Lower Hunter River Health Monitoring Program Legacies of a century of industrial pollution and its impact on the current condition of the lower Hunter River estuary

© 2017 State of NSW and Office of Environment and Heritage With the exception of photographs, the State of NSW and Office of Environment and Heritage are pleased to allow this material to be reproduced in whole or in part for educational and non-commercial use, provided the meaning is unchanged and its source, publisher and authorship are acknowledged. Specific permission is required for the reproduction of photographs. The Office of Environment and Heritage (OEH) has compiled this report in good faith, exercising all due care and attention. No representation is made about the accuracy, completeness or suitability of the information in this publication for any particular purpose. OEH shall not be liable for any damage which may occur to any person or organisation taking action or not on the basis of this publication. Readers should seek appropriate advice when applying the information to their specific needs. All content in this publication is owned by OEH and is protected by Crown Copyright, unless credited otherwise. It is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0) , subject to the exemptions contained in the licence. The legal code for the licence is available at Creative Commons . OEH asserts the right to be attributed as author of the original material in the following manner: © State of New South Wales and Office of Environment and Heritage 2017.

This report was written and researched by Rebecca Swanson, Jaimie Potts and Peter Scanes. It was funded in part by an environmental service order issued to Orica Australia Pty Ltd by the NSW Land and Environment Court. Prepared for the NSW Environment Protection Authority.

Citation: Swanson RL, Potts JD & Scanes PR 2017, Legacies of a century of industrial pollution and its impact on the current condition of the lower Hunter River estuary, Office of Environment and Heritage, Sydney.

Published by: Office of Environment and Heritage 59 Goulburn Street, Sydney NSW 2000 PO Box A290, Sydney South NSW 1232 Phone: +61 2 9995 5000 (switchboard) Phone: 131 555 (environment information and publications requests) Phone: 1300 361 967 (national parks, general environmental enquiries, and publications requests) Fax: +61 2 9995 5999 TTY users: phone 133 677, then ask for 131 555 Speak and listen users: phone 1300 555 727, then ask for 131 555 Email: [email protected] Website: www.environment.nsw.gov.au

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ISBN 978 1 76039 637 4 OEH 2017/0190 August 2017

Find out more about your environment at: www.environment.nsw.gov.au Contents

Executive summary ...... vii 1 Introduction ...... 1 1.1 Purpose of this report ...... 1 1.2 Study area ...... 1 1.3 Structure of review ...... 2 2 Pressures ...... 4 2.1 Industry – past and present ...... 4 2.2 Water pollution in the Hunter River ...... 5 2.3 Agricultural land use ...... 5 2.4 Urbanisation ...... 6 2.5 Mining and power industries ...... 7 2.6 Legacies of heavy industry ...... 7 2.7 Contaminated sites ...... 8 2.8 Current impacts of shipping and industry ...... 17 2.9 Regulation of water pollution ...... 18 2.10 Urban inputs ...... 26 2.11 Pollutant export rates ...... 27 2.12 Inputs from the wider catchment ...... 27 3 Condition ...... 28 3.1 NSW water quality objectives and national water quality guidelines 28 3.2 Historical condition measures ...... 29 3.3 Recent condition measures ...... 39 4 Conclusions and recommendations ...... 69 References ...... 71

iii

iv Abbreviations used in this report

ANZECC Australian and New Zealand Environment Conservation Council ARQ Australian runoff quality ASS acid sulfate soils BHP Broken Hill Proprietary Company Limited BIA benzene impacted area BOD biochemical oxygen demand CCT Carrington Coal Terminal CMA catchment management authority CSIRO Commonwealth Scientific and Industrial Research Organisation CUTEP ‘clean-up to the extent practicable’ CVA Conservation Volunteers Australia DDE dichloro-diphenyl-dichloroethylene DDT dichloro-diphenyl-trichloroethane DIN dissolved inorganic nitrogen DPI NSW Department of Primary Industries EC electrical conductivity EIS environmental impact statement EPA NSW Environment Protection Authority EPL environment protection licence FBZ foreshore buffer zone HBOC Hunter Bird Observers Club HRRP Hunter River Remediation Project HRSTS Hunter River Salinity Trading Scheme HWC Hunter Water Corporation HWCA Hunter Wetlands Centre Australia ISQG interim sediment quality guidelines KIEF Kooragang Island Emplacement Facility LOR limit of reporting MER NSW Natural Resources Monitoring, Evaluation and Reporting Strategy MRL maximum residue limits NCC Newcastle City Council NCIG Newcastle Coal infrastructure Group NFA MRL National Food Authorities’ maximum residue limits + NH4 /NH3 ammonium/ammonia - - NOx nitrate (NO3 ) and nitrite (NO2 ) NPWS NSW National Parks and Wildlife Service

v NTU nephelometric turbidity units NWC Newcastle Wetland Connections NOW NSW Office of Water OCC organochlorine compounds OEH Office of Environment and Heritage PAH polycyclic aromatic hydrocarbons PCB polychlorinated biphenyls 3- PO4 phosphate PRP pollution reduction program PRZ primary remediation zone PSH phase-separated hydrocarbons PWCS Port Waratah Coal Services PWCS-CCT Port Waratah Coal Services Carrington Coal Terminal PWCS-KCT Port Waratah Coal Services Kooragang Coal Terminal RAP remediation action plan SOC State of the Catchments SOE State of the Environment TKN total kjeldahl nitrogen TN total nitrogen TOC total organic carbon TON total organic nitrogen TP total phosphorous TPH total petroleum hydrocarbons TSS total suspended solids TZ total zinc UNSW University of New South Wales VMP voluntary management proposal WRL UNSW Water Research Laboratory WWTW wastewater treatment works

vi Lower Hunter River Health Monitoring Program – Literature and data review

Executive summary In 2014 the NSW Land and Environment Court imposed penalties on Orica Australia Pty Ltd for a number of pollution incidents at their Kooragang and Botany facilities in 2010–11. The monetary penalty was paid to local and state government agencies to fund projects aimed at restoring and enhancing the environment for the benefit of affected neighbouring communities. Part of the Environmental Service Order was issued to the Office of Environment and Heritage (OEH) to implement the Lower Hunter River Health Monitoring Program which included: • a technical assessment of all environmental monitoring data to provide information about the past and current condition of the estuary (this document) • a water quality monitoring program to assess the current status of water quality in the estuary (Swanson et al. 2017a). Very little data had been collected since 2000, during which time land use and activities in the Port of Newcastle had changed considerably, and the population in the region has grown • a stormwater quality monitoring program in the lower estuary during or following rainfall between April and June 2015 to identify current sources of pollutants to the lower estuary (Swanson et al. 2017b). The relative contributions of industrial versus urbanised catchments to nutrient and sediment loads to the estuary is a current debate among stakeholders that requires investigation. There is also a real need from regulatory agencies for current water quality in the lower Hunter River estuary to be assessed, in order to guide future management and regulation of industries operating on the harbour. To complement the scope of the Lower Hunter River Health Monitoring Program, OEH undertook a preliminary ecological assessment in the lower to mid estuary in 2015–16 to assess whether ecological processes in the estuary were impaired as a result of decades of pollution (Swanson et al. 2017c). The main findings from the Lower Hunter River Health Monitoring Program and the OEH ecological assessment are summarised in a project summary report (Swanson et al. 2017d). Newcastle has been a large industrial centre since early last century. The Port of Newcastle is one of Australia’s largest ports in throughput tonnage, and is now the world’s largest port for exporting coal. The lower reaches of the Hunter River estuary at the South Arm, Throsby Creek and the Port of Newcastle are a degraded ecosystem. While there have been many documents produced that describe impacts of industry on the condition of the Hunter River, most of that literature is fragmented and focused on a single development or issue. There have been few attempts to collate the scattered literature into a cohesive description of the pressures and condition of the Hunter estuary. Regulation of wastes from the industrial areas was non-existent for most of last century and untreated industrial waste laden with acids, phenols, ammonium, cyanide and metals was discharged directly to the Hunter River. By the 1970s unregulated industrial pollution resulted in a chronic, as well as an acute, pollution problem. Environmentally destructive agricultural practices and urbanisation of the catchment delivered more pollutants to the estuary, such as sediment, nutrients and pesticides. Ambient concentrations of ammonium, nitrates and phosphates in the estuary from the 1970s to the 1990s were up to 50 times above the national water quality guidelines. Discharge of industrial waste to the estuary led to the enrichment of sediments with heavy metals, polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH) and organochlorine compounds (OCC). Continual dredging of port areas has removed much of the contaminant load from these areas, however, sediments in some undredged areas of the harbour and port are heavily contaminated with heavy metals, PAH, TPH and OCC, such as in Throsby Basin. Contaminated lands from current and former industrial sites still pose a threat to the health of the lower Hunter River estuary. While management of the remediation of these sites has improved, the remediation process is long, as evidenced in the remediation of the former

vii Lower Hunter River Health Monitoring Program – Literature and data review

BHP Steelworks site at Mayfield. This commenced in 2001 and is still ongoing in parts; it has involved up to 17 voluntary management proposals. The remediation of the sediments adjacent to the land-based site, which comprised a component of the larger remediation project, involved removing 800,000 cubic tonnes of contaminated sediments in the Hunter River adjacent to the site. Hunter Wetlands National Park is situated in the lower Hunter Estuary and extends from the suburb of Hexham in the west to Stockton and Fern Bay in the east. It is the largest wetland reserve (6248 hectares) within a single estuary in New South Wales and is managed by the NSW National Parks and Wildlife Service. The Hunter River estuary is recognised as the most important area in New South Wales for shorebirds, with a significant portion of the Hunter Estuary Wetlands listed under the Ramsar convention in 1984. The Hunter Estuary Wetlands Ramsar site is comprised of the Kooragang component of the Hunter Wetlands National Park (formerly Kooragang Nature Reserve) which was listed in 1984, and Hunter Wetlands Centre Australia (formerly Shortland Wetlands) which gained Ramsar listing in 2002. It is an unfortunate irony that large expanses of Ramsar-listed wetlands lie adjacent to the most heavily industrialised port in Australia. A number of wetland and shorebird habitat rehabilitation projects have occurred in the past two decades at Hexham Swamp, Kooragang Wetlands, Tomago – Fullerton Cove and at Shortland Wetlands, significantly improving the condition of these estuarine environments and the quality of habitats for fish, invertebrates and shorebirds. OEH implemented an estuary-wide water quality monitoring program between August 2014 and March 2015 to gain an insight into the current condition of the estuary. Standard water quality parameters and chlorophyll-a, total suspended solids (TSS) and nutrient data were collected on a monthly basis at 14 sites at the Hunter River extending from the estuary mouth to the upper estuary. The main findings were: • Median concentrations of chlorophyll-a were below 5 micrograms per litre (µg/L) at most sites in the routine monitoring program although concentrations as high as 30µg/L were occasionally recorded after rainfall. The highest median concentrations of chlorophyll-a of 3–7µg/L were recorded at mid-estuary sites which exceed NSW trigger values for coastal riverine estuaries (2.3–3.4µg/L chlorophyll-a depending on salinity). • Median concentrations of chlorophyll-a in the mid to upper estuary were considerably lower than the historical median of approximately 15µg/L (pre-2000). Chlorophyll-a concentrations in the lower estuary in 2014–15 were comparable to historical data. • Aside from the occasional spikes in chlorophyll-a, the proportional increase in chlorophyll-a concentrations that we would expect to see in response to elevated nutrient concentrations is not observed in the Hunter River estuary. Shorter residence times of waters in the lower estuary due to flushing with oceanic water may also help to reduce chlorophyll-a concentrations in the lower estuary. • Nutrient concentrations have decreased in the estuary from pre-2000 levels, however, - - concentrations of NOx (nitrate [NO3 ] and nitrite [NO2 ]) and phosphates in 2014–15 were typically well above NSW trigger values for coastal riverine estuaries, with fewer exceedances for ammonium. • Median concentrations of ammonium were highest in the South Arm suggesting that industry is the primary source of ammonium to the estuary. Median concentrations of nitrates and phosphate increased with distance upstream implicating agriculture and intensive horticulture as the dominant source of these nutrients to the estuary. • Turbidity was often below 5 nephelometric turbidity units (NTU) in surface waters of the lower estuary, exceeding NSW trigger values of 2.8–3.5NTU for coastal riverine estuaries. Median values for turbidity increased slightly with distance upstream with occasional high readings following rainfall (>50NTU). Turbidity in the Hunter River estuary may contribute to lower than expected chlorophyll-a concentrations (given the high levels of bioavailable nutrients).

viii Lower Hunter River Health Monitoring Program – Literature and data review

Water quality data collected during the monitoring program was in line with the NSW Natural Resources Monitoring, Evaluation and Reporting Strategy (MER) and protocols, allowing the data to be used to generate ‘report card’ grades for the Hunter River estuary based on comparison to the statewide MER dataset (OEH 2016). Grades in report cards are based on a combined score for water quality (only using turbidity and chlorophyll-a data) and, if present, seagrass distribution in the estuary. Seagrass does not grow in the Hunter estuary so other biological indicators need to be assessed in the future to provide a more comprehensive assessment of the estuary health. Based on water quality alone, the lower Hunter River estuary scored a ‘B’ grading, while the mid and upper estuaries both scored a ‘C’ grading (Swanson et al. 2017a; OEH 2016). The 2014 upper estuary grade ‘C’ can be directly compared to the MER grades for the Hunter River estuary for 2010 (‘D’) and 2013 ('C'). Water quality may have improved in the upper estuary since 2010, however, the ‘D’ grading was likely to have been influenced by breaking drought conditions impacting water quality. Water quality in the lower estuary has improved greatly in the past 15 years with the closure of the BHP Steelworks, tighter monitoring and regulation of industrial discharges, and improvements in industrial site management leading to a reduction in pollutant loads in stormwater. While the lower estuary scored a ‘B’ grading for water quality it is important to realise this grade is based solely on turbidity and chlorophyll-a data, and does not take into account the high concentrations of ammonium, NOx and phosphate, which always exceeded NSW trigger values in the lower estuary. A grade of ‘B’ for the lower estuary may be an overly optimistic score. Despite the persistently high concentrations of inorganic nutrients in the water column, chlorophyll-a levels are not as high as one would expect and algal blooms are rarely seen in the Hunter River estuary. This observation may be the outcome of multiple stressors (turbidity, high nutrient concentration, dissolved metals) acting synergistically to negate the optimal growth of microalgae. Stormwater delivers pollutants from the catchment to receiving waters. OEH implemented an event-based stormwater quality monitoring program in 2014–15 to identify current sources of pollutants to the lower estuary. The program confirmed that industrial sites are indeed a major source of ammonium, nitrates and nitrites (NOx) and phosphates to the lower Hunter estuary, with stormwater runoff for these sites delivering high concentrations of nutrients to localised patches of the estuary. Industrial sources of ammonium and NOx are more widespread (metal, chemical and fertiliser industries) than are sources of phosphate, which in the lower estuary appear to be localised to fertiliser-based industries on Walsh Point and Kooragang Island. In addition to stormwater, ammonium and nitrates are a common by- product of industry and are also a component of process water discharged to the estuary from licensed and unlicensed premises. Concentrations of dissolved inorganic nutrients always exceeded NSW trigger values (and Australian and New Zealand Environment and Conservation Council [ANZECC] guidelines) with the highest concentrations reported in receiving waters of the Walsh Point precinct. One would expect trigger values to be exceeded in receiving waters following rainfall events, but if concentrations are 100 or 1000 times (two or three orders of magnitude) above trigger values then significant localised impacts on the biota in the nearshore habitats are highly probable. High levels of zinc and manganese occur after rainfall in creeks, the South Arm and in port areas, approaching and occasionally exceeding ANZECC guidelines for 80% protection of marine species. Zinc is a common constituent in stormwater and process water discharged from industrial sites. Industrial discharges from secondary metal fabrication and the distribution/export of metal concentrates and roofing in urban areas are likely sources of zinc. Machine wear and tear from vehicles in urban areas, and on-site practices and contaminated landfill in industrial areas, are likely sources of manganese. High concentrations of dissolved copper were widespread in the lower estuary approaching and occasionally exceeding ANZECC guidelines (80% protection level). Leaching of dissolved copper from anti-fouling coatings on ship hulls is a likely constant source as well as fabrication, handling and distribution of metal concentrates. Arsenic is a common by-product of heavy industry and

ix Lower Hunter River Health Monitoring Program – Literature and data review moderate concentrations of arsenic were measured in port areas. Contaminated groundwater at Walsh Point may be contributing to arsenic levels in the South Arm. Newcastle’s industrial past has led to higher than usual background concentrations of metals in the Hunter River, which is unlikely to change with continued inputs from industrial discharges, shipping and port operations. Contaminated sediments in industrial areas (past and current) which are not dredged (e.g. Throsby Creek, Throsby Basin, mid to upper South Arm), and contaminated lands infilled with steelmaking waste during port development, are likely to be contributing to the metal load in the estuary. High concentrations of nutrients nitrate and ammonium, dissolved zinc and manganese, and high counts of faecal coliforms, were recorded in the upper reaches of Throsby Creek after rain events. Population growth will lead to increased inputs of pollutants from urban sources, including nutrients, TSS and faecal coliforms, in urban runoff and sewage treatment wastewater discharges. Diffuse inputs of pollutants from the urban catchments in the lower reaches of the estuary are substantial. Total loads (amounts) of nutrients exported from the agricultural land use in the upper catchment, however, far outweighs total loads exported to the estuary from the lower urbanised and industrialised catchments. Best practice and behaviour change may lead to reductions in diffuse pollution from agricultural and urban areas; this will require continued efforts by local councils and landcare groups in identifying and managing sources and educating the community. There have been great gains in the past five years in reducing the pollutant loads being discharged from licensed industrial premises, through the implementation of pollution reduction programs (PRPs). Tighter regulation of industrial discharges, improved on-site practices through PRPs and remediation of contaminated lands and sediments over the past 15 years have considerably improved the condition of the lower Hunter River estuary. Concentrations of nitrates and ammonium in the main channel of the lower South Arm are likely to be 5 to 10 times lower than before 2000. Point source pollution from industrial sites, however, contributes large amounts of pollutants daily to the lower estuary in wastewater and stormwater discharges. Point source pollution differs from diffuse pollution as it is a constant source of pollutants to the estuary resulting from continuous discharges of wastewater. Point source pollution is also easier to manage and reduce than pollution from diffuse sources. Monthly monitoring of stormwater quality discharged from licensed premises is usually a condition of the environment protection licence (EPL) granted by the NSW Environment Protection Authority (EPA). Concentration limits on stormwater discharges are, however, rarely applied. Where concentration limits on stormwater discharges are not a condition of the licence, the licensee must comply with section 120 of the Protection of the Environment Operations Act 1997, i.e. they are required by law to not pollute waters. Stormwater runoff from licensed premises is undoubtedly polluting waters, and has been shown to contain very high concentrations of pollutants. Large volumes (kilolitres) of treated wastewater are discharged daily from some licensed premises. While concentration limits apply to licensed discharge points, total loads can be in the order of tonnes per year that are being discharged to the estuary. Setting concentration limits for pollutants in stormwater discharges from licensed premises, reducing the volumes of wastewater and stormwater discharges, and increasing the frequency of monitoring, are critical steps towards future tighter regulation of industrial pollution by the EPA. The water quality data collected during this program forms a baseline dataset against which future developments in the lower catchment can be assessed. MER assesses the health of the upper Hunter River estuary every three years, however, more frequent monitoring of all regions of the estuary is recommended to build a long-term dataset which can be used by stakeholders to detect change in condition as a result of management and regulatory actions in the heavily urbanised and industrialised catchment. OEH undertook a preliminary ecological assessment in the lower estuary in 2015–16, however, further investigations of biological indicators (for e.g. fish and macroinvertebrate assemblages, sediment microbial function) are required.

x Lower Hunter River Health Monitoring Program – Literature and data review

1 Introduction

1.1 Purpose of this report The Hunter River and its estuary have a long history of human use and, unfortunately, misuse and contamination. There have been many documents produced that describe aspects of the impacts upon and condition of the Hunter River, but most of that literature is fragmented and focused on a single development or issue. There have been few attempts to collate the scattered literature into a cohesive description of the pressures and condition of the Hunter River estuary. The purpose of this report is to describe briefly what is known about the pressures on the estuary, how those pressures have been managed and how the condition of the estuary has changed over the past 50 years.

1.2 Study area The Hunter River drains one of the largest coastal catchments in New South Wales with a total area of 22,000 square kilometres. It flows through a landscape of agricultural lands with a large number of coalmines and includes some of Australia’s earliest townships at Morpeth and Maitland, discharging to the Tasman Sea at the Port of Newcastle (Figure 1). The Hunter River estuary includes the tidal section of the Hunter River (and its tributaries) which extends 64 kilometres inland to the tidal limits at Oakhampton (Hunter River), Gostwyck (Paterson River) and Seaham Weir (Williams River). The lower Hunter River estuary includes Newcastle Harbour and the Port of Newcastle, Throsby and Styx creeks, North Arm and South Arm (the north and south arms of the Hunter River) to Hexham. Newcastle is located at the mouth of the Hunter River with surrounding suburbs primarily located on the southern side of the river from the city centre to Hexham. Port areas take up a large proportion of riverside land use and include approximately half of South Arm, one-third of Kooragang Island, Throsby Creek and Newcastle Harbour. Banks of the North Arm are largely dominated by Hunter Wetlands National Park and natural mangrove areas. The industrial area of Tomago and the urban area of Stockton are also located on the north arm of the river (Figure 1). Australia’s first exported commodity, coal, was shipped out of Newcastle Harbour in 1799 bound for India, making Newcastle Australia’s first commercial shipping port. Commercial shipping began in the navigable section of the Hunter River soon after the settlement of Morpeth in 1821. Steamships carried passengers from Newcastle to Morpeth from 1824 with a regular service between Sydney and Morpeth commencing in 1831. Morpeth was a bustling trading centre in the mid to late 1800s with ‘every sheepskin, bale of wool, hide, cask of tallow from as far afield as Queensland … at one time shipped from Morpeth’ (Blaxell 2006). Dredging of the Hunter River began as early as 1845 while dredging of Newcastle Harbour began around 1858. Today, port areas require continual dredging to maintain deep water access for shipping operations, removing 250,000–450,000 cubic metres of dredge spoil annually which is then dumped offshore. Large amounts of sand and silt are carried down the Hunter River with river flows, particularly during flood flows, leading to high rates of siltation and infilling of the estuary and harbour, and the loss of seagrass habitat. These are natural processes that have been accelerated by land-use practices in the upper catchment.

1 Lower Hunter River Health Monitoring Program – Literature and data review

1.3 Structure of review The NSW Government has guidelines for monitoring the condition of the State’s natural resources which are outlined in the NSW Natural Resources Monitoring, Evaluation and Reporting Strategy, or MER program (OEH 2016). These guidelines specify two components to assessing estuary health – the first is to determine the pressures on the system, that is, what is the land use in the catchment and what are the associated inputs of pollutants. Different land uses in the catchment result in different inputs of pollutants to the estuary. The other main component to assessing estuary health is to assess the condition of the ecosystem, which can be inferred from the response of biological indicators to the pressures on the system. Water quality in part reflects inputs coming into the system, however, a suite of biological indicators (chlorophyll-a, macrophyte condition and distribution, sediment microbial function, and fish condition and assemblages), are used to assess the condition of estuaries. Management of the estuary and its catchment by government agencies (BMT WBM 2009), through the allocation of reserved lands and conservation areas, for example, leads to benefits in estuary condition by encouraging biodiversity and enhancing ecosystem and community values. This review is divided into two main sections: • Pressures • Condition.

