Water pollution: any change in water quality that can cause
harm to living organisms or make the water unfit for human use
(drinking, agriculture) Chemicals, heat, bacteria, etc Air
pollution: presence of chemicals in the atmosphere in high
concentrations enough to harm organisms, ecosystems, or human-made
materials, or to alter climate From natural and human sources
Slide 3
Types of Pollution Point source pollution Discharge pollutants
into specific locations through drain pipes, ditches, or sewer
lines Factories, mines, oil spills Easy to identify and monitor
Non-point source pollution Broad and diffuse areas from which
pollutants enter water or air Runoff from cropland, feedlots,
streets, lawns, golf courses Difficult to identify and control
Slide 4
Sources of Water Pollution Agricultural Activities Leading
cause of water pollution Sediment, fertilizer, pesticides, bacteria
Industrial Activities Release organic and inorganic compounds
Energy Sources Coal ash, fracking Mining Erosion and runoff of
toxic chemicals Human Sources Garbage--Plastic polymers release
chemicals into water Nurdles! Human wastewater (Sewage and gray
water) Runoff from roadways and parking lots (gasoline and
oil)
Slide 5
Water Pollution Legislation Clean Water Act 1972 Eliminate the
release of high amounts of toxic chemicals into surface water
Finance wastewater management Safe Drinking Water Act 1974 Ensures
safe drinking water for the public EPA sets standards for drinking
water quality Applies to public water systemsnot private wells
Bottled water regulated by the FDA under the Food, Drug and
Cosmetic Act Groundwater contamination is addressed with Resource
Conservation and Recovery Act (Solid and Hazardous Waste disposal)
Superfund (CERCLA) Act (contaminated sites)
Slide 6
List of Water Pollutants Fill in the table of common water
pollutants with their source, specific examples, environmental
impacts (effects), and potential solutions (ways to decrease)
Infection agents (pathogens)give specific species/disease
Oxygen-demanding wastes Inorganic chemicals Organic chemicals Plant
nutrients Sediments Heavy metals Thermal
Slide 7
Pollution in Lakes and Rivers Streams have natural cleansing
cycleif not overloaded with a specific contaminant Developed
countries Laws enacted to protect from point source pollution and
sewage Limited drinking water contamination Developing countries
Serious and growing problem due to less infrastructure and
regulation, especially with sewage Lakes less effective at diluting
pollutants, layers in lake that dont mix regularly Eutrophication-
natural nutrient enrichment Cultural eutrophication- human
activities increase the input of plant nutrients (nitrates and
phosphates) Reduced productivity and increased algal growth
Slide 8
Groundwater Pollution Common pollutants include: Fertilizer
(nitrates), pesticides, gasoline, oil, and other solvents Serious
threat to human health, contaminants fill in porous rock layers in
aquifers Difficult and costly to remove/cleanup pollutants Cant
cleanse itself very quickly; dilute or disperse contaminants Cold
temps, low bacteria and low dissolved oxygen Prevention only way to
deal with this pollution effectively!
Slide 9
Over 1 billion people lack access to clean drinking water
Developed countries have drinking water standards (Safe Drinking
Water Act) Water treated before made available to public Recycling
wastewater (CA and TX)expensive! Developing countries can use
simple technology to purify water Sunlight, Lifestraws, and
powders
Slide 10
Ocean Pollution Coastlines most polluted (where everyone lives)
Untreated sewage, garbage, agricultural runoff Increased nitrates
and phosphates cause toxic algal blooms (red tides), which harm
marine organisms and humans Oil Spillsalso runoff from roads and
parking lots Creates oxygen depleted zones (dead zones) Hypoxic
(low oxygen), results in high bacteria levels Garbage litters ocean
(mostly plastic) Atlantic and Pacific Garbage Patches Best
prevention is to reduce flow of pollution into ocean
Slide 11
Water Quality Testing Fecal Coliforms This nasty stuff is a
certain bacteria that propagate in the digestive tracts of humans
and animals. They coexist with other bacteria so they are often
used as indicators of possible pathogenic contamination. There are
many ways fecal coliform can enter a waterway such as animal waste,
untreated sewage, combined sewage overflow, and septic tanks.
Dissolved Oxygen This test is the most important of the nine water
quality tests to measure water's ability to support plants and
animals. There are many different factors that affect the amount of
dissolved oxygen in water, the main one being temperature. As
temperature rises, less gas will dissolve. Turbidity Turbidity
measures water clarity, which allows sunlight to penetrate to a
greater depth. The main sources of turbidity are erosion, living
organisms, and those from human endeavors pH The pH of water is
important to aquatic life. If the PH falls below 4 or above 9
everything is dead. Total Solids Total solids measures both
dissolved and suspended solids. There are six major types of total
solids; silt, clay, soil runoff, plankton, industrial waste, and
sewage
Slide 12
Temperature Temperature is a very important part of a river's
ecology. There are many natural and human factors that can affect a
river's temperature. Human factors include industry, development,
and dams. If the difference is greater than 2 degrees Celsius, then
there is thermal pollution. To find flow rate you use a buoyant
object, we used an orange, and float it down the river Nitrates
Nitrogen is necessary for plant and animal life. Water is tested
for nitrates to monitor and control eutrophication, which causes
more plant growth and decay Phosphates Phosphates is a nutrient
needed in growth. The phosphate ion is found in shells, bones, and
in animal teeth. By removing phosphorous from sewage the amount of
phosphate ions in the water will be lowered. Biological oxygen
demand BOD is a measure of oxygen removed from an aquatic
environment by aerobic microorganisms. It measures levels of
organic pollution in lakes and streams
Slide 13
Alkalinity Alkalinity is a measure of the capacity of water to
neutralize acids (see pH description). Without this
acid-neutralizing capacity, any acid added to a stream would cause
an immediate change in the pH. Measuring alkalinity is important in
determining a stream's ability to neutralize acidic pollution from
rainfall or wastewater. It's one of the best measures of the
sensitivity of the stream to acid inputs. Carbon Dioxide When the
oxygen concentration in waters containing organic matter is
reduced, the carbon dioxide concentration rises. The rise in carbon
dioxide makes it more difficult for fish to use the limited amount
of oxygen present. To take on fresh oxygen, fish must first
discharge the carbon dioxide in their blood streams and this is a
much slower process when there are high concentration of carbon
dioxide in the water itself. Chlorine Used as a disinfectant in
drinking water; Chlorine causes environmental harm at low levels.
Chlorine is especially harmful to organisms living in water and in
soil..but only in high doses.
Slide 14
Sewage/Wastewater Treatment Septic tank: household sewage and
wastewater is pumped into a holding tank; grease/oil rise to the
top, solids sink to be decomposed by bacteria Some wastewater is
leached out into drainfield to be decomposed by soil and bacteria;
pumped to remove material periodically Wastewater Treatment
Facilities: raw sewage is treated in two steps to remove
particulates Primary: physical treatment/removal of solids
Secondary: biological treatment/removal of solids Before
dischargethe water is treated to remove any remaining
disease-carrying bacteria
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