EPA Superfund Record of Decision · EPA/ROD/R03-04/004 2004 € EPA Superfund Record of Decision:...

EPA/ROD/R03-04/0042004

EPA Superfund

Record of Decision:

NAVAL AMPHIBIOUS BASE LITTLE CREEKEPA ID: VA5170022482OU 03, 04VIRGINIA BEACH, VA12/15/2003

file:///L|/Data/SPIS/pdfprg/rods/coverpage/covR0304004.htm [8/17/2004 12:27:17 PM]

FinalRecord of Decision

Site 9: Driving Range Landfill – OU 3Site 10: Sewage Treatment Plant Landfill – OU4

Naval Amphibious Base, Little CreekVirginia Beach, Virginia

Prepared by

Department of the NavyAtlantic Division

Naval Facilities Engineering CommandNorfolk, Virginia

FinalRecord of Decision

Site 9: Driving Range LandfillSite 10: Sewage Treatment Plant Landfill

Naval Amphibious Base, Little CreekVirginia Beach, Virginia

Prepared by

Department of the NavyAtlantic Division

Naval Facilities Engineering CommandNorfolk, Virginia

II

Contents

1. Declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11.1 Site Name and Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11.2 Statement of Basis and Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11.3 Assessment of the Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11.4 Description of the Selected Remedy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11.5 Statutory Determinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-21.6 Record of Decision Data Certification Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

2. Decision Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12.1 Site Description and History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.1.1 Site 9 Driving Range Landfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12.1.2 Site 10 Sewage Treatment Plant Landfill . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.2 Previous Investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32.2.1 Initial Assessment Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32.2.2 Round 1 Verification Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32.2.3 Interim Remedial Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32.2.4 Remedial Investigation/ Feasibility Study . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32.2.5 Revised Remedial Investigation/ Human Health Risk Assessment/

Feasibility Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32.2.6 Current Investigations: Long-Term Groundwater Monitoring . . . . . . . . . . 2-42.2.7 Follow-Up Surface Soil Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

2.3 Enforcement Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42.4 Community Participation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42.5 Scope and Role of Response Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-42.6 Site Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5

2.6.1 Conceptual Site Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52.6.2 Site Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52.6.3 Surface and Subsurface Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-52.6.4 Sampling Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-62.6.5 Sources of Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-62.6.6 Types of Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-62.6.7 Location of Contamination and Routes of Migration . . . . . . . . . . . . . . . . . 2-62.6.8 Aquifer Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

2.7 Current and Potential Future Site and Resource Uses . . . . . . . . . . . . . . . . . . . . . . . 2-72.7.1 Current Site Land Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-72.7.2 Current Adjacent Site Land Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-72.7.3 Anticipated Future Land Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-82.7.4 Current Groundwater and Surface Water Uses . . . . . . . . . . . . . . . . . . . . . . 2-82.7.5 Future Uses of Ground/Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8

2.8 Summary of Site Risks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-82.8.1 Human Health Risk Assessment Summary . . . . . . . . . . . . . . . . . . . . . . . . . 2-92.8.2 Summary of Ecological Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

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2.9 Remedial Action Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-142.10 Description of Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14

2.10.1 Alternative 1 – No Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-142.10.2 Alternative 2 – Land Use Controls with Long-Term Monitoring . . . . . . . 2-142.10.3 Alternative 3 – Low-Permeability Cap . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15

2.11 Summary of Comparative Analysis of Alternatives . . . . . . . . . . . . . . . . . . . . . . . 2-162.11.1 Threshold Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-172.11.2 Primary Balancing Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-182.11.3 Modifying Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19

2.12 Principal Threat Wastes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-192.13 Selected Remedy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19

2.13.1 Summary of the Rationale for the Selected Remedy . . . . . . . . . . . . . . . . . 2-202.13.2 Description of the Selected Remedy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-202.13.3 Summary of the Estimated Remedy Costs . . . . . . . . . . . . . . . . . . . . . . . . . 2-202.13.4 Expected Outcomes of the Selected Remedy . . . . . . . . . . . . . . . . . . . . . . 2-21

2.14 Statutory Determinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-212.14.1 Protection of Human Health and the Environment . . . . . . . . . . . . . . . . . . 2-212.14.2 Compliance with Applicable or Relevant and Appropriate

Requirements and To-Be-Considered Criteria . . . . . . . . . . . . . . . . . . . . . 2-212.14.3 Cost-Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-222.14.4 Use Permanent Solutions and Alternative Treatment Technologies or

Resource Recovery Technologies to the Maximum Extent Practicable . 2-222.14.5 Preference for Treatment as a Principal Element . . . . . . . . . . . . . . . . . . . 2-232.14.6 Five-Year Review Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

2.15 Documentation of Significant Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23

3. Responsiveness Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Appendixes

A Toxicity DataB Site 9 Risk Assessment TablesC Site 10 Risk Assessment Tables D ARARs

Tables

2-1 Summary of Available Data and Data Selected for Use in the Human Health Risk Assessment for Sites 9 and10

2-2 Occurrence, Distribution and Selection of Chemicals of Concern Site 9 and Site 10, Groundwater

2-3 Medium-Specific Exposure Point Concentration Summary Site 9 and Site 10 Surface Soil, Current

2-4 Medium-Specific Exposure Point Concentration Summary Site 9 and 10 Groundwater, Tap

2-5 Medium-Specific Exposure Point Concentration Summary Site 9 and 10 Groundwater, Excavation Pit

2-6 Medium-Specific Exposure Point Concentration Summary Site 9 Surface Soil, Future

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2-7 Medium-Specific Exposure Point Concentration Summary Site 10 Groundwater,Vapors at Showerhead and Excavation

2-8 Selection of Exposure Pathways Site 92-9 Selection of Exposure Pathways Site 102-10 Exposure Pathways Sites 9 and 102-11 REM Exposure Parameters for Human Health Risk Assessment Sites 9 and 102-12 CT Exposure Parameters for Human Health Risk Assessment Sites 9 and 102-13 Features of Alternatives for Sites 9 and 10 2-14 Analysis of Remedial Alternatives for Landfill Contents and Surface Soil for Site 9

and 102-15 Engineer’s Preliminary Cost Estimate Sites 9 and 10, Alternative 2

Figures

2-1 IR Site and SWMU Locations2-2 Site 9 Groundwater and Surface Soil Sampling Locations 2-3 Site 10 Groundwater and Surface Soil Sampling Locations2-4 Conceptual Exposure Model NAB Little Creek Site 92-5 Conceptual Exposure Model NAB Little Creek Site 10

Acronyms

ARARs applicable or relevant and appropriate requirementsBERA Baseline Ecological Risk Assessmentbgs below ground surfaceBHHRA Baseline human health risk assessmentCERCLA Comprehensive Environmental Response, Compensation, and Liability ActCOCs Chemicals of concernCSFs carcinogenic slope factorsCT central tendencyERA ecological risk assessmentFFA Federal Facilities AgreementFWEI Foster Wheeler EnviresponseHHRA Human Health Risk AssessmentHI hazard indexHQ hazard quotientHRSD Hampton Roads Sanitation DistrictIAS Initial Assessment StudyIR Installation RestorationIRI Interim Remedial InvestigationLUC land use controlMCLs Maximum Contaminant LevelMF modification factorMWR Morale, Welfare, and RecreationNAB Naval Amphibious BaseNavy Department of the NavyNCP National Oil and Hazardous Substances Pollution Contingency PlanNPL National Priorities ListO&M operation and maintenancePCB polychlorinated biphenylPRAP Proposed Remedial Action PlanRAB Restoration Advisory BoardRAO remedial action objectiveRD Remedial Design

VIII

RfD reference doseRI/FS Remedial Investigation/ Feasibility StudyRI/HHRS/ Revised Remedial Investigation/ Human Health Risk Assessment/FeasibilityFS StudyRME reasonable maximum exposureROD Record of DecisionRVS Round 1 Verification Step SARA Superfund Amendments and Reauthorization ActSSL Soil Screening LevelTBC to-be-consideredUfs uncertainty factorsEPA U.S Environmental Protection AgencyVDEQ Virginia Department of Environmental QualityVSWMR Virginia Solid Waste Management Regulations

Record of Decision

Site 9: Driving Range Landfill

Site 10: Sewage Treatment Plant Landfill

1. Declaration

1.1 Site Name and LocationSite 9 Driving Range Landfill and Site 10 Sewage Treatment Plant Landfill Naval Amphibious Base (NAB), Little CreekVirginia Beach, VirginiaEPA ID: VA5170022482

1.2 Statement of Basis and PurposeThis Record of Decision (ROD) presents the Selected Remedy for Site 9 Driving Range Landfilland Site 10 Sewage Treatment Plant Landfill at the Naval Amphibious Base (NAB), LittleCreek, Virginia Beach, Virginia. This determination has been made in accordance with theComprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA),as amended by Superfund Amendments and Reauthorization Act of 1986 (SARA), and to theextent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan(NCP). This decision is based on the Administrative Record file for this site.

The United States Department of the Navy (Navy) and the U.S. Environmental ProtectionAgency (EPA) Region III issue this ROD (jointly). The Commonwealth of Virginia concurs withthe Selected Remedy.

1.3 Assessment of the SiteThe response action selected in this ROD is necessary to protect the public health or welfare orthe environment from actual or threatened releases of hazardous substances from the site(s).

1.4 Description of the Selected RemedyThe Selected Remedy to address contaminated soil and groundwater at Site 9 Driving RangeLandfill and Site 10 Sewage Treatment Plant Landfill is land use controls (LUCs) with long-termgroundwater monitoring. The Selected Remedy was determined based on the evaluation of siteconditions, site-related risks, applicable or relevant and appropriate requirements (ARARs), andRemedial Action Objectives (RAOs).

Creating LUCs and performing long-term groundwater monitoring provide the best alternativefor eliminating current and future exposure pathways to onsite contaminants. Consequently, theLUC objectives are:

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• Prohibit digging into or disturbing the existing cover or contents of the landfills.• Prohibit residential development on the sites.• Prohibit use of the shallow aquifer groundwater beneath the sites other than for

environmental monitoring and testing.

Implementation and maintenance actions to ensure the viability of the LUCs will be described inthe Remedial Design (RD). These actions will prevent unacceptable risks to receptors byeliminating direct exposure to the waste. Long-term groundwater monitoring at Sites 9 and 10will be conducted in accordance with the RD. Within 30 days of finalizing the RD, the Navy willamend the Site Management Plan to include the schedule for RD actions.

1.5 Statutory DeterminationsThe Selected Remedy is protective of human health and the environment, complies with federaland state regulations that are applicable or relevant and appropriate to the remedial action, anduses permanent solutions and alternative treatment (or resource recovery) technologies to themaximum extent practicable. In particular, the Selected Remedy (LUCs with monitoring)provides a level of long-term protection equivalent to the low-permeability cap described inSection 2.10, but at a greatly reduced cost. The Selected Remedy is therefore the most cost-effective remedy. An evaluation of remedial alternatives is provided in Section 2.10.

None of the alternatives examined includes treatment as a remedial option for the followingreasons:

• There are no principal threat wastes at these sites that require treatment. Groundwatercontamination, where present, occurs beneath the landfill in isolated wells and at lowconcentrations, below the relevant and appropriate Safe Drinking Water Act MaximumContaminant Levels (MCLs). No definable plume of contamination was identified and nogroundwater contamination was identified outside the perimeter of the landfill. In general,the EPA does not expect treatment of low concentration waste that poses a low level threatsuch as that present at the site.

• Treatment of the landfill contents is not practicable in a cost-effective manner because of thelarge volume of waste (the landfills cover 24 acres)

• Treatment of the groundwater contamination is not practicable in a cost-effective manner

The selected remedy will result in hazardous substances, pollutants, or contaminants remainingonsite, above levels that allow for unlimited use and unrestricted exposure. Therefore, a statutoryreview will be conducted within 5 years after initiation of the remedial action to ensure that theremedy is protective of human health and the environment.

1.6 Record of Decision Data Certification ChecklistThe following information is included in the Decision Summary section of this ROD. Additionalinformation can be found in the Administrative Record file for NAB Little Creek Sites 9 and 10.

• Chemicals of concern (COCs) and their respective concentrations• Baseline risk represented by the COCs

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• Current and reasonably anticipated future land use assumptions and current and potentialfuture beneficial uses of groundwater used in the baseline risk assessment and ROD

• Potential land and groundwater use that will be available at the site as a result of theSelected Remedy

• Estimated capital, annual operation and maintenance (O&M), and total present worth costs;discount rate; and the number of years over which the remedy cost estimates are projected

• Key factors that led to selecting the remedy (i.e., a description of how the Selected Remedyprovides the best balance of tradeoffs with respect to the balancing and modifying criteria,highlighting criteria key to the decision)

• Sites 9 and 10 do not contain “principal threat waste,” that is, highly toxic or highly mobilewaste that cannot be reliably contained or would pose a significant threat to human health orthe environment if containment failed. Accordingly, this ROD does not discuss a remedy forprincipal threat waste

2. Decision Summary

This ROD describes the Department of the Navy’s (Navy) and the EPA’s selected remedialaction for Site 9 Driving Range Landfill and Site 10 Sewage Treatment Plant Landfill at theNAB, Little Creek, Virginia Beach, Virginia. The Navy is the lead agency and provides fundingfor site cleanups. Sites 9 and 10 (Figure 2-1) are two of several Installation Restoration (IR) siteslocated at the NAB Little Creek facility.

2.1 Site Description and History

2.1.1 Site 9 Driving Range LandfillThe 6-acre Site 9 Driving Range Landfill is located in the northern portion of NAB Little Creek,Virginia Beach, Virginia, northwest of the golf course and east of Beach Drive (Figure 2-2). Anetwork of sand dunes that parallels the Chesapeake Bay shoreline bounds the northernperimeter of the landfill. The landfill generally coincides with the boundaries of the currentlyoperating driving range managed by Little Creek Base Morale, Welfare, and Recreation (MWR).The existing surface features include a relatively level and vegetated (grass turf) soil cover.

The Driving Range Landfill was used for disposal of solid waste from 1952 through 1956, andwas not closed under a regulatory authority program. Prior to landfilling operations, the area wasapparently a marsh or other lowland environment adjoining the easternmost arm of Desert Cove.Historic air photos indicate that the area of Site 9 was dry and isolated from Desert Cove prior tothe start of waste disposal, possibly due to dredge fill. Landfilling methods reportedly entailedthe excavation of trenches with a dragline or other heavy equipment. The trenches were filledwith waste and backfilled. The depth of excavation probably varied but was likely limited by thedepth to the water table, typically within 5 feet of the ground surface.

An incinerator, located on Hewitt Drive opposite the western perimeter of the Driving RangeLandfill, was active during much of this time, and apparently burned combustible materialsgenerated by NAB Little Creek. The resulting ash was disposed of in the Driving RangeLandfill, as were any noncombustible items that bypassed the incinerator. After the incineratorwas decommissioned, solid waste from the base was disposed of directly in the landfill. Some ofthis material may have been burned after being placed in the trenches.

The landfill is estimated to contain about 40,000 cubic yards of waste. Historical data concerningthe types and quantities of wastes in the landfill were not available, but it was reported that theyinclude various hazardous substances such as polychlorinated biphenyls (PCBs) and pesticidesas well as potentially large quantities of used motor oil. Given the sizable population of the baseand resulting significant quantities of nonhazardous solid substances that would be generated, itis likely that the overall quantity of hazardous waste is small compared to the total volume ofsolid waste placed in the landfill.

After landfill operations at the site were terminated, the installation covered the waste with cleansoil and converted the area into a driving range. A berm was constructed, using clean fill, alongthe east side of Hewitt Drive and sewage sludge was brought in from the Hampton

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Roads Sanitation District (HRSD) treatment plant along the southern base boundary to enhancegrowth of the grass.

A soil cover survey (CH2M HILL February 2000) revealed that there are 2 or more (up to 5) feetof cover soil across most of the landfill. In a small area along the southern edge of the site,broken glass mixed with soil was found at depths as shallow as 1 foot below the ground surface(bgs).

2.1.2 Site 10 Sewage Treatment Plant LandfillThe 18-acre Site 10 Sewage Treatment Plant Landfill is located in the northeast portion of NABLittle Creek, due west of the Site 9 Driving Range Landfill (Figure 2-3). The landfill is boundedon the north and the west by sand dunes and combat training beaches, on the south by 11th Streetand recreational facilities (ball fields) that extend onto the landfill area, and on the east by HewittDrive. The landfill’s boundary is generally well defined by the dunes and roads. Existing surfacefeatures include a well-vegetated soil cover that has been partially reclaimed for use as baseballdiamonds and vegetated sand dunes.

The Sewage Treatment Plant Landfill began operating in 1941 and was the first landfill to beused at NAB Little Creek. Landfilling operations began in the southern portion of the area,which included an extension of Desert Cove and associated lowlands. Disposal in this area wasreportedly directly into the water and filled about 5 acres of the cove. Disposal activities thenmoved northward into an area of marshy lowlands, and eventually about 18 acres. The averagedepth of fill in both areas is 6 feet, which yields a combined total volume of waste of 46,500cubic yards.

The types of waste placed in the Sewage Treatment Plant Landfill were predominantly solidsuntil 1952. Subsequently, most of the waste was diverted to the incinerator and the ash wasdisposed of in the Site 9 Driving Range Landfill. Disposal of sewage sludge from the onsitesewage treatment plant, formerly located in the southeast portion of Site 10, continued until1968, the year in which the treatment plant closed. Most of the sewage sludge was disposed ofalong the northwest perimeter of the landfill, near the base of the sand dunes that border thelandfill.

Between 1941 and 1952, this landfill was the only operational landfill on the base, and receivedall of the household and industrial wastes generated on the base, including a variety of hazardoussubstances. A large quantity of demolition debris also was disposed of in the landfill. Historicaldata concerning the actual types and quantities of waste placed in the Sewage Treatment PlantLandfill are not available. It is likely that the volume of hazardous waste disposed of in thelandfill is small relative to the volume of nonhazardous waste.

A soil cover survey (CH2M HILL February 2000) revealed that 2 to 6 feet of cover soil liesacross the entire landfill. The results of the soil cover survey are presented in Appendix C of theRemedial Investigation/Feasibility Study (RI/FS) for Sites 9 and 10 (CH2M HILL February2001).

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2.2 Previous Investigations

2.2.1 Initial Assessment StudyAn Initial Assessment Study (IAS) was completed in December 1984 by Rogers, Golden, andHalpern to evaluate Sites 9 and 10 and to assess potential threat to human health or theenvironment from prior hazardous waste management activities. The IAS recommended aconfirmation study be performed at Sites 9 and 10 to sample site soil and groundwater to verifythe presence of contamination and determine the need for further characterization orremediation.

2.2.2 Round 1 Verification StepThe Round 1 Verification Step (RVS), which is the first step in the confirmation study process,was completed in October 1986 by CH2M HILL. The results of the RVS sampling and analysisactivities indicated that little or no contamination was migrating from the Sites 9 or 10 viagroundwater. The RVS recommended additional sampling to confirm these results.

2.2.3 Interim Remedial InvestigationEbasco Environmental Consultants performed a second round of groundwater sampling at thesites in 1991 as part of the Interim Remedial Investigation (IRI) to confirm the interpretationspresented in the RVS report. The IRI stated that no additional characterization or remediationwas warranted based on the results of the sampling during the RVS and IRI. A limited programof groundwater monitoring was recommended as well as additional characterization for thesurface soils, primarily those within the baseball diamonds and golf practice area at Site 10.

2.2.4 Remedial Investigation/Feasibility StudyFoster Wheeler Enviresponse, Inc. (FWEI) conducted a RI/FS of Sites 9 and 10 from 1993through 1994. The RI/FS included a Phase 1 Baseline Human Health Risk Assessment(BHHRA) that evaluated risks from site contaminants in accordance with current EPA guidanceand based on current land use at the sites. Results of the RI/FS sampling and the BHHRAindicated no current risk posed by contaminants in soil at Site 10, but that groundwater was apotential medium of concern. The RI/FS recommended long-term groundwater monitoring andgroundwater and land use restrictions for Sites 9 and 10 to protect against any adverse risks tohuman health.

2.2.5 Revised Remedial Investigation/Human Health RiskAssessment/Feasibility Study

A revised RI, revised Human Health Risk Assessment (HHRA), and focused FS for Sites 9 and10 at NAB Little Creek was completed in February 2001 (CH2M HILL). The initial RI, HHRA,and preliminary FS performed for these two sites by FWEI in 1994 were not reviewed by theEPA. When the base was placed on the National Priorities List (NPL) in May 1999, the EPArequired that the HHRA for Sites 9 and 10 be rewritten in accordance with current EPAguidelines, and that Sites 9 and 10 be included in the ecological risk assessment (ERA) beingconducted for NAB Little Creek. The revised RI/HHRA/FS was developed in order to meet theregulatory requirements and to incorporate the additional long-term groundwater monitoring datafrom Sites 9 and 10 that had since been collected.

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2.2.6 Current Investigations: Long-Term Groundwater MonitoringA 5-year, semiannual groundwater monitoring program was initiated at Sites 9 and 10 in 1996 inaccordance with the recommendations in the 1994 RI/FS. A 3-year summary report (finalizedMay 2000) was prepared after the sixth round of sampling was completed. In addition, letterreports are prepared following each round of monitoring.

2.2.7 Follow-Up Surface Soil SamplingNine additional surface soil samples were collected in February 2000 from 0 to 6 inches withinSite 10 to characterize areas that were not sampled during the 1994 RI surface soil sampling.These data were analyzed to confirm consistency with surface soil data collected during the 1994RI. However, the data were not validated in time to be used in the revised HHRA. As the datawere consistent with previous data, it is expected that incorporation of the new surface soilsample data would not change the conclusions of the HHRA.

2.3 Enforcement ActivitiesNAB Little Creek was placed on the NPL in 1999. No enforcement activities have been recordedto date at either site. The Federal Facilities Agreement (FFA) provides for CERCLA-directedenforcement activities at the sites.

2.4 Community ParticipationThe NAB Little Creek Restoration Advisory Board (RAB) was formed in 1994. Meetingscontinue to be held to provide an information exchange among community members, the EPA,VDEQ, and the Navy. These meetings are open to the public and are held about every 3 months.A community relations program is being conducted through the IR process.

In accordance with Sections 113 and 117 of CERCLA, the Navy provided a public commentperiod from March 28 through April 30, 2001, for the proposed remedial action described in theFS and the Proposed Plan for Sites 9 and 10. No comments were received from the public.

The Proposed Remedial Action Plan (PRAP) and Revised RI/HHRA/Focused FS are available tothe Public in the Administrative Record and information repositories maintained at the VirginiaBeach Public Library and the Bayside Area Library. The PRAP was available as of March 28,2001. The final RI/FS is also available in the Administrative Record.

A public meeting to present the PRAP for Sites 9 and 10 was held at NAB Little Creek, DrexlerHall on March 28, 2001. Public notice of the meeting and availability of documents was placedin The Virginia Pilot newspaper on March 17, 2001.

2.5 Scope and Role of Response ActionsNAB Little Creek occupies 2,147 acres in the northwest corner of Virginia Beach. It is boundedby the Chesapeake Bay to the north, Lake Bradford to the east, and Shore Drive (U.S. Highway60) to the south and west. The western boundary of the base also coincides with the Norfolk cityline. The western half of the base is primarily industrial, while the eastern half is occupiedprimarily by recreation facilities, commercial establishments, and base housing. A list of all IR

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sites can be found in the current version of the Site Management Plan, which is located in theAdministrative Record. The Site Management Plan contains the location, description,contaminants of concern, and clean-up status of each site. Sites 9 and 10 are included in the SiteManagement Plan.

All documentation related to Sites 9 and 10, as well as all IR sites, is provided in theAdministrative Record. These sites are not part of a larger operable unit and there have been nopast or planned removal actions at either of the sites. The only remedial measures taken consistof a minimum 2-foot soil cover on the landfills (except for a small area on the southern edge ofSite 9 where there is a 1 foot soil cover).

