Water Quality Monitoring Assessment - Mudgeeraba Catchment - August 2013

Markus Race 2015 3508ENV

Water Quality Monitoring Assessment:

Mudgeeraba Catchment - August 2015:

Pollution Chemistry - 3508ENV

Monitoring Team: - Markus Race

- Sean Wotherspoon

- Shannon Cavanough

- Lucy Wang

Figure 1: Sample Site - Mudgeeraba Catchment (Mud 5) Source: Author

https://www.google.com.au/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCLysy8ew3McCFcXhpgodBsQPtA&url=https://www.griffith.edu.au/&bvm=bv.102022582,d.dGY&psig=AFQjCNEJrIsr-6S2l12cVNcDwHTBnHHDaQ&ust=1441421687760928


Executive Summary:

The assessment of water quality and any resulting interaction with the physical/chemical environment

has been considered significant since the National Water Quality Management Strategy (NWQMS)

was founded in 1992 (Australian Government, 2015).

The Australian Government considers clean water a precious commodity and ecological necessity.

However due to urbanisation water is frequently used for multiple purposes in everyday life

including; domestic usage, recreational swimming, agriculture and irrigation, commercial fishing and

industrial usage. These activities overtime can have chronic effects on the surrounding environment

including pollution, acidification and eutrophication. Due to these reasons environmental scientists

conduct research on a regular basis to assess the water quality of a particular catchment.

The following report will use the standard methodological approach to assessing water quality of a

local Gold Coast catchment system. The assessment will be composed of two main factors qualitative

and quantitative data (* see group logbook). The parameters analysed in the initial design are Total

Suspended Solids (TSS), turbidity, faecal coliforms, phosphates, nitrates and In-situ parameters

dissolved oxygen saturation (%), temperature, conductivity and pH. QA/QC methods were also used

throughout the experiment to avoid erroneous data.

The results collected determined that there was a complex relationship connecting biophysical,

biochemical and ecological factors. It was discovered that catchment sites Mud 1-3 showed the

highest concentration of nutrient parameters in the extension phase (ammonia, AHP and chlorophyll)

while Mud 4 showed the highest reading for ammonia of all the sites across the entire assessing

period.

The final result and the next course of action: Mud 4 was shown to be the most affected catchment

area along the Mudgeeraba River and hence; should be monitored and studied to determine mitigation

measures to remove or rehabilitate the catchment system. Further studies are required.


Table of Contents:

1.0 Introduction: ................................................................................................................................ 4

1.1 Forward: .................................................................................................................................. 4

1.2 Mudgeeraba Catchment Overview: ........................................................................................ 5

2.0 Scoping Phase – Project Design Overview: ................................................................................ 6

3.0 In-Situ Field Catchment Analysis: .............................................................................................. 7

3.1 Dissolved Oxygen (DO).......................................................................................................... 7

3.2 pH: .......................................................................................................................................... 7

3.3 Water Temperature: ................................................................................................................ 7

3.4 Conductivity: ........................................................................................................................... 8

4.0 SEQ Water Quality Guidelines 2009: ......................................................................................... 8

5.0 Laboratory Catchment Analysis: ................................................................................................ 9

5.1 Dissolved Heavy Metals: ........................................................................................................ 9

5.2 Phosphates and Nitrates: ......................................................................................................... 9

5.3 Total Suspended Solids (TSS): ............................................................................................. 10

5.4 Turbidity: .............................................................................................................................. 10

5.5 Faecal Bacteria: ..................................................................................................................... 11

5.6 Ammonia: ............................................................................................................................. 11

5.7 Chlorophyll: .......................................................................................................................... 12

5.8 Acid Hydrolysed Phosphates: ............................................................................................... 12

6.0 Methodology: ............................................................................................................................ 13

6.1 Sampling Procedure: ............................................................................................................. 13

6.2 In-Situ measuring apparatus: ................................................................................................ 14

7.0 QA/QC Methods: ...................................................................................................................... 15

8.0 Results: ...................................................................................................................................... 16

8.1 In-Situ Results: ...................................................................................................................... 16

8.2 Laboratory Analysis Results: ................................................................................................ 20

9.0 Discussion of Analysis: ............................................................................................................. 28

9.1 Rainfall Parameter: ............................................................................................................... 28

9.2 In-Situ Parameter Relationships: .......................................................................................... 28

9.3 Laboratory Analysis Relationships: ...................................................................................... 29

9.4 Cumulative Parameter Relationships: ................................................................................... 30

9.5 Previous Case Studies: .......................................................................................................... 31

10.0 Conclusion: ............................................................................................................................... 32

11.0 References ................................................................................................................................. 33


1.0 Introduction:

1.1 Forward:

The assessment of water quality and any resulting interaction with the physical/chemical environment

has been considered significant since the National Water Quality Management Strategy (NWQMS)

was founded in 1992 (Australian Government, 2015). The organisation works with state and territory

governments within the countries of Australia and New Zealand. The objective of the NWQMS seeks

to maintain the quality of the nations’ water sources whilst assisting businesses, industries,

environments and communities that depend on water for their respective developments. (Australian

Government, 2015)

In society, water may be used for recreational, industrial and residential purposes; including domestic

usage, recreational swimming, agriculture and irrigation, commercial fishing, industrial usage and

general scientific investigations (NSW Government Office of Environment & Heritage, 2014). These

activities could eventually cause water pollution, resulting in various testing and monitoring plans of

different catchments that have been identified as polluted.

The following report will investigate by means of conducting a water quality assessment on the in-situ

condition of the Mudgeeraba Catchment during August – October.

