10.2.8_-_ECC_-_CWTP_OM_Manual_B_Code.pdf

TRANSMITTAL OF SHOP DRAWINGS, EQUIPMENT DATA, MATERIAL SAMPLES, OR

MANUFACTURER'S CERTIFICATES OF COMPLIANCE

(Read instructions on the reverse side prior to initiating this form)

SECTION I - REQUEST FOR APPROVAL OF THE FOLLOWING ITEMS (This section will be initiated by the contractor)

DATE TRANSMITTAL NO.

TO: FROM: CONTRACT NO. CHECK ONE:

THIS IS A NEW TRANSMITTAL

THIS IS A RESUBMITTAL OF

TRANSMITTAL ___________

SPECIFICATION SEC. NO. (Cover only one section with each transmittal)

PROJECT TITLE AND LOCATION 01-Main Register CHECK ONE: THIS TRANSMITTAL IS

FOR FIO GA DA CR

ITEM

NO.

a.

DESCRIPTION OF ITEM SUBMITTED

(Type size, model number/etc.)

b.

MFG OR CONTR.

CAT., CURVE

DRAWING OR

BROCHURE NO.

(See instruction no. 8) c.

NO.

OF

COPIES

d.

CONTRACT REFERENCE

DOCUMENT

SPEC.

PARA. NO.

e.

DRAWING

SHEET NO.

f.

FOR

CONTRACTOR

USE CODE

g.

VARIATION

(See

Instruction No. 6) h.

FOR

CE

USE

CODE

i.

REMARKS I certify that the above submitted items have been reviewed in detail and are correct and in the strict conformance with the contract drawings and specifications except as otherwise stated.

NAME AND SIGNATURE OF CONTRACTOR

SECTION II - APPROVAL ACTION

ENCLOSURES RETURNED (List by item No.) NAME, TITLE AND SIGNATURE OF APPROVING AUTHORITY DATE

ENG FORM 4025, MAR 95 (ER 415-1-10) EDITION OF SEP 93 IS OBSOLETE. (Proponent: CEMP-CE)

02/11/2015 01010-44.2

01010

W912DY-10-D-0013 CF01

Southern New Jersey REO 130 North Broadway Gloucester City, NJ 08030

Environmental Chemical Corporation

110 Fieldcrest Avenue

Edison, NJ 08837

FUSRAP Radioactive Soil Removal Deepwater, NJ

X 01010-44.1

X

Plan revised to address USACE C code comments. Re-submitted with RTCs.

43 CWTP O&M Plan PRECON SUBMTL 3 1.3 A N

SHEET 1 OF 1

Digitally signed by David DN: cn=David, o=ECC, ou=Garber, email=dgarber@ecc.net, c=US Date: 2015.02.11 11:35:33 -05'00'

E5ECCPED

Typewritten Text B

E5ECCPED

Typewritten Text

E5ECCPED

Typewritten Text ped

E5ECCPED

Typewritten Text See attached comments.

TRANSMITTAL OF SHOP DRAWINGS, EQUIPMENT DATA,

MATERIAL SAMPLES, OR MANUFACTURER'S

CERTIFICATES OF COMPLIANCE

PROJECT TITLE FUSRAP Radioactive Soil Removal

LOCATION Deepwater, NJ

DATE

CONTRACT NO.

W912DY-10-D-0013 CF01

TRANSMITTAL NO.

PAGE

Attachment to ENG FORM 4025-R Range: Selected Transmittals

02/18/2015 01010-44.2

Item Description Variation QA Code

43 CWTP O&M Plan No B

SECTION III - GOVERNMENT REVIEW REMARKS

Mike Mohn comments:

1. Section 2.3.7, Page 11, Should state the locations of the 5 emergency stop push buttons and have a schematic or map showing them.

2. Section 2.4.2, Page 12, Paragraph should mention whether the 25% caustic solution needs to be kept a certain temp so it does not crystallize out in its drum.

3. Section 5.4.3 Page 50, Should include contact info for the CWTP operators.

4. Section 4.3, Page 24, Should include a summary of the SCADA data that will be recorded, and which column it is recorded on in the data file (column headings).

5. Section Page 43,Should insert a discussion of the operation of the LGAC units, also to include what has to be done to change the lag to lead when the lead vessels are used up. My understanding is that the lead and lag use different hoses/fittings, etc.

Pat Dougherty comments:

1. Daily Operator Log Sheet is a living document that can be improved/added to as needed.

2. Delete "HGL Cosden Forms" and "GETS Daily Walkthrough" from printed version of Daily Operator Log Sheet.

CONSTRUCTION WATER TREATMENT PLANT

OPERATION AND MAINTENANCE PLAN

REMEDIATION SERVICES

FORMERLY UTILIZED SITES

REMEDIAL ACTION PROGRAM (FUSRAP)

AT

FORMER DUPONT CHAMBERS WORK SITE

DEEPWATER, NEW JERSEY

Prepared for

United States Army Corps of Engineers Philadelphia District

Contract Number

W912DY-10-D-0013

Task Order CF01

February 2015

Environmental Chemical Corporation 110 Fieldcrest Avenue, Suite 31

Edison, NJ 08837

CONSTRUCTION WATER TREATMENT PLANT

OPERATION AND MAINTENANCE PLAN

REMEDIATION SERVICES

FORMERLY UTILIZED SITES REMEDIAL ACTION PROGRAM

FORMER DUPONT CHAMBERS WORKS SITE

DEEPWATER, NEW JERSEY

I hereby certify that the enclosed plan, shown and marked in this submittal, is that proposed to be incorporated with contract number W912DY-10-D-0013, “Former DuPont Chambers Works Site, Deepwater, New Jersey.” This plan is in compliance with contract drawings and specifications, and is submitted for Government approval.

