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Submitted to:

NAVFAC Mid-Atlantic 9324 Virginia Avenue, Building Z144 Norfolk, VA 23511

Submitted by:

APTIM Federal Services, LLC 150 Boush Street, Suite 701 Norfolk, Virginia 23510

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Written by: ________________________ Date:

Benjamin L. Porter Senior Project Engineer

Approved by: Date:

Steve Carriere, PMP

Project Manager

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Operations and Maintenance Manual February 2019 iii

Table of Contents ________________________________________________

List of Figures ................................................................................................................................................ v List of Tables ................................................................................................................................................. v List of Appendices ......................................................................................................................................... v Acronyms and Abbreviations ........................................................................................................................ vii

1.0 Introduction ..................................................................................................................................... 1-1

1.1 Regulatory Framework and Authorization ............................................................................ 1-1

1.2 Operation and Maintenance Manual Organization ............................................................... 1-1

1.3 Emergency Personal ............................................................................................................ 1-2

2.0 Site Conditions and Background ..................................................................................................... 2-1

2.1 Site Location ......................................................................................................................... 2-1

2.2 Facility Description and History ............................................................................................ 2-1

2.3 Zones 1 and 2 Descriptions and Histories ............................................................................ 2-2

2.3.1 Zone 1 ..................................................................................................................... 2-2

2.3.2 Zone 2 ..................................................................................................................... 2-4

2.4 Topography and Site Features ............................................................................................. 2-4

2.5 Climate ................................................................................................................................. 2-4

2.6 Geology ................................................................................................................................ 2-5

2.7 Hydrogeology ....................................................................................................................... 2-5

2.8 Contaminants of Concern ..................................................................................................... 2-5

3.0 Biosparge Equipment ...................................................................................................................... 3-1

3.1 Biosparge equipment ............................................................................................................ 3-1

3.2 Biosparge wells .................................................................................................................... 3-3

3.2.1 Shallow Biosparge Wells ......................................................................................... 3-3

3.2.2 Deep Biosparge Wells ............................................................................................. 3-4

3.3 Monitoring Points .................................................................................................................. 3-4

3.4 System Controls ................................................................................................................... 3-4

4.0 Biosparge Operations ..................................................................................................................... 4-1

4.1 System Startup ..................................................................................................................... 4-1

4.2 Routine System Operations .................................................................................................. 4-2

4.3 Default Set Points During Normal Operations ...................................................................... 4-3

4.4 Telemetry Connection .......................................................................................................... 4-3

4.4.1 VPN Connection (smart phones) ............................................................................. 4-3

4.4.2 HMI Interface (smart phones) .................................................................................. 4-4

4.5 System Monitoring ................................................................................................................ 4-4

4.5.1 Startup Operational Monitoring ................................................................................ 4-4

4.5.2 Routine Operational Monitoring ............................................................................... 4-5

4.5.3 Groundwater Monitoring .......................................................................................... 4-5

4.6 Reporting Requirements ....................................................................................................... 4-6

4.7 System Shutdown................................................................................................................. 4-6

5.0 System Maintenance ...................................................................................................................... 5-1

5.1 Biosparge Maintenance ........................................................................................................ 5-1

5.2 Electrical and controls .......................................................................................................... 5-2 iv

5.2.1 Telemetry ................................................................................................................ 5-2

5.3 Biosparge wells and Monitoring wells. .................................................................................. 5-3

6.0 References ..................................................................................................................................... 6-1 v

List of Figures __________________________________________________

Figure 1 Site Location Figure 2 Site Layout Figure 3 Biosparge System Layout Figure 4 System Process and Instrument Diagram

List of Tables ___________________________________________________

Table 1 Biosparge Well Construction Details Table 2 Sample Location, Methods and Schedule

List of Appendices _______________________________________________

Appendix A National Environmental Systems (NES) O&M Manual Appendix B Telemetry Remote Access Appendix C Operation and Maintenance Field Sheets vi vii

Acronyms and Abbreviations ______________________________________

°F Degrees Fahrenheit acfm Actual cubic feet per minute APTIM Aptim Federal Services, LLC CERCLA Comprehensive Environmental Response, Compensation, and

Liability Act COC Contaminant of concern CTDEEP Connecticut Department of Energy and Environmental Protection cy cubic yard DEC Direct exposure criteria DGI Data gap investigation DRO Diesel-range organics ETPH Extractable total petroleum hydrocarbons FS Feasibility Study GRO Gasoline-range organics IRP Installation Restoration Program MW Monitoring well NAPL Nonaqueous phase liquid NAVFAC Naval Facilities Engineering Command Navy U.S. Department of the Navy NES National Environmental Systems NSB Naval Submarine Base NLON New London O&M Operation and maintenance O&MM Operation & Maintenance Manual PLC Programmable logic control Psig Pounds per square inch gauge PVC Polyvinyl chloride PWD Public Works Department RAWP Remedial Action Work Plan RCSA Regulation of Connecticut State Agencies ROI radius of influence RSR Remediation Standard Regulations scfm Standard cubic feet per minute SWPC Surface Water Protection Criteria Tetra Tech Tetra Tech NUS TPH total petroleum hydrocarbons U.S. United States UST Underground storage tank VFD Variable frequency drives VOC Volatile organic compound viii

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1.0 Introduction

The purpose of this Operations and Maintenance (O&M) Manual is to provide the necessary information to operate and maintain the biosparge system located around Building 29 in the lower subase at the Naval Submarine base (NSB)-New London (NLON). This area is part of the Operable Unit 4 in groundwater zones 1 and 2. This work was done under the guidance of the 100% Design Report (APTIM, 2018a) and the approved Remedial Action Work Plan (RAWP), (APTIM, 2018b).

