DQ University LTM Work PlanFinal.pdf

FINAL

LONG-TERM MONITORING

WORKPLAN D-Q UNIVERSITY,

YOLO COUNTY, CALIFORNIA

Prepared fo r

U .S. Army Corps o f Eng ineers

1325 J S t reet

Sacramento, CA 95814

December 13, 2013

FUDS Project No.: J09CA1180

ECS, Inc.

1571 Parkway Loop, Suite B

Tustin, California 92780

Brown and Caldwell

10540 White Rock Road, Suite 180

Rancho Cordova, California 95670

P:\39000\139564 - USACE DQ Univ Remediation\LTM Workplan\Final\DQ University LTM Work PlanFinal.doc

LONG-TERM MONITORING WORKPLAN

D-Q UNIVERSITY, YOLO COUNTY, CALIFORNIA

DISTRIBUTION LIST

Mr. Tim Crummett U.S. Army Corps of Engineers 1325 J Street Sacramento, CA 95814-2922

Mr. Mark Clardy California Regional Water Quality Control Board 11020 Sun Center Drive, Suite #200 Rancho Cordova, CA 95670

Mr. Dhananjay Rawal, REM ECS Inc.

1571 Parkway Loop, Suite B Tustin, CA 92780

Mr. Guy Graening, PE Brown and Caldwell 10540 White Rock Road, Suite 180 Rancho Cordova, CA 95670

Table of Contents D-Q University LTM Workplan i

TABLE OF CONTENTS

LIST OF FIGURES......................................................................................................................................................... II

LIST OF TABLES ........................................................................................................................................................... II

LIST OF ACRONYMS ................................................................................................................................................... III

1. INTRODUCTION ..................................................................................................................................................... 1-1

1.1 FUDS Status and Background ...................................................................................................................... 1-1

1.2 LTM Workplan Purpose and Objectives ....................................................................................................... 1-3

1.3 Project Staffing and Contact Information ...................................................................................................... 1-3

1.4 Workplan Organization ................................................................................................................................. 1-3

2. SITE BACKGROUND ............................................................................................................................................. 2-1

2.1 Site Description and Operational History ...................................................................................................... 2-1

2.2 Summary of Previous Investigations ............................................................................................................. 2-5

2.3 Summary of Contamination in Shallow Groundwater ................................................................................... 2-5

3. GEOLOGIC AND HYDROGEOLOGIC CHARACTERIZATION .............................................................................. 3-1

3.1 Site Geologic and Hydrogeologic Summary ................................................................................................. 3-1

3.2 Site Conceptual Model Summary ................................................................................................................. 3-3

4. LONG-TERM MONITORING AND REPORTING PROGRAM ................................................................................ 4-1

4.1 Purpose, Scope and Data Quality Objectives ............................................................................................... 4-1

4.1.1 Purpose ............................................................................................................................................ 4-1

4.1.2 Scope ................................................................................................................................................ 4-1

4.1.3 Project Objectives ............................................................................................................................. 4-1

4.2 Groundwater Monitoring ............................................................................................................................... 4-1

4.2.1 Analytical Program ............................................................................................................................ 4-2

4.2.2 Water Quality Objectives .................................................................................................................. 4-3

4.2.3 Sampling and Analysis Plan ............................................................................................................. 4-4

4.3 Field Sampling .............................................................................................................................................. 4-6

4.3.1 Fieldwork Preparation and Documentation ....................................................................................... 4-7

4.3.2 Equipment Decontamination ............................................................................................................. 4-7

4.3.3 Depth To Water Measurement .......................................................................................................... 4-7

4.3.4 Purging and Field Parameter Measurement ..................................................................................... 4-7

4.3.5 Sample Collection ............................................................................................................................. 4-8

4.4 Investigation Derived Waste ......................................................................................................................... 4-9

4.5 Reporting and LTM Optimization .................................................................................................................. 4-9

5. QUALITY ASSURANCE PROJECT PLAN ............................................................................................................. 5-1

5.1 Quality Control Samples ............................................................................................................................... 5-1

5.1.1 Field Duplicates ................................................................................................................................ 5-1

5.1.2 Trip Blanks ........................................................................................................................................ 5-1 ii

5.1.3 Temperature Blanks.......................................................................................................................... 5-2

5.1.4 Equipment Rinsate Blanks ................................................................................................................ 5-2

5.1.5 Matrix Spikes and Matrix Spike Duplicates ....................................................................................... 5-2

5.2 Analytical Method Requirements .................................................................................................................. 5-3

6. REFERENCES ....................................................................................................................................................... 6-1

APPENDIX A ................................................................................................................................................................ A Standard Operating Procedures .............................................................................................................................. A

APPENDIX B ................................................................................................................................................................ B Accident Prevention Plan ........................................................................................................................................ B

LIST OF FIGURES

Figure 1-1. Site Location Map .............................................................................................................................. 1-2 Figure 2-1. Sacramento Valley Radio Transmitter Station Layout ........................................................................ 2-2 Figure 2-2. Oblique Aerial Photo of D-Q University and Surrounding Area .......................................................... 2-3 Figure 2-3. D-Q University Layout ........................................................................................................................ 2-4 Figure 4-1. Monitoring Network ............................................................................................................................ 4-5

