Final Pilot Test Results Rpt (2).pdf

FINAL

ENHANCED BIODEGRADATION AND GROUNDWATER RECIRCULATION

PILOT TEST RESULTS REPORT

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

August 29, 2011

FUDS Project No.: J09CA1180 Contract Number: W1912BV-10-D-2012

ECS Inc.

1571 Parkway Loop, Ste B

Tust in, CA 92780-6523

Brown and Caldwel l 10540 White Rock Road, Suite 180 Rancho Cordova, Cal i fornia 95670

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PILOT TEST RESULTS REPORT

D-Q UNIVERSITY, YOLO COUNTY, CALIFORNIA

SIGNATURE PAGE

Approved by:

Wendy Linck, P.G. # 6934 Brown and Caldwell/ECSBC JV Project Manager

Guy Graening, P.E. # M29796 Brown and Caldwell/ECSBC JV Project Engineer

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PILOT TEST RESULTS REPORT

D-Q UNIVERSITY, YOLO COUNTY, CALIFORNIA

DISTRIBUTION LIST

ADDRESS NUMBER OF COPIES

Mr. Tim Crummett ............................................................................... 5 electronic (PDF and Native) and 5 hard copies

U.S. ARMY CORPS OF ENGINEERS

1325 J Street Sacramento, CA 95814-2922

Ms. Conny Mitterhofer ................................................................................................. 1 electronic PDF and 1 hard copy

CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD

11020 Sun Center Drive, Suite #200 Rancho Cordova, CA 95670

Mr. Dhananjay Rawal .................................................................................................. 1 electronic PDF and 1 hard copy ECS, Inc.

1571 Parkway Loop, Suite B Tustin, CA 92780

Ms. Wendy Linck, BC Project Manager 10540 White Rock Road, Suite 180 Rancho Cordova, California 95670 Mr. Guy Graening, BC Project Engineer Mr. Greg Menna, BC Field Team Leader File ........................................................................................................ 1 electronic (PDF and Native) and 1 hard copy

BROWN AND CALDWELL

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

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Table of Contents D-Q Univ. Groundwater Pilot Test Results Report i

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TABLE OF CONTENTS

EXECUTIVE SUMMARY ......................................................................................................................................... ES-1

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

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

1.2 Pilot Test Purpose and Objectives ................................................................................................................ 1-4

1.3 Regulatory Oversight and Authority .............................................................................................................. 1-4

1.4 Report Organization ...................................................................................................................................... 1-4

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

2.1 Site History ................................................................................................................................................... 2-1

2.2 Current Site Features and Use ..................................................................................................................... 2-5

2.3 Areas of Concern .......................................................................................................................................... 2-5

2.4 Previous Investigations – AOC-1 through AOC-5 ......................................................................................... 2-9

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

3.1 Regional Setting ........................................................................................................................................... 3-1

3.2 D-Q University Stratigraphy .......................................................................................................................... 3-6

3.3 D-Q University Hydrogeology ....................................................................................................................... 3-6

3.4 Discussion .................................................................................................................................................. 3-18

4. PILOT TEST DESIGN AND CONSTRUCTION ................................................................................................... 4-1

4.1 Pilot Test Design ........................................................................................................................................... 4-1

4.2 Pilot Test Construction .................................................................................................................................. 4-1

4.2.1 Groundwater Wells and Submersible Pumps ................................................................................... 4-3

4.2.2 Conveyance Network ........................................................................................................................ 4-4

4.2.3 Treatment System............................................................................................................................. 4-5

4.2.4 Electrical Supply ............................................................................................................................... 4-7

4.2.5 Amendment ...................................................................................................................................... 4-7

4.3 Safety Controls and Contingency Plan ......................................................................................................... 4-7

5. PILOT TEST OPERATION AND MONITORING ................................................................................................. 5-1

5.1 Pilot Test Operation ...................................................................................................................................... 5-1

5.2 Pilot Test Optimization .................................................................................................................................. 5-2

5.3 Pilot Test Maintenance ................................................................................................................................. 5-3

5.4 Groundwater Monitoring & Sampling ............................................................................................................ 5-3