This work is being performed under Task Order WE18 under the U.S. Department of the Navy (Navy) Environmental Restoration Program for the United States (U.S.) Department of the Navy (Navy), Naval Facilities Engineering Command (NAVFAC) Mid-Atlantic Contract No. N62470- 16-D-9004.

1.1 Regulatory Framework and Authorization

The contaminants of concern (COCs) identified for Zones 1 and 2 are related to fuels, petroleum, oil, and lubricants that were generated as part of historical Navy-related activities. These COCs are not regulated under Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA does not address discharges of petroleum or petroleum products, therefore, the remedial action related to Zones 1 and 2 are being conducted under the Connecticut Department of Energy and Environmental Protection (CTDEEP) Remediation Standard Regulations (RSRs), Section 22a-133k-1 through 22a-133k-3 of the Regulations of Connecticut State Agencies (RCSA) (CTDEEP, 2017). The Navy, in consultation with the CTDEEP, is the lead agency for investigating, reporting, making remedial decisions, and taking remedial actions at NSB-NLON.

1.2 Operation and Maintenance Manual Organization

This O&M Manual consists of six sections and provides descriptions of the specific activities involved in operating and maintaining this remedial action. This O&M Manual is organized as follows:

• Section 1.0, Introduction—Provides an introduction, regulatory framework, O&M Manual organization and emergency personal.

• Section 2.0, Site Conditions and Background—Presents the site location, description, and history; nature and extent of contamination.

• Section 3.0, Biosparge Equipment—presents a detailed description of all major equipment used on this system including the treatment system wells and controls.

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• Section 4.0, Biosparge Operations—describes a detailed breakdown on how to operate the system during different phases of the treatment along with the monitoring and reporting requirements.

• Section 5.0, System Maintenance —describes what the maintenance needs of the system are along with frequency of required maintenance.

• Section 6.0, References—includes a list of documents used to compile this O&M Manual.

• Appendix A, National Environmental Systems (NES) O&M Manual

• Appendix B, Telemetry Remote Access

• Appendix C, Operation and Maintenance Field Sheets

1.3 Emergency Personnel

Exhibit 1: Emergency Personnel

Naval Facilities Engineering Command-

MIDLANT

Ms. Rachel Watts

757.341.2008 (office)

Rachel.watts@navy.mil Navy Technical Reprehensive /

Remedial Project manager

Naval Facilities Engineering Command-

MIDLANT

Bob Sosnoski

(860) 235-5019

Robert.sosnoski1@navy.mil Onsite Contact

Aptim Federal Services, LLC (APTIM) 150 Boush Street, Suite 701

Norfolk, Virginia 23510

Steve Carriere, PMP

609.234.6361 (mobile)

Steve.carriere@aptim.com Project Manager

APTIM

150 Royall Street

Canton, Massachusetts

Benjamin Porter

781.821.3557 (office)

Benjamin.porter@aptim.com Project Engineer

Emergency (note: Need to state you are located on the lower subase because so that call gets dispatched properly) 911 911

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2.0 Site Conditions and Background

This section presents a general description of the site; the history, topography and site features;

climate, geology, and hydrogeology; and COCs that are presented in greater detail in the Design Report.

2.1 Site Location

NSB-NLON is located in Groton, Connecticut (Figure 1). OU4 is located on 33 acres adjacent to the Thames River that extends south of Pier 2 and north of Pier 33. During previous remedial response actions by the Navy, OU4 was divided into several zones for evaluation, which include nine Installation Restoration Program (IRP) sites. Two of the nine IRP sites are located within Zone 1 (Site 10 and Site 11) and are excluded from Zone 2 (former fuel distribution line) (Figure 2). Zones 1 and 2 in OU4 around Building 29 is the focus of the selected remedy in the Design Report, (APTIM, 2018a) and as supplemented by this RAWP, (APTIM, 2018b).

2.2 Facility Description and History

In 1867, the State of Connecticut donated a 112-acre parcel of land on the eastern bank of the Thames River to the Navy. In 1868, the Navy officially designated the property a Navy Yard, which was used to moor small craft and obsolete warships and served as a coaling station for the Atlantic fleet. The Navy designated the site a submarine base in 1916. During World War I, facilities at the base were extensively expanded; 6 piers and 81 buildings were added. In 1917, a submarine school was established, and in 1918, the Submarine Medical Center was founded.