LIST OF TABLES

Table 1-1. Project Contacts .................................................................................................................................. 1-4 Table 3-1. Well Construction Summary ................................................................................................................ 3-2 Table 3-2. Historical Groundwater Flow Directions and Gradient ......................................................................... 3-2 Table 4-1. Analytical Program .............................................................................................................................. 4-2 Table 4-2. Water Quality Objectives ..................................................................................................................... 4-4 Table 4-3. Sampling and Analysis Plan ................................................................................................................ 4-6 Table 4-4. Field Sampling Requirements ............................................................................................................. 4-7 Table 5-1. Quality Control Sample Requirements ................................................................................................ 5-1 Table 5-2. Analytical Method Requirements - Aqueous ....................................................................................... 5-3 iii

LIST OF ACRONYMS

AOC area of concern AST above ground storage tank bgs below ground surface COC chemical of concern DERP-FUDS Defense Environmental Restoration Program - Formerly Used Defense Site DO dissolved oxygen DoD Department of Defense DWR California Department of Water Resources ECS/BC JV Enviro-Compliance Solutions, Inc. and Brown and Caldwell Joint Venture FS Feasibility Study FUDS Formerly Used Defense Site IDW investigative derived waste LCS/LCSD laboratory control sample/ laboratory control sample duplicate LTM long-term monitoring mL milliliters mg/L milligrams per liter MS/MSD matrix spike/matrix spike duplicate MSL mean sea level ORP oxidation reduction potential PRP potentially responsible party PVC polyvinyl chloride QA/QC quality assurance / quality control QAPP Quality Assurance Project Plan RI Remedial Investigation RPD relative percent difference Site D-Q University SOP Standard Operating Procedures TCE trichloroethylene TDS total dissolved solids TOC total organic carbon TPH-DRO total petroleum hydrocarbons - diesel range organics µg/L micrograms per liter µmhos/cm micromhos per centimeter US EPA U.S. Environmental Protection Agency USACE U.S. Army Corps of Engineers UST underground storage tank VOA volatile organic analysis VOCs volatile organic compounds

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D - Q U N I V E R S I T Y L T M W O R K P L A N

1 . I N T R O D U C T I O N

This workplan describes long-term monitoring (LTM) for impacted groundwater at the D-Q University Formerly Used Defense Site (FUDS) located in Yolo County, California (Site). This workplan was completed by Enviro Compliance Solutions Inc. and Brown and Caldwell Joint Venture (ECS/BC JV) for the U.S. Army Corps of Engineers (USACE), Sacramento District under Contract #W1912BV-10-D-2012. The results of the LTM will be incorporated into annual groundwater monitoring reports for the Site. As shown on Figure 1-1, D-Q University is located in Yolo County on the north side of County Road 31 (West Covell Road) and approximately 9 miles west of Davis, California. The town of Davis is located approximately 14 miles west of Sacramento, California.

1.1 FUDS Status and Background

The land on which D-Q University currently lies was owned and occupied by the U.S. Army from 1952 to 1969 and was most commonly called the former West Coast Relay and Radio Transmitting Station. All real properties formerly owned by, leased by, possessed by, or otherwise under the jurisdiction of the Secretary of Defense or elements of the U.S. military are managed within the FUDS program. Policy and guidance for the FUDS program is provided in USACE Engineering Regulation 200-3-1 (USACE, 2004a). The Remedial Investigation (RI) identified areas of concern (AOCs) where past Department of Defense (DoD) activities at the former station may have impacted the environment. FUDS program funding can only be used to assess and remediate DoD liability at an eligible property, which is defined as real property. Under the FUDS program, land that was previously utilized by DoD and that has no “beneficial use” history will be characterized and, if necessary, remediated to an appropriate standard.

Under the FUDS program, one of the parameters to be considered during the initiation of a project is whether the property (or specific item/site) has been beneficially used by any owner, operator, or other party that may be considered a potentially responsible party (PRP). If USACE determines the contamination was caused solely by DoD, it will be mitigated by USACE through the FUDS program. If an investigation is initiated (by any party) and DoD is determined to be only partially responsible, USACE will investigate to the extent necessary to determine DoD liability.

Consideration must also be given to the ability to identify DoD-generated contaminants from contaminants introduced by other PRPs, on or off the FUDS property. If identification of separate contaminant streams cannot be achieved, or if separate remediation of DoD-generated contaminants cannot be realized, the project may be ineligible for remediation under the FUDS program. If commingled contamination exists, a PRP project must be initiated and the Department of Justice will negotiate a contribution settlement with the current landowner/responsible party based on a liability analysis.

Further, the Defense Environmental Restoration Program – FUDS (DERP-FUDS) policy does not allow the USACE to provide cost recovery to property owners nor does it allow USACE to recover costs from property owners for remedial work. However, the property owner may initiate an investigation and/or clean-up action and subsequently seek cost reimbursement from the Department of Justice by filing a tort claim.

139564

10-16-12

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Figure 1-1

1: Introduction D-Q University LTM Workplan

1-3

The former West Coast Relay and Radio Transmitting Station is a FUDS site as defined by the DERP. The DERP-FUDS statute [10 USC 2701 (a) (2)] requires that projects addressing hazardous substances, pollutants, and contaminants be conducted consistent with the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and the Superfund Amendments and Reauthorization Act of 1986.

The FUDS identification number for D-Q University is J09CA1180.

As part of the FUDS process, a RI was conducted by Brown and Caldwell for the USACE Sacramento District that defined potential source areas, nature and extent of contamination, subsurface characteristics, transport mechanisms, contaminant fate, and a conceptual site model (Brown and Caldwell, 2008a). It eliminated from further consideration those AOCs that pose little or no threat to public health or the environment, determined if there is any potential need for removal action, set priorities for site inspections, and gathered existing data to facilitate later evaluation of the release pursuant to the Hazard Ranking System conducted by the U.S. Environmental Protection Agency (US EPA). The RI identified that the primary chemicals of concern (COCs) are volatile organics compounds (VOCs), primarily trichloroethylene (TCE) in groundwater and total petroleum hydrocarbon diesel range organics (TPH-DRO) in soil and groundwater.

