Draft Final Ops. and Maint. Manual OU-1 (T-25 Area, Bldgs 22, 36 Area, and Bldgs 63, 2, 45 Area).pdf

DRAFT

OPERATIONS AND MAINTENANCE MANUAL

OU-1 T-25 Area, S. Army Buildings 22 and 36 Area, oldier ystems and the Buildings 63, 2, and 45 Area enter Groundwater Treatment System and 1,4-Dioxane Treatment System

U.S. Army Natick Soldier Systems Center Natick, Massachusetts

Prepared for:

U.S. ARMY NATICK SOLDIER SYSTEMS CENTER

NATICK, MASSACHUSETTS

February 2010

Prepared By:

ECC

33 Boston Post Road West Suite 340

Marlborough, MA 01752

Table of Contents

1.0 INTRODUCTION AND BACKGROUND..................................................................1-1

1.1 Background Documents.......................................................................................1-2

1.2 Manual Objectives ...............................................................................................1-3

1.3 Operations and Maintenance Activities Summary ..............................................1-4

1.4 T-25 Area Treatment System Design ..................................................................1-4

1.4.1 Building Containment Features ............................................................1-4

1.4.2 Extraction Well Pumps and Flow Rate Monitoring System.................1-4

1.4.3 Influent Equalization Tank ...................................................................1-5

1.4.4 Particulate Filter System.......................................................................1-5

1.4.5 Air Stripper ...........................................................................................1-5

1.4.6 Vapor-Phase Granular-Activated Carbon.............................................1-6

1.4.7 Liquid-Phase Granular-Activated Carbon ............................................1-6

1.4.8 Programmable Logic Control ...............................................................1-7

1.5 1,4-Dioxane Treatment System Design ...............................................................1-7

1.5.1 Building Containment Features ............................................................1-8

1.5.2 pH Adjustment Tank.............................................................................1-8

1.5.3 Hydrochloric Acid Feed Line to pH Adjustment Tank ........................1-8

1.5.4 Reaction Tank.......................................................................................1-8

1.5.5 Hydrogen Peroxide Feed Line to Reaction Tank..................................1-9

1.5.6 Discharge ..............................................................................................1-9

1.6 Operations and Maintenance Staffing Plan..........................................................1-9

1.6.1 Project Manager....................................................................................1-9

1.6.2 Project Engineer..................................................................................1-10

1.6.3 Operators.............................................................................................1-10

1.7 Procedures for Making Treatment System Modifications .................................1-11

2.0 TREATMENT SYSTEM SAMPLING AND MONITORING GUIDELINES .......2-1

2.1 Treatment System Sampling Program .................................................................2-1

2.1.1 T-25 Treatment System ........................................................................2-1

2.1.2 1,4-Dioxane Treatment System ............................................................2-2

2.2 Treatment System Sampling Locations ...............................................................2-2

2.3 Aqueous Effluent Limits......................................................................................2-3

2.4 Effluent Air Monitoring Guidelines.....................................................................2-4

2.5 Procedure for Notification of Air/Water Discharge Limit Exceedance...............2-4 i

3.0 TREATMENT SYSTEM INSPECTION, MONITORING, AND REPORTING

SCHEDULES .............................................................................................................................3-1

PART II SYSTEM DESCRIPTION

4.0 1,4-DIOXANE CONTROL SYSTEM DESCRIPTION.............................................4-1

5.0 T-25 TREATMENT PLANT CONTROL SYSTEM DESCRIPTION.....................5-1

5.1 Treatment Plant Main Menu Screen ....................................................................5-1

5.2 Treatment Plant System Overview Screen ..........................................................5-3

5.3 Local Wells Control Screen .................................................................................5-4

5.3.1 Lockouts, Failures and Inhibit Conditions............................................5-4

5.3.2 Alarms...................................................................................................5-4

5.4 Remote Wells Control Screen..............................................................................5-6

5.4.1 Special Instructions...............................................................................5-6

5.4.2 Lockouts, Failures and Inhibit Conditions............................................5-6

5.4.3 Alarms...................................................................................................5-6

5.5 Influent/Effluent Pumps Screen...........................................................................5-8

5.5.1 Special Operating Instructions..............................................................5-8

5.5.2 Lockouts, Failures and Inhibit Conditions: ..........................................5-9

5.5.3 Alarms:..................................................................................................5-9

5.6 Motorized Ball Valves Screen ...........................................................................5-11

5.7 Air Stripper/Process Blowers Screen.................................................................5-12

5.7.1 Lockouts, Failures and Inhibit Conditions: ........................................5-12

5.7.2 Alarms:................................................................................................5-13

5.8 Process Heater Screen........................................................................................5-14

5.9 Flow Totalizers Screen ......................................................................................5-15

PART III SYSTEM START-UP, OPERATION, SHUT DOWN

6.0 SYSTEM START-UP, OPERATION, AND SHUT-DOWN PROCEDURES.........6-1

6.1 T-25 TS Start-up ..................................................................................................6-1

6.2 1,4-Dioxane System Start-Up ..............................................................................6-2

