1 Welcome Thanks for joining this ITRC Training

1 Welcome – Thanks for joining this ITRC Training Class ITRC Internet-based training and Technical and Regulatory Guidance Incorporating Bioavailability Considerations into the Evaluation of Contaminated Sediment Sites (CS-1, 2011) Sponsored by: Interstate Technology and Regulatory Council (www. itrcweb. org) Hosted by: US EPA Clean Up Information Network (www. cluin. org)

2 Housekeeping Download slides as PPT or PDF Go to slide 1 Move back 1 slide Move forward 1 slide u u u Go to last slide Course time is 2¼ hours Question & Answer breaks • Phone - unmute #6 to ask question out loud; *6 mute • Simulcast - ? icon at top to type in a question Turn off any pop-up blockers u u u Go to seminar homepage Submit comment or question Report technical problems Move through slides • Arrow icons at top of screen • List of slides on left Feedback form available from last slide – please complete before leaving This event is being recorded Copyright 2014 Interstate Technology & Regulatory Council, 50 F Street, NW, Suite 350, Washington, DC 20001

3 ITRC (www. itrcweb. org) – Shaping the Future of Regulatory Acceptance u u Host organization Network • State regulators u Disclaimer • Full version in “Notes” section • Partially funded by the U. S. § All 50 states, PR, DC government • Federal partners § ITRC nor US government warrantee material § ITRC nor US government DOE DOD endorse specific products EPA • ITRC Industry Affiliates Program • ITRC materials copyrighted u Available from www. itrcweb. org • Technical and regulatory guidance documents • Academia • Community stakeholders • Internet-based and classroom training schedule • More…

4 Meet the ITRC Instructors John Cargill Diana Marquez Delaware Department of Natural Resources and Environmental Control New Castle, Delaware 302 -395 -2622 john. cargill@state. de. us Burns & Mc. Donnell Engineering Company Kansas City, Missouri 816 -822 -3453 dmarque@burnsmcd. com Steve Clough Greg Neumann Haley & Aldrich, Inc. Manchester, New Hampshire 603 -391 -3341 sclough@ haleyaldrich. com New Jersey Department of Environmental Protection Trenton, New Jersey 609 -633 -1354 greg. neumann@ dep. nj. gov

5 ITRC Sediments Team u. States u. Federal Alabama California Delaware Florida Kentucky Michigan New Jersey New York Oklahoma Oregon Pennsylvania Texas Washington u. Universities • Purdue • U. of Florida • U of Texas Navy Army AFCEE EPA Including Region 2 & 5 • USACE • DOE u. Community Stakeholders • Mtn Area Land Trust • AAEJC u. Industry • AMEC • Alta Environmental • AECOM • AFMC • Alcoa • Arcadis • • • • • Agencies • Battelle • Beacon • Brown and • • • Caldwell Bootheel LEPC Burns & Mc. Donnell BP CDM CH 2 MHill CETCO Columbia Analytical Du. Pont Geosyntec EMCBC Environ Exxon. Mobil Haley & Aldrich, Inc • Kleinfelder • Langan • • • • Engineering LATA-Kemron Malcolm Pirnie M. W. Global MWH Reg. Tech Neptune and Co. SAIC W. L. Gore SRNL Test America labs Tetra Tech URS WRI SPAWAR SSC Shell

6 ITRC Web-based Guidance Outline u u u Introduction and background on bioavailability Overview of bioavailability processes Bioavailability pathway exposure assessment • Screening • Background • Pathway exposure assessment § Benthic invertebrates § Fish and water column invertebrates § Wildlife § Plants § Human health u Risk management decision-making http: //www. itrcweb. org/ contseds-bioavailability/

7 What You Will Learn… The intended users of this guidance are individuals who have a working knowledge of contaminated sediment management but seek additional information about bioavailability. u u u What is bioavailability? When do we apply bioavailability adjustments? What are the available tools and how do we use them? How do we use the information to make risk management decisions? You will NOT learn how to conduct a Risk Assessment that incorporates bioavailability.