The greatest risks posed by Sites 9 and 10 are related to the wastes that were buried at the sitesduring their operation as base landfills. No potential residual contamination was identified in thesurface soil that could pose threats to the health and safety of animals or people, such as siteworkers and recreational visitors, as the landfill cover is sufficient and was constructed withclean fill. Erosion of, or excavation into, the existing soil cover could pose a threat through directcontact with landfill contents. Drinking groundwater from beneath the landfills could pose athreat to human health. The risks posed by these potential threats were quantified in the February2001 HHRA and Baseline Ecological Risk Assessment (BERA).

Creating LUCs and performing long-term monitoring provide the best alternative for eliminatingcurrent and future exposure pathways. The LUC objectives are:

• Prohibit digging into or disturbing the existing cover or contents of the landfills.• Prohibit residential development on the sites.• Prohibit use of shallow aquifer groundwater beneath the sites other than for environmental

monitoring and testing.

Within 90 days following the execution of this ROD, the Navy shall develop a RD that shallcontain LUC implementation and maintenance actions, including periodic inspections and longterm groundwater monitoring.

2.6 Site Characteristics

2.6.1 Conceptual Site ModelThe conceptual exposure models shown in Figures 2-4 and 2-5 show transport pathways,exposure media, exposure routes, and potential receptors for Sites 9 and 10, respectively.

2.6.2 Site OverviewSites 9 and 10 are located just south of the southern shore of the Chesapeake Bay. Other surfacewater bodies that adjoin portions of NAB Little Creek include Little Creek Cove, Chubb Lake,and Lake Bradford.

2.6.3 Surface and Subsurface FeaturesThere are no underground storage tanks, aboveground storage tanks, or drum storage areaswithin the boundaries of Sites 9 and 10. Surface structures at Site 9 include a golf equipmentstorage shed in the southwest corner of the site, a lighted tee box structure along the western

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boundary of the site, and a net fence held by utility poles covering the south boundary of the site.The only surface structures at Site 10 are the backstops and dugouts associated with the ballfields and several fences.

2.6.4 Sampling StrategySampling strategy associated with the BHHRA and BERA for Sites 9 and 10 is summarized inTable 2-1; it lists the environmental samples collected at Sites 9 and 10 for evaluation in the riskassessment. The RI results are summarized within the Final RI/HHRA/Focused FS for Sites 9and 10 NAB Little Creek (CH2M HILL February 2001). The results of the additional soilsampling effort are reported in an addendum to the Final RI report. The long-term monitoringresults are documented in letter reports after each round.

2.6.5 Sources of ContaminationThe main source of contamination at Site 9 is the ash and solid waste placed in the landfill. ForSite 10, the main source of contamination is the sewage sludge, industrial and household waste,and demolition debris placed in the landfill.

2.6.6 Types of ContaminationTable 2-2 identifies the chemicals that were selected as COCs for Sites 9 and 10. For Site 9groundwater, antimony is the COC and inorganic chemicals (cadmium, manganese, thallium,and zinc) are the COCs for Site 10 groundwater.

2.6.7 Location of Contamination and Routes of Migration2.6.7.1 Lateral and Vertical Extent of Contamination

To determine the lateral and vertical extent of the Site 9 and 10 landfill wastes, a soil coversurvey was conducted in February 2000.The roughly 40,000 cubic yards of landfill ash and solidwaste associated with Site 9 laterally extends over about 6 acres. The roughly 46,500 cubic yardsof sewage sludge, solid waste, and demolition debris associated with Site 10 extend laterallyover about 18 acres.

2.6.7.2 Current and Potential Future Surface and Subsurface Routes ofExposure and Receptors

Site 9 is currently used as a driving range. Golfers have little or no contact with surface soil atthe site. Site workers mow the grass and collect golf balls with a range picker. These activitiespresent few opportunities for exposure to soils. Since Site 10 is used for ball games and militaryexercises, there is the opportunity for recreating military personnel and others to come in contactwith the surface soil. No construction is anticipated to occur at Sites 9 or 10.

Because the base and surrounding area is used for residential, recreational, industrial, andcommercial purposes, and is not fenced, there is the opportunity for people (not limited to basepersonnel) to have access to both sites. Base employees and trespassers/visitors may have accessto the sites and contact with the surface soil. However, this exposure would be similar to or lessthan exposure by people using the sites during recreational activities and those who performwork at the sites.

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Groundwater from beneath Sites 9 or 10 is not currently used. The City of Virginia Beachsupplies water to NAB Little Creek and surrounding communities. The upper aquifergroundwater (Columbia Aquifer) is not currently used as a potable water supply at the base andis not likely to be used as a future water supply due to the generally poor quality of nativegroundwater. Additionally, the shallow aquifer is generally not capable of supporting a potablesupply due to the low yield. There are no users of the upper aquifer downgradient of Sites 9 or10, and groundwater flow is northwest in the direction of the Chesapeake Bay.

The underlying confined Yorktown Aquifer is not currently used as a potable water supply forthe base and discharges directly from the base to the Chesapeake Bay. It is unlikely that a watersupply well would be installed between the landfills and the Chesapeake Bay since the bay isless than 1,000 feet north of the landfills and the area is composed entirely of dunes and beach.Additionally, due to the Yorktown confining clay layer that separates the Columbia Aquifer fromthe Yorktown Aquifer, contamination that may have leached from the landfills has probably notreached the Yorktown Aquifer, and there are no Yorktown Aquifer wells downgradient of thelandfills.

Contaminants from the sites may migrate in groundwater toward surface water bodies; however,based on the expected dilution of groundwater as it discharges to the bay, aquatic organisms arenot expected to be adversely affected by the landfills.

2.6.8 Aquifer CharacteristicsSites 9 and 10 are located within the Coastal Plain physiographic division, which is underlain bya thick wedge of unconsolidated deposits dipping southeastward toward the Atlantic Ocean,reaching a thickness of 2,000 feet along the shore. Site geology consists of clean and silty sandsto a depth of about 20 feet bgs where the Yorktown Confining Unit is located. Nativegroundwater quality of the shallow water table aquifer is hard and generally of poor quality withlow pH and high iron, and is not widely used as a potable supply (Siudyla 1981). Near tidalsurface waters, the groundwater is typically high in chlorides.

Additional aquifer characteristics are presented in the Final RI/HHRA/Focused FS for Sites 9and 10 NAB Little Creek (CH2M HILL February 2001).

2.7 Current and Potential Future Site and Resource Uses

2.7.1 Current Site Land UsesSite 9 is currently used as a golf driving range managed by Little Creek Base MWR. Site 10 isused as a series of ball fields run by MWR and as a training area for Navy personnel. See section2.6.7.2

2.7.2 Current Adjacent Site Land UsesThe northern perimeter of the Site 9 Landfill is bounded by a network of sand dunes thatparallels the Chesapeake Bay shoreline. The base golf course borders the landfill to the east andsouth. The western boundary of the site is Hewitt Drive, which separates the Site 9 and 10landfills. The dune area to the north is currently used for military combat exercises. The land

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use across Hewitt Drive consists of a small putting green for golf practice and the ball fieldslocated within the boundaries of Site 10.

Site 10 is bordered to the north and west by a network of sand dunes and the Chesapeake Bay,respectively. The southeastern portion of the landfill is used for ball fields, which extend outsideof the landfill boundaries to 10th Street. The southwestern portion of the landfill is bordered by11th Street. Numerous storage facilities are located on the other side of 11th Street. The landfillis bordered on the east by the putting green, an observation point, Hewitt Drive, and Site 9. ANavy vehicle storage area is located near the southwest side of the landfill.

2.7.3 Anticipated Future Land UsesThe Navy does not currently intend to build on Sites 9 and 10, thereby eliminating potentialexposure to the subsurface soils by intrusive activities (e.g., excavations). Current land uses areanticipated to continue indefinitely.

2.7.4 Current Groundwater and Surface Water UsesThere are no groundwater wells located within the boundaries of Sites 9 or 10. A series ofsurficial aquifer irrigation wells are located south of Site 9 within the golf course boundaries.These wells are used infrequently to assist with golf course landscaping.

The City of Virginia Beach supplies potable water to NAB Little Creek and the surroundingresidential area from deep groundwater wells (Potomac Aquifers) and surface water sourcesincluding Lake Gaston at the North Carolina-Virginia border. Little Creek Reservoir/LakeSmith, located upgradient of the base, serves as a secondary drinking water supply for parts ofthe City of Virginia Beach. There are no surface water reservoirs or groundwater supply wellsused as a potable supply near Sites 9 and 10.

There are no surface water bodies within the boundaries of Sites 9 and 10. However, theChesapeake Bay borders both sites to the north. Within the immediate vicinity of the sites, thebay is used for military training exercises that include swimming.

2.7.5 Future Uses of Ground/Surface WaterPotential beneficial uses of ground water and surface water are expected to be the same as thecurrent uses identified above. The remedial action plan for Sites 9 and 10 would prohibit use ofthe shallow aquifer groundwater beneath the landfills for any purpose other than environmentalmonitoring and testing. No additional surface water uses are anticipated.

2.8 Summary of Site RisksThe human health risks associated with exposure to contaminated media (i.e., soil andgroundwater) at Sites 9 and 10 were evaluated in the Final RI/HHRA/Focused FS for Sites 9 and10 NAB Little Creek (CH2M HILL February 2001). The ecological risks associated withexposure to contaminated media at Sites 9 and 10 were evaluated in the Final Baseline (Step 3)ERA IR Sites 9 and 10 NAB Little Creek (CH2M HILL March 2001).

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2.8.1 Human Health Risk Assessment SummaryThe baseline risk assessment estimates what risks the sites pose if no remedial actions are taken.It provides the basis for taking action and identifies the contaminants and exposure pathways thatneed to be addressed by the remedial action. This section of the ROD summarizes the results ofthe baseline risk assessment for this site.

The risk assessment was prepared using conservative assumptions designed to ensure that risksare not understated. Exposure pathways were evaluated for current and potential future site usebased on current site conditions. The conceptual exposure model presents an overview of siteconditions, potential contaminant migration pathways, and exposure pathways to potentialreceptors. Figures 2-4 and 2-5 present the conceptual exposure model for Sites 9 and 10,respectively. These figures identify the potential contaminant source and migration pathways,and the potential pathways by which a human receptor may contact site-related material.

2.8.1.1 Chemicals of Concern

Table 2-2 (groundwater) show the range of detected concentrations and the frequency ofdetection for each COC at Site 9 and Site 10. A detailed discussion determining exposure pointconcentrations, which is the chemical concentration at the point of contact, is provided in Section3.3.3.1 of the RI/FS for Sites 9 and 10 (CH2M HILL February 2001). The exposure pointconcentration used to estimate the risk for each COC and the type of statistical measure itrepresents is presented in Tables 2-3 through 2-7 for Site 9 and 10.

2.8.1.2 Exposure Assessment

Exposure assessment evaluates potential human exposure to the COCs present at or migratingfrom the site. Potential receptors include current and future site workers, current and futurerecreational persons, future residents, and future construction workers. These potential receptorsmay have contact with any contamination in surface soil and/or groundwater through ingestion,dermal absorption, or inhalation. A detailed discussion of exposure assessment is provided inSection 3.3 of the RI/FS for Sites 9 and 10 (CH2M HILL February 2001). Tables 2-8 (Site 9)and 2-9 (Site 10) present an evaluation of the potential exposure pathways and scenarios andidentify the pathways that were chosen for evaluation in the risk assessment, and the rationale forthese choices. The potential exposure pathways identified in the conceptual exposure models thatwere evaluated for Sites 9 and 10 are shown in Table 2-10.

Many of the exposure parameters used in the intake calculations have default values that wereused for the risk assessment. These assumptions, based on estimates of body weights, mediaintake levels, and exposure frequencies and duration, are provided in EPA guidance. Otherassumptions (e.g., for the recreational scenarios) were selected based on consideration oflocation-specific information. Table 2-11 summarizes the reasonable maximum exposure (RME)parameters and Table 2-12 summarizes the central tendency (CT) exposure parameters used forthe risk assessment. Exposure parameters and intake equations for each scenario evaluated forSites 9 and 10 are presented in Appendix E.2, Tables 4.1 through 4.8 (Site 9) and Appendix E.3,Tables 4.1 through 4.10 (Site 10) of the RI/FS (CH2M HILL February 2001).

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2.8.1.3 Toxicity Assessment

The toxicity assessment weighs the available evidence regarding the potential for a particularchemical to adversely affect exposed individuals and provides a numerical estimate of therelationship between the extent of exposure and possible severity of adverse effects.

Toxicity Information for Noncarcinogenic Effects. Noncarcinogenic health effects include avariety of toxic effects on body systems, ranging from renal toxicity (toxicity to the kidneys) tocentral nervous system disorders.

EPA-derived oral and inhalation chronic and subchronic reference doses (RfDs), associateduncertainty factors (Ufs), and modification factors (MFs) for the COCs at Sites 9 and 10 areprovided in Appendix A. These data are also presented in Tables 5.1 and 5.2 in Appendix E.2(Site 9) and Tables 5.1 and 5.2 in Appendix E.3 (Site 10) of the RI/FS (CH2M HILL February2001). These data provide noncarcinogenic risk information that is relevant to the COC in bothsoil and groundwater.

Toxicity Information for Carcinogenic Effects. Potential carcinogenic effects from humanexposure to chemicals are estimated quantitatively using oral carcinogenic slope factors (CSFs),inhalation CSFs, or unit risk factors that convert estimated exposures directly to incrementallifetime cancer risks. EPA-derived oral and inhalation CSFs for the COCs at Site 9 and Site 10are provided in Appendix A. These data are also presented in Appendix E.2, Tables 6.1 and 6.2.(Site 9) and Appendix E.3, Tables 6.1 and 6.2 (Site 10) of the RI/FS (CH2M HILL February2001). These data provide carcinogenic risk information that is relevant to the COCs in both soiland groundwater.

2.8.1.4 Risk Characterization

Site 9 Driving Range Landfill. Risks were evaluated for exposure to Site 9 surface soil andupper aquifer groundwater. Risk characterization tables are provided in Appendix B.

For carcinogens, risks are generally expressed as the incremental probability of an individual’sdeveloping cancer over a lifetime as a result of exposure to the carcinogen. Excess lifetimecancer risk is calculated from the following equation:

Risk = CDI x CSFwhere:

risk = a unitless probability (e.g., 2 x 10-5) of an individual’s developing cancerCDI = chronic daily intake averaged over 70 years (mg/kg-day)CSF = carcinogenic slope factor, expressed as (mg/kg-day)-1.

These risks are probabilities that usually are expressed in scientific notation (e.g., 1x10-6). Anexcess lifetime cancer risk of 1x10-6 indicates that an individual experiencing the reasonablemaximum exposure estimate has a 1 in 1,000,000 chance of developing cancer as a result of site-related exposure. This is referred to as an “excess lifetime cancer risk” because it would be inaddition to the risks of cancer individuals face from other causes such as smoking or exposure totoo much sun. The chance of an individual’s developing cancer from all other causes has

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been estimated to be as high as one in three. EPA’s generally acceptable risk range for site-related exposures is 10-4 to 10-6.

The potential for noncarcinogenic effects is evaluated by comparing an exposure level over aspecified time period (e.g., life-time) with a reference dose (RfD) derived for a similar exposureperiod. An RfD represents a level that an individual may be exposed to that is not expected tocause any deleterious effect. The ratio of exposure to toxicity is called a hazard quotient (HQ).An HQ<1 indicates that a receptor’s dose of a single contaminant is less than the RfD, and thattoxic noncarcinogenic effects from that chemical are unlikely. The Hazard Index (HI) isgenerated by adding the HQs for all chemical(s) of concern that affect the same target organ(e.g., liver) or that act through the same mechanism of action within a medium or across allmedia to which a given individual may reasonably be exposed. An HI<1 indicates that, based onthe sum of all HQ’s from different contaminants and exposure, routes, toxic noncarcinogeniceffects from all contaminants are unlikely. An HI > 1 indicates that site-related exposures maypresent a risk to human health. The HQ is calculated as follows:

Non-cancer HQ = CDI/RfDwhere:

CDI = Chronic daily intakeRfD = reference dose.

CDI and RID are expressed in the same units and represent the same exposure period (i.e.,chronic, subchronic, or short-term)

Site 9 Surface Soil. RME risk estimates for exposure to surface soil were calculated for acurrent/future site worker and an adult and child who would use the site for recreationalactivities in the future (Tables B-1 through B-6). Exposure to surface soil via incidental ingestionand dermal contact was evaluated.

Health risks from surface soil were within acceptable limits for site workers and adult and childrecreational users. That is, cancer risks were all less than 5 x 10-6 and all hazard indices (HIs)were less than 1.

Dieldrin and arsenic are the only hazardous substances detected in the surface soil atconcentrations that exceed the soil to groundwater soil screening level (SSL). Dieldrin wasdetected in only one sample, and is therefore probably not a concern for leaching from the soil togroundwater. Arsenic was detected in all of the surface soil samples at a concentration above theSSLs. However, arsenic has not been detected in groundwater at concentrations that result in anunacceptable risk to any of the receptors evaluated.

Site 9 Groundwater. Upper aquifer groundwater beneath Site 9 is not currently used as a potable water supply and will not likely be used as a potable water supply in the future.However, use of upper aquifer groundwater for drinking water was evaluated as a worst-caserisk estimate. Risk estimates for exposure to groundwater were calculated for child and adultresidents under potential future residential use of the site (Tables B-7 through B-9). Riskestimates for exposure to groundwater also were calculated for future industrial workers underindustrial use of the site (Tables B-10 and B-11), assuming upper aquifer groundwater is used asa water supply for NAB Little Creek. Additionally, risk estimates were calculated for a

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construction worker exposed to groundwater in an open excavation or trench (Tables B-12 andB-13).

The RME noncarcinogenic hazard associated with ingestion of the groundwater by a futureindustrial worker (1.9) exceeds the EPA’s target hazard index (HI) of 1.0. This hazard isprimarily associated with ingestion of the iron and manganese detected in the upper aquifergroundwater. The RME carcinogenic risk to the industrial worker (2 x 10-5) is within the EPA’starget risk range.

Summary of Site 9 Total Risks Across Pathways and Media. Appendix B, Tables B-14.RMEthrough B-21.RME, summarize the RME total potential risks to each receptor. Appendix B,Tables B-22.CT through B-24.CT, summarize the CT total potential risks to each receptor thathave RME risks that exceed EPA benchmark levels. Total potential risks were summarized for acurrent/future site worker, future adult, child, and lifetime resident, future industrial worker,future construction worker, and future adult, and child recreational user. Appendix B, TablesB-25.RME through B-29.CT, show only the chemicals that contribute a hazard greater than 0.1or a carcinogenic risk greater than 10-6 to receptors with noncarcinogenic hazards orcarcinogenic risks greater than the EPA’s benchmark levels of 1.0 for noncarcinogenic hazardsand 10-4 for carcinogenic risks.

Site 10 Sewage Treatment Plant Landfill. Risks were evaluated for exposure to Site 10 surfacesoil and upper aquifer groundwater. Risk characterization tables are provided in Appendix C.

Site 10 Surface Soil. RME risk estimates for exposure to surface soil were calculated for acurrent/future site worker and a current/future adult and child that use the site for recreationalactivities (Appendix C, Tables C-1.RME through C-3.RME, and Tables C-4.RME through C-6.RME). Exposure to surface soil via incidental ingestion and dermal contact was evaluated.

Health risks from surface soil were within acceptable limits for site workers and adult and childrecreational users. That is, cancer risks were all less than 3 x 10-6 and all hazard indices (HIs)were less than 1.

Dieldrin and arsenic are the only hazardous substances detected in surface soil at concentrationsthat exceed the soil to groundwater SSL. Dieldrin was only detected in one sample, and istherefore probably not a concern for leaching from soil to groundwater. Arsenic was detected inall of the surface soil samples at a concentration above the SSL. However, the concentrations ofarsenic found in the Site 10 surface soil are consistent with background levels.

Site 10 Groundwater. Upper aquifer groundwater beneath the site is not currently used as apotable water supply and will not likely be used as a potable water supply in the future.However, future use of upper aquifer groundwater beneath the site for drinking water wasevaluated as a worst-case risk estimate. Risk estimates for exposure to groundwater werecalculated for child and adult residents under potential future residential use of the site(Appendix C, Tables C-7.RME, C-8.RME, and C-9.RME). It was assumed that a residential userwould drink the water and bathe with it. Risk estimates for exposure to groundwater were alsocalculated for future industrial workers under industrial use (Appendix C, Tables C-10.RME andC-11.RME). It was assumed that a worker would be exposed through ingestion only.Additionally, risk estimates were calculated for a construction worker dermally exposed togroundwater in an open excavation trench (Appendix C, Tables C-12 RME and C-13.RME).

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The RME HIs associated with use of the groundwater as a potable residential water supply areabove the EPA’s benchmark HI of 1.0. The HIs for an adult and child resident are 9.6 and 22,respectively. This hazard is primarily associated with ingestion of arsenic, cadmium, iron,manganese, thallium, and zinc in the groundwater. It should be noted that concentrations of botharsenic and iron in the groundwater at Site 10 are consistent with background concentrations.

Summary of Site 10 Total Risks Across Pathways and Media. Appendix C, Tables C-14.RMEthrough C-21.RME, summarize the total RME potential risks to each receptor. Appendix C,Tables C-22.CT through C-25.CT, summarize the total CT potential risks to each receptor withRME risks above EPA target levels. Total potential risks were summarized for a current/futuresite worker, current/future adult and child recreational user, future adult, child, and lifetimeresident, future industrial worker, and future construction worker. Appendix C, TablesC-26.RME through C-32.CT, show only the chemicals that contribute a hazard greater than 0.1or a carcinogenic risk greater than 10-6 to receptors with risks greater than the EPA’s benchmarklevels of 1.0 for noncarcinogenic hazards and 10-4 for carcinogenic risks.

Uncertainty. The risk measures used in risk assessments are estimates given for a conservativeset of assumptions about exposure and toxicity, designed to ensure that risks are not understated.Thus, it is important to specify the assumptions and uncertainties inherent in the risk assessmentto place the risk estimates in proper perspective (EPA 1989). Uncertainty sections aresummarized in the Final RI/HHRA/Focused FS for Sites 9 and 10 NAB Little Creek (CH2MHILL February 2001).

2.8.2 Summary of Ecological Risk AssessmentA multi-site BERA is being conducted for NAB Little Creek that addresses Sites 9 and 10(CH2M HILL March 2001) as well as all other IR sites that are undergoing or have undergoneRIs. The BERA is being conducted separately from this Revised RI/HHRA/FS for Sites 9 and 10(CH2M HILL February 2001). The findings of the ERA are summarized in this section and weretaken into consideration in the evaluation and recommendations of the FS for Sites 9 and 10.

A hazard quotient (HQ) is used to evaluate ecological risks; at or below an HQ of 1, adverseeffects to ecological receptors are not expected. For Sites 9 and 10, risks were evaluated forterrestrial habitats related to the landfills’ surface and the aquatic habitats in the Chesapeake Baythat may be affected by discharges of site-related contaminants in the groundwater.

The risks from surface soil for both sites are low to negligible. The four metals at Site 9 and fivemetals at Site 10 that were present above ecological risk-based screening levels in the soil wereall consistent with background concentrations. Two metals at Site 9 (aluminum and zinc) andfour metals at Site 10 (aluminum, cobalt, nickel, and zinc) were regularly detected in thegroundwater at levels above ecological risk-based screening criteria; however, these chemicalsare expected to have no adverse affects on aquatic organisms present in the bay. This is becauseas groundwater discharges to the surface water in the bay downgradient of the sites, it is dilutedby at least a factor of 10. The resulting concentrations would be below the ecological risk-basedscreening criteria.