However, there were some data gaps identified and additional investigation was proposed in the Data Gap and Treatability Study Workplan (Brown and Caldwell, 2008b). The data gap investigation activities were conducted in August and September 2009.

The Feasibility Study (FS) was conducted at the Site in conjunction with the RI. The FS identified candidate technologies for remediating contaminants in Site groundwater and evaluated their likely effectiveness, implementability, and cost. The Final FS Report (ECS/BC JV, 2012) identified five alternatives; Alternative 1- No Action, Alternative 2 – Monitored Natural Attenuation, Alternative 3 – Enhanced Biodegradation and Groundwater Recirculation, Alternative 4 – Permeable Reactive Barriers, Alternative 5- In Situ Chemical Oxidation Direct Groundwater Injection.

1.2 LTM Workplan Purpose and Objectives

The purpose of this LTM Workplan is to present the methods and procedures that will be used to conduct the fieldwork and laboratory analyses. The objectives of the LTM for the Site are listed below:

To monitor natural processes as they attenuate concentrations of VOCs and TPH-DRO detected in groundwater;

To verify that the plumes remain stable; and

To document progress towards and eventual attainment of remedial action objectives.

1.3 Project Staffing and Contact Information

Contact information for the following personnel associated with this project is provided in Table 1-1.

1.4 Workplan Organization

Background information including Site location, description, and history is presented in Section 2. This section also discusses the AOCs and Site operations. A description of Site geology and hydrogeology is provided in Section 3. The LTM program is presented in Section 4 and includes sampling locations/frequency, sample collection methods, analytical laboratory methods, and reporting details. The Quality Assurance Project Plan in Section 5 provides specific quality assurance and quality control activities designed to achieve the pilot test objectives. Section 6 provides references used in this Workplan.

1: Introduction D-Q University LTM Workplan

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Table 1-1. Project Contacts

Organization Point of Contact Title/Role Phone Numbers Address

USACE Tim Crummett Tim.R.Crummett@usace.army.mil

Project Manager Office: (916) 557-6942 Mobile: (916) 494-2426 Fax: (916) 557-7865

1325 J Street, CESPK-PM Sacramento, CA 95814-2922

USACE

Jim Lukasko James.J.Lukasko@usace.army.mil

Technical Team Lead Office: (916) 557-5392 Fax: (916) 557-5307

1325 J Street, CESPK-CT-B Sacramento, CA 95814-2922

USACE

James Stellmach James.P.Stellmach@usace.army.mil

Project Engineer Office: (916) 557- 9293 Fax: (805) 557-5307

1325 J Street, CESPK-CT-B Sacramento, CA 95814-2922

USACE

John Yaremchuk John.W.Yaremchuk@usace.army.mil

Project Chemist Office: (916) 557- 7504 Fax: (805) 557-5307

1325 J Street, CESPK-CT-B Sacramento, CA 95814-2922

USACE

Marc Sydow Marc.W.Sydow@usace.army.mil

Project Geologist Office: (916) 557- 7078 Fax: (805) 557-5307

1325 J Street, CESPK-CT-B Sacramento, CA 95814-2922

USACE Cory Koger Cory.S.Koger@usace.army.mil

Risk Assessor Office: (916) 557-5112 Fax: (805) 557-5307

1325 J Street, CESPK-CT-B Sacramento, CA 95814-2922

Central Valley Water Board

Mark Clardy mclardy@waterboards.ca.gov

Regulator Office: (916) 464-4719 Fax: (916) 464-4645

11020 Sun Center Drive #200 Rancho Cordova, CA 95670

ECS Inc.

Dhananjay Rawal, REM drawal@ecs-i.com

Subcontractor QC Manager

Office: (714) 259-0295 Mobile: (949) 413-6486 Fax: (714) 259-0296

1571 Parkway Loop, Suite B Tustin, CA 92612

Brown and Caldwell Guy Graening, PE GGraening@brwncald.com

Subcontractor Project Manager

Office: (916) 853-5325 Mobile: (916) 838-2504 Fax: (916) 635-8805

10540 White Rock Road, Ste 180 Rancho Cordova, CA 95670

ECS Inc.

Victor Salcedo vsalcedo@ecs-i.com

Subcontractor Field Team Leader

Office: (714) 259-0295 Mobile: (949) 331-4508 Fax: (714) 259-0296

1571 Parkway Loop, Suite B Tustin, CA 92612

Brown and Caldwell Greg Cole Gcole@brwncald.com

Subcontractor Project Chemist

Office: (916) 853-5320 Mobile: (916)838-2689 Fax: (916) 635-8805

10540 White Rock Road, Ste 180 Rancho Cordova, CA 95670

Brown and Caldwell Jim Bucha, CIH,CSP JBucha@brwncald.com

Subcontractor Health and Safety Officer

Office: (916) 853-5308 Mobile: (916) 216--6374 Fax: (916) 635-8805

10540 White Rock Road, Ste 180 Rancho Cordova, CA 95670

EMAX Laboratories, Inc.

Richard Beauvil rbeauvil@emaxlabs.com

Laboratory Project Manager

Office: (310) 618-8889 x118 Fax: (310) 618-0818

1835 West 205th Street Torrance, CA 90501

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D - Q U N I V E R S I T Y L T M W O R K P L A N

2 . S I T E B A C K G R O U N D

This section provides details about the Site including both historical and current Site uses. Other information summarized below includes property ownership and previous environmental investigations.

