Engineering is the field of expertise that designs, develops, and monitors construction of facilities such as roadway, water supply, and control systems that affect all aspects of daily life. It encompasses many specialties, including civil, structural, water resource, environmental, construction, transportation, geotechnical, industrial, mechanical, electrical, chemical, and agricultural engineering. Engineers complete site investigations, complete planning studies and reports, perform computations, meet with agencies, clients, and the public, develop construction documents, and monitor construction related to the development of such facilities. Engineering technicians assist engineers by performing such tasks as research, quality control, set up and monitoring of instruments, estimation of construction costs, computations, layout designs, specification of construction materials, and preparation of drawings and specifications. Technicians associated with civil engineering may assist engineers on highways, buildings, bridges, dams, wastewater treatment, potable water, and irrigation systems, and related structures and perform duties such as geotechnical investigations, construction inspection, traffic studies, and land-surveying. Those associated with mechanical engineering or similar may assist engineers with product development, fabrication, manufactured or production systems, and related operations. Due to an aging infrastructure and engineering involvement in relatively all aspects of daily life, the demand for engineers and engineering technicians is growing. Cities, counties, state and federal agencies, special districts, private consultants, manufacturing operations, and production plants hire engineers, technicians, and technologists.