Transcript Chapter 15: Freshwater Pollution and Its Control

Chapter 15: Freshwater
Pollution and Its Control
KRISTEN STURDIVAN
HAILEE MAAS
OLIVIA ABBOTT
MEGAN MILLER
Water pollution takes many forms
 Over half the world’s major rivers are seriously
depleted and polluted.
 Pollution: release of matter/energy into the
environment that cause undesirable impacts on
health of humans/organisms (can be physical,
chemical, or biological)
 Nutrient Pollution: excess phosphorus boosts growth
caused by runoff from farms, golf courses, lawns, ad
sewage

Reduce by purchasing phosphate-free detergents and reduce
fertilizers and planting specific vegetation
Water pollution takes many forms (cont.)
 Pathogens and waterborne diseases: can enter
drinking water supplies via human/animal waste



82% population has access to safe water
1.1 billion without safe water supplies
2.4 billion no sewer/sanitation facilities

4/5 lived in rural areas
Water pollution takes many forms (cont.)
 Toxic Chemicals:
pesticides, petroleum
products, and other
synthetic chemicals





Acid rain
Acid drainage
Cause cancer
Poison animals and plants
Alter aquatic ecosystems
 Sediment: rivers
transport sediment from
farmland, mining, clearcutting, and land clearing
for housing development
to different areas
through rivers and
floods.

When a clear-water river
receives a heavy influx of
eroded sediment , aquatic
habitats can change
dramatically
Water pollution takes many forms (cont.)
 Thermal Pollution: raised by the use of water to cool
an industrial facility and putting it back in the river
and removing streamside vegetation that shades
water.
When temperature rises the water’s ability to hold dissolved
oxygen decreases!
Too little heat can also case problems:
• These rivers that have dams (Colorado) and colder
temperatures favor a cold-loving invasive trout species over
the native suckerfish.

Water pollution comes from point and non-point
sources
 Point Sources: discrete locations such as a factory or
sewer pipe
 Non-Point Sources: multiple cumulative inputs over
larger areas such as farms, city streets, and
residential neighborhoods
 US Clean Water Act: targeted industrial discharges
and addressed point-source pollution

Non-Point source pollution still exerts a greater impact on
water quality in he US today!
Scientists use several indicators of water quality
 Forms of water pollution
 1. Physical
 2. Chemical
 3. Biological
 Scientists and technicians measure the properties of
water to characterize its quality.
Biological
 Include the presence of fecal coliform bacteria and
other disease causing organisms
 Algae and aquatic invertebrates are used as
biological indicators of water quality
Chemical
 Includes nutrient concentrations, pH, taste ad ordor,
and hardness

Hard water contains high concentration of calcium and
magnesium ions.
 Dissolved oxygen is an indicator of aquatic
ecosystem health

Surface water low in dissolved oxygen are less capable of
supporting aquatic life
Physical
 Turbidity measures the density of suspended
particles in a water sample


EX: Colorado River
Good indicator of overall water quality
 Water color can reveal particular substances in a
sample
 Tannins- decomposing leaf litter
 Temperature is used to access water quality

Warmer water holds less dissolved oxygen
Groundwater pollution is a serious problem
 Groundwater pollution is mainly caused by
agriculture and industrial practices


Hidden from view
Hard to monitor
 Out of mind until widespread contamination of
drinking supplies is contaminated
 Groundwater pollution retains its contaminants until
they decompose

DDT- found widely in U.S. aquifers even though it was banned
35 years ago
Decomposition of Groundwater
 Groundwater contains less dissolves oxygen, micro
tubes, minerals, and organic matter

Decomposition is slower
 Concentrations of the herbicide alachlor decline by
half after 20 days in soil, but in groundwater this
takes almost 4 years
There are many sources of groundwater pollution
•
Many ground water chemicals can become toxic at certain doses: Aluminum,
Fluoride, Nitrates, & Sulfates.
•
Bangladesh’s wells.
•
Industrial, agricultural, and urban wastes – from heavy metals to petroleum
products to industrial solvents to pesticides- leach through the soil into aquifers.
•
Volatile Organic Compounds (VOCs) were sampled and found in most aquifers and
20% of industrial wells in 2006.
•
Leakage from underground septic tanks, tanks of industrial chemicals, and tanks of
oil and gas pollute ground water
•
EPA work in 2007- confirmed leaks on 468,000 tanks, initiated clean up on
439,000 tanks, and completed clean ups on 357,000 tanks.
•
Once an aquifer is contaminated it is extremely hard to remediate.
There are many sources of groundwater pollution
• Agriculture can pollute the groundwater too:
 Pesticides were detected in over half of the shallow aquifer sites in the
US- mid 1990s.
 Nitrate from fertilizers leech into ground water.
 Nitrates in drinking water has been linked to cancer, miscarriages,
and “blue baby” syndrome.
 Pathogens in the water; Walkerton, ON in 2000 was contaminated
with E Coli – 2,000 became ill and 7 died.
• Manufacturing and military sites have been heavy polluters.
 WW2 TNT producers caused Nitro aromatic by products to seep into
the ground water for miles around
 Cleanup started with the 1980 Superfund legislation.
 The Superfund also helped clean up the Hanford Nuclear Reservation
in WA state – nuclear waste site with a half life of a quarter million
years.
Legislative and regulatory efforts have helped
reduce pollution
•
Many ground water chemicals can become toxic at certain doses: Aluminum,
Fluoride, Nitrates, & Sulfates.
•
Bangladesh’s wells.
•
Industrial, agricultural, and urban wastes – from heavy metals to petroleum
products to industrial solvents to pesticides- leach through the soil into aquifers.
•
Volatile Organic Compounds (VOCs) were sampled and found in most aquifers and
20% of industrial wells in 2006.
•
Leakage from underground septic tanks, tanks of industrial chemicals, and tanks of
oil and gas pollute ground water
•
EPA work in 2007- confirmed leaks on 468,000 tanks, initiated clean up on
439,000 tanks, and completed clean ups on 357,000 tanks.
•
Once an aquifer is contaminated it is extremely hard to remediate.
We treat our drinking water
 Technological advancements allows us to treat
drinking water and waste water.
 The EPA ensures standards are set for over 80
drinking water containments
 Water from an aquifer is treated with chemicals to
remove particular matter
 These matters can be passed through filters of sand,
gravel, and charcoal
It is better to prevent pollution than to mitigate it
after it occurs
 Filtering groundwater before distributing it can be
expensive ($400 million annually)
 Pumping water, treating it, and then injecting the
water back in, takes a lot of time after a while
 Also the clean up bill has been know to be around 1
trillion
 Restricting pollutants elsewhere usually just means
that those pollutants will end up some place else.
Some Things That Work
 You can buy phosphorus-free detergents, or
“environmental friendly” products
 You can become involved in protecting lacal
waterways
Wastewater and its Treatment
 Wastewater *refers to water that has been by people
in some way*
 Examples – water carrying sewage; water from
showers, sinks, washing machines, and dishwashers;
also water used in manufacturing or cleaning
processes by businesses and industries; and storm
water runoff.
 A large amount of waste water can harm ecosystems
and pose treats to the human health