Reviewed by:

ECC Project Manager Date

ECC Quality Control System Manager Date

LIST OF ACRONYMS

% percent ug/L micrograms per liter AHA Activity Hazard Analysis AOC area of concern atm atmospheres BOD Biological Oxygen Demand BPS back pressure sustaining CDD Central Drainage Ditch CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CFR Code of Federal Regulations COC contaminant of concern Ci curie CWTP Construction Water Treatment Plant DCQC Daily Contractor Quality Control DuPont E.I. du Pont de Nemours and Company ECC Environmental Chemical Corporation ERC Emergency Response Coordinator E-STOP Emergency Stop ft/sec feet per second FUSRAP Formerly Utilized Sites Remedial Action Program GAC granular activated carbon gpm gallons per minute HMI Human/Machine Interface HMW high molecular weight

HOA HAND-OFF-AUTO

IPC Inclined Plate Clarifier IRS iron removal system lb pound IX ion exchange LNAPL light non-aqueous phase liquid MF Media Filtration MSDS Material Safety Data Sheet NaOH sodium hydroxide NJDEP New Jersey Department of Environmental Protection O&M operation and maintenance OCS operator control station OU Operable Unit OWS oil water separator P&ID Process and Instrumentation Diagram PAH polycyclic aromatic hydrocarbon pCi/g picocuries per gram PLC Programmable Logic Control PM Project Manager PPE personal protective equipment psi pounds per square inch QAPP Quality Assurance Project Plan QCSM Quality Control System Manager Ra radium (as in Ra-226) RI Remedial Investigation RQ Reportable Quantity

LIST OF ACRONYMS (continued)

SCADA Supervisory Control and Data Acquisition SCADAC SCADA computer Site DuPont Chambers Works FUSRAP Site (aka Chambers Works) SSHO Site Safety and Health Officer SVOC semi-volatile organic compound Th thorium (as in Th-230) TPH total petroleum hydrocarbons TSS total suspended solids U uranium (as in Total U, U-234, U-235, and U-238) UFP Uniform Federal Policy USACE United States Army Corp of Engineers USDOT United States Department of Transportation USEPA United States Environmental Protection Agency VFD variable frequency drive VOC volatile organic compound WTF Waste Transshipment Facility i

