Intro to Water Pollution

Lesson 14.3 Water Pollution

3,800 children die every day
from diseases associated with
unsafe drinking water.

Types of Water Pollution

• Point-source pollution:

From a discrete location, like a factory or sewer
pipe

Lesson 14.3 Water Pollution

Nonpoint-source
pollution: From many
places spread over a
large area, such as
when snowmelt runoff
picks up pollutants along
its path, runoff from a
farm or a street. Difficult
to trace back to specific
source. 96% of water
pollution is this type

Multiple Choice

Pollution from cattle in a pasture

• Point source

• Non-point source

Multiple Choice

Pollution from a dirt road

• point source

• non-point source

Multiple Choice

Pollution from a factory

• point source

• non-point source

What is considered a pollutant?

•Animal waste?
•Cleaners and detergents
•Soap?
•Trash?
•Sediment?
•Pesticides & fertilizers?

•Why are some of these things considered pollutants?
Isn’t soap good? Isn’t sediment (soil) normal?

Categories of Water Pollution

•Nutrient pollution
•Toxic chemical pollution
•Sediment pollution
•Thermal pollution
•Biological pollution

Nutrient Pollution

•When water has high nutrient (nitrates, phosphates)
and low oxygen levels, it is considered eutrophic.

• Eutrophic basically means “good food”

•Too many nutrients (usually phosphorus) speed up the
process causing ALGAE and aquatic plants to grow
REALLY FAST.

• They grow fast and then die. Bacteria decompose them and

USE UP OXYGEN.

• Without enough oxygen, other organisms start to die (have

fish die offs)

• When this is caused by people its called cultural

eutrophication.

Nutrient Pollution

THE PROCESS OF
EUTROPHICATION

Nutrients
build up in

water.

Algae and

aquatic plant

growth

increases.

Organisms die.
Decomposition

requires
oxygen.

Dissolved

oxygen levels

decrease.

Lesson 14.3 Water Pollution

Nutrient Pollution

•Phosphorus pollution mostly comes from nonpoint
sources such as phosphorus rich fertilizers and
detergents carried in runoff or wastewater

•Individuals can help by using less fertilizer and
purchasing phosphate-free detergents

Reorder

Reorder the following steps in Eutrophication

• Nutrients build up in water

• Algae growth increases

• Algae die, decomposition requires oxygen

• Dissolved oxygen levels decrease

• Other organisms like fish die

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Multiple Choice

Eutrophic water has lots of nutrients such as

• phosphates and nitrates

• oxygen and glucose

• sulfates and carbohydrates

• none of these

Multiple Select

Eutrophication is caused by (select all that apply)

• runoff of manure from farms

• runoff of fertilizers and pet waste from lawns and homes

• runoff from detergents (containing phosphates)

• acid mine drainage

Multiple Choice

Most pollution that causes eutrophication is

• point source

• non-point source

Toxic Chemical Pollution

• Occurs when harmful

chemicals are released into
waterways

• Can be organic or inorganic,

point or nonopoint source

• Harms ecosystems and

causes human health
problems including cancer.

• ORGANIC: Petroleum

products like plastics contain
BPA. Organic chemicals
also found in many
pesticides and detergents.

Lesson 14.3 Water Pollution

• INORGANIC: include heavy

metals like mercury, arsenic
and lead. Often released in
industrial/manufacturing
processes

Sediment Pollution

•Unusually large amounts of sediment that change an
aquatic environment

•Sediment pollution results from erosion.

• Land clearing, mining, poor farming practices,

construction…

•Can degrade water quality, cause photosynthesis rates in
plants to decline because water is cloudy.

Lesson 14.3 Water Pollution

Multiple Choice

Which of these organisms are affected by sediment pollution?

• fish and other organisms that move water across gills

• aquatic plants that do photosynthesis

• organisms that use sight to hunt

• all of these

Thermal Pollution

•We use water for cooling industrial processes and power
plants. Water absorbs heat.

• It can also occur when trees/shade bodies are removed.

•The warmer water is the less oxygen it can hold.

•Some organisms can’t survive the lower oxygen levels or
higher water temperatures.

Lesson 14.3 Water Pollution

Biological Pollution

•Biological pollution occurs when
pathogens enter a waterway from
human or animal waste.

•Biological pollution causes more
human health problems than any
other form of water pollution.

Lesson 14.3 Water Pollution

Did You Know?Giardiasis is the
most common form of
waterborne disease in the U.S.

Cholera bacteria

Match

Match the following

• caused by erosion from poor farming techniques, land clearing etc.

• includes heavy metals like arsenic and lead

• can occur when trees and shade are removed from around waterways

• includes bacteria like E. coli.

Sediment pollution

Toxic chemical pollution

thermal pollution

Biological pollution

• Sediment pollution

• Toxic chemical pollution

• thermal pollution

• Biological pollution