Figure 2: Research Team from left to right (Shannon, Lucy and Sean) Source: Author


1.2 Mudgeeraba Catchment Overview:

The Mudgeeraba Catchment covers 121 km2 of the greater Nerang River Catchment which spans

across South East Queensland (SEQ) (CIty of Gold Coast, 2006). As society progresses, the

catchment has been recently exposed to high pressure from rapid development of rural and urban

residential infrastructure.

Since 2001, 28% of total net catchment has been removed (Robertson, et al., 2006).

Consequentially sedimentation has become more apparent in the catchment causing the degradation of

the aquatic ecosystem particularly those basins downstream which act as sinks for the catchment

(Robertson, et al., 2006). The area is also utilised for agricultural purposes (e.g. cattle, crops etc.)

hence runoff from agricultural practices in the form of pesticides and herbicides must be considered in

the following investigation. The Mudgeeraba catchment is considered to be a highly dynamic system

with frequent extreme rainfall and runoff events (18m3 sec-1 Km2). Hydrological processes such as

these can cause debris flow (Robertson, et al., 2006).

The topography and geomorphology of a catchment may cause different responses to high stream

flow moments (Robertson, et al., 2006).

The distribution of riparian vegetation along the river depends on the type of catchment. In general; a

catchment consists of three components upstream, midstream and downstream (Robertson, et al.,

2006).

Upstream; usually mountainous regions. Characteristics: vertical bedrock cliffs, less fertile soils

(compared to downstream) and a greater remnant vegetation density.

Midstream - Downstream; usually semi-alluvial to alluvial regions. Characteristics: riparian

vegetation has been cleared leaving small fragments of vegetation from the adjacent forest along the

riverside. Vegetation in these regions can comprise of both remnant and regrowth riparian vegetation

(Robertson, et al., 2006).

The region of SEQ is classified as a sub-tropical climate with alternating weather and climate

patterns; during summer most of the net annual rainfall occurs with occasional extreme daily rainfall

events. Historically; a daily maxima of 600 mm of rainfall has been documented around Mt

Tambourine (Robertson, et al., 2006).

These events can trigger mudslides and increase the occurrence of debris in the catchment. Since

these disturbances can cause a positive feedback on the already vulnerable system, climate and

weather conditions are an important abiotic variable to consider in the investigation (Robertson, et al.,

2006).


Figure 3: Map of Mudgeeraba Catchment (Source: Google Maps)

2.0 Scoping Phase – Project Design Overview:

The objective of the following water monitoring assessment project is to establish overall health of the

Mudgeeraba Catchment. To achieve a benchmark for the overall catchment health; six sampling sites

will be judged based on both qualitative and quantitative information.

Qualitative:

General aesthetics (vegetation, water colour, animal presence).

Stream characteristics (flow rate, colour, debris evidence).

Anthropogenic (foreign objects, evidence of pollution, biofilm and any industries or activities

that may affect the water quality of the catchment).

Natural processes (wind speed, rainfall evidence, and animal presence and current climate

inducing weather conditions) *(For full descriptions see group logbook).

Quantitative:

In-situ site readings (DO, water temperature, pH and salinity)

Laboratory Analysis (Total Suspended Solids, faecal coliforms, NOxs, phosphates, heavy metals

and turbidity). These parameters will be identical for all sampling sites.

Since the Mudgeeraba Catchment flows through mountainous, recreational, agricultural, semi-

suburban, suburban and suburban grassland regions, to actively obtain unbiased scientific information

sampling sites will be distributed along the entire catchment at a distinct area. There will be a total of

six sampling sites with identical experimental procedures carried out at each site respectively.

Mudgeeraba

Catchment


3.0 In-Situ Field Catchment Analysis:

3.1 Dissolved Oxygen (DO)

Parameter is highly dependent on the overall equilibrium between the total yield of oxygen produced

(e.g. photosynthesis, hydrological processes) and the total amount of oxygen consumed (e.g.

respiration of aquatic life and various chemical reactions) (United States Environmental Protection

Agency, 2012). Biochemical Oxygen Demand (BOD) is the quantity of oxygen required by micro-

bacteria for decomposing waste effluent (i.e. sewage, stormwater, urban runoff and agricultural

practices). Concentrations of DO can also be influenced by water temperature and atmospheric

pressure. (United States Environmental Protection Agency, 2012).

Units: mg/L, % saturation and ppm (Allaby & Park, 2013)

Data Collection Method: YSI Multi-parameter Probe.

3.2 pH:

The parameter of pH can be quite significant in determining water quality since; a slightly acidic pH

can affect aquatic life that live in a particular catchment (i.e. when pH<7 it’s considered slightly

acidic). In these slightly acidic water bodies, access to nutrients (e.g. phosphates and nitrates) may be

limited and any heavy metals present may become soluble in the water and hence; increase in toxicity

(Perlman, 2015). Some serious environmental impacts may occur at these pH values - @ 4.5 pH fish

reproduction can be affected and @ 3.5 pH adult fish mortality begins to increase (Perlman, 2015).

Units: (pH scale ranges from very acidic (1.00) to very alkaline (14.00)).


3.3 Water Temperature:

The temperature of a water-body is significant in determining quantity of dissolved oxygen within the

catchment, since there is a direct relationship between water temperature and DO. I.e. as temperature

decreases the concentration of DO will increase (NSW Government Local Land Services). An

increase in water temperature also increases the rate of biological processes undertaken by aquatic

organisms within the catchment (NSW Government Local Land Services). Factors affecting water

temperature include; seasonality, water storage and shading conditions.

Units: ℃ (i.e. the Celsius reading for the catchment water temperature).



