Attachment_2_NTCRAWP_Final_20230301_REDW_AlderCreek_FiringRange.pdf

Prepared for:

NATIONAL PARK SERVICE

Pacific West Regional Office

333 Bush Street, Suite 500

San Francisco, California 94104

Non-Time Critical Removal Action Work Plan

For

Alder Camp Road Firing Range Soil Removal and Analysis

Redwood National Park

Del Norte County, California

September 12, 2022

Prepared By:

Jared Kemper, P.G.

Project Manager/Geologist

Holly Anne Trejo, P.G.

Principal Geologist

Date Date

Alder Camp Road Firing Range NTCRAWP September 2022 ii

TABLE OF CONTENTS

ACRONYMS AND ABBREVIATIONS ........................................................................................ iv

INTRODUCTION

PURPOSE

SITE CONDITIONS AND BACKGROUND

3.1 Site Location and Description

3.2 Operational History

3.3 Physical and Environmental Setting

3.3.1 Site Hydrogeologic Setting and Sensitive Ecosystems

3.3.2 Previous Site Investigation

3.3.3 Type, Source and Location of Known Contamination

3.3.4 Summary of Soil Results

3.3.5 Regulatory Framework

3.3.6 Removal Action Objectives and Removal Action Levels

3.3.7 ARARs

EE/CA REMOVAL ACTION SUMMARY

4.1 Selected Remedy Description

PRE-DESIGN INVESTIGATION

REMOVAL ACTION PLAN

6.1 Site Visits

6.2 Waste Characterization and Disposal Plan

6.2.1 Field Documentation

6.2.2 Extent of Contamination Sampling Plan

6.2.3 Excavation Plan

6.2.4 Excavation Extents Confirmation Sampling Plan

6.2.5 Waste Characterization Stockpile Sampling Plan

6.2.6 Waste Manifest, Transportation, and Disposal Plan

6.2.7 Backfill and Site Restoration

6.3 Institutional Control Plan

6.4 Cultural Resources Control Plan

EROSION CONTROL PLAN

7.1 Potential Pollutant Sources

7.2 Stormwater and Sediment Control

7.2.1 BMPS for Preconstruction Erosion Control

7.2.2 BMPs for Water Erosion

7.2.3 BMPs for Wind Erosion

7.2.4 BMPs for Tracking Sediment

7.2.5 BMPs for Construction Vehicle and Equipment Spills

7.2.6 Inspection, Maintenance, Repair, and Reporting

7.2.7 Hazardous Material Spill Plan

TRAFFIC CONTROL PLAN

8.1 General Approach

8.1.1 Construction Signs

8.1.2 Traffic Controls

8.1.3 Onsite Traffic

8.1.4 Offsite Traffic

REPORTING

SCHEDULE

REFERENCES

iii

TABLES

Table 1: Summary of Data for Soil Samples by Decision Unit (Patriot, 2015) (embedded) Table 2: Dry Creek Landfill Acceptance Criteria (embedded) Table 3: Estimated Schedule of Work (embedded)

FIGURES

Figure 1: Regional Site Location Map Figure 2: Site Features Map Figure 3: Site Layout Map (Patriot, 2015) Figure 4: Summary of Data for Soil Samples, #40 Sieve, by Decision Unit (Patriot, 2015)

APPENDICES

Appendix A: ARARs from EE/CA (Patriot, 2015) Appendix B: Quality Assurance Project Plan (Patriot, 2015) iv

ACRONYMS AND ABBREVIATIONS

ARAR Applicable or Relevant and Appropriate Regulations

AOC Area of Concern

BMPs Best Management Practice bgs Below ground surface

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CCR California Code of Regulations

CFR Code of Federal Regulations

COCs Constituents of Concern

COR Contracting Officer’s Representative

CRZ Contamination Reduction Zone

DOT Department of Transportation

DQO Data Quality Objective

DU Decision Unit

ECCD Environmental Compliance and Cleanup

ECM ECM Consultants

EE/CA Engineering Evaluation/Cost Analysis

EPA U.S. Environmental Protection Agency

ESD Explanation of Significant Differences

FCLs Final Cleanup Levels

FHWA Federal Highway Administration

GPS Global Positioning System

HASP Site-Specific Safety and Health Plan

HAZWOPER Hazardous Waste Operations and Emergency Response

IDW Investigation-derived waste

ISM Incremental Sampling Methodology mg/kg milligrams per kilogram

MUTCD Manual on Uniform Traffic Control Devices

NPS U.S. Department of the Interior, National Park Service

NTCRA Non-Time Critical Removal Action

NTCRAWP Non-Time Critical Removal Action Work Plan

OSHA Occupational Safety and Health Administration

PA Preliminary Assessment

Pace Pace Analytical

Patriot Patriot Technical Consultants, Inc.

PCL Preliminary Cleanup Level

PDI Pre-Design Investigation

QAPP Quality Assurance Project Plan

RAA Removal Action Alternative

RACR Removal Action Completion Report

RAO Remedial Action Objectives v

REDW Redwood National Park

RG Removal Goal

PCLs Preliminary Cleanup Levels

SAP Sampling and Analysis Plan

SLERA Screening Level Ecological Risk Assessment

STLC Soluble Threshold Limit Concentration

TBC To Be Considered

TCLP Toxicity Characteristic Leaching Procedure

TTLC Total Threshold Limit Concentration

TSD Transport, Storage, and Disposal

UCL Upper Confidence Limit

Versar Versar, Inc.