TABLE OF CONTENTS

1.0 INTRODUCTION

1.1 PURPOSE

1.2 SITE DESCRIPTION

2.0 CONSTRUCTION WATER TREATMENT PLANT

2.1 SYSTEM OVERVIEW

2.2 TREATMENT OVERVIEW

2.2.1 Iron Removal System

2.2.2 Oil/Water Separator

2.2.3 Flocculation and Sedimentation

2.2.4 Polishing

2.3 CONTROLS OVERVIEW

2.3.1 Flow Control

2.3.2 Process Control

2.3.3 Control Philosophy

2.3.4 Process Safety Management

2.3.5 Cascade Control

2.3.6 Modes of Operation

2.3.7 Emergency Stop

2.4 PROCESS DESCRIPTIONS

2.4.1 Mass Transfer

2.4.2 Precipitation

2.4.3 Primary Dewatering

2.4.4 Coagulation

2.4.5 Flocculation

2.4.6 Filtration

2.4.7 Absorption

2.4.8 Ion Exchange

2.5 AUXILIARY SYSTEM DESCRIPTIONS

2.5.1 Influent Equalization Tank

2.5.2 Backwash Storage Tank

2.5.3 Effluent Storage Tanks

2.5.4 Instrumented Discharge Manifold

2.5.5 Effluent Piping

2.5.6 Sampling Ports throughout the CWTP System

3.0 OPERATIONAL MONITORING CRITERIA

3.1 PROCESS EQUIPMENT

3.2 DISCHARGE MONITORING

3.3 CHEMICAL MANAGEMENT

4.0 OPERATIONS

4.1 TREATMENT SYSTEM STARTUP

4.2 TREATMENT SYSTEM SHUTDOWN

4.2.1 Shutdown for Maintenance

4.2.2 Emergency Shutdown

4.3 SCADAC OPERATION

4.3.1 OVERVIEW Screen

4.3.2 Process Menu Screen

ii

4.3.3 Influent pH Control Screen

4.3.4 Process Equipment Speed Controllers Screen

4.3.5 Clarifier Level Loop Controllers Screen

4.3.6 Influent Pump Control Screen

4.3.7 FILTER Group Control Screen

4.3.8 Pressure Filter Screen (typical of all pressure vessels)

4.3.9 Filter Valve Control Screen

4.3.10 Building Ventilation Screen

4.3.11 Alarms Screen

4.3.12 Statistics Screen

4.3.13 Configuration Menu Screen

4.4 PRESSURE FILTER OPERATION

4.4.1 System Description – Multi-media Filtration

4.4.2 Operation

4.4.3 Controls

4.4.4 Operator Control Station Control

4.5 FILTER BACKWASH

4.6 ION EXCHANGE SYSTEM

4.7 SLUDGE HANDLING AND DISPOSAL

5.0 EMERGENCY PLANNING

5.1 PRE-EMERGENCY PLANNING

5.1.1 Planning

5.1.2 Evacuation Plan

5.1.3 Training

5.1.4 Response Coordination

5.2 SUMMARY OF REMEDIAL ACTION FIELD ACTIVITIES

5.2.1 Chemical and Waste Inventory

5.2.2 History of Previous Spills

5.3 PROJECT PERSONNEL RESPONSIBILITIES

5.3.1 Spills

5.3.2 Alarms

5.3.3 Inspection and Monitoring

5.3.4 Chemical Handling Practices

5.4 RELEASE RESPONSE

5.4.1 Responsibilities

5.4.2 Communications

5.4.3 Emergency Telephone List

5.4.4 Accidents and Injuries

5.4.5 Notification

5.4.6 Reportable Quantities

6.0 LONG TERM MAINTENANCE PLAN OVERVIEW

6.1 GENERAL OPERATIONS AND INSPECTION

6.2 CALIBRATION PROCEDURES

6.3 PROCESS EQUIPMENT

6.3.1 Rotating and Reciprocating Equipment

6.3.2 Tanks

6.3.3 Inclined Plate Clarifier

6.3.4 Multi-media Filters

6.3.5 pH Adjustment and Control

6.3.6 Pumps

6.3.7 Carbon Vessels and Carbon

iii

6.3.8 Piping and Valves

6.3.9 Gauges, Meters, Switches and Transducers

6.3.10 Supervisory Control and Data Acquisition System

7.0 RECORDKEEPING AND REPORTING

7.1 MONITORING DATA

7.1.1 Field Data

7.1.2 Electronic Data

7.1.3 Tank Monitoring

7.2 SYSTEM BACKUP REQUIREMENTS

7.3 REPORTING

8.0 SAFETY PRECAUTIONS

8.1 PERSONNEL HAZARDS

8.2 EQUIPMENT AND PRODUCT SAFETY PRECAUTIONS

9.0 REFERENCES

FIGURES

Figure 1. Site Map Figure 2. Construction Water Treatment Plant General Arrangement Figure 3. Treatment Zones Figure 4. Process Flow Diagram Figure 5. Filter Feed Pump Process and Instrumentation Diagram Figure 6. Multi-media Pressure Filter Process and Instrumentation Diagram Figure 7. Filter Remote Control Screen Figure 8. Individual Valve Control Screen Figure 9. Pressure Filter Valve Arrangement Figure 10. Lead/Lag Manifold Configuration

TABLES

Table 1. CWTP Sampling……………………………………………………………………………..17 Table 2. Reportable Quantities ………………………………………………………………………..52

APPENDICES (On Bookmarked CD)

(See Fly Sheets for detailed Table of Contents of Each Appendix)

Appendix A CWTP Manufacturers Product Data and Manuals

Appendix B Hazleton 100 GPM WWTP Operation and Maintenance Manual

Appendix C Process & Instrumentation Diagram and Design Drawings

Appendix D NJPDES Permit Equivalency and Discharge Criteria file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573775 file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573776 file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573777 file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573780 file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573781 file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573782 file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573783 file:///C:/Users/rag/Desktop/ECC%20Dupont/Engineering/Manual/2014-12-16%20CWTP%20O&M%20Plan%20Hazleton%20rev%202.docm%23_Toc406573784 iv

Appendix E Composite Sampling Procedure for Multiple Frac Tank Sampling

Appendix F Benchscale Treatability Report

Appendix G Startup Checklist, Monitoring and Reporting Forms

Appendix H Software Logic and Loop Control Instructions

Construction Water Treatment Plant Operation and Maintenance Plan

Remediation Services Formerly Utilized Sites Remedial Action Program (FUSRAP)

Former DuPont Chambers Work Site, Deepwater, New Jersey

1.0 INTRODUCTION

1.1 Purpose

The United States Army Corps of Engineers (USACE) - Philadelphia District is conducting the environmental remediation and restoration of the DuPont Formerly Utilized Sites Remedial Action Program (FUSRAP) Chambers Works Site (Chambers Works or Site) located in Deepwater, New Jersey. The Site is an active chemical manufacturing facility owned and operated by E.I. du Pont de Nemours and Company (DuPont).

The project involves remediating three areas of concern (AOCs) within two Operable Units (OUs). AOC 1 and AOC 2 are located within Operable Unit 1 (OU 1) and AOC 6 is located within Operable Unit 3 (OU 3). The contaminants of concern (COCs) are uranium (U) including U-234, U-235, and U-238, as well as thorium (Th-230), and radium (Ra-226). Based on review of the data contained in the Remedial Investigation (RI) Report (USACE and Cabrera, June 2011), as well as subsequent groundwater sampling events (USACE, July 2012 and January 2014), soil that contains chemical constituents (coal tar/coal tar distillates, metals, volatile organic compounds [VOCs], semi-VOCs [SVOCs], polycyclic aromatic hydrocarbons [PAHs], etc.) commingled with FUSRAP material in excess of 65 picocuries per gram (pCi/g) of total uranium is expected to be encountered during remediation. The Remedy is excavation and transportation of contaminated soils from the three AOCs for offsite treatment and disposal.

During implementation of the Remedy, construction water will be generated and managed from the following sources:

Groundwater from dewatering of excavation areas before excavation, during active excavation, and during backfilling operations;

Truck and equipment decontamination; and Storm water that enters excavations or that comes in contact with contaminated surfaces or equipment in the Site Support Areas, such as the Waste Transshipment Facility (WTF) and Construction Water Treatment Plant (CWTP) secondary containment areas during precipitation events.

The construction water generated from all three AOCs and the site support areas will be treated on site by the temporary CWTP, located at the southern portion of AOC 2 (OU 1). The CWTP is proposed to operate at the FUSRAP Chambers Works Site continuously during excavation dewatering of AOC 2 and 4 days/week, 10 hours/day during excavation dewatering of AOC 1 and AOC 6. The operating schedule may be adjusted as necessary, depending on project requirements and conditions

Environmental Chemical Corporation (ECC) has developed this Operation and Maintenance (O&M) Plan for the CWTP and submitted it to the USACE, Philadelphia District, as required by Specification 01010 Summary of Work, Section 1.3 Work Plans.

The purpose of this O&M Plan is to provide operating personnel with the understanding, techniques and references necessary to assist in the efficient and effective operation of the CWTP. The CWTP is designed to operate continuously with minimal downtime and on-site operator attention. Included within this O&M Plan are the system operation description, operational monitoring criteria, system startup and shutdown procedures, maintenance requirements, safety precautions, operational problems and troubleshooting guides for the process equipment. This O&M Plan will govern operation and maintenance of the CWTP system from the influent tank, through the point where effluent is discharged to the Central Drainage Ditch

(CDD).

