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OPERATION, MAINTENANCE,

AND MONITORING PLAN

PHASE IIA GROUNDWATER REMEDIATION SYSTEM

BITTERROOT VALLEY SANITARY LANDFILL

RAVALLI COUNTY, MONTANA

OPERATION, MAINTENANCE, AND MONITORING PLAN

PHASE II GROUNDWATER REMEDIATION SYSTEM

BITTERROOT VALLEY SANITARY LANDFILL

RAVALLI COUNTY, MONTANA

Prepared for:

National Institutes of Health Division of Safety

Environmental Protection Branch Building 13, Room 2W64

Bethesda, Maryland 20892

Prepared by:

Tetra Tech, Inc.

2436 Dixon

P.O. Box 2730 Missoula, Montana

January 2007

TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 OPERATION SUMMARY

2.1 System Overview

2.1.1 Groundwater Recovery System

2.1.2 Water Treatment System

2.1.3 Discharge Piping and Bear Creek Outfall

2.1.4 System Monitoring Instruments

2.2 Data Acquisition System

2.3 Alarm Interlock System

3.0 SYSTEM OPERATION

3.1 Start-Up Procedures

3.2 Shutdown Procedures

3.3 Start-Up Following an Emergency Shutdown

3.4 Winter Operation

4.0 HEALTH AND SAFETY

4.1 General Safety Precautions

4.1.1 Electrical Equipment

4.1.2 Mechanical Equipment

4.1.3 Explosion and Fire Hazards

4.2 Safety Equipment

4.3 Personnel Emergencies

5.0 AIR PERMIT REQUIREMENTS

6.0 SYSTEM PUMPING RATES

7.0 OVERSIGHT AND MONITORING OF REMEDIATION SYSTEM

7.1 Routine Monitoring

7.2 Reporting

8.0 REFERENCES

LIST OF TABLES

TABLE 1 BASIC TROUBLESHOOTING GUIDE

TABLE 2 FLOW RATES

TABLE 3 MONITORING FREQUENCY AND PARAMETERS

LIST OF APPENDICIES

APPENDIX A AS-BUILT FIGURES

APPENDIX B AIR STRIPPER MANUFACTURER’S INFORMATION

APPENDIX C MANUFACTURER’S INFORMATION – FLOW METERS, PUMPS,

SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM, SECURITY

SYSTEM

APPENDIX D ELECTRICAL DIAGRAMS

APPENDIX E FIELD MONITORING FORMS

APPENDIX F MONTANA DEPARTMENT OF ENVIRONMENTAL QUALITY

CORRESPONDENCE

Operation, Maintenance, and Monitoring Plan Bitterroot Valley Sanitary Landfill

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1.0 INTRODUCTION

This plan was prepared to guide operation, maintenance, and monitoring of the Phase II Groundwater Remediation System installed during 1998 through 2004 at the Bitterroot Valley Sanitary Landfill. The primary purpose of this plan is to provide a clear understanding of the operation and maintenance requirements for successfully operating and monitoring the system. Additionally, the procedures presented herein are intended to standardize protocol for collection of monitoring data to maintain representativeness and comparability. This plan will be reviewed periodically and updated as necessary.

Section 2 of this document provides summary information for operation and maintenance of the system and Section 3 provides more detailed operation procedures. Section 4 contains health and safety information for operators. Section 5 presents air permit requirements and Section 6 summarizes the flow settings that were used at system start-up and current optimized pumping rates. Section 7 describes the oversight and monitoring requirements associated with system operation. Operators of the system should read each of these sections to gain an understanding of the operation and maintenance issues concerning this groundwater treatment system.

1.1 PURPOSE OF SYSTEM AND LONGTERM STRATEGY

The existing remediation system at the subject property was constructed to provide treatment of groundwater exhibiting concentrations of volatile organic compounds (VOCs). The system consists of a recovery and monitoring well network, conveyance piping, and a remediation enclosure that houses the treatment equipment and related components. The recovery well network has been configured to intercept dissolved phase constituents to prevent further migration offsite and provide hydraulic control of the onsite dissolved phase concentrations by controlling the local groundwater flow gradient.

Recovered groundwater is conveyed back to the remediation enclosure to undergo treatment prior to discharge into Bear Creek. Within the remediation enclosure, air stripping techniques are utilized to maximize a mass transfer of site contaminants from the dissolved phase to the vapor phase. The mass transfer is facilitated by application of Henry’s constant (a relationship of the compounds affinity to occupy specific phases under equilibrium conditions) and counter current flow techniques. During the treatment process, the mass of dissolved phase constituents are imparted to the exhausted air stream and discharged to the atmosphere without treatment.

