Figure 0.1: Sydney catchment area · 2016-12-18 · WaterNSW Annual Water Quality Monitoring Report - Sydney Catchment Area 2015-16 ... 8.1.1 Potentially toxin producing cyanobacteria

Figure 0.1: Sydney catchment area

WaterNSW Annual Water Quality Monitoring Report - Sydney Catchment Area 2015-16

Table of Contents List of Tables .............................................................................................................................. 7

Executive Summary .................................................................................................................... 8

Highlights ................................................................................................................................... 8

1 Introduction .................................................................................................................... 10

1.1 This report ............................................................................................................. 11

2 Overview of the Greater Sydney region water supply network .................................... 12

2.1 Warragamba system ............................................................................................. 14

2.2 Upper Nepean system........................................................................................... 14

2.3 Woronora system .................................................................................................. 15

2.4 Blue Mountains system ......................................................................................... 15

2.5 Shoalhaven system ............................................................................................... 15

2.6 Hawkesbury-Nepean River ................................................................................... 16

3 Sydney catchment area water monitoring program ...................................................... 17

3.1 Quality assurance and quality control .................................................................. 17

3.2 Operating Licence ................................................................................................. 18

3.2.1 Raw water supplied for treatment ....................................................................... 19

3.2.2 Storages ................................................................................................................ 19

3.2.3 Catchments........................................................................................................... 19

3.2.4 Picnic area monitoring ......................................................................................... 19

3.2.5 Algal monitoring ................................................................................................... 19

3.2.6 Cryptosporidium and Giardia monitoring ............................................................ 20

3.2.7 Wet weather monitoring ...................................................................................... 20

3.2.8 Dam seepage ........................................................................................................ 20

3.2.9 Downstream of storages ...................................................................................... 20

3.3 Water Licences ...................................................................................................... 20

3.4 Future directions ................................................................................................... 21

3.4.1 Water Quality Management System .................................................................... 21

3.4.2 Water Quality Event Forecasting System ............................................................. 21

4 Applicable guidelines / benchmarks............................................................................... 22

4.1 Australian Drinking Water Guidelines (ADWG) 2011 ........................................... 22

4.2 Raw water supply agreements.............................................................................. 22

4.3 ANZECC 2000 ......................................................................................................... 25


4.3.1 Benchmarks for storages ...................................................................................... 25

4.3.2 Benchmarks for catchments ................................................................................. 26

4.4 Benchmarks for recreational areas ....................................................................... 26

4.5 Benchmarks for downstream rivers ...................................................................... 27

4.6 Benchmarks for picnic area supplies .................................................................... 27

4.7 Benchmarks for cyanobacteria ............................................................................. 27

4.8 Benchmarks for Cryptosporidium and Giardia ..................................................... 28

5 Routine monitoring ........................................................................................................ 29

5.1 Quality Assurance/Quality Control ....................................................................... 29

5.2 Warragamba system ............................................................................................. 30

5.2.1 Catchments........................................................................................................... 33

5.2.2 Storages ................................................................................................................ 33

5.2.3 Water Filtration Plants ......................................................................................... 33

5.3 Upper Nepean system........................................................................................... 34

5.3.1 Catchments........................................................................................................... 36

5.3.2 Storages ................................................................................................................ 36


5.4 Woronora system .................................................................................................. 37

5.4.1 Catchments........................................................................................................... 39

5.4.2 Storage ................................................................................................................. 39

5.4.3 Water Filtration Plant ........................................................................................... 39

5.5 Blue Mountains system ......................................................................................... 40

5.5.1 Catchments........................................................................................................... 42

5.5.2 Storages ................................................................................................................ 42


5.6 Shoalhaven system ............................................................................................... 43

5.6.1 Catchments........................................................................................................... 46

5.6.2 Recreational Monitoring ...................................................................................... 46

5.6.3 Storages ................................................................................................................ 46


5.7 Algal monitoring .................................................................................................... 47

5.7.1 Warragamba system ............................................................................................ 47

5.7.2 Upper Nepean system .......................................................................................... 48


5.7.3 Woronora system ................................................................................................. 48

5.7.4 Blue Mountains system ........................................................................................ 48

5.7.5 Shoalhaven system ............................................................................................... 48

5.8 Cryptosporidium and Giardia monitoring ............................................................. 49

5.8.1 Catchments........................................................................................................... 49

5.8.2 Storages ................................................................................................................ 49


5.9 Picnic area monitoring .......................................................................................... 50

5.10 Dam seepage monitoring ...................................................................................... 51

6 Monitoring for the Water Licences ................................................................................ 52

6.1 Water quality ........................................................................................................ 52

6.2 Thermal impacts of environmental releases ........................................................ 53

6.2.1 Upper Nepean system .......................................................................................... 53

6.2.2 Woronora system ................................................................................................. 54

6.2.3 Shoalhaven system ............................................................................................... 55

7 Targeted and investigative monitoring .......................................................................... 56

7.1 Wet weather inflow monitoring ........................................................................... 56

7.2 Catchment Risk Characterisation .......................................................................... 58

7.3 Macroinvertebrate monitoring ............................................................................. 59

7.4 Investigative monitoring ....................................................................................... 61

7.4.1 Investigative monitoring for operational decision making .................................. 61

7.4.2 Scientific research ................................................................................................ 63

8 Incidents and events ....................................................................................................... 67

8.1 Major water quality incidents ............................................................................... 67

8.1.1 Potentially toxin producing cyanobacteria in Wingecarribee Reservoir .............. 67

8.1.2 Wet weather incident June 2016 ......................................................................... 68

9 References ...................................................................................................................... 70

10 Glossary .......................................................................................................................... 71

11 Acronyms ........................................................................................................................ 75


List of Figures

Figure 0.1: Sydney catchment area......................................................................................................... 2

Figure 2.1: Schematic of the water supply system ............................................................................... 13

Figure 5.1: Sampling sites in the Warragamba system (including inset Prospect Reservoir) ............... 30

Figure 5.2: Sampling sites in the Upper Nepean system. ..................................................................... 34

Figure 5.3: Sampling sites in the Woronora system. ............................................................................ 37

Figure 5.4: Sampling sites in the Blue Mountains system. ................................................................... 40

Figure 5.5: Sampling sites in the Shoalhaven system ........................................................................... 43

Figure 6.1: Upper Nepean system temperature profile ....................................................................... 54

Figure 6.2: Woronora system temperature profile .............................................................................. 54

Figure 6.3: Shoalhaven system temperature profile ............................................................................ 55

Figure 7.1: Turbidity of intrusions in Lake Nepean following heavy rainfall in August 2015. .............. 61

Figure 8.1: Wet weather inflow into Lake Burragorang showing outlet configuration change. .......... 69


List of Tables Table 2.1: Characteristics of WaterNSW’s major delivery systems in the Sydney catchment area ..... 14

Table 4.1a Health-related water quality characteristics: Synthetic Organics, Radiological and

Pesticide Characteristics ....................................................................................................................... 23

Table 4.2: Raw water supply agreements – Site specific standards ..................................................... 25

Table 4.3: Water quality benchmarks for storages ............................................................................... 26

Table 4.4: Water quality benchmarks for catchment streams ............................................................. 26

Table 5.1: Warragamba system catchments - percentage of samples outside benchmarks. .............. 31

Table 5.2: Upper Nepean catchments - percentage of samples outside benchmarks. ........................ 35

Table 5.3: Woronora system catchments - percentage of samples outside benchmarks. ................... 38

Table 5.4: Blue Mountains system storages - percentage of samples outside benchmarks. ............... 41

Table 5.5: Shoalhaven system catchments - percentage of samples exceeding benchmarks. ............ 44

Table 6.1: Downstream of storages - percentage of samples exceeding benchmarks ........................ 52

Table 7.1: Number of wet-weather samples and events from Type 1 auto-samplers 2015–16. ......... 57


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Executive Summary WaterNSW’s Water Monitoring Program 2015-2020 (WMP) for the Sydney catchment area details a

comprehensive monitoring plan covering catchments, lakes, intakes to water filtration plants, picnic

areas, dam safety and downstream sites. The WMP has been developed in collaboration with NSW

Health, Sydney Water and other wholesale customers. The program, endorsed by NSW Health,

incorporates locations, frequency, benchmarks or guideline values for more than 200 characteristics.

The WMP involves routine and event monitoring employing field sampling, laboratory testing and

telemetered ‘real-time’ data collection. The WMP provides timely water quality data and information

to inform operational decisions and demonstrate compliance.

This report describes the results of the water quality monitoring undertaken by WaterNSW in the

Sydney catchment area during 2015-16. The report is provided to meet WaterNSW’s statutory

obligations under the former Sydney Catchment Authority’s Operating Licence in addition to

providing stakeholders, students, researchers and the general public with water quality information

for waters managed by WaterNSW in the Sydney catchment area.

Highlights Greater Sydney’s dams remained close to full during 2015-16, commencing with the total storage

volume at 92.4% on 1 July 2015 and increasing to 98.3% by the end of the period, following a

significant inflow event in June 2016.

Guided by WaterNSW’s Water Quality Management Framework, WaterNSW successfully delivered

agreed quantities of quality water to customers in full compliance with the Australian Drinking Water

Guidelines (ADWG) for health related characteristics. By using source selection, modelling and

monitoring, WaterNSW avoided or effectively managed water quality incidents to minimise impacts

to customers.

Water supplied to water filtration plants maintained very high compliance with site specific

standards in raw water supply agreements. Source selection and system planning minimised the

impact of elevated true colour on filtration plants supplied by Lake Burragorang, Lake Woronora and

Lake Nepean while true colour in raw water supplied remained below the raw water supply

agreement maximum. The only exceedance of site specific standards was for total iron in raw water

supplied to Wingecarribee Water Filtration Plant but the treated water met the Australian Drinking

Water Guidelines.

WaterNSW manages water supplied at recreational sites in accordance with Quality Assurance Plans

for Picnic Areas based on the NSW Private Water Supply Guidelines. Regular monitoring at three

popular recreation sites in the Shoalhaven area showed high conformance with cyanobacterial

guidelines. There were no detections of E. coli in the picnic area supply, an improvement compared

to the previous year, confirming the effectiveness of disinfection.

Water quality at catchment sites generally remained good although elevated nutrient levels were

observed particularly in catchments with significant agricultural or urban development (e.g.

Wollondilly and Kangaroo Rivers). In contrast, natural catchments (e.g. Burke and Avon Rivers) rarely


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exceeded ANZECC benchmarks and continue to demonstrate the effectiveness of Special Areas in

protecting water quality.

Declining levels of dissolved oxygen were noted at many catchment sites relative to the previous

year but still only slightly below ANZECC benchmark ranges and not indicative of a significant

deterioration in ecosystem health.

Water quality conformance for 2015-16:

Raw Water Supply Agreements 99.99%

Australian Drinking Water Guidelines 100%

Monitoring downstream of WaterNSW storages is undertaken as part of the requirements of the

Water Licences and Approvals package issued by DPI Water. There is increasing deterioration in

water quality as we go further downstream of WaterNSW release points, particularly in the

Hawkesbury – Nepean system. This is indicative of less protected catchment downstream of the

dams.

WaterNSW has continued to deliver a program of scientific research projects through internal and

external collaborative arrangements. Notable research projects with a direct influence on water

quality management completed during the year included an analysis of cyanobacteria and taste and

odour causing substances in Prospect Reservoir, evaluating techniques to detect pollutant sources

and determining that pathogens carried by a small proportion of native animals may be infective to

humans.

New research projects commencing during the year included development of a GIS based water

quality event forecasting system and an investigation into sources of natural organic matter

impacting on treatment processes.

WaterNSW successfully managed water quality incidents as triggered by and in accordance with the

Raw Water Quality Incident Response Plan:

a significant inflow event bringing turbid intrusions to Lake Burragorang and Lake Nepean in

June 2016; and

potentially toxin producing algae in Wingecarribee Reservoir.


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1 Introduction

WaterNSW was formed on 1 January 2015 through the merger of the Sydney Catchment Authority

(SCA) and State Water Corporation. The Water NSW Act 2014 (the Act) transfers the functions of the

previous organisations into the new entity. The Act states under Section 6(1b) that a principal

objective of WaterNSW is to “supply water in compliance with appropriate standards of quality”.

WaterNSW undertakes extensive monitoring within its catchments, storages and raw water supply

system and in rivers downstream of storages in the Sydney catchment area to meet this objective.

WaterNSW’s Water Monitoring Program 2015–2020 for the Sydney catchment area sets out the

location, frequency and analytes monitored. Specific and health-related characteristics are

determined in consultation with our major customers and the program is endorsed by NSW Health as

required under the former Sydney Catchment Authority’s Operating Licence. Monitoring for

operations and planning helps WaterNSW understand the threats to water quality throughout the

supply system, including rivers, reservoirs and the delivery system. This information aids the

selection of the best source water for our customers and the environment.

WaterNSW’s Water Monitoring Program (WMP) is informed by pollution source assessment for the

four priority pollutants -pathogens, nutrients (nitrogen and phosphorus) and suspended solids.

Catchment-to-tap water quality risk assessments are also undertaken for each supply system in

conjunction with NSW Health and customers, and inform the Program to a large extent. The

outcomes of risk assessments assist in prioritising monitoring as well as actions to rectify existing

threats to water quality within drinking water catchments.

Data collected through the WMP is used to:

• provide early detection of possible contaminants in raw water to help protect the health of

more than four million consumers

• assist in proactive operational decisions

• ensure that the raw water delivered to wholesale customers meets agreed standards and

can be treated to meet the Australian Drinking Water Guidelines

• identify and target possible contamination sources in the catchments and storages

• identify emerging water quality issues and address them in forward planning

WaterNSW’s compliance monitoring activities are governed by four key drivers:

Operating licence granted by the Governor of NSW and administered by Independent Pricing

and Regulatory Tribunal (IPART)

Water Licences and Approvals package granted by the Water Administration Ministerial

Corporation and administered by Department of Primary Industries Water (DPI Water)

Raw water supply agreements between the WaterNSW and its wholesale customers

Australian Drinking Water Guidelines.


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1.1 This report

This report describes the results of water quality monitoring undertaken by WaterNSW in the Sydney

catchment area during 2015-16 under the Water Monitoring Program 2015-2020. The report is a

requirement of Sections 2.2.2 and 2.2.3 of the Reporting Manual that supports the Operating Licence

for the former Sydney Catchment Authority. The report also discusses monitoring of temperatures as

required under the Water Licences and Approvals package. As well as meeting WaterNSW’s statutory

obligations, the report aims to provide the community with information on water quality.

More specifically, this report includes:

a summary of the Water Monitoring Program, including objectives relating to monitoring and

applicable guidelines for water quality

a summary of the results of the routine, event and investigative monitoring

analysis of system performance relative to the criteria where relevant water quality or

catchment health benchmarks are available

information on the integrity of the data reported

details of research activities

measures planned or taken to manage water quality incidents


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2 Overview of the Greater Sydney region water supply network

WaterNSW collects water from river catchments to the south and west of Sydney and stores it in

lakes and reservoirs to supply more than four million people in the Greater Sydney region.

It is transported via a network of rivers, lakes, pipes and canals to water filtration plants, where it is

treated for consumers in Sydney, Illawarra, Shoalhaven, Goulburn, Blue Mountains and the Southern

Highlands. Water is also released from storages as environmental flows to maintain the health of the

downstream river systems.

The catchments cover an area of approximately 16,000 square kilometres — extending from the

headwaters of the Coxs River north of Lithgow, south to the source of the Shoalhaven River near

Cooma, and from Woronora in the east to the source of the Wollondilly River near Crookwell in the

west (Figure 0.1).

Raw water is collected from the river systems of five major catchments:

Warragamba

Upper Nepean

Woronora

Shoalhaven

Blue Mountains, including supplements from the Fish River system.

