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HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW

Page i 301020-03413 : 210 FINAL DRAFT: October 2013

Water Quality Study

Burwood Beach WWTW

301020-03413 – 210

October 2013

Infrastructure & Environment 3 Warabrook Boulevard Newcastle, NSW 2304 Australia PO Box 814 NEWCASTLE NSW 2300 Telephone: +61 2 4985 0000 Facsimile: +61 2 4985 0099 www.worleyparsons.com ABN 61 001 279 812

© Copyright 2013 WorleyParsons

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW

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SYNOPSIS

The Burwood Beach Water Quality Study was undertaken to characterise the extent of impacts on the

receiving environment from effluent and waste activated sludge (biosolids) discharges and to define

the near, mid and farfield impacts of the effluent and biosolids plume. The primary objectives of the

water quality monitoring study were to:

Measure physicochemistry parameters and concentrations of nutrients, chlorophyll a and faecal

indicators in the receiving environment, at a range of distances from the outfall, to assess the

gradient of potential impact;

Compare data with relevant guidelines to identify compliance (where applicable). This includes

the Australian and New Zealand Environment and Conservation Council (ANZECC)

Guidelines for Fresh and Marine Water Quality (2000), the New South Wales Environmental

Protection Authority (NSW EPA) Marine Water Quality Guidelines (2000) and the National

Health and Medical Research Council (NHMRC) Guidelines for Managing Risks in

Recreational Waters (2008); and

Measure the footprint of impact on the receiving environment.

Water sampling was undertaken at 32 sites, which were selected in a regularly spaced radial

arrangement around the outfall diffusers (at distances of 0 m, 30 m, 100 m, 250 m, 500 m and 2 km).

The location of sampling sites took into account the locations of the effluent and biosolids outfalls,

prevailing hydrodynamic conditions in the area and plume characteristics. For some summaries, the

distances were also divided into three zones which included the outfall zone (0 and 30 m), the mixing

zone (100, 250 and 500 m) and the reference zone (2 km).

A suite of parameters, including physiochemical, nutrients, chlorophyll a and faecal indicators, were

measured at each site (Table 1). Measurements of physicochemistry and chemistry sampling were

undertaken at two depths (surface and mid-water). A total of 64 water column samples were collected

during each sampling event to test for nutrients, chlorophyll a and faecal indicators (i.e. 32 sites x 2

depths).

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Table 1 Analytical parameters showing their respective LOR and guideline values.

Analytical Parameter Limit of Reporting

(LOR)

Guideline Guideline reference

In-situ physico-chemical

Secchi-disc depth 0.5 m 1.6 m NSW EPA (2000); ANZECC (2000)

Turbidity 0.1 NTU 6 NTU ANZECC (2000)

Temperature 0.01 °C 15-35 °C NSW EPA (2000)

Electrical Conductivity 0.01 mS/cm None defined

Salinity 0.01 ppt None defined

Dissolved Oxygen mg/L None defined (in mg/L) 6

pH 0.1 8 - 8.4 ANZECC (2000)

Nutrients

Organic Nitrogen as N 5 0.01 mg/L None defined

Ammonia as N 0.005 mg/L 0.02 mg/L

0.5 mg/L7

ANZECC (2000)

ANZECC (2000)

Nitrite + Nitrate (NOx) 0.002 mg/L 0.025 mg/L ANZECC (2000)

Dissolved Inorganic Nitrogen (NH3 + NOx)

3 0.005 mg/L None defined

Total Nitrogen as N 4, 5

0.01 mg/L 0.12 mg/L

NSW EPA (2000); ANZECC (2000)

Total Phosphorus as P 0.005 mg/L 0.025 mg/L NSW EPA (2000); ANZECC (2000)

Chlorophyll a 1 0.5 mg/m

3 (i.e. 0.5

µg/L) 1 mg/m

3 ANZECC (2000)

Thermotolerant Faecal Coliforms 2, 9

1 CFU/100 mL 50% of values ≤150 CFU/100 mL

ANZECC (2000)

Enterococci 2, 8

1 CFU/100 mL 95th percentile of values ≤40 CFU/100 mL

NHMRC (2008)

1 Note that an LOR of 1 mg/m

3 was used for chlorophyll a for the first two sampling events, as per the original agreement

between WorleyParsons, the analytical laboratory and Hunter Water. This LOR was subsequently changed to 0.5 mg/m3.

2 Note that for turbid water samples the analytical laboratory advised that the LOR for microbial samples may need to increase

to 2 CFU / 100 ml. This would be based on visual inspection at the laboratory and cannot be based on any predetermined turbidity value.

3 Dissolved parameters (i.e. dissolved inorganic nitrogen) required field filtering.

4 Note that total nitrogen is calculated by the laboratory as a separate analysis and is not determined by calculation (i.e. may

not always equal the sum of nitrogen components as provided in the data).

5 Note that an LOR of 0.05 mg/L

was used for organic nitrogen and total nitrogen for the first two sampling events, this LOR was

subsequently changed to 0.01 mg/L in later sampling rounds.

6 ANZECC Guideline for dissolved oxygen is 90 to 110 % saturation; however dissolved oxygen was measured in mg/L in this

study.

7 Note this refers to ANZECC (2000) default trigger value for ammonia for 99% level of protection of species in marine waters.

8 Note that ANZECC refers to NHMRC 2008 “Guidelines for Managing Risks in Recreational Waters”. These NHMRC Guidelines recommend a 95 % enterococci limit of < 40 cfu/100 mL as this value is below the NOAEL in most epidemiological studies and the AFRI would be negligible.

9 Note that Faecal coliforms are considered by the NHMRC as an unsuitable regulatory parameter but still form part of NSW Water Quality Guidelines with the limit being 50 % < 150 cfu/100 mL.

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Overall ammonia, total nitrogen, chlorophyll a, enterococci and faecal coliforms and to a more limited

extent, total phosphorus, had patterns of decreasing concentrations with distance from the outfall,

suggesting that the Burwood Beach WWTW outfalls are the main source of these components in the

receiving environment. Conversely, in some sampling events, levels of total nitrogen, nitrites +

nitrates and occasionally chlorophyll a were elevated at similar levels across all sites, including outfall,

mixing zone and reference sites.

A trigger index was created which provides a single value to represent the frequency and magnitude

of various parameters that exceeded the respective water quality guideline (i.e. ANZECC 2000; EPA

2000 or NMHRC 2008) across site and depth. The application of the trigger index shows the

frequency and magnitude that the results exceeded the water quality guidelines. In particular,

ammonia, total phosphorus, enterococci and faecal coliforms exceeded the guidelines around the

outfall and then mixing zone with a higher magnitude and frequency in comparison to the reference

sites.

Multivariate analysis suggests that the main factor that influenced the multivariate water quality profile

(which consisted of the results of the nutrients, chlorophyll a and faecal indicators) was sampling time.

Multidimensional scaling (MDS) plots show that samples taken within the same day or within the

same sampling event are the most similar. This shows that temporal variability is the largest cause

of variability in the water quality dataset, which is not surprising or uncommon in marine water quality

programs. In a Permanova analysis, distance based linear modelling (DISTLM), sample time was

found to be a statistically significant predictor of water quality (p value < 0.001) accounting for 61% of

the variation in the multivariate results. The influence of daily variation was eliminated by holding the

factor of daily variation constant in a sequential analysis. The factor of distance from the outfall was

then found to be significant factor (p = 0.001, R2 = 6.5%). This result shows, that despite the day to

day variability, distance from the outfall is a significant predictor of water quality. This shows that

while sample date is the largest contributor to variability in the water quality multivariate profile,

distance from the outfall is still a significant factor which can be detected despite temporal variability.

Other factors that were examined but did not explain the variability in water quality results included

sampling event, season, sampling year, direction from the outfall, depth at site and rainfall in the

preceding days.

The median and 95th percentile water quality results for key parameters are outlined in Table 2.

Overall, the results of the Burwood Beach Water Quality Study suggest that the Burwood Beach

outfall is having an effect on local water quality at distances of at least 500 m from the diffusers.

There is a clear pattern of decreasing concentrations, with higher results in the outfall and mixing

zones in comparison to the reference zone, for the parameters of ammonia, organic nitrogen,

inorganic nitrogen, total nitrogen, total phosphorus, enterococci and faecal coliforms.

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Table 2: Summary of median and 95th percentile data by zone

Parameter

Median Level 95th percentile Guideline

Value

outfall mixing zone reference outfall mixing zone reference

Turbidity (NTU) 2.60 2.40 1.45 12.80 7.16 9.79 61

Temperature (oC) 18.44 18.95 20.63 22.90 22.90 23.10 15- 35

2

Conductivity 5.50 5.50 5.50 5.67 5.67 5.68 -

Dissolved oxygen 7.49 7.40 7.25 9.62 9.69 9.82 -

pH 8.32 8.28 8.27 8.45 8.45 8.39 8- 8.41

Ammonia as N (mg/L) 0.017 0.003 0.003 0.093 0.060 0.021 11

Organic Nitrogen as N (mg/L) 0.115 0.080 0.080 0.230 0.200 0.282 -

Nitrite + Nitrate as N (mg/L) 0.005 0.003 0.003 0.087 0.079 0.073 0.0251

Inorganic Nitrogen as N (mg/L) 0.031 0.012 0.006 0.127 0.079 0.060 -

Total Nitrogen as N (mg/L) 0.160 0.100 0.100 0.340 0.220 0.353 0.111,2

Total Phosphorus as P (mg/L) 0.013 0.009 0.008 0.033 0.020 0.017 0.0251,2

Chlorophyll a (mg/m3) 0.50 0.50 0.25 2.00 1.75 0.80 1

Faecal Coliforms (CFU/100ml) 125.00 6.00 0.50 757.00 202.50 54.60

50% of values < 150

1

Enterococci (CFU/100ml) 26.50 4.00 1.00 180.00 108.00 16.90 95th percentile

< 40 3

1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

Based upon the findings of this study, future increases in effluent and biosolids discharges from the

Burwood Beach WWTW is likely to result in continued impacts to water quality, especially for nutrients

and faecal indicators. This would be dependent on a number of factors including the rate of

discharge, concentrations in the effluent and the dilution in the receiving environment.

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Disclaimer

This report has been prepared on behalf of and for the exclusive use of Hunter Water, and is

subject to and issued in accordance with the agreement between Hunter Water and

WorleyParsons. WorleyParsons accepts no liability or responsibility whatsoever for it in respect of

any use of or reliance upon this report by any third party.

Copying this report without the permission of Hunter Water or WorleyParsons is not permitted.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW

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Internal and Client Review Record

PROJECT 301020-03413 – BURWOOD BEACH WATER QUALITY STUDY

REV DESCRIPTION ORIG REVIEW WORLEY-

PARSONS APPROVAL

DATE CLIENT APPROVAL

DATE

A Draft issued for internal review

J Pallot

Dr K Newton

29 Jan 2012 N/A

B Draft issued for internal review

Dr K Newton

S Codi King

4 Feb 2012

C Draft issued for client review

Dr K Newton / J Pallot

Hunter Water / CEE

14 Feb 2012

D Draft issued for internal review

J Pallot

Dr M Holloway / Dr K Newton

5 Sept 2012

E Draft issued for internal review

J Pallot / Dr K Newton

S Codi King 5 Sept 2012

F Draft 2 issued for client review

Dr K Newton Hunter Water / CEE

6 Sept 2012

G Draft issued for internal review

J Pallot Dr K Newton 30 Oct 2012

H Draft 3 issued for client review

Dr K Newton Hunter Water / CEE

31 Oct 2012

I Draft 4 issued for internal

J Pallot / Dr K Newton

Dr K Newton / S Codi King

15 May 2013

J Draft 4 issued for internal review

J Pallot / Dr M Priestley/ Dr K Newton

S Codi King 30 May 2013

K Final draft issued to client

Dr K Newton / Dr M Priestley

Hunter Water / CEE

October 2013

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CONTENTS

1 INTRODUCTION ................................................................................................................ 1

1.1 Burwood Beach WWTW ..................................................................................................... 1

1.1.1 Treatment Process ................................................................................................. 1

1.1.2 Environmental Protection Licence Conditions ....................................................... 1

1.1.3 Characteristics of Current Effluent and Biosolids Discharges ............................... 4

1.1.4 Effluent and Biosolids Flow Data ......................................................................... 12

1.1.5 Dilution Modeling / Dispersion Characteristics .................................................... 13

1.2 Burwood Beach Marine Environmental Assessment Program ......................................... 14

1.2.1 Initial Consultation ................................................................................................ 14

1.3 Study Area ........................................................................................................................ 15

1.4 Scope of Work / Study Objectives .................................................................................... 15

1.4.1 Null Hypothesis .................................................................................................... 15

1.5 Review of Previous Studies .............................................................................................. 16

1.5.1 Burwood Beach WWTW Water Quality Studies .................................................. 16

2 METHODS ........................................................................................................................ 17

2.1 Sampling Sites .................................................................................................................. 17

2.2 Temporal Assessment ...................................................................................................... 21

2.2.1 Rainfall Prior to Sampling .................................................................................... 21

2.3 Sampling Methods ............................................................................................................ 26

2.3.1 In-situ Physicochemical Water Quality Measurements........................................ 26

2.3.2 Water Quality Sampling ....................................................................................... 26

2.4 Quality Assurance / Quality Control .................................................................................. 29

2.5 Data Management ............................................................................................................ 29

2.6 Data Analysis .................................................................................................................... 30

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2.6.1 Summary Statistics .............................................................................................. 30

2.6.2 Comparison to Water Quality Guidelines ............................................................. 30

2.6.3 Trigger Index ........................................................................................................ 31

2.6.4 Multivariate Analysis ............................................................................................ 32

3 RESULTS ......................................................................................................................... 34

3.1 Data Summaries ............................................................................................................... 34

3.1.1 Sampling Event .................................................................................................... 34

3.1.2 Zone ..................................................................................................................... 43

3.2 Physicochemical Parameters ........................................................................................... 45

3.3 Nutrients, chlorophyll a and faecal indicators ................................................................... 52

3.3.1 Nitrogen Forms .................................................................................................... 52

3.3.2 Total Phosphorus ................................................................................................. 58

3.3.3 Chlorophyll a ........................................................................................................ 59

3.3.4 Faecal Indicators .................................................................................................. 60

3.3.5 Summary of Signature Parameters by Zone ....................................................... 62

3.4 Comparison of Results to Water Quality Guidelines ........................................................ 63

3.4.1 Summary .............................................................................................................. 63

3.4.2 Trigger Index ........................................................................................................ 68

3.5 Multivariate Data Analysis ................................................................................................ 77

3.5.1 Multidimensional Scaling ..................................................................................... 77

3.5.2 Multivariate Multiple Regression (DISTLM) ......................................................... 81

4 DISCUSSION .................................................................................................................... 86

4.1 Water Quality Study .......................................................................................................... 86

4.1.1 Physicochemistry and Qualitative Parameters .................................................... 86

4.1.2 Nutrients, Chlorophyll a and Faecal Indicators .................................................... 87

4.1.3 Analysis of Water Quality Data (nutrients, chlorophyll a and faecal indicators) .. 89

4.2 Patterns between Water Quality Results and Effluent and Biosolids Composition .......... 91

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5 CONCLUSIONS ................................................................................................................ 93

6 ACKNOWLEDGEMENTS ................................................................................................. 95

7 REFERENCES ................................................................................................................. 96

Appendices

APPENDIX 1 – COC FORMS FOR WATER QUALITY ANALYSIS

APPENDIX 2- RAW WATER QUALITY DATA

APPENDIX 3- CEE ANALYSIS OF WATER QUALITY DATA BY ZONE

Figures

Figure 1.1 Location of Burwood Beach WWTW.

Figure 1.2 Burwood Beach WWTW and outfall alignment.

Figure 1.3 Burwood Beach flow data for the study period (July 2011 - May 2013).

Figure 2.1 Water quality sampling sites.

Figure 2.2 Water quality sampling sites close to the Burwood Beach diffusers.

Figure 2.3 Rainfall data for the sampling month.

Figure 2.4 Water sampling equipment.

Figure 3.1 Secchi disc depth.

Figure 3.2 Turbidity.

Figure 3.3 Temperature.

Figure 3.4 Conductivity.

Figure 3.5 Dissolved oxygen.

Figure 3.6 pH.

Figure 3.7 Ammonia as N.

Figure 3.8 Organic Nitrogen as N.

Figure 3.9 Nitrite + Nitrate as N.

Figure 3.10 Inorganic Nitrogen as N

Figure 3.11 Total Nitrogen as N.

Figure 3.12 Total Phosphorus as P.

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Figure 3.13 Chlorophyll a.

Figure 3.14 Enterococci.

Figure 3.15 Faecal coliforms.

Figure 3.16 Trigger index values for all parameters by distance from the outfall.

Figure 3.17 Trigger index values for ammonia by distance from the outfall for each sampling event.

Figure 3.18 Trigger index values for nitrites + nitrates by distance from the outfall for each sampling

event.

Figure 3.19 Trigger index values for total nitrogen by distance from the outfall for each sampling

event.

Figure 3.20 Trigger index values for total phosphorus by distance from the outfall for each sampling

event.

Figure 3.21 Trigger index values for chlorophyll a by distance from the outfall for each sampling event.

Figure 3.22 Trigger index values for enterococci by distance from the outfall for each sampling event.

Figure 3.23 Trigger index values for faecal coliforms by distance from the outfall for each sampling

event.

Figure 3.24 MDS plot of multivariate water quality response data similarity matrix created using the

Gower metric. Symbols are plotted by sample date.

Figure 3.25 MDS plot of the multivariate water quality response data similarity matrix created using

the Gower metric. Samples are plotted by sampling event.

Figure 3.26 MDS plot of the multivariate water quality similarity matrix created using the Gower

metric. Samples are plotted by season with influential variables plotted as a vector overlay.


metric. Samples are plotted by sampling year.


metric. Samples are plotted by distance from the outfall in meters.


metric. Samples are plotted by direction from the outfall.

Figure 3.30 Distance based redundancy analysis plot of the fitted multivariate regression model.

Samples collected in the same sampling year are categorised by coloured symbols.


Samples collected in the same season are categorised by coloured symbols.

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Samples collected in the same sampling event are categorised by coloured symbols.


Samples collected on each day are categorised by coloured symbols.

Figure 3.34 Distance based redundancy analysis (dbRDA) plot of the fitted multivariate regression

model. Samples collected at each sampling distance from the outfall (in meters) are categorised by

coloured symbols.

Figure 4.1 Fortnightly testing of effluent characteristics during the Burwood Beach Water Quality

Study. Red days indicate the effluent or biosolids sampling dates that coincide (within the week prior

to) the closest to the water quality sampling. In effluent, a= ammonium nitrate, b= total nitrogen, c=

nitrates + nitrites, d= total nitrogen, e= total phosphorus and in biosolids, f= ammonium nitrate.

Tables

Table 1.1 Load limits for effluent and biosolids discharges

Table 1.2 Summary of physicochemical, nutrients, metal/metalloid and organics data in effluent

collected by Hunter Water during 2006 - 2013.

Table 1.3 Summary of physicochemical, nutrients, metal/metalloid and organics data in biosolids

collected by Hunter Water during 2006 - 2013.

Table 1.4 Rainfall, effluent and WAS flow data for the study period (July 2011 - May 2013

Table 1.5 Classification of zones based on prior effluent dilution modelling.

Table 2.1 Location of sampling sites including distance and direction from the diffuser.

Table 2.2 Conditions for each water quality survey.

Table 2.3 Analytical parameters showing their respective LOR and guideline values.

Table 3.1 Summary of physicochemistry, nutrients, faecal indicators and chlorophyll a measured in

July 2011, data pooled across sites.


October 2011, data pooled across sites.


February 2012, data pooled across sites.


April 2012, data pooled across sites.

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June 2012, data pooled across sites.


October 2012, data pooled across sites.


February 2013, data pooled across sites.


April 2013, data pooled across sites.

Table 3.9 Summary of median and 95th percentile data by zone

Table 3.10 Number and percentage of samples that exceeded the associated water quality guideline

Table 3.11 Results of the multivariate multiple regression analysis (DISTLM) applied to the water

quality similarity matrix.

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1 INTRODUCTION

1.1 Burwood Beach WWTW

The Burwood Beach Wastewater Treatment Works (WWTW) is located on the central coast region of

NSW approximately 2.5 km south of the city of Newcastle (Figure 1.1). The plant treats wastewater

from Newcastle and the surrounding suburbs, servicing approximately 185,000 people and local

industry. Average dry weather flow is 44 million litres of wastewater (44 ML/d). Over the next 30

years, these flows are expected to increase to 55 - 60 ML/d, even with water conservation measures

in place.

1.1.1 Treatment Process

The secondary treatment process at Burwood Beach consists of physical screening to remove large

and fine particulates, biological filtration and activated sludge processing including aeration and

settling stages. Secondary treated effluent from Burwood Beach WWTW is discharged to the ocean

through a multi-port diffuser which extends 1,500 m offshore, with diffusers at a depth of

approximately 22 m (Figure 1.2). Approximately 2 ML/d of waste activated sludge (biosolids), which

is surplus to treatment requirements, is also discharged to the ocean via a separate multi-port diffuser

that extends slightly further offshore than the effluent outfall. Both the effluent and biosolids outfalls

have been operating in their current configuration since January 1994.

1.1.2 Environmental Protection Licence Conditions

The Environment Protection Licence (EPL) for Burwood Beach WWTW specifies limit conditions for

the operation of the plant. These conditions provide an indication of the characteristics of the effluent

and biosolids discharged into the ocean. Condition L1 specifies that the operation of the outfall must

not cause or permit waters to be polluted (i.e. the licensee must comply with section 120 of the

Protection of the Environment Operations Act 1997). Condition L2 specifies limits relating to total

loads discharged to the ocean (including both the effluent and biosolids). These limits are provided in

Table 1.1. Condition 3 specifies limits to concentrations of suspended solids and oil / grease in the

effluent discharged to the outfall. The three day geometric mean concentration limit for suspended

solids is 60 mg/L and for oil / grease is 15 mg/L. Condition 4 sets volume and mass limits of effluent

and biosolids discharged via the outfalls. The limit for effluent flow rate is 510 ML/d (to allow for

higher flows in wet weather) and for biosolids the flow limit is 5 ML/d. Daily monitoring of flow is

required.

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Figure 1.1 Location of Burwood Beach WWTW.

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Figure 1.2 Burwood Beach WWTW and outfall alignment.

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Table 1.1 Load limits for effluent and biosolids discharges

Parameter Load Limits

kg/year kg/day

Total suspended solids 4,717,189 12,924

Biochemical oxygen demand - -

Total nitrogen 778,257 2,132

Oil and grease 341,290 935

Total phosphorus - -

Zinc 3,943 11

Copper 2,080 5.7

Lead 1,472 4.0

Chromium 224 0.61

Cadmium 124 0.34

Selenium 14 0.038

Mercury 9 0.025

Pesticides and PCBs 7 0.019

1.1.3 Characteristics of Current Effluent and Biosolids Discharges

The final treated effluent and biosolids from Burwood Beach WWTW has been monitored by Hunter

Water for physicochemical parameters, nutrients, and a suite of metals/metalloids and organic

chemicals. A summary of these data collected during the period 2006 - 2013 is provided in Tables

1.2 (effluent) and 1.3 (biosolids) (data courtesy of Hunter Water 2013).

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Table 1.2 Summary of physicochemical, nutrients, metal/metalloid and organics data in effluent collected by Hunter Water during 2006 - 2013.

Group Parameter (units) Period N Median Mean Min Max Std

Error 75%ile 90%ile

Physicochemical Suspended solids (mg/L) 2006-13 449 27 33.6 <1 390 1.6 40 60

UV254nm Transmittance (%T) 2006-13 6 59.2 58.4 43.6 68.31 3.4 62.475 65.705

pH 2006-13 224 7.6 7.6 7 8 0.01 7.7 7.8

Total dissolved solids (mg/L) 2006-13 56 440 448.5 276 734 12.9 487.5 545

Biological Oxygen Demand - total (mg/L) 2006-13 239 23 27.4 <2 144 1.3 36 50

Chemical Oxygen Demand - Flocculated (mg/L) 2006-13 19 42 41.8 32 55 1.6 46 51.4

Grease - total high range (mg/l) 2006-13 3 <5 4.7 <5 10 2.7 6 8.4

Grease - total low range (mg/l) 2006-13 444 <2 2.7 <2 60 0.2 3 5

Ammonium nitrogen (mg/L) 2006-13 70 23.0 21.7 1 33.1 0.8 26.8 29.4

Nitrate + nitrate oxygen (mg/L) 2006-13 236 1.0 1.6 <0.05 14 0.1 2.1 3.7

Total Kjeldahl Nitrogen (mg/L) 2006-13 236 26.9 26.1 2.2 48.7 0.6 33.0 36.9

Total nitrogen (mg/L) 2006-13 236 28.7 27.6 2.45 48.7 0.6 33.6 37.7

Total phosphorus (mg/L) 2006-13 236 2.3 2.64 0.09 8.2 0.11 3.625 4.8

Metals / Metalloids

Silver-Ag-AAS furnace (µg/L) 2006-13 31 1 3.1 <1 18 0.9 2.5 13

Silver Ag-ICP (µg/L) 2006-13 59 0.5 0.7 <1 7 0.1 0.5 1

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Error 75%ile 90%ile

Arsenic As-vga (µg/L) 2006-13 90 1.7 1.8 0.05 3.9 0.1 2.1 2.51

Cadmium Cd-furnace (µg/L) 2006-13 5 <1 <1 <1 <1 - <1 <1

Cadmium Cd-ICP (µg/L) 2006-13 59 <1 0.5 <1 1 <1 <1 <1

Chromium Cr-furnace (µg/L) 2006-13 31 1 1.9 <1 28 0.9 1.2 2

Chromium Cr- ICP (µg/L) 2006-13 59 <1 0.7 <1 2 0.1 0.75 1

Chromium Cr VI-furnace (µg/L) 2006-13 90 <1 0.7 <1 1 - 1 1

Copper Cu-furnace (µg/L) 2006-13 31 17 21.2 4 115 3.5 21 34

Copper Cu-ICP (µg/L) 2006-13 93 0.25 0.4 0.04 1.7 - 0.47 0.728

Mercury Hg-VGA (µg/L) 2006-13 90 <0.1 0.1 <0.1 1.6 - <0.1 0.2

Manganese Mn-furnace (µg/L) 2006-13 31 70 76.0 31 173 6.6 82 105

Manganese-ICP (µg/L) 2006-13 59 61 63.8 27 119 2.0 67.5 80.2

Nickel Ni-furnace (µg/L) 2006-13 90 <1 <1 <1 <1 - <1 <1

Nickel Ni-ICP (µg/L) 2006-13 59 4 5.3 <1 20 0.6 5.5 13.2

Lead Pb-furnace (µg/L) 2006-13 90 3 3.1 <1 17 0.3 4 5

Selenium Se-VGA (µg/L) 2006-13 90 0.1 0.3 <0.1 2 - 0.4 0.6

Zinc Zn (µg/L) 2006-13 31 50 49.4 10 120 4.3 55 70

Zinc Zn-ICP (µg/L) 2006-13 59 24 31.2 4 164 3.2 35 55.8

Organics Aldrin (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 - <0.01 <0.01

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Error 75%ile 90%ile

α-BHC Bhc-a (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 - <0.01 <0.01

β-BHC-b (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 - <0.01 <0.01

α Chlordane (µg/L) 2006-13 90 <0.01 0.000 <0.02 0.003 - <0.01 <0.01

Chlordane (µg/L) 2006-13 90 <0.01 0.001 <0.02 0.020 - <0.01 <0.01

λ Chlordane (µg/L) 2006-13 11 <0.01 0.000 <0.02 0.001 - <0.01 <0.01

Chlorpyrifos (µg/L) 2006-13 90 <0.01 0.007 <0.05 0.629 0.007 <0.01 <0.01

Lindane (µg/L) 2006-13 90 <0.01 0.000 <0.01 0.005 - <0.01 <0.01

DDT (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 - <0.01 <0.01

DDD (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 - <0.01 <0.01

DDE (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 - <0.01 <0.01

Diazinon (µg/L) 2006-13 90 <0.01 0.000 <0.1 0.030 - <0.01 <0.01

Dieldrin (µg/L) 2006-13 90 <0.01 0.000 <0.01 0.012 - <0.01 <0.01

Endosulfan (µg/L) 2006-13 0 <0.01

Endosulfan-s (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Endosulfan-1 (µg/L) 2006-13 0 <0.01

Endosulfan-2 (µg/L) 2006-13 0 <0.01

Endrin (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Heptachlor (µg/L) 2006-13 90 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

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Error 75%ile 90%ile

HCB (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Heptachlor-epoxide (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Methoxychlor (µg/L) 2006-13 90 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Parathion (µg/L) 2006-13 90 <0.1 0.000 <0.1 0.010 0.000 <0.1 <0.1

Total PCBs (µg/L) 2006-13 90 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1

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Table 1.3 Summary of physicochemical, nutrients, metal/metalloid and organics data in biosolids collected by Hunter Water during 2006 - 2013.


Error 75%ile 90%ile

Physicochemical

Total solids (%w/w) 2006-13 458 0.41 0.45 0.00 2.42 0.01 0.50 0.67

Volatile solids (%w/w) 2006-13 440 69.12 66.35 20.61 96.72 0.51 72.68 74.60

Ammonium N_Total (mg/L N) 2006-13 440 24.00 25.03 0.01 85.40 0.55 30.13 39.00

Grease – total low range (mg/L) 2006-13 440 153.5 172.0 1.0 841.0 5.5 230.0 328.2

Fluoride (mg/L) 2006-13 3 0.77 0.67 0.42 0.82 0.13 0.80 0.81

Metals / Metalloids

Silver-Ag-AA Furnace (µg/L) 2006-13 152 22 23 4 63 1 29 40

Silver Ag-ICP (µg/L) 2006-13 279 11 12 0.5 38 0 15 18

Arsenic As-VGA (µg/L) 2006-13 431 14.7 18.33 2.6 130 0.70 19.75 30.5

Cadmium Cd-furnace (µg/L) 2006-13 152 4 5.93 0.5 128 1.04 6 8

Cadmium Cd-ICP (mg/L) 2006-13 279 0.005 0.01 0.005 0.06 0.00 0.01 0.01

Chromium Cr VI-furnace (µg/L) 2006-13 152 1 1.00 1 1 0.00 1 1

Chromium Cr VIi-furnace (µg/L) 2006-13 279 5 10 5 25 0.00 5 25

Chromium Cr-furnace (µg/L) 2006-13 152 46.5 68.16 1 750 7.41 68.5 105

Chromium Cr- ICP (µg/L) 2006-13 279 30 50 5 3200 10 40 70

Copper Cu-furnace (µg/L) 2006-13 152 839 954 125 3930 42.8 1134 1426

Copper Cu-ICP (µg/L) 2006-13 279 830 880 5 3300 20 1000 1300

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Mercury Hg- VGA µg/L) 2006-13 431 3.7 3.93 0.005 10.2 0.08 4.8 6.3

Manganese Mn-furnace (µg/L) 2006-13 152 339 360 33 1270 13.73 446.25 512.5

Manganese -ICP (mg/L) 2006-13 279 0.39 0.41 0.06 1 0.01 0.47 0.57

Nickel Ni-furnace (µg/L) 2006-13 152 40 47.21 13 180 2.49 55 77.7

Nickel Ni-ICP (mg/L) 2006-13 279 0.03 0.04 0.005 0.33 0.00 0.05 0.07

Lead Pb-furnace (µg/L) 2006-13 152 187 224 13 900 11.37 269.25 375

Lead Pb ICP µg/L) 2006-13 279 120 130 10 450 0.01 150 212

Selenium Se-VGA (µg/L)) 2006-13 431 0.1 0.91 0.05 5.9 0.06 1.7 2.7

Zinc Zn (mg/L) 2006-13 152 2.4 3.03 0.78 15.6 0.16 3.515 5.39

Zinc Zn-ICP (mg/L) 2006-13 279 2.2 2.46 0.13 6.9 0.06 2.8 3.7

Organics

Aldrin (µg/L) 2006-13 96 0 0 0 0 0 0 0

α-BHC Bhc-a (µg/L) 2006-13 96 0 0 0 0 0 0 0

β-BHC-b (µg/L) 2006-13 96 0 0 0 0 0 0 0

α Chlordane (µg/L) 2006-13 96 0 0 0 0 0 0 0

Chlordane (µg/L) 2006-13 96 0 0 0 0 0 0 0

λ Chlordane- (µg/L) 2006-13 13 0 0 0 0 0 0 0

Chlorpyrifos (µg/L) 2006-13 96 0 0.003 0 0.239 0.003 0 0

DDT (ug/L) 2006-13 96 0 0 0 0 0 0 0

DDD (µg/L) 2006-13 96 0 0 0 0 0 0 0

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DDE (µg/L) 2006-13 96 0 0 0 0 0 0 0

Diazinon (µg/L) 2006-13 96 0 0 0 0 0 0 0

Dieldrin (µg/L) 2006-13 96 0 0.006 0 0.315 0.004 0 0

Endosulfan-s (µg/L) 2006-13 96 0 0 0 0 0 0 0

Endrin (µg/L) 2006-13 96 0 0 0 0 0 0 0

HCB (µg/L) 2006-13 96 0 0 0 0 0 0 0

Heptachlor-epoxide (µg/L) 2006-13 96 0 0.0001 0 0.013 0.0001 0 2.8

Heptachlor (µg/L) 2006-13 96 0 0 0 0 0 0 0

Lindane (µg/L) 2006-13 96 0 0 0 0 0 0 0

Malathion (µg/L) 2006-13 96 0 0 0 0 0 0 0

Methoxychlor (µg/L) 2006-13 96 0 0 0 0 0 0 0

Parathion (µg/L) 2006-13 96 0 0 0 0 0 0 0

Total PCBs (µg/L) 2006-13 96 0 0 0 0 0 0 0

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1.1.4 Effluent and Biosolids Flow Data

Effluent and WAS flow data for the study period was obtained from the Burwood WWTW. A summary

of flow data for the period July 2011 to May 2013 is provided in Table 1.4 (courtesy of Hunter

Water) and Figure 1.3.