6.3 1,4-Dioxane System Operational Procedures ......................................................6-2

6.4 T-25 TS Operational Procedures .........................................................................6-3

6.5 1,4-Dioxane System Shut-Down .........................................................................6-3

6.6 T-25 TS Shut-Down.............................................................................................6-3

PART IV SYSTEM OPERATIONS AND MAINTENANCE

7.0 T-25 TREATMENT PLANT MONTHLY OPERATION AND MAINTENANCE7-1

7.1 Monthly Treatment System Sampling Procedures ..............................................7-1

7.2 System Inspection Procedures .............................................................................7-1 ii

7.3 Plumbing ..............................................................................................................7-1

7.4 Equipment Maintenance ......................................................................................7-1

7.4.1 Extraction Wells and Pumps.................................................................7-2

7.4.2 Flow Rate Control and Data Recording Procedures.............................7-2

7.4.3 Programmable Logic Control ...............................................................7-2

7.4.4 Equalization Tank.................................................................................7-2

7.4.5 Particulate Filters ..................................................................................7-2

7.4.6 Air Stripper ...........................................................................................7-2

7.4.7 Process Blower and Heater ...................................................................7-3

7.4.8 Vapor-Phase Granular-Activated Carbon Canisters .............................7-3

7.4.9 Liquid-Phase Granular-Activated Carbon Canisters ............................7-3

7.5 Waste Generation, Collection, and Disposal .......................................................7-3

8.0 T-25 TREATMENT PLANT QUARTERLY OPERATION AND

MAINTENANCE.......................................................................................................................8-1

8.1 Building (General) ...............................................................................................8-1

8.2 Plumbing Components.........................................................................................8-1

8.3 Process Component Equipment Maintenance .....................................................8-1

8.3.1 Extraction Wells and Pumps.................................................................8-1

8.3.2 Extraction Well Redevelopment...........................................................8-1

8.3.3 Equalization Tank.................................................................................8-2

8.3.4 Influent and Effluent Pumps .................................................................8-2

8.3.5 Air Stripper ...........................................................................................8-2

8.3.6 Vapor-Phase Granular-Activated Carbon Canisters .............................8-3

8.3.7 Liquid-Phase Granular Activated Carbon Canisters.............................8-3

8.3.8 Process Blower and Heater ...................................................................8-3

8.3.9 Programmable Logic Control Panel .....................................................8-3

8.3.10 Flow Control and Monitoring Systems.................................................8-3

8.4 Quarterly Treatment System Sampling Procedures.............................................8-3

9.0 T-25 TREATMENT PLANT ANNUAL OPERATION AND MAINTENANCE....9-1

9.1 T-25 Building.......................................................................................................9-1

9.2 Plumbing ..............................................................................................................9-1

9.3 Process Component Equipment Maintenance .....................................................9-1

9.3.1 Pressure Gauge and Pressure Switch ....................................................9-1

9.3.2 Extraction Wells and Pumps.................................................................9-1

9.3.3 Equalization Tank.................................................................................9-1 iii

9.3.4 Particulate Filters ..................................................................................9-2

9.3.5 Air Stripper ...........................................................................................9-2

9.3.6 Vapor-Phase Granular-Activated Carbon Canisters .............................9-2

9.3.7 Liquid-Phase Granular-Activated Carbon Canisters ............................9-2

9.3.8 Process Blower and Heater ...................................................................9-2

9.3.9 Programmable Logic Control ...............................................................9-2

9.3.10 Flow Control and Monitoring Systems.................................................9-3

10.0 1,4-DIOXANE SYSTEM MAINTENANCE .............................................................10-1

10.1 MONTHLY OPERATION AND MAINTENANCE........................................10-1

10.2 Monthly Treatment System Sampling Procedures ............................................10-1

10.3 System Inspection Procedures ...........................................................................10-1

10.4 Plumbing ............................................................................................................10-1

10.5 Equipment Maintenance ....................................................................................10-1

10.5.1 Extraction Wells and Pumps...............................................................10-1

10.5.2 Flow Rate Control and Data Recording Procedures...........................10-1

10.5.3 Programmable Logic Control .............................................................10-2

10.5.4 pH Adjustment Tank...........................................................................10-2

10.5.5 HCL pump and feed line to pH Adjustment Tank..............................10-2

10.5.6 Reaction Tank.....................................................................................10-2

10.5.7 H2O2 pump and feed line to Reaction Tank ......................................10-2

10.5.8 Effluent Pump.....................................................................................10-2

10.5.9 Waste Generation, Collection, and Disposal ......................................10-2

11.0 PROCEDURE FOR ADDING NEW EXTRACTION WELLS..............................11-1

11.1 Flow Meters .......................................................................................................11-1

11.2 System Pumps....................................................................................................11-1

11.3 Air Stripper ........................................................................................................11-2

11.4 Liquid Granular Activated Carbon ....................................................................11-2

11.5 Vapor Phase Granular Activated Carbon...........................................................11-2

11.6 Sampling Protocol for New Extraction Well .....................................................11-3

11.7 Troubleshooting for Air/Water Discharge Exceedance.....................................11-3

PART IV EMERGENCY PROCEDURES

12.0 ALARM CONDITIONS AND EMERGENCY RESPONSE - T-25 TREATMENT

PLANT......................................................................................................................................12-1