WET California Title 22 Wet Extract Test

XRF X-ray fluorescence

INTRODUCTION

ECM Consultants (ECM) prepared this Non-Time Critical Removal Action Work Plan (NTCRAWP) for the U.S. Department of the Interior, National Park Service (NPS) to direct excavation and analysis of contaminated soils at the Alder Camp Road Firing Range site (Site) located in Redwood National Park (REDW). NPS is conducting the response action as lead agency under their delegated Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) authority. This NTCRAWP describes the objectives, procedures, and scope of work for the project, which is in Del Norte County, California (Figure 1). ECM executed the work requirements as described in the Statement of Work (Solicitation 104P8521F0091) under Task Order 0040553780, Amendment P00001.

PURPOSE

The purpose of this NTCRAWP is to direct the execution of the removal action at the Site based on the remedial alternative selected in the Action Memorandum (Appendix A, Patriot Technical Consultants, Inc. [Patriot], 2015a) through to completion of the NTCRAWP. The recommended alternative includes excavation of contaminated soils that exceeds preliminary cleanup levels followed by off-site disposal.

SITE CONDITIONS AND BACKGROUND

3.1 Site Location and Description

The Alder Camp Road Firing Range area is located in Redwood National and State Parks in Northern California. The Site is entirely within National Park lands. The NPS has had responsibility for the Site since 1968 and the Site had been used as a firing range for years prior to 1968.

The Site is located approximately 19 miles north of Orick, California off of Highway 101. The Site coordinates are 41°51' 27.5" north (latitude) and -124°07' 57.1" west (longitude). The general location of the Site is shown in Figure 1, the Site features are shown on Figure 2, and the Site layout is shown on Figure 3. The Site is located in an area of second growth forest. The range is a flat grassy area surrounded by alder, herbaceous plants, sword fern, salmonberry, and other shrubs. The firing range within the Site consisted of a line of 12 targets located at the northern end of the Site.

Access to the Site is via an unimproved, gated road that ties into Alder Camp Road. The dirt entrance road is approximately 0.1-mile from Alder Camp Road and terminates at the firing range as shown on Figure 2. The dirt road is closed to the general public and can only be accessed with NPS personnel escort (Patriot, 2015a).

3.2 Operational History

The NPS has had responsibility of the Site since 1968, and the Site had been used as a firing range for years prior to this claim. Several NPS park rangers have historically used the Site twice per year for firearms permit qualifying. It has also been used occasionally by personnel from California State Parks, the Bureau of Land Management, and the Tribal law enforcement agencies. The NPS will discontinue use of the Site as a firing range after the NTCRA is complete (Patriot, 2015a).

The NPS transitioned to “green” ammunition free of heavy metals and volatile organic compounds, in 2008, but lead ammunition was still used for specific qualifications. Other agencies that utilized the range had not transitioned to “green” ammunition and typically used lead-based ammunition. The NPS curtailed the use of lead ammunition in 2012 and eliminated access to the Site by non-NPS staff, thereby prohibiting further use of lead-based ammunition at the Site (Patriot, 2015a).

The small arms firing range is the only known use of the Site other than providing habitat for local species.

3.3 Physical and Environmental Setting

3.3.1 Site Hydrogeologic Setting and Sensitive Ecosystems

As discussed in the Preliminary Assessment Report (Versar, Inc. [Versar], 2011), the Alder Camp Site is located within the Richardson Creek, Klamath River, and the Pacific Ocean watersheds. Richardson Creek and Klamath River provide drinking water for surrounding communities (greater than two miles away). Richardson Creek is located approximately 0.25-miles to the east of the Site and drains easterly to the Klamath River. The Pacific Ocean is located approximately 0.25-miles to the west of the Site. The Klamath River is located approximately one mile to the north of the Site and 1.5 miles to the east of the Site.

Groundwater ranges from approximately 3 to 10 feet below ground surface (bgs). Groundwater is not used for drinking water purposes in the Site area. There are no municipal or private drinking wells downgradient or within four miles of the Site.

Although threatened and endangered species are known to be present in REDW, NPS personnel have noted that none of these species are known to be found in the Site area.

3.3.2 Previous Site Investigation

Patriot completed the Engineering Evaluation Cost Analysis (EE/CA) for the Site in June 2015.

The Site was divided into the following decision units (DU) during EE/CA site characterization activities:

• DU1: Firing range target area

• DU2: Short firing line area

• DU3: Mailbox barricade area

• DU4: Long firing line area

• DU5: Background and one site northwest of the target area

• DU6: Previously unidentified firing line area

The constituents of concern (COCs) identified within DU1 are antimony, copper, and lead. The primary area of contamination at the Site is the natural embankment backstop, which is contained in DU1. The natural embankment backstop is located directly behind the firing range target line. Lead is the most significant contaminant in this area, as the bullets passed through or missed the targets and entered the soil in the embankment over the years. The COCs for DU2, DU3, DU4, and DU6 are antimony, copper, and lead. Barium was found to not pose a risk to human health or the environment at the Site and was not retained as a COC based on the results of the sampling and streamlined risk evaluation (Patriot, 2015a).

The Screening Level Ecological Risk Assessment (SLERA) concluded that potential adverse effects based on exposure to copper in soil exist for ecological receptors within DU2, DU3, DU4, and DU6. Antimony in DU2 presented a potential risk to mammals. Antimony, copper, and lead in DU1 presented a potential risk to ecological receptors, and both antimony and lead posed a potential human health risk (Patriot, 2015b).

3.3.3 Type, Source and Location of Known Contamination

Generally, contaminants may be released by mechanisms such as storm water runoff, wind erosion of surface soil, leaching and infiltration to the subsurface, migration through the subsurface soil to the water table, or excavation within areas of contamination. Once released from the source, contaminants can be transported to and in media such as groundwater, air, surface water, or sediment.

