A.07.23_1c_DRAFT_Building_1206_Investigation_Report.pdf

U.S. Army Corps of Engineers Kansas City District

DRAFT 1200 Area Pre-Design Investigation of Building 1206

Work Summary

USACE Contract No: W912DQ-11-D-3004 Task Order No: 022

Building 1206 Investigation Kansas Army Ammunition Plant Labette County, Kansas

March 20, 2018

DRAFT Pre-Design Investigation Work Summary for

Building 1206

Kansas Army Ammunition Plant Labette County, Kansas

Contract Number: W912DQ-11-D-3004 Task Order No: 022

Prepared by: ___________________________________________ Date:

Karla Leslie CDM Federal Programs Corporation

Approved by: ___________________________________________ Date:

Jacqueline Mosher CDM Federal Programs Corporation Program Manager

This page is intentionally left blank.

i

Table of Contents

Executive Summary ........................................................................................................Ex-1 Site Overview ................................................................................................................................................................... Ex-1 Work Summary ............................................................................................................................................................... Ex-1 Results and Conclusions .............................................................................................................................................. Ex-2

Section 1 Introduction ..................................................................................................... 1-1

1.1 PDI Work Summary Overview ............................................................................................................................ 1-1

1.2 PDI Work Summary Objectives .......................................................................................................................... 1-1

1.3 PDI Work Summary Organization ..................................................................................................................... 1-2

Section 2 Building 1206 Conceptual Site Model and Background ...................................... 2-1

2.1 Building 1206 Historical Operations and Background ............................................................................. 2-1

2.2 Regulatory Framework and History ................................................................................................................. 2-1

2.3 Pre-Investigation Building 1206 Conceptual Site Model ......................................................................... 2-2

2.3.1 Previous Remedial Investigations ....................................................................................................... 2-2

2.3.2 Pre-Investigation Conceptual Site Model ......................................................................................... 2-3

2.3.3 Geology and Hydrogeology ..................................................................................................................... 2-4

2.3.4 Contaminant Extent and Distribution ................................................................................................ 2-4

Section 3 Summary of Pre-Design Investigation Implementation ...................................... 3-1

3.1 PDI Field Activities ................................................................................................................................................... 3-1

3.1.1 Building Material Investigation ............................................................................................................ 3-1

3.1.1.1 Screening Activities (XRF Screening, Cleaning, Sewer Scope) ................................... 3-1

3.1.1.2 East Wall Sampling ....................................................................................................................... 3-2

3.1.1.3 Concrete Core Sample Collection ........................................................................................... 3-2

3.1.2 Overburden Sampling Beneath Building 1206 ............................................................................... 3-3

3.2 PDI Laboratory and Modeling Activities ......................................................................................................... 3-3

3.2.1 Building Material Investigation ............................................................................................................ 3-3

3.2.1.1 Concrete Composite Samples ................................................................................................... 3-3

3.2.1.2 Concrete Cores ............................................................................................................................... 3-4

3.2.1.3 Concrete Leaching Tests............................................................................................................. 3-4

3.2.1.4 East Wall Brick Samples ............................................................................................................. 3-4

3.2.2 Overburden Investigation ....................................................................................................................... 3-4

3.2.3 3D Visualization Modeling ...................................................................................................................... 3-5

3.3 Field Logistics ............................................................................................................................................................. 3-5

3.3.1 Site Access ...................................................................................................................................................... 3-5

3.3.2 Permitting ...................................................................................................................................................... 3-5

3.3.3 Training and Personnel Protection ..................................................................................................... 3-5

3.3.4 Investigation-Derived Waste ................................................................................................................. 3-5

3.3.5 Equipment Staging and Storage ............................................................................................................ 3-5

Section 4 Summary of Results .......................................................................................... 4-1

4.1 Building Material Investigation .......................................................................................................................... 4-1 ii

4.1.1 East Wall .......................................................................................................................................................... 4-1

4.1.2 Concrete .......................................................................................................................................................... 4-2

4.1.3 Concrete Leaching Tests ........................................................................................................................... 4-3

4.2 Overburden Investigation ..................................................................................................................................... 4-4

4.3 Data Quality Evaluation .......................................................................................................................................... 4-5

4.3.1 Data Usability and Assessment Review ............................................................................................. 4-5

4.3.2 Assessment of Data Quality Objectives .............................................................................................. 4-6

4.3.3 Deviations ....................................................................................................................................................... 4-7

Section 5 Investigation Summary ..................................................................................... 5-1

5.1 Summary of Contamination .................................................................................................................................. 5-1

5.2 Remaining Data Gaps............................................................................................................................................... 5-1

Section 6 References ....................................................................................................... 6-1 iii

List of Tables

Table 2-1: KSAAP Cleanup Standards Table 2-2: Building 1206 Concrete Coring Results Table 2-3: Building 1206 Trench Chromium Results Table 2-4: Trench Hexavalent Chromium Results Table 2-5: Trench Sidewall Chromium Results Table 4-1: East Wall Total Chromium (XRF) Results Table 4-2: East Wall Sampling Results Table 4-3: Concrete Slab Total Chromium (XRF) Results Table 4-4: Building Material and Overburden Investigation Results Table 4-5: Concrete Coring Leaching Results