The facility underwent another period of growth during World War II. Between 1935 and 1945, the Navy added more than 180 buildings and acquired land adjacent to NSB-NLON, expanding the facility from 112 acres to 497 acres. The growth of NSB-NLON continued after World War II, and in 1946, the Medical Research Laboratory was established. In 1968, the status of the submarine school was changed from an Activity to a Command, and the submarine school became the largest tenant activity on the base. The Naval Submarine Support Facility was established in 1974, and the Naval Undersea Medical Institute was established the following year. Currently, NSB-NLON consists of more than 207 buildings on 687 acres of land and provides base command for naval submarine activities in the Atlantic Ocean. NSB-NLON also provides housing for Navy personnel and their families and supports submarine training facilities, military offices, medical facilities, and facilities for submarine maintenance, repair, and overhaul.

Most of the Lower Subase construction from approximately Pier 15 to the south, took place in the early 1900s with a major expansion from 1935 to 1940. In 1946, the waterfront, north of

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Pier 15, was developed extensively to accommodate berthing of the reserve fleet. The area was dredged and filled, and bulkheads, piers, support buildings, and utilities were constructed.

Battery overhaul was one of the largest operations at the Lower Subase until the advent of nuclear-powered submarines. Lead-acid battery maintenance and overhaul activities were conducted until the mid-1950s. A classified materials incinerator was also operated in the Lower Subase until 1967. It is possible that the resulting ash was disposed in portions of the Lower Subase. Petroleum products were used by the Navy throughout the Lower Subase. Releases of petroleum products to the environment may have occurred because of leaks from underground storage tanks (USTs) and fuel distribution lines, vehicle and locomotive maintenance operations and associated waste disposal practices, and marine fueling activities. Other ship and submarine maintenance activities (e.g., sandblasting and painting) were also conducted in the Lower Subase and adjacent Thames River (Resolution Consultants, 2017).

2.3 Zones 1 and 2 Descriptions and Histories

The following sections summarize the descriptions and histories for Zones 1 and 2 in OU4.

2.3.1 Zone 1

Zone 1 extends from Darter Road south of Building 89 to the southern side of Corvina Road (Figure 2). The Providence and Worcester Railroad runs along the eastern border of the zone, and the Thames River forms the western border of the zone. Approximately 90 to 95 percent of Zone 1 is paved or covered with buildings, and the land surface slopes gently toward the Thames River. Zone 1 is covered primarily by buildings, concrete, or paving, although some small sections are covered by grass. The main building in Zone 1 is the power plant (Building 29).

There are three sites of concern in Zone 1: (1) IRP Site 10–Fuel Storage Tanks and Tank 54-H,

(2) IRP Site 11–Power Plant Oil Tanks, and (3) Building 89 UST.

IRP Site 10 included five concrete USTs located southwest of Building 107 that were placed into service during World War II. Three of the tanks had 125,000-gallon capacities and were used to store diesel fuel from 1954 to 1987. From 1954 to 1989, two other 25,000-gallon tanks were used to store lubrication and hydraulic oils. A sixth 30,000-gallon tank, 54-H, located adjacent to and north of the 125,000-gallon tanks, was used as a reclamation tank for the other five tanks.

The Navy decommissioned four of the tanks in 1987. In 1989, the Navy decommissioned the 25,000-gallon tanks and installed new steel tanks within the shells of these two tanks to provide secondary containment.

IRP Site 11 includes four 170,000-gallon USTs that were located adjacent to and east of Building 29. These tanks were installed during World War II. Two tanks were used to store No. 6 fuel oil pumped from the tank farm at the southern end of NSB-NLON; one tank was used to store diesel oil and one tank was used to store waste oil generated by the bilge water-oil

2-3 recovery system at the power plant. Past oil leakage was apparent when the old tanks were cleaned; however, the old tanks were repaired and were used as containment structures for three 150,000-gallon steel USTs. Two of the three 150,000-gallon USTs (northern and southern tanks) were abandoned between 2010 and 2011.

The former Building 89 UST was located adjacent to Zone 1. The UST had a capacity of 3,000 gallons, was installed in 1982, and was used for storage of No. 2 fuel oil for power motors operated in Building 89. In 1993, the tank failed tightness testing and was removed by excavation in 1994. Post-excavation soil samples analyzed for total petroleum hydrocarbons (TPH) indicated concentrations were below CTDEEP cleanup criteria.

Historical fuel lines from the tank farm distributed fuel oil to Zones 1 and 2. Some of these fuel lines have been decommissioned and some remain in place. According to the Feasibility Study (FS) (Tetra Tech NUS [Tetra Tech], 2010), in 1996, pressure leak testing was performed on the lines and valves in the fuel distribution system within and adjacent to Zone 1. A section of polyvinyl chloride (PVC) or fiberglass pipe in the diesel oil line at Pier 12 was deemed to be compromised because it failed to hold air at 20 pounds per square inch during a pneumatic test.

The Navy’s Public Works Department replaced this section of pipe. The other sections of line and various valves tested in the portion of the fuel oil distribution system within or adjacent to Zone 1 passed the pressure leak testing. In 1996, pressure leak testing was done on the sections of the lines and valves in the portion of the distribution system within Zone 2, and those sections passed the testing. The lines were subsequently abandoned in place.