Table 1.4 Rainfall, effluent and WAS flow data for the study period (July 2011 - May 2013)

Date

Rainfall (mm)

Secondary Flow (ML)

1

By-Pass Flow (ML)

2

Total Flow (ML)

Biosolids (ML)

3

July 2011 238.2 2068.14 777.24 2845.38 71.66

Aug 2011 47.8 1775.64 0 1775.64 87.73

Sep 2011 136.0 1731.62 205.9 1937.52 82.86

Oct 2011 161.4 1966.85 301.27 2268.12 94.93

Nov 2011 184.5 2004.51 465.58 2470.09 86.71

Dec 2011 110.8 1825.98 6.37 1832.35 92.83

Jan 2012 53.6 1481.64 22.32 1503.96 93.38

Feb 2012 336.7 2296.60 485.42 2782.02 89.47

Mar 2012 188.0 2083.66 403.74 2487.40 96.36

Apr 2012 174.0 1889.04 306.14 2195.18 88.98

May 2012 26.2 1470.51 0 1470.51 94.01

Jun 2012 188.0 2255.16 373.09 2628.25 95.01

Jul 2012 83.5 1839.45 24.17 1863.62 86.77

Aug 2012 71.0 1704.78 62.22 1767.00 93.44

Sep 2012 16.7 1305.15 0 1305.15 87.82

Oct 2012 13.5 1257.72 0 1257.72 76.17

Nov 2012 44.6 1201.80 0 1201.80 86.92

Dec 2012 114.2 1375.59 52.98 1428.57 98.06

Jan 2013 229.0 1488.58 322.25 1810.83 99.86

Feb 2013 175.0 1855.55 397.11 2252.66 87.39

Mar 2013 241.0 1954.00 629.58 2583.58 112.08

Apr 2013 94.5 1702.77 116.92 1819.69 102.98

May 2013 60.0 1538.14 55.7 1593.84 95.64

1 Secondary Flow is total secondary treated flow through the plant (i.e. Total volume of screened and degritted sewage into

secondary plant over a 24 hour period from 12 midnight and discharged to ocean).

2 By-Pass Flow is total volume of screened and degritted sewage which bypasses the secondary plant over a 24 hour period

from 12 midnight and is discharged to ocean

3 Biosolids is the Volume of Waste Activated Sludge pumped from the clarifier underflow over a 24 hour period from 12

midnight and is discharged to ocean.

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Figure 1.3 Burwood Beach flow data for the study period (July 2011 - May 2013).

1.1.5 Dilution Modeling / Dispersion Characteristics

Consulting Environmental Engineers (CEE 2007) calculated a predicted initial dilution for the Burwood

effluent outfall, assuming a discharge rate of 43 ML/d and all duckbill valves in operation. The model

predicted a typical dilution of 219:1 for the effluent field. Allowing for the reduction in dilution due to

the orientation of the diffuser ports parallel to the currents, initial dilution is expected to be in the range

of 180:1 to 220:1. The Water Research Lab (WRL 2007) also carried out field tests of effluent dilution

using rhodamine dye. The dilution of the surface field showed a typical dilution of 185:1. WRL (2007)

reported that the average near-field dilution was 207:1 and the 95th percentile minimum dilution was

78:1. CEE (2010) therefore considers it reasonable to base the environmental risk assessment of the

effects of effluent discharge on an effluent plume near the ocean surface with an initial dilution in the

range of 100:1 to 200:1.

The dilution of a combined biosolids and effluent discharge through the biosolids diffuser was also

calculated (CEE 2007). The CEE model predicted a typical dilution of 475:1 for discharged biosolids

if they rose to the ocean surface, or about 250:1 if trapped by stratification at mid-depth (CEE 2007).

The WRL hydrodynamic computer model showed a median dilution of 300:1, with a minimum dilution

of 100:1 when strong stratification decreases the rise and dilution of the small biosolids plumes, and a

maximum dilution at times of strong currents exceeding 1,000:1 (WRL 2007). The WRL model also

showed the biosolids plume is often trapped well below the surface by the natural stratification of the

ocean water column. WRL field tests of the biosolids plume, with dilution measured using rhodamine

dye, showed a typical dilution of 841:1. WRL reported that the average near-field dilution of the

biosolids plume was 268:1 and the 95th percentile minimum dilution was 205:1, for a submerged

plume (WRL 2007). Based on these results, it is considered reasonable to base the assessment of

the effects of biosolids discharge on two conditions; surface plume with an initial dilution of 300:1 and

submerged plume with an initial dilution of 200:1 (CEE 2010). WRL (1999) modelled the biosolids

plume at 10 m depth and showed that the centre of the plume, at about 10 m depth, the dilution

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achieved is between 200:1 and 1,000:1. At a distance of 200 m from the diffuser, the dilution

exceeds 1,000:1 and increases further with distance travelled. The diluted biosolids extends to the

south of the diffuser, but would be indistinguishable except by the sensitive techniques used in the

field studies. Based on the field tests and dilution modelling undertaken by WRL (1999; 2007) and

CEE (2007), the following mixing zones (Table 1.5) were determined for reporting purposes.

Table 1.5 Classification of zones based on prior effluent dilution modelling.

Distance from Diffuser Zones

< 50 m outfall impact zone outfall impact

> 50 - 100 m

mixing zone

nearfield mixing zone

> 100 - 200 m midfield mixing zone

> 200 - 2,000 m farfield mixing zone

> 2,000 m reference zone reference

1.2 Burwood Beach Marine Environmental Assessment Program

A number of monitoring programs and studies have previously been undertaken to assess the impact

of treated effluent and biosolids discharge on the marine environment at Burwood Beach (e.g. NSW

Environment Protection Authority (NSW EPA) 1994, 1996; The Ecology Lab 1996, 1998; Australian

Water Technologies (AWT) 1996, 1998, 200, 2003; Sinclair Knight Merz (SKM) 1999, 2000; Ecotox

Services Australasia (ESA) 2001, 2005; BioAnalysis 2006; Andrew-Priestley 2011; Andrew-Priestley

et al. 2012). While providing a wealth of data on the marine environment here, it is considered that

these previous studies have not effectively assessed the spatial extent and ecological significance of

the outfalls impact (Consulting Environmental Engineers (CEE) 2010). The aim of the Burwood

Beach Marine Environmental Assessment Program (MEAP) was to establish the impact footprint of

the existing outfall, establish the gradient of impact with distance to the edge of the outfall and predict

the footprint of future discharges.

The Burwood Beach Water Quality Study aimed to address some of the perceived knowledge gaps

by assessing both the spatial and temporal trends of the effluent and biosolids discharges on local

water quality along the effluent and biosolids dispersion pathway, as a function of distance from the

outfall.

1.2.1 Initial Consultation

Prior to commencement of the Burwood Beach MEAP, details of the proposed sampling program and

survey methodology were discussed with Hunter Water, CEE and the NSW EPA (then the Office of

Environment and Heritage (OEH) on 10 October 2011. This initial consultation was undertaken to

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ensure that the proposed MEAP was adequate in addressing the requirements of both the Client

(Hunter Water) and the Regulator (NSW EPA). Water quality parameters to be sampled were

discussed and agreed on. During this meeting, any concerns with the proposed sampling program

were raised and where required the methodology was subsequently altered accordingly.

1.3 Study Area

Burwood Beach is located in Newcastle, on the Hunter Coast of New South Wales (NSW). It lies to

the south of Merewether Beach and to the north of Dudley Beach (Figure 1.1). The seabed in the

vicinity of the outfall consists of small areas of low profile patchy rocky reef, which is subject to strong

wave action and periodic sand movement, interspersed between large areas of soft sediment (sandy)

habitat. These low profile reefs extend to approximately 1 m above the sand. Water depth is

approximately 22 m at the outfall diffuser. Fine mobile sandy sediments occur in the gutters and low-

lying seabed between reef patches. Extensive sandy beaches with intertidal rocky reef habitats occur

along the shoreline adjacent to the outfall.

1.4 Scope of Work / Study Objectives

The Burwood Beach Water Quality Study aimed to characterise the extent of potential impacts to

water quality in the receiving environment from effluent and biosolids discharges, and to define near,

mid and farfield impacts of the plume. Dilution and dispersion characteristics of the effluent and

biosolids discharges were considered in the sampling design.

The primary objectives of the water quality monitoring program were to:

Measure the physicochemistry and concentrations of nutrients, chlorophyll a and faecal

indicators in the receiving environment, at a range of distances from the outfall, to assess the

gradient of potential impacts;

Compare data with relevant guidelines to identify compliance (where applicable). This includes

the Australian and New Zealand Environment and Conservation Council (ANZECC)

Guidelines for Fresh and Marine Water Quality (2000), the New South Wales Environmental

Protection Authority (NSW EPA) Marine Water Quality Guidelines (2000) and the National

Health and Medical Research Council (NHMRC) Guidelines for Managing Risks in

Recreational Waters (2008); and

Measure the footprint of impact on the receiving environment.

1.4.1 Null Hypothesis

The null hypothesis for this study was:

There is no significant difference in the concentration of physicochemical parameters,

nutrients, chlorophyll a or faecal indicators at water quality sampling sites with increasing

distance from the outfalls diffuser.

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1.5 Review of Previous Studies

1.5.1 Burwood Beach WWTW Water Quality Studies

No previous water quality sampling programs have been undertaken to specifically assess the impact

of the Burwood Beach outfall on water quality in the local marine environment. However, Beachwatch

data is collected regularly from nearby beaches. Beachwatch was established in 1989 in response to

community concerns about the impact of sewage pollution on human health and the environment at

Sydney's ocean beaches. Beachwatch provides regular information on water quality to enable people

to make informed decisions about where and when to swim. A total of 127 swimming locations are

monitored in the Sydney, Hunter and Illawarra regions, with a further 129 sites monitored in

partnership with local councils along the NSW coast (NSW Government 2013). Daily bulletins,

monthly and annual reports for all NSW beaches monitored in the program can be obtained from

http://www.environment.nsw.gov.au/beachapp/default.aspx (NSW Government 2013).

Beaches nearby to Burwood Beach that are monitored by Beachwatch for faecal indicators of faecal

contamination (i.e. enterococci) include Bar, Merewether, Burwood North and Burwood South. During

2011- 2012 and 2012- 2013, these beaches were generally graded as suitable for swimming most of

the time but noted that the waters may be susceptible to sources of faecal contamination. These

results show that enterococci levels increase slightly with increasing rainfall. It was outlined that

enterococci levels often exceed the safe swimming limit after rainfall at Bar Beach (after 10 mm) and

Merewether Beach (after 20 mm). For Burwood North and Burwood South, it was outlined that

enterococci levels occasionally exceed the safe swimming limit after 10 mm or more of rainfall.

http://www.environment.nsw.gov.au/beachapp/default.aspx

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2 METHODS

2.1 Sampling Sites

Thirty-two water quality sampling sites were selected in a regularly spaced radial arrangement around

the Burwood Beach outfall diffusers, out to a distance of 2 km (i.e. reference locations). The location

of sampling sites took into account the location of the diffusers, prevailing hydrodynamic conditions in

the area and plume characteristics as determined using a series of aerial photographs

(www.nearmap.com 2011).

Twenty-eight sites were located within 500 m of the diffusers and four reference sites were located at

2 km from the diffusers, in approximately northeast and southwest directions (see Figures 2.1 and

2.2) outside the zone of influence of the diffusers. The distance of reference sites from the diffusers

was considered appropriate based on dilution modelling undertaken by WRL (1999, 2007) and CEE

(2007) (refer to Section 1.1.4).

Each water quality sampling site was allocated a site name and region identification (ID) according to

its distance and direction from the diffusers. Sampling site names, GPS co-ordinates (latitude and

longitude), distance and direction from the diffusers are provided in Table 2.1.

http://www.nearmap.com/

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Figure 2.1 Water quality sampling sites.

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Figure 2.2 Water quality sampling sites close to the Burwood Beach diffusers.

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Table 2.1 Location of sampling sites including distance and direction from the diffuser.

Site Name Distance from Diffuser (m)

Direction Latitude (S)

(WGS84) Longitude (E)

(WGS84)

WQ 1 0 m DIF 32º58.104' 151º45.118'

WQ 2 0 m DIF 32º58.151' 151º45.119'

WQ 3 0 m DIF 32º58.219' 151º45.121'

WQ 4 0 m DIF 32º58.247' 151º45.159'

WQ 5 30 m N 32º58.088' 151º45.119'

WQ 6 30 m E 32º58.192' 151º45.138'

WQ 7 30 m S 32º58.257' 151º45.174'

WQ 8 30 m W 32º58.226' 151º45.099'

WQ 1B 100 m S 32º58.304' 151º45.202'

WQ 9 100 m N 32º58.005' 151º45.119'

WQ 10 100 m E 32º58.159' 151º45.182'

WQ 11 100 m E 32º58.212' 151º45.208'

WQ 12 100 m E 32º58.026' 151º45.222'

WQ 13 100 m S 32º58.301' 151º45.156'

WQ 14 100 m S 32º58.284' 151º45.087'

WQ 15 100 m W 32º58.221' 151º45.054'

WQ 16 100 m W 32º58.142' 151º45.055'

WQ 2B 250 m S 32º58.350' 151º45.232'

WQ 17 250 m N 32º57.969' 151º45.124'

WQ 18 250 m E 32º58.088' 151º45.278'

WQ 19 250 m E 32º58.213' 151º45.315'

WQ 20 250 m E 32º58.031' 151º45.301'

WQ 21 250 m S 32º58.378' 151º45.199'

WQ 22 250 m S 32º58.362' 151º45.054'

WQ 23 250 m W 32º58.239' 151º44.958'

WQ 24 250 m W 32º58.067' 151º44.964'

WQ 3B 500 m S 32º58.444' 151º45.340'

WQ 25 500 m E 32º57.991' 151º45.041'

WQ 26 500 m E 32º58.392' 151º45.043'

WQ 27 500 m S 32º58.489' 151º44.998'

WQ 28 500 m W 32º57.969' 151º44.084'

WQ 29 2 km REFNE 32º57.232' 151º45.878'

WQ 30 2 km REFNE 32º57.637' 151º46.277'

WQ 31 2 km REFSW 32º59.278' 151º44.762'

WQ 32 2 km REFSW 32º59.115' 151º44.037'

N.B. Sites located on the diffuser are allocated to the direction code of ‘DIF’. The reference sites to the north-

east and south-west are labelled ‘REFNE’ and ‘REFSW’ respectively.

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2.2 Temporal Assessment

Eight water quality sampling events were undertaken between July 2011 and April 2013. The majority

of water sampling events were required to be undertaken over a period of two consecutive days to

allow for all sites and parameters to be sampled. All odd numbered sites were sampled on the first

day and even numbered sites on the second day (if not completed on the first day) to ensure that no

one distance or direction was favoured on either day. Sampling events occurred quarterly, with the

timing of sampling heavily influenced by oceanic and weather conditions, due to the coastal and

exposed nature of the Burwood Beach location. For safety and logistical reasons no sampling was

undertaken in swells greater than 2 m maximum. The dates, tidal conditions and wind conditions for

each of the water quality surveys are provided in Table 2.2 below.

Table 2.2 Conditions for each water quality survey.

Survey Sampling

period Date

Tide time

Tide height

Tide time

Tide height

Main Tidal Cycle

Tidal Range (+/- one

day)

Avg Wind

Speed & Dir 9am

(km-1

)

Avg Wind

Speed & Dir 3pm (km

-1)

1 Jul 2011 18/07/11 10:28 1.44 m 1600 0.59 m Ebb - 11 W 13 WSW

1 Jul 2011 19/07/11 11:06 1.44 m 1643 0.63 m Ebb - 15 WSW 22 W

2 Oct 2011 12/10/11 08:11 1.64 m 1423 0.42 m Ebb Spring 11 N 30 SSE

2 Oct 2011 13/10/11 08:43 1.67 m 1500 0.40 m Ebb Spring 20 ESE 22 E

3 Feb 2012 13/02/12 06:15 0.48 m 1215 1.50 m Flood - 15 SSW 24 SE

3 Feb 2012 14/02/12 07:21 0.54 m 1315 1.35 m Flood Neap 11 NW 24 SSE

4 Apr 2012 23/04/12 09:32 1.43 m 1509 0.60 m Ebb - 11 NW 15 NW

5 Jun 2012 27/06/12 07:41 0.47 m 1415 1.55 m Flood Neap - 22 E

5 Jun 2012 28/06/12 08:33 0.49 m 1515 1.63 m Flood Neap - 11 S

6 Oct 2012 15/10/12 07:41 1.79 m 1354 0.24 m Ebb Spring 22 NW 30 ENE

6 Oct 2012 16/10/12 08:26 1.88 m 1445 0.19 m Ebb Spring 24 NW 20 ENE

7 Feb 2013 05/02/13 09:59 0.57 m 1552 1.25 m Flood - 13 SSW 22 ESE

7 Feb 2013 06/02/13 11:14 0.48 m 1709 1.29 m Flood - 9 S 20 E

8 Apr 2013 02/04/13 07:13 0.46 m 1316 1.34 m Flood - 11 WNW 19 SSE

2.2.1 Rainfall Prior to Sampling

Rainfall influences the composition of the final treated effluent and can affect WWTW processing in

terms of the process performance and effluent quality, in particular the removal of particles from

effluent and biosolids (Wilén et al. 2006). Rainfall data for each sampling month is presented below in

Figure 2.3. Yellow stars have been used to show the water quality sampling days for each month

relative to the rainfall measured for that month.

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Figure 2.3 Rainfall data for the sampling month. Sampling days are indicated by yellow stars.

July 2011

October 2011

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Figure 2.3 (Continued) Rainfall data for the sampling month. Sampling days are indicated by

yellow stars.

February 2012

April 2012

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yellow stars.

April 2012 June 2012 June 2012

October 2012

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yellow stars.

April 2013

February 2013

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2.3 Sampling Methods

Water quality sampling was undertaken from a 6.4 m aluminium vessel skippered by Sandy Bottom

Boat Charters, Maryville, NSW.

Samples were collected from two depths at each sampling site; one at the surface (i.e. approximately

1 m below surface) and one at mid-water (i.e. half the total water depth as measured by the boat

depth sounder).

2.3.1 In-situ Physicochemical Water Quality Measurements

In-situ field measurements of physicochemical parameters were taken at the surface and mid-water

using a multi-parameter hand held water quality meter (Figure 2.4). Physicochemical parameters

initially measured at each sampling site were those agreed on by Hunter Water and the NSW EPA

during initial consultation and included water clarity (measured with a Secchi-disc), temperature,

electrical conductivity and turbidity (Table 2.3). However, after the first two events of sampling

WorleyParsons recommended that dissolved oxygen and pH were also measured for future sampling

events as these parameters are regulated under the ANZECC (2000) Guidelines. Subsequently, from

February 2012 onwards, dissolved oxygen and pH were also recorded in-situ.

The measured results of some parameters during some sampling events was unrealistic, based on

scientific knowledge that for marine waters these values are not standard, suggesting likely

instrument error. These values were hence excluded from the analysis but have been highlighted in

the raw results which are attached in Appendix 2.

In particular, the measurements of turbidity during the first three sampling events were suspected to

be inaccurate due to continuous problems with the turbidity sensor. Inaccurate readings can occur if

the probe is not calibrated properly or the turbidity sensor is failing. The probe had been calibrated

and serviced prior to each sampling event but after the third sampling event the sensor failed and

stopped reporting turbidity. The results of the first three sampling events were on a much higher

scale (i.e. up to 50 NTU) and were highly variable compared to the ensuing sampling events. Without

existing baseline levels for this region, identifying this issue was difficult as elevated and variable

readings are not uncommon for coastal zones. Upon subsequent review of the data, the first three

sampling events of turbidity data were removed from the data set. For the following five sampling

events, a new turbidity sensor was calibrated and tested against a turbidity standard (50 NTU) to

ensure that it had been calibrated correctly and provided accurate results.

2.3.2 Water Quality Sampling

A total of 64 water column samples were collected during each sampling event to test for nutrients

(ammonia, organic nitrogen, nitrites + nitrates, dissolved inorganic nitrogen, total nitrogen and total

phosphorus), faecal indicators (enterococci and faecal coliforms) and chlorophyll a (i.e. 32 sites x 2

depths). All water samples were collected using a 6.2 L Beta Water Sampler (Figure 2.4). Sample

bottles were supplied and certified for use by the analytical laboratory for each type of analyses

tested. All water samples were collected by directly decanting into their respective sample bottles,

which were then capped and stored on ice in the dark for transport. All water samples were non-

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filtered water collected directly from the Beta Water Sampler with one exception. Water samples

analysed for dissolved inorganic nitrogen were filtered through a 0.45 µm Sartorius filter in the field

prior to analysis. A chain of custody (COC) form accompanied all samples and denoted that samples

were delivered and a sample receipt notification (SRN) ensured samples were analysed within their

representative holding times (see Appendix 1 for an example). All samples were analysed by a

NATA accredited laboratory experienced in marine water analysis; Australian Laboratory Services

Environmental (ALS Environmental). Analysis is accredited for compliance with ISO/IEC 17025. A

list of all analytical parameters tested, laboratory level of reporting (LOR) and guideline values

(ANZECC 2000 / NSW EPA) are provided in Table 2.3.

Figure 2.4 Water sampling equipment (left: Beta Water Sampler; right: multi probe meter).

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Table 2.3 Analytical parameters showing their respective LOR and guideline values.

Analytical Parameter Limit of Reporting

(LOR)

Guideline Guideline reference

In-situ physico-chemical

Secchi-disc depth 0.5 m 1.6 m NSW EPA (2000); ANZECC (2000)

Turbidity 0.1 NTU 6 NTU ANZECC (2000)

Temperature 0.01 °C 15-35 °C NSW EPA (2000)

Electrical Conductivity 0.01 mS/cm None defined

Salinity 0.01 ppt None defined

Dissolved Oxygen mg/L None defined (in mg/L) 6

pH 0.1 8 - 8.4 ANZECC (2000)

Nutrients

Organic Nitrogen as N 5 0.01 mg/L None defined

Ammonia as N 0.005 mg/L 0.02 mg/L

0.5 mg/L7

ANZECC (2000)

ANZECC (2000)

Nitrite + Nitrate (NOx) 0.002 mg/L 0.025 mg/L ANZECC (2000)

Dissolved Inorganic Nitrogen (NH3 + NOx)

3 0.005 mg/L None defined

Total Nitrogen as N 4, 5

0.01 mg/L 0.12 mg/L

NSW EPA (2000); ANZECC (2000)

Total Phosphorus as P 0.005 mg/L 0.025 mg/L NSW EPA (2000); ANZECC (2000)

Chlorophyll a 1 0.5 mg/m

3 (i.e. 0.5

µg/L) 1 mg/m

3 ANZECC (2000)

Thermotolerant Faecal Coliforms 2, 9

1 CFU/100 mL 50% of values ≤150 CFU/100 mL

ANZECC (2000)

Enterococci 2, 8

1 CFU/100 mL 95th percentile of values ≤40 CFU/100 mL

NHMRC (2008)

1 Note that an LOR of 1 mg/m

3 was used for chlorophyll a for the first two sampling events, as per the original agreement

between WorleyParsons, the analytical laboratory and Hunter Water. This LOR was subsequently changed to 0.5 mg/m3.

2 Note that for turbid water samples the analytical laboratory advised that the LOR for microbial samples may need to increase

to 2 CFU / 100 ml. This would be based on visual inspection at the laboratory and cannot be based on any predetermined turbidity value.

3 Dissolved parameters (i.e. dissolved inorganic nitrogen) required field filtering.

4 Note that total nitrogen is calculated by the laboratory as a separate analysis and is not determined by calculation (i.e. may

not always equal the sum of nitrogen components as provided in the data).

5 Note that an LOR of 0.05 mg/L

was used for organic nitrogen and total nitrogen for the first two sampling events, this LOR was

subsequently changed to 0.01 mg/L in later sampling rounds.

6 ANZECC Guideline for dissolved oxygen is 90 to 110 % saturation; however dissolved oxygen was measured in mg/L in this

study.

7 Note this refers to ANZECC (2000) default trigger value for ammonia for 99% level of protection of species in marine waters.

8 Note that ANZECC refers to NHMRC 2008 “Guidelines for Managing Risks in Recreational Waters”. These NHMRC Guidelines recommend a 95 % enterococci limit of < 40 cfu/100 mL as this value is below the NOAEL in most epidemiological studies and the AFRI would be negligible.

9 Note that Faecal coliforms are considered by the NHMRC as an unsuitable regulatory parameter but still form part of NSW Water Quality Guidelines with the limit being 50 % < 150 cfu/100 mL.

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2.4 Quality Assurance / Quality Control

Quality assurance and quality control (QA/QC) procedures employed by staff working in the field are

listed below:

One blank, replicate and duplicate sample for each chemistry parameter was taken for each

day of sampling.

All field survey staff were appropriately trained in the water sampling techniques used (i.e.

use of the hand held multi-probe and Beta Water Sampler).

Field staff wore disposable nitrile gloves at all times during water sampling to prevent

contamination of water samples. Gloves were changed between sampling sites and depths

at each site.

Quality assurance and quality control (QA/QC) procedures employed by the analytical laboratory

(ALS Environmental) are listed below:

The analytical procedures used by ALS Environmental have been developed from established

internationally recognised procedures such as those published by the United States

Environment Protection Agency (USEPA), American Public Health Association (APHA),

Australian Standard (AS) and National Environment Protection Measures (NEPM).

Laboratory QA/QC was undertaken in accordance with ALS standards. A Quality Control

(QC) Report was generated for every sampling event containing the following information:

o Laboratory Duplicate (DUP) Report; Relative Percentage Difference (RPD) and

Acceptance Limits.

o Method Blank (MB) and Laboratory Control Spike (LCS) Report; Recovery and

Acceptance Limits.

o Matrix Spike (MS) Report; Recovery and Acceptance Limits.

2.5 Data Management

Field survey sheets were completed for each sampling site and field data was entered and stored in a

single electronic database. Preliminary data summaries (spread sheets) were prepared following

receipt of results from the laboratory. Appendix 2 provides a summary of all raw field data.

All data received from the field and laboratory were reviewed and subject to standard checks on the

quality of the data (e.g. through review of laboratory QA/QC) to identify anomalies.

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2.6 Data Analysis

2.6.1 Summary Statistics

Summary statistics of results including the mean, standard deviation, median, minimum and

maximum values were calculated for each sampling event. Individual value plots were used as the

main graphical summary tool to examine individual water quality parameters. These graphs are a

useful representation of data because they show all of the data as well as information about the

geographical location of each sample. Data were plotted by both distance and direction of the site

relative to the diffuser and by depth of sample (surface or mid-water). The applicable water quality

guidelines and associated LOR for each parameter were also plotted on the graphs for ease of

reference.

Where laboratory results were found to be less than the LOR, then half the LOR was used as the

nominal concentration to allow for comparison (as agreed during initial consultation with NSW EPA

and Hunter Water and recommended in ANZECC 2000). A table was also produced which

summarises the number and percentage of samples in each zone that exceeded the water quality

guidelines.

2.6.2 Comparison to Water Quality Guidelines

As requested by the NSW EPA during initial consultation, the water quality objectives in this study

were required to address aquatic ecosystem health and primary contact recreation (i.e. swimming,

diving and surfing) for NSW marine waters.

Water quality results have been compared to the respective guideline levels (as outlined in Table 2.3)

for these objectives taken from:

NSW EPA (2000) - NSW Marine Water Quality Objectives for the Hunter and Central Coast

(http://www.environment.nsw.gov.au/water/mwqo/index.htm);

ANZECC (2000) Guidelines for Fresh and Marine Water Quality (Table 3.3.2: Default

trigger values for slightly to moderately disturbed marine ecosystems in South-eastern

Australia) (http://www.environment.gov.au/water/publications/quality/nwqms-guidelines-4-

vol1.html); and

NHMRC (2008) - Guidelines for Managing Risks in Recreational Waters.

(http://www.nhmrc.gov.au/guidelines/publications/eh38).

The study site is classified as a marine and estuarine ecosystem based upon classifications outlined

in ANZECC (2000). ANZECC (2000) notes that the development of indicators for marine and

estuarine ecosystems is not as developed as for freshwater ecosystems, due to the lack of

understanding of the processes and structure and the high spatial and temporal variability associated

with marine ecosystems.

http://www.environment.nsw.gov.au/water/mwqo/index.htm

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In the current study, parameters, including temperature, turbidity, ammonia, nitrites + nitrates, total

nitrogen, total phosphorus, enterococci, faecal coliforms and chlorophyll a, were compared to

available guideline levels. Secchi disk depth was deemed to be unreliable and was not compared

with the guideline level (see further information in discussion, Section 4.1). Although there is a

guideline available for dissolved oxygen, this is in different units to what was measured in this study

and hence could not be directly compared (i.e. guideline is in % saturation compared to mg/L which

was measured in this study) and was not deemed suitable to translate the data to %.

The ANZECC (2000) guidelines suggest that comparisons are made using median values from at

least five replicate samples. For chemical analyses, this is very costly and not standard practice

therefore comparison of individual values was done. This enabled a higher resolution for patterns of

potential guideline trigger values, both spatially and temporally. However, for chemistry

measurements this method could have resulted in a lower number of values above trigger levels in

the case where there are outlier values.

It should be noted that the guideline value for Secchi-disc depth of 1.6 m is taken from ANZECC

(2000) and is suggested to be important to protect the visual clarity of waters used for swimming in

recreational waters. The guideline was intended as a horizontal water clarity measure using a black

disc but in this study vertical Secchi-disc depth using a black and white disc has been used as a

surrogate. Previous work suggests that these two measures are likely to be highly correlated (Steel

and Neuhausser 2002; Montes-Hugo et al. 2003).

2.6.3 Trigger Index

The trigger index provides a single value to represent the mean frequency and magnitude of various

parameters that exceeded a water quality guideline across site. Similar to the application of water

quality guidelines, the trigger index provides a benchmark to detect possible impacts and to ensure

that environmental values are protected. The application of a trigger index in this program is designed

to provide an overview of the frequency and magnitude that any chemistry results are exceeding the

water quality guideline.

The water quality guidelines outlined in Table 2.3 for nutrient, chlorophyll a and faecal indicators were

used to create the trigger index. Where there is a result for the trigger index, this represents value/s

that has exceeded the guideline for that site. The higher the trigger index, the higher the frequency

and/or magnitude of values that exceeded the guideline value.

The index resulted in high scores for:

1. Sites or depth classes that contained a high number of values that exceeded the triggers (as a

proportion of total samples at that distance);

2. High magnitude of trigger values (based on the guideline level); or

3. High magnitude of trigger values that had a high frequency.

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The trigger index is outlined in Equations 1 to 3 below.

Equation 1. Summary for trigger index for a given distance.

distance Magnitude of exceedance Frequency of exceedanceIndex

Equation 2. Conceptual framework for trigger index calculation for a given distance.

distance

Sum values exceeding the guidelines no. samples exceeding

Guideline value no. samples exceeding total no. samplesIndex

Equation 3. Trigger index for a given distance expressed mathematically.

1

distance

distanceGV

n

i

i EX

EX

EXN

IndexN N

Where:

Indexdistance = the resultant index value for a given distance from the outfall.

EXi = value of result that exceeds guideline level.

GV = guideline value.

NEX = number of samples exceeding the guideline at that distance.

Ndistance = number of samples taken at that distance.

2.6.4 Multivariate Analysis

Multivariate analysis was done in PRIMER 6 (Clarke and Gorley 2006) with the Permanova+ add on

(Anderson et al. 2008) and represents analysis and modelling of the multivariate suite of nutrients

(i.e. ammonia, organic nitrogen, nitrites + nitrates, dissolved inorganic nitrogen, total nitrogen and

total phosphorus), chlorophyll a, faecal indicators (enterococci and faecal coliforms).

Physicochemical parameters were excluded from the multivariate analysis because the homogeneity

of results did not assist with the assessment of variability due to the outfall.

For multivariate analyses, the data is first transformed to achieve similar distribution among data. A

similarity matrix was then created using the Gower metric. A similarity matrix is a matrix of scores

whereby each score represents the similarity between each pairwise comparison of data points. This

quantitative measure is well suited to dealing with data on different scales containing few zero values.

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The multivariate water quality dataset was analysed using distance based linear modelling (DISTLM)

and distance based redundancy analysis (dbRDA). DISTLM is similar to a regression but on a

multivariate dataset (i.e. the similarity matrix) while a dbRDA plot is a visual model that is used to

represent (i.e. illustrate) the results of DISTLM analysis.

Explanatory variables for the analysis were either temporal (sample date, sample event, season and

sampling year), spatial (distance from the outfall, direction from the outfall and depth at sample site)

or environmental (rainfall in the preceding 3, 5, and 7 days). These variables were first inspected for

skewness and kurtosis using draftsman plots. Distance from the outfall was the only variable that was

not normally distributed and was transformed using Log (10 + V) to achieve normal distribution.

A model selection procedure called BEST was used to select the models that best explained the

variation in the dataset. Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC)

were found to best explain the variation in the data and were chosen to represent the dataset. A

dbRDA plot constrained by the model variables was created to illustrate the fitted model.

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3 RESULTS

Water quality data are presented as summaries by water quality parameters across sampling events.

Graphical summaries are also used prior to multivariate analysis.

3.1 Data Summaries

3.1.1 Sampling Event

The following tables (Table 3.1 – 3.8) provide summary of the results for the physicochemistry,

nutrients, chlorophyll a and faecal indicators for all sites complied by sampling event. The summaries

are based on the edited dataset with outlier values removed as highlighted in Appendix 2. These

tables are a summary of the data across all sampling sites. Although the water quality guidelines

(NSW EPA 2000; ANZECC 2000 and NHMRC 2008) are provided in the table, these values should

not be directly compared to the guidelines, as the summary is representative of pooled data across all

32 sampling sites (i.e. including the outfall, mixing zone and reference sites).

It should be noted that the guideline value for Secchi disc depth of 1.6 m is taken from ANZECC

(2000) and is suggested to be important to protect the visual clarity of waters used for swimming in

recreational waters. The guideline was intended as a horizontal water clarity measure using a black

disc but in this study vertical Secchi disc depth using a black and white disc has been used as a

surrogate. Previous work suggests that these two measures are likely to be highly correlated (Steel

and Neuhausser 2002; Montes-Hugo et al. 2003).

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Table 3.1 Summary of physicochemistry, nutrients, faecal indicators and chlorophyll a measured in July 2011, data pooled across sites.