3.4 Conductivity:

The parameter of conductivity measures the ability of a catchment to pass an electrical current. These

electric potentials are directly proportional to the total amount of dissolved matter suspended within

the water column (United States Environmental Protection Agency, 2012). Hence; inorganic dissolved

compounds, anions, cations and complex organic compounds including; phenols, oils and sugars

which don’t react to the measuring probe.

Aside from water temperature (increasing the conductivity of a catchment) other external factors can

also influence the results taken by the measuring probe. Some of these factors include;

urban/industrial runoff (increase conductivity) and surrounding catchment geology (increase

conductivity (United States Environmental Protection Agency, 2012).

Units: micro-Siemens per centimetre (𝜇S/cm)


4.0 SEQ Water Quality Guidelines 2009:

Table 1: South East Queensland Water Quality Guidelines 2009 (Lowland Stream Parameters)

Parameter:

Guideline (Lowland Steams):

Dissolved Oxygen

85 – 110% saturation

pH

6.5 – 8.0 pH

Phosphates

50- micro gram /L

FRP

20 micro-gram/L

NOx

60 - micro gram /L

Total Suspended Solids

6 mg/L

Turbidity

50 NTU

Ammonia

20 micro-gram /L

Chlorophyll -a

5.0 micro-gram/L


5.0 Laboratory Catchment Analysis:

5.1 Dissolved Heavy Metals:

To calculate the concentration (ppm) of certain dissolved heavy metals within a catchment multi-

element methods may be required for environmental management and geochemical analysis. Previous

studies involve using Particle induced X-ray emission (PIXIE) to determine the concentration since

suspended matter within the water column may absorb these analytes. (Carserud, 1983) (Krauskopf,

1956)

These suspended particles within the catchment are comprised of clastic and endogenic materials.

Most clastic materials originate from physical weathering processes and erosion, yielding quartz,

feldspar and mica. On the other hand; endogenic materials are usually associated with the natural

processes of the catchment itself (e.g. precipitation).

5.2 Phosphates and Nitrates:

The parameter of nutrient levels (i.e. phosphates and nitrates) is important to monitoring analysts

because it can be an indication for impending eutrophication of the catchment. This process occurs at

high concentrations (ppm) of nutrient levels. Sources of these nutrients include; sewage, urban runoff,

industrial waste (agricultural pesticides) and natural phosphates from the adjacent bedrock

(Oram, 2014).

The process of Eutrophication; is the gradual decline of stream catchment water quality as a result of

increased nutrients entering through anthropogenic and natural sources. Specifically; phosphates

(PO43-) and nitrates (NO3

2-) which cause explosions of algal growth forming thin layers on the surface

of the catchment. These algal sheets in-turn consume oxygen (respiration) during the night and lower

the overall dissolved oxygen content within the catchment, increasing the mortality of aquatic life in

the process. Hence; high levels of phosphates and nitrates should decrease the total amount of DO in

the catchment. (Oram, 2014)


5.3 Total Suspended Solids (TSS):

The parameter of Total Suspended Solids (TSS) involves any matter that cannot pass through a 2-

micron (0.002cm) filter. These particles may include various types of; silt, clay, plankton, algae, small

debris particles and other particulate matter. Common origins of suspended solids include; industrial

waste water discharge, soil erosion and sewage waste (EPA, 2012).

Previous research has shown that total suspended solids have multiple adverse effects on the

catchment particularly around agricultural areas. It has been documented that toxicants (e.g.

dangerous chemicals) can be transported by the suspended solids and degradation of the water quality

or riparian vegetation within the vicinity. High levels of suspended solids can also lower the water

clarity resulting in direct effects including; increasing water temperature and indirect effects

including; lowering dissolved oxygen due to decrease in photosynthesis (EPA, 2012).

5.4 Turbidity:

The parameter of turbidity is used in conjunction with suspended solids tests to determine the clarity

of water within a catchment (Perlman, 2015). Unlike suspended solids tests which measure the

concentration (ppm) turbidity aesthetics property of a catchment. Turbidity is typically measured

using a turbidity-meter, where light is passed through a water sample and the scattered light is

proportional to the turbidity readout measured in NTU’s (nephelometric turbidity units).

When assessing the turbidity of a catchment; a monitoring analyst must account for geological

processes (erosion), recent weather rainfall events and stream flow velocity. Hydrological processes

including velocity are known to disturb and cycle sediment within the water column. Stagnant water

may produce a green surface layer (low turbidity i.e. less than 10NTU’s) and fast flowing water may

cycle sediment (high turbidity) (Perlman, 2015).

Further research carried out at Chesapeake Bay investigated the properties of submissive riparian

vegetation (e.g. angiosperms and macrophytes). These aquatic plants provide nutrients for shellfish

and finfish as well as affecting nutrient levels, sediment stability and hence turbidity (Dennison, et al.,

1993).


5.5 Faecal Bacteria:

The quantity and species of faecal coliforms is a useful indicator of assessing sewage contamination.

There are two main species of bacteria present with in faeces of animals and humans, faecal coliforms

and faecal streptococci. Environmental Scientists can use data obtained from these groups to

determine the presence of micro-organisms and pathogens that may pose a threat to the catchment and

the surrounding environment (EPA, 2012) (Jolley & English, 2015).

Sources of faecal bacteria include; septic tanks, waste-water treatment plants, agricultural manure

produced from livestock and stormwater runoff (Jolley & English, 2015) (Ferguson, et al., 1996).

Faecal coliforms can also indicate nutrient levels and deplete the total bio-available amount of

dissolved oxygen. The EPA currently uses strands of E.coli and enterococci as benchmarks for

freshwater systems (EPA, 2012).