2 Lower Hunter River Health Monitoring Program – Literature and data review

Figure 1: The Hunter River estuary showing tidal limits (yellow circles) and the wider catchment (Photo: Glamore et al. 2014)

3 Lower Hunter River Health Monitoring Program – Literature and data review

2 Pressures

2.1 Industry – past and present The Broken Hill Proprietary Company Limited (now BHP Billiton) established its blast furnaces and steelworks on the south banks of the Hunter River at Mayfield North in 1915. Deepwater facilities allowed anchorage of ships loaded with iron ore for smelting and export of their iron and steel products. BHP Steelworks became an iconic feature of the landscape and identity of Newcastle until it closed its primary operations in 1999. Industrialisation and World War II saw the development of other heavy industry in Newcastle in the 1930s to 1940s with continued growth into the 1950s. With economic growth booming in the Newcastle region in the 1950s, new land was needed to extend and improve port facilities. Reclamation works began in 1951 to transform a series of low-lying intertidal islands bounded by the North Arm and South Arm of the Hunter River, into a single landmass known today as Kooragang Island. The NSW Department of Public Works declared Kooragang Island a heavy industry zone in 1966, and by 1994 one third of the island was used for industry. In 1983, remaining areas on Kooragang Island were designated a nature reserve after the realisation that estuarine wetlands are vital to the ecology of the Hunter River estuary. Newcastle became a large industrial centre with the region supporting a wide range of primary, secondary and tertiary industries involved with agriculture, mining, manufacturing and transport. While coal, iron and steel products dominated export tonnage, the Port of Newcastle handled a wide variety of bulk and general cargoes, such as phosphatic rock, alumina, limestone, timber, crude tar, petroleum, dolomite and cement. Forgacs Shipyard operated the State’s only dockyard as a floating dock in Newcastle Harbour from 1978–2013, which serviced Navy and trading vessels. Other industries in the lower Hunter region included engineering and fabrication, aluminium production (Tomago, Kurri-Kurri and Cessnock), manufacture of motor vehicles, electrical appliances, textiles and clothing, manufacture of sulfuric acid, fertilisers, compressed gases, asphaltic products, pharmaceutical products and industrial chemicals, production of electrolytic manganese dioxide at BHP’s electro-motive diesel plant, clay products (BHP refractories) magnetite and industrial minerals (at Sandgate). The Port of Newcastle is one of Australia’s largest ports in throughput tonnage, and is now the world’s largest port for exporting coal, exporting 159 million tonnes in 2014. The Port is the economic and trading centre for coal mined from the Hunter Valley, Lake Macquarie, the Central Coast, Gloucester and Liverpool Plain’s coalfields, and for agricultural and manufacturing industries in the region. As such, the Port of Newcastle is considered to be an economic driver for the region and New South Wales. The premium thermal and coking coals mined in the Hunter region are sought after for their clean burning characteristics and low impurities, ash and sulfur content. Coal accounted for 97% of export tonnage in 2014, however, the port handles over 25 different cargoes including alumina, magnetite, metal concentrates, coke, coal tar, cement, oil, fuels and sulfuric acid. Walsh Point industrial precinct manufactures, receives and distributes millions of tonnes of chemicals used for mining (ammonium nitrate for explosives) and agriculture (fertilisers). GrainCorp and Newcastle AgriTerminal at Carrington store grain and distribute it to national and international markets. The closure of the BHP Steelworks in 1999 and the remediation of the former Mayfield site have resulted in the release of 200 hectares of riverside land for further port development.

4 Lower Hunter River Health Monitoring Program – Literature and data review

2.2 Water pollution in the Hunter River Regulation of industrial waste was essentially non-existent for the majority of last century as industrial development and economic growth were paramount in society, with little regard for the environment. It was common practice to discharge untreated industrial waste laden with acids, phenols, ammonium, cyanide and metals directly to the Hunter River. The cumulative impact of unregulated industrial pollution resulted in a chronic, as well as an acute, pollution problem in the Hunter River. There are many examples of pollution events. A discharge of acid effluent from Kooragang Island is purported to have resulted in a large fish kill in October 1972 in which 450 kilograms of dead bream, flathead and jewfish were found on the riverbanks at Stockton (Ruello 1976). Local estimations of the fish kill were greater, indicating the total kill was closer to 4500 kilograms and included 11 fish species and 2 prawn species. Prawns caught in the South Arm near the steelworks were notorious for their ‘gassy’ flavour attributed to chemical effluent discharged in this area, and a complete absence of benthic organisms was common here (Ruello 1976). An episode of severe air pollution in October 1971 triggered a chain of events which led to a public inquiry into pollution from Kooragang Island (Coffey 1973). The early 1970s saw a dramatic increase in public and government interest in the environment, both nationally and internationally. Stricter laws were introduced that worked towards prohibiting discharges of liquid wastes into aquatic environments (Clean Waters Act 1970, Clean Waterways Program 1989) but the regulations were not well-resourced. To this day, kilolitres of industrial wastewaters are discharged daily to the Hunter River. Industrial discharges from larger premises are regulated by the EPA using powers under the Protection of the Environment Operations Act and EPLs. Since 1997 the EPA has also been using powers under the Contaminated Land Management Act 1997 to regulate historical land contamination.

2.3 Agricultural land use Agricultural practices in the early years of European settlement (1800s) in the Hunter Valley had a devastating impact on the natural environment of the region. Excessive land clearing for timber (cedar) and grazing by sheep and cattle resulted in almost complete loss of bush or wetland areas along the riverbanks. The urban areas of Maitland, Morpeth, Paterson, Seaham and Raymond Terrace are located in the immediate vicinity of the rivers alongside economically and socially important agricultural land. Removing wetlands and bush habitats from the banks of the river has played a large role in the hazard level posed by flood events and bank erosion as the natural buffering capacity of these ecosystems was lost. In addition to agricultural practices impacting the landscape, runoff from agricultural land delivers loose sediment, excess fertilisers and pesticides to the Hunter River, contributing to poor water quality. Over-clearing and over-grazing combined with frequent flooding and occasional droughts, led to what has been referred to as the worst land and riverbank erosion in Australia. In 1948 it was estimated that total soil loss from the Hunter Valley was more than 765,000 cubic metres annually or approximately 1 million tonnes (918,000,000 kilograms a year based on weight of top soil). A sediment budget has been derived from available information; for the Hunter River at Singleton the mean annual sediment load is 2 million tonnes and the mean annual suspended sediment load is 1.6 million tonnes (MHL 2003). The typical sediment influx to the lower estuary below Hexham is in the order of 1 million tonnes per year (MHL 2003). The sediment influx to the estuary following flood events can be seen in the photograph in Figure 2.

5 Lower Hunter River Health Monitoring Program – Literature and data review

Figure 2: Image of flood plume from the Hunter River flowing into the Tasman Sea after the storm event of 20–22 April 2015, revealing the sediment load coming off the catchment (Photo: Troy Gaston)

2.4 Urbanisation Newcastle is the second largest city in New South Wales with approximately 150,000 people living in the city and surrounding suburbs. The entire Hunter region accounts for almost 10% of the State’s total population. Population in the Newcastle region is forecast to continue to grow and therefore urban inputs of pollutants to the estuary via diffuse and point sources are predicted to increase unless mitigation action is taken. Diffuse sources include runoff from urban, agricultural and industrial areas, while point sources include effluent from sewage treatment plants or industry. It is well-recognised that stormwater runoff from urban areas has a negative impact on urban waterways, exporting sediment, nutrients, heavy metals, organochlorine and hydrocarbon compounds to the receiving waters. The second major component of urban pollution is sewage effluent discharged from wastewater treatment plants. The Hunter Water Corporation operates wastewater treatment works (WWTW) in the region. Six WWTW discharge treated effluent from the plants to the Hunter River (Morpeth, Singleton, Cessnock, Dungog, Raymond Terrace and Shortland). Wastewater from Newcastle City and surrounding suburbs is treated at one of the larger facilities at Burwood Beach WWTW and discharged to the ocean 1.5 kilometres offshore. There are areas around Hexham and Tomago that are not joined to the reticulated sewerage network and only have septic systems, while industrial sites have small on-site treatment systems which are licensed by the EPA. Industry claims that urban inputs in the form of stormwater runoff and treated sewage effluent are having a more detrimental impact on the condition of the lower Hunter River estuary today than are industrial inputs. OEH implemented two water quality monitoring programs to investigate these claims (discussed in later sections).

6 Lower Hunter River Health Monitoring Program – Literature and data review

2.5 Mining and power industries Mining and power industries have also been an enduring feature of the landscape of the region since European settlement due to easily accessible coal deposits. Coal mines and power stations in the Hunter Valley are among the largest in the State. Competing interests of mining, power and agricultural industries, and the impact of these industries on the ecological health of Hunter River, came to a head in the 1990s. In response, the NSW Government developed the Hunter River Salinity Trading Scheme which only allows discharge of saline mine water from mines during periods of high river flow. The Hunter River Salinity Trading Scheme appears to have led to an improvement in water quality for those reaches of the Hunter River to which the scheme applies (Krogh et al. 2013).

2.6 Legacies of heavy industry

2.6.1 Contaminated landfill A major threat to improving estuary health today is the legacy of contaminated landfill used to reclaim land for port expansion. Contaminants from past landfills can leach into the water table and pollute groundwater. Port areas around Carrington and Mayfield and the industrial sites on Kooragang Island are all situated on reclaimed land but regulation under the Contaminated Land Management Act on these sites will lead to improved management of these sites.

Case study The South Arm of the Hunter River is the favoured area for port expansion. Newcastle Port Corporation (now Port of Newcastle Operations) obtained development consent to extend the shipping channel of the Hunter River South Arm by 3 kilometres, to provide deepwater access to future berth sites (GHD 2003, 2004; ERM 2009). Sediments in the area to be used as a swing basin, approximately 500 metres to the east of Tourle Street Bridge, were investigated for the environmental impact statement (EIS) prepared by GHD (2003). The proposed area for the swing basin encroaches on the adjacent industrial land occupied by OneSteel Manufacturing Pty Ltd. This site is on reclaimed land formed by the filling of Platts Channel and Spit Island between the 1950s and 1970s. The EIS reported that geotechnical logs for boreholes on the OneSteel site located within the vicinity of the proposed swing basin area identified various fill materials such as slag, coke, coal washery reject, bricks, shale, coal and wood. Other potential contaminants cited in the EIS, including asbestos, organochlorine compounds (OCC) and polychlorinated biphenyls (PCB), may also be present on site (GHD 2003). The volume of waste materials used as fill in the reclamation process at this site is largely unknown as is the case for most infilled areas across the port. Other potential sources of groundwater contamination at the OneSteel site include two tar pits within the footprint of the current approved swing basin in the South Arm. In 1968, during construction of bar mill #1, it was reported that a tar pit was encountered to the west of the approved swing basin, however, details as to the nature and extent of the tar pit were not documented (ERM 2009). An unlined pit located in the mill storage and transition area, in existence since the 1980s, was used to collect oily runoff from the adjacent storage area and from bar mill and rod mill backwash sludge. This oily runoff was likely to contain elevated concentrations of metals, cyanide, ammonium and total petroleum hydrocarbons (TPH) which have the potential to leach into groundwater from the unlined pits. OneSteel investigated groundwater quality in the area before the original EIS was prepared and claimed there was no discernible impact on groundwater in downgradient monitoring wells (original report not cited in ERM 2009).

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In 2001–02, OneSteel noted two diffuse seeps with no sheen or odours flowing from the fill aquifer (within the footprint of the swing basin) at approximately 1–2 metres below low tide mark (ERM 2009). Seepage water collected at an undisclosed area, outside of the swing basin but within the OneSteel site, contained concentrations of TPH, copper and manganese in excess of the ANZECC guidelines (ANZECC & ARMCANZ 2000; ERM 2009). The reports containing this data were not cited by ERM (2009). It is possible the seep discussed was discharging groundwater that had been contaminated by the industrial waste disposed of in the unlined pit. This case study illuminates the fact that much of the reclaimed land in port areas is contaminated by the fill used, and by on-site practices of last century, where the extent of the contamination is often only discovered when use of the site is altered.

2.7 Contaminated sites

2.7.1 Overview The management of contaminated land in New South Wales is the responsibility of the EPA, the Department of Planning and Environment and local government. Under the Contaminated Land Management Act, the EPA regulates contaminated sites where the contamination is significant enough to warrant regulation. In these cases the level of contamination poses an unacceptable risk to human health and the environment due to the carcinogenic, toxic or bioaccumulative properties of the contaminants, and there is a risk of exposure to the contaminants. In cases where the contaminant status is not significant enough to warrant regulation, contaminated land can be managed by local councils through land-use planning, regulation and policies. Under the Contaminated Land Management Act, where the contamination status is significant enough to warrant regulation, the EPA can declare land to be ‘significantly contaminated’. Once a declaration is in place, the proponents responsible for the contamination are required to remove, treat or manage the contamination on site in accordance with a voluntary management proposal (called a ‘voluntary remediation proposal’ until 2009) agreed to by the EPA. The EPA can also issue orders under certain sections of the Contaminated Land Management Act. The overarching goal of remediation is to work towards compliance with national guidelines such as the National Environment Protection (Assessment of Site Contamination) Measure 1999 (amended in 2013), and the ANZECC water quality guidelines and sediment quality guidelines (ANZECC & ARMCANZ 2000). The environmental values of a waterway are expressed as water quality objectives which are considered when selecting the most appropriate management options. Where contaminant concentrations are higher than the threshold or trigger value, there may be a risk the environmental value of the waterway will not be protected. The aim of site remediation is to take immediate action to address the likely causes of the contamination, and to clean up the contamination to protect the relevant environmental values as they apply to groundwater and surface waters, with regard to human and ecological health. If contaminant concentrations cannot be reduced to guideline values then a ‘clean-up to the extent practicable’ (CUTEP) approach may be approved by the EPA. A CUTEP remediation approach will only be approved if the nature and extent of the contaminant sources have been identified to the extent practicable, and the proponent is committed to ongoing monitoring and re-evaluation of the clean-up, as the contaminated material is being managed rather than removed or treated. A common approach to managing heavily contaminated areas is to ‘cap and contain’ the area to minimise infiltration and recharge of groundwater, and thereby restrict off-site migration of contaminants. There are a number of contaminated sites in close vicinity to the Hunter estuary which are subject to past or current orders from the EPA (Table 1).

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Table 1: Contaminated sites in the vicinity of the Hunter River or its tributaries

Contaminated sites (near estuary) Orders, notices, voluntary management proposals AGL Gasworks • 3 current / 2 former BHP Kooragang Island Emplacement Facility • 1 current / 1 former BHP Mayfield closure site/adjacent sediments • 6 current / 4 former BHP Mayfield supply area • 3 current / 6 former Koppers Coal Tar Products Mayfield • 2 current OneSteel Mayfield • 2 current Orica – Kooragang Island • 5 current Shell Depot Hamilton • 2 current Steel River Industrial Estate • 3 current

2.7.2 BHP Newcastle Steelworks, Mayfield BHP Newcastle Steelworks operated on the south bank of the South Arm of the Hunter River from 1915 to September 1999. Primary operations included receiving and storage facilities for iron ore, limestone and coal, with associated infrastructure, and facilities for sintering, iron-making, coke-making and processing of coke oven by-products, steelmaking, bloom casting and billet production. Operations at the site produced vast quantities of contaminated industrial waste, particularly from the sinter plant, benzol plant and blast furnace. Historically, solid waste was used as landfill on site as site operations expanded. The site previously consisted of river channels and low lying swamp areas. In particular, the infilled former Platts Channel … is expected to be a major influence on groundwater flow. The site development to date has been created by placement of slag skulls, ash, coal tailings and general building refuse to form the subgrade. (RCA 1999)

Untreated process water laden with heavy metals, TPH and PAH were discharged daily from the site directly to the South Arm of the Hunter River (thousands of kilolitres per day presumably). High concentrations of contaminants also entered the river via groundwater seeps along the 4.5-kilometre shoreline which defined the north and north-east boundary of the 300-hectare site (RCA 1998). When BHP Steelworks closed its operations in 1999, the Main Site was comprised of two areas: the Closure Area (former lot 221 DP1013964) and the Supply Area (former lot 223 DP1013964). Investigations found soil and groundwater at the Main Site to be significantly contaminated with heavy metals (in particular arsenic, chromium, copper, zinc and lead), ammonium, cyanide, phenols, TPH (C6 to C36 range – including benzene, ethyl benzene, toluene and xylene: BTEX) and PAHs (Woodward-Clyde 1999). Arsenic is a known by- product of smelting. Separate investigations into the suitability of dredge spoil for dumping at sea found that sediments adjacent to the Closure Area had elevated levels of TPH and PAH (ANZECC 1998; Simpson et al. 2001a, b, c). The water chemistry and salinity of shoreline seeps were similar to groundwater on site with seepage occurring in dry and wet weather. Seep water contained elevated levels of the metals manganese (0.08–1.4mg/L), lead (<0.02–0.12mg/L), zinc (<0.01–0.02mg/L) and arsenic (<0.002–0.022mg/L) and extremely elevated levels of benzo(a)pyrene (<0.2–0.9µg/L) and total PAH (3.4–1.2µg/L). Heavy metal concentrations often exceeded ANZECC trigger levels while levels of benzo(a)pyrene and total PAH were up to 9,000-times higher than ANZECC guideline values for the protection of aquatic ecosystems (RCA 1998).

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In 1999 the EPA declared the former steelworks site as 'significantly contaminated land' (declaration no. 21022), posing an unacceptable risk to human health and the environment due to the carcinogenic, toxic or bioaccumulative properties of the contaminants. In 2001, the EPA declared both the Closure Area, and the Hunter River sediments adjacent to the Closure Area which fall within 120 metres from the land-based boundary, as a remediation site under s.21 of the Contaminated Land Management Act. BHP Billiton agreed to voluntary remediation of the site and adjacent sediments. A large number of investigations were commissioned to determine the extent of contamination of the Main Site and sediments adjacent to the Closure Area.

Remediation of BHP Main Site Demolition of the above-ground structures was completed in 2005 at which time remediation works began. Stage 1 of the remediation of the Main Site included construction of an upgradient barrier wall around three sides of Area 1 (grey area in Figure 3) and new major drains, re-contouring and filling of Area 1, capping of Area 1 to a permeability of 10-9m/s and minimum thickness of 0.5 metre. Stage 2 of the remediation works was the contouring and capping of Area 2 (blue area in Figure 3). Groundwater monitoring commenced before and after each stage to determine the efficacy of remediation works.

Figure 3: Former BHP Steelworks site showing Closure Area (grey and blue areas) Remediation is completed for the grey section of the Closure Area. Blue areas are still subject to a remediation notice issued to Port of Newcastle Operations Pty Ltd.

The EPA was satisfied the terms of the voluntary remediation proposal for the site were satisfactorily carried out and issued a number of notices to end the declaration of contaminated land as it applies to various lot numbers in the Closure Area. After closure of the BHP Steelworks, ownership of the eastern steelworks Closure Area was transferred from BHP Billiton to the NSW Government in 2002, and the property management was transferred from the Hunter Development Corporation to the Newcastle Port Corporation (now Port of

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Newcastle Operations). Declaration 21022 still applies to the Supply Area and part of the Closure Area, for which a remediation notice was issued to Port of Newcastle Operations Pty Ltd (notice no. 20142802, 20/3/2014: blue areas in Figure 3). Remediation works continue at the site as described in the approved voluntary management proposal (VMP) with performance activities dependent on future industrial use at the site. The EPA considers that the risks to human health and the environment are effectively managed, provided the Contaminated Site Management Plan for the Closure Area Former BHP Steelworks Mayfield Newcastle is implemented.

Hunter River Remediation Project – Stage 1 A remediation site was declared along the south bank of the South Arm of the Hunter River and defined as sediment within 120 metres of the land boundary of the Closure Area (Zone 1). BHP Billiton commissioned extensive investigations from 2000 to 2009 to define the distribution of contaminated sediments and determine the best approach for dredging operations and subsequent treatment of contaminated sediments. An integrated sediment quality ‘triad’ approach was used to assess human health and ecological risk posed by sediments in Zone 1 (URS 2004). Sediment toxicity tests indicated adverse biological effects were likely or probable from all intertidal sites and half the subtidal sites assessed in Zone 1 (URS 2004). The distribution of sediments exceeding ANZECC/ARCMANZ (2000) interim sediment quality guideline (ISQG) high ‘risk’ guideline values for PAHs was restricted to a narrow, mainly intertidal zone sediment in the north-west section of Zone 1, with concentrations of PAH decreasing with distance from the shore. The affected area of contaminated sediments within the Hunter River was referred to as the primary remediation zone (PRZ). URS carried out sediment investigations to define the vertical and lateral extent of contaminated sediments (URS 2006a, b; 2007a), with further sediment coring in the PRZ being commissioned in 2008). URS also did bench-scale testing to evaluate binder and cement additives and addition rates for the treatment of contaminated sediments which were tested in the URS pilot trial (URS 2005, 2007b). Cement stabilisation is a proven treatment method which immobilises contaminants in sediments (URS 2005). An optimisation study on 5250 cubic metres of contaminated sediment tested, refined and validated the chosen protocol for treatment by cement stabilisation and immobilisation of contaminants (BHP 2009a). These studies formed Stage 1 of the Hunter River Remediation Project (HRRP) culminating in the remediation action plan (RAP) which outlined Stage 2 of the HRRP.

Stage 1 outcomes Water quality was monitored in the South Arm of the Hunter River before, during and after the dredging of contaminated sediments for the optimisation study (December 2008). Turbidity and pH were monitored continuously by data loggers deployed upstream and downstream of dredging operations. Grab samples were collected daily from three monitoring stations, at least two hours after dredging had commenced, and were analysed for PAH, TPH, volatile hydrocarbons (BTEX) and TSS. Overall, river quality results were generally and consistently below standard detection limits (limit of reporting: LOR) for PAH and other contaminants. When contaminants were detected above LOR, concentrations did not exceed ANZECC guidelines for protection of aquatic ecosystems (URS 2009). Newcastle Coal Infrastructure Group (NCIG) and BHP Billiton began to collaborate on water quality monitoring as dredging for the optimisation study coincided with ongoing dredging operations for developing the NCIG Kooragang Island Coal Export Terminal on the north side of the South Arm (WorleyParsons 2008). Two months of baseline water quality monitoring was acquired by NCIG (28/9/07 to 28/11/07) as a requirement of EPL 12470. Data were from real-time monitoring stations recording turbidity, electrical conductivity (EC), pH and temperature every 15 minutes. This data was to be used to establish appropriate site-related

11 Lower Hunter River Health Monitoring Program – Literature and data review trigger values for turbidity to be used during dredging operations of HRRP and NCIG in the South Arm. Baseline data for the period of testing was found to be 3.7–5.1NTU with a 99th percentile of 19–31NTU (WorleyParsons 2008). This was considerably lower than the long- term (5.5 year) average turbidity recorded by Manly Hydraulics Laboratory station at Ironbark Creek of 14.3NTU with a 99th percentile of 125NTU. NCIG was required to continue to monitor water quality for the first three months of dredging operations. During this period of monitoring, it was realised the baseline data had been collected by NCIG during a period of low turbidity and were not suitable for use as ‘turbidity’ trigger values for current dredging operations. Instead it was recommended that the turbidity trigger be ‘background + 25% or background + 50NTU, whichever is greater’ with variable nearby sites used to determine background NTU depending on tidal movements (WorleyParsons 2008). Given that the South Arm is an environment of high and variable turbidity which regularly experiences events of 100NTU or more, it was concluded that short- duration events of 50NTU above background caused by dredging would have little detrimental impact on the river.

