Gate 6 Site Characterization Report.pdf

SITE CHARACTERIZATION REPORT

Conducted On:

NAVAL STATION NORFOLK

GATE 6 PROJECT SITE

NORFOLK, VIRGINIA

July 7, 2017

PC # 16-5081

MSA# 17080

Submitted To:

MR. JEFF HALL

SDC GROUP, INC.

1108 TIDEWATER DRIVE, SUITE C

NORFOLK, VIRGINIA 23504

Prepared For:

COMMANDER

NAVAL FACILITIES ENGINEERING COMMAND – MID ATLANTIC

ATTENTION: MR. ALEX MORING

1510 GILBERT STREET

BUILDING N-26, ROOM 3208

NORFOLK, VIRGINIA 23511-3095

Prepared By:

MSA, P.C.

5033 Rouse Drive

Virginia Beach, VA 23462

TEL (757) 490-9264 FAX (757) 490-0634

www.msaonline.com

TABLE OF CONTENTS

PAGE

1.0 SITE ASSESSMENT

1.1 SITE DESCRIPTION

1.1.1 Physical Property Description

1.1.2 Site Topography

1.1.3 Underground Petroleum Lines Description

1.2 RELEASE HISTORY AND INITIAL RESPONSE

1.2.1 Summary of Interim SCR Activities (AOC-1)

1.3 GEOLOGIC INFORMATION

1.3.1 Regional Geology

1.3.2 Soil Investigation

1.4 HYDROGEOLOGIC INFORMATION

1.4.1 Water Resources

1.4.2 Groundwater Investigation and Monitoring Well Installation

1.4.3 Groundwater Flow

1.5 VERTICAL AND LATERAL EXTENT OF PETROLEUM HYDROCARBONS

1.5.1 Free Product

1.5.2 Adsorbed Phase

1.5.3 Dissolved Phase

1.5.4 Vapor Phase

2.0 RISK ASSESSMENT

2.1 DEMOGRAPHICS

2.2 ON-SITE AND OFF-SITE RECEPTORS

2.2.1 Existing Human and Biological Receptors

2.2.2 Potential Human and Biological Receptors

2.2.3 Existing and Potential Potable Water Well Receptors

2.2.4 Surface Water and Non-Potable Water Well Receptors

2.2.5 Utilities, Basements, and Subsurface Structure Receptors

2.3 EXPOSURE TO HYDROCARBONS

2.4 RISK BASED ENDPOINTS

3.0 REMEDIATION ASSESSMENT

3.1 REMEDIATION APPLICABILITY / FEASIBILITY

3.2 PROJECTED REMEDIATION ENDPOINTS

3.3 ESTIMATED TIME FRAME FOR ENDPOINT ACHIEVEMENT

3.4 RECOMMENDATIONS AND REMEDIATION ASSESSMENT SUMMARY

REFERENCES CITED

TABLES

TABLE 1 – PID Meter Readings (ppm)

TABLE 2 – Soil Analytical Results – Monitoring Well (mg/kg)

TABLE 3 – Groundwater Analytical Results – Monitoring Well (mg/L)

TABLE 4 – Free Product Thickness (ft.)

FIGURES

FIGURE 1 - Portion of the U.S.G.S. Norfolk North, Virginia topographic map illustrating the location and topography of the site.

FIGURE 2 – Aerial photograph illustrating AOC-1, AOC-2, and relevant site features.

FIGURE 3 – Approximate locations of subsurface fuel lines beneath Gate 6 site.

FIGURE 4 – Active and alternate JP-5 underground lines within the Gate 6 site.

FIGURE 5 – Subsurface OWWO lines at Gate 6 site.

FIGURE 6 – Soil boring, monitoring well, and sample locations at AOC-1.

FIGURE 7 – Soil boring and sample locations at AOC-2.

FIGURE 8 – Groundwater Flow Direction Map. Data Collected on 6-12-17.

FIGURE 9 – Isoconcentration Map for adsorbed phase TPH-DRO at AOC-1 (mg/kg).

FIGURE 10 – Isoconcentration Map for dissolved phase TPH-DRO at AOC-1 (mg/L).

APPENDICES

APPENDIX A – Photo-Documentation

APPENDIX B – Soil Boring and Well Construction Logs

APPENDIX C – Laboratory Analytical Results and Standard Operating Procedures (SOPs)

APPENDIX D – Slug Test Results

APPENDIX E – Gauge Sheets

APPENDIX F – Qualifications and Limitations

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 1

1.0 SITE ASSESSMENT

MSA, P.C. (MSA) was retained by SDC Group, Inc. (SDC) to conduct a site investigation in conjunction with preparing a Site Characterization Report (SCR) at the Gate 6 property located near the intersection of D Avenue and 2nd Street on Naval Station Norfolk (NAVSTA Norfolk) in Norfolk, Virginia and is referred to hereinafter as “Gate 6 Project Site”. The investigation was prompted by the

Virginia Department of Environmental Quality (VDEQ) after a site contractor identified subsurface petroleum contamination during trenching and excavation activities. Subsequently, the VDEQ assigned pollution complaint case number (PC#) 2016-5081 to the release and requested additional investigation to determine the severity and extent of the release. Since the release was initially reported in November

2015, NAVFAC Mid-Atlantic has prepared and submitted quarterly Interim Draft SCR reports (dated

March 31, 2016, June 9, 2016, September 16, 2016, January 25, 2017, and March 24, 2017) to the

VDEQ. MSA has conducted this SCR investigation in accordance with 9 VAC 25-580-250 (UST

Technical Regulations) and the VDEQ Storage Tank Program Technical Manual.

It should be noted that a change to the original scope of work was approved by the NAVFAC

MIDLANT Contracting Officer Representative (COR) prior to starting work. The scope of work modification included an increase in the number of soil borings advanced at the site and also an increase in the number of soil and groundwater samples collected for laboratory analysis.