T iv

List of Figures Figure 2-1: Location Map Figure 2-2: Installation Map Figure 2-3: 1200 Area Map Figure 2-4: Trench Locations Outside of Building 1206 Figure 2-5: Limestone Potentiometric Surface Figure 2-6: Location of Installed Wells Figure 3-1: Sampling Locations Figure 4-1: East Wall Pre-Cleaning XRF Results Figure 4-2: East Wall Post-Cleaning XRF Results Figure 4-3: Slab Pre-Cleaning XRF Results Figure 4-4: Slab Post-Cleaning XRF Results Figure 4-5: Chromium in Concrete Figure 4-6: Chromium in Overburden Figure 4-7 LeapFrog® Hexavalent Chromium Results in Overburden Figure 4-8: LeapFrog® Total Chromium Results in Overburden Figure 4-9: LeapFrog® Model Overburden Profile Views amm

Make v

Appendices

Appendix A – Historical Building 1206 Photographs and Drawings Appendix B – Boring Logs Appendix C – Photographic Log Appendix D – Field Books and Forms Appendix E – CDM Smith DTL Laboratory Forms Appendix F – Data Usability Assessment Report Appendix G – Field Change Request Forms Appendix H – Geochemical Modeling vi

Acronyms 3D three dimensional APP accident prevention plan Army United States Army bgs below ground surface BRAC Base Realignment and Closure CDM Smith CDM Federal Programs Corporation CDM Smith DTL CDM Smith Denver Treatability Laboratory CFR Code of Federal Regulations CMD Corrective Measures Decision CSM conceptual site model DPT direct-push technology DZI Day and Zimmerman Inc.

EPA United States Environmental Protection Agency ft feet ft3 cubic feet HWM hazardous waste management IDW investigation-derived waste KDHE Kansas Department of Health and Environment KSAAP Kansas Army Ammunition Plant, currently renamed Great Plains Industrial Park MCL maximum contaminant level mg/kg milligrams per kilogram mg/L milligrams per liter mm millimeter MS/MSD matrix spike/matrix spike duplicate PARCCS precision, accuracy, representativeness, comparability, completeness, and sensitivity PDI pre-design investigation QA quality assurance QC quality control RCRA Resource Conservation and Recovery Act RFA RCRA Facility Assessment RRSE relative risk site evaluation SOP standard operating procedure SSHP site-specific health and safety plan SSL southern settling lagoon UFP-QAPP Uniform Federal Policy for Quality Assurance Project Plans URS URS Corporation, Inc.

USACE U.S. Army Corps of Engineers USDA U.S. Department of Agriculture XRF X-ray fluorescence µg/L micrograms per liter

Ex-1

Executive Summary

The United States Army, through a contract with CDM Federal Programs Corporation, has completed fieldwork for the pre-design investigation (PDI) activities of Building 1206 within the 1200 Area of the Kansas Army Ammunition Plant, formerly Kansas Ordnance Plant) (1200 Area), now known as Great Plains Industrial Park) in Labette County, Kansas. This project was performed on behalf of the Army under Contract Number W912DQ-11-D-3004, executed by the United States Army Corps of Engineers. This executive summary provides an overview of the work performed, data collected, interpretations, and overall evaluation of Building 1206 based on the PDI activities.

Site Overview Building 1206 was used for casing rework; the process involved the use of chromic acid solution to remove residual material from the used shells. Spent acid was discharged from Building 1206 into a ditch, which conveyed the material to the Southern Settling Lagoon. These processes resulted in chromium contamination of the onsite overburden, limestone, upper shale, and the building itself. Past removal activities focused on removal of overburden contamination outside of Building 1206. The focus of the PDI investigation was determination of the remaining onsite sources of hexavalent chromium contamination within and beneath Building 1206.

Work Summary PDI characterization activities were completed from September 2017 through November 2017, and included the following activities:

Screening activities were completed within Building 1206, including total chromium determination by X-ray fluorescence on the surface of the concrete slab and east wall both pre- and post-cleaning and completion of a sewer video scope and locate.

Concrete cores were collected from within Building 1206 for hexavalent and total chromium analyses to determine the vertical depth of penetration and horizontal extent of total and hexavalent chromium contamination within the Building 1206 concrete slab.

Direct push technology was utilized to collect overburden cores from beneath the building to determine the vertical and lateral extent of total and hexavalent chromium contamination in overburden materials present underneath the Building 1206 concrete slab and where sub-slab pipelines discharge on the outside of the building.

Brick cores were collected from the east wall of Building 1206 to determine the vertical depth of penetration and horizontal extent of total and hexavalent chromium contamination.

The leaching potential of hexavalent chromium from the contaminated concrete slab materials within Building 1206 was evaluated.

Section 1 • Introduction

Ex-2

Results and Conclusions PDI characterization activities were successful in determining the following:

No significant contamination exists along the east wall.

The surface of the concrete slab near the processing area is contaminated with hexavalent chromium but does not present a continuing source of contamination to the subsurface.

