Transcript WATER QUALITY

WATER QUALITY
Water quality!??
What does “GOOD water quality” mean to you?
2
July 2003
Environment Impact: Pollution
Toxic
pollutio
n
Sediment pollution
IsCan
checking
we check
enough?
for
them?
Bacteria pollution
3 Environment Impact
July 2003
Nutrient pollution
Water contamination sources
Point-source:
contained point of
discharge
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July 2003
Nonpoint-source:
no local point of discharge
Quality checks & monitoring
• Chemical monitoring
–A snapshot in time of certain parameters in a water
sample
–Comparison to a water quality standard
–Usually involves a lab… so it is costly and time
consuming
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July 2003
Quality checks & monitoring
• Biological monitoring or bio-monitoring
– Evaluation of the amounts of some organisms in the
stream
– An overall assessment of the health of the stream
based upon the ecological conditions of the stream
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July 2003
Quality checks & monitoring
• Physical measures of stream health
–Measure of flow, pebble counting, and habitat
evaluations
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July 2003
Chemical testing
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July 2003
Dissolved Oxygen (DO)
• Why oxygen?
– Respiration:
C6H12O6 + O2 6 CO2 + 6 H20 + Energy
– Decomposition (oxidation)
• How much is needed?
Up to about 10ppm of oxygen in water
5-6ppm: sufficient for most species
< 3ppm: stressful to most aquatic species
< 2ppm: fatal to most species
• How does it get into water?
1.Absorption from the atmosphere: contact with water
2.Photosynthesis: Light + 6 CO2 + 6 H2O  (CH2O)6 + 6 O2 )
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July 2003
Dissolved Oxygen (DO)
• Testing?
 Oxido-Reduction:
Reduced_form+ + O2 + H2O  Oxided_form + H3O+
• Tips?
– Do not introduce additional oxygen in the sample!!
– Testing on site!!
– Note time, date, weather, shade, … and temperature!!!
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July 2003
Biochemical Oxygen Demand (BOD)
• Where does Demand come from?
– Bacterial decomposition = oxygen
Measure
consumptionof the amount of organic matter in
water
Measure of the amount of oxygen to be
consumed
• How much is needed?
Below 5ppm of O2, life is threatened!!
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July 2003
Biochemical Oxygen Demand (BOD)
• Testing?
 Oxido-Reduction:
Reduced_form+ + O2 + H2O

Oxyded_form +
H3O+
• Tips?
– Testing 5 days after!! Comparison!!!
– Do not introduce additional oxygen in the sample!!
– Note time, date, weather, shade, etc… !!!
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July 2003
Nitrate
• What is nitrate?
– N2 forms 70% of Earth’s atmosphere, 80% of the air
– Part of proteins, DNA, RNA, vitamins, hormones, enzymes
• Where does nitrate come
Higher
organisms depend on plants to get complex forms of
from?
– Continuous
recycle:acids,
fixed by
algae and
bacteria before plants
nitrogen
(e.g. amino
nucleic
acids)
use ????
– And…
• How does it get into water?
1. NO3- is one of the most water soluble anions known
2. Nitrate does not bind to soils
 washed into streams or rivers (i.e., surface waters)
 through time, leached down through the soil into porous rock
aquifers (i.e., groundwaters)
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July 2003
Nitrate
• What are the problems?
– Because they do not evaporate, nitrates/nitrites are likely to remain in water
until consumed by plants or other organisms
 Health issues!!! Public and livestock!!!
 Environmental harm
• Drinking water (& food!)
Nitrate NO3- is converted in the gut to nitrite NO2 NO2- combines with hemoglobin to metheglobin
blood ability to carry oxygen decreases
“Only 
two
substances pose an immediate threat to health
1.whenever
“Blue babythey
syndrome“
or methemoglobinemia
are exceeded:
bacteria and nitrate.”
2. Cancers
3. Physical defects in the fœtus, miscarriages, low birth weight, and slow
weight gain
10 mg/L nitrate-nitrogen (NO3-N) = 44.3 mg/L nitrate
(NO3- )
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July 2003
Nitrate
• Testing?
