Typical office environment, typical construction environment, extreme weather conditions, high noise level, safety hazards (electric currents, working on scaffolding and high places, exposure to chemicals), atmospheric conditions (fumes, odors, dusts, mists, gases, poor ventilation). Use processes such as physical/chemical primary treatment, conventional activated sludge, biological nutrient removal, fixed-film processes, membrane bio-reactors (MBR), sidestream treatment, tertiary filtration, and disinfection.