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2.0 OPERATION SUMMARY

2.1 SYSTEM OVERVIEW

System operators shall become familiar with this operation and maintenance plan, the as-built drawing set, and the air stripper installation, operation and maintenance manual. The as-built drawing set including system layout, process flow diagrams, mechanical diagrams, and engineering specifications is contained in Appendix A. The installation, operation, and maintenance manual, provided by the air stripper manufacturer, is contained in Appendix B. The user’s guide for the Supervisory Control and Data Acquisition (SCADA) system and the security system are contained in Appendix C.

Major components of the Phase IIA Groundwater Remediation System include:

• Groundwater recovery system;

• Water treatment system components, including air stripper, forced draft blower, effluent discharge pump, batch tank, water piping, and exhaust stack housed in the treatment building;

• Discharge piping and outfall at the North Channel of Bear Creek (Bear Creek); and

• System monitoring components.

Discussions regarding these major system components are provided below.

2.1.1 Groundwater Recovery System

Each of the ten groundwater recovery wells, designated R-1 through R-10 (Sheet 2, Appendix A), are equipped with submersible electric pumps. Note that the designations “S” for shallow and “D” for deep for wells R-3 through R-8 are included in drawings contained in Appendix A. These designations were dropped in the text of this plan and on field forms. Wells R-1 and R-2 were installed during 1994 and operated from 1994 through 1997 as part of the Phase I Groundwater Remediation System. Wells R-1 and R-2 are constructed with conventional slotted PVC pipe (0.010 inch slot size). Wells R-3 through R-8 are constructed with continuous slotted PVC pipe (0.065 inch slot size). Well R-9 is constructed with 0.02 inch continuous slotted PVC from 70 to 80 feet below ground surface (bgs) and with 0.04 inch continuous slotted PVC from 80 to 120.5 feet bgs. Well R-10 is constructed with stainless steel wrapped continuous 0.020 inch slot screen from 50 to 120 feet bgs.

Each submersible pump is equipped with a pump protector and a pump controller. R-7, R-9 and R-10 are equipped with a CU300 Redi-Flow 3TM controller that communicates with the Redi-Flow 3TM pump motor. R-3, -4, -5, -6 and -8 are controlled by Coyote pump protectors and motor controllers. A user-selectable timer on the pump protector determines when the pump will restart and cycle again. Restart times are generally of a duration such that the water level in the well is allowed to recover. The operator will be required to make minor adjustments to pump cycle times due to seasonal groundwater elevation changes. R-1 and R-2 are protected by sensors attached to the drop pipes. When the water level falls below above pump intake sensor, decreased electric current will signal the pump protector to shut the pump off. When the water level rises above the sensor, the pump is automatically re-started.

Water pumped from wells R-1, R-2, R-9 and R-10 flows downhill along the section of piping adjacent to Humdinger Lane (Sheet 2, Appendix A). R-10 is pumped uphill along Humdinger Lane and is combined with R-1 and R-2. R-9 is connected to the piping that was formerly used by R-1. Combination vacuum/pressure relief valves are contained in two manholes situated at the high point between R-1, R-

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2, R-9 and R-10 and the treatment building to allow air to enter/exit both pipes and assist gravity flow.

Water pumped from wells R-3 through R-8 flows under pressure slightly downhill to the treatment building.

2.1.2 Water Treatment System

The water treatment system includes a pre-packaged air stripper unit constructed by Shallow-Tray, Inc.

Operation of the air stripper, including control settings, is discussed in the installation, operation, and maintenance manual provided by the air stripper manufacturer (Appendix B).

Untreated water enters the air stripper inlet and flows downward across four perforated trays. Air is forced into the bottom of the air stripper and travels upward through the perforated trays. This counter current flow maximizes the mass transfer area, causing VOCs to be transferred from the water to air. Following contact with the groundwater (mass transfer), the VOC laden air stream is discharged to the atmosphere through the building exhaust stack.

A system performance estimate was completed by the air stripper vendor using an influent flow rate of 130 gallons per minute (gpm) and VOC concentrations measured in groundwater samples collected from recovery wells during February 1998 (a multiplier of 5 for VOC concentrations was used as a safety factor). The estimate indicated that the air stripper will achieve effluent requirements for the project. Since the system activation in 1998, VOCs have been consistently treated to concentrations below laboratory detection limits for all effluent water. The air stripper has a maximum design flowrate of 550 gpm; however, it has been equipped with a discharge pump sized to provide a maximum discharge flowrate of 270 gpm. Any increase of this discharge rate will require modification of system startup and validation, and startup monitoring procedures to ensure proper treatment of influent concentrations.