The concrete in the trenches is contaminated with hexavalent chromium and may be a continuing source of contamination to the subsurface.

Approximately 8,000 cubic feet of overburden beneath Building 1206 contains hexavalent chromium contamination at concentrations exceeding 64 milligrams per kilogram.

The rail lines, catch basins, and trenches served as preferential pathways for contaminant (chromium and hexavalent chromium) distribution to the subsurface of Building 1206.

This conclusion is based on evaluation of the spatial distribution of contamination in the building materials and overburden beneath Building 1206.

1-1

Section 1 Introduction

The United States Army (Army) Base Realignment and Closure (BRAC) program, through the U.S.

Army Corps of Engineers (USACE) Contract Number W912DQ-11-D-3004, directed and funded a pre-design investigation (PDI) completed by CDM Federal Programs Corporation (CDM Smith) within the 1200 Area of the Kansas Army Ammunition Plant (KSAAP, formerly Kansas Ordnance Plant) (1200 Area) in Labette County, Kansas. KSAAP is a BRAC 2005 installation, since closed, and is now owned by the Great Plains Industrial Park; however, for the sake of consistency between historical site activities and documentation, the area will be called KSAAP in this document. The PDI fieldwork was conducted under the Great Plains Development Authority’s Resource Conservation and Recovery Act (RCRA) permit under which the Army is the operator.

1.1 PDI Work Summary Overview

This work summary describes results from the PDI field characterization activities conducted from September 2017 through November 2017 to evaluate the extent of chromium present within and beneath Building 1206. This work summary includes the PDI work objectives, background information for Building 1206, the PDI technical approach, and a summary of the PDI activities. The investigation was completed in accordance with the Final Pre-Design Investigation Work Plan for 1200 Area Pilot Studies, Building 1206, Kansas Army Ammunition Plant, Labette County, Kansas ([PDI Work Plan] CDM Smith 2017b).

1.2 PDI Work Summary Objectives

The primary objective of the PDI was to collect additional data to assist in the design for remediation of surficial and subsurface chromium and hexavalent chromium contamination at Building 1206. Other objectives included:

Determining the vertical depth of penetration and horizontal extent of total and hexavalent chromium contamination within the Building 1206 concrete slab. Total chromium determination was completed under both pre- and post-cleaning conditions, whereas hexavalent chromium was determined under post-cleaning conditions.

Determining the vertical and lateral extent of total and hexavalent chromium contamination in overburden materials present underneath the Building 1206 concrete slab and where drain lines discharge on the outside of the building.

Evaluating the leaching potential of hexavalent chromium from the contaminated concrete slab materials within Building 1206.

Determining the vertical depth of contamination and horizontal extent of total and hexavalent chromium contamination on the east wall of Building 1206. Total chromium determination was completed under both pre- and post-cleaning conditions, whereas hexavalent chromium was determined under post-cleaning conditions.

Section 1 • Introduction

1-2

1.3 PDI Work Summary Organization

This PDI work summary is organized in the following sections.

Section 1 Introduction – Provides a summary of the PDI objectives and document organization.

Section 2 Building 1206 Conceptual Site Model and Background – Describes the site and regulatory history, current site operations, geology, and hydrogeology. Section 2 also summarizes results from previous investigations conducted at the site.

Section 3 Summary of PDI Implementation – Describes the technical approach used for the PDI field activities, including overburden and building material investigations.

Section 4 Summary of Results – Discusses results from the PDI activities, including contaminant distribution and an assessment of data quality and usability.

Section 5 Investigation Summary – Discusses interpretations of the data presented in Section 4.

Section 6 References – Contains a list of references used for this PDI work summary.

Appendix A – Historical Building 1206 Photographs and Drawings

Appendix B – Boring Logs

Appendix C – Photographic Log

Appendix D – Field Books and Forms

Appendix E – CDM Smith DTL Laboratory Forms

Appendix F – Data Usability Assessment Report

Appendix G – Field Change Request Forms

Appendix H – Geochemical Modeling Calculations

2-1

Section 2 Building 1206 Conceptual Site Model and Background

This section discusses the background, previous investigations, and the conceptual site model (CSM) for Building 1206 in the 1200 Area at the KSAAP site in Labette County, Kansas.

2.1 Building 1206 Historical Operations and Background

KSAAP is in Labette County, Kansas, approximately 20 miles north of the Oklahoma state line and 30 miles west of the Missouri state line, near the town of Parsons (Figure 2-1). Construction of the plant began in August 1941. The plant consists of 21 former active and standby production facilities on 13,727 acres of land and is surrounded by privately owned agricultural and residential land. The site was a government-owned, contractor-operated installation under the jurisdiction of the Joint Munitions Command. From July 1942 to August 1945, KSAAP produced artillery ammunition, bombs, and parts for artillery shells. From the end of 1945 to 1950, the site functioned primarily as a storage facility for ammunition and explosives. From 1950 to 1957, the plant produced bombs, artillery ammunition, artillery component parts, and 105-millimeter

(mm) cartridge cases. From 1957 to 1966, the plant was placed on standby after which activities resumed. In 1970, Day and Zimmerman Inc. (DZI) took over operation as the site contractor. By 1975, production at the site had been reduced to three production lines for making cluster bombs, 105-mm shells, 81-mm mortars, detonators, fuses, primers, lead cup assemblies, and lead azide. This production continued through 2004, and the site closed on November 9, 2005.

