Environmental
engineering is the integration of science and engineering principles to improve the natural environment, to provide
healthy water, air, and land for human habitation and for other organisms, and
to remediate pollution sites. Furthermore it is concerned with finding
plausible solutions in the field of public health, such arthropod-borne diseases, implementing law which promote adequate
sanitation in urban, rural and recreational areas. It involves waste
water management and air
pollution control, recycling, waste
disposal, radiation protection, industrial
hygiene, environmental sustainability, and public
health issues as well as a knowledge of environmental engineering law. It also includes studies on the environmental impact of
proposed construction projects.
Environmental engineers study the
effect of technological advances on the environment. To do so, they conduct
hazardous-waste management
studies to evaluate the significance of such hazards, advise on treatment and
containment, and develop regulations to prevent mishaps. Environmental
engineers also design municipal water supply and industrial
wastewater treatment systems as well as address local
and worldwide environmental issues such as the effects of acid
rain, global
warming, ozone
depletion, water pollution and air pollution
from automobile exhausts and industrial
sources. At many universities,
Environmental Engineering programs follow either the Department of Civil
Engineering or The Department of Chemical Engineering at engineering faculties. Environmental "civil"
engineers focus on hydrology, water resources management, bioremediation, and
water treatment plant design. Environmental "chemical" engineers, on
the other hand, focus on environmental chemistry, advanced air and water
treatment technologies and separation processes.
Additionally, engineers are more
frequently obtaining specialized training in law (J.D.) and are utilizing their technical expertise in the
practices of Environmental engineering law. About four percent of environmental engineers go on to
obtain Board Certification in their specialty area(s) of environmental
engineering (Board Certified Environmental Engineer or BCEE). Most
jurisdictions also impose licensing and registration requirements.
Development
Ever since people first recognized
that their health and well-being were related to the quality of their
environment, they have applied thoughtful principles to attempt to improve the
quality of their environment. The ancient Harappan civilization utilized early
sewers in some cities. The Romans
constructed aqueducts to prevent drought and to create a
clean, healthful water supply for the metropolis of Rome.
In the 15th century, Bavaria
created laws restricting the development and degradation of alpine country that
constituted the region's water supply.
The field emerged as a separate
environmental discipline during the middle third of the 20th century in
response to widespread public concern about water and pollution and
increasingly extensive environmental quality degradation. However, its roots
extend back to early efforts in public health engineering. Modern environmental
engineering began in London
in the mid-19th century when Joseph
Bazalgette designed the first major sewerage system that reduced the incidence of waterborne diseases
such as cholera. The introduction of drinking water treatment and sewage
treatment in industrialized countries reduced waterborne diseases from leading
causes of death to rarities.
In many cases, as societies grew,
actions that were intended to achieve benefits for those societies had
longer-term impacts which reduced other environmental qualities. One example is
the widespread application of the pesticide DDT to control agricultural pests in the years following World
War II. While the agricultural benefits were outstanding and crop yields increased
dramatically, thus reducing world hunger substantially, and malaria was controlled better than it ever had been, numerous
species were brought to the verge of extinction due to the impact of the DDT on
their reproductive cycles. The story of DDT as vividly told in Rachel
Carson's "Silent
Spring" (1962) is considered to be
the birth of the modern environmental movement and the development of the
modern field of "environmental engineering."
Conservation movements and laws
restricting public actions that would harm the environment have been developed
by various societies for millennia. Notable examples are the laws decreeing the
construction of sewers
in London
and Paris
in the 19th century and the creation of the U.S. national park system in the
early 20th century.
Scope
Solid waste management
Solid waste management is the
collection, transport, processing or disposal, managing, and monitoring of
solid waste materials. The term usually relates to materials produced by direct
or indirect human activity, and the process is generally undertaken to reduce
their effect on health, the environment, or aesthetics. Waste management is a
distinct practice from resource recovery, which focuses on delaying the rate of
consumption of natural resources. The management of wastes treats all materials
as a single class, whether solid, liquid, gaseous, or radioactive substances,
and the objective is to reduce the harmful environmental impacts of each
through different methods.