Hunter River Remediation Project – Stage 2 Stage 2 of HRRP saw the implementation of the RAP, i.e. the removal and treatment of contaminated sediment from the PRZ, and transport of treated sediments to Kooragang Island for storage in the Kooragang Island Emplacement Facility (KIEF) – a purpose-built landfill. KIEF was built above the highest aquifer, lined to prevent any potential interaction between sediment, ground and surface waters and was capped upon completion. Sheet pile walls were constructed along the shoreside of the PRZ. For dredging operations, temporary sheet pile walls were erected in the river, along with silt curtains (barriers) to mitigate impacts on water quality. More than 800,000 cubic tonnes of contaminated sediments were dredged from the PRZ and treated on site before transport to KIEF. The HRRP was the largest remediation project of its kind to be undertaken in Australia. The HRRP was recognised by the United Nations Association of Australia, winning the Award for Environmental Best Practice Program at the 2011 World Environment Day Awards, and also winning the National Safety Council of Australia Award for Excellence in Innovative Environmentally Sustainable Work Practices. No pollution events or adverse impacts on river health were recorded from more than 200,000 environmental monitoring measurements taken in the river and surrounding areas (BHP Billiton 2012). The EPA was satisfied the terms of VMPs 26110 and 26120 for the site were satisfactorily carried out and issued a notice of completion, ending the declaration of contaminated land (declaration no. 21022) as it applies to the bed sediments of the Hunter River located adjacent to and within 120 metres of the Closure Area. While BHP Billiton should be applauded for the extensive remediation of the Main Site of the former BHP Steelworks and the adjacent sediments, the western areas of the former site still have a number of declarations in place where former on-site practices of BHP, namely industrial waste disposal, have led to contamination of lands and groundwater. While some remediation of the Steel River site has occurred, remediation of a benzene-impacted area at the OneSteel site is yet to begin, 15 years after the closure of BHP Steelworks.

2.7.3 OneSteel Manufacturing Pty Ltd, Mayfield After closure of the steelworks, all remaining secondary steel finishing activities (rod mill, bar mill and wire mill) continued under a new business spun out from the BHP group, Onesteel, located adjacent to the former steelworks site in Mayfield Industrial Park. The EPA has declared an area of 8200 square metres in the north-west corner of the OneSteel site (part of Lot 222) a ‘benzene impacted area’ (BIA) where relict coke ovens were dumped. Groundwater in the estuarine aquifer within the BIA is contaminated with benzene and PAH

12 Lower Hunter River Health Monitoring Program – Literature and data review including naphthalene. The performance schedule of the approved VMP requires (but is not limited to) investigations of contaminant levels in groundwater, within seep discharges and the fill and estuarine aquifers within or near the BIA. A comprehensive report by Environ Australia was submitted to the EPA in 2015 revealing contaminant concentrations in the extensive network of wells within the BIA, and within seep discharges, from monitoring that occurred between September 2013 (Sep-13) and September 2014 (Sep-14) (Environ 2015). At the centre of the plume, benzene concentrations increased from 145 to 165mg/L in the estuarine aquifer (well E26R) and decreased from 70 to 20mg/L in the fill aquifer (well F20) over the same period (Environ 2015). Likewise TPH (C6–C10 fraction) concentrations increased from 194 to 417mg/L in the estuarine aquifer (well E26R) and decreased from 149 to 30mg/L in the fill aquifer (well F20) over the same period (Environ 2015). Total PAH concentration (predominantly naphthalene) decreased from 49 to 18 mg/L in well F20 with considerably lower concentrations (0.1mg/L total PAH) in well E26R. Benzene and PAHs were either not detected or were below guideline criteria in the monitoring wells along the foreshore with one exception (Environ 2015). The exception was well E33 which saw a spike in benzene concentrations from 0.02mg/L (Sep-13) and 0.06mg/L (Feb-14) to 1.73mg/L in Sep-14. The consultants disregarded this ‘anomalous’ value after subsequent sampling in Jan-15 indicated a return to 0.04mg/L benzene in well E33 (Environ 2015). The higher reading for benzene recorded in Sep-14 may have been a true reading and should not be discounted simply because of a decreased concentration in Jan-15 which could also be explained by migration of benzene off site via seepage from the estuarine layer to the river. Between 1.13–1.73 mg/L of TPH (C10–C28) were detected in well E33 from Sep-13 to Sep-14 which decreased to 0.9mg/L in Jan-15. These data suggest that moderate concentrations of hydrocarbons are present in the estuarine aquifer close to the riverbank. Benzene and TPH were not detected in any seep samples coming from the fill embankment even though a slight hydrocarbon odour was reported for each seep at the time of sampling (Environ 2015). Seep 4 contained PAH at levels that exceeded guideline criteria, in which concentrations of phenanthrene (0.003mg/L) and anthracene (0.001mg/L) increased over the monitoring period to levels that were 5 to 30 times above guideline criteria (Environ 2015). High concentrations of manganese were detected in seep samples and ranged from 0.23mg/L (seep 4) up to 5.0mg/L (seep 2). Concentrations of manganese in seep 3 ranged from 0.75–0.96mg/L over 3 samplings, approximately 10 times the ANZECC interim guideline criteria of 0.08mg/L (Environ 2015). The consultants claim that natural attenuation of hydrocarbons is occurring in the plume by methanogenesis based on the observation that methane concentrations are higher in the plume compared to concentrations upgradient or downgradient of the plume (Environ 2015). Based on this indirect line of evidence, consultants have requested the monitoring period should be extended for another 12 months, for further trend analysis of contaminant concentrations and natural attenuation processes before any remediation works proceed. The consultants claim that concentrations were stable or decreasing, however, benzene concentrations increased in the centre of the plume in the estuarine aquifer from 2013 to 2014 (Environ 2015). While natural attenuation may reduce contaminant concentrations on the outer edge of the plume, it seems highly unlikely that biological activity alone could attenuate higher benzene concentrations at the centre of the plume. Consultants have been requesting further monitoring of the BIA since 2004 ‘to assess natural attenuation processes’ as this has always been their preferred risk management strategy. Over a decade ago, the consultants at the time (CH2M Hill 2004) concluded that existing contamination did not represent a significant risk of harm to human health or the environment. Seep 3 was reportedly under high flow with a slight hydrocarbon odour on all three sampling occasions between Sep-13 to Sep-14 (Environ 2015) yet seep samples

13 Lower Hunter River Health Monitoring Program – Literature and data review contained no benzene or TPH. Seep 3 was located on a site visit in June 2015 which at the time was under high flow and had a strong hydrocarbon odour (Swanson – personal observation). Benzene, toluene, ethylene and TPH were not detected in seep samples despite the strong odour of seep water, however, samples contained up to 1g/L manganese (Swanson – unpublished data). Despite claims to the contrary, existing contamination is likely to pose a significant risk of harm to the environment as contaminants appear to be migrating off site to the Hunter River via seeps from the fill embankment. Further investigation of these seeps is warranted, and seeps located below the low tide mark should be located, from which contaminants may be migrating off site to the Hunter River from the heavily contaminated estuarine aquifer.

2.7.4 Koppers Coal Tar Products, Mayfield Koppers Carbon Materials and Chemicals Pty Ltd in Mayfield West processes coal tar to produce pitch and naphthalene. Soil and groundwater at the site are contaminated with coal tar which includes PAH, in particular naphthalene and benzo(a)pyrene. Capital works required in the VMP include the construction of a barrier wall on Lot 223 North to isolate the most concentrated source of hydrocarbon contaminants from groundwater. Remediation works to be done include capping of affected areas to minimise surface water infiltration and groundwater recharge, removal of free phase contaminants from infilled areas and placement within the barrier wall on Lot 223, and removal of phase-separated hydrocarbons from groundwater on site.

2.7.5 Steel River Industrial Estate, Mayfield This site is located in Mayfield West and originally formed part of BHP Newcastle Steelworks operations but was sold to Steel River Pty Ltd in 2001 after initial remediation at the site. Extensive remediation by BHP Billiton in accordance with a remediation action plan in 1998– 2000 included re-contouring of the site and capping with over 120,000 tonnes of imported coal washery reject material. Capping of the site aimed to minimise dermal contact with contaminated subsurface soil and minimise the infiltration of rainwater and recharging of groundwater. It was hoped that redevelopment of the site would further reduce groundwater recharge but the site remains largely undeveloped. A 20-metre wide easement between the Steel River site and the South Arm of the Hunter River, referred to as the foreshore buffer zone (FBZ), is the primary target area for remediation to ensure there are no unacceptable risks to human health and the environment from groundwater migrating from the Steel River site, through the FBZ and into the Hunter River. Groundwater at the site is contaminated by TPH (including benzene, toluene), PAH, metals (including arsenic), phenols, cyanide and ammonium, as a consequence of on-site operations and using contaminated fill. Until the end of the mid 1950s, the site consisted of a riverbank, a shallow channel called Platts Channel and a low mudflat called Spit Island. Once BHP acquired the land, it began filling the channel with steelmaking by-products, primarily steelmaking slag and coal washery waste. Infilling of the site continued over the course of 30 years. Two VMPs are currently in place that detail required investigations into different remediation options, extensive monitoring of seeps and groundwater bores in the FBZ and the removal of non-aqueous phase liquids from wells. The efficacy of the remediation approach is to be assessed as works proceed. Capping upgrade works are also required on site to meet specified permeability requirements and to achieve a minimum cap life of 25 years.

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2.7.6 AGL Gasworks, Hamilton This site is contaminated with gasworks waste including TPH, benzene, PAH, arsenic and lead. Groundwater at the site is degraded by these contaminants and has the potential to migrate off site to Styx Creek and the Hunter River. The current VMP outlines preliminary remedial works for the site which include locating and sealing preferential pathways for groundwater migration into Styx Creek by way of subsurface drains. Surface water from Styx Creek in the vicinity of the site is to be collected and analysed on a monthly basis. Feasibility studies of appropriate remedial technologies and techniques are underway and will be used to inform the remedial action plan for the site.

2.7.7 Shell Depot, Hamilton Shell ceased using this site for the storage and distribution of fuel in 2014. Operational activities have left the site contaminated with petroleum and TPH including benzene and lead. Groundwater at the site is degraded by petroleum contaminants including phase- separated hydrocarbons (PSH) which have the potential to migrate off site to Styx Creek and ultimately impact the Hunter River. A VMP outlines the monitoring of contaminants in groundwater and surface water, and investigations into the behaviour of the PSH plume and recovery of PSH.

2.7.8 Orica Australia Pty Ltd, Kooragang Island

Contamination of groundwater with arsenic The production of ammonium nitrate for the purposes of manufacturing fertiliser began at the site in 1969. From 1969 to 1994 a solution containing arsenic was used to scrub carbon dioxide from the process gas stream prior to the production of ammonium, with spent waste placed in an arsenic disposal pit in the north-west of the site. Groundwater is contaminated with arsenic at concentrations significantly exceeding ANZECC low-reliability marine trigger values for the protection of aquatic ecosystems (trigger values for As-III: 2.3 µg/L and As-V: 4.5µg/L). Arsenic has migrated off site in groundwater, and has contaminated other landholdings with the potential to impact quality of waters. To date, remediation works have been done in accordance with a number of VMPs including ‘source removal’ in 2005, that is, removal of arsenic-contaminated soil and sludge from the disposal pit to the depth of the groundwater table. URS has investigated a number of potential remediation actions on behalf of Orica including field trials of in-situ geochemical fixation of arsenic (URS 2006c). The site is currently the subject of contaminated site management order #20131407 issued by the EPA, with remediation works aimed at preventing further off-site migration of arsenic-contaminated groundwater. In October 2014 cap and containment remediation technology was selected as the preferred remediation option to meet the objectives of the management order. An impermeable subsurface wall will be installed to prevent the flow of groundwater through the impacted soil in the on-site source area as well as a surface cap to reduce infiltration. Orica is required to do biannual monitoring of dissolved arsenic concentrations in groundwater wells and the long-term data set (~10 years) reveals some insight into the partitioning of arsenic in different groundwater layers (URS 2014a). Arsenic concentrations are usually highest in groundwater wells of intermediate depth (~6 metres) in the fine-grained layer. High arsenic concentrations are also observed in the shallow layer (~3 metres) but are highly variable and likely to be influenced by rainwater recharge. In February 2014, arsenic concentrations in selected wells (MW27A, MW45, MW54) situated 40 metres downgradient of the former sludge pit, show a decreasing trend since source removal in 2005 implying that remediation works are having some impact on site (URS 2014a). However, arsenic

15 Lower Hunter River Health Monitoring Program – Literature and data review concentrations were highest in groundwater wells located on Incitec Pivot land to the east of Heron Road (BP7-6 = 115mg/L, MW50 = 108mg/L) exceeding guideline values by four orders of magnitude. Concentrations of arsenic were considerably higher in wells BP7-3, BP7-6 and BP5-6 in February 2014 when compared to the previous six sampling events, demonstrating that the arsenic plume continues to migrate off site. A cluster of monitoring wells is situated close to the Hunter River between Kooragang Berths 2 and 3 (on Port of Newcastle Operations land) as this area has been identified as the assumed discharge area for the arsenic plume. Arsenic concentrations increased in 5 out of 17 monitoring wells in the assumed discharge area compared to the previous six sampling events, with arsenic concentrations ranging from 3–14mg/L. To investigate the potential impact of discharge of arsenic-contaminated groundwater on river water quality, concentrations of dissolved arsenic (As-III and As-V) were measured in the Hunter River in the assumed area of groundwater discharge, close to the rock revetment between Kooragang Berths 2 and 3 (URS 2013, 2014a). Time-averaged concentrations of As-III (0.35–0.59µg/L) and As-V (0.72–1.04µg/L ) in the assumed area of groundwater discharge were below ANZECC low-reliability marine trigger values for As-III (2.3µg/L) and As-V (4.5µg/L) and background concentrations of arsenic in the Hunter River (3.1µg/L)(URS 2006c). Groundwater in 6-metre deep monitoring wells in the vicinity of the inferred discharge point had total arsenic concentrations of 0.87µg/L and 118µg/L (URS 2013) exceeding the ANZECC low-reliability trigger values by an order of magnitude. Monitoring well data suggests that arsenic in the groundwater plume is diluted by two processes before it reaches the Hunter River. River water is known to influence groundwater wells in this vicinity via river water ingress, and discharging groundwater would be diluted at the groundwater – river water interface at the riverbank. Time-averaged concentrations of arsenic reported by URS (2013, 2014a) concur with data collected by OEH in 2015. OEH implemented a stormwater quality monitoring program in 2015 targeting runoff from industrial sites and urban areas. Water samples were collected in creeks and near drains discharging from industrial sites to the South Arm and North Arm, and were analysed for metals, metalloids and other pollutants. River samples collected near drains from the Orica site contained 2.1 and 1.7µg/L of dissolved arsenic, respectively (Swanson et al. 2017b). These drains are located approximately 500 metres and 750 metres to the south of the assumed point of discharge of the groundwater plume (URS 2014a). Over 18 kilograms of arsenic was discharged from the Orica effluent pipe to the North Arm in 2012–13 and 2013–14 (Orica 2015).

Contamination of groundwater with nutrients Soil and groundwater at the site are also contaminated by nutrients and this is considered to have resulted from historical waste disposal practices, spillages and leaks associated with the production, storage or use of nitrogen-based compounds. Concentrations of ammonium, nitrate and nitrite in groundwater exceed ANZECC trigger values for the protection of aquatic ecosystems (URS 2012a). Nitrate and nitrite contamination are attributable to the nitrification of ammonium within the plume. Ammonium and nitrate have migrated off site and have the potential to impact the quality of waters and sediment in the Hunter River. The site is currently the subject of contaminated site management order #20131408 which requires the development of an environmental management plan to address the risks posed by the nutrient contamination to off-site receptors (Golder Associates 2014). A number of on- site activities have been ceased or modified to reduce further contamination of the site, for example, the practice of discharging scrubber effluent (used to clean ammonium storage tanks) directly to the subsurface environment was discontinued in 2005 and the disposal of general waste to the ‘borrow pit’ ceased in 2000. Other source control works, such as relining the nitrate effluent pond in 2009, have also been done in accordance with EPL 828. Further investigations and monitoring of nutrient levels in groundwater and seeps continue at the site.

16 Lower Hunter River Health Monitoring Program – Literature and data review

Recent monitoring results show that concentrations of ammonium and oxidised nitrogen (i.e. nitrate, nitrite) in groundwater wells typically exceed trigger values (Golder Associates 2015) and often by three orders of magnitude. Concentrations of ammonium and nitrate are very high in groundwater in the vicinity of the ammonium nitrate plant, with nitrate concentrations reaching 5000mg/L and 10,000mg/L in shallow and deeper groundwater respectively (Golder Associates 2014, 2015). Nitrate concentrations in groundwater seeps to the south-east (downgradient) of the contaminated groundwater plume ranged from 1–100mg/L (Golder Associates 2015). OEH collected receiving waters near the seep (in the North Arm) that had the highest reported nitrate concentration (Seep 03, Golder Associates 2015). Receiving waters near the seep contained 200µg/L ammonium and 380µg/L nitrate which are both well above ambient concentrations recorded in the North Arm during OEH water quality monitoring (Figure 14, Swanson et al. 2017b). These data suggest that ammonium and nitrate from contaminated groundwater are migrating off site via seeps discharging to the North Arm of the Hunter River.

2.8 Current impacts of shipping and industry

2.8.1 Dredging of the harbour and South Arm Port of Newcastle Operations Pty Ltd is responsible for over 4600 ship movements a year in the port. Maintenance dredging of the port is undertaken on a continual basis (12 hours a day, 7 days a week) to provide safe, deepwater access to the port. The current maintenance dredging sea dumping permit allows up to 2,500,000 cubic metres of sediment to be dredged from port areas, and dumped at sea. The total annual volume of material dredged from Newcastle Harbour and the lower South Arm between 2000 and 2010 varied from 236,088 to 444,922 cubic metres. The amount of dredge material is predicted to increase to 600,000 cubic metres to accommodate extension of shipping channels and new berths. The South Arm of the Hunter River is the favoured area for port expansion. Port of Newcastle has obtained development consent to extend the shipping channel of the Hunter River South Arm by 3 kilometres to provide deepwater access to future berth sites (GHD 2003; ERM 2009). The Department of Planning issued the development consent in 2005, which described the requirements for the total dredging program in the South Arm of the Hunter River, including specific provisions related to the management of contaminated sediments. Additional berths are planned for the Multi Purpose Terminal at Mayfield (former site of BHP Steelworks) and the Terminal 4 project. On 16 December 2014, the NSW Planning and Assessment Commission reviewed the Terminal 4 project and concluded it was approvable subject to certain conditions. Removing contaminated sediments from the harbour may be viewed as beneficial for the estuary as the contaminant load in the system is reduced (Birch et al. 1997). There are, however, ecological impacts of dredging operations, shipping movements and tug boat operations – in particular, the continual re-suspension of fine sediments from the riverbed in the South Arm and Newcastle Harbour impacting water clarity and potentially releasing and redistributing sediment-bound contaminants to the water column where they become more available to biota.

2.8.2 Pollution The Marine Pollution Act 2012 serves to protect the sea from pollution from ships and boats (including oil spills), however, there are relatively few criminal prosecutions for marine pollution offences. In December 2013, the NSW Land and Environment Court handed down two judgments involving penalties under the Marine Pollution Act in relation to two incidents in the Port of Newcastle. The more serious case involved the 20-year old bulk carrier, MS Magdalene which was loading coal at Kooragang Berth No. 4. During the course of de-

17 Lower Hunter River Health Monitoring Program – Literature and data review ballasting, 72,000 litres of heavy fuel oil and 500 cubic metres of ballast water was discharged into the Hunter River. The oil reached up into the North Arm of the Hunter River affecting saltmarsh, mangroves and sandy beaches in the Ramsar-listed areas of Hunter Wetlands National Park. Newcastle Port Corporation commenced clean-up operations the following morning, accruing $2 million in clean-up costs over a period of six weeks. The oil spill was able to be contained and cleaned up before the arrival of international migratory birds to the wetlands and without causing any permanent harm. The spill impacted the local fauna and ecosystem with oil spotting on protected saltmarsh and mangroves, contamination of invertebrate infauna and 40–50 pelicans were coated in oil. The Australian Pelican Pelecanus conspicillatus is an iconic species which attracts immense interest in the community. Thirty-two pelicans were taken into captivity by NSW National Parks and Wildlife Service suffering from the effects of oil exposure. Twenty-nine adult pelicans were eventually rehabilitated, banded and released following the clean-up. The owners of MS Magdalene were fined $1.2 million in addition to clean-up costs.

2.9 Regulation of water pollution The Protection of the Environment Operations Act 1997 provides the statutory framework for managing water pollution in New South Wales. There is a broad allocation of responsibilities under the Protection of the Environment Operations Act between the EPA, local councils and other public authorities.

2.9.1 Unlicensed discharges to waters Where operational activities at industrial sites are not specified in Schedule 1 of the Protection of the Environment Operations Act, the local council is the regulatory authority for those premises. Local councils regulate matters in regard to pollution issues associated with non-scheduled activities through enforcement powers outlined under the Protection of the Environment Operations Act. Newcastle City Council also undertakes audits of non- scheduled premises through its proactive Business Pollution Prevention Program. These industries are required to comply with the general obligation not to cause water pollution under s.120 of the Protection of the Environment Operations Act. Local Land Services (LLS, previously Catchment Management Authorities) has similar powers and can also act as an appropriate regulatory authority under the Protection of the Environment Operations Act for non-scheduled activities in the catchment. Discharges of stormwater and wastewater from these premises are not reviewed here.

2.9.2 Licensed discharges of industrial waste to estuary waters The EPA is the appropriate regulatory authority for the activities specified in Schedule 1 of the Protection of the Environment Operations Act (scheduled activities) as well as activities undertaken by a State or public authority. The EPA issues environment protection licences (EPLs) to the owners or operators of various industrial premises for activities that are specified in Schedule 1 of the Protection of the Environment Operations Act. Scheduled activities require a licence because the activity has an associated high risk of polluting the environment. Licence conditions relate to pollution prevention and monitoring, cleaner production through recycling and re-use and the implementation of best practice. Discharges from a selection of licensed premises to the lower Hunter River estuary are discussed below.

Port Waratah Coal Services, Carrington Coal Terminal Port Waratah Coal Services Carrington Coal Terminal (PWCS-CCT) is the oldest coal terminal in the port, operating for almost 40 years. The Carrington terminal has capacity to export up to 25 million tonnes per annum (EPL 601). Site operations, waste management

18 Lower Hunter River Health Monitoring Program – Literature and data review and water use, re-use and recycling are limited by its dated infrastructure. Water used on site is directed to a settling pond which is discharged to the South Arm of the Hunter River via a concrete pipe situated behind Dyke 6. Industrial waters are discharged to the estuary routinely (that is, daily) and in times of stormwater overflow when rainfall exceeds the holding capacity of the CCT water management system. Treated effluent from an on-site sewage treatment plant (STP) also discharges at this point. EPL 601 requires the quality of routine discharge to be monitored monthly, testing for pH, TSS (maximum 50mg/L) and biochemical oxygen demand (BOD, max 20mg/L). Volumes of routine discharge are monitored daily and are limited to a maximum of 3000kL/day. There are no limits set on the quality or volumes of overflow discharge, however, CCT is required to monitor discharge quality and volumes daily during overflow events. The TSS load being discharged from PWCS-CCT to estuary waters in routine discharge and stormwater overflow combined, is estimated at 75,000kg for the period April 2012 to October 2014. During this period routine (daily) discharge delivered approximately 4230kg of TSS to the South Arm (Figure 4). This estimate of TSS load in routine discharge is considered to have low confidence as it is based on average daily discharge volumes for the reporting period (reported monthly) and only one measurement of TSS concentration (PWCS 2015). Monitoring data suggests that in excess of 70,000kg of TSS was discharged to the South Arm during stormwater overflow events in the period April 2012 to October 2014 (Figure 5). The estimate of TSS load discharged during stormwater overflows is a more accurate reflection of actual TSS loads entering the estuary because daily monitoring of water quality and volume discharged is required during overflow events, albeit with no set limits (EPL 601).

Figure 4: Estimated TSS in routine discharge from PWCS-CCT

PWCS-CCT is required to monitor discharge volumes daily, but only has to monitor water quality monthly. The data shown here are based on average daily discharge volumes for the month, and one measurement of TSS concentration in the discharge.