An installation map with various areas of interest is provided as Figure 2-2. The 1200 Area (formerly the Casing Rework Area) refers to approximately 49 acres in the south-central portion of KSAAP (Figure 2-3). Building 1206 at the 1200 Area was used for casing rework during the 1950s; the process involved the use of chromic acid solution to remove residual material from the used shells. Little information has been documented regarding the operations within Building 1206 and how the building was retrofitted during the different building functions. However, based on a review of historical photographs and drawings (Appendix A), dip-tanks were present within Building 1206 and contained chromic acid. Spilled and/or spent chromic acid within Building 1206 apparently drained into a series of channels (trenches) on the concrete floor and possibly into sewer pipes underneath the building.

Background associated with activities completed outside of the immediate area surrounding Building 1206 was provided in the pre-design investigation report (CDM Smith 2017a).

2.2 Regulatory Framework and History

The United States Environmental Protection Agency (EPA) issued a RCRA Hazardous Waste Management (HWM) Permit on November 7, 1989, to Kansas Army Ammunition Plant, Parsons, Kansas (EPA RCRA ID# KS0213820467).

Section 2 • Background and Site Conditions

2-2

In November and December of 2000, a relative risk site evaluation (RRSE) was conducted at the 1200 Area (U.S. Army Center for Health Promotion and Preventative Medicine 2000), which collected surface overburden samples around buildings and barricades, sediment samples from two drainage ditches and one settling pond, and two surface water samples. The RRSE was followed by a RCRA Facility Assessment (RFA) of the 1200 Area completed in September 2004 by URS Corporation, Inc. ([URS] 2004). The RFA was followed by a RCRA Facility Investigation (URS 2005), which collected more extensive 1200 Area surface water, overburden, building, and groundwater samples for analysis. Investigations before 2000 included an environmental impact assessment by DZI (1980) and a baseline survey report (Aguirre Engineers, Inc., 1997), but these reports were not specific or comprehensive to the 1200 Area.

The site was classified as a BRAC in 2005 for economic redevelopment purposes. In April 2006, EPA issued a Declaration of Final Site Wide Corrective Measures Decision (CMD) for KSAAP (EPA 2006) along with a Final Permit Decision for the HWM Permit originally submitted in 1989. This document required implementation of corrective measures at the facility. The CMD selected cleanup targets for the entire KSAAP site. The Soil and Groundwater Cleanup Targets Standards are provided in Tables 2-1a and 2-1b, respectively. Specific to the 1200 Area, the corrective measures within the CMD include: (1) a presumptive remedy for the overburden that consists of excavation, onsite treatment (if necessary to meet disposal requirements), and offsite disposal;

(2) long-term monitoring of groundwater; and (3) land use controls. A new permit issued by Kansas Department of Health and Environment (KDHE) in August 2012 modified the existing hazardous waste treatment and storage permit from November 1989 (EPA 2006).

2.3 Pre-Investigation Building 1206 Conceptual Site Model

2.3.1 Previous Remedial Investigations

During the prior PDI investigation in 2016 (CDM Smith 2017a), work was performed throughout the 1200 Area to collect additional information related to hexavalent chromium impacts in overburden, bedrock, and groundwater. However, only one phase (Phase 6) of the previous PDI completed directly involved evaluating impacts in and around Building 1206 and included evaluation of the concrete slab and sub-slab materials, overburden, and shallow bedrock near Building 1206. Within Building 1206, concrete coring and a backpack drill were used to collect surface concrete, sub-slab fill, overburden, and bedrock samples at six locations for analysis of total and hexavalent chromium (shown on Figure 2-4 and Table 2-2) and for leachability tests.

In the immediate vicinity of the building, six trenches were excavated to bedrock to the south and west, shown on Figure 2-4, and overburden samples were collected at the overburden-bedrock interface and on the overburden sidewalls of the trenches. These samples were analyzed for total and hexavalent chromium, and the results of these are provided in Tables 2-3, 2-4, and 2-5.

Additionally, five boreholes (BH-36 through -40) were drilled to approximately 15 feet (ft) below ground surface (bgs) to allow for collection of overburden and bedrock samples around Building 1206, which were analyzed for total and hexavalent chromium. Results associated with this investigation work are described in Section 2.4.

2-3

2.3.2 Pre-Investigation Conceptual Site Model

This section presents a brief CSM for Building 1206, which provides the framework for development of the PDI. The areas of concern include the interior of the building, the subsurface overburden, and the immediate vicinity outside the building where drain lines discharged.

Because documentation related to the historical operations within Building 1206 is limited, the following information is based primarily on historical and current photographs and drawings and the investigation work performed during the previous PDI (CDM Smith 2017a). Relevant historical drawings (primarily “Bldg 1206 Floor Plans A-1206-23” and “Neutral Liquor Building Plumbing Layout P-1206-08” and photographs) are provided in Appendix A.

