Beginning at Wallan north of Melbourne

Beginning at Wallan north of Melbourne, the creek flows 70 km until it joins the Yarra river.
A range of aquatic and semi-aquatic living organisms rely on Merri creek as their habitat or drinking supply. Such animals and plants include: fish, Water Rat, Platypus, frogs and other amphibians, waterbirds, microorganisms, reptiles and the various other species that drink water from Merri creek. Replanting by Merri Creek Management Committee and Friends of Merri Creek, a volunteer group has allowed native vegetation to be more abundant.
The quality of water in the creek is regularly monitored to ensure it is safe for consumption for organisms, which protects the habitat. Conducted regularly by water agencies, water quality tests measure pH, chlorine levels, concentration of calcium carbonate and concentration of nitrates. Water quality testing is conducted monthly for Merri creek Fawkner.
1. Measure 40 mL of each water sample into a clean and dry 50 mL beaker.
2. Label each beaker with the sample it contains.
3. For measuring the temperature, place a thermometer into each water sample for one minute and record the temperature in the table in the ‘Results’ section.
4. To conduct the chlorine test, swirl a chlorine strip in the creek water sample three or four times and remove it. Wait for 10 seconds and hold the paper next to the colour chart section for chlorine. Record the total chlorine concentration and free chlorine in the table in the ‘Results’ section. Repeat the procedure using s new strip for each sample.
5. To conduct the nitrate test, place the nitrate strip into the creek water sample for two seconds and remove it. Wait one minute and check the test strip against the colours on the chart for nitrate concentration. Record the concentration of nitrate in the results section. Repeat for the other water samples, using a new strip for each sample.
6. To conduct the pH and Concentration of CaCO? (total hardness) in ppm concentration test, use the multi-test strip, dip the entire strip into the creek water sample for one second and remove. Do not shake the excess water from the test strip. Hold the strip level for 30 seconds, compare the total hardness and pH pads to the colour chart on the bottle and record your finding in the ‘Results’ section. Repeat the procedure for the other water samples.
It is necessary to measure the temperature of each sample to ensure a fair test is carried out. If the temperature of each water sample is drastically different, it would cause a different amount of solute to be dissolved, which would produce inaccurate results.
The results indicate that every water sample had 0 ppm of concentration of free chlorine, so there was no sample which had a higher concentration than another. This is unexpected as chlorine is usually added to drinking water to kill harmful organisms. Therefore, it is possible that the strips weren’t sensitive enough to sense the presence of chlorine.
As chlorine is a highly efficient disinfectant, it is added to drinking water to kill disease-causing organisms that may be found in the water or in the transportation equipment. Through the addition of chlorine, water is safe for consumption.
The limit for the amount of free chlorine in drinking water is 5 mg/L.
The concentration of free chlorine in the Merri creek water sample was 0 ppm, which was the same result obtained for the other water samples. This may be due to the strips lacking sensitivity and therefore, couldn’t detect the low levels of chlorine.
The Merri creek water sample had the highest nitrate concentration of 2 ppm, followed by commercial drinking water sample of 0.5 ppm. The tap water sample and the distilled water sample both had 0 ppm.
Nitrates naturally occur in soil and water. Some other sources of nitrates in our water ways include inorganic fertilizers, wastewater treatment, sewage, manure storage, septic systems, through the oxidation of other forms of nitrogen, agricultural activities and industrial pollution.
High levels of nitrates in our water ways can create an environment that makes it difficult for aquatic animals to survive. This is because many algae and other plants, that utilize nitrates as food, can cause the dissolved oxygen levels to fluctuate. Also, a human’s red blood cells’ ability to transport oxygen can be impacted by high levels of nitrates. It can also cause condition called “blue baby syndrome” in infants.
Measuring the pH allows us to know the concentration of hydrogen ion, which indicates the acidity or alkalinity of a solution. Pure water has a pH of 7, making it neutral.
I would expect it to be of a pH of 7 because it should not be an acid or base, maintaining neutrality.
Commercial drinking water and distilled water had a pH of 7, while tap water had a pH of 7.5. These are all fairly similar. Drinking water must have a pH of 6.5-8.5 to fall within EPA standards and this may be a reason to prove why this result has been obtained. On the other hand, the Merri creek Fawkner water sample had a pH of 8.5, which is higher than all the other water samples. This may be the case because most aquatic animals prefer to live in a pH between 6.5-9.0 and therefore, this pH is aimed to be achieved. Also, the pH of water for humans’ drinking water is more strictly monitored than the pH of the water for animals.
Some of the disadvantages of hard water are as follows; difficult to lather soap with, when washing white clothes, hard water will stain it to make it grey, can create lime scale in containers which is why it should be avoided in cleaning kitchenware, could clog showerheads and spray nozzles and it could decrease the lifespan of appliances.
Distilled water had the least concentration of CaCO?, which was 25 ppm. Both the tap water and commercial drinking water had the second least, which was 50 ppm. The highest concentration of CaCO? was in the Merri creek water, which was 250 ppm. This may be the case because the Merri creek water is untreated, while drinking water is removed of such high concentration of CaCO?, leaving it with lower levels.
According to my findings, distilled water, tap water and commercial drinking water are safe to drink as they have a pH of or close to 7, contain low levels of nitrates (around 0) and have a low concentration of CaCO?, indicating they are treated.
Some errors include the following; multitasking proved to be difficult, casing some strips to be observed after due time, we didn’t choose one person to view strips and as everyone sees colours differently, accuracy could not be obtained, chlorine strips lacked sensitivity, interruptions with experiment as students shared resources, some instructions were misunderstood and therefore procedures were carried out incorrectly.
In conclusion, Merri creek water is of lower quality in comparison to tap water, commercial drinking water and distilled water due to it containing higher levels of nitrates, higher pH and higher concentration of CaCO?. The tap water and commercial drinking water were quite similar, except for commercial drinking water containing 0.5 ppm of nitrates and tap water having a pH of 7.5. Distilled water had both the lowest pH and concentration of CaCO?. Therefore, according to the experiment, is of the highest quality compared to the other water samples. I could improve this experiment by distributing tasks among the group to obtain the best, most accurate results in the least amount of time. We could also obtain chlorine strips of higher sensitivity. We could select one person from the group, with the best sight of colour, to observe the strips. We should read the instructions carefully before carrying out the experiment. We could also try to be more organised when taking turns using the equipment and materials. Overall, although the experiment had many flaws, the obtained results were able to indicate how the Merri creek water sample differs to other samples as it has a higher mineral concentration.