8 The Problem! u US EPA reports – 10% (1. 2 billion yds 3) of U. S. sediment underlying surface water pose a potential ecological or human health risk u Cost of clean-up is in the trillions u Contaminant concentration in sediment and actual exposure is not a direct relationship u Bioavailability will give a more accurate characterization of exposure Conventional Clamshell Excavator USACE 2008. Technical Guidelines for Environmental Dredging of Contaminated Sediments

9 What is Bioavailability? “…individual physical, chemical, and biological interactions that determine the exposure of plants and animals to chemicals associated with soils and sediment (National Research Council, 2003). ” Specifically, bioavailability addresses the fact that only a fraction of the contaminant concentration present in the environment may be taken up or result in an effect on an organism!

10 How can Bioavailability Make a Difference? u If contaminants are not physically accessible, or chemically or biologically available, they should not be included in the calculation of risk u Can optimize the extent of cleanup required to be protective u Can provide optimization of remedial approach and cost u Can be an important factor in balancing the risks caused by remedial action

11 How is Bioavailability Being Used? u u 2008 – ITRC Team distributed questionnaire to assess extent bioavailability was used for the development of site cleanup levels 35 case studies collected (Table 9 -1 and Appendix D) • Summarized exposure pathways addressed • Summarized contaminants evaluated/addressed • Summarized tools used at each site • Includes contacts for more information about each site

12 Questionnaire Results u Most common exposure pathways evaluated • Benthic exposure • Human health • Pelagic exposure u Most common tools used to assess bioavailability • Bulk sediment chemistry • Tissue sampling (fish, bivalves, other water column receptors) • Porewater chemistry • Bioassays of benthic invertebrates

13 Risk Management Role in Decision. Making u Risk management integrates the results of the risk assessment with • • • u Technical Political Legal Social Economic objectives Bioavailability is used to make risk management decisions within the • Risk assessment - Section 9. 1 • Remedy selection – Section 9. 2, Table 9 -2 • Remedial design/Implementation – Section 9. 2

14 Risk Assessment The assessment of risk to all receptors identified at a contaminated sediment site related to physical, chemical, and biological processes! u u Bioavailability should be used to actively refine conceptual site model (CSM) Risk assessment will likely involve a “weight of evidence” approach, or “multiple line of evidence” approach • Be aware of sources of variation in risk assessments • Collect data essential to risk assessment • Analyze to understand exposure and risk • Remember: bioavailability is highly site specific u u Be aware of your stakeholder interests, and communicate with them regularly View ITRC’s Use of Risk Assessment in Management of Contaminated Sites (Risk-2, 2008) – available from www. itrcweb. org

15 Risk Assessment & Bioavailability u Advantages • If contaminants aren’t bioavailable, then they aren’t included in the evaluation of risk (no exposure) • Optimization of cleanup goals, with a possible cost reduction • More effective use of available resources • Can achieve more accurate defensible cleanup goals while ensuring protection of receptors u Challenges • Uncertain acceptance by regulators, stakeholders, and the public • Bioavailability may vary across a site (or operational units) • Potentially higher site characterization costs • May take longer to gain full understanding of site conditions

16 Remedy Selection u u Bioavailability evaluation within risk assessment process will result in selection of remedy that will better address concerns at site Example: Mocks Pond Case Study • Site history and bulk sediment testing identified contaminants of potential concern (COPCs) • Further evaluated using bioavailability tools § In-situ pore water metal concentrations § Chemical analyses of whole body and fillets of pelagic fish species

17 Remedial Design and Implementation u u Risk mitigation, reduction, or removal is ultimate goal of every remedial action If bioavailability indicates adverse impact to receptors, then design the remedy accordingly Bioavailability measurement tools can be used to monitor effectiveness of remedy Reduction in uncertainty will enhance ability to evaluate monitored natural recovery

