sampling and monitoring of port phillip bay water quality

8/9/2019 Sampling and Monitoring of Port Phillip Bay Water Quality

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421-605 Project Assessment B

421-605 Managing Water Borne Risks

Department of Environmental EngineeringUniversity of Melbourne

Project B: Sampling and MonitoringPort Phillip Bay Water Quality Monitoring Scheme

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Executive SummaryThe Port Phillip Bay Water Quality Monitoring Scheme (PPBWQMS) has set both short-termand long-term monitoring objectives to assess the possibility of algal blooms occurring inPort Phillip Bay,

This proposal has the overall objective of increasing the Victorian Governments ability tounderstand and manage the impact of nitrogen inputs to the Bay (a complex system). It willalso provide the mechanisms to determine the effectiveness of nutrient managementactivities in protecting Bay.

Nitrogen can enter water environments from a number of sources such as agriculturalfertilisers and drainage, septic tanks, sewage discharges, animal wastes and urbanstormwater. Eleven sites have been selected to inform the monitoring objectives, includingtwo reference sites. The main parameters being assessed event based/fortnightly/monthlyinclude:

Chlorophyll A (key indicator for nutrients) Nitrogen (NH 3, NO X and total assessing the extent eutrophication) Suspended solids (assessing water clarity) Dissolved Oxygen, pH, Salinity, turbidity and temperature (Best Management

Practice).

Instantaneous (alert levels) and yearly (statistical analysis) reporting will provide the VictoriaGovernment with the required information to inform management (e.g. enforcement, betterpractice, water sensitive urban design, education).

The PPBWQMS is a five year program that deals specifically with water quality (nitrogen)and algal communities of Port Phillip Bay. The delivery of this proposal has a budgeted costof $750,000 (including data analysis and reporting).


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Contents Page

Executive Summary............................................................................................................ 2 1 Context ......................................................................................................................... 4

1.1 Port Philip Bay....................................................................................................... 4

1.2 Algal Blooms ......................................................................................................... 5

2 Monitoring Objectives .................................................................................................6

2.1 SEPP Guidelines ...................................................................................................72.2 National Water Quality Management Strategy ....................................................... 7

2.3 Current management.............................................................................................8

3 Monitoring Program.....................................................................................................8

3.1 Sampling Sites....................................................................................................... 8

3.2 Water Quality Parameters .....................................................................................93.3 Water Quality Analysis...........................................................................................9

3.4 Sampling Frequency.............................................................................................. 9

3.5 Effectiveness of monitoring program.................................................................... 10

4 Data Analysis and Reporting ....................................................................................11

4.1 Nitrogen and Algal Statistical Analysis................................................................. 114.2 Data Storage .......................................................................................................11

4.3 Comparison with Guidelines ................................................................................ 11

4.4 Reporting............................................................................................................. 11

5 Adaptive Management ............................................................................................... 12

6 Monitoring Budget .....................................................................................................12 7 References ................................................................................................................. 13

8 Appendices ................................................................................................................ 14

Appendix A: Major waterway outfalls into Port Phillip Bay ........................................... 14

Appendix B: Port Phillip Bay Nutrient Monitoring Sampling Sites 15


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1 ContextThis Port Phillip Bay Water Quality Monitoring Scheme (PPBWQMS) is intended to providethe Victorian Government with a prioritised set of specific monitoring actions to beundertaken to inform the possibility of algal blooms occurring via nitrogen inputs into PortPhillip Bay.

Ongoing monitoring and reporting to assess the inputs of nitrogen entering the Bay is anessential component of future management and evaluation. Monitoring options have beenrecommended to:

Set clear and measurable objectives Establish trigger levels, where management intervention may be required Monitoring program to assess the major inputs of nitrogen into the Bay Provide an evaluation and reporting process.

1.1 Port Philip BayThe Port Philip Bay is an important port for Australia, it also supports major commercial andrecreational fishing, providing habitat for 300 fish species and several hundred species ofcrustaceans, jellyfish, corals and sea sponges (Victorian Government, 2008).

Port Phillip Bay is a large (surface area = 1930km 2) and shallow (maximum depth = 24m)coastal embayment. However the catchment area that influences the health of the Bay islarge (9790km) as well as a population of over 3.7 million people living around the Bay(EPA, 2002).

A four year Environmental Study (CSIRO, 1996) concluded that the number one threat to theBay was the nitrogen input from the surrounding catchment (Dr Vincent Pettigrove,Melbourne Water, pers. comm., 2009).

Strategies to reduce Nitrogen loads to the Bay should give this recommendation highest priority (CSIRO, 1996, p28).