The average water flow rate to the air stripper is 115 gpm. This flow rate is based on Tetra Tech’s understanding of the distribution of dissolved phase contaminants gained through groundwater monitoring conducted since February 1998. Flow rates from individual recovery wells may be modified based on fluctuation in groundwater evaluations. If individual recovery well flow rates are modified, the total flow rate may change but is expected to remain below 150 gpm (Maxim 1999).

2.1.3 Discharge Piping and Bear Creek Outfall

A thorough understanding of the piping, valves and controls is necessary for proper operation of the system. Piping, valves and fittings in the treatment building are used to route water and control flow rates. Valves located on piping downstream of the air stripper can be used to direct flow of treated water to four destinations, including:

• Holding tank TK-101 for batch testing;

• Air stripper AS-101 inlet for secondary treatment by re-circulation;

• Infiltration trench piping located adjacent to the northeast corner of the treatment building for discharge of batch tested water; and

• Bear Creek for final discharge of treated water only.

During normal system operation, valves are configured so that all treated water is discharged to Bear Creek.

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Sample ports (Sheet 5, Appendix A) are located at several places to allow collection of water samples.

Sample ports are located on recovery well piping and the manifold for sample system influent water.

Sample ports are also located on effluent pipes from the air stripper for sampling treated water at the batch tank and water being discharged to Bear Creek.

2.1.4 System Monitoring Instruments

Operation of the system is monitored using several instruments which measure flow, pressure and temperature of fluids. The piping and instrument diagram (Sheet 5, Appendix A) provides technical specifications and shows the location of monitoring instruments relative to process flow. The mechanical plan (Sheet 6, Appendix A) shows the location of each instrument within the treatment building. Several of the instruments provide electronic readouts to a system data logger which can be accessed via telephone and modem for monitoring the system remotely.

Electronic flow meters (FE, FI, FIT-101) are installed on the ten influent water lines, the piping exiting the air stripper, and on the discharge pipe leading to Bear Creek (Sheets 5 and 6, Appendix A).

Manufacturer’s information and electrical wiring schematics for all electronic meters are contained in Appendices C and D, respectively.

Mechanical pressure gauges (PI-102) are installed on the eight influent water lines. Electronic pressure gauges (PI, PIT-101) are installed on the manifold pipe near the air stripper inlet, on discharge piping, and on each pumping well. Each electronic pressure gauge provides electronic readouts to the system data logger. The temperature gauge (T-101) on the manifold pipe near the air stripper inlet measures the influent groundwater temperature (Sheet 5, Appendix A).

2.2 DATA ACQUISITION SYSTEM

The SCADA system consists of a data logging system with internal modem connected to ten electronic flow transmitters and two electronic pressure transmitters. Technical specifications for the system components are presented on the piping and instrument diagram (Sheet 5, Appendix A). The user’s guide for the SCADA system is provided in Appendix C. Electrical diagrams showing the wiring schematic for the SCADA system are contained in Appendix D. Parameters which are monitored and recorded by the system include:

• Total volume and flow rate of untreated water entering the treatment building from each recovery well.

• Water pressure in each pumping well.

• Water pressure at the air stripper inlet.

• Total volume and flow rate of treated water leaving the air stripper at a point before batch tank and re-circulation piping.

• Total volume and flow rate of treated water leaving the treatment building through discharge piping including water flowing to the infiltration trench when necessary.

• Water pressure in discharge pipe leading to Bear Creek.

A personal computer and modem with data acquisition software are used to access the data logging system to view current flow conditions. Flow data recorded during the previous 30 days are also uploaded for the system operations database.

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2.3 ALARM INTERLOCK SYSTEM

The treatment system is equipped with several safeguards to prevent untreated water from being discharged to Bear Creek. These safeguards include electrical interlocks which will automatically shut down the recovery pumps and the treatment system if one or more of the following conditions occur:

• High level sensor in air stripper sump is activated;

• High level sensor in building sump is activated;

• High-Low air pressure is measured at the air stripper blower;

• High pressure is measured in the discharge pipe to outfall; and

• Unauthorized personnel enters building doors or window.

