City of Rockdale Water Quality Monitoring Study - Part … of Rockdale Water Quality Monitoring – Report 2013 3 Table of Contents 1. Executive Summary 5 2. Introduction

City of Rockdale Water Quality Monitoring Study - Part A: Report

2014

City of Rockdale Water Quality Monitoring – Report 2013 2

Prepared By Equatica This document has been prepared solely for the benefit of Rockdale City Council and is issued in confidence for the purposes only for which it is supplied. Unauthorised use of this document in any form whatsoever is prohibited. No liability is accepted by Equatica Pty Ltd or any employee, contractor, or sub-consultant of this company with respect to its use by any other person. This disclaimer shall apply notwithstanding that the document may be made available to other persons for an application for permission or approval to fulfil a legal obligation.

Document Control Sheet

Report title: Rockdale Water Quality Monitoring Report – Summary Report

Version: Final v3

Author(s): Andrew McMillan, David Knights

Approved by: David Knights

Signed:

Date: 30 January 2014

File Location: P:\Projects 2400s\2402\

Distribution: Rockdale City Council


Table of Contents 1.� Executive Summary .................................................................................................... 5�2.� Introduction .................................................................................................................. 8�

2.1� Objectives of the study ..................................................................................... 8�2.2� Rockdale environment ...................................................................................... 8�

3.� Water Quality Sampling ............................................................................................ 11�3.1� Water quality monitoring sites ........................................................................11�3.2� Water quality parameters ...............................................................................14�3.3� Rainfall conditions ............................................................................................19�3.4� Limitations and assumptions of the study ....................................................22�

4.� Analysis and Discussion on Rockdale Water Quality ........................................... 23�4.1� Comparison to ANZECC values .....................................................................23�4.2� Overall findings .................................................................................................23�4.3� Summary of each Sub-catchment ...............................................................28�4.3.1� Wolli Creek (Sites 1, 16 & 2) .............................................................................28�4.3.2� Bardwell Creek (Sites 6, 5, 17, 4 & 3) .............................................................28�4.3.3� Bonnie Doon (Site 15) ......................................................................................30�4.3.4� Spring Street (Site 7) .........................................................................................31�4.3.5� Scarborough Ponds (Sites 8, 14B, 14A, 14, 14C & 9) ..................................32�4.3.6� Waradiel Creek (Site 12) .................................................................................35�4.3.7� Bado Berong Creek (Sites 10 & 11) ...............................................................35�4.3.8� Goomun Creek (Site 13) .................................................................................35�4.4� Standout water quality indicators .................................................................36�4.4.1� Nutrients..............................................................................................................36�4.4.2� Heavy Metals ....................................................................................................36�4.4.3� Total Suspended Solids (TSS) ...........................................................................38�4.4.4� Pathogens ..........................................................................................................39�

5.� Comparison of 2012 Rockdale Water Quality to Previous Studies ...................... 42�5.1� Total Nitrogen Summary ..................................................................................42�5.2� Total Phosphorous Summary ..........................................................................43�5.3� Total Suspended Solids Summary ..................................................................43�

6.� Comparison of Rockdale Water Quality to other Local Government Areas ..... 51�6.1� Summary of data and benchmarks .............................................................51�6.2� Total Suspended Solids Summary ..................................................................54�6.3� Total Phosphorous Summary ..........................................................................54�6.4� Total Nitrogen Summary ..................................................................................54�

7.� Conclusion ................................................................................................................. 61�8.� References ................................................................................................................. 62�

Also available:

City of Rockdale Water Quality Monitoring Study - Part B: Appendices

City of Rockdale Water Quality Monitoring Study - Part C: Monthly Reports


Abbreviations ANZECC Australian and New Zealand Environment and Conservation Council

DO Dissolved oxygen

EC Electrical conductivity

LGA Local Government Area

NATA National Association of Testing Authorities, Australia

TKN Total kjeldahl nitrogen

TN Total nitrogen

NOx Nitrate & nitrite

TP Total phosphorous

TSS Total suspended solids

BOD Biochemical oxygen demand

mg/L Milligrams per litre

µg/L Micrograms per litre


1. Executive Summary The City of Rockdale lies within two major catchments - the Cooks River and the Georges River. The City is divided into ten sub-catchments: Wolli Creek, Bardwell Creek, Bonnie Doon, Spring Street, Muddy Creek, Eve Street, Scarborough Ponds, Waradiel Creek, Bado Berong Creek and Goomun Creek. The water quality within these sub-catchments plays an important role in the health of both the waterways and the surrounding environment.

Rockdale City Council has undertaken a Water Quality Monitoring Study to determine the quality of water within its waterways and benchmark them against other similar waterways. As part of this study monthly water quality monitoring was undertaken at 17 sites within eight of the sub-catchments for 12 months from February 2012 to January 2013. A range of parameters that help indicate water quality and stream health was measured and recorded. The results of the monitoring study were evaluated against the previous 1999 Rockdale water quality study, other studies undertaken within the LGA, Australian and New Zealand Environment and Conservation Council guidelines for fresh and marine water quality (ANZECC guidelines), and other semi-urban and urban streams within Sydney.

The outcomes of the monitoring program included some key findings about Rockdale City’s waterways such as highly elevated nutrient levels with high levels of total nitrogen and total phosphorous, while elevated levels of copper were found at some sites. Many sites were found to have low levels of dissolved oxygen. An outline of the results is highlighted in Figure 1: City of Rockdale Water Quality Monitoring Study - key findings.

The results show that for many of its sites Rockdale’s waterways consistently exceeded ANZECC guideline values for nitrogen, nitrates, phosphorous, copper and zinc. Some sites also have values above the average values of Sydney’s urban streams, and are classified as very poorly performing sites according to the new suggested benchmarks for Sydney’s urban streams.

A comparison of the results from the 2012-13 monitoring period, compared with the data from the 1999 monitoring study, indicate that water quality has not changed at most sites. Some sites have shown a deterioration in water quality, particularly in relation to reductions in dissolved oxygen. However, these reductions may be attributed to the dry climatic conditions during the 2012-13 monitoring period.

While the results of the 2012-13 water quality study are somewhat reflective of the pressures on waterways in a highly urbanised environment, the findings show the high degree of susceptibility that Rockdale’s creeks, rivers and wetlands have to the adverse impacts from urban runoff, stormwater, sewage overflows, fertiliser usage and the legacy of former landfill sites.

The study has shown that in Rockdale LGA there are several waterways that are performing significantly worse than typical degraded urban streams impacted by urbanised catchments and diffuse stormwater pollution as shown by the benchmarks developed in Section 6. These are Bardwell Creek (at Bardwell Valley Golf Course), Spring Street Channel Market garden drain within A.S. Tanner reserve (Scarborough Ponds), Kendall Street Reserve and Bicentennial Park Wetland. Council will continue to investigate opportunities to improve water quality at theses sites as well as throughout the LGA.

Several activities have already been undertaken or are currently in development to improve water quality within Rockdale LGA include:

• Improved maintenance of Gross Pollutant Traps, litter traps • Installation of a Rain garden at Gilchrist Park, Bexley North • Installation of a rain garden and creek bank revegetation at Coolibah Reserve,

Bardwell Valley • Installation of floating reed beds at Bicentennial Park, Rockdale • Upgrade of aeration devices in Scarborough Ponds, Monterey • Community education programs (eg. Drain is just for rain)


- WQ monitoring site TN – Total nitrogen - Sub-catchment boundary TP – Total phosphorous - Approximate creek line DO – Dissolved oxygen

TSS - Total suspended solids

Figure 1: City of Rockdale Water Quality Monitoring Study - key findings

Refer to Section 3.1 and Part B: Appendices; Appendix B: Monitoring Site Locations for full details of each monitoring site

Site 4 – Very high TN (likely associated

with landfill)

Site 16 – Large amount of litter

Site 7 – High TN and TP

Site 8 – High TN (likely associated with landfill) and TP

Site 14 – High TP, TN, Arsenic & Chromium (likely associated with market garden)

Site 13 – High TN (likely associated

with landfill)

Site 10 – Low DO

Site 15 – Low DO, high TSS

Site 3 – High TN (diluted from

Site 4)

Site 1 – High copper

Site 2 – High zinc

Site 5 – High nitrates

10

2

4

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2. Introduction Rockdale City Council has undertaken a Water Quality Monitoring Study to determine the quality of water within its waterways and benchmark them against other similar waterways. As part of this study water management specialists, Equatica, undertook monthly water quality monitoring for Council at 17 sites for 12 months from February 2012 to January 2013. Some of the key issues faced by the City of Rockdale regarding water quality include:

• Stormwater runoff which continues to be a major source of pollution and organic matter to local waterways.

• Sewer overflows. • Poor condition and capacity of the existing stormwater infrastructure in some

sub-catchments, much of which is over 50 years old. • Previous drought conditions which have caused a decline in water quality due to

an increase in turbidity, reduction in dissolved oxygen, foul odours, black water, algal blooms and fish kills.

• Poor flushing capacity of some waterways due to flat terrain. • Artificial ‘straight’ nature of some waterways resulting in less meandering as

would occur in a natural setting. • Legacy of previous land use (e.g. landfills).

This report captures, evaluates and summarises the water quality monitoring results of the 12 month monitoring study and benchmarks them against the previous 1999 Rockdale water quality study, other studies undertaken within the LGA, ANZECC guidelines, and other urban streams within Sydney.