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Figure 1: Port Phillip Bay and its surrounding catchments

1.2 Algal BloomsWhile nitrogen is important for plants and animal growth, if an excessive amount of nitrogenis present, algal blooms and nuisance plant growths could occur in the Bay. This can lead toa reduction in habitat for plants and animals and can threaten the valuable aquaticecosystems the Bay supports (e.g. depleted oxygen levels that cause extensive fish kills)(EPA, 2003).

This monitoring program is targeting nitrogen inputs into the Bay, however it is recognisedthat there are many other environmental influences on the Bay (e.g. high temperatures,t i t ti i )

Event: shellfisheries in Port Phillip Bay were affected in 1987 by a bloom of the diatom,Rhizolenia chunii. As a consequence of this bloom, mussels, flat oysters and scallops within the Bay developed a bitter flavour making them unmarketable for seven months causing an estimated loss of $1 million (Robinson and Cully, 2009).


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2 Monitoring ObjectivesMonitoring of the Bay commenced in 1984, although some sites have been discontinued andchemical analysis methods have changed (EPA, 2003). Therefore the PPBWQMS hasestablished both short-term and long-term monitoring objectives with regard to assessing thepotential of algal blooms in the Bay.

The short-term objectives focus on providing the Victorian Government with information onthe current state of nitrogen inputs to help identify water quality/algal community threats tothe Bay. For the longer term, monitoring is targeted at developing a baseline dataset toenable trend analysis and critical assessment of the relationship between nitrogen inputsand algal bloom development.Short-term objectives for the monitoring program are to:

o Provide an overview of water quality (nitrogen) in the Port Phillip Bay and varioussites of influence to the Bay.

o Compare annual water quality conditions and assess compliance with guideline andtrigger values recommended in the Victorian State Environment Protection Policy

(SEPP) and National Water Quality Management Strategy.o Provide an annual time series analysis of nitrogen and algal communities to identify

seasonal changes and interactions.

o Identify management practices that have the potential to improve water quality fromthe various inputs that enter the Bay.

Long-term objectives for the monitoring program are to:

o Establish relationships between water quality and management practices.o Provide a historic time series analysis of nitrogen and algal communities to identify

long-term trends and interactions.

o Identify management practices that have potential to improve water quality in theBay.

Long-term condition monitoring will provide information on whether the water quality(nitrogen) from the various inputs to the Bay are causing a change in or maintaining theoverall condition of the Bay (trend over time).


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2.1 SEPP GuidelinesSEPP objectives have been set to provide assessment criteria to inform water quality inrivers (upland and lowland), estuaries, freshwater lakes and reservoirs. This information hasbeen adapted to inform this PPBWQMS and is illustrated in Table 1 below.

Table 1: General SEPP Environmental Objectives in relation to percentage compliance(EPA, 2002)

Parameter Trigger level Compliance

Low Medium High

Ammonia as N(NH3)

0.02 mg/L 95% withinguideline

Nitrate and Nitriteas N (NO x)


Total Kjeldahl(TKN)


Total SuspendedSolids (mg/L)

50 mg/L 95% withinguideline

Chlorophyll-a (Cl-a) & Phaeophytin-a

5 g/L

(1.5-4 g/L)

95% withinguideline

2.2 National Water Quality Management StrategyThe following national trigger levels for recreational waters have been set by Australian andNew Zealand Guidelines for Fresh and Marine Water Quality (ANZECC Guidelines). Theselevels (Table 2) provide default national guideline values to inform the PPBWQMSevaluation phase (Moss, Brodie and Furnas, 2004).

Table 2: National Water Quality Guidelines (ANZECC, 2000)

Water Quality Parameter Trigger level

Ammonia as N (NH 3) 0.01 mg/L

Nitrate and Nitrite as N (NO x) 0.04 mg/L


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2.3 Current management

It is important to briefly mention the work already undertaken to get to the currentunderstanding of how the Bay interacts with its surrounding environment and aid the designof the PPBWQMS. The following monitoring programs monitor the Bays water quality:

Water Quality Monitoring Program Beach Monitoring Program Turbidity Monitoring Program Plume Intensity & Extent Monitoring Program Nutrient Cycling Monitoring Program Water Quality in Port Phillip & Westernport Catchment Monitoring Program Bacterial Contamination in the Yarra River Monitoring Program (Victorian

Government, 2009).

The intention of this monitoring program is to build on the above existing monitoringprograms that will inform the analysis of nitrogen inputs into the Bay.

3 Monitoring ProgramThis section provides details regarding in situ monitoring of water quality, the collection ofwater and algal samples, and the types of analysis performed on the samples.

3.1 Sampling SitesThe relative contributions of major nitrogen input sources have been approximated to:

Catchment waterways, 3545% Western Treatment Plant 1, 4050% Atmospheric inputs, 1015% Groundwater, 5% (DNRE, 2002).