During alarm conditions, the solenoid valves on influent lines from wells R-1 and R-2 (Sheet 5, Appendix A) will automatically close to prevent water stored in the pipes from entering the building.

The master on/off switch for the system includes a 30-minute delay timer which allows the system to “self start” during power outages. The system is configured so that system will not restart during an alarm condition.

The alarm system includes an automated dialing system (autodialer) which will contact the alarm company which then contacts the operator (i.e., Tetra Tech’s Missoula, Montana office) in the event of an alarm. After business hours the autodialer will contact two home telephone numbers of Tetra Tech employees. The operator must contact the autodialer via touchtone phone to determine the cause of the alarm before re-arming and starting the system. A basic troubleshooting guide is presented in Table 1 which covers the typical alarms encountered and the most probable cause for noted condition.

System operators can use this guide to resolve the basic alarm faults present in the SCADA system.

Troubleshooting steps used to address problems associated with the air stripper are included in Appendix B. The instruction manual for the security system is included in Appendix C.

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TABLE 1

BASIC TROUBLESHOOTING GUIDE

PHASE II GROUNDWATER REMEDIATION SYSTEM

Bitterroot Valley Sanitary Landfill

Alarm

Display/Description Potential Cause Corrective Action

High Level Sensor in Air Stripper Sump

- Electrical Malfunction

- Discharge pump is inoperable

- Malfunctioning float switch (sticking)

- Sump level switch has failed and level is too high

- If system doesn't restart automatically, manually restart system.

- Manually bump discharge pump to ensure operational.

- Check and test float switch to ensure proper operation.

- Check sump level to ensure sump level switch is functioning properly and determine the cause of high water in sump.

Air Stripper Blower High-Low Air Pressure

- (High) Stack has been obstructed or damaged

- (High) Tray holes are becoming plugged

- (Low) Air is bypassing the stripper trays

- Observe stack from exterior of enclosure for integrity.

- Check stripper tray condition for scaling or sediment buildup.

- Check connections of makeup air piping to air stripper.

- Check air stripper tray gaskets and inspect hole covers for proper seal.

High Level Floor Sump - Water makeup line or discharge lines have ruptured

- Roof is leaking

- Inspect water makeup lines, discharge piping, connections, gaskets and inspection covers on air stripper for visible leaks.

- Examine roof from interior for indications of leaking.

Door Switch Alarm - Unauthorized entrance via doors or window

- Visually inspect enclosure from exterior for indications of forced entry. If signs are present call local authorities before entering.

- After on-site visits, the SCADA alarms need to be reset.

Motion Detector - Unauthorized entrance via doors or window

- Visually inspect enclosure from exterior for indications of forced entry. If signs are present call local authorities before entering.

- After on-site visits, the SCADA alarms need to be reset.

- Inspect motion detector for signs of spider webs and other obstructions to the motion sensor.

High Pressure to Flow Piping to Outfall

- Debris obstructing outfall.

- Ice covering outfall.

- Inspect and clean outfall.

- Remove obstructions.

Note: This guide lists possible malfunctions and does not cover all issues that could develop with the system.

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3.0 SYSTEM OPERATION

As part of system operation, it is important to document during each system inspection the system settings, flow rates, and fluid levels. Information presented below should be recorded by the operator and/or technician on the field sheets contained in Appendix E.

Groundwater Recovery Wells – The operator will record the following well parameters:

• Pressure gauge readings;

• Valve settings;

• Flow rates and total flow volumes; and

• Depth to water measurements in wells R-1 through R-10.

Air Stripper – The operator will record the following stripper parameters:

• Influent water temperature;

• Water pressure at air stripper inlet;

• Effluent water flow rate and total volume; and

• Air flow rate and static pressure.

Discharge Piping – The operator will record the following discharge parameters:

• Flow rate and total flow volume to Bear Creek; and

• Water pressure.

In addition to the above parameters, general comments and observations regarding the operational status of the system should be recorded. The oversight and monitoring program presented in Section 7 summarizes water sample collection frequency and laboratory analyses, frequency of inspections, log sheets and a more detailed description of inspection requirements.

3.1 START-UP PROCEDURES

Prior to start-up the following should be completed:

1. Inspect wells and manholes for damage.

2. Inspect Bear Creek outfall for damage.

3. Verify equipment is operating property, including that all system alarm instruments are operating properly.

Start-up can be initiated using these procedures:

1. Check all valve settings on effluent piping from air stripper. Under routine conditions, all valves would be closed with exception of those valves for discharging to Bear Creek. Valves should be adjusted to either fully open or fully closed.