The response action selected in this ROD is necessary to protect the public health or welfare orthe environment from actual or threatened releases of hazardous substances into the environment.

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2.9 Remedial Action ObjectivesThe level of contamination and the potential exposure routes were considered in defining thesite-specific remedial action objectives (RAOs) for protecting public health and the environment.The future protection of environmental resources and the means of minimizing long-termdisruption to current and future facility operations were also considered. The site-specific RAOsfor Sites 9 and 10 are:

• Prevent or minimize direct contact of human and ecological receptors with landfill contents• Prevent unacceptable risks to potential receptors from the groundwater• Control surface water runoff and erosion

The revised HHRA presented in Section 2.8.1 concluded that no unacceptable risk is posed bycontaminants in the soil at Sites 9 or 10. Potential risks from the potable use of groundwater atSites 9 and 10 were identified.

2.10 Description of AlternativesThree remedial alternatives were developed to address risk associated with soil and groundwatercontamination at Sites 9 and 10. The remedial alternatives are discussed in detail in the FS(CH2M HILL February 2001). Each alternative, with the possible exception of the no-actionalternative, was developed to meet the RAOs.

2.10.1 Alternative 1—No ActionThe no-action alternative is required to be evaluated by the NCP and serves as the “baseline”alternative. All other remedial action alternatives are judged against the no-action alternative.Under this alternative, no additional controls or remedial technologies would be implementedand no further site-related monitoring or maintenance would be conducted. CERCLA(Section 121(c)), as amended by the Superfund Amendments Reauthorization Act (SARA 1986),requires that the site be reviewed every 5 years since contamination (i.e., landfill contents) wouldremain onsite. With the exception of the costs to prepare the 5-year review, there are no capitalor O&M costs related to this alternative.

2.10.2 Alternative 2—Land Use Controls with Long-Term MonitoringThe major components of this alternative are LUCs, long-term groundwater monitoring, andpost-closure actions. The capital costs associated with this alternative are $20,000 for each sitefor a Land Use Control Remedial Design, a survey plat and site signage. The annual O&M costsfor each site are estimated to be $35,000 for the first 5 years, and $20,000 for each successiveyear as it is expected that the groundwater monitoring requirements would be reduced after 5years. The total present worth-cost is estimated to be $400,000 for each site.

2.10.2.1 Land Use Controls

The LUC objectives for these sites are:

• Prohibit digging into or disturbing the existing cover or contents of the landfills.• Prohibit residential development on the sites.

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• Prohibit use of the shallow aquifer groundwater beneath the sites other than forenvironmental monitoring and testing.

Within 90 days following the execution of this ROD, the Navy shall develop a RD that shallcontain LUC implementation and maintenance actions, including periodic inspections and long-term groundwater monitoring. The Navy will implement, maintain, monitor and enforce theLUCs according to the RD.

The LUCs shall be maintained on all land and ground water within the boundaries of Sites 9 and10. The site boundaries are shown in Figures 2-2 and 2-3.

The LUCs shall be maintained until the concentrations of hazardous substances in the landfillsand the ground water beneath have been reduced to levels that allow for unlimited exposure andunrestricted use.

2.10.2.2 Long-Term Monitoring

Long-term monitoring at Sites 9 and 10 would involve groundwater monitoring in accordancewith the RD for at least 5 years. The current 5-year groundwater monitoring program initiated in1996 would be considered part of the monitoring program.

2.10.2.3 Post-Closure Requirements

As with Alternative 1, 5-year site reviews will be conducted by the Navy under this alternative,as required by the CERCLA and the NCP, since contamination (i.e., landfill contents) willremain onsite.

2.10.3 Alternative 3—Low-Permeability CapAlternative 3, a containment alternative, involves the installation of a cap over the entire area ofeach landfill. Costs for the demolition of the structures were not included in cost estimates forAlternative 3. The major components of this alternative are:

• Construction of a low-permeability cap• Installation of stormwater controls• LUCs• Long-term groundwater monitoring• Post-closure requirements• Reconstruction of recreational facilities

The capital costs for Site 9 are estimated at $790,000, with annual O&M costs the same asdescribed for Alternative 2. The total present-worth cost for Site 9 is $1.15 million. The capitalcosts for Site 10 are estimated to be $2.33 million, with annual O&M costs the same as describedfor Alternative 2. The total present-worth cost for Site 10 is $2.73 million.

2.10.3.1 Low-Permeability Cap

In accordance with VDEQ solid waste landfill regulations (9 VAC-20-80-270), the coversystem’s design basis requires 3 percent minimum cover slopes, 33 percent maximum sideslopes, contiguous flat runs limited to 150 to 200 feet, and open drainage channels (25-year,24-hour peak storm flow). Additionally, the barrier layer of the cap must be installed below thefrost depth (design frost depth at Site 9 and Site 10 is about 3 inches).

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2.10.3.2 Material Quantity Estimates

The major materials and quantities required for implementation of Alternatives 3 are:

Item Quantity for Site 9 Quantity for Site 10

Leveling Layer 9,680 yd3 29,040 yd3

Low-Permeability Soil Barrier Layer 14,520 yd3 43,560 yd3

Vegetative Support Layer 14,520 yd3 43,560 yd3

Topsoil Layer 4,900 yd3 14,520 yd3

2.10.3.3 Stormwater Controls

The site will be graded to maintain existing drainage divides. Construction of the site cap willrequire the reconstruction of existing stormwater controls through which runoff will be allowedto sheetflow to the existing natural and man-made drainage channels. Swales will be constructedaround the perimeter of each site that will be designed to tie into existing drainage channels.


LUCs at Sites 9 and 10 would be identical to those identified under Alternative 2 to prohibit allactions that may damage the low-permeability cap.




As with Alternatives 1 and 2, 5-year site reviews will be conducted by the Navy under thisalternative, as required by the CERCLA and the NCP, since contamination (i.e., landfillcontents) will remain onsite.

2.10.3.7 Reconstruction of Recreation Facilities

After the cap is constructed on- top of the existing soil cover, the existing driving range andbaseball diamond facilities will be re-established. Costs for the reconstruction of the recreationalfacilities were not included in cost estimates for Alternative 3.

Common elements and distinguishing features of each alternative are presented in Table 2-13.

2.11 Summary of Comparative Analysis of AlternativesThe NCP outlines the approach for comparing remedial alternatives. Evaluation of thealternatives uses “threshold,” “primary balancing,” and “modifying” criteria. To be consideredfor remedy selection, an alternative must meet the two following threshold criteria:

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1. Overall protection of human health and the environment2. Compliance with ARARs and to-be-considered (TBC) criteria

The primary balancing criteria are then considered to determine which alternative provides thebest combination of attributes. The primary balancing criteria are:

• Long-term effectiveness and permanence• Reduction in toxicity, mobility, or volume through treatment• Implementability• Short-term effectiveness• Cost

The alternatives are evaluated further against two modifying criteria:

• Acceptance by the Commonwealth• Acceptance by the community

A summary of comparative analysis of alternatives for Site 9 and 10 is provided in Table 2-14. 2.11.1 Threshold Criteria2.11.1.1 Overall Protection of Human Health and the Environment

All three alternatives protect human health by preventing direct contact with landfill contents,due to the presence of at least 2 feet of existing native soil cover on majority of the landfill. Theperiodic inspections of the cover under Alternatives 2 and 3 ensure the integrity of the cover isnot compromised and guard human and ecological receptors from any future risk of directcontact with the landfill contents. The land use and activity restrictions involved in Alternatives2 and 3 further minimize the possibility of direct contact with the landfill contents. Alternative 3reduces the chance of direct contact with the landfill contents even further, by providing an extralow-permeability cap on the existing soil cover to protect human and ecological receptors fromlandfill contents.

There is no current threat to human health from contact with the groundwater at Sites 9 and 10.There is potential risk of exposure from future drinking water use of groundwater from the watertable aquifer, although the likelihood of this use is considered remote. Alternative 1 does notaddress this potential risk. The long-term groundwater monitoring under Alternatives 2 and 3provides groundwater quality tracking and the LUCs guard against drinking water use of thegroundwater. Alternative 3 reduces infiltration and leaching of contaminants into thegroundwater as compared to the current site conditions due to the additional low-permeabilitycap. However, since drinking water use of the groundwater is unlikely (particularly with land userestrictions in place) and because the affected area of the aquifer is small and is naturally of poorquality, the benefit of reducing infiltration is small.

2.11.1.2 Compliance with Applicable or Relevant and Appropriate Requirements

Major ARARs for Sites 9 and 10 are:

• National and Virginia primary drinking water standards for public water systems (MCLs andVirginia primary MCLs) (40 CFR Part 141 Subparts B & G, 12 VAC 5-590-10 to 1280)

• Virginia Solid Waste Management Regulations (VSWMR) (9 VAC 20-80-10 to 790)

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Alternative 1, no-action, would not comply with VSWMRs for management of a sanitary landfillbecause, among other things, it does not provide for long-term monitoring and maintenance andland use restrictions. This alternative does meet all chemical-specific ARARs for groundwater and TBCs for soil.Alternative 2, LUCs with long-term monitoring, would satisfy the VSWMRs for landfill closureand long-term monitoring. This alternative also meets all chemical-specific ARARs forgroundwater and TBCs for soil.

Alternative 3, low-permeability cap, would satisfy the VSWMRs for landfill closure and long-term monitoring. This alternative also meets all chemical-specific ARARs for groundwater andTBCs for soil.

2.11.2 Primary Balancing Criteria2.11.2.1 Long-Term Effectiveness and Permanence

Alternatives 1 and 2 provide an existing 2-foot physical barrier between the landfill contents andpotential human and ecological receptors. Alternative 3 provides an additional cap on theexisting cover. Alternative 1 provides no permanent means to prevent future use of site in amanner that would result in unacceptable risks from drinking the groundwater or diggingthrough the soil barrier. Alternatives 2 and 3 achieve this through use of LUCs and long-termgroundwater monitoring. All three alternatives would require 5-year reviews because thecontamination would remain onsite.

Because Alternative 3 provides an additional cap on the existing cover, it is considered to be aslightly better alternative at providing long-term effectiveness than Alternative 2. Alternative 1provides no permanent means to prevent future use of the site in a manner that would result inunacceptable risks from drinking the groundwater or contacting the waste.

2.11.2.2 Reduction in Toxicity, Mobility, or Volume through Treatment

None of the alternatives considered in this ROD would reduce toxicity, mobility, or volume ofcontaminants through treatment. Discussions supporting this statement can be found in Sections5.5 and 5.6 of the FS (CH2M HILL 2001).

2.11.2.3 Implementability

Alternatives 1 and 2 are easily implemented. Alternative 2 would require minimal construction(e.g., installing institutional control signage). Alternative 3 is considered to be the most difficultalternative to implement because a cap would have to be constructed over the current ball fieldsand driving range using traditional construction methods. In addition, interrupting use of thedriving range and ball fields at this time would result in loss of revenue for the base. Under bothAlternatives 2 and 3, operation would consist of periodic inspection, long-term monitoring, andrepair of erosion if necessary.

The land use restrictions under Alternatives 2 and 3 would require consent from base commandbefore intrusive work (e.g., excavating, drilling, or development) is initiated at the site.

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2.11.2.4 Short-Term Effectiveness

Alternative 2 would be most effective in the short term. Under Alternative 3, cap constructionand recreational facility construction is expected to take about 3 months. Alternative 1 would bethe least effective in the short-term.

2.11.2.5 Cost

There is no cost associated with Alternative 1, except for the 5-year review costs. The totalestimated present-worth cost of Alternative 2 for each site is $400,000. The total estimatedpresent-worth cost of Alternative 3 for Site 9 is $1,150,000 and for Site 10 is $2,730,000. Costsfor Alternative 3 do not include the costs associated with the reconstruction of the recreationalfacilities and the demolition of buildings prior to installation of the cap.

2.11.3 Modifying Criteria2.11.3.1 Commonwealth of Virginia Acceptance

The VDEQ as the designated state support agency in Virginia has reviewed this ROD and hasgiven concurrence on the Selected Remedy.

2.11.3.2 Community Acceptance

No written comments, concerns, or questions were received by the Navy, the EPA, or theCommonwealth of Virginia during the public comment period from March 28 to April 30, 2001.A public meeting was held on March 28, 2001, to present the Proposed Plan for Sites 9 and 10 toanswer any questions on the Proposed Plan and on the documents in the information repositories.No one from the public participated in the public meeting.

2.12 Principal Threat WastesThe NCP establishes an expectation that the EPA will use treatment to address the principalthreats posed by a site whenever practicable. Principal threat wastes are those source materialsconsidered to be highly toxic or highly mobile that generally cannot be contained in a reliablemanner or would present a significant risk to human health or the environment should exposureoccur. There are no principal threat wastes present at the Driving Range Landfill and the SewageTreatment Plant Landfill.

2.13 Selected RemedyAlternative 2 is the Selected Remedy for Site 9 and 10, employing LUCs with long-termmonitoring. Based on available information and the current understanding of site conditions, thisalternative provides the best balance with respect to the nine NCP criteria for both sites at NABLittle Creek. The preferred alternative meets the following statutory requirements of CERCLA:

• Protection of human health and the environment• Compliance with ARARs of federal and Virginia environmental laws• Cost-effectiveness• Use of permanent solutions and alternative treatment technologies to the maximum extent

practicable

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2.13.1 Summary of the Rationale for the Selected Remedy2.13.1.1 Site 9

LUCs with long-term monitoring is the selected remedial alternative for Site 9 because itachieves the RAOs, meets the ARARs, guards against future risk, and is cost-effective. WhileAlternative 3 also meets the RAOs and ARARs, it adds little to no benefit over Alternative 2 fora substantial additional cost. In addition, the use of groundwater at Site 9 is unlikely; therefore,the benefit of reducing infiltration from a low-permeability cap is small. Alternative 1 currentlymeets the RAOs and ARARs, but does not provide for long-term groundwater quality tracking orguard against future risk.

2.13.1.2 Site 10

LUCs with long-term monitoring is the selected remedial action for Site 10 because it achievesthe RAOs, meets the ARARs, guards against future risk, and is cost-effective. While Alternative3 also meets the RAOs and ARARs, it adds little to no benefit over Alternative 2 for asubstantial additional cost. In addition, the use of groundwater at Site 10 is unlikely and, basedon seasonal high water table elevations and depth of waste, the landfill wastes are in contact withthe water table; therefore, the benefit of reducing infiltration from a low-permeability cap issmall. Alternative 1 currently meets the RAOs and ARARs, but does not provide for long-termgroundwater quality tracking or guard against future risk.

2.13.2 Description of the Selected RemedyThe Selected Remedy for both Sites 9 and 10 of LUCs with long-term monitoring consists ofadministrative measures (land use restrictions, periodic inspections) with long-term monitoringconducted to ensure there is no degradation of groundwater quality at the site.


The Selected Remedy for both Sites 9 and 10 of LUCs with long-term monitoring consists ofadministrative measures with long-term monitoring as described in Alternative 2.




5-year site reviews will be conducted by the Navy under this alternative, as required by theCERCLA and the NCP, since contamination (i.e., landfill contents) will remain onsite.

2.13.3 Summary of the Estimated Remedy CostsPreliminary cost estimates for the Selected Remedy of LUCs and long-term monitoring ispresented in Table 2-15. The information in this cost estimate is based on the best availableinformation regarding the anticipated scope of the remedial alternative. Changes in the costestimate are likely to occur as a result of new information and data collected during theengineering design of the remedial alternative. Major changes may be documented in the form ofa memorandum in the

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Administrative Record file. This is an order-of-magnitude engineering cost estimate that isexpected to be within +50 percent to -30 percent of the actual project costs.

2.13.4 Expected Outcomes of the Selected RemedyThe Navy uses Site 9 as a golf driving range and Site 10 as recreational ball fields and has noplans to disturb the soil cover on the landfill. In accordance with the LUC objectives, the Navyshall restrict future groundwater use at Sites 9 and 10 to environmental monitoring and testingonly. Groundwater quality will be re-assessed after 5 years of monitoring. If groundwatercontamination has naturally attenuated to levels within residential use criteria, quantitative riskand groundwater use restrictions may be reassessed.

2.14 Statutory DeterminationsRemedial actions must meet the statutory requirements of Section 121 of CERCLA. Remedialactions undertaken at NPL sites must achieve adequate protection of human health and theenvironment, comply with ARARs of both federal and state laws and regulations, becost-effective, and use, to the maximum extent practicable, permanent solutions and alternativetreatment or resource recovery technologies. In addition, CERCLA includes a preference forremedies that employ treatment that permanently and significantly reduces the volume, toxicity,and/or mobility of hazardous waste as the principal element and a bias against offsite disposal oruntreated wastes. The following discussion summarizes the statutory requirements that are metby the selected remedial alternative.

2.14.1 Protection of Human Health and the EnvironmentThe Selected Remedy will protect human health and the environment through the use of LUCs,post-closure care, and long-term monitoring. There is no unacceptable risk from the surface soilunder current site conditions because existing soil cover and LUCs prevent current exposure tosite contaminants. The periodic inspections of the cover ensure the integrity of the cover is notcompromised and guard human and ecological receptors from any future risk of direct contactwith the landfill contents. The land use and activity restrictions further minimize the possibilityof direct contact with the landfill contents.

LUCs restricting groundwater use eliminate the threat to human health from contact with thegroundwater at Sites 9 and 10. The long-term groundwater monitoring provides groundwaterquality tracking and the LUCs guard against using the groundwater as drinking water.

2.14.2 Compliance with Applicable or Relevant and Appropriate Requirementsand To-Be-Considered Criteria

The Selected Remedy will meet all identified ARARs. Federal and state ARARs for Sites 9 and10 are summarized in Appendix D. The tables summarize the potential ARARs by classification.In addition, other TBC criteria are included as appropriate for each classification. Theclassifications of ARARs identified include chemical-specific, location-specific, and action-specific. The Site 9 and 10 landfill cover soils will be maintained, and land use and groundwateruse limitations will be documented. Long-term groundwater monitoring will ensure compliancewith ARARs and TBCs. If the remedy goals are not met, additional remedial actions could beimplemented in the future.

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2.14.3 Cost-EffectivenessThe Selected Remedy is cost-effective and represents a reasonable value for the money to bespent. In making this determination, the following definition was used: “A remedy shall becost-effective if its costs are proportional to its overall effectiveness.” This was accomplished byevaluating the overall effectiveness of those alternatives that satisfied the threshold criteria.Overall effectiveness was evaluated by assessing balancing criteria in combination. Overalleffectiveness was then compared to costs to determine cost-effectiveness. The relationship of theoverall effectiveness of this remedial alternative was determined to be proportional to its costs,and hence this alternative represents a reasonable value for the money to be spent.

The total estimated present-worth cost of the Selected Remedy for each site is S400,000. Thetotal estimated present-worth cost of Alternative 3 (low-permeability cap) for Site 9 is$1,150,000 and for Site 10 is $2,730,000. The Selected Remedy is cost-effective because itprovides protection of human health and the environment that is proportional to the cost. TheSelected Remedy minimizes short-term environmental impacts, provides long-term protection ofhuman health and the environment, and meets all identified ARARs.

Groundwater risks at Sites 9 and 10 are relatively low, and the shallow groundwater is naturallyof poor quality and not used as a potable supply. Therefore, the associated risks and significantlyhigher cost of installing a low-permeability cap, as a means of reducing the risks is notwarranted. Additionally, while a low-permeability cap remedy also meets the RAOs andARARs, the benefit of reducing infiltration to a naturally poor quality aquifer and where aportion is below the water table adds little to no benefit for a substantial additional cost.

2.14.4 Use Permanent Solutions and Alternative Treatment Technologies orResource Recovery Technologies to the Maximum Extent Practicable

The Navy, EPA, and the Commonwealth of Virginia determined that the Selected Remedyrepresents the maximum extent to which permanent solutions and treatment technologies can beused in a practicable manner at Sites 9 and 10. Of those alternatives that are protective of humanhealth and the environment and comply with ARARs, the Navy, EPA, and the Commonwealth ofVirginia determined that the Selected Remedy provides the best balance of tradeoffs in terms ofthe balancing criteria, while also considering the statutory preference for treatment as a principalelement and bias against offsite treatment and disposal, and considering state and communityacceptance.

The Selected Remedy represents the maximum extent to which permanent solutions andtreatment are practicable at these sites. The Selected Remedy provides the best balance oftradeoffs as compared to the other alternatives. In particular, the Selected Remedy (LUCs withmonitoring) provides a level of long-term protection equivalent to the low-permeability cap, butat greatly reduced cost. The Selected Remedy is therefore the most cost-effective.

None of the alternatives examined includes treatment as principal element, for several reasons.First, there is no principal threat waste at these sites that requires treatment. Second, treatment ofthe landfill contents is not practicable in a cost-effective manner because of the large volume ofwaste (the landfills cover 24 acres). Third, treatment of the groundwater contamination is notpracticable in a cost-effective manner. Groundwater contamination, where present, occursbeneath the landfill in isolated wells and at low concentrations, below the relevant andappropriate Safe Drinking Water Act MCLs. No definable plume of contamination was identified

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and no groundwater contamination was identified outside the perimeter of the landfill. For suchlow concentration waste that poses a low level, long-term threat, the EPA does not generallyexpect to use treatment as a remedy.

2.14.5 Preference for Treatment as a Principal ElementThe Selected Remedy does not use treatment for the reasons given above. It therefore does notsatisfy the statutory preference for treatment as a principal element. Note that the EPA generallyexpects to use treatment to address principal threat waste and that no principal threat waste existsat Sites 9 or 10.

2.14.6 Five-Year Review RequirementsBecause this remedy will result in hazardous substances, pollutants, or contaminants remainingonsite above levels that allow for unlimited use and unrestricted exposure, the Navy will conducta statutory remedy review within 5 years after initiating remedial action to ensure that theremedy continues to provide adequate protection of human health and the environment.

2.15 Documentation of Significant ChangesThe Selected Remedy was the preferred alternative in the PRAP and was presented at the publicmeeting held on March 28, 2001. No significant changes were made to the preferred remedialaction alternative in the Proposed Plan.

3. Responsiveness Summary

In accordance with the Sections 113 and 117 of CERCLA, the Navy provided a public commentperiod from March 28 through April 30, 2001, for the proposed remedial action described in theFS and the Proposed Plan for Sites 9 and 10. Public input is a key element in the decisionmaking process.

The PRAP is available to the public in the Administrative Record. The RevisedRI/HHRA/Focused FS is also available in the Administrative Record. The informationrepositories for the Administrative Record are maintained at the Virginia Beach Central Library(4100 Virginia Beach Boulevard, Virginia Beach, Virginia 23452) and the Bayside Area Library(956 Independence Boulevard, Virginia Beach, Virginia 23455). The PRAP was made availableon March 28, 2001.

A public meeting to present the PRAP for Sites 9 and 10 was held at NAB Little Creek, DrexlerManor, on March 28, 2001. Public notice of the meeting and availability of documents wasplaced in The Virginia Pilot newspaper on March 17, 2001.

No written comments, concerns, or questions were received by the Navy, the EPA, or theCommonwealth of Virginia during the public comment period. No one from the public attendedthe public meeting on March 28, 2001. Navy representatives were available to present theProposed Plan for Sites 9 and 10 to answer any questions on the Proposed Plan and on thedocuments in the information repositories.

