Environmental Factors: Performance of essential functions may require exposure to such adverse environmental conditions as high pressure gas & water lines, insects, poisonous plants, animals, dirt, dust, pollen, odors, wetness, humidity, rain, fumes, temperature and noise extremes, machinery, vibrations, traffic hazards, toxic agents, electric currents, disease, raw sewage, blood, or pathogenic substances. PERFORMANCE APTITUDES: Physical Abilities: Tasks involve the regular and sustained performance of moderately physically demanding work, typically involving some combination of climbing and balancing, stooping, kneeling, crouching, crawling, and prolonged sitting, and that may involve the lifting, carrying, pushing, and/or pulling of moderately heavy objects and materials (20-50 pounds); may occasionally involve heavier objects and materials (up to 100 pounds).