Environmental impact assessment and mitigation
Scientists have developed air
pollution dispersion models to evaluate the concentration of a pollutant at a
receptor or the impact on overall air quality from vehicle exhausts and
industrial flue gas stack emissions. To some extent, this field overlaps the
desire to decrease carbon dioxide and other greenhouse gas emissions from
combustion processes. They apply scientific and engineering principles to
evaluate if there are likely to be any adverse impacts to water quality, air
quality, habitat
quality, flora
and fauna,
agricultural capacity, traffic
impacts, social impacts, ecological impacts, noise impacts, visual (landscape)
impacts, etc. If impacts are expected, they then develop mitigation measures to
limit or prevent such impacts. An example of a mitigation measure would be the
creation of wetlands
in a nearby location to mitigate the filling in of wetlands necessary for a
road development if it is not possible to reroute the road.
In the United States, the practice
of environmental assessment was formally intitiated on January 1, 1970, the
effective date of the National
Environmental Policy Act (NEPA).
Since that time, more than 100 developing and developed nations either have
planned specific analogous laws or have adopted procedure used elsewhere. NEPA
is applicable to all federal agencies in the United States.
Water supply and treatment
Engineers and scientists work to
secure water supplies for potable and agricultural use. They evaluate the water
balance within a watershed
and determine the available water supply, the water needed for various needs in
that watershed, the seasonal cycles of water movement through the watershed and
they develop systems to store, treat, and convey water for various uses. Water
is treated to achieve water quality objectives for the end uses. In the case of
a potable water
supply, water is treated to minimize the risk of infectious disease
transmission, the risk of non-infectious illness, and to create a palatable
water flavor. Water distribution systems are designed and built to provide
adequate water pressure and flow rates to meet various end-user needs such as
domestic use, fire suppression, and irrigation.
Waste heat conveyance and cause
There are numerous wastewater
treatment technologies. A wastewater treatment train can consist of a primary
clarifier system to remove solid and floating materials, a secondary treatment
system consisting of an aeration
basin followed by flocculation
and sedimentation or an activated
sludge system and a secondary clarifier, a
tertiary biological nitrogen
removal system, and a final disinfection process. The aeration basin/activated sludge system removes
organic material by growing bacteria (activated sludge). The secondary
clarifier removes the activated sludge from the water. The tertiary system,
although not always included due to costs, is becoming more prevalent to remove
nitrogen and phosphorus
and to disinfect the water before discharge to a surface water stream or ocean
outfall.
Air pollution management
Scientists have developed air pollution
dispersion models to evaluate the concentration of a
pollutant at a receptor or the impact on overall air quality from vehicle exhausts and industrial flue
gas stack emissions. To some extent, this
field overlaps the desire to decrease carbon
dioxide and other greenhouse
gas emissions from combustion
processes.
Carrying out these key tasks
The U.S. Environmental
Protection Agency (EPA) is one of the many agencies
that work with Environmental Engineers to solve key issues. An important
component of EPA’s mission is to protect and improve air, water, and overall
environmental quality in order to avoid or mitigate the consequences of harmful
effects.
Education
Courses aimed at developing
graduates with specific skills in environmental systems or environmental
technology are becoming more common and fall into broads classes:
- Mechanical engineering that designs machines and mechanical systems for the environmental used such as water treatment facility, pumping stations, garbage segregation plants and other mechanical facilities.
- Environmental engineering or environmental systems courses oriented towards a civil engineering approach in which structures and the landscape are constructed to blend with or protect the environment;
- Environmental chemistry, sustainable chemistry or environmental chemical engineering courses oriented towards understanding the effects (good and bad) of chemicals in the environment. Focus on mining processes, pollutants and commonly also cover biochemical processes;
- Environmental technology courses oriented towards producing electronic or electrical graduates capable of developing devices and artifacts able to monitor, measure, model and control environmental impact, including monitoring and managing energy generation from renewable sources.
Prominent environmental engineers