The characteristics of each system are summarised in Table 2.1, including catchment areas and

storage capacities. The transfer routes for water around the system and approximate number of

people supplied by that part of the system are shown in the water supply system schematic (Figure

2.1).

The Australian Drinking Water Guidelines framework for management of water supplies covers the

whole supply chain from source to the consumer to ensure safe drinking water. WaterNSW is

responsible for managing part of this supply chain (catchment, storages and raw water supply

system); and recognises the importance of this approach and works closely with upstream

stakeholders and downstream customers to ensure raw water supplied for treatment is of

appropriate quality. Raw water is treated by the customers who report on drinking water quality.


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Figure 2.1: Schematic of the water supply system


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Table 2.1: Characteristics of WaterNSW’s major delivery systems in the Sydney catchment area

Delivery System

Major Storages Total Capacity

(ML) Operating

Capacity* (ML) Catchment Area (km

2)

Warragamba Burragorang 2,031,000 2,027,000 9,051

Prospect 48,200 33,330 10

Upper Nepean Cataract 97,370 97,190 130

Cordeaux 93,640 93,640 91

Upper Cordeaux 1 775 Nil Included in Cordeaux

Upper Cordeaux 2 1,180 Nil Included in Cordeaux

Avon 214,360 146,700 142

Nepean 68,100 67,730 320

Woronora Woronora 71,790 71,790 75

Shoalhaven Yarrunga 85,500 7500 5,750

Bendeela 1,200 900 Included in Shoalhaven

Fitzroy Falls 22,920 9,950 31

Wingecarribee 25,880 24130 40

Blue Mountains Lower Cascade 305 305 3

Middle Cascade 167 167 2

Upper Cascade 1,791 1,791 2

Medlow 326 326 5

Greaves 301 301 7

* The total capacity of a reservoir is the amount of water it can hold when full. Operational restrictions may reduce the amount of useable water (Operating Capacity) that can be supplied to customers.

2.1 Warragamba system

The Warragamba delivery system consists of two large diameter pipes which transport water by

gravity from Lake Burragorang to water filtration plants (WFP) at Warragamba, Orchard Hills and

Prospect. Prospect Reservoir can supply directly to Prospect WFP. Water from the Upper Nepean

system is also supplied to Prospect via the Upper Canal.

Lake Burragorang, which sits behind Warragamba Dam, is the largest reservoir in the Sydney

catchments with the capacity to supply up to 80% of greater Sydney’s water. One quarter of the

catchment is a declared Special Area, where public access is restricted to protect water quality and is

mostly natural bushland. The rest of the catchment has eight local council areas with several

different types of land use.

2.2 Upper Nepean system

The Upper Nepean system is fed by four dams - Nepean, Avon, Cordeaux and Cataract. These dams

collect water from rivers on the Illawarra Plateau to supply water to Sydney through Broughtons Pass

Weir and the Upper Canal. The Macarthur WFP supplies drinking water sourced from the head of the

Upper Canal delivery system at Broughtons Pass Weir to the Camden, Campbelltown and Wollondilly

local government areas.


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The Nepean catchment is mostly natural bushland with some grazing and cropping in the upper

Nepean River catchment. Forestry, intensive agriculture and mining also occur within this catchment.

Lake Nepean supplies the Nepean WFP, which provides drinking water to the surrounding rural area

and the local townships of Bargo, Thirlmere, Picton and The Oaks.

Lake Avon supplies the Illawarra region and comprises mostly protected bushland. Water is

transported from the upper reaches of Lake Avon by gravity or by pumping to the Illawarra WFP for

supply to the Illawarra region. Water from Lake Nepean can also be transferred via a tunnel to Lake

Avon to supplement supply to the Illawarra region.

Cordeaux and Cataract catchments are mostly Special Areas, containing largely unspoilt bushland.

These lakes provide water supply to Macarthur WFP or the Upper Canal.

2.3 Woronora system

The Woronora system delivers water via a pipe system from Lake Woronora to Woronora WFP,

which supplies approximately 100,000 residents of Helensburgh, Engadine and parts of Sutherland

Shire. Lake Woronora is located on the southern outskirts of Sydney on the western side of

Heathcote National Park.

2.4 Blue Mountains system

The Blue Mountains delivery system is a complex system that can deliver water from both within and

outside the Blue Mountains bushland catchments. The system provides water to residents of the

middle and upper Blue Mountains from Lake Greaves, Lake Medlow and the three Cascade lakes at

Katoomba. These lakes are five of the smallest reservoirs managed by WaterNSW in the Sydney

catchment area.

All five lakes contribute to the supply of water to the Cascade WFP, which can also be supplemented

with water transferred from Lake Oberon on the Fish River or from the Duckmaloi River at Duckmaloi

Weir (both west of the Great Dividing Range).

Water from Warragamba Dam (treated at the Orchard Hills WFP) is pumped up the mountains to

supplement the system, supplying water to residents of the lower to middle Blue Mountains.

2.5 Shoalhaven system

The Shoalhaven system is a network of dams, pumps, canals and pipelines that transfer water from

the catchments of the Shoalhaven River via Wingecarribee Reservoir to either the Warragamba or

the Upper Nepean systems to supply Sydney and the Illawarra region during times of drought.

Wingecarribee Reservoir supplies water to Wingecarribee WFP, operated by Wingecarribee Shire

Council to supply drinking water for consumers in the Southern Highlands. Wingecarribee Reservoir

can also transfer raw water to Goulburn Mulwaree Council to supplement storage levels in Goulburn

Mulwaree’s water supply dams if required.


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The system is also used by Origin Energy to generate electricity. Power generation involves the

regular exchange of stored waters between Lake Yarrunga, Bendeela Pondage and Fitzroy Falls

Reservoir. Bendeela Pondage is a very small impoundment in the delivery system between Lake

Yarrunga and Fitzroy Falls Reservoir. Raw water from Bendeela Pondage is treated at the Kangaroo

Valley WFP operated by Shoalhaven City Council to supply drinking water for the residents of

Kangaroo Valley.

WaterNSW releases water from Lake Yarrunga downstream into the Shoalhaven River for the

Shoalhaven City Council to treat and supply its customers.

The major storage is Lake Yarrunga, at the junction of the Kangaroo and Shoalhaven Rivers. The

catchment has a variety of land uses, including bushland, dairy farming, beef and sheep production,

and rural residential.

2.6 Hawkesbury-Nepean River

The Hawkesbury–Nepean River sits below the major storage reservoirs in the Warragamba and

Nepean catchments. It is sustained by:

flows from local catchments

spills from WaterNSW storages

environmental flow and other releases from WaterNSW storages which help maintain and

improve the ecological health of the river

flows of treated effluent from Sydney Water’s waste water and recycled water treatment

plants.

DPI Water licenses various water extractors along the length of the Hawkesbury–Nepean River for

agricultural and some industrial use. Sydney Water also draws and treats water from the river at

North Richmond to supply consumers in that area.


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3 Sydney catchment area water monitoring program

The Water Monitoring Program 2015-2020 (WMP) covers routine, targeted, investigative and event-

based monitoring over the Sydney catchment area of operations.

The WMP covers catchments, storages, inlets to water filtration plants, picnic taps, transfer canals

and pipelines, as well as rivers downstream of water supply dams and weirs. Monitoring includes

physical, chemical, biological, radiological, hydrological and meteorological parameters through on-

line instruments, field sampling and laboratory analysis. A key feature of the WMP is an agreed list of

water quality characteristics. The list contains:

those characteristics that cannot be modified or removed by conventional treatment and for

which Australian Drinking Water Guidelines (ADWG) must not be exceeded; and,

those characteristics for which ADWG exist but are not applicable to raw water, where

WaterNSW must endeavour to supply raw water so that it can be treated to meet the ADWG.

WaterNSW is subject to a range of statutory requirements and standards set by regulatory agencies.

The principal documents that outline requirements on WaterNSW with respect to water monitoring

are listed below.

SCA Operating Licence (Part 2), Water NSW Act 2014 (Division 4)

SCA’s Water Licences and Approvals Package under Water Management Act 2000

Memorandum of Understanding (MoU) between NSW Health and WaterNSW (Parts 5-8)

Water NSW Act 2014 (Part 20-21)

Raw Water Supply Arrangements

Private Water Supply Guidelines and Public Health Act 2010

Water Act 2007 (Commonwealth)

Water NSW Act 2014.

3.1 Quality assurance and quality control

The Water Monitoring Program 2015–2020 specifies the requirements for water sample collection

and analysis. It describes sampling locations and frequencies, and the parameters to be analysed.

Additional samples are collected and analysed for quality assurance and quality control (QA/QC)

purposes. The QA/QC program provides confidence in the sampling data collected.

Water quality data integrity is assured through the design of the routine and QA/QC sampling

regimes and the analysis tools used to review data once it is delivered to WaterNSW. The primary

goal of field collected QA/QC samples is to identify, quantify and document bias and variability in

data that result from the collection, processing and handling of samples. This process also assists in

identifying opportunities to improve sampling methodologies. This is particularly important when

sampling for parameters that are likely to be present at very low concentrations (due to

measurement uncertainty).

Field collected QA/QC samples include field duplicates and field blanks. Trip blanks are also prepared

and taken on designated sampling trips.


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The collection and analysis of routine and QA/QC water samples is performed by service providers.

Service providers are contracted to include requirements for quality assurance practices in the

monitoring, sampling, testing and reporting processes. A chain of custody system allows individual

samples to be tracked from field collection, through laboratory analysis, to the transfer of results to

WaterNSW’s database.

WaterNSW’s analytical service providers have management systems that require them to maintain

their own internal QA/QC program. These systems are accredited with the National Association of

Testing Authorities (NATA) and ISO 17025. The analytical service providers conduct internal quality

control analysis per each batch of samples including matrix spikes, duplicates, blanks, replicate

analysis and inter laboratory proficiency trials. The service providers’ QA/QC specialists analyse

conformance with specified standards of accuracy and precision to identify any contamination,

outliers or errors.

Further details of the QA/QC monitoring for 2015-16 are included in Section 5.1.

3.2 Operating Licence

The Operating Licence and Reporting Manual require WaterNSW to:

Maintain a water quality management system consistent with the framework for managing

water quality as outlined in the ADWG.

Maintain a water quality monitoring program to the satisfaction of NSW Health.

Submit a report to IPART and NSW Health each financial year regarding its monitoring of

water quality.

The ADWG framework recommends monitoring for verification of water quality with short term

evaluation of results to enable incident response and corrective action. The ADWG framework also

recommends investigative and research monitoring and long term evaluation of results for continual

improvement.

Routine water monitoring provides information for compliance and operational decision-making.

Monitoring in catchments and storages is used to provide early warning of any risks, while

monitoring at the inlet of filtration plants is used to verify the effectiveness of controls.

Routine monitoring is supplemented by event and investigative monitoring targeting specific issues,

knowledge gaps or to assess the effectiveness of management strategies, investigations into

incidents or events or research to build knowledge of the water supply system. The outcomes of

specific non-routine monitoring projects are also used to inform the review of routine monitoring.


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3.2.1 Raw water supplied for treatment

Raw water is monitored in the delivery system and at inlets to WFPs prior to the water treatment

process. This helps verify that water quality meets the agreed criteria and ADWG for health related

characteristics. It also confirms the effectiveness of source selection decisions.

3.2.2 Storages

Storages are monitored at various sites and depths to provide detailed information on lake

conditions and processes. Monitoring is supported by modelling that assists in assessing current

conditions and predicting possible changes. Profiling of storages (i.e. measuring parameters at

discrete depths) is undertaken routinely to assist in selecting optimal supply depth to prevent

contaminants entering the water supply.

3.2.3 Catchments

Routine sampling of catchment streams enables the quality of catchment waters to be assessed and

any contamination identified at an early stage. This allows water quality hazards to be managed

within an adaptive management framework and for the effectiveness of interventions to be

quantified. Hydrometric monitoring measures rainfall and inflows to storages to help predict and

quantify inflow events, flooding and any associated water quality risks.

3.2.4 Picnic area monitoring

WaterNSW supplies chlorinated water to picnic areas at Fitzroy Falls Reservoir (including the National

Parks and Wildlife Service’s visitor centre), Cataract, Cordeaux and Avon dams. WaterNSW has

developed and implements the Drinking Water Quality Management Plan for Picnic Areas in line with

NSW Private Water Supply Guidelines that include the required monitoring for individual supply

areas.

3.2.5 Algal monitoring

Algae are routinely monitored in major storages to provide early warning of possible bloom

conditions. This helps minimise impact of algae in raw water supplied to customers for treatment It

also helps avoid the contamination of downstream waterways through environmental releases or

transfers. A seasonal sampling program, usually conducted between October and May, applies in

storages with a history of algal activity. Monitoring frequency is increased in response to triggers

specified in WaterNSW’s Cyanobacteria Response Plan.


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3.2.6 Cryptosporidium and Giardia monitoring

A consolidated monitoring program for Cryptosporidium and Giardia was implemented in April 2001,

following an agreement between the Ministers of NSW Health, Sydney Water and the Sydney

Catchment Authority (WaterNSW). This program remained in place for 2015–16.

3.2.7 Wet weather monitoring

Wet weather samples provide information on pollutant load associated with rain events or large

inflows. The collection and analysis of wet weather water samples across the catchments is essential

in identifying potential pollution sources. WaterNSW has installed autosamplers at strategic locations

in the catchment, which are triggered by changes in river levels.

3.2.8 Dam seepage

WaterNSW is required to monitor the structural integrity of prescribed dams, including seepage in,

around and through its structures. Dam seepage monitoring is undertaken to comply with Dams

Safety Act 1978.

3.2.9 Downstream of storages

A number of sites downstream of WaterNSW storages are routinely monitored in accordance with

Water Licence requirements. Sites are maintained as per an agreement with NSW Office of

Environment and Heritage and included in the triennial audits of Sydney’s drinking water

catchments.

3.3 Water Licences

DPI Water has issued the SCA (WaterNSW) a Water Licences and Approvals Package under the Water

Management Act 2000, which is a combination of ‘Water Access Licences’ and ‘Water Supply Work

and Water Use Approvals’. The Water Licences require environmental flows to be released from

reservoirs to help maintain the ecological health of downstream rivers. Water released from

reservoirs into rivers can be colder or warmer than the receiving water depending on the level of the

water offtake in the reservoir (deeper water is usually colder than surface water) and the time of the

year. WaterNSW undertakes temperature and routine water quality monitoring at a number of

downstream sites to assess impacts of releases on downstream river systems.


21

3.4 Future directions

3.4.1 Water Quality Management System

Australian Drinking Water Guidelines recommend identifying and using critical control points to

manage barriers in a water supply system. WaterNSW avoids contaminants from entering the water

supply to water filtration plants by effective operation of multi-level offtake and source selection.

Critical limits for turbidity have been agreed with Sydney Water. More work will be done in the

coming year to measure turbidity online and to generate alarms as early warning, so actions can be

taken before issues escalate. WaterNSW is working with Sydney Water to include source water

quality information in the web-based daily water quality dashboard available to the public.

3.4.2 Water Quality Event Forecasting System

Gura is a water quality event forecasting system which has been developed to bring together

disparate sources of information to inform the planning and management of responses to a water

quality event. The system delivers observed (sampled), real-time (hydrometrics) and forecast

(modelled) water quality data alongside ancillary information (e.g. radar and rainfall) within a spatial

context. The system is expected to support the day-to-day operations of the business by providing an

integrated spatial view of water quality data, catchment condition, and current and forecast rainfall.

Gura is intended to enable WaterNSW to forecast events in the Sydney catchment area in time to

implement planned responses. The goal is that every event that represents a potential hazard to

public health is rated as medium or lower risk.

