for the site. determined. Scientistsbelieve that there is a certain dose ofa MontanaStateLibrary Progress 3 0864 1005 0899 6 Information from the toxicity assessment and the combinedriskfrom multiplepathways. LaterintheSuperfund exposureassessmentarecombinedintheriskcharacterizationto process,MDHESwillevaluatepotentialsiteremedial alternatives determinecurrentandpotentialrisks. Inthisfinalportionofthe andcomparehowwellthosealternativescanreducethecurrent risk assessment, numerical risk values are calculated for each andpotentialrisks fromsitecontamination. contaminant and each exposure pathway and for the total What considered an "acceptable " risk? is EPAhassetariskrangefromone-in-ten-thousand(1in warranted depending upon on site-specific circumstances, 10,000or 104)toone-in-one-million(1 in 1,000,000orlO"*)as,, potential cumulative effects from contaminants, and the the cleanup goal for Superfund sites. A risk of one-in-one- determinationoftheagencies. millionmeansthatonepersonoutofonemillioncoulddevelop Fornoncarcinogens,risksareassessedby comparing cancerasaresultofalifetimeexposuretothesitecontaminants. estimatedexposureswitha "safe" dose definedby areference Thisreferstotheincrementalriskthatisaboveandbeyondthe dose (RfD) (see above). Where estimated exposures exceed probabilitythatanindividualmaydevelopsomeformofcancer RfDs,thepotentialforadversenoncancereffectsisassumedto fromothercommon sources. bepresent. Risksarenotquantifiedinthesamewaythatcancer Ingeneral.risksgreaterthenonein10,000areconsidered risks are, but generally can be assumed that the greater the unacceptableandwarrantriskreduction, usuallyintheformof differencebetween estimated exposures andRfDs, the greater cleanup. Risks less then one in 1,000,000 are generally thepotentialforadverseeffects. Ahazardindexofone(1)which consideredacceptableandrequirenocleanupactiontobetaken. means that estimated exposure is equal to the RfD, while an Whenrisks fall withintheriskrange,between oneand 10,000 indexoftwo(2) means thattheestimatedexposure istwiceas and one in 1,000,000, cleanup action may or may not be large as the RfD. In general, risks exhibiting a hazard index greaterthenone (1) willrequiresomeform ofcleanup. ononorsncawskta&wcsomawujmt STREAMS!DE TAJUNGS VICINITY WAP PREPAREDTOR ARCO ANACONDA, MONTANA i^IaEnvironmental F1CURE P»S«4 Progress The Risk Assessment findings Human Health Risk Assessment Conclusions TheStreamsideTailingsBaselineHumanHealthRisk Assessmentevaluates threeexposurescenariostodeterminethe healthrisksifnoactionweretobetakenatthesite. Thisincludesrisksrelatedtositeusebyresidents,workers(occupational),and recreationists. Risksweredividedintothosewhichmaycausecancerandthosewhichcauseadversehealtheffectsotherthancancer (non-carcinogenicrisks). Potential human health effects Residents StreamsideTailingscontaminantsmaypresentahumanhealththreattoexposed -To evaluate residential people. Following is a brief summary of potential health effects from the primary exposure to floodplain contaminants, contaminantsofconcern. MDHES considered a house located outside, but adjacent to, the 100-year Arsenic-Ingestionofhighlevelsofarsenicmaycausedigestivepain,nausea,vomiting floodplain withayardleading down to anddiarrhea. Ingestionmayalsoleadtodecreasedproductionofredandwhitebloodcells, SilverBowCreek.Underthis scenario, abnormalheartfunction,bloodvesseldamage,liverandkidneyinjury,andimpairednerve childrenandadultscouldbeexposedto function. At lower levels ofexposure, ingestion may also result in skin problems, a contaminatedsoils located outside and conditionknowna"blackfoot"disease,andincreasedriskofskin,liver,bladder,kidney inside the floodplain and within the and lung cancers. Inhalation effects are similar to ingestion effects, especially the residentialyard.Exposuretocreekwater increased risk oflung cancer. In fact, lung disease associated with arsenic inhalation andsedimentswasevaluatedunderthe exposurewasfirstrecognizedinastudyofworkerhealthattheoldsmelterinAnaconda. recreationalscenario(below). Thevast Arsenic is considered to have both carcinogenic (cancer-causing) and noncarcinogenic majority ofresidents in Rocker, Silver (thosewhichcauseadversehealtheffectsotherthancancer)effects. Bow, Ramsay, and Opportunity live outsidetheareaofgreatestimpactfrom Cadmium-Breathinghighlevelsofcadmiumseverelydamagesthelungsandcancause tailings and their exposure to death. Eatingfoodordrinkingwaterwithveryhighlevelsseverelyirritatesthestomach, contaminantsisexpectedtobelimited. leadingtovomitinganddiarrhea. Long-termexposuretolowerlevelsmayresultinkidney Theprimarycarcinogenicrisk disease, lung damage and fragile bones. There is some