19 Lower Hunter River Health Monitoring Program – Literature and data review

Figure 5: Monitoring data for stormwater overflow discharges from PWCS-CCT for EPL 601 A. Estimated TSS (kg) discharged to waters during each overflow event calculated from measured TSS (mg/L) in discharge and, B. estimated volume of discharge for each event.

Port Waratah Coal Services, Kooragang Coal Terminal Port Waratah Coal Services Kooragang Coal Terminal (PWCS-KCT) has a capacity of 120 million tonnes per annum. The water management system at PWCS-KCT allows re-use and recycling of site water so that it is rare for routine discharge to waters to occur. In the event of stormwater overflow, KCT occasionally discharges to water and is required to monitor water quality (oil/grease, pH and TSS) monthly during discharge (EPL 1552). For the period April to December 2014 there was not any routine or overflow discharge to waters from this site.

20 Lower Hunter River Health Monitoring Program – Literature and data review

Port Waratah Coal Services Fines Disposal Facility A fines disposal facility is located adjacent to the PWCS-KCT on Kooragang Island where clean dredge material obtained during dredging berth pockets for the PWCS KCT is applied to land (EPL 5022). A leachate drain discharges on average 500kL/day to the South Arm from dredged sediments and surface water (from rainfall and on-site water use) infiltrating the cells. It is a requirement of EPL 5022 that water quality in the leachate sump and leachate drain are assessed monthly for the following contaminants: TSS (maximum 50mg/L), lead, manganese, zinc, PAH, phenols and pH. Monitoring frequency is not specified in the licence for discharge volumes, however, a limit of 10,000kL/day applies. Monitoring data for the period April 2012 to November 2014 show typical daily discharge volumes in the order of 500kL but can be as high as 2000kL/day. While concentrations of most contaminants in the discharge are low or below detection, manganese concentrations are consistently between 1–2mg/L which is more than 12–25 times the ANZECC (interim) guideline value of 80µg/L for protection of marine species. Groundwater monitoring at this site shows elevated concentrations of manganese at most locations, up to 2.9mg/L and frequently above 0.5mg/L. Manganese contamination of groundwater is a long-standing issue at this site which has not been resolved but has been linked to landfilling at the site (RCA 2006). For the period April 2012 to November 2014, it is estimated that 2000kg of TSS, 375kg of manganese and 3kg of zinc were discharged to the South Arm from the leachate drain of the fines disposal facility. These estimates may be overestimating or underestimating actual loads of contaminants entering the South Arm as contaminant concentrations used are from one sampling day per month whereas discharge volumes are reported daily (PWCS 2015).

Newcastle Coal Infrastructure Group Newcastle Coal Infrastructure Group (NCIG) is the newest coal terminal in the Port commencing operations in 2010 at Kooragang 8 and 9 berths (berth 10 is for unladen vessels). NCIG has an installed capacity of 66 million tonnes per annum. Water management systems on site allow for re-use and recycling of site water so there is no need for routine discharge to waters. Kooragang berths K8, K9 and K10 require frequent dredging for deepwater access to maintain coal loading operations. NCIG was required to monitor turbidity continuously during dredging operations at four monitoring points (Ash Island, Rail Bridge, Tourle Street, BHP Wharf; EPL 12740). EPL 12740 was surrendered in 2013 as regular monitoring found median turbidity levels were usually at an acceptable level during routine dredging operations. There were frequent spikes of high turbidity while dredging but these events were short-lived, and thought to have little detrimental impact on a system where highly variable turbidity conditions exist. NCIG is required to monitor selected groundwater bores biannually or annually as a condition of EPL 12693. Monitoring data from December 2014 indicate high concentrations of ammonium, 630 and 3300µg/L, at sampling Points 1 and 20, respectively. Manganese concentrations of 390µg/L also exceeded the ANZECC (interim) guideline value of 80µg/L for protection of marine species. Limits are not specified for ammonium or manganese in EPL 12693 presumably because groundwater at this site already contained high levels of manganese and ammonium before NCIG site operations commenced (RCA 2006). High background levels of manganese in groundwater is a long-standing issue at this site which remains unresolved with contaminated landfill the likely source (RCA 2006).

21 Lower Hunter River Health Monitoring Program – Literature and data review

Orica Australia Pty Ltd, Kooragang Island Orica Australia Pty Ltd (Orica) operates an ammonium nitrate manufacturing facility on Walsh Point, Kooragang. The site commenced production of ammonium nitrate in 1969 for the purpose of fertiliser manufacture, operating under a number of related entities including Industrial Chemicals Ltd, Incitec Pivot Ltd (now a subsidiary of Orica IC Assets Pty Ltd). Today Orica manufactures approximately 400,000 tonnes of ammonium nitrate which is used primarily used for explosives in the mining industry, in addition to use as fertiliser. Ammonium (360,000 tonnes) and nitric acid (330,000 tonnes) are also manufactured at the facility to use for the manufacture of ammonium nitrate.

Discharges from effluent pipe Orica disposes of an average of 2000–2500kL of industrial wastewater per day via an effluent pipe discharging to the North Arm of the Hunter River (EPL 828 allows up to 4500 kL/day). It is a requirement of EPL 828 that effluent is monitored for: concentrations of total nitrogen (TN), TSS), arsenic, chromium and zinc daily; pH and temperature continuously; and oil and grease twice weekly (Orica 2015). Approximate annual loads of contaminants that have been discharged via the effluent pipe since 2009 are summarised in Table 2. These loads are estimates only as they are based on average concentrations of contaminants in the effluent, and average daily discharge volumes, reported by Orica in its annual returns submitted to the EPA. From 2009–10 to 2013–14 an average of 0.5 tonnes per day of TN entered the lower Hunter River estuary, or approximately 200 tonnes per year. The total nitrogen load was reduced to approximately 143 tonnes per year in 2014–15. The amount of zinc being discharged via the effluent has been significantly reduced from over 9 tonnes in 2009–10 to approximately 0.27 tonnes in 2013–14 and 2014–15. Conversely, the discharge of TSS via the effluent pipe has increased from 0.26 tonnes in 2009–10, to 14.7 tonnes in 2013–14 and 10 tonnes in 2012–13 and 2014–15 (Table 2). While nitrogen in effluent is currently measured as TN, the majority of the nitrogen being discharged to the North Arm is likely to be bioavailable ammonium and nitrates. The effluent pipe is located on the riverbed at approximately 5 metres depth, and is fitted with a number of diffusers. Effluent is discharged in an area of high flow under the working assumption that the nitrogen will be flushed out to the ocean on outgoing tides. However, as the discharge occurs continuously in an area where the water residence time is up to two days (Figure 22), and biological uptake rates are measured in hours, this assumption is unlikely to be true. It is more likely that a significant proportion of the bioavailable nitrogen is taken up by primary producers (algae) in the river and associated wetlands and subsequently accumulated in riverbed sediments – particularly when discharged effluent is transported upstream on incoming tides.

Discharges from stormwater drains Orica has six other licensed monitoring points which discharge stormwater from the site via drains to the South Arm and North Arm of the river. Surface water from on-site operations such as dispatch, receiving, transport and storage of chemicals; wash-downs of equipment and vehicles and low rainfall are diverted from six different catchments to separate stormwater drains. Orica is required by EPL 828 to monitor contaminant concentrations (TN, phosphate, TSS, As, Cr-IV, Zn, oil and grease) in discharge from stormwater drains on a monthly basis. Since July 2014, Orica has also had to monitor volumes of stormwater discharged at each point. Orica will soon be required to monitor constituent species of nitrogen (ammonium and nitrates) in effluent and stormwater discharges as a condition of EPL 828. Concentrations of TN are highest in discharges from monitoring points 13 and 14 (Figure 6). Average concentrations of TN in stormwater from these points have reduced from approximately 500mg/L in 2009–10 to 270mg/L in 2013–14 due to improvements to on-site operations and management of surface waters in recent years.

22 Lower Hunter River Health Monitoring Program – Literature and data review

Table 2: Approximate annual loads of contaminants discharged to the North Arm of the Hunter River through Orica's effluent pipe (EPA licensed point 23) Data are approximate only as they based on mean concentrations of contaminants and mean daily discharge volumes provided by Orica to the EPA in its annual returns. Reporting Arsenic Chromium (VI) Zinc Total nitrogen TSS Oil &grease period kg/y kg/y kg/y kg/y kg/y kg/y 2009–10 - 1.5 9272 200,903 255 850 2010–11 8.2 16.4 247 200,563 9617 904 2011–12 10.8 10.1 216 191,753 9371 721 2012–13 18.5 5.6 371 189,906 10,375 834 2013–14 18.4 <9 276 190,247 14,705 735 2014–15 9.1 <9 273 143,000 10,013 546

Figure 6: Average concentrations of total nitrogen (mg/L) in discharges from Orica stormwater drains (EPA monitoring points 10, 14 & 15) to the South Arm and from Orica stormwater drains (EPA monitoring points 11, 12 & 13) to the North Arm for each reporting period (April through to March) Each point drains individual catchments on the Orica site. Ammonium is stored in Catchment 1. A small section of the ammonium plant is situated in Catchment 2 with the main area situated in Catchment 3. The nitric acid plant is in Catchment 4. Ammonium nitrate is stored in Catchment 5 and shipped out from Catchment 6.

Nitrogen load from Orica’s Kooragang Facility in context URS compiled indicative nutrient contributions to the Hunter River arising from diffuse and point sources within the Hunter River catchment (URS 2012b) using data from the National Pollution Inventory (NPI). Diffuse source data was from the 1999–2000 reporting period and point source data was from the 2010–11 reporting period. In this analysis it was estimated that 5214 tonnes of total nitrogen (TN) enter the river each year from point and diffuse sources in the catchment (URS 2012b). In 2010–11, Orica’s Kooragang facility discharged approximately 210 tonnes of TN from the effluent pipe to the North Arm (Table 2) of the

23 Lower Hunter River Health Monitoring Program – Literature and data review

Hunter River which represents approximately 4% of the TN load from the entire catchment. Orica’s Kooragang facility only occupies an area of approximately 0.25 square kilometres, or 0.001% of the entire Hunter River catchment (22,000 square kilometres), and yet it discharges 4% of the total TN load to the estuary. Discharges from Orica’s Kooragang facility are disproportionate to its small size, making it a significant hotspot for nitrogen pollution in the lower Hunter River catchment. When one considers only dissolved inorganic nitrogen (DIN) inputs to the lower Hunter estuary, this disproportionate effect is magnified considerably. Ammonium is a form of DIN that is readily bioavailable, that is, rapidly used by plants for growth; this can have adverse effects on aquatic ecosystems if present in excessive amounts. Any facility that discharges or emits more than 10 tonnes of ammonium, or 15 tonnes of TN, to air, land or waters is required to report its emissions annually to the NPI. Orica discharged 130 tonnes of ammonium in effluent to the North Arm of the Hunter River in 2010–11 which represents 60% of the total TN discharged from this licensed point. The proportion of DIN to TN discharged in effluent in the past three reporting periods (2011–12, 2012–13, 2013–14) has been steady at 50% of the TN load. Given the nature of operational activities at this site, it is highly likely that nitrates make up most of the remaining proportion of TN reported by Orica to the NPI. If we consider only ammonium inputs from the major point sources in the lower estuary (that is, those listed on the NPI), then discharges of ammonium from Orica’s Kooragang facility account for 98% of the total ammonium load to the lower estuary. This figure does not take into account the ammonium being discharged by other licensed and unlicensed premises, however, these inputs are likely to be small by comparison. Stormwater discharges of nitrogen from the Orica site are not reported to NPI and are thus not included in this calculation. Nor have contributions from atmospheric deposition of air pollutants emitted from the Orica site been included in this calculation. Ambient climatic conditions have a large influence on the proportion of gaseous nitrogenous pollutants emitted to air that subsequently enter estuary or oceanic waters via atmospheric deposition at the air–water interface. In the 2013–14 reporting period, 45 tonnes of ammonium, 16 tonnes of nitric acid and 620 tonnes of oxides of nitrogen (nitrates and nitrites) were emitted to air from stacks at the Orica Kooragang facility. The larger wastewater treatment works (WWTW) in the region operated by Hunter Water Corporation (HWC) are the only other industries listed in the NPI (in addition to pesticide and chemical manufacture industries) (www.npi.gov.au). Five WWTW are listed in the NPI for discharging significant quantities of nitrogen to the Hunter River (Morpeth, Singleton, Cessnock, Dungog and Shortland), however, most of these discharge to the upper estuary. Only Shortland WWTW discharges treated effluent to the lower Hunter estuary. Shortland WWTW discharged 1.8 and 2.2 tonnes of ammonium to the South Arm in 2012–13 and 2013–14, respectively, which comprised approximately 5% of the TN discharged from the site in each reporting period (www.npi.gov.au). The annual reports for the Shortland WWTW state that over 190 and 98 tonnes of ammonium were reprocessed on site in 2012–13 and 2013–14, respectively, substantially reducing the nitrogen load being discharged to the river. Reprocessing and recycling of nitrogen waste for re-use on site or elsewhere is the way forward to reduce the load of pollutants discharged to the estuary by chemical and fertiliser industries.

Incitec Pivot Limited The Incitec Pivot Limited (IPL) site currently operates as a fertiliser bagging and distribution centre handling phosphorus (e.g. super phosphate) and nitrogen-based products (e.g. mono- and di-ammonium phosphates, urea) on Walsh Point. The facility also receives, stores and dispatches sulfuric acid and ammonium nitrate in bulk. The site has been used for a range of fertiliser manufacturing and storage purposes over the past 40 years. The existing stormwater pipe network drainage to the western boundary collects stormwater from the site

24 Lower Hunter River Health Monitoring Program – Literature and data review and discharges via the north, south and central drains, corresponding to three licensed monitoring points 1, 2 and 7. Stormwater discharged from each of these drains is monitored monthly for quality during discharge, in accordance with EPL 11781. These drains connect to drainage infrastructure along Heron Road, Kooragang so stormwater from the site mixes with runoff from Heron Road before discharging to the South Arm of the Hunter River (JBS Environmental 2005). The requirement for monitoring of constituent species for nitrogen and phosphorous compounds and volumes of discharge as a condition of EPL 11781 was first implemented in July 2013. Composite grab samples representative of discharge concentrations are collected and analysed for pH and concentrations (mg/L) of TSS, sulfur, sulfate, zinc (dissolved and total), ammonium, nitrite, nitrate, total kjeldahl nitrogen, total nitrogen, total phosphorous, phosphorous reactive, phosphate and sulfide (dissolved and total). The IPL site discharges an estimated 60,000kL of stormwater to the South Arm annually (IPL 2015). The current EPL does not impose any limits on concentrations or volumes discharged from the site. As such IPL must comply with the general obligation not to cause off-site water pollution under s.120 of the Protection of the Environment Operations Act. The site has been the subject of a number of pollution reduction programs in recent years which have improved site surface water and stormwater management, reduced tracking of materials and captured pollutants from the road bulk load out area for off-site disposal. BMT WBM was contracted by IPL to review the effectiveness of recent stormwater management improvements for the period July 2012 to 30 September 2014 (BMT WBM 2014). Table 3 shows the average concentrations of contaminants in discharges before significant improvements were made on site. Average concentrations of total nitrogen in discharge waters have decreased substantially from 2010–11 to 2013–14 (Table 4) suggesting that on- site improvements addressed in a number of pollution reduction programs are taking effect.

Table 3: Water quality data for discharges from Incitec site at EPA monitoring points 1, 2 & 7 (northern, southern and central drains) May 2009 to December 2011 (URS 2012b) This data was collected before considerable improvements to stormwater management on site. Point 1 Point 2# Point 3 Parameter (mg/L) Max Min Mean Max Min Mean Max Min Mean Total nitrogen (as N) 488 8.8 9.7 383 2.3 55 746 5.2 99 Phosphate 760 7.4 145 488 8.3 100 342 14.0 104 Zinc 3.69 0.12 0.85 3.0 0.071 0.64 2.94 0.22 0.96 TSS 680 14 136 1126 7 176 498 14 122 pH (pH units) 7.8 5.9 6.44 7.3 2.9 5.81 8.8 2.6 6.10 # Concentrations (mg/L)

Table 4: Average total nitrogen (mg/L) in stormwater discharges from Incitec site at EPA monitoring points 1, 2 & 7 (northern, southern and central lines) 2010–11 to 2013–14 This data reflects some improvement to stormwater management on site (Source: annual returns submitted to EPA). Total nitrogen – average (mg/L) Monitoring point 2010–11 2011–12 2012–13 2013–14 1 – northern drain 206 87 146 99 2 – southern drain 157 28 48 83 7 – central drain 66 52 108 70

25 Lower Hunter River Health Monitoring Program – Literature and data review

Weighted average concentrations for TSS, TP, TN and total zinc (TZ) were used to estimate loads coming off the Incitec site to reflect total loads coming off the site (URS 2014b). The estimated average annual load reductions for a representative 10-year period (Table 5) indicate the recent works completed on site have reduced nutrient loads in stormwater by more than 20% (URS 2014b). The estimated average annual loads of TSS and TZ have reduced by 38% and 55% respectively. Drainage line cleaning in particular was thought to be a key contributor to the estimated load reductions. These pollutants are most associated with runoff from road and roof surfaces. The management of spills from access roads and the installation of a wheel wash bay are also likely to have contributed to the reduction in pollutants loads discharged to the estuary (URS 2014b).

Table 5: Estimated annual loads of contaminants in stormwater discharge from Incitec drainage lines based on weighted average concentrations in discharge before and after significant improvements were made on site (URS 2014b) TSS = total suspended solids, TP = total phosphorus, TN = total nitrogen, TZ = total zinc Pre-December 2012 Post-December 2012 (kg/year) (kg/year) TSS TP TN TZ TSS TP TN TZ 1 – northern drain 6200 1900 3300 46 3900 1600 2600 19 2 – southern drain 600 100 200 7 500 100 200 4 7 – central drain 900 400 500 3 400 200 300 2 Total load 7700 2400 4000 56 4800 1900 3100 25 Load reduction (%) – – – – 38 21 23 55

2.10 Urban inputs Domestic use of chemicals high in ammonium and phosphate (cleaning products, washing detergents and fertilisers), animal waste and human biological waste are the primary sources of nutrient pollution from urban areas.

2.10.1 Wastewater

Wastewater treatment plants Treated sewage effluent is the primary point source of pollution arising from urbanised areas. Three wastewater treatment works (WWTW) operated by Hunter Water Corporation at Morpeth, Raymond Terrace and Shortland discharge secondary treated effluent to the Hunter River estuary. The majority of human effluent from the Newcastle region is treated at Burwood Beach WWTW which discharges at ocean outfalls and not to the estuary. The quality of treated sewage effluent discharging to the estuary from WWTW at Morpeth, Raymond Terrace and Shortland is monitored as a condition of EPLs 10693, 217 and 1683. Morpeth and Raymond Terrace WWTW discharge treated effluent to the upper estuary and Shortland WWTW discharges to the lower estuary. Treated effluent usually contains low counts of faecal coliforms, and 1–10mg/L of nutrients, oil/grease and suspended solids. However, very large volumes (thousands to millions of litres) of treated effluent are discharged from these WWTW daily. Following periods of heavy rainfall, high counts of faecal coliforms are often found in urban waterways that receive stormwater runoff. This is the result of overflows occurring in the sewerage network as a result of increased stormwater flows, resulting in untreated sewage

26 Lower Hunter River Health Monitoring Program – Literature and data review entering the stormwater network, which drain into the estuary. In some cases during heavy rainfall, untreated sewage may be diverted to storage ponds holding treated effluent, which in turn may overflow into adjacent creeks, creeks leading to the estuary.

Smaller sewage treatment systems Some areas of Hexham, Tomago, Mayfield North and Kooragang Island are not joined to the reticulated sewerage network. Small sewage treatment systems service industrial sites while septic systems remain on some domestic properties. Effluent entering the river from these areas is not treated to the same quality as that discharged from the larger treatment plants.

2.11 Pollutant export rates Surface runoff across a catchment during rainfall carries sediment and pollutants from the land into the nearest waterway. The pollutants carried in overland flow or leached into groundwater are referred to as diffuse source pollution. Different land uses generate differing amounts of diffuse pollution, with the largest quantities of nutrients being exported from intensive horticulture and agriculture, and low-scale urban areas without sewage disposal or treatment systems. The concentration of total nitrogen (TN) and total phosphorous (TP) generated in the catchment and exported to waterways can be estimated from land-use information and nutrient generation rates developed for particular land-use types. The Hunter Estuary Processes Study (MHL 2003) analysed nutrient generation in each of 14 subcatchments of the Hunter River estuary standardised to area (per hectare) to identify ‘hotspots’ (Marston 1993; Smalls 1986; USEPA 2001; MHL 2003). The largest export rates occur in the subcatchment of Throsby Creek, Kooragang Island and Ironbark Creek which indicates that the Newcastle urban areas contribute significantly to nutrient loads in the estuary.

2.12 Inputs from the wider catchment Inputs from the wider catchment are a mixture of urban runoff and point sources (WWTW) from regional centres, mine discharge and diffuse runoff from agricultural land. This runoff is delivered to the estuary via the Hunter River and associated tributary rivers and streams. Pressures on the State’s natural resource assets including estuaries and coastal lakes were compiled in State of the Catchment reports (DECCW 2010a, b). In these reports it was estimated the entire catchment of the Hunter River exports approximately 3042 tonnes of nitrogen, 390 tonnes of phosphorus and 96,685 tonnes of suspended solids per annum to the estuary (DECCW 2010a, b). These estimates of annual sediment and nutrient exports were based on modelling of freshwater surface flows generated for different land-use classes, and data on measured median sediment and nutrient concentrations obtained from published scientific literature, and from NSW Government agencies, that was collected up to 2009. Based on these loads plus measures of land clearing and population change in the Hunter catchment, the Hunter estuary was given a HIGH overall pressure rating. Pressure and condition data for the Hunter estuary are discussed further in a later section. URS (2012b) compiled another estimate of the total nutrient load exported to the Hunter River based on data in the National Pollution Inventory. In the URS estimate, point source data and diffuse data are based on 2010–11 and 1999–2000 reporting periods, respectively. Total nitrogen input to the Hunter River was estimated at 5214 tonnes per annum. Total phosphorous input to the Hunter River was estimated at 573 tonnes per annum. Diffuse data used in this estimate is from 15 years ago and is likely to have changed considerably either through altered land use or implementation of best practice. Likewise, point source emissions from industry have possibly improved though pollution reduction programs while inputs from WWTW are likely to have increased due to the growing population in the region.

27 Lower Hunter River Health Monitoring Program – Literature and data review

3 Condition

Estuary health is the proper ecological functioning of the estuary. It is best measured as ecological outcomes, and is influenced by the status of a variety of physical and chemical properties collectively called ‘water quality’. For example, salinity, pH, temperature and dissolved oxygen are measured routinely in water quality assessments. Concentrations of nutrients and suspended solids (including sediment) in estuary waters are measured occasionally in some programs. Estuary health cannot be assessed by measuring water quality alone. These data, however, can provide insight on inputs of pollutants to the system, such as nutrients and sediment, under a given set of environmental conditions. Many processes that affect the nutrient concentrations in estuaries, for example, river flows, stormwater drainage, industrial inputs, sewage inputs, have magnitudes that fluctuate greatly with changing seasons and weather conditions. Any given data set only provides a snapshot of water quality in that location at the time of collection. Water quality data along with a suite of biological indicators (chlorophyll-a, macrophyte distribution, macroinvertebrate assemblages and condition, fish assemblages and condition, sediment microbial function) ought to be assessed for a comprehensive assessment of estuary condition.