PARAMETER N MEDIAN MEAN STDEV MIN MAX Guideline Value

Surface samples

Secchi Disc Depth (m) 27 2 2 1 1 5 1.61

Turbidity (NTU) 29 * * * * * 61

Temperature (ºC) 29 17.27 17.30 0.12 17.14 17.61 15-352

Conductivity (field; mS/cm) 29 5.51 5.51 0.01 5.49 5.53 None

Ammonia as N (mg/L) 29 0.027 0.030 0.026 0.003 0.081 0.021

Organic Nitrogen as N (mg/L) 29 0.05 0.10 0.09 0.05 0.40 None

Nitrite + Nitrate as N (mg/L) 29 0.080 0.080 0.004 0.074 0.088 0.0251

Inorganic Nitrogen as N (mg/L) 29 0.040 0.038 0.010 0.005 0.050

None

Total Nitrogen as N (mg/L) 29 0.13 0.13 0.03 0.08 0.19 0.121,2

Total Phosphorus as P (mg/L) 29 0.018 0.018 0.004 0.010 0.026 0.0251,2

Chlorophyll a (mg/m3) 29 1 1 0 1 2 1

1

Enterococci (cfu/100ml) 29 40 76 94 1 370 Median ≤ 403

Faecal Coliforms (cfu/100ml) 29 140 153 147 1 400 95th percentile ≤ 1501

Midwater samples

Turbidity (NTU) 29 * * * * * 61

Temperature (ºC) 29 17.25 17.29 0.14 17.12 17.59 15-352


Ammonia as N (mg/L) 29 0.003 0.011 0.015 0.003 0.056 0.021



Inorganic Nitrogen as N (mg/L) 29 0.040 0.042 0.007 0.030 0.050

None




1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

* These parameters were not obtained due to technical issues with the water quality meter during this sampling round.

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Table 3.2 Summary of physicochemistry, nutrients, faecal indicators and chlorophyll a measured in October 2011, data pooled across sites.

PARAMETER N MEDIAN MEAN STDEV MIN MAX Guideline Value1

Surface samples


Turbidity (NTU) 25 * * * * * 61

Temperature (ºC) 25 18.51 18.52 0.15 18.25 18.91 15-352


Ammonia as N (mg/L) 32 0.003 0.005 0.004 0.003 0.019 0.021



Inorganic Nitrogen as N (mg/L) 32 0.003 0.005 0.004 0.003 0.019 None






Midwater samples

Turbidity (NTU) 25 * * * * * 61

Temperature (ºC) 25 18.50 18.41 0.49 17.70 19.06 15-352


Ammonia as N (mg/L) 32 0.003 0.009 0.018 0.003 0.072 0.021







1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)


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Table 3.3 Summary of physicochemistry, nutrients, faecal indicators and chlorophyll a measured in February 2012, data pooled across sites.


Surface samples


Turbidity (NTU) 32 * * * * * 61

Temperature (ºC) 32 22.04 22.04 0.27 21.45 22.51 15-352


Dissolved oxygen (mg/L) 32 7.61 7.56 0.14 7.15 7.71

pH 32 8.08 8.09 0.04 8.00 8.19 8-8.41

Ammonia as N (mg/L) 32 0.003 0.003 0.000 0.003 0.003 0.021






Chlorophyll a (mg/m3) 32 0.38 0.44 0.25 0.25 1.0 1

1



Midwater samples

Turbidity (NTU) 32 * * * * * 61

Temperature (ºC) 32 18.52 18.04 2.01 15.07 21.13 15-352



pH 32 * * * * * 8-8.41

Ammonia as N (mg/L) 32 0.006 0.021 0.035 0.003 0.155 0.021







1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)


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Table 3.4 Summary of physicochemistry, nutrients, faecal indicators and chlorophyll a measured in April 2012, data pooled across sites.


Surface samples


Turbidity (NTU) 32 2.4 2.4 0.6 0.9 4.2 61

Temperature (ºC) 32 22.16 22.18 0.11 22.04 22.74 15-352



pH 32 8.43 8.42 0.04 8.23 8.47 8-8.41

Ammonia as N (mg/L) 32 0.003 0.003 0.000 0.003 0.003 0.021







1



Midwater samples

Turbidity (NTU) 32 2.3 2.5 0.8 1.2 5.7 61

Temperature (ºC) 32 21.87 21.90 0.18 21.24 22.48 15-352



pH 32 8.44 8.44 0.01 8.40 8.46 8-8.41

Ammonia as N (mg/L) 32 0.003 0.016 0.029 0.003 0.134 0.021

1 Organic Nitrogen as N (mg/L) 32 0.05 0.06 0.05 0.03 0.27 None






1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

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Table 3.5 Summary of physicochemistry, nutrients, faecal indicators and chlorophyll a measured in June 2012, data pooled across sites.

PARAMETER N MEDIAN MEAN STDEV MIN MAX Guideline

Value1

Surface samples


Turbidity (NTU) 32 1.5 1.7 0.9 0.6 4.6 61

Temperature (ºC) 32 17.00 16.95 0.15 16.60 17.10 15-352

Conductivity (field; mS/cm) 32 * * * * * None


pH 32 8.24 8.24 0.01 8.21 8.26 8-8.41

Ammonia as N (mg/L) 32 0.030 0.033 0.027 0.003 0.080 0.021






Chlorophyll a mg/m3) 32 0.25 0.25 0.0 0.25 0.25 1

1



Midwater samples

Turbidity (NTU) 32 1.4 1.4 0.4 0.6 2.7 61

Temperature (ºC) 32 17.00 16.94 0.13 16.50 17.10 15-352

Conductivity (field; MS/cm) 32 * * * * * None


pH 32 8.24 8.23 0.01 8.18 8.25 8-8.41

Ammonia as N (mg/L) 32 0.011 0.020 0.031 0.003 0.153 0.021







1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)


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Table 3.6 Summary of physicochemistry, nutrients, faecal indicators and chlorophyll a

measured in October 2012, data pooled across sites.


Surface samples


Turbidity (NTU) 32 1.0 1.0 0.0 1.0 1.0 61

Temperature (ºC) 32 18.25 18.25 0.19 17.70 18.60 15-352

Conductivity (field) (field; mS/cm) 32 * * * * * None

Dissolved oxygen (mg/L) 32 * * * * *

pH 32 8.33 8.32 0.01 8.30 8.34 8-8.41

Ammonia as N (mg/L) 32 0.042 0.041 0.039 0.000 0.111 0.51







1



Midwater samples

Turbidity (NTU) 32 1.0 1.0 0.0 1.0 1.0 61

Temperature (ºC) 32 18.00 18.06 0.08 18.00 18.30 15-352

Conductivity (field) (field; mS/cm) 32 * * * * * None

Dissolved oxygen (mg/L) 32 * * * * *

pH 32 8.32 8.32 0.02 8.29 8.37 8-8.41

Ammonia as N (mg/L) 32 0.018 0.021 0.022 0.000 0.090 0.51







1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)


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measured in February 2013, data pooled across sites.

PARAMETER N MEAN STDEV MEDIAN MIN MAX Guideline Value1

Surface samples


Turbidity (NTU) 32 3.9 1.3 3.5 1.9 8.2 61

Temperature (ºC) 32 22.85 0.27 22.80 22.50 23.40 15-352



pH 32 8.20 0.04 8.20 8.16 8.34 8-8.41

Ammonia as N (mg/L) 32 0.007 0.009 0.003 0.003 0.044 0.51







1



Mid-water samples

Turbidity (NTU) 32 2.8 0.4 2.8 2.0 3.7 61

Temperature (ºC) 32 22.60 0.12 22.60 22.50 22.90 15-352



pH 32 8.18 0.03 8.18 8.14 8.24 8-8.41

Ammonia as N (mg/L) 32 0.023 0.029 0.007 0.003 0.121 0.51







1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

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measured in April 2013, data pooled across sites.

PARAMETER N MEAN STDEV MEDIAN MIN MAX Guideline Value1

Surface samples


Turbidity (NTU) 32 1.5 1.5 0.9 0.1 5.7 61

Temperature (ºC) 32 22.82 0.22 22.80 22.00 23.20 15-352



pH 32 * * * * * 8-8.41

Ammonia as N (mg/L) 32 0.051 0.033 0.061 0.003 0.125 0.51







1



Mid-water samples

Turbidity (NTU) 32 0.3 0.3 0.2 0.0 1.6 61

Temperature (ºC) 32 22.82 0.08 22.80 22.60 23.00 15-352



pH 32 * * * * * 8-8.41

Ammonia as N (mg/L) 32 0.016 0.016 0.013 0.003 0.092 0.51






Chlorophyll a (mg/m3)) 32 0.50 0.25 0.50 0.25 1.30 1

1



1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

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3.1.2 Zone

The following table (Table 3.9) provides a summary of water quality data by distance from the outfall which is divided into zones (0 m and 30 m- outfall zone,

100 m, 250 m and 500 m- mixing zone, 2 km – reference zone). This table is a summary of the data pooled across all sampling events. The NSW Marine

Water Quality Objectives (NSW EPA), ANZECC (2000) and NHMRC (2008) guideline values are also provided in the table.

Table 3.9 Summary of median and 95th percentile data by zone

Parameter

Median Level 95th

percentile n Guideline Value

outfall mixing zone reference outfall

mixing zone reference outfall

mixing zone reference

Turbidity (NTU) 2.60 2.40 1.45 12.80 7.16 9.79 121 281 52 61

Temperature (oC) 18.44 18.95 20.63 22.90 22.90 23.10 130 306 56 15- 35

Conductivity (mS/cm) 5.50 5.50 5.50 5.67 5.67 5.68 81 186 32 -

Dissolved oxygen (mg/L) 7.49 7.40 7.25 9.62 9.69 9.82 80 200 40 -

pH 8.32 8.28 8.27 8.45 8.45 8.39 64 160 32 8- 8.41

Ammonia as N (mg/L) 0.017 0.003 0.003 0.093 0.060 0.021 134 312 60 11

Organic Nitrogen as N (mg/L) 0.115 0.080 0.080 0.230 0.200 0.282 134 312 60 -

Nitrite + Nitrate as N (mg/L) 0.005 0.003 0.003 0.087 0.079 0.073 134 312 60 0.0251

Inorganic Nitrogen as N (mg/L) 0.031 0.012 0.006 0.127 0.079 0.060 134 312 60 -

1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Table 3.9 (continued) Summary of median and 95th percentile data by zone

Parameter

Median Level 95th percentile n Guideline

Value outfall mixing zone reference outfall mixing zone reference outfall mixing zone reference

Total Nitrogen as N (mg/L) 0.160 0.100 0.100 0.340 0.220 0.353 134 312 60 0.121,2

Total Phosphorus as P (mg/L) 0.013 0.009 0.008 0.033 0.020 0.017 134 312 60 0.0251, 2

Chlorophyll a (mg/m3) 0.50 0.50 0.25 2.00 1.75 0.80 134 312 60 1

1

Enterococci (CFU/100ml) 26.50 4.00 1.00 180.00 108.00 16.90 134 312 60 95th percentile

< 40 3

Faecal Coliforms (CFU/100ml) 125.00 6.00 0.50 757.00 202.50 54.60 134 312 60 50% of values

< 1501

1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

This table shows is a clear overall pattern of decreasing concentrations, with the highest results in the outfall, followed by the mixing zone in comparison to

the reference zone, for the parameters of ammonia, inorganic nitrogen, total nitrogen, total phosphorus, enterococci and faecal coliforms. The median, and

where relevant 95th percentile, results are discussed for each parameter in Section 3.2.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


3.2 Physicochemical Parameters

The following section outlines the physicochemistry results graphed across all distances and sampling events. The results are discussed in the order of:

patterns over sampling events, patterns between zones, and overall median of zones (Table 3.9) followed by comparison to water quality guidelines (where

applicable). As outlined in Section 3.1.2 and Table 3.9, the overall medians by zone were calculated on data which was pooled across all sampling events

and divided into zones (0 m and 30 m- outfall, 100 m, 250 m and 500 m- mixing zone, 2 km – reference).

Figures 3.1- 3.5 are based on the edited dataset with outlier values removed as highlighted in Appendix 2.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Figure 3.1 provides Secchi disc depth data for each sampling event. The results during the first four sampling events were higher and more variable. There

is a pattern in the sampling events, July 2011 to April 2012, of increasing Secchi disc depth with distance from the outfall. This pattern is not the same for the

final four sampling events, where Secchi disc measurements were generally homogenous between sites (ranging from 1 to 2). There is no water quality

guideline available for Secchi disc.

Figure 3.1 Secchi disc depth.

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Se

cch

i Dis

c D

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th (

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October 2011 February 2012 April 2012 June 2012 October 2012 February 2013 April 2013

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mp

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Surface, October 2011 Surface, February 2012 Surface, April 2012 Surface, June 2012 Surface, October 2012 Surface, February 2013 Surface, April 2013

Midwater, July 2011 Midwater, October 2011 Midwater, February 2012 Midwater, April 2012 Midwater, June 2012 Midwater, October 2012 Midwater, February 2013 Midwater, April 2013

DIF

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HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Turbidity data are presented in Figure 3.2. The data from the first three months of sampling was removed as many of the values obtained during this event

were thought to have been erroneous due to equipment malfunction. The results were similar during the first three sampling events. During February 2013

and April 2013, turbidity in the surface waters was higher and more variable. Overall, median values were similar among zones with 2.60 NTU in the outfall

zone, 2.40 NTU in the mixing zone and 1.45 NTU in the reference zone (Table 3.9). In February 2013, there were some values that exceeded the ANZECC

(2000) water quality guideline of 6 NTU. This included one measurement of 8.2 NTU at 250 m and two measurements of 6.2 NTU at 500 m.

Figure 3.2 Turbidity.

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loro

ph

yll

a (

mg

/L)


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WQ Guideline


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WQ Guideline

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Direction

LOR (2011) = 1 mg/L LOR (2012 & 2013) = 0.5 mg/L WQ Guideline = 1 mg/L

WQ Guideline

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Temperature data is provided in Figure 3.3. There are consistent seasonal patterns with similar profiles seen over the sampling years. In the warmer

summer months of February and April mean water temperatures range from 21.5 to 23.4°C in surface waters and from 15.1 to 23°C in mid-waters (due to

colder and variable results in February 2012). The mid-water results in February 2012 were highly variable and colder in comparison to February 2013.

February 2012 coincides with a reported cyclonic eddy upwelling of deeper and cooler waters from the continental shelf into coastal waters in the region from

Sydney to Bryon Bay (IMOS 2012). In the cooler winter months (i.e. June, July and October during both sampling years) mean water temperatures were

similar between the surface and mid-waters and ranged from 16.5 to 19.1°C. Overall, water temperature was cooler in the outfall and mixing zones in

comparison to the reference zone (with medians of 18.44°C in the outfall zone, 18.95°C in the mixing zone and 20.63°C in the reference zone) (Table 3.9).

With the exception of measurements in the mid-water during February 2012, all values fell within the NSW EPA (2000) guideline of 15- 35°C.

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Te

mp

era

ture

(C

)



DIF

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E

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Direction

Figure 3.3 Temperature.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Conductivity (electrical conductivity), which is shown in Figure 3.4, was found to be homogenous across sites and between the sampling events of July 2011

and April 2012. The data results were generally similar between sampling events, the highest levels were recorded in the February 2013 sampling event

(ranging from 5.27 to 5.9 mS/cm). Release of effluent from the WWTW provides a source of freshwater which may mean that the receiving environment could

be expected to show a decrease in conductivity and salinity. However there were no patterns with distance from the outfall with median values of 5.5 mS/cm

in all zones (Table 3.9). There is no water quality guideline available for conductivity.

Figure 3.4 Conductivity.

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HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Dissolved oxygen (DO) data is shown in Figure 3.5. Measurements of this variable were taken from the February 2012 sampling event onwards at both the

surface and mid-water. Within sampling events, the data is generally homogenous between sites and depths. Between February 2012 and June 2012, the

levels of DO were similar at surface waters ranging from 6.92 to 8.5 mg/L, but were more variable at mid-waters ranging from 5.06 to 9.86 mg/L. This is likely

due to the shelf intrusion reported in February 2012. Concentrations of DO were highest during February 2013 (ranging from 9.36 L to 10.18 mg/L). Overall,

there was no pattern with distance from the outfall with medians of 7.49 mg/L in the outfall zone, 7.40 mg/L in the mixing zone and 7.25 mg/L in the reference

zone (Table 3.9). The water quality guideline available for dissolved oxygen is in % saturation whereas mg/L was measured in this study, hence it was not

compared.

Figure 3.5 Dissolved oxygen.

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Dis

so

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n (

mg

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Surface, A pril 2012 Surface, June 2012 Surface, October 2012 Surface, February 2013 Surface, A pril 2013

Midwater, February 2012 Midwater, A pril 2012 Midwater, June 2012 Midwater, October 2012 Midwater, February 2013 Midwater, A pril 2013

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HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


pH data are presented in Figure 3.6. Data were collected from the April 2012 sampling event onwards, at both the surface and mid-water. Within sampling

events, pH was homogenous between sites and there was no relationship seen with distance from the outfall. All sampling events had similar pH levels.

Overall, the median values were similar between zones with medians of 8.32 in the outfall zone, 8.28 in the mixing zone and 8.27 in the reference zone

(Table 3.9). There is no water quality guideline available for pH.

Figure 3.6 pH.

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HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


3.3 Nutrients, chlorophyll a and faecal indicators

The following section outlines the nutrient, chlorophyll a and faecal indicator results graphed across

all distances and sampling events. The results are discussed in the order of: patterns over sampling

events, patterns between zones, and overall median of zones (Table 3.9) followed by comparison to

water quality guidelines (where applicable). As outlined in Section 3.1.2 and Table 3.9, the overall

medians by zone were calculated on data which was pooled across all sampling events and divided

into zones (0 m and 30 m- outfall, 100 m, 250 m and 500 m- mixing zone, 2 km – reference).

3.3.1 Nitrogen Forms

Nitrogen was measured in each water sample in the following forms:

Ammonia as N (NH4, LOR = 0.005 mg/L)

Organic nitrogen as N (LOR = 0.01 mg/L)

Nitrites + nitrates (NO2- + NO3

-, LOR = 0.002 mg/L)

Dissolved inorganic nitrogen (DIN) (LOR = 0.005 mg/L)

Total nitrogen (LOR = 0.01 mg/L)

Where samples were below the LOR, concentrations were reported as half the LOR, which is how

data below the LOR is typically treated by ANZECC (2000) for site comparisons.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Ammonia as N is shown in Figure 3.7. High levels of ammonia were detected in July 2011, June 2012, October 2012 and April 2013. Ammonia values

decreased with distance from the outfall during July 2011, June 2013, October 2012 and April 2013. Overall, ammonia levels were highest at the outfall with

a median of 0.017 mg/L in the outfall zone, followed by 0.003 mg/L in both the mixing zone and reference zone (Table 3.9). The ammonia concentration

exceeded the guideline of 0.02 mg/L in all sampling events, and occurred in both surface and mid-water samples for the majority of events (i.e. July 2011,

June 2012, October 2012, February 2013 and April 2013).

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L)


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WQ Guideline


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WQ Guideline

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Figure 3.7 Ammonia as N.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Organic nitrogen as N is presented in Figure 3.8. Concentrations of organic nitrogen did not appear to vary seasonally and for most sampling events were

similar around the outfall and at reference sites. For both the June 2012 and October 2012 events there is some evidence to suggest a trend of diminishing

organic nitrogen values with increasing distance from the diffuser, regardless of direction. Overall, organic nitrogen decreased with distance with medians of

0.115 mg/L in the outfall zone, 0.080 mg/L in the mixing zone and reference zones (Table 3.9). There is no defined water quality guideline for organic

nitrogen.

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Figure 3.8 Organic Nitrogen as N.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Nitrites + nitrates are shown in Figure 3.9. High levels of nitrites + nitrates occurred in three of the eight sampling events (July 2011, February 2012 and

June 2012). Both winter sampling events (July 2011 and June 2012) had high levels of nitrites + nitrates which appear to be seasonal, with homogenous

findings across all sites. Similar levels were observed at all sample sites. During February 2012, there was a similar profile of variability as was seen in the

water temperature findings, and this event coincided with an upwelling event. Values were highest during July 2011 (i.e. ranging from 0.072 mg/L to 0.094

mg/L). Overall, values were slightly higher in the outfall zone with a median of 0.005 mg/L compared to a median of 0.003 mg/L for both the mixing zone and

reference zone (Table 3.9). ANZECC (2000) guidelines were exceeded at all or some sampling sites in July 2011 (100 % of values), February 2012 (22% of

values), June 2012 (100 % of values) and April 2013 (2% of values).

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rite

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itra

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s N

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WQ Guideline


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WQ Guideline

DIF

N

E

S

W

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Direction


Figure 3.9 Nitrite + Nitrate as N.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Dissolved inorganic nitrogen (DIN) as N is shown in Figure 3.10. The results show patterns of decreasing DIN with distance from the outfall in surface and

mid-water samples during the June 2012, October 2012, February 2013 and April 2013 sampling events, and in mid-water samples for the February 2012

event. No strong trends were observed for the other sampling events. Overall, there was a pattern of decreasing concentrations with distance from the

outfall with medians of 0.031 mg/L in the outfall zone, 0.012 mg/L in the mixing zone followed by 0.006 mg/L in the reference zone (Table 3.9). There is no

defined water quality guideline for inorganic nitrogen.

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Surface, July 2011


Ino

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L)


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N

E

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Figure 3.10 Inorganic Nitrogen as N.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Figure 3.11 shows total nitrogen as N. During July 2011 and from June 2012 onwards, there was a pattern of decreasing total nitrogen with distance from

the outfall. Values were highest during June 2012, ranging from 0.04 to 0.54 mg/L at the outfall and 30 m, 0.01 to 0.34 mg/L at 100 - 500 m sites and 0.04 to

0.36 mg/L at the reference sites. During the June 2012 and February 2013 sampling events, there were values at the reference sites that were similar to

those measured at the outfall. During all sampling events, there were values that exceeded the ANZECC (2000) water quality guideline of 0.12 mg/L. There

was a higher frequency and magnitude of values that exceeded the guideline during the last four sampling events; June 2012, October 2012, February 2013

and April 2013. Overall, there was a median of 0.16 mg/L in the outfall zone, followed by 0.10 mg/L in the mixing zone and 0.10 in the reference zone (Table

3.9). The high proportion of values (across all zones) that exceed the ANZECC (2000) water quality guide of 0.12 mg/L suggests the need for further

investigations to develop a site specific trigger value for total nitrogen.

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Figure 3.11 Total Nitrogen as N.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


3.3.2 Total Phosphorus

Total phosphorus, a measure of all forms of phosphorus (orthophosphate, condensed phosphate and organic phosphate) was measured at all water quality

sites (Figure 3.12). . The highest values of total phosphorus were detected in June 2012, October 2012 and April 2013. There was a clear relationship with

distance from the outfall, with phosphorus being higher at sites that were closest to the outfall and this pattern was most apparent during October 2012.

Overall, there were medians of 0.013 mg/L for the outfall zone, 0.009 mg/L for the mixing zone and 0.008 mg/L for the reference zone (Table 3.9).

Concentrations of total phosphorus exceeded the ANZECC (2000) guideline value of 0.025 mg/L during six of the eight sampling events, with all but one of

those values detected within 500 m of the outfall.

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Surface, July 2011


To

tal P

ho

sp

ho

rus a

s P

(m

g/

L)


LOR

WQ Guideline


LOR

WQ Guideline

DIF

N

E

S

W

REFNE

REFSW

Direction


Figure 3.12 Total Phosphorus as P.

HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


3.3.3 Chlorophyll a

Chlorophyll a data are shown in Figure 3.13. Where samples were below the LOR, they were reported as half the LOR (1 mg/L in 2011 and 0.5 mg/L in 2012

and 2013). The highest results were measured during October 2012 (which ranged from < LOR to 3 mg/m3) and February 2013 (< LOR - 2.3 mg/ m

3).

During October 2012 and February 2013, values were elevated of a similar magnitude out to 500 m of the outfall. However, overall there wasn’t a strong

pattern with distance with a median of 0.50 mg/m3 for both the outfall and mixing zone and 0.25 mg/m

3 for the reference zone (Table 3.9). The ANZECC

(2000) guideline of 1 mg/L for chlorophyll a was exceeded the most during October 2012 and February 2013 in 45% and 31% of samples, respectively, with

all of these occurring within 500 m of the outfall. There were also occasional (i.e. 1.5% to 5% of total samples) exceeded values seen at 500 m or at

reference sites during most of the sampling events (i.e. during July 2011, October 2011, February 2012, April 2012 and April 2013).

Figure 3.13 Chlorophyll a.

3

2

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Surface, July 2011


Ch

loro

ph

yll

a (

mg

/L)


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WQ Guideline


LOR

WQ Guideline

DIF

N

E

S

W

REFNE

REFSW

Direction

LOR (2011) = 1 mg/L LOR (2012 & 2013) = 0.5 mg/L WQ Guideline = 1 mg/L

HUNTER WATER

WATER QUALITY STUDY

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3.3.4 Faecal Indicators

Enterococci data are presented in Figure 3.14. The July 2011, June 2012, February 2013 and April 2013 sampling events had the highest levels of

enterococci values within 500 m of the outfall. There were no apparent seasonal patterns but levels were generally highest during the last four sampling

events. There was a pattern of decreasing enterococci concentrations with distance from the outfall. At times, concentrations of enterococci were also

elevated at the reference sites. Overall, there was a median of 26.50 CFU/ 100 mL in the outfall zone, 4 CFU/ 100 mL in the mixing zone and 1 CFU/ 100 mL

in the reference zone (Table 3.9). The NHRMC (2008) guideline is ≤ 40 CFU/ 100 mL for the 95th percentile of data. Overall, this guideline was exceeded in

the outfall and the mixing zone with 95th percentiles of 180 CFU/ 100 mL and 108 CFU/100 mL, respectively (Table 3.9). In comparison, the 95th percentile

of the reference zone was 16.90 CFU/ 100 mL.

Figure 3.14 Enterococci.

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Surface, July 2011


En

tero

co

cci (C

FU/

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0m

l; L

OG

sca

le)


LOR

WQ Guideline


LOR

WQ Guideline

DIF

N

E

S

W

REFNE

REFSW

Direction

LOR = 1 CFU/100ml WQ Guideline = 40 CFU/100ml

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Surface, July 2011


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tero

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cci (C

FU/

10

0m

l; L

OG

sca

le)


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WQ Guideline


LOR

WQ Guideline

DIF

N

E

S

W

REFNE

REFSW

Direction


HUNTER WATER

WATER QUALITY STUDY

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Faecal coliforms are shown in Figure 3.15. A similar pattern was found to enterococci, where the highest values were measured in July 2011, June 2012,

February 2013 and April 2013 and within 500 m of the outfall. The magnitude and frequency of elevated faecal coliform values was similar at the outfall in

comparison to sites within the mixing zone (100 - 500 m). The highest value recorded was 5500 CFU/100 mL at the outfall during April 2013. Similarly to

enterococci, water quality guideline values were exceeded during all sampling events with higher levels frequently found at outfall sites relative to reference

sites. Overall, there were medians of 125 CFU/ 100 mL in the outfall zone, 6 CFU/ 100 mL in the mixing zone and 0.5 CFU/ 100 mL in the reference zone

(Table 3.9). The ANZECC guideline is that 50% of samples are ≤ 150 CFU/ 100 mL and overall the median of the outfall zone exceeded this guideline.

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Surface, July 2011


Fae

ca

l C

olif

orm

s (

CFU

/1

00

ml;

LO

G s

ca

le) Surface, October 2011 Surface, February 2012 Surface, April 2012 Surface, June 2012 Surface, October 2012 Surface, February 2013 Surface, April 2013

LOR

WQ Guideline


LOR

WQ Guideline

DIF

N

E

S

W

REFNE

REFSW

Direction


Figure 3.15 Faecal coliforms.

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3.3.5 Summary of Signature Parameters by Zone

A separate analysis of the water quality data by zone was undertaken by CEE and the full report is

provided in Appendix 3. The water quality dataset was pooled over sampling events and was divided

into four zones for an overall comparison and assessment of the impact footprints.

This analysis suggests that ammonia, organic nitrogen, total nitrogen, total phosphorus, enterococci

and faecal coliforms have a clear and consistent footprint which extended to 100- 500 m from the

outfall depending on the parameter.

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Page 63 301020-03413 : 210 FINAL DRAFT : October 2013 301020-03413-210Rev K: October 2013

3.4 Comparison of Results to Water Quality Guidelines

3.4.1 Summary

The water quality parameters, results and percentage of samples that exceeded guidelines along with

the available NSW EPA and ANZECC (2000) water quality guidelines, are presented in Table 3.10.

The overall number (index) of values that exceed water quality guidelines by sample distance from

the outfall is shown in Figure 3.16. Please note that this table includes all sites sampled during this

study (i.e. due to the patterns that were observed with distance from the outfall if the reference sites

were removed then the percentages would be higher for many of the parameters). Graphical

representations of the trigger index for each parameter tested are provided in Figures 3.16 to 3.23.

The individual results for enterococci and faecal coliforms are directly compared to the guideline in

Table 3.10, although it should be noted that these guidelines refer to percentages or percentiles of

data (i.e. enterococci is 95th percentile < guideline and faecal coliforms is 50% of values < guideline).

A summary per sampling event to highlight guideline values that were exceeded follows;

July 2011 – Pattern of impact evident for ammonia, and total nitrogen, enterococci, and faecal

coliforms in terms of how they exceeded the guideline. Samples exceeding the water quality

guideline levels were found in a predominantly southerly and westerly direction but some to the

east of the outfall as well. All samples at both depths returned values of nitrate + nitrite that

exceeded the guideline level. This same pattern was evident in winter 2012.

October 2011 – Many of the parameters tested were uniformly below the LOR. High ammonia

concentrations (above water quality guidelines) were observed between 0 m and 250 m from the

outfall. There was a similar pattern of total nitrogen and chlorophyll a levels around the outfall,

mixing zone and reference sites. One outfall site had high levels of enterococci and faecal

coliforms in the sample taken at mid-water.

February 2012 – Water quality values were exceeded for ammonia, total nitrogen, total

phosphorus, enterococci and faecal coliforms within 250 m from the outfall. This sampling event

coincided with a reported cold water upwelling along the coast from Sydney to Bryon Bay. Mid-

water samples were colder and had more variable water temperature and nitrites + nitrates

results in comparison to the other February sampling event.

April 2012 – There were fewer samples that exceeded the guidelines during this sampling

event in comparison to other sampling events. Water quality values were exceeded for total

nitrogen, total phosphorus and chlorophyll a, mainly at reference sites. Enterococci and faecal

coliform values exceeded water quality guidelines exclusively within 250 m of the outfall.

June 2012 – There were a large number of oxidised nitrogen values that were found to exceed

the guidelines across all spatial sites at both the surface and mid-water. There were patterns of

decreasing concentrations of ammonia, total nitrogen, total phosphorus, enterococci and faecal

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Page 64 301020-03413 : 210 FINAL DRAFT : October 2013 301020-03413-210Rev K: October 2013

coliforms, with distance from the outfall. These parameters also had a higher proportion and

magnitude of values that exceeded the guidelines around the outfall sites which diminished with

distance from the outfall.

October 2012 – This sampling event showed similar patterns to the previous event in June

2012. Ammonia, total nitrogen, total phosphorus, chlorophyll a, enterococci and faecal coliforms

frequently exceeded the respective water quality guidelines around the outfall with decreasing

concentrations with distance from the outfall. There were no parameters that exceeded the

guidelines at reference sites.

February 2013 – There were high levels of total nitrogen which exceeded the guidelines but

with a similar magnitude and frequency across all sites. Strong gradients with distance from the

outfall were apparent for ammonia, enterococci, faecal coliforms and chlorophyll a. Chlorophyll a

was also elevated around the outfall, showing a pattern of decreased values with distance from

the outfall, although the levels were lower in comparison to the October 2012 sampling event.

April 2013 – Total nitrogen exceeded guideline levels across all sites. Ammonia, enterococci

and faecal coliforms all exhibited patterns of decreasing trigger values with distance from the

outfall, but of a lower magnitude to that observed during October 2012 and January 2013. Levels

of chlorophyll a were lower in comparison to the October 2012 and January 2013 sampling events

and similar to all other sampling events.

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Table 3.10 Number and percentage of samples that exceeded the associated water quality guideline values.

July 2011

Parameter WQ Guideline

Outfall Mixing Zone Reference

N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 22 50 32 47 4 0

Nitrate + Nitrite (mg/L) 0.0251 22 100 32 100 4 100

Total Nitrogen as N (mg/L) 0.121, 2 22 55 32 44 4 0

Total Phosphorus as P (mg/L) 0.0251,2 22 9 32 3 4 0


Enterococci (CFU/100ml) 95th percentile ≤ 403 22 55 32 47 4 0

Faecal Coliforms (CFU/100ml) 50% of values ≤1503 22 55 32 41 4 0

October 2011



N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 16 13 40 5 8 0







February 2012



N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 16 31 48 10 8 0







1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

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Table 3.10 (continued) Number and percentage of samples that exceeded the associated water quality guideline values.

April 2012



N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 16 6 48 8 8 25







June 2012



N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 16 69 48 29 8 13







October 2012



N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 16 94 48 40 8 0







1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

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Table 3.10 (continued) Number and percentage of samples that exceeded the associated water quality guideline values.

February 2013



N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 16 50 48 15 8 0







April 2013



N %

Exceeded N

%

Exceeded N

%

Exceeded

Ammonia as N (mg/L) 0.021 16 75 48 35 8 13





Enterococci (CFU/100ml) 95th percentile ≤ 403 16 81 48 33

8 0


1 ANZECC (2000),

2 NSW EPA (2000),

3 NHMRC (2008)

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3.4.2 Trigger Index

Surface and midwater samples were combined for each sampling parameter being compared to the

guidelines (ANZECC 2000; NSW EPA 2000 or NHMRC 2008). The frequency and magnitude of

results that exceeded the guideline levels were plotted by distance from the outfall using a trigger

index. An overview for each parameter is provided in Figure 3.16 and a breakdown of the triggers

index by sampling event is shown in Figures 3.16 to 3.23.

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Figure 3.16 Trigger index values for all parameters by distance from the outfall. Data from all sampling events are combined.

