# Consultation on the Two-dimensional Exposure Rainfall-Runoff Assessment (TERRA) Watershed Model and Its Use in the FIFRA Ecological Risk Assessment for Antimicrobial Uses of Copper1FIFRA SCIENTIFIC ADVISORY PANELConsultationOctober 25-26, 2011U.S. Environmental Protection AgencyOffice of Pesticide ProgramsWashington, DC

# Presentations to the SAPIntroduction of OPP Aquatic Exposure Assessment ProcesszPart 1: Dr. James Hetrick, EPAEcological Risk Assessment FrameworkExposure Modeling ApproachesOther Modeling ApproachesExposure for Conventional Uses of CopperzPart 2: Dr. Siroos Mostaghimi, EPAExposure for Antimicrobial Uses of CopperOverview of the Two-dimensional Exposure Rainfall-Runoff Assessment(TERRA) Model: Dr. Mark Velluex, ACC/HydroQualApplication of TERRA in Antimicrobial Exposure Assessment: Dr. MarkVelluex, ACC/HydroQualEPA Review of the TERRA Model: Dr. Stephen Wente, EPA2

# Introduction to the Office of Pesticide Program’s Environmental Exposure Modeling and Assessment Part 1: Dr. James Hetrick, USEPAFIFRA SCIENTIFIC ADVISORY PANELConsultationOctober 25-26, 2011U.S. Environmental Protection AgencyOffice of Pesticide ProgramsWashington, DC3

# Ecological Risk Assessment Framework4

# Risk Assessment Framework5

# Terminology for Copper6zIonic copper= Cu2+zDissolved Copper= Ioniccopper + Inorganic Complexes+ Organic ComplexeszSorbed Copper= coppersorbed to sediment/soilzCopper MineralsCu2+InorganiccoppercomplexesOrganiccoppercomplexesSorbed copperonsoil/sedimentCopperMineralsBound CopperDissolved Copper

# Problem Formulation Stressor Use Characterization7StressorComponentsAntimicrobial UsesConventional UsesUse PatternAlgaecideMicro-biocideAlgaecideFungicideHerbicideMollusicideDistributionUrbanResidentialMarinasUrbanResidentialAgriculturalRatesWood:0.06-0.13 lbs/ft3Crops:0.6-36 kg/haShingles:2 – 20% byweightSurface Water: 0.2 to 2.5 mg/L

# Problem Formulation Environmental Chemistry for CopperzSoil/Sediment PartitioningpHCation exchange capacityOrganic carbonzChemical SpeciationDifferent valence states (Cu0, Cu+,Cu2+)Inorganic complexes (CuOH+, Cu(OH)2, Cu(OH)3_, Cu(OH)42-,



# etc.)Organic complexes (DTPA, ETDA, humic acids, fulvic acids,



# etc.)zSoil and Aquatic ChemistryMineral equilibriaSoil solution and water chemistry8

# Problem Formulation Conceptual Model9TransportProcessesOverlandFlowErosionInfiltrationDeposition/ResuspensionSurfaceWaterTerrestrialUseSiteApplicationRateLeachingRateAquaticUseSiteApplicationRateLeachingRateChemicalProcessesSorption/DesorptionPrecipitation/DissolutionComplexationSedimentETransport ProcessesDispersionDeposition/ResuspensionFlowCChemical ProcessesSorption/DesorptionPrecipitation/DissolutionComplexation

# Exposure Modeling Approaches10

# Aquatic Exposure Assessment Conventional PesticideszTiered Surface Water Modeling Process forNational Exposure AssessmentSystematic, rapid screening approach for assessing pesticiderisk•Tier 1 modeling-High End Exposure Estimation–Pass-Low probability of risk for adverse effects–Fail-Risk for adverse effects cannot be precluded.•Tier 2 modeling-Refined Exposure Modeling–Considers representative meteorology, soil, application methods,application timing for pesticide use sites11

# Exposure Assessment Process Conventional PesticideszField-scale model scenario10 hectare field•Uniform soil properties•Runoff, eroded sediment,spray drift moves into pond•100% treated withpesticide1 hectare pond•20E6 liter volume•No outflow (static)1210 haWatershedRunoff, Erosion, Spray Drift1 ha StaticPond