In reviewing the current water quality programs (namely EPA, 2002) the following sites havebeen selected for the PPBWQMS:

1. Corio Bay (near industrial and domestic inputs)

2. Werribee (Long Reef site, 1km from the treatment plant)

3. Hobsons Bay (incorporating the Yarra-Maribyrnong rivers influence on the Bay)

4. Mordialloc / Patterson / Kananook Waterways (east side of the Bay)

5. Reference sites (Central and Dromana considered distant from catchmentinfluences)

Refer to Appendix A, B and C for further information on the sites selected for thePPBWQMS


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3.2 Water Quality Parameters

Chlorophyll a is considered the key indicator for nutrients and is used as it is an integrativemeasure of nutrient status (EPA, 2002). Nitrogen (NH 3, NO x and total) and suspended solids(water clarity) will also be tested for (Refer to Table 3 below).

It is best management practice to monitor for the following additional parameters: Dissolved Oxygen, pH, Salinity, turbidity and temperature

This will enable a better understanding of the interactions occurring at the time of samplingand will be useful in reporting an incident.

3.3 Water Quality AnalysisMelbourne Water personnel will collect water quality and algal samples at each of the fivesite areas. Physical and descriptive attributes of each site is listed in Appendix C. Theadditional water quality parameters will be tested using a suitable hand hold in situ meter.

Water quality samples collected from each site will be analysed at a National Association ofTesting Authorities (NATA) accredited laboratory. Variables assessed as part of this

monitoring program as well as the methods used are presented in Table 3.Table 3: Water quality analysis methods and detection limits

Parameter Detection Limit Method

Ammonia as N (NH 3) 0.002 mg/L Automated ascorbic acid molybditecolorimetric analysis

Nitrate and Nitrite as N (NO x) 0.003 mg/L Cd reduction followed bycolorimetric method usingdiazotisation

Total Kjeldahl (TKN) 0.01 mg/L Acid digestion using Hg catalystfollowed by colormetric analysisusing salicylate hypochlorite

Chlorophyll-a (Cl-a) &

Phaeophytin-a

0.05 g/L ISO International Standard

Spectrophotometric method using aUV Spectrophotometer

Suspended Solids N/A Measured by weight after filteringwater sample through a glass filtermembrane (0.45 m)


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3.5 Effectiveness of monitoring programTo a large extent, the ability of this program to provide an early warning of a possible algalbloom event in the Bay (due to changes in the nitrogen cycle) will depend on the type,magnitude, duration and location of any possible impact (Longmore, 2000).

The temporal variability of surface water in the Bay is substantial, therefore an adaptivemanagement program has been recommended (refer to Section 5). The temporal andspatial considerations, site selection, sampling precision, timing and frequency, andmeasurement parameters outlined in the PPBWQMS are considered appropriate to informthe monitoring objectives (refer to Table 4):

Selection of appropriate sampling sites: a total of eleven sites distributed throughoutthe Bay (including known areas of nitrogen inputs and reference sites).

Parameters to be monitored: Chlorophyll a, Nitrogen and suspended solids to informthe likelihood of an algal bloom event

Frequency of sampling: fortnightly / monthly

Table 4: PPBWQMS scale triplet (adapted from: Grayson and Moore, 2009)

Space Time

Spacing 11 sites Fortnightly to Monthly

Support Water quality and algalsamples

Instantaneous measurementat time of sample collected

Extent 11 sites assessing an area ofapproximately 100 metreseach

Five years initially,information from existingprograms will beincorporated into the analysis


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4 Data Analysis and ReportingIn achieving the monitoring objectives (stated in Section 2) the following statistical analysesof data, storing of data and results and analysis the results will be undertaken.

4.1 Nitrogen and Algal Statistical AnalysisTo aid the evaluation of nitrogen inputs and algal bloom potential, the following analysisactivities will be undertaken:

Descriptive summary statistics and time series analysis of water quality and algalcommunities for each monitoring year. The range of data between the 25 th and 75 th percentiles will indicate the values that are considered to be normal or expected.

Comparison of test data with background data (reference sites) and trigger values. Comparison to long-term statistics (data from other monitoring programs will be

utilised. Water quality modelling: methods of inference, multivariate analysis, power analysis,

regression techniques, trend analysis (Longmore, 2000 and EPA, 2003).

4.2 Data StorageThe water quality information collected will be stored in a database (MS Access) anduploaded to the Victorian Water Quality Database ( www.vicwaterdata.net ).

4.3 Comparison with GuidelinesThe general health of the Bay will be assessed by comparing water quality and algalcommunities with guideline and trigger values recommended by the Victorian SEPP forWaters of Victoria (EPA, 2003) and the National Water Quality Management Strategy(ANZECC, 2000). Following comparison with the guidelines, the percentage compliance ofeach parameter tested will be calculated using the equation below.