Table 2-1Summary of Available Data and Data Selected for Use in the Human Health Risk Assessment for Sites 9 and 10

NAB Little Creek, Sites 9 and 10Groundwater - # samples (event) Surface Soils - # samples (event)

Site Number VOCs SVOCsMetals

Pesticides PCBs VOCs SVOCs Metals Pesticides PCBs TOCTotal DissolvedSite 9 4 (RI) 4 (RI) 4 (RI) 6 (RI) 6 (RI) 6 (RI) 6 (RI) 6 (RI) 6 (RI)

6 (L1) 6 (L1) 6 (L1)6 (L2) 6 (L2) 6 (L2)6 (L3) 6 (L3) 6 (L3)6 (L4) 6 (L4) 6 (L4)6 (L5) 6 (L5) 6 (L5) 6 (L5) 6 (L5)6 (L6) 6 (L6) 6 (L6) 6 (L6) 6 (L6)

6(L7)*6(L8)*

Site 10 5 (RI) 5 (RI) 5 (RI) 8 (RI) 8 (RI) 8 (RI) 8 (RI) 8 (RI) 8 (RI)8 (L1) 8 (L1) 8 (L1) 9 (SS)* 9 (SS)*8 (L2) 8 (L2) 8 (L2)8 (L3) 8 (L3) 8 (L3)8 (L4) 8 (L4) 8 (L4)8 (L5) 8 (L5) 8 (L5) 8 (L5) 8 (L5)7 (L6) 7 (L6) 7 (L6) 7 (L6) 7 (L6)

8(L7)*8(L8)*

BOLD AND ITALIC ENTRIES - DATA THAT ARE QUANTITATIVELY EVALUATED IN THE HUMAN HEALTH RISK ASSESSMENT* DATA THAT ARE QUALITATIVELY EVALUATED IN THE HUMAN HEALTH RISK ASSESSMENTRI - Remedial Investigation - 1994L1- Long Term Monitoring Round 1 - May 1996L2 - Long Term Monitoring Round 2 - Dec 1996L3 - Long Term Monitoring Round 3 - May 1997L4 - Long Term Monitoring Round 4 - Dec 1997L5 - Long Term Monitoring Round 5 - May 1998L6 - Long Term Monitoring Round 6 - Dec 1998L7 - Long Term Monitoring Round 7 - May 1999L8 - Long Term Monitoring Round 8 - Jan 2000SS - Site 10 Surface Soil Sampling - Jan 2000

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Table 2.2OCCURRENCE, DISTRIBUTION AND SELECTION OF CHEMICALS OF CONCERN

Site 9 and 10, Little Creek

Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water

CAS Chemical Minimum [1] Minimum Maximum [1] Maximum Units Location Detection Range of Concentration [2] Background [3] Screening [4] Potential Potential COC Rationale for [5]

Number Concentration Qualifier Concentration Qualifier of Maximum Frequency Detection Used for Value Toxicity Value ARAR/TBC ARAR/TBC Flag Contaminant

Concentration Limits Screening Value Source Deletion

or Selection

SITE 9

7440-36-0 Antimony 2.80E+00 J 9.70E+00 J UG/L LS09-MW05-98D 4/12 2 - 2.6 9.70E+00 N/A 1.46E+00 N 6.0E 00 MCL YES ASL

SITE 10

7440-43-9 Cadmium 8.60E+00 J 8.60E+00 J UG/L LS10-MW01-98B 1/15 0.2 - 0.4 8.60E+00 N/A 1.83E+00 N 5.0E+00 MCL YES ASL

7439-96-5 Manganese 2.50E+00 J 2.45E+03 UG/L LS10-MW08-98D 15/15 2 - 2 2.45E+03 N/A 7.30E+01 N 5.0E+01 SMCL YES ASL

7440-28-0 Thallium 2.60E+00 J 2.60E+00 J UG/L LS10-MW05-98B 1/15 1.7 - 4 2.60E+00 N/A 2.56E-01 N 2 MCL YES ASL

7440-66-6 Zinc 1.32E+01 J 8.87E+03 J UG/L LS10-MW01-98B 5/15 4 - 4 8.87E+03 N/A 1.10E+03 N 5.0E+03 SMCL YES ASL

Notes Definitions[1] Minimum/Maximum detected concentration. For inorganics, unfiltered results used following U.S. EPA Region Ill guidance (08/10/92). SQL = Sample Quantification Limit[2] Maximum concentration is used for screening. COC = Chemical of Concern[3] Background values not available. ARAR/TBC = Applicable or Relevant and Appropriate Requirement/[4] Risk-Based Concentration Table, October 27, 1999, U.S. EPA Region III, Jennifer Hubbard. Other Material To Be Considered

Tap Water RBC (Cancer benchmark value = 1E-06, adjusted HQ=0.1). J = Estimated ValueRBC value for Chromium VI used for total chromium. K = Biased High Lead screening toxicity value is 15 ug/L, the Safe Drinking Water Act Action Level for lead. L= Biased Low

[5] Rationale Codes C = CarcinogenicSelection Reason: Above Screening Levels (ASL) N = Noncarcinogenic Deletion Reason: No Toxicity Information (NTX) MCL = Safe Drinking Water Act Maximum Contaminant Level

[6] Scientific Notation is used to present this information SMCL = Secondary Maximum Contaminant Level i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 AL = Safe Drinking Water Act Action Level

1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01 UG/L = Micrograms of Chemical Per Liter of Water

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Table 2.3MEDIUM-SPECIFIC EXPOSURE POINT CONCENTRATION SUMMARY


Scenario Timeframe: Current/Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil

Chemical Units Arithmetic 95% UCL of Maximum Maximum EPC Reasonable Maximum Exposure Central Tendency

of Mean Normal Detected Qualifier Units

Concern Data Concentration Medium Medium Medium Medium Medium Medium

EPC EPC EPC EPC EPC EPC

Value Statistic Rationale Value Statistic Rationale

SITE 9

Aluminum MG/KG 6.08E+03 9.01E+03 1.03E+04 MG/KG 9.01E+03 95% UCL-N W-test (5) 6.08E+03 Mean-N W-test (5)

Arsenic MG/KG 2.35E+00 3.09E+00 3.10E+00 MG/KG 3.09E+00 95% UCL-N W-test (5) 2.35E+00 Mean-N W-test (5)

Iron MG/KG 6.16E+03 8.70E+03 9.29E+03 J MG/KG 8.70E+03 95% UCL-N W-test (5) 6.16E+03 Mean-N W-test (5)

Manganese MG/KG 6.35E+01 1.21E+02 2.02E+02 J MG/KG 2.02E+02 Max W-test (1,2) 3.82E+01 Mean-T W-test (1)

SITE 10

Aluminum MG/KG 5.15E+03 7.02E+03 9.04E+03 MG/KG 7.02E+03 95% UCL-N W-Test (5) 5.15E+03 Mean-N W-Test (5)

Arsenic MG/KG 1.96E+00 2.64E+00 4.00E+00 MG/KG 3.36E+00 95% UCL-T W-Test (4) 1.74E+00 Mean-T W-Test (4)

Iron MG/KG 5.17E+03 7.02E+03 1.09E+04 MG/KG 8.00E+03 95% UCL-T W-Test (4) 4.64E+03 Mean-T W-Test (4)

Non-detects are represented in the data set by using 1/2 the sample quantitation limit and for duplicates the maximum value was used.W - Test: Developed by Shapiro and Wilk, refer to Supplemental Guidance to RAGS: Calculating the Concentration Term, OSWER Directive 9285.7-081, May 1992.Options: Maximum Detected Value (Max); 95% Upper Confidence Level of the Mean (UCL) of Normal Data (95% UCL-N); 95% Upper Confidence Level of the Mean (UCL) of Log-transformed

Data (95% UCL-T); Mean of Log-transformed Data (Mean-T); Mean of Normal Data (Mean-N).

(1) Shapiro-Wilk W Test indicates data are log-normally distributed.(2) 95% UCL (or mean) exceeds maximum detected concentration. Therefore, maximum concentration used for EPC.(3) Shapiro-Wilks W Test indicates data are normally distributed.(4) Shapiro-Wilks W Test inconclusive. Data closer to a lognormal distribution than normal distribution.(5) Shapiro-Wilks W Test inconclusive. Data closer to a normal distribution than lognormal distribution.(6) Scientific Notation is used to present this information

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01




Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water






SITE 9

4-Methylphenol UG/L 2.30E+01 NC 4.10E+01 UG/L 4.10E+01 Max W-test (7) 2.30E+01 Mean-N W-test (7)

Antimony UG/L 2.98E+00 4.52E+00 9.70E+00 J UG/L 9.70E+00 Max W-test (4,2) 2.07E+00 Mean-T W-test (4)

Arsenic UG/L 2.02E+00 2.94E+00 6.90E+00 J UG/L 3.77E+00 95% UCL-T W-test (4) 1.65E+00 Mean-T W-test (4)

Barium UG/L 1.16E+02 1.82E+02 4.69E+02 J UG/L 1.82E+02 95% UCL-N W-test (5) 1.16E+02 Mean-N W-test (5)

Iron UG/L 7.74E+03 1.24E+04 2.31E+04 J UG/L 2.31E+04 Max W-test (1,2) 3.10E+03 Mean-T W-test (1)

Manganese UG/L 3.89E+02 6.01E+02 1.43E+03 J UG/L 1.43E+03 Max W-test (1,2) 1.81E+02 Mean-T W-test (1)

SITE 10

Benzene UG/L 5.50E+00 NC 1.00E+00 J UG/L 1.00E+00 Max W-test (7) 1.00E+00 Max W-test (7,2)



Cadmium UG/L 7.30E-01 1.72E+00 8.60E+00 J UG/L 8.60E+00 Max W-test (4,2) 2.14E-01 Mean-T W-test (4)

Chromium UG/L 4.11E+00 5.27E+00 1.33E+01 UG/L 1.33E+01 Max W-test (4,2) 3.77E+00 Mean-T W-test (4)

Iron UG/L 8.37E+03 1.22E+04 2.53E+04 UG/L 1.22E+04 95% UCL-N W-test (5) 8.37E+03 Mean-N W-test (5)

Manganese UG/L 4.97E+02 7.91E+02 2.45E+03 UG/L 2.45E+03 Max W-test (4,2) 2.33E+02 Mean-T W-test (4)

Nickel UG/L 1.22E+01 2.63E+01 1.24E+02 UG/L 1.45E+01 95% UCL-T W-test (4) 5.17E+00 Mean-T W-test (4)

Thallium UG/L 1.07E+00 1.26E+00 2.60E+00 J UG/L 2.60E+00 Max W-test (4,2) 1.02E+00 Mean-T W-test (4)

Zinc UG/L 6.07E+02 1.65E+03 8.87E+03 J UG/L 8.87E+03 Max W-test (4,2) 8.53E+00 Mean-T W-test (4)

For organic constituents only used data from monitoring well LS09-UST3 since organic constituents only detected in this well. For inorganic constituentsused unfiltered data from all wells since no clear contaminant pattern identified.

Non-detects are represented in the data set by using 1/2 the sample quantitation limit and for duplicates the maximum value was used.W - Test: Developed by Shapiro and Wilk, refer to Supplemental Guidance to RAGS: Calculating the Concentration Term, OSWER Directive 9285.7-081, May 1992.Options: Maximum Detected Value (Max); 95% Upper Confidence Level of the Mean (UCL) of Normal Data (95% UCL-N); 95% Upper Confidence Level of the Mean (UCL) of L


(1) Shapiro-Wilk W Test indicates data are log-normally distributed.(2) 95% UCL (or mean) exceeds maximum detected concentration. Therefore, maximum concentration used for EPC.(3) Shapiro-Wilks W Test indicates data are normally distributed.(4) Shapiro-Wilks W Test inconclusive. Data closer to a lognormal distribution than normal distribution.(5) Shapiro-Wilks W Test inconclusive. Data closer to a normal distribution than lognormal distribution.(6) Shapiro-Wilks W Test inconclusive. Data not closer to either lognormal or nomal distribution. Higher of normal or log-transformed value used for EPC.(7) Less than 3 samples, therefore maximum concentration used as RME EPC and arithmetic mean concentration used as CT EPC.(8) Scientific Notation is used to present this information





Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Excavation Pit






SITE 9

4-Methylphenol UG/L 2.30E+01 NC 4.10E+01 UG/L 4.10E+01 Max W-test (7) 2.30E+01 Mean-N W-test (7)



Barium UG/L 1.16E+02 1.82E+02 4.69E+02 J UG/L 1.82E+02 95% UCL-N W-test (5) 1.16E+02 Mean-N W-test (5)

Iron UG/L 7.74E+03 1.24E+04 2.31E+04 J UG/L 2.31E+04 Max W-test (1,2) 3.10E+03 Mean-T W-test (1)

Manganese UG/L 3.89E+02 6.01E+02 1.43E+03 J UG/L 1.43E+03 Max W-test (1,2) 1.81E+02 Mean-T W-test (1)

SITE 10




Cadmium UG/L 7.30E-01 1.72E+00 8.60E+00 J UG/L 8.60E+00 Max W-test (4,2) 2.14E-01 Mean-T W-test (4)

Chromium UG/L 4.11E+00 5.27E+00 1.33E+01 UG/L 1.33E+01 Max W-test (4,2) 3.77E+00 Mean-T W-test (4)

Iron UG/L 8.37E+03 1.22E+04 2.53E+04 UG/L 1.22E+04 95% UCL-N W-test (5) 8.37E+03 Mean-N W-test (5)

Manganese UG/L 4.97E+02 7.91E+02 2.45E+03 UG/L 2.45E+03 Max W-test (4,2) 2.33E+02 Mean-T W-test (4)

Nickel UG/L 1.22E+01 2.63E+01 1.24E+02 UG/L 1.45E+01 95% UCL-T W-test (4) 5.17E+00 Mean-T W-test (4)

Thallium UG/L 1.07E+00 1.26E+00 2.60E+00 J UG/L 2.60E+00 Max W-test (4,2) 1.02E+00 Mean-T W-test (4)

Zinc UG/L 6.07E+02 1.65E+03 8.87E+03 J UG/L 8.87E+03 Max W-test (4,2) 8.53E+00 Mean-T W-test (4)

For organic constituents only used data from monitoring well LS09-UST3 since organic constituents only detected in this well. For inorganic constituentsused unfiltered data from all wells since no clear contaminant pattern identified.

Non-detects are represented in the data set by using 1/2 the sample quantitation limit and for duplicates the maximum value was used.W - Test: Developed by Shapiro and Wilk, refer to Supplemental Guidance to RAGS: Calculating the Concentration Term, OSWER Directive 9285.7-081, May 1992.Options: Maximum Detected Value (Max); 95% Upper Confidence Level of the Mean (UCL) of Normal Data (95% UCL-N); 95% Upper Confidence Level of the Mean (UCL) of


(1) Shapiro-Wilk W Test indicates data are log-normally distributed.(2) 95% UCL (or mean) exceeds maximum detected concentration. Therefore, maximum concentration used for EPC.(3) Shapiro-Wilks W Test indicates data are normally distributed.(4) Shapiro-Wilks W Test inconclusive. Data closer to a lognormal distribution than normal distribution.(5) Shapiro-Wilks W Test inconclusive. Data closer to a normal distribution than lognormal distribution.(6) Shapiro-Wilks W Test inconclusive. Data not closer to either lognormal or nomal distribution. Higher of normal or log-transformed value used for EPC.(7) Less than 3 samples, therefore maximum concentration used as EPC.(8) Scientific Notation is used to present this information


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Site 9, Little Creek

Scenario Timeframe: Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil

Chemical Units Arithmetic 95% UCL of Maximum Maximum EPC Reasonable Maximum Exposure Central Tendencyof Mean Normal Detected Qualifier Units

Concern Data Concentration Medium Medium Medium Medium Medium MediumEPC EPC EPC EPC EPC EPCValue Statistic Rationale Value Statistic Rationale

Aluminum MG/KG 6.08E+03 9.01E+03 1.03E+04 MG/KG 9.01E+03 95% UCL-N W-Test (5) 6.08E+03 Mean-N W-test (5) Arsenic MG/KG 2.35E+00 3.09E+00 3.10E+00 MG/KG 3.09E+00 95% UCL-N W-Test (5) 2.35E+00 Mean-N W-test (5) Iron MG/KG 6.16E+03 8.70E+03 9.29E+03 J MG/KG 8.70E+03 95% UCL-N W-Test (5) 6.16E+03 Mean-N W-test (5) Manganese MG/KG 6.35E+01 1.21E+02 2.02E+02 J MG/KG 2.02E+02 Max W-Test (1,2) 3.82E+01 Mean-T W-test (1)

Non-detects are represented in the data set by using 1/2 the sample quantitation limit and for duplicates the maximum value was used.W - Test: Developed by Shapiro and Wilk, refer to Supplemental Guidance to RAGS: Calculating the Concentration Term, OSWER Directive 9285.7-081, May 1992.Options: Maximum Detected Value (Max); 95% Upper Confidence Level of the Mean (UCL) of Normal Data (95% UCL-N); 95% Upper Confidence Level of the Mean (UCL) of Log-transformed Data

(95% UCL-T); Mean of Log-transformed Data (Mean-T); Mean of Normal Data (Mean-N).

(1) Shapiro-Wilk W Test indicates data are log-normally distributed.(2) 95% UCL (or mean) exceeds maximum detected concentration. Therefore, maximum concentration used for EPC.(3) Shapiro-Wilks W Test indicates data are normally distributed.(4) Shapiro-Wilks W Test inconclusive. Data closer to a lognormal distribution than normal distribution.(5) Shapiro-Wilks W Test inconclusive. Data closer to a normal distribution than lognormal distribution.(6) Normal mean value used.(7) Log normal mean value used.(8) Scientific Notation is used to present this information


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Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Air Exposure Point: Upper Aquifer - Water Vapors at Showerhead







Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Air Exposure Point: Upper Aquifer - Water Vapors at Excavation







Benzene only used data from monitoring well LS10-MW06 since benzene only detected in this well.Non-detects are represented in the data set by using 1/2 the sample quantitation limit and for duplicates the maximum value was used.W - Test: Developed by Shapiro and Wilk, refer to Supplemental Guidance to RAGS: Calculating the Concentration Term, OSWER Directive 9285.7-081, May 1992.Options: Maximum Detected Value (Max); 95% Upper Confidence Level of the Mean (UCL) of Normal Data (95% UCL-N); 95% Upper Confidence Level of the Mean (UCL) of Log-transformed


(1) Shapiro-Wilk W Test indicates data are log-normally distributed.(2) 95% UCL (or mean) exceeds maximum detected concentration. Therefore, maximum concentration used for EPC. (3) Shapiro-Wilks W Test indicates data are normally distributed.(4) Shapiro-Wilks W Test inconclusive. Data closer to a lognormal distribution than normal distribution.(5) Shapiro-Wilks W Test inconclusive. Data closer to a normal distribution than lognormal distribution.(6) Shapiro-Wilks W Test inconclusive. Data not closer to either lognormal or nornal distribution. Higher of normal or log-transformed value used for EPC.(7) Less than 3 samples, therefore maximum concentration used as EPC.(8) Normal mean value used.(9) Scientific Notation is used to present this information

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 1001.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01

Page 1 of 2 04/16/2003

TABLE 2-8

SELECTION OF EXPOSURE PATHWAYS


Scenario Medium Exposure Exposure Receptor Receptor Exposure On-Site/ Type of Rationale for Selection or Exclusion

Timeframe Medium Point Population Age Route Off-Site Analysis of Exposure Pathway

Current Groundwater GroundwaterUpper Aquifer - Tap

Resident AdultDermal

AbsorptionOn-site None Groundwater not currently used on site as a water supply.

WaterIngestion On-site None Groundwater not currently used on site as a water supply.

ChildDermal


Ingestion On-site None Groundwater not currently used on site as a water supply.

Surface Soil Surface Soil Site Surface SoilOther Recreational

AdultDermal

AbsorptionOn-site None Golfers hit from elevated tees on a concrete platform and do not contact soil.

PersonIngestion On-site None Golfers hit from elevated tees on a concrete platform and do not contact soil.

ChildDermal

AbsorptionOn-site None Golfers hit from elevated tees on a concrete platform and do not contact soil.

Ingestion On-site None Golfers hit from elevated tees on a concrete platform and do not contact soil.

AirEmissions from exposed Other Recreational

Adult Inhalation On-site None Golfers hit from elevated tees on a concrete platform and do not contact soil.soil Person

Child Inhalation On-site None Golfers hit from elevated tees on a concrete platform and do not contact soil. Current/Future Surface Soil Surface Soil Site Surface Soil

Other Worker AdultDermal

AbsorptionOn-site Quant

Site workers could contact surface soil while mowing grass and collecting golfballs.

Ingestion On-site QuantSite workers could contact surface soil while mowing grass and collecting golfballs.

Air Emissions from exposed Other WorkerAdult Inhalation On-site Quant

Site workers may inhale vapors and dust from soil while mowing grass orsoil collecting golf balls.

Groundwater GroundwaterUpper Aquifer - Tap


AbsorptionOff-site None Groundwater downgradient of site is not used as a water supply.

WaterIngestion Off-site None Groundwater downgradient of site is not used as a water supply.

ChildDermal


Ingestion Off-site None Groundwater downgradient of site is not used as a water supply.

AirUpper Aquifer -Water

Resident Adult Inhalation Off-site None Groundwater downgradient of site is not used as a water supply.Vapors at Showerhead

Child Inhalation Off-site None Groundwater downgradient of site is not used as a water supply.

Future Groundwater GroundwaterUpper Aquifer - Tap

WaterResident Adult

DermalAbsorption

On-site QuantAlthough unlikely, groundwater evaluated for use as future potable watersupply.

Ingestion On-site QuantAlthough unlikely, groundwater evaluated for use as future potable watersupply.

ChildDermal


Although unlikely, groundwater evaluated for use as future potable watersupply.


Child/AdultDermal




Industrial Worker AdultDermal

AbsorptionOn-site None Industrial workers are assumed not to shower while at work.


Page 2 of 2 04/16/2003

TABLE 2-8





Future Groundwater GroundwaterUpper Aquifer - Construction

WorkerAdult

DermalAbsorption

Off-site QuantConstruction workers may contact groundwater downgradient of site whileperforming construction or excavation activities.Excavation Pit

Ingestion Off-site NoneIncidental ingestion of groundwater by construction workers would be minimalduring construction or excavation activities.


Vapors at ShowerheadResident Adult Inhalation On-site Quant


Child Inhalation On-site None Children are assumed not to shower.

Child/Adult Inhalation On-site None Children are assumed not to shower.

Industrial Worker Adult Inhalation On-site None Industrial workers are assumed not to shower while at work.

Upper Aquifer - Water ConstructionWorker

Adult Inhalation Off-site QuantConstruction workers may inhale vapors from groundwater downgradient ofsite while performing construction or excavation activities.Vapors at Excavation

Surface Soil Surface Soil Site Surface SoilOther Recreational

PersonAdult

DermalAbsorption

On-site Quant Adults may contact surface soil while recreationally using area.

Ingestion On-site Quant Adults may contact surface soil while recreationally using area.

ChildDermal

AbsorptionOn-site Quant Children may contact surface soil while recreationally using area.

Ingestion On-site Quant Children may contact surface soil while recreationally using area.


AbsorptionOn-site None

Site is a landfill, will not be used for future residential development withoutfurther study.

Ingestion On-site NoneSite is a landfill, will not be used for future residential development withoutfurther study.

ChildDermal

AbsorptionOn-site None

Site is a landfill, will not be used for future residential development withoutfurther study.

Ingestion On-site NoneSite is a landfill, will not be used for future residential development withoutfurther study.

AirEmissions from exposed Other Recreational

Adult Inhalation On-site Quant Adults may inhale vapors or dust from soil while recreationally using area.soil Person

Child Inhalation On-site Quant Children may inhale vapors or dust from soil while recreationally using area.

Quant = Quantitative Analysis

Page 1 of 2 04/16/2003

TABLE 2-9





Current Groundwater Groundwater Upper Aquifer - Tap Water Resident AdultDermal



ChildDermal

On-site None Groundwater not currently used on site as a water supply.Absorption


Current/Future Surface Soil Surface Soil Site Surface Soil Other Worker AdultDermal


Site workers could contact surface soil while mowing grass and maintainingbaseball fields.

