1. Chapter 17
Water Sample Analysis

2. Water sample analysis
Key Knowledge • existence of water in all three states at Earth’s surface including the distribution and proportion of available drinking water • sampling protocols including equipment and sterile techniques for the analysis of water quality at various depths and locations • the definition of a chemical contaminant and an example relevant to a selected water supply.

3. Water sources on Earth Location of water State of matter Volume (km3)
Oceans
Liquid
Ice caps and glaciers
Solid
Groundwater
Ground ice and permafrost
Lakes
Soil moisture
17 000
Water vapour in the atmosphere
Gas
13 000
Rivers
2 100

4. The water cycle

5. Main processes in the water cycle
Heat from the sun causes the water to evaporate
Water vapour is transported around the globe and condenses to form clouds
Water precipitates as rain, hail and snow and falls to the ground

6. Australia’s water supplies
40% of the worlds population lives where there is limited fresh water.
Australia has close to 5% of the worlds land mass but only 1% of the water carried by rivers.
Australia is the worlds driest inhabited continent and has variable rainwater.
Look up the ‘Great Artesian Basin’ – what is it and why is it important?

7. Potable water (clean drinking water)
Sources
Reservoirs filled by run-off from rivers and streams
Water obtained directly from rivers and lakes
Groundwater (bore water)
Recycled water
Desalinated water

8. Drinking water in Victoria
Most Victorians drinking water is supplied by mains supply (reticulated water)
Other sources include – rainwater tanks, bores, dams, rivers and creeks
Lowest risk Mains water
Rainwater
Deep groundwater
Shallow groundwater
Highest risk Surface water

9. Water Quality
We are lucky in Australia that our drinking water is of such high quality. This is not the case worldwide.
Chemical contamination can occur from time to time and this section looks at the types and how samples are obtained for analysis

10. Chemical contaminants
Many different types of substances are soluble in water.
Water pollution may be caused by human activity. Contamination can occur from
Run-off from farms and cities
Run-off from industrial and mining wastes
Lead used in solder in copper water pipes
Chemical contaminants can be naturally occurring or synthetic. The main types of chemical contamination involve
Heavy metals
Pollutants from fertilizers
Organic pollutants

11. Heavy metal containation
Heavy metals such as Lead and Mercury can contaminate water and cause serious health effects such as
Cancer
Organ and nervous system damage
Even death
Guidelines in Australia about safe drinking water values are monitored by local water authorities.
Heavy metal
Guideline value (mgL-1 or ppm)
Arsenic
0.01
Cadmium
0.002
Copper 2
Chromium
0.05 (as Cr(VI))
Lead
Mercury
0.001

12. Water sampling
To make sure water is safe to drink testing takes place.
Decision have to be taken about where to take samples from and the protocols that will be used.
PROTOCOLS
Containers being used
Sampling methods
Sampling depth
Sampling location

13. Checklist Read Chapter 17 and make your notes 17.1 Q 1-4 p434
Chapter review p
Worksheets 40 and 41 from the student workbook