Other utilities located in Zone 1 include steam/condensate, water, sanitary sewer, storm sewer, natural gas, and electrical. Soil data collected during the FS (Tetra Tech, 2010) and Data Gap Investigation (DGI) (Tetra Tech, 2012) indicated extractable total petroleum hydrocarbon (ETPH) concentrations that exceeded the Industrial/Commercial Direct Exposure Criterion (DEC) RSRs in saturated soils at depths ranging from 8 to 12 feet below ground surface, located across Zone 1. Kriging statistical analysis performed by Tetra Tech indicated soil concentrations exceeding DEC Remediation Standard Regulations (RSR) criteria in the saturated zone. There were no exceedances within the unsaturated zone. Groundwater data collected across Zone 1 during the FS (Tetra Tech, 2010) and DGI (Tetra Tech, 2012) indicated multiple concentrations that exceeded the Surface Water Protection Criterion (SWPC). Data collected during the FS (Tetra Tech, 2010) indicated TPH concentrations ranging up to 16,000 micrograms per liter (µg/L). Groundwater samples from the DGI (Tetra Tech, 2012) demonstrated ETPH concentrations ranging up to 33,000 µg/L.

Nonaqueous phase liquid (NAPL) was found in one well during historical gauging events in Zone 1, with an approximate thickness of 0.5 feet. An estimated 1,100 gallons of ETPH was

2-4 calculated based on locations where NAPL was observed and TPH soil concentrations exceeded 25,000 milligrams per kilogram.

It was presumed that the soil and groundwater impacts in Zone 1 were likely the result of possible leaks or historical spills associated with on-site USTs and subsurface fuel oil distribution lines (Resolution Consultants, 2017).

2.3.2 Zone 2

Zone 2 extends from the southern boundary of Zone 1 along Corvina Road south to Capelin Road to north of Building 31 (Figure 2). The Providence and Worcester Railroad runs along the eastern border of Zone 2, and the Thames River forms the western border of Zone 2. The ground surface of Zone 2 slopes gently to the Thames River, and approximately 90 to 95 percent of the surface is paved or covered with buildings. Multiple buildings exist in Zone 2 including Buildings 17, 20, 38, 75, 328, and 548. Utilities including a former subsurface fuel line, steam/condensate, water, sanitary sewer, storm sewer, natural gas, and electrical exist in Zone 2.

Historical soil data collected during the FS (Tetra Tech, 2010) indicated TPH concentrations were below DEC RSR criteria for the majority of Zone 2, with the exception of the northern boundary adjacent to Zone 1. There were no exceedances in the unsaturated zone of Zone 2.

Groundwater data collected during the FS (Tetra Tech, 2010) indicated TPH concentrations that exceeded the SWPC at one location (well 13MW6) within Zone 2. The TPH contamination source in Zone 2 is associated with the former subsurface fuel oil distribution lines and at least in part attributable to releases within Zone 1 (Resolution Consultants, 2017).

2.4 Topography and Site Features

NSB-NLON is fairly flat on the lower portion of the harbor’s eastern shore and has highly urbanized surroundings. The elevation of the entire NSB-NLON ranges from about sea level on the northern portion of the base to below sea level on the southern portion of the base. Zone 1 and Zone 2 are approximately 90 to 95 percent paved or covered with buildings

(NAVFAC, 2017).

2.5 Climate

The climate of NSB-NLON is considered to be cool and cloudy, and is moderated by its proximity to the Thames River. There are generally warm to hot summers and cold winters. In New London (Groton, Connecticut), the warmest and coldest months of the year are July (mean temperature of 81 degrees Fahrenheit [°F]) and January (mean temperature of 22°F), respectively. Annual precipitation averages 49.67 inches (Climate-data.org, 2017).

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2.6 Geology

Below the surface, NSB-NLON has five bedrock formations including Alaskite Gneiss, Granitic Gneiss, Mamacoke Formation, Plainfield Formation, and Westerly Granite. Along the surface, NSB-NLON consists of unconsolidated glacial materials including stratified drift and glacial till.

Stratified drift deposited among the base are sorted as silt, sand, and gravel, which are the product from glacial meltwater streams. Glacial till is a dense, heterogeneous mixture of clay, silt, sand, and rock fragments placed by glacial ice and exposed only on bedrock highs and averages about less than 10 feet in thickness. Within Zone 1 and Zone 2, a silty sand layer underlies sand and gravel backfill along with debris fill. The sand and silty sand are interpreted as natural deposits of stratified drift.

2.7 Hydrogeology

In general, the direction of groundwater flow across NSB-NLON is west across the base and towards the Thames River. The water table surface follows the topography and bedrock surface locally. The groundwater also flows towards two valleys, which both lead towards the Thames River, and can also flow from the western edges of three hills to the Thames River. The vertical component of groundwater is downward in upland areas. Upward gradients may occur at the base of hills, resulting in shallow bedrock groundwater discharge into stream valleys and wetland seeps (Resolution Consultants, 2017).

The Thames River is a tidally influenced river in which the tides impact the discharge of groundwater daily. During the Remedial Investigation, it was discovered that during low tide the results of discharged groundwater to the river were greater and during high tide the results were the opposite; groundwater discharge flow would come to a halt, normally within 300 feet of the Thames River, but flow was not effected in other areas of NSB-NLON (Tetra Tech, 2010).