2. Start up air stripper following manufacturer’s O&M manual instructions contained in Appendix B

3. Verify that air flow rates are appropriate and pressure readings are within the normal operating range.

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4. Turn on desired wells at breaker panel and switch located on west end of electrical fuse box (controlling R-1, -2, -9 and -10), monitor flow rates, and adjust flow rates as needed using appropriate valves Water flow rates from each of the wells will be determined at the time of initial start-up. Previous settings should be reviewed for determining suitable water flow rates..

The operating configuration of the system and objectives will change over time due to dynamic site conditions in addition to executing the specific site remediation goals. Therefore, the existing system settings and recovery well pumping rates must be periodically reviewed to ensure the operating configuration is appropriate for the current conditions at that time.

3.2 SHUTDOWN PROCEDURES

Routine shutdown can be completed following these procedures:

1. Deactivate all recovery well pumps by disengaging breakers located in breaker panel and switch located on west end of electrical fuse box.

2. Allow 10 to 15 minutes to treat water remaining in air stripper before throwing disconnect on air stripper control panel to off position.

Emergency shutdowns are automatically completed by the alarm interlock system during alarm conditions described in Section 2.3. Emergency shutdown can be completed manually by throwing the main breaker located in the breaker panel at the southwest corner of the building to the OFF position.

3.3 START-UP FOLLOWING AN EMERGENCY SHUTDOWN

Procedures for system start-up following an emergency shutdown are:

1. Contact the system using a touch-tone phone to determine the cause of the alarm condition.

2. If necessary, physically repair/remove the cause of the alarm condition (e.g., empty the floor drain and air stripper sump).

3. Use a touch-tone phone to rearm the alarm interlock system and start the treatment system. (if the cause of the alarm condition is not repaired/removed, the system will not restart).

If it is necessary to visit the site during an alarm condition, use procedures presented in Section 3.1 and Section 3.3 to restart the system.

3.4 WINTER OPERATION

During freezing temperatures, additional attention needs to be placed on operation and maintenance of the system. In winter operation, the operator must verify that both electric heaters (Sheet 6, Appendix A) are operating satisfactorily and the thermostat is set at 55 degrees Fahrenheit. If the system is deactivated for any reason, drain the holding tank, air stripper, and water pipes to prevent freeze damage. The Bear Creek discharge point shall be periodically inspected for ice buildup that could obstruct the flow of discharge water.

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4.0 HEALTH AND SAFETY

Health and safety aspects of the operation and maintenance of the Phase II Groundwater Remediation System are described below.

4.1 GENERAL SAFETY PRECAUTIONS

Safety begins with recognition of the risks associated with work activities and formulating appropriate procedures to minimize those risks. This chapter does not constitute a comprehensive health and safety plan, but will draw attention to several specific risks associated with operation and maintenance of the system and methods of managing those risks. General safety measures to be followed when working around the system include the following:

• Use appropriate personal protective equipment (PPE), including chemical-resistant gloves, boots, coveralls, and eye protection during contact with untreated groundwater.

• Do not eat, drink, or smoke in or around the treatment building, recovery wells, or outfall.

Avoid touching face with hands or objects to avoid possible ingestion of hazardous substances.

• Do not work alone in potentially hazardous areas.

• Maintain a first-aid kit and fire extinguisher in a readily accessible location.

4.1.1 Electrical Equipment

Electrical equipment is present in the treatment building and at the well heads. Even low energy circuits can produce 10 to 100 milliampere (mA) shocks to a well-grounded person. Shocks of 10 to 100 mA are considered severe; shocks of 100 mA and above are lethal. The following precautions shall be included in work procedures for servicing electrical equipment:

• Only qualified personnel familiar with the electrical equipment shall be permitted to work on it.

Specific objectives shall be outlined beforehand and the hazards associated with these activities identified. Appropriate safety procedures shall be followed to mitigate these hazards.

• Whenever a question exists whether site personnel can safely perform the needed repairs, the services of a qualified electrician shall be obtained.

• Circuit diagrams must be carefully read and understood before beginning work

• Control circuits to be repaired must be isolated from other control circuits or electrical devices Particular care must be exercised when working with switches or other devices in which the supply side often remains live when the switch is in the off position.

• Any electrical equipment being inspected or repaired must be isolated from all sources of electrical power.

• A lock-out/tag-out procedure shall be followed to ensure that circuit remains deactivated during the course of the work.