2.1 Objectives of the study The key objectives of the study are to:

• Establish baseline data on the water quality of local creeks, wetlands and other waterways over a 12 month period.

• Provide an understanding of the health of the local waterways and endeavour to identify any illegal discharges into these waterways.

• Establish environmental performance indicators, which can generate consistent, comparable and focussed information on trends in water quality.

• Provide information to the community on the quality of local waterways. • Enable comparison to previous water quality studies. • Guide Council’s decision making to improve water quality.

To meet these objectives this report delivers:

• An updated baseline data set on the water quality of local creeks, wetlands and drains.

• A comparison of findings from this study to previous water quality studies undertaken by Rockdale City Council.

2.2 Rockdale environment Rockdale City Council is located on the shores of Botany Bay, 12 kilometres from Sydney’s central business district. The city covers an area of approximately 29.8 square kilometres and is defined by natural boundaries of the Cooks River and Wolli Creek in the north, Botany Bay in the east and the Georges River in the south. Rockdale’s Local Government Area falls within the Sydney Basin Bioregion. The area is highly urbanised with only 81 hectares of native vegetation remaining in the form of bushland, wetlands, dunes and seagrass meadows (growing offshore in the shallow intertidal waters of Botany Bay). Most of the open space (parks and reserves) is scattered along creek lines such as Wolli and Bardwell Creeks, the wetlands corridor (Marsh Street Wetland, Eve Street


Wetland, Spring Street Wetland, Landing Lights Wetland, Kings Road Wetland, Bicentennial Pond, Patmore Swamp, Scarborough Ponds and Tonbridge Creek/Hawthorne Street Natural Area), and the coastline. The City of Rockdale is characterised by three geological types: Quaternary Alluvium (sands, silts and clays) in the eastern parts; Hawkesbury Sandstone sequence (medium to coarse-grained quartz sandstone with minor shale and laminite lenses) to the west and the Wianamatta Group Shales of the Liverpool sub-group (black to dark grey siltstone and laminate) present on the more elevated areas in the western-most part of the LGA. The elevation within the City ranges from 0m to 120m and is characterised by low undulating areas in the south and east with slopes of less than 2%. There is a low plateau located in the north-western parts which is incised by several streams that have cut small valleys producing slopes up to 30% gradient in Bardwell Valley. The City of Rockdale lies within two major catchments – the Cooks River and the Georges River. These two catchments are further divided into ten sub-catchments (Figure 2: Major Catchments and Sub-catchments in the City of Rockdale).

Figure 2: Major Catchments and Sub-catchments in the City of Rockdale

(from State of the Environment – Supplementary Report 2010-2011) Rockdale is located within the sub-tropical climatic zone and has a typically temperate climate with warm wet weather prevailing in the autumn and summer while cool dry weather is most common during the winter and spring. Local climatic conditions vary according to topographic features and distance from the sea. Temperatures, recorded at


Mascot Airport since 1929, show an average 26oC maximum (January and February) and 6.8oC minimum (July). Mean annual rainfall is 1106.4mm, with a maximum fall in June (126.2mm), and minimum falls in September (62.6mm). Average monthly rainfall around Rockdale is shown in Figure 3: Mean rainfall for BOM stations near Rockdale. Winds are predominantly from the South and North-East in summer and from the South and South-West in winter.

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Figure 3: Mean rainfall for BOM stations near Rockdale


3. Water Quality Sampling

3.1 Water quality monitoring sites A total of seventeen sites were initially monitored throughout the LGA. The location of thirteen of the sites (sites 1 to 13) was determined by the 1999 Rockdale water quality study. The other four sites were chosen to achieve a greater coverage of the Local Government Area. The description and locations of the sites are outlined in Table 1: Monitoring Sites and descriptions and displayed in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. Each site location with map and coordinate reference can be found in Part B: Appendices; Appendix B: Monitoring Site Locations. Sites 14A - Scarborough Ponds, Scott Street, Monterey, 14B - Scarborough Ponds, A.S. Tanner Reserve (north) and 14C - Scarborough Ponds, Barton Street, Monterey were added in July 2012, to further investigate the source of poor water quality results obtained at Site 14 – Scarborough Ponds, Scott Street, Monterey. Table 1: Monitoring Sites and descriptions

Site No.

Waterway Site Location Site Description

Cooks River Catchment

1 Wolli Creek Bonalbo Street, Kingsgrove

Concrete channel in parkland at end of street. Access via gate on upstream side of pedestrian bridge.

2 Wolli Creek Henderson Street, Turrella

Concrete weir upstream of pedestrian bridge at end of street. Sample taken upstream of weir.

3 Bardwell Creek

Hannam Street, Bardwell Valley

Creek in parkland at end of street. Sample taken under trees close to railway bridge.

4 Bardwell Creek

Pile Street, Bardwell Valley

Creek in gully at end of street. Access creek past white gate. Sample taken downstream of stormwater pipe entering creek below gate.

5 Bardwell Creek

Ellerslie Road, Bardwell Valley

Concrete channel in parkland below end of road. Access via Preddy Avenue. Sample taken at pedestrian bridge at end of concrete channel.

6 Bardwell Creek

Croydon Road, Hurstville

Concrete channel in Bexley Golf Course opposite 173 Croydon Road. Sample at pedestrian bridge within golf course.

7 Spring Street Channel

West Botany Street, Rockdale

Concrete channel within reserve off West Botany Street. Access via entry road to golf driving range. Sample taken upstream of vehicular access bridge opposite entry to driving range.

15 Levey Street Wetland

Levey Street, Wolli Creek

Small mangrove wetland between Marsh Street and one way road to Levey Street.

16 Wolli Creek Slade Road, Bardwell Valley

Creek adjacent to railway line. Sample taken near Iloura Park, accessed from Johnston Street.

17 Bardwell Creek

Hillcrest Avenue, Bardwell Valley

Creek in golf course. Sample taken just upstream of pedestrian bridge


Site No.

Waterway Site Location Site Description

Botany Bay Catchment

8 Bicentennial Park Pond

President Avenue, Rockdale

Concrete culvert in roadside verge on northern side of President Avenue.

9 Tonbridge Creek

Culver Street, Monterey

Natural channel in parkland at end of street. Sample taken downstream pedestrian bridge and stormwater pipe at southern end of pond.

14 Scarborough Ponds

Scott Street, Monterey

Pond within A.S. Tanner Reserve. Sample taken where the drain from the market garden enters the pond.

14A Scarborough Ponds

Scott Street, Monterey

Channel within A.S. Tanner Reserve. Sample taken in the drain from the market garden just upstream of the culvert below the playing field.

14B Scarborough Ponds

A.S. Tanner Reserve (north), Monterey

Pond within A.S. Tanner Reserve. Sample taken adjacent to the north-eastern extent of the playing field.

14C Scarborough Ponds

Barton Street, Monterey

Pond within A.S. Tanner Reserve. Sample taken adjacent to the south-eastern extent of the playing field near bridge.

Georges River Catchment

10 Bado Berong Creek

Russell Avenue, Sans Souci

Natural channel within ‘green’ corridor. Sample taken at concrete culvert northern side of Russell Avenue.

11 Bado Berong Creek

Soult Street, Sans Souci

Natural channel within reserve opposite Soult Avenue. Sample taken downstream pedestrian bridge

12 Waradiel Creek

Peter Depena Reserve, Sandringham

Channel within reserve via Sanoni Avenue and sailing club carpark. Sample taken upstream tidal gate.

13 Goomun Creek

Kendall Street Reserve, Sans Souci

Channel within reserve off Kendall Street. Sample taken at Lawson Street. Vehicle access on western side of oval.


- WQ monitoring site - Sub-catchment boundary - Approximate creek line

Figure 4: Location of the Water quality monitoring sites within Rockdale City Council

4

2

10

Wolli Creek

Bardwell Creek

Spring St Drain

Bado Berong Creek

Goomun Creek

Waradiel Creek

Bicentennial and Scarborough ponds corridor

14


3.2 Water quality parameters The parameters analysed during this study included:

• pH - used as an indicator to determine whether the water is acidic or alkaline. The pH scale ranges from 0 which is extremely acidic to 14 which is extremely alkaline. A pH of 7 is neutral. “The optimal pH for most organisms in Australian waters is pH 6.5 to pH 8.2. Changes in pH outside this normal range will cause a reduction in species diversity, as the more sensitive species disappear. Acidic water can cause fish and other aquatic organisms to suffer from skin irritations, tumours, ulcers and impaired gill function. Extremely high or low pH levels will lead to the death of aquatic life. Small changes in pH can greatly influence the solubility and biological availability (amount that can be utilised by aquatic life) of nutrients (e.g. phosphorus, nitrogen and carbon) and heavy metals (e.g. lead, copper and cadmium). Levels of pH below 5.5 can cause heavy metals trapped in sediments to be released in forms that can be toxic to aquatic organisms.” (Streamwatch, 2003)

• Temperature - a basic physical characteristic of water and an important factor with regard to the functioning of aquatic ecosystems. Growth and metabolism, timing and success of reproduction, mobility and migration patterns and production may all be altered by changes in ambient temperature regimes (ANZECC 1992)

“Temperature has a major influence on the biological activity and growth of aquatic organisms. Temperature affects:

o the rate of photosynthesis of plants

o the metabolic rate of aquatic animals

o rates of development, timing and success of reproduction

o mobility of aquatic organisms

o migration patterns of aquatic organisms

o the amount of oxygen that can be dissolved in the water (the higher the temperature the lower the dissolved oxygen carrying capacity)

o the sensitivity of organisms to toxins, parasites and diseases.