1.1 Site Description

1.1.1 Physical Property Description

The Gate 6 Project Site is located in the southwestern portion of NAVSTA Norfolk, adjacent to Pier 1, in Norfolk, Virginia (Figure 1). An active construction project that involves significant excavation and earthwork activities, discussed in more detail below, is currently in progress at the project site and includes a much larger area known as the Gate 6 Project subject property. NAVSTA Norfolk is the largest Naval Base in the world and is located immediately east of the Elizabeth River and south of

Willoughby Bay. The military installation encompasses over 4,600 acres and facilitates approximately

170 tenants and activities to support the operational readiness of the US Atlantic Fleet. The primary mission of NAVSTA Norfolk is to support the assigned fleet units and shore activities incidental to these

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 2 operations, to support aviation activities for aircraft both stationed at and transiting, and to provide bulk fuel storage.

Specifically, two (2) areas of concern (AOC) were identified within the Gate 6 Project Site, near the intersection of D Avenue and 2nd Street, and were included as part of this SCR investigation (Figure 2).

Specifically, AOC-1 is located to the east of the fence line for building CEP-204 and to the west of 2nd

Street. A stormwater BMP (filter basin) is located within AOC-1 and is identified on Figure 2. AOC-2 is located immediately north of the south wall barge fueling area on D Avenue.

According to information obtained from the most recent Interim Draft Site Characterization Report, dated March 24, 2017 and prepared by NAVFAC Mid-Atlantic, the Gate 6 Project property is a small portion of the Virginia Department of Transportation (VDOT) I-564 Intermodal Connector Project – a major project to be executed by the Federal Highway Administration (FHWA), Eastern Federal Lands

Highway Division (EFLHD) which also includes: the new Route 564 (I-564) Intermodal Connector, a reconfigured NAVSTA Norfolk commercial vehicle inspection station, the relocation of a portion of

NAVSTA Norfolk’s Patrol Road and Ingersol Road, and the addition of a new access road to the

Virginia Port Authority’s North Gate Terminal. The Intermodal Connector will extend from the existing section of I-564 near Terminal Blvd. (on the east) to the NAVSTA Norfolk Gate 6 and Norfolk

International Terminal (NIT) (on the west) to create roughly 2.82 miles of four-lane highway. Upon completion, the I-564 Intermodal Connector Project will facilitate Patriot Crossing, which will connect

I-564 to the Monitor-Merrimac Memorial Bridge-Tunnel. Under the Gate 6 Project; the NAVSTA

Norfolk Gate 6 Entry Control Point (ECP) shall be relocated and will be provided with adjacent roadways (including utilities and security infrastructure), and structural and utility interface with the

VDOT extension of I-564. Construction activities for the Gate 6 Project began in the fall of 2015 and are currently ongoing. It was initially estimated that construction will be completed by the fall of 2017;

however it is likely that the scheduled completion date will not be met.

1.1.2 Site Topography

Based on the 7.5 minute Norfolk North, Virginia USGS Quadrangle Topographic Map, the site lies approximately 10-15 feet above mean sea level (Figure 1). Based on known regional hydrology, groundwater in the general area most likely occurs at a depth of approximately 4-6 feet below the

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 3 ground surface and is inferred to flow in a general westerly direction. Actual local groundwater flow is controlled by stratigraphy, topography, water table fluctuations, and stormwater drainage ditches which are influenced by rainfall, evapo-transpiration, and pumping that occurs throughout the year.

1.1.3 Underground Petroleum Lines Description

As part of the interim site characterization efforts, NAVFAC Mid-Atlantic personnel have identified the status and location of underground lines within the limits of the Gate 6 Project property and which are associated with the transport of petroleum substances. Specifically, abandoned and in-use fuel lines, an

Oily Waste/Waste Oil (OWWO) force main and lines; along with various associated valve pits, are located beneath the Gate 6 ECP construction footprint and the general project area is located on a portion of NAVSTA Norfolk that has a history of underground fuel transfer operations dating back to at least the 1940’s. The locations of identified fuel lines are included as Figures 3, 4, and 5 of this report and were prepared by NAVFAC and previously included in Interim Draft SCR reports. The following excerpt, which provides a description of relevant underground lines, was obtained from the most recent

Interim Draft SCR report (dated March 24, 2017):

The first tank farm for bulk petroleum storage at Naval Station Norfolk, consisting of tanks CEP-1, CEP-2, CEP-3, and the CEP-4 pump house, was constructed between 1940 and 1945 and is still operational. Underground piping transferred diesel fuel marine (DFM, or F-76) from the CEP tank farm to a location between Piers 1 and 2 for pier-side fueling. Fuel distribution drawings show three 12” lines coming from the CEP-4 pump house traveling west to 2nd Street, where they take a 90 degree turn to the north, followed by a 90 degree turn to the west; tying into the pier-side fuel distribution system. A segment of the abandoned lines was uncovered for removal during a driveway replacement project at

Building CEP-113 in March 2016. At this time, it was discovered that two abandoned 4” fuel lines were also present within the same excavation, and it was noted that the three largest fuel lines were 10”, 12”, and 12” in diameter. All five lines were disconnected, cleaned, and filled with concrete. Approximately

1,100’ of the piping was cut out and removed during the CEP-113 project. An additional 75’ of the abandoned lines were cut and removed this quarter during Gate 6 ECP project planned utility demolition. It is unclear when pier-side fueling operations using these lines ceased. Installation records for these five fuel lines are not available, however, it is estimated that they were installed in the 1950’s.

The CEP tank farm is currently used to store reclaimed fuel oil (FOR). Two underground fuel oil

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 4 pipelines travel east beneath D Avenue from their connection point at the south wall barge fueling facility. From D Avenue, the lines turn 90 degrees north between CEP-1 and CEP-2 before connecting to the CEP-4 pump house.

