Title: Water Pollution
1Water Pollution
2Chapter 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
3Vocabulary Words
- 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
4Identifying Pollution
- Which of the beakers on the front table contain
polluted water? - Chlorine, specific conductance
- Acid, pH
- Organic constituents, lab analysis
- Sediment, visual identification
- Surfactants, visual identification
5We All Live Downstream
- Today, everybody is downstream from somebody
else, William Ruckelshaus - What does that mean?
- How does that affect your water quality?
6Frontline Poisoned Waters
- http//video.pbs.org/video/1114515379/
7Water 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?
8- All substances are poisons, there is none which
is not a poison. The right dose differentiates a
poison and a remedy. - Paracelsus (1493-1541)
9Toxicology
- 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.
10Definitions 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.
11The 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.
12The source of it all
- Point source pollution that comes from a
specific location
Sludge from a copper mine.
Industrial discharge
13Other Sources
- Non-point source pollution that occurs from
multiple sources with no single polluter
identified.
14Who 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
15What is water polluted with?
- Disease-causing agents
- Oxygen demanding waste
- Plant nutrients (NO3-, PO43-)
- Organic chemicals (solvents, petroleum)
- Inorganic chemicals (Fe, Pb, NH3)
- Sediment
- Heat
16What are they polluting?
17What else are they polluting?
18Effects 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.
19Waterborne Diseases
20What is clean or safe?
- The definition of clean or safe water is very
dependent on its use and the laws that affect
the source and discharge of the water. - Example pH
- RCRA 2 gt S.U. gt 12.5
- SDWA 6.5 gt S.U. gt 8.5
- HMTA those substances which cause visible
destruction to skin tissue
21The Water
- Drinking Water Safe Drinking Water Act
- Surface Water Clean Water Act
- Groundwater CWA, RCRA as Solid Waste, CERCLA
for clean-up
22Surface Water
- Surface Water is polluted by
- human activity
- industrial activity
- power plants
23Freshwater Sources
24Water Quality
- There are two classes of water quality standards
- biological
- chemical
25Chemical 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
26WQI Parameters
- Dissolved Oxygen (DO)
- pH
- Temperature Change (?T)
- Fecal Coliform
- Biochemical Oxygen Demand (BOD)
- Nitrates
- Total Phosphates
- Total Dissolved Solids (TDS)
- Turbidity or Total Suspended Solids (TSS)
27Q Value
- Measurements of each parameter are taken and
recorded and then are converted into a Q value
28(No Transcript)
29Water Quality Factor Weights
- The Q value for each parameter is determined
and multiplied by a weighting factor - Dissolved oxygen 0.17
- Fecal coliform 0.16
- pH 0.11
- Biochemical oxygen demand 0.11
- Temperature change 0.10
- Total phosphate 0.10
- Nitrates 0.10
- Turbidity 0.08
- Total solids 0.07
30Final calculation
- The weighted Q values are added for all of the
parameters and compared to a water quality index
scale
31The Scale
- Water Quality Index Scale
- 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
32Dissolved 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?
33Gas 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.
34Where 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
35DO Test
- The test for DO determines the availability of
oxygen for aquatic life - A high concentration of DO indicates high water
quality
36 Water Quality
DO (ppm) at 20C
Good
89
Slightly polluted
6.78
Moderately polluted
4.56.7
Heavily polluted
Below 4.5
Gravely polluted
Below 4
Fig. 21-3, p. 496
37Reference
http//www.indiana.edu/bradwood/eagles/waterquali
ty.htm
38Physical 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.
39Climate 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.
40Human-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.
41Farming 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.
42Changes 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.
43Calculating 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.
44Using 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.
45The 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.
46Biochemical 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.
47Biochemical 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.
48Sources 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.
49Point Sources of Organic Matter
- Point sources of organic pollution include
- pulp and paper mills
- meat-packing plants
- food processing industries
- wastewater treatment plants.
50Non-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.
51Changes 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.
52Cause 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.
