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Remediation Technologies Screening Matrix, Version 4.0  
Chapter 9 Free-Product Recovery
Table of Contents


9-2 Hazard Analysis

Principal unique hazards associated with free-product recovery include:

Physical Hazards Chemical Hazards Radiological Hazards Biological Hazards

a. Physical Hazards

(1) Description: Soil boring using hollow-stemmed augers prior to well installation may cause a fire or explosion during drilling into soils saturated with flammable and/or combustible materials. Sparks generated when an auger contacts rocks, metal, or other underground objects may ignite a flammable atmosphere inside the bore hole. This is considered an unlikely, but potential hazard.

Control: The potential for a fire or explosion may be controlled as necessary by using mud or water rotary drilling methods, which add moisture to the cutting area. CONTROL POINT: Construction, Maintenance

(2) Description: Fire, explosion or electrocution hazards may exist when using hollow-stemmed auger drilling methods if the rotating auger contacts or ruptures underground utilities such as electrical 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 drilling may be allowed. When raising a drill mast, always have an observer to the side to observe and supervise. Do not move the drilling rig with the mast raised. CONTROL POINT: Design, Construction, Maintenance

(3) Description: During the transfer of flammable or combustible liquids (such as jet fuel) from the recovery well, a fire or explosion hazard may exist. The liquid may be ignited by improperly selected or installed equipment. Emissions from the collection equipment may also be ignited, possibly causing a fire or explosion. Ejector pumping systems produce mixtures of flammable vapors and air which may ignite and explode.

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 for the identified hazard areas. Controls to help prevent a fire or explosion include electrical system design and installation of equipment appropriate to any hazard area. Equipment should be grounded and/or provided with ground fault interrupter circuit (GFIC) protection if required by EM 385-1-1 or NFPA 70 requirements. Piping systems and ejectors that mix air with flammable vapors should not be used. CONTROL POINT: Design, Construction, Operations, Maintenance

(4) Description: During installation of the extraction trenches, workers may be seriously injured or killed by heavy equipment such as front-end loaders and backhoes. Heavy equipment may also generate elevated noise levels, which may damage worker hearing.

Control: Heavy equipment should be equipped with a backup alarm that alerts workers. When approaching operating equipment, the approach should be made from the front and within view of the operator, preferably making eye contact. Hearing protection should be worn when working around operating equipment. CONTROL POINT: Construction, Maintenance

(5) Description: Walls of trenches used for free-product recovery may collapse, causing workers to fall into the excavation.

Control: The integrity of the excavation should be determined by a competent person before workers are allowed to walk near the edge of the excavation. As a precaution, workers should not approach the edge of the excavation without fall protection. CONTROL POINT: Design, Construction, Maintenance

(6) Description: Skimmer belts used for free-product removal from trenches are often equipped with unguarded pulleys, which may cause entanglement of loose clothing.

Control: Unguarded pulleys and other moving or rotating mechanical devices should be guarded, and workers informed to operate the equipment only with the machine guarding in place. CONTROL POINT: Design, Construction, Operations, Maintenance

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

Control: Fluid level indicators equipped with automatic shut-off switches should be installed on free-product recovery tanks to help prevent overflowing. Regular inspections of the collection equipment should be performed to identify and repair system leaks. CONTROL POINT: Design, Operations, Maintenance

(8) Description: Vapors discharged from oil/water separators may expose workers to VOCs via an inhalation exposure.

Control: The discharge from the oil/water separators should be vented above the breathing zone of workers. CONTROL POINT: Design

(9) 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

(10) Description: Manual lifting of heavy objects may expose workers 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: Process and equipment piping for the collection, transfer, treatment, and storage of recovered free product may leak and create an exposure pathway either by ingestion/inhalation/dermal contact for workers operating or maintaining the system. Workers may be exposed to waste materials, such as benzene in gasoline or other hydrocarbons in jet fuel. The exposure may cause skin, eye, and respiratory tract irritation and other symptoms.

Control: Regular system inspection and maintenance will prevent or minimize leaks and any resulting exposure. Leaks should be detected by a regular leak detection process using O2 meters, explosivity meter, PIDs, OVA, leak detection fluids, and other appropriate methods. Also, personal protective equipment (PPE) should be worn (e.g. an air-purifying respirator with organic vapor cartridges and nitrile gloves for exposure to gasoline). CONTROL POINT: Operations, Maintenance

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

Control: During installation of wells and trenches, 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 an air-purifying respirator equipped with approved filter/cartridges (e.g. HEPA(N100, R100, P100) filters for particulates, OV cartridges for vapors, or combination filter/cartridges for dual protection). 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 PPE specified will be appropriate for the respective chemical hazard(s). CONTROL POINT: Construction, Operations, Maintenance

(3) Description: During operation of the free-product recovery trenches and collection equipment, workers may be exposed to chemical materials, such as jet fuel, hydrogen sulfide, VOCs and biologically generated byproducts (e.g. vinyl chloride, methane).

Control: During operation of free-product recovery trenches and collection equipment, workers may need to wear respiratory protection (e.g. an air-purifying respirator with organic vapor cartridges) to control inhalation exposures to VOCs. An analysis of the type of respirator required should be performed before issuing PPE. The analysis should include a chemical waste profile on the waste materials to help ensure that the respirator and filter/cartridge specified will be appropriate for the respective chemical hazard. CONTROL POINT: Operations, Maintenance

c. Radiological Hazards

Description: Radioactive materials may have been buried, or naturally occurring radioactive material (NORM) may be present in soils, sludge and groundwater. Radioactive materials may become entrained with the free product and eventually build up as scale in pipes and handling systems. Some radioactive materials may present an external exposure hazard. All radioactive materials may present an internal exposure hazard through inhalation or ingestion. Exposure to radiation using this remediation technology may be rare.

Control: The presence of radioactive materials may be known or the soil, sludge, or groundwater may be tested to determine if radioactive materials are present. If any radioactive material above background levels is found, a qualified health physicist should be consulted to determine exposure potential and any necessary engineered controls or PPE. CONTROL POINT: Design, Construction, Operations, Maintenance

d. Biological Hazards




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