A few feet west of 2nd Street, an 8” JP-5 transfer line travels north beneath the Gate 6 ECP location from its connection point at the south wall barge fueling area. This line currently serves as an alternate for the active JP-5 line that also connects at the south wall barge fueling area. The active line travels west beneath D Avenue, where it ties into Valve Pit 5 and continues north beneath pier-side parking just east of 3rd Street. While the alternate line is not currently in use, it is maintained and regularly tested.

The line is blank flanged at Valve Pit 7 for future use.

Underground transfer lines for the OWWO collection system are also present beneath the Gate 6 ECP project location. A 10” OWWO line and an 8” JP-5 line connecting Craney Island to Naval Station

Norfolk were installed in 1980. Both lines connected to Naval Station Norfolk at Valve Pit 5 and continued east beneath D Avenue, where they tied into existing piping at the CEP-4 pump house. A

16”OWWO force main runs south beneath 2nd Street and then east beneath D Avenue where it connects to the OWWO holding tank, CEP-11. The force main and tank CEP-11 were also installed in 1980.

Portions of the OWWO force main are being replaced under the Gate 6 ECP contract. Because the

OWWO line is active, the new force main will be installed and connected prior to any abandonment in place or removal of force main scheduled for replacement.

1.2 Release History and Initial Response

The following excerpt was obtained from the most recent Interim Draft SCR report (dated March 24, 2017):

On October 26, 2015, petroleum contamination was encountered by a contractor within a test boring located in the area of planned excavation (AOC-1) for the Gate 6 Project (Figure 2). Petroleum contaminated soil and the presence of petroleum sheen on the groundwater were observed within the boring. Upon observing the subsurface contamination, the contractor dug out a few feet in each direction of the boring in an attempt to identify a release source. Approximately three feet west of the test boring, an abandoned 12 inch diameter fuel line was discovered. The section of fuel line exposed by

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 5 the contractor appeared to be in excellent condition with the outer paint layer still fully intact.

Subsequently, the area was backfilled in anticipation of a heavy precipitation event. NAVFAC

Environmental personnel reviewed available facility records and drawings to determine if the petroleum contamination was associated with a documented historic release or open Installation Restoration site.

Once it was determined that this contamination was likely attributed to an unknown subsurface release, the incident was reported to the VDEQ on November 2, 2015. Subsequently, a release letter was issued by VDEQ requesting site characterization and identifying this release as PC# 2016-5081.

In order to streamline the site characterization investigation and minimize impact to the Gate 6 Project;

NAVFAC Environmental personnel requested (and received) an extended due date for submission of the

Final SCR to VDEQ-TRO provided that:

The Navy immediately reports to VDEQ any petroleum contamination encountered during the

Gate 6 Project as required by State Water Control Law. Petroleum contaminated areas will be documented and a minimum of one soil sample shall be collected and analyzed. If groundwater is encountered within contaminated areas, a groundwater sample shall be collected also.

Any petroleum-saturated soil encountered will be excavated and appropriately stored and managed for disposal in accordance with state and federal regulations.

Free product encountered during excavation shall be recovered to the maximum extent practicable.

Petroleum-contaminated groundwater extracted during construction activities will be properly managed and disposed of in accordance with state and federal regulations.

The Navy will provide interim SCRs to VDEQ on a quarterly basis which summarize contamination encountered and actions taken.

In addition to the initial release discussed above, a site contractor tasked with replacing a JP-5 line “T” joint (located along D Avenue; north of the south wall barge fueling area) identified a sheen on groundwater seepage that had entered the excavation on March 15, 2017; petroleum impacted soil was not encountered. This area of concern is identified as area of concern 2 (AOC-2). NAVFAC

Environmental reported the release to the VDEQ on March 17, 2017; the VDEQ case manager stated that this incident could be investigated in conjunction with the SCR investigation for AOC-1 as they are

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 6 both located within the Gate 6 Project area. According to information obtained from NAVFAC, the groundwater seepage was containerized in frac tanks; no soil was excavated as impacted soil was not identified. Prior to backfilling the excavation, one soil sample was collected on March 29, 2017 for

Total Petroleum Hydrocarbons – Diesel Range Organics (TPH-DRO), Total Petroleum Hydrocarbons –

Gasoline Range Organics (TPH-GRO), and Benzene, Toluene, Ethylbenzene and Xylenes (BTEX) analysis. The analytical report revealed a TPH-DRO concentration of 22.9 mg/kg; no other analyzed constituent was detected above laboratory detection limits. On June 8, 2017, a 2-hour pressure test was performed on the JP-5 line from the south wall to Valve Pit 7; the line passed. In addition, an integrity test was performed on segmented portions of the line. Segment 1 included the portion of the line that extends from the south wall to Valve Pit 5; Segment 2 included the portion of the line extending from

Valve Pit 5 to Valve Pit 7. Both segments revealed passing test results. Line testing was contracted out by the NAVFAC Atlantic office. Once the contractor submits their final reports to the NAVFAC contracting officer, copies will be sent to the NAVFAC Mid-Atlantic environmental office and the

POL/Tank Program Manager will subsequently forward the results to VDEQ. Contractor deliverables are expected to be received by July 15, 2017.

1.2.1 Summary of Interim SCR Activities (AOC-1)

MSA was provided with five (5) Interim Draft SCR reports (dated March 31, 2016, June 9, 2016, September 16, 2016, January 25, 2017, and March 24, 2017) that were prepared by NAVFAC and previously submitted to the VDEQ as part of the SCR phase of investigation. It should be noted that each Interim Draft SCR report contains applicable supporting documentation for the monitoring quarter

(i.e. site maps, analytical reports, disposal manifests, etc.) Relevant information pertaining to site activities associated with the identification of petroleum contamination, abatement actions taken, and the management of petroleum contaminated media contained in each report is summarized below.

