Transcript Water Pollution - A.P. Environmental Science

Water Pollution
Chapter 21
Chapter 21
• Identify what pollutes water and the source of
the pollution.
• Identify the major pollution problems affecting
our waterways including oceans, surface water
and groundwater
• Determine methods to “clean up” water
• Describe state and federal water legislation
Vocabulary Words
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Water pollution
point/non-point source
Biological Oxygen Demand (BOD)
Chemical Oxygen Demand (COD)
sludge
Safe Drinking Water Act
Clean Water Act
Oil Spill Prevention & Liability Act
Identifying Pollution
• Which of the beakers on the front table contain
polluted water?
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Chlorine, specific conductance
Acid, pH
Organic constituents, lab analysis
Sediment, visual identification
Surfactants, visual identification
We All Live Downstream
• “Today, everybody is downstream from
somebody else,” William Ruckelshaus
▫ What does that mean?
▫ How does that affect your water quality?
“Frontline: Poisoned Waters”
• http://video.pbs.org/video/1114515379/
Water Pollution
• Water pollution is any chemical, biological or
physical change in water quality that has a
harmful effect on living organisms or makes
water unsuitable for desired uses.
▫ Who decides if water is “harmful”?
▫ What does “harmful” mean?
▫ Which “living organisms” matter?
• “All substances are poisons, there is none which
is not a poison. The right dose differentiates a
poison and a remedy.”
Paracelsus (1493-1541)
Toxicology
• The study of the interaction between chemical
agents and biological systems.
• Toxicity is the relative ability of a substance to
cause adverse effects in living organisms.
Definitions of “harmful”
• Toxic refers to a parameter, constituent to
pollutant that has an LD50; in other words, it has
been known to kill organisms (usually humans)
• Hazardous refers to a compound which causes
acute or chronic health problems, including, but
not limited to, death.
The point is . . .
• If the chemicals and biological agents that we
use and produce as waste products were not
“harmful” in some way to some population,
there would be no point in studying water
pollution.
The source of it all
• Point source: pollution that comes from a
specific location
Sludge from a
copper mine.
Industrial discharge
Other Sources
• Non-point source: pollution that occurs from
multiple sources with no single polluter
identified.
Who are the polluters?
• The major source of 41-48% water pollution is
agriculture according to the EPA.
▫ Connect the dots from population growth, food
production, water use and water pollution.
• Industrial Facilities
• Municipal
• Mining
What is water polluted with?
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Disease-causing agents
Oxygen demanding waste
Plant nutrients (NO3-, PO43-)
Organic chemicals (solvents, petroleum)
Inorganic chemicals (Fe, Pb, NH3)
Sediment
Heat
What are they polluting?
Types
Examples
Sources
 Infectious agents  Bacteria, viruses,  Human and
parasites
animal waste
 Oxygendemanding waste
 Biodegradable
animal waste &
plant debris
 Sewage, animal
feedlots, food
processing plants,
pulp mills
 Sewage, animal
waste, fertilizers
 Plant nutrients
 NO3, PO4, SO4
 Organic
chemicals
 Petroleum
 Industry, farms,
products, plastics, households
cleaners, etc.
What else are they polluting?
Types
Examples
 Inorganic
chemicals
 Acids, salts,
metal compounds
 Sediment
 Clay, sand, silt
 Thermal
 Heat
Sources
 Industry,
households,
surface runoff
 Erosion, farms,
industry
 Power plants,
nuclear facilities,
industry
Effects of Pollution
• The two major effects of water pollution are:
▫ exposure to infectious agents from contaminated
drinking water; and,
▫ not having enough water for effective sanitation.
Waterborne Diseases
Type of
Organism
Disease
Effects
Bacteria
 Typhoid fever  diarrhea, vomiting, inflammation
 Enteritis
 stomach pain, nausea, vomiting
Virus
 Hepatitis B
Parasites  Dysentery
 Giardiasis
Parasitic
worms
 Schistosomiasis
 fever, severe headache,
jaundice, enlarged liver
 diarrhea, abdominal pain
 diarrhea, cramps, fatigue
 Abdominal pain, rash, anemia,
chronic fatigue
What is “clean” or “safe”?
• The definition of clean or safe water is very
dependent on it’s use and the laws that affect the
source and discharge of the water.
▫ Example: pH
 RCRA: 2 > S.U. > 12.5
 SDWA: 6.5 > S.U. > 8.5
 HMTA: those substances which cause visible
destruction to skin tissue
The Water
• Drinking Water: Safe Drinking Water Act
• Surface Water: Clean Water Act
• Groundwater: CWA, RCRA as Solid Waste,
CERCLA for clean-up
Surface Water
• Surface Water is polluted by:
▫ human activity
▫ industrial activity
▫ power plants
Freshwater Sources
Water Quality
• There are two classes of water quality standards:
▫ biological
▫ chemical
Chemical Water Quality
• Water Quality Index (WQI) is a set of standard
test parameters used to compare water quality
all around the country.