3.1 NSW water quality objectives and national water quality guidelines Over the past decade, governments have opted for a holistic approach to the sustainable management of natural resources. The NSW Water Quality Objectives provide goals focused on management of waterways in order to maintain the relevant environmental values (aquatic ecosystem protection, recreational amenity, visual amenity, drinking water and agricultural waters) chosen by the community. This guidance is intended mainly for local councils and State government to consider and include in strategic, catchment and land-use planning. They are based on measurable environmental values. Importantly, the guiding principles are that where the environmental values are being achieved in a waterway, they should be protected, and where the environmental values are not being achieved in a waterway, all activities should work towards their achievement over time. The Australian National Water Quality Management Strategy (NWQMS) aims to achieve the sustainable use of Australia's and New Zealand's water resources by protecting and enhancing their quality while maintaining economic and social development. The Australian and New Zealand Guidelines for Fresh and Marine Water Quality (commonly referred to as the ANZECC guidelines) are a key document in this strategy (ANZECC & ARMCANZ 2000). The ANZECC guidelines provide criteria for screening of contaminant concentrations in groundwater or surface waters for the protection of: • 99% of marine species for ‘pristine’ systems • 95% of marine species for ‘slightly to moderately disturbed’ systems • 80% of marine species for ‘highly disturbed’ systems. The general policy nationally is that the level of protection applied to most waterways is the protection of 95% of marine species. A lower level of 80% protection may apply to ‘highly disturbed’ systems, however, the 80% protection level may only be considered as a short- term measure (e.g. a maximum of five years in many cases), with the aim of eventually restoring it to the 95% status. It is not acceptable to allow poor environmental management to continue beyond the short term. The lower Hunter River estuary is classified in accordance with guidance documentation as a ‘Waterway Affected by Urban Development’ and as a ‘highly disturbed ecosystem’, or ‘Condition 3 Ecosystem’.

28 Lower Hunter River Health Monitoring Program – Literature and data review

3.2 Historical condition measures

3.2.1 Closures under the Fisheries and Oysters Farms Act 1935 Decades of chronic water pollution led to the enrichment of riverbed sediments with industrial contaminants. Analysis of surface sediments for compliance with dredging specifications detected high concentrations of heavy metals in sediments from Newcastle Harbour in the mid-1970s, and from the South Arm in the 1980s (MSB 1976, 1989). Concentrations of lead and zinc in oysters collected from the South Arm of the Hunter River in 1987 were found to be up to three times the National Food Authorities’ Maximum Residue Limits (NFA MRL) for commercial sale. In September 1987, the South Arm was subject to oyster and mussel collection closures for 20 years, gazetted under the Fisheries and Oyster Farms Act 1935 (NSW Gazette No.126). In 1985, a 20-year fish and oyster ban was placed on Throsby Creek, north of Cowper Street Bridge in case of contaminated marine life, and on fishing by means of mesh nets downstream of the State Dockyard Wharf to the breakwaters at the river mouth to prevent depletion of bass and blue groper stocks. Neither of these bans have been lifted due to the high levels of industrial contaminants in river sediments in the South Arm and Throsby Creek. Despite concerns about pollution, a prawn fishery still operates in the Hunter River estuary with the bulk of fishing activity carried out in the North Arm between Hexham and Raymond Terrace.

3.2.2 Contaminants in aquatic environments The most common contaminants in urban and industrial runoff are organochlorine compounds (OCC), heavy metals, polycyclic aromatic hydrocarbons (PAH), total petroleum hydrocarbons (TPH), nutrients (nitrogen and phosphorous) and sediment. Sediments play an important role in the cycling of contaminants, being both intermediate and final sinks for pollutants (Hart 1982; Phillips & Rainbow 1993). Many industrial chemicals persist in the environment due to their hydrophobic nature and the inability of microorganisms to metabolise or breakdown complex chemical structure. These properties cause these chemicals to accumulate in organisms and the effect is magnified up the food chain – hence the name ‘persistent organic pollutants’ (Edge et al. 2014; Weijs et al. 2013). Degraded environments also appear to favour invasive species over native species (Dafforn et al. 2009). OCC were widely used in industry and as pesticides although dichloro-diphenyl- trichloroethane (DDT) use has been banned in Australia since 1987. Chlordane and dieldrin were widely used as termiticides in the housing industry, and as pesticides in agricultural and urban settings, while polychlorinated biphenyls (PCB) were used widely in electrical equipment. OCC were introduced to the marine environment through industrial discharge and urban runoff and are known as persistent organic pollutants, as they bind to soil particles and accumulate in the fatty tissues of animals (Hardiman & Pearson 1995; Scanes 1997; Weijs et al. 2009, 2013). The use of many OCCs is banned in Australia due to greater awareness of their toxicity and persistence in nature. Steelmaking generated many pollutants which led to extensive contamination of the main site of BHP Steelworks at Mayfield, Newcastle and adjacent riverbed sediments (discussed in Section 2.7.2). Operation of sinter plants and coke ovens produced dust, heavy metals, sulfur dioxide, hydrochloric acid, hydrofluoric acid, PAH and persistent organic pollutants; pelletisation and operation of blast furnaces generated large volumes of wastewater containing these pollutants. Historically, estuary waters and sediments, and biota in the vicinity of BHP Steelworks, were heavily impacted by industrial pollutants from the site culminating in the closure of the South Arm to oyster and mussel collection in 1987. Estuaries are efficient sinks for heavy and trace metals (henceforth referred to as metals) in particular due to the geochemistry that occurs in estuarine waters. Changes in salinity, pH

29 Lower Hunter River Health Monitoring Program – Literature and data review and redox occur when large volumes of industrial wastewater enter estuary waters, inducing metal sorption processes where metals adhere to suspended sediment particles which ultimately settle to the bed of the waterway. Metals are mainly adsorbed to the fine sediment fraction so sediments that contain a large proportion of fine grain fraction have a greater capability of accumulating contaminants compared with more coarse sediments (Krumgalz et al. 1992). Enriched sediments also act as a source of contaminants in the estuary when sediments are disturbed or resuspended into the water column through dredging and shipping activity, and hence become available to biota (Edge et al. 2014). Industrial wastewater discharged to rivers and estuaries leads to increased concentrations of dissolved and particulate metals in the water column which in turn accumulate in sediments and some aquatic organisms (The Ecology Lab 1998; Ingelton 1994; Phillips & Yim 1981; Birch et al. 1997). All metals have background concentrations and are expected to be found in environmental samples, such as oysters and sediments (Underwood & Chapman 1995; Scanes & Roach 1999; Roach 2005; Robinson et al. 2005). Some metals are essential, mainly in trace concentrations, for various metabolic processes in organisms. However, above certain concentrations metals and other contaminants may become acutely or chronically toxic to benthic or benthic-associated fauna. Metal toxicity causes adverse effects on reproductive processes, enzyme function and metabolism in aquatic organisms (Cox 1995). Metal toxicity will impact human health if contaminated seafood is consumed. Metal burdens in oysters are indicative of current or recent pollution of the waterway, as oysters have been shown to lose their trace metal burdens once exposure is removed (Pringle et al. 1968; Phillips & Rainbow 1993).

3.2.3 Water quality assessments In the following analyses, the procedures set out in the National Water Quality Management Strategy were used to assess the status of state variables. Concentrations of potential toxins (metals and organic contaminants) were compared to the ANZECC guideline screening level for 80% protection of marine species. The ANZECC guidelines also provide default trigger values for biophysical and chemical variables in a range of types of water body but strongly recommend that locally relevant trigger values be derived and used where possible. The NSW Natural Resources Monitoring, Evaluation and Reporting Program (MER) has developed trigger values for NSW estuaries (referred to below as NSW trigger values) from a + 3- statewide dataset for TP, TN, ammonium (NH4 ), nitrate and nitrite (NOx), phosphate (PO4 ), turbidity and chlorophyll-a. NSW trigger values are the 80th percentile of data for reference systems and are specific to different types of estuary and, for rivers, to biophysical zones (delineated by salinity) within the estuary.

Water quality data collected by NSW Government agencies Very little water quality data was collected in the Hunter River before 2000. The State Pollution Control Commission (SPCC) collected water quality data in the South Arm and Fullerton Cove in 1977–78 (Table 6). The data reflect the heavily industrialised catchment of the South Arm in particular with extremely high levels of zinc (595µg/L) which is over ten times the ANZECC guideline screening level for 80% protection of marine species (43µg/L). There is no trigger level provided for iron but extremely high levels (2808µg/L) were measured in the South Arm, undoubtedly related to the iron-ore smelting at the nearby Steelworks. Levels of ammonium and orthophosphate are also extremely high especially considering these nutrients are rapidly metabolised by biota so levels suggest saturation of the water column. The concentrations of ammonium and phosphate were 30 and 60 times higher than the NSW trigger values of 8µg/L and 2.8µg/L for riverine estuaries (saline reaches), respectively. Concentrations of phosphate in Fullerton Cove in 1977–78 were almost 20 times the NSW trigger value, and are likely to be derived from agricultural land use in the catchment.

30 Lower Hunter River Health Monitoring Program – Literature and data review

Table 6: Water quality data collected by State Pollution Control Commission 1977–78 from the South Arm adjacent to the Steelworks site and in the middle of Fullerton Cove Mean of four measurements; data reproduced from Hodda & Nicholas (1986). South Arm Fullerton Cove Pollutants (µg/L) 1977–78 1977–78 Iron 2808 195 Zinc 595 18 Lead 21 0 Ammonium 256 0 Orthophosphate 176 49

Table 7: Water quality data collected by BHP in 1982 from the South Arm adjacent to the Steelworks site and the North Arm near the entrance to Fullerton Cove Data reproduced from Hodda & Nicholas (1986). Metallic pollutants = total filterable + non-filterable recoveries. Pollutants (µg/L) South Arm 1982 North Arm 1982 Iron 3600 - Zinc 76 - Lead 24 - Ammonium 462 0 Orthophosphate 26 10

Table 8: BHP water quality data (µg/L) from 1998, presumably collected in the South Arm and Steelworks channel – sampling locations map cited in GHD (2001) was missing

ANZECC Location Heavy metal trigger 1 2 3 4 5 6 7 (µg/L) values* (µg/L) Non-filterable residues (mg/L) 16.2 18.3 14.7 – 13.1 13.6 16.6 pH (pH units) 8.0 8.1 8.1 8.0 8.1 8.1 8.1 Temperature (°C) 21.2 20.7 21.2 20.8 20.2 20.1 20.0 Manganese (µg/L) 80** 54.8 61.2 67.1 44.3 39.9 52.7 43.3 Cyanide (µg/L) 2, 14# 3 8 7 5 4 3 3 Phenols (µg/L) 270, 720 2 10 15 2 3 3 3 Nitrates (µg/L) 5.1^ 320 320 5040 300 280 280 2510 Orthophosphate (µg/L) 2.8^ 40 40 30 30 30 30 40

Source: BHP (1998) cited in GHD 2001. *ANZECC trigger values citing guideline values for 99% and 80% protection of aquatic ecosystems. **ANZECC interim guideline value. #ANZECC guideline value for un-ionised cyanide HCn. ^NSW trigger value for nitrate/phosphate in saline reaches of riverine estuaries. Data on metal concentrations were collected by the EPA in the 1990s and reported by ERM Mitchell McCotter (1996). Data were difficult to interpret as low detection limits for analyses at the time were well above ANZECC guideline concentration values (for example, cadmium: detection limit of 100µg/L and guideline values of 0.7–36 µg/L). Only concentrations of lead and zinc in estuary waters were above detection limits. Very high levels of zinc are reported in the lower North Arm (up to 930µg/L) and one likely source is Orica’s effluent pipe which

31 Lower Hunter River Health Monitoring Program – Literature and data review discharges to the North Arm (ERM Mitchell McCotter 1996). Orica discharged 270kg of zinc in their effluent pipe in 2014–15 however 920kg of zinc was discharged in 2009–10 (Table 2: annual returns submitted by Orica to EPA). Very high levels of lead were reported in the South Arm nearby the Steelworks (ERM Mitchell McCotter 1996).

Water quality data collected by BHP Water quality data collected by BHP in the South Arm in 1982 (Table 7) show similar concentrations to 1977–78 (Table 6) except for higher levels of ammonium and lower levels of zinc. Metals were not detected in the North Arm near Fullerton Cove and there were moderate levels of phosphate (10µg/L) implying this mid-section of the North Arm is least impacted by industry. Water quality data were also collected by BHP in 1998 (Table 6), however, the source document was missing the map showing the exact location of sampling sites (GHD 2001). As the water quality data were collected by BHP, the sites are most probably in the South Arm and Steelworks Channel (i.e. the main channel of Newcastle Harbour leading to the South Arm). Most notable are the extremely high levels of nitrates in the water column at most locations (280–320µg/L) with extraordinarily high levels at locations 3 and 7 (5040 and 2510µg/L). Based on pollutant concentrations it is possible that location 3 was a sampling point near the main discharge drain from the BHP site, while location 7 may have been nearer to stormwater drains from sites on Walsh Point. Concentrations of nitrate in the river locations were at least 50 times higher than the NSW trigger value of 5.1µg/L for nitrate/nitrite in saline reaches of riverine estuaries.

Sanderson & Redden 2001 Data collected by Hunter Water Corporation (HWC; 1993–2000) and by the EPA (1975– 2000) on 25 water quality variables were compiled into a database by Sanderson & Redden (2001). Data were collected at irregular spatial and temporal scales with the majority collected between 1997 and 2000. Data collected by HWC also had a wet-weather bias when higher concentrations of pollutants are expected in receiving waterways. Sanderson & Redden (2001) made the following qualitative assessment of trends through time and space using the compiled dataset, though the acknowledged biases should have been more explicitly taken into account when interpreting patterns. • Dissolved inorganic nitrogen (DIN = ammonium and nitrates/nitrites – NOx) levels in the estuary were high with a distributed source of DIN along the lower reaches of the river. • NOx had increased slightly in the North Arm and South Arm from 1975–2000. • Ammonium concentrations were stable. • A weak source of total phosphorous (TP) was located around 40 kilometres upstream (between Raymond Terrace and Morpeth) with TP decreasing downstream probably due to settling of particulate phosphorous. • Chlorophyll-a concentrations were high upstream with concentrations decreasing downstream towards the mouth (Figures 9, 10). • Nutrients and chlorophyll-a concentrations in the estuary well exceeded ANZECC guidelines. The spatio-temporal properties of all chlorophyll-a data collected between 1975 and 2000 indicate the highest concentrations occurred in the lower estuary in the 1980s, and in the mid to upper estuary in the early 1990s. The majority of data from the mid to late 1990s were collected in the lower estuary so no spatial trends are available, and consistent temporal trends are not apparent (Figure 7). Time-averaged means of chlorophyll-a along the length of the estuary (Figure 8) indicate that chlorophyll-a concentrations were highest upstream, decreasing towards the mouth. All available data on state and biological variables collected in the Hunter estuary from 1975–2000 are presented in a variety of spatio-temporal contexts in Sanderson & Redden (2001).

32 Lower Hunter River Health Monitoring Program – Literature and data review

Figure 7 Chlorophyll-a (µg/L) data collected between 1975 and 2000 along the length of the estuary Chlorophyll-a data (Y-axis) was collected on the date shown (X-axis) at variable distances upstream from the mouth (Z-axis).

Figure 8: Time-averaged concentrations of chlorophyll-a data (µg/L) collected between 1975 and 2000

Top plot, median: bold font and mean: normal font. Based on all data collected at different locations from estuary mouth (0 km) and sites further upstream (bottom plot) (Sanderson & Redden 2001).

33 Lower Hunter River Health Monitoring Program – Literature and data review

Water quality in Throsby Creek, Hunter Water Corporation Hunter Water Corporation conducted limited stormwater sampling in Throsby Creek in the late 1990s at the Hannell Street Bridge. Dry weather samples were taken monthly and wet weather samples were collected during significant rain events meaning the data is skewed towards wet conditions. It should also be noted that urban runoff concentrations would be diluted by incoming tides as the creek is tidal at the Hannell Street Bridge. The small samples size (~ 20 samples) is insufficient enough to draw conclusions from about the overall quality of stormwater entering the creek but provides some indication. Suspended solids (SS) were high in Throsby Creek in 1998–99 due to sediment runoff from roads, denuded banks and median strips in the Throsby Creek catchment. Faecal coliform levels were high which is expected after a rain event. Nitrogen and phosphorous levels also significantly exceed ANZECC guidelines (Table 9).

Table 9: Water quality in Throsby Creek sampled by Hunter Water in 1997–98 monthly and during rain events (n=20); data extracted from a table in Newcastle City Council’s Stormwater Management Plan (NCC 2004) Max rain Parameter Sampling dates Min Max Mean (mm) Biological oxygen demand (mg/L) 8/5/96 to 20/11/98 5 6 5.04 101.4 Dissolved oxygen (mg/L) 2/7/97 to 20/11/98 3.62 9.1 6.96 101.4 Faecal coliforms (col/100ml) 13/12/95 to 4 36000 6303 52.4 20/11/98 Suspended solids (mg/L) 2/7/97 to 20/11/98 14 388 61 101.4 Total organic carbon (mg-N/L) 13/12/95 to 0.01 1.6 0.34 52.4 20/11/98 Total phosphorous (mg-P/L) 13/12/95 to 0.016 0.39 0.12 52.4 20/11/98

3.2.4 Sediment condition

Broadscale survey of sediment contamination in lower estuary An extensive survey of contaminants in sediments from the Hunter River estuary in the early 1990s found sediments to be highly enriched in metals and other contaminants in undredged areas of Throsby Creek, the South Channel and Newcastle Harbour (Batley & Brockbank 1992; Ingleton 1994). Metal concentrations in surficial sediments were consistently greater than three times background levels, and half of the metal load was biologically available. Dieldrin, chlordane, dichloro-diphenyl-dichloroethylene (DDE) and DDT were present in significant concentrations above suggested criteria in undredged sediments directly adjacent to the harbour (Ingleton 1994; Birch et al. 1997) whereas sediments within dredged areas of the harbour had negligible levels of organochlorine and pesticide contaminants (Batley & Brockbank 1992). Four geochemically distinct areas were identified in the lower estuary where regionally distinct distributions of metallic contaminants suggested separate sources (Birch et al. 1997). The more diverse mix of metals in Throsby Creek (chromium, copper, lead and zinc) reflected a varied source of light industry. Anomalously high cadmium concentrations in Throsby Basin suggest it has a separate source to that of Throsby Creek, probably as a consequence of loading operations (Birch et al. 1997). A large progressive decrease in metal concentrations down Steelworks Channel strongly suggested that the Steelworks was a

34 Lower Hunter River Health Monitoring Program – Literature and data review more substantial source of metallic contamination than the coal-loading operations occurring at the time. The process of enrichment of sediments was found to be rapid (at the time) as metal concentrations increased rapidly in unpolluted sediments that were introduced into dredged areas of the harbour (Birch et al. 1997). Deep sediment cores from adjacent to BHP Steelworks revealed the impact this industry had on sediment quality. Coal tar and coal were commonly found deep within sediments (100– 300mm) while the upper 200mm of sediment cores had a strong hydrocarbon and diesel odour. These cores also had enriched concentrations of zinc, lead and cadmium. Metal concentrations in local bituminous coals are low compared to world averages (Swaine 1977), however, cadmium, copper, lead and zinc are substantially higher in slag, a by-product of steelmaking. Slag in several cores taken adjacent to this smelter indicated a nearby waste dump site (Birch et al. 1997). Industrial waste was commonly used as landfill for site and port expansion or was commonly disposed of in unlined pits.

Analysis of maintenance dredge spoil Newcastle Harbour and the South Arm of the Hunter River require continual maintenance dredging to maintain deepwater access. Dredge spoil which complies with defined contaminant load criteria is allowed to be disposed of at sea at a pre-designated dump site. Contaminant concentrations in maintenance dredge sediments are not checked every time, but occasionally undergo checks that contaminant loads in spoil meet guidelines for disposal at sea (ANZECC 1998; Environment Australia 2002). Analysis of surface sediments from various sites in Newcastle Harbour in the mid 1970s, and from the South Arm of the Hunter River in the 1980s, detected high concentrations of heavy metals (MSB 1976, 1989). WorleyParsons (2011) compiled all available data on dredge spoil analysis of contaminants from 1985 to 2009. Concentrations of zinc in surficial sediments (50–100mm depth) from Throsby Creek, Throsby Basin and the lower South Arm or ‘Steelworks Channel’ usually exceeded the screening level of 200mg/kg and often exceeded the maximum level of 410mg/kg for the period 1986–1993. Deeper cores from Throsby Basin revealed extremely high levels of zinc (2000–5000mg/kg) and manganese (4500–10,500mg/kg) and other contaminants which ultimately led to the cessation of dredging in Throsby Basin as contaminant loads were too high for disposal at sea. Sediments from areas that were continually dredged usually had lower levels of contaminants due to frequent removal by dredging and replacement with uncontaminated upper estuary muds.

Sediment analysis in the South Arm for extension of shipping channel The Commonwealth Scientific and Industrial Research Organisation (CSIRO) was engaged by Newcastle Port Corporation to assess the suitability of dredged sediment for disposal at sea, in accordance with the ANZECC Interim Ocean Disposal Guidelines (1998). The initial studies by CSIRO assessed the chemical contaminant load and ecotoxicology of selected sediments from the South Arm (Simpson et al. 2001a, b). These tests included analyses of total sediment concentrations of metals and PAH, analyses of acid volatile sulfide and simultaneously extracted metals (bioavailable component), radionuclides, tributyltin, elutriate tests for metals, PAH and organochlorine pesticide release, and toxicity tests using bioassays with benthic microalgae and burrowing amphipods (Simpson et al. 2001a, b). Concentrations of acid-soluble zinc, lead, mercury and nickel, and PAHs in the tested sediments exceeded ANZECC guidelines, however, it was concluded that in the majority of sediments tested, the contaminant load was largely not bioavailable (Simpson et al. 2001a, b). When analysing sediments closer to the BHP site, concentrations of PAH were considerably higher and whole sediments were considerably more toxic in bioassays (Simpson et al. 2001c). Approximately half of the sediments adjacent to the BHP site had total PAH concentrations up to 3 times the guideline screening level for disposal at sea, and individual PAH concentrations (e.g., naphthalene) were up to ten times the guideline

35 Lower Hunter River Health Monitoring Program – Literature and data review maximum level (Simpson et al. 2001c). It was these findings that led the EPA to declare these sediments as significantly contaminated lands (discussed later). Further testing was sought to determine the contaminants that were the principal cause of toxicity in sediments adjacent to the former BHP Steelworks, and the relationship between contaminant concentration and toxicity to marine organisms (Simpson et al. 2001d). Chemical analyses and toxicity testing eliminated metal contaminants (Ag, As, Cd, Cu, Hg, Ni, Pb, Se and Zn), organochlorine pesticides, ethylbenzene and xylene (BTEXs) and dissolved sulfide and ammonium as possible toxicants (Simpson et al. 2001d). The study concluded that PAHs were the only possible toxicants in those sediments exhibiting a toxic effect in bioassays (Simpson et al. 2001d). This study also concluded that sediment with total PAH concentrations greater than 200mg/kg (normalised to 1% total organic carbon [TOC]), were unsuitable for unconfined sea disposal. Concentrations less than 100mg/L total PAHs were deemed as posing a low risk to marine organisms and thus suitable for unconfined sea disposal (Simpson et al. 2001d). Further investigation into the contaminants causing toxicity found the lowest total PAH concentration to cause any toxicity was 75mg/kg while the lowest TPH concentration to cause toxicity was 450mg/kg (Simpson et al. 2002). These results only apply to acute toxicity tests so the concentrations of PAH and TPH that cause chronic effects on marine organisms remain unknown. Based on available data and the possibility of chronic effects, the authors recommended that for the protection of ecosystem and human health, sediments with total PAH concentrations greater than 15mg/kg (normalised to 1% TOC) were unsuitable for unconfined sea disposal (Simpson et al. 2002).

Sediment analysis in Throsby Creek 1996–97 Hunter Water Corportion in conjunction with the Hunter Catchment Management Trust analysed two sediment samples from Throsby Creek in 1996–97 (upstream, opposite the Tighes Hill Bridge and in the main channel just upstream of the marina). The results were presented in the NCC Stormwater Management Plan (2004), however, only one value was shown (Table 10). Presumably the data are an average of the two samples, even though they were taken some distance apart. Concentrations of lead and zinc exceed interim sediment quality guideline criteria (ISQG high ‘risk’ value) posing a high risk of deleterious effects to aquatic organisms. Copper, mercury and nickel were above the trigger value (ISQG low 'trigger') which means there was cause for further investigation.