According to the first Interim Draft SCR (dated March 31, 2016), the contractor returned to the site on

December 3, 2015 to excavate just enough soil in the immediate vicinity of the test boring (where petroleum impact was identified) to facilitate the collection of one soil and one groundwater sample. A soil sample was collected at a depth of three feet and was analyzed for Total Petroleum Hydrocarbons –

Diesel Range Organics (TPH-DRO) using EPA SW-846 Method 8015C and for Total Metals using EPA

SW-846 Method 6010C. The TPH-DRO concentration detected in the soil sample was determined to be

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 7

405 mg/kg. Minor total metals concentrations were also detected in the sample. The collected groundwater sample was analyzed for TPH-DRO using EPA SW-846 Method 8015C, total metals using

EPA SW-846 Method 6010C, and a suite of waste characterization analyses to determine whether or not groundwater extracted from the site would be eligible for disposal to the OWWO collection system owned and operated by NAVFAC Mid-Atlantic. The TPH-DRO concentration in the groundwater sample was determined to be 8.4 mg/L. Minor total metal concentrations and volatiles were also detected in the sample. While it was anticipated that additional areas revealing subsurface petroleum impact would be encountered, the initial discovery of petroleum contamination resulted in construction project delays and no additional areas of impact were identified during this monitoring quarter

(December 2015 – February 2016).

Based on information obtained from the second Interim Draft SCR (dated June 9, 2016) for the March -

May 2016 monitoring period, a small pocket of petroleum saturated soil was encountered during excavation activities performed on May 4, 2016. The approximately 2’ X 2’ area of impact was located approximately 4-5’ below the surface and was identified beneath an abandoned storm drain that was located within the same utility corridor where petroleum impact was originally identified. Evidence of petroleum impacted groundwater (i.e. free product or sheen) was not observed. Subsequently, approximately 100 cubic yards of petroleum impacted soil was excavated and stockpiled on site pending disposal. The soil was stockpiled on plastic sheeting and covered with plastic to prevent the migration of contaminants and to provide erosion and sediment control. It is important to note that petroleum saturated soil was estimated to account for less than a ton of the petroleum impacted soil removed. In addition, approximately 5,700 gallons of groundwater that was generated from the utility corridor area was removed and containerized in frac tanks pending disposal. It was concluded that this area was likely the northern limit of residual petroleum impact within AOC-1. Additional trenching and excavation activities throughout the utility corridor area (associated with the Gate 6 construction project) revealed that the southern limit of the residual plume is at or near the original test boring location where petroleum impact was initially identified.

The next Interim Draft SCR (dated September 16, 2016) summarized site activities conducted during the

June – August 2016 monitoring period. Petroleum contaminated media was not encountered during this monitoring period. Prior to disposing of the contaminated soil and groundwater that were recovered

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 8 during the previous monitoring period, one soil sample and one groundwater sample were collected from each waste stream to characterize the material. Specifically, a grab sample was collected from the containerized groundwater May 4, 2016 and was analyzed for the following: TPH-DRO, Total

Petroleum Hydrocarbons – Gasoline Range Organics (TPH-GRO), Volatile Organic Compounds

(VOCs), Semi-Volatile Organic Compounds (SVOCs), Metals, and Mercury. The TPH-DRO concentration in the groundwater sample was determined to be 9,500 ug/L and the TPH-GRO concentration in the groundwater sample was determined to be 76 ug/L. Minor concentrations of

Metals, SVOCs, and VOCs were also detected in the sample. A grab sample was collected from the stockpiled soil on June 15, 2016 and was analyzed for Benzene, Toluene, Ethylbenzene and Xylenes

(BTEX). Analysis determined there were no detectable quantities of the BTEX constituents detected in the sample. A composite sample was also collected from the stockpiled soil and was analyzed for the following: TPH-DRO, TPH-GRO, VOCs, Metals, and Mercury. Soil sample analysis revealed a TPH-

DRO concentration of 1,900 mg/kg and a TPH-GRO concentration of 51 mg/kg. Minor concentrations of Metals and VOCs were also detected in the sample. The impacted soil and groundwater that were recovered during the previous quarter were transported to permitted disposal facilities following sampling efforts. Approximately 8,000 gallons of petroleum contaminated groundwater and 248.24 tons of petroleum contaminated soil were disposed at C&M Industries, Inc. and Clearfield MMG, respectively during this monitoring period. The report concluded that subsurface petroleum contamination does not appear to present a significant risk to human health or the environment based on site observations and the reduction of the source area.

According to the fourth Interim Draft SCR (dated January 25, 2017), no new areas of subsurface petroleum contamination was identified during this monitoring period (September – November 2016).

However, residual impact within the previously identified utility corridor area (AOC-1) was encountered again on October 24, 2016. Specifically, impacted soil was observed at a depth of 6-7 feet below the surface as contractors passed back through the known plume area. Neither free product nor petroleum saturated soil was identified; petroleum odors were detected. As such, approximately 48 cubic yards of potentially impacted soil was excavated and stockpiled on site pending disposal sampling. A composite soil sample was collected from the stockpile on January 3, 2017. Based on the analytical results, no detectable concentrations of any analyzed parameter (TPH-GRO, TPH-DRO, BTEX, Metals, Mercury, Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 9

Extractable Organic Halogens (EOX), and Polychlorinated Biphenyls (PCBs)) were identified and the stockpiled soil will likely be returned to their excavation for site restoration.

On November 11, 2016, subcontractors were onsite to remove portions of five abandoned fuel lines from beneath 2nd Street. These abandoned lines were running from east to west beneath the roadway, and were positioned a few feet below the OWWO force main running north to south beneath 2nd Street.