A major basin divide is present along the edges of Baldwin Hill, with the surface water and groundwater on the western end being a part of the Thames Major Basin and discharging into the Thames River. For Zone 1 and Zone 2, groundwater flow is southwesterly with a velocity around

1.63 feet per day (AGVIQ Environmental Services, 2016).

2.8 Contaminants of Concern

The COCs for soil and groundwater at Zones 1 and 2 consist of TPH; diesel-range organics (DRO), oil-range organics, and gasoline-range organics (GRO). It is evident that petroleum products were also used within the Lower Subase area of NSB-NLON due to leaks from USTs and fuel distribution lines, waste disposal practices, marine fueling activities, and vehicle and locomotive maintenance operations.

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3.0 Biosparge Equipment

The main System is located a customized 20 feet Conex box on the southeast side of Building 29 with an auxiliary manifold located on the northwest side of Building 29. The system consist of two blowers, 30 biosparge wells, piping manifold system, process controls with telemetry along with all needed pipe fittings, gauges and valves. Figure 3 shows the location of the the treatment system, auxiliary manifold and biosparge wells. Figure 4 shows the process and control diagram along with how the major equipment is connected.

3.1 Biosparge equipment

Detailed as-builts drawings, equipment specifications and equipment maintenance requirements for the the Biosparging equipment is provided in the NES O&M Manual in Appendix A. NES was the fabrication company who physically built the biosparge system and supplied the as built drawings of the equipment. NES also has supplied the U.S. Navy with a one-year warranty on all parts and equipment as outlined in the NES O&M Manual.

The primary purpose of the biosparge system is to inject air into the soil and groundwater to oxygenate the groundwater to biologically enhance the aerobic biologic activities and natural biodegradation of the fuel related contaminates. This is achieved by taking low-pressure compressed air [around 15 pounds per square inch gauge (psig)] and injecting through a piping manifold system and into the 30 different biosparge wells. The biosparge wells are broken up into two groups with the deep wells located on the east side of building 29 and the shallow wells located on the west side of Building 29 along the Thames River. Monitoring wells around the site will be used to monitor volatile organic compound (VOC) vapor data, pressures, dissolved oxygen levels in groundwater and water levels to help determine the effectiveness of the treatment system.

The biosparge system is comprised of the following major equipment along with all supporting valves, gauges and fittings. A detail breakdown of all equipment including supporting material is provided in the NES Operation & Maintenance Manual O&MM in Appendix A.:

• Two Rotary Claw Compressors: Busch Mink MM 1102BP, 70 standard cubic feet per minute (scfm) @ 15 psig, 10 HP, 230V, 360 rpm TEFC. The two blowers are plumbed in parallel and can be operated together or individually. It is anticipated that the maximum injection rate will be up to 140 scfm at 15psig with both units running at 100% (60Hz).

The minimum flow rate is anticipated to be 35 scfm at 15 psig with a single unit running at 50% (30Hz).

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• Two air-to-air heat exchangers: AKG Series CC200 max flowrate of 245 scfm with ½ HP, 240V motor. The heat exchanger is to to cool the heated compressed air following the rotary claw compressor.

• Pressure Relief Valves: The pressure relieve valve is part of the standard Busch compressor package and is set and has been set at 25 psig and is stamped with the pressure setting stamped on the Busch compressor.

• Total system flow: A digital flow meter with output to the programmable logic control (PCL) (model CDI-5400) is installed on both the main effluent line and axillary line sparge line. The flow data for these two points can be accessed through the telemetry system by both smart phone and computer. The purpose of this meter is to back up the the combined flow of the rotameters to confirm accuracy and also remotely monitor the status of the system.

• Thirty Biosparge well Rotameters: Dwyer Series RMC range no. 121 (scfm 1 to 10 scfm) with a 10” scale and +/-5% accuracy. It is a precision flowmeter suitable for both gas and liquid. Each biosparge well is equipped with a flow control valve and rotameter to accurately control flow at each injection point.

• Process Control Equipment including Programmable logic control (PLC) and telemetry: the system is controlled by a programmable logic control device, a touch screen interface and online telemetry accessible remotely by smart phone or computer.

Additional details of this process control equipment will be provided in Section 3.4.

• Two Variable Frequency Drives (VFD): Dura Pulse AC Drive 230V VFD has been installed for each compressor. The VFD controls have been intergraded into the touchscreen and operations on the actual VFD is not needed outside of the touch screen.

Through the process control, the two VFD and compressors can operate independently of each other from 30Hz to 60Hz and set up by the touchscreen. Specific details of the VFD can be found in the NES O&MM.

• Shutter Mounted Fan: Canard Model AX16-2 1/2HP, 115V, 2,370 scfm at static pressure vent fan mounted on the sidewall of the biosparge treatment system. The fan is connected to a high temporary sensor that controls when the fan is operated. The purpose of the fan is to keep heat down through ventilation in the main biosparge treatment building.

• Process Bleed valve: A 1” gate valve is is installed prior to biosparge manifold to relieve/bleed any excess pressure or reduce flows to below the minimum

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VFD/compressor flow capability of 35 acfm at 15 psig. The bleed valve will be utilized if total flow is required to be between 0 and 35 acfm.

