Water Quality Presentation

What will we know?

8.E.1.3 – WATER QUALITY

★

What makes water potable

★

How turbidity, temperature, pH, and

dissolved oxygen can effect the health of a water
system

★

What bioindicators are and how they can

help determine the health of a water system

★

What the EPA is and how they help keep our
waters clean

What effects it?

WATER SYSTEM HEALTH

PHYSICAL

CHEMICAL

BIOLOGICAL

- Temperature
- Turbidity
- Water

Movement

- Dissolved oxygen

(+ other gases)

- pH
- Nitrates
- Salinity

- Fish
- Algae
- Insects
- Plants

★ When it comes to the health of a water system, there are many

factors that go into it. The balance between physical, chemical
and biological variables determines the health of a water system

These
variables are
subject to
change from
both natural
and man-made
forces

Why do we care?

WATER SYSTEM HEALTH

★ Freshwater is a major concern because it is the source of water for

humans and animals

★ Our freshwater that we use can be classified as SAFE or POTABLE

HEALTHY ENOUGH TO BATHE

IN AND CLEAN WITH
HEALTHY
ENOUGH

TO

DRINK

vs.

PHYSICAL INDICATORS

temperature

★

The temperature of a body of water determines the
organisms that can live there

★

Many organisms have a preferred temperature range
where they will thrive

★THINK ABOUT IT! Can we live in -50 degree weather but SOME
CAN!

★

As the temperature increases:

★It is able to dissolve more sediment which can block light and not allow
photosynthesis to occur

★It dissolves LESS oxygen (because particles are moving too fast and
O2 can escape into the air) and may not contain enough for organisms
to survive

BETTER

FOR

AQUATIC

LIFE!

PHYSICAL INDICATORS

HIGH TURBIDITY

(CLOUDY)

LOW

TURBIDITY

(Clear)

Turbidity

★

Turbidity is how clear/cloudy a body of water is

★Cloudiness is due to the amount of sediment dissolved in the water

★A HIGH turbidity = not potable

★Can lead to increased temperatures, decreased DO, and impairment of some
aquatic organisms

MOST

POTABLE!

CHEMICAL INDICATORS

dissolved oxygen

★Dissolved oxygen is the amount of oxygen in water that is available for aquatic
organisms to use

★The level of oxygen in surface water is important for many organisms such as zooplankton and
fish to thrive

★There are two ways oxygen gets into the water:

1.

From the AIR (being trapped
by waves and moving
currents)

2.

From PLANTS releasing
O2 during photosynthesis

CHEMICAL INDICATORS

pH level

★The pH of a body of water determines how acidic or how basic it is

★pH is measured on a scale from 0-14

o0-6: ACIDIC

o7: NEUTRAL

o8-14: BASIC (Alkaline)

★The pH of water is known to have a synergistic effect, which means that materials (iron, aluminum, ammonia,
mercury) introduced into bodies of water can have more or less of an impact based on the pH of the water
❑

EXAMPLE: Metals in more acidic water can become more
dangerous or poisonous than they normally would be in neutral
water

CHEMICAL INDICATORS

nitrates + phosphates

★

Nitrates and phosphates come from Nitrogen and Phosphorous,
which are essential nutrients for healthy plant growth.
★Too many nitrates or phosphates in drinking water can make it unhealthy

SOURCES OF NITRATES

SOURCES OF PHOSPHATES

- Runoff contaminated with

fertilizers

- Septic tank leaks
- Sewage

- Human and animal waste
- Laundry
- Cleaning and industrial waste

CHEMICAL INDICATORS

salinity

★ Salinity is the measure of salt in water and can be an

indicator of how healthy a water system is

★

Salinity can enter water systems through natural processes of weathering
rocks from wind and rain

★

High concentrations of salinity can cause vegetation to become unhealthy
or die and can lead to a decrease in biodiversity

AMOUNT OF
DIFFERENT SPECIES
LIVING IN AN AREA

BIOLOGICAL INDICATORS

bioindicators

★ Biological indicators (Bioindicators) are macroinvertebrates that can give

an indication of how healthy a water system is.

★

The presence and numbers of the types of fish, insects, algae, plants and other
aquatic organisms can tell us how healthy the water they live in is

★

These organisms are usually easy to collect and identify

★

These organisms are used to measure water health because many are very sensitive
to pollution.

o Poor water quality is indicated by a few number of bioindicators organisms in one

place

bioindicators

BIOLOGICAL INDICATORS

The species in the GREEN to
the right is a bioindicator species
because it is
disturbance-intolerant (which
means it does not handle a
change in the water well).
- As the water withdrawal occurs,
and the water system is less
healthy for these organisms, their
abundance numbers begin to
drop.

WATER STEWARDSHIP

protecting our water

★ There has only been a growing awareness and concern for water pollution

for the past 45-50 years. Before that, there was little concern about what
was being put or dumped into our water systems.
★

Part of this awareness came with the development of the Environmental Protection
Agency (EPA) in 1970

★

In 1972, the Clean Water Act established the regulations on putting pollutants
into the water

This gave the EPA the
authority to test for pollutants
and chemicals in the water
and set maximum amounts

allowed to be found in the
water

WATER STEWARDSHIP

before the EPA

The Cuyahoga
River in
Cleveland was
so polluted with
oils and
chemicals that
the water
actually set fire!

after the EPA

WATER STEWARDSHIP

Now you
can swim
in that
same river!