Ingestion On-site QuantSite workers could contact surface soil while mowing grass and maintainingbaseball fields.

Other RecreationalPerson

AdultDermal

On-site Quant Adults may contact surface soil while recreationally using area.Absorption

Ingestion On-site Quant Adults may contact surface soil while recreationally using area.

ChildDermal

AbsorptionOn-site Quant Children may contact surface soil while recreationally using area.

Ingestion On-site Quant Children may contact surface soil while recreationally using area.

AirEmissions from exposed

Other Worker Adult Inhalation On-site QuantSite workers may inhale vapors and dust from soil while mowing grass ormaintaining baseball fields.soil

Other RecreationalAdult Inhalation On-site Quant Adults may inhale vapors or dust from soil while recreationally using area.

Person

Child Inhalation On-site Quant Children may inhale vapors or dust from soil while recreationally using area.

Groundwater Groundwater Upper Aquifer - Tap Water Resident AdultDermal



ChildDermal




Resident Adult Inhalation Off-site None Groundwater downgradient of site is not used as a water supply.Vapors at Showerhead

Child Inhalation Off-site None Groundwater downgradient of site is not used as a water supply.

Table 2-10Exposure Pathways

NAB Little Creek, Sites 9 and 10Media Exposure Current/Future Future

Route Site* Recreational Industrial Recreational Residential ConstructionWorker Adult Child Worker Adult Child Adult Child Worker

Site 9Surface Soil

Ingestion X X XDermal X X XInhalation

GroundwaterIngestion X X XDermal X X XInhalation

Site 10Surface Soil

Ingestion X X X X1 X1Dermal X X X X1 X1Inhalation

GroundwaterIngestion X X XDermal X X XInhalation X X

X Quantitative evaluation.X1 Same as current/future scenario* For Site 9, site worker mows grass, picks up golf balls, and maintains driving range.

For site 10, site worker mows grass and maintains fields.

Table 2-11Reasonable Maximum Exposure (RME) Parameters for Human Health Risk Assessment

NAB Little Creek, Sites 9 and 10Industrial Residential Recreational

Site Construction Child Adult Lifetime Adult ChildWorker Worker (age 1-6) (age 1-6)

General Receptor FactorsBody Weight (kg) 70a 70a 15a 70a 70a 15a

Media-Specific FactorsSoil

Ingestion Rate (mg/day) 100a 100a 200a

Skin Surface Area1 (cm2) 5,300c 5,300c 3,400m

Soil Adherence Factor (mg/cm2-day) 1d 1d 1d

Dermal Absorption Factor Solids2 Chemical Specific Chemical SpecificExposure Frequency3 (days/year) 250a/ 104f 104f 104f

Exposure Duration (years) 25a 24a 6d

GroundwaterIngestion Rate (L/day) 1a 1d 2d

Ingestion Rate (mg-year/kg-day) 1.09h

Inhalation Rate (m3/day) 20 0.83a

Skin Surface Area4 (cm2) 5,300c 7,500g 20,000d 7,500g, 20,000d

Permeability Constant (cm/hour) Chemical Specificc Chemical Specificc

Exposure Time (hours/day) 8e 0.33c 0.2c 0.33c, 0.2c

Exposure Frequency (days/year) 250a 250a 350a 350a 350a

Exposure Duration (years) 25a 1a 6a 24a 30

Notes:1. Worker and adult recreationalist skin surface area includes head, hands, forearms, and lower legs.

Child recreationalist wearing shorts and short sleeve shirt.2. Based on EPA Region III Technical Guidance “Assessing Dermal Exposure from Soil”, December 1995. For constituents with no specific values, used default

volatile organics value of 20%, semi-volatile organics value of 10%, and Inorganics value of 1%.3. Exposure frequency of 250 days/year for Site 9 and 104 days/year for site 10.4. Total body surface area.

Sources:a. USEPA, 1991. Human Health Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors.b. USEPA, 1993. Superfund’s Standard Default Exposure Factors for the Central Tendency and Reasonable Maximum Exposure.c. USEPA, 1992. Dermal Exposure Assessment: Principles and Applications. Office of Research and Development.

EPA/600/8-91/011B. January 1992.d. USEPA, 1997. Exposure Factors Handbook. EPA/600/P-95/002Fa.e. Professional judgment, assuming worker would work at site 8 hours per day.f. Professional judgment, assuming 2 days per week for 52 weeks per year for soil.g. EPA, 1997b: Risk Assessment Guidance for Superfund. Vol.1: Supplemental guidance, Dermal Risk Assessment Guidance. Interim Guidance. NCEA-W-0364.h. Calculated using equations in EPA Region III Risk-Based Concentration Table, October 1999.

Table 2-12Central Tendency (CT) Exposure Parameters for Human Health Risk Assessment

NAB Little Creek, Sites 9 and 10Industrial Residential Recreational

Site Construction Child Adult Lifetime Adult ChildWorker Worker (age 1-6) (age 1-6)

General Receptor FactorsBody Weight (kg) 70a 70a 15a 70a 15a

Media-Specific FactorsSoil

Ingestion Rate (mg/day) 50b 480a 100b 50b 50b 100b

Skin Surface Area1 (cm2) 2,000c 2,000c 2,900m 5,300c 2,000c 3,700d

Soil Adherence Factor (mg/cm2-day) 0.2c 0.2c 0.2c 0.2c 0.2c 0.2c

Dermal Absorption Factor Solids2 Chemical Specific Chemical Specific Chemical SpecificExposure Frequency (days/year) 219b 125k 234b 234b 52h 52h

Exposure Duration (years) 5b 1a 6a 9b 9b 9g

GroundwaterIngestion Rate (L/day) 1d 1.4b

Ingestion Rate (mg-year/kg-day) 0.58n

Inhalation Rate (m3/day) 0.83a

Skin Surface Area4 (cm2) 6,500m 18,000m

Permeability Constant (cm/hour) Chemical Specificc

Exposure Time (hours/day) 0.33c 0.2c

Exposure Frequency (days/year) 234b 234b

Exposure Duration (years) 6a 9b

Notes:1. Worker and adult recreationalist skin surface area includes head and hands.

Child recreationalist wearing shorts and short sleeve shirt.2. Based on EPA Region III Technical Guidance “Assessing Dermal Exposure from Soil”, December 1995. For constituents with no specific values, used default

volatile organics value of 20%, semi-volatile organics value of 10%, and Inorganics value of 1%.3. Exposure frequency of 250 days/year for Site 9 (working at driving range) and 104 days/year for site 10 (mowing baseball fields, assuming 2 days

per week, 52 weeks per year).4. Total body surface area.

Sources:a. USEPA, 1991. Human Health Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors.b. USEPA, 1993. Superfund’s Standard Default Exposure Factors for the Central Tendency and Reasonable Maximum Exposure.c. USEPA, 1992. Dermal Exposure Assessment: Principles and Applications. Office of Research and Development.

EPA/600/8-91/011B. January 1992.d. USEPA, 1997. Exposure Factors Handbook. EPA/600/P-95/002Fa. e. Professional judgment, assuming 1/2 the RME value.f. USEPA, 1996a. Soil Screening Guidance: User’s Guide. EPA/540/R-96/018. g. Assuming adolescents from 9 to 18 years of age. h. Professional judgment, assuming 1/2 the RME value.j. Professional judgement, assuming trespasser/visitor would spend a maximim of 1.8 hours contacting site soil while passing through site.k. Professional judgement, assuming construction projects last 1/2 year.I. USEPA, 1989. Risk Assessment Guidance for Superfund, Volume I - Human Health Evaluation Manual (Part A). EPA/540/1-89/002.m. EPA, 1997b: Risk Assessment Guidance for Superfund. Vol.1: Supplemental guidance, Dermal Risk Assessment Guidance.

Interim Guidance. NCEA-W-0364.

TABLE 2-13Features of Alternatives for Sites 9 and 10

Alternative Main Components Applicable Standards Present Worth Cost

1- No Action Existing 2 feet of soilcover

Meets All ARARs $0

Does not guard againstfuture risk

Does not track ground-water quality

2- Land use controls withLong-term Monitoring

Land use controls Meets all ARARs $400,000 (Site 9)

Long-term monitoring Guards against future risk $400,000 (Site 10)

Periodic soil coverinspections

Tracks groundwaterquality

3- Low-Permeability Cap Installation of cap overexisting 2 feet of soilcover

Meets all ARARs

Guards against future risk

$1,150,000 (Site 9)*

$2,730,000 (Site 10)*

Reconstruction ofrecreational facilities

Tracks groundwaterquality

Installation of stormwatercontrols

Land use controls

Long-term monitoring

Periodic soil coverinspections

* Note: Costs for reconstruction of recreational facilities and demolition of buildings not included

Table 2-14Analysis of Remedial Alternatives for Landfill Contents and Surface Soil for Site 9

Evaluation CriteriaAlternative 1

No ActionAlternative 2

Institutional Controls with LTMAlternative 3

Low-Permeability Cap

Overall Protection of Human Health and Environment

Exposure to LandfillContents

No reduction in risk of exposure overcurrent levels. Two feet of existing soilcover minimizes exposure to waste. Nounacceptable risk is posed by current soilconditions at the site.

No unacceptable risk is posed by current soil conditions at the site. Two feet ofexisting soil cover minimizes exposure tolandfill contents.

No unacceptable risk is posed by current soilconditions at the site. Human and ecologicalexposures to landfill contents are reduced bythe physical barrier provided by the cap inaddition to the 2 feet of existing soil cover.

Prevention ofunacceptable risk topotential receptors to thegroundwater

Potential risk to receptors from the watertable aquifer is posed by currentconditions at the site if the groundwater isused as a potable supply. However,potable use of the groundwater is unlikely(although no measures would be in placeto prevent it).

Potential risk to receptors from the watertable aquifer is posed by current conditionsat the site if groundwater is used as potablewater supply. However, potable use of thegroundwater is unlikely and institutional controls would prevent potable use. Thecurrent soil cover allows an estimated 40%(HELP model) of precipitation to infiltratethrough the landfill into the water tableaquifer. LTM will detect any change incurrent groundwater concentrations.

Potential risk to receptors from the water tableaquifer is posed by current conditions at the site ifgroundwater is used as a potable water supply.However, potable use of the groundwater isunlikely and institutional controls would preventpotable use. The cap over the existing soil coverwould allow an estimated 31 % (HELP model) ofprecipitation to infiltrate and reach landfillcontents, a difference of 9% over the currentconditions. Because the use of the water tableaquifer for potable water is unlikely, the benefit ofreducing infiltration is not warranted. LTM willdetect any change in current groundwaterconcentrations.

Control of surface waterrun-off and erosion.

Stormwater run-off would be controlledunder this alternative through the existingdrainage network of pipes and channels.Erosion of landfill cover is minimized dueto level topography, however, no annualinspections or maintenance will occur toensure this.

Stormwater run-off would be controlledunder this alternative through the existingdrainage network of pipes and channels.Erosion of landfill contents is minimized dueto level topography and annual inspections.

Surface controls include earth grading to controlstormwater run-off, placing measures to controlerosion, and reconstruction of existing swalesafter cap installation.

Compliance with ARARs

Chemical-Specific ARARs

Location-Specific ARARs

Action-Specific ARARs

No chemical-specific ARARS wereiden-tified for soil because there is nounacceptable risk posed by surface soil.Currently meets drinking water ARARs(MCLs) but exceeds tap water RBCs forseveral metals.

Not relevant.

Not relevant.

No chemical-specific ARARs were identifiedfor soil because there is no unacceptablerisk posed by surface soil. Land-userestrictions prevent use as water supply,therefore, potential drinking water ARARswould be met. LTM would trackgroundwater quality to prevent furtherdegradation.

Meets all location-specific ARARs.

Meets all action-specific ARARs.

No chemical-specific ARARs were identified forsoil because there is no unacceptable risk posedby surface soil. Air quality standards would be metby implementing proper construction controltechnologies (i.e. wetting) during earth-movingactivities. Land-use restrictions prevent use aswater supply, therefore, potential drinking waterARARs would be met. LTM would trackgroundwater quality to prevent furtherdegradation.

Meets all location-specific ARARs.

Meets all action-specific ARARs.

Long Term Effectiveness and Permanence

Landfill Contents andSurface Soil

Need for 5-Year Review

Source not remediated. No unacceptablerisk is posed by soil at current siteconditions. Potential risk posed bygroundwater. Existing two foot physicalbarrier between the landfill contents andpotential human and ecological receptors.No permanent means to prevent future useof site in a manner that would result inunacceptable risks to groundwater andsoil.

Because contaminated material (landfillcontents) remains onsite, 5-year reviewswould be required

Source not remediated. No unacceptablerisk is posed by soil at current siteconditions. Potential risk posed bygroundwater. Existing two foot physicalbarrier between the landfill contents andpotential human and ecological receptors.Institutional controls and monitoring wouldbe relied upon to eliminate unacceptablerisks to groundwater and soil.

See Alternative 1.

Source not remediated. No unacceptable risk isposed by soil at current site conditions. Potentialrisk posed by groundwater. Provides a 6.5 footthick physical barrier between the landfill contentsand potential human and ecological receptors.Institutional controls and monitoring would berelied upon to eliminate unacceptable risks togroundwater and soil

See Alternative 1.

Reduction of Toxicity, Mobility, or Volume

Table 2-14Analysis of Remedial Alternatives for Landfill Contents and Surface Soil for Site 9

Evaluation CriteriaAlternative 1

No ActionAlternative 2

Institutional Controls with LTMAlternative 3

Low-Permeability Cap


Type and Quantity ofResiduals Remaining AfterRemediation

Toxicity associated with contaminatedmedia would remain at current levels.Mobility of contaminants is minimized dueto the 2 feet of existing soil cover. Volumereduction is not attained.

No treatment under-taken. Therefore,landfill contents remain onsite beneaththe existing soil cover.

Toxicity associated with contaminatedmedia would remain at current levels.Mobility of contaminates is minimized due tothe 2 feet cover. Volume reduction is notattained.

No treatment under-taken. Therefore,landfill contents remain onsite beneath theexisting soil cover.

Toxicity associated with contaminated mediawould remain at current levels. Mobility ofcontaminants may be reduced with the additional4.5 foot cap on existing soil cover. Volumereduction is not attained.

No treatment under-taken. Therefore, landfillcontents remain onsite beneath the cap andexisting soil cover.

Short-Term Effectiveness


Time Until Action isComplete

Remedy implementation does not add torisk.

Not applicable.

Remedy implementation does not add torisk.

Minimal time required.

A moderate amount of construction traffic will beassociated with hauling material from offsitesources.

Cap construction and recreational facilityconstruction is expected to take approximatelythree months.

Implementability

Ability to Construct andOperate

Ease of ImplementingAdditional Action ifNeeded

Ability to MonitorEffectivness

Not applicable.

Very easy implement additional action.

Easily monitored during 5-year sitereviews.

Minimal construction required. Operationwould consist of annual inspection, long-term monitoring, and repair of erosion ifnecessary. Land-use restrictions wouldrequire consent from base command.

Very easy to implement additional action.

Easily monitored during 5-year site reviews.Periodic inspection of the soil cover willensure its integrity has not beencompromised. LTM will also be used toevaluate the groundwater quality.

The cap and driving range would be constructedusing traditional construction methods.Interrupting use of the driving range this timewould result in loss of revenue for the base.Operation would consist of long-term monitoring,and repair of erosion if necessary. Land-userestrictions would require consent from basecommand.

Capping layers could be added at significantexpense.

Easily monitored during 5-year site reviews.Periodic inspection of the cap will ensure itsintegrity has not been compromised. LTM also willbe used to evaluate groundwater quality.

Site 9 - Cost

Capital CostAnnual O&M Cost

Present-Worth

$0$0

$0

$0$32,450 (Year 0-5)$17,583 (Year 6-30)

$380,340

$789,640$32,450 (Year 0-5)$17,583 (Year 6-30)

$1,152,255

Site 10 - Cost

Capital CostFirst-Year Annual O&MCostPresent-Worth

$0$0

$0

$0$34,550 (Year 0-5)$19,683 (Year 6-30)

$380,340

$2,327,399$34,550 (Year 0-5)$19,683 (Year 6-30)

$2,725,462

Table 2-15 Engineer’s Preliminary Cost EstimateSite 9 and 10, Driving Range Landfill and Sewage Treatment Plant Landfill, NAB Little CreekAlternative 2: Institutional Controls with Long-Term Groundwater Monitoring

Cost ComponentEstimatedQuantity Unit

UnitCost

Capital Cost Resource

I. Cap Materials1. Seeding and Mulching 0 MSF $ - $ - Engineer’s Estimate2. 6-inch Topsoil/Plantable Soil (Del./Dump) 0 CY $ - $ - Engineer’s Estimate

Topsoil backfil, w/dozer, 200 hp 0 CY $ - $ - Engineer’s Estimate3. 18-inch Vegetative Support Layer 0 CY $ - $ - Engineer’s Estimate

Borrow backfill, w/dozer, 200 hp 0 CY $ - $ - Engineer’s EstimateCompact vegetative support layer 0 CY $ - $ - 022 226 5600

4. 18-inch Low Hyd. Cond. Layer (Del./Dump) 0 CY $ - $ - Engineer’s EstimateBackfill, w/dozer, 200 hp 0 CY $ - $ - Engineer’s EstimateCompact 0 CY $ - $ - 022 226 5600

5. 1-foot Leveling Layer 0 CY $ - $ - Engineer’s EstimateBorrow backfill, w/dozer, 200 hp 0 CY $ - $ - Engineer’s EstimateCompact base layer 0 CY $ - $ - 022 226 5600

6. Soil Testing 0 LUMP $ - $ - Engineer’s EstimateSubtotal $ -

II. Stormwater Management Features1. Construct Swales 0 CY $ - $ -

Subtotal $ -

Subtotal $ -

III. Miscellaneous*1. Erosion Control 0 AC $ 900.00 $ - Engineer’s Estimate

Subtotal $ -

SUBTOTAL - CUMULATIVE CAPITAL COSTS $ -

IV. General Requirements1. Payment & Performance Bonds 2% $ -2. Mobilization/Demobilization Heavy Equipment EA $ 2,500.00 $ -3. Insurance 2% $ -4. Jobsite OH 5% $ -

Subtotal $ -

TOTAL - CUMULATIVE CAPITAL COST $ -

Construction Management 20% $ -

Engineering and Inspection Services 20% $ -

Health & Safety (Level D) 10% $ -

Contingency 25% $ -

GRAND TOTAL $ -

Short Term Expenses (Years 0 - 5)I. GW Monitoring/Fieldwork/Reporting

1. GW monitoring/Fieldwork 2 ROUND $ 10,000.00 $ 20,00 Engineer’s Estimate2. Analyses, data validation, sample management 2 ROUND $ 15,000.00 $ 30,000 Engineer’s Estimate3. Letter Report 2 EA $ 1,400.00 $ 2,800 Engineer’s Estimate4. 5 year LTM Report 1 EA $ 2,000.00 $ 2,000 Engineer’s Estimate

II. Mowing/Fertilization/Reseeding 24 AC $ 175.00 $ 4,200 Engineer’s Estimate

III. Localized Erosion Repair 1 LUMP $ 2,000.00 $ 2,000 Engineer’s Estimate

IV. Miscellaneous Repairs (Fencing, Signs, ect.) 1 LUMP $ 2,000.00 $ 2,000 Engineer’s Estimate

V. Annual Inspections 1 LUMP $ 4,000.00 $ 4,000 Engineer’s Estimate

Year 0-5 O&M COST TOTAL $ 67,000

Annual Expenses (Years 6 - 30)I. Mowing/Fertilization/Reseeding 24 AC $ 175.00 $ 4,200 Engineer’s Estimate

II. Localized Erosion Repair 1 LUMP $ 2,000.00 $ 2,000 Engineer’s Estimate

III. Miscellaneous Repairs (Fencing, Signs, ect.) 1 LUMP $ 2,000.00 $ 2,000 Engineer’s Estimate

IV. GW Monitoring/Fieldwork/Reporting1. GW monitoring/Fieldwork 1 ROUND $ 10,000.00 $ 10,000 Engineer’s Estimate2. Analyses, data validation, sample management 1 ROUND $ 12,000.00 $ 12,000 Engineer’s Estimate3. Letter Report 1 EA $ 1,200.00 $ 1,200 Engineer’s Estimate4. 3 year LTM Report 1 EA $ 1,866.67 $ 1,867 Engineer’s Estimate

V. Annual Inspections 1 LUMP $ 4,000.00 $ 4,000 Engineer’s Estimate

YEAR 6-30 O&M COST TOTAL $ 37,267

PRESENT WORTH $760,679 4.2% Discount Rate

Appendix A TABLE A-1

NON-CANCER TOXICITY DATA -- ORAL/DERMAL


Chemical Chronic/ Oral RfD Oral RfD Oral to Dermal Adjusted Units Primary Combined Sources of RfD: Dates of RfD:

of Subchronic Value Units Adjustment Dermal Target Uncertainty/Modifying Target Organ Target Organ (3)

Concern Factor (1) RfD (2) Organ Factors (MM/DD/YY)

Aluminum Chronic 1.0E+00 mg/kg-day 27% 2 7E-01 mg/kg-day CNS 100 NCEA 08/26/1996Subchronic N/A

Antimony Chronic 4.0E-04 mg/kg-day 10% 4.0E-05 mg/kg-day Blood 1000 IRIS 06/17/1998Subchronic 4.0E-04 mglkg-day 10% 4.0E-05 mg/kg-day Blood 1000 HEAST 07/08/1998

Arsenic Chronic 3.0E-04 mg/kg-day 95% 2.9E-04 mg/kg-day Skin 3 IRIS 06/17/1998Subchronic 3.0E-04 mg/kg-day 95% 2.9E-04 mg/kg-day Skin 3 HEAST 07/08/1998

Cadmium (Water) Chronic 5.0E-04 mg/kg-day 5% 2.5E-05 mg/kg-day Kidney 10 IRIS 06/17/1998Subchronic N/A

Chromium (hexavalent) Chronic 3.0E-03 mg/kg-day 1% 3.0E-05 mg/kg-day NOAEL 500 IRIS 06/17/1998Subchronic 2.0E-02 mg/kg-day 1% 2.0E-04 mg/kg-day NOAEL 100 HEAST 07/08/1998

Iron Chronic 3.0E-01 mg/kg-day 20% 6.0E-02 mglkg-day Gastrointestinal 1 NCEA 07/23/1996Subchronic N/A

Manganese (nonfood) Chronic 2.0E-02 mg/kg-day 35% 7.0E-03 mg/kg-day CNS 1 IRIS 06/17/1998Subchronic N/A

Nickel Chronic 2.0E-02 mg/kg-day 10% 2.0E-03 mg/kg-day Whole body 300 IRIS 06/22/1998Subchronic 2.0E-02 mg/kg-day 10% 2.0E-03 mg/kg-day Whole body 300 HEAST 07/08/1998

Thallium Chronic 7.0E-05 mg/kg-day 100% 7.0E-05 mg/kg-day Liver & Blood R3Subchronic N/A

Zinc Chronic 3.0E-01 mg/kg-day 25% 7.5E-02 mg/kg-day Blood 3 IRIS 06/22/1998Subchronic 3.0E-01 mg/kg-day 25% 7.5E-02 mg/kg-day Blood 3 HEAST 07/08/1998

Benzene Chronic 3.0E-03 mg/kg-day 100% 3.0E-03 mg/kg-day Liver 3000 NCEA 07/02/1996Subchronic 3.0E-03 mg/kg-day 100% 3.0E-03 mg/kg-day Liver 3000 NCEA 07/02/1996

N/A = Not Applicable or Not Available.