18 Limitations and Uncertainty u u There are uncertainties with data assessment methods and models Aquatic environments are dynamic, which may alter physical, chemical and biological properties, and therefore bioavailability factors, through time Stakeholder interests and land usage at or surrounding a site can change over time, thus shifting remedial priorities Regulatory acceptance cannot be assumed Just remember. . . u Collect data that answers a question about the site u Knowing your site and good communication is the key

19 Contaminated Sediment Assessment Approach

20 Scoping Your Site…. Chapter 2 u u Site history - Due Diligence Site boundaries (extent of contamination) Contaminants of potential concern (COPC) Conceptual site model (CSM) – source, exposure pathway/route, receptors, space, time, fate & transport

21 Processes to Consider During Scoping • • Physical Bed Transport Deposition/ Resuspension Bioturbation Advection/diffusion Grain size COPC distribution Burial Temperature Caution – Sediment are mixtures Chemical • Sorption/desorption • Transformation/ degradation • Geochemical (TOC, salinity, p. H, Redox) • • • Biological Uptake Biotransformation Bioaccumulation Mode of action Critical body burden

22 Example Conceptual Site Model Anacostia River Permitted Facility Discharge Urban • Storm Water Tributaries • Sewer • Water Treatment Plant • CSO Tidal Mixing/ Potomac River Surface Water Flow Direction Volatilization Uncharacterized Point Discharges Precipitation Non-Point Surface Run-off Suspended Dissolution Particles Bioaccumulation Adsorption Desorption Groundwater Recharge Resuspension Deposition Burial Surface Sediment Deep Sediment Epifauna Infauna Erosion Flow Direction Bed Load Transport Groundwater Discharge

23 Screening Your Site…Chapter 3 u u Screening values (e. g. SQVs) are not site specific Conservative values • Levels below which there is a good probability there is low risk • Values above screening levels do not imply unacceptable level of risk Determine if there is a need for further investigation u Do not use as clean up levels/PRGs Many SQVs have been established u Beware – know how your screening levels were derived! (e. g. Mc. Donald 2000 “consensus” values) u

24 Screening and Bioavailability u u Normalization of bulk sediments (section 3. 1. 2. 2) can be applied within the screening process under some state regulatory programs (e. g. TOC for PAHs/Eq. P; iron, aluminum for metals) However the assessment of site impacts is improved by incorporating bioavailability in later stages of the site investigation using site specific considerations Source: NRC, 2003

25 Specific Exposure Pathways

26 Most Common Exposure Pathways

27 Benthic Pathway…Chapter 4

28 Procedures for Assessing Bioavailability to Benthic Invertebrates u Sediment Quality Triad (SQT): Chemistry (bulk sediment and pore water concentration) Toxicity (solid phase; extract/leachate; bioaccumulation) Biology (macroinvertebrate abundance, diversity, benthic indices, body burden)

29 Tools to Assess the Benthic Pathway; Chemical - Sediment u SEM/AVS • Simultaneously Extracted Metals/ Acid Volatile Sulfides u SEM-AVS/f. OC No Toxicity Uncertain Toxicity Probable From EPA-600 -R-02 -011, 2005 130 3000

30 Tools to Assess the Benthic Pathway; Chemical - Porewater u u Porewater (Direct) • • • Centrifugation (lab) Syringes/suction devices Piezometers Ultraseep/Trident probe SPME (solid phase microextraction; EPA SW-846 8272; ASTM D 73 -63 -07) Porewater (Indirect) • Peeper • SPMD (semi-permeable • • membrane device) / dialysis bags Diffusion in thin films (DGT) SPME, POM (Polyoxymethylene) film, PE (Polyethylene) strips GORE® Module Diffusive flux Surface Water Oligochate Sediment Surface Sediment Particles Porespace filled with water (porewater)

31 Tools to Assess the Benthic Pathway; Chemical - Porewater (Direct) – Suction Devices Airstone “Before” Airstone “After”