The current version of Gura includes basic mapping data, water monitoring sites, real time water

quality data and a pollution risk layer incorporating real time groundcover values. The next steps in

the development of Gura are:

1. Combine pollution risk analysis with forecast rainfall and other factors such as runoff generation and distance to storage to improve its value and useability

2. Enhance real time water quality and quantity data

3. Implement a dashboard view of each water storage supply catchment.


22

4 Applicable guidelines / benchmarks

WaterNSW has adopted nationally recognised standards and guidelines for a range of water quality

characteristics in each part of the water supply network. Different guidelines and standards apply to

each part of the supply cycle as water passes from catchment waterways into lakes and then into the

delivery network or downstream rivers.

4.1 Australian Drinking Water Guidelines (ADWG) 2011

The Australian Drinking Water Guidelines (NHMRC, 2011) apply to any water intended for drinking,

irrespective of the source or where it is consumed. The ADWG framework for managing drinking

water quality advocates risk management and preventive measures at all barriers from catchment to

consumer.

For water quality characteristics that have been specified as ‘health related’, including metals,

pesticides and synthetic organic compounds (Table 4.1a-b), raw water must conform to the ADWG.

As conventional water treatment methods are not designed to remove these compounds from raw

water, it is preferable to avoid them in the raw water supply through catchment and storage

management practices.

Routine monitoring of radionuclides is performed at water filtration plants by screening for gross

alpha and gross beta activity concentrations. Testing for individual radionuclides is performed in the

case of a positive gross alpha or gross beta result. Radionuclides are not presented in the results

section of this report, but are included in Appendix A.

4.2 Raw water supply agreements

WaterNSW has established terms and conditions of supply with wholesale customers to ensure

treated water is not harmful to consumers’ health. Raw water supplied for treatment is required to

conform to site-specific standards specified in raw water supply agreements (Table 4.2). These

standards are based on the treatment capabilities of the plants and the natural characteristics of the

catchment. This ensures that raw water can be treated to meet ADWG requirements.


23

Table 4.1a Health-related water quality characteristics: Synthetic Organics, Radiological and Pesticide Characteristics

SYN

THET

IC O

RG

AN

ICS

- R

AD

IOLO

GIC

AL

- P

ESTI

CID

ES

SPECIFIC WATER CHARACTERISTIC DRIVER ADWG (2011)

Health Guideline

Synthetic Organic Compounds

1,1-Dichloroethane

Operating Licence1

NA

1,2-Dichloroethane 0.003 mg/L

1,2-Dichloroethene 0.06 mg/L

1,3-Dichloropropene (cis- and trans-) 0.1 mg/L

Benzene 0.001 mg/L

Hexachlorobutadiene 0.0007 mg/L

Vinyl chloride 0.0003 mg/L

Trichloroethylene NA

Pesticides

2,4-D 0.03 mg/L

Acephate 0.008mg/L

Aminopyralid NA

Amitrole 0.009 mg/L

Atrazine 0.02 mg/L

Azinphos-methyl 0.03 mg/L

Chlorfenvinphos 0.002 mg/L

Chlorothalonil 0.05 mg/L

Chlorpyrifos 0.01 mg/L

Clopyralid 2 mg/L

Diazinon 0.004 mg/L

Dichlobenil 0.01 mg/L

Dimethoate 0.007 mg/L

Diuron 0.02 mg/L

Fluproponate 0.009 mg/L

Fluroxypyr NA

Glyphosate 1.0 mg/L

Hexazinone 0.4 mg/L

MCPA (2-methyl-4-clorophenoxyacetic acid) 0.04 mg/L

Metsulfuron-methyl 0.04 mg/L

Picloram 0.3 mg/L

Simazine 0.02 mg/L

Triclopyr 0.02 mg/L

Trifluralin 0.09 mg/L

Radiological2

Gross alpha

0.5 Bq/L

Gross beta 0.5 Bq/L

Notes:

1 Section shaded yellow contains health related water quality characteristics. These characteristics must not exceed Australian Drinking Water Guidelines (NHMRC, 2011) in raw water supplied as treatment may not remove them. Minimising these in raw water effectively minimises risk to consumers.

2 Australian Drinking Water Guidelines recommends that a screening level test is performed for radiological parameters.


24

Table 4.1b: Health and Aesthetic Water Quality Characteristics: Physical, Chemical, Biological and Organic Characteristics

PH

YSI

CA

L -

CH

EMIC

AL

- B

IOLO

GIC

AL

- O

RG

AN

IC

SPECIFIC WATER CHARACTERISTIC DRIVER ADWG (2011)

Health Guideline

Arsenic

Barium

Beryllium

Boron

Iodide

Mercury

Molybdenum

Selenium

Silver

Tin

ADWG (2011)1

Health Guideline

0.01mg/L

2 mg/L

0.06mg/L

4 mg/L

0.5 mg/L

0.001 mg/L

0.05 mg/L

0.01 mg/L

0.1 mg/L

N/A

Antimony

Cadmium

Chromium (CrVI)

Copper

Lead

Nickel

ADWG (2011)2

Health Guideline via NSW Private Water

Supply Guidelines (2014)

0.003 mg/L

0.002 mg/L

0.05 mg/L

2 mg/L

0.01 mg/L

0.02 mg/L

E. coli

Enterococci

C. perfringens

Cryptosporidium

Giardia

Toxin producing cyanobacteria

Toxicity

Total cyanobacteria biovolume

Operating Licence3 Seek advice from NSW Health

Geosmin

MIB

Total dissolved solids

Operational

N/A

N/A

N/A

Algae (ASU)

Alkalinity

Aluminium

Hardness

Iron

Manganese

True colour

Turbidity

Water Supply Agreements Refer to Water Supply

Agreements

Total cyanobacteria biovolume

Microcystis aeruginosa

Toxicity

Enterococci

Water Licences and Approvals Package

(WLAP)4

Refer to Guidelines for Managing

Risks in Recreational Water

(NHMRC 2008)

Chlorophyll-a

Lorenzen

Phaeophytin

Secchi depth

Operational

N/A

N/A

N/A

N/A

Notes:

1 Section shaded yellow contains health related water quality characteristics – these characteristics must not exceed Australian Drinking Water Guidelines (NHMRC, 2011) in raw water supplied as treatment may not remove them. Minimising these in raw water effectively minimises risk to consumers.

2 Section shaded orange contains health related water quality characteristics for private water supplies – these characteristics must not exceed Australian Drinking Water Guidelines (NHMRC, 2011) in treated waters.


25

3 Section shaded blue contains characteristics for which drinking water guidelines exist but these are not applicable for raw water. However, WaterNSW must endeavour to supply the best quality raw water available so that it can be treated to meet Australian Drinking Water Guidelines.

4 Section shaded green contains characteristics which apply for recreational waters and releases.

Table 4.2: Raw water supply agreements – Site specific standards

Turb

idit

y

Tru

e C

olo

ur

@4

00

nm

Iro

n

Man

gan

ese

Alu

min

ium

Har

dn

ess

Alk

alin

ity

pH

Od

ou

r

Alg

ae

NTU CU mg/L mg/L mg/L mg/L as

CaCO3

mg/L as

CaCO3 pH units Rating ASU

Prospect WFP

40 60 3.50 1.40 2.6 25 – 70 15 - 60

NA

NA

1000(i)

Warragamba WFP 2000

Orchard Hills WFP

Macarthur WFP

Based on Demand

(ML/day)

185 - <265 10

40

0.60 0.20 0.40 6 – 30

15

100(ii) 125 - <185 25 0.80 0.25 0.50

6 – 32.20 80 - <125 50 1.10 0.30 0.75 500(ii)

<80 60 1.30 0.35 0.95

Illawarra WFP 10

50 1.1 0.4 1.4 30 10 Not

objectionable 5000

Woronora WFP 70 1 0.1 0.4 2 – 30 15

Nepean WFP 150 60

5.0 1.5 1.0 2 – 35 0.5 – 25

NA

2000 Cascade WFP 15 3.0 0.3 0.2 40 30

Kangaroo Valley WFP 20

70 1.1 NA NA 36.5

29

6.5 – 8.5 5000 Wingecarribee WFP 40 35

Goulburn Mulwaree

(i) Maximum for Prospect WFP is 1000 ASU, except if turbidity is greater than 10 NTU or true colour is greater than 30 CU, then the algae

maximum will be 500 ASU.

(ii) Algal limits for Macarthur WFP (average of 3 samples): 500 ASU small individual cells (<10 μm) of filamentous or colonial species, typically Chlorella, Dolichospermum, Monodus and Melosira; or 100 ASU large (>10 μm) cells, branching species, and/or gelatinous species, typically Asterionella, Taballaria, Fragillaria, Synedra, Cyclotella, Dinobryan, Elakatothrix, and Volvox.

(iii) Upper limits are shown for analytes where ranges are not provided.

4.3 ANZECC 2000

The Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000) (referred to

as ANZECC, 2000) provide a guide for setting water quality objectives required to sustain current or

likely future environmental values for natural and semi-natural water resources in Australia and New

Zealand. Water quality in WaterNSW’s metropolitan storages, catchment waterways and

downstream rivers are compared against relevant sections of the ANZECC Guidelines.

4.3.1 Benchmarks for storages

Benchmarks for storages are derived from the guidelines for freshwater lakes and reservoirs

(ANZECC, 2000) for the 95-99 percent level of species protection (Table 4.3).


26

Table 4.3: Water quality benchmarks for storages

Analyte Units Benchmark range

pH pH units 6.5 - 8.0

Chlorophyll-a μg/L < 5

Dissolved oxygen %sat 90 - 110

Total nitrogen mg/L < 0.35

Total phosphorus mg/L < 0.01

Turbidity NTU < 20.0

Total manganese mg/L < 1.9

Total aluminium mg/L < 0.055

4.3.2 Benchmarks for catchments

WaterNSW benchmarks water quality in metropolitan catchment streams against the ANZECC (2000)

guideline ranges for upland rivers (Table 4.4).

Table 4.4: Water quality benchmarks for catchment streams


pH pH units 6.5 – 8.0


Dissolved oxygen % sat 90 - 110



Turbidity NTU < 25

4.4 Benchmarks for recreational areas

To minimise risks to public health, WaterNSW manages recreational exposure risk by benchmarking

water quality against the NHMRC Guidelines for Managing Risks in Recreational Waters (2008) and

the Cyanobacterial Response Plan. Primary and secondary contact guidelines are available in (Table

4.5).

Table 4.5: Water quality benchmarks for recreation areas

Analyte Units

Primary Contact Secondary Contact

Minor Alert

Threshold

Major Alert

Threshold Alert Threshold

Enterococci cfu/100mL < 40 < 200 <200

Microcystis aeruginosa cells/mL < 5,000 < 50,000 <50,000

Total cyanobacteria biovolume mm3/L < 0.4 < 4 <4

Algal toxins (Microcystin-LR equivalents) µg/L NA < 10 <10


27

4.5 Benchmarks for downstream rivers

Benchmarks for water quality downstream of WaterNSW’s dams and weirs are derived from ANZECC

lowland rivers ecosystem types (Table 4.6). Table 4.6: Water quality benchmarks downstream of storages




Dissolved oxygen %sat 85 - 110



Turbidity NTU < 50

4.6 Benchmarks for picnic area supplies

Benchmarks for the picnic area supplies are based on ADWG (2011) threshold ranges, where relevant

(Table 4.7). Some benchmarks are prompts for action, such as chlorophyll-a, which triggers algal

monitoring in the picnic area supply.

Table 4.7: Water quality guidelines for specific parameters at picnic areas

Analyte Units Threshold

Free chlorine residual mg/L > 0.5


Turbidity NTU < 5

Total Iron mg/L < 0.3

Total Aluminium mg/L < 0.2

Total Manganese mg/L < 0.1

E. coli orgs/100mL Should not be detected

Algal toxins (Microcystin-LR equivalents) μg/L <1.3

Chlorophyll-a μg/L <5

Potentially toxin producing algal cells cells/mL <6,500(i)

(i) See cyanobacteria benchmarks in Table 4.8.

4.7 Benchmarks for cyanobacteria

WaterNSW routinely monitors levels of algae in major storages to provide early warning of possible

bloom conditions and to ensure that raw water supplied to customers can be treated to meet

drinking water guidelines and have high aesthetic quality. Algal monitoring is also conducted to avoid

contaminating downstream waterways through environmental releases or transfers.

Despite the fact that Australian Drinking Water Guidelines (NHMRC, 2011) stipulate cyanobacteria

guidelines and alert levels for treated drinking water, WaterNSW applies those guidelines to the raw

water supplied for treatment in Greater Sydney. Lake Yarrunga and Fitzroy Falls Reservoir being the

only WaterNSW storages in the Sydney drinking water catchment with recreational access,

WaterNSW applies the National Health and Medical Research Council Recreational Waters Guidelines


28

(NHMRC, 2008) for catchments and lakes (Table 4.8). The raw water and picnic areas benchmarks are

from the ADWG.

Table 4.8: Cyanobacteria benchmarks throughout Sydney drinking water catchment

Analyte Units Threshold

Catchment and lake sites(i)

Cells Microcystis aeruginosa cells/mL 50,000

Toxicity Microcystin (LR toxicity equivalents) μg/L 10

Biovolume Total cyanobacteria mm3/L 4

Raw water and picnic area water supplies(ii)

Cells Microcystis aeruginosa cells/mL 6,500

Cylindrospermopsis raciborskii cells/mL 15,000

Dolichospermum circinale cells/mL 20,000

Toxicity Microcystin (LR toxicity equivalents) μg/L 1.3

Cylindrospermopsin μg/L 1.0

Saxitoxin μg/L 3.0

Biovolume Potentially microcystin-producing species mm3/L 0.6

Potentially cylindrospermopsin-producing species mm3/L 0.6

Potentially saxitoxin-producing species mm3/L 5

(i) National Health and Medical Research Council Guidelines for Managing Risks in Recreational Water 2008.

(ii) These triggers are based on cell counts, toxin concentration and biovolume ADWG 2011 specify actions in response to

various alert level ranges for Microcystis aeruginosa, Dolichospermum circinale and Cylindrospermopsis raciborskii, and

the consolidated biovolumes of the species known to produce microcystin, saxitoxins and cylindrospermopsin toxins.

4.8 Benchmarks for Cryptosporidium and Giardia

The ADWG do not contain guideline values for Cryptosporidium and Giardia in raw or treated

drinking water. However, ADWG (2011) recommends a multi-barrier approach to minimise the risks

of these pathogens. Investigative testing is encouraged in response to events (e.g. heavy rainfall) that

could increase the risk of contamination. WaterNSW implements additional monitoring during high

risk events.

Cryptosporidium and Giardia monitoring in the catchments is undertaken to provide an early warning

to enable optimal configuration of the raw water supply system in the event of high levels of

Cryptosporidium and/or Giardia detections within the storages. Catchment monitoring also

contributes to the understanding of sources which can then improve the robustness of risk

assessments and catchment actions.

WaterNSW responds to detections of Cryptosporidium and Giardia in raw water supply in accordance

with the Raw Water Quality Incident Response Plan (RWQIRP) developed in consultation with NSW

Health and customers. The RWQIRP identifies four event levels for raw water:

Alert Level: 1 – 10 (oo)cysts (/10 L adjusted for recovery)

Minor Incident: 11 – 100 (oo)cysts (/10 L adjusted for recovery)

Major Incident: 101 – 1000 (oo)cysts (/10 L adjusted for recovery)

Emergency: >1000 (oo)cysts (/10 L adjusted for recovery).


29

5 Routine monitoring

Water quality monitoring was conducted as per the Water Monitoring Program 2015-2020. Samples

were collected from catchment streams, storages and delivery sites and analysed by NATA accredited

laboratories. Online instruments were used to supplement this monitoring. The results are compared

with appropriate guidelines, standards/benchmarks in the sections that follow. Overall conformance

with ADWG and Raw Water Supply Agreements were 100% and 99.99% respectively. This confirmed

that WaterNSW’s proactive offtake and source selection was effective in avoiding contaminants from

entering water supplied for treatment.