Table 10: Dissolved metal concentrations in sediment collected at two sites in Throsby Creek (NCC 2004) ISQG values are shown (ANZECC & ARMCANZ 2000). Data are bold if they exceed ISQG low trigger and orange bold with an asterisk if they exceed high risk criteria. Heavy metals / metalloids Throsby Creek ISQG ISQG (mg/kg dry weight) 1996–97 low trigger high risk Copper 110 65 270 Lead *330 50 220 Zinc *730 200 410 Mercury 0.3 0.15 1 Cadmium 1.3 1.5 10 Nickel 45 21 52 Arsenic 6.9 20 70

36 Lower Hunter River Health Monitoring Program – Literature and data review

3.2.5 Bioaccumulation in aquatic fauna

Investigations by the EPA In 1992–93, the EPA investigated metal and organochlorine concentrations in fish and oysters collected from areas subject to closure of fishing and oyster collection. Marine organisms collected from the South Arm of the Hunter River between Hexham to Walsh Point, Throsby Creek and Newcastle Harbour were analysed for organochlorine and trace metal content. The mean concentrations of the majority of organochlorines and metals in organisms were below the NFA MRLs, however, chlordane, zinc, selenium and copper exceeded the NFA MRLs (Table 11, EPA 1994). Chlordane is a carcinogenic persistent- organic-pollutant that was used extensively as a termiticide in the housing industry up to 1995 and enters waterways in diffuse urban runoff. Organochlorine burdens in oysters have been found to be proportional to the concentration of chlordane in the seawater due to rapid accumulation and depuration rates, as is the case for metals (Vreeland 1974 EPA 1996; Scanes 1998). NSW Fisheries found similar levels of bioaccumulation in 1987 with very high levels of zinc found in oysters collected from the South Arm at Sandgate (1640mg/kg) and from pylons adjacent to BHP Steelworks (2900mg/kg) (EPA 1994).

Table 11: Contaminants that exceeded maximum residue limits in fish and oysters from Newcastle waters in 1992 (EPA 1994)

Contaminant % samples concentration NFA MRL exceeding Area Organism (mean: mg/kg) (mg/kg) NFA MRL Throsby Creek Wild oysters Chlordane 0.17 0.05 100 Zinc 1669 1000 95 Selenium 1.2 1.0 80 South Arm Wild oysters Copper 70.4 70 52 Zinc 1681 1000 96 Newcastle Harbour Fish Chlordane 0.01–0.03 0.5 25 Dieldrin 0.03 0.1 4 Coastal waters Hammerhead shark Mercury 0.58 0.5 90

The Hunter Environmental Monitoring Program (1992–1996) was designed to investigate contaminant concentrations in the marine waters of the Hunter region in response to concern about elevated levels of contaminants found in fish from Newcastle coastal waters in 1990 (Cole 1990). Studies by NSW Fisheries in the 1980s found trace amounts of DDT and its metabolites, dieldrin and PCBs in the tissues of fish caught in the vicinity of shoreline outfalls in Newcastle (EPA 1995). A later study by Hunter Water Board in 1989–90 found a greater range of organochlorine compounds in fish collected in these areas (EPA 1995). The Hunter River, the ‘dredge spoil’ disposal site and sewage effluent from Burwood Beach, Belmont Beach and Boulder Bay wastewater treatment plants were listed as potential sources of contaminants. Oysters were deployed at each of the sewage outfalls, at the dredge disposal site and the entrance to Newcastle Harbour, and at appropriate control sites. After six months, oysters were collected along with sediment from each site, and analysed for contaminants. The majority of samples reported a ‘not detected’ or trace result. Metal concentrations in oysters were within or below the range of concentrations found in estuarine areas of New South Wales (EPA 1996). Concentrations of selenium were high across all sample sites which appears to be a common phenomenon throughout NSW marine waters. Higher concentrations of selenium are reported for estuarine sediments compared to sediments from the continental shelf (Birch 2000).

37 Lower Hunter River Health Monitoring Program – Literature and data review

Many sediment samples contained significantly higher concentrations of zinc, lead or manganese at the entrance to Newcastle Harbour and the spoil ground, relative to control locations (EPA 1996). Univariate analysis found that cobalt, lead and zinc were at significantly higher concentrations in oysters deployed at the harbour entrance compared to control locations. Multivariate analysis, however, made no clear distinction between metal loads in oysters deployed at the different locations despite the higher concentrations measured in sediments (EPA 1996). Scanes (1993) demonstrated it was the surrounding waters that affected the metal load in cockles and oysters rather than the sediment they inhabited.

3.2.6 Early investigations for BHP

Bioaccumulation in aquatic fauna The Ecology Lab Pty Ltd investigated the bioaccumulation of contaminants in aquatic fauna in the Hunter River in 1998. They explored the relationship between concentrations of contaminants present in wild oysters and distance upstream and downstream of the BHP Steelworks site. Another component of the study compared contaminant levels to oysters deployed in two reference estuaries, Port Stephens and Hawkesbury River, which are estuaries subject to anthropogenic pollution but without the influence of BHP Steelworks and extensive port operations. The analysis concluded that BHP was a source of bioavailable lead, zinc and chromium in the estuary of the Hunter River (The Ecology Lab 1998), a finding supported by other studies (Birch et al. 1997). Oysters from the Hunter River had higher concentrations of lead and were the only oysters to contain tin, with shipping activities the likely cause of this (tin being present in leachate from anti-fouling paints). Concentrations of copper, lead and zinc in oysters from some Hunter River sites were above NFA MRL (The Ecology Lab 1998). Concentrations of PAH were consistently higher in oysters sampled adjacent to BHP and showed strong relationships with distance upstream. Oysters at a downstream site adjacent to a local discharge point from Dyke Wharves had consistently high concentrations of PAH which resulted in no relationship with downstream (The Ecology Lab 1998). Oysters were sampled at sufficient distance (~3 kilometres) from BHP to reach background levels for most contaminants, however, lead and zinc tended to be higher at the Hunter sites indicating that levels of lead and zinc were generally high throughout the Hunter River estuary in 1998.

Human health and ecological risk assessment of sediments A human health and ecological risk assessment of sediments from the South Arm of the Hunter River used an integrated sediment quality ‘triad’ approach which assessed combined chemistry, ecotoxicity and benthic community data for surficial sediments (URS 2004). Chemicals of potential concern were principally PAH, TPH, cadmium, copper, nickel, lead, mercury and zinc. Concentrations of these contaminants in surface waters were evaluated and did not exceed ANZECC trigger levels so were not assessed further in the study. Risk to human health was deemed as essentially negligible, as human exposure to contaminated sediments, fish and crustaceans from the South Arm was unlikely (as recreational fishers use other locations in the estuary). There was potential for unacceptable risks to human health if oysters from target areas were to be consumed frequently but given closure of the fishery this too was unlikely. Sediment toxicity tests indicated a risk to ecological health as adverse biological effects were found to be likely or probable at all intertidal sites and 6 out of 10 subtidal sites assessed in Zone 1 (adjacent to the BHP Steelworks site), and at two sites in the North Arm. Although causation was not established, a correlation between highly contaminated sediment and differences in benthic community within the intertidal sediment of Zone 1 was apparent (URS

38 Lower Hunter River Health Monitoring Program – Literature and data review

2004). Generally a benthic community in an impacted environment is composed of fewer taxa with few individuals, or many individuals dominated by only a few taxa. This pattern was not observed when assemblages were compared to reference areas as a more diverse array of taxa were observed at sites in the South Arm, compared to fewer taxa observed at reference sites in the North Arm of the Hunter River, Hawkesbury River and Georges River. Based on benthic community data, the consultants claimed there was little evidence of a major impact on benthic community despite sediments being enriched in PAH and some trace metals (URS 2004). More taxa were observed at South Arm sites in spite of poor quality/toxicity of sediments (contaminants, sheen, odorous, anoxic), however, the condition of the animals observed was not assessed. Sediment toxicity assays indicated adverse effects were likely or probable so it is likely that observed fauna would have suboptimal condition. Overall very few taxa were detected at reference sites in the Hawkesbury and Georges River suggesting that these sites may not have been a good representation of ‘reference’ condition.

3.3 Recent condition measures

3.3.1 Seagrass The Hunter River is the only barrier river estuary in New South Wales that does not have any seagrass (Creese et al. 2009). There are no historical records confirming the presence or absence of seagrass, however, anecdotal evidence from fisherman’s catch from the late 1800s suggests seagrass was once present in the Hunter River. ‘Some of the species of flathead will venture up the rivers into fresh water. Thus Platycephalus fuscus [the dusky flathead] comes up the river Hunter as far as West Maitland, where it is caught abundantly by the anglers in summer’ (Tenison-Woods [1882] cited in Pepperell; date of publication not provided). It is highly probable that the long history of development and historically large inputs of sediments and nutrients from the catchment were responsible for the loss of seagrass from the Hunter River and its estuary.

3.3.2 Riparian vegetation condition assessments The degradation of habitat and loss of biodiversity with the Hunter estuary is intrinsically linked to the ongoing settlement, urbanisation and development of the Hunter estuary catchment (Williams et al. 2000; MacDonald 2001). Native riparian vegetation is in poor condition, resulting in impacts upon bank stability, but also reducing its potential use for faunal habitat corridors. In the lower estuary, land clearing and reclamation for urban and industrial areas and port facilities have also reduced habitat cover and diversity. Restriction of tidal inundation has severely impacted estuarine habitats, resulting in the conversion of saltmarsh and mangrove areas to monospecific fresh/brackish wetlands (i.e. Phragmites australis) typical of highly disturbed ecosystems (Chambers et al. 1999). Reduction of habitat diversity has had subsequent effects on biodiversity in the area.

3.3.3 Wetland condition

Hunter Wetlands National Park The Hunter Wetlands National Park (reserved in 2006) is situated in the lower Hunter estuary and extends from the suburb of Hexham in the west to Stockton and Fern Bay in the east (Figure 9). The reserve includes the Stockton Sandspit, Fullerton Cove, parts of both arms of the Hunter River, the Tomago and Hexham wetlands as well as Kooragang, Ash, Sandy,

39 Lower Hunter River Health Monitoring Program – Literature and data review

Smith, Hexham and Campbell islands. It is the largest wetland reserve (6248 hectares) within a single estuary in New South Wales and is managed by the NSW National Parks and Wildlife Service. The Hunter estuary is recognised as the most important area in New South Wales for shorebirds (Smith 1991; Birdlife International 2015) with a significant portion of the Hunter estuary wetlands listed under the Ramsar convention in 1984. Hunter estuary wetlands provide refuge for over 250 bird species, including 45 species listed under the international Japan and Australia Migratory Bird Agreement (JAMBA), China and Australia Migratory Bird Agreement (CAMBA) and Australia and South Korea Migratory Bird Agreement (SKAMBA). The Hunter Estuary Wetlands Ramsar site is comprised of the Kooragang component of the Hunter Wetlands National Park (formerly Kooragang Nature Reserve) which was listed in 1984 and Shortland Wetlands (now called the Hunter Wetlands Centre Australia) which gained Ramsar listing in 2002. It is an unfortunate irony that large expanses of Ramsar-listed wetlands lie adjacent to the most heavily industrialised port in Australia. Anecdotal and scientific evidence suggests there has been a 70% reduction in the numbers of migratory birds observed in wetlands in the Newcastle region in recent years (HBOC 2007; Brereton & Taylor-Wood 2010). The decline in observed numbers of migratory birds reflects a worldwide trend which is directly linked to habitat loss. It is estimated that approximately half of the worlds’ wetlands have been destroyed by urbanisation of coastal areas (Streever 1999). In the past decade, huge expanses of mudflat habitat in the Yellow Sea between China and Korea have disappeared and this loss of habitat is likely to be linked to the reduction in migratory bird sightings in wetlands such as the Newcastle region. In just over 25 years of monitoring migratory shorebirds in Australia, some species such as the curlew sandpiper have decreased by 50– 80%. In 2007 alone up to 150,000 shorebirds went missing in Australia which has been linked to the destruction of large expanses of the intertidal ecosystem in the Yellow Sea.

Wetland rehabilitation in the Hunter Estuary From the 1980s there has been an increase in community interest in wetland conservation in the Hunter estuary which was in part triggered by the washout of a culvert on a tidal creek on Kooragang Island in April 1990. This event re-established full tidal flow onto what had once been wetland and revealed the immediate benefits of simple and inexpensive rehabilitation techniques. A number of wetland rehabilitation projects have occurred since then at Hexham Swamp, Kooragang Wetlands, Tomago–Fullerton Cove and at Shortland Wetlands. Significant shorebird rehabilitation projects have been completed by NPWS in various locations throughout the reserves including the Kooragang Dykes, Windeyers Reach, Stockton Sandspit and Tomago.

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Figure 9: Hunter Wetlands National Park (shaded) showing Ramsar-listed areas (hatched) The larger hatched area is the Kooragang Wetlands and the smaller shaded area is Hunter Wetlands Centre Australia.

Hexham Swamp Rehabilitation Project Hexham Swamp Rehabilitation Project involved the progressive opening of eight floodgates on Ironbark Creek from 2008–2013 to reinstate tidal inundation to Hexham Swamp (HCR CMA 2013). The floodgates were installed in the early 1970s for flood mitigation and to improve the productivity of agricultural lands (Evans 1999). By 2002, mangrove distribution had reduced from 180 to 22 hectares, saltmarsh had reduced from 900 to 6 hectares and common reed (Phragmites australis) had expanded its range from 170 to 1005 hectares (SEWPAC 2012). Opening the floodgates has led to a notable transition from Phragmites- dominated freshwater wetland to a mosaic of habitats including mangroves, saltmarsh and open water; the restoration of habitat for juvenile fish and prawns and an increase in visitation of waterbirds including migratory waders (HCR CMA 2013; DPI 2013, 2015).

Shortland Wetlands Rehabilitation The Hunter Wetlands Centre Australia (HWCA), formerly Shortland Wetlands, is a small (42- hectare) complex of wetlands located to the south-east of Hexham Swamp, and is well known as a centre of excellence in wetland conservation and management, education and research. HWCA has recently made the site predator-proof through fencing and fox-baiting as it intends to re-introduce native animals as the next phase of the rehabilitation of the wetlands (HWCA 2009). Pre-release compounds and feeding stations have been built in preparation for the safe reintroduction of swamp and red necked wallabies, bandicoots, various possums, reptiles and brush turkeys and other once-endemic species to the site. Almost 30 years on, HWCA and the local community in partnership with Newcastle City Council have restored a highly degraded site into a thriving wetland.

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Kooragang Wetland Rehabilitation Project The Kooragang Wetland Rehabilitation Project was launched in 1993 and was a major NSW Government capital work from 1996 to 2007 with funding from all levels of government and sponsors and support from volunteers. Initial project sites were Ash Island, Tomago Wetlands and Stockton Sandspit with the integrated program of ecological restoration activities continuing today across the estuary. In the project, culverts were removed from two creeks on Kooragang Island to reinstate tidal flow to the creeks and ponds upstream, to improve the value of fish and crustacean habitat, and shorebird habitat (Streever 1999). A study by NSW Department of Primary Industries compared control, reference and manipulated locations, and provided invaluable insight on the long-term response associated with wetland rehabilitation (Boys & Williams 2012). The results provided irrefutable evidence that the presence of culverts at Kooragang Island had significantly changed the fish and decapod assemblage of tidal creeks (Boys & Williams 2012). In this study, a clear succession in the fish and decapod assemblage of Fish Fry Creek occurred as two distinct changes over 16 years in response to culvert removal. The first change occurred immediately and persisted for at least six years following culvert removal. Although there was no net increase or decrease in the number of species inhabiting the creek during this time, there was a significant change in assemblage composition. A secondary significant shift in the assemblage of Fish Fry Creek was observed sometime between years 8–10 (6–8 years after culvert removal). It was only at this time that the assemblage of Fish Fry Creek could be judged to be fully matured and equivalent to that of unrestricted reference creeks (Boys & Williams 2012). These results demonstrate that the usual three-year monitoring period for rehabilitation studies is likely to not be an appropriate timescale to detect positive outcomes of rehabilitation works of this nature.

Stockton Sandspit and Tomago Wetlands Stockton Sandspit is a small area within the Hunter Wetlands National Park but provides vital habitat for shorebirds spending the summer months feeding and resting in the estuary before the long return flight to their breeding grounds in the northern hemisphere. NPWS, Kooragang Wetland Rehabilitation Project, Newcastle City Council and volunteer groups, such as the Hunter Bird Observers Club (HBOC) and Conservation Volunteers Australia (CVA) have rehabilitated the Sandspit, providing a variety of favoured roost habitats, as well as feeding and breeding opportunities for resident ground-nesting shorebirds (HCR CMA 2010; HBOC 2014). Currently, NPWS staff and volunteers from HBOC and CVA maintain the saltmarsh and shelly sand areas on Stockton Sandspit as roost habitat which requires the removal of all mangrove seedlings before they take hold (OEH 2014). The Tomago Wetlands Rehabilitation Project is restoring 500 hectares of abandoned grazing paddocks back to a saltwater ecosystem through the controlled reintroduction of tidal flows. NPWS collaborated with Department of Primary Industries, Hunter Local Land Services, UNSW Water Research Laboratory and HBOC to restore estuarine habitats including saltmarsh, shallow lagoons, mudflats, tidal creeks and reed beds, created feeding grounds for the return of over 3000 sharp-tailed sandpiper and other species of shorebirds to the site (Russell et al. 2012). The project has been recognised as a world-leading example of eco- engineering, winning an Engineers Australia Engineering Excellence Award for Environment and Heritage.

3.3.4 Review of condition for Ramsar listing The Hunter Estuary Wetlands Ramsar site (i.e. the Kooragang component and Hunter Wetlands Centre Australia) was re-assessed in 2010 against the current Ramsar criteria (Brereton & Taylor-Wood 2010). The critical ecosystem components, subcomponents and processes that define the ecological character of the Kooragang Wetlands at the time of listing were found to be:

42 Lower Hunter River Health Monitoring Program – Literature and data review

• waterbirds, particularly migratory shorebirds • the green and golden bell frog (Litoria aurea), a nationally listed threatened species • Sarcocornia saltmarsh which supports migratory shorebirds • intertidal mudflats which provide foraging habitat for migratory shorebirds • hydrology (tidal regime and freshwater inflows) which is a major influence on the distribution and extent of saltmarsh and mangroves (Brereton & Taylor-Wood 2010). The review identified the major threats to the ecological character of the Hunter Estuary Wetlands Ramsar site were a decline in saltmarsh extent due to: • changes in tidal range from dredging, flood mitigation and drainage works and increased sedimentation (as a result of past catchment clearing) leading to mangrove expansion replacing saltmarsh habitat • changes in fresh water/salt water balance due to changes in land drainage and exclusion of tidal waters essential for saltmarsh (Brereton & Taylor-Wood 2010). As saltmarsh is an important foraging and roosting habitat (diurnal and nocturnal) for migratory shorebirds, the loss of these habitats on Kooragang is likely to have led to the recent decline in migratory shorebirds visitations (Brereton & Taylor-Wood 2010).

3.3.5 Compensatory Habitat and Ecological Monitoring Program Industry has funded some projects to rehabilitate Hunter Wetlands over the years, usually as a condition of being granted development consent. The Compensatory Habitat and Ecological Monitoring Program (CHEMP) details the compensatory habitat program that Newcastle Coal Infrastructure Group (NCIG) undertook for green and golden bell frog habitat lost or degraded by the construction of the coal export terminal at Kooragang Island (NCIG 2010). Ecological surveys in 2007 found that 8.4 hectares of green and golden bell frog habitat was lost during construction of the terminal. NCIG committed to a variety of works to offset biodiversity impacts created by construction of the terminal. Part of these offsets is development of a 78-hectare green and golden bell frog habitat on Ash Island, part of the Hunter Wetlands National Park. The program included a suite of research initiatives that aim to increase the current level of knowledge relating to the population dynamics of the green and golden bell frog and its habitat in and around Hunter Wetlands National Park and the Hunter estuary (Hamer et al. 2009; Pizzatto et al. 2014). NCIG in partnership with the University of Newcastle and NPWS completed the construction of the new habitat in November 2014, including the shaping of aquatic and terrestrial habitat. Captive-bred frogs are currently being introduced into the habitat with the aim of establishing a sustainable population of green and golden bell frogs in an area of the national park where the species was previously known to exist.

3.3.6 Groundwater Tidal flows are critically important in maintaining healthy wetlands closer to the coast whereas wetlands further inland are heavily reliant on groundwater. Wetlands occur where groundwater discharges to a river or creek or where the groundwater is at or close to the surface (e.g. sand dunes). Local groundwater systems therefore play a crucial role in maintaining the viability of wetland areas. Changes in the volume or quality of the groundwater flow to wetlands will impact their sustainability. Groundwater use and land reclamation through urbanisation and industrialisation are the major drivers of loss of wetland habitat in the Hunter region. The Hunter Valley is the largest coastal catchment user of groundwater in the State, most of which is pumped from high-yielding bores (MHL 2003).

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3.3.7 Acid sulfate soil survey Acid sulfate soils (ASS) are naturally occurring on low-lying land surrounding Australian estuaries but become problematic after exposure, usually following drainage works on floodplains. Management of surface drainage lowers the water table, interfering with groundwater recharge, ultimately depleting groundwater aquifers. These processes can result in the oxidation of sulfidic soils and leaching of acid into the waterway, impacting water quality. Associated aquatic-dependent ecosystems such as wetlands and saltmarsh are impacted by changes to water quality, including infauna and migratory birds. NSW Department of Primary Industries investigated the distribution of ASS in the lower Hunter river estuary in 2008. Fullerton Cove of the North Arm is considered the highest priority for ASS management as sulfidic soils were detected only 50 centimetres from the soil surface. Acid water enters the drainage system and then the estuary at the Fullerton Ring drain floodgates. The northern boundary of Tomago Wetlands was found to have high stored acidity. By opening the floodgates in affected areas, neutralising tidal water is allowed to flow into the drains to buffer acid discharge before it enters the estuary. At Hexham Swamp, high risk areas were found adjacent to Ironbark and Fishery creeks. There is an additional risk of surface sulfide accumulation at this site as these creeks receive a lot of stormwater runoff from the surrounding hills. Floodgates have now been re-opened at Ironbark Creek with noticeable improvements to water flow and wetland regeneration. The Hunter Wetlands Centre Australia continues to rehabilitate and restore ecosystem function at this site (HWCA 2009). The fringing urban environment of Ironbark Creek requires careful management to ensure acid effects are not amplified. All sites at Ash Island (Kooragang Wetlands) were classed as medium risk as acidic soils were primarily found in deeper layers. The central area may be exporting some acid through groundwater seepage but natural water regimes typify this site and these flows neutralise any acid before it reaches the Hunter River.

3.3.8 Water quality monitoring programs NSW Government agencies have done a limited amount of water quality monitoring in the Hunter River estuary in recent years. Most of the water quality data collected over the past decade was collected by environmental consultants commissioned by industry for short-term studies targeted to a specific area (South Arm), issue (e.g. turbidity) or development application (BHP 2009a, b; URS 2012b, c). For example, water quality data were collected by BHP and NCIG during dredging operations in the South Arm as part of the Hunter River Remediation Project and for the development of the NCIG site and berth maintenance (2008–2013) (WorleyParsons 2008).