5.4.1 Sampling and Analysis Plan ............................................................................................................. 5-3

5.4.2 Baseline Monitoring .......................................................................................................................... 5-4

5.4.3 Performance Monitoring .................................................................................................................... 5-5

5.5 Data Review ................................................................................................................................................. 5-6

5.5.1 Analysis ............................................................................................................................................ 5-6

5.5.2 Conclusions ...................................................................................................................................... 5-7 ii

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6. TREATMENT EVALUATION AND CONCLUSIONS ........................................................................................... 6-1

6.1 Site Contaminant and Daughter Products .................................................................................................... 6-1

6.2 Bioparameter Data ........................................................................................................................................ 6-5

6.3 Products of Degradation ............................................................................................................................... 6-7

6.4 Conclusions .................................................................................................................................................. 6-8

7. REFERENCES .................................................................................................................................................... 7-1

APPENDIX A: BORING LOGS ..................................................................................................................................... A

APPENDIX B: TREATMENT SYSTEM OPERATION AND MAINTENANCE DOCUMENTATION ............................... B

APPENDIX C: GROUNDWATER MONITORING RESULTS SUMMARY TABLES ...................................................... C

APPENDIX D: GROUNDWATER MONITORING FIELD SHEETS ............................................................................... D

APPENDIX E: LABORATORY ANALYTICAL DATA (CD) ........................................................................................... E

LIST OF FIGURES

Figure 1-1. Site Location Map .............................................................................................................................. 1-2 Figure 2-1. Sacramento Valley Radio Transmitter Station Layout ........................................................................ 2-3 Figure 2-2. Oblique Aerial Photo of D-Q University and Surrounding Area .......................................................... 2-6 Figure 2-3. D-Q University Layout ........................................................................................................................ 2-7 Figure 2-4. Areas of Concern ............................................................................................................................... 2-8 Figure 3-1. Geologic Map of the Vicinity of D-Q University .................................................................................. 3-3 Figure 3-2. Geologic Section from Winters to Davis along Putah Creek Channel ................................................ 3-5 Figure 3-3. Locations of Hydrostratigraphic Cross Section A-A’ ........................................................................... 3-7 Figure 3-4. Hydrostratigraphic Cross Section A-A’ ............................................................................................... 3-8 Figure 3-5. Hydrostratigraphic Cross Section B-B’ and C-C’ ................................................................................ 3-9 Figure 3-6. Potentiometric Surface Map, February 11, 2011.............................................................................. 3-17 Figure 4-1. Pilot Test Configuration ...................................................................................................................... 4-2 Figure 4-2. Process and Instrumentation Diagram ............................................................................................... 4-6 Figure 6-1. TCE Concentrations Contours, February 11, 2011 ............................................................................ 6-4 iii

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LIST OF GRAPHS

Graph 6-1. TCE Histogram with Operational Milestones ...................................................................................... 6-2 Graph 6-2. Declining TCE Concentrations in Downgradient Wells of the Source Area ........................................ 6-3

PLATE

Plate 1. Map of Cross Sections with Well and Boring Locations

LIST OF TABLES

Table 2-1. Maximum Detected COC Concentrations ......................................................................................... 2-10 Table 3-1. Well Construction Summary .............................................................................................................. 3-11 Table 3-2. Historical Groundwater Elevations .................................................................................................... 3-12 Table 3-3. Historical Groundwater Flow Directions and Gradient ....................................................................... 3-16 Table 4-1. Pilot Test Well Construction Summary ................................................................................................ 4-4 Table 4-2. Summary of Treatment System Alarms .............................................................................................. 4-8 Table 5-1. Summary of Treatment System Operation .......................................................................................... 5-1 Table 5-2. Analytical Program .............................................................................................................................. 5-3 Table 5-3. Sampling and Analysis Plan ................................................................................................................ 5-4 Table 5-4. Trigger Values for Compliance Wells .................................................................................................. 5-5 Table 5-5. Quality Control Sample Requirements ................................................................................................ 5-6 Table 5-6. Analytical Completeness by Method ................................................................................................... 5-7 iv

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LIST OF ACRONYMS

AOC Area of Concern AST above ground storage tank bgs below ground surface BTEX benzene, toluene, ethylbenzene, and total xylenes BC Brown and Caldwell

CCR California Code of Regulators CERCLA Comprehensive Environmental Response, Compensation, and Liability Act COC chemical of concern CPT cone penetrometer test

DERP Defense Environmental Restoration Program DERP-FUDS Defense Environmental Restoration Program - Formerly Used Defense Site DO dissolved oxygen DoD Department of Defense DWR California Department of Water Resources

ECS Enviro Compliance Solutions, Inc.

