Water Quality Indicators &
Water Pollution
EPA - Environmental Protection
Agency
 Government
agency responsible
for protecting
human health and
the environment
 Helps enforce
water quality
standards
Potable Water
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Water that is considered
safe to drink = drinking
water
Not all water is
considered "potable," and
we have to monitor the
quality of our water to
make sure it is safe for us
to drink.
We use many tests to
make sure our water is
"potable" or safe to drink
pH test

3. pH - measures
how acidic or basic
the water is
 7.0 is neutral
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less than 7= acidic
higher than 7=basic
pure water has a value
of 7 on the pH scale
Acid rain major
source of the problem
Temperature
Temperature: average amount of heat in
water
Varies due to seasons or location (higher
elevations have cooler water)
Cold water is better because it holds more
oxygen.
Turbidity
Turbidity- clearness of water
Affected by sediment, excessive algae
growth and storms.
Cloudy water is bad.
In surface bodies of water, high turbidity can
lead to increased water temperatures and
low dissolved oxygen, which are not good
for the health of aquatic organisms.
Chlorine
 Water
can come from a variety of sources,
such as lakes and wells, that can be
contaminated with germs which can make
people sick.
 Germs can also contaminate water as it
travels through miles of piping to get to a
community. To prevent this, water
companies add a disinfectant that kills
germs.
 The most commonly added disinfectants
are chlorine and monochloramine.
Copper
Copper occurs in drinking water primarily
due to its use in plumbing materials and
the corrosion of copper pipes. As with lead,
all water is corrosive toward copper to
some degree, even water termed noncorrosive or water that is treated to make it
less corrosive.
 The maximum contaminate goal for
drinking water for copper is 1.3 ppm. (limit
for safe drinking water)
Hardness
 Hard
water is water that contains
dissolved substances called minerals.
These minerals contain the elements
calcium or magnesium.
Hard water is not a health risk but is a
nuisance because of mineral buildup on
plumbing fixtures and poor soap and or
detergent performance.
Phosphates/Nitrates
 4.
Phosphates and nitrates- come from
fertilizer and animal waste
 Causes algal blooms which depletes the
oxygen which kills the fish
Nitrates/ nitrites continued
 The
drinking water standard for nitrate-N is
10 ppm, or one hundredth of a gram in
one liter of water. The nitrite-N standard is
1 ppm. These standards only regulate
public water supplies, but the health risks
are the same for private well owners.
Nitrates/ Nitrites
 Nitrates
are essential plant nutrients, but in
excess amounts they can cause significant
water quality problems.
 Sources of nitrates include wastewater
treatment plants, runoff from fertilized
lawns and cropland, failing on-site septic
systems, runoff from animal manure
storage areas, and industrial discharges
that contain corrosion inhibitors.
Bioindicators
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The presence, condition, and
numbers of fish, insects
(macroinvertebrates), algae,
plants, and other aquatic life
provide accurate info about the
health of freshwater
macro= large / invertebrate=
without a backbone

macroinvertibrates=
organisms without a
backbone that are large
enough to be seen without
microscope
Good water quality = lots of
biodiversity
Poor water quality= little
biodiversity
Types of water pollution

Point Source

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Pollution flowing from a
single and identifiable
source such as a discharge
pipe from a factory,
roadway, or leaking
undergroud storage tank
Non-Point Source

Pollution collected by rain
falling over a larger
watershed which is then
carried by runoff to a
nearby lake or stream, or
by infiltration into the
groundwater
Point Source Pollution

Hazardous and toxic materials from manufacturing and
industry discharged directly into water - usually through a
pipe or a leaky underground tank
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oil and gasoline
solvents
toxins and poisons
heavy metals (arsenic, lead, mercury, etc.)
Thermal pollution - heated water caused dissolved oxygen (DO)
content in a body of water to decrease - can result in fish kills
Point source pollution became addressed by the Clean
Water Act of 1972
Non-Point Source Pollution

Harder to figure out exactly where it's coming
from
 pollutants collected by rainwater falling over a
large watershed and carried directly into a river,
lake, or stream
 Gas, oil, chemicals, detergents, and other
pollutants collected off of driveways, roads, and
city streets flow directly down drains and storm
sewers into a nearby body of water untreated
Non-Point Source Pollution
(continued)
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Modern Farming is a major source of non-point source
pollution
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Pesticides (bug killers) and herbicides (weed killers) can wash
into nearby lakes and rivers
Crop fields, especially after harvest, can wash large amounts of
dirt and sediment into nearby likes and rivers
Animal waste and manure can be a source of nutrients and
harmful bacteria
Fertilizer can be a source of nutrients, such as nitrogen and
phosphorus, entering nearby lakes and rivers leading to the
serious problem of eutrophication (can make algae grow too
much and water loses oxygen = death of fish)