12.1 Switches and Alarm Controls ............................................................................12-1

12.1.1 Float Switches.....................................................................................12-1 iv

12.1.2 Water Sensor Float Switch .................................................................12-1

12.1.3 Pressure Switches ...............................................................................12-2

12.1.3.1 Bag Filter ............................................................................................12-2

12.1.3.2 Air Stripper Pressure Switch ..............................................................12-2

12.1.4 Temperature Switch............................................................................12-2

12.2 SCADA Call Out ...............................................................................................12-4

12.3 Alarm Conditions...............................................................................................12-4

12.3.1 Air-Stripper Blower Low Air Pressure...............................................12-4

12.3.2 Air-Stripper High Sump Level ...........................................................12-4

12.3.3 High Filter Pressure Skid....................................................................12-5

12.3.4 Equalization Tank High Sump Level..................................................12-5

12.3.5 Equalization Tank Low Sump Level ..................................................12-6

12.3.6 High Floor Sump ................................................................................12-6

12.3.7 Heater High Discharge Air Temperature............................................12-6

12.4 Recommended List of Spare Parts.....................................................................12-7

13.0 ALARM CONDITIONS AND EMERGENCY RESPONSE – 1,4-DIOXANE

SYSTEM ...................................................................................................................................13-1

13.1 Switches and Alarm Controls ............................................................................13-1

13.1.1 Float Switches.....................................................................................13-1

13.1.2 Water Sensor Float Switch .................................................................13-1

13.1.3 pH Switch ...........................................................................................13-1

13.1.4 ORP Switch ........................................................................................13-1

13.2 SCADA Call Out ...............................................................................................13-2

13.3 Alarm Conditions...............................................................................................13-2

13.3.1 Groundwater Low- Flow Alarm .........................................................13-2

13.3.2 Groundwater High-Flow Alarm..........................................................13-2

13.3.3 Low pH Alarm....................................................................................13-3

13.3.4 High pH Alarm ...................................................................................13-3

13.3.5 High Water Level in pH Adjustment Tank.........................................13-4

13.3.6 High Water level in Reaction Tank ....................................................13-4

13.3.7 Low ORP Alarm .................................................................................13-4

13.3.8 VFD Fault Alarm................................................................................13-5

13.3.9 High Floor Sump Level Alarm ...........................................................13-5

13.3.10 Auxiliary Alarm..................................................................................13-5

13.4 Recommended List of Spare Parts.....................................................................13-5 v

PART V - TROUBLESHOOTING

14.0 T-25 TREATMENT SYSTEM TROUBLESHOOTING - MANUFACTURER’S

INSTRUCTIONS .....................................................................................................................13-1

14.1 Influent and Effluent Pumps ..............................................................................14-1

14.1.1 Motor Not Running.............................................................................14-1

14.1.2 Little or No Liquid Delivered .............................................................14-1

14.1.3 Power Consumption Too High .......................................................... 14-2

14.1.4 Excessive Noise and Vibration ...........................................................14-2

14.2 Shallow Tray Aeration System ..........................................................................14-2

14.2.1 Blower Will Not Start or Run .............................................................14-2

14.2.2 Effluent Pump Will Not Shut Off .......................................................14-3

14.2.3 Pump Will Not Run or Pump Water...................................................14-3

14.2.4 Low Air Pressure/Vacuum in Stripper Tank ......................................14-3

14.2.5 High Pressure/Vacuum in Stripper .....................................................14-4

14.2.6 Water Will Not Flow into the Unit .....................................................14-4

14.2.7 Iron Fouling ........................................................................................14-4

14.2.8 Volatile Organic Compound Removal is Less Than Expected ..........14-5

14.3 Process Blower...................................................................................................14-6

14.3.1 Capacity or Pressure Rating................................................................14-6

14.3.2 Vibration and Noise ............................................................................14-6

14.3.3 Overheated Bearings...........................................................................14-6

14.4 Flow Controller..................................................................................................14-7

14.4.1 CAL Menu Error Codes......................................................................14-7

14.4.2 RELAY Menu Error Codes ................................................................14-7

14.4.3 OUTPUT Menu Error Codes..............................................................14-7

15.0 1,4-DIOXANE SYSTEM TROUBLESHOOTING...................................................15-1

15.1 Effluent Pump ....................................................................................................15-1

15.2 Flow Controller..................................................................................................15-1

15.3 Clamp Mount Mixers.........................................................................................15-1

15.3.1 Vibration and Noise ............................................................................15-1

15.4 Chemical Metering Pumps.................................................................................15-2

15.4.1 Pump Will Not Run or Pump Chemical .............................................15-2

16.0 REFERENCES.............................................................................................................16-1 vi