The presence of elevated contaminant concentrations has been confirmed by soil sampling and analysis during the EE/CA. The known contaminants have been located in surface and near-surface soils. The risk to surface water and underlying groundwater is not considered likely due to the Site’s location in relation to existing water bodies. As stated in the PA, lead is relatively immobile in the subsurface and it is unlikely that lead has migrated below surface to a depth sufficient to contact groundwater (Versar, 2011). Due to the low risk, risk to surface water and groundwater has been excluded from the scope of removal action (Patriot 2015a).

As described in Section 3.3.2, soil samples were collected throughout the Site at each investigated DU as part of the EE/CA. Each DU was found to have exceeded the presented ecological screening levels of antimony, copper, and lead within each DU and have been identified as requiring cleanup.

3.3.4 Summary of Soil Results

Table 1 below presents the laboratory results for the collected soil samples for surface and near-surface soils presented in the Patriot EE/CA. A summary of the analytical data for antimony, barium, copper, and lead are shown on Figure 4.

• DU-1 (Target Area and Backstop): Several surface and near-surface samples were taken within this area. Lead concentrations were the most significant in this area and ranged from 83 milligrams per kilograms (mg/kg) to 36,000 mg/kg in surface soil samples (0”-3” bgs) and ranged from 160 mg/kg to 2,900 mg/kg in near-surface soil (6”- 12” bgs). Antimony concentrations ranged from 88 mg/kg to 130 mg/kg in surface soil samples (0”-3” bgs). One near-surface sample (RNP-AC-DU1-3_D) (6”-12” bgs) reported an antimony concentration of 16 mg/kg. Copper was detected at concentrations ranging from 44 mg/kg to 1,100 mg/kg at surface samples (0”-3” bgs) and from 36 mg/kg to 420 mg/kg in near-surface soil samples (6”-12” bgs). Barium was not detected in any samples within this area.

• DU-2 (Short Firing Line): One composite surface sample (0”-6”) was collected within this area. Barium was reported at 51 mg/kg and copper was reported at 68 mg/kg.

Antimony and lead were not detected above their respective reporting limits.

• DU-3 (Mailbox Barricade): One composite surface sample (0”-6”) was collected within this area. Barium was reported at 120 mg/kg and copper was reported at 55 mg/kg.

Antimony and lead were not detected above their respective reporting limits.

• DU-4 (Long Firing Line): One composite surface sample (0”-6”) was collected within this area. Barium was the only metal detected at a concentration of 1.5 mg/kg. Antimony, copper, and lead were not detected above their respective reporting limits.

• DU-5 (Background): Several surface and near-surface samples were taken within this area. One surface sample (RNP-AC-DU5-1) (0”-3” bgs) reported barium and copper at concentrations of 22 mg/kg and 42 mg/kg, respectively. Barium and copper concentrations in deeper surface samples (0”-6” bgs) ranged from 14 mg/kg to 24 mg/kg, and 23 mg/kg to 34 mg/kg, respectively. In two near-surface composite soil samples (6”-12” bgs), barium ranged from 21 mg/kg to 32 mg/kg, and copper ranged from 30 mg/kg to 40 mg/kg.

• DU-6 (Unidentified Firing Line): One composite surface sample (0”-6”) was collected within this area. Barium was reported at 35 mg/kg and copper was reported at 68 mg/kg.

Antimony and lead were not detected above their respective reporting limits.

Table 1: Summary of Laboratory Data for Soil Samples by Decision Unit (Patriot, 2015)

Sample ID Depth

(inches bgs) Antimony (mg/kg)

Barium (mg/kg)

Copper (mg/kg)

Lead (mg/kg)

Decision Unit 1 Laboratory Data Target Area and Backstop, Near-Surface Soil

RNP-AC-DU1-2_D 6”-12” <3.0 -- 60 940

RNP-AC-DU1-3_D 6”-12” 16.0 -- 420 2,900

RNP-AC-DU1-

6Comp_D

6”-12” <3.0 -- 36 160

Decision Unit 1 Laboratory Data Target Area and Backstop, Surface Soil

RNP-AC-DU1-1 0”-3” <3.0 -- 93 83

RNP-AC-DU1-2 0”-3” <3.0 -- 440 7,700

RNP-AC-DU1-3 0”-3” 88 -- 910 19,000

RNP-AC-DU1-3 Dup

0-3

1,100

36,000

RNP-AC-DU1-4 0-3 <3.0 -- 44 2,800

RNP-AC-DU1-5 0-3 <3.0 -- 72 170

RNP-AC-DU1-6 Comp 0-3 95 -- 800 17,000

RNP-AC-DU1-7 Comp 0-3 <3.0 -- 48 100

RNP-AC-DU1-8 Comp 0-3 <3.0 -- 88 380

Decision Unit 2 Laboratory Data Short Firing Line, Surface Soil

RNP-AC-DU2-1 Comp 0-6 <3 51 68 <3

Decision Unit 3 Laboratory Data Mailbox Barricade, Surface Soil

RNP-AC-DU3-1 Comp 0-6 <3 120 55 <3

Decision Unit 4 Laboratory Data Long Firing Line, Surface Soil

RNP-AC-DU4-1 Comp 0-6 <3 1.5 <1 <3

Decision Unit 5 Laboratory Data Background, Surface, and Near-Surface Soil

RNP-AC-DU5-1 0-3 <3 22 42 <3

Sample ID Depth

(inches bgs) Antimony (mg/kg)

Barium (mg/kg)

Copper (mg/kg)

Lead (mg/kg)

1DU51A Comp 0-6 <3 14 34 <3

1DU52A 0-6 -- 14 27 <3

1DU53A 0-6 -- 15 32 <3

3DU51A Comp 0-6 <3 18 24 <3

3DU52A 0-6 -- 24 24 <3

3DU53A 0”-6” -- 23 23 <3

1DU51B Comp 6-12 <3 21 40 <3

3DU51B Comp 6-12 <3 32 30 <3

Decision Unit 6 Laboratory Data Previously Unidentified Firing Line, Surface Soil