Each person associated with the operation of the CWTP will become familiar with all of the above-referenced information to ensure that proper operation, maintenance, and safety procedures are followed.

1.2 Site Description

The Chambers Works is located in Pennsville and Carneys Point Townships, on the southwestern shore of New Jersey, along the Delaware River, north of the I-295 Delaware Memorial Bridge, and adjacent to the residential community of Deepwater, NJ (see Figure 1 below). The Chambers Works extends 2.7 miles between Helms Cove to the north and the Salem Canal to the south. Henby Creek separates the active Chambers Works manufacturing area from the former Carneys Point Dye Works. The former Pennsylvania and Reading Seashore Line railroad track bounds the property to the east.

Three locations have been identified for remediation. Those locations include:

OU 1, AOC 1

OU 1, AOC 2

OU 3, AOC 6

The locations of OU 1 (AOC 1 and AOC 2) and OU 3 (AOC 6) are shown on Figure 1.

Figure 1. Site Map

2.0 CONSTRUCTION WATER TREATMENT PLANT

The USACE uses hydraulic control structures, soil excavation and disposal to contain and remediate impacted areas associated with the DuPont Chambers Works FUSRAP Site. Existing and infiltrating groundwater and local rainfall run-off is collected from the excavations, handling areas, dewatering wells, and sumps, and treated in a CWTP and discharged to the CDD.

CWTP system operation and maintenance is described in this O&M Plan. Manufacturer’s literature, located in Appendix A, contains additional detailed operation and maintenance information for equipment and components used in the CWTP. Appendix B contains the original Hazleton 100 GPM Waste Water Treatment Plant (WWTP) Operations and Maintenance (O&M) Manual in its entirety, which contains the vendor Manuals and product data for equipment that originally existed in the Hazleton Floc trailer and filter trailer. Some of this material also resides in Appendix A for easy referral. Remaining appendices contain references and documents to assist in operation and improve understanding of the system. The entire manual should be read prior to taking charge of the operation or repair of the system.

2.1 System Overview

Groundwater and rainfall runoff from construction dewatering enters the CWTP through two mobile storage tanks (frac tanks) where debris and grit is allowed to settle out, and where light non-aqueous phase liquid (LNAPL) is initially separated from the influent. Water collected from AOC 1 and AOC 2 is pumped directly to the CWTP. Water from the WTF and AOC-6 will be collected in local frac tanks, then transferred to the CWTP by truck. Actual flow rates are determined by field conditions, rate of construction water withdrawal, and transport from the AOC construction areas to the CWTP. The flow rate through the CWTP may change as work progresses.

Construction water is drawn from the influent storage, treated through the CWTP and stored in effluent tanks. Quality testing of the effluent tank water will determine if it is acceptable for discharge to the CDD.

Treated water which does not meet the CDD discharge criteria is sent back to the influent tank to be re-treated through the CWTP until it meets discharge criteria. Treated water which meets the discharge criteria is discharged to the CDD with concurrence from USACE and/or DuPont, as required. The CWTP can operate in batch mode or continuous discharge mode, depending on approved discharge criteria and effectiveness of treatment.

The CWTP is a single train treatment process comprised of several mobile storage tanks and treatment trailers connected in series. The combined system operating range is between 1 and 80 gallons per minute (gpm). Water flows from right to left in the CWTP General Arrangement shown in Figure 2.

Figure 2

Trash pumps and hoses are used to transfer water from excavation sumps and dewatering systems into the influent frac tanks located adjacent to the Influent ModuTank. Overflow from the frac tanks, free of debris and grit is stored in a 165,000-gallon Influent ModuTank located on the right in Figure 2. The combined volume of these tanks reduces surges in flow and permits some management of the operating schedule.

The stored construction water is pumped into the treatment train by the influent pump, where it flows through a series of treatment operations (summarized below). Each operation is designed to remove certain contaminants and incrementally clean the water. After the last polishing operation, where special ion exchange resins provide radionuclide removal, the treated water is stored in the 165,000-gallon Effluent ModuTank located on the left in Figure 2. Once testing confirms the treated water quality meets permitted requirements, it is pumped through a discharge pipe to local drainage. Solids removed during treatment are further dewatered in a sludge filter box in the center top of the graphic and disposed with excavated soils.

The Effluent ModuTank storage capacity may be supplemented with additional storage tanks. The second set of effluent storage tanks will provide the capability to alternate treatment, sampling, analytical and approval cycles between the two effluent tank systems, to allow for continuous water treatment.

2.2 Treatment Overview

The CWTP capacity is 70 gpm at design conditions. The treatment train is comprised of four primary treatment zones connected in series and is depicted in Figure 3. The primary treatment zones are:

Iron Removal System (IRS) Oil Water Separator (OWS) Flocculation and Sedimentation (COAG and FLOCC) Effluent polishing (FILTER, CARBON, IX)

Raw water is pumped from the Influent ModuTank to the iron removal system (IRS) using a progressing cavity electric pump with a variable frequency drive (VFD). This low shear, positive displacement pump is designed to prevent product emulsification.

2.2.1 Iron Removal System

The IRS is a modified frac tank, designed to precipitate and remove iron by clarification to minimize fouling of the oil water separator (OWS). Chemicals required in the process, such as sodium hydroxide (caustic) for pH adjustment and clarification aids (coagulants), are injected at several locations in the piping connecting the influent pump discharge to the IRS System.

The following two process control loops are associated with the IRS treatment zone and affect all remaining treatment;

Treatment flow rate and pH.

Once a treatment flow rate is selected, the influent pump speed is automatically controlled to maintain that flow. Similarly, a treatment pH is selected and the controller automatically varies the pulse rate of the caustic feed pump, as needed to maintain that pH. The IRS tank provides retention time for precipitation reactions to equilibrate. The pH-adjusted water flows up through an inclined plate clarifier (IPC) suspended in the tank.