“Most aquatic organisms are cold blooded, which means they are unable to internally regulate their core body temperature. All species of aquatic organisms have preferred temperature ranges. As the temperature gets too far above or below the preferred range, the number of species and the number of individuals of a species decreases until finally there are few, or none.” (Streamwatch, 2003)

• Electrical conductivity (EC) - used as simple measures of the mineral salt content of a waterway. “Electrical conductivity is a measure of the physical ability of a sample to carry an electric current. Electrical conductivity is an indirect method of measuring salinity and includes the measurement of all salts and organic acids.

Salt is present naturally in the Australian landscape and originates from the weathering of rocks, salt spray from the ocean or where prehistoric deposits remain, when the sea level was much higher.

Salts control osmotic pressure and affect which species can survive in the water. If the concentration of salts is too high, water bugs and plankton adapted to freshwater will have difficulty keeping water inside them, and will shrivel and die. Many aquatic species can only survive in a very narrow range of salt


concentration. Adverse impacts are likely in freshwater when salt concentrations reach 1500�S/cm.” (Streamwatch, 2003)

• Dissolved oxygen (DO) - Nearly all aquatic organisms require dissolved oxygen for respiration. If dissolved oxygen concentrations in the water become low, many organisms suffer physiological stress and may die. Low oxygen levels can cause the release of metals and chemicals from sediment, taste and odour problems, fish kills and disruption of plant growth or other ecological processes (DLWC 1995).

“DO concentration is a measure of the availability of oxygen to aquatic organisms. Oxygen is a fundamental requirement for aquatic organisms that respire aerobically; and the concentration of DO affects the distribution, physiological activity and behaviour of aquatic animals. A DO concentration of less than 2mg/L is likely to have deleterious effects on aquatic invertebrates and fish. The result of lower DO is stress on in-stream animals and the exclusion of sensitive species.

The concentration of DO limits, and is limited by, the ecological processes of primary production and respiration that produce and consume oxygen, respectively. DO concentration is highly dependent on temperature, and fluctuates over a 24 hour period under natural conditions. Under some conditions (e.g. low flow, high temperatures), high biological oxygen demand associated with plant respiration and microbial decomposition can lead to very low DO concentrations. Large daily fluctuations in DO place pressure on ecological function.” (SEQ Healthy Waterways)

• Turbidity - gives an indication of the amount of suspended matter present in a body of water. High turbidity values will limit the depth to which light can penetrate a waterbody, thereby limiting the light available for photosynthesis. “High turbidity can reduce light penetration and smother organisms living in or on the bottom sediments of aquatic habitats. If light penetration is reduced significantly, plant growth may decrease, impacting on the organisms that are dependent on the plants for food or shelter. This can result in a reduced rate of photosynthesis by plants and a lesser quantity of oxygen being released into the water.

Very high levels of turbidity for a short period of time may not be significant however long-term high turbidity can reduce biodiversity.” (Streamwatch, 2003)

• Total suspended solids (TSS) - are the mass of materials suspended in the water. The main impact of suspended solids is optical, with the resulting reduction in light penetration. “Suspended solids can suffocate aquatic organisms (by clogging or damaging gills), prevent proper egg or larval development and potentially interfere with particle feeding activities.” (Streamwatch, 2003) “Longer term impacts of high suspended solids include alteration of in-stream dynamics and receiving water bodies (e.g. blocking channels and filling river pools), potential flooding problems and loss of aquatic flora and fauna habitat.” (WA Dept. of Water)

• Nitrogen species: o total nitrogen (TN) – This is one of the key nutrient indicators in water.

Elevated levels of nutrients can shift the equilibrium of an ecosystem to form algal blooms, aquatic weed infestation and potentially toxic algae species (blue green algae). All of these can cause imbalances further downstream.

“Nitrogen is an essential element for both plants and animals to survive. It enters waterways naturally either from the breakdown of dead organic matter or via atmospheric nitrogen gas fixation by specially adapted


plants. Excess nitrogen in rivers enhances nutrient enrichment, leading to algal blooms, fish kills and weed infestation.

Total nitrogen is a measure of all forms of nitrogen in the water including ammonia, nitrate, nitrite and organic nitrogen.

Anthropogenic sources of nitrogen include fertilisers, animal droppings, combustion of fossil fuels and plant debris.” (WA Dept. of Water)

nitrate & nitrite (NOx) – These are the oxidised forms of nitrogen. “Oxidised nitrogen is a stimulant for algal growth and is a common ingredient in fertilisers. High levels of dissolved forms of nitrogen (nitrate, nitrite and ammonia/ammonium) can also be toxic to many aquatic organisms and can prevent the water from being used as a potable supply.” (WA Dept. of Water)

o Total Kjeldahl Nitrogen (TKN) – ammonia-fixed and organic nitrogen are commonly associated with low oxygen environments. “Ammonia can be a nutrient or a toxicant. Ammonium is the ionised form and is a non-toxic nutrient and Ammonia is the unionised form and is a toxin. Sources of ammonia include a range of industrial processes, agricultural fertilisers and the decomposition of organic wastes.” (WA Dept. of Water) Ammonia is highly toxic to aquatic life. One short episode of high ammonia in a waterway may be devastating to invertebrate animals and fish. The source of ammonia is generally the biodegradation of putrescible waste, such as household rubbish or sewage.

• Total Phosphorous (TP) - plant nutrients phosphorus and nitrogen are often measured as indicators of overall water quality. Generally non-toxic, but in excess, they are potentially serious pollutants that can support nuisance growths of algae and aquatic plants. Australian native plants are typically and uniquely intolerant to high phosphorus levels, so native riparian vegetation can be affected.

“Phosphorus (P) is a nutrient essential to the growth of plants and animals. Total phosphorus is a measurement of all forms of phosphate compounds in a sample -orthophosphate, condensed phosphates and organically bound phosphates.

Available phosphorus is a measurement of the phosphate compounds that are soluble in water and therefore available to be absorbed by plants.

Phosphorus occurs naturally in low concentrations in Australian soils and water. Native vegetation (both aquatic and terrestrial) have adapted to these low levels. In contrast, many introduced plants and weeds are adapted to the higher phosphorus levels in the Northern Hemisphere.

Phosphorus is derived from the weathering of rocks and the decomposition of organic material. Phosphorus occurs as phosphate compounds. These compounds limit and control the rate and the abundance of plant growth.

Consequences of high phosphate levels are:

o an abundance of algae and aquatic weeds (e.g. blue-green algal blooms)

o waterways choked with vegetation resulting in reduced penetration of light

o increased biological oxygen demand

o reduced dissolved oxygen which can lead to fish kills

o reduced animal and plant diversity (exotic species are favoured, to the detriment of native species)


o eutrophication.” (Streamwatch, 2003)

• Biochemical oxygen demand (BOD – 5 day) - provides a relative measure of the oxygen demand of the sample in question. It is desirable that environmental waters have a low BOD (< 2mg/L) thus have a minimal tendency to lower the dissolved oxygen of the system.

Biochemical oxygen demand (BOD) is a measure of the amount of organic matter in water. High BOD levels can mean that oxygen is being produced during the day by aquatic plants and consumed overnight - causing the DO level to drop and animals to die.

• Chlorophyll a - a plant pigment which provides a measurement of the quantity of suspended single-celled algae in the water column. High levels of chlorophyll ‘a’ represents an algal bloom.

• Enterococci - Group of faecal bacteria common to the faecal matter of warm-blooded animals, including humans; a subset of the faecal streptococci, but generally the vast majority; now referred to in Europe as the intestinal enterococci.

Runoff from urban environments often causes elevated levels of microbiological parameters such as Enterococci and Faecal Coliforms. This is largely a result of animal and human faecal matter being washed into stormwater systems. Presence of faecal coliforms may also indicate seepage of domestic and industrial sewage into the environment.

• Metal Contaminants - can be toxic to human and fauna. Metal contamination sources include industrial and household chemicals, runoff from roof and guttering, motor vehicle usage, sewage and industrial processes.

o Lead - is toxic to human and aquatic life. It is also very stable and can bioaccumulate.

“Lead is a cumulative, general metabolic poison which bioaccumulates in animals, plants and bacteria and is highly poisonous to both plants and animals. Lead persists in the environment for long periods and does not readily breakdown. The main source of lead in urban runoff is from petrol additives. Other sources include tyres, industrial and mining emissions, manufacturing and smelting industries, lead water pipes and soldered joints, burning of fossil fuels, plastic pipes and guttering, and paints.” (WA Dept. of Water)

o Nickel – can be toxic in larger doses.

“Nickel is relatively non-toxic and there is little evidence of bioaccumulation. Nickel in stormwater is usually associated with suspended solids and organic matter. Sources of nickel include corrosion of welded metal plating, wear of moving parts in engines, electroplating and alloy manufacture and equipment used for food production.” (WA Dept. of Water)

o Arsenic – “Arsenic is highly toxic to aquatic life and bioaccumulates in some animals. Arsenic is very persistent in the environment and can inhibit plant growth. Sources of arsenic include the combustion of fossil fuels, primary production of iron, steel, copper, nickel and zinc, use of pesticides, weed killers and fungicides, wood treatment products and burning of treated wood. High arsenic concentrations can also be found in acidic groundwater.” (WA Dept. of Water)

o Cadmium - toxicity of cadmium to aquatic biota is dependent on hardness, pH, water temperature and the presence of organic


compounds with lower toxicity in waters with higher hardness (ANZECC 1992). Aquatic plants have been found to be sensitive to cadmium concentrations as low as 2 µg/L (ANZECC 1992).