A research paper published on Science Direct in 1996, mentions various bacteriological testing on six

different estuaries in Sydney, Australia. The scientists discovered the relationship between rainfall

and an increase in the concentration of faecal bacteria in selected sediments (Ferguson, et al., 1996).

5.6 Ammonia:

High concentrations of ammonia can degrade water quality and due to its toxicological properties may

pose a threat to catchment welfare. Sources of ammonia include; wastewater, agricultural runoff,

fertilizer groundwater contamination and stormwater discharges. Ammonia is formed from inorganic

nitrogen by bacteria living in aerobic waters and sediments (Environmental Protection Agency, 2012).

However, the un-ionised ammonia suspended in the water column at equilibrium with ammonia and

hydroxide ions is more toxic. Le Chatelier’s Principle states that adding stress to one side of the

equilibrium will shift it in the other direction. Hence; increasing pH and Temperature results in an

increase of un-ionised ammonia (Environmental Protection Agency, 2012).


5.7 Chlorophyll - 𝜶:

The parameter of chlorophyll is an extension to the phosphates, nitrates and ammonia tests.

Environmental Scientists can model the relationship of nutrient bioavailability with chlorophyll

because the compound exists in marine phytoplankton biomass and these organisms have a high

chlorophyll to nutrient ratio (AIMS, 2014).

Chlorophyll concentrations can also be affected by rainfall, seasonal variation (summer), water

temperature and light intensity increase. High nutrient reading in a catchment may also be evident of

impending eutrophication which in extreme circumstances can lower dissolved oxygen saturation and

cause hypoxic or anoxic situations (Ozcoasts, 2015).

Research by AIMS (Australian Institute of Marine Science) through monitoring has been conducted

since 1999 for water quality assessments (AIMS, 2014).

5.8 Acid Hydrolysed Phosphates:

The parameter of Acid Hydrolysed Phosphates (AHP) is a more accurate extension to the phosphates

analytical test. Since; the Total Phosphorus (TP) available in a catchment is the sum of the dissolved

(orthophosphate), the inorganic and organic phosphates. Under normal circumstances the inorganic

phosphate is difficult to analyse using the standard method for phosphates. Hence; nitric acid, heat or

enzymes can be added to the inorganic (un-reactive) phosphates using the AHP method to separate the

phosphates from precipitate or microbes (ASA Analytics, 2015).

AHD is affected by temperature increase and pH.

Research conducted by Monsanto in 1995 determined that an increase in temperature speeds up the

overall reaction and a decrease in pH (acidify) will increase the rate of the overall reaction. Hence;

why nitric acid was added to a centrifuged phosphate mixture (AmeriWest Water Services Inc., 2013).


6.0 Methodology:

6.1 Sampling Procedure:

Table 2: Sampling Procedures for Catchment Study

Parameter:

Description:

TSS and Turbidity:

All samples and replicates were taken using 500

mL plastic bottles using an extension rod. No

filtration or special considerations were

required.

Nitrates and Phosphates:

Acid Hydrolysed Phosphates:

Ammonia (NH4)


mL plastic bottles using an extension rod.

Filtration was required but no special

considerations were required.

Total Faecal Coliforms:


mL glass bottles using an extension rod. No

filtration was required but all bottles were

wrapped in aluminium foil.

Chlorophyll 𝜶


mL plastic bottles using an extension rod. No

filtration was used but all samples were kept in

the dark during sampling.


6.2 In-Situ measuring apparatus:

To measure the In-Situ measurements across the catchment sites, an YSI

probe was used to measure the following parameters; Dissolved Oxygen,

Water Temperature, Conductivity and pH.

During sampling the probe was dunked about 10cm into the water body

and the resulting values for the above parameters were recorded in the

group logbook * (see appendix).

Table 3: Preservation and Special Considerations for Water Quality Parameters

Parameter:

Total

Volume

(mL)

Bottle

Type:

Number of

Bottles

Preservation

Method

Special

Considerations

TSS and

Turbidity

1000 mL

Plastic

6 x 1000 mL

Cold

None

Nitrates,

Phosphates,

Acid

Hydrolysed

Phosphates

250 mL

Plastic

(FP)

12 x 250 mL

Cold

Filtering

Total Coliforms

500 mL

Glass

6 x 500 mL

Cold

Dark (foil)

Chlorophyll 𝜶

1000 mL

Plastic

6 x 1000 mL

Cold

Dark (foil)


7.0 QA/QC Methods:

Field Log Book:

To insure all scientific investigating was credible, all field observations from the YSI Probe and the

current aesthetic/ physiological conditions and of the site where recorded by date and time. The Field

Log Book was updated upon each visit to the six catchment sites across a total of 10 weeks.

Calibration of the YSI Field Probe:

To insure all data received was scientifically accurate with minimal bias, the YSI Probe was

calibrated before going out into the field. When measuring DO (%) saturation concentrations the YSI

was also shaken and allowed to equilibrate for about 2 minutes.

Clean / Dirty Hands Technique – Not Used because all samples were filtered in the main lab.

Field Blanks / Controls:

To insure all lab analysis or field methodology was not erroneous, field blanks were collected at each

catchment site during the course of the water quality assessment. These blanks were treated under

identical circumstances to the main samples collected at each respective site.

QC Recovery:

QC Recovery (%) = 𝑀𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑉𝑎𝑙𝑢𝑒

𝑇𝑟𝑢𝑒 𝐶𝑜𝑛𝑐𝑒𝑛𝑡𝑟𝑎𝑡𝑖𝑜𝑛 * 100


8.0 Results:

8.1 In-Situ Results:

Figure 4: Dissolved Oxygen (% saturation) for the assessment period.

As seen in Figure 4; DO saturation (%) decreases across all catchments during the assessing period.