5.1 Quality Assurance/Quality Control

During 2015-16, 5,236 routine samples were collected for testing. Routine sampling was conducted

in accordance with the program; however in a small number of situations sites could not be visited

on every occasion. Site visitation in some instances was restricted due to access issues, typically

surrounding safety, wet weather or land-holder permission. There were also a small number of

instances where lab analysis could not be performed on samples provided. There were 598 quality

assurance and quality control (QA/QC) samples taken over this period which is equivalent to 11.4% of

the routine samples collected. This included 337 duplicate samples (6.4%), 130 field blanks (2.5%)

and 125 trip blanks (2.4%). See Glossary for descriptions of types of QA/QC samples.

Trip blanks

A total of ten trip blank samples detected at least one analyte. Detections ranged across eight

parameters; total coliforms, nitrogen (total and total kjeldahl), odour, chlorophyll-a, lorenzen,

phaeophytin and algae. All deionised water supplied to the sampling teams is quality control checked

on a monthly basis to ensure that it is below the limit of reporting. Water is provided to samplers on

a weekly stock to ensure that water doesn’t age. All of these detections were very low, just above

the limit of reporting and did not significantly affect the interpretation of sample results.

Field blanks

A total of twelve field blank samples detected at least one analyte. Detections ranged across nine

parameters; filtered sodium, oxidised nitrogen, Enterococci, E. coli, chlorophyll-a, phaeophytin,

odour, dissolved organic carbon and total organic carbon. This is a reduction in both the total field

blank detections reported during 2014-15 as well as a reduction in the parameters detected, with no

metal detections reported this year. Most detections were very low, just above the limit of reporting

and did not significantly affect interpretation of sample results.

Duplicates

Duplicate sample variations were infrequent, variable and did not indicate any systemic issues with

sampling and/or laboratory quality control and assurance processes.


30

5.2 Warragamba system

Sampling sites in the Warragamba system (including Prospect Reservoir) are shown in Figure 5.1

below.

Figure 5.1: Sampling sites in the Warragamba system (including inset Prospect Reservoir)


31

Table 5.1: Warragamba system catchments - percentage of samples outside benchmarks.

Site

Stat

ion

Co

de

Physico-Chemical Nutrients Metals Cyanobacteria

Alk

alin

ity

(mgC

aCO

3/L

)

Dis

solv

ed O

xyge

n (

%Sa

t)

pH

(La

b/F

ield

)

Tota

l Har

dn

ess

(mgC

aCO

3/L

)

Tru

e C

olo

ur

at 4

00

nm

Turb

idit

y La

b/F

ield

(N

TU)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

Are

al S

tan

dar

d U

nit

(al

gae)

Ch

loro

ph

yll-

a (u

g/L)

Catchments (compliance with ANZECC guidelines – refer Table 4.4). Where there is no applicable benchmark cells are greyed out.

Farmers Creek Mt Walker E046

67 33

0 100 100

25

Coxs River at Lithgow (next to the Power Station) E0321

42 100

0 100 25

0

Coxs River D/S Lake Lyell E0114

67 92

0 100 58

17

Coxs River U/S Lake Lyell E0115

0 100

0 91 82

18

Coxs River @ Kelpie Point E083

27 9

0 25 17

17

Kowmung River @Cedar Ford E130

42 0

0 8 17

8

Kedumba River@ Maxwells Crossing E157

50 8

0 92 0

0

Gibbergunyah Ck 400m d/s of Mittagong STP Disch. E203

27 0

9 100 100

33

Nattai River @ The Crags E206

27 9

9 100 42

25

Nattai River @ Smallwoods Crossing E210

64 0

0 67 0

17

Little River @ Fireroad W4I E243

67 33

0 0 0

8

Wingecarribee River @ Berrima E332

91 9

18 100 100

100

Wollondilly River @ Murrays Flat E409

67 25

0 100 87

65

Wollondilly River @ Golden Valley E450

80 20

10 100 25

17

Wollondilly at Upper Tarlo E4122

100 0

9 100 82

45

Mulwaree River @ Towers Weir E457

75 58

17 100 100

77

Wollondilly River @ Jooriland (Fowlers Flat) E488

42 75

0 100 8

8

Werriberri Creek @ Werombi E531

100 8

0 50 25

0

Tonalli River at Fireroad W2 E551

100 0

0 11 11

0

Storages (compliance with ANZECC guidelines – refer Table 4.3)

Lake Burragorang @ 500m u/s Dam Wall DWA2

24 45

0 33 4 6

0

8


32

Site

Stat

ion

Co

de


Alk

alin

ity

(mgC

aCO

3/L

)

Dis

solv

ed O

xyge

n (

%Sa

t)

pH

(La

b/F

ield

)

Tota

l Har

dn

ess

(mgC

aCO

3/L

)

Tru

e C

olo

ur

at 4

00

nm

Turb

idit

y La

b/F

ield

(N

TU)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

Are

al S

tan

dar

d U

nit

(al

gae)

Ch

loro

ph

yll-

a (u

g/L)

Lake Burragorang @ 14km u/s of Dam Wall DWA9

34 39

0 35 2 11

0

4

Lake Burragorang 9km d/s of DWA15 DWA12

31 49

0 33 8 0

0

3

Lake Burragorang @ 4KM U/S BUTCHERS CK. DWA15

43 57

0 25 0 0

0

28

Lake Burragorang @ Kedumba River arm DWA19

64 31

0 25 25 8

0

76

Lake Burragorang @ Coxs Arm 37km u/s Dam DWA21

67 43

0 25 42 0

0

56

Lake Burragorang @ Woll. Arm 23 km u/s Dam DWA27

38 45

0 36 10 6

0

8

Lake Burragorang @ Wollondilly Arm, 40km from dam DWA39

60 24

0 50 42 33

0

39

Lake Burragorang @ Woll. Arm 300m u/s of Nattai R. DWA311

55 40

0 50 8 25

0

6

Lake Prospect @ Midlake RPR1

0 2

0 0 4 4

0

8

Lake Prospect @ Inlet to RWPS RPR6

7 0

0 0 0 50

0

33

Raw Water (compliance with raw water supply agreement site specific standards - refer Table 4.2)

Orchard Hills WFP raw water HBR1 0

0 0 0

0 0 0 0

Warragamba WFP raw water HWA2 0

0 0 0

0 0 0 0

Prospect WFP inlet - Channel 2, 2nd dosing bridge PWFP10 0

0 0 0

0 0 0 0


33

5.2.1 Catchments

These catchments continue to regularly return values for nutrients (nitrogen and phosphorus) and

chlorophyll-a exceeding the ANZECC benchmarks. Protected natural catchments such as the

Kowmung, Kedumba and Little rivers returned much better values than those from catchments

dominated by agricultural and urban land uses, such as the Wollondilly, Mulwaree and

Wingecarribee rivers. This is particularly evident at sites downstream of sewage treatment plants

such as those on the Farmers and Gibbergunyah creeks.

5.2.2 Storages

A significant inflow event in June 2016 brought nutrients, turbidity and elevated true colour into the

storage. This event was successfully managed to avoid impacts on water supplied for treatment

(refer to Section 8.1).

Nutrient concentrations in Lake Burragorang recorded some increases, which corresponded to lake

turnover in late winter 2015 and the significant inflow event in early June 2016.

Algal activity throughout the reporting period was moderate and followed the typical seasonal

pattern. Toxins (microcystin) remained below the limit of detection.

Some variance with dissolved oxygen compliance is noted throughout the storage when compared to

last year, but no definitive trend is identified. Dissolved oxygen concentrations in the surface waters

vary significantly throughout the day, and between sampling events due to turbulence and algal

respiration.

True colour peaked at times throughout the year in response to inflow events. These peaks were

avoided in the raw water supply by using outlet depth selection.

5.2.3 Water Filtration Plants

For the 2015-16 reporting period, all water sample results were within the raw water supply

agreement standards for raw water supplied to Warragamba, Orchard Hills and Prospect water

filtration plants. All water samples were well below ADWG for health related characteristics.


34

5.3 Upper Nepean system

Sampling sites in the Upper Nepean system are shown in Figure 5.2 below.

Figure 5.2: Sampling sites in the Upper Nepean system.


35

Table 5.2: Upper Nepean catchments - percentage of samples outside benchmarks.

Site

Stat

ion

Co

de


Alk

alin

ity

(mgC

aCO

3/L

)

Dis

solv

ed O

xyge

n (

%Sa

t)

pH

(La

b/F

ield

)

Tota

l Har

dn

ess

(mgC

aCO

3/L

)

Tru

e C

olo

ur

at 4

00

nm

Turb

idit

y La

b/F

ield

(N

TU)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

Are

al S

tan

dar

d U

nit

(al

gae)

Ch

loro

ph

yll-

a (u

g/L)


Nepean River @ Inflow to Lake Nepean E601 0 0 0 80 0 20

Burke River @ inflow to Lake Nepean E602 0 42 0 0 0 0

Nepean River @ AT McGuire's Crossing E697 8 0 0 92 25 25

Flying Fox Creek No.3 E604 9 9 0 18 9 0

Avon River - Summit Tank E610 17 25 0 0 0 0

Cataract River inflow E609 55 91 0 0 18 0

Cordeaux River at causeway between U.Cord. 1 & 2 E680 17 17 0 8 0 0

Goondarin Creek inflow E608 17 17 0 8 8 0

Sandy Creek inflow E6006 42 75 0 0 8 0


Lake Avon @ Dam Wall DAV1 14 50 0 0 4 0 0 3

Lake Avon @ Upper Avon Valve Chamber DAV7 16 29 0 0 0 9 0 30

Lake Cataract @ Dam wall DCA1 8 55 0 0 8 58 0 0

Lake Cordeaux @ Dam wall DCO1 40 8 0 4 21 17 0 28

Lake Nepean @ 300m u/s dam wall DNE2 48 25 0 45 77 91 0 33


Nepean WFP raw water HNED 0 0 0 0 0 0 0 0

Illawarra WFP raw water IWFP-R 0 0 0 0 0 0 0 0

Macarthur WFP raw water at Inlet to PS HMAC1 0 0 0 0 0 0 0 0


36

5.3.1 Catchments

Upper Nepean catchment sites continued to perform well against ANZECC benchmarks and

demonstrate the benefit of Special Areas. The Nepean River catchment sites recorded the highest

nutrient levels of the Upper Nepean catchments, although there were improvements recorded at

both these sites this year. pH was regularly outside the ANZECC benchmark range at some sites but is

considered to be the natural condition and the result of local geology. Turbidity achieved full

compliance at all sites in 2015-16.

5.3.2 Storages

Water quality in the Upper Nepean lakes continued to record a high compliance against ANZECC

benchmarks. Chlorophyll-a exceedance against the ANZECC benchmark increased in Lake Avon, Lake

Nepean and Lake Cordeaux this year. Despite more frequent exceedances, the highest

concentrations recorded in Lake Nepean and Lake Cordeaux were less than the peaks recorded last

year.

Aluminium exceedance at Lake Nepean increased slightly this year. Lake Nepean typically records the

highest aluminium concentrations from the Upper Nepean lakes. Peaks in total aluminium were

recorded following the heavy rainfall and inflow received in June 2016. The local geology and wet

weather runoff influences the aluminium concentrations received in the lake. Similar to the

catchment sites, local geology results in pH levels outside of the ANZECC range.


There were no routine water sample results outside of the raw water supply agreement standards

for raw water supplied to Macarthur, Illawarra and Nepean water filtration plants.

All samples were below ADWG for health related characteristics.


37

5.4 Woronora system

Sampling sites in the Woronora system are shown in Figure 5.3 below.

Figure 5.3: Sampling sites in the Woronora system.


38

Table 5.3: Woronora system catchments - percentage of samples outside benchmarks.

Site

Stat

ion

Co

de


Alk

alin

ity

(mgC

aCO

3/L

)

Dis

solv

ed O

xyge

n (

%Sa

t)

pH

(La

b/F

ield

)

Tota

l Har

dn

ess

(mgC

aCO

3/L

)

Tru

e C

olo

ur

at 4

00

nm

Turb

idit

y La

b/F

ield

(N

TU)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

Are

al S

tan

dar

d U

nit

(al

gae)

Ch

loro

ph

yll-

a (u

g/L)


Waratah Rivulet d/s Flatrock Crossing E6131

67 0

0 0 0

0

Woronora River E677

67 100

0 8 0

0


Lake Woronora @ Dam Wall DWO1

25 32

0 0 0 71

0

0


Woronora WFP HWO1-A 0

0 0 0

0 0 0 0


39

5.4.1 Catchments

Water quality at Lake Woronora catchment sites was consistently good. Low pH in the Woronora

River catchment is common due to groundwater infiltration from surrounding Hawkesbury

sandstone. A small number of samples exceeded the ANZECC benchmarks for nutrients, however

chlorophyll-a remained low in these rivers.

The number of samples of dissolved oxygen saturation outside the benchmarks increased this year.

The average dissolved oxygen saturation during 2015-16 was 87.6% in the Waratah Rivulet and

83.5% saturation in the Woronora River. These dissolved oxygen saturation levels are only slightly

below the lower benchmark range of 90% saturation and do not indicate any issues with catchment

health.

5.4.2 Storage

Water quality in Lake Woronora remained good with high compliance against ANZECC benchmarks.

Naturally low pH water from the Woronora River resulted in some samples falling below the ANZECC

benchmark. Aluminium is typically above the benchmark in Lake Woronora, caused by leaching from

soil and rock in the catchment. Full compliance was achieved this year for nutrients, an improvement

over last year which recorded 8% of samples exceeding nitrogen and phosphorus benchmarks.

5.4.3 Water Filtration Plant

Consistent with previous years, routine water quality monitoring at Woronora water filtration plant

recorded full compliance against raw water supply agreement standards and ADWG for all samples.

Special sampling following the significant rain and inflow event in June 2016, however, did record

high levels of aluminium (see Section 8.1).


40

5.5 Blue Mountains system

Sampling sites in the Blue Mountains system are shown in Figure 5.4 below.

Figure 5.4: Sampling sites in the Blue Mountains system.


41

Table 5.4: Blue Mountains system storages - percentage of samples outside benchmarks.

Site

Stat

ion

Co

de


Alk

alin

ity

(mgC

aCO

3/L

)

Dis

solv

ed O

xyge

n (

%Sa

t)

pH

(La

b/F

ield

)

Tota

l Har

dn

ess

(mgC

aCO

3/L

)

Tru

e C

olo

ur

at 4

00

nm

Turb

idit

y La

b/F

ield

(N

TU)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

Are

al S

tan

dar

d U

nit

(al

gae)

Ch

loro

ph

yll-

a (u

g/L)

Storages (compliance with ANZECC guidelines – refer Table 4.3). Where there is no applicable benchmark cells are greyed out.

Lake Greaves @ dam wall DGC1 90 100 0 0 21 100 0 14

Lake Lower Cascade@ 50m U/S DLC1 76 0 0 0 8 0 0 0

Lake Top Cascade @ 100m u/s Dam Wall DTC1 88 0 0 4 0 25 0 14


Cascade WFP raw water HCSR 0 0 0 0 0 0 0 0


42

5.5.1 Catchments

The Blue Mountains catchments are very small (less than 20 km2 in total) and inflow water quality is

represented by water quality in the lakes. There are no routine monitoring sites in the Blue

Mountains catchments.

5.5.2 Storages

Typical of the Blue Mountains lakes, dissolved oxygen was regularly below the ANZECC benchmark of

90% saturation. Destratification fans are employed throughout most of the year to maintain elevated

dissolved oxygen saturation levels. Dissolved oxygen saturation levels in Lake Greaves were lower

than typical this year, largely due to a period where the Greaves Creek Dam destratification fan was

out of operation.