▫ An numerical WQI is assigned based on the
results of nine (9) separate parameters
WQI Parameters
 Dissolved Oxygen (DO)
 pH
 Temperature Change (ΔT)
 Fecal Coliform
 Biochemical Oxygen Demand (BOD)
 Nitrates
 Total Phosphates
 Total Dissolved Solids (TDS)
 Turbidity or Total Suspended Solids (TSS)
Q Value
• Measurements of each parameter are taken and
recorded and then are converted into a “Q value”
Water Quality Factor Weights
• The “Q” value for each parameter is
determined and multiplied by a weighting
factor:

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
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

Dissolved oxygen
Fecal coliform
pH
Biochemical oxygen demand
Temperature change
Total phosphate
Nitrates
Turbidity
Total solids
0.17
0.16
0.11
0.11
0.10
0.10
0.10
0.08
0.07
Final calculation
• The weighted “Q values” are added for all of the
parameters and compared to a water quality
index scale
The Scale
• Water Quality Index Scale
▫
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91 - 100 : Excellent Water Quality
71 - 90 : Good Water Quality
51 - 70 : Medium or Average Quality
26 - 50 : Fair Water Quality
0 - 25 : Poor Water Quality
Dissolved Oxygen
• Oxygen gas is not very soluble in water.
• As the temperature of a liquid increases, the
solubilities of gases in that liquid decrease.
▫ T, Solubility
Gas Solubility
• We can use the Second Law of
Thermodynamics to explain why.
• Heating a solution of a gas enables the particles
of gas to move more freely between the
solution and the gas phase.
• The Second Law predicts that they will shift to
the more disordered, more highly dispersed,
and therefore, more probably gas state.
Where does DO come from?
• Most of the DO in surface water comes from
contact with the atmosphere.
▫ Splashing and flowing water traps oxygen
▫ Photosynthetic organisms also produce oxygen
DO Test
• The test for DO determines the availability of
oxygen for aquatic life
• A high concentration of DO indicates high water
quality
Water
Quality
DO (ppm) at 20°C
Good
8–9
Slightly
polluted
6.7–8
Moderately
polluted
Heavily
polluted
Gravely
polluted
4.5–6.7
Below 4.5
Below 4
Fig. 21-3, p. 496
Reference
http://www.indiana.edu/~bradwood/eagles/waterquality.htm
Physical Influences on Dissolved
Oxygen
• Water temperature and the volume of water
moving down a river (discharge) affect dissolved
oxygen levels. Gases, like oxygen, dissolve more
easily in cooler water than in warmer water. In
temperate areas, rivers respond to changes in air
temperature by cooling or warming.
Climate and DO
• River discharge is related to the climate of an
area. During dry periods, flow may be severely
reduced, and air and water temperatures are
often higher. Both of these factors tend to reduce
dissolved oxygen levels. Wet weather or melting
snows increase flow, with a resulting greater
mixing of atmospheric oxygen.
Human-Caused Changes in Dissolved
Oxygen
• The main factor contributing to changes in
dissolved oxygen levels is the build- up of organic
wastes.
▫ Organic wastes consist of anything that was once
part of a living plant or animal, including food,
leaves, feces, etc.
▫ Organic waste can enter rivers in sewage, urban and
agricultural runoff, or in the discharge of food
processing plants, meat packing houses, dairies, and
other industrial sources.
Farming and Dissolved Oxygen
• A significant ingredient in urban and agricultural
runoff are fertilizers that stimulate the growth of
algae and other aquatic plants. As plants die,
aerobic bacteria consume oxygen in the process of
decomposition. Many kinds of bacteria also
consume oxygen while decomposing sewage and
other organic material in the river.
Changes in Aquatic Life
 Depletions in dissolved oxygen can cause major shifts
in the kinds of aquatic organisms found in water
bodies.
 Species that cannot tolerate low levels of dissolved
oxygen-mayfly nymphs, stonefly nymphs, caddisfly
larvae, and beetle larvae-will be replaced by a few kinds
of pollution-tolerant organisms, such as worms and fly
larvae.
 Nuisance algae and anaerobic organisms (that live
without oxygen) may also become abundant in waters
with low levels of dissolved oxygen.
Calculating Percent Saturation
• The percent saturation of water with dissolved
oxygen at a given temperature is determined by
pairing temperature of the water with the
dissolved oxygen value, after first correcting
your dissolved oxygen measurement for the
effects of atmospheric pressure. This is done
with the use of the correction table and the
percent saturation chart.