Partially treated water overflows from the IRS clarifier and flows by gravity to the OWS. Solids collected in the IRS are transferred to a container based filter box for secondary dewatering. Filtrate from the filter

Figure 3 box is returned to the IRS reaction area.

2.2.2 Oil/Water Separator

The OWS is designed to remove free oils and grease as well as emulsified product. When required, an emulsion breaking chemical is injected into the gravity piping prior to the OWS. The OWS is a coalescing type separator using a plate pack. Absorbent pads are initially being used to collect any free product that separates. Product recovery skim weirs and storage tank are available if the volume of recovered product exceeds practical absorption. Partially treated water flows from the OWS separation chamber by gravity to a coagulant mix tank (COAG).

2.2.3 Flocculation and Sedimentation

The COAG Tank and FLOCC Trailer equipment combine to form a flocculation and sedimentation system that is designed to agglomerate extremely small particles so they can be removed by clarification and filtration. Two clarification aids are used in series, a coagulant and a flocculent.

COAGULENT

The COAG tank is designed to mix primary coagulants or counter-ion chemicals prior to flocculation.

Coagulant is injected into the gravity piping between the OWS discharge and the COAG tank. Two variable speed mixers and an observation point are provided for operations to optimize this process. Charge adjusted water is pumped to the Flocc Trailer by the Flocc Feed Pump.

FLOCCULENT

Water enters the FLOCC Trailer through a reaction tube. The reaction tube can be preceded by an optional reactor/stripper (Maxi-Strip). Various reagents to adjust pH or facilitate additional precipitation may also be introduced here, if required. In the start-up configuration, a high molecular weight (HMW) flocculent chemical is injected in the Flocc Feed Pump discharge pipe prior to the reaction tube. The HMW flocculent is produced from a polymer emulsion in a make down Polyblend unit.

The water flows by gravity down through the reaction tube and across a chemical addition zone to an upwell flocculator. In the horizontal section or zone, additional ports for clarification aids are provided. Depending on operating conditions, this is the alternate injection location for the HMW polymer.

Water with coagulant or flocculants added flows up through a Flocc tube which contains an adjustable variable speed mechanical upwell flocculator and observation point used to optimize water clarity.

Flocculated water overflows to a fluidized bed contact chamber called a Flocc tunnel. The U shaped flow through the Flocc tunnel assists in both the flocculation and precipitation unit operations.

Conditioned water then overflows to an IPC for primary removal of the precipitated solids. The clarified water is called supernatant and is pumped by a high pressure centrifugal pump through a bag filter to the pressurized effluent polishing system located in the next two trailers.

The underflow solids (sludge) collected in the clarifier and the flocc tunnel are manually pumped to the sludge filter box for secondary dewatering with the IRS sludge. All filtrate returns to the IRS. Sludge handling and disposal is discussed in Section 4.7.

2.2.4 Polishing

The pressurized effluent polishing is comprised of the following three pressure vessel systems in series:

Multi-media Filtration (FILTER) Granular Activated Carbon (GAC) Absorption Ion Exchange

FILTER

Pressurized discharge from the bag filter feeds six parallel multi-media filter vessels located in the FILTER trailer. The multi-media in the vessels trap small flocculated particles not removed by clarification. Solids collected in the media are regularly flushed back to the Influent ModuTank during the filter cleaning (backwash) cycles.

CARBON

Filtered water leaves the FILTER Trailer and continues under pressure through two parallel GAC vessels followed by a single lag GAC vessel. The GAC vessels are located in the ProACT Trailer. The GAC can absorb many constituents and is used to further polish the water. The completely pre-treated water flows under pressure to radiation removal located in the FILTER Trailer. Any solids collected from the GAC vessels are periodically flushed (backwashed) to the Influent ModuTank.

The still pressurized water is directed through two groups of three parallel vessels. Radiation removal is accomplished by a proprietary resin designed to remove radionuclides (uranium) in a unit operation called ion exchange (IX). The now treated water flows by gravity to the Effluent ModuTank. The IX units can be flushed (backwashed) to the Influent ModuTank.

2.3 Controls Overview

The CWTP utilizes an automated control system to assist the operator in processing water. System control is distributed among local controllers located near the equipment and processes they are operating. The local controllers are linked by a network to two main Programmable Logic Controls (PLCs) and the PLCs are connected to a Supervisory Control and Data Acquisition (SCADA) computer.

The SCADA system interfaces with 8 industrial type computers through the networks, either PLC or operator control station (OCS) units to control some operating functions. In addition to data logging, three principle functions are handled through computer control.

Flow control functions are automated to insure a path for water through the system, provide a stable flow rate, and minimize surging; this allows the operator to optimize continuous processes and to stop flow when needed to handle low tank levels, upsets or equipment failures.

Automated process control functions assist the operator by performing maintenance level cleaning of the pressure filters, holding pH constant, and starting/stopping chemical addition.

Alarm handling and annunciation gives the operator the quickest notice of problems in the treatment works and in some cases handles trouble with a safe unattended shutdown.

2.3.1 Flow Control

Flow through the entire CWTP is coordinated by three VFD driven pumps with automatic control loops to provide a continuous stable flow through all the separate process equipment. Once set, the individual controllers will maintain a constant flow indefinitely, provided there is water available.

The influent pump speed is modified to maintain a constant flow rate from the Influent ModuTank into the IRS. The water flows by gravity through the IRS and OWS to the COAG tank.

The Flocc Trailer feed pump draws from the COAG tank and discharges into the Flocc Trailer.

The pump speed is modified to maintain a constant level in the COAG tank. Maintaining a constant level in the COAG tank forces the Flocc Trailer feed pump to match the upstream flow. The water then flows by gravity through the Flocc Trailer to a clearwell.