Nitrogen and phosphorus levels recorded improvements this year throughout the Blue Mountains

lakes.

pH and aluminium are naturally higher in the Lake Greaves catchment and were above the ANZECC

benchmarks on all occasions. There were slight increases in the aluminium in Top Cascade Lake;

however there were no significant impacts on water quality supplied to the water filtration plant.


All samples at the Cascade water filtration plant were compliant with raw water supply agreement

standards and ADWG.


43

5.6 Shoalhaven system

Sampling sites in the Shoalhaven system are shown in Figure 5.5 below.

Figure 5.5: Sampling sites in the Shoalhaven system


44

Table 5.5: Shoalhaven system catchments - percentage of samples exceeding benchmarks.

Site

Stat

ion

Co

de


Alk

alin

ity

(mgC

aCO

3/L

)

Dis

solv

ed O

xyge

n (

%Sa

t)

pH

(La

b/F

ield

)

Tota

l Har

dn

ess

(mgC

aCO

3/L

)

Tru

e C

olo

ur

at 4

00

nm

Turb

idit

y La

b/F

ield

(N

TU)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

Are

al S

tan

dar

d U

nit

(al

gae)

Ch

loro

ph

yll-

a (u

g/L)


Kangaroo River @ Hampden Bridge E706 25 8 0 75 100 17

Mongarlowe R. at Mongarlowe E822 0 8 0 8 17 0

Shoalhaven R @ Fossickers Flat E847 0 8 8 58 58 0

Shoalhaven R @ Mount View E860 17 0 0 33 83 0

Shoalhaven R @ Hillview E861 8 0 8 33 25 0

Boro Ck @ Marlowe E890 100 67 8 50 100 50

Gillamatong Creek @ Braidwood E891 83 0 0 100 92 58

Corang River E8311 18 45 0 18 0 0

Brogers Creek@Clinton Park E7021 17 42 0 33 92 8

Kangaroo River at Oakdale E7061 17 17 0 8 42 0

Bundanoon Creek at the Rocks E520 17 0 0 18 0 0

W.MEADOW CK AT GUAGE E300 67 58 8 100 67 8

Caalang CK Old Kangaloon Rd Ford E301 25 17 0 100 33 8


Bendeela Pondage DBP1 57 0 0 50 100 100 0 92

Lake Yarrunga@ 100m from Dam Wall DTA1 55 6 6 41 100 86 0 33

Lake Yarrunga @ Shoalhaven River DTA5 44 13 3 36 100 95 0 27

Lake Yarrunga @ Kangaroo R at Bendeela PS DTA8 53 13 0 60 100 100 0 68

Lake Fitzroy Falls @ Midlake DFF6 8 0 0 100 100 100 0 100

Wingecarribee Lake at outlet DWI1 23 1 6 88 100 100 0 100


45

Site

Stat

ion

Co

de


Alk

alin

ity

(mgC

aCO

3/L

)

Dis

solv

ed O

xyge

n (

%Sa

t)

pH

(La

b/F

ield

)

Tota

l Har

dn

ess

(mgC

aCO

3/L

)

Tru

e C

olo

ur

at 4

00

nm

Turb

idit

y La

b/F

ield

(N

TU)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

Are

al S

tan

dar

d U

nit

(al

gae)

Ch

loro

ph

yll-

a (u

g/L)


Kangaroo Valley WFP Inlet HKV1 0 0 0 0 0 0 0

Wingecarribee WFP raw water HWI1 0 0 0 0 0 17 0


Sydney Catchment Area Annual Water Quality Monitoring Report 2015-16 46

5.6.1 Catchments

As in previous years, nutrients were regularly above the ANZECC benchmark while median

chlorophyll-a rarely exceeded the 5 µg/L benchmark. Located directly downstream of the Braidwood

township and sewage treatment plant, Gillamatong Creek once again recorded the highest number

of nutrient and chlorophyll-a exceedances. Further downstream concentrations are significantly

reduced by dilution and in-stream processes.

5.6.2 Recreational Monitoring

Water quality for primary and secondary contact recreational users of Bendeela Campground and

secondary contact recreation at Lake Yarrunga and Fitzroy Falls Reservoir was predominately good,

conforming with relevant cyanobacteria guidelines. Full conformance to major alert levels for

cyanobacterial guidelines were achieved during the reporting period. Exceedances of primary contact

minor alert levels were associated with a Cyanonephron sp. bloom (Lake Yarrunga) and one sample

of Oscillatoria sp. at Bendeela Campground.

Occasional elevated counts of indicator bacteria exceeding minor alert benchmarks were noted and

managed accordingly through public notification. Enterococci sp. measurements exceeding major

primary/secondary contact alert levels during the reporting period were associated with higher flow.

Peaks of Enterococci sp. were recorded following rainfall when utilisation of the recreation area was

low.

Table 5.6: Recreational monitoring - percentage of samples exceeding benchmarks

Site

Stat

ion

co

de

Primary Contact Minor Alert Benchmark Percentage Exceedance

Primary Contact Major Alert/Secondary Contact Benchmark Percentage Exceedance

Ente

roco

cci (

cfu

/10

0ml)

Mic

rocy

stin

LR

eq

uiv

(ug/

L)

Tota

l Cya

no

bac

teri

al

bio

volu

me

(m

m3/

L)

Mic

rocy

stis

aer

ug

ino

sa

cou

nt

(cel

ls/m

L)

Ente

roco

cci (

cfu

/10

0ml)

Mic

rocy

stin

LR

eq

uiv

(ug/

L)

Tota

l Cya

no

bac

teri

al

bio

volu

me

(m

m3/

L)

Mic

rocy

stis

aer

ug

ino

sa

Co

un

t (c

ells

/mL)

Bendeela Camping Ground DPAE 58 0 3 0 6 0 0 0

Lake Yarrunga DTA8 NA NA NA NA 9 0 0 0

Fitzroy Falls DFF NA NA NA NA 0 0 0 0

5.6.3 Storages

All storages in the Shoalhaven system continued to record high non-compliance with nutrient and

chlorophyll-a benchmarks.

High numbers of toxin producing cyanobacteria were closely monitored in Wingecarribee Reservoir

throughout the reporting period. Algae cells and toxins were effectively managed by the use of

powdered activated carbon in the treatment process.




All water quality parameters were maintained within the raw water supply agreement standards for

Kangaroo Valley water filtration plants. Wingecarribee water filtration plant met the raw water

supply agreement standards for most analytes, with high levels of iron recorded for a number of

months (see Appendix for more details).

All samples were below ADWG for health related characteristics.

5.7 Algal monitoring

WaterNSW samples are analysed for algae and cyanobacteria concurrently with routine catchment

and storage monitoring (Section 3.2). At locations with a history of algal activity, seasonal monitoring

is conducted more frequently in the warmer months between October and May to facilitate early

detection of emerging algal events. Routine algal monitoring at WFPs is also undertaken.

Reported results consider both routine and seasonal monitoring. Statistical summaries are provided

in Appendix A. Refer to Section 4.7 for relevant benchmarks.

5.7.1 Warragamba system

Waterways in the Wollondilly River catchment frequently exceeded the chlorophyll-a criterion (>5

µg/L), which is the trigger for further algal analysis. Particularly, Wingecarribee River at Berrima Weir

exceeded the threshold in all reported samples for nutrients and chlorophyll-a. The Wollondilly River

inflow site (DWA39) exceeded the criterion for chlorophyll-a in 33% of the samples taken.

Sites in the Coxs River subcatchment exceeded the chlorophyll-a threshold less often. These

exceedances were not an issue as all Warragamba catchment sites complied with the NHMRC

recreational guidelines for potentially toxin producing cyanobacteria count, toxicity and

cyanobacteria biovolume.

All Lake Burragorang sites complied with the benchmarks. Chlorophyll-a concentration rarely

exceeded 5 μg/L in the gorge; only approximately 10% of the samples near the dam wall (peak value

5.5 µg/L) and in two samples at the junction (peak value 7.5 µg/L). Chlorophyll-a was occasionally

elevated in the upper reaches, with the highest result of 7.1 μg/L in the Coxs arm and 6.5 μg/L in the

Wollondilly arm. Populations of potentially toxin producing algal species remained low and similar to

concentrations observed in 2014-15. Algal toxins were below the limit of detection.

Chlorophyll-a concentrations in Prospect Reservoir exceeded 5 μg/L in 10% of the routine samples

collected. Concentrations of potentially toxin producing algal species remained below threshold

levels of concern and no algal toxins were detected.



Raw water supplied to Orchard Hills, Warragamba and Prospect WFPs continued to meet RWSA and

ADWG criteria with respect to algae. There were no detections of the potentially toxin producing

cyanobacteria Dolichospermum circinale or Microcystis aeruginosa in the raw water.

5.7.2 Upper Nepean system

Catchment sites in the Upper Nepean system showed very little sign of algae in 2015-16, except the

Nepean River at McGuires Crossing, which exceeded the chlorophyll-a criterion (5 μg/L) in a quarter

of all samples (maximum 8.8 µg/L). One sample at the Nepean River inflow site exceeded the

criterion (maximum 6.6 µg/L).

Avon, Cataract and Cordeaux catchment sites did not report any exceedance of chlorophyll-a

criterion. Potentially toxin producing cyanobacteria was not reported at any of these sites.

Storage sites in the Upper Nepean system rarely exceeded the 5 μg/L chlorophyll-a criterion for

additional algal analysis. Among the monthly samples, Lake Cordeaux exceeded the criterion in a

quarter of samples (maximum 8.9 µg/L). Lake Nepean samples exceeded the criterion in 30%

samples (maximum 10.3 µg/L). Potentially toxin producing species were rarely detected and toxin

analysis was not required.

Raw water supplied to Nepean, Macarthur and Illawarra WFPs complied with the cyanobacteria

guidelines and standards during 2015-16.

5.7.3 Woronora system

As in previous years, chlorophyll-a remained below the threshold for additional analysis in catchment

samples. There were nil potentially toxin producing species detected in raw water supplied for

treatment.

5.7.4 Blue Mountains system

Chlorophyll-a concentrations exceeded 5 µg/L, in less than 10% of routine samples in Top Cascade

Lake (maximum of 5.6 µg/L) and in Lake Greaves (maximum of 5.6 µg/L). The samples from Lower

Cascade Lake did not exceed the criterion. Potentially toxin producing species were not detected at

a level of concern in any of the storages.

5.7.5 Shoalhaven system

Presence of algae is historically common in the Shoalhaven system and chlorophyll-a exceeded the

5 μg/L criterion at a number of catchment sites at least once during the year. Chlorophyll-a

exceeded the criterion in 58% samples in Gillamatong Creek, near Braidwood, with a maximum

concentration of 33.8 μg/L. The sites at Fossickers Flats and Mountview in the Shoalhaven River did



not exceed the criterion in the reporting year. The Hampden Bridge site on the Kangaroo River

exceeded the chlorophyll-a criterion twice throughout the year.

Chlorophyll-a exceeded the 5 μg/L threshold in over 90% samples from Bendeela Pondage and in all

samples at Wingecarribee Reservoir and Fitzroy Falls Reservoir. Chlorophyll-a criterion was exceeded

Lake Yarrunga in 33% samples and more frequently in the Kangaroo River arm. However, all lake sites

complied with the recreational guidelines for potentially toxin producing cyanobacteria cell counts,

toxicity and cyanobacteria biovolume.

Raw water supplied to Kangaroo Valley complied with ADWG cyanobacteria guidelines in 2015-16.

An alga bloom of Microcystis aeruginosa in Wingecaribee Reservoir established in January 2016 and

persisted for a number of months. See Section 8.2 for more details.

5.8 Cryptosporidium and Giardia monitoring

Routine monitoring is undertaken in catchments, storages and delivery networks at varying

frequencies as agreed between WaterNSW, Sydney Water and NSW Health. Statistical summaries are

provided in Appendix A.

5.8.1 Catchments

Monitoring for Cryptosporidium and Giardia is undertaken at seven selected streams in the

Warragamba catchment as part of the routine program. The sampling schedule is monthly, except for

Werriberri Creek (E531) which is weekly. This section discusses routine monitoring for

Cryptosporidium and Giardia, refer to Section 7.1 for wet weather monitoring.

Cryptosporidium oocysts were detected in 2% samples from Werriberri Creek (E531) and 8% samples

from Kedumba River (E157), with maximum concentrations of 7 and 1 oocysts/10 L respectively.

Giardia was detected at four of the seven catchment sites, the highest concentration being

2 cysts/10L at Wollondilly at Jooriland (E488). Overall, oocysts were detected in 3% samples, with

none being detected at the Coxs River (E083), Kedumba River (E157) or Little River (E243) sites.

5.8.2 Storages

Routine monitoring was conducted six days per week at one lake site in Lake Burragorang (DWA2),

weekly at two offtake sites in Prospect (RPR1) and Wingecarribee (DWI1) reservoirs, and monthly at

Prospect Reservoir (RPR6). There were no (oo)cyst detections at Lake Burragorang or Prospect

Reservoir during 2015-16. Giardia was detected in 2% samples from DWI1 (up to 2 cysts /10L). The

results are detailed in Appendix A.


A joint monitoring program in raw water at the inlet of water filtration plants is undertaken by

Sydney Water and results are provided to WaterNSW and NSW Health for:

Macarthur WFP (MACSP1A)



Prospect WFP (COMP14 or relevant composite)

Nepean, Illawarra, Woronora and Cascade WFP composite (COMP16).

There were no incident level detections of Cryptosporidium or Giardia from routine monitoring of

water filtration plants during 2015-16.

The Prospect WFP sample is a composite of the sources supplying raw water. Approximately 84% of

samples were below the level of detection for Cryptosporidium and Giardia. The minor incident level

of 10 (oo)cysts/10L was not exceeded during the year. The maximum detection of 5.4 oocysts/10L

and 2.8 cysts/10L were slightly higher than last year.

Pathogens in the Macarthur WFP supply were detected less frequently during 2015-16 than in the

previous year with concentrations remaining below the minor incident level. Cryptosporidium was

detected in 3.8% samples at a concentration of 2 oocysts /10L. Giardia was detected in 3.8% samples

at a concentration of 1 cyst/10L. The results were similar for COMP16 samples, with Cryptosporidium

detected in 3.8% samples at a concentration of 1 oocyst/10L and Giardia detected in 5.8% samples at

a concentration of 1 cyst/10L.

5.9 Picnic area monitoring

Routine monitoring is undertaken in Avon, Cataract, Cordeaux and Fitzroy Falls picnic areas where

disinfected water is supplied directly from storages after chlorination, or in the case of Fitzroy Falls

Reservoir where potable water is cartered and receives supplementary chlorination. The results from

picnic area monitoring are compared to applicable guidelines and are presented in Table 5.7.

Table 5.7: Picnic areas - percentage of samples exceeding benchmarks.