Using the Conversion Charts
 To calculate percent saturation, first correct your
dissolved oxygen value (milligrams of oxygen per
liter) for atmospheric pressure. Look at the
correction chart. Using either your atmospheric
pressure (as read from a barometer) or your
local altitude (if a barometer is not available),
read across to the right hand column to find the
correction factor. Multiply your dissolved oxygen
measurement by this factor to obtain a corrected
value.
The Meaning of Percent Saturation
• Rivers that consistently have a dissolved oxygen
value of 90 percent or higher are considered
healthy, unless the waters are supersaturated due
to cultural eutrophication.
• Rivers below 90 percent saturation may have
large amounts of oxygen-demanding materials,
i.e. organic wastes.
Biochemical Oxygen Demand (BOD)
• When organic matter decomposes, it is fed upon
by aerobic bacteria. In this process, organic
matter is broken down and oxidized (combined
with oxygen). Biochemical oxygen demand is a
measure of the quantity of oxygen used by these
microorganisms in the aerobic oxidation of
organic matter.
Biochemical Oxygen Demand (BOD)
• When aquatic plants die, they are fed upon by
aerobic bacteria. The input of nutrients into a
river, such as nitrates and phosphates,
stimulates plant growth. Eventually, more plant
growth leads to more plant decay. Nutrients,
then, can be a prime contributor to high
biochemical oxygen demand in rivers.
Sources of Organic Matter
• There are natural sources of organic material
which include organic matter entering lakes
and rivers from swamps, bogs, and vegetation
along the water, particularly leaf fall.
• There are also human sources of organic
material. When these are identifiable points
of discharge into rivers and lakes, they are
called point sources.
Point Sources of Organic Matter
• Point sources of organic pollution include:
 pulp and paper mills;
 meat-packing plants;
 food processing industries;
 wastewater treatment plants.
Non-point Sources of Organic Matter
• Urban runoff of rain and melting snow that
carries sewage from illegal sanitary sewer
connections into storm drains; pet wastes from
streets and sidewalks; nutrients from lawn
fertilizers; leaves, grass clippings, and paper
from residential areas;
• Agricultural runoff that carries nutrients, like
nitrogen and phosphates, from fields;
• Runoff from animal feedlots that carries fecal
material into rivers.
Changes in Aquatic Life
• In rivers with high BOD levels, much of the
available dissolved oxygen is consumed by
aerobic bacteria, robbing other aquatic
organisms of the oxygen they need to live.
▫ Organisms that are more tolerant of lower
dissolved oxygen may appear and become
numerous, such as carp, midge larvae, and sewage
worms. Organisms that are intolerant of low
oxygen levels, such as caddisfly larvae, mayfly
nymphs, and stonefly nymphs, will not survive.
Cause and Effect
▫ As organic pollution increases, the ecologically
stable and complex relationships present in waters
containing a high diversity of organisms is
replaced by a low diversity of pollution-tolerant
organisms.
Fig. 21-4, p. 497
pH
• Water contains both H+ (hydrogen) ions and
OH- (hydroxyl) ions. The pH test measures the
H+ ion concentration of liquids and substances.
Changes
in
pH
• It is important to remember that for every
one unit change on the pH scale, there is
approximately a ten-fold change in how acidic
or basic the sample is.
▫ The average pH of rainfall over much of the
northeastern United States is 4.3, or roughly
ten times more acidic than normal rainfall of
5.0-5.6.
▫ Lakes of pH 4 (acidic) are roughly 100 times
more acidic than lakes of pH 6.
Human-Caused Changes in pH
• In the U.S., the pH of natural water is usually
between 6.5 and 8.5, although wide variations
can occur. Increased amounts of nitrogen oxide
(NOx) and sulfur dioxide (SO-2), primarily from
automobile and coal-fired power plant
emissions, are converted to nitric acid and
sulfuric acid in the atmosphere.
Acid Neutralization
• Acid rain is responsible for thousands of lakes in
eastern Canada, northeastern United States,
Sweden, and Finland becoming acidic. If
limestone is present, the alkaline (basic)
limestone neutralizes the effect the acids might
have on lakes and streams.
▫ The areas hardest hit by acid rain and snow are
downwind of urban/industrial areas and do not
have any limestone to reduce the acidity of the
water.
Changes in Aquatic Life
• Changes in the pH value of water are important
to many organisms. Most organisms have
adapted to life in water of a specific pH and may
die if it changes even slightly. This has happened
to brook trout in some streams in the Northeast.
pH Extremes
• At extremely high or low pH values (e.g., 9.6 or
4.5) the water becomes unsuitable for most
organisms. For example, immature stages of
aquatic insects and young fish are extremely
sensitive to pH values below 5.
▫ Very acidic waters can also cause heavy metals,
such as copper and aluminum, to be released into
the water.