• Main Treatment Building: The main treatment building is a customized 20ft x 8 ft shipping container that is equipped with an 8ft wide side door and a standard access door on the long side. The container holds all the biosparge system with the exception of the equipment located inside the auxiliary manifold building. The building is powered by 240volt, 3 phase 200 amp breaker that controls all the treatment system equipment.

Details of the the equipment placement is shown in the as-built drawings presented in Appendix A.

• Auxiliary manifold Building: The auxiliary manifold building is a 6-3/4 x 3-3/8 galvanized steel shed manufactured by West. This shed is an auxiliary building located on the northwest side of Building 28 that is connected to the Main Treatment Building by a 3” aluminum auxiliary pipe. This building holds the auxiliary manifold that has the flow control and rotameters for biosparge wells BSW13 through BSW30. This shed is equipped with a 20 amp 120v utility plug and ceiling light. Details of the the equipment placement is shown in the as-built drawings presented in Appendix A.

3.2 Biosparge wells

A total of thirty biosparge wells (BSW1 through BSW30) have been installed as part of the biosparge system. The spacing of the wells is based on an estimated 1:1 ratio of vertical depth of well screen below the water table versus the radius of influence (ROI) that is anticipated from treatment areas. The ROI assumes a 20 percent overlap at the treatment areas. The depths of the biosparge wells along with their construction details are provided in Table 1. The biosparge wells were generally constructed of 2-inch Schedule 40 PVC with a 2-foot well screen in the saturated zone. Biosparge wells BSW1 through BSW12 are considered the deep biosparge wells and located on the east side of Building 29 and biosparge wells BSW13 through BSW30 are considered to be the shallow biosparge wells and located on the west side of Building 29 along the Thames River. The locations of the biosparge wells are shown on Figure 3.

3.2.1 Shallow Biosparge Wells

The shallow biosparge wells (BSW13 through BSW30) located on the west side of Building 29 along the Thames River had a target depth of 15 feet below ground surface with the screens approximately 10 feet under the mean groundwater depths. The shallow wells have an approximately spacing of about 15 feet apart assuming a 20 radius of influence.

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3.2.2 Deep Biosparge Wells

The deep biosparge wells (BSW1 through BSW12) located on the east side of Building had a target depth of 20 feet below ground surface with the screens approximately 15 feet under the mean groundwater depths. The shallow wells have an approximately spacing of about 20 feet apart assuming a 25 radius of influence.

3.3 Monitoring Points

Six new monitoring wells (1MW6 through 1MW11) were installed to help monitor the progress of the treatment system. The locations of these wells is identified in Figure 3. Details of the well construction is provided in Table 1. In addition to the new monitoring wells installed, wells MW1-PD1, 1MW1S, 1MW2, 1MW4, 13MW3, TMW4 and also TMW5 will also be used as monitoring points. Each point will be monitored for wellhead pressure, well head VOC concentration, dissolved oxygen concentration in groundwater and water level.

3.4 System Controls

The biosparge system is controlled by a virtual controlled touch screen on the main control panel at the site. The touch screen controls the VFD, PCL, cellular modem and all relays for the compressors and heat exchangers. The major components of the control system are provided below Details on how to remotely connect to the system is provided in Appendix B (Telemetry Remote Access).

• Main power disconnect panel: 280 volt, 200 amp, 3 phase power. Located on the outside of the treatment system.

• Two emergency shut off valves, one located on the right side of the access door and one on the main control panel inside the treatment system.

• 24 volt power converter: IDEC PS5B-VE24. Used to power control sensors such has flow meters, pressure and temperature gauges.

• PLC: CLICK Ethernet basic PLC unit used to control system including turning on and off the compressors and heat exchangers, monitoring control sensors (flow, pressure and temp gauges), initiating alarms, controlling the wireless system and interfacing connecting all system together including VFD, motors and touchscreen.

• Wireless airlink getaway with antenna: Sierra Wireless Airlink ES450 Gateway.

Wireless gateway for connecting control system to the cellular network systems. This allows remote access to the system and also allows the system to send out alarm notifications.

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• Touch Screen: 8” C-more color touch panel EA9-T8CL. Used for complete system controls for both auto and virtual hand operations. Touch screen controls also allows to set points action points for alarms, notify of alarms and set VFD frequency settings. The touch screen also displaces virtual total flow.

• Batter back up: Battery backup system allows 10 minutes of half load power to allow enough time to send a system down alarm to the the notification personal. The backup system controls the touch screen, PLC and wireless gateway equipment.

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4.0 Biosparge Operations

The following sections provide detailed instructions on how to start up, operate, monitor and shut down the system. Prior to operating the system all applicable documents should be completely reviewed including this O&M manual and and site health and safety plane (APTIM, 2017).

4.1 System Startup

To start the system the following steps must be taken.

1. Determine the desired flow rates of the biosparge system. The normal operating design flow rates are 4 acfm for BSW1 through BSW12 and 3 acfm for wells BSW13 through

BSW30.

