201• 529 • 5151www.hydroqual.com

HydroQual Capabilities for Pathways Analysis in Support of Natural Resource Damage Assessment

HydroQual Capabilities for Pathways Analysis in Support of Natural Resource Damage Assessment

Why Consider Models for Pathways Analysis?

Why Consider Models for Pathways Analysis?

• Models link the sources with observed body burdens in organisms

• Models can add value to data by extending spatial and temporal coverage

• Models have predictive capabilities - what will the future of the resource be after remedial action?

Pathways Analysis Model ComponentsPathways Analysis Model Components

Noted HydroQual Model Component Experts

Noted HydroQual Model Component Experts

• Hydrodynamic Transport – Nicholas Kim

• Organic Carbon Production – James Fitzpatrick

• Chemical Fate and Transport – Robin Landeck Miller

• Biotic Ligand Model – Robert Santore

• Food Chain/Bioaccumulation – Kevin Farley

• Toxicity Prediction – Joy McGrath

Hydrodynamic TransportHydrodynamic Transport

•Rivers, lakes, streams, estuaries, coastal ocean, embayments in 1-D, 2-D, or 3-D

•Landside loadings and atmospheric exchanges and fluxes

•Several model codes (ECOM, EFDC, RRMP, SWMM)

•Accounts for physical movement of the water and dissolved and particulate substances

Selected Hydrodynamic Circulation StudiesSelected Hydrodynamic Circulation Studies

Sediment TransportSediment Transport

•Directly linked to hydrodynamic model results

•Can be used to support contaminant fate and transport with “foc” approach

•Addresses both cohesive and non-cohesive sediment types

•ECOMSED and GLERL codes

•Provides vertical phase transport terms for particulate contaminants (settling, burial, resuspension)

Organic Carbon ProductionOrganic Carbon Production

•Directly linked to hydrodynamic model results

•May also be linked to sediment transport model results

•A refinement over “foc” approaches (particularly for low molecular weight PCB homologs)

•RCA code

•Provides direct calculation of the phase to which hydrophobic organic contaminants partition with independent checks

Selected Eutrophication StudiesSelected Eutrophication Studies

Contaminant Fate and TransportContaminant Fate and Transport

•Directly linked to hydrodynamic transport and organic carbon production model results

•Multiple pollutant types (HOC’s, metals, methyl mercury)

•Can be modified to support relevant processes (volatilization, photolysis, dechlorination, phase partitioning)

•WASTOX, GISTOX, RCATOX codes

•Provides for the movement and transformation of dissolved and particulate phases of contaminants

Selected Toxic/Chemical Fate ModelingSelected Toxic/Chemical Fate Modeling

Housatonic River & NY/NJ Harbor recently completed

The Biotic Ligand Model (BLM)The Biotic Ligand Model (BLM)

• Uses standard chemical parameters as inputs (pH, DOC, alkalinity, cations, anions)

• Can predict metal toxicity to aquatic organisms

• BLM predictions can be used to assess potential risk due to environmental metal concentrations

• Can be used to look at spatial, temporal trends in a water body or region

Generalized BLM FrameworkGeneralized BLM Framework

Competing Cations

Metal ion

M+2

Free

H+

Ca+2

Na+

OrganicLigandComplexes

InorganicLigandComplexes

Gill Surface(biotic ligand)

Metal BindingSite

M OH+

M CO3+

M Cl+

M - DOC Metal ion

M+2

Free

San Francisco Bay Case StudySan Francisco Bay Case Study

Sal

i ni ty

(ppt

)D

OC

(mg/

L)pH

0

10

20

30

40

02468

10

456789

10

02468

10

-10 0 10 20 30 40 50

WE

R

Distance from Golden Gate Bridge (miles)

PREDICTED AVERAGE AND RANGE

BAY-WIDE

WER = 1.7

(Data: S.San Francisco Bay RMP, 1993 - 1996)

BLM Application StatusBLM Application Status

• Applied to Cu, Ag, Zn

• Cd, Ni, Pb under development

• No Al or Cr

• Acute toxicity, aqueous exposures

• Mostly freshwater

Where BLM is HeadingWhere BLM is Heading

• Chronic Exposures

• Multiple routes of exposure (i.e., particulate metals)

• Multiple metals

• Include sediment pore water effects in addition to SEM:AVS

Toxicity PredictionToxicity Prediction

• Answer the question, “What level of a contaminant causes an effect?”

• Difficult because bioavailability varies over a wide range of contaminant concentrations

• Approaches developed:Equilibrium partitioningSEM:AVSNarcosis theory/target lipid model

• Has led to sediment quality criteria

Selected Ecological Risk EvaluationsSelected Ecological Risk Evaluations

• Sediment concentrations normalized to correct for varying bioavailability.

• Published by EPA ORD as “Sediment Quality Benchmarks” (2000)

- Nonionic Organics (EPA-822-R-00-001, -002) - Dieldrin, Endrin (EPA-822-R-00-003, -004) - Cd, Cu, Ni, Pb, Zn and Ag as mixtures (EPA-822-R-00-005) - Total PAHs as mixtures

Equilibrium Partitioning (EqP)Equilibrium Partitioning (EqP)

Pore Water NormalizationPore Water Normalization

• Narcotics

• Based on Universal Narcosis Slope

• Toxicity is Additive

• Lipid Based Body Burden

PAH CriteriaPAH Criteria

Predicted Toxicity for Single PAHs and PAH Mixtures in Sediments

Predicted Toxicity for Single PAHs and PAH Mixtures in Sediments

Contact InformationContact Information

Further information on HydroQual’s Natural Resource Damage Assessment services may be obtained from:

Robin Landeck MillerHydroQual, Inc.

1200 MacArthur BoulevardMahwah, New Jersey 07430

201-529-5151 ext. 7119rmiller@hydroqual.com