During the first sampling event (12/8) all the catchment sites recorded a value between than the max

and min SEQ Water Quality Guideline trigger, indicating a healthy oxygenic catchment.

During the second and third sampling events (25/8 – 16/9) there was a decrease in DO below the SEQ

Water Guideline limit for Mud 3-5, indicating dissolved oxygen saturation (%) has decreased while

during the fourth sampling event (7/10) there was an increase for sites Mud 4-6.

0

20

40

60

80

100

120

140

12-Aug 25-Aug 16-Sep 7-Oct

Dis

solv

ed O

xyge

n (

% s

atu

rati

on

)

Month

Dissolved Oxygen (% saturation)

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


As seen in Figure 5; Water Temperature (℃) showed a clear increase across all catchments during the

assessing period. Most notably, catchment site MUD 6 has the most dramatic variation. During the

first sampling event (12/8) this site was the coldest of all the sites and towards the end of the assessing

period (7/10) had warmed up and become the warmest of all the sites. The trend observed here, can be

correlated to the depth of the catchment site and the seasonal variation.

0

5

10

15

20

25


Tem

per

atu

re (

C)

Month

Water Temperature

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6

Figure 5: Water Temperature for the assessment period.


As seen in Figure 6; Conductivity (mS/cm) has shown an increase across all catchment sites during

the assessing period. Mud 5 and Mud 6 in particular, exhibited higher conductivity probably due to

the depth, proximity and access to estuarine water bodies. These results don’t differ significantly

across all sampling events (12/8 – 7/10). The graph was also logged because some of the values

recorded were outliers with extremely high conductivity values.

0

0.5

1

1.5

2

2.5

3

3.5

4


LOG

-C

on

du

ctiv

ity

(mS/

cm)

Month

LOG - Conductivity (mS/cm)

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6

Figure 6: LOG - Conductivity (mS/cm) for the assessment period


Figure 7: pH scale readings for the assessing period

As seen in Figure 7; pH scale has shown minimal variation activity across all catchment sites during

the assessing period with the exception of Mud 1. Sampling event (16/9) for Mud 1 is the most

interesting; during this period, the pH value was almost 9 which is considered slightly alkaline for a

catchment site and above the SEQ Water Quality trigger value but since this phenomenon is non-

recurring during the remaining weeks it’s considered insignificant. Since pH of 7 is considered

neutral. Rainfall has also been documented during the assessing period and may have contributed to

the abnormal pH reading.

0

1

2

3

4

5

6

7

8

9

10


pH

(sc

ale)

Month

pH

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


8.2 Laboratory Analysis Results:

Figure 8: Turbidity (NTUs) for the assessing period

As seen in Figure 8; Turbidity has shown a significant increase across all catchments during the

assessing period in particular Mud 4. During sampling events (12/8 – 7/10) turbidity had increased for

sites Mud 3-6 while Mud 1-2 remained unchanged. However; during sampling event (7/10) there was

a dramatic increase in nearly all the catchment sites, with the exception of Mud 5-6.

These spikes during sampling event (7/10) is probably due to recent rainfall washing sediment,

agricultural runoff and urban pollutants into catchment sites Mud 1-4.

All results were below the SEQ Water Quality Guideline trigger value for 2009.

0

5

10

15

20

25


Turb

idit

y (N

TUs)

Month

Turbidity (NTUs)

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


Figure 9: TSS (mg/L) for the assessing period

As seen in Figure 9; TSS has fluctuated across all catchments during the assessing period. During

sampling event (12/8) TSS readings were just above the SEQ Water Quality Guideline trigger value

for each catchment site. Of particular interest is the obvious spike reading for sampling event (25/8)

for Mud 5, it is unknown exactly what has caused such a high reading above the SEQ Water

Guideline trigger value, however, it appears not to be the usual TSS reading for that particular

catchment site when comparing it to the next sampling event (7/10).

0

10

20

30

40

50

60


TSS

-m

g/L

Month

Total Suspended Solids (TSS)

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


As seen in Figure 10; Faecal Coliform Activity fluctuates across all catchment sites during the

assessing period. During the assessment period there appears to be an increase in CPU/100 mL for

Faecal Coliforms. Mud 2 is of particular interest, the analysis shows a CPU/100mL for approximately

800 Faecal Coliforms during sampling event (Week 5). These results can be explained because Mud 2

is closest to recreational areas and septic tanks which could have contributed to the increase of faecal

coliform activity. Rainfall has also linked to increased faecal coliform activity, since major rainfall

events occurred during sampling events (Weeks 5-10) the number of coliforms at each catchment site

has increased.

No sampling event was recorded for Week 7.

0

100

200

300

400

500

600

700

800

900

Week 3 Week 5 Week 10

CFU

/10

0 m

L

Faecal Coliform CFU/100 mL

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6

Figure 10: Bacterial Quantity (10mL) for Weeks 3-10 during the assessing period


Figure 11: NOx’s (ppb) for the assessing period

As seen in Figure 11; NOx concentrations remained steady across all catchment sites during the

assessing period with the exception of Mud 3. During sampling event (12/8 – 25/8) NOx readings

were particularly high. This could be due to the various agricultural and farm practices in the local

area considering nitrates are a component of some pesticides and herbicides. During sampling event

(12/8 – 7/10) there was also exceptionally high NOx readings for Mud 2 and Mud 3.

All measurements were below the SEQ Water Guideline trigger value.

0

10

20

30

40

50

60

70


(NO

xs)

-P

Pb

Month

Nitrous Oxides (NOXs) - Group

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


As seen in Figure 12; Ammonia has remained constants across all catchment sites during the assessing

period with the exception of Mud 4 which stretched significantly over the SEQ Water Guideline

trigger value. These high readings may be attributed to runoff from the agricultural practices further

upstream. Since the extension analysis began after the second sampling event, there are no previous

results for sampling events (12/8 – 7/10).