List of Tables

Table 1-1 O&M Activities Summary – T-25 TS Table 1-2 O&M Activities Summary – 1,4-Dioxane TS Table 2-1 Treatment System Sampling and Analysis Schedule Table 2-2 Current Method Reporting Limits (MRLs) Table 2-3 Ambient Water Quality Criteria for COCs Table 12-1 Treatment System Contact List

List of Figures

Figure 1-1 Site Location Figure 1-2 Site Layout Figure 1-3 Site System and Well Location Figure 1-4 T-25 Treatment System Figure 1-5 1,4-Dioxane Unit Process and Instrumentation Diagram Figure 2-1 TS Aqueous Discharge to Non-Potable System and Main Outfall Figure 2-2 Decision Matrix for Notification Process Figure 4-1 1,4-Dioxane Multi-Parameter Control Panel – Start-up Configuration Figure 5-1 Treatment System Main Menu Screen Figure 5-2 Treatment System Overview Screen Figure 5-3 Local Wells Control Screen Figure 5-4 Remote Wells Control Screen Figure 5-5 Influent/Effluent Pumps Screen Figure 5-6 Motorized Ball Valves Screen Figure 5-7 Air Stripper/Process Blowers Screen Figure 5-8 Process Heater Screen Figure 5-9 Flow Totalizers Screen Figure 6-1 T-25 Treatment Plant Process and Instrumentation Diagram Figure 6-2 Programmable Logic Control Start-up Configuration Figure 12-1 Pressure Switch Settings for Particulate Filters vii

List of Appendices Appendix A Standard Operating Procedures (provided on CD-ROM only) Appendix B MADEP Emissions Standard Calculations (provided on CD-ROM only) Appendix C Electrical Wiring Logic, and Panel Layout Drawings (provided on CD-ROM only) Appendix D Equipment Specification Sheets and User’s Manual for T-25 System Components

(provided on CD-ROM only) Appendix E As-builts Appendix F Dioxane Treatment System Documentation (provided on CD-ROM only) Appendix G Treatment Plant Discharge Results – Sampling Program Support Documentation Appendix H Remote Access Instructions for Treatment Plant viii

Acronyms and Abbreviations

ADL Arthur D. Little, Inc.

AWQC Ambient Water Quality Criteria COC contaminant of concern DDT dichloro-diphenyl-trichloroethane EPA United States Environmental Protection Agency ºF degrees Fahrenheit gpm gallons per minute H-O-A Hand-Off-Auto hp horsepower I/O input/output LGAC liquid-phase granular-activated carbon LTMP Long Term Monitoring Plan MADEP Massachusetts Department of Environmental Protection NEEP North East Environmental Products NSSC Natick Soldier Systems Center O&M Operation and Maintenance PCE tetrachloroethene PE Project Engineer P&ID Process and Instrumentation Design PID photoionization detector PLC programmable logic controller PM Project Manager ppbv parts per billion by volume PPE personal protective equipment psi pounds per square inch PVC polyvinyl chloride ROD Record of Decision SCADA Supervisory Control and Data Acquisition SOP standard operating procedure SSC Soldier Systems Center TCE trichloroethene TCLP Toxicity Characteristic Leaching Procedure TS treatment system ug/L micrograms per liter VGAC vapor-phase granular-activated carbon VOC volatile organic compound ix

Draft Operations and Maintenance Manual Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007

1.0 INTRODUCTION AND BACKGROUND

ECC prepared this Operations and Maintenance (O&M) Manual for the U.S. Army Natick Soldier Systems Center (NSSC) T-25 Area groundwater treatment system (TS) and 1,4-dioxane TS. The T-25 Area groundwater TS treats groundwater from the following areas: the T-25 Area, Buildings 22 and 36 Area, and Buildings 63, 2, and 45 Area. The 1,4-Dioxane TS was commissioned and installed to work in cooperation with the T-25 Area groundwater TS. Figures 1-1 and 1-2 depict the site location and site layout of the NSSC.

This O&M Manual is written for the NSSC in compliance with the contract requirements and specifications of contract number W912CG-05-D-0007. This manual serves as a companion document to the Draft Final Long Term Monitoring Plan (LTMP) (ECC, 2009).

The content in this manual is based on an existing May, 2004 O&M Manual written by ICF Consulting, Inc. (ICF) for the TS designed and operated for Building 94 only. Modifications made to the ICF Consulting, Inc. O&M Manual include new O&M information for the additional components used to treat groundwater from the Buildings 22 and 36 Area and the Buildings 63, 2, and 45 Area, and information regarding the operation and maintenance of the 1,4-Dioxane TS designed and installed to treat 1,4-dioxane in groundwater from the Buildings 63, 2 and 45 Area.

This O&M Manual outlines the following procedures:

• Operating and maintaining the current TS that services three NSSC areas of groundwater extraction

• Monitoring and notifying in the event of a contaminant discharge exceedance

• Modifying the TS

• Operating and maintaining the 1,4-dioxane treatment system

• Troubleshooting problems

NSSC is located approximately 17 miles west-southwest of Boston in Natick, Massachusetts. The NSSC is a research facility encompassing approximately 78 acres on a small peninsula extending from the eastern shoreline of the South Pond of Lake Cochituate (Figures 1-1 and 1-2). Lake Cochituate is made up of three connected ponds that include the North Pond, Middle Pond, and South Pond. The properties surrounding NSSC are a mixture of residential, commercial/retail, and light industrial areas.