(1) Refer to Risk Assessment Guidance for Superfund (RAGS), Part A. Source is EPA Region III Oral Absorption Values for Oral-to-Dermal Extrapolation, April 8, 1999.

For constituents not available in the Region III document the following general values were used: VOCs - 80%, Pesticides/PCBs - 50%, and metals - 20%.

ATSDR = Agency for Toxic Substances and Disease Registry

IRIS = Integrated Risk Information System

HEAST= Health Effects Assessment Summary Tables

NCEA = National Center for Environmental Assessment

R3 = EPA Region III RBC Table

(2) Adjusted dermal RfD = Oral RfD x Oral to Dermal Adjustment Factor

(3) For IRIS values, provide the date IRIS was searched. RESP = Respiratory System

For HEAST values, provide the date of HEAST. CNS = Central Nervous System

For NCEA values, provide the date of the article provided by NCEA. NOAEL = No adverse effect level

(4) Scientific Notation is used to present this information

i.e.1.00E+02 is the scientific notation for one times ten to the power of 2, or 100

1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01

04/16/2003


NON-CANCER TOXICITY DATA -- INHALATION


Chemical Chronic/ Value Units Adjusted Units Primary Combined Sources of Dates (3)

of Subchronic Inhalation Inhalation Target Uncertainty/Modifying RfC:RfD: (MM/DD/YY)

Concern RfC RfD (1) Organ Factors Target Organ

(2)

Aluminum Chronic 5.00E-03 mg/m3 1.00E-03 mg/kg-day CNS 300 NCEA 06/20/1997

Subchronic N/A

Antimony Chronic N/A

Subchronic N/A

Arsenic Chronic N/A

Subchronic N/A

Cadmium Chronic 2.21E+01 mg/m3 5.70E-05 mg/kg-day Kidney 10 IRIS 06/17/1998

Subchronic N/A

Chromium Chronic 1.05E-04 mg/m3 3.00E-05 mg/kg-day NOAEL 100 NCEA 11/18/1997

Subchronic 4.00E-06 mg/m3 3.00E-04 mg/kg-day NOAEL 100 NCEA 11/18/1997

Iron Chronic N/A

Subchronic N/A

Manganese Chronic 5.01E-05 mg/m3 1.43E-05 mg/kg-day CNS 1 IRIS 06/17/1998

Subchronic N/A

Nickel Chronic N/A

Subchronic N/A

Thallium Chronic N/A

Subchronic N/A

Zinc Chronic N/A

Subchronic N/A

Benzene Chronic 5.95E-03 mg/m3 1.70E-03 mg/kg-day Liver 10 NCEA 07/02/1996

Subchronic 5.95E-02 mg/m3 1.70E-02 mg/kg-day Liver 100 NCEA 07/02/1996

N/A = Not Applicable ATSDR = Agency for Toxic Substances and Disease Registry

(1) RfC (m3/day) x 20 m3/day x 1/70 kg = RfD (mg/kg-day) IRIS = Integrated Risk Information System(2) HEAST, Alternative Methods used as source of barium values. HEAST= Health Effects Assessment Summary Tables

Chromium and cadmium values were withdrawn from HEAST, but available in Region III RBC Table. HEAST(A) = Health Effects Assessment Summary Tables, Alternate Methods

(3) For IRIS values, provide the date IRIS was searched. HEAST(W)= Health Effects Assessment Summary Tables, Withdrawn

For HEAST values, provide the date of HEAST. NCEA = National Center for Environmental Assessment

For NCEA values, provide the date of the article provided by NCEA.


i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100


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CANCER TOXICITY DATA -- ORAL/DERMAL


Chemical Oral Cancer Oral to Dermal Adjusted Dermal Units EPA Source Date (2)

of Slope Factor Adjustment Cancer Slope Factor (1) Carcinogen (MM/DD/YY)

Concern Factor Group

Aluminum N/A

Antimony N/A

Arsenic 1.5E+00 95% 1.6E+00 (mg/kg-day) -1 A IRIS 07/08/1998

Cadmium-Water N/A

Chromium (hexavalent) N/A

Iron N/A

Manganese (nonfood) N/A

Nickel N/A

Thallium N/A

Zinc N/A

Benzene 5.2E-02 100% 5.2E-02 (mg/kg-day) -1 A IRIS 03/01/2000

N/A-Not available EPA Carcinogen Group:

IRIS = Integrated Risk Information System A - Human carcinogen

HEAST= Health Effects Assessment Summary Tables B1 - Probable human carcinogen - indicates that limited human data are available

NCEA = National Center for Environmental Assessment B2 - Probable human carcinogen - indicates sufficient evidence in animals and

U = Under review. inadequate or no evidence in humans

C - Possible human carcinogen

D - Not classifiable as a human carcinogen

E - Evidence of noncarcinogenicity

(1) Refer to Risk Assessment Guidance for Superfund (RAGS), Part A. Source is EPA Region III Oral Absorption Values for Oral-to-Dermal Extrapolation , April 8, 1999.


(2) For IRIS values, provide the date IRIS was searched.

For HEAST values, provide the date of HEAST.

For NCEA values, provide article date provided by NCEA.




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CANCER TOXICITY DATA -- INHALATION


Chemical Unit Risk Units Adjustment (1) Inhalation Cancer Units Weight of Evidence/ Source Date (2)

of Slope Factor Cancer Guidance (MM/DD/YY)

Concern Description

Aluminum N/A

Antimony N/A

Arsenic 4.0E-03 (ug/m3) -1 3500 1.5E+01 (mg/kg-day) -1 A IRIS 06/13/1998

Cadmium 1.8E-03 (ug/m3) -1 3500 6.3E+00 (mg/kg-day) -1 B1 IRIS 06/13/1998

Chromium 1.2E-02 (ug/m3) -1 3500 4.1E+01 (mg/kg-day) -1 A HEAST 06/13/1998

Iron N/A

Manganese N/A

Nickel N/A

Thallium N/A

Zinc N/A

Benzene 8.3E-06 (ug/m3) -1 3500 2.9E-02 (mg/kg-day) -1 A IRIS 06/13/1998

IRIS = Integrated Risk Information System EPA Group:

HEAST= Health Effects Assessment Summary Tables A - Human carcinogen

NCEA = National Center for Environmental Assessment B1 - Probable human carcinogen - indicates that limited human data are available

U = Under review. B2 - Probable human carcinogen - indicates sufficient evidence in animals and

N/A = Not Available inadequate or no evidence in humans


(1) Adjustment Factor applied to Unit Risk to calculate Inhalation Slope Factor = D - Not classifiable as a human carcinogen

70kg x 1/20m3/day x 1000ug/mg E - Evidence of noncarcinogenicity




For RBC values, provide the date of last change In the Tables.

(3) Scientific Notation Is used to present this information




NON-CANCER TOXICITY DATA -- ORAL/DERMAL


Chemical Chronic/ Oral RfD Oral RfD Oral to Dermal Adjusted Units Primary Combined Sources of RfD: Dates of RfD:

of Subchronic Value Units Adjustment Dermal Target Uncertainty/Modifying Target Organ Target Organ (3)

Concern Factor (1) RfD (2) Organ Factors (MM/DD/YY)

Aluminum Chronic 1.0E+00 mg/kg-day 27% 2.7E-01 mg/kg-day CNS 100 NCEA 08/26/1996

Subchronic N/A

Antimony Chronic 4.0E-04 mg/kg-day 10% 4.0E-05 mg/kg-day Blood 1000 IRIS 06/17/1998

Subchronic 4.0E-04 mg/kg-day 10% 4.0E-05 mg/kg-day Blood 1000 HEAST 07/08/1998

Arsenic Chronic 3.0E-04 mg/kg-day 95% 2.9E-04 mg/kg-day Skin 3 IRIS 06/17/1998

Subchronic 3.0E-04 mg/kg-day 95% 2.9E-04 mg/kg-day Skin 3 HEAST 07/08/1998

Barium Chronic 7.0E-02 mg/kg-day 100% 7.0E-02 mg/kg-day Cardiovascular 3 IRIS 06/17/1998

Subchronlc 7.0E-02 mg/kg-day 100% 7.0E-02 mg/kg-day Cardiovascular 3 HEAST 07/08/1998

Iron Chronic 3.0E-01 mg/kg-day 20% 6.0E-02 mg/kg-day Gastrointestinal 1 NCEA 07/23/1996

Subchronic N/A

Manganese (nonfood) Chronic 2.0E-02 mg/kg-day 35% 7.0E-03 mg/kg-day CNS 1 IRIS 06/17/1998

Subchronic N/A

4-Methylphenol Chronic 5.0E-03 mg/kg-day 65% 3.3E-03 mg/kg-day CNS, RESP & Whole Body 1000 HEAST 07/08/1998

Subchronic 5.0E-03 mg/kg-day 65% 3 3E-03 mg/kg-day CNS, RESP & Whole Body 1000 HEAST 07/08/1998

N/A = Not Applicable or Not Available.

(1) Refer to Risk Assessment Guidance for Superfund (RAGS), Part A. Source is EPA Region III Oral Absorption Values for Oral-to-Dermal Extrapolation , April 8, 1999.


IRIS = Integrated Risk Information System

HEAST= Health Effects Assessment Summary Tables

NCEA = National Center for Environmental Assessment

(2) Adjusted dermal RfD = Oral RfD x Oral to Dermal Adjustment Factor

(3) For IRIS values, provide the date IRIS was searched. RESP = Respiratory System

For HEAST values, provide the date of HEAST. CNS = Central Nervous System

For NCEA values, provide the date of the article provided by NCEA. NOAEL = No adverse effect level




04/16/2003

Appendix a TABLE A-6

NON-CANCER TOXICITY DATA -- INHALATION


Chemical Chronic/ Value Units Adjusted Units Primary Combined Sources of Dates (3)

of Subchronic Inhalation Inhalation Target Uncertainty/Modifying RfC:RfD: (MM/DD/YY)

Concern RfC RfD (1) Organ Factors Target Organ

(2)

Aluminum Chronic 5.00E-03 mg/m3 1.00E-03 mg/kg-day CNS 300 NCEA 06/20/1997

Subchronic N/A

Antimony Chronic N/A

Subchronic N/A

Arsenic Chronic N/A

Subchronic N/A

Barium Chronic 4.90E-04 mg/m3 1.40E-04 mg/kg-day Cardiovascular HEAST(A)

Subchronic N/A

Iron Chronic N/A

Subchronlc N/A

Manganese Chronic 5.01E-05 mg/m3 1.43E-05 mg/kg-day CNS 1 IRIS 06/17/1998

Subchronic N/A

4-Methylphenol Chronic N/A

Subchronic N/A

N/A = Not Applicable ATSDR = Agency for Toxic Substances and Disease Registry

(1) RfC (m3/day) x 20 m3/day x 1/70 kg = RfD (mg/kg-day) IRIS = Integrated Risk Information System(2) HEAST, Alternative Methods used as source of barium values. HEAST= Health Effects Assessment Summary Tables

Chromium and cadmium values were withdrawn from HEAST, but available in Region III RBC Table. HEAST(A) = Health Effects Assessment Summary Tables, Alternate Methods

(3) For IRIS values, provide the date IRIS was searched. HEAST(W)= Health Effects Assessment Summary Tables, Withdrawn

For HEAST values, provide the date of HEAST. NCEA = National Center for Environmental Assessment





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TABLE 6.1

Appendix A Table A-7

CANCER TOXICITY DATA -- ORAL/DERMAL


Chemical Oral Cancer Oral to Dermal Adjusted Dermal Units EPA Source Date (2)

of Slope Factor Adjustment Cancer Slope Factor (1) Carcinogen (MM/DD/YY)

Concern Factor Group

Aluminum N/A

Antimony N/A

Arsenic 1.5E+00 95% 1.6E+00 (mg/kg-day) -1 A IRIS 07/08/1998

Barium N/A

Iron N/A

Manganese (nonfood) N/A

4-Methylphenol N/A

N/A-Not available EPA Carcinogen Group:

IRIS = Integrated Risk Information System A - Human carcinogen

HEAST= Health Effects Assessment Summary Tables B1 - Probable human carcinogen - indicates that limited human data are available

NCEA = National Center for Environmental Assessment B2 - Probable human carcinogen - indicates sufficient evidence in animals and

U = Under review. inadequate or no evidence in humans


D - Not classifiable as a human carcinogen

E - Evidence of noncarcinogenicity

(1) Refer to Risk Assessment Guidance for Superfund (RAGS), Part A. Source is EPA Region III Oral Absorption Values for Oral-to-Dermal Extrapolation, April 8, 1999.




For NCEA values, provide article date provided by NCEA.




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CANCER TOXICITY DATA -- INHALATION


Chemical Unit Risk Units Adjustment (1) Inhalation Cancer Units Weight of Evidence/ Source Date (2)

of Slope Factor Cancer Guidance (MM/DD/YY)

Concern Description

Aluminum N/A

Antimony N/A

Arsenic 4.0E-03 (ug/m3) -1 3500 1.5E+01 (mg/kg-day) -1 A IRIS 06/13/1998

Barium N/A

Iron N/A

Manganese N/A

4-Methylphenol N/A

IRIS = Integrated Risk Information System EPA Group:

HEAST= Health Effects Assessment Summary Tables A - Human carcinogen

NCEA = National Center for Environmental Assessment B1 - Probable human carcinogen - indicates that limited human data are available

U = Under review. B2 - Probable human carcinogen - indicates sufficient evidence in animals and

N/A = Not Available inadequate or no evidence in humans


(1) Adjustment Factor applied to Unit Risk to calculate Inhalation Slope Factor = D - Not classifiable as a human carcinogen

70kg x 1/20m3/day x 1000ug/mg E - Evidence of noncarcinogenicity




For RBC values, provide the date of last change in the Tables.




TABLE B-1.RMECALCULATION OF NON-CANCER HAZARDS

REASONABLE MAXIMUM EXPOSURESite 9, Little Creek

Scenario Timeframe: Current/Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Worker Receptor Age: Adult

Exposure Chemical Medium Medium Route Route EPC Intake Intake Reference Reference Reference Reference HazardRoute of EPC EPC EPC EPC Selected (Non-Cancer) (Non-Cancer) Dose (2) Dose Units Concentration Concentration Quotient

Concern Value Units Value Units for Hazard Units UnitsCalculation (1)

Ingestion Aluminum 9.01E+03 mg/kg 9.01E+03 mg/kg M 8.8E-03 mg/kg-day 1.0E+00 mg/kg-day N/A N/A 8.8E-03Arsenic 3.09E+00 mg/kg 3.09E+00 mg/kg M 3.0E-06 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 1.0E-02Iron 8.70E+03 mg/kg 8.70E+03 mg/kg M 8.5E-03 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 2.8E-02Manganese 2.02E+02 mg/kg 2.02E+02 mg/kg M 2.0E-04 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 9.9E-03

(Total) 5.7E-02

Dermal Aluminum 9.01E+03 mg/kg 9.01E+03 mg/kg M 4.7E-03 mg/kg-day 2.7E-01 mg/kg-day N/A N/A 1.7E-02Arsenic 3.09E+00 mg/kg 3.09E+00 mg/kg M 5.1E-06 mg/kg-day 2.9E-04 mg/kg-day N/A N/A 1.8E-02Iron 8.70E+03 mg/kg 8.70E+03 mg/kg M 4.5E-03 mg/kg-day 6.0E-02 mg/kg-day N/A N/A 7.5E-02Manganese 2.02E+02 mg/kg 2.02E+02 mg/kg M 1.0E-04 mg/kg-day 7.0E-03 mg/kg-day N/A N/A 1.5E-02

(Total) 1.3E-01

Total Hazard Index Across All Exposure Routes/Pathways 1.8E-01

(1) Specify Medium-Specific (M) or Route-Specific (R) EPC selected for hazard calculation.(2) Chronic.(3) Scientific Notation is used to present this information




Scenario Timeframe: Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Adult




(Total) 2.4E-02


(Total) 5.2E-02






Scenario Timeframe: Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Child




(Total) 2.2E-01


(Total) 1.6E-01




TABLE B-4.RMECALCULATION OF CANCER RISKS



Exposure Chemical Medium Medium Route Route EPC Selected Intake Intake Cancer Slope Cancer Slope CancerRoute of EPC EPC EPC EPC for Risk (Cancer) (Cancer) Factor Factor Units Risk

Concern Value Units Value Units Calculation (1) Units

Ingestion Aluminum 9.01E+03 mg/kg 9.01E+03 mg/kg M 3.1E-03 mg/kg-day N/AArsenic 3.09E+00 mg/kg 3.09E+00 mg/kg M 1.1E-06 mg/kg-day 1.5E+00 (mg/kg-day) -1 1.6E-06Iron 8.70E+03 mg/kg 8.70E+03 mg/kg M 3.0E-03 mg/kg-day N/AManganese 2.02E+02 mg/kg 2.02E+02 mg/kg M 7.1E-05 mg/kg-day N/A

(Total) 1.6E-06

Dermal Aluminum 9.01E+03 mg/kg 9.01E+03 mg/kg M 1.7E-03 mg/kg-day N/AArsenic 3.09E+00 mg/kg 3.09E+00 mg/kg M 1.8E-06 mg/kg-day 1.6E+00 (mg/kg-day) -1 2.9E-06Iron 8.70E+03 mg/kg 8.70E+03 mg/kg M 1.6E-03 mg/kg-day N/AManganese 2.02E+02 mg/kg 2.02E+02 mg/kg M 3.7E-05 mg/kg-day N/A

2.9E-06

Total Risk Across All Exposure Routes/Pathways 4.5E-06

(1) Specify Medium-Specific (M) or Route-Specific (R) EPC selected for risk calculation.(2) Scientific Notation is used to present this information




Scenario Timeframe: Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Adult




(Total) 6.5E-07


1.2E-06






Scenario Timeframe: Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Child




(Total) 1.5E-06


8.6E-07






Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water Receptor Population: Resident Receptor Age: Adult



Ingestion 4-Methylphenol 4.01E+01 µg/L 4.01E+01 µg/L M 1.1E-03 mg/kg-day 5.0E-03 mg/kg-day N/A N/A 2.2E-01Antimony 9.70E+00 µg/L 9.70E+00 µg/L M 2.7E-04 mg/kg-day 4.0E-04 mg/kg-day N/A N/A 6.6E-01Arsenic 3.77E+00 µg/L 3.77E+00 µg/L M 1.0E-04 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 3.4E-01Barium 1.82E+02 µg/L 1.82E+02 µg/L M 5.0E-03 mg/kg-day 7.0E-02 mg/kg-day N/A N/A 7.1E-02Iron 2.31E+04 µg/L 2.31E+04 µg/L M 6.3E-01 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 2.1E+00Manganese 1.43E+03 µg/L 1.43E+03 µg/L M 3.9E-02 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 2.0E+00

(Total) 5.4E+00

Dermal 4-Methylphenol 4.10E+01 µg/L 4.01E+01 µg/L M 8.8E-05 mg/kg-day 3.3E-03 mg/kg-day N/A N/A 2.7E-02Antimony 9.70E+00 µg/L 9.70E+00 µg/L M 5.3E-07 mg/kg-day 4.0E-05 mg/kg-day N/A N/A 1.3E-02Arsenic 3.77E+00 µg/L 3.77E+00 µg/L M 2.1E-07 mg/kg-day 2.9E-04 mg/kg-day N/A N/A 7.1E-04Barium 1.82E+02 µg/L 1.82E+02 µg/L M 1.0E-05 mg/kg-day 7.0E-02 mg/kg-day N/A N/A 1.4E-04Iron 2.31E+04 µg/L 2.31E+04 µg/L M 1.3E-03 mg/kg-day 6.0E-02 mg/kg-day N/A N/A 2.1E-02Manganese 1.43E+03 µg/L 1.43E+03 µg/L M 7.8E-05 mg/kg-day 7.0E-03 mg/kg-day N/A N/A 1.1E-02

(Total) 7.3E-02

Total Hazard Index Across All Exposure Routes/Pathways 5.4E+00





Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water Receptor Population: Resident Receptor Age: Child



Ingestion 4-Methylphenol 4.01E+01 µg/L 4.01E+01 µg/L M 2.6E-03 mg/kg-day 5.0E-03 mg/kg-day N/A N/A 5.2E-01Antimony 9.70E+00 µg/L 9.70E+00 µg/L M 6.2E-04 mg/kg-day 4.0E-04 mg/kg-day N/A N/A 1.6E+00Arsenic 3.77E+00 µg/L 3.77E+00 µg/L M 2.4E-04 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 8.0E-01Barium 1.82E+02 µg/L 1.82E+02 µg/L M 1.2E-02 mg/kg-day 7.0E-02 mg/kg-day N/A N/A 1.7E-01Iron 2.31E+04 µg/L 2.31E+04 µg/L M 1.5E+00 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 4.9E+00Manganese 1.43E+03 µg/L 1.43E+03 µg/L M 9.1E-02 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 4.6E+00

(Total) 1.3E+01


(Total) 1.9E-01






Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water Receptor Population: Resident Receptor Age: Child/Adult



Ingestion 4-Methylphenol 4.1E+01 µg/L 4.10E+01 µg/L M 6.1E-04 mg/kg-day N/AAntimony 9.70E+00 µg/L 9.70E+00 µg/L M 1.4E-04 mg/kg-day N/AArsenic 3.77E+00 µg/L 3.77E+00 µg/L M 5.6E-05 mg/kg-day 1.5E+00 (mg/kg-day) -1 8.4E-05Barium 1.82E+02 µg/L 1.82E+02 µg/L M 2.7E-03 mg/kg-day N/AIron 2.31E+04 µg/L 2.31E+04 µg/L M 3.4E-01 mg/kg-day N/AManganese 1.43E+03 µg/L 1.43E+03 µg/L M 2.1E-02 mg/kg-day N/A

(Total) 8.4E-05

Dermal 4-Methylphenol 4.10E+01 µg/L 4.10E+01 µg/L M 7.5E-05 mg/kg-day N/AAntimony 9.70E+00 µg/L 9.70E+00 µg/L M 3.1E-07 mg/kg-day N/AArsenic 3.77E+00 µg/L 3.77E+00 µg/L M 1.2E-07 mg/kg-day 1.6E+00 (mg/kg-day) -1 2.0E-07Barium 1.82E+02 µg/L 1.82E+02 µg/L M 5.9E-06 mg/kg-day N/AIron 2.31E+04 µg/L 2.31E+04 µg/L M 7.5E-04 mg/kg-day N/AManganese 1.43E+03 µg/L 1.43E+03 µg/L M 4.6E-05 mg/kg-day N/A

(Total) 2.0E-07



i.e.1.00E+02 is the scientific notation for one times ten to the power of 2, or 1001.00E-02 Is the scientific notation for one times ten to the power of -2, or 0.01



Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water Receptor Population: Industrial Worker Receptor Age: Adult



Ingestion 4-Methylphenol 4.10E+01 µg/L 4.10E+01 µg/L M 4.0E-04 mg/kg-day 5.0E-03 mg/kg-day N/A N/A 8.0E-02Antimony 9.70E+00 µg/L 9.70E+00 µg/L M 9.5E-05 mg/kg-day 4.0E-04 mg/kg-day N/A N/A 2.4E-01Arsenic 3.77E+00 µg/L 3.77E+00 µg/L M 3.7E-05 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 1.2E-01Barium 1.82E+02 µg/L 1.82E+02 µg/L M 1.8E-03 mg/kg-day 7.0E-02 mg/kg-day N/A N/A 2.5E-02Iron 2.31E+04 µg/L 2.31E+04 µg/L M 2.3E-01 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 7.5E-01Manganese 1.43E+03 µg/L 1.43E+03 µg/L M 1.4E-02 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 7.0E-01