2.1 Site Description and Operational History

In 1952, 651.55 acres of agricultural land were acquired by the U.S. Army for the Sacramento Valley Radio Transmitter Station to support the Signal Corps Radio Station (call letters: WVY) (Hoover et al., 1990;

Dynamac, 1992).

For this report, the 651.55 acres is referred to as the Site. The former West Coast Relay and Radio Transmitting Station are referred to as the Station and the current D-Q University as the Campus.

Essentially, the Site includes the surrounding agricultural fields and the former Station or the current Campus.

Improvements to the Site during U.S. Army occupation included the construction of a transmitter building (Building #100), a power generation building (Building #101), a relay building (Building #102), barracks (Building #103), storage buildings, two incinerators, utilities, six underground storage tanks (USTs), four above ground storage tanks (ASTs) inside Building #100, twenty-two transformers, two waste oxidation lagoons, two cooling water injection (disposal) wells, and one cooling water supply well (Dynamac, 1992).

Buildings and features present during the occupation of the property by the U.S. Army as the Sacramento Valley Radio Transmitter Station are shown on Figure 2-1.

At the time of the acquisition by D-Q University, the Station contained all of the original buildings, most of the generating and pumping machinery, two waste oxidation lagoons, two cooling water injection wells, six USTs, six ASTs, two incinerators, and 13 of the transformers. The other nine transformers were removed prior to the property transfer. All USTs, one AST not in use within Building #101, the incinerator located west of Building #103, and 10 of the 13 transformers have been removed by USACE from the Station. The incinerator east of Building #102 and three of the four ASTs inside Building #101 had been removed prior to USACE involvement (USACE, 1997). The facilities, three remaining transformers, and two other ASTs are still being used by D-Q University.

There are no structures within a 1-mile radius other than those associated with the Campus or farming activities. As shown on Figure 2-2, the Campus is surrounded by agricultural lands that are currently leased to farmers that plant and harvest alfalfa. As shown on Figure 1-1, the Yolo County Airport is approximately

1.75 miles northeast from D-Q University. The layout and current use of the facilities and locations of groundwater wells, waste oxidation lagoons, and other pertinent structures are identified in Figure 2-3.

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10-16-12 Sacramento Valley Radio Transmitter Station Layout

2-1

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10-16-12 D-Q University Layout

2-3

2: Site Background D-Q University LTM Workplan

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2.2 Summary of Previous Investigations

As part of the FUDS process, an RI, inclusive of a Data Gap RI (Brown and Caldwell, 2010), was conducted by Brown and Caldwell for the USACE Sacramento District that defined potential source areas, nature and extent of contamination, subsurface characteristics, transport mechanisms, contaminant fate, and a conceptual site model (Brown and Caldwell, 2008). It eliminated from further consideration those AOCs that pose little or no threat to public health or the environment, determined if there is any potential need for RA, set priorities for site inspections, and gathered existing data to facilitate later evaluation of the release pursuant to the Hazard Ranking System conducted by the USEPA. The RI identified that the primary COCs are VOCs, primarily TCE in groundwater and TPH-DRO in soil and groundwater. The groundwater AOCs and the focus of this Workplan are: the TCE groundwater plume (AOC-4); and the diesel groundwater plume (AOC-5) at the former location of USTs #1-4. A summary of these AOCs is provided below.

TCE Groundwater Plume (AOC-4) - The horizontal and vertical extent of TCE-impacted groundwater is defined and is primarily found within a sand/gravel unit at 25 feet to 40 feet bgs. Reported detections of TCE were found in deeper groundwater (between 80 feet and 145 feet bgs) but needs to be confirmed.

TCE in deeper groundwater appears isolated near GW-601. TCE degradation via reductive dechlorination is minimal based on data collected to date which indicate minor concentrations of TCE degradation (or breakdown) products in site groundwater samples.

TPH-DRO Groundwater Plume (AOC-5) - The extent of TPH-DRO in shallow groundwater has been defined in the area of former fuel oil USTs #1-4. As reported for TCE, TPH-DRO was also found in deeper groundwater (between 80 feet and 145 feet bgs). TPH-DRO was found in multiple deeper groundwater samples and likely originates from lubricating oil associated with the former Cooling Water Supply Well. The horizontal extent of this deeper impact of TPH-DRO is greater in aerial extent than reported in shallow groundwater and appears to originate at the former well. In addition, the deeper TPH-DRO impacts appear unassociated with the impacted shallow groundwater resulting from the former USTs #1-4. A profile of TPH-DRO indicates that the well may be the vertical conduit through which the TPH-DRO was able to get into deeper groundwater.

2.3 Summary of Contamination in Shallow Groundwater

The following summary describes the nature and extent of impacts to shallow groundwater from the two groundwater AOCs, TCE (AOC-4) and TPH-DRO (AOC-5). Supporting information can be found in the RI (Brown and Caldwell, 2008) and the Data Gap RI (Brown and Caldwell, 2010).

TCE Groundwater Plume (AOC-4) - The horizontal and vertical extent of TCE-impacted groundwater is defined and is primarily found within a sand/gravel unit at 25 feet to 40 feet bgs. The residual source area of TCE in shallow groundwater is located approximately 20 feet east of Building #100 based on 1998 boring SS-7 (1,700 µg/L) and 2006 cone penetrometer test boring GW-601 (1,100 µg/L).