“Cadmium is highly toxic and accumulates in the liver and kidneys of animals. It is a known carcinogen (World Health Organisation 1984). Sources of cadmium include combustion, wear of tyres and brake pads, possible combustion of lubricating oils, industrial emissions, agricultural use of sewage sludge, fertilisers and pesticides, corrosion of galvanised metals and landfill leachate (presumably contaminated by discarded rechargeable batteries).” (WA Dept. of Water)

o Chromium – “Chromium occurs in both trivalent and hexavalent forms. Trivalent chromium is considered to be practically non-toxic. In chlorinated or aerated water, hexavalent chromium is the predominant form and is toxic to aquatic organisms and a carcinogen to animals and humans. Chromium in stormwater is mostly associated with suspended solids.

Sources of chromium include the chemical manufacturing industry (e.g. dyes for paints, rubber and plastic products), the metal finishing industry (e.g. chrome plating), manufacturers of pharmaceuticals, wood, stone, clay and glass products, electrical and aircraft manufacturers, steam and air conditioning supply services, cement producing plants (cement contains chromium), incineration of refuse and sewage sludge, combustions of oil and coal.” (WA Dept. of Water)

o Copper - it is extremely toxic to aquatic life with acute toxicity recorded as low as 17 µg/L in some freshwater species and chronic values for toxicity as low as 4 µg/L.

“Copper is commonly found as the Cu2+ ion in natural waters. This ion is potentially very toxic to aquatic life, both acutely and chronically. It is quickly accumulated in both plants and animals. The toxicity of copper greatly increases with decreasing water hardness and dissolved oxygen concentrations. Sources of copper include wear of vehicle tyres and brake pads, metal industry and domestic products, corrosion of brass and copper pipes, sewage treatment plant effluent, electroplating wastes, pesticides, fungicides, algicides and brake lining.” (WA Dept. of Water)

o Zinc - toxicity of zinc varies with hardness and pH with lower toxicity in waters with higher hardness and lower pH (ANZECC, 1992). In the form of zinc chromate, it is considered to be a carcinogen, although the more common toxic reaction to zinc is skin irritations (Sittig 1985).

“Zinc bioaccumulates easily in plants and animals and is mostly associated with dissolved solids, although it will adsorb to suspended particles. Sources of zinc in stormwater include wear from tyres and brake pads, combustion of lubricating oils, and corrosion of galvanised roofs, pipes and other metal objects.” (WA Dept. of Water)

• Organochlorine Pesticides and Organophosphorus Pesticides – (only tested for at Site 14 – Scarborough Ponds, Scott Street, Monterey).

“Organochlorine Pesticides are an organic compound containing chlorine. They are not easily broken down and can persist in the environment for a long time. They include chlordane, dieldrin and aldrin which have been banned in NSW.

Organophosphate Pesticides are made up of hydrocarbon compounds which contain phosphorus, for example, chlorpyrifos and parathion. They are best


known for their ability to persist in the environment, however, they degrade in the environment faster than organochlorine pesticides.” (Sydney Water, 2011)

Details of the analytical methods and detection limits used to determine these parameters are provided in Part B: Appendices; Appendix A: Monitoring parameters. These parameters were chosen for monitoring because they:

• Provide a good indication of stream health • Are the most common causes of degradation of stream health • Are commonly monitored by Local Councils across Australia, providing

opportunity for comparison • Were used in previous Rockdale City Council studies and so can be compared • Are readily able to be tested without significant laboratory analysis costs.

Enterococci was decided to be measured instead of e-coli as it provides a better indicator of human sewage contamination. Pesticides were monitored at Site 14 – Scarborough Ponds, Scott Street, Monterey due to its close location to the market garden.

3.3 Rainfall conditions Rainfall conditions can influence water quality in waterways a great deal and especially in highly urbanised areas where volumes of inflows from stormwater runoff are much higher than in naturally vegetated areas. Rain events typically result in an increase in stormwater runoff leading to greater water flows in creeks and increased volumes in wetlands. This causes a dilution effect and at sites where dry weather flows have elevated pollutants the stormwater flows can lower concentrations of most water quality parameters. Stormwater flows from rain events can also produce elevated levels of pollutants as they are transferred from surfaces in the catchment to streams. Higher water volumes also tend to increase dissolved oxygen, primarily due to increased flushing. In contrast, dry weather conditions often result in higher concentrations of nutrients particularly at landfill sites, and metals and lower dissolved oxygen levels, simply due to the lack of flushing activity. The monitoring period of the water quality study was characterised by some moderate rainfall initially followed by an extensive dry spell. Initially (February to May), the City of Rockdale experienced relatively wet conditions followed by an extended dry period (June to January). Details of the rainfall conditions during the sampling period are outlined in Table 2: Sampling dates and antecedent rainfall conditions (gathered from Bureau of Meteorology rain gauges at Sydney Airport and Sans Souci). The antecedent rainfall conditions (i.e. rainfall prior to a sampling event), are also provided. The monitoring dates were generated randomly at the initiation of the project, but altered throughout the 12 months to enable wet and semi-wet events to be captured. For the 1999 water monitoring study two sampling conditions were determined:

• Dry – “a period when less than 10mm of rain had fallen in the catchment in the preceding 72 hours” and

• Wet – “when greater than 25mm of rain had fallen in the previous 24 hours” (Rockdale, 1999, p.5)

For the current study an additional sampling condition was designated:

• Semi-Wet – rainfall of between 5 and 25mm in the 24 hours prior to sampling.


Table 2: Sampling dates and antecedent rainfall conditions

Event Sampling Date

Antecedent rainfall

Observed flow conditions

Classific-ation

Sampling day and

preceding 24 hours

Prec-eding 7

days

Prec-eding 14

days

Prec-eding 28

days

Feb-12 29/02/2012 27.4 3.8 60.4 130.0 Moderate - high Semi-wet Mar-12 28/03/2012 5.4 2.8 42.2 194.0 Low Dry Apr-12 19/04/2012 65.4 105.4 114.2 123.6 High Wet

May-12 21/05/2012 11.0 11.0 11.0 13.6 Low Semi-wet Jun-12 26/06/2012 6.2 0.6 28.0 192.8 Moderate Semi-wet Jul-12 30/07/2012 2.8 10.0 16.8 50.6 Low Dry

Aug-12 28/08/2012 0.0 6.2 6.2 12.6 Low Dry Sep-12 27/09/2012 0.0 1.8 6.8 8.4 Low Dry Oct-12 31/10/2012 0.0 0.0 1.6 22.0 Low Dry Nov-12 29/11/2012 0.0 8.8 18.6 39.8 Low Dry Dec-12 26/12/2012 16.8 21.4 21.4 26.6 Low - moderate Semi-wet Jan-13 23/01/2013 0.4 2.8 12.0 12.0 Low Dry

The additional Semi-Wet sampling condition was designated to ensure that the most common runoff generating rainfall events were captured in the study. 30% of rainfall days are between 5mm and 25mm. Figure 5 shows examples of the three different flow conditions for ‘dry’, ‘semi-wet’ and ‘wet’ for Site 1 – Wolli Creek, Bonalbo Street, Kingsgrove.


Dry conditions

(31 October 2012)

Semi-wet conditions

(26 June 2012)

Wet conditions

(19 April 2012)

Figure 5: Site 1 – (Wolli Creek, Bonalbo Street, Kingsgrove) Flow variation for rainfall

conditions


3.4 Limitations and assumptions of the study The methodology adopted for this study involved the taking of individual monthly grab samples at a number of locations across the City. There are limitations in using grab sampling to determine the water quality of receiving waters. For this study only one wet weather event was sampled due to the dry climatic conditions and timing of sampling days. Taking one grab sample during a rainfall event is not sufficient to provide an indication of wet weather water quality. A number of samples need to be taken to provide a representative sample. Dry weather receiving water conditions, particularly for streams and creeks, tends to be more constant for most parameters, although it can vary widely for parameters such as dissolved oxygen and temperature due to climatic conditions as well as other factors such as dry weather spills, illegal discharges and leaks from sewers. A key assumption of this study is that the water quality data should be generally looked at in its entirety rather than at individual samples, particularly during wet weather events.


4. Analysis and Discussion on Rockdale Water Quality This section provides a summary of the significant findings of this study. Complete records of all the results from the entire sampling period are provided in Part B: Appendices; Appendix D: Complete results tables and charts. Charts for each water quality parameter, showing results over 12 months compared to Australian and New Zealand Environment and Conservation Council guidelines for fresh and marine water quality (ANZECC guideline) trigger values are also provided in Part B: Appendices; Appendix D: Complete results tables and charts.

