WATER QUALITY 2 July 2003 Water quality!?? What does “GOOD water quality” mean to you?
-
Upload
madeleine-amberly-wood -
Category
Documents
-
view
219 -
download
1
Transcript of WATER QUALITY 2 July 2003 Water quality!?? What does “GOOD water quality” mean to you?
WATER QUALITY
2July 2003
Water quality!??What does “GOOD water quality” mean to
you?
3July 2003
Environment Impact: Pollution
Environment Impact
Toxic polluti
on
Sediment pollution
Nutrient pollution
Bacteria pollution
Can we check for them?
Is checking enough?
4July 2003
Water contamination sources
Point-source:contained point of
discharge
Nonpoint-source:no local point of discharge
5July 2003
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
6July 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
7July 2003
Quality checks & monitoring
•Physical measures of stream health–Measure of flow, pebble counting, and habitat evaluations
8July 2003
Chemical testing
9July 2003
– Respiration: C6H12O6 + O2 6 CO2 + 6 H20 + Energy
– Decomposition (oxidation)
Up to about 10ppm of oxygen in water5-6ppm: sufficient for most species < 3ppm: stressful to most aquatic species < 2ppm: fatal to most species
1.Absorption from the atmosphere: contact with water2.Photosynthesis: Light + 6 CO2 + 6 H2O (CH2O)6
+ 6 O2 )
Dissolved Oxygen (DO)
•Why oxygen?
•How much is needed?
•How does it get into water?
BACTERIA ACTIVITY
10July 2003
Dissolved Oxygen (DO)
•Testing?Oxido-Reduction:
Reduced_form+ + O2 + H2O Oxided_form +
H3O+
• Tips?
– Testing on site!!
– Do not introduce additional oxygen in the sample!!
– Note time, date, weather, shade, … and temperature!!!
11July 2003
– Bacterial decomposition = oxygen consumption
Below 5ppm of O2, life is threatened!!
Biochemical Oxygen Demand (BOD)
•Where does Demand come from?
•How much is needed?
Measure of the amount of organic matter in waterMeasure of the amount of oxygen to be consumed
12July 2003
Biochemical Oxygen Demand (BOD)
•Testing?Oxido-Reduction:
Reduced_form+ + O2 + H2O
Oxyded_form + H3O+
• Tips?– Testing 5 days after!!
– Do not introduce additional oxygen in the sample!!
– Note time, date, weather, shade, etc… !!!
Comparison!!!
13July 2003
– N2 forms 70% of Earth’s atmosphere, 80% of the air– Part of proteins, DNA, RNA, vitamins, hormones,
enzymes
1. NO3- is one of the most water soluble anions known
2. Nitrate does not bind to soilswashed into streams or rivers (i.e., surface waters) through time, leached down through the soil into porous
rock aquifers (i.e., groundwaters)
Nitrate•What is nitrate?
•How does it get into water?
Higher organisms depend on plants to get complex forms of nitrogen (e.g. amino acids, nucleic acids)
•Where does nitrate come from?
– Continuous recycle: fixed by algae and bacteria before plants use
Non-point source
pollution
– And… ????
16July 2003
1. “Blue baby syndrome“ or methemoglobinemia2. Cancers3. Physical defects in the fœtus, miscarriages, low birth weight, and slow weight gain
– 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
Nitrate
•What are the problems?
•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
10 mg/L nitrate-nitrogen (NO3-N) = 44.3
mg/L nitrate (NO3- )
“Only two substances pose an immediate threat to health whenever they are exceeded: bacteria and nitrate.”
18July 2003
Nitrate
•Testing?
1.Reduction of nitrate to nitrite
NO3- + 2 H3O+ NO2
- + 3
H2O
2.+ sulfanilamide + N-(1-napththyl)-ethylenediamene-dihydrochloride (NED)
reddish purple• Tips?
– NTR
Rural communities are the most threatened populations
Nitrate is the limiting factor in marine eutrophication (e.g.,estuaries, coastal
waters)
19July 2003
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?
20July 2003
– And???