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Chlorophyll a Enterococci Faecal Coliforms Nitrite + Nitrate Total Nitrogen Total Phosphorus

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The frequency and magnitude of values that exceeded water quality guidelines for ammonia was greater around the outfall relative to the reference sites

during four of the eight sampling events (June 2011, July 2012, October 2012 and April 2013) (Figure 3.17). At other times there appeared to be a similar but

much smaller effect. At the reference sites, there were few values that exceeded the guidelines for ammonia suggesting that the outfall is responsible for the

localised enrichment of ammonia in the water column.

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Figure 3.17 Trigger index values for ammonia by distance from the outfall for each sampling event.

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Levels of nitrites + nitrates were above guideline values during three of the eight sampling events (July 2011, February 2012 and June 2012) (Figure 3.18).

All sites in the winter sampling events (July 2011 and June 2012) had values that exceeded guidelines, at all distances, with a similar magnitude and

frequency from the outfall to the reference sites.

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July 2011

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Figure 3.18 Trigger index values for nitrites + nitrates by distance from the outfall for each sampling event.

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The patterns of values that exceeded water quality guidelines for total nitrogen are similar to those seen for ammonia, suggesting that it is the ammonia

nitrogen component that is driving the high nitrogen values (Figure 3.19). Interestingly the trigger index is comparable for total nitrogen at the reference sites

to the outfall site in February 2013.

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July 2011

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Figure 3.19 Trigger index values for total nitrogen by distance from the outfall for each sampling event.

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The trigger index results for total phosphorus suggest that effluent discharge may be responsible for some of the higher values of phosphorus, at least some

of the time (Figure 3.20). There was a clear pattern of values that exceeded the guidelines with distance from the outfall during June 2012. Patterns with

distance from the outfall can also be seen during February 2012, October 2012 and April 2013. Results from the other four sampling events do not suggest

an outfall impact.

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Figure 3.20 Trigger index values for total phosphorus by distance from the outfall for each sampling event.

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Chlorophyll a exceeded the water quality guidelines during most sampling events (Figure 3.21). Samples from October 2012 and February 2013 show large

and frequent values that exceeded guidelines between 0 - 500 m from the outfall. There were no values at the reference sites that exceeded the guidelines

for chlorophyll a during these events. However, during October 2011, February 2012 and April 2012, there were values that exceeded the guidelines at the

reference sites.

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Figure 3.21 Trigger index values for chlorophyll a by distance from the outfall for each sampling event.

HUNTER WATER

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For some sampling events, there was a pattern evident between enterococci trigger values and distance from the outfall (Figure 3.22). High frequencies and

magnitudes of guideline values that were triggered occurred in four of the eight sampling events. During July 2011, June 2012, October 2012 and April 2013

enterococci trigger indexes were quite high within 500 m of the outfall. Out of all sampling events, there were only two values that triggered above guidelines

that occurred at a reference site and these were both during June 2012. All other trigger values occurred within 500 m of the outfall.

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Figure 3.22 Trigger index values for enterococci by distance from the outfall for each sampling event.

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A detectable outfall impact effect was apparent for faecal coliform results for almost all sampling events (i.e. July 2011, June 2012, October 2012, February

2013 and April 2013) but was much larger in some than others (Figure 3.23). There were no values of faecal coliforms that exceeded the guidelines at any of

the reference sites. Samples from April 2013 contained the highest levels of faecal coliforms.

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Figure 3.23 Trigger index values for faecal coliforms by distance from the outfall for each sampling event.

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3.5 Multivariate Data Analysis

3.5.1 Multidimensional Scaling

A similarity matrix of multivariate water quality response data was created using the Gower metric in

PRIMER 6 (Clarke and Gorley 2006). The multidimensional scaling plots (MDS) were plotted

represent modelling of the multivariate suite of nutrients (ammonia, organic nitrogen, nitrites +

nitrates, dissolved inorganic nitrogen and total nitrogen), faecal indicators (enterococci and faecal

coliforms) and chlorophyll a. Physicochemical parameters were not included in the analysis (see

Section 2.6.4).

The multidimensional scaling (MDS) plots are presented in Figures 3.24 to 3.29 and graph the factors

of sample date, sampling event, season and sampling year. The MDS plots are a series of graphs

that group the data by different factors (for each of these graphs the points are in the same positions

but are highlighted in different colours by different factors).

The sample date, sampling event, season and sampling year all appear to contribute to the

organisation of samples in the plots. These results suggest that water quality in this area changes

over time and can be differentiated by temporal scales as short as a single day. When samples on

the MDS plots were coded by distance or direction from the outfall, no obvious grouping of samples

were apparent based on these categories (Figures 3.28 and 3.29).

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Resemblance: S15 Gower

Sample date18/07/2011

19/07/2011

12/10/2011

13/10/2011

13/02/2012

14/02/2012

23/04/2012

27/06/2012

28/06/2012

15/10/2012

16/10/2012

5/02/2013

6/02/2013

2/04/2013

2D Stress: 0.14

Figure 3.24 MDS plot of multivariate water quality response data similarity matrix created

using the Gower metric. Symbols are plotted by sample date.


Sampling periodJuly 2011

October 2011

February 2012

April 2012

June 2012

October 2012

February 2013

April 2013

2D Stress: 0.14

Figure 3.25 MDS plot of the multivariate water quality response data similarity matrix created

using the Gower metric. Samples are plotted by sampling event.

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SeasonSpring

Summer

Autumn

Winter

Ammonia Surface

Nitrite + Nitrate Surface

Inorganic Nitrogen Surface

Total Nitrogen Surface

2D Stress: 0.14


metric. Samples are plotted by season with influential variables plotted as a vector overlay.


Sampling Year2011/12

2012/13

2D Stress: 0.14


metric. Samples are plotted by sampling year.

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Distance0

30

100

250

500

2000

2D Stress: 0.14


metric. Samples are plotted by distance from the outfall in meters.


DirectionDIF

N

S

E

W

REFNE

REFSW

2D Stress: 0.14


metric. Samples are plotted by direction from the outfall. The category ‘DIF’ includes all sites

located on the outfall. Directional categories include sites between 30 m and 500 m. The

reference sites are indicated by ‘REFNE’ and ‘REFSE’.

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3.5.2 Multivariate Multiple Regression (DISTLM)

A permutational multivariate multiple regression analysis (also known as distance based linear

modelling or DISTLM) was performed on the water quality response data similarity matrix (comprised

of the multivariate suite of nutrients (ammonia, organic nitrogen, nitrites + nitrates, dissolved inorganic

nitrogen and total nitrogen), faecal indicators (enterococci and faecal coliforms) and chlorophyll a.

The aim of the analysis was to determine the combination of explanatory parameters that best

accounted for the variability observed in the dataset. Model selection was performed using the

selection procedure ‘BEST’ and the individual selection criteria Akaike Information Criterion (AIC) and

Bayesian Information Criterion (BIC). The analyses produced a list of the 10 most useful models

according to each selection criteria. The chosen model was ranked within two AIC and BIC points of

the best solution but contained one less variable than the models at the top of each list.

The selected model contained just two of the possible 16 variables. These were ‘sample date’ and

‘distance from diffuser’. Results of sequential tests performed using this model (Table 3.11) show

that ‘sample date’ accounts for 60.8% of the variation observed in the dataset (p-value = 0.001).

When ‘sample date’ is held constant a further 6.5% of the variation can be explained by a sites

distance from the outfall (p = 0.001). The total amount of variation explained by this model was

therefore 67%, which is fairly high for this type of study. It does however suggest that there are other

factors yet to be accounted for which drive local water quality in this area.

Table 3.11 Results of the multivariate multiple regression analysis (DISTLM) applied to the

water quality similarity matrix.

Variable SS (trace) Pseudo-F P-value Proportion Cumulative proportion

Residual df

Sample date 25365 28.601 0.001 0.6087 0.609 239

Distance 2692.2 9.256 0.001 0.0646 0.673 234

The fitted model was chosen using the BEST procedure in DISTLM and explains a total of 67% of the

variability in the dataset. SS (trace) = regression explained sums of squares; Pseudo-F = permutational

test statistic; Proportion = amount of variation explained by each parameter after the previous

parameters have been sequentially fitted; df = degrees of freedom.

Results of the multivariate regression analysis are illustrated by a distance based redundancy

analysis (dbRDA) plot constrained by the variables ‘sample date’ and ‘distance’ (Figures 3.33 to

3.34). These plots tell us that the two dbRDA axes display 75.1% of the fitted variation in the model

and 50% of the total variation in the dataset. That is, this plot is a good representation of the model

and a reasonable representation of the real-world variability in the dataset. Further insight can be

gained by plotting samples according to explanatory variables not included in the model. Observed

patterns can be more easily discerned in this way (relative to the original MDS plots) because

variability due to daily water quality fluctuations and distance from the outfall have been accounted

for.

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Figure 3.30 shows that there are likely to be inter-annual differences in water quality in this area as

samples are segregated by sampling year. It is clear from Figure 3.30 that the multivariate water

quality profile of each sample is most similar to other samples collected in the same year. The

exception to this is one sampling event from each year, which are segregated. These two sampling

events are both winter months (see Figures 3.30 and 3.31). This dataset is limited to just two years

of sampling however so it is difficult to determine the source of this variability.

As can be seen in Figure 3.31, the winter months are separated from samples taken during other

times of the year. It can be clearly seen here that the coastal water quality is quite different in winter

compared to other times of the year. The multivariate water quality profile of samples is generally

more similar during spring, summer and autumn. This is predominantly due to increased oxidised

nitrogen levels at that time. The distribution of samples, when denoted by sampling events (Figure

3.32), shows that there is quite a strong association between samples taken within two days of each

other. It is clear from this plot that the multivariate water quality profile of each sample is most similar

to other samples collected in the same event and that sampling events can be easily differentiated.

It is sample date however which most strongly groups the samples and which is the variable that

explains most variation in the dataset. Figure 3.33 shows that the multivariate water quality profile of

each sample is most similar to other samples collected on the same day.

Sample distance from the diffuser has been indicated on the plot in Figure 3.34 and shows that there

is a clear delineation of samples by distance from the diffuser within each day of sampling. This

illustrates the significance of the outfall as a driver of local water quality. Notably, samples taken on

the outfall (i.e. distance of 0 m) appear to segregate from samples taken at the next nearest two

distances which are 30 m and 100 m. Within a number of sampling days, samples taken at 250 m

and 500 m are grouped with samples taken at the reference sites (2 km). This model suggests

therefore that at those times, there is a relationship with distance from the outfall in the immediate

vicinity of the outfall (i.e. out to 100 m and to a lesser extent to 250 m). At other times it appears likely

that there is a more pronounced gradient effect occurring as water quality changes with distance from

the outfall.

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1050-5-10-15

10

5

0

-5

-10

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dbRDA1 (38% of fitted, 25.6% of total variation)

db

RD

A2

(3

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% o

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.7%

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2012/13

Year

Sampling

Figure 3.30 Distance based redundancy analysis plot of the fitted multivariate regression

model. Samples collected in the same sampling year are categorised by coloured symbols.

1050-5-10-15

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db

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Spring

Summer

Autumn

Winter

Season


model. Samples collected in the same season are categorised by coloured symbols.

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1050-5-10-15

10

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db

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July 2011

October 2011

February 2012

April 2012

June 2012

October 2012

February 2013

April 2013

Sampling Period


model. Samples collected in the same sampling event are categorised by coloured symbols.

1050-5-10-15

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db

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15/10/2012

16/10/2012

5/02/2013

6/02/2013

2/04/2013

18/07/2011

19/07/2011

12/10/2011

13/10/2011

13/02/2012

14/02/2012

23/04/2012

27/06/2012

28/06/2012

Sample date


model. Samples collected on each day are categorised by coloured symbols.

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1050-5-10-15

10

5

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db

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0

30

100

250

500

2000

Distance

Figure 3.34 Distance based redundancy analysis (dbRDA) plot of the fitted multivariate

regression model. Samples collected at each sampling distance from the outfall (in meters) are

categorised by coloured symbols.

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4 DISCUSSION

4.1 Water Quality Study

The objective of this study was to characterise the impacts of Burwood Beach WWTW discharge of

effluent and biosolids on water quality in the receiving environment. To assess the gradient and

extent of impact of discharges on the receiving environment, physicochemical parameters and

concentrations of nutrients, chlorophyll a and faecal indicators were measured at increasing distances

from the Burwood Beach WWTW outfall diffusers. Parameters were compared to the relevant

guidelines to identify compliance. This included the Australian and New Zealand Environment and

Conservation Council (ANZECC) Guidelines for Fresh and Marine Water Quality (2000), the New

South Wales Environmental Protection Authority (NSW EPA) Marine Water Quality Guidelines (2000)

and the National Health and Medical Research Council (NHMRC) Guidelines for Managing Risks in

Recreational Waters (2008).

For the purpose of this study, impacts were defined as differences or patterns of decreasing

concentrations or guideline exceeded values of parameters with distance from the outfall.

4.1.1 Physicochemistry and Qualitative Parameters

Physicochemical parameters, including dissolved oxygen, turbidity and pH did not vary across sites or

exhibit any relationship with distance from the outfall. Temperature exhibited a clear seasonal

pattern with the exception of measurements at the mid-water depth during February 2012, which were

variable and colder in comparison to the other February sampling event in 2013. This pattern is

suggested to be due to a reported cyclonic eddy during this event (see Section 4.1.2 for further

discussion), but highlights that the physicochemical data can sometimes provide insight into

environmental patterns that may help to explain the data. Dissolved oxygen and pH did not exhibit

strong spatial patterns but did vary considerably between sampling events. Parameters such as

dissolved oxygen also varied between two sampling days within single sampling events.

Turbidity provides an indication of the presence of suspended particulate and colloidal matter in the

water column and can be elevated in the receiving environment of WWTWs due to the release of

sewage effluent and biosolids. In addition, in offshore coastal regions, turbidity can be elevated due

to factors such as wind, waves and current or due to processes such as upwelling (Everett et al.

2012). During the first three sampling events of this study, turbidity was removed from the data set.

The remaining five sampling events showed a very similar pattern for turbidity and few values were

found to exceed the ANZECC (2000) guideline.

The ANZECC (2000) guidelines outline using a measure of light attenuation, such as a Secchi disc

depth, in coastal and marine waters instead of turbidity. However, the use of the Secchi disc to

measure water clarity in coastal and marine waters, over repeated sampling events, is also

questionable and would not be recommended for future water quality programs around Burwood

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Beach WWTW. The Secchi disc is a subjective parameter which is impacted by user bias. Its use

should also really be standardised for the time of day, weather conditions, especially sunlight and the

swell conditions. For these reasons it is not considered a practical and useful measure in coastal

marine water quality programs. An alternative measure, which could be used in combination with

instrument measurements of turbidity, would be measurement of the total suspended solids (TSS) in

the water samples collected in-situ. Total suspended solids (TSS) in water samples has been shown

to have a direct linear relationship with turbidity (Packman et al. 1999). It is an analytical

measurement that compliments turbidity as it provides a weight measurement of the particulate

material in water samples and does not rely on a calibrated instrument. Another alternative for

measuring light attenuation is measurement of the Photosynthetically Active Radiation (PAR), which

represents the fraction of sunlight with a spectral range from 400 to 700 nm, expressed in µmol

(photons) m-2

s-1

or microEinsteins. Increases in PAR enhance the light reactions of photosynthesis

before reaching a saturation point. In any region, the amount of photosynthetically active radiation

changes seasonally and varies depending on time of day.

Other parameters suggested by the ANZECC (2000) guidelines that were measured in this study

were the presence of an odour and surface scum or oils at each sample site. Odour may not be

reliable as it is dependent on the wind direction and subjectivity of the observer. The same applies for

the measure of ‘surface scum or oils’. The presence of sea foam is common on the ocean and could

be unrelated to an outfall. The variable of the presence or absence of a visible plume was included

and a basic analysis indicated that the presence of a plume is strongly and positively correlated with

distance from the outfall. This variable stills has the inevitable potential for observer bias and

subjective interpretation.

The physicochemical results are important as they provide baseline data for this region and will help

in the design and interpretation of future water monitoring programs.

4.1.2 Nutrients, Chlorophyll a and Faecal Indicators

Spatial trends indicated that some of the tested parameters had relationships with distance from the

outfall. Within some sampling events, levels of ammonia, total nitrogen, enterococci and faecal

coliforms and chlorophyll a, and to a more limited extent, total phosphorus, were all found to decrease

with distance from the outfall, suggesting that the outfalls are a significant source of these

constituents in the receiving environment surveyed. This pattern was evident during July 2011 and

the latter four sampling for the parameters of ammonia, total nitrogen, enterococci and faecal

coliforms. For chlorophyll a, this pattern was evident in October 2012 and February 2013.

Separate analysis of the nutrient, chlorophyll a and faecal indicator data was undertaken by CEE

(2013) with the dataset pooled over sampling events and divided into zones (Appendix 3). This

analysis outlines the extent of the footprint for selected parameters. The following parameters were

noted to have a footprint that impacts on water quality: ammonia, organic nitrogen, total nitrogen, total

phosphorus, enterococci and faecal coliforms. The results for ammonia, enterococci and faecal

coliforms show that there are clear and consistent footprints which extend to over 500 m from the

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outfall. The footprint for organic nitrogen extends to over 100 m from the outfall. The footprints for

total nitrogen, total phosphorus extend to over 250 m from the outfall.

It is well established that the NSW coastline receives nutrient rich eddies from the East Australian

Current (EAC) (Suthers et al. 2011). Local changes in coastal bathymetry are thought to predispose

certain areas, including Port Stephens, Newcastle, Port Hacking to Wollongong and Jervis Bay, to

EAC induced slope water intrusions (Lee et al. 2001). The main flow of the EAC is known to separate

from the NSW coast at Port Stephens, which is approximately 25 km NE of Newcastle. The coastal

circulation north of Port Stephens is dominated by a southward flowing EAC that is highly energetic,

flowing with currents of 2 m s-1

. Topographic variations near Laurieton (north of Port Stephens) are

thought to create high bottom stress that drives the EAC down the coast to Port Stephens where it

then upwells and separates from the coast. Instability along the front of the warm EAC current and

the colder Tasman sea has been shown to often lead to the formation of large (~150 km) warm core

anticyclonic eddies and smaller (20 – 50 km) cyclonic eddies that may persist for days to many weeks

at a time (Cresswell and Legeckis 1986; Pritchard et al. 2001). Separations of the EAC along the

north coast of NSW have been shown to correspond with high levels of chlorophyll a mass along the

shelf (Tranter et al. 1986). These periods of upwelling have been found to be seasonal (peaking

during summer/spring) (Pritchard et al. 1998). Where parameters exceeded the guidelines with a

similar magnitude across all sites, this could be due to upwelling events; although this is speculation

without knowing the timing of most upwelling events during the study period. Elevated values could

also potentially be due to alternative sources of nutrients, such as terrestrial runoff, or other natural

processes such as upwelling events.

The highly variable mid-water results recorded in the February 2012 sampling event are likely to have

been caused by a cold water upwelling event or shelf intrusion. During January - March 2012, the

website for the Integrated Marine Observing System (IMOS) reported that there was a cyclonic eddy

upwelling of deeper and cooler waters from the continental shelf in coastal waters from Sydney to

Bryon Bay (IMOS 2012). The nitrite + nitrate values that exceeded guidelines observed in the

February 2012 sampling event all occurred at mid-water. There were also lower temperatures

recorded at the mid-water depth which mimic the nitrite + nitrate results. Interestingly, high levels of

oxidised nitrogen were also observed in February 2012 around the Boulder Bay WWTW in the

concurrent water quality study for that outfall. Based on this information, it is suggested that this cold

water eddy may have caused nitrites + nitrates to be highly variable and exceed guidelines. Water

quality profiling through the water column to depth (i.e. collection of physicochemical readings every

0.5 m) is one way to assess the stratification of the water column and understand impacts from

upwelled water in this region.

Chlorophyll a concentrations were elevated within 500 m of the outfall during October 2012 and

February 2013. In October 2012 and February 2013, there was 45% and 31 %, respectively, of total

samples that exceeded the ANZECC (2000) guideline of 1 mg/L and all were within 500 m of the

outfall. During October 2012 and February 2013, there was also observed elevated values of some

nutrients (i.e. ammonia, organic nitrogen, total nitrogen and total phosphorus) in comparison to most

sampling events. While the outfall could be responsible for this pattern during October 2012 and

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February 2013, during some sampling events there was also occasional increase of chlorophyll a,

over 500 m from the outfall. Increases in chlorophyll a were noted in some samples (i.e. 1.5- 5 % of

total samples) during July 2011, October 2011, February 2012, April 2012 and April 2013 at sites

located at 500 m or 2 km. These sporadic and occasional occurrences of chlorophyll a at sites > 500

m do suggest that there is also an alternative source of chlorophyll a in the study area, which should

be considered in interpreting the findings.

The faecal indicators enterococci and faecal coliforms also showed strong evidence of outfall related

elevation in most sampling events. High CFU counts were often present at distances of 0 m to 500 m

but were then very low at the reference sites (2 km). Although the Burwood Beach outfall is located

1500 m offshore, the exceedance graphs suggest that the waters within 500 m of the outfall would not

be suitable for primary contact recreation (such as swimming and diving) on almost any of the days

sampled in this study. There is Beachwatch data for enterococci for the same period as this study

which includes only 4 values that exceeded guidelines in 169 samples (NSW OEH 2013). The main

limitation of comparing sites within 500 m of the outfall with sites at 2 km is evident here. We have no

information (apart from Beachwatch data) about what is occurring between 500 m and 2 km. The

findings of this study suggest that the footprint of impact from Burwood Beach on enterococci levels is

between 500 m and > 2 km. It is recommended that future programs include sampling sites at 750 m,

1000 m and 1500 m from the outfall along the north-east/south-west axis to enable better resolution

of the zone of impact for enterococci and also for other parameters.

4.1.3 Analysis of Water Quality Data (nutrients, chlorophyll a and

faecal indicators)

The Burwood Beach WWTW is likely responsible for the observed patterns for ammonia, total

nitrogen, enterococci, faecal coliforms and to a more limited extent, total phosphorus. For ammonia,

there was an increased magnitude and frequency of samples that didn’t meet water quality guideline

values with proximity to the outfall in seven of the eight sampling events. For enterococci and faecal

coliforms, this pattern was strong for four sampling events (July 2011, June 2012, October 2012 and

April 2013) and to a lesser extent for the other four sampling events. For faecal coliforms, this pattern

was evident in February 2013 and April 2013. Total phosphorus was elevated at the outfall sites in

five of the eight sampling events. A multivariate regression analysis was used to confirm this

hypothesis and determine the size of that effect. This analysis showed that date of sampling was the

most significant factor in explaining fluctuations in the multivariate dataset (p = 0.001, R2 = 60%)

showing that water quality fluctuates over very short periods, i.e. daily. This is not surprising given

that in each sampling event, sampling was undertaken over two days. Daily variability seen in the

water quality could be due to natural variation (e.g. currents, tides, upwelling etc.), anthropogenic

sources (i.e. the outfall or otherwise) or both. There will also be an interaction between environmental

and anthropogenic sources as different conditions (i.e. water temperature, salinity and pH) will

influence the behaviour and concentrations of anthropogenic sources of nutrients, chlorophyll a and

faecal indicators upon entering the receiving environment of the outfall (Hughes 2003). High temporal

variability in marine water quality programs are common but can pose a challenge in determining if

there are significant impacts due to a point source such as WWTW. The influence of daily variation

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was thus eliminated by holding the factor of daily variation constant in a sequential analysis. The

factor of distance from the outfall was then found to be significant factor (p = 0.001, R2 = 6.5%). This

result shows, that despite the day to day variability, distance from the outfall is a significant predictor

of water quality. This analysis supports the graphs and summary of the results which suggest that

during this study Burwood Beach WWTW was a significant source of ammonia, total nitrogen,

enterococci, faecal coliforms and to a more limited extent, total phosphorus. While the amount of

variation caused by distance from the outfall (6.5%) may seem small in comparison to daily variation

(60%), the small contribution to overall variability is enough to show clear patterns where water quality

guidelines are triggered for nutrients, chlorophyll a and faecal indicators with distance from the outfall.

Aside from sampling date and distance from the outfall, the multivariate analysis considered other

factors that may have influenced the water quality. Diffuser flow rates, depth at site, direction from

outfall, rainfall in the preceding days, numerous functions of site co-ordinates, season and sampling

year were not significant factors that attributed to the variation in the multivariate water quality profile.

The inclusion of natural sources of variation (i.e. such as upwelling, current and other environment

sources) could improve the models capacity to represent real world fluctuations in water quality

around the outfall. The strength and direction of the current are likely to be important as stronger

currents create higher dilution which should result in lower concentrations of the discharge. The

current transports the plume and so it would be expected that only the sites down-current of the

diffuser will have any contribution from the discharge. This has the potential to create large variability

in the measurements even if the relative effect of the plume is large.

Another factor that could have attributed to the variability observed in this study could be that the

sampling was undertaken over different tides (ebb and flood) and moon phases (spring and neap),

which can also introduce variability into datasets as these factors are known to influence water

chemistry (Sutherland 1981; Pennock et al. 1994; Olila and Reddy 1995; ANZECC 2000). It is

outlined in ANZECC (2000) that the full tidal and diurnal ranges of physicochemical parameters,

including over sunny and dull days, of that region should be firstly be understood in order to

adequately interpret data in relation to anthropogenic impacts. This source of variation could be

partially addressed by holding one factor consistent, i.e. sampling over both ebb and flood tides,

holding the moon phase consistent, or by sampling over spring and neap moons, holding the tide

consistent. Logistically, albeit difficult (due to having to mobilise quickly when weather conditions

permit and undertake all the sampling within one day), it can be done in future programs to help

address this issue. It would be advisable that future studies consider sampling over both ebb/flood

tides to address the potential influence of these factors to help eliminate some variation.

Mention should also be made here of the methodology used in determining the occurrence of water

quality guidelines that are triggered. The ANZECC (2000) guidelines recommend that median values

from a minimum sample N of five are used to compare with low risk trigger values. For chemical

analyses, this is very costly and not standard practice therefore comparison of individual values was

done. It should be considered that the ANZECC (2000) procedure of using median values from a

sample number of 5 could have revealed a lower number of values above trigger levels for the

nutrient, chlorophyll a and faecal indicator results as it would have likely reduced the risk of potential

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outlier measurements exceeding the trigger index. By comparing individual results to the guidelines a

higher resolution can be attained for patterns of guideline values that are triggered both spatially and

temporally. This more conservative approach is complemented by the multivariate analysis that

calculates the contribution of the outfall to water quality variability over time and space. What neither

of these measures does is quantify the effect of the outfall on the marine ecology of the region.

As well as providing assessment of the impacts of the Burwood Beach WWTW on water quality in the

receiving environment, this study has developed baseline data for the region which will help with the

design and implementation of future water monitoring programs.

4.2 Patterns between Water Quality Results and Effluent and Biosolids Composition

As provided in the introduction, the composition (including a suite of physicochemical and nutrient

parameters) of final treated effluent and biosolids has been routinely monitored by Hunter Water and

this data is available from 2006 - 2013. Concentrations of ammonium nitrogen, nitrites + nitrates, total

kjeldhal nitrogen and total nitrogen were examined in effluent and biosolids during the period of the

current water quality study (Figure 4.1), to attempt to predict any relationships with the composition of

effluent and biosolids and values that exceeded guidelines observed in the receiving environment.

Unfortunately, no data is available for enterococci or faecal coliforms, which were also found to be an

issue in this study. One of the concerns with comparing the water quality data to the effluent and

biosolids data is that the sampling dates do not coincide. The closest available effluent and biosolids

sampling dates are highlighted on Figure 4.1 and these were within one week prior to those dates of

the water sampling study. However, there is considerable short term variability in the results of the

effluent and biosolids data between the fortnightly / monthly sampling. It would be valuable if future

water quality monitoring programs could match the sampling dates to those of the effluent and

biosolids testing, although this may not be possible due to difficulties in finding suitable water

sampling conditions and having to undertake license sampling on specified days.

In the current water quality study, ammonia was elevated during the last four sampling events,

including June 2012, October 2012, February 2013 and April 2013. In the effluent, ammonia was

found to be elevated in effluent sampled in October 2012 and February 2013. In the biosolids,

ammonia was also elevated in biosolids in October 2012.

The concentrations of nitrates + nitrites in effluent does not provide any insight into the results of the

water quality study as the patterns in effluent do not match that found in the water quality study (i.e.

levels were elevated during July 2011, February 2011 and June 2012). However, the concentrations

of total nitrogen in effluent may relate to values that exceeded guidelines that were observed during

the water quality study. Levels of total nitrogen were elevated in effluent sampled in October 2012

and February 2013, in comparison to other sampling events. In the water quality study, total nitrogen

was elevated during the last four sampling events which included October 2012 and February 2013.

Total phosphorus in effluent does not provide any insight into the relationships observed in the water

quality study, as levels in effluents were similar in those months that coincided with water sampling.

There was an overall trend in the water quality data for elevated levels of many parameters (i.e.

ammonia, total nitrogen, chlorophyll a, enterococci, faecal coliforms and chlorophyll a) during July

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2011 and the last four sampling events from June 2012 onwards. The effluent and biosolids

chemistry results in Table 1.2 could partially help to explain this trend for ammonia and total nitrogen,

but again this is a large assumption without knowing what the effluent and biosolids concentrations

were on the water sampling dates.

Figure 4.1 Fortnightly testing of effluent characteristics during the Burwood Beach Water

Quality Study. Red days indicate the effluent or biosolids sampling dates that coincide (within

the week prior to) the closest to the water quality sampling. In effluent, a = ammonium nitrate,

b = total nitrogen, c = nitrates + nitrites, d = total nitrogen, e = total phosphorus and in

biosolids, f = ammonium nitrate.

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5 CONCLUSIONS

During half the sampling events (July 2011, June 2012, October 2012 and April 2013), there

was a clear footprint of elevated ammonia which extended to over 500 m from the outfall.

Organic nitrogen was elevated during some sampling events at the outfall and at 100 m

which could suggest an occasional footprint extending to 100 m from the outfall.

For total nitrogen, there was a consistent footprint to more than 250 m from the outfall,

particularly during the latter four sampling events.

Chlorophyll a was elevated around the outfall and mixing zones during October 2012 and

February 2013. There were also sporadic occurrences at > 500 m during other sampling

events.

Enterococci and faecal coliforms showed a footprint which extended to more than 500 m from

the outfall during most sampling events.

The high proportion of total nitrogen values (across all zones) that exceed the water quality

guideline of 0.12 mg/L suggests the need for further investigation to develop a site specific

trigger value for total nitrogen.

Other physiochemical parameters, including dissolved oxygen and pH were homogenous

across site within sampling events but varied over sampling events and should continue to be

monitored in all future WQ programs.

Water quality within 500 m of the Burwood Beach WWTW outfall rarely met the guidelines for

primary contact recreation (ANZECC 2000; NSW EPA 2000). Two parameters were

responsible for these results including enterococci and faecal coliforms.

A multivariate analysis (of nutrients, chlorophyll a and faecal indicators) found that local water

quality was highly variable on temporal scales from days to seasons, which is not surprising

for marine water quality programs. When the factor of daily variability was held constant, it

was seen that distance from the outfall is a significant predictor of water quality. This

suggests that the outfall has an effect on local water quality across the range of parameters

measured.

The highly variable mid-water results recorded in the February 2012 sampling event are likely

to have been caused by a cold water upwelling event or shelf intrusion.

The composition of Burwood Beach WWTW effluent and biosolids, sampled at times before

the water quality study (though on different days), partially helps to explain some of the water

quality results including the trends observed for ammonia and total nitrogen.

Based upon the findings of this study, any future increases in effluent and biosolids

discharges from the Burwood Beach WWTW is likely to result in continued impacts to water

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quality, especially for nutrients, chlorophyll a and faecal indicators. This would be dependent

on a number of factors including the rate of discharge, concentrations in the effluent and the

dilution in the receiving environment.

In summary, the water quality data indicates a footprint of the outfall discharge extending to

about 500 m from the outfall.

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WATER QUALITY STUDY

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6 ACKNOWLEDGEMENTS

We would like to thank those that assisted with the design and implementation of this study. Hunter

Water, Consulting Environmental Engineers (CEE), NSW EPA, NSW Marine Parks and NSW DPI

Fisheries assisted with the design of the sampling program and methodology. CEE also provided a

separate analysis of the data. Sandy Bottom Boat Charters, a commercial fishing charter, provided a

boat for sampling. WorleyParsons undertook all the water sampling, data analysis and report

preparation. Australian Laboratory Services (ALS) undertook all the water chemistry analysis.