4.1 Comparison to ANZECC values The ANZECC guidelines are currently the only ‘standard’ available in Australia for assessing stream health. There are no specific guidelines for urban stream environments. The data collected was compared to the ANZECC guidelines trigger values for “slightly disturbed ecosystems”, which are currently the best values for water quality indicators for urban streams in Australia. ANZECC does have information for “highly disturbed systems” category, but the guidelines only provide indicators for “slightly disturbed ecosystems” in south-eastern Australia. The guidelines also “recommend that guideline trigger values for slightly–moderately disturbed systems also be applied to highly disturbed ecosystems wherever possible” (ANZECC, p.3.1-22). The monitored toxicant values in this study are assessed against the ANZEC protection level concentrations for freshwater where 95% of species are expected to be protected (Refer ANZECC table 3.4.1). The values for 80% protection are also provided in the charts for reference. The ANZECC guidelines trigger values for physical and chemical stressors were taken for aquatic ecosystems for lowland rivers and estuaries (Refer ANZECC tables 3.3.2 and 3.3.3). Where a pollutant concentration is below the threshold value or within the desirable range the impact on aquatic ecosystems is appropriate for the stream condition or level of protection. Where a parameter is higher than the threshold value or outside the desirable range there may be a risk of degradation of aquatic ecosystems. The ANZECC guidelines recommend adopting locally relevant reference values. Currently this is not available and this study will contribute to the body of work to determine appropriate benchmarks for urban streams in Sydney. The ANZECC ‘slightly disturbed ecosystems’ trigger values suit an aspiration to improve urban stream water quality.

4.2 Overall findings In general, much of the water quality was typical of results expected for urban stormwater based on literature used for urban stormwater quality modelling (Walsh et al). The instances where the water quality showed unusual trends are highlighted below. A summary of the findings for each Sub-catchment within the LGA is provided in Table 3.


Table 3: Overall findings for each sub-catchment

Catchment (Summary reference and page number)

Site (ordered from Upstream to

Downstream) Water quality

Wolli Creek

4.3.1 p.28

1 High copper; one high dry weather TSS event; highest pH & highest average pH;

16 Large amount of litter; High copper;

2 High zinc; lowest average pH;

Bardwell Creek

4.3.2 p.28

6 Low TP

5 High TSS & nitrates; High copper

17 Low TP; High copper and zinc

4 Very high TN; Low TP; one slightly high TSS

3 High TN (diluted from Site 4)

Bonnie Doon

4.3.3 p.30

15 (tidal) High TSS/turbidity; Low DO; High zinc

(nb Site 15 is not within primary catchment)

Spring Street

4.3.4 p.31

7 (tidal) High TN, nitrates and TP; High copper; lowest pH

Muddy Creek - No sites monitored

Eve Street - No sites monitored

Scarborough Ponds

4.3.5 p.31

8 High TN (likely associated with landfill) and TP

14 High TP, TN, arsenic & chromium and nitrates

9 (tidal) High cadmium, copper & zinc

Waradiel Creek

4.3.6 p.35

12 (tidal) Low TN

Bado Berong Creek

4.3.7 p.35

10 (tidal) Low DO, Low TN

11 (tidal) Low TN

Goomun Creek

4.3.8 p.35

13 (tidal) High TN

The comparison of average values at each site are shown in Figure 6 to Figure 9 for

• Total nitrogen (TN) • Nitrates (NOx) • Total phosphorous (TP) • Turbidity

These are the key indicators of stream water quality and showed the most significant trends. Metal contaminants were generally not detected, but the sites where they were found are discussed in Section 4.4.2. Comparison of water quality indicators (e.g. metals) to the


ANZECC guidelines is provided in Part B: Appendices; Appendix D: Complete results tables and charts. These figures show that the average concentrations for the water quality monitoring sites throughout Rockdale are significantly greater than the threshold for slightly disturbed ecosystems. For example:

• Total nitrogen: the average value is at least 50% higher than the guidelines for lowland rivers, and is typically 100% to 200% higher for most of Rockdale sites.

• Nitrates: the average value is at least 50% higher than the guidelines for lowland rivers, and is typically 300% to 1000% higher for most of Rockdale sites.

• Total phosphorous: the average value is typically 50% to 100% higher for most of Rockdale sites

There were consistently elevated levels of TN and TP. For almost half of Rockdale’s sites the minimum monitored value during the 12 months of sampling was greater than the ANZECC guideline value. This shows:

1) The disturbed nature of Rockdale’s urban streams. 2) That a better benchmark for urban streams is required. The ANZECC guidelines for

“slightly disturbed ecosystems” are not appropriate for urban waterways. The ANZECC guidelines provide no other guidance for disturbed ecosystems other than for slightly disturbed ecosystems. Hence a key part of this study has been to provide more useful benchmarks for fully urbanised streams. This is supported in Section 6 where data from other LGAs is compared to Rockdale’s water quality.

A key finding of this study is that the waterways within the Rockdale LGA are significantly degraded ecosystems. As outlined above the 12 month water quality monitoring has shown that the sites have significantly poorer water quality than natural or slightly disturbed natural ecosystems.

Total Nitrogen

0.5 0.35 0.3

1.19

2.76

8.52

14.71

2.53

1.41

5.336.05

1.08 0.90 0.75 0.74

3.06 3.122.41

1.11 0.99

00.5

11.5

22.5

33.5

44.5

55.5

66.5

77.5

88.5

99.510

10.511

11.512

12.513

13.514

14.515

15.5

ANZECC Lo

wland R

iver

ANZECC

Lake

ANZECC

Estu

ary 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Figure 6: Total Nitrogen (TN) - Average concentration at each site compared to ANZECC Guidelines for Slightly Disturbed Ecosystems


Nitrates

0.04 0.01 0.015

0.43

0.790.67

0.97

1.58

0.81

3.41

0.74

0.17 0.12 0.08 0.110.23

1.17

1.43

0.09 0.060.17

0.38

1.07

00.10.20.30.40.50.60.70.80.9

11.11.21.31.41.51.61.71.81.9

22.12.22.32.42.52.62.72.82.9

33.13.23.33.43.53.6

ANZECC Lo

wland Ri

ver

ANZECC La

ke

ANZECC

Estu

ary 1 2 3 4 5 6 7 8 9 10 11 12 13 14 14A

14B

14C 15 16 17

Figure 7: Nitrates (NOx) - Average concentration at each site compared to ANZECC Guidelines for Slightly Disturbed Ecosystems

Total Phosphorous

0.05 0.01 0.03 0.07 0.07 0.06 0.05 0.10 0.060.11

0.36

0.11 0.150.08

0.160.07

0.61

2.22

0.12 0.10 0.13 0.09 0.07

00.10.20.30.40.50.60.70.80.9

11.11.21.31.41.51.61.71.81.9

22.12.22.32.4

ANZECC Lo

wland R

iver

ANZECC La

ke

ANZECC

Estu

ary 1 2 3 4 5 6 7 8 9 10 11 12 13 14 14A

14B

14C 15 16 17

Figure 8: Total Phosphorous (TP) - Average concentration at each site compared to ANZECC Guidelines for Slightly Disturbed Ecosystems


Turbidity

25

10

0.75

36.0

7.5

18.2

30.6

11.25.9 5.8 5.1 4.2 7.2

2.5 4.0 5.1 6.7

149.4

14.210.7

05

101520253035404550556065707580859095

100105110115120125130135140145150155160

ANZECC

Low

land Rive

r

ANZECC La

ke

ANZECC Es

tuary 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Figure 9: Turbidity - Average concentration at each site compared to ANZECC Guidelines for Slightly Disturbed Ecosystems This is consistent with research from around Australia which has shown that all indicators of stream health, including water quality, deteriorate with urbanisation in the catchment (see Walsh et al. 2004, for example). The key factors in the degradation of most urban streams are:

• Diffuse runoff from urban stormwater, increasing the quantity of pollutants entering the waterway

• Increased peak flows and frequency of high flows • Urbanisation, creating changes to urban waterways including road crossings,

changes to the channel form and changes to the flow regime (e.g. impoundments for urban ponds and lakes).

Characteristics of Rockdale’s waterways which are contributing to poor water quality include:

• Highly impervious catchments with residential, industrial and commercial land uses and little attenuation of flows or improvement in water quality prior to discharge to the waterways

• A wide variety of degraded stream forms including concrete lined channels (e.g. Wolli Creek), artificial waterbodies (e.g. Bicentennial Ponds) and streams impaired by poor water quality, erosion, weeds, loss of riparian zone and structures (e.g. Bardwell Creek)

• Lack of vegetated riparian zones, apart from the steeper gully areas of Bardwell Creek

• Many streams have little or no buffer from urban land uses with development occurring directly adjacent to the waterway (e.g. Wolli Creek)


4.3 Summary of each Sub-catchment

The following is a summary of the major findings for each sub-catchment looking from the upstream sites to the downstream sites.