RNP-AC-DU6-1 Comp 0-6 <3 35 68 <3

Decision Unit 1 Laboratory Data California Title 22 Wet Extraction Test

Sample ID Depth

(inches bgs) Antimony

(mg/L) Barium (mg/L)

Copper (mg/L)

Lead (mg/L)

RNP-AC-DU1-2 0-3 4.8 -- 19 490

RNP-AC-DU1-4 0-3 13 -- 7 1,200

RNP-AC-DU1-8 Comp 0-3 1.1 -- 49 110

Notes:

bgs = below ground surface Comp = Composite of three sub-samples within immediate area “--" = not analyzed or not available “<” = result is qualified as non-detected at the estimated limit DUP = duplicate sample mg/kg = milligrams per kilogram

3.3.5 Regulatory Framework

The NTCRA is being performed in accordance with CERCLA and the Applicable or Relevant and Appropriate Requirements (ARARs) described in Section 3.3.6 below and included in Appendix A.

3.3.6 Removal Action Objectives and Removal Action Levels

Removal Action Objectives (RAOs) for the Site were developed as part of the EE/CA to address antimony, copper, and lead concentrations exceeding human health and ecological removal goals. The RAOs for the Site are:

1. Prevent or reduce the potential for human and ecological exposure to COCs in soil; and

2. Prevent or reduce potential migration of COCs via surface runoff, erosion, and wind dispersion.

Preliminary Cleanup Levels (PCLs) were developed in the EE/CA to drive the cleanup for the Site. The PCLs identified in the EE/CA for antimony, copper, and lead for the protection of the environment are more stringent than the human health receptors and, therefore, drive the PCLs for all COCs at the Site.

Final Cleanup Levels (FCLs) were established in the Action Memorandum to address antimony, copper, and lead contamination at the Site. However, an Explanation of Significant Differences (ESD) to Cleanup Levels was issued by the Environmental Compliance and Cleanup Division

(ECCD) on June 22, 2022 (NPS, 2022). The ESD states, “ECCD has determined it is appropriate to revise the [FCLs] for the Alder Camp Site to remove contamination that exceeds naturally-occurring background concentrations, instead of using [FCLs] that are based on the generic screening levels that were utilized in the Site EE/CA.” A Pre-Design Investigation (PDI) is recommended to establish accurate and representative background values as described in Section 5.

3.3.7 ARARs

Pursuant to its delegated CERCLA lead agency authority, NPS has identified ARARs and To Be Considered (TBCs) for the Site. The results of the ARAR analysis, including state ARARs, are summarized in Appendix A (Patriot, 2015).

EE/CA REMOVAL ACTION SUMMARY

4.1 Selected Remedy Description

Based on a comparative analysis of Removal Action Alternatives (RAAs) developed as part of the 2015 EE/CA, Alternative 2, Excavation and Off-Site Disposal, was selected as the preferred alternative for the Site. Alternative 2 consists of excavation and disposal of contaminated soils exceeding the human health and ecological preliminary remediation goals for the Site.

Excavation and off-Site disposal involves the removal of the contaminated materials, classification of the waste as RCRA Subtitle C or other regulated hazardous waste, and subsequent disposal at a facility licensed to accept the waste. The type of facility is dependent on the class and concentration of hazardous materials in the waste. Wastes found to exceed State or Federal guidelines for hazardous material must be treated or transported to a RCRA landfill for disposal. Wastes not exceeding the guidelines can be placed in any landfill licensed to accept the waste. All excavated wastes will be managed in accordance with all applicable federal, state, and local requirements.

This alternative provides immediate protection of human health and the environment and complies with the ARARs for the Site.

PRE-DESIGN INVESTIGATION

Prior to the implementation of the removal action, a Pre-Design Investigation (PDI) will be conducted to establish background concentrations in soil. The background concentrations will replace the FCLs published in the Action Memorandum and will be the removal goals (RGs) for this Site. Specifically, the contractor should design a PDI Work Plan for surface and subsurface soil within DU5 that includes 3 incremental sampling methodology (ISM) samples and 10 discrete samples for each depth interval. The DU5 area is shown on Figures 3 and 4.

A PDI Background SAP will be submitted for NPS approval.

REMOVAL ACTION PLAN

6.1 Site Visits

ECM performed an initial field visit to the Site on November 2, 2021, to confirm the information provided in the previous reports and ensure accurate measurements. Prior to the Site visit, ECM evaluated the EE/CA report for discussion with NPS.

Prior to excavation, the Contractor will conduct a pre-construction Site visit with the NPS. The Contractor will complete and perform all notifications, permits, and compliance requirements to ensure a safe removal project. The excavation area will be demarcated as a safe work zone, including delineation of wetlands and utility clearances. Figure 2 shows the estimated combined excavation boundary area based on the EE/CA site investigation and based on field observations during ECM’s site visit. Figure 3 shows the individual excavation areas. The Contractor will coordinate with NPS, local Park air program, and state officials on all necessary activities. The Contractor will confine operations within the limits shown on Figure 3 and Figure 4 for the project to prevent damage to natural surroundings.

6.2 Waste Characterization and Disposal Plan

6.2.1 Field Documentation

The Contractor field personnel will document all X-ray fluorescence (XRF) readings and soil samples from the excavation area. Sample locations, XRF results, sample labels, collection time, and chain of custody (C-O-C) documents will be completed and included in the closeout report. Additionally, digital photos will be taken of the Site prior to any ground disturbing activities, as well as throughout the excavation work, including sample locations. Post-excavation photos will be collected to document final conditions before departing the Site.