Based on the known operational information for the KSAAP 1200 Area, chromic acid solutions consisting of approximately 1% sodium dichromate and 10% sulfuric acid were used to clean spent brass artillery shells in the 1950s. Following cleaning in the acid solution, detergents were utilized to neutralize and flush chromic acid and suspended materials from the shells. Finally, shells were rinsed with water to remove any residual processing wastes and prepare the shells for reuse. Each of these processes resulted in a waste stream that was handled differently.

The chromic acid solution was held in dip tanks in the eastern portion of Building 1206. Once the chromic acid was spent, it was emptied into a series of below-grade, concrete-lined trenches that ultimately emptied into an unlined ditch leading to the southern settling lagoon (SSL). Evidence of the acid solution has been observed on the building walls, in the concrete slab, in overburden materials beneath Building 1206, and in subsurface locations outside of Building 1206.

Additionally, based on review of the Building 1206 plumbing layout drawing (Appendix A) and historic and recent photos, catch basins located at the end of some of the concrete trenches near the dip tank area were connected to three sub-slab 6-inch pipelines that exited out the western side of the building. These 6-inch pipeline exit points are shown on the Building 1206 floor plan (Appendix A). Two railroad lines extend nearly the entire length of the building, and a series of concrete curbs are present (presumably to aid in spill control during prior operations. The catch basins, trenches, curbs, and rail lines are shown on the Building 1206 floor plan. The catch basins and 6-inch sub-slab pipelines were apparently installed during the original building construction and then trenches were installed and connected to them when the building was repurposed for casing rework. Because the rail lines were cut during installation of the trenches, the rail lines were installed prior to the casing rework.

Based on further review of schematics and photos, the western trenches in the slab flowed to the catch basins and were not connected to the east trench that drained out of the building on the southern wall. Although plans are available showing that the trenches near the processing area were to be filled with concrete, apparently they were simply filled with gravel and the curbing was not removed. Therefore, the surface of the concrete in the bottom of the trenches, which has high hexavalent chromium concentrations, was installed during the repurposing of the building (and thus contained processing waste—chromic acid, detergent, or rinse water—in direct contact). The trenches were then connected to the pre-existing catch basins, which were used as drains and conveyance for processing waste.

Because the building had multiple historical uses and the documentation of use and the different phases of construction are not available, data gaps associated with a full understanding of the

2-4 historical use of the building and how construction activities may have impacted release (or attenuation) of hexavalent chromium in the building exist. However, based on the photographs and evaluation of drawings, multiple features in the building may have resulted in release of hexavalent chromium to the concrete slab and sub-slab materials, including the dip tanks, and cracks and seams in the concrete associated with the rail lines, trenches, catch basins, and the 6-inch sub-slab pipelines.

2.3.3 Geology and Hydrogeology

KSAAP is in the southeastern part of the Osage Cuesta Physiographic Division of the Central Lowland Province on Pleistocene terrace clays to recent floodplain clays, sands, and gravels.

Lowland surficial geology consists mainly of terrace and floodplain alluvial deposits. Shallow subsurface geology generally consists of interbedded marine and non-marine shales and limestones. The stratigraphic formations of the geologic units, from youngest (shallowest) to oldest (deepest), are Lenepah, Nowata, Altamont, Bandera, Pawnee, Labette, and Fort Scott.

Exposed consolidated rocks consisting of marine and non-marine shales and limestones are of Pennsylvanian in age. Alluvial sediments are of Pleistocene age. In 1990, U.S. Department of Agriculture (USDA) Soil Conservation Service identified the KSAAP soils as silt loams, very fine sandy loams, and silty clay loams (USDA 1990).

Lithologic units at the 1200 Area consist of an overburden that is predominantly low plasticity clay, with an average thickness of 4.1 ft. Underlying the overburden is weathered limestone with significant vugs and fracturing and an average thickness of 5.3 ft. The weathered limestone acts as a porous medium rather than a fracture-dominated flow system due to the intense weathering and is a primary groundwater flow pathway. Competent limestone is then encountered, with an average thickness of 5.4 ft. Few fractures are present, and fracture flow dominates water movement. Beneath the competent limestone lies another key hydrogeologic feature—the limestone/shale interface, which is also a primary pathway for water flow. The weathered shale (6 inches to 2.5 ft thick) and, competent shale provide the vertical extent of the lithologic units of interest.

Approximately 4 to 8 ft of overburden is present near Building 1206, underlain by weathered limestone for approximately 7 ft, competent limestone for approximately 5 ft, and shale underlying these lithologic units. The October 2015 potentiometric surface in the limestone bedrock (shown on Figure 2-5) in the northern portion of the site indicates that groundwater flow trends toward the west/northwest. Around Building 1206, depth to water was approximately 15 ft bgs in MW-3-10 (shale well), whereas depth to groundwater in MW-3-14 (limestone-shale well) ranged from 3.4 ft bgs in May 2015 to 9.06 ft bgs in October 2015.