evidence, primarily in animal topeoplelivingonornearthesitecomes studies,thatbreathingcadmium maycauselungcancer. entirely from potential exposure to arsenic in soil and groundwater (see Copper--Ingestionofexcessiveamountsofcoppermayresultinadverseaffects tothe Table 1). Elevated concentrations of digestivesystem,kidneysandliver. Chronicover-exposuretocoppermaycauseanemia. arsenic can be found in tailings areas Ingestion of coppersalts may cause salivation, digestive irritation, nausea, vomiting, suchastheRamsayFlatsandinshallow gastric pain, gastritis, and diarrhea although relatively high levels of exposure are (lessthan20feetbelowgroundsurface), necessarytoinducetheseeffects.Eyecontactwithcoppersaltsmayresultinconjunctivitis near-stream groundwater. andcorneallesions. Copperis notknowntocausecancer. Noncarcinogenic risks exceeded acceptable levels for arsenic Lead—LeadcanaffectmanyOrgansandsystemsofthebody,butthemostsensitiveisthe in soils under the residential scenario. central nervous system,especially in young children whosebodiesare still developing. As with the carcinogenic risks, the Harmful effects may includepremature births, reducedbirth weight, decreased mental noncarcinogenic risks vary depending abilityofinfants,learningdifficultiesandreducedchildhoodgrowth. Inadults,leadmay ontheamountofcontaminationaperson decreasereaction time,cause weakness offingers, wrists orankles and possiblyaffect comes in contact with on site. memory. Leadmayalsocauseanemia,abortionandmaydamagethemalereproductive Noncarcinogenicrisksrelatedtoarsenic, system. ' cadmium, copper and zinc in groundwaterwerefoundonlyinshallow, Mercury-Exposuretohighlevelsofmercurycanpermanentlydamagethebrain,kidneys, near-stream groundwater within and anddevelopingfetus. Thenervoussystem isverysensitivetomercury'seffects. Mental directly adjacent to the 100-year effects may include personality changes, tremors, changes in vision or hearing, and floodplain. The risks posed by lead difficulties withmemory. contaminationinsoilaregenerallywithin the acceptable range based on the risk Zinc- Aswithcopper,acertainamountofzinc isrequired in humansdiets. Extremely model used inButte. highdosesofzinchavebeenshown tobefatal in animaltests. Atlowerdoses,zincmay Limited groundwater data causedigestivedistressand tissuealteration,andpancreaticabnormalities. Ingestionof demonstrate that shallow groundwater zinc hasalsobeenlinkedtoanemiainhumansandanimals. Zincmayalsocauseadverse exceeds drinking water standards in affectstotheliverandkidneys. Chronicexposuretozincmustbeatextremelyhighlevels someareasandalsosuggestthatdeeper toproduceadverse healtheffects. site groundwater does not presently ., Progress ' exceeddrinkingwaterstandards. Most,ifnotall,watersupply riskassessment. Theconclusionsare generallyqualitativeand wellsarelocatedindeepergroundwater. TheStateofMontana focus on whethertheenvironment(plantand animal life) isor presendyprohibitstheconstructionofshallow wells(less than maybe adversely impacted. 20feetbelowthetopofthewatertable) in floodplains. InSilverBowCreek,whichisdevoidoffishandmany otheraquaticlifeforms,thepresenceofminewastecontamination Occupational istheprimaryfactorlimitingthehealthoftheaquaticenvironment The "occupational scenario" evaluates the risk to Thesecontaminantsaffectboththewaterqualityandstreambed workers within the siteand focuses on agricultural workers in sediments in SilverBowCreekandcreateatoxicenvironment areas outside the 100-year floodplain. The risk assessment forfishandmostaquatic insects(benthic macroinvertebrates). indicatesthatcarcinogenicriskfallswithinanacceptablerange Other concernswhichmayaffectthehealthofSilverBowCreek (seeTable1). Noncarcinogenicriskstoagriculturalworkersare include siltation of the stream bottom, channelization, and mostlyrelated toarsenic and arealso generally acceptable. If disturbanceofadjacentlandand streamside(riparian)habitat workers were to equally divide their work timebetweenareas Inadditiontothemetalsassociatedwithminingwaste, insideandoutsidethefloodplaintheirrisksmightbehigherby therisk assessment alsoevaluated the risk to the environment afactorofthree(3) andcouldexceedacceptablelevels. from pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons(PAH),bothofwhichoriginatedfromanupstream Recreationists woodtreatingSuperfundsite,aswellasfromdissolvedoxygen, Both carcinogenic and noncarcinogenic risks to site ammonia, and nitrogen. The Ecological Risk Assessment visitorsareposedbyfutureuseoftherailroadbeds(seeTable1) evaluatespotentialeffectsofthesecontaminantsinsoil,surface Thiscouldbecome a majorconcern ifpresentplans foruse of water, and in-stream sediments. PCP and