Nitrates
• Nitrogen is a much more abundant nutrient than
phosphorus in nature.
• Blue-green algae, the primary algae of algal
blooms, are able to use N2 and convert it into
forms of nitrogen that plants can take up
through their roots and use for growth:
ammonia (NH3) and nitrate (NO3-).
Nitrates
• How do aquatic animals obtain the nitrogen they
need to form proteins?
▫ they either eat aquatic plants and convert plant
proteins to specific animal proteins,
▫ or, they eat other aquatic organisms which feed
upon plants.
Nitrates
• As aquatic plants and animals die, bacteria break
down large protein molecules into ammonia.
▫ Ammonia is then oxidized (combined with
oxygen) by specialized bacteria to form nitrites
(NO2) and nitrates (NO-3). These bacteria get
energy for metabolism from oxidation.
Nitrates
• Excretions of aquatic organisms are very rich in
ammonia, although the amount of nitrogen they
add to waters is usually small.
▫ Duck and geese, however, contribute a heavy load
of nitrogen (from excrement) in areas where they
are plentiful. algae into ammonia and nitrates.
Eutrophication
• Eutrophication promotes more plant growth and
decay, which in turn increases biochemical
oxygen demand.
▫ However, unlike phosphorus, nitrogen rarely
limits plant growth, so plants are not as sensitive
to increases in ammonia and nitrate levels.
Sources of Nitrates
• Sewage is the main source of nitrates added by
humans to rivers and lakes.
• Septic systems are common in rural areas.
▫ In properly functioning septic systems, soil
particles remove nutrients like nitrates and
phosphates before they reach groundwater.
Sources of Nitrates
• When septic system drainfields are placed too
close to the water table, nutrients and bacteria
are able to percolate down into the groundwater
where they may contaminate drinking water
supplies.
• Septic tanks must also be emptied periodically,
to function properly.
Problems with Nitrate Contaminated
Water
• Water containing high nitrate levels can cause a
serious condition called methemoglobinemia
(met-hemo-glo-bin-emia), if it is used for infant
milk formula.
▫ This condition prevents the baby's blood from
carrying oxygen; hence the nickname "blue baby"
syndrome.
Water Temperature
• The water temperature of a river is very
important for water quality.
▫ Many of the physical, biological, and chemical
characteristics of a river are directly affected by
temperature.
Temperature Influences
 the amount of oxygen that can be dissolved in
water;
 the rate of photosynthesis by algae and larger
aquatic plants;
 the metabolic rates of aquatic organisms;
 the sensitivity of organisms to toxic wastes,
parasites, and diseases.
• Remember, cool water can hold more oxygen
than warm water, because gases are more
easily dissolved in cool water.
Human-Caused Changes in
Temperature
• Thermal pollution is an increase in water
temperature caused by adding relatively warm
water to a body of water.
▫ Industries, such as nuclear power plants, may
cause thermal pollution by discharging water
used to cool machinery.
▫ Thermal pollution may also come from
stormwater running off warmed urban surfaces,
such as streets, sidewalks, and parking lots.
Human Temperature
▫ People also affect water temperature by cutting
down trees that help shade the river, exposing the
water to direct sunlight.
▫ Soil erosion can also contribute to warmer water
temperatures. Soil erosion raises water
temperatures because it increases the amount of
suspended solids carried by the river, making the
water cloudy (turbid). Cloudy water absorbs the
sun's rays, causing water temperature to rise.
Changes in Aquatic Life
• As water temperature rises, the rate of
photosynthesis and plant growth also increases.
▫ More plants grow and die.
▫ As plants die, they are decomposed by bacteria
that consume oxygen.
▫ Therefore, when the rate of photosynthesis is
increased, the need for oxygen in the water (BOD)
is also increased.
Hot Animals
• The metabolic rate of organisms also rises with
increasing water temperatures, resulting in even
greater oxygen demand.
▫ The life cycles of aquatic insects tend to speed up
in warm water.
▫ Animals that feed on these insects can be
negatively affected, particularly birds that depend
on insects emerging at key periods during their
migratory flights.
Temperature Adaptations
• Most aquatic organisms have adapted to survive
within a range of water temperatures. Some
organisms prefer cooler water, such as trout,
stonefly nymphs, while others thrive under
warmer conditions, such as carp and dragonfly
nymphs.
▫ As the temperature of a river increases, cool water
species will be replaced by warm water organisms.
Temperature and Toxicity
• Temperature also affects aquatic life's sensitivity
to toxic wastes, parasites, and disease.
▫ Thermal pollution may cause fish to become more
vulnerable to disease, either due to the stress of
rising water temperatures or the resulting
decrease in dissolved oxygen.
Turbidity
• Turbidity is a measure of the relative clarity of
water: the greater the turbidity, the murkier the
water.