– Part of DNA, RNA, ADP and ATP
Phosphate
•Why phosphate?necessary 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
25July 2003
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
Phosphate
•What are the problems?
•How much is needed?– …
2. Environmental Effects– …
27July 2003
Phosphate•Testing?
1. phosphate with acidified molybdate reagent
PO43- + 12 MoO4
2- + 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.
28July 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?
29July 2003
pH
•Why pH and what pH?
basesacids0 1 2 4 5 6 7 8 9 10111213143
sea
water
ammoniaacid rain
most fishes die
normal
stream water
fish repro.affected
most fishes die
best foralgae
mosquitolarvae die
30July 2003
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:
– ???
32July 2003
• 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
pH
• Other factors?Synergy effect!!!
• 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.
33July 2003
pH
•Testing?Litmus paper:– Litmus: purple lichen which is red in acid solution and blue
in alkali.– Invented by a gentleman who wanted to measure how acid
his beer was. To make beer or wine, you have to use yeast, and yeast uses enzymes… Enzymes only work if the pH is right.What he discovered was that acids and alkalis make the colours in plants change.
• Tips?
– Don’t pollute the tester!!
Universal indicator paper can change from blue to green to yellow to red. Universal indicator is a mixture of dyes which all change when you change the pH
Grind up some red cabbage. You get a red liquid.Pour some ammonia: what is the color of the liquid now?…
34July 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?
35July 2003
– Live in large numbers in the intestines of animals: aid in the digestion
– Some might be infected with diseasese.g. waterborne pathogenic diseases: typhoid fever, gastroenteritis, hepathite A, diphteria, tuberculosis
1. Overflow or poor treatment of domestic sewage2. Non-point source of human and animal waste
Coliform bacteria
•Why coliform bacteria?
•How does it get into water?
200 colonies per 100ml
•What is an acceptable limit?
Bacteria are removed by disinfection and/or filtration
36July 2003
Coliform bacteria
•Testing?
• Tips?
– Keep the tube vertical!!!
– Fermentation means incubation too!!
– Note weather conditions!…
1. Counting using filter2. "Presence/Absence method“:
– Enzymatic substrates + incubation for 24hrChange of yellow color = presence of Coliform
bacteriaFluorescence under ultra-violet = presence of
E.Coli bacteria
37July 2003
• Other factors?
Coliform bacteriaSeparate or combined sewer 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.
38July 2003
Coliform bacteria… exercises
• Are there treatment or prevention measures?
• What are the standards in your watershed?
39July 2003
– 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.
Turbidity
•What is turbidity?A physical measure
40July 2003
Turbidity
•What are the problems?
41July 2003
Turbidity problems…
42July 2003
Turbidity• Testing?
NTU
Secchi disk(JTU)• Tips?
– Testing on site!!!
– Avoid glaring effect!!! Avoid your shadow!!!
43July 2003
Turbidity… exercises
• What are the units of turbidity measurements?
• Are there treatment or prevention measures?
• What are the standards in your watershed?
44July 2003
– t° DO : affect DO, and chemical reactivity in general– Different temperature environments different species – All species are negatively impacted by rapid fluctuations
Temperature
•Why temperature?A physical measure
– Season, day/night, weather,…– Current, hot sources (geothermie)– Depth (Hypolimnion…)
•Why does temperature vary?
– Human activites: cities, removal of vegetation, plume, stream widening or shallowing, industry, global warming, etc…
45July 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!!!
46July 2003
Temperature• Testing?
• Tips?
– Testing on site!!!– Don’t hold the container!!!
– Thermometer
– Be careful the way you hold the thermometer!!
Units?
47July 2003
Temperature… exercises
• What are the units of t° measurements?
• Are there treatment or prevention measures?
• What are the standards in your watershed?
48July 2003
– 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
Hardness
•What is hardness?
•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
49July 2003
Hardness
•What are the effects?