6.2.2 Extent of Contamination Sampling Plan

The extent to which COCs associated with the Site may have migrated within the soil has not yet been determined. Therefore, the Contactor will perform in-process characterization screening using XRF to determine the lateral and vertical extent of contamination. Section

5.1.3.1 below details the procedure for XRF sampling and quality control.

The Contractor will use an XRF meter to scan surface soils in an outer perimeter around sample locations shown on Figure 4 from the EE/CA in order to delineate the lateral extent of contamination at the Site.

The Contractor will complete step-out XRF readings 25 feet in an outward direction from each existing sample location that exceeds RGs defined in the PDI for a given COC and record XRF readings for antimony, copper, and lead on field sheets. The contractor will continue stepping outward in 25-foot increments until all three COCs are confirmed below their respective RGs at DU1 and for copper at DU2, DU3, and DU6. The EE/CA and Action Memorandum do not recommend removal action at any of the DU5 locations.

Once XRF readings for antimony, copper, and lead in the step-out samples are recorded below the RGs for all three COCs, the bounds of the excavations will be set. The Contractor will use a global positioning system (GPS) unit to record the location of each XRF sample, along with the bounds of each final excavation area. Wooden stakes or flagging will be used along the perimeter of the excavation area to indicate the extents of the excavation.

6.2.2.1 XRF Sampling and Quality Control Procedure

XRF analysis requires dry conditions; soils must contain 20 percent or less moisture by volume for accurate measurements. Samples containing greater than 20 percent moisture must be dried prior to XRF analysis. Prior to the start of XRF monitoring each day and once in the middle of the day (twice per day), the Contractor will analyze a blank and known standard with the XRF. The resulting data from a blank should contain no or trace amounts of the elements of interest. The standard includes known concentrations of elements. XRF readings taken of the known standard will be compared against the known contents of the standard to note the accuracy and precision of the XRF results. Analyzing a standard prior to beginning analysis is essential because it confirms that the XRF instrument is functioning to specifications and producing accurate results. Results for the analysis of standards throughout the field effort will be logged and compared against the certified values of the standard for each relevant COC.

Standard checks will be reported in a quality control summary table in the Removal Action Completion Report (RACR). In addition, the XRF supplier will ensure that the XRF has been properly calibrated within the past twelve months and the calibration certification will be provided in the RACR. If possible, the Contractor will obtain the XRF with the most recent calibration record.

Surface detritus, organic material, debris, and large gravel (>1/4 inch), if present, will be cleared away from each sample location to reveal solid media. Disturbance of solid media should be minimized to collect a representative sample. The sample will be positioned in front of the XRF probe window with the probe window in direct contact with the soil surface to be analyzed.

Sample analysis will then be initiated by depressing the XRF trigger and exposing the sample to primary radiation from the source for at least one minute, ensuring that the XRF unit is programmed to record each of the COCs.

X-rays from the sample enter through the detector window and are converted into electric pulses in the detector. The longer the X-ray exposure during each XRF reading, the lower the level of detection will be and the more accurate the sample results will be. The Contractor should test the XRF in the field and adjust the exposure time as necessary to give a level of detection that is lower than the RGs for each COC.

6.2.3 Excavation Plan

The following sections provide procedures to complete excavation activities at the Site.

6.2.3.1 Mobilization and Housekeeping

The Contractor will mobilize equipment operator, supervisor, and labor personnel to complete the excavations. Excavation activities will be performed during the dry part of the year.

Excavation of contaminated soils will not be conducted during severe weather conditions (i.e., heavy rain and/or winds). In addition, the Contractor will not conduct any excavation work if precipitation is present in the area to eliminate the potential for storm runoff and erosion at the Site. Hours of construction will be limited to 7 a.m. to 6 p.m., Monday through Friday. All field activities at the Site shall be conducted under the supervision of a California-licensed Professional Engineer (P.E.) or Professional Geologist (P.G.) The Contractor will incorporate decontamination methods for all vehicles, trucks, and construction equipment used at the Site.

Every day, prior to commencement of work, all equipment will be inspected for leaks and repaired immediately. Equipment that is leaking will not be used and will be removed from the Site. Absorbent materials will be available at the job site in the event of spills. The Contractor will install barrier tape where directed by NPS Park staff. The Contractor will always have a minimum of two rolls of barrier tape onsite.

The Contractor field supervisor must be capable and qualified to be in charge of fire protection.

All Site employees must be HAZWOPER qualified per Occupational Safety and Health Administration (OSHA) 29 Code of Federal Regulations (CFR) Part 1910.120(h) with current certification. Site sampling personnel must be qualified and experienced in U.S. Environmental Protection Agency (EPA) methods and sampling protocols.

6.2.3.2 Excavation Demarcation

Once mobilized to the Site, the Contractor will provide temporary barriers to protect existing trees, plants, and root zones within the work area. Brush will be cleared to expose soils within the excavation area as approved by NPS personnel. The Contractor will not remove, injure, or destroy trees or other plants without prior approval. If roots or branches of trees within the work area need removal, the Contractor will consult with the Park Representative and obtain approval prior to removing. The Contractor will carefully supervise excavating, grading, filling, and other construction operations near trees to prevent damage.

The Contractor will notify the Park Representative and utility companies of proposed locations and times for excavation. The Contractor will complete a USA dig alert prior to excavation. The Contractor will be responsible for locating and preventing damage to known utilities.

6.2.3.3 Soil Excavation

As described in the EE/CA, there will be two excavations at the Site, one at DU1 and one encompassing DU2, DU3, DU4, and DU6. The size of each excavation will be dependent on the XRF step-out screening results, but the combined surface area of excavated soil is estimated to be approximately 0.13 acres. Location and areas for each excavation are shown on Figure 3.

