Under direct or general supervision, operates, monitors, and maintains plant equipment including engines, motors, boilers, compressors, and pumps to control unit processes; monitors and controls wastewater flow; performs adjustments and repairs to plant equipment; collects samples for laboratory testing; performs minor maintenance such as flushing sludge lines to digesters, adding oil, and cleaning drains; and performs duties as assigned. Mobility to work the plant; to sit, stand, and walk on level, uneven, or slippery surfaces; frequently reach, twist, turn, kneel, bend, stoop, squat, crouch, grasp, and make repetitive hand movement in the performance of daily duties; to climb and descend ladders, to operate varied hand and power tools and equipment, and to operate a motor vehicle and visit various OC San sites, projects, and/or meetings.