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Appendix 1 – Chain of Custody Forms for Water Quality

Analysis

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Appendix 2 – Raw Water Quality data

July 2011

Sample date:Sampling period

Sample ID DirectionDistance

from diffuser (m)

DepthChlorophyll a (mg/m3)

Enterococci (CFU/100ml)

Faecal Coliforms

(CFU/100ml)

Organic Nitrogen as N (mg/L)

Ammonia as N (mg/L)

Nitrite + Nitrate as N (mg/L)

Inorganic Nitrogen as N (mg/L)

Total Nitrogen as N (mg/L)

Total Phosphorus as P (mg/L)

Depth at site (m)

Depth at mid water (m)

Sechi Disc Depth (m)

Turbidity (NTU)

Temperature (oC)

Conductivity (mS/cm)

pHDissolved oxygen (mg/L)

Salinity (‰)

18/07/2011 July 2011 WQ1S DIF 0 Surface <1 <1 <1 0.2 <0.005 0.085 0.03 0.13 0.017 24 12.0 2.25 3.6 17.39 5.5218/07/2011 July 2011 WQ1M DIF 0 Midwater <1 <1 <1 0.2 0.006 0.077 0.04 0.09 0.017 24 12.0 4.1 17.16 5.5118/07/2011 July 2011 WQ2S DIF 0 Surface 1 <1 1 0.2 <0.005 0.086 0.04 0.1 0.015 24.4 12.2 4.5 3.8 17.44 5.5218/07/2011 July 2011 WQ2M DIF 0 Midwater <1 <1 <1 0.2 <0.005 0.086 0.03 0.09 0.017 24.4 12.2 4.1 17.32 5.5218/07/2011 July 2011 WQ3S DIF 0 Surface <1 <1 <1 0.2 <0.005 0.088 0.04 0.09 0.018 26.2 13.1 2 11 17.51 5.5218/07/2011 July 2011 WQ3M DIF 0 Midwater <1 1 <1 0.1 <0.005 0.09 0.05 0.09 0.016 26.2 13.1 6.8 17.47 5.5218/07/2011 July 2011 WQ4S DIF 0 Surface <1 70 200 0.2 0.048 0.084 0.03 0.16 0.022 21.9 11.0 2.5 3.9 17.37 5.5118/07/2011 July 2011 WQ4M DIF 0 Midwater <1 60 250 0.2 0.046 0.083 0.04 0.14 0.022 21.9 11.0 3.8 17.41 5.5118/07/2011 July 2011 WQ5S DIF 30 Surface <1 <1 <1 0.2 <0.005 0.083 0.04 0.1 0.015 21.3 10.7 2.5 4.4 17.36 5.5118/07/2011 July 2011 WQ5M DIF 30 Midwater <1 <1 <1 0.1 <0.005 0.084 0.04 0.1 0.013 21.3 10.7 4.4 17.3 5.5118/07/2011 July 2011 WQ6S DIF 30 Surface <1 50 280 0.2 0.081 0.076 0.03 0.18 0.02 22.3 11.2 1.75 5.9 17.33 5.5018/07/2011 July 2011 WQ6M DIF 30 Midwater <1 4 48 0.1 0.011 0.084 0.03 0.11 0.015 22.3 11.2 4.4 17.39 5.5218/07/2011 July 2011 WQ7S DIF 30 Surface 2 70 250 0.1 0.068 0.081 0.04 0.18 0.018 23.6 11.8 2 4.6 17.33 5.5018/07/2011 July 2011 WQ7M DIF 30 Midwater <1 2 1 <0.1 <0.005 0.086 0.04 0.1 0.014 23.6 11.8 4.6 17.44 5.5218/07/2011 July 2011 WQ8S DIF 30 Surface 1 180 250 0.1 0.056 0.08 0.04 0.17 0.026 21.1 10.6 2.25 5 17.33 5.5018/07/2011 July 2011 WQ8M DIF 30 Midwater <1 210 280 <0.1 0.014 0.077 0.04 0.1 0.021 21.1 10.6 5.9 17.14 5.5118/07/2011 July 2011 WQ9S N 100 Surface <1 <1 <1 0.1 <0.005 0.083 0.04 0.08 0.014 22.6 11.3 2.25 5.6 17.5 5.5218/07/2011 July 2011 WQ9M N 100 Midwater 1 1 <1 <0.1 <0.005 0.084 0.04 0.09 0.014 22.6 11.3 5.4 17.4 5.5118/07/2011 July 2011 WQ10S NE 100 Surface <1 40 130 0.2 0.052 0.082 <0.01 0.14 0.01 23.5 11.8 2 4.6 17.38 5.5018/07/2011 July 2011 WQ10M NE 100 Midwater <1 <1 1 <0.1 <0.005 0.087 0.05 0.1 0.012 23.5 11.8 4.4 17.52 5.5218/07/2011 July 2011 WQ11S E 100 Surface <1 12 73 0.1 0.038 0.083 0.04 0.13 0.016 23.4 11.7 2.25 4.8 17.36 5.5018/07/2011 July 2011 WQ11M E 100 Midwater <1 1 1 <0.1 <0.005 0.088 0.05 0.09 0.014 23.4 11.7 4.1 17.51 5.5218/07/2011 July 2011 WQ12S SE 100 Surface <1 <1 <1 <0.1 <0.005 0.085 0.05 0.09 0.016 23.3 11.7 4.5 17.61 5.5218/07/2011 July 2011 WQ12M SE 100 Midwater <1 <1 <1 0.4 <0.005 0.088 0.05 0.1 0.015 23.3 11.7 4.3 17.59 5.5218/07/2011 July 2011 WQ13S S 100 Surface <1 170 280 0.4 0.025 0.083 0.04 0.13 0.023 23 11.5 5.3 17.42 5.5118/07/2011 July 2011 WQ13M S 100 Midwater <1 20 24 0.1 <0.005 0.094 0.05 0.1 0.017 23 11.5 4.2 17.47 5.5219/07/2011 July 2011 WQ14S SW 100 Surface <1 260 360 <0.1 0.044 0.076 0.04 0.16 0.023 20.1 10.1 1.75 4.9 17.17 5.5319/07/2011 July 2011 WQ14M SW 100 Midwater <1 210 90 <0.1 0.012 0.077 0.04 0.1 0.014 20.1 10.1 4 17.22 5.5119/07/2011 July 2011 WQ16S NW 100 Surface <1 140 400 0.1 0.063 0.074 0.03 0.17 0.02 22.3 11.2 2 6.5 17.14 5.5019/07/2011 July 2011 WQ16M NW 100 Midwater <1 160 300 <0.1 0.047 0.075 0.04 0.14 0.032 22.3 11.2 6.2 17.16 5.5119/07/2011 July 2011 WQ1BS SE 100 Surface <1 170 400 0.2 0.055 0.075 0.04 0.16 0.022 22.3 11.2 1 9.1 17.16 5.4919/07/2011 July 2011 WQ1BM SE 100 Midwater <1 120 300 <0.1 0.033 0.076 0.04 0.13 0.02 22.3 11.2 8 17.15 5.5119/07/2011 July 2011 WQ17S N 250 Surface <1 24 140 <0.1 0.021 0.077 0.04 0.11 0.015 22 11.0 2 5.6 17.18 5.5119/07/2011 July 2011 WQ17M N 250 Midwater <1 16 62 <0.1 0.006 0.075 0.05 0.09 0.015 22 11.0 3.8 17.15 5.5119/07/2011 July 2011 WQ18S NE 250 Surface <1 96 290 <0.1 0.027 0.076 0.04 0.1 0.018 25.1 12.6 2.25 3.7 17.18 5.5119/07/2011 July 2011 WQ18M NE 250 Midwater <1 64 220 <0.1 0.01 0.076 0.04 0.1 0.012 25.1 12.6 3.6 17.16 5.5119/07/2011 July 2011 WQ20S SE 250 Surface <1 <2 <2 <0.1 <0.005 0.082 0.04 0.09 0.016 24 12.0 2 20.8 17.27 5.5119/07/2011 July 2011 WQ20M SE 250 Midwater <1 <2 <2 <0.1 <0.005 0.084 0.04 0.1 0.014 24 12.0 13.8 17.22 5.5119/07/2011 July 2011 WQ22S SW 250 Surface <1 200 240 <0.1 0.034 0.076 <0.01 0.13 0.02 23 11.5 2 6.4 17.22 5.5119/07/2011 July 2011 WQ22M SW 250 Midwater <1 100 68 <0.1 0.009 0.079 0.05 0.09 0.018 23 11.5 6.3 17.25 5.5119/07/2011 July 2011 WQ24S NW 250 Surface <1 76 280 <0.1 0.053 0.075 0.04 0.15 0.021 23.4 11.7 2 4.9 17.18 5.5019/07/2011 July 2011 WQ24M NW 250 Midwater <1 6 34 <0.1 0.006 0.074 0.04 0.1 0.019 23.4 11.7 5.3 17.15 5.5119/07/2011 July 2011 WQ2BS SE 250 Surface <1 140 210 <0.1 0.054 0.074 0.04 0.15 0.02 22.5 11.3 1.5 4.7 17.18 5.5019/07/2011 July 2011 WQ2BM SE 250 Midwater <1 180 440 <0.1 0.056 0.076 0.03 0.15 0.02 22.5 11.3 3.7 17.2 5.5119/07/2011 July 2011 WQ25S NE 500 Surface <1 18 20 <0.1 0.008 0.076 0.05 0.09 0.014 25.3 12.7 2 3.2 17.22 5.5119/07/2011 July 2011 WQ25M NE 500 Midwater <1 20 38 0.1 0.006 0.075 0.05 0.1 0.018 25.3 12.7 2.9 17.13 5.5119/07/2011 July 2011 WQ26S SE 500 Surface <1 <2 <2 <0.1 <0.005 0.087 0.05 0.09 0.018 26.1 13.1 2.75 2.9 17.22 5.5219/07/2011 July 2011 WQ26M SE 500 Midwater <1 <2 <2 <0.1 <0.005 0.087 0.05 0.12 0.017 26.1 13.1 2.4 17.32 5.5119/07/2011 July 2011 WQ27S SW 500 Surface <1 <2 <2 0.1 <0.005 0.08 0.04 0.09 0.016 24 12.0 2.25 2.8 17.29 5.5219/07/2011 July 2011 WQ27M SW 500 Midwater <1 <2 <2 0.2 <0.005 0.08 0.04 0.1 0.018 24 12.0 2.9 17.27 5.5119/07/2011 July 2011 WQ28S NW 500 Surface <1 100 230 <0.1 0.045 0.074 0.05 0.14 0.02 19 9.5 2 3.3 17.21 5.5019/07/2011 July 2011 WQ28M NW 500 Midwater <1 8 50 <0.1 <0.005 0.076 0.05 0.1 0.014 19 9.5 3.7 17.21 5.5019/07/2011 July 2011 WQ3BS SE 500 Surface <1 370 400 <0.1 0.068 0.078 0.04 0.19 0.022 19.9 10.0 1.75 5 17.21 5.5019/07/2011 July 2011 WQ3BM SE 500 Midwater <1 300 200 <0.1 0.029 0.078 0.03 0.18 0.038 19.9 10.0 4.1 17.22 5.5119/07/2011 July 2011 WQ29S REFNE 2000 Surface <1 <2 <2 <0.1 <0.005 0.075 0.04 0.09 0.01 19.2 9.6 2.75 4.1 17.22 5.5119/07/2011 July 2011 WQ29M REFNE 2000 Midwater <1 <2 <2 <0.1 <0.005 0.072 0.04 0.09 0.012 19.2 9.6 3.4 17.12 5.5119/07/2011 July 2011 WQ30S REFNE 2000 Surface <1 <2 <2 <0.1 <0.005 0.081 0.04 0.09 0.016 25.3 12.7 2.25 2.9 17.27 5.5119/07/2011 July 2011 WQ30M REFNE 2000 Midwater <1 <2 <2 <0.1 0.005 0.084 0.05 0.1 0.015 25.3 12.7 3.4 17.3 5.51

NB1: Where data are preceded by a less than sign (<), the concentration was below the limit of reporting for that analysis.

NB2: Data for pH, dissolved oxygen and salinity were collected from February 2012 onwards.

October 2011

Sample date: Sampling period Sample ID DirectionDistance from

diffuser (m)Depth

Chlorophyll a (mg/m3)


Faecal Coliforms

(CFU/100ml)


Ammonia as N (mg/L)





Depth at site (m)



Turbidity (NTU)

Temperature (oC)



Salinity (‰)

12/10/2011 October 2011 WQ1S DIF 0 Surface <1 <1 4 0.07 0.019 <0.002 0.019 0.09 0.012 22.1 11.1 4 7.1 18.48 5.4412/10/2011 October 2011 WQ1M DIF 0 Midwater <1 64 180 0.16 0.071 0.003 0.074 0.23 0.019 22.1 11.1 7.3 17.85 5.4512/10/2011 October 2011 WQ2S DIF 0 Surface <1 <1 <1 0.12 0.006 <0.002 0.006 0.13 0.016 21.5 10.8 3.512/10/2011 October 2011 WQ2M DIF 0 Midwater <1 2 6 0.14 <0.005 <0.002 <0.005 0.14 0.014 21.5 10.812/10/2011 October 2011 WQ3S DIF 0 Surface <1 29 74 0.12 <0.005 <0.002 <0.005 0.12 0.018 22.4 11.2 2.5 7 18.51 5.4412/10/2011 October 2011 WQ3M DIF 0 Midwater <1 2 4 0.07 <0.005 <0.002 <0.005 0.07 0.006 22.4 11.2 7 17.9 5.4412/10/2011 October 2011 WQ4S DIF 0 Surface <1 11 59 0.14 0.009 <0.002 0.009 0.15 0.01 22.8 11.4 312/10/2011 October 2011 WQ4M DIF 0 Midwater <1 19 62 0.09 0.007 <0.002 0.007 0.1 0.015 22.8 11.412/10/2011 October 2011 WQ5S DIF 30 Surface <1 8 35 0.06 <0.005 <0.002 <0.005 0.06 0.01 22.4 11.2 4 6.6 18.47 5.4412/10/2011 October 2011 WQ5M DIF 30 Midwater 2 5 32 0.09 0.01 <0.002 0.01 0.1 0.01 22.4 11.2 7 18.02 5.4413/10/2011 October 2011 WQ6S DIF 30 Surface <1 <2 2 0.09 <0.005 <0.002 <0.005 0.09 0.01 21.9 11.0 3 13.1 18.4 5.4113/10/2011 October 2011 WQ6M DIF 30 Midwater <1 18 40 <0.05 0.072 <0.002 0.072 0.11 0.021 21.9 11.0 12.8 18.85 5.4612/10/2011 October 2011 WQ7S DIF 30 Surface <1 <1 2 0.09 0.008 <0.002 0.008 0.1 0.013 24 12.0 3 6.1 18.54 5.4412/10/2011 October 2011 WQ7M DIF 30 Midwater <1 <1 2 0.07 <0.005 <0.002 <0.005 0.07 0.008 24 12.0 7.6 17.97 5.4413/10/2011 October 2011 WQ8S DIF 30 Surface <1 <2 2 0.08 <0.005 <0.002 <0.005 0.08 0.016 20.9 10.5 3 13.9 18.34 5.4013/10/2011 October 2011 WQ8M DIF 30 Midwater <1 <2 <2 <0.05 <0.005 0.002 <0.005 <0.05 0.005 20.9 10.5 13.6 19.02 5.4812/10/2011 October 2011 WQ9S N 100 Surface <1 1 1 0.12 <0.005 <0.002 <0.005 0.12 0.017 21.3 10.7 3.5 5.6 18.49 5.4412/10/2011 October 2011 WQ9M N 100 Midwater <1 1 2 0.1 <0.005 <0.002 <0.005 0.1 0.01 21.3 10.7 5.5 18.05 5.4413/10/2011 October 2011 WQ10S NE 100 Surface <1 2 2 0.08 0.008 <0.002 0.008 0.09 0.012 24.6 12.3 3.5 13.8 18.58 5.4413/10/2011 October 2011 WQ10M NE 100 Midwater <1 2 6 0.06 0.005 <0.002 0.005 0.06 0.01 24.6 12.3 17 19.01 5.4812/10/2011 October 2011 WQ11S E 100 Surface <1 <1 <1 0.08 <0.005 <0.002 <0.005 0.08 0.016 24.5 12.3 4.5 5.6 18.56 5.4512/10/2011 October 2011 WQ11M E 100 Midwater 1 1 11 0.07 <0.005 <0.002 <0.005 0.07 0.012 24.5 12.3 6.9 17.7 5.4413/10/2011 October 2011 WQ12S SE 100 Surface <1 <2 <2 0.05 0.006 <0.002 0.006 0.06 0.012 24.2 12.1 4 5.6 18.52 5.4313/10/2011 October 2011 WQ12M SE 100 Midwater <1 <2 <2 <0.05 <0.005 <0.002 <0.005 <0.05 0.011 24.2 12.1 5.6 19.01 5.4812/10/2011 October 2011 WQ13S S 100 Surface <1 1 <1 0.12 0.008 <0.002 0.008 0.13 0.014 23.8 11.9 3.5 5.5 18.57 5.4412/10/2011 October 2011 WQ13M S 100 Midwater 2 18 150 0.08 0.022 <0.002 0.022 0.1 0.013 23.8 11.9 6.8 17.8 5.4413/10/2011 October 2011 WQ14S SW 100 Surface <1 <2 <2 0.07 <0.005 <0.002 <0.005 0.07 0.014 22.5 11.3 4 5.9 18.46 5.4113/10/2011 October 2011 WQ14M SW 100 Midwater <1 <2 <2 <0.05 <0.005 <0.002 <0.005 <0.05 0.009 22.5 11.3 7.1 19.06 5.4812/10/2011 October 2011 WQ15S W 100 Surface <1 <1 <1 0.08 0.009 <0.002 0.009 0.09 0.015 21.7 10.9 4.5 4.7 18.58 5.4412/10/2011 October 2011 WQ15M W 100 Midwater <1 2 3 0.08 <0.005 <0.002 <0.005 0.08 0.011 21.7 10.9 5.1 17.91 5.4413/10/2011 October 2011 WQ16S NW 100 Surface <1 <2 <2 0.06 <0.005 <0.002 <0.005 0.06 0.005 20.7 10.4 2.5 4.4 18.4 5.4013/10/2011 October 2011 WQ16M NW 100 Midwater <1 <2 <2 0.05 <0.005 <0.002 <0.005 0.05 0.01 20.7 10.4 4.3 18.5 5.4112/10/2011 October 2011 WQ17S N 250 Surface 2 1 <1 0.13 0.01 0.004 0.014 0.14 0.018 22.5 11.3 3.5 6.3 18.51 5.4412/10/2011 October 2011 WQ17M N 250 Midwater 1 <1 7 0.13 <0.005 <0.002 <0.005 0.13 0.015 22.5 11.3 8 17.99 5.4513/10/2011 October 2011 WQ18S NE 250 Surface <1 <2 <2 0.05 0.007 <0.002 0.007 0.06 0.006 25.2 12.6 4 4.4 18.55 5.4213/10/2011 October 2011 WQ18M NE 250 Midwater <1 28 50 0.05 0.048 <0.002 0.048 0.1 0.013 25.2 12.6 4.7 19.02 5.4912/10/2011 October 2011 WQ19S E 250 Surface <1 <1 <1 0.07 0.008 <0.002 0.008 0.08 0.009 25.4 12.7 3 5.4 18.63 5.4512/10/2011 October 2011 WQ19M E 250 Midwater 1 <1 <1 0.08 <0.005 <0.002 <0.005 0.08 0.013 25.4 12.7 5.5 17.8 5.4313/10/2011 October 2011 WQ20S SE 250 Surface <1 2 <2 <0.05 <0.005 <0.002 <0.005 <0.05 0.009 25.3 12.7 2.5 3.8 18.78 5.4613/10/2011 October 2011 WQ20M SE 250 Midwater <1 <2 <2 <0.05 <0.005 <0.002 <0.005 <0.05 0.006 25.3 12.7 3.7 18.97 5.4812/10/2011 October 2011 WQ21S S 250 Surface <1 3 9 0.1 <0.005 <0.002 <0.005 0.1 0.017 25.1 12.6 3.5 5.4 18.25 5.4012/10/2011 October 2011 WQ21M S 250 Midwater <1 2 5 0.08 <0.005 <0.002 <0.005 0.08 0.013 25.1 12.6 5.8 18 5.4513/10/2011 October 2011 WQ22S SW 250 Surface <1 <2 <2 0.06 <0.005 <0.002 <0.005 0.06 0.01 29.4 14.7 4 3.9 18.8 5.4713/10/2011 October 2011 WQ22M SW 250 Midwater <1 <2 2 0.06 <0.005 <0.002 <0.005 0.06 <0.005 29.4 14.7 4.1 18.81 5.4712/10/2011 October 2011 WQ23S W 250 Surface <1 3 3 0.11 <0.005 <0.002 <0.005 0.11 0.013 19.5 9.8 212/10/2011 October 2011 WQ23M W 250 Midwater <1 1 9 0.1 <0.005 <0.002 <0.005 0.1 0.014 19.5 9.813/10/2011 October 2011 WQ24S NW 250 Surface <1 <2 <2 0.06 <0.005 <0.002 <0.005 0.06 0.013 23 11.5 3.5 4.3 18.44 5.4013/10/2011 October 2011 WQ24M NW 250 Midwater <1 <2 <2 0.06 <0.005 <0.002 <0.005 0.06 0.012 23 11.5 4.6 18.59 5.4512/10/2011 October 2011 WQ25S NE 500 Surface <1 <1 4 0.08 0.006 <0.002 0.006 0.09 0.011 24.3 12.2 312/10/2011 October 2011 WQ25M NE 500 Midwater <1 1 3 0.08 <0.005 <0.002 <0.005 0.08 0.009 24.3 12.213/10/2011 October 2011 WQ26S SE 500 Surface <1 <2 <2 <0.05 <0.005 <0.002 <0.005 <0.05 0.007 26.3 13.2 3.5 4.2 18.91 5.4213/10/2011 October 2011 WQ26M SE 500 Midwater <1 4 2 <0.05 <0.005 <0.002 <0.005 <0.05 <0.005 26.3 13.2 4.1 18.92 5.4812/10/2011 October 2011 WQ27S SW 500 Surface <1 1 10 0.08 0.009 <0.002 0.009 0.09 0.01 23 11.5 3.512/10/2011 October 2011 WQ27M SW 500 Midwater <1 4 29 0.08 <0.005 <0.002 <0.005 0.08 0.01 23 11.513/10/2011 October 2011 WQ28S NW 500 Surface <1 <2 <2 0.05 <0.005 <0.002 <0.005 0.05 0.01 19.8 9.9 3.5 4 18.4 5.4013/10/2011 October 2011 WQ28M NW 500 Midwater <1 <2 <2 0.05 <0.005 <0.002 <0.005 0.05 <0.005 19.8 9.9 4.5 18.33 5.4112/10/2011 October 2011 WQ29S REFNE 2000 Surface <1 <1 <1 0.13 <0.005 <0.002 <0.005 0.13 0.02 18 9.0 212/10/2011 October 2011 WQ29M REFNE 2000 Midwater 2 <1 <1 0.1 <0.005 <0.002 <0.005 0.1 0.01 18 9.012/10/2011 October 2011 WQ30S REFNE 2000 Surface <1 <1 <1 0.12 <0.005 0.003 <0.005 0.12 0.01 24.8 12.4 412/10/2011 October 2011 WQ30M REFNE 2000 Midwater <1 <1 <1 0.06 <0.005 <0.002 <0.005 0.06 0.008 24.8 12.413/10/2011 October 2011 WQ31S REFSW 2000 Surface <1 <2 <2 0.08 <0.005 <0.002 <0.005 0.08 0.013 24.2 12.1 2 4.4 18.41 5.4113/10/2011 October 2011 WQ31M REFSW 2000 Midwater <1 <2 <2 <0.05 <0.005 <0.002 <0.005 <0.05 <0.005 24.2 12.1 4 18.53 5.4513/10/2011 October 2011 WQ32S REFSW 2000 Surface <1 <2 <2 0.06 <0.005 <0.002 <0.005 0.06 0.008 20.9 10.5 2.5 4.1 18.33 5.3913/10/2011 October 2011 WQ32M REFSW 2000 Midwater <1 <2 <2 <0.05 <0.005 <0.002 <0.005 <0.05 0.01 20.9 10.5 4 18.72 5.40


NB2: Data for pH, dissolved oxygen and salinity were collected from February 2012 onwards.

February 2012


diffuser (m)Depth



Faecal Coliforms

(CFU/100ml)


Ammonia as N (mg/L)





Depth at site (m)



Turbidity (NTU)

Temperature (oC)



Salinity (‰)

14/02/2012 February 2012 WQ1S DIF 0 Surface <1 8 13 <0.05 <0.005 <0.002 <0.005 <0.01 0.005 21.7 10.8 3.5 x 21.85 5.44 8.13 7.69 36.0614/02/2012 February 2012 WQ1M DIF 0 Midwater <1 32 93 <0.05 0.03 0.1 0.13 0.17 0.028 21.7 10.8 x 15.07 5.51 7.88 5.63 36.613/02/2012 February 2012 WQ2S DIF 0 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 21.8 10.9 4 6.2 22.37 5.47 8.08 7.26 36.3113/02/2012 February 2012 WQ2M DIF 0 Midwater <0.5 <1 <1 <0.05 <0.005 0.005 0.005 <0.01 <0.005 21.8 10.9 5 19.5 5.49 8.01 7.01 36.8313/02/2012 February 2012 WQ3S DIF 0 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.006 21.6 10.8 4.5 11.5 22.38 5.47 8.08 7.69 36.3113/02/2012 February 2012 WQ3M DIF 0 Midwater <0.5 <1 <1 <0.05 <0.005 0.003 <0.005 <0.01 <0.005 21.6 10.8 11.4 21.13 5.48 8.05 7.22 36.413/02/2012 February 2012 WQ4S DIF 0 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.007 22.3 11.1 4 x 22.51 5.47 8.08 7.65 36.8813/02/2012 February 2012 WQ4M DIF 0 Midwater <0.5 <1 <1 <0.05 <0.005 0.003 <0.005 <0.01 0.006 22.3 11.1 13.7 18.76 5.53 7.95 6.46 36.7714/02/2012 February 2012 WQ5S DIF 30 Surface <1 6 11 <0.05 <0.005 <0.002 <0.005 <0.01 0.006 21.7 10.9 2.5 x 21.81 5.43 8.1 7.58 35.9714/02/2012 February 2012 WQ5M DIF 30 Midwater <1 71 160 <0.05 0.1 0.131 0.231 0.27 0.026 21.7 10.9 x 16.44 5.53 7.91 5.59 36.914/02/2012 February 2012 WQ6S DIF 30 Surface <1 2 1 <0.05 <0.005 <0.002 <0.005 0.02 0.006 21.6 10.8 3.5 x 21.87 5.43 8.19 7.64 36.0114/02/2012 February 2012 WQ6M DIF 30 Midwater <1 67 170 <0.05 0.101 0.154 0.255 0.24 0.045 21.6 10.8 24.8 16.21 5.54 7.91 5.17 36.7214/02/2012 February 2012 WQ7S DIF 30 Surface <1 <1 3 <0.05 <0.005 0.009 0.009 0.02 0.011 23.4 11.7 3 x 21.65 5.40 8.1 7.15 35.7514/02/2012 February 2012 WQ7M DIF 30 Midwater <1 43 140 <0.05 0.035 0.103 0.138 0.17 0.023 23.4 11.7 25.2 16.89 5.52 7.98 5.84 36.6514/02/2012 February 2012 WQ8S DIF 30 Surface <1 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 21.1 10.5 4 x 21.85 5.42 8.1 7.3 3614/02/2012 February 2012 WQ8M DIF 30 Midwater <1 66 190 <0.05 0.155 0.149 0.304 0.34 0.038 21.1 10.5 x 15.5 5.53 7.9 5.06 36.5514/02/2012 February 2012 WQ9S N 100 Surface <1 1 3 <0.05 <0.005 <0.002 <0.005 <0.01 0.009 22.7 11.3 3.5 x 21.84 5.44 8.19 7.58 36.0314/02/2012 February 2012 WQ9M N 100 Midwater <1 1 10 <0.05 0.01 0.116 0.126 0.11 0.02 22.7 11.3 10.3 15.5 5.54 7.85 5.19 36.7914/02/2012 February 2012 WQ10S NE 100 Surface <1 <1 2 0.2 <0.005 0.003 <0.005 0.2 0.036 23.8 11.9 3.5 6 21.45 5.35 8.12 7.62 35.4314/02/2012 February 2012 WQ10M NE 100 Midwater <1 250 300 <0.05 0.015 0.018 0.033 0.03 0.01 23.8 11.9 2.7 15.62 5.53 7.87 5.9 36.5913/02/2012 February 2012 WQ11S E 100 Surface 1 <1 <1 <0.05 <0.005 <0.002 <0.005 0.02 0.009 24.0 12.0 3.5 1.5 21.5 5.35 8.1 7.5 35.4114/02/2012 February 2012 WQ11M E 100 Midwater <1 10 35 <0.05 0.025 0.085 0.11 0.13 0.017 24.0 12.0 4 15.34 5.53 7.91 5.5 36.613/02/2012 February 2012 WQ12S SE 100 Surface <0.5 <1 <1 <0.05 <0.005 0.002 <0.005 <0.01 <0.005 23.8 11.9 3.5 x 22.22 5.47 8.06 7.62 36.313/02/2012 February 2012 WQ12M SE 100 Midwater <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 23.8 11.9 x 19.87 5.52 7.93 6.26 36.713/02/2012 February 2012 WQ13S S 100 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 23.4 11.7 4 x 22.33 5.47 8.05 7.64 36.3113/02/2012 February 2012 WQ13M S 100 Midwater <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.006 23.4 11.7 x 18.53 5.53 7.89 9.86 36.613/02/2012 February 2012 WQ14S SW 100 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 21.8 10.9 4.5 x 22.25 5.47 8.08 7.69 36.313/02/2012 February 2012 WQ14M SW 100 Midwater <0.5 <1 <1 <0.05 0.005 0.01 0.015 <0.01 0.006 21.8 10.9 x 20.87 5.42 8.05 7.31 36.5313/02/2012 February 2012 WQ15S W 100 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.006 21.1 10.6 4.5 11.4 22.33 5.47 8.08 7.68 36.313/02/2012 February 2012 WQ15M W 100 Midwater <0.5 5 <1 <0.05 <0.005 0.008 0.008 <0.01 0.007 21.1 10.6 12.7 20.4 5.50 8.02 7.52 36.5313/02/2012 February 2012 WQ16S NW 100 Surface <0.5 1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.008 21.4 10.7 4 11.9 22.34 5.47 8.09 7.68 36.3113/02/2012 February 2012 WQ16M NW 100 Midwater <0.5 2 2 <0.05 <0.005 0.003 <0.005 <0.01 0.007 21.4 10.7 12.11 20.9 5.49 8.05 6.92 36.4514/02/2012 February 2012 WQ17S N 250 Surface 1 2 1 <0.05 <0.005 <0.002 <0.005 0.01 0.007 22.3 11.1 3.5 14.8 21.88 5.43 8.09 7.49 35.9814/02/2012 February 2012 WQ17M N 250 Midwater 1 7 63 <0.05 0.022 0.077 0.099 0.13 0.02 22.3 11.1 12.8 18.59 5.51 7.91 5.54 36.6714/02/2012 February 2012 WQ18S NE 250 Surface 1 <1 <1 <0.05 <0.005 0.003 <0.005 0.02 0.009 24.5 12.2 4 25.8 21.77 5.39 8.12 7.53 35.9514/02/2012 February 2012 WQ18M NE 250 Midwater <1 28 57 0.07 0.025 0.087 0.112 0.18 0.025 24.5 12.2 28.9 17 5.52 7.92 5.53 36.7514/02/2012 February 2012 WQ19S E 250 Surface <1 4 1 <0.05 <0.005 0.003 <0.005 0.01 0.011 25.1 12.5 3.5 x 21.62 5.35 8.11 7.46 35.414/02/2012 February 2012 WQ19M E 250 Midwater <1 30 97 <0.05 0.028 0.096 0.124 0.1 0.022 25.1 12.5 2.3 15.72 5.48 7.9 5.55 37.2813/02/2012 February 2012 WQ20S SE 250 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 24.5 12.3 4 x 22.21 5.47 8.05 7.65 36.313/02/2012 February 2012 WQ20M SE 250 Midwater <0.5 <1 <1 <0.05 <0.005 0.002 <0.005 <0.01 0.006 24.5 12.3 x 19.05 5.52 7.87 5.8 36.6213/02/2012 February 2012 WQ21S S 250 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 23.8 11.9 5 x 22.23 5.47 8.06 7.65 36.313/02/2012 February 2012 WQ21M S 250 Midwater <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.009 23.8 11.9 x 19.17 5.52 7.88 6.05 36.6513/02/2012 February 2012 WQ22S SW 250 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 23.2 11.6 4.5 x 22.25 5.47 8 7.65 36.313/02/2012 February 2012 WQ22M SW 250 Midwater <0.5 <1 <1 0.06 <0.005 <0.002 <0.005 0.06 0.007 23.2 11.6 x 20.24 5.50 7.99 6.64 36.5713/02/2012 February 2012 WQ23S W 250 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.011 20.0 10.0 4.5 x 22.25 5.49 8.77 7.66 36.313/02/2012 February 2012 WQ23M W 250 Midwater <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 0.005 20.0 10.0 x 20.68 5.50 8.02 7.08 36.5514/02/2012 February 2012 WQ24S NW 250 Surface <1 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 22.6 11.3 3.5 x 21.99 5.46 8.09 7.46 36.2414/02/2012 February 2012 WQ24M NW 250 Midwater <1 32 110 <0.05 0.05 0.113 0.163 0.14 0.023 22.6 11.3 7.2 15.26 5.54 7.85 5.17 36.8514/02/2012 February 2012 WQ25S NE 500 Surface 1 <1 <1 <0.05 <0.005 0.002 <0.005 <0.01 0.008 25.1 12.5 4 x 21.91 5.39 8.05 7.5 35.9414/02/2012 February 2012 WQ25M NE 500 Midwater <1 <1 <1 <0.05 0.007 0.038 0.045 0.06 0.014 25.1 12.5 x 17.44 5.52 7.91 5.5 36.7513/02/2012 February 2012 WQ26S SE 500 Surface <0.5 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 25.9 13.0 4 x 22.22 5.47 8.05 7.59 36.3113/02/2012 February 2012 WQ26M SE 500 Midwater <0.5 <1 <1 <0.05 <0.005 0.002 <0.005 <0.01 0.005 25.9 13.0 x 17 5.54 7.85 6.02 36.8713/02/2012 February 2012 WQ27S SW 500 Surface <0.5 <1 <1 <0.05 <0.005 0.011 0.011 <0.01 0.005 23.5 11.7 4.5 x 22.2 5.47 8.04 7.55 36.313/02/2012 February 2012 WQ27M SW 500 Midwater <0.5 <1 <1 <0.05 0.011 0.02 0.031 <0.01 0.01 23.5 11.7 x 18.5 5.52 7.94 6.36 36.9314/02/2012 February 2012 WQ28S NW 500 Surface <1 <1 1 <0.05 <0.005 <0.002 <0.005 0.02 0.006 18.7 9.4 4.5 x 21.96 5.47 8.06 7.49 36.2814/02/2012 February 2012 WQ28M NW 500 Midwater <1 1 4 <0.05 0.006 0.02 0.026 0.04 0.011 18.7 9.4 x 17.71 5.57 7.89 5.46 36.6214/02/2012 February 2012 WQ29S REFNE 2000 Surface <1 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 18.7 9.3 5 x 22.03 5.46 8.12 7.26 36.2214/02/2012 February 2012 WQ29M REFNE 2000 Midwater 2 <1 <1 <0.05 <0.005 0.032 0.032 0.05 0.014 18.7 9.3 x 19.89 5.49 8.07 6.88 36.4714/02/2012 February 2012 WQ30S REFNE 2000 Surface <1 <1 <1 <0.05 <0.005 <0.002 <0.005 <0.01 <0.005 25.0 12.5 4.5 10.2 22.02 5.43 8.11 7.71 3614/02/2012 February 2012 WQ30M REFNE 2000 Midwater <1 <1 <1 <0.05 0.009 0.049 0.058 0.05 0.015 25.0 12.5 9.3 15.43 5.55 7.88 5.37 36.8413/02/2012 February 2012 WQ31S REFSW 2000 Surface <0.5 <1 <1 <0.05 <0.005 0.006 0.006 <0.01 0.006 23.9 11.9 4.5 x 22.18 5.47 8.05 7.52 36.2713/02/2012 February 2012 WQ31M REFSW 2000 Midwater <0.5 <1 <1 <0.05 <0.005 0.004 <0.005 <0.01 0.005 23.9 11.9 x 19 5.52 7.78 6.33 36.4913/02/2012 February 2012 WQ32S REFSW 2000 Surface <0.5 <1 <1 <0.05 <0.005 0.005 0.005 <0.01 0.007 20.5 10.2 4 10 22.05 5.27 8.03 7.62 36.2713/02/2012 February 2012 WQ32M REFSW 2000 Midwater <0.5 <1 <1 <0.05 <0.005 0.006 0.006 <0.01 <0.005 20.5 10.2 10 20.01 5.47 7.9 7.24 36.3