OEH water quality monitoring programs Office of Environment and Heritage (OEH) has been monitoring water quality and biological indicators in NSW estuaries for the Natural Resources Monitoring, Evaluation and Reporting (MER) program since 2006 (OEH 2016; Roper et al. 2011). A number of ‘sentinel’ estuaries are monitored each year, while estuaries from each of three (former) Catchment Management Authority (CMA) regions are assessed on a rolling three-year basis. Estuaries in the former Hunter–Central Rivers CMA were selected for the MER program in 2010–2011, which included the Hunter River. In addition to the MER program, OEH implemented an estuary-wide water quality monitoring program from August 2014 to March 2015 for the Lower Hunter River Health Monitoring Program to gain an insight into current conditions in the estuary (Swanson et al. 2017a). Standard water quality variables and chlorophyll-a, TSS and nutrient data were collected on a monthly basis at 14 sites in the Hunter River estuary extending from the estuary mouth to the upper estuary (Figure 10).

44 Lower Hunter River Health Monitoring Program – Literature and data review

A summary of results from the OEH MER program in 2011 and OEH water quality monitoring program 2014–15 follows this section. All the data from the OEH water quality monitoring program 2014–15 can be found in the technical report (Swanson et al. 2017a). Data collected by OEH are compared to pre-2000 levels reported in Sanderson & Redden (2001), however, that data compilation did have a wet-weather bias (concentrations of nutrients are always higher in receiving waters following rainfall).

Figure 10: OEH water quality monitoring program sampled water quality at 14 sites each month from August 2014 to March 2015 Standard physico-chemical parameters were assessed and water samples were collected on each sampling for analysis of nutrients, total suspended solids, turbidity and chlorophyll-a.

Chlorophyll-a The concentration of chlorophyll-a in the water column is used as a proxy for the biomass of microalgae, and as an indicator of ecological response to the amount of bioavailable nutrients in the water column. Chlorophyll-a is one of the condition indicators (along with turbidity) that are used by OEH to assess the health of NSW estuaries (OEH 2016). The NSW trigger values for chlorophyll-a that apply to coastal rivers are between 2.3 and 3.4 µg/L depending on the salinity at the site. Chlorophyll-a concentrations in the mid estuary in 2011 are similar to data collected in 2014– 15 (Figures 11, 12). Median concentrations of chlorophyll-a in 2014–15 were below 5µg/L at most sites in the routine monitoring program although concentrations as high as 30µg/L were occasionally recorded after rainfall (Figure 12). The highest median concentrations of chlorophyll-a of 3–7 µg/L were recorded at mid estuary sites in 2014–15. Sites in the mid to upper estuary receive primarily urban and agricultural inputs whereas sites in the lower

45 Lower Hunter River Health Monitoring Program – Literature and data review estuary receive urban and industrial inputs. Median concentrations of chlorophyll-a in the mid to upper estuary during 2014–15 (Figure 12) were considerably lower than the historical median of approximately 15µg/L (Figures 7, 8). Peaks in chlorophyll-a concentration usually occur in response to moderate to high levels of bioavailable nutrients in the water column suggesting that nutrient inputs may have decreased in the mid to upper estuary over the past decade. Chlorophyll-a concentrations in the lower estuary in 2014–15 are comparable to historical data (Figures 7, 12). Aside from the occasional spikes in chlorophyll-a, the proportional increase in chlorophyll-a concentrations that we would expect to see in response to elevated nutrient concentrations is not observed in the Hunter River estuary. There is no obvious explanation but turbidity has been implicated for similar patterns in other systems (e.g. Karuah River, Haine et al. 2013). Another theory is that synergistic effects of multiple stressors (moderate turbidity, nutrient/metal toxicity) are keeping microalgal growth to low levels.

Figure 11: Chlorophyll-a concentrations in the North Arm and mid estuary of the Hunter River Data were collected in 2011 for the NSW MER program which monitors water quality in NSW coastal estuaries. The North Arm site is near HNT3, and the mid estuary site is near HNT5 (location in Figure 10, more data in Figure 12).

46 Lower Hunter River Health Monitoring Program – Literature and data review

Figure 12: Box plots of chlorophyll-a concentrations in surface waters at 14 sites in the Hunter River estuary in 2014–15 (Swanson et al. 2017a) Data were collected by OEH each month from August 2014 to March 2015 to assess current water quality in the Hunter River estuary (n= 8 for all sites except HNT1.5 where n=5). In this and all subsequent box plots, the central bar in each box is the median value, top and bottom of the boxes represent the 25th and 75th percentiles and the bars indicate minima and maxima in each data set.

Figure 13: Comparison of historical and recent water quality data collected between August and October in the lower South Arm Data from1972–2000 is from Sanderson & Redden 2001 (only showing data collected in the South Arm during August, September, October). Data from 2011 is from URS 2012c. Data from 2014 is from the OEH water quality monitoring program (pooling two sites from the lower South Arm).

47 Lower Hunter River Health Monitoring Program – Literature and data review

Nutrients Ammonium and bioavailable oxidised nitrogen (NOx) concentrations recorded in the South Arm of the Hunter River during August to October of any year between 1975 and 2000 in the data compilation by Sanderson & Redden (2001) were extracted and compared to nutrient data collected in the South Arm during August to October of 2012 (URS 2012c) and 2014 (Swanson et al. 2017a, Figure 13). Median concentrations of ammonium and NOx in 2011 and 2014 were considerably lower than concentrations recorded in the South Arm between 1975 and 2000 (Figure 13). Nutrient data presented in Tables 6 to 9 clearly show very elevated levels of ammonium and NOx in the South Arm during the 1970s, 80s and 90s. Before 2000, ammonium concentrations in the estuary exceeded 25µg/L in 90% of the data, and were above >640µg/L in 10% of the data (Sanderson & Redden 2001; MHL 2003). Inputs of dissolved inorganic nutrients to the estuary from industrial wastewater discharges is likely to have decreased over the past 15 years leading to the decline in nutrient concentrations in the South Arm (Figure 14). Data from 2011 and 2014 were, however, collected during periods of low rainfall which may also partially explain the lower values as nutrient concentrations in receiving waters usually peak after rainfall. Further, data collected by HWC presented in Sanderson & Redden (2001) did have a wet-weather bias so differences between historical and recent data may also reflect periods of high versus low rainfall. Although nutrient concentrations have decreased in the estuary from pre-2000 levels, concentrations of phosphate and NOx in 2014–15 (Figure 14B, C) were typically well above NSW trigger values for coastal riverine estuaries, with fewer exceedances for ammonium (Figure 14A, Swanson et al. 2017a). Median concentrations of ammonium were highest in the South Arm suggesting that industry is the primary source of ammonium to the estuary. Nitrate and ammonium concentrations increase in the South Arm near Ironbark Creek after rainfall and discharges from the Shortland WWTW is likely to be a primary source. Median concentrations of nitrates and phosphate increased with distance upstream implicating agriculture and intensive horticulture as the dominant sources of these nutrients to the upper estuary (Figure 14B, C).

Turbidity Turbidity is a measure of water clarity with higher values indicating more suspended solids in the water column. Turbidity is the second condition indicator used by OEH to assess the health of NSW estuaries (OEH 2016). The Hunter River is a turbid system particularly following rainfall when river flows carry fine sediments down from the upper catchment (Figure 2). Shipping activity in port areas also causes frequent localised spikes in turbidity. Only moderate levels of turbidity were recorded during the OEH water quality monitoring program 2014–15 (Swanson et al. 2017a). Turbidity was often below 5NTU in surface waters of the lower estuary which is just above NSW trigger values of 2.8–3.5NTU for coastal riverine estuaries (Figure 15), and was rarely above 10NTU even after rainfall. Median values for turbidity increased slightly with distance upstream but the occasional high readings following rainfall (>50NTU) are an order of magnitude greater than the NSW trigger value for upper estuarine waters. Turbidity in the Hunter River estuary may contribute to lower than expected chlorophyll-a concentrations given the high levels of bioavailable nutrients. Shorter residence times of waters in the lower estuary due to flushing with oceanic water may also help to reduce chlorophyll-a concentrations.

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Figure 14: Dissolved inorganic nutrient concentrations (µg/L) in surface waters at 14 sites in the Hunter River estuary from August 2014 to March 2015 A – ammonium, B – phosphate, C –nitrate/nitrite. Data is presented as box plots showing median, 25th and 75th percentiles, minima and maxima (n = 8). See Figure 10 for site locations.

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Figure 15: Turbidity of surface waters at 14 sites in the Hunter River estuary from August 2014 to March 2015 Data is presented as box plots showing median, 25th and 75th percentiles, minima and maxima (n = 8). See Figure 10 for site locations.

Health of the Hunter – Hunter River estuary report card 2016 Water quality data collected during the OEH monitoring program was in line with NSW Natural Resources Monitoring, Evaluation and Reporting (MER) protocol allowing the calculation of water quality grades (Roper et al. 2011; OEH 2016). The water quality grades assigned to the lower, mid and upper estuary, based on comparison with the statewide MER dataset, are presented in the Health of the Hunter – Hunter River estuary report card 2016 (OEH 2017). Grades on OEH-developed report cards are based on scores for water quality (only using turbidity and chlorophyll-a data) and, if present, on seagrass distribution in the estuary. Seagrass, however, does not grow in the Hunter estuary so other biological indicators were investigated in a preliminary ecological assessment (Swanson et al. 2017c) discussed in later sections. Based on turbidity and chlorophyll-a data collected during the OEH water quality monitoring program 2014–15, the lower Hunter River estuary scored a ‘B’ water quality grade, while the mid and upper estuaries both scored a ‘C’ grade (Table 12, Swanson et al. 2017a). The 2014 upper estuary grade ‘C’ can be directly compared to the MER grades for the Hunter River estuary for 2010 (‘D’) and 2013 (‘C’) as the data was also collected in the upper estuary. Water quality may have improved in the upper estuary since 2010 but it is also likely that the ‘D’ grading was influenced by breaking drought conditions impacting water quality (Table 13). Hunter River estuary grades can be compared to MER grades assigned to other highly modified estuaries in the statewide MER program (Table 14) with Parramatta River estuary being rated as having poorer condition. Parramatta River, Georges River and Hawkesbury River are ‘drowned river valleys’ which are quite different to riverine estuaries like the Hunter River estuary so water quality grades are not directly comparable as they are quite different sytems (Roy et al. 2001). Nevertheless they provide an interesting comparison based on the extent of catchment modification.

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Water quality in the lower estuary is likely to have improved greatly in the past 15 years with the closure of the BHP Steelworks, tighter monitoring and regulation of industrial discharges, and improvements in industrial site management leading to a reduction in pollutant loads in stormwater. While the lower estuary scored a ‘B’ grade for water quality it is important to realise this grade is based solely on turbidity and chlorophyll-a data. Additionally, concentrations of chlorophyll-a, a biological indicator, were lower than we would expect given the high concentrations of ammonium, NOx and phosphate, which always exceeded NSW trigger values in the lower estuary. A grade of ‘B’ for the lower estuary may be an overly optimistic score (Table 12). OEH conducted a preliminary ecological assessment in 2015–16 to complement the findings of the Lower Hunter River Health Monitoring Program (Swanson et al. 2017c). OEH has produced the Health of the Hunter – Hunter River estuary report card 2016 which provides an overview of the current condition of the estuary (OEH 2017). Further investigations into the impacts that decades of pollution have had on the condition of additional biological indicators (for example, fish and macroinvertebrate assemblages, sediment microbes) are warranted.

Table 12: Turbidity, chlorophyll and overall water quality grades assigned to the upper, middle and lower estuary based on data collected in the OEH monitoring program 2014–15

Hunter River Turbidity grade Chlorophyll-a grade Water quality grade Lower estuary B B B Middle estuary C C C Upper estuary D B C The relationship between NSW scores, zones and grade scores are shown in the diagram below (OEH 2017a). The relative position of individual turbidity and chlorophyll grades assigned to the lower, mid and upper estuary are also displayed on the coloured scale bar.

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Table 13: Comparison of turbidity, chlorophyll-a and overall water quality grades assigned to the upper Hunter River estuary based on data collected in 2014 (for this program), 2013 and 2010 (for the MER program)

Upper estuary Hunter River Turbidity grade Chlorophyll-a grade Water quality grade 2014 D B C 2013 D B C 2010 F D D

Table 14: Comparison of turbidity, chlorophyll-a and overall water quality grades assigned to the Hawkesbury River, Georges River, Parramatta River and Hunter River based on data collected for the 2013 MER program All these rivers have highly modified catchments. Note that data for the MER program is collected in the mid to upper estuary. Upper estuary (MER 2013) Turbidity grade Chlorophyll-a grade Water quality grade Hunter River D B C Hawkesbury River C D C Georges River C B B Parramatta River C F F

OEH stormwater quality monitoring program 2015

Lower estuary Stormwater runoff is a diffuse source of pollution that carries nutrients, sediment and organic contaminants from urban areas into creeks and drains and ultimately to the Hunter River estuary. OEH implemented an ‘event-based’ stormwater quality program in 2014–15 which targeted stormwater runoff from industrial sites and urban areas in the lower estuary to identify current sources of pollutants (Swanson et al. 2017b). Hotspots for nutrient and dissolved metal pollution are shown in Figure 16. A summary of pollutants to the lower estuary, likely sources and their current status of the pollutants is shown in Table 15. More detailed results from the OEH stormwater monitoring program are reported elsewhere (Swanson et al. 2017b). The main findings show: • Industrial sites are a major source of ammonium, nitrates and nitrites (NOx) and phosphates to the lower Hunter estuary with stormwater runoff for these sites delivering very high concentrations of nutrients to localised patches of the estuary. Concentrations of pollutants can be extremely high in stormwater discharges from certain industrial sites. These drains can be regarded as point source pollution. • Concentrations of ammonium were often >1000µg/L in receiving waters during rain events with a maximum of 57,600µg/L detected. Concentrations of nitrates were often >1000µg/L in receiving waters with a maximum of 3,600µg/L detected. Concentrations of phosphates were usually below 100µg/L except at one site where a maximum of 35,000µg/L was detected (Figure 16). • Industrial sources of ammonium and NOx are more widespread (metal, chemical and fertiliser industries) than are sources of phosphate, which in the lower estuary appear to be localised to fertiliser-based industries on Walsh Point/Kooragang Island.

52 Lower Hunter River Health Monitoring Program – Literature and data review

• High concentrations of nitrates (max 420µg/L), ammonium (max 200ug/L) and phosphate (max 50µg/L) were measured in Throsby Creek with higher concentrations upstream implicating urban runoff as the primary source. Ironbark Creek is a source of nitrate to the mid estuary, likely to originate from urban runoff and discharges or overflows from Shortland WWTW. • High concentrations of dissolved zinc, copper and/or manganese were measured in port areas and in urban creeks, often approaching or exceeding ANZECC guideline criteria for 80% protection of marine ecosystems (Figure 16). • Industrial discharges from secondary metal fabrication and the handling and export of metal concentrates in port areas, and roofing in urban areas, are likely sources of zinc. Machine wear and tear from vehicles in urban areas, and on-site practices and contaminated landfill in industrial areas, are likely sources of manganese. Shipping (anti- fouling coatings, dispatch) and contaminated landfill are the likely sources of copper to the estuary. • High counts of faecal coliforms were found in the upper reaches of Throsby Creek and in the South Arm following rainfall. These data suggest that metal toxicity, coupled with other stressors such as frequent spikes in turbidity and excessive nutrient concentrations, may lead to suboptimal growth and metabolism of microalgae in the Hunter estuary, resulting in lower than expected chlorophyll- a concentrations. Newcastle’s industrial past has led to higher than usual background concentrations of metals in the Hunter River, which is unlikely to change with continued inputs from industrial discharges, shipping and port operations. Contaminated sediments in industrial areas (past/current) which are not dredged (e.g. Throsby Creek, Throsby Basin, mid to upper South Arm), and contaminated lands infilled with steelmaking waste during port development, are likely to be contributing to the metal load in the estuary.

Creeks and wetlands in the urban catchment There has been very little monitoring of quantity and quality and flows into and out of the urban catchments. A new program is underway which is monitoring water quality at 15 sites in the Boatman’s Creek catchment for the Newcastle Wetland Connections (NWC) program. The NWC program has received funding to improve the connectivity of the wetlands in the area. Water quality of flows into areas where future works are planned was monitored from December 2013 to December 2014. Most sites were sampled at least five times and some sites could only be sampled after rainfall. Parameters being assessed at each site are pH, electrical conductivity, temperature, TSS, dissolved oxygen, turbidity, total organic nitrogen 3- (TON), Total kjeldahl nitrogen (TKN), TN, TP and PO4 . Water quality data were compared to ANZECC guidelines for fresh and marine water quality (ANZECC 2000) and Australian runoff quality (ARQ) characteristics of ‘All Urban Areas’ (Engineers Australia 2006). The ARQ is not appropriate for impact assessment; it is merely a gauge of the relativity to other urban areas. Four sites were found to have poor to very poor water quality: University Wetland, Jersey Street Wetland, Market Swamp and Newcastle Wetland Reserve (Lucas 2014). These sites are all wetlands which are known to have highly variable water quality over time. Restoring connectivity of these water bodies to the natural catchment drainage is likely to improve the water quality at these sites (Lucas 2014). To assess longitudinal water quality of both Bowinbah Creek and Dark Creek, stormwater quality was investigated at eight sites over three months (Everingham 2014). In general, data averages for all parameters were similar to other urban areas (compared to ARQ) but ANZECC guidelines were exceeded for some parameters. Dissolved oxygen (DO) and turbidity typically increased after rainfall with increased flow and decreased in the absence of rain (Everingham 2014). The NWC program is ongoing.

53 Lower Hunter River Health Monitoring Program – Literature and data review

Figure 16: ‘Hotspots’ in the lower estuary for dissolved inorganic nutrient and dissolved metal pollution based on data collected in the OEH stormwater quality monitoring program (Swanson et al. 2017b)

54 Lower Hunter River Health Monitoring Program – Literature and data review

Table 15: The most common pollutants in the Hunter River estuary in 2015 – sources and current status of the pollutants *Indicates the pollutant was detected in this location during OEH water quality monitoring programs in 2014–15 (Swanson et al. 2017a, b). ‘Hotspots’ for nutrient and dissolved metal pollution are summarised in Figure 16. Pollutant Source Current status Metals • Steelmaking process water and by products. Slag • Primary operations for steelmaking ceased in 1999. Contamination of groundwater, soil from landfill area still of Zinc (Zn) and other waste used widely as landfill across the concern as there is little documentation on location of sites Lead (Pb) port (Zn, Pb, Cd, Cu, Cr, Ni) infilled and composition of fill Copper (Cu) Manganese (Mn) • Contaminated riverbed sediments e.g. upstream of • Site remediated by BHP Billiton. Contaminated sediments Nickel (Ni) former BHP Steelworks (Zn, Pb, Cd, Cu, Cr, Ni, Hg) adjacent to site removed during HRRP, however, there is Chromium (Cr) legacy contamination in South Arm. Ongoing management of Cadmium (Cd) some areas on main site Mercury (Hg) • Carrington Concentrates Loader (Cu, Zn, Pb) • A likely source of copper, zinc to channel* • OneSteel Wire and Tube Mills • A likely source of Zn and Mn to South Arm* • Contaminated site – Kooragang Island groundwater • A likely source of Mn to South and North Arm* contaminated by manganese from landfill. Kooragang Dykes made from slag • Urban source/engine use/ contaminated landfill (Mn) • A likely source of Mn in Throsby Creek* • Zinc is used as a fertiliser additive (Incitec and • A source of Zn – discharged to the South and North Arm* IMPACT Fertilisers) • By-product in industrial wastewater (Zn) (Orica • A source of Zn to the North Arm and channel* effluent pipe) • Coal dust particles (low levels) – atmospheric • Unknown contribution deposition • Contaminated sites – AGL Gasworks and Shell • Currently subject to remediation Depot, Hamilton (Pb) • Forgacs floating dockyard (Sn, Ni, Cu) • Ceased operation in 2013 but legacy of heavily contaminated sediments remains in Throsby Creek/Basin • Anti-fouling paints – commercial vessels (Cu, Zn) • Ongoing source in port areas* • Anti-fouling paints – marina for recreational vessels • Ongoing but likely to be a minor source in Throsby Creek* (Cu) Metalloids • Contaminated site – Walsh Point groundwater • Ongoing remediation, management and monitoring Arsenic contaminated by arsenic • Orica wastewater • As discharged in effluent pipe (~18kg/y)

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Pollutant Source Current status • Common by-product of heavy industry • Higher than usual background levels of arsenic in Hunter River • Common contaminant at industrial sites (e.g. AGL • Currently subject to remediation Gasworks, Steel River) • By-product of smelting – former BHP site was • Site remediated, ongoing management contaminated with arsenic Polyaromatic • Coal tar, tar pits identified (Mayfield precinct) • Contained, ongoing remediation and management hydrocarbons • Contaminated site – former BHP site, adjacent • Contained, ongoing remediation and management (PAH) sediments (PAH) • Contaminated site: Koppers Coal Tar products. Soil • Currently subject to remediation and groundwater contaminated with naphthalene, benzo(a)pyrene • Unidentified unlined disposal pits • Unknown contribution Total petroleum • Contaminated site – AGL Gasworks. Site • Currently subject to remediation hydrocarbons contaminated by PAH, TPH (TPH) • Urban source – car exhaust, car tyres • Possible source of PAH to Throsby Creek* including BTEX: • Contaminated site – OneSteel. Groundwater • Currently subject to remediation benzene, toluene, contaminated by benzene and PAH ethyl-benzene, • Contaminated site – Steel River. Groundwater • Currently subject to remediation xylene contaminated by TPH, PAH + Dissolved inorganic • Chemical industry (Orica – NH4 , NOx) • Ongoing very large inputs from effluent pipe in North Arm and nutrients stormwater discharges. Potential for further reduction of inputs through pollution reduction programs Ammonium/ammonia + • (NH4 /NH3 – majority • Fertiliser industry (Incitec, Impact) and other non- Ongoing large inputs from wastewater, and stormwater runoff + 3- is ammonium form at scheduled premises (NH4 , NOx, PO4 ) from access roads and site. Potential for further reduction of pH<9) inputs through pollution reduction programs + • • NH4 , NOx migrating off site via seeps to North Arm of Hunter Nitrates/nitrites (NOx) Contaminated site – Orica Walsh Point. Groundwater + 3- contaminated by NH4 , NOx River* Phosphate (PO4 ) + • NH4 is a common contaminant of land used for • BHP site remediated. Sections of OneSteel and Steel River heavy industry (e.g. former BHP Steelworks, sites currently subject to remediation. A possible source of + OneSteel, Steel River) NH4 to South Arm + • NH4 is widely used in industrial processes e.g. • Daily discharge of 1–2kg/day ammonium in wastewater OneSteel – secondary steel production

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Pollutant Source Current status + 3- • Wastewater treatment plants (NH4 , NOx, PO4 ) • Ongoing inputs to Hunter River at Raymond Terrace* and Morpeth at low to moderate concentrations. Overflow from Shortland WWTW a likely source of nitrates to the mid- estuary* • Stormwater runoff from urban areas (domestic use, • Ongoing urban inputs to Throsby Creek and Ironbark Creek* + 3- NH4 , NOx, PO4 ) • Stormwater runoff agricultural areas (fertiliser use, • Ongoing agricultural inputs to upper and mid estuary (NOx, + 3- 3- NH4 , NOx, PO4 ) PO4 in particular)* Total suspended • PWCS Carrington Coal Terminal • Ongoing inputs to South Arm/ channel. Site subject to solids (TSS) pollution reduction programs to improve quality of discharge • PWCS Fines Disposal Facility • Ongoing inputs to South Arm • Chemical/fertiliser industry • Ongoing inputs. Sites subject to pollution reduction programs • Wastewater treatment plants to improve quality of discharge. • Atmospheric deposition from coal piles • Unknown contribution • Wastewater treatment plants • A likely source of TSS to the mid estuary* • Stormwater runoff from urban areas (construction, • Ongoing source to lower estuary via urban creeks* unsealed roads and kerbs) • Stormwater runoff from agricultural areas (bank • Ongoing source to upper to mid estuary* erosion, cleared land)

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3.3.9 Sediment condition Shallow benthic sediments play a vital role in the primary productivity of estuaries and in the internal recycling of nutrients. For example, ammonium and nitrates are converted to nitrogen gas by microbes living on the sediment surface in a process called denitrification. The recycling of nutrients by the sediment microbial community removes surplus nutrients from sediments and estuary waters in healthy systems. When sediments are unhealthy they no longer recycle nutrients. Instead, they potentially become a source of nutrients to estuary waters. Enrichment of sediments with high levels of organic carbon or high levels of industrial contaminants impairs metabolic processes carried out by the benthic community. Highly enriched or contaminated sediments may become net consumers of oxygen rather than net producers of oxygen. OEH has investigated three aspects of sediment condition between 2014 and 2016: • contamination of sediments by heavy metals and hydrocarbons, and organic enrichment shown by total organic carbon content • benthic productivity and respiration • abundance of benthic microalgae living on surface of riverbed sediments.