ELAP Environmental Laboratory Accredi ESL Environmental Screening Level

FS Feasibility Study FUDS Formerly Used Defense Site

GAC granular activated carbon gpm gallons per minute GSA General Services Administration

HDPE high density polyethylene

LCS laboratory control sample

MCL maximum contaminant level mg/kg milligrams per kilogram mg/L milligrams per liter MS/MSD matrix spike/matrix spike duplicate MSL mean sea level mV millivolts

ND not detected NDAI No Department of Defense Action Indicated vi

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NELAP National Environmental Laboratory Accreditation Program

OEHHA Office of Environmental Health Hazard Assessment ORP oxidation reduction potential

PDF Adobe portable document format PLC programmable logic controller PRP potentially responsible party PVC polyvinyl chloride

QA quality assurance QAPP Quality Assurance Project Plan QC quality control

RA removal action RI Remedial Investigation RPD relative percent difference RSL Regional Screening Level

SARA Superfund Amendments and Reauthorization Act Site D-Q University

T&O taste & odor threshold TCE trichloroethylene TDS total dissolved solids TEA terminal electron acceptor TOC total organic carbon TPH-DRO total petroleum hydrocarbons - diesel range organics TPH-GRO total petroleum hydrocarbons - gasoline range organics TPH-MRO total petroleum hydrocarbons - motor oil range organics

UCL upper confidence limit µg/L micrograms per liter USA Underground Service Alert USACE U.S. Army Corps of Engineers USEPA U.S. Environmental Protection Agency UST underground storage tank

VOCs volatile organic compounds

WDRs Waste Discharge Requirements WQO Water Quality Objective

ES-1

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D - Q U N I V . G R O U N D W A T E R P I L O T T E S T R E S U L T S R E P O R T

E X E C U T I V E S U M M A R Y

This report presents the results of a pilot test of enhanced biodegradation and groundwater recirculation technologies for the D-Q University Formerly Used Defense Site (FUDS) located in Yolo County, California (Site). This document was prepared by Brown and Caldwell (BC) for the U.S. Army Corps of Engineers (USACE), Sacramento District under Enviro Compliance Solutions Inc., (ECS); ECSBC Joint Venture, Contract # W1912BV-10-D-2012. The U.S. Army occupied the land on which D-Q University currently lies and the surrounding farm land from 1952 to 1969, an area totaling 651 acres (Site). The site has operated as D-Q University since 1971.

The purpose of the pilot test was to evaluate if enhanced biodegradation and groundwater recirculation can remediate TCE in the apparent TCE source area. The results of the pilot test will assist in the evaluation of remediation technologies in the Feasibility Study.

The objectives of the pilot test were to:

Conduct field activities in a safe manner;

Increase the rate of anaerobic biodegradation of TCE by amending the groundwater with nutrients;

Evaluate the need for bioaugmentation;

Assess the appropriate flow rates and combination of extraction and injection that distribute the amendment thoroughly by recirculating groundwater through the treatment zone;

Reduce TCE mass in dissolved and adsorbed phases present in the apparent TCE source area;

Determine any effects of the amendment on secondary water quality parameters; and Maintain operational uptime of at least 90 percent for the treatment system.

A total of 10 groundwater wells were installed during August 2009 and October 2009 to support the pilot test: three extraction wells (DQ-GEW-1 through -3), five injection wells (DQ-GIW-1 through -5), and two monitoring wells (DQ-GMW-7 and -7A). In November 2009, a treatment system was installed to control and monitor the pilot test components, adjust extraction and injection flow rates, remove TCE, and amend the treated water with the substrate and nutrients (carbohydrate substrate). The system operated 1 month in November/December 2009 and then for 6 months from August 2010 to February 2011. After 7 combined months of operation, the treatment system had extracted, and treated a total of 3,282,461 gallons.