▫ Turbidity increases as a result of suspended solids
in the water that reduce the transmission of light.
▫ Suspended solids are varied, ranging from clay,
silt, and plankton, to industrial wastes and
sewage.
Sources of Turbidity
• High turbidity may be caused by soil erosion,
waste discharge, urban runoff, abundant bottom
feeders (such as carp) that stir up bottom
sediments, or algal growth.
• The presence of suspended solids may cause
color changes in water, from nearly white to redbrown, or to green from algal blooms.
Changes in Aquatic Life
• At higher levels of turbidity, water loses its ability to
support a diversity of aquatic organisms.
 Waters become warmer as suspended particles absorb
heat from sunlight, causing oxygen levels to fall (warm
water, less O2).
 Photosynthesis decreases because less light penetrates
the water, causing further drops in oxygen levels.
 The combination of warmer water, less light, and oxygen
depletion makes it impossible for some forms of aquatic
life to survive.
Suspended Solids
▫ Suspended solids can clog fish gills, reduce growth
rates, decrease resistance to disease, and prevent
egg and larval development.
▫ Particles of silt, clay, and organic materials can
smother the eggs of fish and aquatic insects, as well
as suffocate newly-hatched insect larvae.
▫ Material that settles into the spaces between rocks
makes these microhabitats unsuitable for mayfly
nymphs, stonefly nymphs, caddisfly larvae, and
other aquatic insects living there.
Fecal Coliform Bacteria
• Fecal coliform bacteria are found in the feces of
humans and other warm-blooded animals.
▫ These bacteria can enter rivers directly or from
agricultural and storm runoff carrying wastes
from birds and mammals, and from human
sewage discharged into the water.
Pathogenic Organisms
• Fecal coliform by themselves are not dangerous
(pathogenic) .
▫ Fecal coliform bacteria naturally occur in the
human digestive tract, and aid in the digestion of
food.
▫ In infected individuals, pathogenic organisms are
found along with fecal coliform bacteria.
Presence of Both
• If fecal coliform counts are high (over 200
colonies/100 ml of water sample) in the river,
there is a greater chance that pathogenic
organisms are also present.
▫ Diseases and illness such as typhoid fever,
hepatitis, gastroenteritis, dysentery, and ear
infections can be contracted in waters with high
fecal coliform counts.
What to monitor?
• Pathogens are relatively scarce in water, making
them difficult and time-consuming to monitor
directly. Instead, fecal coliform levels are
monitored, because of the correlation between
fecal coliform counts and the probability of
contracting a disease from the water.
Municipal Monitoring
• Sanitary wastes (from toilets, washers, and
sinks) flow through sanitary sewers and are
treated at the wastewater treatment plant.
▫ Storm sewers carry rain and snow melt from
streets, and discharge untreated water directly
into rivers.
▫ Heavy rains and melting snow wash animal
wastes from sidewalks and streets and may wash
fecal coliform into the storm sewers.
Standards
Phosphorus
• Phosphorus is usually present in natural waters
as phosphate .
▫ Organic phosphate is a part of living plants and
animals, their by-products, and their remains.
▫ Inorganic phosphates are ions and are bonded to
soil particles; there are some phosphates present
in laundry detergents.
Phosphorus is essential
• Phosphorus is a plant nutrient needed for
growth, and a fundamental element in the
metabolic reactions of plants and animals.
▫ Plant growth is limited by the amount of
phosphorus available.
▫ In most waters, phosphorus functions as a
"growth-limiting" factor because it is usually
present in very low concentrations.
Phosphorus is scarce
• The natural scarcity of phosphorus can be
explained by its attraction to organic matter and
soil particles.
▫ Any unattached or “free" phosphorus, in the form
of inorganic phosphates, is rapidly taken up by
algae and larger aquatic plants.
▫ Because algae only require small amounts of
phosphorus to live, excess phosphorus causes
extensive algal growth called "blooms."
Eutrophication
• Most of the eutrophication occurring today is
human-caused (cultural eutrophication).
• Phosphorus from natural sources generally
becomes trapped in bottom sediments or is
rapidly taken up by aquatic plants. Forest fires
and fallout from volcanic eruptions are natural
events that cause eutrophication.
Sources of Phosphorus
• Phosphorus comes from several sources: human
wastes, animal wastes, industrial wastes, and
human disturbance of the land and its
vegetation.
▫ Sewage effluent (out flow) should not contain
more than 1 mg/ L phosphorus according to the
U.S. EPA.
Sources of P
▫ Storm sewers sometimes contain illegal
connections to sanitary sewers. Sewage from these
connections can be carried into waterways by
rainfall and melting snow.
▫ Phosphorus-containing animal wastes sometimes
find their way into rivers and lakes in the runoff
from feedlots and barnyards.