2.3.4 Contaminant Extent and Distribution

In overburden cores collected in 2016 from beneath the Building 1206 concrete slab, hexavalent chromium was present above 64 milligrams per kilogram (mg/kg) in four locations. During trenching work, directly southwest of Building 1206, field X-ray fluorescence (XRF) total chromium measurements were as high as 7,908 mg/kg, and hexavalent chromium was as high as 2,990 mg/kg. Overburden thicknesses at direct-push technology (DPT) and boring locations near Building 1206 ranged from 4 to 8 ft. Most of the overburden samples from the DPT and borings

2-5 had low total chromium, below background boring values (approximately 115 mg/kg), but five samples had total chromium concentrations between approximately 500 and 1,200 mg/kg.

Within Building 1206, four of the six concrete core sampling locations were analyzed for total chromium. These measurements were obtained by placing the XRF instrument directly on the concrete. These four locations (CC-1 through CC-4) are all located on the eastern side of the building where the chromic acid tanks were historically used. Total chromium at these four locations had a maximum value of 62,000 mg/kg, and composite samples of the concrete at these points had hexavalent chromium up to 48 mg/kg. These results demonstrate that the concrete and other surfaces within Building 1206 likely contain elevated concentrations of total and hexavalent chromium.

The groundwater plume directly west of Building 1206 is probably caused by a secondary source of chromium near the southwest of Building 1206. High chromium concentrations were observed during the trenching, and confirmation borings indicated that the contamination does not extend into bedrock. Hexavalent chromium concentrations exceeded 930 micrograms per liter (µg/L) in wells MW-3-14 and 17-24 (Figure 2-6), indicating the plume migrates northwest. However, data from MW-26-24 and MW-16-24 indicate that hexavalent chromium does not continue to migrate northwest but instead migrates west, which generally follows the estimated groundwater flow path. The contamination likely is related to the copper chromate precipitate present at the overburden/limestone interface beneath the former chromic acid discharge trench.

2-6

This page is intentionally blank.

3-1

Section 3 Summary of Pre-Design Investigation Implementation

This section summarizes the field, laboratory, and modeling activities used to conduct the PDI in Building 1206. Methods, analytical procedures, and quality assurance sampling are summarized below.

Field activities completed for the PDI included:

Building material investigation (concrete, wall)

Overburden investigation

In addition, the PDI included the following laboratory-related activities:

Sample processing and in-house analysis

Leaching tests

Analytical laboratory analysis

3.1 PDI Field Activities

3.1.1 Building Material Investigation

Hexavalent chromium contamination was investigated in the materials of Building 1206; the concrete slab and east wall were screened by XRF, samples of the concrete slab were collected by hand drill and concrete corer, and samples of the brick east wall were collected using a hand drill.

Further detail regarding the building material investigation rationale can be found in the PDI Work Plan (CDM Smith 2017b). The first phase of investigation was completed September 14 to 29, 2017; during this phase, all field XRF screening activities, east wall sampling, and concrete slab investigation were completed. Field books and field forms can be found in Appendix D.

Details of the investigation follow.

3.1.1.1 Screening Activities (XRF Screening, Cleaning, Sewer Scope) The entire concrete slab surface near former processing features was screened with an XRF instrument in a 20-foot by 10-foot gridded configuration to determine the extent of total chromium contamination and identify background concentrations on the surface of the concrete.

The main L-shaped area of the building was screened, resulting in 62 XRF screening points. The surface of the eastern wall was also screened by XRF at a transect located 4 ft above the floor, on a 20-foot horizontal spacing, which resulted in 10 XRF screening points.

Based on previously collected samples and the historical uses of Building 1206, 15 sample locations were predetermined (Figure 3-1). The predetermined sample locations were also screened using XRF, resulting in 15 additional XRF screening points. In the search for a

Section 3 • Summary of Pre-Design Investigation Implementation

3-2 background location, as well as for the investigation of features of interest, 17 additional locations were screened for total chromium using XRF.

Following determination of surface contaminant extent, low-pressure washing and scrubbing of the floor and eastern wall with a water/bleach mixture was completed to remove chromium dust and hantavirus concerns. Care was taken during washing to prevent the rinse water from flowing into the drains or exiting the building. Following washing, the concrete slab surface was re-screened with an XRF in a 10-foot by 10-foot gridded configuration to identify areas of high, medium, and low total chromium concentrations. This resulted in 111 XRF screening locations on the concrete slab surface. Post-cleaning, the eastern wall was re-screened by XRF on a 2-foot vertical by 10-foot horizontal gridded configuration, resulting in 50 XRF screening points.

Sewer inspection and utility location were completed on September 18 and 28, 2017 at all catch basins within Building 1206. Each of the catch basins along the east wall directly connect with the corresponding catch basin in the center of the building. The three sub-slab pipelines connect to a central line on the outside of the building that runs parallel to the building to the north. Video could not be used in the southern and central pipelines because the lines contained murky standing water. Video from the northern pipeline did not reveal any structural issues within the pipe beneath the building.

3.1.1.2 East Wall Sampling

Utilizing the total chromium by XRF screening results described above, 12 sampling locations on the east wall were selected. One-inch core samples were collected with a hand drill and shipped to the CDM Smith Denver Treatability Laboratory (CDM Smith DTL) for determination of total and hexavalent chromium.