TCE is the contaminant in the portion of the Site where the pilot test occurred (i.e., the apparent TCE source area and treatment zone). Signs of biodegradation of TCE breakdown consist primarily of the presence of cis-1,2-DCE, trans-1,2-DCE, vinyl chloride, and ethene. At the Site, breakdown products are not typically found, with the exception of minor concentrations of cis-1,2-DCE and vinyl chloride. The introduction of the amendment was designed to stimulate the required microorganisms and create reducing conditions.

During the pilot test, signs of biodegradation were present in all 10 of the sampling events with varying detections of cis-1,2-DCE, trans-1,2-DCE, vinyl chloride, and ethane but not consistently.

Conclusions and lessons learned identified during the 2009 and 2010/2011 Pilot Test operational timeframes are noted below.

Executive Summary D-Q Univ. Groundwater Pilot Test Results Report

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Conclusions The treatment system was maintained with greater than 90% operational uptime;

TCE has decreased from 86 to 4.1 µg/L in the treatment zone (monitoring wells DQ-GMW-7 and 7A, respectively);

DO has decreased to below 0.5 mg/L and ORP has decreased to below 50 mV which are conditions typically required for reducing conditions and anaerobic bacteria to function;

Nitrate and sulfate have decreased to 1.39 mg/L and 53 mg/L, respectively, but may still be at concentrations that compete with reductive dechlorination (i.e., sulfate reducing bacteria may be active);

A system flow rate of 10 gpm and amendment dose of 200 lbs per week appear to be the optimal treatment settings to achieve the target dose of amendment in the treatment zone;

TOC increased to near or exceeding the 30 mg/L target for the carbon-based amendment. Operation of the system created a gradient for site groundwater, in the direction of Site extraction wells. These patterns suggest that the amendment was distributed thoroughly by recirculating groundwater through the treatment zone;

Concentrations of biodegradation products (ethene, ethane, chloride) have remained constant while methane concentrations have increased significantly indicating that methanogenic microorganism activity has likely increased;

Changes to secondary water quality parameters included a temporary increase of arsenic, manganese and iron. Other secondary water quality parameters (i.e., pH and TDS) remain unchanged; and

The lack of TCE daughter products prevents a definitive conclusion that biodegradation rates have increased and an assessment of whether bioaugmentation is needed. However, it appears that the combined technologies of groundwater recirculation and enhanced biodegradation have been effective at reducing TCE concentrations.

Based upon the results of the pilot test, the technologies evaluated appear to be effective at reducing TCE concentrations in groundwater and should be considered in the evaluation of alternatives presented in the Site FS.

Lessons Learned The treatment system should only be operated at a flow rate necessary to achieve proper distribution of amendment throughout the treatment zone. Operating the treatment system at higher flow rates will likely introduce oxygenated water and oxidizing conditions that are counter-productive to the goal of establishing reducing conditions in the treatment zone. Measuring TOC concentration in extraction wells and performance monitoring wells was an effective indicator of proper amendment distribution since the amendment is composed primarily of carbon. Measuring DO and ORP concentration in these wells was an effective indicator of reducing conditions in the treatment zone. For this Site, an extraction flow rate of approximately 10 gpm was optimum for distributing the amendment and establishing reducing conditions.

Mechanical challenges such as fouling were encountered with injecting the amendment mix which was viscous. Intuitively, fouling can be reduced by thinning the mixture (i.e., decreasing the ratio of powder to water) and injecting the mixture into the treatment system flow over a longer period of time (i.e., decreasing the mixture injection rate).

Electrical power may be unreliable or unsafe at former military installations resulting in delays to the implementation of remedial actions. At this Site, permanent electrical power was assumed to be available and safe since the current property owner had been occupying several buildings for many years. However, an electrical contractor determined that the existing electrical system was unreliable and unsafe.