The Filter feed pump draws from the clearwell and pumps the water through the pressure polishing system to the Effluent ModuTank. The Filter feed pump speed is modified to maintain a constant level in the clearwell, also matching upstream flow.

2.3.2 Process Control

The speed or number of pulses per minute of the metering pump that supplies the caustic is modified to maintain the pH in the IRS at the operator selected set point regardless of changes in flow, temperature or water chemistry. pH is adjusted with caustic prior to the IRS to assist in the precipitation of iron and to provide a pH environment where chemical clarification aids and emulsion breakers are the most effective.

In addition to the pH control loop, all chemical metering pumps, when operated in automatic, receive a permit to operate from the control system that stops chemical addition during upsets or periods of no flow.

Automatic stopping of chemical feed during disruption greatly shortens the time needed to produce acceptable water during restarts.

2.3.3 Control Philosophy

The operational intention of this control system is to treat water unattended continuously depending on water management requirements. Startup, calibration, water testing, operational monitoring and adjustments, and maintenance attention are required.

All process controls are automatic. Process set point values and configuration are controlled by the plant operator. The control system will maintain those set points indefinitely, dependent on instrument calibration and chemical inventories.

Redundant equipment is not required for operation; trouble is handled by a safe, unattended shutdown of the entire treatment system. Trouble is alarmed at the main power distribution panel and SCADA computer

(SCADAC).

Control reliability is provided by conservative design and practical protection provided through protective housings.

Normal operating mode is automatic. With the exception of electric current protection devices, all normal equipment safety controls are bypassed when equipment is operated in the “HAND” mode.

2.3.4 Process Safety Management

Normal safety overloads are provided for all rotating equipment in the motor starter or drive controller.

The HAND-OFF-AUTO selector switch or soft key for any tripped equipment must be returned to OFF before attempting to correct any trouble conditions. Any trouble that may be a hazard or cause a process upset will result in a shutdown and alarm. Refer to the troubleshooting section of the manual.

To accommodate maintenance and manual operation, all 260-volt rotating equipment will have a HAND- OFF-AUTO selector switch or soft key. In addition, a run indicating display will be located on the respective local control panel showing equipment status.

CAUTION

Equipment in HAND mode may automatically restart after a power outage.

The HAND position disables cascade control and starts the selected equipment overriding most interlocks. Extreme care should be exercised when operating in HAND mode.

The HAND position disables level control and may cause pump damage if operated improperly.

Extreme care should be exercised when operating in HAND mode.

2.3.5 Cascade Control

All equipment associated with the treatment of water is connected by what is known as a cascade control system. This simply means that from a water flow perspective, upstream equipment cannot run unless the equipment immediately downstream is "OK" or running.

There are eight equipment groups in the cascade control scheme. Their cascade order is determined by water flow.

Chemical Pumps

Influent Pump

Flocculation Feed Pump

Flocculation Equipment

Filter Feed Pump

Pressure Filter System

Ion Exchange System

Flow Path

The flow path must be OK to operate the ion exchange system in AUTO. The ion exchange system must be online to operate the pressure filter system in AUTO. The pressure filter system must be online to operate the filter feed pump in AUTO. The filter feed pump must be online or ready to operate the flocculation equipment in AUTO. The flocculation equipment must be on-line to operate the flocculation feed pump in AUTO. The flocculation feed pump must be on-line to operate the influent pump in AUTO.

The influent pump and flow must be OK to operate the chemical feed pumps in AUTO.

While there are additional subordinate and intra-system permissives involved in automatic operation, the cascade order forms the fundamental basis of control.

2.3.6 Modes of Operation

There are three modes of operation within the automatic control system.

STARTUP

RUN

SHUTDOWN

STARTUP mode is initiated by depressing the System Start pushbutton with the required equipment configured in AUTO and the system off. Some alarms and most process trips are disabled during STARTUP mode. A successful completion of STARTUP mode initiates RUN mode. In RUN mode, all alarms are armed and process trips are enabled.

SHUTDOWN is used to stop the system quickly in standard cascade order. Severe equipment failure or automatically detected process safety issues will trigger SHUTDOWN mode. SHUTDOWN can be initiated by an operator.

All modes are sequential and can only exist individually.

2.3.7 Emergency Stop

An EMERGENCY STOP (E-stop) pushbutton is provided at five locations throughout the CWTP.

Depressing an E-stop will stop all pumping and rotating equipment connected to the area controller. The E-stop action also will stop all other equipment connected to any controller on the CWTP network.

Not included in the E-stop are area sumps which operate independently by pump mounted floats, temporary equipment run by extension cords, or diesel engines.

2.4 Process Descriptions

The water treatment process incorporates six primary unit operations and several secondary operations divided into three groups; inorganic solids handling (pretreatment), oil/water separation and radiation removal. Figure 4 illustrates the process flow, showing the following treatment processes:

Mass Transfer (optional) Precipitation Emulsion Breaking Oil/Water Separation Coagulation Flocculation Clarification Filtration Absorption

Each process is described below.

2.4.1 Mass Transfer

Mass transfer is used to dissolve oxygen into the water to oxidize iron. The reaction tube on the Flocc Trailer is designed to accept aeration equipment. The basis for the unit operation of mass transfer (air stripping or oxidation) is the relationship between the vapor pressure and solubility of the given substance in water. This is defined by the Henry's Law. The relationship is represented by the following equation:

y = (kh) (x)

Where: y = partial pressure of compound in the air, in atmospheres (atm) x = gaseous compound in solution, in mole fraction kh = Henry's Law Constant, in atm/mole fraction

The Henry's Law Constant is used to determine the partial pressure of the compound in the vapor phase over a liquid solution of known concentration.