Erosion is a source
• Soil erosion contributes phosphorus to rivers.
 The removal of natural vegetation for farming or
construction exposes soil to the eroding action of rain and
melting snow.
 Draining swamps and marshes for farmland or
construction projects releases phosphorus that has
remained dormant in years of accumulated organic
deposits.
 Drained wetlands no longer function as filters of silt and
phosphorus, allowing more runoff -and phosphorus- to
enter waterways.
Impacts of Cultural Eutrophication
• The first symptom of cultural eutrophication is an
algal bloom that colors the water a pea-soup green.
• The advanced stages of cultural eutrophication can
produce anaerobic conditions in which oxygen in
the water is completely depleted.
 These conditions usually occur near the bottom of a
lake or impounded river stretch, and produce gases
like hydrogen sulfide, unmistakable for its "rotten egg"
smell.
Changes in Aquatic Life
• Cultural eutrophication causes a shift in aquatic
life to a fewer number of pollution tolerant
species.
▫ The species that can tolerate low dissolved oxygen
levels include-carp, midge larvae, sewage worms
(Tubifex), and others.
Reversing the Effects of Cultural
Eutrophication
 Aquatic ecosystems have the capacity to recover if
the opportunity is provided by:
 Reducing our use of lawn fertilizers;
 Encouraging better farming practices;
 Preserving natural vegetation whenever possible,
particularly near shorelines; preserving wetlands to absorb
nutrients and maintain water levels; enacting strict
ordinances to prevent soil erosion;
 Supporting measures (including taxes) to improve
phosphorus removal by wastewater treatment plants and
septic systems; treating storm sewer wastes if necessary;
encouraging homeowners along lakes and streams to invest
in community sewer systems;
Biological Monitoring
• You can determine the toxicity of an effluent or
water sample to determine the LD50
▫ Ceriodaphnia dubia
▫ Daphnia pulex
▫ Pimephales promelas
• Stream monitoring: collect samples of
organisms and collect data regarding
identification and numbers
Save Our Streams
• http://www.vasos.org/pages/gettingstarted.htm
l
• http://www.vasos.org/pages/documents/vasoss
tandardoperatingprocedures.pdf
Using Insects to Study Stream Health
• A sample of stream insects, or
“macroinvertebrates” is collected, identified and
counted.
• http://www.vasos.org/ModifiedBugIDCardoct2
004.pdf
Sensitive Insects
# Types x 3
•
•
•
•
•
•
•
caddisfly larva
hellgrammite
mayfly nymph
gilled snails
riffle beetle adult
stonefly nymph
water penny larva
Somewhat Sensitive Insects
# Types x 2
•
•
•
•
•
•
•
•
beetle larva
clams
crane fly larva
crayfish
damselfly nymph
dragonfly nymph
scuds
sowbugs
• fishfly larva
• alderfly larva
• blackfly larva
• atherix
Very Tolerant Organisms
# Types x 1
•
•
•
•
aquatic worms
pouch (& other) snails
leeches
midge larva
The Quality Rating Scale
• WATER QUALITY RATING
• Excellent (>22)
Good (17-22)
Fair (11-16)
Poor (<11)
What about groundwater?
• Groundwater pollution caused by human
activities usually falls into one of two categories:
point-source pollution and nonpoint-source
pollution.
▫ Point-source contamination originates from a
single tank, disposal site, or facility. Industrial
waste disposal sites, accidental spills, leaking
gasoline storage tanks, and dumps or landfills are
examples of point sources.
Non-point Source Groundwater
Contamination
• Chemicals used in agriculture, such as fertilizers,
pesticides, and herbicides are examples of
nonpoint-source pollution because they are spread
out across wide areas.
▫ Runoff from urban areas is a nonpoint source of
pollution.
▫ Because nonpoint-source substances are used over large
areas, they collectively can have a larger impact on the
general quality of water in an aquifer than do point
sources,
Leaking
tank
Water
table
Groundwater
flow
Free gasoline
dissolves in
Gasoline
groundwater
leakage plume
(dissolved
(liquid phase)
phase)
Migrating
vapor phase
Contaminant plume moves
with the groundwater
Water well
Fig. 21-8, p. 502
Contamination can move!
• Groundwater tends to move very slowly and with little
turbulence, dilution, or mixing.
▫ Therefore, once contaminants reach groundwater, they
tend to form a concentrated plume that flows along with
groundwater.
▫ Despite the slow movement of contamination through an
aquifer, groundwater pollution often goes undetected for
years, and as a result can spread over a large area. One
chlorinated solvent plume in Arizona, for instance, is 0.8
kilometers (0.5 miles) wide and several km long!
Groundwater Migration
• Groundwater migration models use hydrology,
geology and soil science to predict the flow of the
aquifer and the subsequent contamination.