4.1.2 Mechanical Equipment

Mechanical equipment in the treatment building poses the following hazards:

• Moving parts (blower shaft, etc.);

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• Hot surfaces;

• Tripping and lifting hazards (tripping hazards exist elsewhere on the site where system components extend above ground level.); and

• Electrical components.

Particular care must be exercised to prevent automatic or accidental activation of machinery during maintenance or repair work. The following guidelines shall be followed when working around mechanical equipment:

• Do not wear loose clothing when working around exposed moving (rotating) parts.

• Identify specific work objectives beforehand, and determine the potential hazards associated with these activities.

• Use PPE appropriate for the hazards identified during task planning.

• Disconnect mechanical components from electrical power source before beginning work.

• Follow lock-out/tag-out procedures.

• Use caution in proximity to moving parts and hot surfaces.

• Maintain area in a clean and orderly condition to minimize potential tripping hazards. Fixed objects can be painted in bright colors.

• Use proper lifting techniques.

• Maintain guards and safety devices on equipment used in performing the work. Observe safety guidelines provided by equipment supplier.

4.1.3 Explosion and Fire Hazards

The current remediation system should not pose a threat for explosion hazards. Fire hazards could result from smoking, dropping matches or lit cigarettes, or use of open flames within the treatment building. Malfunctioning electrical equipment can also produce fires. Fires may be sustained by combustible waste materials or stored flammable and combustible materials such as petroleum products and lumber. Fires are classified in the following three categories:

• Class A - Ordinary combustible materials, including wood, coal, paper, and fabrics (can be extinguished by cooling).

• Class B - Flammable liquids and gases, including petroleum products (can be extinguished by eliminating the supply of oxygen).

• Class C - Electrical fires, i.e. fires in or near energized electrical equipment (can be extinguished by introducing nonconductive agents).

The following measures shall be taken to reduce fire hazards:

• Keep combustible and flammable materials away from potential sources of ignition. Store such materials in appropriate areas with “No Smoking” and “No Open Flame” warning signs.

• Provide fire extinguishers inside the treatment building and in site vehicles/equipment Fire extinguishers should be rated for all classes of fire that may be anticipated for the area where the extinguisher is to be placed. Use wall-mounted, portable extinguishers for site structures.

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Label each fire extinguisher with the location where it is to be stationed. Alternatively, fire extinguishers rated for all classes (Class ABC for all types of fires) may be used at all locations.

Fire extinguishers must be serviced regularly in accordance with supplier’s instructions.

4.2 SAFETY EQUIPMENT

Before initiating work, perform the following:

• Identify the potential contaminants.

• Determine the maximum concentrations anticipated for potential worker exposure (if data are unavailable, conservative assumptions may be necessary).

• Determine routes of exposure for the substances identified as potential contaminants.

Appropriate PPE can then be selected. Levels of PPE are classified as follows:

• Level A: This is the highest level of protection. It includes protection against respiratory contaminants through use of a SCBA, and protection against exposure through ingestion and absorption by the use of a complete, fully-encapsulated suit. Multiple gloves and clothing layers may be used for protection against mixtures of chemicals with different properties.

• Level B: Respiratory protection is the same as Level A, but the protection against ingestion and absorption is reduced by replacing the fully encapsulated suit and multiple protective layers with a less restrictive protective suit.

• Level C: Respiratory protection consists of an air-purifying respirator. The protective clothing is less effective and less restrictive than Levels A and B, and often consists of a tyvek coverall and rubber gloves and boots.

• Level D: PPE consists of hard hat, safety glasses, steel-toed boots, and cloth coveralls. Level D provides minimal protection against chemical hazards and primary protection from physical hazards.

It should be noted that the majority of onsite activities can be safely performed using PPE Level D and below. However, the operators and/or technicians will evaluate the planned activities and relative risks of exposure associated, prior to arriving at the site to ensure the proper level of PPE is available in the event that an upgrade is necessary.

4.3 PERSONNEL EMERGENCIES

Accidents, even apparently minor ones, should be reported to the worker’s supervisor and the site safety officer. In case of serious accidents, follow these steps:

• Stay with the victim and have someone else call for help.

• If no one else is available, stabilize the victim to the extent possible.

• Dial 911 using a cell phone or the phone located in the southwest corner of the treatment building to contact Ambulance/Fire Department/Police/Sheriff.