0

10

20

30

40

50

60

70

80

90

16-Sep 7-Oct

(NH

4)

-P

Pb

Month

Ammonia (NH4)

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6

Figure 12: Ammonia (ppb) for the assessing period


Figure 13: FRP (ppb) for the assessing period

As seen in Figure 13; FRB has dramatically increased across catchment sites during the assessing

period. During sampling event (16/9) the FRB concentration has increased significantly for Mud 5

and Mud 6 and is above the SEQ Guidelines while during sampling event (7/10) the FRB

concentration has increased significantly for Mud 1-4 and is also above the SEQ Guideline trigger

value.

0

10

20

30

40

50

60

70

80

90

100


FRP

-P

Pb

Month

Filterable Reactive Phophate (FRP)

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


Figure 14: AHP (ppb) for the assessing period

As seen in Figure 14; AHP has shown fluctuation across the catchment sites during the assessing

period. In particular, during sampling event (16/9) there was a spike in the total nitrogen released after

undergoing hydrolysis. While during sampling event (7/10) with the exceptions of Mud 6 and Mud 2

showed a significance increase in bioavailable hydrolysable phosphates. Since the extension analysis

began after the second sampling event, there are no previous results for sampling events (16/9 – 7/10).

0

10

20

30

40

50

60

70

80

16-Sep 7-Oct

AH

P -

PP

b

Month

Acid Hydrolysed Phosphates (AHP)

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


Figure 15: Chlorophyll for the assessing period

As seen in Figure 15; Chlorophyll has shown fluctuation across the catchment sites during the

assessing period. In particular, during sampling event (7/10) there was a spike in the concentration of

chlorophyll for Mud 1. A high concentration of chlorophyll as mentioned previously has been linked

to high biomass of phytoplankton.

Another observation for sampling events (16/9 – 7/10) showed that Mud 3 and Mud 4 also exhibited

reasonably high chlorophyll concentrations above the SEQ Water Guideline trigger value.

0

5

10

15

20

25

16-Sep 7-Oct

Ch

loro

ph

yll (

a) -

PP

b

Month

Chlorophyll (a) Concentration

MUD 1

MUD 2

MUD 3

MUD 4

MUD 5

MUD 6


9.0 Discussion of Analysis:

9.1 Rainfall Parameter:

The water quality assessment was run over three months from August 25th - October 7th.

The objective of this assessment was to assess the current health and establish a baseline water quality

of the overall catchment using multiple qualitative and quantitative parameters.

Over the course of the assessment, fluctuations in the data was observed on multiple parameters due

to external factors including rainfall and seasonal variation. These external factors are important to

consider, accounting for as many variables as possible lowers the uncertainty associated with the

measurement. As mentioned before, rainfall can dramatically affect multiple parameters of a

catchment by introducing new pollutants and sediments which may lead to degradation of water

quality.

9.2 In-Situ Parameter Relationships:

Dissolved Oxygen and Temperature:

As previously stated, Dissolved Oxygen (DO) is inversely correlated to temperature – hence; as the

temperature of the catchment increases the DO in that catchment should consequentially decrease

accordingly. The data collected throughout this assessment also shows this trend; during sampling

(25/8) the DO saturation was very high for all the catchment sites. Whereas; towards the end of the

experiment - seasonal variation had caused all the catchment sites to increase in water temperature

(Figure 5). Which resulted in the gradual decline of DO saturation (%) (Figure 4).


9.3 Laboratory Analysis Relationships:

FRP and Turbidity:

It was initially hypothesised that a greater concentration of TSS would directly correlate to an increase

in turbidity – this was later rejected. Instead it appeared that FRP was directly correlated to turbidity –

i.e. as the concentration of FRP increases the turbidity should increase.

The data shows collected shows this trend; during the sampling event (12/8) Mud 4 had a value of 25

ppb (Figure 13) and the turbidity for Mud 4 has a value of 7.5 NTUs. Then; towards the end of the

assessment – sampling event (7/10) Mud 4 has a value of greater than 100 ppb and higher turbidity

reading of 20 NTUs.

TSS and Rainfall:

During sampling event (12/8) TSS for Mud 5 is shown just below the SEQ Water Guideline trigger

value (Figure 9), while during sampling event (25/8) Mud 5 is shown to have a high TSS

concentration significantly different from the other sites during that sampling event (Figure 9).

It is hypothesised; that the recent rainfall washed particulate waste matter (sediment, dust or animal

faeces) into the catchment (25/8) and during a later assessment moment (16/9 – 7/10) was flushed

downstream reducing the TSS concentration to a normal level.

AHP and Chlorophyll:

During the sampling event (16/9) Chlorophyll for Mud 1 was shown to be 5ppb whereas; later during

the next sampling event (7/10) Chlorophyll for Mud 1 has increased by a factor of five yielding

approximately 25 ppb (Figure 15). As stated previously; chlorophyll can be a useful indicator for

detecting water quality because the chlorophyll pigment is stored in the tissues of phytoplankton.

Interestingly; during sampling event (16/9) AHP for Mud 1 was shown to be approximately 23ppb

and following a similar trend to chlorophyll yields an increase to 53ppb during the sampling event

(7/10). Therefore; it can be extrapolated that AHP can affect the amount of chlorophyll at each

catchment site.


9.4 Cumulative Parameter Relationships:

NOXs:

Nitrous Oxides has shown a steady decrease across the sampling periods (12/8 – 7/10). A gradual

declining trend is most likely caused by two possibilities; sources producing these NOXs have been

less frequent or riparian vegetation is collecting the Nitrates and using them as a source of nutrients.