A piece of concrete support affixed to a 5’ length of abandoned pipe came into contact with, and subsequently cracked, the plastic OWWO force main during removal. The broken OWWO main released approximately 700 gallons of oily waste to the soil. Groundwater was not present in the excavation. The OWWO force main was shut down to stop the release and allow for repairs. NAVFAC

Oil Recovery Services was contacted and a vacuum truck was immediately dispatched for cleanup. The release was contained within the excavation and 700 gallons of oily waste was recovered by vacuum extraction. Once the oily waste was extracted from the excavation, potentially impacted soils were removed (estimated to be less than 1 cubic yard) and added to the existing stockpile of petroleum-contaminated soils being managed onsite. A 5-Day Letter was submitted to the VDEQ-TRO Pollution

Response Program (PReP) via e-mail on November 15, 2016. No further action has been requested by the VDEQ regarding this release. Groundwater generated during dewatering activities was treated with

Granular Activated Carbon (GAC) and discharged under a General VPDES Permit for Petroleum

Contaminated Sites, Groundwater Remediation, and Hydrostatic Tests (VPDES Permit # VAG830509).

Compliance monitoring did not reveal any effluent exceedances and no free product, petroleum sheen, or petroleum odors were observed in groundwater encountered during project activities. Additional groundwater characterization efforts within AOC-1 and along D Avenue (to the east of the D Avenue and 2nd Street intersection) were also performed during this monitoring quarter. The only sample that revealed a detectable, albeit relatively minor, TPH-DRO concentration (1.5 mg/L) was the sample collected from within AOC-1.

The final Interim Draft SCR report (dated March 24, 2017) stated that no new areas of petroleum contamination were identified during the monitoring period (December 2016 – February 2017) and neither petroleum contaminated soil nor free product was observed. VPDES compliance sampling did not reveal any effluent exceedance for treated and discharged groundwater and petroleum contaminated groundwater was not encountered.

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 10

Report conclusions state that excavation activities performed thus far for the Gate 6 project appear to have defined the extent of the petroleum contaminant plume and the residual contamination does not appear to present a significant risk to human health or the environment. It does not appear that a significant quantity of petroleum saturated soil is located at the site and free product has not been detected. Excavation down to the groundwater table has occurred in close proximity to the test boring where contamination was initially observed and, horizontally, in all directions surrounding the test boring. It appears that petroleum contamination encountered within AOC-1 of the Gate 6 project is confined to a very small area within the utility corridor running north-south on the west side of 2nd

Street. Based on the subsurface conditions encountered thus far and the extensive excavation that has occurred for the Gate 6 project, it is assumed that the residual petroleum contamination is due to a historic release, likely from a fuel line or fuel line valve pit, and that of which has migrated through the porous fill of the utility corridor that maintains several in-use and out-of-use utility lines.

1.3 Geologic Information

1.3.1 Regional Geology

The project site is located in the Atlantic Coastal Plain Physiographic Province, which is characterized by low elevations and gently sloping relief. In general, the geology underlying the outer Atlantic

Coastal Plain Physiographic Province consists of a clastic wedge of sedimentary deposits, which thickens to the east and thins to the west toward the Piedmont. These deposits range in age from Late

Cretaceous to Quaternary. A thin wedge of early Cretaceous (Potomac Group), Tertiary (Pamunkey and

Chesapeake Groups) and Quaternary (Columbia Group) sediments cover early Mesozoic sedimentary and Paleozoic crystalline rocks of the Piedmont (Johnson et al., 1987). The Cretaceous and Quaternary sediments are generally composed of sands and gravels deposited in fluvial-estuarine environments, whereas the Tertiary units are predominantly finer sands, silts and clays of marine origin.

Unconformably underlying the sediments is a crystalline basement composed of igneous and metamorphic rock ranging in age from Precambrian to Paleozoic. The basement surface forms the basal limit of the Coastal Plain hydrogeologic system. At the Gate 6 Project Site, the depth to the crystalline basement rock is greater than 1,500 feet (Meng and Harsh, 1988 and Hamilton and Larson, 1988).

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 11

According to the Geologic Map and Generalized Cross Sections of the Coastal Plain and Adjacent Parts of the Piedmont, Virginia (1989, Mixon et. al) the site’s surface geology is identified as “Qtl”, which is identified as the Lynnhaven Member of the Tabb Formation of Upper Pleistocene age. Generally speaking, the Tabb Formation is made up of three members and is comprised of sand, silt, clay, and peat of coast-parallel plains seaward of Suffolk and Harpersville scarps. The sediments of the Lynnhaven

Member are 0-20 feet thick and described as “pebbly to cobbly, fine to coarse gray sand grading upward into clayey and silty fine sand and sandy silt; locally, at base of unit, medium to coarse cross-bedded sand and clayey silt containing abundant plant material fill channels cut into underlying stratigraphic units. Unit is surficial deposit of broad swale extending southward from Norfolk and of extensive lowlands bounded on landward side by river-bay-, and ocean-facing scarps having low altitudes of 15-

18 feet.” Thickness is as much as 80 feet.

1.3.2 Soil Investigation

On May 1 – 5, 2017, MSA was onsite to advance fifteen (15) soil borings (SB-1 through SB-15) within two areas of concern (AOC-1 and AOC-2) at the Gate-6 Project Site in an effort to delineate the plume and to identify the most suitable monitoring well locations for this investigation (Figures 6 and 7). The soil borings were advanced using an EarthProbe direct-push rig with stainless steel sampling equipment to varying depths. A Photo-Ionization Detector (PID) meter, visual observations, and olfactory methods were used during the field investigation to identify subsurface soil that was potentially impacted with petroleum. Encountered groundwater was also inspected for visual and olfactory evidence of potential contamination. Upon completion, the soil cuttings were returned to each respective boring location.

Photographs of site characterization activities are included as Appendix A.

Specifically, ten (10) soil borings (SB-1 through SB-10) were advanced within AOC-1 and five (5) soil borings (SB-11 thru SB-15) were advanced within AOC-2. The soil borings were advanced to a depth of approximately 9 feet, 12 feet, or 15 feet, depending on site observations at each soil boring location.