# Aquatic Exposure Assessment Conventional

PesticidesGENEECzMetamodel PRZM/EXAMSzYazoo, MS sitezSingle runoff eventzApplication rate and methodzSpray driftzKoc/Kd, aerobic soil half-life,hydrolysis half-life, photolysishalf-life, aquatic metabolismhalf-lifezDaily peak, 4-day average, 21-day average, 60-day average,90-day average EECPRZM/EXAMSzRepresentative crop site scenariosMeteorology•30 yearsSoilszApplication Rate, Method, andTimingzSpray DriftzKoc/Kd, aerobic soil half-life, hydrolysishalf-life, photolysis half-life, aquaticmetabolism half-life,benthicmetabolism half-life,volatilizationz1 in 10 year daily peak, 4-day average,21-day average, 60-day average, 90-day average, annual average, and 30-year annual average EEC13Tier 1 ModelingTier 2 Modeling

# Schematic of PRZM/EXAMS Modeling1414Pesticide AppliedPRZMRunoff/Erosion/LeachingModelSpray Drift•Default•Models-AgDRIFT-AGDISPEXAMSSurface Water Quality ModelEstimated EnvironmentalConcentration (EEC)Physical PropertiesSpray EquipmentsMeteorological dataWater PropertiesWater Body GeometryPesticide PropertiesSoil PropertiesSoil/crop ManagementMeteorological DataPesticide PropertiesDaily Temperature

# PRZM/EXAMS Modeling Output150.0010.0020.0030.0040.0050.0060.0070.0080.00 1 355 709 1063 1417 1771 2125 2479 2833 3187 3541 3895 4249 4603 4957 5311 5665 6019 6373 6727 7081 7435 7789 8143 8497 8851 9205 9559 9913 10267 10621

Dissolved Copper (μg/L)Time (Days)0.001.002.003.004.005.006.007.008.009.00 1 344 687 1030 1373 1716 2059 2402 2745 3088 3431 3774 4117 4460 4803 5146 5489 5832 6175 6518 6861 7204 7547 7890 8233 8576 8919 9262 9605 9948 10291 10634

Pesticide (μg/L)Time (Days)16Concentration (μg/L)101001000

Exceedance Frequency0102030405060708090100Yearly Peaks: acuteYearly Avg.:chronic

# Other Modeling Approaches17

# Reviews of Watershed/Basin Scale ModelszUSEPA, 1998- FIFRA SAPBasin scale models require calibrationNo subroutines for addressing plant growth, pesticide degradation,and agronomic practices.zOW Review, 1997Found major difference in spatial resolution, physical and chemicalprocesses, and CPU requirementszHydroQual, 2010Few models had the capabilities to simulate chemical transport18

# Watershed Modeling in OPP and Other

ProgramszOffice of Pesticide Programs(OPP)PRZM/EXAMS Index Reservoir•Drinking water assessmentszOffice of Water (OW)Total Maximum DailyLoad (TMDL)Water Quality CriteriazOffice of Solid Waste andEmergency Response (OSWER)Superfund Sites19

# Exposure Modeling Approaches: Conventional Uses of Copper20

# Risk Assessment Process for CopperzEstimate environmental concentrations ofdissolved copperzCalculate the cupric ion (Cu2+) concentrationusing the Biotic Ligand ModelzDerive site specific toxicity values for Cu2+using the Biotic Ligand ModelzCalculate risk quotients21

# OPP Risk Assessment Strategy for Copper22Biotic LigandModel(Speciation Mode)Exposure:Developing Activity-basedSite Specific EECsEffects:Developing ActivitybasedSite Specific LC50sSite SpecificDaphnia magnaLC50(mol Cu2+/L)Site SpecificUSGS Water QualityMonitoring DataSite Specific RQsDaphnia magna(unitless)Site specific EECs(mol Cu2+/L)Site SpecificDaphnia magnaLC50(ppb)Biotic LigandModel(Toxicity Mode)MODELSIMULATIONS(Site SpecificScenarios)EECs (ppb)[Cu]total dissolved