Either way, a decrease in NOXs being distributed in the catchment improves its water quality.

AHP:

AHP has shown a steady increase across the sampling periods (12/8 – 7/10). As mentioned

previously; the total phosphorus (TP) is a combination of reactive, unreactive (Inorganic) and organic

phosphorus. Hence; with the exception of Mud 2 and Mud 6 .The total concentration of phosphorus

has increased over the sampling period.

FRB and Turbidity:

FRB has shown a sharp increase across the sampling periods (12/8 – 7/10). As mentioned previously a

relationship has been identified between these two parameters. An increase of turbidity due to higher

concentrations of phosphorus could increase the risk of pathogens and algae that may cause

eutrophication and deplete the DO % saturation available to the aquatic organisms that survive off the

catchment.

Ammonia:

NH4 has remained relatively steady during the sampling period with the exception of Mud 4 whose

ammonium concentration has been excessively high. As is indicated by the ammonia Mud 4 is

alkaline and probably does not support a great deal of aquatic biodiversity.

Chlorophyll:

Chlorophyll has shown a strong increase particularly for Mud 1 and Mud 3. All the above parameters

can affect chlorophyll. Hence; these catchment sites have high nutrient runoff loads due to farm land

and septic tanks within the area. Therefore it is a logical conclusion that sites Mud 1 and Mud 3 are

the most susceptible to contamination and degradation of water quality.


9.5 Previous Case Studies:

Griffith University - Mudgeeraba Catchment Study 2006: The objective of the assessment was to enable recommendations and sustainable

management plans for the catchment system (Robertson, et al., 2006).

Key Findings:

The ecological condition of the Mudgeeraba Creek Catchment was found to be good

based on the parameters of standard water quality assessing and riparian vegetation.

However; further downstream evidence of water quality degradation became evident

including; high concentrations of ammonia, chlorophyll – a, TSS and faecal coliforms

(Robertson, et al., 2006).

Griffith University - Water Quality Assessment for Mudgeeraba Catchment 2014:

The objective of the assessment was to determine the current water quality and establish

baseline conditions for the Mudgeeraba Catchment.

Key Findings:

High concentrations of FRP had been recorded at Mud 4 and it was established this site

exhibited primary production. High turbidity and TSS readings can also increase the

water temperature leading to the depletion of DO and ultimately anoxic catchments. The

NOS differentiation between catchments can be attributed to different land uses and

activities.

Comparisons with this assessment report:

Mudgeeraba Catchment Creek – Good Ecological Condition.

Water quality degradation became evident downstream including; high concentrations

of ammonia and medium concentrations of TSS and faecal coliforms.

High concentrations of FRP, turbidity and TSS had been recorded at Mud 4.


10.0 Conclusion:

After conducting field work and experimental lab analysis on various water quality parameters over a

course of three months (August – October) the following conclusions can be drawn about the overall

health of the Mudgeeraba Catchment:

- The catchment itself is a complex network of various ecological, biophysical and biochemical

parameters with distinct Water Guideline trigger values for each division of the catchment (i.e.

upper, middle or lower catchment). This experimental methodology incorporated the SEQ Water

Guideline trigger values for the lower-stream (2009).

- Rainfall within the catchment appears to be a driving force for its current water quality, heavy

rainfalls for example can wash sediment, pollutants and general debris into the waste water

possibly resulting in a pollution event.

- The environmental impacts of solids suspended in the water column, the total nitrogen and

phosphorous available is all cumulative. For example a catchment with higher loads of nitrogen

and phosphorous will yield more chlorophyll accumulated with the biomass of marine surface

phytoplankton causing secondary impacts including eutrophication. It was evident that over the

duration of the catchment assessment and analysis sites Mud 1, Mud 2 and Mud 3 showed high

loads of nutrients due to natural processes (erosion and sedimentation) and anthropogenic

activities including agricultural and sewage treatment processes.

- The parameter assessing ammonia concentration also proved quite interesting; Mud 4 was shown

to be a highly inhospitable environment for minimal biodiversity. Due to its toxicological

properties Mud 4 is considered to be officially the most polluted and affected area of the entire

scoped catchment system.

- To summarise sites Mud 2, Mud 3 and especially Mud 4 should be continually monitored and

assessed for changes in water quality. These three locations along the catchment resulted in

breeches of the SEQ Water Quality Guideline trigger values however; further studies are required

for more accurate data on the Mudgeeraba Catchment system.


11.0 References

Australian Government Department of Environment, 2015. National Water Quality Managment

Strategy. [Online]

Available at: http://www.environment.gov.au/water/quality/national-water-quality-management-

strategy

AIMS, 2014. [Online]

Available at: http://www.aims.gov.au/docs/research/water-quality/monitoring/chlorophyll-

monitoring.html

Allaby, M. & Park, C., 2013. A Dictionary of Environment and Conservation. s.l.:Oxford University

Press.

AmeriWest Water Services Inc., 2013. Polyphosphates Stability?. [Online]

Available at: http://www.ameriwestwater.com/faq/polyphosphates-stability

ASA Analytics, 2015. Phosphorus Analysis Classifications. [Online]

Available at: http://www.asaanalytics.com/total-phosphorous.php

Carserud, L., 1983. Dissolved and Suspended Heavy Metals in Stream Water. Ecological Bulletins, pp.

73-84.