53 Normal clean water organisms (Trout, perch,
bass, mayfly, stonefly)
Trash fish (carp, gar, leeches)
Fish absent, fungi, sludge worms, bacteria (anae
robic)
Trash fish (carp, gar, leeches)
Clean Normal clean water organisms (Trout,
perch, bass, mayfly, stonefly)
Types of organisms
8 ppm
Dissolved oxygen (ppm)
8 ppm
Clean Zone
Biological oxygen demand
Recovery Zone
Septic Zone
Decomposition Zone
Clean Zone
Fig. 21-4, p. 497
54pH
- Water contains both H (hydrogen) ions and OH-
(hydroxyl) ions. The pH test measures the H ion
concentration of liquids and substances.
55Changes 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.
56Human-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.
57Acid 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.
58Changes 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.
59pH 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.
60Nitrates
- 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-).
61Nitrates
- 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.
62Nitrates
- 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.
63Nitrates
- 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.
64Eutrophication
- 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.
65Sources 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.
66Sources 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.
67Problems 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.
68Water 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.
69Temperature 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.
70Human-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.
71Human 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.
72Changes 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.
73Hot 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.
74Temperature 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.
75Temperature 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.
76Turbidity
- 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.
77Sources 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 red-brown,
or to green from algal blooms.
78Changes 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.
79Suspended 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.
80Fecal 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.
81Pathogenic 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.
82Presence 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.
83What 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.
84Municipal 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.
85Standards
86Phosphorus
- 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.
87Phosphorus 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.
88Phosphorus 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."
89Eutrophication
- 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.
90Sources 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.
91Sources 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.
92Erosion 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.
93Impacts 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.
94Changes 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.
95Reversing 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
96Biological 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
97Save Our Streams
- http//www.vasos.org/pages/gettingstarted.html
- http//www.vasos.org/pages/documents/vasosstandard
operatingprocedures.pdf
98Using Insects to Study Stream Health
- A sample of stream insects, or
macroinvertebrates is collected, identified and
counted. - http//www.vasos.org/ModifiedBugIDCardoct2004.pdf
99(No Transcript)
100(No Transcript)
101Sensitive Insects Types x 3
- caddisfly larva
- hellgrammite
- mayfly nymph
- gilled snails
- riffle beetle adult
- stonefly nymph
- water penny larva
102Somewhat 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
103Very Tolerant Organisms Types x 1
- aquatic worms
- pouch ( other) snails
- leeches
- midge larva
104The Quality Rating Scale
- WATER QUALITY RATING
- Excellent (gt22)Good (17-22)Fair (11-16) Poor
(lt11)
105What 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.
106Non-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,
107 Leaking tank
Aquifer
Bedrock
Water table
Groundwater flow
Free gasoline dissolves in groundwater (dissolved
phase)
Gasoline leakage plume (liquid phase)
Migrating vapor phase
Water well
Contaminant plume moves with the groundwater
Fig. 21-8, p. 502
108Contamination 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!
109Groundwater 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.
110Groundwater 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.
111Groundwater 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.
112Groundwater Clean-up
- The EPA decides who is responsible for the
clean-up process and monitors progress. - Containment
- Removal
- Bioremediation
- Treatment
113Ocean 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.
114NOAAs 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.
115 Urban sprawl Bacteria and viruses from sewers and
septic tanks contaminate shellfish beds
Cities Toxic metals and oil from streets and
parking lots pollute waters
Industry Nitrogen oxides from autos
and smokestacks, toxic chemicals, and heavy
metals in effluents flow into bays and estuaries.
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.
Red tides Excess nitrogen causes explosive growth
of toxicmicroscopic algae, poisoning fish
and marine mammals.
Closed shellfish beds
Closed beach
Oxygen-depleted zone
Toxic sediments Chemicals and toxic metals
contaminate shellfish beds, kill spawning fish,
and accumulate in the tissues of bottom feeders.
Healthy zone Clear, oxygen-rich waters promote
growth of plankton and sea grasses, and support
fish.