April 2012


diffuser (m)Depth



Faecal Coliforms

(CFU/100ml)


Ammonia as N (mg/L)





Depth at site (m)



Turbidity (NTU)

Temperature (oC)



Salinity (‰)

23/04/2012 April 2012 WQ1S DIF 0 Surface <0.5 5 12 <0.05 <0.005 0.006 0.006 <0.05 0.008 20 10.0 4 2.8 22.14 5.48 8.46 7.11 36.3823/04/2012 April 2012 WQ1M DIF 0 Midwater <0.5 6 6 0.08 <0.005 0.007 0.007 0.09 0.013 20 10.0 2.6 21.88 5.50 8.45 6.79 36.5123/04/2012 April 2012 WQ2S DIF 0 Surface <0.5 8 17 <0.05 0.008 0.004 0.012 0.06 0.009 20.5 10.3 5 2.3 22.16 5.48 8.44 7.09 36.3823/04/2012 April 2012 WQ2M DIF 0 Midwater <0.5 5 11 0.1 <0.005 0.005 0.005 0.11 0.01 20.5 10.3 3 21.77 5.49 8.44 6.59 36.4123/04/2012 April 2012 WQ3S DIF 0 Surface <0.5 28 41 <0.05 0.018 0.004 0.022 <0.05 0.01 20 10.0 4.5 3.3 22.04 5.49 8.43 6.92 36.4123/04/2012 April 2012 WQ3M DIF 0 Midwater <0.5 78 200 0.07 0.068 0.01 0.078 0.15 0.018 20 10.0 2.9 22.01 5.49 8.44 6.68 36.4523/04/2012 April 2012 WQ4S DIF 0 Surface <0.5 5 43 <0.05 0.012 0.005 0.017 <0.05 0.007 23.5 11.8 3 2.4 22.13 5.48 8.43 7.11 36.3823/04/2012 April 2012 WQ4M DIF 0 Midwater <0.5 4 33 <0.05 <0.005 0.008 0.008 0.05 0.01 23.5 11.8 2.4 21.84 5.49 8.45 6.7 36.4723/04/2012 April 2012 WQ5S DIF 30 Surface <0.5 2 6 <0.05 <0.005 0.003 <0.005 0.05 0.009 23 11.5 4 2.4 22.15 5.48 8.44 7.07 36.3823/04/2012 April 2012 WQ5M DIF 30 Midwater <0.5 4 11 <0.05 <0.005 0.009 0.009 <0.05 0.01 23 11.5 2.5 21.88 5.50 8.44 6.68 36.523/04/2012 April 2012 WQ6S DIF 30 Surface <0.5 10 11 <0.05 <0.005 0.004 <0.005 <0.05 0.008 21.5 10.8 4.5 2.3 22.08 5.48 8.43 6.94 36.423/04/2012 April 2012 WQ6M DIF 30 Midwater <0.5 1 6 <0.05 0.009 0.013 0.022 <0.05 0.007 21.5 10.8 2.2 21.98 5.49 8.45 6.68 36.4123/04/2012 April 2012 WQ7S DIF 30 Surface <0.5 12 12 <0.05 0.006 0.005 0.011 <0.05 0.008 23.5 11.8 4.5 2.5 22.15 5.48 8.43 7.1 36.3723/04/2012 April 2012 WQ7M DIF 30 Midwater 1 <1 9 <0.05 0.009 0.005 0.014 0.05 0.009 23.5 11.8 2.3 21.85 5.50 8.45 6.71 36.5123/04/2012 April 2012 WQ8S DIF 30 Surface <0.5 11 58 <0.05 0.005 0.003 0.008 <0.05 0.008 21.5 10.8 4 2.5 22.16 5.48 8.43 7.1 36.3723/04/2012 April 2012 WQ8M DIF 30 Midwater <0.5 26 69 <0.05 0.007 0.004 0.011 0.06 0.01 21.5 10.8 2.2 21.81 5.48 8.44 6.65 36.3423/04/2012 April 2012 WQ9S N 100 Surface <0.5 2 4 <0.05 <0.005 0.003 <0.005 0.05 0.009 24 12.0 3.5 2.5 22.16 5.48 8.43 7.1 36.5523/04/2012 April 2012 WQ9M N 100 Midwater <0.5 5 6 0.05 0.006 0.01 0.016 0.07 0.009 24 12.0 2.7 21.84 5.50 8.4 6.68 36.5523/04/2012 April 2012 WQ10S NE 100 Surface <0.5 5 5 <0.05 <0.005 0.006 0.006 <0.05 0.007 24 12.0 4 2.4 22.14 5.48 8.44 7.07 36.3923/04/2012 April 2012 WQ10M NE 100 Midwater <0.5 <1 5 <0.05 <0.005 0.008 0.008 <0.05 0.008 24 12.0 2.5 21.87 5.40 8.45 6.67 36.5223/04/2012 April 2012 WQ11S E 100 Surface <0.5 7 9 <0.05 <0.005 0.004 <0.005 <0.05 0.008 24 12.0 4.5 2.4 22.16 5.48 8.44 7.1 36.3723/04/2012 April 2012 WQ11M E 100 Midwater <0.5 1 2 <0.05 <0.005 <0.002 <0.005 <0.05 0.008 24 12.0 2.3 21.96 5.48 8.44 6.64 36.3923/04/2012 April 2012 WQ12S SE 100 Surface <0.5 3 7 0.09 <0.005 <0.002 <0.005 0.09 0.008 24 12.0 4.5 2.3 22.15 5.48 8.43 7.12 36.3423/04/2012 April 2012 WQ12M SE 100 Midwater <0.5 5 25 0.05 <0.005 0.01 0.01 0.06 0.01 24 12.0 2.2 21.94 5.50 8.45 6.7 36.4223/04/2012 April 2012 WQ13S S 100 Surface <0.5 6 34 0.07 0.008 0.004 0.012 0.08 0.013 23.5 11.8 4 2.1 22.15 5.48 8.44 7 36.3723/04/2012 April 2012 WQ13M S 100 Midwater <0.5 4 77 <0.05 <0.005 0.005 0.005 <0.05 0.01 23.5 11.8 2.2 22.04 5.48 8.45 6.7 36.4123/04/2012 April 2012 WQ14S SW 100 Surface <0.5 2 9 <0.05 <0.005 <0.002 <0.005 <0.05 0.008 21 10.5 3.5 2.6 22.17 5.48 8.44 7.09 36.3623/04/2012 April 2012 WQ14M SW 100 Midwater <0.5 190 400 0.18 0.017 0.004 0.021 0.2 0.062 21 10.5 2.3 21.99 5.49 8.45 6.73 36.4523/04/2012 April 2012 WQ15S W 100 Surface <0.5 4 24 <0.05 <0.005 0.003 <0.005 0.05 0.008 21 10.5 4.5 2.8 22.17 5.48 8.44 7.18 36.3723/04/2012 April 2012 WQ15M W 100 Midwater <0.5 75 200 0.06 0.134 0.02 0.154 0.21 0.024 21 10.5 3 21.81 5.50 8.45 6.59 36.4923/04/2012 April 2012 WQ16S NW 100 Surface <0.5 4 8 <0.05 <0.005 0.002 <0.005 0.05 0.008 22 11.0 4 2.9 22.15 5.48 8.43 7.17 36.3723/04/2012 April 2012 WQ16M NW 100 Midwater <0.5 <1 5 0.05 <0.005 0.009 0.009 0.06 0.009 22 11.0 3.4 21.75 5.52 8.44 6.51 36.4123/04/2012 April 2012 WQ17S N 250 Surface <0.5 4 5 <0.05 <0.005 0.008 0.008 <0.05 0.008 22.8 11.4 4 3.7 22.16 5.48 8.43 6.93 36.3923/04/2012 April 2012 WQ17M N 250 Midwater <0.5 7 24 0.06 <0.005 <0.002 <0.005 0.06 0.009 22.8 11.4 3.3 21.84 5.50 8.44 6.64 36.5223/04/2012 April 2012 WQ18S NE 250 Surface <0.5 8 7 <0.05 <0.005 0.004 <0.005 <0.05 0.009 24.8 12.4 4 2.4 22.14 5.48 8.43 7.07 36.3923/04/2012 April 2012 WQ18M NE 250 Midwater <0.5 3 19 <0.05 0.046 0.003 0.049 <0.05 <0.005 24.8 12.4 2.5 21.84 5.49 8.45 6.65 36.423/04/2012 April 2012 WQ19S E 250 Surface <0.5 3 6 <0.05 <0.005 0.005 0.005 <0.05 0.008 25.5 12.8 4 2.3 22.17 5.48 8.44 7.13 36.3323/04/2012 April 2012 WQ19M E 250 Midwater <0.5 <1 5 0.06 <0.005 0.003 <0.005 0.06 0.011 25.5 12.8 2.2 22.04 5.49 8.44 6.67 36.4223/04/2012 April 2012 WQ20S SE 250 Surface <0.5 4 2 <0.05 <0.005 <0.002 <0.005 <0.05 0.008 25.5 12.8 5 1.9 22.74 5.47 8.45 7.12 36.3323/04/2012 April 2012 WQ20M SE 250 Midwater <0.5 4 34 <0.05 <0.005 0.002 <0.005 0.05 0.008 25.5 12.8 2.1 21.83 5.50 8.45 6.62 36.5123/04/2012 April 2012 WQ21S S 250 Surface <1.0 3 36 0.06 <0.005 0.004 <0.005 0.06 0.009 25 12.5 5.5 1.8 22.18 5.47 8.47 7.42 36.323/04/2012 April 2012 WQ21M S 250 Midwater <1.0 2 7 <0.05 <0.005 0.004 <0.005 <0.05 0.008 25 12.5 1.9 21.87 5.49 8.46 6.69 36.4723/04/2012 April 2012 WQ22S SW 250 Surface <1.0 8 9 <0.05 0.006 0.003 0.009 0.05 0.008 22 11.0 6 1.5 22.2 5.48 8.45 7.01 36.3623/04/2012 April 2012 WQ22M SW 250 Midwater 1 5 28 0.1 <0.005 0.002 <0.005 0.1 0.008 22 11.0 2 21.85 5.50 8.46 6.71 36.5123/04/2012 April 2012 WQ23S W 250 Surface <1.0 1 2 <0.05 0.007 0.004 0.011 0.06 0.007 23.5 11.8 4 2.2 22.16 5.48 8.44 7.14 36.3723/04/2012 April 2012 WQ23M W 250 Midwater <1.0 40 150 <0.05 0.068 0.011 0.079 0.08 0.013 23.5 11.8 3.6 22.48 5.51 8.44 6.51 36.5823/04/2012 April 2012 WQ24S NW 250 Surface <1.0 4 8 0.06 0.009 0.002 0.011 0.07 0.008 23 11.5 4 2.6 22.14 5.48 8.43 7.07 36.323/04/2012 April 2012 WQ24M NW 250 Midwater <1.0 <1 4 0.06 <0.005 0.011 0.011 0.07 0.01 23 11.5 3.1 21.86 5.51 8.43 6.42 36.5723/04/2012 April 2012 WQ25S NE 500 Surface <1.0 1 7 <0.05 <0.005 0.004 <0.005 <0.05 0.007 25 12.5 4 2.7 22.12 5.48 8.43 6.99 36.4523/04/2012 April 2012 WQ25M NE 500 Midwater <1.0 3 2 0.07 <0.005 0.003 <0.005 0.07 0.011 25 12.5 2.2 21.99 5.48 8.45 6.78 36.4423/04/2012 April 2012 WQ26S SE 500 Surface <1.0 3 3 <0.05 0.068 0.005 0.073 0.09 0.008 26 13.0 5 2.3 22.2 5.48 8.4 7.08 36.3323/04/2012 April 2012 WQ26M SE 500 Midwater <1.0 3 35 <0.05 <0.005 0.002 <0.005 <0.05 0.006 26 13.0 1.8 22.17 5.48 8.46 6.82 36.3723/04/2012 April 2012 WQ27S SW 500 Surface <1.0 <1 31 <0.05 0.008 0.004 0.012 <0.05 0.008 23.4 11.7 4.5 1.7 22.18 5.47 8.33 7.05 36.3323/04/2012 April 2012 WQ27M SW 500 Midwater <1.0 4 1 0.06 0.007 0.002 0.009 0.07 0.008 23.4 11.7 1.2 21.85 5.50 8.44 6.75 36.5723/04/2012 April 2012 WQ28S NW 500 Surface <1.0 2 7 <0.05 <0.005 0.004 <0.005 <0.05 0.008 19 9.5 5 4.2 22.15 5.48 8.43 7.09 36.3823/04/2012 April 2012 WQ28M NW 500 Midwater <1.0 4 8 0.06 0.006 0.017 0.023 0.08 0.012 19 9.5 3.9 21.95 5.51 8.43 6.41 36.5523/04/2012 April 2012 WQ29S REFNE 2000 Surface <1.0 2 8 <0.05 <0.005 0.005 0.005 <0.05 0.009 19 9.5 5 2.4 22.22 5.48 8.42 7.04 36.3623/04/2012 April 2012 WQ29M REFNE 2000 Midwater <1.0 <1 9 <0.05 <0.005 0.013 0.013 <0.05 0.009 19 9.5 5.7 21.24 5.40 8.43 6.29 36.5523/04/2012 April 2012 WQ30S REFNE 2000 Surface 2 7 10 <0.05 <0.005 0.007 0.007 <0.05 0.011 25 12.5 4 2.3 22.17 5.48 8.43 7.03 36.3323/04/2012 April 2012 WQ30M REFNE 2000 Midwater <1.0 2 3 <0.05 <0.005 0.005 0.005 <0.05 0.01 25 12.5 2.2 21.82 5.50 8.44 6.72 36.523/04/2012 April 2012 WQ31S REFSW 2000 Surface <1.0 8 17 0.08 0.039 0.006 0.045 0.12 0.009 24 12.0 5 1 22.3 5.46 8.39 7.1 36.223/04/2012 April 2012 WQ31M REFSW 2000 Midwater <1.0 7 27 0.08 0.016 0.004 0.02 0.1 0.008 24 12.0 1.2 21.8 5.49 8.41 6.74 36.423/04/2012 April 2012 WQ32S REFSW 2000 Surface <1.0 2 3 0.18 0.009 0.005 0.014 0.19 0.009 21 10.5 5 0.9 22.23 5.47 8.23 7.19 36.3223/04/2012 April 2012 WQ32M REFSW 2000 Midwater <1.0 19 54 0.27 0.067 0.009 0.076 0.35 0.034 21 10.5 1.7 21.99 5.51 8.42 6.52 36.52


June 2012


diffuser (m)Depth



Faecal Coliforms

(CFU/100ml)


Ammonia as N (mg/L)





Depth at site (m)



Turbidity (NTU)

Temperature (oC)



Salinity (‰)

27/06/2012 June 2012 WQ1S DIF 0 Surface <0.5 170 200 0.19 0.074 0.037 0.111 0.3 0.034 19.5 9.8 3 2.1 17 5.89 8.21 7.6 38.427/06/2012 June 2012 WQ1M DIF 0 Midwater <0.5 42 130 0.42 0.079 0.039 0.118 0.54 0.027 19.5 9.8 1.9 16.9 5.92 8.21 7.6 38.627/06/2012 June 2012 WQ2S DIF 0 Surface <0.5 170 230 0.23 0.069 0.037 0.106 0.34 0.023 21.2 10.6 3 4.6 17 5.88 8.23 7.6 38.527/06/2012 June 2012 WQ2M DIF 0 Midwater <0.5 130 190 0.1 0.038 0.038 0.076 0.18 0.016 21.2 10.6 1.8 17 5.90 8.24 7.7 38.527/06/2012 June 2012 WQ3S DIF 0 Surface <0.5 160 160 0.2 0.068 0.037 0.105 0.3 0.013 22.2 11.1 3 2.5 17 5.90 8.23 7.5 38.527/06/2012 June 2012 WQ3M DIF 0 Midwater <0.5 200 200 0.28 0.153 0.037 0.19 0.47 0.031 22.2 11.1 2.1 17 5.91 8.21 8.3 38.627/06/2012 June 2012 WQ4S DIF 0 Surface <0.5 130 190 0.15 0.054 0.037 0.091 0.24 0.026 23 11.5 2.5 2.1 17 5.91 8.24 8.5 38.627/06/2012 June 2012 WQ4M DIF 0 Midwater <0.5 4 9 <0.05 0.01 0.036 0.046 0.04 0.008 23 11.5 1.1 17 5.92 8.24 7.7 38.727/06/2012 June 2012 WQ5S N 30 Surface <0.5 110 210 0.14 0.055 0.039 0.094 0.23 0.017 21.4 10.7 3 2.2 16.9 5.91 8.22 8.4 38.627/06/2012 June 2012 WQ5M N 30 Midwater <0.5 11 43 0.1 0.015 0.038 0.053 0.15 0.011 21.4 10.7 2.7 17 5.90 8.23 7.9 38.627/06/2012 June 2012 WQ6S E 30 Surface <0.5 120 160 0.18 0.065 0.038 0.103 0.28 0.024 21.4 10.7 2 2.2 17 5.91 8.24 7.9 38.627/06/2012 June 2012 WQ6M E 30 Midwater <0.5 130 170 0.1 0.069 0.038 0.107 0.21 0.022 21.4 10.7 1.5 17 5.90 8.24 7.6 38.627/06/2012 June 2012 WQ7S S 30 Surface <0.5 160 180 0.22 0.064 0.037 0.101 0.32 0.034 23.2 11.6 2.5 2.2 17 5.91 8.24 7.6 38.627/06/2012 June 2012 WQ7M S 30 Midwater <0.5 6 11 0.11 0.014 0.036 0.05 0.16 0.006 23.2 11.6 1.9 17 5.91 8.22 7.7 38.627/06/2012 June 2012 WQ8S W 30 Surface <0.5 4 1 0.11 0.012 0.038 0.05 0.16 0.014 20.8 10.4 2.5 2.8 17 5.91 8.24 8.2 38.627/06/2012 June 2012 WQ8M W 30 Midwater <0.5 4 4 <0.05 0.016 0.037 0.053 0.1 0.014 20.8 10.4 1.4 17 5.92 8.2 7.7 38.727/06/2012 June 2012 WQ9S N 100 Surface <0.5 42 130 0.09 0.04 0.038 0.078 0.17 0.013 22.8 11.4 2.5 1.3 17 5.91 8.22 7.9 38.627/06/2012 June 2012 WQ9M N 100 Midwater <0.5 25 79 0.12 0.012 0.044 0.056 0.18 0.009 22.8 11.4 1.4 17 5.91 8.22 9.6 38.627/06/2012 June 2012 WQ10S E 100 Surface <0.5 170 250 0.09 0.08 0.037 0.117 0.21 0.024 24 12.0 3 1.3 17 5.91 8.24 7.5 38.627/06/2012 June 2012 WQ10M E 100 Midwater <0.5 60 180 0.22 0.015 0.038 0.053 0.27 0.03 24 12.0 1.7 17 5.93 8.24 7.7 38.727/06/2012 June 2012 WQ11S E 100 Surface <0.5 200 210 0.18 0.044 0.041 0.085 0.26 0.036 24 12.0 2 2.3 17 5.92 8.23 7.7 38.627/06/2012 June 2012 WQ11M E 100 Midwater <0.5 130 150 <0.05 0.015 0.037 0.052 0.08 0.017 24 12.0 1.1 17 5.92 8.23 8.2 38.727/06/2012 June 2012 WQ12S E 100 Surface <0.5 2 1 0.06 <0.005 0.038 0.038 0.1 0.016 24 12.0 3 1 17.1 5.91 8.26 7.4 38.627/06/2012 June 2012 WQ12M E 100 Midwater <0.5 7 7 0.06 <0.005 0.037 0.037 0.1 0.014 24 12.0 1.4 17.1 5.91 8.23 7.8 38.627/06/2012 June 2012 WQ13S S 100 Surface <0.5 7 1 <0.05 <0.005 0.036 0.036 0.08 0.014 23.5 11.8 3 0.9 17.1 5.92 8.25 7.5 38.727/06/2012 June 2012 WQ13M S 100 Midwater <0.5 5 <1 0.11 <0.005 0.036 0.036 0.15 0.016 23.5 11.8 1.1 17.1 5.92 8.24 7.9 38.727/06/2012 June 2012 WQ14S S 100 Surface <0.5 <1 <1 0.05 <0.005 0.037 0.037 0.09 0.013 22 11.0 2.5 2.9 17.1 5.91 8.24 7.5 38.727/06/2012 June 2012 WQ14M S 100 Midwater <0.5 4 2 <0.05 <0.005 0.037 0.037 0.06 0.008 22 11.0 1.3 17 5.93 8.24 7.8 38.727/06/2012 June 2012 WQ15S W 100 Surface <0.5 11 <1 <0.05 <0.005 0.035 0.035 0.06 0.008 21.6 10.8 2.5 2.1 17.1 5.91 8.25 7.6 38.627/06/2012 June 2012 WQ15M W 100 Midwater <0.5 1 <1 0.06 <0.005 0.036 0.036 0.1 0.012 21.6 10.8 1.2 17 5.93 8.24 7.8 38.627/06/2012 June 2012 WQ16S W 100 Surface <0.5 82 140 0.1 0.069 0.036 0.105 0.2 0.022 22 11.0 2.5 2.9 17.1 5.90 8.24 7.5 38.527/06/2012 June 2012 WQ16M W 100 Midwater <0.5 78 120 0.06 0.046 0.036 0.082 0.14 0.012 22 11.0 1.5 17 5.92 8.24 7.8 38.627/06/2012 June 2012 WQ17S N 250 Surface <0.5 72 110 0.05 0.044 0.036 0.08 0.13 0.017 22.5 11.3 2.5 1.2 17 5.91 8.24 7.5 38.627/06/2012 June 2012 WQ17M N 250 Midwater <0.5 19 32 <0.05 0.011 0.037 0.048 0.06 0.009 22.5 11.3 1.2 16.9 5.92 8.23 7.7 38.728/06/2012 June 2012 WQ18S E 250 Surface <0.5 110 150 0.08 0.06 0.042 0.102 0.18 0.032 24 12.0 2.5 1.7 16.7 5.90 8.25 7.4 38.528/06/2012 June 2012 WQ18M E 250 Midwater <0.5 34 42 0.12 <0.005 0.039 0.039 0.16 0.013 24 12.0 2.2 16.8 5.92 8.23 7.9 38.627/06/2012 June 2012 WQ19S E 250 Surface <0.5 <1 <1 0.1 <0.005 0.036 0.036 0.14 0.012 24.8 12.4 3 1 17.1 5.92 8.24 7.5 38.727/06/2012 June 2012 WQ19M E 250 Midwater <0.5 1 <1 <0.05 0.006 0.037 0.043 0.06 0.011 24.8 12.4 0.7 17.1 5.91 8.23 7.9 38.728/06/2012 June 2012 WQ20S E 250 Surface <0.5 120 140 0.1 0.045 0.038 0.083 0.18 0.022 24 12.0 2.5 1 16.8 5.89 8.26 7.4 38.428/06/2012 June 2012 WQ20M E 250 Midwater <0.5 80 26 0.1 0.013 0.04 0.053 0.15 0.015 24 12.0 1.3 16.9 5.92 8.24 7.5 38.727/06/2012 June 2012 WQ21S S 250 Surface <0.5 39 120 <0.05 0.038 0.036 0.074 0.12 0.013 23.5 11.8 1.9 17 5.90 8.24 7.5 38.627/06/2012 June 2012 WQ21M S 250 Midwater <0.5 5 28 0.05 0.009 0.038 0.047 0.1 0.014 23.5 11.8 1.4 17 5.92 8.24 7.5 38.728/06/2012 June 2012 WQ22S S 250 Surface <0.5 110 130 0.07 0.033 0.038 0.071 0.14 0.02 21.5 10.8 3 0.6 16.8 5.89 8.24 7.4 38.428/06/2012 June 2012 WQ22M S 250 Midwater <0.5 89 46 <0.05 <0.005 0.038 0.038 0.07 0.008 21.5 10.8 0.6 17 5.92 8.24 7.9 38.727/06/2012 June 2012 WQ23S W 250 Surface <0.5 2 <1 0.08 <0.005 0.035 0.035 0.11 0.015 19 9.5 3 0.7 17.1 5.91 8.24 7.5 38.627/06/2012 June 2012 WQ23M W 250 Midwater <0.5 1 1 <0.05 <0.005 0.034 0.034 0.08 0.016 19 9.5 1.1 17 5.93 8.23 7.7 38.728/06/2012 June 2012 WQ24S W 250 Surface <0.5 51 130 0.06 0.026 0.039 0.065 0.12 0.018 22 11.0 2.5 1.7 16.8 5.90 8.24 7.4 38.528/06/2012 June 2012 WQ24M W 250 Midwater <0.5 120 84 <0.05 <0.005 0.038 0.038 0.08 0.014 22 11.0 1.5 16.8 5.92 8.23 7.6 38.727/06/2012 June 2012 WQ25S E 500 Surface <0.5 120 130 <0.05 0.023 0.031 0.054 0.09 0.018 25.7 12.9 2.5 1.6 17 5.92 8.23 7.5 38.727/06/2012 June 2012 WQ25M E 500 Midwater <0.5 14 44 <0.05 <0.005 0.034 0.034 0.02 <0.005 25.7 12.9 0.9 17 5.93 8.24 7.6 38.728/06/2012 June 2012 WQ26S E 500 Surface <0.5 130 120 0.1 0.02 0.038 0.058 0.16 0.016 26 13.0 3 0.7 16.9 5.91 8.24 7.3 38.628/06/2012 June 2012 WQ26M E 500 Midwater <0.5 11 14 0.07 <0.005 0.04 0.04 0.11 0.009 26 13.0 1.5 16.9 5.93 8.23 7.6 38.627/06/2012 June 2012 WQ27S S 500 Surface <0.5 2 1 <0.05 <0.005 0.034 0.034 0.02 0.011 24 12.0 3 0.9 17.1 5.92 8.24 7.6 38.727/06/2012 June 2012 WQ27M S 500 Midwater <0.5 1 1 <0.05 <0.005 0.029 0.029 0.06 0.009 24 12.0 1.02 17.1 5.92 8.24 7.7 38.728/06/2012 June 2012 WQ28S W 500 Surface <0.5 49 92 0.07 0.021 0.038 0.059 0.13 0.015 18.3 9.2 2.5 1.3 16.8 5.90 8.25 7.4 38.528/06/2012 June 2012 WQ28M W 500 Midwater <0.5 22 120 0.09 0.035 0.037 0.072 0.16 0.014 18.3 9.2 1.4 16.8 5.91 8.24 7.7 38.527/06/2012 June 2012 WQ29S REFNE 2000 Surface <0.5 70 140 0.06 0.02 0.033 0.053 0.11 0.015 19.7 9.9 2.5 0.7 16.8 5.91 8.25 7.7 38.227/06/2012 June 2012 WQ29M REFNE 2000 Midwater <0.5 45 150 <0.05 0.024 0.039 0.063 0.08 0.017 19.7 9.9 1 16.7 5.93 8.24 8.1 38.728/06/2012 June 2012 WQ30S REFNE 2000 Surface <0.5 16 22 0.31 0.009 0.044 0.053 0.36 0.017 25 12.5 2 0.9 16.6 5.93 8.21 7.5 38.528/06/2012 June 2012 WQ30M REFNE 2000 Midwater <0.5 13 36 0.26 0.015 0.052 0.067 0.33 0.016 25 12.5 1.4 16.5 5.93 8.18 7.8 38.627/06/2012 June 2012 WQ31S REFSW 2000 Surface <0.5 <1 1 <0.05 <0.005 0.036 0.036 0.04 0.012 24.7 12.4 3 0.9 16.8 5.90 8.25 7.8 38.527/06/2012 June 2012 WQ31M REFSW 2000 Midwater <0.5 2 1 0.05 <0.005 0.039 0.039 0.09 0.015 24.7 12.4 0.7 16.8 5.90 8.25 7.8 38.528/06/2012 June 2012 WQ32S REFSW 2000 Surface <0.5 2 <1 0.07 <0.005 0.039 0.039 0.11 0.012 20 10.0 2 0.7 16.6 5.89 8.24 7.4 38.428/06/2012 June 2012 WQ32M REFSW 2000 Midwater <0.5 2 <1 <0.05 <0.005 0.039 0.039 0.01 0.015 20 10.0 1.5 16.7 5.92 8.23 8 38.6


NB2: Data in italics were not included in statistical analyses due to suspected equipment malfunction.