1. Reduction of nitrate to nitrite
NO3- + 2 H3O+ 
NO2- + 3 H2O
2. + sulfanilamide + N-(1-napththyl)-ethylenediamenedihydrochloride (NED)
 reddish purple
Rural communities are the
• Tips?
most threatened populations
– NTR
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July 2003
Nitrate is the limiting factor in
marine eutrophication
(e.g.,estuaries, coastal waters)
Nitrate… exercises
• What is the nitrate cycle?
• What are the causes of nitrate polluiton?
Treatments?
• What are the consequences for the
environment & industries?…
Eutrophication?
• What are the standard acceptable level of
nitrate for the environment?
• What are the standards in Egypt? In your
watershed?
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July 2003
Phosphate
• Why phosphate?
– Part of DNA, RNA, ADP and ATPnecessary components of life
• Where does phosphate come
from?
– Natural P deposits occur primarily as phosphate mineral apatite.
– P is only freely soluble in acid solutions under reducing conditions. In the
soil, it is rapidly immobilized as calcium or iron phosphate. Most of the P in
soils is adsorbed to soil particles or incorporated into organic matter.
– P in water exist in a particulate phase or a dissolved phase:
• E.g. particulate matter: plankton.
• E.g. dissolved phase: includes inorganic P, organic P excreted by
organims
– And???
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July 2003
Phosphate
• What are the problems?
1. Health Effects
– P itself does not have any notable health effects
– However, a phosphate level > 1.0 mg/L may interfere with coagulation in
water treatment plants
 organic matter and attached microorganisms may not be completely
removed from the treated water
2. Environmental Effects
– …
• How much is needed?
–…
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July 2003
Phosphate
• Testing?
1. phosphate with acidified molybdate reagent
PO43- + 12 MoO42- + 27 H+  H3PO4 (MoO3)12 + 12 H2O
2. Reduction of phosphomolybdate heteropolyacid
H3PO4 (MoO3)12  Phosphomolybdenum blue Mo(V)
 Blue color
• Tips?
– When algae is prevalent (summer…), some phosphate
will bound up in the algae. This phosphate is not
available for use by other plants and should not be
included in the measurement.
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July 2003
Phosphate… exercises
• What is the phosphate cycle?
• What is special to lake?…Hypolimnion
• What are the causes of phosphate
pollution? Treatments?
• What are the consequences for the
environment & industries?…
• What are the standard acceptable level of
phosphate for the environment?
• What are the standards in Egypt? In your
watershed?
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July 2003
pH
• Why pH and what pH?
acids
bases
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
acid rain
ammonia
normal
sea
stream water water
most fishes die
mosquito
larvae die
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July 2003
fish repro.
affected
most fishes die
best for
algae
pH
• What are the problems?
1. Health Effects:
Low pH water
 pipes corrosion in potable water plants
– Release of (heavy) metal ions such as copper,
lead, zinc, and cadmium into the treated
drinking water…
– Replacement costs!
2. Environment impact:
– ???
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July 2003
pH
• Other factors?
Synergy effect!!!
• Important in surface waters:
– E.g.: 4.0 mg/l of iron at pH=4.8  not toxic
0.9 mg/l of iron at pH=5.5  fish die
• Special significance in wastewater treatment:
The steps involved in water and wastewater treatment require specific
pH levels. In order for coagulation (a treatment process) to occur, pH
and alkalinity must fall within a limited range. Chlorination, a
disinfecting process for drinking water, requires a pH range that is
temperature dependent.
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July 2003
pH
• Testing?
Litmus paper:
– Litmus:
lichen
is red
in get
acida solution
and blue in alkali.
Grind purple
up some
red which
cabbage.
You
red liquid.
– Invented
by a ammonia:
gentlemanwhat
who is
wanted
to measure
hownow?…
acid his beer
Pour some
the color
of the liquid
was. To make beer or wine, you have to use yeast, and yeast uses
UniversalEnzymes
indicator
paper
from blue to
enzymes…
only
work can
if thechange
pH is right.
green
yellow to
red.
indicator
a colours in
What
he to
discovered
was
thatUniversal
acids and alkalis
makeisthe
mixture
of dyes which all change when you change
plants
change.
the pH
• Tips?