Oxygen-depleted zone Sedimentation and
algae overgrowth reduce sunlight, kill beneficial
sea grasses, use up oxygen, and degrade habitat.
Fig. 21-10, p. 505
116The 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.
117Solutions
- Dilution is NOT the solution to pollution!
- Even though it rhymes!
118 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
119 Solutions
Groundwater Pollution
Cleanup
Prevention
Pump to surface, clean, and return to aquifer
(very expensive)
Find substitutes for toxic chemicals
Keep toxic chemicals out of the environment
Inject microorganisms to clean up contamination
(less expensive but still costly)
Install monitoring wells near landfills and
underground tanks
Require leak detectors on underground tanks
Pump nanoparticles of inorganic compounds to
remove pollutants (may be the cheapest, easiest,
and most effective method but is still being
developed)
Ban hazardous waste disposal in landfills and
injection wells
Store harmful liquids in aboveground tanks with
leak detection and collection systems
Fig. 21-9, p. 504
120 Solutions
Coastal Water Pollution
Prevention
Cleanup
Reduce input of toxic pollutants
Improve oil-spill cleanup capabilities
Separate sewage and storm lines
Ban dumping of wastes and sewage by maritime and
cruise ships in coastal waters
Sprinkle nanoparticles over an oil or sewage
spill to dissolve the oil or sewage without
creating harmful by-products (still under
development)
Ban ocean dumping of sludge and hazardous dredged
material
Protect sensitive areas from development, oil
drilling, and oil shipping
Require at least secondary treatment of coastal
sewage
Regulate coastal development
Use wetlands, solar-aquatic, or other methods to
treat sewage
Recycle used oil
Require double hulls for oil tankers
Fig. 21-14, p. 509
121 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
122OCEAN 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 worlds population lives near on
or near the coast. - The EPA has classified 4 of 5 estuaries as
threatened or impaired.
123 Urban sprawl Bacteria and viruses from sewers and
septic tanks contaminate shellfish beds
Cities Toxic metals and oil from streets and
parking lots pollute waters
Industry Nitrogen oxides from autos
and smokestacks, toxic chemicals, and heavy
metals in effluents flow into bays and estuaries.
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.
Red tides Excess nitrogen causes explosive growth
of toxicmicroscopic algae, poisoning fish
and marine mammals.
Closed shellfish beds
Closed beach
Oxygen-depleted zone
Toxic sediments Chemicals and toxic metals
contaminate shellfish beds, kill spawning fish,
and accumulate in the tissues of bottom feeders.
Healthy zone Clear, oxygen-rich waters promote
growth of plankton and sea grasses, and support
fish.
Oxygen-depleted zone Sedimentation and
algae overgrowth reduce sunlight, kill beneficial
sea grasses, use up oxygen, and degrade habitat.
Fig. 21-10, p. 505
124OCEAN POLLUTION
- Harmful algal blooms (HAB) are caused by
explosive growth of harmful algae from sewage and
agricultural runoff.
Figure 21-11
125Oxygen 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
126Case 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
127OCEAN 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.
128OCEAN OIL POLLUTION
- Tanker accidents and blowouts at offshore
drilling rigs can be extremely devastating to
marine life (especially diving birds, left).
Figure 21-13
129 Solutions
Coastal Water Pollution
Prevention
Cleanup
Reduce input of toxic pollutants
Improve oil-spill cleanup capabilities
Separate sewage and storm lines
Ban dumping of wastes and sewage by maritime and
cruise ships in coastal waters
Sprinkle nanoparticles over an oil or sewage
spill to dissolve the oil or sewage without
creating harmful by-products (still under
development)
Ban ocean dumping of sludge and hazardous dredged
material
Protect sensitive areas from development, oil
drilling, and oil shipping
Require at least secondary treatment of coastal
sewage
Regulate coastal development
Use wetlands, solar-aquatic, or other methods to
treat sewage
Recycle used oil
Require double hulls for oil tankers
Fig. 21-14, p. 509