3.1.1.3 Concrete Core Sample Collection

A five-point composite sample of concrete (each sampling point was approximately 1 inch in depth) was collected using a hand drill from each of the 15 pre-selected concrete sampling/sub-slab investigation locations as shown on Figure 3-1, plus a background location, following the pre-cleaning XRF screening. The composite samples were sent to the CDM Smith DTL where total chromium by XRF and hexavalent chromium using extraction by SW-846 Method 3060 (modified by standard operating procedure [SOP] 7-12) and HACH portable spectrophotometer (Powder Pillow Method 8023) were determined.

A five-point composite sample of concrete was collected from 18 additional locations based on results of the post-clean XRF and sewer scope. The composite samples were sent to the CDM Smith DTL and analyzed for total and hexavalent chromium as described above. Based on the total and hexavalent chromium results determined at the CDM Smith DTL, a total of 22 locations were selected for concrete core and overburden sampling.

Concrete core samples were collected using a concrete coring machine with a three-inch core bit at the 22 locations. Following coring, the cores were shipped to the CDM Smith DTL for processing and analysis as discussed in Section 3.2.1.2.

3-3

3.1.2 Overburden Sampling Beneath Building 1206

The TRIAD approach (Interstate Technology & Regulatory Council 2007) was implemented to guide the overburden investigation. The first phase of investigation (Phase 1) was completed between September 14 and 29, 2017. During this phase, overburden collection was guided by the results of the building material investigation. Locations of overburden collection were either co-located with the concrete slab sampling locations or outside the building near the identified sub-slab pipelines. The second phase of overburden sampling (Phase 2) was completed between November 6 and 10, 2017, with additional locations selected to delineate the hexavalent chromium contamination in overburden, guided by the overburden results from Phase 1.

Overburden samples were collected using DPT drilling continuous sampling techniques (MacrocoreTM). Field books and field forms are presented in Appendix D. The following paragraphs provide detail of the investigation.

During Phase 1, overburden samples were collected at each of 21 concrete core sampling locations (one location was too close to the wall, and overburden could not be collected) and at four locations outside of Building 1206 (Figure 3-1). Overburden samples were composited approximately every 6 inches, with sampling completed to bedrock. Samples were shipped to the CDM Smith DTL for processing and analysis of total and hexavalent chromium.

Based on the results from Phase 1, 13 overburden sampling locations within Building 1206 were selected for Phase 2. The overburden was collected using the same technique and sent to the CDM Smith DTL for processing and analysis. Based on the total chromium results, an additional nine locations were sampled, and the overburden was shipped to the CDM Smith DTL for processing and analysis.

3.2 PDI Laboratory and Modeling Activities

3.2.1 Building Material Investigation

Following the completion of field sampling activities, laboratory investigations to determine the extent of chromium contamination in Building 1206 were completed. The following sections describe the analytical procedures and analyses completed for this investigation. SOPs are provided in the Uniform Federal Policy Quality Assurance Project Plan (UFP-QAPP) 1200 Area Pre- Design Investigation, Building 1206, Kansas Army Ammunition Plant, Labette County, Kansas (CDM Smith 2017c). CDM Smith DTL laboratory forms are presented in Appendix E.

3.2.1.1 Concrete Composite Samples

The five-point composite samples of the concrete slab surface collected during the screening activities were sent to the CDM Smith DTL, and total chromium was measured by XRF directly on the homogenized and sieved material (SOP 1-15). The samples were analyzed for hexavalent chromium using extraction by SW-846 Method 3060 (modified by SOP 7-12) and analysis by HACH portable spectrophotometer (Powder Pillow Method 8023). A total of 34 samples were analyzed, and 6 confirmation samples were submitted for standard turnaround time analysis by the subcontract laboratory for hexavalent chromium by SW-846 Method 3060 (alkaline extraction) and SW-846 Method 7199 (ion chromatography).

3-4

3.2.1.2 Concrete Cores

Upon receipt at the CDM Smith DTL, the 22 concrete cores were split vertically and screened in ¼-inch vertical increments along the cut surface using XRF. Due to the lack of chromium penetration into the concrete, as determined by the XRF screening, only five cores (rather than the expected 15 cores) were selected for depth-discrete sampling for hexavalent chromium using extraction procedure SW-846 Method 3060 (modified by SOP 7-12) and HACH portable spectrophotometer method (Powder Pillow Method 8023). A total of seven depth-discrete samples were analyzed for hexavalent chromium. Six samples were selected for subcontractor laboratory total chromium confirmation sampling (digestion by SW-846 Method 3050 and analysis by SW-846 Method 6020).

