Because the knowledge and duties of chemical engineers cut across many fields, the engineer applies principles of chemistry, physics, mathematics, and mechanical and electrical engineering in their work. Major types of industries include refining petroleum, pulp and paper, pharmaceuticals, synthetic fibers, and polymers. Civil engineering is a people-serving profession, concerned with the planning, design, construction and operation of large, complex systems such as buildings, dams, roads, water purification and treatment systems, highways, rapid transit and rail systems, bridges, ports and harbors, airports, tunnels, power generating systems, and structural components of aircraft and ships. Civil Engineers understand the structure of materials such as concrete and soil, and need to understand the codes associated with building large structures. Civil engineers work closely with architects and land surveyors in thier work, and rely heavily on mechanics and materials science.
Environmental engineers are primarily concerned with cleaning up waste.
The waste may be soil contamination, air pollution, or water pollution. Environmental engineers are faced with understanding the laws associated with environmental standards, and heavily rely on chemistry and geology in thier work. Environmental engineering uses many disciplines from both chemical and civil engineering. Some schools offer environmental engineering courses as a part of a civil or chemical engineering program. Engineers may be found at hazardous waste sites, taking soil samples, in a laboratory evaluating samples, they may be in an office developing plans for cleaning a site, or designing a treatment facility.