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5.0 AIR PERMIT REQUIREMENTS

Tetra Tech (formerly Maxim) contacted the Montana Department of Environmental Quality (DEQ) Air and Waste Management Bureau regarding the need for an air quality permit for the air stripper’s discharge. In a letter to Maxim dated October 28, 1997 (Appendix F), the Air and Waste Management Bureau stated that an air quality permit would not be required due that conservative calculations estimating the potential to emit (PTE) fail to exceed the state threshold (25 tons per year) initiating permit requirements. The PTE submitted to the DEQ was estimated using analytical data for groundwater samples collected from recovery wells in July 1997.

Actual emission rates will be estimated annually using VOC concentrations measured in influent and effluent samples collected from the system. Tetra Tech will notify the DEQ if the emission rates approach the 25 tons per year threshold. In the nine years since activation, emission levels have remained well below this threshold.

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6.0 SYSTEM PUMPING RATES

This section summarizes system optimization. Table 2 indicates the initial pumping rate (design), the pumping rate for which the batch testing results (validation) support adequate treatment, and the average yearly pumping rate for each recovery well. The rates indicated are established as target values for each recovery well and were developed based on pump test results presented in a separate site document titled Predesign and Design Report, Phase II Groundwater Remediation, Bitterroot Valley Sanitary Landfill dated May 1998.

Target pumping rates used during initials system start-up were modified during system validation (batch testing) to obtain instrument and control settings. Additional system optimizations were performed during subsequent operation and maintenance monitoring to account for seasonal water level fluctuations and to incorporate additional system components. The system flow settings can be optimized as future monitoring data is obtained and the objectives of system operation evolve.

Future operation of the system requires periodic review of monitoring data and site groundwater elevations to ensure recovery well pumps are configured and operating appropriately. System validation, target pumping rates and average yearly pumping rates are summarized below.

TABLE 2

FLOW RATES

PHASE II GROUNDWATER REMEDIATION SYSTEM

Bitterroot Valley Sanitary Landfill

System Validation

Design Pump Rate

Average Pumping Rates1 Well

Measured in gpm R-1,2 &10 10 25 9.0

R-3 1.5 1.5 0 R-4 10 29 27.7 R-5 5 9 0 R-6 10 35 22.2 R-7 10 30 15.14 R-8 10 30 13.0 R-9 10 10 4.6

Notes: gpm = gallons per minutes 1 Average yearly pumping rate (2006 data) affected by seasonal low water and down time due to Operation and Maintenance and insufficient water levels in wells.

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7.0 OVERSIGHT AND MONITORING OF REMEDIATION SYSTEM

This section is intended to guide monitoring of the Phase II groundwater remediation system. The process of remediation system oversight and monitoring includes the following.

1. System Validation – Perform batch testing to confirm that the treatment system can adequately treat influent groundwater, to be completed upon initial start up and following installation of any additional recovery wells. Procedures and results from system validation during initial startup are described in Operation, Maintenance, and Monitoring Plan (Maxim 1999).

2. System Start-Up – Adjust target pumping rates based upon result of system validation and activate the system. Initial start-up adjustments are described in Operation, Maintenance, and Monitoring Plan (Maxim 1999). Initial start-up occurred on July 10, 1998.

3. Start-up Monitoring – Ensure that the treatment system is operating properly and continues to adequately treat influent groundwater. Start-up monitoring results are described in Operation, Maintenance, and Monitoring Plan (Maxim 1999).

4. Routine Monitoring – Perform routine system monitoring to ensure the system operates properly, assess the groundwater capture zone of recovery wells R-1 through R-10, and demonstrate improvements in downgradient groundwater water quality.

Routine monitoring procedures, frequency, laboratory analyses, and reporting are describe below.

7.1 ROUTINE MONITORING

The routine monitoring period began after the start-up monitoring period was complete in January 1999. Table 3 presents monitoring frequencies and parameters.

Methods used for collecting samples from monitoring wells and monitoring well locations are presented in a separate site document on file with the DEQ titled Amended Work Plan Groundwater Monitoring, Bitterroot Valley Sanitary Landfill (Maxim 2002). Treatment system water samples shall be collected by opening sample port valves and holding pre-preserved sample containers directly under the sample port.

Sample containers will be sealed with no headspace. A field duplicate sample shall be collected during each sampling event. Samples shall be shipped in ice-filled coolers with chain-of-custody documentation to the Northern Analytical Laboratory in Billings, Montana for analysis of VOCs according to EPA Method 524.2.