CIty of Gold Coast, 2006. Mudgeeraba Creek, Clear Island Waters & Robina Lakes Catchment

Stormwater Management Plan. [Online]

Available at: http://www.goldcoast.qld.gov.au/environment/mudgeeraba-creek-clear-island-waters-

robina-lakes-catchment-stormwater-management-plan-3945.html

Dennison, W. C. et al., 1993. Assessing Water Quality with Submersed Aquatic Vegetation.

Bioscience, pp. 86-94.

Department of Ecology State of Washington, 2015. Water Quality Improvement Project Wenatchee

River Area: Dissolved Oxygen & pH. [Online]

Available at: http://www.ecy.wa.gov/programs/wq/tmdl/WenatcheeMulti/DOpH.html

[Accessed 10 2015].

Environmental Protection Agency, 2012. Ammonia Toxicity. [Online]

Available at: http://water.epa.gov/type/watersheds/archives/chap3.cfm

EPA, 2012. 5.11 Fecal Bacteria. [Online]

Available at: http://water.epa.gov/type/rsl/monitoring/vms511.cfm

EPA, 2012. What are total solids and why are they important?. [Online]


Ferguson, C. M., Coote, B. G., Ashbolt, N. J. & Stevenson, L. M., 1996. Relationships between

indicators, pathogens and water quality in an estuarine system. Water Research, pp. 2045-2054.

Jenne, E. A., 1997. Trace element sorption by sediments and soils - soils and processes..

Jolley, L. W. & English, W. R., 2015. What is Fecal Coliform? Why is it Important?. [Online]

Available at:

http://www.clemson.edu/extension/natural_resources/water/publications/fecal_coliform.html


Krauskopf, K. B., 1956. Factors controlling the concentration of thirteen rare metals in sea-water.

NSW Government Local Land Services, n.d. Water quality. [Online]

Available at: http://www.lls.nsw.gov.au/land-and-water/water/quality

NSW Government Office of Environment & Heritage, 2014. Water Quality. [Online]

Available at: http://www.environment.nsw.gov.au/water/waterqual.htm

Oram, P. G. (. M. B., 2014. Phosphates in the Environment. [Online]

Available at: http://www.water-research.net/index.php/phosphates

Ozcoasts, 2015. Chlorophyll a concentrations. [Online]

Available at: http://www.ozcoasts.gov.au/indicators/chlorophyll_a.jsp

Perlman, H., 2015. pH -- Water properties. [Online]

Available at: http://water.usgs.gov/edu/ph.html

Perlman, H., 2015. Turbidity. [Online]

Available at: http://water.usgs.gov/edu/turbidity.html

Portanger, C., Schmidt, L., Giddy, J. & Dawood, J., 2014. Water Quality Assessment and Investigation

for Mudgeeraba Catchment, s.l.: s.n.

Queensland Government, 2009. Queensland Water Quality Guidelines , Gold Coast: Queensland

Government.

Robertson, A. et al., 2006. Mudgeeraba & Worongary Creek Catchment Management Study, Gold

Coast: Griffith University.

United States Environmental Protection Agency, 2012. Water: Monitoring & Assessment. [Online]


United States Environmental Protection Agency, 2012. What is conductivity and why is it important?.

[Online]



Appendix:

Sampling Sites:

Mudgeeraba Sampling Site 1 – Informally; Mud 1.

Mountainous:

Upstream; where the catchment flows through Austin-Ville, the catchment appears relatively

intact. Although a causeway is present alongside the river, anthropogenic disturbances are

minimal.

There is evidence of dense canopy riparian vegetation along the alluvial flats, no significant

foreign objects in catchment, and no signs of eutrophication or pollution.

Mudgeeraba 1:



Mountainous - Recreational:

Upstream; where the catchment flows through Austin-Ville, the catchment appears relatively

intact. Although a causeway is present alongside the river, anthropogenic disturbances are

minimal.

There is evidence of dense canopy riparian vegetation along the alluvial flats, no significant

foreign objects in catchment, and no signs of eutrophication or pollution.

Mudgeeraba 2:



Agricultural:

Midstream; further down the catchment, consequences of urbanisation become significant.

Agricultural practices and septic waste disposal are present. The water is quite stagnant and

there’s evidence of biofilm on the water surface (i.e. possible signs of eutrophication). It is

hypothesised that the concentration of phosphates and nitrates may higher in Mud 3.

Anthropogenic disturbance is high.

Riparian vegetation along the catchment has been fragmented due to residential infrastructure.

Mudgeeraba 3:



Semi-Suburban:

Midstream; further down the catchment, adjacent to Firth Park (Mudgeeraba)

urbanisation has become significant. Effluent waste from further upstream

has polluted the catchment. The water also appears quite stagnant and the

colour is dark brown (possibly due to erosion and sedimentation).


Riparian mid-story and canopy riparian vegetation along the catchment has

been fragmented due to man-made parks, skate-parks and recreational sport

infrastructure,

Mudgeeraba 4:



Suburban:

Downstream; further down the catchment, at Robina urbanisation is significant. The

natural catchment no longer exists and had been replaced with an artificial creek. The

region is predominantly intended for residential and commercial purposes.


Any riparian vegetation from the original catchment is non-existent and animals that

benefit from a suburban lifestyle including; ibis’, crows, magpies and swans are more

common.

Mudgeeraba 5:



Suburban:

Downstream; further down the catchment, at Clear Island Waters (Robina)

urbanisation is significant. The artificial catchment appears to contain a greater

density of canopy riparian vegetation along the river.

On the opposite side of the bridge, there is evidence of housing infrastructure

indicating residential development. Anthropogenic disturbance is high. There

may also be pollution present in the catchment.

Mudgeeraba 6:


SEQ Water Quality Guideline Trigger Values:

Documents

Water Quality Monitoring Assessment - Mudgeeraba Catchment - August 2013