Site

Stat

ion

Co

de

Free

Ch

lori

ne

resi

du

al m

g/L

pH

(La

b/F

ield

)

Turb

idit

y La

b/F

ield

(N

TU)

Alu

min

ium

To

tal (

mg/

L)

Iro

n T

ota

l (m

g/L)

Man

gan

ese

Tota

l (m

g/L)

E. c

oli

(org

s/1

00m

L)

Ch

loro

ph

yll-

a (u

g/L)

Toxi

c C

yan

ob

acte

rial

Co

un

t

(cel

ls/m

L)

Mic

rocy

stin

LR

eq

uiv

(u

g/L)

Avon Dosing Reservoir Tap HAVR 46 0 2 NA NA NA NA NA NA NA

Cataract Dosing Reservoir Tap HCAR 32 17 2 NA NA NA NA NA NA NA

Cordeaux Dosing Reservoir Tap HCOR 32 0 4 NA NA NA NA NA NA NA

Fitzroy Falls Dosing Reservoir Tap HFFR 15 0 2 NA NA NA NA NA NA NA

Avon Picnic Area Tap HAV3 96 12 2 0 2 0 0 0 NA NA

Cataract Picnic Area Tap HCA1 64 25 2 0 57 11 0 0 NA NA

Cordeaux Picnic Area Tap HCO6 98 0 0 6 56 12 0 0 NA NA

Fitzroy Falls Picnic Area Tap HFFR2 43 0 0 6 2 2 0 0 NA NA

Bendeela Picnic Area Tap HBPP1 NA 0 0 0 0 0 NA NA NA NA

Nepean Picnic Area Tap HNEP1 NA 0 0 0 0 0 NA NA NA NA

Warragamba Picnic Area Tap HWAP1 NA 0 0 0 0 0 NA NA NA NA

Wingecarribee Picnic Area Tap HWIP1 NA 0 0 0 0 0 NA NA NA NA

Woronora Picnic Area Tap HWOP1 NA 100 0 0 0 0 NA NA NA NA



Chlorine levels were typical for the picnic areas. Median free chlorine values at the four dosing sites

ranged from 0.58 mg/L to 0.88 mg/L; which is within the operational targets of 0.5 to 1.2 mg/L. There

were occasions where weekly measurements declined below the benchmark of 0.5 mg/L, however

the chlorine contact times generally remained high during these periods to ensure effective

disinfection. The effectiveness of chlorination at the picnic areas is based on the chlorine

concentrations at the dosing sites, chlorine contact times at the dosing plant and the absence of

bacterial indicators in the picnic area tap. There were no E. coli detections at the tap sites in the

picnic areas during 2015-16. Daily operational monitoring records of chlorine and flow at Avon,

Cataract, Cordeaux and Fitzroy Falls picnic areas are used to calculate chlorine contact time (C.t). The

systems achieved the target of 15 mg/L.min for the majority of the time.

Annual sampling of the five picnic areas supplied by reticulated town water showed full compliance

for most analytes and sites. The only exception was the pH at the Woronora picnic area with a result

of 5.6 pH units. The aesthetic and health benchmarks were met for all sites.

5.10 Dam seepage monitoring

WaterNSW is required to monitor the structural integrity of dams. Chemical analysis forms part of

this monitoring, and samples of the ground water and seepage are routinely taken at specific

locations at “significant” or higher consequence category dams. Results from the testing are analysed

by the Dam Engineer and are published in the Annual and Five yearly Surveillance reports submitted

to the NSW Dam Safety Committee for review and endorsement.

Chemical monitoring of seepage waters is conducted at WaterNSW dams to:

Determine the origin and/or path of leakage

Assess concrete degradation

Assess dispersive behaviour and erodability of embankment and foundation materials.

The dams sampled for chemical analysis of seepage waters this year were Avon, Top Cascade,

Cataract, Cordeaux, Nepean, Prospect, Tallowa, Warragamba, Wingecarribee and Woronora. All of

these dams are tested annually.

Prospect and Wingecarribee dams are of earth embankment construction and are tested for a variety

of metals, particularly their sodium absorption ratio. Metals testing is also conducted at concrete and

masonry construction dams (Avon, Top Cascade, Cataract, Cordeaux, Nepean, Tallowa, Warragamba

and Woronora), with net calcium levels measured as the key indicator of concrete degradation.

A site upstream in the storage is tested at all dams to provide a control point. A variety of sites

downstream at these dams are also tested. For example, net levels of calcium (i.e. calcium levels at

the test site minus calcium levels in the storage water) are included in an equation to determine

concrete degradation rates.

No safety concerns (relating to chemical monitoring or concrete degradation) were identified for any

dams during 2015-16.



6 Monitoring for the Water Licences

6.1 Water quality

WaterNSW undertakes sampling of waters downstream of storages in accordance with the

requirements of the Water Licences. The results of downstream sampling are reported against

ANZECC guidelines in Table 6.1.

Table 6.1: Downstream of storages - percentage of samples exceeding benchmarks

Site

Stat

ion

Co

de

Nu

mb

er o

f sa

mp

les

pH

(La

b/F

ield

)

Turb

idit

y La

b/F

ield

(N

TU)

Dis

solv

ed O

xyge

n (

%Sa

t)

Nit

roge

n T

ota

l (m

g/L)

Ph

osp

ho

rus

Tota

l (m

g/L)

Ch

loro

ph

yll-

a (u

g/L)

Wingecarribee River

Wingecarribee River @ Sheepwash Bridge E303 12 8 0 8 75 8 100

Shoalhaven River

Shoalhaven R @ d/s Tallowa Dam E851 12 0 0 8 0 0 33

Woronora River

Woronora River @ the Needles G0515 12 83 0 83 0 0 0

Nepean River

Nepean River @ Yarramundi N44 11 0 0 27 91 18 91

Nepean River @ Penrith Weir N57 11 9 0 45 45 9 73

Nepean River 500m D/S of confluence of Warra River N64 11 9 9 18 82 9 55

Warragamba River U/S of confluence of Nepean River N641 11 0 9 27 18 0 18

Nepean River @ Wallacia Bridge N67 12 0 8 50 92 8 67

Nepean River @ Sharpes Weir N75 12 0 0 17 82 0 50

Nepean River @ Menangle Bridge N85 12 0 0 67 17 8 25

Pheasant's Nest Weir Pool N86 9 0 0 11 0 0 0

Cataract River @ Broughtons Pass N881 13 0 0 15 0 0 0

Nepean River @ Maldon Weir N92 12 50 0 17 0 0 25

Water quality in the Hawkesbury-Nepean system typically declines in a downstream direction. This

trend is particularly evident in chlorophyll-a concentration, which increases downstream of

WaterNSW control structures (Pheasants Nest, Broughtons Pass).

All samples at the Wingecarribee River site exceeded the chlorophyll-a benchmark of 5 µg/L. This

result is similar to last year.

The dissolved oxygen and pH in the Woronora River were outside of ANZECC benchmarks for the

majority of samples. Much like pH in Lake Woronora and Woronora River (upstream of Lake

Woronora), pH was below the ANZECC benchmark and is the result of local geology. Dissolved

oxygen was below ANZECC benchmarks, although levels were above 50% saturation. At this level,

ecological communities are not considered to be impacted.



6.2 Thermal impacts of environmental releases

Water released from storages can often be significantly warmer or cooler than downstream systems

due to the depth of offtake, thermal stratification and greater thermal mass. Large releases of

thermally disparate waters into downstream systems can significantly impact on downstream

riverine systems though disruption of fish migration and alteration of macroinvertebrate

assemblages. To investigate the effect of environmental releases, water temperature is measured at

a number of locations downstream of WaterNSW storages.

To determine potential thermal impacts, the temperature of storage inflows and environmental

releases for the reporting period are compared. Storage inflows provide a measure of expected

water temperatures in the natural conditions. Downstream temperatures are taken from the closest

downstream hydrometric station.

Only systems with environmental release requirements are presented, namely the Upper Nepean,

Woronora and Shoalhaven systems.

6.2.1 Upper Nepean system

The Upper Nepean System comprises of the Avon, Cataract, Cordeaux and Nepean catchments, all of

which are subject to environmental releases. While WaterNSW endeavours to provide the highest

quality water for environmental release, system configuration precludes selection specifically for

environmental releases from the Upper Nepean storages. All Upper Nepean environmental releases

are sourced from offtake depths determined to provide the highest quality water for human

consumption. As such, WaterNSW is particularly interested in detecting suppressed downstream

water temperatures as a result of deep water offtakes.

Daily (every 15 minutes) temperature data was recorded at the following hydrometric stations and

represent reference catchment conditions:

Avon catchment - Avon River at Summit Tank

Cataract catchment – Cataract River at Corrimal

Cordeaux catchment – Sandy Creek at Fire Road 15

Nepean catchment – Nepean River at Nepean Dam inflow

Downstream water temperature was recorded at Menangle Weir on the Nepean River which

represents the first hydrometric station after the confluence of all Upper Nepean storage releases.

The station is approximately 20 km downstream of Lake Cordeaux which is the furthest Upper

Nepean storage.

As shown in Figure 6.1, downstream temperatures at Menangle Weir are consistently higher than the

inflow reference temperatures, indicating no persistent downstream cold water pollution as a result

of environmental releases. Furthermore, downstream temperatures and reference temperature

profiles exhibit small scale changes and seasonal trends. Reference temperatures display greater

small scale variability due to smaller flows.



Figure 6.1: Upper Nepean system temperature profile

6.2.2 Woronora system

As with the Upper Nepean storages, the system configuration at Lake Woronora does not support

offtakes specifically for environmental releases. As a result, environmental releases may be

significantly cooler than surface waters due to thermal stratification. Downstream water

temperatures in the Woronora River are recorded to detect any evidence of persistent cold water

pollution.

Reference temperatures for the Woronora catchment are recorded daily at the major inflow

locations to Lake Woronora:

Woronora River at Fire Rd 9F

Waratah Rivulet at Flatrock Crossing

Downstream temperatures were recorded daily at The Needles on the Woronora River,

approximately 10 km downstream from the environmental release point.

As seen in Figure 6.2, the downstream temperature in the Woronora River at the Needles closely

matches that of the reference temperatures recorded at upstream sites. Both show a strong seasonal

trend and show very similar small scale variations resulting from local weather conditions.

Figure 6.2: Woronora system temperature profile



6.2.3 Shoalhaven system

Since 2008, environmental releases from Lake Yarrunga have been predominantly supplied via an

overshot gate on the dam which allows for the preferential release of surface waters. There is also a

high level outlet which contributes to the environmental release via the fishway. As surface waters

are not subject to thermal stratification, they should more closely match downstream temperatures.

Reference temperatures for Lake Yarrunga are recorded daily on the major tributaries:

Shoalhaven River at Fossickers Flat

Kangaroo River at Hampden Bridge

Downstream temperatures were recorded daily at:

Shoalhaven River downstream of Tallowa Dam

Shoalhaven River at Grassy Gully

The downstream site at Tallowa Dam is immediately downstream of the environmental releases and

provides a good measure of the release temperature. Grassy Gully is approximately 20 km further

downstream.

Figure 6.3 shows that temperatures at both downstream sites closely match those of the upstream

reference sites. The similarity between the two downstream sites suggests the environmental

releases are very near ambient condition. The Kangaroo River catchment is small, so temperatures

fluctuate more in response to local rain events.

Figure 6.3: Shoalhaven system temperature profile



7 Targeted and investigative monitoring

WaterNSW undertakes targeted and investigative monitoring to understand and assess impacts that

are not addressed by the routine monitoring program. The results of the monitoring are discussed in

greater detail in the sections below.

A summary of water quality incidents during 2015-16 is included in Section 8.

7.1 Wet weather inflow monitoring

WaterNSW conducts wet weather sampling to assist in evaluating impacts on water quality from

runoff during significant rainfall events. A key component of the wet weather monitoring program is

the use of auto-sampler stations at strategic catchment sites which are programmed to automatically

take samples once a river height trigger has been reached.

Wet weather monitoring is used to quantify the water quality risks for incoming waters to storages.

During high rainfall events, catchments are often closed to operational traffic and storages closed to

boat traffic to protect the health and safety of staff and contractors. Using auto-samplers helps to

acquire valuable water quality information on the effects of rainfall events.

Auto-samplers are programmed to collect samples for:

total organic carbon, suspended solids, total phosphorus, total nitrogen, total aluminium,

total iron and total manganese (Type 1);

total nitrogen, total phosphorus, Cryptosporidium and Giardia (Type 2);

Or both Type 1 and Type 2.

Where specific water quality issues have been identified, additional characteristics are analysed on

request. At high priority reservoir inflow locations, both auto-sampler types have been installed.

Given the differing sampling mechanisms, trigger values may differ between the two auto-sampler

types. Type 2 samples are reserved for locations identified as potentially significant pathogen

sources, requiring a much larger sample volume (hence the lower number of samples). Table 7.1

shows the number of Type 1 auto-samples collected for each site during the year. Table 7.2 shows

the number of wet weather samples analysed for Cryptosporidium and Giardia.



Table 7.1: Number of wet-weather samples and events from Type 1 auto-samplers 2015–16.

Station Code*

System

Auto-sampler Type 1

Number of samples

Number of events

E0114 Warragamba 7 1




E083 Warragamba 7 2

E130 Warragamba 8 2

E157 Warragamba 5 1



E300 Wingecarribee 7 2






E488 Warragamba 8 2


E6006 Cordeaux 14 1

E602 Nepean 24 2

E604 Avon 37 3

E608 Shoalhaven 4 1

E609 Cataract 7 1

E610 Avon 9 1

E6131 Woronora 4 1

E680 Cordeaux 14 3

E7021 Shoalhaven 63 4








TOTAL SAMPLES 647

* Refer to catchment maps in Section 5 for location of auto-sampler sites.



Table 7.2: Number of wet-weather samples analysed for Cryptosporidium and Giardia from Type 2 auto-samplers and grab samples collected during 2015-16. The number of positive detections is also summarised for each event.

Station Code

System

Auto-sampler Type 2 and Wet Weather grab samples

Positive Pathogens Results

Number of samples

Number of Events

Cryptosporidium Giardia

DNE1 Nepean 45 2 3 20




DWA2 Warragamba 23 2 0 0

E0114 Warragamba 1 1 0 0

















7.2 Catchment Risk Characterisation

The average pathogen risk for catchments supplying each storage lake was determined from an

assessment of catchment hazards and historical water quality monitoring data based on the Health

Based Targets (HBT) procedure developed by Water Services Association of Australia (WSAA).

It is recognised that the greatest challenges to water treatment occur during heavy rain events when

contaminants from the catchment and higher river flows cause a decrease in water quality. At such

times water quality monitoring is increased at raw water intakes and selected catchment and storage

sites. The Pathogen Campaign Monitoring Program was instituted to enhance pathogen monitoring

during high inflow events at selected catchment sites to allow the pathogen risk to be refined during

events.

During an event the pathogen risk factors such as the condition of the storages and catchments,

rainfall, inflow volumes, reports of overflows from STPs, dairy effluent ponds and stormwater

overflows, and turbidity and pathogen data are used to reassess pathogen risk.

Cryptosporidium testing will be done not only to confirm the presence but to assess the viability and

infectivity of oocysts. This information is expected to assist in refining catchment Cryptosporidium

risk in the future.



7.3 Macroinvertebrate monitoring

The Macroinvertebrate Monitoring Program (MMP) is an annual assessment of the ecological health

of stream sites in the Sydney drinking water catchments. Macroinvertebrate sampling was conducted

at 63 sites in 27 sub-catchments, collecting 126 individual samples. Site information and the

AUSRIVAS ratings for each site are presented in Table 7.3. In 2015, 28 of 59 sites (47%) had AUSRIVAS

ratings that were at Reference (A rating) or Above Reference condition (X rating). This is a slight

improvement in ecosystem health based on 2014 ratings. A total of four sites could not be rated and

considered to be Outside the Experience of the Model (OEM), as these sites did not meet the criteria

used by the AUSRIVAS modelling software to rate sites.

Three sites from the Tallowa Dam catchment were sampled for a second consecutive year in order to

address perceived declines in ecological health in the local area. Two of the sites (MMP98 and

MMP192) had improved results compared with the 2014 results and one declined (MMP52). Whilst

there are only a small number of samples collected so far, the results at these sites are similar to

other sites from within the same sub-catchments. Fluctuations in ecosystem health like this are

consistent with previous findings. Monitoring at these sites will continue for a period to determine if

any significant sub-catchment declines are occurring.

The Warragamba Dam catchment has 12 sub-catchments, with macroinvertebrate sampling

conducted at 26 sites in 2015. Fifty-four per cent of sites were rated to be in Reference or Above

Reference condition, slightly less than the 2014 results. Only one individual sample (MMP37)

received the highest AUSRIVAS rating of Above Reference condition in 2015.