Significant and costly upgrades would be required to provide a reliable power supply. In some cases where the remedial action is of short duration (e.g., a pilot test), a portable generator is a reliable, fast, and economical alternative.

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D - Q U N I V . G R O U N D W A T E R P I L O T T E S T R E S U L T S R E P O R T

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

This report presents the results of a pilot test of enhanced biodegradation and groundwater recirculation technologies for the D-Q University Formerly Used Defense Site (FUDS) located in Yolo County, California (Site). This document was prepared by Brown and Caldwell (BC) for the U.S. Army Corps of Engineers (USACE), Sacramento District under Enviro Compliance Solutions Inc., (ECS); ECSBC Joint Venture, Contract # W1912BV-10-D-2012. The findings of the pilot test will be incorporated into the evaluation of remediation technologies in the Feasibility Study (FS) for the Site. D-Q University is a FUDS located in Yolo County on the north side of County Road 31 (Covell Road) and approximately 9 miles west of Davis, California. The town of Davis is located approximately 14 miles west of Sacramento, California. The location of D-Q University is provided on Figure 1-1. This report summarizes two pilot test operational periods; from November 11, 2009 through December 10, 2009 and from August 27, 2010 through February 11, 2011.

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.

1: Introduction D-Q Univ. Groundwater Pilot Test Results Report

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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 (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA). The FUDS identification number for D-Q University is J09CA1180.

As part of the FUDS process, an RI was conducted by BC 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 (BC, 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 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 (USEPA). The RI identified that the primary chemicals of concern (COC) are volatile organics compounds (VOCs), primarily trichloroethylene (TCE) in groundwater and diesel range organics (TPH-DRO) in soil and groundwater. However, there were some data gaps identified and additional investigation was conducted in August and September 2009 (BC, 2009a).

The FS is the next step in the FUDS process and is being conducted at the Site. The FS identifies candidate technologies for remediating contaminants in Site groundwater and evaluates their likely effectiveness, implementability, and cost. To support the evaluation of candidate remedial technologies, treatability studies are often conducted on Site materials at the bench-scale or pilot-scale. Candidate remedial technologies at the Site include groundwater extraction/treatment and in situ enhanced biodegradation. The data gap investigation included the following field activities to support the evaluation of these technologies:

An aquifer test to determine Site aquifer properties and pumping rates; and A bench-scale treatability study of enhanced biodegradation using samples of Site soil and groundwater.

The aquifer test was conducted in August and September 2009 and the treatability study was conducted from September through December 2009 (BC, 2009a). Results of the aquifer test and the treatability study were used in the design of the pilot test.

No significant dechlorination has occurred in groundwater at the Site most likely due to aerobic conditions and the lack of a soluble, biodegradable carbon/energy source existing in the saturated zone. Groundwater sampling and analysis near the TCE source area in early 2009 indicated aerobic conditions with dissolved oxygen (DO) greater than 2 milligrams per liter (mg/L) and oxidation-reduction potential (ORP) values primarily positive (i.e., above zero millivolts [mV]). Total organic carbon (TOC) values are insignificant at less than 5 mg/L and indicate a lack of carbon/energy source and electron donors. Concentrations of TCE breakdown products (i.e., cis- and trans-1,2-dichloroethylene, vinyl chloride, and ethene) are low or not detected in groundwater.

During a meeting on March 17, 2009, the USACE expressed a desire to reduce contaminant mass in the apparent TCE source area of the shallow groundwater plume and several remediation options were discussed.

In a subsequent meeting on April 9, 2009 with the California Regional Water Quality Control Board – Central Valley Region (Central Valley Water Board), the USACE expressed a preference for a remedial technology that amends and recirculates groundwater to enhance the biodegradation of TCE via anaerobic reductive dechlorination. The Central Valley Water Board was amenable to groundwater amendment and recirculation and indicated the pilot test remediation approach would fit under the General Waste Discharge Requirements (WDRs) Order No. R5-2008-0149 for in situ groundwater remediation (Central Valley Water Board, 2008).