• Good effect!!: “water could be a major contributor of Ca and Mg to the diet”
1. Health:
2. Environment & industry:
• Scale…in pipe, tanks…
• Chemical processes affected, e.g. lathering & washing
on glasses & clothes…
• Skin irritation, dull hairs, etc…
• More detergents used…
50July 2003
Hardness
•How much is needed?In the U.S.A:
Classification mg/l or ppmSoft 0 - 17.1Slightly hard 17.1 - 60Moderately hard 60 - 120Hard 120 - 180Very Hard > 180
51July 2003
Hardness… exercises
• Are there treatment or prevention measures?
• What is the classification in your watershed?
• Is your watershed affected?
52July 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
– Natural concentration largely influenced by the underlying geology…
– Faults might allow brine formation
• Where do salts come from?
– 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
53July 2003
Salinity
•What are the problems?
• 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?
1. Health:
2. Environment & industry:
• Shift in water population• Chemical processes affected (especially within
plant…)• Dissolved salts may encrust or corrode metallic
surfaces
54July 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
55July 2003
Salinity… exercises
• What is the salinity situation of your watershed?
56July 2003
Testing… exercises
• The units
• Standards in Egypt and in your watershed
• Point source vs. non-point source
• Chain reaction…
57July 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
58July 2003
Biological monitoring
59July 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…
60July 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
61July 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 collectand… without expensive equipmentEvaluation of impacts of
toxic, sediment, and nutrient pollution, but not bacteria pollution
62July 2003
Benthic macro-invertebrates & classification
• Description…
• What to look for?…
63July 2003
Benthic macro-invertebrates
•Compare these…
Illustrations from:Voshell, J. R., Jr. [2002]: Guide to the Common Freshwater Invertebrates of North America.MacDonald and Woodward Publishing Co.
64July 2003
Benthic macro-invertebrates
•Compare those…
Illustrations from:Voshell, J. R., Jr. [2002]: Guide to the Common Freshwater Invertebrates of North America.MacDonald and Woodward Publishing Co.
65July 2003
Benthic macro-invertebrates
•And those…
Illustrations from:Voshell, J. R., Jr. [2002]: Guide to the Common Freshwater Invertebrates of North America.MacDonald and Woodward Publishing Co.
66July 2003
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.
67July 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.
68July 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
69July 2003
Physical Testing
71July 2003
Practice…
72July 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
73July 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
75July 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!
76July 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
77July 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
78July 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.
79July 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.
80July 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 macro-
invertebrates 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.
81July 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.
Guidelines to Scoring Habitat Parameters: http://www.sosva.com/
82July 2003
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?
85July 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.
87July 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
88July 2003
Field sheet example•Front Page of Field Sheets:
Basic Stream Information - Save Our Streams Stream Quality SurveyDate: 10-Jul-2001 Stream: Muddy Creek Station #: MUD 1 # of Participants: 2Group/Individual: Virginia Save Our StreamsName of Monitor: Jay GilliamCounty: Rockingham Latitude:38 27 54 Longitude: 78 58 33Location: Off Route 33, downstream of WLR plant in HintonAverage Stream Width: 15 feet Average Stream Depth: 12 inchesFlow Rate: NormalWeather Last 72 hours: rain 72 hours ago, sunny currentlyWater Temperature: 44°FCollection Time: Net 1 = 20 seconds; Net 2 = 27 seconds
89July 2003
Field sheet example•Sample Tally Sheet:
Macro invertebrate Count Macro invertebrate CountWorms 18 Caddisflies 0Planatarians 36 Common Netspinner 32Leeches 13 Beetles 4Crayfish 1 Midges 19Sowbugs 5 Blackflies 13Scuds 11 True Flies 4Stoneflies 0 Gilled Snails 2Mayflies 34 Lunged Snails 9Dragonflies/Damselflies 1 Clams 0Hellgrammites/Fishflies/Alderflies 2
TOTAL 204 TOTAL INTOLERANT 76 TOTAL TOLERANT 72
90July 2003
Sampling tips
• Percentages vs. amounts representativity of small numbers!!
• Sample vs. populationrepresentativity of the population!!
•Please, no over-sampling!!– Sample a monitoring site only 4 times a year - during the seasons.
91July 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!