(Total) 1.9E+00









Ingestion 4-Methylphenol 4.10E+01 µg/L 4.10E+01 µg/L M 1.4E-04 mg/kg-day N/AAntimony 9.70E+00 µg/L 9.70E+00 µg/L M 3.4E-05 mg/kg-day N/AArsenic 3.77E+00 µg/L 3.77E+00 µg/L M 1.3E-05 mg/kg-day 1.5E+00 (mg/kg-day) -1 2.0E-05Barium 1.82E+02 µg/L 1.82E+02 µg/L M 6.4E-04 mg/kg-day N/AIron 2.31E+04 µg/L 2.31E+04 µg/L M 8.1E-02 mg/kg-day N/AManganese 1.43E+03 µg/L 1.43E+03 µg/L M 5.0E-03 mg/kg-day N/A

(Total) 2.0E-05






Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Excavation Pit Receptor Population: Construction Worker Receptor Age: Adult




(Total) 4.1E-01


(1) Specify Medium-Specific (M) or Route-Specific (R) EPC selected for hazard calculation.(2) Subchronic. If subchronic value not available, chronic value used.(3) Scientific Notation is used to present this information







Dermal 4-Methylphenol 4.10E+01 µg/L 4.10E+01 µg/L M 2.7E-06 mg/kg-day N/AAntimony 9.70E+00 µg/L 9.70E+00 µg/L M 5.7E-08 mg/kg-day N/AArsenic 3.77E+00 µg/L 3.77E+00 µg/L M 2.2E-08 mg/kg-day 1.6E+00 (mg/kg-day) -1 3.6E-08Barium 1.82E+02 µg/L 1.82E+02 µg/L M 1.1E-06 mg/kg-day N/AIron 2.31E+04 µg/L 2.31E+04 µg/L M 1.4E-04 mg/kg-day N/AManganese 1.43E+03 µg/L 1.43E+03 µg/L M 8.5E-06 mg/kg-day N/A

(Total) 3.6E-08




04/16/2003

TABLE B-14.RMESUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COCs


Scenario Timeframe: Current/Future Receptor Population: Other Worker Receptor Age: Adult

Medium Exposure Exposure Chemical Carcinogenic Risk Chemical Non-Carcinogenic Hazard QuotientMedium Point

Ingestion Inhalation Dermal Exposure Primary Ingestion Inhalation Dermal ExposureRoutes Total Target Organ Routes Total

Surface Soil Surface Soil Site Surface Soil Arsenic 1.6E-06 2.9E-06 4.5E-06 Aluminum CNS 8.8E-03 1.7E-02 2.6E-02(Total) 1.6E-06 2.9E-06 4.5E-06 Arsenic Skin 1.0E-02 1.8E-02 2.8E-02

Iron GI 2.8E-02 7.5E-02 1.0E-01Manganese CNS 9.9E-03 1.5E-02 2.5E-02

(Total) 5.7E-02 1.3E-01 1.8E-01

Total Risk Across Soil 4.5E-06 Total Hazard Index Across All Media and All Exposure Routes 1.8E-01

Total Risk Across All Media and All Exposure Routes 4.5E-06

Total CNS HI = 5.1E-02

(1) Scientific Notation is used to present this information Total Skin HI = 2.8E-02

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 Total GI HI = 1.0E-01


04/16/2003



Scenario Timeframe: Future Receptor Population: Resident Receptor Age: Adult



Groundwater Groundwater Upper Aquifer - Tap Water 4-Methylphenol CNS 2.2E-01 2.7E-02 2.5E-01Antimony Blood 6.6E-01 1.3E-02 6.8E-01Arsenic Skin 3.4E-01 7.1E-04 3.5E-01Barium Cardio 7.1E-02 1.4E-04 7.1E-02Iron GI 2.1E+00 2.1E-02 2.1E+00Manganese CNS 2.0E+00 1.1E-02 2.0E+00

(Total) 5.4E+00 7.3E-02 5.4E+00

Total Risk Across Groundwater N/A Total Hazard Index Across All Media and All Exposure Routes 5.4E+00

(1) Scientific Notation is used to present this information Total CNS HI = 2.2E+00

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 Total Blood HI = 6.8E-01

1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01 Total Skin HI = 3.5E-01

Total Cardio HI = 7.1E-02

Total GI HI = 2.1E+00

04/16/2003



Scenario Timeframe: Future Receptor Population: Resident Receptor Age: Child



Groundwater Groundwater Upper Aquifer - Tap Water 4-Methylphenol CNS 5.2E-01 6.0E-02 5.8E-01Antimony Blood 1.6E+00 3.8E-02 1.6E+00Arsenic Skin 8.0E-01 2.1E-03 8.1E-01Barium Cardio 1.7E-01 4.1E-04 1.7E-01Iron GI 4.9E+00 6.1E-02 5.0E+00Manganese CNS 4.6E+00 3.2E-02 4.6E+00

(Total) 1.3E+01 1.9E-01 1.3E+01


(1) Scientific Notation is used to present this information Total CNS HI = 5.2E+00

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 Total Blood HI = 1.6E+00

1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01 Total Skin HI = 8.1E-01



04/16/2003



Scenario Timeframe: Future Receptor Population: Resident Receptor Age: Child/Adult



Groundwater Groundwater Upper Aquifer - Tap Water Arsenic 8.4E-05 2.0E-07 8.5E-05(Total) 8.4E-05 2.0E-07 8.5E-05

Total Risk Across Groundwater 8.5E-05 Total Hazard Index Across All Media and All Exposure Routes N/A




04/16/2003



Scenario Timeframe: Future Receptor Population: Industrial Worker Receptor Age: Adult



Groundwater Groundwater Upper Aquifer - Tap Water Arsenic 2.0E-05 2.0E-05 4-Methylphenol CNS 8.0E-02 8.0E-02(total) 2.0E-05 2.0E-05 Antimony Blood 2.4E-01 2.4E-01

Arsenic Skin 1.2E-01 1.2E-01Barium Cardio 2.5E-02 2.5E-02Iron GI 7.5E-01 7.5E-01Manganese CNS 7.0E-01 7.0E-01

(Total) 1.9E+00 1.9E+00

Total Risk Across Groundwater 2.0E-05 Total Hazard Index Across All Media and All Exposure Routes 1.9E+00


(1) Scientific Notation is used to present this information Total Blood HI = 2.4E-01

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 Total Skin HI = 1.2E-01

1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01 Total Cardio HI = 2.5E-02

Total GI HI ô 7.5E-01

04/16/2003



Scenario Timeframe: Future Receptor Population: Construction Worker Receptor Age: Adult



Upper Aquifer -Excavation Groundwater Groundwater Pit Arsenic 3.6E-08 3.6E-08 4-Methylphenol CNS 5.6E-02 5.6E-02

(total) 3.6E-08 3.6E-08 Antimony Blood 1.0E-01 1.0E-01Arsenic Skin 5.4E-03 5.4E-03Barium Cardio 1.1E-03 1.1E-03Iron GI 1.6E-01 1.6E-01Manganese CNS 8.5E-02 8.5E-02

(Total) 4.1E-01 4.1E-01

Total Risk Across Groundwater 3.6E-08 Total Hazard Index Across All Media and All Exposure Routes 4.1E-01






04/16/2003



Scenario Timeframe: Future Receptor Population: Other Recreational Person Receptor Age: Adult





(Total) 2.4E-02 5.2E-02 7.6E-02







04/16/2003



Scenario Timeframe: Future Receptor Population: Other Recreational Person Receptor Age: Child





(Total) 2.2E-01 1.6E-01 3.8E-01






1.00E-02 Is the scientific notation for one times ten to the power of -2, or 0.01

04/16/2003

TABLE B-22.CTSUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COCs

CENTRAL TENDENCYSite 9, Little Creek




Groundwater Groundwater Upper Aquifer -Tap Water 4-Methylphenol CNS 5.9E-02 9.0E-03 6.8E-02Antimony Blood 6.6E-02 1.7E-03 6.8E-02Arsenic Skin 7.0E-02 1.9E-04 7.1E-02Barium Cardio 2.1E-02 5.5E-05 2.1E-02Iron GI 1.3E-01 1.7E-03 1.3E-01Manganese CNS 1.2E-01 8.5E-04 1.2E-01

(Total) 4.7E-01 1.3E-02 4.8E-01

Total Risk Across Groundwater N/A Total Hazard Index Across All Media and All Exposure Routes 4.8E-01






04/16/2003






Groundwater Groundwater Upper Aquifer -Tap Water 4-Methylphenol CNS 2.0E-01 1.9E-02 2.2E-01Antimony Blood 2.2E-01 4.7E-03 2.3E-01Arsenic Skin 2.3E-01 5.2E-04 2.4E-01Barium Cardio 7.1E-02 1.5E-04 7.1E-02Iron GI 4.4E-01 4.7E-03 4.5E-01Manganese CNS 3.9E-01 2.4E-03 3.9E-01

(Total) 1.6E+00 3.2E-02 1.6E+00







04/16/2003






Groundwater Groundwater Upper Aquifer -Tap Water 4-Methylphenol CNS 3.9E-02 3.9E-02Antimony Blood 4.4E-02 4.4E-02Arsenic Skin 4.7E-02 4.7E-02Barium Cardio 1.4E-02 1.4E-02Iron GI 8.8E-02 8.8E-02Manganese CNS 7.8E-02 7.8E-02

(Total) 3.1E-01 3.1E-01







02/22/2001

TABLE B-25 RMERISK ASSESSMENT SUMMARY





Groundwater Groundwater Upper Aquifer - Tap Water 4-Methylphenol CNS 2.2E-01 2.7E-02 2.5E-01Antimony Blood 6.6E-01 1.3E-02 6.8E-01Arsenic Skin 3.4E-01 7.1E-04 3.5E-01Iron GI 2.1E+00 2.1E-02 2.1E+00Manganese CNS 2.0E+00 1.1E-02 2.0E+00

(Total) 5.3E+00 7.3E-02 5.4E+00


Total Blood HI = 6.8E-01

Total Skin HI = 3.5E-01


Total CNS HI = 2.2E+00

02/22/2001

TABLE B.26 RMERISK ASSESSMENT SUMMARY





Groundwater Groundwater Upper Aquifer - Tap Water 4-Methylphenol CNS 5.2E-01 6.0E-02 5.8E-01Antimony Blood 1.6E+00 3.8E-02 1.6E+00Arsenic Skin 8.0E-01 2.1E-03 8.1E-01Barium Cardio 1.7E-01 4.1E-04 1.7E-01Iron GI 4.9E+00 6.1E-02 5.0E+00Manganese CNS 4.6E+00 3.2E-02 4.6E+00

(Total) 1.3E+01 1.9E-01 1.3E+01


Total Blood HI = 1.6E+00





02/22/2001

TABLE B-27.RMERISK ASSESSMENT SUMMARY





Groundwater Groundwater Upper Aquifer - Tap Water Antimony Blood 2.4E-01 2.4E-01Arsenic Skin 1.2E-01 1.2E-01Iron GI 7.5E-01 7.5E-01Manganese CNS 7.0E-01 7.0E-01

(Total) 1.8E+00 1.8E+00

Total Risk Across Groundwater Total Hazard Index Across All Media and All Exposure Routes 1.8E+00



Total GI HI = 7.5E-01


02/22/2001

TABLE B-28.CTRISK ASSESSMENT SUMMARY





Groundwater Groundwater Upper Aquifer - Tap WaterIron GI 1.3E-01 1.7E-03 1.3E-01Manganese CNS 1.2E-01 8.5E-04 1.2E-01

(Total) 2.5E-01 2.6E-03 2.5E-01




02/22/2001

TABLE B-29.CTRISK ASSESSMENT SUMMARY





Groundwater Groundwater Upper Aquifer - Tap Water 4-Methylphenol CNS 2.0E-01 1.9E-02 2.2E-01Antimony Blood 3.2E-01 6.8E-03 3.2E-01Arsenic Skin 2.3E-01 5.2E-04 2.3E-01Iron GI 4.4E-01 4.7E-03 4.5E-01Manganese CNS 3.9E-01 2.4E-03 3.9E-01

(Total) 1.6E+00 3.4E-02 1.6E+00






TABLE C-1.RMECALCULATION OF NON-CANCER HAZARDS





Ingestion Aluminum 7.02E+03 mg/kg 7.02E+03 mg/kg M 2.9E-03 mg/kg-day 1.0E+00 mg/kg-day N/A N/A 2.9E-03Arsenic 3.36E+00 mg/kg 3.36E+00 mg/kg M 1.4E-06 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 4.6E-03Iron 8.00E+03 mg/kg 8.00E+03 mg/kg M 3.3E-03 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 1.1E-02

(Total) 1.8E-02

Dermal Aluminum 7.02E+03 mg/kg 7.02E+03 mg/kg M 1.5E-03 mg/kg-day 2.7E-01 mg/kg-day N/A N/A 5.6E-03Arsenic 3.36E+00 mg/kg 3.36E+00 mg/kg M 2.3E-06 mg/kg-day 2.9E-04 mg/kg-day N/A N/A 8.0E-03Iron 8.00E+03 mg/kg 8.00E+03 mg/kg M 1.7E-03 mg/kg-day 6.0E-02 mg/kg-day N/A N/A 2.9E-02

(Total) 4.2E-02






Scenario Timeframe: Current/Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Adult




(Total) 1.8E-02


(Total) 4.2E-02






Scenario Timeframe: Current/Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Child




(Total) 1.7E-01


(Total) 1.3E-01




TABLE C-4.RMECALCULATION OF CANCER RISKS





Ingestion Aluminum 7.02E+03 mg/kg 7.02E+03 mg/kg M 1.0E-03 mg/kg-day N/AArsenic 3.36E+00 mg/kg 3.36E+00 mg/kg M 4.9E-07 mg/kg-day 1.5E+00 (mg/kg-day) -1 7.3E-07Iron 8.00E+03 mg/kg 8.00E+03 mg/kg M 1.2E-03 mg/kg-day N/A

(Total) 7.3E-07

Dermal Aluminum 7.02E+03 mg/kg 7.02E+03 mg/kg M 5.4E-04 mg/kg-day N/AArsenic 3.36E+00 mg/kg 3.36E+00 mg/kg M 8.3E-07 mg/kg-day 1.6E+00 (mg/kg-day) -1 1.3E-06Iron 8.00E+03 mg/kg 8.00E+03 mg/kg M 6.2E-04 mg/kg-day N/A

1.3E-06






Scenario Timeframe: Current/Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Adult




(Total) 7.0E-07


1.3E-06






Scenario Timeframe: Current/Future Medium: Surface Soil Exposure Medium: Surface Soil Exposure Point: Site Surface Soil Receptor Population: Other Recreational Person Receptor Age: Child




(Total) 1.6E-06


9.4E-07






Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water Receptor Population: Resident Receptor Age: Adult



Ingestion Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 2.7E-05 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 9.1E-03Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 8.5E-05 mg/kg-day 4.0E-04 mg/kg-day N/A N/A 2.1E-01Arsenic 2.60E+01 µg/L 2.60E+01 µg/L M 7.1E-04 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 2.4E+00Cadmium 8.60E+00 µg/L 8.60E+00 µg/L M 2.4E-04 mg/kg-day 5.0E-04 mg/kg-day N/A N/A 4.7E-01Chromium 1.33E+01 µg/L 1.33E+01 µg/L M 3.6E-04 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 1.2E-01Iron 1.22E+04 µg/L 1.22E+04 µg/L M 3.4E-01 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 1.1E+00Manganese 2.45E+03 µg/L 2.45E+03 µg/L M 6.7E-02 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 3.4E+00Nickel 1.45E+01 µg/L 1.45E+01 µg/L M 4.0E-04 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 2.0E-02Thallium 2.60E+00 µg/L 2.60E+00 µg/L M 7.1E-05 mg/kg-day 7.0E-05 mg/kg-day N/A N/A 1.0E+00Zinc 8.87E+03 µg/L 8.87E+03 µg/L M 2.4E-01 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 8.1E-01

(Total) 9.5E+00

Dermal Benzene 1.00E+00 µg/L 5.24E-01 µg/L R 1.9E-06 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 6.3E-04Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 1.7E-07 mg/kg-day 4.0E-05 mg/kg-day N/A N/A 4.2E-03Arsenic 2.60E+01 µg/L 2.60E+01 µg/L M 1.4E-06 mg/kg-day 2.9E-04 mg/kg-day N/A N/A 4.9E-03Cadmium 8.60E+00 µg/L 8.60E+00 µg/L M 4.7E-07 mg/kg-day 2.5E-05 mg/kg-day N/A N/A 1.9E-02Chromium 1.33E+01 µg/L 1.33E+01 µg/L M 7.3E-07 mg/kg-day 3.0E-05 mg/kg-day N/A N/A 2.4E-02Iron 1.22E+04 µg/L 1.22E+04 µg/L M 6.7E-04 mg/kg-day 6.0E-02 mg/kg-day N/A N/A 1.1E-02Manganese 2.45E+03 µg/L 2.45E+03 µg/L M 1.3E-04 mg/kg-day 7.0E-03 mg/kg-day N/A N/A 1.9E-02Nickel 1.45E+01 µg/L 1.45E+01 µg/L M 7.9E-08 mg/kg-day 2.0E-03 mg/kg-day N/A N/A 4.0E-05Thallium 2.60E+00 µg/L 2.60E+00 µg/L M 1.4E-07 mg/kg-day 7.0E-05 mg/kg-day N/A N/A 2.0E-03Zinc 8.87E+03 µg/L 8.87E+03 µg/L M 2.9E-04 mg/kg-day 7.5E-02 mg/kg-day N/A N/A 3.9E-03

(Total) 8.9E-02


(1) Specify Medium-Specific (M) or Route-Specific (R) EPC selected for hazard calculation.For benzene, route exposure concentration is water minus amount volatilized (see Table 7.8.RME.a)

(2) Chronic.(3) Scientific Notation is used to present this information




Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water Receptor Population: Resident Receptor Age: Child



Ingestion Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 6.4E-05 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 2.1E-02Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 2.0E-04 mg/kg-day 4.0E-04 mg/kg-day N/A N/A 5.0E-01Arsenic 2.60E+01 µg/L 2.60E+01 µg/L M 1.7E-03 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 5.6E+00Cadmium 8.60E+00 µg/L 8.60E+00 µg/L M 5.5E-04 mg/kg-day 5.0E-04 mg/kg-day N/A N/A 1.1E+00Chromium 1.33E+01 µg/L 1.33E+01 µg/L M 8.5E-04 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 2.8E-01Iron 1.22E+04 µg/L 1.22E+04 µg/L M 7.8E-01 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 2.6E+00Manganese 2.45E+03 µg/L 2.45E+03 µg/L M 1.6E-01 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 7.8E+00Nickel 1.45E+01 µg/L 1.45E+01 µg/L M 9.2E-04 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 4.6E-02Thallium 2.60E+00 µg/L 2.60E+00 µg/L M 1.7E-04 mg/kg-day 7.0E-05 mg/kg-day N/A N/A 2.4E+00Zinc 8.87E+03 µg/L 8.87E+03 µg/L M 5.7E-01 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 1.9E+00

(Total) 2.2E+01

Dermal Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 8.2E-06 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 2.7E-03Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 4.9E-07 mg/kg-day 4.0E-05 mg/kg-day N/A N/A 1.2E-02Arsenic 2.60E+01 µg/L 2.60E+01 µg/L M 4.1E-06 mg/kg-day 2.9E-04 mg/kg-day N/A N/A 1.4E-02Cadmium 8.60E+00 µg/L 8.60E+00 µg/L M 1.4E-06 mg/kg-day 2.5E-05 mg/kg-day N/A N/A 5.4E-02Chromium 1.33E+01 µg/L 1.33E+01 µg/L M 2.1E-06 mg/kg-day 3.0E-05 mg/kg-day N/A N/A 7.0E-02Iron 1.22E+04 µg/L 1.22E+04 µg/L M 1.9E-03 mg/kg-day 6.0E-02 mg/kg-day N/A N/A 3.2E-02Manganese 2.45E+03 µg/L 2.45E+03 µg/L M 3.9E-04 mg/kg-day 7.0E-03 mg/kg-day N/A N/A 5.5E-02Nickel 1.45E+01 µg/L 1.45E+01 µg/L M 2.3E-07 mg/kg-day 2.0E-03 mg/kg-day N/A N/A 1.1E-04Thallium 2.60E+00 µg/L 2.60E+00 µg/L M 4.1E-07 mg/kg-day 7.0E-05 mg/kg-day N/A N/A 5.9E-03Manganese 8.87E+03 µg/L 8.87E+03 µg/L M 8.4E-04 mg/kg-day 7.5E-02 mg/kg-day N/A N/A 1.1E-02

(Total) 2.6E-01






Scenario Timeframe: Future Medium: Groundwater Exposure Medium: Groundwater Exposure Point: Upper Aquifer - Tap Water Receptor Population: Resident Receptor Age: Child/Adult



Ingestion Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 1.5E-05 mg/kg-day 5.2E-02 (mg/kg-day) -1 7.8E-07Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 4.6E-05 mg/kg-day N/AArsenic 2.60E+01 µg/L 2.60E+01 µg/L M 3.9E-04 mg/kg-day 1.5E+00 (mg/kg-day) -1 5.8E-04Chromium 8.60E+00 µg/L 8.60E+00 µg/L M 1.3E-04 mg/kg-day N/ACadmium 1.33E+01 µg/L 1.33E+01 µg/L M 2.0E-04 mg/kg-day N/AIron 1.22E+04 µg/L 1.22E+04 µg/L M 1.8E-01 mg/kg-day N/AManganese 2.45E+03 µg/L 2.45E+03 µg/L M 3.7E-02 mg/kg-day N/ANickel 1.45E+01 µg/L 1.45E+01 µg/L M 2.2E-04 mg/kg-day N/AThallium 2.60E+00 µg/L 2.60E+00 µg/L M 3.9E-05 mg/kg-day N/AZinc 8.87E+03 µg/L 8.87E+03 µg/L M 1.3E-01 mg/kg-day N/A

(Total) 5.8E-04

Dermal Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 1.9E-06 mg/kg-day 5.2E-02 (mg/kg-day) -1 1.0E-07Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 1.0E-07 mg/kg-day N/AArsenic 2.60E+01 µg/L 2.60E+01 µg/L M 8.4E-07 mg/kg-day 1.6E+00 (mg/kg-day) -1 1.3E-06Chromium 8.60E+00 µg/L 8.60E+00 µg/L M 2.8E-07 mg/kg-day N/ACadmium 1.33E+01 µg/L 1.33E+01 µg/L M 4.3E-07 mg/kg-day N/AIron 1.22E+04 µg/L 1.22E+04 µg/L M 4.0E-04 mg/kg-day N/AManganese 2.45E+03 µg/L 2.45E+03 µg/L M 7.9E-05 mg/kg-day N/ANickel 1.45E+01 µg/L 1.45E+01 µg/L M 4.7E-08 mg/kg-day N/AThallium 2.60E+00 µg/L 2.60E+00 µg/L M 8.4E-08 mg/kg-day N/AZinc 8.87E+03 µg/L 8.87E+03 µg/L M 1.7E-04 mg/kg-day N/A

(Total) 1.4E-06




TABLE C-10. RMECALCULATION OF NON-CANCER HAZARDS





Ingestion Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 9.8E-06 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 3.3E-03Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 3.0E-05 mg/kg-day 4.0E-04 mg/kg-day N/A N/A 7.6E-02Arsenic 2.60E+01 µg/L 2.60E+01 µg/L M 2.5E-04 mg/kg-day 3.0E-04 mg/kg-day N/A N/A 8.5E-01Cadmium 8.60E+00 µg/L 8.60E+00 µg/L M 8.4E-05 mg/kg-day 5.0E-04 mg/kg-day N/A N/A 1.7E-01Chromium 1.33E+01 µg/L 1.33E+01 µg/L M 1.3E-04 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 4.3E-02Iron 1.22E+04 µg/L 1.22E+04 µg/L M 1.2E-01 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 4.0E-01Manganese 2.45E+03 µg/L 2.45E+03 µg/L M 2.4E-02 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 1.2E+00Nickle 1.45E+01 µg/L 1.45E+01 µg/L M 1.4E-04 mg/kg-day 2.0E-02 mg/kg-day N/A N/A 7.1E-03Thallium 2.60E+00 µg/L 2.60E+00 µg/L M 2.5E-05 mg/kg-day 7.0E-05 mg/kg-day N/A N/A 3.6E-01Zinc 8.87E+03 µg/L 8.87E+03 µg/L M 8.7E-02 mg/kg-day 3.0E-01 mg/kg-day N/A N/A 2.9E-01