2. Close all BSW gate valves (valves that control flow to the sparge wells)

a. Valves 301 to 312 in main system.

b. Valves 401 to 418 in auxiliary enclosure.

3. Close main buttery fly valve to auxiliary enclosure.

4. Open bleed valves V102 and V202 to exhaust sparge air out of silencers F102 and F202.

5. Turn on all breakers in distribution panel to activate VFDs and local control panel.

6. On the HMI touch screen located on the local control panel confirm desired set points for hand set points (default 300 seconds) and low and high flow warnings. Recommend 20% above and below desired total flow rate.

7. Set high and low temporary alarms located to the right of the main control panel. Default is is 115⁰F and low is 40⁰F.

8. Under the system controls tab on the HMI Touch screen press the VFD command button and set the frequency to 45 Hz for both VFD-1 and VFD-2.

9. Check the total run time for the compressors BL-101 and BL-102. Whatever compressors has the lowest run time press the “Auto” button for the compressor and heat exchanger.

a. Note: One compressor should now be running and 100% of the flow should be going through the bleed valve.

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10. Open all BSW gate valves and main buttery fly valve to auxiliary enclosure at locations where biosparging is desired to 100%.

11. Close bleed valves V102 and V202 to exhaust sparge air out of silencers F102 and F202.

12. Confirm flow rates at all BSW wells. Adjust VFD and compressor operations until flows are slightly above desired flow rates. Use the following iterative steps to get optimal operational conditions.

a. If total flow is below desired flow increase VFD frequency to 60 Hz and check flow rates.

b. If flow rates are still below desired flow return VFD frequency back to 45 Hz and startup second compressor. Once both compressors are on increase both VFD frequencies until you hit 60 Hz or just above desired flow rates.

c. Once flow rates are above desired flow rates reduce VFD(s) frequency until flow rates are just above desired flow [approximately 0.5 to 1.0 actual cubic feet per minute (acfm)] above desired flow at each injection location). Then adjust BSW flow control valves at each location to get desired injection rates.

d. During initial startup it is recommend to first get flow rates to about ½ of normal operating conditions and then check system and monitoring wells for any anomalies before complete ramp up.

13. Start operational startup monitoring as outlined in Section 4.5.1 of this document.

4.2 Routine System Operations

Once the system has started up as described in Section 4.1. The system should be at a minimum reviewed remotely at least once a week and site visits a minimum of once a month to fulfill the recommended maintenance schedule as outlined in Section 5.1. However, during start up, system changes or unusual observed anomalies the site visits should be increased to properly control and monitor the system. Visits will also be increased during start up to fulfill startup monitoring requirements outlined in Section 4.5.1 monitoring requirements.

During routine operations the field O&M sheets provided in Appendix C should be filled out every time on site and flow rates should be reviewed and adjusted to achieve desired flow rates.

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4.3 Default Set Points During Normal Operations

Once the system is operating it is important to ensure that the system is operating under the correct operational parameters. The table in Exhibit 2 illustrates the minimum, maximum and typical observed values of the system.

Exhibit 2: Normal Operating Parameters for Biosparge System

Monitoring Parameter Units Minimum Maximum Normal

Operations

BSW1 through BSW 12 acfm 0 6 4

BSW13 through BSW 30 acfm 0 5 3

BSW1 through BSW 30 psig 0 15 10

FI-101 (main system flow) acfm 0 72 48

FI-201 (Axillary Flow) acfm 0 85 51

VFD(s) Hz 30 60 Varied

Hand settings (BL101 & 201 and

HE101 & HE201)

seconds 5 300 300

Main low flow warning acfm 0 600 35

Axillary low flow warning acfm 0 600 40

Low temp alarm ⁰F -40 220 40 high temp alarm ⁰F -40 220 115

4.4 Telemetry Connection

The system can be remotely operated and monitored by both IOS and and android mobile devices. A detailed description of the setup is provide in Appendix B titled Telemetry Remote Access. In order to connect a VPN app and a HMI remote app must be downloaded to the smart phone. Once downloaded follow the set up guidance on the app or detailed in Appendix B.

Below is the log in information required to connect to the system:

4.4.1 VPN Connection (smart phones)

App name: Cisco AnyConnect Username: NES18106 Password: Rtech60181

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4.4.2 HMI Interface (smart phones)

App name: C-more Remote HMO IP Address: 172.30.36.3

Full Access Password: ASGrton1 Username: admin

Limited Access Password: ASGrton2 Username: operator

4.5 System Monitoring

The system has two kinds of monitoring the first is operational monitoring and the second is groundwater monitoring. The purpose of the operational monitoring is to monitor and control the operations of the biosparge system. This data will be used to adjust and modify how the system is actually operated. The purpose of the groundwater monitoring is to help determine how successful the treatment system with respect to meeting its remediation goals and reducing contaminate mass in the groundwater. For the operational monitoring there is two phases of operations a startup phase that has a higher frequency of monitoring and a routine monitoring once the system has been is in more of a steady state. Both operational monitoring and groundwater monitoring will be reported in an annual report. Details of both the monitoring and reporting requirements are outlined in the following sections.

4.5.1 Startup Operational Monitoring

During operational startup the frequency of monitoring must be increased to ensure proper control of the system. During initial startup or prolong shut down (greater than 2 weeks) the following site visit startup schedule should be followed.