– Don’t pollute the tester!!
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July 2003
pH… exercises
• What are the impact of pH changes?
• What are the consequences for the
environment & industries?…
• Are there treatment or prevention
measures?
• What are the standards in your watershed?
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July 2003
Coliform bacteria
• Why coliform bacteria?
– Live in large numbers in the intestines of animals: aid in the
digestion
– Some might be infected with diseases
e.g. waterborne pathogenic diseases: typhoid fever, gastroenteritis,
hepathite A, diphteria, tuberculosis
• How does it get into water?
1. Overflow or poor treatment of domestic sewage
2. Non-point source of human and animal waste
• What is an acceptable limit?
200 colonies per
100ml
Bacteria are removed by disinfection and/or
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filtration
July 2003
Coliform bacteria
• Testing?
1. Counting using filter
2. "Presence/Absence method“:
– Enzymatic substrates + incubation for 24hr
Change of yellow color = presence of Coliform bacteria
Fluorescence under ultra-violet = presence of E.Coli
bacteria
• Tips?
– Fermentation means incubation too!!
– Keep the tube vertical!!!
– Note weather conditions!…
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July 2003
Coliform bacteria
Separate or combined sewer
• Other factors?
system?
• 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 waters directly into rivers
• Heavy rains and melting snow wash bird and pet wastes from
sidewalks and streets into storm drains
In a combined sewer system, both sanitary waste and storm runoff are
treated at a wastewater treatment plant. After a heavy rain, untreated or
inadequately treated waste may be diverted into the river to avoid
flooding the wastewater treatment plant. To avoid this problem, some
cities have built retention basins to hold excess wastewater and prevent
untreated waste from being discharged into rivers. Without retention
basins, heavy rain conditions can result in high fecal coliform counts
downstream from sewage discharge points.
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July 2003
Coliform bacteria… exercises
• Are there treatment or prevention
measures?
• What are the standards in your watershed?
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July 2003
Turbidity
• What is turbidity?A physical measure
– A measurement quantifying the degree to which light traveling
through a water column is scattered by the suspended organic
(including algae) and inorganic particles.
suspended load  =
light scattering 
– The velocity of the water resource largely determines the
composition of the suspended load. Suspended loads are carried in
both the gentle currents of lentic (lake) waters and the fast currents
of lotic (flowing) waters.
Even in flowing waters, the suspended load usually consists of
grains less than 0.5 mm in diameter. Suspended loads in lentic
waters usually consist of the smallest sediment fractions, such as
silt and clay.
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July 2003
Turbidity
• What are the problems?
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July 2003
Turbidity problems…
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July 2003
Turbidity
• Testing?
NTU
• Tips?
Secchi disk
(JTU)
– Testing on site!!!
– Avoid glaring effect!!! Avoid your shadow!!!
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July 2003
Turbidity… exercises
• What are the units of turbidity
measurements?
• Are there treatment or prevention
measures?
• What are the standards in your watershed?
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July 2003
Temperature
• Why temperature?A physical measure
– t°   DO : affect DO, and chemical reactivity in general
– Different temperature environments  different species
– All species are negatively impacted by rapid fluctuations
• Why does temperature vary?
– Season, day/night, weather,…
– Current, hot sources (geothermie)
– Depth (Hypolimnion…)
– Human activites: cities, removal of vegetation, plume, stream
widening or shallowing, industry, global warming, etc…
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July 2003
Temperature
• What are the problems?
– Lack of oxygen (DO capacity , blooms in matter organic
decomposition)
– Species not adapted to rapid fluctuation physiological damages
– Shift of population
– Shift of reproduction timing such that predators are most abundant
during the early stages of life, or no even not triggered.
– E.g., the green crab in Maine (U.S.A) was not reduced by the
natural winter die-off predator/prey ratio un-balanced
– Higher temperatures, higher coagulation and flocculation rates
more effective water treatment!!!