▫ Methods are very complex.
▫ Computer based models are used to predict the
potential reach of the contaminated plume.
Groundwater Laws
• The two major federal laws that focus on
remediating groundwater contamination include
the Resource Conservation and Recovery Act
(RCRA) and the Comprehensive Environmental
Response, Compensation, and Liability Act
(CERCLA), also known as Superfund.
Groundwater Laws: RCRA and CERCLA
▫ RCRA regulates storage, transportation, treatment,
and disposal of solid and hazardous wastes, and
emphasizes prevention of releases through
management standards in addition to other waste
management activities.
▫ CERCLA regulates the cleanup of abandoned waste
sites or operating facilities that have contaminated
soil or groundwater. CERCLA was amended in 1986 to
include provisions authorizing citizens to sue violators
of the law.
Groundwater Clean-up
• The EPA decides who is responsible for the
clean-up process and monitors progress.
▫
▫
▫
▫
Containment
Removal
Bioremediation
Treatment
Ocean Pollution
• 80 percent of pollution to the marine
environment comes from land-based sources,
such as runoff pollution. Runoff pollution
includes many small sources, like septic tanks,
cars, trucks and boats, plus larger sources, such
as farms, ranches and forest areas.
NOAA’s Role
 The Commerce Department's National Oceanic and
Atmospheric Administration (NOAA) works with the
Environmental Protection Agency, Department of
Agriculture and other federal and state agencies to
develop ways to control runoff pollution.
 NOAA's Coastal Zone Management Program is
helping to create special non-point source pollution
control plans for each participating coastal state.
When runoff pollution does cause problems, NOAA
scientists help track down the exact causes and find
solutions.
Industry
Nitrogen oxides
from autos and
smokestacks,
toxic chemicals,
and heavy metals in
effluents flow into
bays and estuaries.
Cities
Toxic metals
and oil from
streets and
parking lots
pollute waters;
Urban sprawl
Bacteria and viruses
from
sewers and septic
tanks contaminate
shellfish beds
Construction sites
Sediments are washed into
waterways, choking fish and plants,
clouding waters, and blocking
sunlight.
Farms
Runoff of pesticides, manure, and
fertilizers adds toxins and excess
nitrogen and phosphorus.
Closed
shellfish beds
Closed
beach
Oxygen-depleted
zone
Red tides
Excess nitrogen causes
explosive growth of
toxicmicroscopic algae,
poisoning fish and
marine mammals.
Toxic sediments
Chemicals and toxic
metals contaminate
shellfish beds, kill
spawning fish, and
accumulate in the tissues
of bottom feeders.
Oxygen-depleted zone
Sedimentation and algae
overgrowth reduce sunlight,
kill beneficial sea grasses, use
up oxygen, and degrade habitat.
Healthy zone
Clear, oxygen-rich
waters promote growth
of plankton and sea grasses,
and support fish.
Fig. 21-10, p. 505
The Law
 The Ocean Dumping Act has two basic aims: to
regulate intentional ocean disposal of materials, and to
authorize related research.
 Title I of the Marine Protection, Research, and Sanctuaries Act of
1972, contains permit and enforcement provisions for ocean
dumping.
 Research provisions are contained in Title II, concerning general and
ocean disposal research;
 Title IV, which established a regional marine research program; and
 Title V, which addresses coastal water quality monitoring.
 The third title of the MPRSA, authorizes the establishment of marine
sanctuaries.
Solutions
• Dilution is NOT the solution to pollution!
▫ Even though it rhymes!
Solutions
Water Pollution
• Prevent groundwater contamination
• Reduce nonpoint runoff
• Reuse treated wastewater for irrigation
• Find substitutes for toxic pollutants
• Work with nature to treat sewage
• Practice four R's of resource use (refuse,
reduce, recycle, reuse)
• Reduce air pollution
• Reduce poverty
• Reduce birth rates
Fig. 21-18, p. 517
Solutions
Groundwater Pollution
Prevention
Find substitutes for toxic
chemicals
Keep toxic
chemicals out of
the environment
Install monitoring wells
near landfills and
underground tanks
Require leak detectors
on underground tanks
Ban hazardous waste
disposal
in landfills and
injection wells
Store harmful liquids in
aboveground tanks with leak
detection and collection systems
Cleanup
Pump to surface,
clean, and return
to aquifer (very
expensive)
Inject
microorganisms
to clean up
contamination (less
expensive but still
costly)
Pump
nanoparticles of
inorganic compounds
to remove pollutants
(may be the cheapest,
easiest, and most
effective method but is
still being developed)
Fig. 21-9, p. 504
Solutions
Coastal Water Pollution
Prevention
Reduce input of toxic pollutants
Cleanup
Improve oil-spill cleanup
capabilities
Separate sewage and storm lines
Ban dumping of wastes and sewage
by maritime and cruise ships in
coastal waters
Ban ocean dumping of sludge and
hazardous dredged material
Sprinkle nanoparticles over an oil or
sewage spill to dissolve the oil or
sewage without
creating harmful by-products
(still under development)
Protect sensitive areas from
development, oil drilling, and
oil shipping
Require at least secondary
treatment of coastal sewage
Regulate coastal development
Recycle used oil
Use wetlands, solar-aquatic,
or other methods to treat sewage
Require double hulls for oil tankers
Fig. 21-14, p. 509
What Can You Do?