Henry's Law is valid for most dilute solutions provided that the compound does not ionize or react in the liquid phase. Gases like oxygen will dissolve into water and gases like carbon dioxide or VOCs will exit water simultaneously; both actions are considered mass transfer.

2.4.2 Precipitation

The plant is currently using a pH dependent precipitation process where the IRS neutralizes or increases the pH with a 25% caustic solution to a pH range between 8.2 and 9.0 standard units. While iron solubility is very low over a range of pH, the speed at which the iron is oxidized and precipitates increases with increasing pH and this range allows for rapid reaction while optimizing downstream processes. If the iron is incompletely oxidized, increasing the pH will cause more iron to precipitate.

2.4.3 Primary Dewatering

Both the IRS and the Flocculation and Sedimentation systems employ primary dewatering or clarification.

Simply stated, the water is clarified by allowing the solids to settle by gravity under quiescent conditions.

The basis of primary dewatering or clarification is the differential settling rates of solids within a liquid controlled by apparent specific gravity, viscosity, and fluid kinetic energy characteristics. The essential sizing equations are derived from Stokes’ Law and the dimensionless Reynolds number.

The particle size of iron hydroxide/calcite precipitating in this process is typically 0.4 micron (0.0004 inch).

Particles of this size are classified as clays and are considered colloids. In addition to the standard colloids, the excavation areas may contain highly charged natural clays below 0.2 microns. Small particles have high surface area to volume ratios and as such, generate friction forces close to gravitational or buoyant forces at small velocities. Ferric hydroxide also produces a high surface charge density. Colloids typically attract a tightly bound layer of water (stern layer) containing ions opposite in charge to the surface charge of the particle, making their “apparent specific gravity” closer to 1 (or water) and greatly increasing the time to settle out of the treatment stream.

To improve this characteristic, mechanisms are employed to thin the stern layer, clump the particles together, or some combination of the two. Most often chemical settling aids, called coagulation, along with specific energy mixing, called flocculation, are the mechanisms.

Figure 4. Process Flow Diagram

2.4.4 Coagulation

Coagulation uses a chemical settling aid, often inorganic that neutralizes the surface charge density of the particle and charge of the water, thinning the stern layer and permitting the particles to attract one another.

Gentle mechanical agitation is used to disperse the agent and increase the likelihood particles get close enough to each other to be affected by weak mechanisms like Van der Waals forces.

2.4.5 Flocculation

Flocculation is more of a mechanical settling aid with particles clumping together by enmeshment. This technique uses a sufficient form of agitation to cause particles to bump into others for a period of time until large gelatinous clumps, or floc, are created. Optimally, the mixing energy is controlled to balance between enmeshment and shear, in a manner to produce the largest possible floc. A chemical settling aid, usually a long chain polymer, is used as the nucleus for these floc. Depending on the charge density of the particles, flocculants can have an opposing charged radical attached to the polymer backbone to aid in attracting the particles and, to some extent, neutralizing the surface charge.

The FLOCC Trailer uses a combination of contact clarification with an attached settling zone. Separating these two components of conventional contact clarification allow for integral electrostatically stable colloid entrapment and desaturation enhancement. Conventional contact clarification uses sludge recycled from within the contact zone or fluidized bed. This design feature can accommodate almost unlimited solids handling without load limiting the high rate clarification while giving the process stability of a continuous blow down contact clarifier.

The FLOCC Trailer employs a specific two zone, slow speed flocculator to optimize the flocculation time without significantly increasing the shear. Slow speed flocculation is followed by a plug flow contact zone, called a floc tunnel. The floc tunnel uses a mechanical distributor to insure even flow. The floc tunnel is a plug flow fluidized bed as well as an energy diffuser prior to the clarifier entrance.

The high rate, inclined plate style clarifier uses dual side plate entrance and individual plate space orifice discharge. It is sized conventionally and is dependent on the settling rate of the conditioned floc and the flow rate through the system. The solid particles must settle and slide out of the flow stream without disrupting the local flow regime at the entrance.

2.4.6 Filtration

Multi-media entrapment filtration is used as polishing in this process. Filtration is defined by a type of mechanism used to stop a solid, suspended material or different fraction of bulk flow while allowing a portion of the bulk flow to pass. Multi-media entrapment filtration uses a deep bed of sized individual particles to trap particulates remaining in a fluid as it passes through the bed.

The multi-media pressure filter group uses anthracite coal, sand, garnet and gravel layers as its filter bed.

These materials were selected for size and specific gravity. The bed is cleaned of trapped materials by reversing the flow and “backwashing” the filter. During backwash the velocity is designed to lift the media in such a manner as to allow the trapped particles to escape without flushing the media. The different specific gravities of the layers cause them to separate while settling back into position after backwashing.

2.4.7 Absorption

GAC is a form of media used to absorb certain gases and ions. The term activated refers to the conditioning of carbon during production so as to produce microscopic pores whose size determines which size and shape molecules become trapped or absorbed into the carbon particles. Certain compounds can also adsorb to the surface of the particles. GAC is used primary to remove VOCs.

Absorption unit operation will also remove most radioactive gases that may be present such as radon, as well as trap or filter other inorganic or organic species that may escape the multi-media filters and interfere with the downstream performance of the proprietary ion exchange resin.

The GAC vessels will be arranged in a lead/lag configuration. Two vessels in parallel will comprise the lead component, followed in series by a single vessel in lag position. Each GAC vessel is rated for 3,000 pounds (lbs) of GAC and contains approximately four feet of GAC, designed to adsorb organic compounds.

Specifications for the GAC units are provided in Appendix A.

The estimated organics loading for these units, and the carbon usage estimates based on planned hours of operation and AOC specific average influent organics concentration data, are provided in the Design of Construction Water Treatment Plant document.

