Environmental engineering is the application of science and engineering principles to minimise the adverse effects of human activities on the environment (pollution of air, water, and/or land resources), and to provide healthful water, air and land for human habitation and for other organisms. Although it is widely considered impossible to eliminate all negative impact, it is thought human effects can be decreased and controlled through public education, conservation, regulations, and the application of good engineering practices (set up of processes, and facilities).

Development of environmental engineering

Two of the principal environmental problems are

  • the increasing number of humans on Earth. Along this line, one of the first applications of environmental engineering is the removal of sewage from cities, which became increasingly important as population grew. There was (and in many countries, still is) initially no treatment: wastes are, for example, simply brought to the nearest stream. However, since sewage disposal eventually damages natural waters, methods of treating wastewater prior to discharge were developed. This has evolved into a large industry.
  • the second major factor is the rising standard of living in many nations, such as in Europe and Australia. A higher living standard generates more consumption of natural resources and more wastes. The standard of living of developed nations is due in part to development of synthetic chemical industry in the 20th century and to the exploitation of fossil fuels for energy production. These industries produced toxic and hazardous chemicals in great quantities long before they were known to be dangerous. Unlike sewage, even small amounts of these molecules may be harmful, but the technology to detect them at low levels did not exist when the new industries appeared. It was then impossible to detect and identify them as factors in human health or environmental problems. There were initially no attempts to control their production, use and disposal.

"Pollutants" may be chemical, biological, thermal, radioactive, or even mechanical. Environmental engineering emphasizes several areas: process engineering, environmental chemistry, water and wastewater treatment (sanitary engineering), waste reduction, and pollution prevention. It is a synthesis, incorporating elements from civil engineering, chemical engineering, public health, mechanical engineering, chemistry, biology and geology.