1: Introduction D-Q Univ. Groundwater Pilot Test Results Report

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1.2 Pilot Test Purpose and Objectives

The purpose of the pilot test was to evaluate if enhanced biodegradation and groundwater recirculation can remediate TCE in the apparent TCE source area. The results of the pilot test will assist in the evaluation of remediation technologies in the FS. Specific objectives of the pilot test were to: 1) evaluate effective rates of carbon/energy additions that are needed to enhance the anaerobic dechlorination process; and 2) assess the appropriate extraction and injection rates and pumping/injecting scheme that will allow the highest degree of contact with these amendments to the affected area.

The objectives of the pilot test were to:

Conduct field activities in a safe manner;

Increase the rate of anaerobic biodegradation of TCE by amending the groundwater with nutrients;

Evaluate the need for bioaugmentation;

Assess the appropriate flow rates and combination of extraction and injection that distribute the amendment thoroughly by recirculating groundwater through the treatment zone;

Reduce TCE mass in dissolved and adsorbed phases present in the apparent TCE source area;

Determine any effects of the amendment on secondary water quality parameters; and Maintain operational uptime of at least 90 percent for the treatment system.

1.3 Regulatory Oversight and Authority

A draft final version of the Enhanced Biodegradation and Groundwater Recirculation Pilot Test Workplan (Workplan) was delivered to the Central Valley Water Board on August 14, 2009. The Central Valley Water Board provided conditional notice to proceed on September 29, 2009 which allowed the pilot test wells to be installed. On October 28, 2009, the Central Valley Water Board provided notice to proceed which allowed the treatment system to be installed and operated. On October 30, 2009, the Central Valley Water Board provided comments on the draft final version of the Workplan. On November 25, 2009, a final version of the Workplan (BC, 2009b) was prepared that incorporated the Central Valley Water Board’s comments. Yolo County Environmental Health permitted and inspected the installation of groundwater wells.

1.4 Report 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. Section 4 presents the design and construction details of the pilot test. Information on the operation and monitoring of the treatment system is presented in Section 5. The effectiveness of the enhanced biodegradation and groundwater recirculation technologies and conclusions from operation are evaluated in Section 6. Section 7 provides references used in this report.

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D - Q U N I V . G R O U N D W A T E R P I L O T T E S T R E S U L T S R E P O R T

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

This section summarizes historical and current Site uses and previous environmental investigations relevant to the pilot test. A more detailed description of Site background information can be found in the Data Gap Remedial Investigation and Treatability Study Report (Brown and Caldwell, 2009a).

2.1 Site History

The land currently occupied by D-Q University was originally part of the Rancho Rio de los Putos land grant.

In 1842, William Wolfskill obtained the grant while living in Los Angeles. The area was divided and sold to individual landowners and used primarily for dry farming. 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).

The 651.55 acres is referred to as the Site. The former West Coast Relay and Radio Transmitting Station is 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.

The pilot test is located just east of the Transmitter Building (also known as the Operations Building) which had a primary function of operating the water-cooled radio transmitters (electric-powered). According to 1960 as-built drawings of the station, this building contained six areas. The main uses of these areas or rooms are provided below.

Radio Repair Shop – repair electronic components, including cleaning and soldering, but no plating, stripping, or etching Water Cooling Room – housed chillers and ancillary cooling equipment, such as condensers; cooling water likely treated to prevent corrosion, condenser water was untreated Operations Room – location of the radio transmitters, series of utility trenches within the building’s foundation collected any cooling water leakage. A sump, located in the northwest corner of the building, collected any water and pumped the water into a 6-inch diameter drain line that exits the building and outfalls in the ditch north of the building

Storage Room – used for general storage Maintenance Storage Room – assumed use based on size and close proximity to radio repair shop to store spare parts for radios and their maintenance Transformer Yard – an enclosed area outside the southeast corner of the building that housed electrical service transformers mounted to a concrete pad. A drain in the concrete pad is connected to a line that outfalls in the drainage ditch north of the building

2: Site Background D-Q University Groundwater Pilot Test Workplan

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In 1969, the property was designated as surplus and turned over to the General Services Administration (GSA). In January 1971, the Department of Transportation conveyed 4.85 acres by quitclaim deed to the county of Yolo for right-of-way purposes and in April of the same year, the Department of Health, Education, and Welfare conveyed by quitclaim deed 643.05 fee acres and 3.65 easement acres to D-Q University, with the stipulation that the property must be used continuously for educational purposes during the following 30 years. Permanent ownership of the land was acquired by D-Q University in 2001. At the time of quitclaim, 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.

