Environmental Impact

Assessment of Projects
What does
environment mean?
• Environment meaning
Environment can be defined as a sum of all the
living and non-living elements and their effects that
influence human life. While all living or biotic
elements are animals, plants, forests, fisheries, and
birds, non-living or abiotic elements include water,
land, sunlight, rocks, and air.
 Water Pollution

Air Pollution

Green House Gases Emissions

Soil Pollution

Solid Wastes

Hazardous Wastes

Noise Pollution
 1- Pollution Type and
Mitigation (water, air,
emissions, solid wastes, soil,
Course sound,)
Content 2- EIA report (Objectives,
Benefits, Content, Projects
Classification, Appendix)
Water Pollution
Water
pollution
definition
The release of substances into
subsurface groundwater or into lakes,
streams, rivers, estuaries, and oceans to
the point where the substances interfere
with the beneficial use of the water or
with the natural functioning of
ecosystems. In addition to the release of
substances, such as chemicals, trash, or
microorganisms, water pollution may
also include the release of energy, in the
form of radioactivity or heat, into bodies
of water.
Water pollutants

• Water bodies can be polluted by a wide

variety of substances, including
pathogenic microorganisms, putrescible
organic waste, fertilizers and plant
nutrients, toxic chemicals, sediments,
heat, petroleum (oil), and radioactive
substances. Several types of water
pollutants are considered below. (For a
discussion of handling sewage and other
forms of waste produced by human
activities, see waste disposal and solid-
waste management.)
 Water pollution
sources

• Water pollutants come from either point sources or

dispersed sources (non-point). A point source is a pipe
or channel, such as those used for discharge from an
industrial facility or a city sewerage system. A non-point
source is a very broad unconfined area from which a
variety of pollutants enter the water body, such as the
runoff from an agricultural area. Point sources of water
pollution are easier to control than dispersed sources
because the contaminated water has been collected and
conveyed to one single point where it can be treated.
Pollution from dispersed sources is difficult to control,
and, despite much progress in the building of modern
sewage-treatment plants, dispersed sources continue to
cause a large fraction of water pollution problems.
 Water pollution sources

• Domestic sewage

Domestic sewage is the primary source of pathogens (disease-causing microorganisms) and putrescible organic substances. As
organics are decomposed naturally in the sewage by bacteria and other microorganisms, the dissolved oxygen content of the water
is depleted. This endangers the quality of lakes and streams, where high levels of oxygen are required for fish and other aquatic
organisms to survive. Sewage-treatment processes reduce the levels of pathogens and organics in wastewater but do not eliminate
them completely.
Domestic sewage is also a major source of plant nutrients, mainly nitrates and phosphates. Excess nitrates and phosphates in
water promote the growth of algae. When the algae die, oxygen dissolved in the water declines because microorganisms use
oxygen to digest algae during the process of decomposition. Anaerobic organisms (organisms that do not require oxygen to live)
then metabolize the organic wastes, releasing gases such as methane and hydrogen sulfide, which are harmful to the aerobic
(oxygen-requiring) forms of life. This process is called eutrophication. Eutrophication is a naturally occurring and slow, and process.
However, when it is accelerated by human activity and water pollution, it can lead to the premature aging and death of a body of
water
 Water pollution sources

• Solid waste
Solid waste includes garbage, rubbish, electronic waste, trash, and
construction and demolition waste, all of which are generated by
individual, residential, commercial, institutional, and industrial activities.
In some places, solid waste is intentionally dumped into bodies of water.
Land pollution can also become water pollution if the trash or other
debris is carried by animals, wind, or rainfall to bodies of water.
Significant amounts of solid waste pollution in inland bodies of water can
also eventually make their way to the ocean. Solid waste pollution is
unsightly and damaging to the health of aquatic ecosystems and can harm
wildlife directly. Many solid wastes, such as plastics and electronic waste,
break down and leach harmful chemicals into the water, making them a
source of toxic or hazardous waste.
Water pollution sources

• Toxic Waste
Waste is considered toxic if it is poisonous, radioactive, explosive, carcinogenic (causing cancer),
mutagenic (causing damage to chromosomes), teratogenic (causing birth defects), or bioaccumulative (that
is, increasing in concentration at the higher ends of food chains). Sources of toxic chemicals include
improperly disposed wastewater from industrial plants and chemical process facilities (lead, mercury,
chromium) as well as surface runoff containing pesticides used on agricultural areas.
• Sediment
Sediment (e.g., silt) resulting from soil erosion or construction activity can be carried into water bodies by
surface runoff. Suspended sediment interferes with the penetration of sunlight and upsets the ecological
balance of a body of water. Also, it can disrupt the reproductive cycles of fish and other forms of life, and
when it settles out of suspension it can smother bottom-dwelling organisms.
Water pollution sources

• Thermal Pollution
Heat is considered to be a water pollutant because it decreases the capacity of water to hold dissolved
oxygen in solution, and it increases the rate of metabolism of fish. Valuable species of game fish (e.g.,
trout) cannot survive in water with very low levels of dissolved oxygen. A major source of heat is the
practice of discharging cooling water from power plants into rivers; the discharged water may be as much
as 15 °C (27 °F) warmer than the naturally occurring water. The rise in water temperatures because of
global warming can also be considered a form of thermal pollution.
• Petroleum (oil) pollution
Petroleum (oil) pollution occurs when oil from roads and parking lots is carried in surface runoff into water
bodies. Accidental oil spills are also a source of oil pollution. Oil slicks eventually move toward shore,
harming aquatic life and damaging recreation areas.
What Are the Effects of Water Pollution?
 What Are the Effects of Water Pollution?
• On the environment

➢ In order to thrive, healthy ecosystems rely on a complex web of animals, plants, bacteria, and fungi—all of which interact, directly or
indirectly, with each other. Harm to any of these organisms can create a chain effect, imperiling entire aquatic environments.

➢ When water pollution causes an algal bloom in a lake or marine environment, the proliferation of newly introduced nutrients stimulates
plant and algae growth, which in turn reduces oxygen levels in the water. This dearth of oxygen, known as eutrophication, suffocates plants
and animals and can create “dead zones,” where waters are essentially devoid of life.

➢ Chemicals and heavy metals from industrial and municipal wastewater contaminate waterways as well. These contaminants are toxic to
aquatic life—most often reducing an organism’s life span and ability to reproduce—and make their way up the food chain as predator
eats prey. That’s how tuna and other big fish accumulate high quantities of toxins, such as mercury.

➢ Much of this solid debris, such as plastic bags and soda cans, gets swept into sewers and storm drains and eventually out to sea, turning
our oceans into trash soup and sometimes consolidating to form floating garbage patches. Discarded fishing gear and other types of debris
are responsible for harming more than 200 different species of marine life.

➢ Meanwhile, ocean acidification is making it tougher for shellfish and coral to survive. Though they absorb about a quarter of the carbon
pollution created each year by burning fossil fuels, oceans are becoming more acidic. This process makes it harder for shellfish and other
species to build shells and may impact the nervous systems of sharks, clownfish, and other marine life.
Your assignment