The recommended change out period for these units when processing water from each AOC is:

AOC 1 24 days AOC 2 14 days AOC 6 24 days

Based on groundwater quality data there are high VOCs within AOC 2; therefore, the lead GAC vessels will need shorter change-out periods. The actual change-out period can vary depending upon the actual level of organics in the construction water entering the GAC units.

It should be noted that methylene chloride is a weak adsorbing compound with an average influent concentration of 27 micrograms per liter (ug/L) in AOC 2 (Table 1B of the CWTP Design Report) and discharge criteria of 6 ug/L (NJPDES Permit # NJ0005100). Carbon change outs would be required if the discharge criteria between GAC units for methylene chloride is not met during sampling events.

It should be noted that vinyl chloride cannot be treated by carbon. Vinyl chloride adsorbs very poorly onto carbon in water phase applications. The highest concentration of vinyl chloride is observed in AOC 2, as 115 ug/L (Table 1B of the CWTP Design Report). If the influent concentration of vinyl chloride exceeds the discharge criteria, the CWTP will required to be upgraded appropriately.

Treatment monitoring will be conducted at the influent point to the GAC units, between the lead and lag GAC units (i.e., mid-points) and at the effluent point of the GAC units. When concentrations from a mid-point sample exceed discharge criteria, either the lead/lag configuration may be switched (a new GAC unit will replace the previous lead unit and be operated as the lag unit) or the carbon will be replaced in the affected vessel with fresh carbon. Alternately, the project team may decide to change out the GAC in all three vessels when the mid-point concentration indicates breakthrough.

2.4.8 Ion Exchange

Ion exchange (IX) is another media-based unit operation. Unlike carbon which physically absorbs compounds, bonding replacement is the mechanism utilized by IX. The media used is generically called resin and is formulated specifically to remove certain radioactive species that can dissolve in water and form ions.

Specifications for the IX units are provided in Appendix A.

The strong anionic resin (Dowex 1 supplied by Dow Chemical or SIR1200 supplied by ResinTech) is to be used for removal of uranium from construction water. Within the Design of Construction Water Treatment Plant document, the highest levels of uranium at AOC 2 were used to develop the resin design.

Refer to Appendix A of the Design of Construction Water Treatment Plant document for supporting resin usage calculations. If the units are used until exhaustion, approximately one change out of six vessels is calculated to be required during AOC-2 remediation. The actual resin usage will be dependent on influent concentrations, and will be changed out when analytical results indicate breakthrough.

There are two sets of three IX units currently operated in parallel. Radionuclide concentrations will be monitored at the influent and effluent to the IX units. When concentrations at the IX effluent location indicate contaminant breakthrough, the resin will be replaced with fresh resin. Each of the IX columns holds approximately 1,150 lbs of resin, or about 6,900 lbs total.

The proprietary resin media is only produced in a few locations and is expensive, so care must be taken to prevent contamination and ensure its effectiveness. This is easily accomplished by proper maintenance and operation of the treatment system upstream of the IX units. Remain aware of any unexpected contamination of the water to be treated, such as free product or floating greases, that may overwhelm the pretreatment processes and don’t bypass treatment steps without full knowledge of its effect on the process. The IX vessels may be backwashed if the differential pressure across the vessels indicate media fouling.

2.5 Auxiliary System Descriptions

2.5.1 Influent Equalization Tank

The Influent Equalization Tank receives incoming flow from groundwater and collected storm water. The tank holds approximately 165,000 gallons. In addition, two 21,000-gallon frac tanks will be provided. A total influent storage of 207,000 gallons will handle the combined construction dewatering water and surface water volume from storm events. The purpose of the equalization tank is to equalize variations in influent flow and pollutant variations to ensure downstream process efficiency. The Influent Equalization Tank also serves as a settling tank to remove influent suspended solids. These solids may be removed manually from the tank, depending upon the rate of accumulation.

A floating cover will be installed on the ModuTank for controlling odor and reducing VOC emissions. The two influent frac tanks will have internal weirs to help segregate LNAPLs for removal and promote settling of suspended solids.

Specifications for the influent equalization tank and frac tanks are provided in Appendix A.

2.5.2 Backwash Storage Tank

One 21,000-gallon frac tank will be used to store effluent from the process to backwash the sand filters, GAC vessels, and the IX reactors. The total backwash volume required for maintenance of the filtration units is estimated as 9,000 gallons per day. The total backwash volume for the GAC units is estimated as 11,895 gallons per backwash and the total backwash volume for the IX units is 4,500 gallons per backwash.

The 21,000-gallon capacity is sufficient to provide backwashes of multiple units before requiring a re-fill.

Refilling the backwash storage tank is part of the effluent discharge cycle, clean water is diverted from the effluent discharge by the operator as necessary to maintain an adequate supply of water in the backwash storage tank for automated backwash of the units.

Specifications for the backwash supply storage tank are provided in Appendix A.

2.5.3 Effluent Storage Tanks

Treated flow is stored in effluent holding tanks with a total capacity of 168,000 gallons. A floating cover will be installed on the ModuTank for controlling odor and reducing VOC emissions. This treated water will be analyzed prior to discharge to ensure it meets permit discharge criteria. Treated water which does not meet the CDD discharge criteria will be sent back to the influent tank to be re-treated through the CWTP until it meets discharge criteria. Treated water which meets the discharge criteria will be discharged to the CDD with concurrence from USACE and/or DuPont as required. A non-resettable magnetic flow meter is provided for measuring flow from the effluent storage tanks to the CDD. Discharge can only be initiated by an Operator, no automatic start is allowed.

The effluent storage capacity may be supplemented with additional storage tanks. The second set of effluent storage tanks will provide the ability to alternate sampling, analytical and approval cycles between the two effluent tank systems, allowing continuous water treatment.

Specifications for the effluent equalization tank and frac tanks are provided in Appendix A.

2.5.4 Instrumented Discharge Manifold

An electric centrifugal pump is used to…