TCE does not appear to be degrading via reductive dechlorination. There are essentially no daughter or degradation products found in soil or groundwater. Cis-1,2-dichoroethylene (cis-1,2-DCE) has been reported in groundwater but only three times since 1997. Other natural attenuation mechanisms, such as dilution or dispersion, do not appear to be significantly affecting the plume. This fact is also supported by no decrease or increase in TCE concentration trends for the permanent groundwater monitoring wells.

TPH-DRO Groundwater Plume (AOC-5) - The size of TPH-DRO in the shallow groundwater is defined as the small area southeast of and resulting from the former USTs #1-4. RI data indicate that TPH- DRO concentrations range from 250 to 480 µg/L in the area of the former tanks. The TPH-DRO shallow groundwater plume is completely contained within the TCE shallow groundwater plume.

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D - Q U N I V E R S I T Y L T M W O R K P L A N

3 . G E O L O G I C A N D H Y D R O G E O L O G I C C H A R A C T E R I Z A T I O N

This section provides the setting for site-specific geology and hydrogeology and presents a summary of the site conceptual model.

3.1 Site Geologic and Hydrogeologic

Summary

As summarized in the RI (Brown and Caldwell, 2008) and the Data Gap RI (Brown and Caldwell, 2010), subsurface stratigraphy for the Site is interpreted from cone penetrometer test logs and geologic boring and well logs. The maximum depth penetrated is 165 feet bgs. The stratigraphy (depicted in the graphic to the right), is comprised of fine-grained units of silt and clay interlayered with a predominant shallow layer of coarse-grained sand and gravel. CW-2 is the former Cooling Water Supply well (Figure 1-2). The nearest cone penetrometer test log to CW-2 is CPT-601, approximately 45 feet away. Small discrete sand lenses were found at depths greater than 40 feet bgs but are discontinuous. The shallow sand/gravel layer is a relatively continuous and generally encountered at 25 feet bgs to 40 feet bgs with a thickness of approximately 15 feet underlying the Site to approximately 8 feet on the south side of County Road 31.

Based on the data collected to date, there appears to be three hydrostratigraphic zones. They are outlined below in order of appearance from ground surface to the maximum depth logged (165 feet bgs):

Low permeable silts and clays (0 to 25 feet bgs1), Permeable relatively continuous sand/gravel unit (generally at 25 feet bgs to 40 feet bgs), and Low permeable silts and clays and discontinuous sand/gravel units

(generally 40 feet bgs to 165 feet bgs).

Groundwater was first encountered at the top elevation of the sand/gravel unit generally at 25 feet bgs beneath the Station. During the RI in all phases of water level monitoring, static water levels rose to depths above the top of the screened interval for all Site wells. This information suggests confined or semi-confined conditions within the shallow units.

There is connection between the wells screened within the 25 to 40 foot sand/gravel unit. Evaluations performed under an aquifer test (Brown and Caldwell, 2010) showed that wells screened within these zones generally respond consistently with each other indicating that they are hydraulically connected. The maximum fluctuation of groundwater elevations in the wells during the period of monitoring is approximately 6 feet.

A groundwater monitoring well construction summary is provided in Table 3-1. The locations of wells included in the monitoring program are shown on Figure 4-1. Direction of groundwater flow is generally towards the east to southeast with a gradient ranging from 0.001 to 0.004 (Table 3-2).

1 Maybe as deep as 30 feet bgs south of County Road 31.

3: Geologic and Hydrogeologic Characterization D-Q University LTM Workplan

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Table 3-1. Well Construction Summary

Well ID Date

Installed

Top of Casing Elevation (feet MSL)

Ground Surface

Elevation (feet MSL)

Total Depth (feet)

Casing Diameter &

Type

Screen Interval

(feet bgs)

Screen Interval

(feet

MSL)

Slot Size

(inches)

GWM-1 1/4/01 102.78 103.12 27 4 inch PVC 12 to 27 90 to 75 0.010

GWM-3 1/5/01 101.98 102.42 27 4 inch PVC 12 to 27 89 to 74 0.010

GWM-4 4/20/01 101.88 102.31 26 4 inch PVC 11 to 26 90 to 75 0.010

GWM-5 2/20/01 102.41 102.85 28 4 inch PVC 13 to 28 89 to 74 0.010

GWM-6 2/20/01 103.13 103.42 28 4 inch PVC 13 to 28 90 to 75 0.010

DQ-GMW-7 8/10/09 101.67 102.37 40 2 inch PVC 25 to 40 76 to 61 0.020

DQ-GMW-8 8/6/2012 102.69 103.19 45 4 inch PVC 26.5 to 41.5 76 to 91 0.020

DQ-GMW-9 8/14/2012 101.23 101.70 45 4 inch PVC 26.5 to 41.5 74 to 89 0.020

DQ-GMW-10 8/16/2012 101.90 102.47 44 4 inch PVC 28 to 43 73 to 88 0.010

DQ-GMW-11 8/9/2012 104.29 101.37 40 4 inch PVC 27 to 42 77 to 92 0.020

DQ-GMW-12 8/15/2012 104.36 101.61 45 4 inch PVC 30 to 45 74 to 89 0.020

DQ-GMW-13 8/8/2012 102.17 99.04 40 4 inch PVC 21.5 to 36.5 80 to 95 0.020

DQ-GMW-14 8/7/2012 102.02 99.04 45 4 inch PVC 25 to 40 77 to 92 0.020

DQ-GMW-15 8/13/2012 101.77 98.82 40 4 inch PVC 25 to 40 76 to 91 0.020

DQ-GIW-2 10/21/09 * 102.51 28 4 inch PVC 18 to 28 84 to 74 0.030

DQ-GEW-3 8/12/09 * 102.84 35 4 inch PVC 15 to 35 87 to 67 0.030

MSL = mean sea level bgs = below ground surface PVC = poly vinyl chloride *Top of well casing was reconfigured for the 2012 monitoring event. Top of well casing has not been resurveyed.