2.2 Current Site Features and Use

There are no structures within a 1-mile radius other than those associated with the Campus or farming activities. Surrounding the Campus are agricultural lands that are currently leased to farmers that plant and harvest alfalfa (Figure 2-2). The Yolo County Airport is approximately 1.75 miles northeast from D-Q University (Figure 1-1). 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. The current use of the buildings is summarized below.

Building 100: Cultural Arts Center Building 101: Storage and Auto Repair Shop Building 102: Administration Offices and Classrooms Building 103: Dormitory and Cafeteria Building 104: Vacant Building 107: Pump House (stores a 200 foot below ground surface [bgs] well and fire system) Building 109: Storage

2.3 Areas of Concern

The AOCs that were investigated for the RI are summarized below. All AOCs are shown in Figure 2-4. Each area is described in detail in the following sections.

AOC-1: soil adjacent to the incinerator pad west of Building #103 AOC-2: soil on the east side of Building 100 (potential TCE source area) AOC-3: soil at the former site of USTs #1-4 AOC-4: TCE groundwater plume AOC-5: diesel groundwater plume at the former site of USTs #1-4

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2.4 Previous Investigations – AOC-1 through AOC-5

This section provides a summary of previous environmental investigations performed at the Site. Sample locations are shown on Plate 1 at the end of the report. Table 2-1 summarizes maximum detected concentrations for COCs identified from these investigations.

During the RI, a soil removal action (RA) was performed by USACE from three AOCs: transformer area at the southeast corner of Building 100; transformer area south of Building 102; and Drum Storage Area (USACE, 2008a). The objective of the RA was to remove and dispose of soil with contaminants above comparison criteria. These AOCs are noted on Figure 2-4.

During previous investigations and the RA, if contaminants in Site soil were not detected above the comparison criteria, the area that the sample represented was not considered for additional sampling and was identified as No Department of Defense Action Indicated (NDAI). Any area in where contamination was found to be above comparison criteria was recommended for further action.

The two primary COCs are TCE and TPH-DRO. Benzene, toluene, ethylbenzene, and total xylenes (BTEX), common petroleum hydrocarbons, are secondary COCs and will be evaluated along with TPH- DRO since they are from the same source area.

Based on the RI, two of the five AOC meet the requirements for NDAI. They are:

Soil adjacent to the incinerator pad west of Building 103 (AOC-1), and Soil on the east side of Building 100 (potential TCE source area) (AOC-2).

A summary of the RI conclusions (Brown and Caldwell, 2008) for the remaining AOCs are:

Soil at the former site of USTs #1-4 (AOC-3) - The extent of TPH-DRO in soil has been defined in the area of former fuel oil USTs #1-4.

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) within thin discontinuous lenses of fine sand. TCE in deeper groundwater appeared isolated near GW-601 and the former Cooling Water Supply Well. 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 was 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 originated from leaking lubricating oil from the pump shaft when it broke at depth during abandonment of the former Cooling Water Supply Well. In addition, the deeper TPH-DRO impacts at 84 and 94 feet bgs are unassociated with the impacted shallow groundwater resulting from the former USTs #1-4. The highest concentrations are at the deeper depths, not beneath the former USTs, and the stratigraphy indicates few discontinuous thin lenses of fine sand beneath the preferred water-bearing zone at 25 to 40 feet bgs. A profile of TPH-DRO indicates that the well may be the vertical conduit through which the TPH-DRO was able to get deeper.

In September 2009, a data gap RI was completed to accomplish the following objectives:

Complete the vertical delineation of TCE in deeper groundwater (AOC-4) in the TCE source area;

Complete the vertical delineation of TPH-DRO in deeper groundwater at the former site of USTs #1-4

(AOC-5);

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Install two groundwater wells (GMW-7/GMW-7A) to support the bench scale treatability study and for remedial alternative planning;

Conduct the aquifer test to determine hydrogeologic characteristics of the shallow water-bearing zone for remedial alternative planning; and

Complete the RI and set priorities for the FS.