According to the Massachusetts Department of Environmental Protection (MADEP), NSSC is located in a Zone 2 aquifer and is located approximately 2,500 feet southeast of the Springvale Municipal Water Supply Well Field. Figures 1-3 depicts the locations of NSSC contaminant plumes as well as the site extraction wells (EWs), monitoring wells, and TS.

The TS was initially constructed for a treatability study of the T-25 Area groundwater, which contains elevated concentrations of trichloroethene (TCE) and tetrachloroethene (PCE).

In accordance with the approved Treatability Study Work Plan (Arthur D. Little, Inc. [ADL], 1997), the U.S. Army commenced operation of the TS in November 1997. After an extensive

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007 treatability study, the groundwater extraction and treatment system was approved through the Record of Decision (ROD) in September 2001. In April 2003, three additional extraction wells were brought on line and one existing well was taken off line. The system utilized four extraction wells (MW-90B-4, MW-94B-4, MW-95B-4, MW-96B-4) until September 2006, when MW-96B- 4 was shut down to accommodate the HRC bioremediation pilot test. The system then used three extraction wells located in the T-25 Area until August 22, 2007.

In August 2007, seven additional extraction wells from two additional separate contaminated groundwater plumes were connected to the T-25 Area TS and the monitoring systems were updated. These seven extraction wells each add approximately 2 gallons per minute (gpm) of additional flow to the T-25 Area TS, which already treats approximately 60 to 70 gpm of contaminated water. The changes to the TS are depicted on the as-built figure (Appendix E).

Consistent with Unites States Environmental Protection Agency (EPA) guidance, an Explanation of Significant Difference (ESD) was submitted in November 2007 to document this change in conditions at the treatment facility.

1,4-dioxane had been discovered within the TCE plume at the Buildings 63, 2 and 45 Area in groundwater samples from monitoring well MW124B-2 in March 2005, and subsequent monitoring verified that 1,4-dioxane concentrations are confined to a small area in the vicinity of MW124B-2. Because the existing treatment units in the T-25 treatment plant for PCE and TCE (air stripping and granular activated carbon filtration) are ineffective for 1,4-dioxane treatment, a small ex-situ wellhead treatment unit was installed near the location of EW-4 to treat the extracted groundwater from the Buildings 63, 2 and 45 Area before conveyance to the Building 94 Treatment Plant. Fenton’s Reagent, an advanced oxidation process utilizing hydrogen peroxide, was selected as the treatment technology to destroy the 1,4-dioxane. The wellhead treatment unit was delivered to the site in August 2008, and was operational in September 2008.

1.1 Background Documents

Groundwater associated with the T-25 Area contains concentrations of TCE and PCE above the Federal and State of Massachusetts drinking water maximum contaminant levels of 5.0 micrograms per liter (ug/L). The following reports summarize groundwater contamination conditions at T-25:

• Final Phase I Remedial Investigation Report: T-25 Area at the U.S. Army Natick Research, Development, and Engineering Center (ADL, 1996)

• Final Phase II Remedial Investigation Report: T-25 Area at the U.S. Army Soldier Systems Command (ADL, 1998)

To evaluate whether or not groundwater contamination at T-25 could be contained using the proposed extraction well system, a Focused Feasibility Study was performed at NSSC in 1999 (Final Focused Feasibility Study/Treatability Study Report for the T-25 Area at the U.S. Army Soldier Systems Center [SSC] [ADL, 1999]). The Focused Feasibility Study also assessed the effectiveness of the proposed extraction well system. The Focused Feasibility Study

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007 recommended the installation of a groundwater extraction and TS in the T-25 Area. This system was installed in 1997.

The 1997 Phase II Water Supply Well Remedial Investigation revealed that a TCE plume beneath the site extended from Building 2 to the south/southwest. A smaller plume was also identified near Building 42. The majority of the groundwater plume is overlain with 10-20 feet of non-impacted groundwater.

Historically, TCE was used in large volumes in the climatic control chamber, which is located in Building 2. TCE was formerly used by the U.S. Army in a cooling brine solution that was stored in three 1,000-gallon tanks located in Building 2. However, the climatic control chambers were remodeled and the TCE storage tanks were replaced with diethyl benzene.

Under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) Federal Facility Agreement (Section 120) with the EPA, the U.S. Army agreed to provide a pilot study work plan evaluating the effectiveness of treating groundwater plumes located at the Buildings 22 and 36 Area and the Buildings 63, 2, and 45 Area at the existing plant.

In October 2004, a Draft Feasibility Study was performed for the Buildings 22 and 36 Area. This Draft Feasibility Study presented six alternatives for groundwater treatment at the SSC. In January 2007, the Final Pilot Study Work Plan for Groundwater Containment at Buildings 22 and 36 and Buildings 63, 2, and 45 for the T-25 Area at the U.S. Army Soldier Systems Center (ECC, 2007) was prepared for the groundwater containment at the Buildings 22 and 36 Area and the Buildings 63, 2, and 45 Area.