32 Tools to Assess the Benthic Pathway; Chemical - Porewater (Indirect) – SPMD/Dialysis Bags SPMD “Before” SPMD “After”

33 Tools to Assess the Benthic Pathway; Chemical - Porewater (Indirect) – “Peepers” Assembled Sampler components Clear acrylic body Cell Membrane Lexane wedge Dialysis Base plate membrane Cover

34 Tools to Assess the Benthic Pathway; Chemical - Porewater (Indirect) – “Peepers” Depth (cm) 40 Water column 20 0 Black ooze -20 -40 -60 -80 0 Photographs courtesy of A. Lee Gustafson, Net Zero LLC 1 2 3 4 Arsenic (mg/L) Tan medium sand 5 6 South Central North

35 Tools to Assess the Benthic Pathway; Chemical - Porewater (Direct) – Trident Probe and Ultraseep Trident Probe* Ultraseep* *http: //www. oceanscience. com/pdf/ultraseep_trident. pdf

36 Tools to Assess the Benthic Pathway; Chemical - Porewater (Direct/Indirect) – SPME (Solid Phase Micro Extraction) Syringe Sample Vial

37 u u Tools to Assess the Benthic Pathway; Chemical - Porewater (Indirect) – GORE® Module Screening tool that can be used to sample porewater Measure concentrations in GORE lab only Cord Verified use in groundwater attached to To Surface float or Mainly effective for VOCs insertion probe Multiple sorbents in sample Water and soil particles remain outside GORE-TEX membrane Organic vapors pass through

38 Tools to Assess the Benthic Pathway; Biological - Sediment Toxicity Tests Hyalella azteca FRESHWATER Neanthes arenaceodentata BRACKISH OR SALTWATER Chironomus dilutus Eohaustorius estuarius

39 Tools to Assess the Benthic Pathway; Biological - Macroinvertebrate Surveys “Pollution Sensitive” “Pollution Tolerant” Benthic Metrics: Abundance, Richness, %EPT, %Dominance, %Chironomids, Hilsenhoff’s or Shannon-Weiner Diversity Indices

40 Tools to Assess the Benthic Pathway; Biological - Minimally Disturbed Stream Photos courtesy of Susan Davies, Maine DEP

41 Tools to Assess the Benthic Pathway; Biological - Stream Adjacent to Shopping Mall Photos courtesy of Susan Davies, Maine DEP

42 Tools to Assess the Benthic Pathway Predictive u u Sediment – Pore Water Exposure Equilibrium partitioning Narcosis model SEM-AVS/f. OC Biotic ligand model Biota Sediment Carbon Ca 2+ Na+ H Competing Cations Biotic Ligand Model M-DOC M 2+ Organic Matter Complexation Free Metal + Ion Pore Water Equilibrium partitioning M-Biotic Ligand Site of Action MOH MHCO 3+ MCl+ Inorganic Ligand Complexation Tipping, 1994

43 Case Study Using the Benthic Pathway Tectronix Wetlands Beaverton, OR u Historic operations → sediment metals exceeding Oregon Department of Environmental Quality (DEQ) Level II screening level values • Assessed chemistry, toxicity, SEM/AVS, TOC § Maximum (SEM-AVS)/foc was ~10 less than EPA’s adverse effect level • Toxicity tests § Hyalella azteca mortality § Chironomus dilutus growth § No adverse effect on amphipods or midges u u Assessment concluded concentrations did not pose potential risks to benthic community NFA for stretch of Beaverton Creek based on • Results from bulk sediment chemistry • Toxicity testing • Comparison to (∑SEM-AVS)/f. OC toxicity threshold Photo courtesy Kathleen Hurley

44 Questions & Answers

45 Fish and Water Column Invertebrates Pathway…Chapter 5

46 Tools to Assess the Fish and Water Column Invertebrates Pathway Chemical u Measure water quality above sediment bed → compare to • National recommended water quality concentration • State water quality standards u Measure water and tissue residues → compare to • Bioaccumulation Factors (BAF) • Critical Body Burden (CBB): ~2. 5 umol/g wet weight • Toxicity Reference Values (TRV) u Measure Biota-sediment accumulation factors (BSAFs) = [COPCtissue/flipid] / [COPCsed/f. OC] • <1 or >1?