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July 2003
Temperature
• Testing?
– Thermometer
Units?
• Tips?
– Testing on site!!!
– Don’t hold the container!!!
– Be careful the way you hold the thermometer!!
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July 2003
Temperature… exercises
• What are the units of t° measurements?
• Are there treatment or prevention
measures?
• What are the standards in your watershed?
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July 2003
Hardness
• What is hardness?
– The sum of polyvalent cations dissolved in the water,
i.e., calcium (calcite CaCO3) & magnesium (magnesite MgCO3 ) + iron
(Fe), strontium (Sr), manganese (Mn)
– Usually reported as an equivalent quantity of CaCO3
• Where does dissolved minerals come
from?
– As water moves through soil and rock, it dissolves very small
amounts of minerals and holds them in solution
= primarily a function of the geology of the area within which the
surface water is flowing
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July 2003
Hardness
• What are the effects?
1. Health:
• Good effect!!: “water could be a major contributor of Ca and Mg to
the diet”
• Skin irritation, dull hairs, etc…
2. Environment & industry:
• Scale…in pipe, tanks…
on glasses & clothes…
• Chemical processes affected, e.g. lathering & washing
• More detergents used…
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July 2003
Hardness
• How much is
Inneeded?
the U.S.A:
Classification
Soft
Slightly hard
Moderately hard
Hard
Very Hard
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July 2003
mg/l or ppm
0 - 17.1
17.1 - 60
60 - 120
120 - 180
> 180
Hardness… exercises
• Are there treatment or prevention
measures?
• What is the classification in your watershed?
• Is your watershed affected?
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July 2003
Salinity
• What are salts?
– In natural waters, they are anions such as carbonates, chlorides,
sulfates, and nitrates (primarily in ground water), and cations such as
potassium (K), magnesium (Mg), calcium (Ca), and sodium (Na)
– Needed for life
• Where do salts come from?
– Natural concentration largely influenced by the underlying geology…
– Faults might allow brine formation
– Through time, salts are removed from the sedimentary rocks by wind
and water erosion. While evaporation will create salt precipitation
– Salts are present in the rain
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July 2003
Salinity
• What are the problems?
1. Health:
• Sodium sulfate and magnesium sulfate above 250 mg/l in drinking
water may produce a laxative effect.
• Excess sodium affect low sodium diets and pregnant women
suffering from toxemia
• High blood pressure?
2. Environment & industry:
• Shift in water population
• Chemical processes affected (especially within plant…)
• Dissolved salts may encrust or corrode metallic
surfaces
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July 2003
Salinity
• What do cause salinity variation?
– Weather
– Irrigation with inadequate drainage or excessive evaporation from
agricultural fields may lead to an accumulation of salts in the soil
– Runoff from urban areas after rain or where salt is used for de-icing
– Inorganic chemical industry may release dissolved cations in
effluent waters
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July 2003
Salinity… exercises
• What is the salinity situation of your
watershed?
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July 2003
Testing… exercises
• The units
• Standards in Egypt and in your watershed
• Point source vs. non-point source
• Chain reaction…
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July 2003
Testing tips
• Blank tube
–Coloured sample?!! compared to one or more reference
points (e.g., distilled water, untreated sample, and reagent blank i.e., treated distilled water)
• Use of the same tube
 eliminates glassware errors
• Comparison
 concert among you when comparing to chart
• Sampling from tap:
–Leave water running for few minutes
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July 2003
Biological monitoring
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July 2003
Environment impact: bio-monitoring
• What is bio-monitoring?
One type of bio-monitoring is to evaluate the benthic
invertebrates that live in the stream:
– Benthic means bottom-dwelling
– Invertebrates are organisms without a backbone
– Macro means that are visible to the naked eye; Micro…
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July 2003
Environment impact: bio-monitoring
• What will we be doing?
In a nutshell:
1. we are getting into the stream
2. using a net we will collect critters that live on the bottom of the
stream
3. we will sort and identify our catch
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July 2003
Why Study the Stream-Bottom Macro-
invertebrates?