In summary, the data gap RI data did not find any other TCE or TPH-DRO source areas other than what has already been defined in shallow groundwater. The area planned for the pilot test is the only TCE source area at the site.

Table 2-1. Maximum Detected COC Concentrations

COC

Maximum Detected Concentration

Comparison Criteria Soil Samples (location and depth)

Groundwater Samples (location and depth) trichloroethylene ND 1,700 µg/L (east of Bldg 100, at 15 feet bgs)

2.8 mg/kg (Residential RSL/USEPA, 2011) 5 µg/L (MCL/California, 2003)

1.7 µg/L (PHG/OEHHA, 2009) 310 µg/L (T&O/Central Valley Water Board, 2008) cis-1,2-dichloroethene ND

19 µg/L (near fm Cooling Water Supply Well, at 14 feet bgs)

160 mg/kg (Residential RSL/USEPA, 2011) 6 µg/L (MCL/California, 2003) 100 µg/L (PHG/Central Valley Water Board, 2008) benzene 0.27 mg/kg (USTs #1-4, at 14 feet bgs)

11 µg/L (USTs#1-4, at 20 feet bgs)

1.1 mg/kg (Residential RSL/USEPA, 2011) 1 µg/L (MCL/California, 2003)

0.15 µg/L (PHG/OEHHA, 2001) 170 µg/L (T&O/Central Valley Water Board, 2008), toluene 0.24 mg/kg (USTs #1-4, at 14 feet bgs)

10 µg/L (USTs#1-4, at 20 feet bgs)

5,000 mg/kg (Residential RSL/USEPA, 2011) 150 µg/L (MCL/California, 2003) 42 µg/L (T&O/Central Valley Water Board, 2008) ethylbenzene 4.2 mg/kg (USTs #1-4, at 20 feet bgs)

5.2 µg/L (USTs#1-4, at 20 feet bgs)

5.4 mg/kg (Residential RSL/USEPA, 2011) 300 µg/L (MCL/California, 2003) 300 µg/L (PHG/ Central Valley Water Board, 2008) 29 µg/L (T&O/Central Valley Water Board, 2008) total xylenes 1.2 mg/kg (USTs #1-4, at 20 feet bgs)

45 µg/L (USTs#1-4, at 20 feet bgs)

630 mg/kg (Residential RSL/USEPA, 2011) 1,750 µg/L (MCL/California, 2003) 1,800 µg/L (PHG/ Central Valley Water Board, 2008)

TPH-DRO

15,000 mg/kg (USTs #1-4, at 20 feet bgs)

12,000 mg/kg (drum storage area, at 0.5 foot bgs)*

1,200,000 µg/L (USTs #1-4, at 12 feet bgs)

83 mg/kg (ESL/SF Water Board, 2007) 100 µg/L (ESL/SF Water Board, 2007) 100 µg/L (T&O/Central Valley Water Board, 2008)

TPH-MO

160 mg/kg (oxidation lagoon #2, at 0.5 foot bgs)

790 mg/kg (drum storage area, at 0.5 foot bgs)*

410 mg/kg (ESL/ SF Water Board, 2007)

TPH-GRO 160 mg/kg (USTs #1-4, at 20 feet bgs) --

83 mg/kg (ESL/SF Water Board, 2007) 100 µg/L (ESL/ SF Water Board, 2007) 5 µg/L (T&O/Central Valley Water Board, 2008)

Bolded values are above the comparison criteria.

*A soil removal action was performed in 2006 that properly disposed of impacted soil with confirmation samples that met comparison criteria (USACE, 2008b).

-- = not analyzed ND = not detected above reporting limits RSL = Regional Screening Level CCR = California Code of Regulations MCL = Maximum Contaminant Level PHG = Public Health Goal ESL = Environmental Screening Level mg/kg = milligrams per kilogram OEHHA = Office of Environmental Health Hazard Assessment TPH-DRO = total petroleum hydrocarbons in the diesel range TPH-GRO = total petroleum…