13-2 Hazard Analysis

Principal unique hazards associated with composting include:

a. Physical Hazards

(1) Description: During soil excavation and compost pile construction, workers may be seriously injured or killed by heavy equipment such as front-end loaders and scrapers. Construction may include the preparation of berms which may be steep and become slippery in wet or rainy conditions.

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. Workers should refrain from walking on or near the berms, especially during or after periods of heavy rainfall. CONTROL POINT: Construction, Operations, Maintenance

(2) Description: Windrows require periodic aeration using specialized equipment for turning the compost. The mixing equipment may be equipped with a rotary device which lifts and turns the material. Other devices, such as a "scarab"-type device may throw debris during the turning process. Pre-screening or sizing equipment, such as grinders, shakers, and screeners, may pose machine guarding hazards with unguarded equipment. Appendages or loose clothing may become entangled in pulleys, drive shafts, and other moving equipment.

Control: Workers should keep clear of operating equipment and approach only when within view of the operator. All moving or rotating equipment must be guarded to prevent accidental contact. Workers should only operate the system with the machine guards in place. CONTROL POINT: Construction, Operations, Maintenance

(3) Description: Workers may be exposed to puncture and cut hazards to feet and hands from rough or jagged waste material during composting operations.

Control: Workers should wear safety boots with steel shanks to prevent cuts to the bottom of the foot. Workers should minimize manual handling of waste material, and wear cut-resistant gloves if contact with waste materials is necessary. CONTROL POINT: Construction, Operations, Maintenance

(4) Description: Trip hazards may exist with hoses and piping systems used for irrigation of the composting unit.

Control: Workers should exercise caution when walking over hoses and pipes. In heavily traveled areas, extra lighting may be needed to ensure walkways are adequately illuminated. CONTROL POINT: Design, Maintenance

(5) Description: Fire hazards may exist with composting, as elevated temperatures and drying may increase the potential for spontaneous combustion.

Control: Periodic mixing of composting material and maintenance of the proper water content will help to control compost temperature and prevent fires. Reducing the dimensions of the compost windrows (and the piles of compost) may also prevent temperatures from exceeding desired levels. CONTROL POINT: Design, Operations

(6) Description: Depending on soil types, exposure to respirable quartz may be a hazard. Consult geology staff to confirm the presence of a respirable quartz hazard (e.g. to determine if soil types are likely to be rich in respirable quartz). As an aid in determining respirable quartz exposure potential, sample and analyze site soils for fines content by ASTM D422, followed by analysis of the fines by X-Ray Diffraction to determine fine material quartz content.

Control: Worker exposure to dust rich in respirable quartz may be minimized by periodically wetting the soil with water or amended water or by the use of respiratory protection, such as a air-purifying respirator equipped with a HEPA(N100, R100, P100) filter/cartridge. CONTROL POINT: Construction, Operations

(7) Description: Workers may be exposed to electrocution hazards when working around electrical utilities such as overhead power lines.

Control: The location of overhead power lines, either existing or proposed, should be noted in the pre-design phase. All lifting equipment, such as cranes, forklifts, and drilling rigs, should remain at least 10 feet from the power line, according to Occupational Safety and Health Administration (OSHA) regulation 29 CFR 1926.550 and EM 385-1-1, Section 11.E. CONTROL POINT: Design, Construction, Operations

(8) Description: The heavy equipment (small and large) used to move compost, soil, and liner materials on steep slopes may roll over, seriously injuring or killing the operator.

Control: The angle of the slope should be designed to minimize the potential for roll-over. The construction contractor must maintain safe operating conditions for equipment during construction. Heavy equipment should be equipped with roll-over protective devices (ROPS), should not be operated on excessively steep slopes or unstable ground. CONTROL POINT: Design, Construction, Operations

(9) Description: During the implementation of field activities, equipment and workers may come in close proximity to traffic. Equipment may also need to cross public roads. The general public may be exposed to traffic hazards, and the potential for accidents during loading and transporting soil.