A rating system will be employed to categorise the sites into a low, medium or high risk foran algal bloom event.

4.4 ReportingAfter each monitoring event a brief status report will be provided to the VictorianGovernment to report on the possibility of algal blooms occurring in the Bay. The followingalert system outlined in Table 5 will be used.

Table 5: Alert Level triggers for PPBWQMS (Adapted from ANZECC, 2000 and EPA, 2003)

% Compliance = (Number of samples within guidelines / Total number of samples) x 100


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5 Adaptive ManagementPredicting how the Bay will respond to different levels of nitrogen inputs is difficult as theinteractions between water, processes and biota are extremely complex. Adaptivemanagement will provide the means through which this monitoring program andmanagement interventions will be refined over time as new information and data becomeavailable. The proposed adaptive management framework for the PPBWQMS is shown inFigure 2.

Figure 2: PPBWQMS Adaptive Management Program

6 Monitoring BudgetIt is proposed that this monitoring program occurs for the next five years. On completion ofthis period the program will be formally reviewed to determine whether the program isproviding adequate information into the long-term monitoring objectives


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7 ReferencesANZECC, 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Vol 1, Australian and New Zealand Environment and Conservation Council andAgriculture and Resource Management Council of Australia and New Zealand, Canberra.

CSIRO, 1996. Port Phillip Bay Environmental Study, Melbourne. [Date accessed: 30September 2009], available at: http://www.melbournewater.com.au/content/library/ publications/reports/rivers_and_creeks_reports/Port_Phillip_Bay_Environmental_Study.pdf

DNRE 2002, Port Phillip Bay Environmental Management Plan: Background Document,

Department of Natural Resources and Environment, Melbourne.EPA Victoria, 2003. State Environment Protection Policy. Waters of Victoria. Policy ImpactStatement, June 2003

EPA Victoria, 2001. Environment Report: Port Phillip Bay Water Quality Long-term trends in nutrient status and clarity, 1984-1999. Melbourne.

Grayson, R. and Moore, G., 2009. Sampling Issues and Instrumentation, Centre for

Environmental Applied Hydrology, University of Melbourne, Melbourne.Longmore, A., 2000. Port Phillip Bay Nutrient Monitoring Proposal Scientific and TechnicalAdvice. Marine and Freshwater Resources Institute Report No 16. Fisheries Victoria,Melbourne.

Molloy, R., 2009. Marine and Coastal Pollution Urban and Industrial Sources, Presentation 421-605 Managing Water Bourne Risks, University of Melbourne, 10 September

Moss, A., Brodie, J. and Furnas, M., 2004. Water quality guidelines for the Great Barrier

Reef World Heritage Area: a basis for development and preliminary values, QueenslandEnvironmental Protection Agency, Brisbane.

Robinson, J. and Cully, T., 2009. Australian Online Coastal Information, Coastal CRC [Dateaccessed: 30 September 2009], available at: http://www.ozcoasts.org.au/indicators/econ_ cons_algal_blooms.jsp

Victorian Government, 2008. Port Phillip Bay Natural Events, Office of EnvironmentalMonitor, Melbourne.


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Group 202_Project B_Final.doc Page 14 of 16

8 Appendices

Appendix A: Major waterway outfalls into Port Phillip Bay


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Appendix B: Port Phillip Bay Nutrient Monitoring Sampling Sites


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Appendix C: Sampling Sites - Physical and Descriptive AttributesSite Area Number of sites Frequency Comments

Corio Bay

(Near industrial anddomestic inputs)

1. Moolap outlet site

2. Avalon outlet site

3. Bay site (downstream ofinfluences)

October-March - Fortnightly

April-September - Monthly

Werribee

(Long Reef site, 1km fromthe treatment plant)

4. Downstream of two WTPoutlet sites

5. Downstream of Little River Bay

6. Downstream of the WerribeeRiver



Hobsons Bay

(Incorporating the Yarra-Maribyrnong rivers

influence on the Bay)

7. Yarra River (Upstream ofoutfall to the Bay)

8. Bay site (downstream of

Yarra/Maribyrnong entranceto the Bay)



Mordialloc / Patterson /Kananook Waterways

(East side of the Bay)

9. Patterson River entrance tothe Bay)

All year: Monthly Potential Hot Spot Sandringham Beach (mayrequire more intensive monitoring)

Reference sites

Central Bay and Dromana

considered distant fromcatchment influences

10. Dromana

11. Central Bay

All year: Monthly

PPBWQMS Costs:

Sampling: $50 per sample (~$10,000 per year) Water quality analysis: $200 per sample (including chlorophyll a) (~$40,000 per year)

Reporting: Instant and yearly reports ($100,000 per year)

Five year program: $750,000 excl GST

sampling and monitoring of port phillip bay water quality

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