# Water Quality Statistics for 811 USGS Monitoring Sites23ParameterUnitsData Range forBLMMissingDataLow ValueHigh ValueMedianValueAverageValueTemperature0C10 to 2501024.517.417.2pH4.9 to 9.205.059.28.07.85Cuug/L3631.051.41.22.61DOCmg/L0.05 to 29.6500.229.23.004.06Humic Acid2%10 to 6001029.1514.9016.69Ca2+mg/L0.204 to 120.2400.9511437.640.62Mg2+mg/L0.024 to 51.900.1851.810.613.02Na+mg/L0.16 to 236.900.8819010.321.09K+mg/L0.039 to 278.400.09182.22.93SO42-mg/L0.096 to 278.400.1027026.144.46Cl-mg/L0.32 to 279.7200.322661122.66Alkalinitymg/L1.99 to 36002.0311116120.61S2-mg/LND811NDNDNDND

# PRZM/EXAMS Modeling Conventional Uses of Copper24PRZM/EXAMS Inputs•Kd400 L/kg (Sand)3600 L/kg (Clay)•12 crops modeled•CA, MN, NC, TX, PA, FL, IL, OH,GA, ID,ME•Application Rate0.59 to 35.62 kg Cu/ha•First-year Peak Concentration1.8 μg/L - 350 μg/LRelationship of Cu Application Rateand Peak Cu ConcentrationCu Application Rate (lb Cu/A)0 510 15 20 25 30 35

P e a k C u

2 + C o n c ( u g / L )020406080100Y=-0.3800+2.5358(X) r2=0.75

# Risk Description of Conventional Uses of CopperToxicity Profile for 

# Daphnia magnazThreshold for 5% ofUSGS sites exceedingOPP level of concern of0.53.4 μg Cu/L1.68 kg Cu/ha25Acute Site ExceedanceCu Concentration (ug/L)0100200300400

Percent Site Exceeding LOC0102030405060708090100Rainbow Trouty=-0.8624 + 0.244*X, R2=0.9865Daphnia magnay=105.53(1-e-0.0143*X), R2=0.9957

# Uncertainties, Limitations, Assumption Conventional Copper Exposure AssessmentzAssume chemical equilibria controls ionic copper concentrationsNo reaction kineticszPRZM/EXAMS modeling with the static pond predicted year-toyear accumulation of copper concentration in the water columnNo mineral precipitation/dissolutionNo sediment burialzMedian water quality data at each site were used26

# Introduction to the Office of Pesticide Program’s Environmental Exposure Modeling and Assessment Part 2: Dr. Siroos Mostaghimi, EPAFIFRA SCIENTIFIC ADVISORY PANELConsultationOctober 25-26, 2011U.S. Environmental Protection AgencyOffice of Pesticide ProgramsWashington, DC27

# EXPOSURE ASSESSMENT FOR ANTIMICROBIAL USES OF

COPPER2829



# OutlinezMajor Use PatternsWood PreservativesRoof ShinglesAntifoulant PaintszExposure Assessments for Major UsesResidential Uses – Treated WoodResidential Uses – Roof ShinglesMarinas/Harbors – Antifoulant Paint30 

# Major Usage Patterns – Wood PreservativeszApplied to wood by pressure treatment to prevent wooddecay31 

# Major Usage Patterns – Roof ShingleszMixed into component materials of shingles to prevent algaeformation32 

# Major Usage Patterns – AntifoulantszMixed into paints and then applied to boat hulls/bottoms toprevent biofoulingzUsed Marine Antifoulant Model to Predict EnvironmentalConcentrations (MAMPEC)

# Exposure Assessment for Antimicrobial Copper33Biotic LigandModel(Speciation Mode)Exposure:Developing Activity-basedSite Specific EECsEffects:Developing ActivitybasedSite Specific LC50sSite SpecificDaphnia magnaLC50(mol Cu2+/L)Site SpecificUSGS Water QualityMonitoring DataSite Specific RQsDaphnia magna(unitless)Site specific EECs(mol Cu2+/L)Site SpecificDaphnia magnaLC50(ppb)Biotic LigandModel(Toxicity Mode)Using emission rates, and specificscenarios based on use patterns toestimate the dissolved Cuconcentration in a standard pondEECs (ppb)[Cu]total dissolved34 