Week 1: The day of startup and following day (two consecutive days follow startup)

Week 2: Two non-consecutive days following the week after start up

Week 3: One site visit

Week 4: One site visit

Week 6: One site visit

Week 8: One site visit monthly thereafter as described in Section 4.5.2.

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During the startup operational monitoring site visits the field sheets and mainatence logs (Attachement C) should be filled out each time an operator is on site to perform a site visit. In additional to the routine monitoring the system flow rates should be checked and rebalanced so that air injection flow rates can match the desired flow rate as much as possible.

4.5.2 Routine Operational Monitoring

During routine operational monitoring it is recommended that sites visits and operational monitoring should be completed no less than once a month with weekly checks of the system through remote monitoring. During the monthly site visits all operation and maintenance field sheets should be completely filled and all maintiance outlined in Section 5.1 should be performed and documented. Sites visits should be increased if unanticipated or more complex maintence is required or the field parameters appear to be inconsistent with past field sheet data.

All field sheets and mainatence logs (Attachement C) should be scanned and uploaded to a central file location for future monitoring.

4.5.3 Groundwater Monitoring

Routine groundwater samples will be collected from existing wells (13MW6, MW1 1PDI, 1MW1S, 1MW2, 1MW3, 1MW4, 13MW2, TMW2, and TMW4) and the six newly installed wells (1MW6, 1MW7, 1MW8, 1MW9, 1MW10, and 1MW11). The data to be collected at these wells will be be compared to baseline and previously collected performance monitoring data when available. The analytical requirements and sampling procedures for the groundwater sampling event are presented in detail in the the Work plans, Appendix C Sampling and Analysis Plan (APTIM, 2018b).

Groundwater samples will be collected semi-annually for the first two years of operations then annually thereafter. Samples will be collected using a low flow sampling technique outlined in the Sampling and Analysis Plan using the standard operating procedure SOP-EI-FS111. Samples will be collected for geochemical parameters in the field including oxidation-reduction potential, dissolved oxygen, specific conductivity, pH, temperature and turbidity along with analytical parameters ETPH by CT-ETPH, Total Organic Carbon by SW-846-9060A and nitrates by SW- 846-6056A. Details on how to handle, pack and ship the samples is provided in the Work plans, Appendix C Sampling and Analysis Plan (APTIM, 2018b). Table 2 details the sample locations, method and schedule and locations of sample locations are shown in Figure 3.

To collect representative samples of site groundwater, sampling of all OU4 monitoring wells will be performed during periods of low tide. The time of low tide (i.e., the optimum time for sampling and collecting water levels at each monitoring well) at OU4 wells will be approximated by the time of low tide at the entrance to Smith Cove, which is located on the opposite side of the Thames River. The time of low tide at Smith Cove will be determined by adding the National

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Oceanic and Atmospheric Administration (NOAA) estimated 10-minute lag time for the entrance to Smith Cove to the low-tide predictions at the NOAA New London, Connecticut, State Pier station (#8461490). Tidal predictions for Station #8461490 can be obtained from the NOAA web site at http://tidesandcurrents.noaa.gov/noaatidepredictions/NOAATidesFacade.jsp?Stationid=8461490

Because the wells are equally close to the Thames River, well-specific time lags have not been determined. Well purging should begin approximately 1 hour prior to the predicted low tide and sampling will begin after purging is complete.

4.6 Reporting Requirements

Reporting of the construction operations and performance monitoring will be completed in a forthcoming construction completion report, this O&M manual and annual performance monitoring reports incorporated into the annual monitoring reports. The annual reports will consist both the routine annual monitoring and performance evaluation of the system. Annual reporting will continue as long as the biosparge system is in operations.

4.7 System Shutdown

To shut down the system the following steps must be taken.

1. Open bleed valves V102 and V202 to exhaust sparge air out of silencers F102 and F202.

2. Under the system controls tab on the HMI Touch screen place both the compressors and heat exchangers to the “OFF” position.

3. Close all BSW gate valves (valves that control flow to the sparge wells) o Valves 301 to 312 in main system.

o Valves 401 to 418 in auxiliary enclosure.

4. Close main buttery fly valve to auxiliary enclosure.

5. Turn off all breakers in distribution panel for complete shutdown. If power to system is still needed but the biosparge is to be shut down turn off the motor starter breakers only.

The shutdown of the system will typically occur during both routine and non-routine maintenance and once the system has meets its remedial action objects outlined in Section 2.9 of the biosparge work plan (APTIM, 2018a) that state the system must reduce the risk to current and/or future receptors and attenuate COC concentrations in groundwater to below the CTDEEP

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RSRs prior to reaching surface water (the Thames River). The CTDEEP RSRs for this site is 470 micrograms per liter of ETPH.

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5.0 System Maintenance

It will be assumed that all maintenance will be completed by a trained and competent person. In the event the maintenance requirements are beyond what the O&M operator is qualified to do such as electrical work the operator is required to procure the properly qualified personal. Work will be completed in accordance to all base safety requirements and the base approved health and safety plan (APTIM, 2017).