10-2 Hazard Analysis

Principal unique hazards associated with dual-phase extraction (bioslurping) include:

a. Physical Hazards

(1) Description: During the installation of groundwater extraction or monitoring wells, soil boring using hollow-stemmed augers may cause a fire or explosion during drilling into soils saturated with flammable or combustible materials. Sparks generated when a metal auger strikes against rocks, metal, or other underground objects may ignite a flammable atmosphere inside the bore hole.

Control: If drilling activities are expected to take place in areas known or suspected to contain soils saturated with flammable or combustible materials, use methods such as mud or water rotary drilling, which add moisture to the cutting area. CONTROL POINT: Design, Construction

(2) Description: Fire, explosion, or electrocution hazards may exist when using hollow-stemmed auger drilling methods if the rotating auger contacts and ruptures underground utilities such as electrical and/or gas lines, or comes in contact with overhead electric lines.

Control: To control utility contact hazards, identify the location of all below- and above-ground utilities prior to drilling. Contact local utilities and public works personnel to determine the locations of utilities. When there is any doubt or uncertainty, perform a utility survey, probe with a metal rod, or hand excavate to determine the exact location of utilities prior to drilling. Once utilities are located, careful excavation by backhoe may be allowed. When raising a drill mast, always have an observer to the side to observe and guide. Do not move the drilling rig with the mast raised. CONTROL POINT: Design, Construction

(3) Description: During the transfer of extracted flammable or combustible liquids (such as jet fuel) and gas from the recovery wells, a fire or explosion hazard may exist. The liquid or gas may be ignited by equipment or from the discharge of static electricity.

Control: Verify that the hazardous area classifications, as defined in NFPA 70-500-1 through 500-10, are indicated on the drawings. All controls, wiring, and equipment should be in conformance with the requirements of EM 385-1-1, Section 11.G and NFPA 70 for the identified hazard areas. Controls to help prevent a fire and explosion include appropriate design and installation of equipment. Equipment should be grounded and/or provided with ground fault interrupter circuit (GFIC) protection if required by EM 385-1-1, Section 11 or NFPA 70 requirements. CONTROL POINT: Design, Construction, Maintenance

(4) Description: If the product recovered by the technology is a flammable or combustible liquid (such as jet fuel), a fire or explosion hazard may exist with the product recovery tank.

Control: All controls, wiring, and equipment should be in conformance with the requirements of EM 385-1-1, Section 11.G and NFPA 70 for the identified hazard. CONTROL POINT: Design, Construction, Maintenance

(5) Description: Emissions from collection equipment may be ignited, possibly causing a fire or explosion. In addition, ejector pumping systems produce mixtures of flammable vapors and air which may be ignited and result in an explosion.

Control: Regular inspections of the collection equipment should be performed to identify and repair system leaks. In addition, the use of piping systems and ejectors that mix air with flammable vapors should not be used. CONTROL POINT: Design, Operations, Maintenance

(6) Description: Loose clothing may become entangled in cables used to raise and lower drilling tools and equipment or on other equipment. Direct push drilling methods using hydraulic pressure to advance a soil boring may pose a crushing hazard to hands and/or feet.

Control: Cable systems should be used with caution, and inspected regularly for loose strands or frayed wires which may entangle loose clothing. Personnel should keep hands and feet away from hydraulic push equipment. CONTROL POINT: Construction, Operations, Maintenance

(7) Description: The rotating auger of a drill rig poses a hazard to workers as loose clothing may become entangled with the revolving auger.

Control: Controls to help prevent workers from becoming entangled with the revolving augers include securing all loose clothing, using low-profile auger pins, and using long-handled shovels to remove soil cuttings from the borehole. CONTROL POINT: Construction, Maintenance

(8) Description: Containment tanks used for storage of recovered free product may overflow, creating the potential for fire or explosion.

Control: Fluid level indicators approved by NFPA for use with the fuels encountered should be installed on free-product recovery tanks to help prevent overflowing. CONTROL POINT: Design, Operations, Maintenance

(9) Description: Piping systems which become plugged may induce failure of the vacuum pump, causing an electrical fire.

Control: Piping systems should be periodically inspected and cleaned to help prevent buildup of material which may cause blockage. CONTROL POINT: Design, Operations, Maintenance

(10) Description: Workers may be exposed to elevated temperatures due to excess heating of blowers and other process equipment. The exposure may induce heat stress.

Control: Blowers, motors, and other equipment should be correctly sized to prevent overheating. CONTROL POINT: Design, Maintenance

(11) Description: Separators that generate flammable vapors may explode if ignited.