Table 3-2. Historical Groundwater Flow Directions and Gradient

Date Generalized Flow Direction Gradient (feet/feet) Data Source

1/01 Southeast* 0.0009* (A)

4/11/02 East to southeast 0.0008 to 0.001 (B)

8/8/02 Northeast to east to southeast 0.001 to 0.003 (B)

3/24/03 Northeast to southeast 0.001 to 0.003 (B)

9/10/03 Northeast to southeast 0.001 to 0.004 (B)

12/15/03 Northeast to southeast 0.0009 to 0.008 (B)

4/8/04 East to southeast 0.001 --

5/30/06 East to southeast 0.001 --

6/21/07 East to northeast 0.003 (C)

6/9/08 East to northeast 0.005 (D)

* Based on wells DQ-GWM-1 through DQ-GWM-3

(A) SCA, 2001. Final Report – Groundwater Site Investigation and Supplemental Groundwater Site Investigation, D-Q University, Yolo County, California. October.

(B) USACE, 2004b. Annual Groundwater Monitoring Report, D-Q University, Yolo County, California. September.

(C) USACE, 2008a. Annual 2007 Groundwater Monitoring Report, D-Q University, Yolo County, California. May.

(D) USACE, 2009. Annual 2008 Groundwater Monitoring Report, D-Q University, Yolo County, California. July.

3: Geologic and Hydrogeologic Characterization D-Q University LTM Workplan

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3.2 Site Conceptual Model Summary

Hydrostratigraphic cross sections indicate alluvial sediments at the Site were deposited as part of the Tehama Formation and consist primarily of silts and clays with coarse-grained sediments. There is a relatively continuous sand/gravel unit generally at 25 feet bgs to 40 feet bgs that extends beneath the Site.

Data Gap RI groundwater samples collected at multiple depths suggest that there is only one water-bearing unit with paths of preferential groundwater flow within the shallow sand/gravel at 25 to 40 feet bgs. Beneath this sand/gravel unit is a fine-grained unit consisting of silt and clay that extends to depths of at least 165 feet bgs based on Data Gap RI drilling. Discontinuous thin lenses of fine sand were observed during Data Gap RI drilling. A connection between the primary shallow water-bearing unit and the deeper sand formation could not be established.

Based on groundwater elevations measured in permanent groundwater monitoring wells screened within the shallow sand/gravel unit and the depth to first encountered groundwater, groundwater conditions are confined or semi-confined. Additional groundwater elevation data collected within deeper discontinuous sand lenses supports the same conditions to the maximum depth penetrated where groundwater was encountered (150 feet bgs).

Groundwater flow is south-southeast, the same direction as the long axis of the TCE and TPH-DRO plume, and under a flat gradient of 0.001 to 0.009. On February 11, 2011, groundwater elevations reflected extraction and the rebound of water levels while the pilot test system was in operation. The extent of the TCE and TPH-DRO is laterally defined and contained within this shallow water-bearing zone at 25 to 40 feet bgs. The TCE plume extends nearly 2,800 feet to County Road 31; however, the TPH-DRO plume is much smaller and contained within the area of the former Station.

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D - Q U N I V E R S I T Y L T M W O R K P L A N

4 . L O N G - T E R M M O N I T O R I N G A N D R E P O R T I N G P R O G R A M

The components of the LTM plan consist of specifying sampling locations, sampling frequency, and an analytical protocol, data analysis, and developing a contingency plan. The following sections present a summary description of the proposed monitoring and reporting program.

4.1 Purpose, Scope and Data Quality Objectives

4.1.1 Purpose

The purpose of continued groundwater monitoring is to provide field and analytical data to support an evaluation of current Site conditions.

4.1.2 Scope

The groundwater monitoring scope includes annual groundwater sample collection, analysis and reporting. It is anticipated the monitoring program will be implemented until the dissolved phase constituents achieve RAOs.

4.1.3 Project Objectives

The project objectives of groundwater monitoring at the Site are listed below:

Monitor dissolved phase VOC concentrations in groundwater;

Monitor water quality and biological parameters to verify intrinsic biodegradation;

Determine the mass reduction of product and biodegradation rates;

Verify plume stability for the protection of human health and the environment;

Evaluate the need for LTM optimization; and

Discontinue monitoring when VOC concentrations meet the RAOs.

These project objectives will be met through implementation of the proposed long-term groundwater monitoring plan discussed in this section.

4.2 Groundwater Monitoring

Annual monitoring is recommended in order to measure seasonal variations in water levels and groundwater quality that will influence data interpretation. Thirteen monitoring wells were selected for sampling to meet the project objectives. The monitoring wells selected for LTM will provide sufficient groundwater data needed to determine changes in concentrations within the dissolved phase plume and to determine biodegradation rates. The selected monitoring wells are located at the plume boundaries, the plume core, and at background locations. The biodegradation rates will be determined using selected wells that lie along two different downgradient flow vectors.

4: Long-Term Monitoring and Reporting Program D-Q University LTM Workplan

4-2

4.2.1 Analytical Program

As shown in Table 4-1, groundwater samples will be analyzed for various chemical classes in the LTM.