The total volume of waste to be excavated and disposed from the Site is estimated to be 1,225 cubic yards. The actual volume will vary based upon soil sampling confirmation results obtained during the removal action.

The area of DU1 that will be excavated as guided by in-process sampling and analysis but is estimated in the EE/CA to be around 100 feet by 100 feet with the Firing Range Target Area (shown in Figure 3) roughly in the center. Contamination is assumed to extend down to 1 foot bgs in 80 percent of DU1 in areas with the least bullet impacts. Contamination is assumed to extend 3 feet bgs in 20 percent of DU1 containing the backstop area with the most bullet impacts. It is assumed in the EE/CA cost evaluation that 2 feet deep from 80 percent and 5 feet deep from 20 percent of DU1 will be excavated due to sloughing and mixing of higher surface contamination with deeper soil during excavation. The total volume of waste to be removed from DU1 is estimated to be 825 cubic yards based on these assumptions. The actual area and depth will vary as necessary to attain the cleanup levels and confirmed XRF readings collected by the Contractor during excavation. The outer perimeter of the DU1 excavation will be recorded on GPS.

DU1 is bounded on three sides by forest and the backstop hill, so equipment and waste generated during the excavation is assumed to enter and exit from the southwest toward the other DUs. The open space containing DU2, DU3, DU4, and DU6 are assumed to be used for equipment handling and two staging piles for exhumed contaminated soil.

The excavation at DU2, DU3, DU4, and DU6 (shown in Figure 3) will be approximately 100 feet wide by 325 feet long and will be confirmed XRF readings collected by the Contractor during excavation. As stated in the EE/CA, the excavation exclusive of DU1 is assumed to be contaminated to an average depth of 1 foot. The volume of waste from the Area of Concern (AOC) exclusive of DU1 is assumed to be around 400 yards. The outer perimeter of the excavation will be recorded on GPS.

6.2.3.4 Soil Stockpiling

The excavated soil will be placed into two staging piles on site, one for DU1 and one for DU2, DU3, DU4, and DU6. All impacted soil will be placed in approved roll-off boxes or stockpiled on thick plastic sheeting, and immediately covered for protection from the elements (wind and/or rain) with similar plastic sheeting for temporary storage prior to transport and disposal at a licensed facility. Based on laboratory data collected during the EE/CA, it is assumed that soil from DU1 will be more contaminated and should thus be stockpiled and sampled for waste characterization separate from the rest of the excavated soil. In the event that stockpiled waste requires treatment, keeping stockpiles separate should reduce treatment costs.

Stockpiles will be characterized as described in Section 5.1.6 below.

6.2.4 Excavation Extents Confirmation Sampling Plan

Once soil is excavated to the extent defined by the step-out sampling described in Section

5.1.2 and soils are stockpiled as described in Section 5.1.3, the floor and sidewalls of each excavation will be evaluated.

Per the EE/CA, confirmatory samples will be collected as three ISM (30 increments) samples from each of DU1, DU2, DU3, DU4, and DU6, and from the whole AOC, resulting in 18 samples to demonstrate attainment of the cleanup levels. All soil samples for laboratory analysis will be collected in accordance with the PDI and the Patriot Quality Assurance Project Plan (QAPP) included in Appendix B (Patriot, 2014). Six of the 18 samples would also be used for QA/QC.

A portion of the 30-equal volume increment samples should be collected in the sidewalls, while the remaining samples should be collected in an even spacing in the excavation floor. The spacing of each floor and sidewall sample will be dependent upon the extent of the excavations.

Enough sample volume must be collected from each of the 30 equal volume increments (approximately 1kg per ISM sample) to meet the laboratory volume requirement. The composite samples will be thoroughly homogenized in a sample-dedicated freezer bag before transferring to laboratory supplied glassware and transporting on ice under C-O-C to Pace Analytical (Pace).

One field blank will be collected for each of the five DUs, plus the whole AOC. Laboratory supplied deionized water will be used to collect the field blanks.

The samples will be analyzed by Pace for lead, copper, and antimony using EPA Method 6010B to confirm that concentrations in soil that will be left in place meet the RGs established in the PDI. If excavation extent confirmation samples exceed RGs, additional excavation will be required in the area of the exceeding samples until RGs are met.

6.2.5 Waste Characterization Stockpile Sampling Plan

Once soil is excavated to the extent of contamination defined by the XRF step-out screening and confirmatory composite sampling has been completed on the excavation floor and sidewalls, the excavated soil stockpiles will be evaluated.

Samples are necessary for use in waste designation and identification of treatment requirements. Three five-point composite sample will be collected from each stockpile for laboratory analysis. Composite subsamples will be collected from each stockpile such that the composite sample for each staging pile represents the entire staging pile. The composite sample will be homogenized to ensure even distribution of each subsample. The composite sample will be placed into laboratory supplied glassware and transported to the laboratory under C-O-C procedures.

The EE/CA cost estimate assumes the soil within each staging pile will not be designated as hazardous waste and therefore will not require treatment prior to off-site disposal. Analysis of the composite samples will be run in triplicate for total metals by EPA Method 6010B, EPA’s toxicity characteristic leaching procedure (TCLP), EPA’s Soluble Threshold Limit Concentration (STLC), EPA’s Total Threshold Limit Concentration (TTLC), and the California Title 22 Wet Extract Test (WET).

Soil will be disposed of off Site at an appropriately permitted recycling and/or disposal facility based on the results of stockpile samples.

The Dry Creek Landfill, located in Jackson County, Oregon, is the anticipated landfill to be used for the disposal of Site contaminated soil. Characterization of soils for disposal will be performed according to landfill acceptance criteria, 27 California Code of Regulations (CCR) 20210, and the judgement of the responsible professional.

The Dry Creek Landfill acceptance criteria is provided below in Table 2.