(Total) 3.4E+00




TABLE C-11 RMECALCULATION OF CANCER RISKS





Ingestion Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 3.5E-06 mg/kg-day 5.2E-02 (mg/kg-day) -1 1.8E-07Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 1.1E-05 mg/kg-day N/AArsenic 2.60E+01 µg/L 2.60E+01 µg/L M 9.1E-05 mg/kg-day 1.5E+00 (mg/kg-day) -1 1.4E-04Chromium 8.60E+00 µg/L 8.60E+00 µg/L M 3.0E-05 mg/kg-day N/ACadmium 1.33E+01 µg/L 1.33E+01 µg/L M 4.6E-05 mg/kg-day N/AIron 1.22E+04 µg/L 1.22E+04 µg/L M 4.3E-02 mg/kg-day N/AManganese 2.45E+03 µg/L 2.45E+03 µg/L M 8.6E-03 mg/kg-day N/ANickel 1.45E+01 µg/L 1.45E+01 µg/L M 5.1E-05 mg/kg-day N/AThallium 2.60E+00 µg/L 2.60E+00 µg/L M 9.1E-06 mg/kg-day N/AZinc 8.87E+03 µg/L 8.87E+03 µg/L M 3.1E-02 mg/kg-day N/A

(Total) 1.4E-04









Dermal Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 9.2E-06 mg/kg-day 3.0E-03 mg/kg-day N/A N/A 3.1E-03Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 1.3E-06 mg/kg-day 4.0E-05 mg/kg-day N/A N/A 3.2E-02Arsenic 2.60E+01 µg/L 2.60E+01 µg/L M 1.1E-05 mg/kg-day 2.9E-04 mg/kg-day N/A N/A 3.7E-02Cadmium 8.60E+00 µg/L 8.60E+00 µg/L M 3.6E-06 mg/kg-day 2.5E-05 mg/kg-day N/A N/A 1.4E-01Chromium 1.33E+01 µg/L 1.33E+01 µg/L M 5.5E-06 mg/kg-day 2.0E-04 mg/kg-day N/A N/A 2.8E-02Iron 1.22E+04 µg/L 1.22E+04 µg/L M 5.1E-03 mg/kg-day 6.0E-02 mg/kg-day N/A N/A 8.5E-02Manganese 2.45E+03 µg/L 2.45E+03 µg/L M 1.0E-03 mg/kg-day 7.0E-03 mg/kg-day N/A N/A 1.5E-01Nickle 1.45E+01 µg/L 1.45E+01 µg/L M 6.0E-07 mg/kg-day 2.0E-03 mg/kg-day N/A N/A 3.0E-04Thallium 2.60E+00 µg/L 2.60E+00 µg/L M 1.1E-06 mg/kg-day 7.0E-05 mg/kg-day N/A N/A 1.5E-02Zinc 8.87E+03 µg/L 8.87E+03 µg/L M 2.2E-03 mg/kg-day 7.5E-02 mg/kg-day N/A N/A 2.9E-02

(Total) 5.2E-01


(1) Specify Medium-Specific (M) or Route-Specific (R) EPC selected for hazard calculation.(2) Subchronic. If subchronic value not available, chronic value used.(3) Scientific Notation is used to present this information







Dermal Benzene 1.00E+00 µg/L 1.00E+00 µg/L M 1.3E-07 mg/kg-day 5.2E-02 (mg/kg-day) -1 6.8E-09Antimony 3.10E+00 µg/L 3.10E+00 µg/L M 1.8E-08 mg/kg-day N/AArsenic 2.60E+01 µg/L 2.60E+01 µg/L M 1.5E-07 mg/kg-day 1.6E+00 (mg/kg-day) -1 2.5E-07Chromium 8.60E+00 µg/L 8.60E+00 µg/L M 5.1E-08 mg/kg-day N/ACadmium 1.33E+01 µg/L 1.33E+01 µg/L M 7.9E-08 mg/kg-day N/AIron 1.22E+04 µg/L 1.22E+04 µg/L M 7.3E-05 mg/kg-day N/AManganese 2.45E+03 µg/L 2.45E+03 µg/L M 1.5E-05 mg/kg-day N/ANickel 1.45E+01 µg/L 1.45E+01 µg/L M 8.6E-09 mg/kg-day N/AThallium 2.60E+00 µg/L 2.60E+00 µg/L M 1.5E-08 mg/kg-day N/AZinc 8.87E+03 µg/L 8.87E+03 µg/L M 3.2E-05 mg/kg-day N/A

(Total) 2.5E-07




TABLE C-14.RMESUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COCs


Scenario Timeframe: Current/Future Receptor Population: Other Worker Receptor Age: Adult




Iron GI 1.1E-02 2.9E-02 4.0E-021.8E-02 4.2E-02 6.1E-02

(Total)



Total CNS HI 8.5E-03

(1) Scientific Notation is used to present this information Total Skin HI 1.3E-02

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 Total GI HI 4.0E-02


TABLE C-15 RMESUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COCs

REASONABLE MAXIMUM EXPOSURESite10, Little Creek

Scenario Timeframe: Current/Future Receptor Population: Other Recreational Person Receptor Age: Adult




Iron GI 1.1E-02 2.9E-02 4.0E-02(Total) 1.8E-02 4.2E-02 6.1E-02









Scenario Timeframe: Current/Future Receptor Population: Other Recreational Person Receptor Age: Child




Iron GI 1.0E-01 8.6E-02 1.9E-01(Total) 1.7E-01 1.3E-01 3.0E-01












Groundwater Groundwater Upper Aquifer - Tap Water Benzene Liver 9.1E-03 6.3E-04 9.8E-03Antimony Blood 2.1E-01 4.2E-03 2.2E-01Arsenic Skin 2.4E+00 4.9E-03 2.4E+00Cadmium Kidney 4.7E-01 1.9E-02 4.9E-01Chromium NOAEL 1.2E-01 2.4E-02 1.5E-01Iron GI 1.1E+00 1.1E-02 1.1E+00Manganese CNS 3.4E+00 1.9E-02 3.4E+00Nickel Whole Body 2.0E-02 4.0E-05 2.0E-02Thallium Liver/Blood 1.0E+00 2.0E-03 1.0E+00Zinc Blood 8.1E-01 3.9E-03 8.1E-01

(Total) 9.5E+00 8.9E-02 9.6E+00

Groundwater AirUpper Aquifer - WaterVapors at Showerhead Benzene 8.9E-10 8.9E-10 Benzene Liver 5.3E-05 5.3E-05

(Total) 8.9E-10 8.9E-10 (Total) 5.3E-05 5.3E-05


Total Liver HI = 1.0E+00

(1) Scientific Notation is used to present this information Total Blood HI = 2.1E+00

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 Total Skin HI = 2.4E+00

1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01 Total Kidney HI = 4.9E-01

Total NOAEL HI = 1.5E-01



Total Whole Body HI = 2.0E-02






Groundwater Groundwater Upper Aquifer - Tap Water Benzene Liver 2.1E-02 2.7E-03 2.4E-02Antimony Blood 5.0E-01 1.2E-02 5.1E-01Arsenic Skin 5.6E+00 1.4E-02 5.6E+00Cadmium Kidney 1.1E+00 5.4E-02 1.2E+00Chromium NOAEL 2.8E-01 7.0E-02 3.5E-01Iron GI 2.6E+00 3.2E-02 2.6E+00Manganese CNS 7.8E+00 5.5E-02 7.9E+00Nickel Whole Body 4.6E-02 1.1E-04 4.6E-02Thallium Liver/Blood 2.4E+00 5.9E-03 2.4E+00Zinc Blood 1.9E+00 1.1E-02 1.9E+00

(Total) 2.2E+01 2.6E-01 2.2E+01


Total Liver HI = 2.4E+00

(1) Scientific Notation is used to present this information Total Blood HI = 4.8E+00

i.e. 1.00E+02 is the scientific notation for one times ten to the power of 2, or 100 Total Skin HI = 5.6E+00

1.00E-02 is the scientific notation for one times ten to the power of -2, or 0.01 Total Kidney HI = 1.2E+00










Groundwater Groundwater Upper Aquifer - Tap Water Benzene 7.8E-07 1.0E-07 8.8E-07Arsenic 5.8E-04 1.3E-06 5.8E-04

(Total) 5.8E-04 1.4E-06 5.9E-04

Groundwater Air*Upper Aquifer - WaterVapors at Showerhead Benzene 8.9E-10 8.9E-10

(Total) 8.9E-10 8.9E-10


*Calculated for adult exposure only.




TABLE C-20 RMESUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COCs





Groundwater Groundwater Upper Aquifer - Tap Water Benzene 1.8E-07 1.8E-07 Benzene Liver 3.3E-03 3.3E-03Arsenic 1.4E-04 1.4E-04 Antimony Blood 7.6E-02 7.6E-02

1.4E-04 1.4E-04 Arsenic Skin 8.5E-01 8.5E-01Cadmium Kidney 1.7E-01 1.7E-01Chromium NOAEL 4.3E-02 4.3E-02Iron GI 4.0E-01 4.0E-01Manganese CNS 1.2E+00 1.2E+00Nickel Whole Body 7.1E-03 7.1E-03Thallium Liver/Blood 3.6E-01 3.6E-01Zinc Blood 2.9E-01 2.9E-01

(Total) 3.4E+00 3.4E+00


Total Liver HI = 3.7E-01










Scenario Timeframe: Future Receptor Population: Construction Worker Receptor Age: Adult



Groundwater GroundwaterUpper Aquifer - ExcavationPit Benzene 6.8E-09 6.8E-09 Benzene Liver 3.1E-03 3.1E-03

Arsenic 2.5E-07 2.5E-07 Antimony Blood 3.2E-02 3.2E-02(Total) 2.5E-07 2.5E-07 Arsenic Skin 3.7E-02 3.7E-02

Cadmium Kidney 1.4E-01 1.4E-01Chromium NOAEL 2.8E-02 2.8E-02Iron GI 8.5E-02 8.5E-02Manganese CNS 1.5E-01 1.5E-01Nickel Whole Body 3.0E-04 3.0E-04Thallium Liver/Blood 1.5E-02 1.5E-02Zinc Blood 2.9E-02 2.9E-02

(Total) 5.2E-01 5.2E-01

Groundwater AirUpper Aquifer - WaterVapors at Excavation Pit Benzene 6.3E-10 6.3E-10 Benzene Liver 9.0E-05 9.0E-05

(Total) 6.3E-10 6.3E-10 (Total) 9.0E-05 9.0E-05










TABLE C-22.CTSUMMARY OF RECEPTOR RISKS AND HAZARDS FOR COCs

CENTRAL TENDENCYSite10, Little Creek




Groundwater Groundwater Upper Aquifer - Tap Water Benzene Liver 4.3E-03 3.8E-04 4.7E-03Antimony Blood 4.4E-02 1.1E-03 4.5E-02Arsenic Skin 2.1E-01 5.5E-04 2.1E-01Cadmium Kidney 5.5E-03 2.8E-04 5.8E-03Chromium NOAEL 1.6E-02 4.1E-03 2.0E-02Iron GI 3.6E-01 4.6E-03 3.6E-01Manganese CNS 1.5E-01 1.1E-03 1.5E-01Nickel Whole Body 3.3E-03 8.5E-06 3.3E-03Thallium Liver/Blood 1.9E-01 4.8E-04 1.9E-01Zinc Blood 3.6E-04 2.3E-06 3.7E-04

(Total) 9.7E-01 1.3E-02 9.9E-01















Groundwater Groundwater Upper Aquifer - Tap Water Benzene Liver 1.4E-02 1.6E-03 1.6E-02Antimony Blood 1.5E-01 3.2E-03 1.5E-01Arsenic Skin 6.8E-01 1.5E-03 6.9E-01Cadmium Kidney 1.8E-02 7.8E-04 1.9E-02Chromium NOAEL 5.4E-02 1.2E-02 6.5E-02Iron GI 1.2E+00 1.3E-02 1.2E+00Manganese CNS 5.0E-01 3.1E-03 5.0E-01Nickel Whole Body 1.1E-02 2.4E-05 1.1E-02Thallium Liver/Blood 6.2E-01 1.3E-03 6.2E-01Zinc Blood 1.2E-03 6.3E-06 1.2E-03

(Total) 3.2E+00 3.6E-02 3.3E+00















Groundwater Groundwater Upper Aquifer - Tap Water Benzene 2.8E-07 3.6E-08 3.1E-07Arsenic 3.8E-05 9.3E-08 3.8E-05

(Total) 3.9E-05 1.3E-07 3.9E-05





WDC022870001.ZIP 11/12/2003Tab9.12.ct(C-25)_REV 2:05 PM






Groundwater Groundwater Upper Aquifer - Tap Water Benzene 3.2E-08 3.2E-08 Benzene Liver 2.9E-03 2.9E-03Arsenic 4.4E-06 4.4E-06 Antimony Blood 3.0E-02 3.0E-02

4.4E-06 4.4E-06 Arsenic Skin 1.4E-01 1.4E-01Cadmium Kidney 3.7E-03 3.7E-03Chromium NOAEL 1.1E-02 1.1E-02Iron GI 2.4E-01 2.4E-01Manganese CNS 1.0E-01 1.0E-01Nickel Whole Body 2.2E-03 2.2E-03Thallium Liver/Blood 1.3E-01 1.3E-01Zinc Blood 2.4E-04 2.4E-04

(Total) 6.5E-01 6.5E-01










F-1

Appendix DFederal Location-Specific ARARs

Feasibility Study of Site 9 and Site 10 at NAB Little Creek

Location Requirement Prerequisite CitationARAR

Determination Comment

Endangered Species Act of 1978*Endangeredspecies

Action to ensure that anyaction is not likely tojeopardize the continuedexistence of endangeredor threatened species oradversely affect itscritical habitat.

Applies to actions thataffect endangered orthreatened species ortheir habitat.

16 USC 1536(a),1538, 153950 CFR Part 402

Relevant andappropriate.

No state or federally listed threatened orendangered species were found to exist at NABLittle Creek. Two rare plant species were found atthe base, however. Therefore, the requirements ofthe Endangered Species Act of 1973 (16 USC1536(a)) are relevant and appropriate toremediation activities occurring at Site 9 and 10. Tomeet this requirement, restricted access signs willbe put up at each landfill.

Migratory bird area

Protects almost allspecies of native birds inthe U.S. from unregulated taking whichcan include poisoning athazardous waste sites

Presence of migratorybirds

16 USC Section 703 Applicable Migratory birds are encountered at Site 9 and 10.These requirements are applicable to any responseactions that could result in unregulated “taking” ofnative birds. To meet this requirement, restrictedaccess signs will be put up at each landfill

Environmentallyand EconomicallyBeneficialLandscapePractices on FederalLandscapedGrounds

Establishes guidelines toassist federal agencies inthe implementation ofenvironmentally andeconomically beneficiallandscape practices

Landscaping on federalgrounds

60 FR 40837(August 10, 1995)

To-be-considered

Native drought-tolerant species will be used tocover the landfills in furtherance of this order. Tomeet this requirement, restricted access signs willbe put up at each landfill

* Statutes and policies, and their citations, are provided as headings to identify general categories of potential ARARs for the convenience of the reader. Listing the statutesand policies does not indicate that DON accepts the entire statutes or policies as potential ARARs. Specific potential ARARs are addressed in the table below each generalheading; only substantive requirements of the specific citations are considered potential ARARs.

ARARs - Applicable or relevant and appropriate requirements.CFR - Code of Federal Regulations.USC - United States Code.FR – Federal Regulation

F-2

Appendix DVirginia Location-Specific ARARs


Location Requirement Prerequisite Citation ARAR Determination Comment

Virginia Endangered Plant and Insect Species Act; Virginia Board of Game and Inland Fisheries*

Endangeredplant andinsectspecies

Action to conserve endangered orprotected plant and insect species

Applies to actionsthat affect endan-gered or pro-tected plant andinsect species.

Code of VirginiaSections 3.1-1023, -1027, -1028

2 VAC 5-320-10

Relevant and Appropriate Two rare plant species were identified on base.Virginia Department of Agriculture and ConsumerServices will be notified of this project. The Navyrequests determination if proposed activities (i.e.,putting up restricted access signs) will affectendangered plants or insects.

* Statutes and policies, and their citations, are provided as headings to identify general categories of potential ARARs for the convenience of the reader. Listing the statutesand policies does not indicate that Navy accepts the entire statutes or policies as potential ARARs. Specific potential ARARs are addressed in the table below each generalheading; only substantive requirements of the specific citations are considered potential ARARs.

ARARs- Applicable or relevant and appropriate requirementsVAC – Virginia Administrative CodeUSC – United States CodeCFR – Code of Federal Regulations

F-3

Appendix DFederal Chemical-Specific ARARs



Groundwater

State Water Control Law

Protects the existing high quality ofState waters and restores thequality of all other State waters;safeguards the clean waters andprevents pollution increases; andpromotes water conservationefforts.

State water. Code of VirginiaSections 62.1-44.2 to 44.38:28

Relevant and appro-priate

The Commonwealth of Virginia considers allgroundwater as a potential drinking water source.

Safe Drinking Water Act (SDWA), 42 USC 300*

National primary drinking waterstandards are health-basedstandards for public water systems(maximum contaminant levels[MCLs]).

Public watersystem.

40 CFR Part 141Subparts B & G

Relevant and appro-priate

MCLs are relevant and appropriate for groundwaterdetermined to be a current or potential source ofdrinking water. The Commonwealth of Virginiaconsiders all groundwater as a potential drinkingwater source.

* Statutes and policies, and their citations, are provided as headings to identify general categories of potential ARARs for the convenience of the reader. Listing the statutesand policies does not indicate that DON accepts the entire statutes or policies as potential ARARs. Specific potential ARARs are addressed in the table below each generalheading; only substantive requirements of the specific citations are considered potential ARARs.

ARARs-Applicable or relevant and appropriate requirements. SMCL – Secondary Maximum Contaminant Level

CFR- Code of Federal Regulations SDWA – Safe Drinking Water Act

MCL- Maximum Contaminant Level.

MCLG – Maximum Contaminant Level Goal

TBC- To Be Considered

F-4

Appendix DVirginia Chemical-Specific ARARs



Groundwater

Virginia Drinking Water Standards*

Primary drinking water standardsare health-based standards forpublic water supplies (primarymaximum contaminant levels[PMCLs]).

Public watersystem.

12 VAC 5-590-10 Relevant and appropriate Virginia PMCLs are similar to federal MCLs. PMCLsare relevant and appropriate for groundwaterdetermined to be a current or potential source ofdrinking water. The Commonwealth of Virginiaconsiders all groundwater as a potential drinkingwater source.

Secondary drinking waterregulations are chemical basedstandards for qualities of publicwater supplies (secondary MCLs[SMCLs]).

Public watersystem.

12 VAC 5-590-390

To be considered Virginia SMCLs are similar to federal SMCLs. InVirginia, SMCLs are enforceable only for potablewater supplies. The Commonwealth of Virginiaconsiders all groundwater as a potential drinkingwater source.

Virginia Groundwater Standards*

Establishes groundwater standardsfor State Antidegradation Policy.

Standards areused when noMCL is available.

9 VAC 25-260-5to 550

Relevant and appropriate Relevant and appropriate when MCLs are notavailable, or when standards are more stringentthan MCLs. Standards are relevant and appropriatebecause the Commonwealth of Virginia considersall groundwater as a potential drinking water source.

* Statutes and policies, and their citations, are provided as headings to identify general categories of potential ARARs for the convenience of the reader. Listing the statutes andpolicies does not indicate that Navy accepts the entire statutes or policies as potential ARARs. Specific potential ARARs are addressed in the table below each general heading;only substantive requirements of the specific citations are considered potential ARARs.

ARARs - Applicable or relevant and appropriate requirements.VAC – Virginia Administrative Code.VR – Virginia Regulation.MCL – Maximum Contaminant Level.PMCL – Primary Maximum Contaminant Level.SMCL – Secondary Maximum Contaminant Level.

F-5

Appendix DVirginia Action-Specific ARARs


Action Requirement Prerequisite Citation ARAR Determination Comment

Virginia Waste Management Act

Enacted laws to govern solid wasteactivities within theCommonwealth, including theoperation of sanitary landfills andother facilities involved with thetreatment, storage, or disposal ofnonhazardous solid waste.

Solid wastelandfills in theCommonwealth

Code of Virginia,Sections 10.1-1400 to 1457

Relevant and appropriate Virginia Waste Management Act (Code of VirginiaSections 10.1-1400 to 1457) are relevant andappropriate to Sites 9 and 10.

Virginia Solid Waste Regulations

Closure ofConstruction/DemolitionDebrisLandfills andIndustrialWasteLandfills

Closure and post-closure carerequirements forconstruction/demolition debrislandfills and for industrial wastelandfills.

Landfills used todisposeconstruction/demolition debris and/orindustrial wastes.

9 VAC 20-80-10 to 790

9 VAC 20-80-260Sections D-F;9 VAC 20-80-270Section D-F

Relevant and appropriate Industrial waste landfill requirements of 9 VAC 20-80-260 and 20-80-270 are relevant and appropriateto Sites 9 and 10. Requirements are not applicableto the landfills because they ceased operation priorto the promulgation of these regulations.

Hazardous Waste Management Regulations

Identificationand listing ofhazardouswaste

Defines wastes subject toVHWMR. Wastes are defined ashazardous either because theyexhibit a hazardous characteristicor because the waste is “listed” ashazardous

Groundwater. 9 VAC 20-80-10 to 790

Relevant and appropriate Hazardous Waste Management Regulations of 9VAC 20-80-10 to 790 are relevant and appropriateto Sites 9 and 10. Regulations are applicable to thegroundwater because it is considered a hazardouswaste under 9 VAC 20-60-261.

* Statutes and policies, and their citations, are provided as headings to identify general categories of potential ARARs. Specific ARARs are addressed in the table below each general heading.

**Applicable, RA-Relevant and appropriate, TBC- To Be Considered

ARAR- Applicable or relevant and appropriate requirement

CFR- Code of Federal Regulations USC- United States Code

F-6

Appendix DVirginia Action-Specific ARARs


Action Requirement Prerequisite Citation ARAR Determination Comment

Virginia Regulations Governing the Transportation of Hazardous Waste

RegulationsGoverningtheTransportation ofHazardousMaterials

Establishes rules and regulationsdesignating the manner andmethod by which hazardousmaterials shall be loaded,unloaded, packed, identified,marked, placarded, stored, andtransported.

Hazardousmaterialsgenerated.

9 VAC 20-110-10to 30

Relevant and appropriate All off-site transport (i.e., off NAB Little Creekproper) of hazardous materials generated as aresult of removal/remedial actions, including IDW, atNAB Little Creek must comply with the substantiveand administrative requirements of this section. Inaddition, the substantive regulations in this sectionmay be relevant and appropriate for on-site (i.e., onNAB Little Creek) transport of hazardous materials.

* Statutes and policies, and their citations, are provided as headings to identify general categories of potential ARARs. Specific ARARs are addressed in the table below each general heading.

**Applicable, RA-Relevant and appropriate, TBC- To Be Considered

ARAR- Applicable or relevant and appropriate requirement

CFR- Code of Federal Regulations USC- United States Code

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