1.2 Manual Objectives

The objective of this O&M Manual is to serve as a management and procedure tool to assist personnel with operation of the T-25 Area TS and the 1,4-dioxane TS. By establishing the baseline for the operation and maintenance of these two systems, this O&M Manual provides users with both detailed standard operating procedures (SOPs) and general guidelines and policy information needed to access information that may not be contained within this manual.

Competent management, combined with correct operating and maintenance procedures for the TS, are essential to ensure continued compliance with applicable Federal, State, and local regulations.

The manual serves as a resource for:

• System design information

• Equipment information

• Monthly, quarterly, and annual operating procedures, inspections, maintenance, and repair procedures

• Guidelines for troubleshooting, sampling, and monitoring

• Procedures for adding new EWs

• Requirements for recordkeeping and reporting

1-3

Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007

• O&M Manual revisions

1.3 Operations and Maintenance Activities Summary

A summary of monthly, quarterly, and annual O&M activities can be found in Section 7.0, Section 8.0, and Section 9.0, respectively, as well as in Table 1-1. Section 10.0 and Table 1-2 provide a summary of O&M activities for the 1,4-dioxane system.

1.4 T-25 Area Treatment System Design

As illustrated in Figure 1-4, the T-25 Area TS is based on groundwater pump-and-treat technology. Groundwater is extracted from the subsurface via extraction wells, pumped through a particulate filter, and then treated with an air stripper that removes the primary volatile organic contaminants (TCE and PCE). Vapors from the air stripper are heated and then treated using granular-activated carbon. Groundwater is pumped through granulated-activated carbon.

In addition to treating contaminated groundwater (i.e., reducing contaminant mass from the groundwater plumes), pumping through the extraction wells induces a hydraulic gradient that provides hydraulic control for plume containment.

As described in the following subsections, the major components of the T-25 Area TS are:

• Building containment features

• Extraction well pumps and flow rate monitoring components

• Influent equalization tank

• Particulate filters

• Air stripper

• Carbon adsorption canisters

• Process blower and heater

• Programmable logic controller (PLC)

1.4.1 Building Containment Features

The TS building was constructed to provide secondary containment in the event of a plumbing or component leak. The building’s interior perimeter is equipped with a 1-foot-wide berm that can hold approximately 11,100 gallons of water. The floor slopes towards a floor sump equipped with a high water level indicator. If this water level indicator is activated, the system will shut down and the system’s SCADA system telephones the on-call TS operator for notification. TS alarm conditions are further discussed in Section 12.0.

1.4.2 Extraction Well Pumps and Flow Rate Monitoring System

A full-scale groundwater extraction and treatment system has operated at the site since November 1997.

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010

Initially, the system operated two extraction wells (EWs). In the spring of 2003, three additional EWs were brought on line, while one existing EW was taken off line (ICF, 2004), and the system operated four extraction wells: MW-90B-4, MW-94B-4, MW-95B-4 and MW-96B-4. In September 2006, MW-96B-4 was taken off-line for the HRC Pilot Study. The TS was expanded and updated in 2007 with the addition of seven EWs for the treatment of groundwater extracted from the Buildings 22 and 36 Area (EW-5, EW-6, EW-7, and EW-8) and from the Buildings 63, 2, and 45 Area (EW-2, EW-3 and EW-4).

In total, ten EWs are currently utilized to contain three plumes at NSSC. Each of the seven new extraction wells adds approximately 2.0 gpm additional flow to the TS. The new wells each use a ½ horsepower (hp) motor. Extraction wells MW-90, 94, 15 and 96 are each equipped with 2 hp submersible pumps capable of producing approximately 60 gpm flow rate with approximately 76 feet of total dynamic head. The pump intakes are located immediately above the top of each well screen.

EW flow rates are monitored by paddle-wheel flow sensors, with an accuracy of +/- 0.1 percent.

The extraction well pump rates are controlled by throttling the flow with butterfly valves or gate valves. Flow readings are recorded by a monitoring panel through which the operator can download flow data.

1.4.3 Influent Equalization Tank

Groundwater is pumped into a 3,000-gallon holding tank for equalization prior to treatment.

This holding tank serves to equalize any variations in contaminant concentration or extraction flow prior to pumping the groundwater into the system, ensuring a consistent hydraulic and contaminant loading to the TS. This equalization tank provides a 20-minute retention time so larger suspended solids settle out prior to treatment. To minimize fugitive VOC emissions, the equalization tank is covered and a drop tube directs influent flow below the hydraulic surface.

Equalization tank head space vapors are collected with a vapor scavenging system and treated by a VGAC unit prior to emission.

1.4.4 Particulate Filter System

A particulate filter system is located prior to the air stripper to reduce the risks of iron fouling or plugging of the air stripper and the liquid-phase granular-activated carbon (LGAC) canisters (see Figure 1-4). The particulate filter system consists of two stainless-steel bag canisters, operating in parallel, each of which contain a poly-mesh 100-micron bag filter.

