All roles may entail, to varying extents, the following physical demands: - Long periods (potentially exceeding 8 hours per day) of walking, standing, sitting, bending, pushing, pulling, climbing, lifting, balancing, stooping, twisting, squatting, handling materials, repetitive hand-wrist motions, and traversing uneven surfaces; - Exposure to both extreme heat and cold; - Exposure to loud noises, fumes, and airborne particles; In addition to the above demands inherent in every role, the following roles may entail unique physical demands, including: - Operators/Drivers may work inside or outside vehicles and may operate vehicles for over 8 hours per day. - Maintenance Employees may be exposed to toxic or caustic chemicals in a ventilated maintenance shop and may work with personal computers, laptops, electronic hand-held devices, complex electrical schematics, diagnostic software and testing devices, and other heavy machinery.