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III. Environmental Setting, Impacts, and Mitigations L. Public Health and Safety vehicle occupants and in spilling of the wastes. Section IIID,Transportation discusses traffic accidents on the access roads to the Austin Road Landfill in greater detail. Landfill Gas h Organic wastes and refuse boned in landfills gradually decomposethrou h g physical and biochemical processes. As decomposition proceeds,methane(a non-toxic but flammable and explosive gas) and carbon dioxide(a nontoxic gas) are produced as organisms degrade organic matter into simpler compounds. Under the anaerobic phase of decomposition(i.e.,without oxygen),methane continues to be generated until all organic matter in the landfill has decomposed.The presence of moisture in a landfill can speed waste decomposition and increase the rate of gas generation. The composition of landfill gas is typically 45 to 60 percent methane,40 to 55 percent carbon dioxide,and small amounts of other gases (Ventura County Resource Management Agency, 1991;U.C. Davis, 1989). Landfill gases tend to accumulate in landfills and gradually seep out along paths of least resistance such as cracks or fissures. If methane gas enters confined spaces, such as buildings,it can become explosive and present a significant threat to health and safety. The lower explosive concentration limit for methane is 5.3 percent. The CCR,Title 14,Sections 17628 and 18222 require landfills to have and describe their systems for monitoring, venting,controlling,and possible use of landfill gas. The Austin Road Landfill has a landfill gas control system. The system collects landfill gas and delivers it to a gas power generation facility northwest side of the landfill. Operation of the landfill gas control system generates a liquid condensate byproduct that contains toxic organic constituents in both an aqueous phase(water soluble) and a hydrocarbon phase(water insoluble). The hydrocarbon phase of the condensate must be managed as a hazardous waste. The aqueous phase may be a hazardous waste depending on the levels of dissolved contaminants. Pathogens and Vectors Municipal Solid Waste(MSW)can contain various types of human pathogenic organisms including:bacteria, viruses,protozoa,and helminths(parasitic worms). Pathogenic microorganisms can originate from a number of sources in municipal solid waste,such as animal feces,human feces in diapers, sewage sludge,and even from contaminated materials such as glass, metal, plastic,paper, and yard wastes(Thomas Reid Associates, 1988). These organisms HI.L.10