1.4.5 Air Stripper

Groundwater is pumped from the equalization tank, through a particulate filter, and then into the air stripper. Air stripping technology is based on the principle that volatile contaminants can be removed from aqueous waste streams by blowing air through a liquid-phase interface. The

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007 volatile components are transferred from the aqueous phase to the gaseous phase at a rate dependent on the process variables and contaminant characteristics.

The air stripper currently operating in the NSSC T-25 Area TS is a shallow tray air stripper equipped with four trays that provide the appropriate surface area, air/water interface, and removal efficiency. The air stripper is equipped with a 10-hp blower that supplies approximately 700 cubic feet per minute of airflow. The air stripper is rated for a maximum flow rate of 160 gpm.

1.4.6 Vapor-Phase Granular-Activated Carbon

The T-25 Area TS includes two 1,000-pound carbon VGAC adsorption canisters for removal of volatile organics from the air-stripper off-gas. Activated carbon treatment efficiently removes organics from the stripper's off-gas and allows for compliance with applicable air pollution control regulations.

The air-stripper's off-gas, which contains water vapor and volatiles stripped from the groundwater, first passes through a heater followed by a dual-bed carbon adsorption system that is operated similarly to the liquid carbon adsorption equipment. The heater is a 8.0 kilowatt convective space heater that increases the temperature of the off-gas in order to lower the relative humidity.

The heater is controlled by a thermoswitch located downstream of the heater. The thermoswitch is factory set to maintain the off-gas air stream entering the primary VGAC at a temperature of approximately 90 degrees Fahrenheit (°F). The thermoswitch maintains the air stream at this temperature by turning the heater on and off.

When the temperature of the air stream falls below a temperature of approximately 85°F, the thermoswitch turns the heater on. When the temperature reaches approximately 95°F, the thermoswitch turns the heater off. The off-gas temperature discharging from the air stripper is maintained year round between 50°F and 60°F due to the fairly constant temperature of the groundwater. The decrease in the relative humidity of the air stream entering the primary VGAC increases the lifetime of the vapor-phase carbon units and, thus, improves the cost-effectiveness of this portion of the TS. Carbon regeneration is discussed in Section 7.5 of this O&M Manual and SOP 19.0 (Appendix A).

1.4.7 Liquid-Phase Granular-Activated Carbon

The liquid effluent from the stripper is polished using carbon to adsorb any organic contaminants remaining in the stripped groundwater stream. Although the air stripper is capable of reducing the PCE and TCE concentrations to non-detectable concentrations, the liquid-phase activated carbon has been included as a contingency, in case the air stripper malfunctions or compounds other than those previously detected are extracted from the aquifer.

The carbon-polishing equipment minimizes the potential for discharge of effluent that does not meet the discharge criteria. The LGAC equipment consists of two steel canisters containing 2,000 pounds each of granular-activated carbon. The carbon canisters are operated in series with a

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007 primary carbon unit and a secondary carbon unit. LGAC is described in Section 7.4.9 of this O&M Manual.

1.4.8 Programmable Logic Control

The PLC (see Plate 1) controls the operation of the following TS components by a computer program built into the unit:

• Ten extraction well pumps (three extraction wells wired through separate panel)

• Two transfer pumps

• Two process blower fan motors

• One in-line duct heater for the air stripper off-gas

• Two motorized ball valves located on Skid 1

The PLC also controls the system alarms triggered by conditions including:

• High and low equalization tank levels

• High filter pressure for the particulate filter canisters

• High air-stripper sump level

• Low air pressure in the air stripper

• High pressure in the liquid-phase carbon canisters

• High floor sump water level

• High air temperature out of the duct heater and into the vapor phase

• Dioxane Treatment System Shutdown

Responses to these alarm conditions are also controlled by the PLC. The alarm conditions and PLC response are presented in Section 12.0 of this O&M Manual.

The PLC also includes a monitoring panel, which is connected to the NSSC network, allowing remote access to the system. As such, the operator can view real time aqueous flow rates for each extraction well, the system aqueous flow rate, level of groundwater in the equalization tank, the air flow rate from the air stripper, and any alarm conditions that may have been activated. Extraction well flow rates can be downloaded and the alarm checked and re-set.

The PLC is further described in Section 5.0.

1.5 1,4-Dioxane Treatment System Design

1,4-dioxane occurs in a portion of the solvent plume in the Buildings 63, 2 and 45 Area. During 2008 an ex situ wellhead treatment unit was installed to treat the groundwater from the extraction wells in the Buildings 63, 2 and 45 Area to remove the 1,4-dioxane before this groundwater is pumped to the T-25 Area Treatment Plant. The influent flow rate to this treatment unit is approximately 6.0 gpm, the combined flow from extraction wells EW-2, EW-3 and EW-4.

