2.1:monitoring water quality

2.1:Monitoring Water Quality

GO C2Identify processes for Measuring the Quantity of Different Substances in the Environment and for Monitoring air and water Quality.

Guided QuestionGuided Question

Why is it important to monitor the quality of water?

Would you Drink this water?

MonitoringMonitoring:: keeping track of something for keeping track of something for a specific purpose.a specific purpose.

Water quality is determined by what water is Water quality is determined by what water is used for. It is regulated by technicians used for. It is regulated by technicians

Their are five categories of water use:Their are five categories of water use:

1.1. Human drinking waterHuman drinking water2.2. Recreation such as swimmingRecreation such as swimming3.3. Livestock drinking waterLivestock drinking water4.4. IrrigationIrrigation5.5. Protection of aquatic lifeProtection of aquatic life

Biological IndicatorsBiological Indicators Scientist use organisms that live in the water to Scientist use organisms that live in the water to

help determine water quality. help determine water quality.

Microbiological IndicatorsMicrobiological Indicators Microscopic organisms such as bacteria can Microscopic organisms such as bacteria can

cause serious health problems if they are cause serious health problems if they are present in high enough numbers.( E coli present in high enough numbers.( E coli bacteria)bacteria)

Aquatic InvertebratesAquatic Invertebrates Invertebrates are animals Invertebrates are animals without backboneswithout backbones. .

They are used for monitoring because different They are used for monitoring because different invertebrates prefer different living conditions.invertebrates prefer different living conditions.

Examples of IndicatorsExamples of Indicators

Biological IndicatorsBiological Indicators Which organisms indicate a high level of dissolved OWhich organisms indicate a high level of dissolved O22? good water conditions ? good water conditions

Which organisms indicate a low level of dissolved OWhich organisms indicate a low level of dissolved O22? poor water conditions ? poor water conditions

Dissolved Dissolved Oxygen Oxygen

levellevel

ConsequencesConsequences

Dissolved Dissolved OO22

8 8 Excellent Excellent

Large variety of invertebrates (insect larvae, Large variety of invertebrates (insect larvae, beetles, worms) Many species of fish and other beetles, worms) Many species of fish and other desirable organismsdesirable organisms


6 Good6 Good

Few mayfly larvae, some stonefly larvae, some Few mayfly larvae, some stonefly larvae, some beetles, many midge larvae, many worms beetles, many midge larvae, many worms

including leechesincluding leeches Dissolved Dissolved

OO22

4 Low4 Low

Freshwater shrimp, many midge larvae, many Freshwater shrimp, many midge larvae, many worms including leeches. Some species have worms including leeches. Some species have difficulty living in critical levels. difficulty living in critical levels.


2 Very 2 Very LowLow

Many midge larvae, some worms including Many midge larvae, some worms including leeches leeches


0 Critical0 Critical

No species of game fish exist, some midge No species of game fish exist, some midge larvae, some worms larvae, some worms

Chemical Factors that Affect Chemical Factors that Affect OrganismsOrganisms

Water found in our environment may contain Water found in our environment may contain many different organic and inorganic compounds. many different organic and inorganic compounds. The concentration of these compounds affects The concentration of these compounds affects water quality. water quality.

The following are monitored as indicators of water The following are monitored as indicators of water quality:quality: Dissolved oxygenDissolved oxygen AcidityAcidity Heavy metalsHeavy metals Plant nutrientsPlant nutrients (such as nitrogen and phosphorus)(such as nitrogen and phosphorus) PesticidesPesticides SaltsSalts (such as sodium chloride and magnesium sulfate)(such as sodium chloride and magnesium sulfate)

Dissolved OxygenDissolved Oxygen

The level of dissolved oxygen The level of dissolved oxygen depends on:depends on: Temperature (due to change Temperature (due to change

in seasons)in seasons) Turbulence (due to wind or Turbulence (due to wind or

the speed of moving water)the speed of moving water) Photosynthesis of aquatic Photosynthesis of aquatic

plants or algaeplants or algae # of organisms using up the # of organisms using up the

oxygenoxygen

Dissolved oxygen is essential Dissolved oxygen is essential for the health of aquatic for the health of aquatic

life.life.

AcidityAcidity Precipitation with a pH lower than 5.6 is Precipitation with a pH lower than 5.6 is

considered considered acid rain/snowacid rain/snow. . Acid precipitation causes major problems in the Acid precipitation causes major problems in the

spring spring when the snow melts and flows into when the snow melts and flows into aquatic systems. aquatic systems. Spring acid shock Spring acid shock causes serious causes serious harm to the eggs and young offspring of fish.harm to the eggs and young offspring of fish.

As the acidity increases the diversity of organisms As the acidity increases the diversity of organisms decreases! decreases!

Most fish disappear if the water’s pH falls to 4.5.Most fish disappear if the water’s pH falls to 4.5.