Table 4-1. Analytical Program

Suite Chemical Class Purpose

A VOCs (TCE, cis- and trans-1,2-DCE, vinyl chloride) Site contaminant and daughter products

B Total and Dissolved Metals (arsenic, iron, manganese) General Minerals (full list)

Bioparameter data / products of degradation

C Total Dissolved Solids Dissolved Gases (methane, ethane, ethene) Total Organic Carbon

Products of degradation

The chemical classes can generally be grouped by Site contaminant and daughter products, bioparameter data, and products of degradation.

Site Contaminant and Daughter Products. TCE is the primary Site contaminant. TCE breakdown products consist primarily of cis-1,2-DCE, trans-1,2-DCE, and vinyl chloride. At the Site, the microorganisms required to reductively dechlorinate cis-1,2-DCE may not be present in sufficient populations to play a significant role. Furthermore, the reduction of TCE requires modestly reduced ORP values. The subsequent conversion of cis-1,2-DCE to vinyl chloride requires more reducing conditions.

Thus at some Sites conditions result in what has been referred to as “DCE stall.” However, cis-1,2-DCE and vinyl chloride may undergo oxidative degradation under aerobic iron reducing, and manganese reducing conditions. Thus, it is possible that TCE is converted to cis-1,2-DCE and the latter is then converted to carbon dioxide, water, and chloride ion through other microbial processes.

Bioparameter Data. This type of data can be used to indirectly demonstrate that biodegradation is occurring. Each sequential terminal electron acceptor process changes the redox potential of groundwater, with reducing conditions increasing through the sequence: oxygen, nitrate, manganese, iron, sulfate, and carbon dioxide. Dissolved oxygen (DO) is typically the first electron acceptor utilized by microorganisms because it is the most thermodynamically favorable electron acceptor (i.e., microorganisms are able to extract more energy from oxygen than from other electron acceptors). DO is included in the field sampling.

- Nitrate: If present in the groundwater, nitrate will generally be utilized once DO has been depleted to concentrations below approximately 0.5 milligrams per liter (mg/L). High nitrate concentrations (>

1.0 mg/L) may be competitive, but not necessarily inhibitory, with reductive dechlorination. Nitrate levels are typically lower within the source and plume areas compared with background levels or nitrate concentrations downgradient, side-gradient, and upgradient of the plume due to denitrification by microorganisms.

- Manganese: Manganese (IV) is utilized as the electron acceptor once nitrate concentrations have been depleted. The utilization of manganese (IV) as an electron acceptor results in the formation of the more soluble form of manganese, manganese (II). Thus, an increase in manganese (II) concentrations indicates that manganese reducing bacteria are active in degradation processes. Elevated manganese (II) levels provide an indication of conditions favorable for reductive dechlorination. Manganese data is difficult to quantitatively interpret because elevated dissolved phase manganese is observed in areas with active degradation processes and may also be present downgradient of any feature (e.g., building, 4-3 parking lot) that impedes infiltration. This manganese originates from native minerals rather than anthropogenic sources.

- Iron: The next electron acceptor to be used once manganese (IV) is depleted is iron (III). The utilization of iron (III) as an electron acceptor results in an increase in the more soluble form of iron, iron (II). Thus, as for manganese, an increase in dissolved iron (II) is an indication that iron reducing bacteria are participating in biodegradation of electron donors and is also an indication of conditions favorable for reductive dechlorination. As for manganese, quantitative interpretation of iron (II) is complex. The solubility of iron (II) can be enhanced by the presence of partially degraded organic compounds that can act as complexing agents. Conversely, iron (II) formed during biodegradation can be biased low due to re-precipitation as sulfides or carbonates, or by adhering to the mineral surface. In general, less than 10 percent of iron (II) formed from biodegradation is present in the aqueous phase.

- Sulfate: Sulfate may also be used as an electron acceptor once dissolved oxygen and nitrate have been depleted. The utilization of sulfate results in the production of sulfide or it may be incorporated into organic sulfur compounds. The formation of sulfide may go undetected because sulfide forms precipitates with many metals, including iron, and is readily oxidized during sampling and sample handling. High sulfate levels (> 20 mg/L) may be competitive and thus inhibitory with reductive dechlorination, however, some sulfate-reducing bacteria are able to carry out reductive dechlorination.

Products of Degradation. Products of degradation include ethene, ethane, chloride, methane, and total organic carbon. There also may be increases in total dissolved solids (TDS) due to chloride production and reducing conditions might result in temporary increases of certain metals (e.g., arsenic).

- Ethene, Ethane, and Chloride: The biodegradation of chlorinated hydrocarbons results in the production of ethene, ethane, and chloride. An increase in ethene and/or chloride concentrations within the plume relative to background concentrations indicates that reductive dechlorination is an active degradation process.

- Methane: The presence of methane may indicate degradation via methanogenesis whereby acetate is split to form carbon dioxide and methane or carbon dioxide is used as an electron acceptor and is reduced to methane. Methane presence in groundwater is indicative of strongly reducing conditions and of conditions favorable to reductive dechlorination. However, methane formation competes for hydrogen, which is necessary for reductive dechlorination, therefore, methane provides both an indication of conditions favorable to reductive dechlorination and suggests that a competitive reaction is also occurring. Methane may be observed at points distant from its formation due to its high volatility and low solubility. In order to provide an understanding of Site conditions methane data must be viewed collectively with other data.

4.2.2 Water Quality Objectives

In the general Waste Discharge Requirements Order No. R5-2008-0149 for in situ groundwater remediation (Central Valley Water Board, 2008), Water Quality Objectives are listed for potential waste constituents of concern at the Site. The Waste Discharge Requirements are being used as a guide for this LTM and the Water Quality Objectives are provided in Table 4-2.

