Rock Type

Geology
The rock type which was sitting around the pond was a sandstone.Overall centennial park location sits on the area known as the Botany Sands. It’s on the northern edge of the Botany Basin.The geology of Centennial Parklands comprises a complex of Aeolian Sand dunes, with an underlying layer of interbedded clays, peats and sands.  The landform is of rounded sand dunes, with local depressions and exposed water tables of ponds and marshes
 

Second lot of sample + Background information on geology

Today the second lot of samples were taken. These include 3 water and soil samples taken from 3 different areas of the pond. This lot of samples was taken in fine conditions with no rainfall present in the two days before.

Background info on geology: http://www.centennialparklands.com.au/

• Bands and lenses of Waverley Coffee Rock, a finely textured soft impermeable mudstone occur at numerous locations in the lower lying sections of the Parklands. The resultant podsolised soil profiles are azonal, acidic and with only weakly differentiated or non existent horizon development.

• The Botany Sands overlay the northern edge of the Botany Basin and are composed of a complex of Aeolian sand dunes of the Holocene era, of variable thickness, with an underlying layer of inter-bedded clays, peats and sands. This material resulted in a natural landform of rounded sand dunes and expanses of gentle slopes with local depressions and exposed water tables (ponds and marshes)

• The original soil type for the Centennial Parklands is a white crystalline wind-blown sand of the Holocene era, overlying Hawkesbury Sandstone which outcrops at the northern edge of Centennial Park before dipping to depths of between eight to two hundred and fifty meters south towards Botany Bay. 

 unidentified rocks on the bank of the pond

Water Sample Testing;

Today water samples were tested for its phosphate contents, salt contents and pH contents. Here are the results from testing so far.

                                                                                                                                                    

The first test done was the phosphate test. This was done using phosphate strips.

Phosphate Testing	Test 1(ppm)	Test 2(ppm)	Average (ppm)
Area 1	25	25	25
Area 2	25	25	25
Area 3	25	10	17.5

Phosphate strips

The next test done was to test the water samples pH. This was done using a pH probe

pH testing	Test 1	Test 2	Average
Area 1	6.9	6.8	6.8
Area 2	6.9	6.7	6.8
Area 3	7	6.8	6.9

pH probe

The final test, was testing the water samples for salt content. This was done using silver nitrate and a conductivity probe. When silver nitrate is poured into the sample water if there is a white precipitate(silver chloride) it means there is salt content in the water. Also when depositing of the silver nitrate DO NOT POUR IT DOWN THE DRAIN. Silver nitrate is harmful to the marine life so you must ensure you put waste products into a waste bucket and ensure it is disposed of properly.

Silver nitrate testing	Results
Area 1	A mild silver chloride precipitate formed when the water samples came into contact with the silver nitrate.
Area 2	A mild silver chloride precipitate formed when the water samples came into contact with the silver nitrate.
Area 3	A mild silver chloride precipitate formed when the water samples came into contact with the silver nitrate.

After this was done the salt content was then measured using a conductivity probe.

Conductivity probe	Test 1(ppm)	Test 2(ppm)	Average(ppm)
Tap water	220		220
Area 1	186	184	185
Area 2	206	208	207
Area 3	182	179	181

Problems faced throughout the testing

When testing for the salt content of the water samples problems arrose while testing the water with silver nitrate. The silver nitrate was inconsistent in sample area number 1. The first test formed massive amounts of silver nitrate.However, this was countered by the conductivity probe as it showed a low salt content. The silver nitrate test had to be redone on a separate day and the results supplemented the conductivity tests. There was low amounts of precipitate forming in the test tube 1(containing water from sample area 1) which the conductivity probe had predicted twice.

Test tube 1(far left) showed high levels of salt

Risk Assessment records

Correction; Turbidity test is done using a Turbidimeter not a turbidity probe

Sampling

Today i assessed areas of the park in which i thought were suitable for my testing. I have concluded with testing the 'Duck Pond'. I found this pond suitable due to the fact that there is essentially 3 different type of environments around the pond. These samples were taken after a day of heavy rain.

• Sample area 1; manmade warf to allow visitors to feed the ducks off while 5 meters or so from the shore of the lake. It is located just across from the food kiosk.

Sample Area 1

Storm water drain

• Sample area 2; this area is pretty secluded and is on the far side of the pond(from the main road cutting through the park). However there is a storm water drain running into this area.

Sample Area 2

• Sample area 3; this area is across from the manmade warf. There is not much feeding in this area however there seems to be a lot of ducks in the area.

Sample Area 3

Observations; When getting samples i have observed that the amount of pollution around the pond is unacceptable. There is wet pieces of bread floating in some areas just rotting.  There is also the plastic materials floating all around the lake. The turbidity of the water also seems high.

Hypothesis for test
I presume that this lot of testing will have a higher salt level, higher turbidity and pH than that of when there is no rainfall. Due to rain being slightly acidic i presume that the water will be acidic, also runoff can contain salt. The turbidity will be higher due to more movement/disturbances in the water.

Flow chart

Experimental Plan


Thursday the 15th of March--> Establish a chosen area + specific parts in the parkt

Saturday 17th of March--> Collect samples today from 'duck pond' inside centennial park. Choose three areas 1. Affected by Human Impacts
         2. Secluded area with low human impact but with a geographic problem i.e storm water pipe
         3. Secluded area with low human impact. No geographic/ artificial influence

Monday 19th-23rd--> Complete first lot of sampling. Have results for all soil and water samples.

Saturday 24th or 25--> Collect second lot of samples today. Collect samples from the exact same place as last week

Monday 26th-29th--> Finish all testing. Organise all testing data.

Friday 30th of march to the 1st of April--> Have a first draft of open ended investigation write up completed.

Monday 2nd of April--> Hand in Write up