Heavy MetalsHeavy Metals Heavy metals have a density of Heavy metals have a density of

5g/cm5g/cm33 or higher or higher Include copper, zinc, lead, mercury, Include copper, zinc, lead, mercury,

cadmium and nickelcadmium and nickel They naturally occur in rocks and soilThey naturally occur in rocks and soil They are mined to make: batteries, They are mined to make: batteries,

tires, paints, pipes, thermometers tires, paints, pipes, thermometers and fertilizersand fertilizers

Heavy metals must be monitored Heavy metals must be monitored because they can be toxic to a because they can be toxic to a variety of organismsvariety of organisms

Plant NutrientsPlant Nutrients (Phosphorus and Nitrogen Content)(Phosphorus and Nitrogen Content)

Phosphorus and nitrogen are Phosphorus and nitrogen are important for all living things, but too important for all living things, but too much can cause problems. Excess much can cause problems. Excess PP and and NN22 comes from: comes from: Sewage outfallsSewage outfalls Runoff from fertilized fieldsRunoff from fertilized fields

High amounts of P and NHigh amounts of P and N22 cause: cause:

Increased growth in algae and green plants Increased growth in algae and green plants

Plants dies and becomes food for bacteria Plants dies and becomes food for bacteria that decompose itthat decompose it

Bacteria increase in number Bacteria increase in number

Increased bacteria use up dissolved oxygen Increased bacteria use up dissolved oxygen

Fish and aquatic insects cannot survive Fish and aquatic insects cannot survive

PesticidesPesticides Some pesticides have long lasting effects as Some pesticides have long lasting effects as

they do not break down quickly and last in the they do not break down quickly and last in the environment for a long period of time ( DDT)environment for a long period of time ( DDT)

Most are now used for ONE growing seasonMost are now used for ONE growing season They do however create organisms that can They do however create organisms that can

become RESISTANT to the pesticidebecome RESISTANT to the pesticide Larger numbers of pesticides are creating Larger numbers of pesticides are creating

problems in the environment as if they are problems in the environment as if they are mixed together they create a TOXIC mixed together they create a TOXIC substancesubstance

TOXICITY – describes how poisonous a TOXICITY – describes how poisonous a substance is substance is

Measuring ToxicityMeasuring Toxicity Toxins or poisons are substances that Toxins or poisons are substances that

produce serious health problems or death produce serious health problems or death when introduced into an organism. when introduced into an organism.

In order to compare toxins, a measurement In order to compare toxins, a measurement called called LD50LD50 is used. is used.

LDLD stands for stands for lethal doselethal dose; ; 5050 represents represents 50%50%..

LD50 is the LD50 is the amount of a substance that amount of a substance that causes 50% of animals to die if they are given causes 50% of animals to die if they are given a specified dose of the substance all at once.a specified dose of the substance all at once.

Table salt – 3000mg/kg, Caffeine – 192 mg/kg, Table salt – 3000mg/kg, Caffeine – 192 mg/kg, DDT 87mg/kg (all given to rats by mouth)DDT 87mg/kg (all given to rats by mouth)

Measuring Chemicals in the Measuring Chemicals in the EnvironmentEnvironment

The concentration of chemicals in the The concentration of chemicals in the environment is usually measured in environment is usually measured in parts per million (ppm)parts per million (ppm)

One part per million means that one One part per million means that one unit of an element can be found in unit of an element can be found in one million units of solutionone million units of solution

Some times the concentrations are Some times the concentrations are expressed in expressed in parts per billion parts per billion (ppb)(ppb) or or parts per trillion (ppt)parts per trillion (ppt)

1 ppm1 ppm is about the same as 1 drop of is about the same as 1 drop of food colouring in a half filled bath tubfood colouring in a half filled bath tub

1 ppb1 ppb is about the same as 1 drop of is about the same as 1 drop of food colouring in a swimming poolfood colouring in a swimming pool

1 ppt1 ppt is about the same as 1 drop of is about the same as 1 drop of food colouring in 1000 swimming food colouring in 1000 swimming poolspools

Determining ppmDetermining ppm

ppm= ppm= Part (g or mL) Part (g or mL) ie. 1 Part per ie. 1 Part per million million 1 000 000 mL 1 000 000 mL millilitresmillilitres

ppm =ppm = mg mg = = mg mg = = g or mL _ g or mL _

L 1 000mL 1 000 000mL L 1 000mL 1 000 000mL

ExampleExample

If there are 20 mg of oxygen If there are 20 mg of oxygen dissolved in 5 L of water, how many dissolved in 5 L of water, how many ppm of dissolved oxygen is there?ppm of dissolved oxygen is there?

ppm = ppm = 20 mg 20 mg = 4 mg/L = 4 ppm= 4 mg/L = 4 ppm

5 L5 L

Example 2Example 2 If there is 5mL of oxygen dissolved in If there is 5mL of oxygen dissolved in

995 mL of water, how many ppm of 995 mL of water, how many ppm of dissolved oxygen is there?dissolved oxygen is there?

ppm = ppm = g or mL _ g or mL _

1 000 000mL 1 000 000mL

ppm = ppm = 5 mL 5 mL = 0.005 mL/mL = 0.005 mL/mL

1000mL1000mL

ppm = ppm = 0.0050.005 = 5000 ppm = 5000 ppm

10001000

Water Quality – Hot Water Quality – Hot TopicTopic

http://www.youtube.com/watch?v=2igTexiW3bg

Do you think it will be banned?Do you think it will be banned? Do you think it Do you think it should should be?be? Could it be a risk to humans?Could it be a risk to humans? Should it be used, even if not a risk Should it be used, even if not a risk

to human?to human? Homework: can you find any Homework: can you find any

triclosan in your home?triclosan in your home?

2.1:monitoring water quality

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