Control: Verify that the hazardous area classifications, as defined in NFPA 70-500-1 through 500-10, are indicated on the drawings. All controls, wiring, and equipment should be in conformance with the requirements of EM 385-1-1, Section 11.G and NFPA 70 for the identified hazard areas. Equipment should be grounded and/or provided with ground fault interrupter circuit (GFIC) protection if required by EM 385-1-1, Section 11 or NFPA 70 requirements. Only trained, experienced workers should be permitted to work on the systems. The areas should also be adequately ventilated to help prevent the accumulation of flammable gases. Appropriate lockout/tag out equipment and procedures should be included in the O&M of the system. Fire extinguishers rated for energized electrical systems should be readily available where electrical equipment is installed and operated. CONTROL POINT: Design, Operations, Maintenance

(12) Description: Steam pressure washing of equipment may expose workers to thermal or burn hazards, eye hazards due to flying projectiles dislodged during pressure washing, slip hazards from wet surfaces, and noise hazards.

Control: Thermal burns may be prevented by using insulated gloves (e.g. silica fabric gloves). Eye injuries and hearing loss may be prevented by wearing safety goggles and hearing protection during pressure washing activities. Slip hazards may be controlled by workers wearing slip-resistant boots, and draining water away from the decontamination operation into a tank or pit. Walking surfaces should be drained and free of standing liquids or mud. CONTROL POINT: Construction, Operations, Maintenance

(13) Description: High levels of noise may be generated by blowers and compressors and may result in hearing loss. Unguarded blowers and fans may entangle workers' clothing, causing injury.

Control: Equipment noise should be controlled with the use of insulation materials, barriers, proper lubrication and maintenance of equipment. Hearing protection should be used when working in areas of elevated noise levels during either operations or maintenance. All moving and rotating equipment should be guarded and workers should be informed that all such equipment should only be operated with the guards in place. CONTROL POINT: Design, Operations

(14) Description: Manual lifting of heavy objects may expose workers to injuries to back, arm, and shoulder injuries.

Control: Workers should not be required to lift heavy loads manually. Some loads may require two people. Proper lifting techniques include stretching, bending at the knees, and bringing the load close to the body prior to lifting (see EM 385-1-1, Section 14.A). Mechanical lifting equipment, such as forklifts, should be used to lift or to move loads. CONTROL POINT: Design, Construction, Operations, Maintenance

b. Chemical Hazards

(1) Description: Piping systems may leak from over-pressurization and spray workers with liquid waste materials. As a result, workers may be exposed through the inhalation/ingestion/dermal contact routes.

Control: Regular system inspection, testing, and maintenance will prevent or minimize leaks and resulting exposures. Hazard warning alarms which alert workers of vessel over-pressurization, may also be installed. CONTROL POINT: Design, Operations, Maintenance

(2) Description: During well installation, workers may be exposed to contaminants, such as VOCs, dusts, and metals, in soil and development water through the inhalation/ingestion/dermal contact routes.

Control: During well installation, workers may need to apply water or an amended water solution to the area to help control the generation of airborne dusts, particulates, and VOCs. Workers may also use respiratory protection, including the use of approved filter/cartridges(e.g. HEPA(N100, R100, P100) filters for particulates, OV cartridges for vapors, or combination filter/cartridges for dual protection). Personal exposure may be controlled by the use of personal protective equipment (PPE). An analysis of the work tasks and potential for chemical exposure should be performed to determine the correct PPE and/or respirator cartridge(s), if needed. The analysis should include a chemical waste profile to help ensure that the PPE specified will be appropriate for the respective chemical hazard(s). CONTROL POINT: Construction, Operations, Maintenance

(3) Description: During operation of a dual-phase extraction system, workers may be exposed to chemical materials, such as hydrogen sulfide, VOCs, and intermediate byproducts.

Control: During operation of the free-product recovery equipment, workers may need to wear respiratory protection to control inhalation exposures to VOCs. Prior to issuing respiratory protection equipment, an analysis of the type of respirator to be worn should be performed. The analysis should include a chemical profile on the waste materials to help ensure that the specified respirator and filter/cartridge will be appropriate for the respective chemical hazard. CONTROL POINT: Design, Operations, Maintenance

c. Radiological Hazards

Description: In some geological settings, workers may be exposed to naturally occurring radon gas. Radon gas and radon progeny do not present a significant external hazard. While radon progeny may present an internal hazard, quantities of radon progeny normally present would not pose a significant exposure hazard.

Control: Proper operation of emission control technologies will limit exposure to acceptable levels. Should excessive levels be suspected from previous site knowledge or should excessive levels or radon be encountered, a qualified health physicist should be consulted for proper guidance. CONTROL POINT: Design, Operations, Maintenance

d. Biological Hazards

Description: NONAPPLICABLE

Control: NONAPPLICABLE