Macroinvertebrate monitoring was conducted at 28 sites from 12 Tallowa Dam sub-catchments in

2015. Thirty-six per cent of sites had AUSRIVAS ratings in a Reference condition and none Above

Reference condition. Despite this result it is an improvement in ecological health when compared to

the previous year’s findings. Catchment wide, 64% of sites were in less than reference condition.

Four sites in the Metropolitan dams catchment were monitored for macroinvertebrates in 2015. The

small number of sites prevents clear trends from emerging; despite this the majority of ratings

increased in ecological health and were rated in a Reference condition. One site was rated as Below

Reference condition.

AUSRIVAS ratings for the three Blue Mountains sub-catchment sites were variable in 2015, similar to

2014 findings. Health at the Woronora Dam sub-catchment sites were stable, remaining at Below

Reference condition at E677 and dropped two grades at E678 from Reference Condition in 2014 to

Well Below Condition in 2015.



Table 7.3: AUSRIVAS ratings for each site sampled in 2015. Site conditions are reference (A rating), Below Reference (B), Well Below Reference (C), Above Reference (X rating), Outside the Experience of the Model (OEM).

Site Code Site Name Edge

AUSRIVAS rating

Site Code Site Name Edge

AUSRIVAS rating

Warragamba Dam sites Tallowa Dam sites

E130 Kowmung River at Cedar Ford B MMP16 Witts Creek at Krawarree Road B

MMP14 Kowmung River at Kowmung Fire Trail A MMP17 Shoalhaven River at Farringdon Crossing B

MMP251 Tonalli River u/s Lake Burragorang FSL A E890 Boro Creek at Marlowe C

MMP59 Butchers Creek u/s of Lake Burragorang C MMP33 Kings Creek u/s of Boro Creek C

E243 Blue Gum Creek at Fire Road W4I B E860 Shoalhaven River at Mount View A

MMP05 Little River at Fire Trail W4I A MMP62 Jembaicumbene Creek at Bendoura B

E157 Kedumba River at Kedumba Crossing A A8 Bungonia Creek at Bungonia B

MMP76 Leura Falls Creek at FT W7F A E847 Shoalhaven River at Fossickers Flat B

E086 Cox’s River at Kelpie Point OEM MMP98 Barbers Creek at Tallong B

MMP55 Little River at Six Foot Track B MMP11 Titringo Creek at High Forest B

A5 Mulwaree River at Lake Bathurst A MMP12 Endrick River at Nerriga A

E457 Mulwaree River at The Towers B MMP08 Boggy Creek u/s of Shoalhaven River A

E206 Nattai River at The Crags A MMP09 Jerrabattgulla Creek at Warragandra B

E210 Nattai River at the causeway B E706 Kangaroo River at Hampden Bridge A

A16 Cox’s River at Lidsdale OEM MMP43 Kangaroo River at upper Kangaroo Valley A

MMP37 Cox’s River at McKanes Bridge X E8311 Corang River at Meangora A

MMP27 Wollondilly River at Goonagulla A E861 Shoalhaven River at Hillview B

Uwol1 Wollondilly River at Baw Baw Bridge B MONG1 Mongarlowe River at Charleyong B

E531 Werri Berri Creek at The Oaks B R13 Mongarlowe River at Monga A

MMP03 Werri Berri Creek at Serenity Park A E8361 Nerrimunga Creek at Minshull Trig B

U10 Wingecarribee River at Berrima A MMP192 Budjong Creek at Sandy Point B

Winge2 Wingecarribee River at Greenstead B MMP51 Jacqua Creek at Lumley Road C

A6 Tarlo River at Tarlo A MMP52 Nadgigomar Creek at Oallen Ford C

E488 Wollondilly River at Jooriland OEM MMP258 Durran Durra Creek at Nerriga Road B

MMP130 Long Swamp Creek u/s Paddy's River A R7 Mulloon Creek at Tawarri A

MMP226 Tarlo River at Swallowtail Pass A REED1 Reedy Creek at Mayfield Road B

Blue Mountains Dams sites MMP06 Shoalhaven River at Yarra Glen A

MMP246 Woodford Creek u/s Woodford Dam A MMP269 Jinden Creek at Tallanganda State Forest no sample

MMP39 Woodford Creek at Woodford Dam OEM R8 Currumbene Creek at Krawarree Road A

MMP60 Cascade Creek d/s of lower Cascade Dam C Metropolitan Dams sites

Woronora Dam sites E604 Flying Fox Creek No.3 u/s of Gauge B

E677 Woronora River at Fire Road 9F B MMP100 Wongawilli Creek d/s of Fire Road 6 A

E678 Waratah Rivulet at Flat Rock Crossing C MMP136 Lizard Creek d/s Fire Road 8H A

MMP20 Nepean River at Maguires Crossing A



7.4 Investigative monitoring

WaterNSW’s investigative monitoring program is designed to target known risks, emerging issues

and to enhance modelling and management options. Investigative monitoring can be used for

identifying pollution sources, understanding pollutant fate and transport in a variety of flow

conditions, and investigating the risk of pollutants reaching inflows and raw water off-take points.

Investigative monitoring is also one method used in evaluating the effectiveness of actions in the

catchments and storages to address pollutants.

7.4.1 Investigative monitoring for operational decision making

7.4.1.1 Wet weather event August 2015

Heavy rain fell from 24 to 26 August 2015 throughout the metropolitan catchments. This resulted in

inflow intrusions into multiple storages. The inflows were tracked using the in-lake vertical profilers

and thermistor systems. Additional water quality monitoring was undertaken to assess the changes

in lake water quality and the potential impact of the inflows on raw water supply. This information

was used to assess what lake depths were impacted by the inflows, magnitude of impacts, and,

where the best quality water for supply was located. Auto-samplers were analysed to assess

Cryptosporidium risk during this event.

An unusual phenomenon occurred in Lake Nepean with two large wet weather intrusions arriving in

the lake, which were positioned along the surface and also the bottom. The first intrusion entered

along the bottom of the lake and was mainly from the Nepean River catchment. The second intrusion

entered along the surface of the lake and was believed to have originated in the Burke River

catchment. Figure 7.1 shows the vertical profiler monitoring of turbidity in Lake Nepean, and the high

turbidity (>30 NTU) which was associated with these two intrusions. The Nepean WFP was supplied

from in between these intrusions (bold white line in Figure 7.1), with this zone initially only slightly

impacted by the wet weather inflows.

Figure 7.1: Turbidity of intrusions in Lake Nepean following heavy rainfall in August 2015. The solid white lines indicate the depth of the open water supply outlet to Nepean WFP. Dotted lines indicate the closed water supply outlet depth.



Intensive water monitoring was conducted to track poor quality water which arrived at the dam wall

and provide information on risks to the water supply to Nepean WFP and downstream customers.

This provided information on water quality changes associated with the dam spilling and water

quality changes as the intrusions converged and mixed throughout the water column. Prior system

planning for outlet screen placement, combined with in-lake instruments and special event water

monitoring, minimised the impacts on raw water supply to customers. Full compliance against the

Raw Water Supply Agreement for Nepean WFP was achieved during this event.

7.4.1.2 Potential sources of taste and odour producers in the Blue Mountains

A special monitoring program was undertaken for the most common taste and odour compounds, 2-

methylisoborneol (MIB) and geosmin, in the Blue Mountains. Knowledge regarding the presence of

MIB and geosmin in the Blue Mountains lakes and Oberon supply is valuable for developing

strategies to reduce the potential for taste and odour in the water supplied by Cascades WFP.

Monitoring in the Blue Mountains lakes recorded concentrations of MIB and geosmin below the

odour thresholds for the general population. This monitoring showed production of MIB was

seasonally influenced, with increases recorded from December and peaking in April. MIB was not

detected from June to early November. Geosmin was generally detected at low levels throughout the

year, with peaks recorded in November to December.

Taste and odour algae taxa were compared against the MIB and geosmin concentrations. Algae did

not appear to be an obvious source or provide a direct relationship to presence of these metabolites.

Review of odour intensity and descriptors did not draw a direct link to MIB and geosmin as being the

cause of odour. This special monitoring program provided insights into which sources are likely to

contribute taste and odour compounds. Findings showed that detections were at very low levels and

were unlikely to pose any significant taste and odour issues in the water supplied in the Blue

Mountains.

7.4.1.3 Oberon supply recommencement

A special monitoring program was undertaken in February 2016 to gather information on water

quality changes during recommencement of supply from the Fish River (Oberon) Pipeline at Leura,

following a two week period of inactivity. WaterNSW aims to reduce any water quality impacts

associated with recommencement of the Fish River transfers.

Monitoring during the recommencement of the Fish River transfers showed that there was a higher

concentration of iron, manganese, turbidity and suspended solids present in the pipeline. Water

quality conditions had generally improved in the Fish River Pipeline on the fourth day following

recommencement; however iron, manganese and turbidity remained slightly elevated. The dilution

of this relatively small volume from the Fish River Pipeline into Top Cascade Lake negated any water

quality issues for raw water supply to the Cascades WFP.



A two week period of inactivity of the Fish River Pipeline was shown to have minimal impact on

water quality at the Leura monitoring site. This information confirmed that the current protocols are

appropriate in preventing any water quality issues into Top Cascade Lake and raw water to the

Cascades WFP.

7.4.2 Scientific research

7.4.2.1 Completed Projects

Benthic cyanobacteria and taste and odour compounds

The project investigated the presence, development and control of benthic cyanobacteria in Prospect

Reservoir, with a focus on whether potential taste & odour issues could be predicted. This study built

on findings from an earlier project which investigated the sources of MIB and geosmin in the

reservoir. Information was obtained to assist in the prediction of when water supplied from Prospect

Reservoir may be at risk of taste and odour problems occurring.

Cryptosporidium and Giardia in animals

Cryptosporidium and Giardia are a major public health concern for water utilities, with these

pathogens potentially transmitted through contaminated drinking and recreational waters. The aim

of the project was to determine, through genotyping, whether native animals (marsupials), pre-

weaned cattle and sheep could be ruled out as potential source of pathogens infective to humans. If

pathogens carried by these animals could be shown to be not infective to humans, less effort could

be directed to protecting waterways from these risks.

The project confirmed that human infective pathogens can occur in kangaroos/wallabies, but whilst

they can occur the material risk is considered small, relative to the risk posed by cattle. The project

outcomes have been used to prioritise source water protection initiatives.

Stormwater pollution passive sampling investigation

The use of passive sampling techniques to detect pollutants and identify point sources was

evaluated. Three passive samplers were trialled; these were an ammonia passive sampler (Polymer

Inclusion Membranes), trace metals and hydrocarbons sampler (Granular Activated Carbon) and a

pesticides sampler (polytetrafluroethylene membrane, Empore Disk).

It was determined that all three techniques could provide useful and cost effective tools which could

be used for the identification of a range of specific point sources of pollution. The project outcomes

are available for use as an investigative tool for regulation in the drinking water catchments.

Councils involved in the trial process and Sydney Water Corporation have expressed interest in

utilising the monitoring techniques.

Risk assessment tools to manage risks from extreme events

The aim of this project was to identify and evaluate risk management approaches that enable

WaterNSW to assess and mitigate the water quality impacts of extreme events. The experiences of

key stakeholders who have managed the water quality impacts of past extreme events was captured,

as well as water monitoring data and climate predictions to characterise the dynamic relationships

between extreme events and recorded water quality.



Environmental tracers (pharmaceutical and personal care products) for quantifying

pollutant pathways.

Detection of pharmaceutical products in water was used as a means of confirming human faecal

sources which are more likely to be human infective than natural sources.

The first stage of the project, the completion of a literature review, has been completed. The scope

of the second stage of the work was developed taking into account the outcomes of the Passive

Sampling investigations project and outcomes of the literature review. Delivery of stage 2 of this

project will be through the Water Research Australia (WaterRA) project Smart monitoring for

microbial risk assessment which has recently commenced.

7.4.2.2 Ongoing Projects

Campaign pathogen monitoring program

The purpose of long term campaign monitoring program is to gain a better understanding of the

pathogen risk at times when it is expected to be the greatest challenge to water treatment. To

achieve this it is necessary to conduct more pathogen monitoring during heavy rain events. The

increased wet weather dataset and additional knowledge on Cryptosporidium infectivity and human

pathogenicity will enable reliable risk assessments to be conducted for the Sydney water supplies.

Campaign monitoring was triggered by events in July and August during 2015 and two events in June

2016. The campaign monitoring program will continue in 2016-17 to build upon the number of wet

weather events sampled.

Pathogen Catchment Risk Categorisation.

This project proactively prepares WaterNSW to meet health based targets proposed for inclusion the

Australian Drinking Water Guidelines. Some subcatchments are inherently more or less likely to

contribute infective pathogens to inflows, so characterising these risks will inform the level of

response required during an inflow event.

The project work is on schedule with the catchment assessments completed for all Metropolitan

catchments in 2015. This is an ongoing project based upon continuous improvement and maintaining

the ability of WaterNSW to respond to developments in health based targets for pathogens.

The relevance and applicability of this work for undertaking risk assessments for drinking water

supplies at rural recreational areas is being considered.

Onsite sewage evaluation study – post upgrade review

The former SCA invested $12.7 M to support the construction of Robertson and Kangaroo Valley

sewerage systems. A review has been undertaken to validate expenditure on catchment

management and assist in justifying future expenditure and advocacy.

Sampling for the project was completed in early July 2016 and a draft report has been prepared. The

outcomes of the project are currently being assessed and scope for further work considered.



Developing Evidence Based Grazing Practice.

The evidence collected through this project will assist in evaluating the effectiveness of improved

grazing practices. In particular the quantification of pollutant loads from grazing properties will

inform prioritisation of catchment interventions on grazing land.

Alternative methods/sites are being considered for phase two of the evaluation of grazing practices.

A review of progress to date is currently being undertaken to determine the most appropriate means

of delivering client needs.

Natural Organic Matter (NOM) Investigation

The project is a joint initiative with Sydney Water to address problems associated with NOM in raw

water. Better management of NOM in raw water will reduce treatment costs, reducing overall cost to

the end consumer.

The project is being focussed on the Lake Nepean system where NOM has been problematic in

recent years. Sampling for the project has commenced recently and the results are starting to

become available for analysis.

On-line monitoring of cyanobacteria

Effective and timely monitoring of cyanobacteria is a major challenge for WaterNSW. The project,

being run as an ARC Linkage project with the UNSW as the lead research group, is supporting the

ongoing development of an effective on-line tool for monitoring of cyanobacteria.

On-line monitoring provides real time information on cyanobacteria population dynamics during

algal incidents at lower cost compared to conventional sampling. Techniques such as in-situ

fluorescence probes and remote sensing have advanced considerably in recent years to the point

where they are becoming potentially useful tools.

The project focusses on the validation and application of cyanobacterial in-situ fluorescence probes

and the development of smart intensive water treatment plant monitoring.

Water quality event forecasting system

A water quality event forecasting system is being developed by WaterNSW (see Section 3.4 Future

Directions for details). This will assist in forecasting water quality events in time for full

implementation of a planned response.

Koi herpes virus release

DPI Fisheries propose to release Koi herpes virus (KHV) in 2018 to control European carp in Australian

waterways. If the release goes ahead there is a concern that in the short term the resulting fish kill

could have a significant impact on water quality in water supply storages.

Work is underway to undertake a field based trial of the potential water quality impacts of decaying

carp. The research is to be undertaken in Prospect Reservoir using large field based mesocosms

which will mimic the natural conditions in the reservoir. A range of carp densities, ranging from the

typical densities thought to be present in the WaterNSW storages through to higher ‘worse case’

densities, will be assessed in terms of their impact on water quality over a period of weeks to

months. Parameters to be measured include nutrients, dissolved oxygen and taste and odour

compounds.



Compilation of mining monitoring spatial database, analysis of data & evaluation of

impacts of longwall mining on swamps.

This project aims to provide evidence of cumulative mining impacts for use in responding to the

Planning Assessment Commission.