Encountered soils at the site were primarily comprised of silty sand, silt, and sand. Moist soil conditions were typically observed between 2 and 4 feet below grade and free water was present in the borings upon completion indicating that the water table had been encountered. Petroleum odors and staining were observed in five (5) soil boring locations (all located within AOC-1) from either immediately below the surface at SB-1 and SB-10 or from approximately 2-3 feet below the surface at the remaining

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 12 locations (SB-2, SB-4, and SB-7) to approximately 10-12 ft. below the ground surface (bgs). Petroleum impact was not identified at any soil boring location within AOC-2. Soil boring logs are included as

Appendix B. PID meter readings are summarized below in Table 1.

TABLE 1: Maximum PID Meter Readings (ppm)

Soil Boring

ID

Depth

0-3 ft.

Depth

3-6 ft.

Depth

6-9 ft.

Depth

9-12 ft.

Depth

12-15 ft.

SB-1 290.6 128.5 30.2 ----- -----

SB-2 149.2 1,800 625 ----- 0.0

SB-3 0.0 0.0 0.0 0.0 -----

SB-4 0.0 >12,000 ----- 0.0 0.0

SB-5 0.0 0.0 0.0 0.0 -----

SB-6 0.0 0.0 0.0 ----- -----

SB-7 0.0 44.0 64.6 5.8 -----

SB-8 0.0 0.0 0.0 0.0 -----

SB-9 0.0 0.0 0.0 0.0 -----

SB-10 143.2 775.4 89.3 ----- -----

SB-11 0.0 0.0 0.0 0.0 -----

SB-12 0.0 0.0 0.0 0.0 -----

SB-13 0.0 0.0 0.0 0.0 0.0

SB-14 0.0 0.0 0.0 0.0 -----

SB-15 0.0 0.0 0.0 0.0 -----

Notes: Maximum PID reading is identified.

One (1) soil sample (SS-1 through SS-15) was collected from each soil boring (SB-1 through SB-15) for laboratory analysis from either immediately above the water table or from the depth exhibiting the greatest concentration of petroleum impact as determined by the field investigation, with one exception.

Two (2) soil samples (SS-2A and SS-2B) were collected from SB-2. The soil samples were collected in laboratory provided sample containers, placed on ice, and shipped under chain of custody to the

VELAP-certified laboratory ESC Lab Sciences Services, Inc. located in Mount Juliet, Tennessee. The samples were analyzed for Total Petroleum Hydrocarbons-Gasoline Range Organics (TPH-GRO), Total

Petroleum Hydrocarbons-Diesel Range Organics (TPH-DRO), Benzene, Toluene, Ethylbenzene and

Xylene (BTEX), and Methyl-tert-butyl-ether (MTBE) using EPA Methods 8015B and 8021, respectively. A summary of the soil analytical data is included in Table 2. The laboratory analytical report, chain-of-custody, and sampling protocol are included as Appendix C.

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 13

TABLE 2: Soil Analytical Results (mg/kg)

Soil Sample

ID

Sample

Date

Sample

Depth

TPH-

GRO

TPH-

DRO

Benzene

Ethyl-

Benzene Toluene

Total

Xylenes

MTBE

SS-1 5-1-17 3 ft. 6.91 85.7 0.000899 0.00300 ND 0.0382 ND

SS-2A 5-1-17 3.5 ft. 67.9 1,710 0.0121 0.0334 ND 0.151 ND

SS-2B 5-1-17 11 ft. 3.85 768 ND 0.00410 ND 0.0300 ND

SS-3 5-1-17 7 ft. ND ND 0.000712 0.00432 ND ND ND

SS-4 5-1-17 4 ft. 216 31,100 0.0890 ND ND 2.47 ND

SS-5 5-2-17 4 ft. ND ND 0.000617 0.00278 ND ND ND

SS-6 5-2-17 4.5 ft. ND ND 0.000617 0.00411 ND ND ND

SS-7 5-3-17 5.5 ft. 2.96 234 0.000497 0.00351 ND 0.0206 ND

SS-8 5-3-17 5.5 ft. ND ND 0.000451 0.00369 ND ND ND

SS-9 5-3-17 3.75 ft. ND ND 0.000710 0.00452 ND ND ND

SS-10 5-3-17 4 ft. 85.8 1,050 0.00596 0.0367 0.152 0.601 ND

SS-11 5-2-17 5 ft. ND 6.44 0.000923 0.00387 ND ND ND

SS-12 5-2-17 5 ft. ND ND ND 0.00144 ND ND ND

SS-13 5-2-17 5 ft. ND ND 0.000661 0.00301 ND ND ND

SS-14 5-3-17 6 ft. ND ND 0.000513 0.00237 ND ND ND

SS-15 5-3-17 5.5 ft. ND ND 0.000531 0.00236 ND ND ND

Notes: ND = Not Detected Above Laboratory Detection Limit

It is important to note that at the time of this SCR investigation, the investigated areas (AOC-1 and

AOC-2) were located within an active construction site (Gate 6 Project). Abandoned, active, and inactive lines and utilities are also located throughout the Gate 6 Project Site; primarily throughout

AOC-1. Because access was limited by these factors, accessible soil boring locations had to be selected in areas that would not interfere with ongoing construction activities and in areas that would not impact subsurface lines and utilities. While these site conditions limited access, their presence did not affect the results or conclusions identified in this report.

1.4 Hydrogeologic Information

1.4.1 Water Resources

No surface water bodies were observed at the project site. The nearest surface water body is the

Elizabeth River which is located approximately 1,000 feet to the west of AOC-1; a manmade waterway that allows for pier access from the Elizabeth River is located approximately 350 feet south of AOC-1.

Based on the results of this SCR investigation, groundwater currently occurs at a depth of approximately

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 14

4-6 feet below the ground surface and is inferred to flow in a general westerly direction. Groundwater at the site is tidally influenced. Actual local groundwater flow is controlled by stratigraphy, topography, water table fluctuations, and stormwater drainage ditches which are influenced by rainfall, evapo-transpiration, and pumping that occurs throughout the year.