• Link in the aquatic food chain
• Differ in their sensitivity to water pollution
• Information about the quality of a stream over
looong periods of time
– water analysis only provides information for the time of sampling
– fish can move away from polluted water and return when conditions
• Relatively easy to collect
and… without expensive equipment
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July 2003
Evaluation of impacts of toxic,
sediment, and nutrient
pollution, but not bacteria
pollution
Benthic macro-invertebrates & classification
• Description…
• What to look for?…
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July 2003
Benthic macro-invertebrates
• Compare these…
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July 2003
Illustrations from:
Voshell, J. R., Jr. [2002]: Guide to the
Common Freshwater Invertebrates of
North America.
MacDonald and Woodward Publishing Co.
Benthic macro-invertebrates
• Compare those…
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July 2003
Illustrations from:
Voshell, J. R., Jr. [2002]: Guide to the
Common Freshwater Invertebrates of
North America.
MacDonald and Woodward Publishing Co.
Benthic macro-invertebrates
• And those…
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July 2003
Illustrations from:
Voshell, J. R., Jr. [2002]: Guide to the
Common Freshwater Invertebrates of
North America.
MacDonald and Woodward Publishing Co.
Micro-invertebrates
• Identifying microscopic invertebrates
– The presence or absence of certain types of algae and diatoms
are associated with certain water conditions. Note that the
healthiest pond water has a tremendous amount of biodiversity,
whereas the healthiest drinking water has no living organisms.
• Identifying macro-invertebrates
– Note how they move, how they breathe and how they interact
with each other. What are their body adaptations for living in the
sample area? Record what you see and tally the population of
your sample.
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July 2003
Micro-invertebrates
• Algae
– A special form of "plant" life, marine or freshwater,
that lack roots, stems, and leaves and that ranges
in size from microscopic single cells (uni-cellulars)
to multi-cellular structures, such as seaweeds.
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July 2003
Micro-invertebrates
• Algae
Note that the healthiest pond
water has a tremendous
amount of biodiversity,
whereas the healthiest
drinking water has no living
organisms
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July 2003
Physical Testing
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July 2003
Practice…
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July 2003
Chemical testing
1.Preparation
– selecting an appropriate riffle
– approaching the site
2.Sampling & habitat assessment
– filling out the 1st page of the data sheet
3.Testing
– recording the data
– plotting
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July 2003
Bio-monitoring
1. Preparation
–
–
–
–
selecting an appropriate riffle
approaching the site
positioning the net
rubbing the rocks and disturbing the substrate
2. Sampling & habitat assessment
– filling out the 1st page of the data sheet
3. Identify the macro-invertebrates
– counting
– recording the data
– statistics
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July 2003
Material maintenance
• Inspection of your net:
– Look for rips or tears and repair
– Make sure net is tied securely to the poles
• Cleansing:
– Clean the material after each sampling!
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July 2003
Pick your riffle
• A shallow, fast-moving area
• Depth of 3 to 12 inches (8 to 30 cm)
• Stones of cobble-sized (2 to 12 inches = 5 to 30cm or
larger)
– Size is important:
(1) Macro-invertebrates prefer these stones for protection and food
supply
(2) Bubbling of the water over the rocks provides needed oxygen for
healthy growth
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July 2003
At the site
• Setting Up the Net:
– Approach your riffle from downstream
– Place the kick seine perpendicular to the flow
of water immediately downstream of the 1x1
foot area in the riffle
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July 2003
At the site
• Placing the Net:
– The bottom, weighted edge of the net should fit tightly against the
stream bottom
– Select some rocks from outside your sampling area, clean them off
(outside of the net), and place them on the bottom of the net to
hold the net firmly to the bottom. This will prevent insects from
escaping under the net.
– Tilt the net back, so the water flowing through the net covers a
large portion of the net, however, be careful not to tilt the net so
much that water flows over the top, allowing organisms to escape.
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July 2003
At the site
• Sampling:
– Quickly sample the targeted area for 20 seconds.
