Preparing for Fieldwork

The videos below demonstrate the geographical fieldwork techniques that will be required for the activities on pages 4 & 5 of the Student Fieldwork Booklet.

Learning Intention

Investigate geographical fieldwork techniques that will allow us to make enquiries about water quality and health.

Inquiry Questions

What is the relationship between Turbidity, Ammonia and Phosphorous with Water Quality at Lake Albert?

Water Quality Fieldwork Techniques

The fieldwork tests that you will be using at Lake Albert include:

  • Turbidity
  • Ammonia
  • Phosphorous (phosphate)
  • pH
  • Water Temperature

Water Turbidity Testing

  1. Collect 2 nephelometer tubes and join together
  2. View the secchi disk
  3. Agitate the water to ensure no settling to the bottom
  4. Fill slowly with water until you can no longer see the secchi disk
  5. Make note of Nephelometer Turbidity Units ( NTU's) on the scale
  6. Repeat a second time working with greater care for accuracy
  7. Record NTU's as a measure of water sediment turbidity.

Nephelometer tube

Secchi disk - waves

Normal range in freshwater is less that 30 NTUs.

The lowest NTU reading is 7 units as this equipment and test does not have the accuracy to measure any lower.

Secchi disk - triangles

The Nephelometer scale reads between 7 and 500 NTU's.

Water samples should be collected without disturbing the silt on the bottom. If the sample is left too long settling of sediment to the bottom will give a less than accurate reading.

Water Phosphorous Testing

  1. Collect water sample
  2. Fill vial to the 10ml mark
  3. Bend test strip in half
  4. Put lit on vial and invert slowly 5 times
  5. Remove lid and test strip
  6. Compare water in vial against the colour chart
  7. Record Phosphorous result in parts per billion
  8. Normal freshwater range is between 5 - 50 ppb

Phosphorous results

Phosphorous is measured in parts per billion (PPB) of phosphate

Phosphorous instructions

Water Ammonia Testing

  1. Collect water sample
  2. Fill vial with water
  3. Place in test strip for 5 seconds
  4. Remove strip
  5. Compare raised pad on strip with colour chart
  6. Record Ammonia test result in parts per million
  7. Normal freshwater range is below 0.25 ppm

Ammonia results

Ammonia is measured in parts per million ( PPM)

Ammonia instructions

pH Water Testing

  1. Measure 10mls of test water into the specimen jar
  2. Add one pH test tablet
  3. Shake until dissolved
  4. Wait 5 minutes for colour to develop
  5. Check colour against the chart
  6. Record pH result as a measure on the 0 - 14 pH scale
  7. Follow teacher instruction to dispose of waste

Water Temperature Testing

  1. Collect water sample
  2. Take infra-red thermometer out of its pouch
  3. Use the ruler to hold the IR thermometer 30cm away
  4. Pull trigger to collect the temperature
  5. Record data
  6. Dispose of water and return equipment