The project site is located within the Coastal Plain Aquifers which are composed of unconsolidated sediments, Cretaceous to recent age, overlying a bedrock basement. These sediments dip gently eastward and are subdivided into four major aquifers, from the land surface downward. The aquifers are separated by confining beds that restrict, but do not prevent, vertical flow between the aquifers. The water table aquifer is typically the first aquifer encountered below the land surface. Specifically, the water table aquifer at the project site is known as the Columbia aquifer and consists of sand, silt, and some gravel at depths generally less than 50 ft. The water table aquifer is adequate enough to supply pumping rates of 10 to 50 gallons per minute for domestic needs. The groundwater quality of the water table aquifer is highly variable with iron and hydrogen sulfide often causing a problem and may be easily polluted (Smith and Ellison, 1985).

Active potable water supply wells were not found at the Gate 6 Project Site (or on adjacent properties in the immediate area) as the property is located within NAVSTA Norfolk which is supplied with potable water by public utilities.

1.4.2 Groundwater Investigation and Monitoring Well Installation

Groundwater samples (WS-1 through WS-15) were collected from each soil boring using a peristaltic pump and clean flexible tubing on May 1-3, 2017, with one exception (Figures 6 and 7). A water sample was not collected from soil boring SB-2 as evidence of free product was observed during the field investigation. The samples were collected in laboratory-provided glass sample jars with the appropriate preservative, placed on ice, and shipped under chain of custody to ESC Lab Sciences located in Mount Juliet, Tennessee. The groundwater samples were analyzed for TPH-GRO, TPH-DRO, BTEX, and MTBE using EPA Methods 8015B and 8021, respectively. The laboratory analytical report, chain-of-custody, and sampling protocol are included as Appendix C. A summary of the groundwater analytical data is included in Table 3.

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 15

TABLE 3: Groundwater Analytical Results (mg/L)

Water

Sample ID

Sample

Date

Sample

Depth

TPH-

GRO

TPH-

DRO

Benzene

Ethyl-

Benzene Toluene

Total

Xylenes

MTBE

WS-1 5-1-17 6 ft. ND 3.71 ND ND ND ND ND

WS-3 5-1-17 8 ft. ND 0.446 ND ND ND ND ND

WS-4 5-1-17 8 ft. ND 0.604 ND ND ND ND ND

WS-5 5-2-17 8 ft. ND 0.190 ND ND ND ND ND

WS-6 5-2-17 7 ft. ND 0.163 ND ND ND ND ND

WS-7 5-3-17 8 ft. 0.303 5.41 0.00130 ND ND ND ND

WS-8 5-3-17 8 ft. ND 0.330 ND ND ND ND ND

WS-9 5-3-17 8 ft. ND 1.02 ND ND ND ND ND

WS-10 5-3-17 8 ft. ND 1.15 ND ND ND ND ND

WS-11 5-2-17 8 ft. ND 0.233 ND ND ND ND ND

WS-12 5-2-17 8 ft. ND 0.253 ND ND ND ND ND

WS-13 5-2-17 8 ft. ND 0.233 ND ND ND ND ND

WS-14 5-3-17 8 ft. ND 0.160 ND ND ND ND ND

WS-15 5-3-17 8 ft. ND 0.327 ND ND ND ND ND

Notes: ND = Not Detected Above Laboratory Detection Limit

On May 4 and May 8, 2017, five (5) two-inch diameter PVC monitoring wells were installed using hollow stem augers to monitor for the presence of free product within AOC-1. Because the field investigation did not reveal any significant impact at AOC-2, no monitoring wells were installed in that area. Specifically, three (3) monitoring wells (MW-1, MW-2, and MW-3) were installed to a depth of approximately 12 feet bgs and two (2) monitoring wells (MW-4 and MW-5) were installed to a depth of approximately 13 feet bgs. The monitoring wells are constructed of either two (2) or three (3) feet of schedule 40 PVC casing and ten (10) feet of 0.020 slot PVC screen, depending on well location. The annulus of the soil borings was filled with #2 well gravel followed by a bentonite seal to approximately

1 foot beneath the surface. At the surface, the top of each well casing was fitted with a threaded PVC cap and a manhole set in concrete was installed flush with the ground surface. Well construction logs are included as Appendix B. The location of each monitoring well is shown on Figure 6. The generated soil cuttings were placed in to five (5) 55-gallon drums and staged onsite pending waste characterization analysis. The results of the disposal sampling efforts completed on May 8, 2017 did not reveal hazardous waste characteristics. On June 26, 2017, the material was transported to Clearfield

MMG for disposal. Clearfield MMG will forward the final copies of the disposal manifest and disposal certificate directly to NAVFAC upon completion.

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 16

The act of installing a monitoring well has the effect of disturbing the subsurface materials surrounding the borehole which can, in turn, clog the water bearing formation in the vicinity of the well. To counter the effects of monitoring well installation, thus allowing for data collection representative of the subsurface, a monitoring well must be developed. This was accomplished by over pumping each well until the development water appeared to be free of fine sediment. During development activities, free product accumulation, albeit minor, was observed on the surface of the generated development water at

MW-2 and MW-3. The well development water was containerized in five (5) 55-gallon drums and staged onsite pending waste characterization analysis. The results of the disposal sampling efforts completed on May 10, 2017 did not reveal hazardous waste characteristics. On June 26, 2017, the material was transported to Clearfield MMG for disposal. Clearfield MMG will forward the final copies of the disposal manifest and disposal certificate directly to NAVFAC upon completion.