47 Tools to Assess the Fish and Water Column Invertebrates Pathway Biological u u u Conduct sediment toxicity tests using appropriate organisms and conditions Measure in situ bioavailability from field-collected organisms Conduct population surveys → compare to “reference” conditions

48 Tools to Assess the Fish and Water Column Invertebrates Pathway Predictive u Accumulation factors • Bioconcentration factors § USEPA EPISuite • Bioaccumulation factors § Public domain § Peer-reviewed literature • Biota-sediment accumulation factors § e. g. U. S. Army Corp of Eng or ORD BSAF Dbase • Biomagnification factors u u Biotic ligand model (metals) Food web models

49 Case Study Using the Fish and Water Column Invertebrates Pathway Mc. Cormick and Baxter Superfund Site, OR u u u Residual creosote-derived contaminants including PAHs and dioxins Assessments • • Sediment chemistry Bioassays Tissue residues in fish and crayfish Fish histopathology Results • Sediment chemistry and toxicity testing § Indicated area of the Willamette River - likely to be toxic • Tissue residues for PAHs were low in § Crayfish (Pacifastacus leniusculus) § Large scale sucker (Catastomus macrocheilus) § Examination of 249 fish livers found no statistical differences between the site and upstream locations u ROD required placement of an impermeable cap, based on • Sediment chemistry and bioassay data • Continuing NAPL discharges from sediments to Willamette River

50 Wildlife Pathway…Chapter 6

51 Tools to Assess the Wildlife Pathway: Indirect Measures u Wildlife effects (already known) • Bulk sediment (mg/kg) • Literature BAFs • Percent of diet u u u Saltwater (Sandpiper) Calculate: dose (mg/kg/day) Compare: to threshold reference value (TRV) Pass? • Yes → NFA • No → SLERA/BERA u Freshwater (Mallard) Exposure/effect: bioaccessibility in sediment Dose (mg/kg/day) = % Sediment (in diet) CSED (mg/kg) x %diet (kg/day) = mg/kg/day

Tools to Assess the Wildlife Pathway; Indirect Measures log. W-PBET gizzard Pb (mg kg-1) 52 4 3 2 1 0 0 1 2 3 4 5 6 7 Blood Pb (mg kg-1, wet weight) Photo courtesy of Nick Basta, Soil & Envir. Chemistry, Ohio State Univ. Furman et al. , J. Environ. Qual. 35: p. 450 https: //www. soils. org/publications/ jeq/articles/36/3/899

53 Tools to Assess the Wildlife Pathway; Direct Measures u Tissue residue analysis • Need clear endpoints u Toxicity testing • Expensive but sitespecific u Food web modeling • Simple vs. complex u Population surveys 13. 8 ppm Tertiary consumers 2. 07 ppm Secondary consumers 0. 23 ppm Primary consumers 0. 04 ppm Producers • Consider scale vs. home range

54 Plants Pathway…Chapter 7

55 Tools to Assess the Plants Pathway u u u Bioassay (e. g. seedlings) Bioaccumulation (vegetative) Plant toxicity (e. g. boron)

56 Human Health Pathway…Chapter 8

57 Exposure in Human Health Pathway u Direct contact with sediment • Ingestion • Dermal contact u Consumption • Fish • Wildlife • Plant Incidental Sediment Ingestion Fish & Wildlife Ingestion Fish Water Fowl Aquatic Surface Water Vegetation Benthic Pore Organisms Water Soil/Groundwater Sediment

58 Direct Contact u Preliminary screening • Compare bulk sediment concentrations to human healthbased soil screening levels (SSLs) u Refine screening levels • Modify exposure variables • Modify bioavailability assumptions § Adherence of sediments to skin § Dermal absorption efficiency § Gastrointestinal absorption efficiency