The development of improved data management and statistical tools for analysis of mining

monitoring data will allow WaterNSW to check the findings of reports provided by mining companies,

assess cumulative impacts over time and provide evidence to require remediation.

An initial assessment of the cumulative impacts of longwall mining in the catchments has been

completed. Possible methods to further develop this assessment are being considered through an

options analysis process.

7.4.2.3 WaterRA collaborative projects

WaterNSW is supporting the following WaterRA projects which have recently commenced.

Smart monitoring for microbial risk assessment

The aim of this project is to develop and refine monitoring techniques that will better inform the

catchment hazard assessment process, at the same time aiming to reduce the overall cost of

monitoring. This project relates to work already completed on environmental tracers and if

successful, will deliver stage 2 of that project.

Toxic cell oxidisation

The aim of this project is to improve the knowledge of the oxidisation process of cyanobacteria in

fresh and wastewater, in order to optimise treatment. This work is related to the previous work

undertaken on benthic cyanobacteria and taste and odour and may assist in addressing the issues in

the Cascades water supply system.

Management of environmental E. coli

The aim of this project is to develop a management response which includes research into

identification methods, treatment efficacy and decision support tools for water utilities and

regulators. WaterNSW has strong evidence for the autochthonous growth of E. coli blooms in our

waterways and would benefit from being able to characterise these strains as posing low risk to

public health.



8 Incidents and events

Water quality incidents are managed in accordance with the WaterNSW Raw Water Quality Incident

Response Plan. The plan sets out agreed water quality trigger levels for various actions and

notifications. Any issue that poses a potential risk to public health is reported to NSW Health

immediately and incident responses are developed in consultation with relevant stakeholders.

The Water Monitoring Program also specifies monitoring required in anticipation of events which

pose potential threats to raw water quality, such as large inflow events and seasonal turnover in Lake

Burragorang. The pre-planned monitoring during periods leading to and during such events allows

operational changes to be made proactively and prevents such events manifesting into incidents.

During 2015–16 there were four major and three minor water quality incidents recorded in the

Sydney catchment area of operations (see Appendix B for details of these incidents).

8.1 Major water quality incidents

There were four major water quality incidents during 2015-16. Prompt notifications and effective

incident response ensured no reported issues or customer complaints relating to the water supply.

Two examples of the incident management response are discussed below; the potentially toxin

producing cyanobacteria bloom in Wingecarribee Reservoir (see Section 8.1.1) and wet weather

incident June 2016 (see Section 8.1.2).

8.1.1 Potentially toxin producing cyanobacteria in Wingecarribee Reservoir

A significant and persistent bloom of toxin producing cyanobacteria affected Wingecarribee

Reservoir between December 2015 and August 2016. Potentially toxin producing cells peaked in the

lake on 27 June with 22,210 cells/mL of Microcystis (unknown species and M.aeruginosa) and

Phormidium (unknown species) and coincided with an influx of nutrients from a rain event.

Supplemental sampling in the lake and at the inlet to the water filtration plant was undertaken

throughout this period to inform the treatment process and assess any likely impact on public health.

As with most toxin producing blooms in this storage, the count was dominated by the

cyanobacterium Microcystis, which on this occasion produced concentrations of the cyanotoxin

Microcystin LR equivalent, which was monitored extensively throughout the period. Toxin production

peaked at 0.85 µg/L on 2 May, but remained below the Australian Drinking Guideline value of

1.3 µg/L (see Figure 8.2).

Algal blooms are common in Wingecarribee Reservoir and the Wingecarribee Water Filtration Plant

has been designed to manage algal cells and toxins using Dissolved Air Floatation and Powered

Activated Carbon (PAC). PAC dosing continued throughout this event as a precaution and the water

was successfully treated to meet ADWG with no increase in customer complaints.



Figure 8.2: Potentially toxin producing cyanobacteria counts and microcystin LR- equivalent toxin in Wingecarribee Reservoir (DWI1) and raw water to Wingecarribee Water Filtration Plant (HWI1).

8.1.2 Wet weather incident June 2016

A significant wet weather event in June 2016 impacted the greater Sydney water supply system

requiring intensive monitoring and manipulation of the systems configuration. This event was initially

classed as a significant incident by WaterNSW management. The incident was later upgraded to

major following very poor water quality in Lake Nepean and the Nepean WFP being temporarily

unable to treat the water. Incident management included establishing an Incident Management

Team and opening the Emergency Control Centre to minimise impacts from the wet weather event,

while ensuring health and safety of staff and business continuity.

This east coast low pressure system resulted in unprecedented inflows in Werriberri Creek, just 3 km

upstream of Warragamba Dam. The quality and physical characteristics of the inflow was assessed

and its progress followed through to its intrusion into the lake. This intrusion was of poor quality and

could impact the open outlets in their current position. A timely reconfiguration of the outlets

resulted in no adverse impacts to the supply.

Figure 8.1 shows the turbidity in Lake Burragorang as measured by the in-lake vertical profiler. The

warmer colours on the figure show rises in turbidity (up to 25 NTU) which were associated with the

Werriberri Creek wet weather intrusion. Water supply outlets were relocated to avoid these

intrusions and ensure no adverse effects were experienced by the downstream customers.



Figure 8.1: Wet weather inflow into Lake Burragorang showing outlet configuration change. The solid white lines indicate depth of the open water supply outlets supplying to water filtration plants. Dotted lines indicate the available closed water supply outlet depths.

Inflows arising from the June wet weather event also impacted the Upper Nepean and Woronora

storages. Lake Nepean experienced significant inflows during this event, with the intrusion rapidly

impacting a large proportion of the water column. Nepean Water Filtration Plant was required to

shut down for a short period of time while critical infrastructure was repaired and the outlets

reconfigured to draw from high in the water column, avoiding the worst of the turbid water intrusion

(turbidity up to 90 NTU) before supply was recommenced.

A large intrusion entered Lake Woronora which initially entered as a flow along the bottom half of

the water column. The intrusion later mixed up throughout the water column, with the greatest

mixing during the period from 14 to 18 June. Despite the outlet move there were minor impacts on

raw water quality during this period.

Typically, large inflows transport iron and aluminium from the catchment into the storages, and on

this occasion Lake Woronora was particularly impacted with aluminium from the underflow that

entered the lake. Additional special sampling conducted during the event revealed total aluminium

values above the 0.4 mg/L Raw Water Supply Agreement threshold between the 14 and 19 June

2016. This was a treatment issue only, as there is no health based guideline value for aluminium.

After 19 June, natural oxidisation and sedimentation resulted in aluminium decreases in the lake and

the raw water supply.

Subsequent inflows and water quality changes from this event were identified and tracked

throughout the lakes using the vertical profiler systems (where available), thermistors, as well as

undertaking additional water monitoring in the following days and weeks.



9 References

ANZECC (2000). Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

Australian and New Zealand Environment and Conservation Council and Agriculture and Resource

Management Council of Australia and New Zealand, Australia.

Governor of NSW (2012). Operating Licence for the Sydney Catchment Authority 2012-2017. Issued

under the Sydney Water Catchment Management Act 1998, New South Wales Government, Sydney.

IPART (2014). Reporting manual for Sydney Catchment Authority. Independent Pricing and

Regulatory Tribunal, Sydney.

NHMRC (2008). Guidelines for Managing Risks in Recreational Water. National Health and Medical

Research Council, Canberra.

NHMRC (2011). Australian Drinking Water Guidelines. National Health and Medical Research Council

and the Natural Resource Management Ministerial Council, Commonwealth of Australia, Canberra.

NSW Health (2014). NSW Private Water Supply Guidelines. NSW Health, Sydney.

NSW Office of Water (2012). Sydney Catchment Authority Water Licences and Approvals Package.

Water Administration Ministerial Corporation, Penrith.

Sydney Catchment Authority and Sydney Water Corporation (2013). Sydney Catchment Authority and

Sydney Water Corporation Raw Water Supply Agreement. Sydney Catchment Authority and Sydney

Water Corporation, Sydney.

Sydney Catchment Authority (2012). Healthy Catchments Strategy 2012 – 2016. Sydney Catchment

Authority, Penrith.

Sydney Catchment Authority (2010). Raw Water Quality Incident Response Plan. Sydney Catchment

Authority, Penrith.

Sydney Catchment Authority and NSW Health (2011). Memorandum of Understanding. Sydney

Catchment Authority and NSW Health, Sydney.

Sydney Catchment Authority and Shoalhaven City Council (2010). Sydney Catchment Authority and

Shoalhaven City Council Raw Water Supply Agreement. Sydney Catchment Authority and Shoalhaven

City Council, Nowra.

Sydney Catchment Authority and Wingecarribee Shire Council (2010). Sydney Catchment Authority

and Wingecarribee Shire Council Raw Water Supply Agreement. Sydney Catchment Authority and

Wingecarribee Shire Council, Bowral.

WaterNSW (2014). Water Monitoring Program 2015 – 2020. WaterNSW, Penrith.



10 Glossary

Aesthetic Considered pleasant to the senses.

Algae Simple chlorophyll-bearing plants, mostly aquatic and microscopic in

size.

Algal ASU Areal standard unit (a measure of filter clogging potential of algae)

Algal bloom Rapid growth of algae in surface waters due to an increase in

nutrients such as nitrogen and phosphorus and ideal conditions for

proliferation.

Alkalinity The capacity to neutralise acid.

Analytes Physical, chemical and biological properties analysed.

Catchment Area where water is collected by the natural landscape. In a

catchment, all rain and run-off water eventually flows to a creek,

river, lake or ocean, or into the groundwater system.

Chlorophyll-a

Colour

Green pigments in plants.

Colour is a measure of the absorption of light in certain frequencies by

water. Colour in water may result from the presence of natural

metallic ions (iron and manganese), humus and peat materials, algae

and industrial wastes. True colour is the colour of water with no

suspended material present.

Composite sample A sample made up of component samples or collected at more than

one location.

Contaminant Biological (e.g. bacterial and viral pathogens) and chemical

introductions capable of producing an adverse effect in biota.

Cyanobacteria A division of photosynthetic bacteria that can produce toxins,

formerly known as blue–green algae.

Cyanotoxin Toxin produced by some cyanobacteria.

Cyst A resting spore of many algae and protozoa.

Detection limit The smallest concentration or amount of a substance that can be

reported as present with a specified degree of certainty by definite

complete analytical procedure.

Diurnal Daily.



Dissolved oxygen The amount of oxygen dissolved in water.

Environmental flow Water released from reservoirs aimed at improving and maintaining the

ecological health of the river downstream.

Epilimnion The warmer upper layer of water in a stratified lake.

Eutrophic Water bodies rich in mineral and organic nutrients that promote a

proliferation of plant life.

Field Blank For QA/QC purposes, a blank sample measures the magnitude of

contaminant concentration that may have been introduced as a result

of sampling-related activities. Blank water is specially prepared distilled,

deionised or sterilised water that is laboratory produced, quality-

controlled, and carries a certificate of analyte concentrations for each

lot of water produced. Field blank samples are collected and processed

in the field site in the same manner, and using the same equipment, as

the primary sample. These samples are analysed along with routine

samples and collected on the same trip. This helps to identify sources of

contamination.

Field duplicate The primary purpose of duplicate samples is to identify and/or quantify

the variability in all, or part, of the sampling and analysis system.

Duplicate, triplicate, or greater multiples are considered ‘identical’ or

‘almost identical’ in composition and are analysed for the same

properties. Variations between the primary sample and the duplicate

should be within the laboratories prescribed limits of the analytical

methodology for each parameter analysed

Hardness A measure of the concentration of calcium and magnesium ions in

water, frequently expressed as mg/L calcium carbonate equivalent

(CaCO3).

Hypolimnion The colder lower layer of water in a stratified lake.

Indicator A parameter that can be used to provide a measure of the quality of

water or the condition of an ecosystem.

Limit of reporting Limit of Reporting (LOR) is a minimum value determined for each analyte, above the detection limit, where there is a high confidence in the reporting of that value.

Median The value of the middle item when the data are arranged in an

increasing or decreasing order of magnitude.

Metal Certain opaque, fusible, ductile, and typically lustrous substances that

yield basic oxides and hydroxides that generally occur in trace amounts



in living organisms. Can become toxic at higher concentrations.

Nutrients Compounds required for growth by plants and other organisms. Major

plant nutrients are phosphorus and nitrogen.

Oligotrophic Water bodies with low primary productivity, the result of low nutrient

content.

Oocyst Dormant but resistant phase of the life cycle of some protozoa.

Parameter A measurable or quantifiable characteristic or feature.

Pathogens Disease-causing organisms, such as bacteria and viruses.

Pesticide A chemical that is toxic to pests.

pH A measure of the degree of acidity or alkalinity, expressed on a

logarithmic scale of one to 14 (one is most acid, seven neutral and 14

most alkaline).

Physicochemical Refers to the physical (e.g. temperature, electrical conductivity) and

chemical (e.g. concentrations of nitrate, mercury) characteristics of

water.

Reservoir An artificial body of water, often behind a dam.

Runoff The portion of precipitation that flows towards streams, either above or

below ground, often carrying dissolved or suspended material.

Sediment Soil or other particles that settle to the bottom of lakes, rivers, and

other waters.

Special Area Areas of unspoilt bushland close to reservoirs that act as a buffer zones

to help stop pollutants from entering reservoirs.

Stratification Arrangement of layers, especially of water having different physico-

chemical properties in lakes.

Thermal stratification The formation of distinct layers in lakes based on temperature, usually

most pronounced during the summer months.

Thermocline A region of rapidly changing temperature in a lake, found between the

epilimnion and hypolimnion.

Thermotolerant

coliforms

Bacteria used as a primary indicator of sewage pollution.

Thermotolerant coliforms may in some instances include bacteria of

environmental rather than faecal origin.

Toxin A poisonous substance of biological origin.



Turbidity A measure of the amount of suspended material (usually fine clay or silt

particles) in water and thus the degree of scattering or absorption of

light in the water.

Trip blank For QA/QC purposes, trip blank sample bottles are filled with clean

water at the service providers’ depots prior to a sampling run. This

helps to identify contamination that may occur during transportation,

or from the containers themselves

Trophic status Categorisation based on the level of nutrient enrichment in a lake

which could lead to algal growth e.g. oligotrophic (low mineral and

nutrient concentrations), eutrophic (high mineral and nutrient

concentrations).

Water column The region of water between the surface and bottom of a lake or river.

Water filtration plant A treatment plant that improves water quality by removing impurities

through filtration.

Water quality benchmark The recommended quality of water for various uses based on

evaluation of scientific data.



11 Acronyms

ADWG Australian Drinking Water Guidelines

ASU Areal standard unit (a measure of filter clogging potential of algae)

ANZECC Australian and New Zealand Environment and Conservation Council

AUSRIVAS Australian Rivers Assessment System

CFU Colony forming units (a measure of microorganisms)

DPI Department of Primary Industries

IPART Independent Pricing and Regulatory Tribunal

LOR Limit of Reporting

mg/L Milligrams per litre

mm Millimetres

ML Megalitre (one million litres)

ML/d Megalitres per day

MMP Macroinvertebrate monitoring program

NATA National Association of Testing Authorities

NHMRC National Health and Medical Research Council

NOW New South Wales Office of Water

NTU Nephelometric turbidity units

QA/QC Quality assurance and quality control

RWQIRP Raw Water Quality Incident Response Plan

RWSA Raw Water Supply Agreement

μg/L Micrograms per litre

SCA Sydney Catchment Authority

STP Sewage treatment plant

SWC Sydney Water Corporation

WFP Water filtration plant

WMP Water monitoring program

Documents

Figure 0.1: Sydney catchment area · 2016-12-18 · WaterNSW Annual Water Quality Monitoring Report - Sydney Catchment Area 2015-16 ... 8.1.1 Potentially toxin producing cyanobacteria