4.3.1 Wolli Creek (Sites 1, 16 & 2)

Sampling was taken at three sites within the Wolli Creek sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. These locations included (from upstream to downstream) Site 1 - Bonalbo Street, Kingsgrove; Site 16 - Slade Road, Bardwell Valley and Site 2 - Henderson Street, Turrella. Site 1 showed high levels of copper, with every sample exceeding the 80% protection value, such that the average copper concentration was more than double the 80% protection level. Site 16 is around 1km downstream of Site 1, and experienced slightly lower levels of copper than Site 1, most likely through some dilution, but still has an average copper concentration more than one and a half times the ANZECC 80% protection level. The potential sources of elevated copper include wear of vehicle tyres and brake pads from roads, the metal industry (potentially in the Kingsgrove Industrial Estate or Vanessa Street Industrial Park) and domestic products. The average zinc concentrations found were (moving downstream) 0.18 mg/L at Site 1, 0.28 mg/L at Site 16 and 0.32 mg/L at Site 2. At Site 2, 4 of the 6 sampled events exceeded the 80% protection level and at Site 16, 2 samples exceeded the 80% protection level. Whilst the upstream Wolli Creek Sites (1 and 16) had average levels of TN, Site 2 showed higher levels as it is downstream of the junction with Bardwell Creek which has a significant TN source as discussed in Section 4.3.2. Site 1 also showed a high pH reading of 8.52 (March 2012) which is just above the ANZECC guidelines range. As described in Section 4.4.3, Site 1 also experienced an event with a very high dry weather TSS reading which was likely due to construction activity. Site 16 is located in a vegetated area where the creek includes a pool area. The pools were observed to often have a significant amount of litter floating on the surface. Whilst the upstream reach of Site 1 was found to have very high levels of dissolved oxygen, likely to be from the aeration caused by the wide and shallow channel flows, Sites 16 and 2 tended to have very low levels of dissolved oxygen. These low DO levels could be associated with the sampling sites being located at relatively stagnant pools where degradation of organic matter is occurring.

4.3.2 Bardwell Creek (Sites 6, 5, 17, 4 & 3) Sampling was taken at five sites within the Bardwell Creek sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. These locations included (from upstream to downstream) Site 6 - Croydon Road, Hurstville; Site 5 - Ellerslie Road, Bardwell Valley; Site 17 - Hillcrest Avenue, Bardwell Valley; Site 4 - Pile Street, Bardwell Valley and Site 3 - Hannam Street, Bardwell Valley. Figure 10 shows the average TN concentrations moving downstream. Upstream of Site 4, TN values are typically about 2 mg/L in dry and wet events. At Site 4 the TN concentration increases significantly to 20 mg/L in dry conditions, and in wet events is approximately 3 to 7 mg/L. TN concentrations are also significantly elevated at Site 3, with a dry weather concentration of approximately 9 mg/L.


As can be seen in Figure 11 this same pattern is repeated with Total Kjeldahl Nitrogen (TKN) values which show a similar large increase between Site 4 and Site 17, while Figure 12 shows that there is no similar increase in nitrates between Site 4 and Site 17. The monitoring indicates that there is likely to be a point source discharge of groundwater nitrogen entering the creek (or one of its tributaries) between Site 17 and Site 4. The elevated TN is also reflected at Site 3 and even further downstream at Site 2 in Wolli Creek. The high values of TKN suggest that the nitrogen is likely to be in the form of ammonia. TKN is the sum of organic nitrogen, ammonia, and ammonium in the water, and the organic nitrogen concentrations are likely to be low based on experience with other landfill impacted sites. This is likely to be associated with the historic former landfill at the Bardwell Valley Golf Course site, with the anaerobic decomposition of organic matter and subsequent leaching of ammonia into the waterway. Figure 12 shows that Bardwell Creek experienced extremely high nitrate concentrations, possibly coming from the upper reaches of the catchment which are outside the Rockdale LGA. This may be able to be further investigated with Hurstville City Council.

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Figure 10: Total nitrogen (TN) averages for Bardwell Creek sub-catchment


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Figure 12: Bardwell Creek nitrates (NOx) averages In addition to nutrients, all sites in Bardwell Creek were found to have elevated levels of copper and zinc often above the 80% protection level, as outlined in Section 4.4.2. Site 4 also had a substantial amount of iron bacteria growth on the rocky stream bed, and an acrid odour was often observed.

4.3.3 Bonnie Doon (Site 15) Sampling was taken at one site (Site 15 - Levey Street, Wolli Creek) within the Bonnie Doon sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. However, the location of Site 15 is not within the primary Bonnie Doon catchment; it is a small poorly flushed mangrove wetland directly connected to the Cooks River with a catchment including a section of Marsh Street. The majority of the Bonnie


Doon catchment drains to a channel at the western side of Cahill Park, around 350m to the northwest of Site 15. The mangrove wetland was observed to often have suspected iron bacteria covering the surface and lower branches of the mangroves. The site was also found to have very low dissolved oxygen levels, creating conditions where iron becomes more soluble. The poor flushing of the wetland is likely to contribute to high levels of suspended solids and turbidity.

4.3.4 Spring Street (Site 7) Sampling was taken at one site (Site 7 - West Botany Street, Rockdale) within the Spring Street Channel sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. Site 7 is potentially impacted by the market gardens near the Landing Lights wetland. Pollution from market gardens is typically in the form of nitrates from fertiliser application. The nitrate leaches from the soil and accumulates in the groundwater and then moves into the adjacent waterways. This action is increased in sandy environments. It is also possible that the industrial land uses within the catchment are generating excess nitrate. However, it is considered that this is less likely than the market garden due to the relatively low levels of industrial land use within the sub-catchment. The sub-catchment is predominantly residential with only a relatively small area of industrial catchment (in the upstream reaches of the catchment). Unlike other sites which experience a dilution effect during wet weather, particularly large wet weather events, Spring Street Channel does not experience a dilution during wet weather with the wet weather average similar to dry weather averages. The Spring Street Channel also experiences very high nitrogen levels. However, unlike other sites, the composition of nitrogen in the Spring Street sub-catchment is dominated by nitrates, with additional relatively high levels of TKN, which is likely to be ammonia.

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Figure 13: Nitrogen Values for Spring St Sub-catchment

Additional investigations would need to be undertaken to confirm this preliminary analysis.


The Spring Street drain also included high zinc levels with two readings greater than the 80% protection level and 2 readings higher than the 95% protection level. Further to this Site 7 recorded the highest zinc reading at 0.11 mg/L which is three times the 80% protection level. Site 7 also recorded elevated copper concentrations with 4 readings greater than the 80% protection level.

4.3.5 Scarborough Ponds (Sites 8, 14B, 14A, 14, 14C & 9) Sampling was taken at six sites within the Scarborough Ponds sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. These locations included (from upstream to downstream) Site 8 - President Avenue, Rockdale; Site 14B – A.S. Tanner Reserve (north), Monterey; Site 14A – Scott Street, Monterey; Site 14 - Scott Street, Monterey; Site 14C - Barton Street, Monterey and Site 9 – Culver Street, Monterey. Site 8 - President Avenue, Rockdale (Bicentennial Ponds) has previously been studied and shown to be impacted by local historic landfills. This study confirms the finding of that report with very high levels of ammonia entering the ponds from the adjacent landfill. These high levels of ammonia are actually diluted during large runoff events which act to flush the ponds. During large wet weather events the stormwater runoff reduces the nitrogen values back to typical urban runoff conditions. In the early stages of the monitoring study some unusual results (extremely high TP and very high metals in wet weather) were found at Site 14 - Scott Street, Monterey, which Council designated appropriate for further investigation. From July 2012 three additional sites were sampled around Site 14. These included Site 14A - Scott Street, Monterey (at the inlet of the culvert), Site 14B - A.S. Tanner Reserve (north), Monterey (pond at north-east corner of filed) and Site 14C - Barton Street, Monterey (south-east of field near bridge). An aerial photograph showing the additional sampling sites at A.S. Tanner Reserve is provided in Figure 14.

Figure 14: Additional water monitoring sites within the Scarborough Ponds sub-catchment

14

14A 14B

14C

Stormwater channel

Outlet to pond

Pipe


Figure 15: Site 14A – (Scarborough Ponds Scott Street, Monterey) stormwater channel from Market Garden to culvert The market garden drains into a reed (typha) filled stormwater channel, as shown in Figure 15: Site 14A – (Scarborough Ponds Scott Street, Monterey) stormwater channel from Market Garden to culvert. This channel acts as a de-facto wetland particularly during small flows. The channel may be leaching phosphorus that has been trapped within the channel during dry weather periods. This is because at the end of the channel (at Site 14A) there are high phosphorous levels during dry weather. Site 14A has relatively low levels of DO (an average of around 5 mg/L) which indicates that the channel is anaerobic, particularly at the bottom of the channel. Anaerobic conditions typically lead to the re-release of phosphorous from the sediment layer at the base of the channel. Figure 16 shows the average TP concentrations and Figure 17 shows the average TN concentrations at each of the monitoring sites within the sub-catchment. Both these figures show that the highest concentrations of nutrients can be found at Site 14A, which is the downstream end of the drainage channel from the market garden. The water quality monitoring indicates that Site 14C (downstream of the market garden outlet) is more or less identical to Site 14B (upstream of the market garden outlet). This suggests that the runoff from the market gardens, with high phosphorus loads, is causing a localised impact on water quality at the pipe outlet at Site 14 within the pond, but that the pond is assimilating and retaining the phosphorous within the pond. During a major wet weather event in April 2012, there was a very high reading of 14mg/L nitrogen at Site 14. However, drawing conclusions from one sample should be used with caution as this is from a single grab sample during wet weather events.


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Figure 16: Total phosphorous (TP) Averages for Scarborough Ponds sub-catchment (July 2012

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Figure 17: Total nitrogen (TN) Averages for Scarborough Ponds sub-catchment (July 2012 –

January 2013) In addition to the high nutrient levels Site 14 showed elevated levels of metals with copper up to three times the 80% protection level and chromium above the 95% protection level. Arsenic was also commonly found with one event greater than the 95% protection level.


In addition high levels of copper and zinc as commonly found across the LGA, Site 9 had one event with cadmium concentration greater than the 95% protection level. . Australian Runoff Quality (Engineers Australia, 2006) suggests potential sources of cadmium include “the wear of vehicle tyres and brake pads, lubricating oils, metal industry and domestic products, pesticides, fertilisers and agricultural chemicals”.