59 Human Consumption of Fish and Shellfish u Contaminants of concern • Primarily concerned with bioaccumulative constituents • In general bioaccumulation concerns should be limited to select classes of organics (pesticides, PCBs, dioxins) and mercury u Adjust screening levels • Contaminant concentration available in sediment pore water (Section 4) • Site specific conditions such as TOC or fish lipid fraction u Direct tissue analysis

60 Human Consumption of Fish and Shellfish u Adjust screening levels – example (Text Box 8 -1) • Recreational human fisherman screening level = 0. 019 mg/kg for hexachlorobenzene (HCB) § Default values for fish lipid fraction = 0. 03 § Sediment fraction organic carbon (foc) = 0. 01 • Site-specific screening level = 0. 28 mg/kg § Used site-specific fish lipid fraction of 0. 02 and foc of 0. 10 • Applying site-specific information raises screening value 15 x

61 Human Consumption of Wildlife and Plants u Wildlife • Incidental ingestion of sediment, aquatic vegetation and benthic and/or pelagic organisms • Obtain information on dietary habits of species of concern • Addressed in Chapter 6 u Plants • Grown in contaminated area (e. g. seaweed, wild rice) or crops in dredge spoils • Tissue sampling to determine COPCs • Addressed in Chapter 7

62 u u Case Study – Industri-plex Superfund Site Once nation’s leading producer of lead arsenate 2 -step study of arsenic in river sediments • Step 1 – Narrow focus for live tests § In vitro test on river sediments from four areas § Sediments in reactor that simulates the stomach fluid of humans • Step 2 – Test relative bioavailability to humans § Tested two sets of river sediment materials § Immature swine fed dough balls with sediment test materials § RBA of the site sediments were 37% and 51%, respectively u Study reduced the estimated human health risk in half

63 Case Study Using Bioavailability Indiana Steel and Wire Site - Mocks Pond

64 Site Description and Background u u Galvanizing plant, Muncie, Indiana 2. 8 acre former limestone quarry • Received plant production wastewater from 1962 -1973 • Lime was added to neutralize wastewater before discharge to pond • Pond contained 51, 000 cubic yards of stabilized spent pickling sludge • Sediment samples contained high concentrations § Heavy metals (Sb, As, Cd, Cr, Cu, Pb, and Zn) § Cyanide

65 Site Characterization Efforts u Sediment and surface water investigations • Sediment toxicity and leachability studies (1980’s) • Waste characterization study (1993) • Standard bulk chemistry sediment and surface water sampling for metals and cyanide (1999) u Biological assessment • Water column properties assessment including plankton type • Macroinvertebrate and fish surveys • Fish tissue sampling for metals and cyanide • Wildlife surveys

66 Site Characterization Results: Surface Water and Sediment u Physical nature of the sludge not conducive to benthic organisms • Fine grained • No organic matter/nutrients u u u Neutralization of the wastewater discharge with lime forming insoluble metal hydroxides suggested lack of metals bioavailability Preliminary surface water sampling results in compliance with water quality standards Sediment results exceed sediment screening criteria (SSC) Concentration SSC Cr 21 - 2, 100 ppm 120 ppm Cu 150 - 6, 210 ppm 100 ppm Pb 201 - 8, 000 ppm 82 ppm

67 Site Characterization Results: Biological Assessment u Healthy populations • Present § Pelagic fish § Phytoplankton § Zooplankton species • Absent § Benthic fish § Macroinvertebrates

68 Bioavailability Investigation Activities: Human Health Risk Assessment u Screened sediment and fish data • Indiana Tier II residential cleanup goals for soil • EPA Region III Residential RBCs for fish tissue u u u COPECs in sediment: Sb, Cr, Pb and Zn Fish tissue: As Exposure routes • Incidental ingestion • Dermal contact • Ingestion of fish u Receptors • Future construction workers • Park worker and recreational visitors • Anglers

69 Bioavailability Investigation Activities: Human Health Risk Assessment (continued) u Used exposure modeling to determine risk • IEUBK model for Pb • Intake modeling for other metals Conclusion: Remediation of pond sediment is necessary to address direct contact issues with Pb in sediment to the future construction worker and ingestion of arsenic in fish tissue for future recreational anglers.