Water Pollution
• Fertilize garden and yard plants with manure or compost
instead of commercial inorganic fertilizer.
• Minimize your use of pesticides.
• Do not apply fertilizer or pesticides near a body of water.
• Grow or buy organic foods.
• Do not drink bottled water unless tests show that your tap
water is contaminated. Merely refill and reuse plastic bottles
with tap water.
• Compost your food wastes.
• Do not use water fresheners in toilets.
• Do not flush unwanted medicines down the toilet.
• Do not pour pesticides, paints, solvents, oil, antifreeze, or other
products containing harmful chemicals down the drain or
onto the ground.
Fig. 21-19, p. 517
OCEAN POLLUTION
• Oceans, if they are not overloaded, can disperse
and break down large quantities of degradable
pollutants.
• Pollution of coastal waters near heavily
populated areas is a serious problem.
▫ About 40% of the world’s population lives near on
or near the coast.
▫ The EPA has classified 4 of 5 estuaries as
threatened or impaired.
Industry
Nitrogen oxides
from autos and
smokestacks,
toxic chemicals,
and heavy metals in
effluents flow into
bays and estuaries.
Cities
Toxic metals
and oil from
streets and
parking lots
pollute waters;
Urban sprawl
Bacteria and viruses
from
sewers and septic
tanks contaminate
shellfish beds
Construction sites
Sediments are washed into
waterways, choking fish and plants,
clouding waters, and blocking
sunlight.
Farms
Runoff of pesticides, manure, and
fertilizers adds toxins and excess
nitrogen and phosphorus.
Closed
shellfish beds
Closed
beach
Oxygen-depleted
zone
Red tides
Excess nitrogen causes
explosive growth of
toxicmicroscopic algae,
poisoning fish and
marine mammals.
Toxic sediments
Chemicals and toxic
metals contaminate
shellfish beds, kill
spawning fish, and
accumulate in the tissues
of bottom feeders.
Oxygen-depleted zone
Sedimentation and algae
overgrowth reduce sunlight,
kill beneficial sea grasses, use
up oxygen, and degrade habitat.
Healthy zone
Clear, oxygen-rich
waters promote growth
of plankton and sea grasses,
and support fish.
Fig. 21-10, p. 505
OCEAN POLLUTION
• Harmful algal blooms (HAB) are caused by
explosive growth of harmful algae from sewage and
agricultural runoff.
Figure 21-11
Oxygen Depletion in the Northern
Gulf of Mexico
• A large zone of
oxygen-depleted
water forms for
half of the year in
the Gulf of Mexico
as a result of HAB.
Figure 21-A
Case Study: The Chesapeake Bay – An
Estuary in Trouble
• Pollutants from six
states contaminate
the shallow estuary,
but cooperative
efforts have reduced
some of the pollution
inputs.
Figure 21-12
OCEAN OIL POLLUTION
• Most ocean oil pollution comes from human
activities on land.
▫ Studies have shown it takes about 3 years for many
forms of marine life to recover from large amounts of
crude oil (oil directly from ground).
▫ Recovery from exposure to refined oil (fuel oil,
gasoline, etc…) can take 10-20 years for marine life to
recover.
OCEAN OIL POLLUTION
• Tanker accidents
and blowouts at
offshore drilling rigs
can be extremely
devastating to
marine life
(especially diving
birds, left).
Figure 21-13
Solutions
Coastal Water Pollution
Prevention
Reduce input of toxic pollutants
Cleanup
Improve oil-spill cleanup
capabilities
Separate sewage and storm lines
Ban dumping of wastes and sewage
by maritime and cruise ships in
coastal waters
Ban ocean dumping of sludge and
hazardous dredged material
Sprinkle nanoparticles over an oil or
sewage spill to dissolve the oil or
sewage without
creating harmful by-products
(still under development)
Protect sensitive areas from
development, oil drilling, and
oil shipping
Require at least secondary
treatment of coastal sewage
Regulate coastal development
Recycle used oil
Use wetlands, solar-aquatic,
or other methods to treat sewage
Require double hulls for oil tankers
Fig. 21-14, p. 509