Sewage pollution occurs when untreated sewage is discharged into water bodies. This causes ecological damage like eutrophication and increases nutrients that can lead to algal blooms and lack of oxygen. It also poses health risks as it can spread disease and contaminate shellfish. While wastewater irrigation provides nutrients for crops, prolonged use poses risks to soil, groundwater, and the environment through salt accumulation and excess nutrients leaching below the root zone. Proper treatment of sewage and wastewater is needed to remove pollutants before discharge or reuse.

1. WELCOME

3. • Sewage is defined as the wastewater that
comes from a single house or entire
community. Wastewater consists of anything
and everything that goes down a drain. The
pollution that occur through the sewage is
termed as sewage pollution.

4. These include:
 soap suds or a milky-looking discharge in the
water grey coloured water a noticeable
sewage smell
 pollution can kill fish and other aquatic life
and also affect biodiversity, amenity value
and the use of water and land for
agricultural purposes

5. Causes of sewage pollution:
 Domestic households, industrial and
agricultural practices produce waste water
that can cause pollution of many lakes and
rivers.
 Improper disposal of sewage: when
untreated sewage is discharged into rivers
and seas, can cause pollution.

7.  Domestic sewage: It is a waste water generated
from household activities. Sewage also includes
liquid waste from industry and commerce.
 Organic and inorganic materials such as
phosphates and nitrates also cause sewage
pollution. Organic from food and vegetables and
inorganic from soaps and detergents.
 Improper handling of waste water is the main
reason behind pollution.

8. Effects of sewage in freshwater ecosystems
Dumping sewage into water bodies, such as
rivers or lakes, creates a human health hazard
but can also negatively disrupt the river and lake
ecosystems. The sewage contaminates the water,
spreads disease, and leads to environmental
degradation (WQM 2004).

9.  Increased organic matter river reduces
the amount of dissolved oxygen
 Sewage heightens the levels of nutrients,
increasing the bioavailability of nutrients
 increase the turbidity reduces light
available fish gills and respiratory
structures
 Sewage can introduce pesticides, other
chemicals, and heavy metals into the
water column.
 Microbial pathogens

10. Ecological Damage
Sewage-contaminated water causes eutrophication,
which is the increase in concentration of chemical
elements required for life.
The nitrates, phosphates, and organic matter found
in human waste serves as a food for algae and
bacteria.
This causes these organisms to overpopulate to the
point where they use up most of the dissolved
oxygen that is naturally found in water, making it
difficult for other organisms in this aquatic
environment to live.

12. • The bacteria are basically strangling the other
organisms. Some of the organisms that do
overpopulate from this can also be disease-
causing microorganisms.
• Phosphates are also found in soaps and
detergents, but there are other household
products that we use everyday that can be toxic
to many animals and humans if they are
dumped directly into a water body.

13. Health Risks:
Bathers are at increased risk of contracting illness
due to bacteria and viruses present in sewage effluent.
Gastrointestinal disorders have been linked to sewage
pollution, with viruses implicated as the cause.
Shellfish strain water through their gills to trap
microscopic plants and animals for food. If the water
was contaminated with disease-causing bacteria, these
could be consumed as food by shellfish. When eaten
raw or partially cooked, these shellfish can make people
sick.

15. Economic Loss:
Debris associated with sewage probably has the
highest monetary cost associated with its presence
on our beaches due to the resulting loss of tourism
in addition to blockage removal. The closing of
commercial shellfish beds due to sewage
contamination can lead to high income loss.

16. Clean beaches have many advantages for humans and
commercial seafood farms as well as for the wildlife:
• They are safer for the public.
• They encourages people to come and use them,
which will improve local economy.
• They benefits everyone now and in the future.

17. Potential impacts of wastewater in environment
1.Public Health & Other living organism
2.Crops
3.Social Resources
4.Ground Water resources
5.Property values
6.Ecological impacts
7.Social Impacts

18. 1. Public health& other living organisms:
Use of untreated sewage water pose a high risk to
human health& other living organisms in all groups
as it contain pathogenic microorganisms which
have the potential to cause diseases

19. 2.Crops
Wastewater (treated and untreated) is extensively
used in agriculture because it is a rich source of
nutrients and provides all the moisture necessary for
crop growth.
Most crops give higher than potential yields with
wastewater irrigation; reduce the need for chemical
fertilizers, resulting in net cost savings to farmers.

20. 3.SoilResources
Wastewater can also contain salts that may accumulate in the
root zone with possible harmful impacts on soil health and
crop yields. The leaching of these salts below the root zone
may cause soil and groundwater pollution.
Prolonged use of saline and sodium rich wastewater is a
potential hazard for soil as it may erode the soil structure and
effect productivity. This may result in the land use becoming
non-sustainable in the long run.

21. 4.Groundwater Resources
Wastewater application has the potential to affect
the quality of groundwater resources in the long
run through excess nutrients and salts found in
wastewater leaching below the plant root zone.
For instance the quality of groundwater would
determine the magnitude of the impact from
leaching of nitrates.

22. 5.Ecological Impacts
When drainage water from wastewater irrigation schemes
drains particularly into small confined lakes and water bodies
and surface water, and if phosphates in the orthophosphate
form are present, the remains of nutrients may cause
eutrophication (Smith et al. 1999).
For example, overloading of organic material resulting in
decreases in dissolved oxygen may lead to changes in the
composition of aquatic life, such as fish deaths and reduced
fishery.

23. 6.Social Impacts
Social impacts are the concerns/doubts expressed by the
public about wastewater irrigation
 General concerns such as nuisance, poor environmental
quality, poor hygiene, odour, noise, higher probability of
accidents, etc.
 Social concerns such as food safety, health and welfare,
impaired quality of life, loss of property values, and
sustainability of land use.
 Natural resource concerns such as pollution of vital water
resources, loss of fish, wildlife, exotic species, etc.

24. Wastewater can also be used for producing rapidly growing
pulpwood, such as eucalyptus, on public lands, along canal
banks, roads and greenbelts etc.
These plants can be harvested every 8 to 10 years to
generate revenue, along with the added advantage of
working as natural air conditioners and greenhouse gas sinks,
for ameliorating the highly polluted urban environments.
The main benefits from wastewater irrigation are effective
water and nutrient recycling, higher crop yields, a diversified
cropping pattern, and disposal cost savings
Economics of Wastewater Irrigation

25. CONCLUSION:
It used to be said that “the solution to pollution is
dilution.”
Discharging sewage directly into a nearby body of
water, it’s better to let it pass through a combination
of physical, biological, and chemical processes that
remove some or most of the pollutants. This takes
place in sewage treatment plants