4.3.6 Waradiel Creek (Site 12)

Sampling was taken at one site (Site 12 – Peter Depena Reserve, Sandringham) within the Waradiel Creek sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. Site 12 is an estuarine channel that is subject to tidal flushing. Apart from some low dissolved oxygen events leading to an average DO of 4.5 mg/L or 54% saturation, Site 12 had few reportable water quality issues. One sampling event found an elevated Nickel reading, though it was just below the 95% protection level.

4.3.7 Bado Berong Creek (Sites 10 & 11)

Sampling was taken at two sites within the Bado Berong sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. These locations included (from upstream to downstream) Site 10 – Russell Avenue, Sans Souci and Site 11 - Soult Street, Sans Souci. Both Sites 10 and 11 are tidally influenced. The dissolved oxygen levels found at Site 10 were very low, with an average of 2.5mg/L or 26% saturation. Site 11 was slightly better with an average of 4.7mg/L and 57% saturation. Site 11 was often observed to have an organic odour that could be associated with organic degradation which may also lead to low DO levels. Whilst it was not located on GIS data there was anecdotal evidence (from a local resident) that there have been possible sewer overflows in the vicinity of Site 10.

4.3.8 Goomun Creek (Site 13) Sampling was taken at one site (Site 13 – Kendall Street Reserve, Sans Souci) within the Goomun Creek sub-catchment as shown in Figure 4: Location of the Water quality monitoring sites within Rockdale City Council. Kendall St Reserve was formerly a market garden then turned into a landfill site which has since been capped, covered with topsoil and is currently used as a sports field. Landfills are a well known source of ammonia in groundwater due to the anaerobic breakdown of organic matter creating soluble ammonia which is then leached out of the landfill if it is not properly contained. Site 13 recorded:

• TN levels of 3 mg/L in dry weather • TKN levels of 2.7 mg/L in dry weather

The high levels of TKN are almost certainly due to high levels of ammonia coming from the landfill.


4.4 Standout water quality indicators

4.4.1 Nutrients The sites found to have elevated levels of nutrients are generally addressed within Section 4.3. Figure 18 shows a summary of the average TN concentrations at Sites 7 - Spring Street Channel, West Botany Street, Rockdale, Site 8 - Bicentennial Park Pond, President Avenue, Rockdale and Site 13 - Goomun Creek, Kendall Street Reserve, Sans Souci, compared to typical values for urban stormwater for dry and wet weather conditions for total nitrogen. It shows the elevated levels of nitrogen at each of these sites compared to typical urban stormwater values (and the significant ‘flushing’ of Site 8 in large wet weather events). These three sites are compared as these are the other outliers aside from the Bardwell Creek sites. All other sites were within the range expected of typical urban stormwater.

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Figure 18: Sites 7, 8 and 13 with elevated nitrogen levels

4.4.2 Heavy Metals Heavy metals can be toxic to humans and fauna. Australian Runoff Quality (Engineers Australia, 2006) suggests potential sources of copper include wear of vehicle tyres and brake pads, the metal industry and domestic products. Zinc can also come from wear of vehicle tyres and brake pads or corrosion of metal objects or weathering of galvanized roofing. These metals are unlikely to be point sources, but diffuse pollutants generated throughout catchments. Most sites were found to have non-detectable levels of many of the heavy metals tested. The ANZECC protection level (99%, 95%, 90% or 80%) signifies the percentage of species expected to be protected. For example if the water quality is maintained below the 95% protection level, then 95% of species are assumed to be protected. If the water quality exceeds the 80% protection level then less than 80% of species are assumed to be protected; it is assumed that at least 20% of the species are at risk of harm or death.


Table 4: Heavy metals summary highlights that most of the heavy metals concentrations were relatively low compared to the ANZECC. Figure 19 shows that a significant number of sites had many samples exceeding the 80% protection level for copper. Figure 20 shows that many sites had a number of events where zinc concentrations were greater than the 95% protection level and some with concentrations greater than the 80% protection level. In addition, Site 14 – Scarborough Ponds, Scott Street, Monterey was found to have high concentrations for arsenic and chromium, which could be associated with pesticide or fertilizer use in the market garden. Table 4: Heavy metals summary Analyte Number of samples

where concentration was less than the detection level

(of 112 samples)

Sites which experienced concentrations greater than the ANZECC 95%

protection level (Site – number of events)

Sites which experienced concentrations greater than the ANZECC 80%

protection level (Site – number of events)

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Chromium 102 14 – 2

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Copper 35 Refer Figure 19 Refer Figure 19 Lead 93 - - Nickel 58 - - Zinc 28 Refer Figure 20 Refer Figure 20

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4.4.3 Total Suspended Solids (TSS) Total suspended solids (TSS) concentrations were generally low, with the exception of some outlying events. The only site that experienced consistently high TSS levels was Site 15 – Levey Street Wetland, Levey Street, Wolli Creek, which is a poorly flushed small mangrove wetland. High concentrations of suspended solids were also experienced during dry weather. The foremost incident at Site 1 – Wolli Creek, Bonalbo Street, Kingsgrove, on 27 September 2012, as shown in Figure 21, may have been the result of construction works.

Figure 21: Site 1 – Wolli Creek, Bonalbo Street, Kingsgrove, high TSS event September 27 2012 (Left) and normal low flows (Right)


4.4.4 Pathogens The average results for Enterococci for the different sampling conditions are shown in Figure 23. A chart showing complete statistical results is provided at Figure 61 in Part B: Appendices; Appendix D: Complete results tables and charts. Enterococci levels were relatively high at some sites, with readings up to 25,000 CFU/100mL during wet weather. Note that enterococci concentrations in raw sewage are around 105 – 106 (NHMRC, 2008, p.61). As expected, Figure 23 shows that the enterococci counts were much higher in the significant wet weather event compared to ‘semi-wet’ and dry weather. Site 12 - Waradiel Creek, Peter Depena Reserve, Sandringham and Site 15 - Levey Street Wetland, Levey Street, Wolli Creek also experienced relatively high enterococci counts in dry weather. Figure 22 shows there are a large number of potential sewer overflow locations within the Rockdale LGA from the Sydney Water sewerage system. These are typically only activated in significant wet weather events. However, the study revealed some sites with high enterococci results are not explained by the overflow points. For example, Site 14 - Scarborough Ponds, Scott Street, Monterey has a very high enterococci reading in wet weather, but Council has no record of a sewer overflow point upstream of Site 14. This indicates that either the database of overflow points may not be complete or the source of enterococci could be from domestic pets or wildlife.


- WQ monitoring site - Sub-catchment boundary - Sewer overflow point

Figure 22: Water quality sites with all potential sewer overflow locations


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City of Rockdale Water Quality Monitoring Study – Report 2013 42

5. Comparison of 2012 Rockdale Water Quality to Previous Studies

Results for key parameters are presented in this section and compared with the results of previous Rockdale water quality studies. Note that Site 14 – Scarborough Ponds, Scott Street, Monterey; Site 15 – Levey Street Wetland, Levey Street, Wolli Creek; Site 16 – Wolli Creek, Slade Road, Bardwell Valley and Site 17 – Bardwell Creek, Hillcrest Avenue, Bardwell Valley were first sampled in 2012 and so are not included in this analysis. Summary data comparing the mean values for pollutants sampled in the 1999 and 2012 studies are provided in Table 5. The values highlighted are those where a statistically significant difference was found using the t-test. Whilst there are many sites for which the mean values differ, the variance and low number of samples (particularly for wet weather) resulted in the test for significance not being met. The following section describes the key observed trends for total nitrogen, total phosphorous and total suspended solids. These parameters were analysed because these are the key indicators of stream water quality. Charts comparing all parameters are provided in Part B: Appendices; Appendix E: Charts comparing results of previous water quality studies.

5.1 Total Nitrogen Summary Figure 24 and Figure 25 shows the statistics for TN in different conditions across the 1999, 2007 and 2012 water quality studies. They show the following key trends: Site 4 – Bardwell Creek, Pile Street, Bardwell Valley – the high dry weather TN concentrations

are the same in 2012 (average of 20.3 mg/L) as they were in 1999 (average of 20.7 mg/L). Similarly, the downstream Sites 3 (and Site 2 – Wolli Creek) show elevated TN levels in both studies, though dilution occurs downstream of Site 4.

Site 5 – Bardwell Creek, Ellerslie Road, Bardwell Valley – 1999 wet weather TN was much higher than 2012. The average wet weather TN concentration for Site 5 in 1999 was 5.9 mg/L (from 3 events), and the single wet weather event in 2012 had a TN concentration of 2.7 mg/L. However grab sampling results in wet weather can be misleading due to the fluctuations in water quality during the event.

Site 6 – Bardwell Creek, Croydon Road, Hurstville – 1999 wet weather TN was much higher than 2012. The average wet weather TN concentration for Site 6 in 1999 was 7.1 mg/L (from 3 events), and the single wet weather event in 2012 had a TN concentration of 2.4 mg/L. However as per Site 5, this is not conclusive due to the limited number of event samples.

Site 7 – Spring Street Channel, West Botany Street, Rockdale – High TN levels similar in 1999 (average of 6.1 mg/L) to 2012 (average of 6.7 mg/L).