3.2.1.3 Concrete Leaching Tests

Leaching tests (SOP 7-13) on the surface of the concrete slab were completed for eight samples at the CDM Smith DTL. A 1-inch (in depth) slice was collected from the top of each unused half of core, and all non-leach surfaces (i.e., the sides and bottom) were coated with a waterproof epoxy to form a seal. The cores were leached using synthetic rain water (western United States region buffered deionized water to pH 5.0 [SW-846 Method 1312]) with a 9:1 liquid to solid ratio (SW- 846 Method 1315). Hexavalent chromium in the leachate was determined by HACH portable spectrophotometer (Powder Pillow Method 8023), and six confirmation samples were sent to a subcontract laboratory for determination of hexavalent chromium (SW-846 Method 7199). The photographic log of the leach samples can be found in Appendix C, and CDM Smith DTL laboratory forms can be found in Appendix E. The results of the leaching tests were used to evaluate the potential for building materials to serve as a source of contamination; the calculations can be found in Appendix H.

3.2.1.4 East Wall Brick Samples

Twelve, one-inch diameter core samples from the east wall were shipped to the CDM Smith DTL for further analysis. Six of the samples were ground to a powder less than 2 mm, and total chromium by XRF and hexavalent chromium using extraction SW-846 Method 3060 (modified by SOP 7-12) and HACH portable spectrophotometer (Powder Pillow Method 8023) were determined. Three confirmation samples were submitted to the subcontract laboratory for analysis of hexavalent chromium by SW-846 Method 3060 (alkaline extraction) and SW-846 Method 7199 (ion chromatography).

3.2.2 Overburden Investigation

The overburden samples from both phases of fieldwork were composited approximately every 6 inches and shipped to the CDM Smith DTL. All samples were dried (via oven overnight at 22 degrees Celsius), and the top (shallowest) interval of all borings and four to six additional depth intervals were dis-aggregated using mortar and pestle. This resulted in a total of 274 processed samples, which were subsequently analyzed for total chromium by XRF. Based on the results of total chromium, 48 samples were submitted to the subcontract laboratory for analysis of hexavalent chromium by SW-846 Method 3060 (alkaline extraction) and SW-846 Method 7199 (ion chromatography). CDM Smith DTL laboratory forms can be found in Appendix E.

3-5

3.2.3 3D Visualization Modeling The three-dimensional (3D) Leapfrog® model was used to evaluate the site geologic, hydrogeologic, and contaminant data. The software was used to develop a 3D visual representation of the site geology and contamination to use as a CSM and for evaluating potential areas of incomplete data. The model provides the ability to integrate geologic information, environmental contamination data, site buildings, roads, aerial photographs, and other site features into a single visualization. Following the PDI activities, the model was updated to provide a visual representation of the site geology and distribution of contamination beneath Building 1206.

3.3 Field Logistics

This subsection details the steps that were taken to ensure the fieldwork was completed according to plan. Steps include site access, permitting, training, management of investigation-derived waste (IDW), and storage.

3.3.1 Site Access

The CDM Smith team coordinated with USACE to obtain site access for all required site personnel (including subcontractors) and vehicles. CDM Smith worked with USACE to ensure proper communication with the tenant, Great Plains Industrial Park, and other onsite contractors.

3.3.2 Permitting

All boreholes were drilled and abandoned in accordance with KDHE and the Kansas Bureau of Water regulations by a Kansas licensed well driller.

3.3.3 Training and Personnel Protection

Safety and health requirements for this project were presented in the Accident Prevention Plan (APP)/site-specific health and safety plan (SSHP) (CDM Smith 2017d). Prior to the start of field activities, field personnel reviewed and signed the APP/SSHP acknowledgement forms and conformed to the requirements of the APP/SSHP throughout project activities.

All personnel and subcontractors working on the site were trained to work on hazardous waste sites in accordance with Occupational Safety and Health Administration requirements defined in the Code of Federal Regulations (CFR) 29 CFR 1910.120(e). Before work began on the site, subcontractors submitted copies of current training certification for each employee to the site safety and health officer. Subcontractors also possessed any specific training necessary to complete their respective work activities on the site.

3.3.4 Investigation-Derived Waste

IDW did not accumulate on site from the activities because overburden and concrete were either collected and shipped for sampling or stored on site.

3.3.5 Equipment Staging and Storage

A Conex box was staged on site for equipment staging and storage. A portable toilet was rented for onsite activities from September 2017 through November 2017.

3-6

4-1

Section 4 Summary of Results

This section describes the results of the Building 1206 PDI, including contaminant extent in the building materials (Section 4.1) and overburden (Section 4.2) and the results of the data quality assessment (Section 4.3).

4.1 Building Material Investigation

To evaluate the extent of total and hexavalent chromium in Building 1206, a building material investigation was performed September 14 to 29, 2017, as described in Section 3.1.1. Figure 3-1 shows the sampling locations within Building 1206.

4.1.1 East Wall

The east wall was screened by XRF for total chromium under both pre- and post-cleaning conditions. Figure 4-1 presents the total chromium results under pre-cleaning conditions.

Following the cleaning with water/bleach solution, the eastern wall was re-screened by XRF.

Figure 4-2 presents the total chromium results under post-cleaning conditions along the eastern wall, and Table 4-1 presents the results from both pre-and post-cleaning XRF screening. All results for total chromium in the pre-cleaning screening were below 400 mg/kg; the highest concentrations were 354 mg/kg at E60 H4 and 262 mg/kg at E100 H4. All results for total chromium in the post-cleaning screening were below 1,000 mg/kg.