PAH were not railroadbedsasatrailsystem aredeveloped. Risksexceedthe considered significant contaminants in stream sediments. acceptableEPAriskrange. Elevatedlevelsofarsenicwherepast Ammonia, nitrogen, and dissolved oxygen are adversely ore concentrate spills occurred on the railroad beds create a impacting water quality in some areas of Silver Bow Creek hazardtorecreationalusersandwouldthereforerequirecleanup. whichareaffectedby theseparameters. Asin theresidential scenario, using the Butte model, therisks posedby leadarewithin theacceptablerange. Soil Many near-stream surface soil areas are critically impactedbytailingsdepositsanddevoidofvegetation. Surface The Ecological Risk Assessment soilriskismeasuredintermsofthetoxicityofcontaminantsto The Ecological Risk Assessment is conducted in a plants (phytotoxicity). The contaminants posing the greatest mannersimilarto,althoughlessspecificthanvthehumanhealth threatinsurfacesoilsincludearsenic,copper,lead,andzinc(see Table 1 Simplified Summary of Human Health Risks Carcinogenic Risk for Exposure to: Exposure Medium Residential Occupational Recreationists Soil Unacceptable Acceptable Acceptable NA NA Instream Sediment 1 Acceptable Surface Water NA1 NA Acceptable Ground Water Unacceptable NA NA Air Acceptable Acceptable Acceptable NA NA Railroad Materials 1 Unacceptable • NA - Not analyzedfor this exposure scenario, - See page 4-125 ofDraft Baseline Risk Assessment for "Residents who Recreate" within the site. Progress Table2). Moderatethreatsareposedbycadmiumandmercury. lesserextent,lowdissolvedoxygenareotherlimitingfactorsin certainreachesofSilverBowCreek. SurfaceWater Surfacewaterhasbeenseverelyimpactedthroughout Sediment the length of Silver Bow Creek and serves as a contaminant ContaminatedsedimentsinSilverBowCreekactasa pathway to sediments and the aquatic environment. In Silver critical contaminant pathway to impacted surface water and Bow Creek, trout populations have been eliminated entirely, aquatic life, particularly aquatic insects (benthic due,inpart,tocontaminatedsurfacewater. macroinvertebrates). Risksfromsurfacewaterrelatetohowthecontaminants Contaminants in sediment posing a high risk to the mayadversely affectaquaticplants, fishandotherstreamlife. environmentarearsenic,cadmium,copper, lead,mercury,and Surfacewatercontaminantswhichposethe greatestrisktothe zinc(seeTable2). Mercuryisacontaminantwhichconcentrates healthofthestreamincludecopperandzinc(seeTable2). Zinc inplantandanimaltissue(bioaccumulation)andcanpotentially isasignificantthreatinupstreamsectionsofSilverBowCreek, moveupinthefoodchain(biomagnification). Mercuryposesa but concentrations and potential risks decrease somewhat small current threat because there are no fish in the creek. downstream. Cadmium,lead,mercury,andpentachlorophenol However,fishandotherbiotaexposedtothelevelsofmercury areconsideredmoderatethreats. Ammonia,nitrogen,and toa currentlyin thecreek sedimentcouldbeatrisk. Table 2 Summary Simplified of Ecological Risks to Silver Bow Creek Contaminant Soils Surface Instream Water Sediments Contaminants Throughout Creek Arsenic High Low High Cadmium Moderate Moderate High Copper High High High Lead High Moderate High Mercury Low to Mod. Low to Mod. High Zinc High High High Contaminants in Limited Reaches of Creek Polycydic Aromatic Unknown/ Low Low Hydrocarbons Probably low Pentachlorophenol Unknown/ Moderate Low Probably low Ammonia Mod. to High1 Dissolved Oxygen Low to High1 Nitrogen Mod. to High1 - Location/timing dependent, See Baseline Risk Assessment, Executive Summary Table. ES - 10 I Are you on our mailing list? Ifyou wish your name to be added to or deleted from the mailing list for Streamside Tailings, or ifyou wish to update your address, please fill out, detach, and mail the following form to Jim MT Ford, Montana Department ofHealth and Environmental Sciences, P.O. Box 200901, Helena, 59620-0901. Name Address City, State Zip- Ifyou receive this progress report by mail, there is no need to complete this form, unless you wish to have your name removed from the list or have youraddress changed. If so, please check below. Remove Change l_. 1,500copies ofthispublic documentwerepublishedatanestimatedcostof.30 percopy,foratotal costof $866 which includes$450 forprinting and $416 fordistribution. & (ta eta Send us your comments! The comment period on the Streamside Tailings Baseline Risk Assessment Report ends MONDAY, APRIL 1995 10, Send your comments to: MDHES Jim Ford, Site Project Officer P.O. Box 200901 Helena, Montana 59620-0901 & & 03 <&' e^ eta eta Superfund Program Montana Department ofHealth and Environmental Sciences P.O. Box200901 Helena, Montana 59620-0901