Water Quality Testing

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Water Quality Testing

• Ms. DC and Ms. Arya

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What should we test our water for??
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What is Turbidity?

• Measurement of how clear the water is
• Unclear water is said to be turbid.
• Turbidity is caused by matter such as clay, silt,
  and other material in the water
• Could be the result of soil erosion, run-off, and
  algal blooms

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Test Your Water Turbidity

• 1. Pour 25 mL of water into the turbidity beaker.
• 2. Use the Secchi disk to measure turbidity

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What are Phosphates?

• Phosphates come from phosphorus, a plant nutrient
  
• Frequently found in run-off from construction
• Used as a fertilizer for landscaping

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Phosphates

• Can cause algal blooms which remove oxygen from
  the water
• Over HALF of all phosphates in water come from
  household detergents

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Testing Your Water for Phosphates

• 1. Using the 25 mL from turbidity testing, pour 5
  mL into a test tube.
• 2. Add one Phosphorus TesTab.
• 3. Cap the tube and mix until tablet dissolves.
• Wait for 5 minutes.

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What are nitrates?

• Nitrates come from nitrogen, a nutrient that
  helps plants grow
• High levels of nitrates cause aquatic plant and
  algal blooms which remove oxygen from water
• Unpolluted waters usually contain about 4 parts
  per million of nitrates
• Above 40 parts per million is unsafe for drinking

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Nitrates

• Nitrates get into our watershed by
• Human and Animal wastes
• Decomposing organic matter
• (matter that was once living breaking down)
• Lawn and crop fertilizer run-off

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Test Your Water for Nitrates

• 1. Using the water from the turbidity experiment,
  pour 5 mL of water into a clean test tube
• 2. Add one Nitrate 1 TesTab. Cap the tube and
  mix until tablet dissolves
• 3. Add one Nitrate 2 CTA TesTab. Cap tube and
  mix.
• 4. Wait 5 minutes.

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What is Dissolved Oxygen?

• Just like animals on land, aquatic animals need
  oxygen to live
• Oxygen is dissolved in the water
• Algal blooms use up all the oxygen leaving little
  for the animals in the water

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Testing Your Water for Dissolved Oxygen

• 1. Pour 5 mL of water into the test tube.
• 2. Put one TesTab into the tube and dissolve the
  tablet.
• 3. Compare the color the water turns to the chart.

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What is pH?

• One of the most common water tests
• Results tell you how basic or acidic the water is
• A pH range of 6.5 to 8.2 is healthy for most
  organisms
• Blue Crabs need a pH of 8.0
• Rapidly growing algae can increase the pH of water

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Measure Your Waters pH

• 1. Pour 10 mL from the turbidity experiment into
  a test tube
• 2. Add one pH Wide Range TesTab
• 3. Cap the tube and mix until the tablet is
  dissolves.
• 4. Compare to color chart.

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Coliform Testing

• Coliform is a group of bacteria that is commonly
  found in animal feces
• High coliform amounts can result in disease in
  aquatic animals as well as people swimming in
  that water

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Testing Your Water for Coliform

• Write your name on your nutrient agar plate
• Dip a sterile swab into your water
• Streak your nutrient agar plate
• Put your plate in the middle of the table
• Ms. DC will put your plate in an incubator (37C)
  overnight. You will look at your plates tomorrow.