October 2012


diffuser (m)Depth



Faecal Coliforms

(CFU/100ml)


Ammonia as N (mg/L)





Depth at site (m)



Turbidity (NTU)

Temperature (oC)



Salinity (‰)

15/10/2012 October 2012 WQ1S DIF 0 Surface 1 57 480 0.3 0.062 0.006 0.068 0.37 0.026 23 11.5 2.5 <2 17.7 5.81 8.33 11.44 32.415/10/2012 October 2012 WQ1M DIF 0 Midwater 2 20 88 0.2 0.012 0.002 0.014 0.21 0.019 23 11.5 <2 18 5.82 8.34 11.15 32.115/10/2012 October 2012 WQ2S DIF 0 Surface 3 72 350 0.14 0.111 0.004 0.115 0.25 0.025 21.9 11.0 2.5 <2 18.1 5.78 8.34 11.47 31.915/10/2012 October 2012 WQ2M DIF 0 Midwater 2 43 210 0.11 0.072 0.004 0.076 0.19 0.024 21.9 11.0 <2 18 5.77 8.33 11.23 31.915/10/2012 October 2012 WQ3S DIF 0 Surface 2 120 560 0.19 0.09 0.003 0.093 0.28 0.023 19.5 9.3 2 <2 18.1 5.69 8.34 11.61 31.615/10/2012 October 2012 WQ3M DIF 0 Midwater <0.5 52 210 0.18 0.041 <0.002 0.041 0.22 0.023 19.5 9.3 <2 18 5.80 8.33 11.43 32.115/10/2012 October 2012 WQ4S DIF 0 Surface 1 62 230 0.11 0.088 0.003 0.091 0.2 0.024 21.4 10.7 2 <2 18.1 5.79 8.33 11.48 31..915/10/2012 October 2012 WQ4M DIF 0 Midwater 2 32 120 0.12 0.036 <0.002 0.036 0.16 0.022 21.4 10.7 <2 18 5.79 8.34 11.65 32.115/10/2012 October 2012 WQ5S N 30 Surface 2 41 260 0.14 0.036 0.003 0.039 0.18 0.022 21.8 10.9 2.5 <2 18.2 5.78 8.33 11.95 3215/10/2012 October 2012 WQ5M N 30 Midwater 2 27 210 0.22 0.021 0.003 0.024 0.24 0.017 21.8 10.9 <2 18.1 5.79 8.34 11.82 32.116/10/2012 October 2012 WQ6S E 30 Surface 2 95 240 0.5 0.058 0.004 0.062 0.56 0.03 22.4 11.0 2 <2 18.1 5.78 8.34 11.65 3216/10/2012 October 2012 WQ6M E 30 Midwater 1 51 180 0.09 0.029 <0.002 0.029 0.12 0.018 22.4 11.0 <2 18 5.83 8.35 11.58 32.215/10/2012 October 2012 WQ7S S 30 Surface 2 67 230 0.17 0.06 0.002 0.062 0.23 0.04 24 12.0 2.5 <2 18.1 5.80 8.34 11.59 31.915/10/2012 October 2012 WQ7M S 30 Midwater 2 33 170 0.1 0.026 <0.002 0.026 0.13 0.018 24 12.0 <2 18 5.79 8.3 11.54 3216/10/2012 October 2012 WQ8S W 30 Surface 3 110 260 0.13 0.054 0.003 0.057 0.19 0.019 22.1 11.0 2 <2 18 5.80 8.33 11.65 3216/10/2012 October 2012 WQ8M W 30 Midwater 2 150 250 0.17 0.036 0.003 0.039 0.21 0.025 22.1 11.0 <2 18 5.82 8.37 11.54 32.215/10/2012 October 2012 WQ9S N 100 Surface 2 <1 5 0.08 <0.005 <0.002 <0.005 0.08 0.017 22.6 11.3 2.5 <2 18.3 5.79 8.32 11.78 32.215/10/2012 October 2012 WQ9M N 100 Midwater 1 4 2 0.18 <0.005 0.002 <0.005 0.18 0.018 22.6 11.3 <2 18.1 5.78 8.32 12.23 3215/10/2012 October 2012 WQ10S E 100 Surface 3 87 250 0.14 0.102 0.003 0.105 0.25 0.033 23.6 11.8 2.5 <2 18.1 5.77 8.33 11.83 31.915/10/2012 October 2012 WQ10M E 100 Midwater 2 52 200 0.11 0.048 0.002 0.05 0.16 0.018 23.6 11.8 <2 18.1 5.79 8.34 11.62 3215/10/2012 October 2012 WQ11S E 100 Surface 2 110 230 0.14 0.02 <0.002 0.02 0.16 0.022 24.8 12.4 2.5 <2 18.2 5.79 8.31 11.49 3215/10/2012 October 2012 WQ11M E 100 Midwater <0.5 41 81 0.11 0.007 0.002 0.009 0.12 0.016 24.8 12.4 <2 18.2 5.79 8.29 11.74 3215/10/2012 October 2012 WQ12S E 100 Surface 2 57 220 0.11 0.099 0.003 0.102 0.21 0.026 23.6 11.8 2.5 <2 18.2 5.78 8.33 11.73 31.915/10/2012 October 2012 WQ12M E 100 Midwater 3 42 170 0.15 0.044 0.003 0.047 0.2 0.026 23.6 11.8 <2 18.2 5.79 8.33 11.63 3215/10/2012 October 2012 WQ13S S 100 Surface 2 260 190 0.17 0.048 0.004 0.052 0.22 0.044 23.6 11.8 2.5 <2 18.2 5.82 8.31 11.78 3215/10/2012 October 2012 WQ13M S 100 Midwater 2 67 240 0.17 0.023 <0.002 0.023 0.19 0.03 23.6 11.8 <2 18.1 5.79 8.31 12.16 3215/10/2012 October 2012 WQ14S S 100 Surface 2 1000 540 0.17 0.084 0.002 0.086 0.26 0.042 23.6 11.8 2.5 <2 18.2 5.77 8.31 11.66 31.915/10/2012 October 2012 WQ14M S 100 Midwater 1 79 270 0.09 0.025 0.003 0.028 0.12 0.022 23.6 11.8 <2 18 5.80 8.3 11.42 32.115/10/2012 October 2012 WQ15S W 100 Surface 2 62 300 0.12 0.062 0.003 0.065 0.18 0.023 21.4 10.7 2.5 <2 18.1 5.78 8.33 12.09 32.215/10/2012 October 2012 WQ15M W 100 Midwater <0.5 32 250 0.11 0.046 <0.002 0.046 0.16 0.019 21.4 10.7 <2 18 5.84 8.3 11.61 32.115/10/2012 October 2012 WQ16S W 100 Surface 2 52 230 0.11 0.099 0.002 0.101 0.21 0.022 20 10.0 3 <2 18.3 5.77 8.31 11.48 3215/10/2012 October 2012 WQ16M W 100 Midwater <0.5 76 230 0.11 0.09 0.002 0.092 0.2 0.016 20 10.0 <2 18 5.80 8.3 10.87 3215/10/2012 October 2012 WQ17S N 250 Surface 2 <1 <1 0.07 <0.005 <0.002 <0.005 0.07 0.016 22.9 11.5 2.5 <2 18.3 5.79 8.3 11.97 3215/10/2012 October 2012 WQ17M N 250 Midwater 2 1 5 0.07 <0.005 <0.002 <0.005 0.07 0.008 22.9 11.5 <2 18 5.79 8.31 12.3 3215/10/2012 October 2012 WQ18S E 250 Surface <0.5 34 52 0.11 0.06 0.003 0.063 0.17 0.018 23.9 12.0 2.5 <2 18.3 5.79 8.33 11.12 3215/10/2012 October 2012 WQ18M E 250 Midwater <0.5 11 9 0.11 0.025 0.002 0.027 0.14 0.014 23.9 12.0 <2 18.1 5.79 8.3 11.45 3215/10/2012 October 2012 WQ19S E 250 Surface 1 <1 <1 0.08 <0.005 <0.002 <0.005 0.08 0.006 25.5 12.7 2.5 <2 18.3 5.79 8.33 12.1 3215/10/2012 October 2012 WQ19M E 250 Midwater 1 <1 <1 0.12 <0.005 <0.002 <0.005 0.12 0.009 25.5 12.7 <2 18.3 5.78 8.32 12.17 3215/10/2012 October 2012 WQ20S E 250 Surface <0.5 16 66 0.1 0.077 0.002 0.079 0.18 0.014 24.2 12.1 2.5 <2 18.3 5.78 8.31 11.04 31.915/10/2012 October 2012 WQ20M E 250 Midwater 1 16 32 0.09 0.028 0.004 0.032 0.12 0.011 24.2 12.1 <2 18 5.79 8.33 11.33 32.115/10/2012 October 2012 WQ21S S 250 Surface 3 <1 <1 0.09 <0.005 <0.002 <0.005 0.09 0.006 24 12.0 2.5 <2 18.2 5.78 8.31 12.04 3215/10/2012 October 2012 WQ21M S 250 Midwater <0.5 <1 <1 0.11 <0.005 0.003 <0.005 0.11 0.012 24 12.0 <2 18 5.79 8.3 12.2 3215/10/2012 October 2012 WQ22S S 250 Surface <0.5 65 54 0.13 0.063 0.003 0.066 0.2 0.022 22 11.0 2.5 <2 18.3 5.75 8.31 11.24 31.915/10/2012 October 2012 WQ22M S 250 Midwater <0.5 45 34 0.14 0.023 <0.002 0.023 0.16 0.015 22 11.0 <2 18.1 5.79 8.32 11.29 32.115/10/2012 October 2012 WQ23S W 250 Surface 2 8 2 0.1 <0.005 0.004 <0.005 0.1 0.008 19.8 9.4 2.5 <2 18.3 5.79 8.31 11.69 3215/10/2012 October 2012 WQ23M W 250 Midwater <0.5 24 59 0.09 0.008 <0.002 0.008 0.1 0.01 19.8 9.4 <2 18 5.79 8.33 11.45 3215/10/2012 October 2012 WQ24S W 250 Surface <0.5 2 <1 0.08 <0.005 <0.002 <0.005 0.08 0.007 22 11.0 2.5 <2 18.6 5.79 8.3 11.16 3215/10/2012 October 2012 WQ24M W 250 Midwater 2 2 12 0.1 <0.005 <0.002 <0.005 0.1 0.01 22 11.0 <2 18 5.79 8.33 12.1 3215/10/2012 October 2012 WQ25S E 500 Surface 2 <1 <1 0.09 <0.005 <0.002 <0.005 0.09 0.006 25.5 12.5 2.5 <2 18 5.79 8.31 11.43 3215/10/2012 October 2012 WQ25M E 500 Midwater <0.5 <1 <1 0.07 <0.005 <0.002 <0.005 0.07 0.007 25.5 12.5 <2 18.1 5.79 8.3 11.95 3215/10/2012 October 2012 WQ26S E 500 Surface <0.5 5 <1 0.11 0.032 <0.002 0.032 0.14 0.005 25.5 12.5 2.5 <2 18.4 5.80 8.3 11.03 32.115/10/2012 October 2012 WQ26M E 500 Midwater <0.5 3 <1 0.16 0.015 <0.002 0.015 0.18 0.012 25.5 12.5 <2 18 5.80 8.33 11.92 32.115/10/2012 October 2012 WQ27S S 500 Surface <0.5 59 18 0.14 0.015 <0.002 0.015 0.16 0.011 23.8 12.0 2.5 <2 18.3 5.80 8.31 11.39 3215/10/2012 October 2012 WQ27M S 500 Midwater <0.5 51 47 0.15 0.008 0.002 0.01 0.16 0.008 23.8 12.0 <2 18 5.80 8.32 11.91 32.115/10/2012 October 2012 WQ28S W 500 Surface <0.5 <1 <1 0.09 <0.005 <0.002 <0.005 0.09 <0.005 18.5 9.2 2.5 <2 18.6 5.79 8.33 11.38 3215/10/2012 October 2012 WQ28M W 500 Midwater <0.5 <1 1 0.11 <0.005 <0.002 <0.005 0.11 <0.005 18.5 9.2 <2 18.1 5.79 8.31 11.85 32.115/10/2012 October 2012 WQ29S REFNE 2000 Surface <0.5 1 <1 0.11 <0.005 0.003 <0.005 0.11 0.008 17.9 9.0 2.5 <2 18.4 5.82 8.33 11.17 32.115/10/2012 October 2012 WQ29M REFNE 2000 Midwater <0.5 <1 <1 0.08 0.011 0.004 0.015 0.1 0.012 17.9 9.0 <2 18.1 5.79 8.32 12.13 32.115/10/2012 October 2012 WQ30S REFNE 2000 Surface <0.5 1 9 0.1 <0.005 <0.002 <0.005 0.1 <0.005 24.5 12.2 2.5 <2 18.5 5.79 8.33 11.27 32.115/10/2012 October 2012 WQ30M REFNE 2000 Midwater <0.5 <1 <1 0.09 <0.005 <0.002 <0.005 0.09 0.007 24.5 12.2 <2 18.1 5.80 8.31 11.99 32.115/10/2012 October 2012 WQ31S REFSW 2000 Surface <0.5 7 1 0.08 <0.005 0.002 <0.005 0.08 0.006 24 12.0 2.5 <2 18.5 5.80 8.31 11.61 3215/10/2012 October 2012 WQ31M REFSW 2000 Midwater <0.5 11 56 0.12 <0.005 0.003 <0.005 0.12 0.006 24 12.0 <2 18.1 5.79 8.33 12.23 3215/10/2012 October 2012 WQ32S REFSW 2000 Surface <0.5 1 <1 0.11 <0.005 <0.002 <0.005 0.11 0.009 20.7 10.4 2.5 <2 18.6 5.80 8.32 12.24 3215/10/2012 October 2012 WQ32M REFSW 2000 Midwater <0.5 4 28 0.1 <0.005 <0.002 <0.005 0.1 0.008 20.7 10.4 <2 18.1 5.79 8.3 12.53 32



February 2012


diffuser (m)Depth



Faecal Coliforms

(CFU/100ml)


Ammonia as N (mg/L)





Depth at site (m)



Turbidity (NTU)

Temperature (oC)



Salinity (‰)

5/02/2013 February 2013 WQ1S DIF 0 Surface 1.1 34 660 0.22 0.044 0.007 0.051 0.27 0.008 21.2 10.6 2 4.3 22.5 5.63 8.2 9.62 39.25/02/2013 February 2013 WQ1M DIF 0 Midwater 1.4 59 1200 0.38 0.121 0.013 0.134 0.51 0.018 21.2 10.6 3.1 22.5 5.67 8.19 9.54 39.55/02/2013 February 2013 WQ2S DIF 0 Surface <1.0 18 210 0.16 0.014 0.005 0.019 0.18 <0.005 21.4 10.7 2.5 4.3 22.5 5.64 8.16 9.53 39.35/02/2013 February 2013 WQ2M DIF 0 Midwater <0.5 23 300 0.16 0.087 0.011 0.098 0.26 <0.005 21.4 10.7 2.9 22.6 5.67 8.16 9.38 39.45/02/2013 February 2013 WQ3S DIF 0 Surface 1.2 51 1100 0.21 0.024 0.007 0.031 0.24 <0.005 20 10.0 3 5.8 22.5 5.62 8.19 9.69 39.25/02/2013 February 2013 WQ3M DIF 0 Midwater 1.3 40 750 0.14 0.068 0.008 0.076 0.22 <0.005 20 10.0 3.1 22.5 5.67 8.18 9.47 39.55/02/2013 February 2013 WQ4S DIF 0 Surface 0.8 69 610 0.11 0.008 0.004 0.012 0.12 <0.005 21 10.5 2.5 2.5 22.9 5.66 8.18 9.51 39.45/02/2013 February 2013 WQ4M DIF 0 Midwater 0.6 1 <1 0.14 <0.005 0.005 0.005 0.14 <0.005 21 10.5 3.3 22.6 5.65 8.16 9.68 39.45/02/2013 February 2013 WQ5S N 30 Surface 0.5 8 9 0.2 <0.005 0.005 0.005 0.2 <0.005 21 10.5 2.5 3.1 22.5 5.65 8.18 9.56 39.45/02/2013 February 2013 WQ5M N 30 Midwater 0.9 36 770 0.19 0.065 0.007 0.072 0.26 0.008 21 10.5 2.6 22.5 5.67 8.17 9.47 39.56/02/2013 February 2013 WQ6S E 30 Surface 0.6 2 28 0.19 0.009 <0.002 0.009 0.2 <0.005 20 10.0 2.5 2.5 22.9 5.67 8.34 9.52 39.56/02/2013 February 2013 WQ6M E 30 Midwater 0.5 1 40 0.15 0.025 0.003 0.028 0.18 <0.005 20 10.0 2.4 22.6 5.68 8.21 9.67 39.65/02/2013 February 2013 WQ7S S 30 Surface 0.5 <1 2 0.2 <0.005 0.005 0.005 0.2 <0.005 22.8 11.4 2.5 3.5 22.6 5.64 8.17 9.64 39.35/02/2013 February 2013 WQ7M S 30 Midwater 1.7 2 2 0.16 <0.005 0.005 0.005 0.16 <0.005 22.8 11.4 2.5 22.5 5.67 8.14 9.55 39.56/02/2013 February 2013 WQ8S W 30 Surface 0.9 1 45 0.16 0.016 <0.002 0.016 0.18 <0.005 20.2 10.1 2.5 4.9 22.8 5.61 8.23 9.5 39.36/02/2013 February 2013 WQ8M W 30 Midwater 1.3 4 300 0.15 0.041 0.003 0.044 0.19 <0.005 20.2 10.1 2.8 22.9 5.67 8.2 9.38 39.65/02/2013 February 2013 WQ9S N 100 Surface 1.1 5 10 0.13 <0.005 0.006 0.006 0.14 <0.005 22.3 11.1 1.5 3.7 22.6 5.63 8.23 9.5 39.25/02/2013 February 2013 WQ9M N 100 Midwater 1.9 46 680 0.2 0.034 0.006 0.04 0.24 0.006 22.3 11.1 3 22.5 5.67 8.16 9.36 39.56/02/2013 February 2013 WQ10S E 100 Surface 0.7 1 1 0.16 <0.005 <0.002 <0.005 0.16 <0.005 23 11.5 2 1.9 23.1 5.65 8.24 9.65 39.46/02/2013 February 2013 WQ10M E 100 Midwater 0.9 <1 1 0.19 0.006 0.003 0.009 0.2 <0.005 23 11.5 2.2 22.6 5.68 8.22 9.59 39.65/02/2013 February 2013 WQ11S E 100 Surface 1.2 1 3 0.2 <0.005 0.004 <0.005 0.2 <0.005 23.6 11.8 1.5 3 22.6 5.66 8.19 9.55 39.45/02/2013 February 2013 WQ11M E 100 Midwater 1.3 <1 <1 0.16 <0.005 0.005 0.005 0.17 <0.005 23.6 11.8 2.6 22.5 5.67 8.17 9.53 39.56/02/2013 February 2013 WQ12S E 100 Surface 0.7 1 <1 0.16 <0.005 <0.002 <0.005 0.16 <0.005 23.6 11.8 2 3.1 23.1 5.65 8.23 9.56 39.56/02/2013 February 2013 WQ12M E 100 Midwater 0.6 <1 1 0.24 <0.005 <0.002 <0.005 0.24 <0.005 23.6 11.8 2.4 22.8 5.67 8.22 9.58 39.55/02/2013 February 2013 WQ13S S 100 Surface 1.6 4 <1 0.15 <0.005 0.006 0.006 0.16 <0.005 23.1 11.5 2 3 22.6 5.65 8.18 9.5 39.45/02/2013 February 2013 WQ13M S 100 Midwater <0.5 1 <1 0.18 <0.005 0.007 0.007 0.19 <0.005 23.1 11.5 2.5 22.5 5.67 8.16 9.58 39.56/02/2013 February 2013 WQ14S S 100 Surface 0.6 95 280 0.16 0.023 0.003 0.026 0.19 0.006 21.4 10.7 2.5 4.8 22.9 5.65 8.22 9.41 39.46/02/2013 February 2013 WQ14M S 100 Midwater 0.6 10 230 0.24 0.039 0.004 0.043 0.28 0.006 21.4 10.7 3.1 22.6 5.67 8.19 9.4 39.65/02/2013 February 2013 WQ15S W 100 Surface <0.5 4 12 0.16 0.01 0.006 0.016 0.18 <0.005 20.4 10.2 2 3 22.6 5.66 8.18 9.41 39.45/02/2013 February 2013 WQ15M W 100 Midwater 0.8 2 <1 0.2 <0.005 0.006 0.006 0.21 <0.005 20.4 10.2 2.8 22.5 5.67 8.16 9.55 39.56/02/2013 February 2013 WQ16S W 100 Surface 0.8 8 13 0.17 <0.005 0.002 <0.005 0.17 <0.005 21.9 10.8 2 3.5 22.9 5.65 8.21 9.55 39.46/02/2013 February 2013 WQ16M W 100 Midwater 1.1 2 39 0.19 0.028 0.003 0.031 0.22 <0.005 21.9 10.8 2.8 22.7 5.66 8.19 9.51 39.55/02/2013 February 2013 WQ17S N 250 Surface 1.4 4 <1 0.2 <0.005 0.005 0.005 0.2 <0.005 21.4 10.7 2 3.5 22.6 5.65 8.17 9.58 39.35/02/2013 February 2013 WQ17M N 250 Midwater 1 49 450 0.12 0.029 0.006 0.035 0.16 <0.005 21.4 10.7 2.7 22.5 5.66 8.16 9.45 39.56/02/2013 February 2013 WQ18S E 250 Surface 0.5 1 <1 0.16 <0.005 <0.002 <0.005 0.16 <0.005 23.9 12.0 2 3.1 23.1 5.66 8.21 9.43 39.56/02/2013 February 2013 WQ18M E 250 Midwater 0.9 1 <1 0.18 0.006 <0.002 0.006 0.19 <0.005 23.9 12.0 2.1 22.7 5.68 8.2 9.56 39.65/02/2013 February 2013 WQ19S E 250 Surface 1.6 <1 3 0.22 <0.005 0.005 0.005 0.22 <0.005 24.8 12.4 2.5 4.5 22.7 5.66 8.17 9.41 39.45/02/2013 February 2013 WQ19M E 250 Midwater 0.9 2 <1 0.29 <0.005 0.006 0.006 0.3 <0.005 24.8 12.4 3.3 22.5 5.67 8.16 9.59 39.56/02/2013 February 2013 WQ20S E 250 Surface 0.6 2 1 0.2 <0.005 <0.002 <0.005 0.2 <0.005 23.6 11.8 2.5 2.7 23.1 5.67 8.2 9.72 39.66/02/2013 February 2013 WQ20M E 250 Midwater 0.9 7 <1 0.2 0.017 0.003 0.02 0.22 <0.005 23.6 11.8 2 22.7 5.67 8.17 9.7 39.65/02/2013 February 2013 WQ21S S 250 Surface 1.2 4 60 0.2 <0.005 0.004 <0.005 0.2 <0.005 22.4 11.2 2.5 3.3 22.6 5.65 8.18 9.56 39.35/02/2013 February 2013 WQ21M S 250 Midwater 0.9 48 450 0.2 0.052 0.008 0.06 0.26 0.01 22.4 11.2 2.8 22.5 5.67 8.16 9.4 39.56/02/2013 February 2013 WQ22S S 250 Surface 0.6 29 150 0.25 0.012 <0.002 0.012 0.26 0.005 21.6 10.8 2 8.2 23 5.65 8.21 9.78 39.46/02/2013 February 2013 WQ22M S 250 Midwater 0.5 8 48 0.2 0.038 0.003 0.041 0.24 0.005 21.6 10.8 3.1 22.6 5.67 8.18 9.65 39.65/02/2013 February 2013 WQ23S W 250 Surface 1.5 <1 <1 0.14 <0.005 0.005 0.005 0.15 <0.005 19.1 9.5 2 3.8 22.7 5.65 8.18 9.42 39.35/02/2013 February 2013 WQ23M W 250 Midwater <0.5 <1 <1 0.22 <0.005 0.004 <0.005 0.22 0.007 19.1 9.5 2.7 22.5 5.66 8.16 9.55 39.46/02/2013 February 2013 WQ24S W 250 Surface 0.5 2 <1 0.22 <0.005 <0.002 <0.005 0.22 <0.005 21.1 10.5 2 3.3 23.3 5.66 8.21 9.56 39.66/02/2013 February 2013 WQ24M W 250 Midwater 0.7 4 <1 0.2 <0.005 <0.002 <0.005 0.2 <0.005 21.1 10.5 3.1 22.6 5.67 8.18 9.79 39.55/02/2013 February 2013 WQ25S E 500 Surface 2.3 <1 <1 0.14 <0.005 0.004 <0.005 0.14 <0.005 24.4 12.2 2 2.7 22.8 5.66 8.18 9.65 39.45/02/2013 February 2013 WQ25M E 500 Midwater 1.1 2 <1 0.11 <0.005 0.007 0.007 0.12 <0.005 24.4 12.2 2.3 22.5 5.68 8.17 9.65 39.66/02/2013 February 2013 WQ26S E 500 Surface 1.1 3 <1 0.18 <0.005 <0.002 <0.005 0.18 <0.005 25 12.5 2.5 6.2 23.1 5.67 8.21 9.69 39.66/02/2013 February 2013 WQ26M E 500 Midwater 0.9 5 <1 0.18 <0.005 <0.002 <0.005 0.18 <0.005 25 12.5 3.2 22.8 5.67 8.21 9.89 39.55/02/2013 February 2013 WQ27S S 500 Surface 1.4 <1 <1 0.19 <0.005 0.004 <0.005 0.19 <0.005 22.4 11.2 2.5 6.2 22.8 5.65 8.17 9.68 39.45/02/2013 February 2013 WQ27M S 500 Midwater 0.6 4 <1 0.13 0.008 0.005 0.013 0.14 <0.005 22.4 11.2 3.2 22.5 5.67 8.17 9.6 39.56/02/2013 February 2013 WQ28S W 500 Surface 0.8 4 <1 0.23 <0.005 0.003 <0.005 0.23 <0.005 17.5 7.8 2 3.3 23.4 5.66 8.23 9.56 39.66/02/2013 February 2013 WQ28M W 500 Midwater 0.8 2 <1 0.19 <0.005 <0.002 <0.005 0.19 <0.005 17.5 7.8 3 22.9 5.67 8.24 9.77 39.66/02/2013 February 2013 WQ29S REFNE 2000 Surface <0.5 3 <1 0.18 <0.005 0.003 <0.005 0.18 <0.005 18.4 9.2 2 4.7 23.4 5.67 8.21 9.95 39.56/02/2013 February 2013 WQ29M REFNE 2000 Midwater <0.5 15 <1 0.15 0.02 <0.002 0.02 0.17 <0.005 18.4 9.2 2.7 22.6 5.68 8.21 9.66 39.66/02/2013 February 2013 WQ30S REFNE 2000 Surface <0.5 3 <1 0.18 <0.005 <0.002 <0.005 0.18 <0.005 24.6 12.3 2 3.1 23.1 5.67 8.24 9.66 39.56/02/2013 February 2013 WQ30M REFNE 2000 Midwater <0.5 7 <1 0.18 <0.005 <0.002 <0.005 0.18 <0.005 24.6 12.3 2.2 22.8 5.68 8.24 9.69 39.65/02/2013 February 2013 WQ31S REFSW 2000 Surface 0.8 <1 <1 0.14 <0.005 0.003 <0.005 0.14 <0.005 22.6 11.3 2 4.7 22.7 5.65 8.17 9.42 39.45/02/2013 February 2013 WQ31M REFSW 2000 Midwater 0.8 <1 <1 0.16 <0.005 0.006 0.006 0.17 <0.005 22.6 11.3 2.7 22.5 5.67 8.17 9.73 39.66/02/2013 February 2013 WQ32S REFSW 2000 Surface 0.5 2 10 0.4 0.011 0.003 0.014 0.41 <0.005 20 10.0 2 3.7 23.1 5.68 8.28 10.18 39.66/02/2013 February 2013 WQ32M REFSW 2000 Midwater 0.7 2 <1 0.39 0.012 <0.002 0.012 0.4 <0.005 20 10.0 3.7 22.6 5.67 8.24 9.77 39.5


April 2013


diffuser (m)Depth



Faecal Coliforms

(CFU/100ml)


Ammonia as N (mg/L)





Depth at site (m)



Turbidity (NTU)

Temperature (oC)



Salinity (‰)

2/04/2013 April 2013 WQ1S DIF 0 Surface 0.7 96 1200 0.23 0.083 0.003 0.086 0.32 0.007 21.8 10.9 2 0.8 22.7 4.80 8.62 7.08 40.12/04/2013 April 2013 WQ1M DIF 0 Midwater 0.7 12 190 0.46 0.025 <0.002 0.025 0.48 0.006 21.8 10.9 0.5 22.9 4.87 9.11 6.69 40.92/04/2013 April 2013 WQ2S DIF 0 Surface 0.8 60 400 0.15 0.071 <0.002 0.071 0.22 0.005 22 11.0 2 0.2 22.8 4.88 9.44 7.13 40.82/04/2013 April 2013 WQ2M DIF 0 Midwater <0.5 32 220 0.16 0.012 <0.002 0.012 0.17 <0.005 22 11.0 0 22.9 4.89 9.25 6.45 412/04/2013 April 2013 WQ3S DIF 0 Surface 0.9 100 1400 0.18 0.125 <0.002 0.125 0.31 0.009 21 10.5 2 1.2 22.8 4.82 9.2 7.73 40.32/04/2013 April 2013 WQ3M DIF 0 Midwater <0.5 380 1200 0.23 0.033 <0.002 0.033 0.26 0.01 21 10.5 1.6 22.8 4.89 9.15 8.52 41.12/04/2013 April 2013 WQ4S DIF 0 Surface 0.7 370 5500 0.21 0.068 <0.002 0.068 0.28 0.04 22.4 11.2 1 2.6 22.9 4.88 9.37 6.85 412/04/2013 April 2013 WQ4M DIF 0 Midwater 0.7 120 250 0.13 0.012 <0.002 0.012 0.14 <0.005 22.4 11.2 0 22.9 4.90 9.26 6.43 41.12/04/2013 April 2013 WQ5S N 30 Surface 0.6 110 510 0.19 0.06 0.003 0.063 0.25 <0.005 21.2 10.6 2 1.1 22 4.86 9.2 7.48 40.62/04/2013 April 2013 WQ5M N 30 Midwater 0.7 10 61 0.16 0.012 <0.002 0.012 0.17 <0.005 21.2 10.6 0.4 22.9 4.89 9.15 6.83 412/04/2013 April 2013 WQ6S E 30 Surface 0.7 140 450 0.14 0.086 0.005 0.091 0.23 0.006 21.4 10.7 2 0.5 22.8 4.88 9.28 6.91 40.92/04/2013 April 2013 WQ6M E 30 Midwater 0.6 95 390 0.18 0.025 <0.002 0.025 0.2 <0.005 21.4 10.7 0.3 22.8 4.90 9.26 6.65 41.12/04/2013 April 2013 WQ7S S 30 Surface 0.9 120 360 0.21 0.046 <0.002 0.046 0.26 0.032 22.8 11.4 2 0.6 22.4 4.88 9.2 7.62 40.92/04/2013 April 2013 WQ7M S 30 Midwater 0.6 150 400 0.17 0.022 <0.002 0.022 0.19 0.007 22.8 11.4 0.6 22.8 4.89 9.15 7.02 41.12/04/2013 April 2013 WQ8S W 30 Surface 0.7 130 450 0.13 0.065 0.003 0.068 0.2 0.006 21 10.5 2 4.4 22.8 4.89 9.21 6.79 412/04/2013 April 2013 WQ8M W 30 Midwater 0.5 130 350 0.14 <0.005 <0.002 <0.005 0.14 <0.005 21 10.5 0.1 22.8 4.90 9.27 6.63 41.12/04/2013 April 2013 WQ9S N 100 Surface 0.7 40 280 0.15 0.031 <0.002 0.031 0.18 <0.005 23.1 11.6 2.5 1.6 22.8 4.89 9.28 7.29 41.12/04/2013 April 2013 WQ9M N 100 Midwater 0.9 20 91 0.16 0.009 <0.002 0.009 0.17 <0.005 23.1 11.6 0.4 22.8 4.89 9.17 7.08 41.12/04/2013 April 2013 WQ10S E 100 Surface 0.5 60 340 0.14 0.076 0.003 0.079 0.22 <0.005 23.6 11.8 2 0.6 22.8 4.88 9.28 6.43 412/04/2013 April 2013 WQ10M E 100 Midwater <0.5 40 190 0.13 0.018 0.004 0.022 0.15 <0.005 23.6 11.8 0.5 22.8 4.90 9.26 6.63 41.22/04/2013 April 2013 WQ11S E 100 Surface 0.9 200 2000 0.16 0.072 0.012 0.084 0.24 0.015 23.6 11.8 1.5 2.4 22.8 4.88 9.22 6.92 40.92/04/2013 April 2013 WQ11M E 100 Midwater 0.6 150 330 0.16 0.011 <0.002 0.011 0.17 <0.005 23.6 11.8 0.9 22.8 4.89 9.17 6.61 412/04/2013 April 2013 WQ12S E 100 Surface 0.6 180 390 0.14 0.061 <0.002 0.061 0.2 0.018 23.8 11.9 1.5 2.1 23 4.89 9.36 6.4 41.12/04/2013 April 2013 WQ12M E 100 Midwater 0.5 46 84 0.13 0.008 <0.002 0.008 0.14 <0.005 23.8 11.9 0.1 22.9 4.90 9.27 6.57 41.22/04/2013 April 2013 WQ13S S 100 Surface 0.9 1000 1500 0.17 0.071 <0.002 0.071 0.24 0.018 23 11.5 1.5 1.8 22.8 4.88 9.29 6.5 40.92/04/2013 April 2013 WQ13M S 100 Midwater 0.6 50 150 0.16 0.014 <0.002 0.014 0.17 <0.005 23 11.5 0.1 22.8 4.89 9.18 6.6 412/04/2013 April 2013 WQ14S S 100 Surface 0.9 120 360 0.14 0.087 0.002 0.089 0.23 0.009 22 11.0 2 4.6 22.9 4.89 9.37 7.66 41.12/04/2013 April 2013 WQ14M S 100 Midwater 0.5 60 140 0.13 0.01 <0.002 0.01 0.14 <0.005 22 11.0 0.3 22.8 4.89 9.29 6.91 41.12/04/2013 April 2013 WQ15S W 100 Surface 0.5 120 410 0.14 0.093 0.002 0.095 0.24 <0.005 20.5 10.3 3 5.7 22.8 4.87 9.24 6.63 40.92/04/2013 April 2013 WQ15M W 100 Midwater 0.8 52 150 0.17 <0.005 0.002 <0.005 0.17 <0.005 20.5 10.3 0.7 22.8 4.89 9.19 6.46 412/04/2013 April 2013 WQ16S W 100 Surface 0.6 60 230 0.12 0.088 0.039 0.127 0.25 <0.005 21.2 10.6 2 0.6 22.8 4.88 9.38 6.68 40.92/04/2013 April 2013 WQ16M W 100 Midwater <0.5 40 110 0.12 0.01 0.004 0.014 0.13 <0.005 21.2 10.6 0.1 22.8 4.88 9.28 6.58 412/04/2013 April 2013 WQ17S N 250 Surface <0.5 16 43 0.14 0.037 <0.002 0.037 0.18 <0.005 21.8 10.9 2.5 0.6 22.9 4.89 9.29 6.9 41.12/04/2013 April 2013 WQ17M N 250 Midwater <0.5 20 77 0.19 0.017 <0.002 0.017 0.21 <0.005 21.8 10.9 0.4 22.7 4.89 9.2 6.61 412/04/2013 April 2013 WQ18S E 250 Surface <0.5 46 110 0.14 0.077 0.005 0.082 0.22 <0.005 24.4 12.2 1.5 0.3 22.9 4.88 9.28 7.46 40.92/04/2013 April 2013 WQ18M E 250 Midwater <0.5 10 54 0.12 0.016 <0.002 0.016 0.14 <0.005 24.4 12.2 0.3 22.8 4.89 9.26 6.55 41.12/04/2013 April 2013 WQ19S E 250 Surface <0.5 160 270 0.16 0.064 <0.002 0.064 0.22 0.01 24.4 12.2 2.5 1.4 22.9 4.89 9.3 6.76 412/04/2013 April 2013 WQ19M E 250 Midwater 0.6 180 360 0.5 0.016 <0.002 0.016 0.52 <0.005 24.4 12.2 0.4 22.9 4.89 9.21 6.68 41.12/04/2013 April 2013 WQ20S E 250 Surface 0.8 <1 2 0.11 0.008 <0.002 0.008 0.12 <0.005 25 12.5 2 2.3 22.8 4.88 9.41 6.27 412/04/2013 April 2013 WQ20M E 250 Midwater 0.6 4 5 0.14 0.012 0.003 0.015 0.15 <0.005 25 12.5 1 22.9 4.90 9.29 6.74 41.22/04/2013 April 2013 WQ21S S 250 Surface <0.5 34 160 0.11 0.047 0.013 0.06 0.17 <0.005 22.8 11.4 2.5 0.1 22.9 4.88 9.28 6.64 412/04/2013 April 2013 WQ21M S 250 Midwater <0.5 25 59 0.12 0.022 0.004 0.026 0.15 <0.005 22.8 11.4 0.1 22.8 4.89 9.22 6.63 41.12/04/2013 April 2013 WQ22S S 250 Surface <0.5 3 1 0.22 0.008 0.003 0.011 0.23 <0.005 23 11.5 2 0.5 23 4.90 9.43 6.71 412/04/2013 April 2013 WQ22M S 250 Midwater 0.7 <1 5 0.16 0.014 <0.002 0.014 0.17 <0.005 23 11.5 0.2 22.8 4.89 9.29 6.61 41.12/04/2013 April 2013 WQ23S W 250 Surface <0.5 36 110 0.2 0.016 0.002 0.018 0.22 <0.005 19.1 9.6 2 0.3 22.4 4.88 9.36 6.86 40.82/04/2013 April 2013 WQ23M W 250 Midwater 0.6 110 240 0.16 0.092 0.003 0.095 0.25 0.005 19.1 9.6 0 22.8 4.88 9.24 6.56 412/04/2013 April 2013 WQ24S W 250 Surface <0.5 21 44 0.12 0.061 0.005 0.066 0.19 <0.005 24 12.0 2 1 22.9 4.89 9.43 5.91 412/04/2013 April 2013 WQ24M W 250 Midwater <0.5 5 3 0.14 0.016 0.002 0.018 0.16 <0.005 24 12.0 0.1 22.7 4.89 9.31 6.02 412/04/2013 April 2013 WQ25S E 500 Surface 0.7 32 7 0.13 0.059 <0.002 0.059 0.19 <0.005 25.3 12.7 2 4.1 23 4.88 9.43 5.8 412/04/2013 April 2013 WQ25M E 500 Midwater 1.3 16 24 0.13 0.009 <0.002 0.009 0.14 <0.005 25.3 12.7 0.2 22.9 4.89 9.29 5.87 41.12/04/2013 April 2013 WQ26S E 500 Surface 1.8 <1 <1 0.12 0.01 0.002 0.012 0.13 <0.005 26.4 13.2 1.5 3.2 22.9 4.88 9.44 6.44 412/04/2013 April 2013 WQ26M E 500 Midwater <0.5 <1 <1 0.14 <0.005 0.002 <0.005 0.14 <0.005 26.4 13.2 0.5 22.8 4.88 9.3 6.1 412/04/2013 April 2013 WQ27S S 500 Surface <0.5 7 <1 0.14 0.012 <0.002 0.012 0.15 <0.005 23.8 11.9 2 0.5 22.8 4.89 9.21 7 412/04/2013 April 2013 WQ27M S 500 Midwater 0.7 12 35 0.14 0.02 0.003 0.023 0.16 <0.005 23.8 11.9 0 22.8 4.89 9.24 7.03 412/04/2013 April 2013 WQ28S W 500 Surface <0.5 12 9 0.16 0.048 0.002 0.05 0.21 <0.005 19.1 9.6 2.5 1.1 22.9 4.80 9.31 6.43 412/04/2013 April 2013 WQ28M W 500 Midwater 0.5 10 13 0.12 0.015 <0.002 0.015 0.14 <0.005 19.1 9.6 0 22.7 4.89 9.26 6.51 41.12/04/2013 April 2013 WQ29S REFNE 2000 Surface 0.7 2 <1 0.2 <0.005 <0.002 <0.005 0.2 <0.005 18.4 9.2 1.5 0.4 23.1 4.89 9.4 6.52 41.12/04/2013 April 2013 WQ29M REFNE 2000 Midwater <0.5 <1 <1 0.17 <0.005 <0.002 <0.005 0.17 <0.005 18.4 9.2 0.2 22.9 4.89 9.27 5.92 41.12/04/2013 April 2013 WQ30S REFNE 2000 Surface <0.5 <1 <1 0.14 <0.005 <0.002 <0.005 0.14 0.005 25.5 12.8 2 0.1 23.2 4.90 9.37 6.35 41.12/04/2013 April 2013 WQ30M REFNE 2000 Midwater <0.5 <1 <1 0.12 0.006 <0.002 0.006 0.13 <0.005 25.5 12.8 0 23 4.90 9.28 5.89 41.22/04/2013 April 2013 WQ31S REFSW 2000 Surface <0.5 <1 <1 0.17 <0.005 0.01 0.01 0.18 <0.005 23.6 11.8 2 0.1 23 4.90 9.36 6.63 41.12/04/2013 April 2013 WQ31M REFSW 2000 Midwater <0.5 <1 <1 0.14 0.01 <0.002 0.01 0.15 <0.005 23.6 11.8 0.1 22.7 4.89 9.26 6.86 412/04/2013 April 2013 WQ32S REFSW 2000 Surface <0.5 <1 <1 0.13 0.006 0.002 0.008 0.14 <0.005 20.3 10.2 2.5 0.4 22.8 4.88 9.34 6.87 40.92/04/2013 April 2013 WQ32M REFSW 2000 Midwater <0.5 1 9 0.13 0.027 0.003 0.03 0.16 <0.005 20.3 10.2 0.2 22.6 4.88 9.27 6.67 40.9