# Conceptual Model for Antimicrobial Uses of CopperTreated Wood Decking, Fencing, Utility Poles, ShinglesAquatic PlantsInvertebrates, VertebratesIndividual OrganismsReduced survivalGrowth reductionReduced reproductionFood ChainReduced productionShift in community competitionHabitat ChangeReduction in primaryproductivityStressorSourceReceptorAttributeChangeLeaching from Wood and ShinglesExposureMediaWater/SedimentRainRunoff35 

# Antimicrobial Residential Scenario for Copper Used on Shingles and WoodAssumptions:zDeck, fencing ,utilitypoles and shingleson residentialproperty have allbeen treatedzResidential propertiesare adjacent andshare fencingzRunoff from thewatershed andproperties flows intothe same pondthrough impervioussurfaces.36 

# Residential Uses – Treated Wood Variable ValuesParameterValueUnitsHousing Density9.88houses/haTotal Number House in Watershed98.8housesRainfall event (upper 10 percentile in Jackson,Mississippi)0.125mPond Volume20E6litersPole exposed surface area4.38m2Deck exposed surface area17.84m2Wood fence exposed surface area146.32m2Exposed surface area for decks in 10 Ha1762.59m2Exposed surface area for wood fences in 10 Ha14456.42m2Exposed surface area for poles in 10 Ha432.74m2Total exposed surface area for decks, fences andpoles16651.75m2Copper emission rate for treated wood3.2mg Cu2+m-2mm-1rainfall37Tier 1 Modeling: ImperviousSurfaceszDissolved Cu concentration=333 μg/LAssumes direct runoff into pondAssumes runoff over impervioussurface (driveway, etc.)z97 % of USGS sites exceededthe LOC of 0.5Refined Modeling: PerviousSurfaceszUsing PRZM/EXAM derived regressionequationsAssumed runoff over soilSingle event conc.= 2.29 μg Cu/Lz3.3% of USGS sites exceed theLOC of 0.530 year daily time series (Jackson, MS)

Cu Concentration (ug/L)01234Concentration for 5%of Sites Exceed Acute Daphnia LOC 

# Exposure Assessment for Antimicrobial Uses of Copper on Wood38 

# Residential Uses – Roof Shingles Variable ValuesParameterValueUnitsHousing density9.88houses/haTotal number house in watershed98.8housesRainfall event (upper 10thpercentile inJackson, Mississippi)0.125mPond volume20E6litersRoof area per house232.36m2Copper emission rate (Maximum)0.38mg Cu2+m-2mm-1rainfallCopper emission rate (Minimum)0.05mg Cu2+m-2mm-1rainfallCopper emission rate (Average)0.16mg Cu2+m-2mm-1rainfall

# Exposure Assessment for Antimicrobial Uses of Copper on Roof Shingles39Tier 1 Modeling: Impervious SurfaceszEstimated Dissolved Cu Concentration =22.96 μg/LAssumed direct runoff into pondAssumed runoff over impervious surface (driveway, etc.)Assumed average emission rate from shingles (0.16 mg m-2mm-1)Assumed 4 houses per acrezUsing BLM , 18 % of USGS sites exceeded the LOC of0.5

# Exposure Assessment for Antimicrobial Uses of Copper on Roof Shingles40Refined Modeling: Pervious SurfaceszUsing PRZM/EXAM derived regression equationsAssumed runoff over soilUsed Jackson, Mississippi weather dataApplication rates for single events ranged from 0.00012 to0.0711 lb/A CuzNo USGS site exceed the LOC of 0.5

# Uncertainties, Limitations, Assumption for Antimicrobial Copper Exposure AssessmentzLack of reliable informationNumber of houses per acrePercentages of roof shingle and wood structures treated withcopper•Assumed 100% of roofs and wood structures were treated with copperSize of wood structures and roof surface areaRatio of pervious and impervious areas in a watershedzVariationCopper emission rates from wood and shingles•Used average rates for shinglesEnvironmental factors•Assumed a one rainfall event of 0.125 meters4142 

# Questions