– To sample, lift and rub underwater all large rocks in the sample
area to dislodge any clinging organisms. Rub all exposed
surfaces of rocks in the sampling area that are too large to lift. Do
this for approximately 15 seconds.
– Dig around in the small rocks and sediments on the streambed in
order to dislodge any burrowing macro-invertebrates for
approximately 5 seconds.
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July 2003
At the site
• Remove the net:
– After sampling for 20 seconds,
carefully rub off any rocks used to
anchor the net. Then remove the
net with an upstream scooping
motion to keep all the macroinvertebrates in the net.
• ‘Clean’ the net:
– Cradle the contents of the screen and lift them out of the water and
into a bucket. Splash the side to wash the contents into a bucket.
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July 2003
Habitat assessment
• This is an important portion of the monitoring
• It can help identify sources of pollution and stressors to the
macro-invertebrate population
• The 1st times, fill out your habitat assessment as
completely and thoroughly as possible. Subsequent
monitoring events can focus on the changes that occur
between events.
E.g. erosion may be low the first time you monitor your site,
but could be occurring on a much larger scale the second
time you monitor. It is important to note this change.
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July 2003
Guidelines to Scoring Habitat Parameters: http://www.sosva.com/
Habitat assessment
• Fishes? (a barrier!?!)
• Algae? (colour & extent)
• Water color
• Odor
•
•
•
•
Color & type of material at the bottom of the riffle
Stability of the streambed
Stream channel shade
Vegetation type on the immediate bank
• Stream bank erosion potential
• Land uses in the surrounding (H, M, L)
• Litter/sewage mouth?
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July 2003
At school
• Sorting:
– Place organisms that look alike into groups
– Use primarily body shape and number of legs and tails to
identify the critters, since the same family or order can vary
considerably in size and color
• Counting…
– Empty shells do not count!
– You must continue the sampling and picking process until you
have over 200 organisms or you have collected 4 nets.
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July 2003
Filling out the field data sheets
• The first page of the field sheets has important information
about:
– the site
– who collected the data
– the date
– weather conditions
– general stream conditions (temperature, height, etc)
– sampling time
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July 2003
Field sheet example
• Front Page of Field Sheets:
Basic Stream Information - Save Our Streams Stream Quality Survey
Date:
10-Jul-2001
Stream:
Muddy Creek Station
#:
MUD 1
# of Participants:
2
Group/Individual:
Virginia Save Our Streams
Name of Monitor:
Jay Gilliam
County:
Rockingham Latitude:38 27 54 Longitude: 78 58 33
Location:
Off Route 33, downstream of WLR plant in Hinton
Average Stream Width: 15 feet
Average Stream Depth: 12 inches
Flow Rate:
Normal
Weather Last 72 hours: rain 72 hours ago, sunny currently
Water Temperature:
44°F
Collection Time:
Net 1 = 20 seconds; Net 2 = 27 seconds
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July 2003
Field sheet example
• Sample Tally Sheet:
Macro invertebrate
Count
Worms
18
Planatarians
36
Leeches
13
Crayfish
1
Sowbugs
5
Scuds
11
Stoneflies
0
Mayflies
34
Dragonflies/Damselflies
Hellgrammites/Fishflies/
Alderflies
2
TOTAL 204
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July 2003
Macro invertebrate
Caddisflies
Common Netspinner
Beetles
Midges
Blackflies
True Flies
Gilled Snails
Lunged Snails
1 Clams
Count
0
32
4
19
13
4
2
9
0
TOTAL INTOLERANT 76 TOTAL TOLERANT 72
Sampling tips
• Percentages vs. amounts
 representativity of small numbers!!
• Sample vs. population
representativity of the population!!
• Please, no over-sampling!!
– Sample a monitoring site only 4 times a year - during
the seasons.
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July 2003
SAFETY!!!
• Wash your hands after getting into any stream: bacteriological
pollution!!!
• Glass may be hidden in the bottom of the stream - watch out for
it!
• If you do get a cut or scrape while in the stream, clean the
wound… Again, bacteriological pollution...
• Always sample in pairs!
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July 2003