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010

The 1,4-dioxane treatment unit consists of the following components, as illustrated on Figure 1-5:

1. Building Containment Features

2. pH Adjustment Tank

3. Hydrochloric acid feed line to pH adjustment tank

4. Reaction tank

5. Hydrogen peroxide feed line to reaction tank

6. Discharge pump to convey water via the EW-2 through EW-8 pipeline to the T-25 treatment plant

1.5.1 Building Containment Features

The 1,4-dioxane treatment building was constructed to provide secondary containment in the event of a plumbing or component leakage, and for weather protection. The shed is equipped with two heaters and a corrosion-resistant exhaust fan. Drums of chemicals are stored on polyethylene spill pallets. The reaction tanks are placed within a polyethylene spill containment system, and the floor of the shed is lined with rubber matting. There is a floor sump within the spill containment system for the pH tank and reaction tank, equipped with a high water level indicator. If this high water level indicator is activated, the system will shut down and the system’s telemetry module telephones the on-call TS operator for notification. TS alarm conditions are discussed in Section 13.0.

1.5.2 pH Adjustment Tank

Combined groundwater pumped from extraction wells EW-2, EW-3, and EW-4 enters the dioxane treatment shed and is directed to the 100-gallon polyethylene pH adjustment tank, where hydrochloric acid (HCL) is dosed into the tank via a chemical metering pump. Flow entering the pH tank is monitored by a paddle-wheel flow sensor; when flow is less than 1.0 gpm, an alarm is triggered and the dioxane system is shut down, as well as the T-25 TS. A pH probe mounted in the tank controls the amount of HCL added by the metering pump in order to maintain a pH of approximately 3.5. Contents of the tank are mixed with a clamp mount mixer. The tank provides an approximate 20-minute average retention time, and ensures a consistent flow rate and water quality to the reaction tank. Water flows via a gravity overflow to the Reaction Tank.

1.5.3 Hydrochloric Acid Feed Line to pH Adjustment Tank

A chemical metering pump feeds HCl from a 55-gallon drum to the pH adjustment tank. The speed of the pump is controlled by the pH sensor in the pH Adjustment Tank. HCl is transferred and discharged through LDPE polyethylene tubing, which is suspended above the pH adjustment tank liquid level.

1.5.4 Reaction Tank

Water in the 350-gallon reaction tank is mixed via clamp mount mixer with hydrogen peroxide (H2O2), and, if necessary, iron sulfate (FeSO4). Pilot tests conducted prior to system design and construction determined that there was adequate dissolved iron naturally occurring within the

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007 groundwater at the Buildings 63, 2, and 45 Area, such that added FeSO4 would not be necessary as a catalyst for Fenton’s reaction to occur. H2O2 is metered into the tank at a constant rate of 0.5 gallons per day (gpd) via a variable speed chemical pump. An ORP sensor continuously records tank ORP levels, and there are high- and low- water level sensors that will trigger alarms and system shut-down (dioxane and T-25 systems) if the water level within the tank reaches a height of 4.5 feet. This 350-gallon tank provides a retention time of approximately 30 minutes.

1.5.5 Hydrogen Peroxide Feed Line to Reaction Tank

H2O2 is added to the Reaction Tank via a variable speed chemical pump directly from the H2O2 chemical drum through LDPE polyethylene tubing. Dose control is manual, and the pump is set at the lowest possible setting of 5%. The discharge from the tubing is suspended above the liquid level in the reaction tank.

1.5.6 Discharge

After treatment, water is pumped from the reaction tank via a 3-phase, 1/3-hp effluent pump to the pipeline leading from the Buildings 63, 2, and 45 Area, to join flows from the Buildings 22 and 36 Area, from extraction wells EW-5, EW-6, EW-7 and EW-8. The effluent is controlled by the water level sensor in the reaction tank, programmed to maintain the water level at approximately

2.5 feet (or to maintain the tank half full). The combined flow from extraction wells EW-2 through EW-8 is then conveyed to the T-25 TS and enters the building as one combined flow, EW-2-8.

1.6 Operations and Maintenance Staffing Plan

The recommended staffing for the NSSC O&M activities includes a Project Manager (PM), Project Engineer (PE), and TS operators. The following paragraphs summarize the responsibilities associated with each position.

1.6.1 Project Manager

Mr. Robert Tess, P.E., is the ECC PM for NSSC O&M activities. The ECC PM is a supervisory position that directs the overall operation, maintenance, monitoring, and management of the NSSC

TS.

In general, the PM is in charge of developing plans and reports, ensuring that the plans are carried out, supervising and directing on-site operation of TS, and ensuring compliance with contractual requirements.

Other responsibilities include:

• Ensuring properly qualified operators are performing their functions

• Ensuring that operator training is provided as needed

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Ground Water Treatment System ECC U.S. Army Natick Soldier Systems Center February 2010 Natick, Massachusetts Contract No. W912CG-05-D-0007

• Providing necessary resources such as tools and personal protective equipment for operators to perform their duties

• Troubleshooting assistance

• Modifications to improve operation and maintenance

• Budget and performance reports

• Ensuring competency and safety of operation

• Ensuring compliance with all permit requirements

• Approving all changes in TS operation

• Performing other related administrative and management work, as required

The contact information for the Project Manager and an alternate is:

• Project Manager: Mr. Robert Tess, P.E.

o Work Phone: (508)…