70 Bioavailability Investigation Activities: Ecological Risk Assessment u Screened sediment and fish tissue data • Sediment criteria § Assessment and Remediation of Contaminated Sediments (ARCS) Program for the Great Lakes Threshold Effects Levels (TELs) § Lowest Effects Levels (LELs) (Persuad, 1993) § Washington State Lowest Apparent Effects Thresholds (LAETs) • Fish tissue criteria § Compared to background concentrations from White River

71 Bioavailability Investigation Activities: Ecological Risk Assessment (continued) u Sediment COPCs u • Sb, As, Cd, Cr, Cu, Pb, Hg, • Benthic invertebrate • Piscivorous birds • Piscivorous mammals Ni, Ag, Zn and cyanide u Fish tissue COPCs • None (concentrations less than background) u Exposure routes • Incidental ingestion • Dermal contact • Ingestion of fish Receptors u Used dietary exposure modeling to determine risk to higher trophic level organisms Conclusion: Considerable level of risk exist to benthic organisms, benthic fish and submerged and emergent aquatic macrophytes from sediment exposures due to levels of metals in sediment and the absence of these feeding guilds in the pond

72 Remedial Design: Sediment Excavation and Capping u u Dredging sediment to clear water depth of 10 feet Placement of a geotextile fabric liner followed by a subaqueous fine to medium grain sand cap atop the residual sediment Post-construction monitoring (borings/bathymetry) Five years of annual post-remedial monitoring to evaluate cap performance in restricting the migration of constituents into the biotic zone

73 5 Year Post-Remedial Monitoring and Bioavailability Testing u 5 Year Annual Monitoring Plan Pore water sampling to evaluate cap performance • In situ sampling via large diameter peepers • Inserted 10 centimeters into the sediment u u Surface water sampling to assess functional effects on the water column community Sediment sampling to confirm isolation of metal contamination

74 Post-Remedial Monitoring/ Bioavailability Investigation Findings u u Post-Construction Monitoring Results Cap performed in accordance with design • Uniformly overlies pond bottom • Physically stable • Effectively isolating the residual underlying sediment 5 Yr Annual Monitoring Results Sediment, surface water and pore water quality met site-specific standards • Metals tightly sequestered • Metals not biologically available

75 Sediment Quality Improvements and Case Study Summary Initial Post-Remedial Concentrations Range (1999) (at 5 th Year) Sediment Cleanup Standard Constituent (mg/kg) Antimony 36 to 315 0. 034 to 0. 11 B 64 Arsenic 8. 9 to 18 2. 2 to 6. 7 48 Cadmium 1. 3 to 12 0. 13 to 0. 39 3. 2 Chromium 21 to 2, 100 ND 120 Copper 150 to 6, 210 5. 9 to 80. 4 100 Lead 201 to 8, 000 4. 6 to 63. 8 82

76 Overall Course Summary u Bioavailability should be an integral part of characterization and remedial decision making u Bioavailability can be assessed throughout the process but is more justifiable after the initial screening process u Bioavailability will help you refine your exposure results and refine your risk management decisions See also: ITRC’s Remedy Selection for Contaminated Sediments http: //www. itrcweb. org/contseds_ remedy-selection/

77 Thank You for Participating u Question and answer break u Links to additional resources • http: //www. clu-in. org/conf/itrc/Con. Seds/resource. cfm u Feedback form – please complete • http: //www. clu-in. org/conf/itrc/Con. Seds/feedback. cfm Need confirmation of your participation today? Fill out the feedback form and check box for confirmation email.