HUNTER WATER

WATER QUALITY STUDY

BURWOOD BEACH WWTW


Appendix 3 – CEE Analysis of Water Quality Data by

Zone

30 August 2013 Bruce Cole Science Officer Wastewater Planning Hunter Water Corporation 36 Honeysuckle Drive, Newcastle NSW 2300 Dear Bruce, Hunter Water Corporation is conducting a three year environmental assessment of their ocean outfall discharges at Burwood Beach and Boulder Bay. A water quality study is a component of the assessment and is being conducted by Worley Parsons. The collected water quality data was sent to CEE for an independent review of the effects of the outfall discharge on water quality in Burwood Beach. Our interpretation of the water quality data from Burwood Beach is presented in this report. Water Quality Monitoring The water quality monitoring was undertaken to characterise the changes to water quality in Burwood Beach as a result of the effluent discharge and to define the footprint of the changes. Water samples were collected from a boat at a range of distances from the outfall and analysed to determine the concentrations of nutrients (ammonia, oxidised nitrogen, total nitrogen and total phosphorus), microbiological indicators (enterococci and faecal coliforms) and phytoplankton (chlorophyll-a) in a NATA-accredited laboratory. Physicochemical parameters (salinity, temperature, dissolved oxygen and pH) were measured in-situ at the same time as the water samples were collected. Water samples were collected at thirty sites, which were arranged in a radial pattern (at distances of 0 m, 30 m, 100 m, 250 m and 500 m) around the outfall diffuser, with reference sites at a distance of approximately 2 km from the outfall (as shown in Figures 1 and 2). The location of sampling sites took into account the site of the diffuser, prevailing hydrodynamic conditions in the area and plume characteristics. Eight sets of water samples were undertaken over a two year period with samples being collected on each occasion from sites on the surface and at mid-depth. A total of 60 water samples were collected during each sampling round. Table 1 shows the parameters tested, with the level of reporting (LOR) and the water quality guideline levels for each parameter.

CEE PTY LTD ACN 245 986

Environmental Scientists and Engineers

Level 1, 90 Bridge Road, PO Box 201, Richmond VIC 3121

TEL 03 9429 4644 FAX 03 9428 0021 EMAIL [email protected]

Burwood Beach Water Quality Assessment 2

Figure 1 - Location of Burwood Beach Outfall and Monitoring Sites


Figure 2 - Location of Burwood Beach Outfall and Monitoring Sites


Table 1 - Water Quality Parameters

Burwood Beach Waste Water Treatment Works (WWTW) The source of the effluent discharged through the Burwood Beach outfall is the Burwood Beach Wastewater Treatment Works (WWTW). The Burwood Beach WWTW treats wastewater from Newcastle and the surrounding suburbs, serving approximately 185,000 people with an average dry weather flow of 48 million litres of wastewater per day (48 ML/d). Over the next 30 years these flows are expected to increase to 55 - 60 ML/d, even with water conservation measures in place. The secondary treatment process at Burwood Beach WWTW consists of fine screening to remove large and coarse particulates, followed by biological secondary treatment using an innovative cascading filter and activated sludge process including settling. The secondary effluent from Burwood Beach WWTW is discharged to the ocean through a multi-port diffuser which extends 1,500 m offshore, with eight multi-port diffusers at a depth of approximately 22 m. Approximately 2 ML/d of activated sludge, which is surplus to treatment requirements, is discharged to the ocean via a separate multi-port diffuser that extends slightly further offshore than the effluent outfall. Both outfalls have been operating in their current configuration since January 1994.


Effluent Quality The median effluent quality from the Burwood Beach WWTW, based on extensive monitoring by HWC between 2006 and 2013, is summarized in the table below.

Table A – Effluent Characteristics and Signature of Effluent After Dilution

Water Quality Parameter

Units Median Level in Effluent

90 % Level in Effluent

Median Level in Sludge

After Effluent Dilution

After Sludge Dilution

Ammonia mg/L 23 29 24 0.128 0.120

Oxidised Nitrogen mg/L 1.6 3.7 1.0 0.009 0.005

Total Nitrogen mg/L 28 38 29 0.156 0.145

Total Phosphorus mg/L 2.6 4.8 2.3 0.014 0.012

Suspended Solids

mg/L 27 80 3,200 0.2 16

BOD mg/L 23 60 4,000 0.1 20

Salinity ppt 0.5 0.8 0.5 0.003 0.003

Enterococci cfu/ 100 mL

160,000 400,000 1,250,000 900 6,300

Faecal Coliforms cfu/ 100mL

2,500,000 5,000,000 5,500,000 14,000 28,000

From examination of the analyses summarized in the table, it is apparent that the median concentrations of nutrients (ammonia, oxidized nitrogen, total nitrogen and total phosphorus) are very similar in effluent and sludge. On the other hand, the median suspended solids and BOD concentrations are very different in effluent and sludge, with much higher levels of these constituents in the sludge (reflecting the high organic solids content in the sludge). The concentrations of enterococci and faecal coliforms are high in both effluent and sludge, with particularly elevated levels in the sludge. Initial Dilution Consulting Environmental Engineers (CEE 2007) calculated a typical initial dilution of 219:1 for the Burwood effluent outfall, assuming a discharge rate of 43 ML/d and all duckbill valves in operation. Allowing for the reduction in dilution due to higher flows and the orientation of the diffuser ports parallel to the currents, initial dilution now is expected to be around 180:1. The Water Research Lab (WRL 2007) carried out field tests of effluent dilution using rhodamine dye. The dilution of the surface field showed a typical dilution of 185:1. WRL reported an average near-field dilution of 207:1. It is therefore reasonable to base the environmental risk assessment of the effects of effluent discharge on an effluent plume near the ocean surface with an initial dilution in the range of 180:1.


CEE also calculated the dilution of the combination of sludge and effluent discharge through the sludge diffuser. The model predicts a typical dilution of 475:1 if the discharged sludge rises to the ocean surface, and about 250:1 if the sludge plume is trapped by stratification at mid-depth (CEE, 2007). As a check, the WRL computer model showed a median dilution of 300:1, with a minimum dilution of 100:1 when strong stratification decreases the rise and dilution of the small sludge plumes, and a maximum dilution at times of strong currents exceeding 1,000:1 (WRL, 2007). The WRL model shows the sludge plume is often trapped well below the surface by the natural stratification of the ocean water column. Based on this range of dilution values, the initial dilution assumed for the sludge discharge in this report is 200:1. Signature of Effluent in Burwood Beach The second last column of Table A shows the expected increase in concentration of the various parameters in ocean waters above the diffuser with effluent discharge at the median concentration at a dilution of 180:1. It is appreciated that the effluent concentrations vary over a range, as illustrated in Table A, and that the dilution also varies over a range, depending on the currents, wave conditions and discharge rate. Nonetheless, the concentrations in the final column dilution of Table A give an indication of the expected signature of the effluent constituents above ambient concentrations in the coastal waters at the Burwood Beach outfalls. The final column of Table A shows the expected increase in concentration of the various parameters in ocean waters above the diffuser with sludge discharge at the median concentration at a dilution of 200:1. It can be seen that the predicted increment in concentrations of nutrients are much the same for the diluted effluent and sludge plumes. For ammonia, as an example, the increment is 128 ug/L for effluent and 120 ug/L for sludge. For total nitrogen, as another example, the increment is 156 ug/L for effluent and 145 ug/L for sludge. Thus it is not possible or necessary to distinguish between the effluent or sludge plumes in terms of effects on nutrient concentrations in the ocean waters near the outfall. The sludge plume may be detected in terms of the changes in solids levels (increase of about 16 mg/L of SS (which should increase turbidity significantly). There is potentially a large increase in enterococci and faecal coliforms particularly in the sludge plume, which has a signature of 6,300 cfu/100 mL for enterococci and 28,000

cfu/100 mL for faecal coliforms. Despite there being such a large difference between the enterococci signature for effluent (900 cfu/100 mL) and sludge (6,300 cfu/100 mL), this does not show up in the monitoring data as a difference in samples collected on the surface (more likely to contain diluted effluent) and mid-water (more likely to contain diluted sludge). The 90 percentile concentrations for enterococci in all water quality samples collected at the outfall and 30 m distance sites was 160 cfu/100 mL for surface samples and 130 cfu/100 mL for mid-water samples. The 90 percentile enterococci level at 100 m from the outfall was 200 cfu/100 mL for surface samples and 130 cfu/100 mL for mid-water samples.


Interpretation of Water Quality Data The Worley Parsons report provides a series of statistical analyses of the water quality data including distance based linear modelling (DISTLM) and distance based redundancy analysis (dbRDA) using the software program PRIMER 6 with the Permanova+ addition. Response variables for the analysis consisted of a surface and mid-water variable for concentrations of each organic and inorganic parameter measured. Data were then analysed by Worley Parsons using a non-metric multidimensional scaling (MDS) plot to ascertain potentially important variables (sample date, season, year, distance from the outfall, direction from the outfall and depth at sample site). Rainfall in the preceding 7, 5 and 3 days was also examined. In this report, the raw data are directly compared for four zones at different distances from the outfall:

1. Samples at the outfall and 30 m distance (128 samples); 2. Samples at 120 m distance (128 samples); 3. Samples at 250 m distance (124 samples); and 4. Samples from 500 m and 2,000 m distance (126 samples).

The measured concentrations in each zone for each parameter have been sorted and plotted from highest to lowest concentration for the four zones. Strictly speaking, the numbers should be normalized to a common total, but the raw comparison is sufficient to show the differences between the concentration patterns in the various zones. The highest 40 concentrations in each zone are then tabulated to allow direct comparison of values. Colours are used in the tables to distinguish between various concentrations (eg, all values higher than the ANZECC guideline limit are coloured yellow). This allows the reader to make a direct comparison of the number of samples in each zone, including the zone for distant samples (500 m and 2,000 m), which exceed the guideline trigger. Comments are made on the figures and tabulated values in the following sequence:

1. Parameter concentrations as a function of distance from the outfall – ie, whether the highest concentrations occur in Zone 1, with progressively lower concentrations in Zone 2 and Zone 3, and lowest concentrations in Zone 4 (corresponding to a readily detected outfall effect), or whether there are a similar range of concentrations in each zone (corresponding to no clearly observable footprint of the outfall for a water quality parameter);

2. Whether the difference in concentrations in Zone 1 (at the outfall) compared to the concentrations in Zone 4 match the expected increment due to the effluent discharge as listed in Table A;

3. Proportion of samples with low concentrations (eg, at or near the level of reporting) in each Zone, indicating good water quality;

4. Proportion of samples in each Zone with elevated concentrations (eg, above the ANZECC guideline default trigger level); and

5. Estimated spatial footprint of the outfall for each parameter.


Ammonia Figure 1 shows the sorted ammonia concentrations for each of the four zones. The highest concentration was measured in the outfall zone and for most of the range there is a consistent trend in ammonia concentration with distance, with highest concentrations in the outfall zone, somewhat lower concentrations at 100 m distance, lower concentrations at 250 m distance and lowest concentrations in the 500 m and reference zone. For about 60 sets of samples, there appears to be a tendency for the concentrations at the outfall to be 50 to 60 ug/L higher than for the reference zone. This increase is about half of the signature of ammonia in the diluted effluent and sludge plumes of 120 to 128 ug/L respectively (see table A). Table 1 lists the top 40 ammonia concentrations measured in the four zones. There are many samples above the ammonia trigger level of 20 ug/L, including 16 samples collected in Zone 4. There are many more samples with higher ammonia levels in and near the outfall. The ammonia signature (< 120 ug/L) is large and therefore easily detected in this monitoring program. In summary, there is a clear and consistent footprint of elevated ammonia concentration detected in this water quality study which extends to 500 m from the outfalls.

Figure 1 - Burwood Beach Water Quality – Ammonia


Table 1 - Top 40 Ammonia Concentrations per Area - Burwood Beach

(mg/L)

0-30 m 100 m 250 m 500-2000 m

0.155 0.134 0.092 0.068

0.153 0.102 0.077 0.068

0.125 0.099 0.077 0.067

0.121 0.099 0.068 0.059

0.111 0.093 0.064 0.048

0.101 0.090 0.063 0.045

0.100 0.088 0.061 0.039

0.090 0.087 0.060 0.035

0.088 0.084 0.06 0.032

0.087 0.080 0.056 0.029

0.086 0.076 0.054 0.027

0.083 0.072 0.053 0.024

0.081 0.071 0.052 0.023

0.079 0.069 0.05 0.021

0.074 0.063 0.048 0.020

0.072 0.062 0.047 0.020

0.072 0.061 0.046 0.020

0.071 0.055 0.045 0.020

0.071 0.052 0.044 0.016

0.069 0.048 0.038 0.015

0.069 0.048 0.038 0.015

0.068 0.047 0.037 0.015

0.068 0.046 0.034 0.015

0.068 0.046 0.033 0.012

0.068 0.044 0.029 0.012

0.068 0.044 0.028 0.011

0.065 0.044 0.028 0.011

0.065 0.04 0.027 0.011

0.065 0.039 0.026 0.010

0.064 0.038 0.025 0.010

0.062 0.034 0.025 0.009

0.06 0.033 0.023 0.009

0.06 0.031 0.022 0.009

0.058 0.028 0.022 0.009

0.056 0.025 0.021 0.009

0.055 0.025 0.017 0.008

0.054 0.025 0.017 0.008

0.054 0.023 0.016 0.008


Oxidised Nitrogen Figure 2 shows the sorted oxidized nitrogen concentrations for each of the four zones. The highest concentration was measured at the outfall zone and there is a small but consistent pattern of higher oxidised nitrogen concentrations at the outfall zone compared to the other three zones. Concentrations at the 100 m zone are slightly higher than for the other two zones, but there is little difference between the oxidised nitrogen concentrations in the 250 m zone and the 500 m reference zone. The reason for this is that the signature for oxidised nitrogen in the diluted plumes is only 5 to 9 ug/L (see Table A) which is small in relation to the ambient concentrations of oxidised nitrogen. Table 2 lists the top 40 oxidised nitrogen concentrations in the four zones. From the table, there are many events where the oxidised nitrogen at the outfall zone is about 20 ug/L above the reference zone. There are many events in all Zones where the measured oxidised nitrogen concentration exceeded the trigger level of 25 ug/L including many samples from the reference zones. This suggests a locally derived trigger for oxidised nitrogen would be higher than the default value. In summary, oxidized nitrogen appears to be more elevated at the outfall and 100 m zones compared to the reference zone, suggesting a footprint extending about 100 m from the outfall.

Figure 2 - Burwood Beach Water Quality - Oxidised Nitrogen

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

1 5 9

13

17

21

25

29

33

37

41

45

49

53

57

61

65

69

73

77

81

85

89

93

97

10

1

10

5

10

9

11

3

11

7

12

1

12

5

Oxi

dis

ed

Nit

roge

nm

g/L

Sorted sample number

0-30 100 250 500-2000


Table 2 - Top 40 Oxidised Nitrogen Concentrations per Area - Burwood Beach (mg/L)

0-30 m 100 m 250 m 500-2000 m

0.154 0.116 0.113 0.087

0.149 0.094 0.096 0.087

0.131 0.088 0.087 0.084

0.103 0.088 0.084 0.081

0.100 0.087 0.082 0.080

0.090 0.085 0.079 0.080

0.088 0.085 0.077 0.078

0.086 0.084 0.077 0.078

0.086 0.083 0.076 0.076

0.086 0.083 0.076 0.076

0.085 0.083 0.076 0.075

0.084 0.082 0.076 0.075

0.084 0.077 0.075 0.074

0.084 0.076 0.075 0.072

0.083 0.076 0.074 0.052

0.083 0.075 0.074 0.049

0.081 0.075 0.042 0.044

0.08 0.074 0.040 0.040

0.077 0.044 0.039 0.039

0.077 0.041 0.039 0.039

0.076 0.039 0.038 0.039

0.039 0.038 0.038 0.039

0.039 0.038 0.038 0.038

0.038 0.038 0.038 0.038

0.038 0.037 0.038 0.038

0.038 0.037 0.037 0.037

0.038 0.037 0.037 0.036

0.038 0.037 0.036 0.034

0.037 0.037 0.036 0.034

0.037 0.036 0.036 0.033

0.037 0.036 0.035 0.032

0.037 0.036 0.034 0.031

0.037 0.036 0.013 0.029

0.037 0.036 0.011 0.02

0.037 0.035 0.011 0.02

0.036 0.02 0.008 0.017

0.036 0.018 0.008 0.013

0.013 0.012 0.006 0.011

0.013 0.01 0.006 0.01

0.011 0.01 0.005 0.009


Total Nitrogen Figure 3 shows the sorted total nitrogen concentrations for each of the four zones. The highest concentrations are in the outfall zone, although a few high concentrations also were recorded in Zone 4. There is a consistent trend in total nitrogen concentration with distance, with highest concentrations in the outfall zone, somewhat lower concentrations at 100 m distance, lower concentrations at 250 m distance and lowest concentrations in the 500 m reference zone. The concentrations in the outfall zone are generally 80 to 150 ug/L higher than in the reference zone. This difference corresponds to the signature of the plumes of 145 to 156 ug/L (see Table A). It is estimated that the elevated total nitrogen level extends out to beyond the 250 m zone. Table 3 lists the top 40 total nitrogen concentrations in the four zones. All of the values listed in the table exceed the ANZECC default trigger level of 120 ug/L. From the table, the total nitrogen at the outfall zone is 60 to 150 ug/L above the other zones. The 90 percentile concentrations for the four zones are 320 ug/L for Zone 1; 240 ug/L for Zone 2, 220 ug/L for Zone 3 and 200 ug/L for Zone 4. This suggests a footprint extending out to more than 250 m from the outfall. In summary, there appears to be a consistent footprint of elevated total nitrogen concentrations detected in this water quality study to more than 250 m from the outfall.

Figure 3 - Burwood Beach Water Quality - Total Nitrogen


Table 3 - Top 40 Total Nitrogen Concentrations per Area - Burwood Beach

(mg/L)

0-30 m 100 m 250 m 500-2,000 m

0.56 0.28 0.52 0.41

0.54 0.27 0.30 0.40

0.51 0.26 0.26 0.36

0.48 0.26 0.26 0.35

0.47 0.25 0.25 0.33

0.37 0.25 0.24 0.23

0.34 0.24 0.23 0.21

0.34 0.24 0.22 0.20

0.32 0.24 0.22 0.19

0.32 0.24 0.22 0.19

0.31 0.24 0.22 0.19

0.30 0.23 0.22 0.19

0.30 0.22 0.22 0.19

0.28 0.22 0.22 0.18

0.28 0.22 0.21 0.18

0.28 0.21 0.20 0.18

0.27 0.21 0.20 0.18

0.27 0.21 0.20 0.18

0.26 0.21 0.20 0.18

0.26 0.21 0.20 0.18

0.26 0.20 0.19 0.18

0.26 0.20 0.19 0.17

0.25 0.20 0.18 0.17

0.25 0.20 0.18 0.17

0.24 0.20 0.18 0.16

0.24 0.20 0.18 0.16

0.24 0.20 0.18 0.16

0.24 0.20 0.17 0.16

0.23 0.19 0.17 0.16

0.23 0.19 0.17 0.16

0.23 0.19 0.16 0.15

0.23 0.18 0.16 0.15

0.22 0.18 0.16 0.14

0.22 0.18 0.16 0.14

0.22 0.18 0.16 0.14

0.21 0.18 0.15 0.14

0.21 0.17 0.15 0.14

0.21 0.17 0.15 0.14

0.20 0.17 0.15 0.14

0.20 0.17 0.15 0.14


Total Phosphorus Figure 4 shows the sorted total phosphorus concentrations for each of the four zones. There is a consistent trend in total nitrogen concentration with distance, with highest concentrations in the outfall zone, somewhat lower concentrations at 100 m distance, lower concentrations at 250 m distance and lowest concentrations in the 500 m reference zone. For much of the range, the concentration in the outfall zone was 7 to 18 ug/L above the concentration in the reference zone. This difference corresponds to the signature of total phosphorus in the diluted effluent and sludge plumes of 12 to 14 ug/L (see table A). This suggests a footprint of elevated total phosphorus at the outfall zone extending out to beyond 250 m distance. Table 4 lists the top 40 total phosphorus concentrations in the four zones. In all rows of the table total phosphorus concentrations at the outfall zone is at least 7 ug/L above the concentration in the reference zone, with the concentrations in other zones being between these two values. The 90 percentile concentrations for the four zones are 26 ug/L for Zone 1; 23 ug/L for Zone 2, 18 ug/L for Zone 3 and 16 ug/L for Zone 4. This suggests a footprint extending further than 250 m from the outfall. Note that there are samples in all zones that exceed the default trigger level of 25 ug/L. In summary, there appears to be a consistent footprint of elevated total phosphorus concentrations detected in this water quality study extending over 250 m from the outfall.

Figure 4 - Burwood Beach Water Quality - Total Phosphorus


Table 4 - Top 40 Total Phosphorus Concentrations per Area - Burwood Beach

(mg/L)

0-30 100 250 500-2000

0.045 0.062 0.032 0.038

0.04 0.044 0.025 0.034

0.04 0.042 0.023 0.022

0.038 0.036 0.022 0.02

0.034 0.036 0.022 0.02

0.034 0.033 0.022 0.018

0.032 0.032 0.021 0.018

0.031 0.03 0.02 0.018

0.03 0.03 0.02 0.018

0.028 0.026 0.02 0.017

0.027 0.026 0.02 0.017

0.026 0.024 0.02 0.017

0.026 0.024 0.019 0.016

0.026 0.023 0.018 0.016

0.026 0.023 0.018 0.016

0.025 0.023 0.018 0.016

0.025 0.022 0.018 0.015

0.024 0.022 0.018 0.015

0.024 0.022 0.017 0.015

0.024 0.022 0.017 0.015

0.023 0.022 0.016 0.015

0.023 0.02 0.016 0.015

0.023 0.02 0.016 0.014

0.023 0.02 0.015 0.014

0.022 0.019 0.015 0.014

0.022 0.018 0.015 0.014

0.022 0.018 0.015 0.014

0.022 0.018 0.015 0.013

0.022 0.018 0.015 0.012

0.021 0.017 0.014 0.012

0.021 0.017 0.014 0.012

0.02 0.017 0.014 0.012

0.019 0.017 0.014 0.012

0.019 0.017 0.014 0.012

0.019 0.016 0.014 0.011

0.018 0.016 0.013 0.011

0.018 0.016 0.013 0.011

0.018 0.016 0.013 0.011

0.018 0.016 0.013 0.011

0.018 0.016 0.013 0.011


Chlorophyll-a Figure 5 shows the sorted chlorophyll-a concentrations for each of the four zones. The highest concentration was much the same in each zone. For most of the distribution the sorted chlorophyll-a measurements at the outfall and 100 m zone are a bit higher than at the 250 m and reference zones. It would not be expected that the soluble nutrients in the Burwood Beach effluent could be converted to phytoplankton (and thus increase chlorophyll levels) within a day or less. Thus no increase in chlorophyll-a level is expected at the outfall or surrounding zones. Table 5 lists the top 40 chlorophyll-a concentrations in the four zones. From the table, it is apparent that chlorophyll-a is higher at the outfall and 100 m zones. The reason for this is not known.

Figure 5 - Burwood Beach Water Quality - Chlorophyll-a


Table 5- Top 40 Chlorophyll-a Concentrations per Area - Burwood Beach (mg/m3)

0-30 m 100 m 250 m 500-2000 m

3 3 3 2.3

3 3 2 2

2 2 2 2

2 2 2 2

2 2 2 2

2 2 2 1.8

2 2 1.6 1.4

2 2 1.5 1.3

2 2 1.4 1.1

2 2 1.2 1.1

2 2 1 1

2 2 1 0.9

2 1.9 1 0.8

2 1.6 1 0.8

1.7 1.3 1 0.8

1.4 1.2 1 0.8

1.3 1.1 1 0.7

1.3 1.1 1 0.7

1.2 1 1 0.7

1.1 1 1 0.7

1 1 0.9 0.6

1 1 0.9 0.5

1 1 0.9 0.5

1 0.9 0.9 <1.0

1 0.9 0.8 <1.0

1 0.9 0.7 <1.0

0.9 0.9 0.7 <1.0

0.9 0.9 0.6 <1.0

0.9 0.8 0.6 <1.0

0.9 0.8 0.6 <1.0

0.8 0.8 0.6 <1.0

0.8 0.7 0.6 <1.0

0.7 0.7 0.5 <1.0

0.7 0.7 0.5 <1.0

0.7 0.6 0.5 <1.0

0.7 0.6 <1.0 <1.0

0.7 0.6 <1.0 <1.0

0.7 0.6 <1.0 <1.0

0.7 0.6 <1.0 <1

0.6 0.6 <1.0 <1


Enterococci Figure 6 shows the sorted enterococci concentrations for each of the four zones. The highest concentration was measured at the 100 m zone and for most of the distribution the sorted enterococci measurements at the outfall and 100 m zones are similar and generally higher than the levels at the 250 m and reference zones. The enterococci signature of the effluent and sludge are 900 and 6,300 cfu/100 m/L respectively. There appears to be a section of the range in Figure 6 where concentrations at the outfall zone are about 100 cfu/100 m/L higher than in the reference zone. This suggests a footprint of elevated enterococci at the outfall zone. Table 6 lists the top 40 enterococci concentrations in the four zones. From the table, there are many samples where the enterococci level in all zones (and especially near the outfall) exceeds an indicative level of 40 cfu/100 mL. This suggests elevated enterococci occurs over a wide area and the outfall is not the only source of enterococci. The 90 percentile concentrations for the four zones are 150 cfu/100 mL for Zone 1; 170 cfu/100 mL for Zone 2, 110 cfu/100 mL for Zone 3 and 50 cfu/100 mL for Zone 4. This suggests a footprint extending further than 250 m from the outfall. In summary, there appears to be a consistent footprint of elevated enterococci concentrations detected in this water quality study extending at least 500 m from the Burwood Beach outfalls, but much lower than the expected signature values.

Figure 6 - Burwood Beach Water Quality - Enterococci


Table 6- Top 40 Enterococci Concentrations per Area - Burwood Beach

(CFU/100mL)

0-30 m 100 m 250 m 500-2,000 m

380 1000 200 370

370 1000 180 300

210 260 180 130

200 260 160 120

180 250 140 100

170 210 120 70

170 200 120 59

160 200 110 51

160 190 110 49

150 180 110 45

150 170 100 32

140 170 96 22

130 170 89 20

130 160 80 19

130 150 76 18

130 140 72 16

130 130 65 16

120 120 64 15

120 120 51 14

120 120 49 13

120 110 48 12

110 95 46 12

110 87 45 11

110 82 40 11

100 79 39 10

96 78 36 8

95 76 34 8

95 75 34 7

78 67 34 7

72 62 32 7

71 60 30 7

70 60 29 7

70 60 28 5

69 60 28 5

67 57 25 4

67 52 24 4

66 52 24 4

64 52 21 4

62 50 20 4

60 46 19 4


Faecal Coliforms Figure 7 shows the sorted faecal coliform levels for each of the four zones. The highest level was measured in the outfall zone. There is a consistent trend in faecal coliform level with distance, with highest concentrations in the outfall zone, somewhat lower concentrations at 100 m distance, lower concentrations at 250 m distance and lowest concentrations in the 500 m-reference zone. The faecal coliform signature of the effluent and sludge are 14,000 and 28,000 cfu/100 m/L respectively. There appears to be a section of the range in Figure 6 where concentrations at the outfall zone are about 500 to 1,000 cfu/100 m/L higher than in the reference zone. This suggests a footprint of elevated faecal coliform at the outfall zone but much lower than the expected signature increment. Table 7 lists the top 40 faecal coliform concentrations in the four zones. There is a clear trend with a higher proportion of samples exceeding 200 cfu/100 mL at sites closer to the outfall. This suggests elevated faecal coliform levels occur over a wide area and the outfall may not be not the only source of faecal coliforms. The 90 percentile concentrations for the four zones are 500 cfu/100 mL for Zone 1; 300 cfu/100 mL for Zone 2, 150 cfu/100 mL for Zone 3 and 50 cfu/100 mL for Zone 4. This suggests a footprint extending further than 250 m from the outfall. In summary, there appears to be a consistent footprint of elevated faecal coliform concentrations detected in this water quality study extending at least 500 m from the Burwood Beach outfalls.

Figure 7 - Burwood Beach Water Quality - Faecal Coliforms


Table 7- Top 40 Faecal Coliform Concentrations per Area - Burwood Beach

(CFU/100mL)

0-30 m 100 m 250 m 500-2,000 m

5500 2000 450 400

1400 1500 450 230

1200 680 440 200

1200 540 360 150

1200 410 290 140

1100 400 280 130

770 400 270 120

750 400 240 120

660 390 240 92

610 360 220 56

560 360 210 54

510 340 160 50

480 330 150 47

450 300 150 44

450 300 150 38

400 300 140 36

400 300 140 35

390 280 130 35

360 280 130 31

350 280 120 29

350 270 110 28

300 250 110 27

300 250 110 24

280 250 110 22

280 240 97 20

260 230 84 18

260 230 77 17

250 230 68 14

250 230 66 13

250 230 63 10

250 220 62 10

250 210 60 10

240 200 59 9

230 200 59 9

230 190 57 9

230 190 54 9

220 180 54 8

210 170 52 8

210 150 50 7

210 150 48 7


Summary The purpose of the water quality monitoring was to characterise the changes to water quality in the area of the Burwood Beach outfalls as a result of the effluent discharge and to define the footprint of the changes. Based on this examination and interpretation of the raw water quality data, the following conclusions are drawn.

1. There is a clear and consistent footprint of elevated ammonia concentration detected in this water quality study which extends to 500 m from the outfalls.

2. The concentrations of oxidised nitrogen are elevated above the ANZECC default trigger levels in the four zones. This suggests a locally derived trigger would be higher than the default value.

3. Oxidised nitrogen appears to be more elevated at the outfall and 100 m zones compared to the reference zone, suggesting a footprint extending about 100 m from the outfall.

4. There appears to be a consistent footprint of elevated total nitrogen concentrations detected in this water quality study to more than 250 m from the outfall.

5. There appears to be a consistent footprint of elevated total phosphorus concentrations detected in this water quality study extending over 250 m from the outfall.

6. There appears to be a consistent footprint of elevated enterococci concentrations detected in this water quality study extending at least 500 m from the Burwood Beach outfalls

7. There appears to be a consistent footprint of elevated faecal coliform concentrations detected in this water quality study extending at least 500 m from the Burwood Beach outfalls.

8. In summary, the water quality data indicate a footprint of the outfall discharge extending to about 500 m from the outfall and possibly further for ammonia, total nitrogen, total phosphorus, enterocooci and faecal coliforms.

Regards, Ian Wallis

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