Monitoring water quality
This activity provides opportunities for students to monitor the water quality in their local area, using a range of tests, and to draw conclusions about human impacts on the quality of water in their catchment area.
Science and Society
5.3 Students analyse the relationship between social attitudes and decisions about the applications of science.
6.3 Students use scientific concepts to evaluate the costs and benefits of applications of science (including agricultural and industrial practices).
- Water quality monitoring equipment:
- Thermometer (temperature)
- Turbidity tube (turbidity)
- Electrical conductivity meter (salinity)
- Test strips or aquarium pH test kit (pH)
- Stopwatch and orange (flow rate)
- collection jars
- map of catchment (see introductory activity ‘Which catchment area do I live in?’)
- Resource Sheet 7 - Stream Habitat Assessment (PDF, 242K)* for each group if you also plan to assess riparian vegetation at the sites you visit
- Resource Sheet 8 - Conducting a Waterbug Survey (PDF, 119K)* for each group if you also plan to conduct a macro-invertebrate survey at the sites you visit
- Resource Sheet 9 - Monitoring Water Quality (PDF, 63K)* for each group
Approaches to sampling
Two approaches to sampling can be taken, depending on the accessibility of a suitable local waterway to the school.
1. Single site sampling
Students can sample from the same location at the same time every week for the duration of the module. Students could sample from a site once to gain an appreciation of the site and then analyse subsequent weekly samples in the laboratory. Sampling over a number of weeks aids students’ understanding of the significance of the tests. It is useful to link in a riparian vegetation assessment and a waterbug survey to gain a more complete picture of the ecology of the waterway (see developmental activity ‘Assessing waterways’).
2. Multi-site sampling and catchment crawls
Alternatively, students can sample three or four different sites along a waterway on a single day. The sites should be a couple of kilometres apart and have a variety of landforms and vegetation. For instance, a range of sites could be well shaded, in full sun or below a stormwater outlet. If access is difficult, samples could be collected and taken to the classroom for analysis. However, if students have not visited a site, they will be unable to visualise the associated landforms and vegetation. If a range of sites are chosen in lower, middle and upper parts of a catchment, this method of sampling is often referred to as a ‘catchment crawl’. At each stop students investigate similar characteristics or parameters so that a comparative overview can be taken of the catchment. This can be achieved by:
- taking photographs or making sketches at different sites
- conducting water quality tests
- conducting habitat and riparian vegetation assessments
- land use surveys etc.
After the excursion, students draw conclusions about the relative health of the waterway at the various sites and the possible human impacts that may affect the waterway.
Other parameters can be tested, depending on the availability of equipment, the skill level of the students and the risk assessments of the tests. These include dissolved oxygen, phosphates, nitrates and faecal coliforms.
Water monitoring kits
Some local councils and regional natural resource management bodies will lend water quality test kits to interested groups.
Time: 30 minutes for information retrieval; 30 minutes for monitoring (or one-day excursion plus another 40 minute lesson for collation and interpretation of data, if you choose to do a catchment crawl)
- collecting information
- interpreting data
- inferring from data
- making links
- making comparisons
Students reflect on the investigation they are about to conduct. Questions to support reflection might include:
- How has human population and land use changed in this area in the last 100 years (or longer)?
- Did people in the past have sufficient knowledge and equipment to investigate this area as you are going to investigate it?
- In the past, would the effects of land management practices be immediately evident to people?
- Could current practices be contributing to degradation of the environment?
Working in groups, students collect their water samples from the site/sites concerned. The group will also need to take notes describing the human impacts that are visible adjacent to the sampling site. Students analyse their sample and record the data in a table. If sampling is to occur over a number of weeks, groups could take turns to perform a particular test. Data from the whole class could then be collated.
Students complete the retrieval table in Resource Sheet 9 from the information cards, which give background information on each of the tests. Guided by the teacher, students discuss the significance of their test results and draw conclusions about the effect that human impacts may have on the water quality at their sites. Ideas from the introductory activity ‘Which catchment area do I live in?’ could also be linked at this time.
Individually, students write a short report tabulating their data, graphing their results and explaining their conclusions. The report should also offer suggestions for actions that could be taken to improve the quality of the water so that the natural resources of the area can be used without causing long-term environmental damage.
Where human impacts have occurred, students should say in the report whether there is evidence that the behaviour of people has now changed to address any of these impacts, or whether the cause of the impact still remains.
Students should also indicate whether they think social attitudes would support the solutions that they have proposed to improve water quality.
Gathering information about student learning
Sources of information could include:
- group data sheets
- individual student reports
- anecdotal records of students’ contributions to discussion.
(The ‘Monitoring water quality’ activity is adapted from Foster 1995, Waterwatch action by school communities)
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Last updated 2 August 2010