Immediately following and extending for a brief time after a repair is made to the system, it is possible that VOCs may be detected in some samples collected if the system repair required solvent bonding (pipes, flanges, sump seams, etc) due to solvents and adhesives used during construction/repair getting entrained in the process flow. Organic solvents and adhesives containing such compounds as toluene and methylene chloride are sometimes used to complete repairs of the PVC piping network and/or system seams which could consequently be detected in analytical samples. It is anticipated that if minute quantities of VOCs are present in the piping, they would be flushed out in a relatively short period of time following the repair and therefore it is critical to note when repairs are made relative to sample collection events.

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TABLE 3

MONITORING FREQUENCY AND PARAMETERS

PHASE IIA GROUNDWATER REMEDIATION SYSTEM

Bitterroot Valley Sanitary Landfill

MONITORING ACTIVITY1

MONTH(S)

FREQUENCY

Sample Influent & Effluent

Record Operating

Parameters

Inspect

Equipment and Perform

Maintenance Activities

Remote Verify

Operation

Measure Water Levels

Sample Recovery

Wells

ALL Monthly

#1, #4, #7, #10 Quarterly

#1 & #6 Semi-Annual

Notes: 1 Field forms summarizing the monitoring locations and parameters are included in Appendix E of the Operation, Maintenance, & Monitoring Plan Indicates monitoring activity will be performed.

Month(s) Indicates month of calendar year.

Quarterly Indicates one monitoring events will be performed per three months.

Semi-Annual Indicates two monitoring events will be performed per year.

The routine monitoring period began at Month #1 (January 1999), after start-up monitoring was completed. Start-up monitoring procedures are included in Operation, Maintenance, and Monitoring Plan, (Maxim 1999) and include the following monitoring activities (Table 3 lists these activities and the monitoring frequency):

• Obtaining water samples from the ten recovery wells for VOC analysis on a semiannual basis.

Sampling will be arranged to coincide with the project’s comprehensive groundwater monitoring occurring in the months of January and July.

• Collecting influent and effluent samples on a quarterly basis. These data should help in documenting the gradual improvement in groundwater quality downgradient of the recovery system.

• Measuring levels in project monitoring wells on a quarterly basis and recording data on field forms (BR-GW-2, -3, -36D, -37S, -38D, -39S, -40D, -41S, -49D, -50D, -54D, -55S, -58S, -81S, - 82D, -87S, -89S, and -92D, SA-8, -9, -14 and -15, Recovery wells R-1, -2, -3S, -4D, -5S, -6D, -7S, -8D, -9D, and -10, and piezometers P-1, P-2, and P-3).

• Record operating parameters on field forms (Appendix E).

• Verify system operation and upload system data using SCADA system on a biweekly basis.

7.2 REPORTING

The DEQ in a letter (Appendix F) from the Permits Section of the Water Protection Bureau stated on November 10, 1997, to the CECRA Program Hazardous Waste Site Cleanup Bureau, that a Montana Pollution Discharge Elimination System (MPDES) permit will not be required for this project if

Tetra Tech, Inc. January 2007 Page 16 substantive requirements of CECRA (Section 75-10-721) are met. These substantive conditions consist of meeting discharge limits of non-detection (less than or equal to upstream background) at the required reporting values established in Circular WBQ-7, Montana Numeric Water Quality Standards, September

1999 (DEQ).

The monitoring program presented in this document is designed to ensure that the treatment system effluent meets WQB-7 reporting limits (for example, under EPA Method 524.2 the reporting limit for chloroform is 0.5 micrograms per liter).

Tetra Tech will prepare quarterly data summary reports documenting the results of groundwater recovery and treatment system monitoring. DEQ will also be notified within 24 hours if laboratory analyses indicate detectable concentrations of VOCs have occurred in samples of discharged water.

Tetra Tech, Inc. January 2007 Page 17

8.0 REFERENCES

DEQ, 1999. Circular WQB-7, Montana Numeric Water Quality Standards, Montana Department of Environmental Quality. September.

Maxim Technologies. 1998. Predesign and Design Report, Phase IIA Groundwater Remediation, Bitterroot Valley Sanitary Landfill, Ravalli County, Montana. July.

__. 1999. Operation, Maintenance, and Monitoring Plan. Phase II Groundwater Remediation System, Bitterroot Valley Sanitary Landfill. Ravalli County, Montana. January.

__. 2002. Amended Final Work Plan, Groundwater Monitoring, Bitterroot Valley Sanitary Landfill. Ravalli County, Montana. December.