Table 2: Dry Creek Landfill Waste Acceptance Criteria

Metal STLC Acceptance Criteria

TCLP Acceptance Criteria

TTLC Acceptance Criteria

Antimony 15 mg/kg -- 500 mg/kg

Barium 100 mg/kg 100 mg/kg --

Copper 25 mg/kg -- 2,500 mg/kg

Lead 5 mg/kg 5 mg/kg 1,000 mg/kg Notes:

“--" = not analyzed or not available “<” = result is qualified as non-detected at the estimated limit mg/kg = milligrams per kilogram STLC = Soluble Threshold Limit Concentration TCLP = Toxicity Characteristic Leaching Procedure TTLC = Total Threshold Limit Concentration

Soils for off-site disposal will be shipped and labeled appropriately to meet California Department of Transportation (DOT) requirements.

The Contractor will clear the entire impacted area of debris. In order to control the area of contamination, the Contractor will not, at any time, extend or stockpile the contaminated soil outside of the safe work area zone.

6.2.5.1 Investigation-Derived Waste Handling

All investigation-derived waste (IDW) related with soil confirmation sampling will be disposed along with the excavated soil. IDW may include used personal protective equipment (e.g., nitrile gloves) that will be disposed of off-site.

6.2.6 Waste Manifest, Transportation, and Disposal Plan

The Contractor will handle, characterize, identify, label, and package all waste generated as a result of the soil removal action in accordance with all applicable federal, state, and local laws.

The Contractor will also be responsible for packaging, labeling, and preparing the manifest and other shipping documents and will make all necessary arrangements for any off-Site transportation and disposal of waste.

The Contractor will dispose of contaminated soils at Dry Creek Landfill, located in Jackson County, Oregon. Other alternative disposal facilities must be approved by NPS prior to commencement of the NTCRA.

Once confirmation sampling has indicated that all impacted materials have been excavated from the Site, the Contractor will submit copies of sampling results from the testing laboratory, manifests and certificates of disposal for solid and hazardous waste, and any other individual reports specified in individual sections for approval. All plans and reports will be submitted to the appropriate personnel at the NPS. A copy will also be submitted to the Contracting Officer’s Representative (COR).

The Contractor will mobilize to the Site to meet with the NPS to complete the final inspection and ensure that all field activities have been completed as contracted. While on Site, the Contractor will oversee the removal of the profiled waste. A licensed transport, storage, and disposal (TSD) company, in good standing with the State of California, will be used. The Contractor will be responsible for verifying the TSD company’s credentials. The waste manifest/bill of lading will be sent to the NPS within 2 weeks of disposal.

6.2.7 Backfill and Site Restoration

The Contractor will mobilize a tracked skid-steer, or similar equipment, to the Site to backfill the excavation area. Native material will be sourced from adjacent borrow locations identified by the NPS Representative. If required by NPS, the Contractor will prepare a revegetation plan with input from NPS biologist.

The Contractor will utilize borrow material identified at the Site by the NPS field representative, if needed. The Site will be recontoured to match existing topography as indicated by the NPS field representative. All equipment, construction debris, and related items will be removed from the Site prior to final inspection and approval by NPS.

6.3 Institutional Control Plan

Temporary institutional controls will be used to protect workers and the public from exposure to contamination and industrial hazards. Institutional controls apply at the contaminated waste Site, adjacent areas used for handling waste, and other areas where industrial hazards may be present such as heavy equipment use areas.

Institutional controls will be used to limit access to the Site and ensure safe transportation practices are in place during the NTCRA. The Site access road is gated where it diverges from Alder Camp Road. The gate should remain closed and locked during implementation of the removal action, including contamination delineation and stockpiling of soils at the Site, to minimize public access.

The Contractor will use a spotter to unlock and open the gate to allow access to trucks and equipment entering and exiting the Site. The Contractor will post signage on Alder Camp Road while waste materials are being transported offsite to indicate that slow moving trucks are present.

If the dirt access road is muddy during transportation of waste material offsite, and trucks track soil onto pavement, the Contractor will be responsible for road sweeping. If conditions are dry and dust is present, the Contractor will be responsible for dust suppression.

6.4 Cultural Resources Control Plan

In the unlikely event that human remains, funerary objects, sacred objects, or objects of cultural patrimony are discovered during project activities, park Law Enforcement and park Section 106 NHPA Coordinator will be notified immediately, the area will be protected from further disturbance, and the regulations implementing the Native American Graves Protection and Repatriation Act (43 CFR Part 10) shall be followed. Ensure that all project workers are informed of the penalties for illegally collecting artifacts or intentionally damaging archeological sites or historic properties. Ensure that all project workers are instructed on how to respond to an inadvertent discovery.

If unknown cultural resources are uncovered during the project, all work will be stopped in the discovery area pending further investigation and consultation by park Section 106 NHPA Coordinator and park cultural resources specialists. If concealed archaeological resources are encountered during project activities, all necessary steps will be taken to protect them from further disturbance; and the park cultural resources staff will be notified immediately upon their discovery.

EROSION CONTROL PLAN

The erosion control plan has been prepared for site-specific activities that may affect sediment or surface water drainage at the Site. The plan includes procedures for implementing best management practices (BMPs) for controlling sediment and stormwater runoff into nearby drainages. The purpose of this plan is to identify and evaluate all pollution sources associated with construction activities that may affect the quality of sediment or surface water in nearby drainages and incorporate site-specific BMPs that will prevent pollutants from migrating offsite.

The following subsections discuss potential pollutant sources, BMPs to be used (as appropriate), and inspection and reporting protocols for prevention of pollution to sediment and stormwater.

7.1 Potential Pollutant Sources

The major potential pollutant sources that will be present during the removal action include sediment and stormwater runoff. In addition, common construction practices have the potential to cause pollution via processes other than erosion. There is potential for non-storm water discharge as part of the construction process.