Site 8 – Bicentennial Park, President Avenue, Rockdale – High TN levels relatively consistent across 1999 (average of 6.9 mg/L), 2007 (average of 7.0 mg/L), 2010 (average of 9.3 mg/L) and 2012 (average of 6.6 mg/L).

Site 13 - Goomun Creek, Kendall Street Reserve, Sans Souci – TN levels were much higher in 1999 (average of 10.1 mg/L) compared to 2012 (average of 3.0 mg/L). This could possibly suggest improvement as landfill matures. The nutrient load from landfills decreases over time as the organic material is digested.

All other sites have similar normal levels as with previous studies.


5.2 Total Phosphorous Summary Figure 26 and Figure 27 shows the statistics for TP in different conditions across the 1999, 2007 and 2012 water quality studies. They show the following key trends: Sites in Bardwell Creek (Sites 3, 4, 5 & 6) in wet weather events in 1999 appear to have experienced much higher TP concentrations than in 2012. This could be event specific, as the nutrient loads during individual wet weather events can vary substantially, particularly when only single grab samples are taken.

Site 8 – 1999 was normal, 2007 & 2010 very high, and 2012 back to moderately high All other sites similar normal levels

5.3 Total Suspended Solids Summary Figure 28 and Figure 29 shows the statistics for TSS in different conditions across the 1999, 2007 and 2012 water quality studies. They show the following key trends:

Site 1 – had high wet (307mg/L) and dry weather (394 mg/L) events in 1999, but normal concentrations in 2012 apart from the dry weather 200 mg/L event (suspected of being building site pump out).

Site 5 – had an extreme wet weather event (1860mg/L) in 1999, but normal concentrations in 2012.

Site 8 – had some extreme events in 2007 & 2010, but normal concentrations in 2012. All other sites similar normal levels.


Table 5: Comparison of means from 1999 and 2012 studies

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6. Comparison of Rockdale Water Quality to other Local Government Areas

Water quality monitoring data was collected from a range of Councils across Sydney as well as Sydney Water’s monitoring data. The sites are all from urban and semi urban freshwater streams, with varying degrees of imperviousness, native vegetation cover, differing channel and riparian forms. Data was generally from grab sampling and given that some data sets did not differentiate between wet and dry samples all data was combined. Whilst data was sourced for 200 water quality monitoring sites, not all sites were included in the analysis. The sites excluded from the analysis were:

– estuarine – downstream of STP’s – with less than 6 monitoring events – within National Parks (non-urbanised)

For each site, the average, median and 80th percentile concentrations were calculated for TSS, TP, and TN. These parameters were chosen for the initial analysis given their impacts on stream environments and their use in urban water quality modelling. Figure 31, Figure 32 and Figure 33 show statistical data for each of the water quality monitoring sites in Sydney, with the sites ordered according to their median water quality value (shown as a blue bar). The average values for each monitoring site are included (shown as a green triangle symbol), and often indicate where outlying sampling events have occurred, where the average value is much greater than the median value. This indicates that the average value is not representative of the typical water quality.

6.1 Summary of data and benchmarks A summary of the statistical data from all the Sydney water quality sites is shown in Table 6. The typical median and 80th percentile values have been chosen as suggested benchmark values for assessing urban stream water quality in Sydney as shown in Table 7, and described as follows:

– Any sites with a median water quality monitoring value less than the ANZECC guideline value should be considered ‘excellent’.

– Any sites with a median water quality monitoring value between the ANZECC guideline value and the median water quality value for Sydney are considered as ‘good’.

– Any sites with a median water quality monitoring value between the median and 80th percentile water quality values for Sydney are considered as ‘poor’; and

– Any sites with a median water quality monitoring value greater than the median 80th percentile water quality value for Sydney are considered as ‘very poor’.

These benchmarks are shown graphically in Figure 30. The data from which the benchmarks have been developed includes some sites where the upstream catchment has a relatively low catchment imperviousness. The benchmarks attempt to capture the entire range of sites and environments found in Sydney. As such the Rockdale sites are being compared to some sites that are in better condition and may be expected to have different water quality.


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6.2 Total Suspended Solids Summary For TSS there was data available for 73 Sydney sites. In Figure 31 Site 15 – Levey Street Wetland, Levey Street, Wolli Creek, is reported as being the worst performing site in all of the Sydney water quality data. However, this site is not a typical urban stream as it is a poorly flushed estuarine wetland. As shown in Figure 34, based on the suggested Sydney urban stream benchmarks, of the 13 freshwater sites in Rockdale 4 are classified as ‘good’, 8 are ‘poor’ and 1 is ‘very poor’.

6.3 Total Phosphorous Summary For TP there was data available for 159 Sydney sites. Figure 32 shows that Site 8- President Avenue, Rockdale and Site 10– Russell Avenue, Sans Souci are amongst the worst performing sites in all of the Sydney sites. However, some Rockdale sites, such as Site 17 - Hillcrest Avenue, Bardwell Valley and Site 4 - Pile Street, Bardwell Valley have TP concentrations typical of the Sydney urban streams included in the analysis. As shown in Figure 35, based on the suggested Sydney urban stream benchmarks, of the 13 freshwater sites in Rockdale 6 are classified as ‘good’, 5 are ‘poor’ and 2 are ‘very poor’.

6.4 Total Nitrogen Summary For TN there was data available for 150 sites. Figure 33 shows that Sites 3, 4, 7 and 8 are the worst performing sites for TN when viewed in comparison to other urban streams in Sydney. As shown in Figure 36, based on the suggested Sydney urban stream benchmarks, of the 13 Rockdale freshwater sites 5 are ‘poor’ and 8 are ‘very poor’.

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7. Conclusion The study has shown that in Rockdale LGA there are several waterways that are performing significantly worse than typical degraded urban streams impacted by urbanised catchments and diffuse stormwater pollution as shown by the benchmarks developed in Section 6. These are Bardwell Creek (at Bardwell Valley Golf Course), Spring Street Channel Market garden drain within A.S. Tanner reserve (Scarborough Ponds), Kendall Street Reserve and Bicentennial Park Wetland. Council will continue to investigate opportunities to improve water quality at theses sites as well as throughout the LGA.

Several activities have already been undertaken or are currently in development to improve water quality within Rockdale LGA and include:

• Improved maintenance of Gross Pollutant Traps, litter traps – reduces the amount of gross litter such as plastic bottles and bags from entering our waterways,

• Installation of a rain garden at Gilchrist Park, Bexley North – rain gardens treat local stormwater to remove chemicals, nutrients and sediment, allows water retention and absorption (replenishes the water table),

• Installation of a rain garden and creek bank revegetation at Coolibah Reserve, Bardwell Valley - creek bank revegetation provides erosion control during flooding events and increases the vegetation corridor for small bird and animal habitat,

• Installation of floating reed beds at Bicentennial Park, Rockdale - floating reed beds are rafts of vegetation used in lakes to treat water quality issues and reduce algal blooms,

• Upgrade of aeration devices in Scarborough Ponds. Monterey – replenish low oxygen levels lower in the water column helping to minimise odour issues and reduce anaerobic conditions,

• Community education programs (eg. Drain is just for rain)

Rockdale LGA Water Quality Monitoring – Summary Report 62

8. References ANZECC Guidelines (2000), Australian and New Zealand guidelines for fresh and marine water quality, National Water Quality Management Strategy paper No. 4, Australian and New Zealand Environment and Conservation Council, October 2000, available at: http://www.environment.gov.au/water/policy-programs/nWater Qualityms/ ANZECC (Australian and New Zealand Environment and Conservation Council) (1992). Australian and New Zealand guidelines for fresh and marine waters. Australian and New Zealand Environment and Conservation Council, Canberra. Conacher Travers Pty Ltd (2006), Rockdale Biodiversity Survey, prepared for Rockdale City Council Engineers Australia (2006), Australian Runoff Quality – A guide to Water Sensitive Urban Design. Nalco (2008), Water Quality Data Analysis - October 2007 to May 2008; prepared for Rockdale City Council Rockdale City Council (1999), Water Quality Monitoring Report. Sampling and analysis by AWT Science, Technology and Environment; Final report prepared and published by Rockdale City Council Rockdale City Council (2010-2011), State of Environment – Supplementary Report SEQ Healthy Waterways; Methods and indicators, available at: http://www.healthywaterways.org/EcosystemHealthMonitoringProgram/ProgramComponents/FreshwaterMonitoring/MethodsandIndicators.aspx Sittig, M 1985. Handbook of Toxic and Hazardous Chemicals and Carcinogens. 2nd ed. Noyes Publications. Streamwatch (2003), The Streamwatch Manual – 3rd Edition, Available at: http://www.streamwatch.org.au/cms/resources/ Sydney Water (2011) Water quality testing FAQ’s and glossary, available at: http://www.sydneywater.com.au/web/groups/publicwebcontent/documents/document/zgrf/mdq2/~edisp/dd_046373.pdf Walsh, C. J., Leonard, A. W., Ladson, A. R. and Fletcher, T. D. (2004) Urban stormwater and the ecology of streams, Cooperative Research Centre for Freshwater Ecology and Cooperative Research Centre for Catchment Hydrology, Canberra, ACT. WA Department of Water, Background information for measured parameters (website); http://www.water.wa.gov.au/idelve/srwqm/measured.htm

Documents

City of Rockdale Water Quality Monitoring Study - Part … of Rockdale Water Quality Monitoring – Report 2013 3 Table of Contents 1. Executive Summary 5 2. Introduction