After installing all of the monitoring wells, the tops of each monitoring well casing were surveyed by

MSA within 0.01-ft accuracy using an arbitrary benchmark of +15 ft. The arbitrary 15-ft benchmark was established at the northern corner of the fence located between AOC-1 and building CEP-204. The top-of-casing elevations allow for the calculation of the relative groundwater elevation based on the depth to the water table. By gauging the wells with an oil/water interface probe, a water table surface map can be constructed and then the groundwater flow direction can be determined. Groundwater flow was determined to be in a general westerly direction. A site map illustrating the relative groundwater elevations and groundwater flow direction, as measured on June 12, 2017 is provided as Figure 8.

1.4.3 Groundwater Flow

A site-specific hydraulic gradient of 0.00278 feet/foot and a westerly groundwater flow direction were calculated using the relative well locations, groundwater elevations from the June 12, 2017 well gauging event and the measured distances between wells. It should be noted that this site-specific information was generated using three monitoring wells and may not be representative of the entire site.

On May 25, 2017, MSA performed a slug test adjacent to monitoring well (MW-4). The slug test was performed to estimate the hydraulic conductivity (K) of the aquifer which is accomplished by the instantaneous injection or withdrawal of a known volume of water and then measuring the artificial fluctuation of the groundwater level. An electronic data logger was used to record the slug test data and

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 17 the slug test was performed three times to ensure accuracy. Using the data generated from the slug test, the hydraulic conductivity was determined using aquifer software and is identified below:

K = 5.04 ft/day

The slug test graph generated from the monitoring well is included as Appendix D.

The groundwater flow velocity was calculated using the following equation:

Velocity (ft/day) = K (h4-h2) nl where:

K = hydraulic conductivity: 5.04 feet/day h4-h2 = groundwater elevation: h4 = 7.92 ft. and h2 = 7.67 ft.

n = effective porosity: 0.25 (estimated based on soil type) L = distance: 90 ft.

The resulting velocity was calculated to at 0.056 feet/day or 20.44 feet/year.

1.5 Vertical and Lateral Extent of Petroleum Hydrocarbons

The physical and chemical properties of the compounds in the petroleum, and the nature of the environment, into which the release occurred, control the fate of a potential subsurface release of petroleum hydrocarbons. The combination of these factors will cause the hydrocarbons to partition into four phases in the subsurface environment. These phases are the vapor, adsorbed, dissolved, and free product hydrocarbon phases. Each potential phase of petroleum hydrocarbon impact at the project site is discussed below. The site-specific discussion of petroleum impact is based on the results of the site characterization activities performed at the site.

1.5.1 Free Product

Petroleum hydrocarbons have a specific gravity of less than one and will therefore float on water. They tend to accumulate on the water table, gradually spread out across the water table as a thin film, and migrate outward from the point of release. The presence of free product in the subsurface is gauged with an oil/water interface probe, which is able to detect as little as 0.01 feet of free product on the water table.

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 18

MSA was onsite May 17, June 6, and June 12, 2017 to manually gauge the onsite monitoring wells to determine if free product is present at the Gate 6 Project Site. A measurable thickness of free product was not observed during any of the site visits. Gauge sheets for each site visit are included as Appendix

E. Table 4 summarizes identified free product thickness levels.

TABLE 4: Free Product Thickness (ft.)

Date MW-1 MW-2 MW-3 MW-4 MW-5

5-17-17 0.0 0.0 0.0 0.0 0.0

6-6-17 0.0 0.0 0.0 0.0 0.0

6-12-17 0.0 0.0 0.0 0.0 0.0

In addition, extensive subsurface excavation activities throughout both AOC-1 and AOC-2 have not revealed evidence that a measurable thickness of free product is present in the subsurface. Based on the absence of free product in onsite monitoring wells and contractor observations collected during the course of the Gate 6 Project, it does not appear that significant and/or widespread free phase impact is present at the site.

1.5.2 Adsorbed Phase

MSA was onsite May 1-5, 2017 to collect soil samples from ten (10) soil borings (SS-1 through SS-10) advanced throughout AOC-1 and from five (5) soil borings (SS-11 through SS-15) advanced throughout

AOC-2. The field investigation and the analytical results did not reveal significant adsorbed phase impact at any boring location advanced within AOC-2; TPH-GRO and MTBE were not detected in any of the analyzed samples and the maximum detected TPH-DRO concentration was 6.44 mg/kg. While relatively minor concentrations of benzene and ethylbenzene were also identified, they do not appear to present a significant concern.

Both the field investigation and the analytical results revealed evidence of adsorbed phase impact in select borings (SB-1, SB-2, SB-4, SB-7, and SB-10) advanced within AOC-1. Specifically, petroleum odors and staining were identified at a depth of approximately 0.5-3 feet, depending on boring location, to a maximum depth of 10-12 feet bgs. In addition, evidence of relatively small, thin pockets of saturated soil was observed at SB-2 and SB-4. The analytical report revealed detectable TPH

Site Characterization Report. NAVSTA Norfolk – Gate 6 Project. Norfolk, VA MSA Project # 17080 19 concentrations in five (5) soil samples (SS-1, SS-2, SS-4, SS-7, and SS-10); a maximum TPH-DRO concentration of 31,100 mg/kg was detected in SS-4 and a maximum TPH-GRO concentration of 216 mg/kg was detected is SS-4. The other four (4) soil samples that revealed detectable TPH-DRO concentrations ranged from 85.7 mg/kg (SS-1) to 1,710 mg/kg (SS-2); detectable TPH-GRO concentrations ranged from 2.96 mg/kg (SS-7) to 85.8 mg/kg (SS-10). Relatively minor concentrations of select BTEX constituents were also identified in all of the analyzed soil samples; MTBE was not identified in any of the analyzed samples.

Residual adsorbed phase petroleum contamination is present throughout AOC-1 with the most significant impact located immediately adjacent to subsurface utilities and active and/or abandoned fuel lines that are currently (or were previously) present at the site as small isolated pockets of saturated soil were also identified in the area of SB-2 and SB-4.