The following activities have the potential to dislodge sediment that may enter nearby areas:

• Mobilization;

• Clearing and grubbing;

• Excavation

• Vehicle tracking; and

• Grading/site restoration.

In addition, the following wastes generated by construction activities have been identified as potential sources of pollution if in contact with stormwater runoff:

• General trash generated by onsite workers;

• Fuels, oils, fluids, lubricants, and grease used by various construction equipment;

• Runoff from decontamination activities;

• Runoff from dust control; and

• Sanitary and septic waste generated by onsite workers.

7.2 Stormwater and Sediment Control

Since the Site is currently delineated to an area of approximately one-fourth of an acre, the removal action is not expected to exceed 1 acre. A Stormwater Pollution Prevention Plan (SWPPP) is not required for Site removal activities.

Discharge of stormwater as well as non-stormwater erosion (i.e., wash water) into drainages and local watersheds are the greatest potential sources for offsite migration of contaminated materials.

The Contractor will install BMPs, such as straw wattles and jute blankets, as needed to reduce the potential for stormwater runoff into local watersheds. The Contractor will construct and use a contaminant reduction zone (CRZ) with runoff controls to prevent potential wash water runoff during decontamination activities. The Contractor will practice good housekeeping during all Site activities.

The following subsections describe the BMPs to control erosion and sediment.

7.2.1 BMPS for Preconstruction Erosion Control

Erosion controls will be implemented during the site mobilization phase to reduce sediment and other pollutant discharges. Erosion control features (e.g., jute blanket, straw wattle) will be installed along the perimeter of downgradient drainages, as appropriate.

7.2.2 BMPs for Water Erosion

During a rain event, straw wattles and silt fencing will be used along exposed slopes during construction activities. These BMPs will intercept and settle out soil particles that have been detached and transported by the force of water, thus preventing sediment erosion. Water erosion is not expected to pose a threat during dry weather.

7.2.3 BMPs for Wind Erosion

Water will be sprayed on dust produced during excavation activities. Spraying excess water will be avoided, since it could result in uncontrolled runoff. All stockpiled soil will always be covered with plastic sheeting when not in use. Sandbags will be used to weigh down the plastic sheets to secure each cover.

7.2.4 BMPs for Tracking Sediment

Vehicles and equipment entering and exiting the Site will be inspected for sediment prior to entering or leaving the Site. Observed sediment will be swept or washed from the equipment and vehicles before leaving the site.

7.2.5 BMPs for Construction Vehicle and Equipment Spills

Onsite heavy equipment will be inspected daily for leaking oil and fluids. Any leaks from vehicles on site will be immediately reported to the driver or operator. Absorbent pads will be stored onsite in a hazardous materials spill kit near Site activities, which will be readily available during if leaking oil or fluids are observed. The Health and Safety Plan (HASP) will need to include spill prevention protocols. All equipment fueling operations will be conducted within controlled areas and will be closely monitored to reduce the potential for a spill.

Light-duty vehicles will be stored in designated staging areas away from the work areas. All light-duty vehicles and construction equipment will be inspected for leaks daily and be maintained. Minor repairs will be conducted at the Site. Major repairs will require that the vehicle be taken out of service and repaired off site. Fueling and washing of light duty vehicles will not occur on Site.

7.2.6 Inspection, Maintenance, Repair, and Reporting

The Contractor will perform daily inspections of BMPs to ensure erosion controls are in place and effective throughout all construction activities. The Contractor will conduct routine inspections and maintenance procedures to ensure the following:

• Erosion and excessive displacement of sediment from active work areas has not occurred;

• Surface water is not significantly ponding; and

• Site access is secure.

Detailed inspections will be conducted prior to and following anticipated storm events.

Inspections will ensure the integrity of installed BMPs. The field logs will summarize the BMPs implemented, the results of BMP inspections, and any response actions taken.

7.2.7 Hazardous Material Spill Plan

The Contractor will make all reasonable efforts to minimize accidental spills of fuel and oil during field activities. Field personnel will be equipped with dry absorbent pads, absorbent materials, and shovels to clean up spills immediately. All containers will have appropriate labels for associated hazards. Safety Data Sheets and containment criteria will be maintained on site and monitored by the Site Safety and Health Officer. Containers will be constructed with closable lids, which will be kept closed except when in direct use. Empty drums and containers will be kept in a designated area.

TRAFFIC CONTROL PLAN

This project requires the mobilization of equipment, support vehicles, and materials that may potentially impact traffic along Coastal Drive and Alder Camp Road (Figure 2). Although ECM does not anticipate significant impacts to the surrounding roads, the procedures discussed in this section will be followed if offsite vehicle traffic becomes impacted by the removal activities.

This plan applies specifically to the mobilization, waste transportation, and demobilization phases of the work.

This traffic control plan describes the procedures for controlling traffic along Coastal Drive and Alder Camp Road during transportation of equipment and materials to and from the Site, during waste hauling, and during transport of borrow source materials to the Site. Figure 2 shows the Site access routes and locations.

This traffic control plan is in accordance with the “Manual on Uniform Traffic Control Devices (MUTCD) for Streets and Highways” (Federal Highway Administration (FHWA), 2012). This traffic control plan ensures that adequate consideration will be given for the safety and convenience of motorists, pedestrians, and workers during construction.

8.1 General Approach

The general traffic controls discussed below are most applicable to work at the Site.

• All traffic at the construction Site will be routed with traffic control devices and road layouts comparable to those for normal highway situations.

• Traffic movement will be maintained as normal as practical. Reduced speed zoning will be avoided as much as practical. Preparations for safe traffic control for work and construction vehicles will be made.

• All traffic control devices will be…