Control: Where equipment is to cross roads, warning signs should be used according to the criteria of the Department of Transportation Manual on Uniform Traffic Devices for Streets and Highways. A traffic management plan should be developed before remediation activities commence to help prevent accidents involving site trucks and automobiles. EM 385-1-1, Section 21.I.10 provides plan details. CONTROL POINT: Design, Construction, Operations

b. Chemical Hazards

(1) Description: Workers may be exposed to contaminants of concern and degradation products of contaminants. Exposure may occur via inhalation/ingestion/dermal contact routes of exposure during loading, unloading, preprocessing, tilling, turning and other operations where soils are agitated.

Control: An analysis of the work tasks and potential for chemical exposure should be performed to determine the correct personal protective equipment (PPE) and/or respirator cartridge(s), if needed. The analysis should include obtaining specific chemical hazard information to ensure that the PPE specified will be appropriate for the respective chemical hazard. Workers may also use respiratory protection including the use of an air-purifying respirator equipped with HEPA(N100, R100, P100) filters and organic vapor cartridges. CONTROL POINT: Operations

(2) Description: If composting facilities are enclosed or tented, workers entering the facility may be entering a confined space and require respiratory protection. Elevated levels of CO₂ may accumulate during composting. It is also typical for some ammonia gas to be generated during composting. Exposure to ammonia vapors may occur, especially during windrow turning operations. Although aerobic conditions should be maintained in the compost, if anaerobic conditions are allowed to develop, methane and hydrogen sulfide may be generated.

Control: Prior to each entry into the enclosed or tented area, the atmosphere within the tent should be tested to ensure a safe atmosphere. If the testing indicates atmospheric contaminants or oxygen depletion, a confined-space entry program should be developed and implemented. CONTROL POINT: Design, Operations

(3) Description: Some materials used in composting may be explosive, especially when in contact with other incompatible materials (e.g. ammonium nitrate and fuels). Others may be hygroscopic, which may result in chemical reactions.

Control: Workers should minimize contact with acidic or corrosive chemical materials by using mechanical chemical delivery methods. Where contact is required, workers should wear gloves (e.g. nitrile) and other personal protective equipment that is resistant to the materials handled. All chemical reagents used in composting should be segregated to prevent accidental mixing of reactive chemicals, especially ammonium nitrate fertilizers and fuels. CONTROL POINT: Design, Operations

c. Radiological Hazards

Description: NONAPPLICABLE

Control: NONAPPLICABLE

d. Biological Hazards

(1) Description: Composting activities may expose workers via inhalation/ingestion/dermal contact exposure routes to pathogenic microbes. The hazard may be increased during dry and windy periods when microbe-entrained dusts may become airborne from soil agitation, by aerators, or from wind. Exposure may occur during agitation of the waste material. It is possible for pathogens to be present in compost amendments (e.g. bird manure has been implicated as a source of histoplasmosis.) Exposure to mold spores, including Aspergillus fumigates, may occur during composting operations. Inhalation of pathogenic microbes may cause allergic reactions or illness.

Control: The amount of airborne dust, and consequently the amount of exposure, may be controlled by the periodic application of water to the active area. Personal protective equipment, such as rubber gloves, should be used to help prevent dermal exposure to microorganisms, and respiratory protection (e.g. air-purifying respirator with HEPA(N100, R100, P100) filter/cartridge) may be used during dusty periods. CONTROL POINT: Construction, Operations

(2) Description: Snakes and other potentially harmful animals are attracted to the higher temperatures associated with composting operations.

Control: Workers should be informed of the potential for snakes and other animals around the compost facility, especially during cooler periods. Loud noises, such as talking and stamping or scuffing feet, may help to alert animals to the presence of workers in the area. CONTROL POINT: Operations, Maintenance

(3) Description: Workers may be exposed to a wide array of biological hazards, including snakes, bees, wasps, massive fly hatches, ticks, hornets, and rodents, during any phase of remediation. The symptoms of exposure vary from mild irritation to anaphylactic shock and death. Exposure to deer ticks may cause Lyme disease.

Control: Periodic inspections of the site should be performed to identify stinging insect nests and for the presence of snakes. Professional exterminating companies should be consulted for removal. Tick and insect repellents may be used for exposure control. However, workers should check their skin and clothing for ticks periodically throughout the work day. CONTROL POINT: Construction, Operations, Maintenance