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Table 4-2. Water Quality Objectives

Constituent WQO (µg/L) Reference trichloroethylene 0.8 µg/L California Public Health Goal tetrachloroethylene 0.06 µg/L California Public Health Goal vinyl chloride 0.05 µg/L California Public Health Goal cis-1,2-dichloroethene 6 µg/L Primary Maximum Contaminant Level trans-1,2-dichloroethene 10 µg/L Primary Maximum Contaminant Level

1,2-dichloroethane 0.4 µg/L California Public Health Goal

1,1-dichloroethene 6 µg/L Primary Maximum Contaminant Level

1,1-dichloroethane 3 µg/L California Public Health Goal

1,2,3-trichloropropane 0.0007 µg/L Draft California Public Health Goal

1,2-dichloropropane 0.5 µg/L California Public Health Goal

1-chloropropane 280 µg/L IRIS propene 28 µg/L Taste and Odor iron 300 µg/L Secondary Maximum Contaminant Level manganese 50 µg/L Secondary Maximum Contaminant Level hexavalent chromium 2 µg/L Draft California Public Health Goal total chromium 50 µg/L Primary Maximum Contaminant Level total dissolved solids 450 mg/L Food and Agricultural Organization sulfate 250 mg/L Secondary Maximum Contaminant Level sodium 20 mg/L USEPA Health Advisory bromate 10 µg/L Primary Maximum Contaminant Level chloride 106 mg/L Agricultural Water Quality Goal – Food and Ag

4.2.3 Sampling and Analysis Plan

As shown on Table 4-3 and Figure 4-1, there are 16 monitoring wells that will be sampled on an annual basis to monitor the TCE plume: GMW-6 will be used to monitor upgradient of the plume; GIW-2, GEW-3, GMW-1, GMW-3, GMW-4, GMW-5, GMW-7, GMW-9, GMW-10, and GMW-12 are in-plume wells;

DQMW-8 and GW,-11 are crossgradient wells; and GMW-13, GMW-14, and GMW-14 are wells located either downgradient or near the toe of the plume.

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TITLE

D-Q University, Yolo County, California

Monitoring Network

PROJECT

DATE 12-12-13

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TCE Isoconce ntration Contours – Nove mbe r 19-20, 2012

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Table 4-3. Sampling and Analysis Plan

Well ID Location Relative to TCE Plume Rationale

Monitoring Events

Constituent Suite

DQ-GMW-1 In Plume Defines plume boundary to northeast near agricultural fields Annually A, B, C

DQ-GMW-3 In Plume Immediately downgradient of former source area; Within the 50 µg/L concentration contour

Annually A, B, C

DQ-GMW-4 In Plume Defines plume boundary to northeast near agricultural fields Annually A, B, C

DQ-GMW-5 In Plume Immediately downgradient of former source area; within the 50 µg/L concentration contour; currently the maximum TCE concentration

Annually A, B, C

DQ-GMW-6 Upgradient Indication of upgradient groundwater conditions Annually A, B, C

DQ-GMW-7 Former source area Monitors former source area; within the 50 µg/L concentration contour Annually A, B, C

DQ-GMW-8 Crossgradient Defines plume boundary to west near Buildings 102 and 103 Annually A, B, C

DQ-GMW-9 In Plume Within the 5 µg/L concentration contour Annually A, B, C

DQ-GMW-10 In Plume Defines split of higher and lower concentration areas Annually A, B, C

DQ-GMW-11 Crossgradient Defines plume boundary to east near sewage ponds Annually A, B, C

DQ-GMW-12 In Plume Defines split of higher and lower concentration areas Annually A, B, C

DQ-GMW-13 In plume / crossgradient

Defines plume boundary to southeast near agricultural fields Annually A, B, C

DQ-GMW-14 In plume / Crossgradient

Defines toe of plume boundary near County Road 31 (West Covell Road) Annually A, B, C

DQ-GMW-15 Downgradient Indication of downgradient groundwater conditions Annually A, B, C

DQ-GIW-2 Former source area Monitors former source area Annually A, B, C

DQ-GEW-3 Former source area Immediately downgradient of former source area Annually A, B, C

4.3 Field Sampling

Standard Operating Procedures (SOPs) for adding entries to a field log book, sampling groundwater, decontaminating equipment, measuring depth to water, calibrating equipment, handling samples and documentation, attaching custody seals, labeling samples, shipping and packaging samples, and filling out

4-7 chain of custodies. The SOPs are included as Appendix A. An Accident Prevention Plan for these activities is included as Appendix B.

4.3.1 Fieldwork Preparation and Documentation

Prior to beginning the monitoring event, the following preparatory steps will be completed.

Contact the laboratory for sample containers/coolers and equipment suppliers for meters/equipment.

Notify the laboratory regarding samples with short hold times (e.g., 24 hours for hexavalent chromium) prior to sample shipment.

Conduct a field activity readiness review.

Document the monitoring event with field notes and groundwater field data sheets.

4.3.2 Equipment Decontamination

Prior to beginning the monitoring event and after collection of each sample, all non-disposable purging and sampling equipment (e.g., pump, water level meter) will be decontaminated using phosphate-free detergent and de-ionized water.

4.3.3 Depth To Water Measurement

Prior to purging, the depth to water will be measured in each groundwater monitoring well. An electric water level meter will be used to measure static water level to the nearest 0.01 foot. Groundwater elevation will be determined by subtracting the depth to water measurement from the surveyed elevation of the notch in the top of the well casing. The groundwater elevation will be reported in feet above mean sea level (MSL).

4.3.4 Purging and…