Industrial contaminants Estuarine sediments were collected from Newcastle Harbour, South and North Arms and the upper estuary in 2014 by OEH and were analysed for metals and PAH (Figure 17, Swanson et al. 2017c). Sediments collected from the undredged area of South Arm (E5) contained elevated levels of nickel and zinc between the ISQG low trigger and ISQG high values for risk to aquatic organisms (ANZECC & ARMCANZ 2000). Throsby Creek (E9) sediments were extremely toxic with zinc levels 2.5 times above the ISQG high value meaning there is a high probability of deleterious effects. Levels of copper, lead and nickel were above ISQG low values (Table 16) in Throsby Creek. Similar levels of contamination in Throsby Creek sediments have been reported elsewhere (Edge et al. 2104). Throsby Creek has not been dredged for almost two decades due to the levels of contamination present, with deeper cores in some areas containing extremely high concentrations of contaminants (WorleyParsons 2011). Other sites at the harbour entrance (E1, E2), channel (E3) and South Arm (E4) that are dredged regularly, and sites in the North Arm (E6, E7) and near Hexham (E8), contained low levels of metals (Table 16). Sediment from site E9 in Throsby Creek was the only site which contained levels of total PAH that exceeded the ISQG low value of 4000µg/kg (Figure 18). Sediment from Throsby Creek (E9) contained levels of total PAH that exceeded the ISQG low value of 4000µg/kg for total PAH (Figure 18, Swanson et al. 2017c). PAH which exceeded the ISQG low guidelines in sediments in Throsby Creek (E9) were acenapthene, phenanthrene, benzo(a)pyrene, dibenzoanthracene, chysene, fluoranthene and pyrene. The South Arm and Channel have higher levels of PAH relative to the North Arm sites but total PAH were below ISQG low values. Levels of acenapthene and fluorene, two low molecular weight PAH, however, exceeded ISQG low values at E5 and E1. Site E5 in the South Arm is likely to be located close to the border of the extent of dredging operations in the South Arm. Levels of PAH were higher at the mouth (E1) than in the channel suggesting that the mouth is not dredged as regularly as the main channel.

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Figure 17: Sites where sediments were collected by OEH and analysed for metals and PAH content during low-flow conditions in 2014 Site EX was recently dredged. Sites E1–E4 are routinely dredged to maintain deepwater access for shipping while sites E5–E9 are not dredged (however E5 is very close to dredging area).

Table 16: Dissolved metal concentrations in surface sediments collected throughout the Hunter estuary n=1, location of sites sampled are shown in Figure 16. ISQG low trigger and high risk values shown (ANZECC & ARMCANZ 2000). Data exceeding ISQG low values are in bold. Data exceeding ISQG high values are in orange bold with an asterisk. Total organic carbon (TOC) is also shown (wet weight: ww%). Contaminant data are standardised to 1% (TOC). Metal Dry weight (mg/kg) Sites E1 E2 E3 E4 E5 E6 E7 E8 E9 ISQG ISQG low high Copper 4 5 20 2 28 <0.1 2 3 146 65 270 Lead 3 2 10 3 23 <0.1 0 0 144 50 220 Mercury <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 0.15 1

Nickel 10 10 26 12 40 4 10 12 39 21 52 Silver <0.1 <0.1 0 <0.1 0 <0.1 <0.1 <0.1 0 1 4

Zinc 42 34 122 61 295 24 35 33 *968 200 410 Arsenic 4 6 7 5 10 2 2 1 12 20 70 TOC ww% 0.49 0.79 1.70 0.20 2.50 <0.1 0.19 0.18 7.1

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Figure 18: Total PAH in estuarine sediments (µg/kg dry weight) ISQG low trigger value for total PAH is 4000µg/kg (dry weight). See Figure 17 for site locations.

Figure 19: Benthic community respiration (BCR) in sediments collected from two sites in Throsby Creek (TC1, TC2), South Arm (SA1, SA2) and the North Arm (NA1, NA2) n=3. Consumption of oxygen (respiration) by microalgae in suspension in estuary water is also shown. TC water is from Throsby Creek and SA-NA water was collected from the South Arm and North Arm.

Total organic carbon The total organic carbon (TOC) content of estuarine sediments is the net result of carbon inputs minus remineralisation, and export due to resuspension. The distribution of TOC broadly follows a pattern of highest in upper estuarine reaches (~5%), moderate in middle

60 Lower Hunter River Health Monitoring Program – Literature and data review reaches (~0.5–2%), and low in the marine delta reaches of the lower estuary (<0.2%). There is considerable variation in TOC content across depth gradients due to differences in bed shear stress caused by tidal currents and wind wave energy that serve to winnow out and redistribute fine TOC. The preliminary survey showed that sediment TOC in the Hunter River estuary was relatively high in some reaches of the lower estuary and low in the middle estuary sites (Table 16). Throsby Creek sediments contained a TOC content of 7% which is relatively high for Australian estuaries (Eyre 1998; Ferguson et al. 2003; Eyre et al. 2011) and indicates that these sediments are highly enriched with TOC. It is likely the bulk of this enrichment arises from catchment sources delivered during stormwater runoff events. Due to its position in the lower estuary, freshwater runoff entering the creek mixes with oceanic water causing flocculation of fine suspended material including TOC. The creek also experiences relatively high phytoplankton blooms during low flow periods, and settling of phytoplankton detritus likely contributes to sediment TOC. The high sediment TOC in Throsby Creek is consistent with the high benthic community respiration rates measured there during this study (Figure 19). The central basin of the dredged zone in the harbour (site E3) also recorded relatively high TOC (1.7%) compared to expected values for lower estuary sediments. It is likely the large increase in water depth caused by dredging has reduced bed shear stress in this region allowing the settling of fines. This reach also experiences large phytoplankton blooms during low flow periods which would contribute to sediment TOC. Similarly, the entrance channel sites (E1 and E2) had higher than expected TOC values, most likely due to the combined effects of dredging on bed shear stress and high pollutant concentrations in the water column. Sediment from the mid South Arm (E5) had a moderate TOC content of 2.5% (Table 16), which is considerably higher than expected for a lower estuary reach, and higher than comparable sites in the North Arm of the river (e.g. sites E6 and E7). This indicates high rates of TOC enrichment in this reach and is consistent with the high rates of benthic community respiration measured during this study (Figure 19) The source of enrichment in this reach most likely arises from a combination of high phytoplankton detritus during low flow periods, and the advection of pollutants upstream from the harbour reach due to tidal currents. The middle estuary sites of the North Arm (E7 and E8) recorded relatively low TOC contents (Table 16). It is unclear why TOC contents were so low at these sites given the moderate rates of benthic community respiration measured in the reach (Figure 19). It is noted, however, that TOC samples were taken from channel sediments experiencing high current energies, whereas benthic metabolism samples were taken from more protected shallower regions of the reach. There were close relationships between TOC content and the concentrations of heavy metal contaminants in the sediments. This most likely reflects the scavenging of heavy metals by organic matter before being deposited in sediments (Lin & Chen 1998). There is a high affinity between heavy metals and organic matter in estuarine waters, particularly in the absence of clay particles (Forstner & Wittman 1981). It is likely therefore, that TOC enrichment of the lower Hunter River estuary is serving to retain heavy metal pollutants in the sediments, and may be an important vector of pollutants to detrital foodchains. Given the high rates of benthic community respiration and productivity recorded in places like Throsby Creek, it is also likely that large shifts in sediment redox occur over the diel cycle which may promote the mobilisation of heavy metals into bioavailable forms. This area warrants further research to assess the full implications for estuary health and toxicity risks.

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Benthic community respiration OEH conducted a preliminary ecological assessment in the lower estuary in 2015–16 (Swanson et al. 2017c). One aspect of the study was to assess the production and consumption of oxygen by benthic microalgae living on the surface of riverbed sediments. Sediment cores and estuary water were collected from two sites in Throsby Creek, the South Arm and the North Arm of the Hunter River. The cores and site water were transported to the laboratory and incubated in site water in chambers under dark and light conditions. At the beginning and end of the experiment, dissolved oxygen concentrations were measured in the site water in which the sediment was incubating. Data from the light incubations provided an estimate of oxygen production or ‘productivity’ of the benthic microalgae). Data from the dark incubations provide an estimate of oxygen consumption by the benthic community (microalgae and bacteria) and this is called benthic community respiration (Figure 19). -2 -1 Mean BCR rates exceeded minus 1500 µmol O2.m .hr in sediments collected from TC2 and SA2 (Figure 19, Swanson et al. 2017c). Denitrification is a critical process in aquatic ecosystems whereby benthic microbes convert ammonium and nitrates to nitrogen gas which removes excess nutrients from the water column and sediments. Denitrification efficiency in sediments decreases when organic matter content increases and BCR rates in sediments -2 -1 exceed minus1500 µmol O2.m .hr (Eyre & Ferguson 2009). In this instance, sediments can become a source of bioavailable nutrients to estuary waters instead of recycling nutrients to inert nitrogen gas.

Figure 20: Chlorophyll-a concentrations in surficial sediments collected from Throsby Creek (TC1, TC2), the South Arm (SA1, SA2) and the North Arm (NA1, NA2: Swanson et al. 2017c) Chlorophyll-a is used as a proxy measure for the abundance of benthic microalgae living on the sediment surface.

Benthic microalgae The concentration of chlorophyll-a on the surface of sediment cores was also measured as an indication of the abundance of benthic microalgae (Figure 20, Swanson et al. 2017c). The chlorophyll-a content of surface sediments is an indicator of the living and dead microalgal biomass (benthic and pelagic microalgae). Sediment chlorophyll-a can be used as a proxy for the presence and abundance of benthic microalgae, however, it can also reflect the level of enrichment of sediments with labile organic carbon arising from the settling of

62 Lower Hunter River Health Monitoring Program – Literature and data review phytoplankton detritus. The abundance of benthic microalgae on sediments increases in response to excess nutrients in waters which in turn increases the organic matter content of sediments when microalgae decompose. High carbon content in sediments reduces sediment quality by interfering with critical denitrification processes (Eyre & Ferguson 2009). A previous study reported that Newcastle sediments contained 15µg/g of chlorophyll-a (Dafforn et al. 2014). The OEH study reported a similar mean value from all sites (17.5µg/g of chlorophyll-a, Figure 20) with sediments from Throsby Creek having the highest concentrations (25 and 40µg/g of chlorophyll-a). Throsby Creek sediments also contained very high organic matter content (Table 16). Chlorophyll-a concentrations on sediments at SA1 and SA2 were lower than expected given the high nutrient concentrations in estuary waters (Figure 14), however, South Arm sediments were also found to have high concentrations of zinc and nickel (Site E5: Table 16). It is possible that metal contamination in South Arm sediments and waters is reducing benthic microalgal growth in the South Arm. In summary, sediment condition was found to be very poor in Throsby Creek and in the mid South Arm based on the high contaminant load, high organic carbon content and high respiration rates of the benthic community in these sediments (Swanson et al. 2017c).

3.3.10 Bioaccumulation Burwood Beach Wastewater Treatment Facility (WWTW) is the largest WWTW managed by Hunter Water Corporation servicing the city and inner suburbs of Newcastle. Hunter Water Burwood Beach Oyster Study assessed the potential for effluent and biosolid discharge from the Burwood Beach WWTW to lead to bioaccumulation of chemicals using Sydney rock oysters (Saccostrea glomerata) as a biomonitor (WorleyParsons 2013). Oysters were deployed for two months, on three separate occasions, at the position of the outfall, and 100 metres, 500 metres and 2000 metres either side of the outfall. The study site is approximately 6 kilometres to the south of the entrance to Newcastle Harbour and the nearby (2 kilometres offshore) dumping ground for dredge spoil from the Port of Newcastle. Southerly currents predominate in the region so the study site is in the path of outbound flow of the Hunter River. Most metal and metalloid concentrations were lower than, or similar to background levels for oysters in NSW estuaries reported by Scanes & Roach (1999) except for copper, mercury, selenium and zinc which were higher than background across most sites (Figure 19). Oysters were tested for metals and metalloids prior to each deployment and concentrations of most metals increased following deployment in Burwood Beach WWTW receiving waters, including arsenic, cadmium, copper, lead, mercury, nickel, selenium, silver and zinc. Increased metal concentrations were found in oysters deployed at most sites and seem to reflect higher background levels of metals in offshore waters. Dredge spoil from Newcastle Harbour and the South Arm of the Hunter River has been dumped offshore for decades, approximately 7 kilometres to the north-east of Burwood Beach WWTW. While limits are set as to contaminant loads allowed in dredge spoil, millions of tonnes of sediments containing background levels of metals and contaminants are dumped offshore annually which is likely to enrich offshore sediment, and coastal waters with metals and other contaminants. Data from the OEH stormwater monitoring program (Swanson et al. 2017b) reveal high levels of dissolved zinc in the lower estuary originating from industrial and urban sources. It is likely the Hunter estuary acts as a source of dissolved metals to the offshore which could explain some of the results of the Burwood Beach oyster study.

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Figure 21: Concentrations of zinc in Saccostrea glomerata tissue (mg/kg, wet weight) following eight weeks offshore deployment during January–April 2012, May–July 2012 and March–May 2013 (mean +/- standard error) For each site, n= 2–3 replicate samples with 10 composite oysters/replicate. LOR = Limit of reporting. Dark shading of grey bars are near the outfall and shading gets lighter with distance from outfall (WorleyParsons 2013).

3.3.11 State of the Catchments 2010 and State of the Environment 2012 The 2010 State of the Catchments (SOC) reports document the pressures on, and condition of, 11 natural resource assets under the NSW Natural Resources Monitoring Evaluation and Reporting (MER) program. Data was collected and analysed up until early 2009 by Department of Environment, Climate Change and Water (DECCW, now OEH) and NSW Office of Water (NOW). State of the Environment 2012 (SOE) reports were prepared by the EPA using data largely collected by DECCW and NOW.

Estuarine ecosystems The indicators of estuary condition used for SOC reporting were: • eutrophication: chlorophyll-a, macroalgae and turbidity • habitat distribution: change in seagrass, mangrove and saltmarsh (macrophytes) extent • fish assemblages: species diversity and composition, species abundance, nursery function and trophic integrity (food web). A condition index was calculated for each estuary by averaging the unweighted individual scores for each condition indicator and applying expert opinion to test whether the results look reasonable. For the Hunter River, a score was not available for the indicators: chlorophyll-a, macroalgal, turbidity and fish, due to a lack of data. This meant that an Overall Condition Index score for the Hunter River could not be made.

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The macrophyte distribution in the lower Hunter River estuary is largely dominated by mangroves. Mangrove data was considered to be baseline and so mangrove condition was not assessed (DECCW 2010a). Saltmarsh (% distribution) was rated as being in good condition which differs from the assessment of Brereton & Taylor-Wood (2010). A conservative assessment was used in the analysis in SOC reporting which adopted a wide range for acceptable levels of change in saltmarsh distribution due to unknown levels of natural variation and little available data. Seagrass condition in the Hunter River was rated as very poor condition due to the absence of seagrass in the Hunter estuary (DECCW 2010a; Creese et al. 2009). The Hunter River estuary was rated as having an Overall Pressure Index score of High. The pressure score (Very high, High, Moderate, Low, Very low) given for each pressure indicator is shown in brackets: Cleared land (High), Population (Moderate), Sediment input (High), Nutrient input (High), Freshwater flow (Moderate), Disturbed habitat (Very low), Tidal flow (Very high) and Fishing (High). While this review is largely focused on the Hunter River Estuary, the condition of the river in the upper catchment is discussed briefly below. Land use and river condition in the upper catchment can affect estuary condition as river waters carry pollutants and sediment downstream through the estuary as it flows eastward to the ocean.

Riverine ecosystems Riverine ecosystem condition across the State was assessed using water quality, macroinvertebrate, fish and hydrology indicators for SOC and SOE reporting. Only water quality results are presented here. Water quality condition was described as the percentage of samples exceeding the ANZECC water quality guidelines for turbidity and total phosphorus (ANZECC & ARMCANZ 2000). Trend information is provided for the water quality indicators: electrical conductivity, turbidity and temperature. The NSW discrete water quality data archive (Triton database managed by the NSW Office of Water [NOW]) was evaluated using a long-term trend analysis (30–35 years). Condition was described for macroinvertebrates, fish and hydrology by using a five-point scale, a similar ranking process based on the Sustainable Rivers Audit (Davies et al. 2008).

Water quality Water quality data for Hunter River sites in the upper catchment suggests that condition may have worsened since the last reporting period (SOE 2009; DECCW 2010b). Phosphorus is regularly above trigger values (>50% of the time) at most sites in the upper and middle reaches of major inland rivers of New South Wales but exceedances are usually less frequent in coastal rivers. The Hunter River is an exception to the trend of lower exceedances for coastal rivers. SOE (2012) reports that over 50–75% of samples collected from the Hunter River at Luskintyre, Singleton and Moses Creek exceeded ANZECC guidelines for TP, compared to 25–50% exceedance in SOE (2009). Water quality remains poor at the Hunter River, Musselbrook with >75% of samples exceeding ANZECC guidelines for TP in SOE (2009) and SOE (2012). High phosphorus levels are considered to be the most significant risk factor for eutrophication in fresh water, in conjunction with other factors such as nitrogen, light conditions and water temperature (Davis & Koop 2006). Total nitrogen (TN) concentrations in over 75% of samples collected from the Hunter River at Luskintyre and Musselbrook exceeded ANZECC guidelines, while 50–75% of samples from Singleton, Moses Creek and Moona Flats exceeded ANZECC guidelines for TN (SOE 2012). Total nitrogen data was not reported in SOE 2009. State of the Catchments (2010) reported that the majority of samples from sites on the Hunter River had turbidity levels that exceeded ANZECC guidelines. Turbidity levels in the Hunter River usually (>90% samples) exceed guideline levels at Luskintyre, Singleton and Moses Crossing. Trend data reported a trend of increasing turbidity for all sites on the Hunter

65 Lower Hunter River Health Monitoring Program – Literature and data review

River. This is no surprise considering land use in the catchment is dominated by mining and agriculture. The lower Hunter River estuary is known as a turbid system, and has a long-term average (5.5-year) turbidity at the mouth of Ironbark Creek of 14.3NTU (99th percentile: 125NTU). Shipping activity continuously resuspends sediments in Newcastle Harbour and the South Arm.

Other indicators Other indicators of riverine condition were reported in SOE (2012) which are summarised below. NOWs assessment of hydrological condition of the State’s rivers was based on hydrological stress at low flows. The Hunter River was rated as having a: • moderate hydrological condition • very poor physical form condition • moderate riparian condition • very poor overall fish condition. Fish results were very poor, mostly due to a new measure for recruitment, which was found to be poor in coastal rivers. The endangered population of the Darling River hardyhead has not been observed in the headwaters of the Hunter River since 2003 despite extensive sampling throughout its potential distribution (DPI 2014). Impacts of fish barriers (weirs, floodgates) on the movement upstream of estuarine species and the spate of flooding in coastal catchments in 2010–11 may be contributing factors to low recruitment. The Seaham Weir on the Williams River was ranked as high priority (1b) for future remediation works with the potential to open 100 square kilometres of fish habitat (DECCW 2010b).

3.3.12 Hunter Catchment Salinity Assessment (2013) Electrical conductivity (EC) is used as a surrogate measure for the total salt concentration in water and can be significantly affected by river flows. Thus assessments of changes or trends in EC should also consider variation in flow. NOW has a number of gauging stations on the Hunter River that have been monitoring EC and flow data continuously for 10–20 years (data can be downloaded from Hydstra database and the KWiQM water quality database). In the 1990s, concerns about the impacts of salty discharges from mines to the river on river health and the availability of fresh water for irrigation of agricultural land led to the development of the NSW Governments’ Hunter River Salinity Trading Scheme (HRSTS). HRSTS began in 1995 as a pilot study with regulation commencing in 2002, and only permits discharges of salty waters from mines during periods of high or flood flow (DEC 2003). A recent review by OEH into the effectiveness of the scheme on improving water quality of the Hunter River concluded that HRSTS was likely to have: • reduced EC levels at (and immediately upstream of) Singleton and Greta • potentially reduced EC levels at monitoring stations between Denman and Singleton • had little effect on flows and EC levels upstream of Denman (Krogh et al. 2013). The condition of the Hunter River between Greta and Denman appears to have improved over the past 20 years since the HRSTS was introduced.

3.3.13 Models for the Hunter estuary

Hydrology and flushing time The largest contributions to the water budget of the Hunter River are the tidal prism (+/- 18250GL), catchment runoff (1800GL) and groundwater inflows (183GL) while rainfall (30GL) and evaporation (minus 26GL) are negligible by comparison (MHL 2003). At the mouth the

66 Lower Hunter River Health Monitoring Program – Literature and data review tidal contribution is 10 times the catchment runoff. Further upstream the tidal prism diminishes and the relative importance of catchment runoff increases. An estuary-wide two-dimensional hydrodynamic model was developed by BMT WBM and was applied to investigate ocean exchange and flushing within the Hunter River estuary considering the ‘e-folding’ flushing time (Figure 22, BMT WBM 2012). The e-folding flushing time is the time taken for average tidal conditions to reduce the concentration of a conservative constituent at every model point inside the lower estuary from a value of 1.0 to a value of 0.368 (1/e) under the forcing of ocean water (concentration of 0.0) and the physical processes of advection and dispersion (BMT WBM 2012). Generally, areas close to the ocean will have a very short flushing time – indicative of the time it takes for water particles at these locations to be advected out of the estuary system, while areas near the tidal limits of the estuary have long flushing times and are much more influenced by freshwater inflows to the estuary (BMT WBM 2012).

Figure 22: E-folding flushing time for the lower Hunter River Estuary (BMT WBM 2012) Only the channel and lower North Arm have flushing times less than two days. The South Arm e- folding flushing time is in the order of four to six days.

3.3.14 Review of available models for the Hunter estuary NSW Government agencies, Office of Environment and Heritage (OEH), NSW Office of Water (NOW) and Newcastle City Council (NCC) commissioned UNSW Water Research Laboratory (WRL) to review available models and existing data for the Hunter River. The overarching objective of the Hunter Valley Hydrodynamic Platform and Model Scoping Study (Glamore et al. 2014) is to provide a whole-of-government physical processes model or ‘suite of models’ for the Hunter River and its estuary. A review of existing data identified there are significant data gaps pertaining to catchment inflows and water quality parameters, with the highest priority data gaps including bathymetric and inflow data between the catchment and upper tidal pool with no measured flow data for local catchment runoff into the Hunter River estuary between major inflow boundaries and the Newcastle Harbour entrance. The data

67 Lower Hunter River Health Monitoring Program – Literature and data review review highlighted that previously collected water quality data (other than salinity concentrations) is of limited value for model calibration or verification. The lack of recent field data, or the limited availability of data to support refined hydrodynamic or water quality models, was a significant concern noted with previous models (Glamore et al. 2014).

Filling data gaps

Water quality monitoring programs Monitoring data alone cannot be used to describe ecological processes, i.e. mechanisms by which the system maintains itself in equilibrium or by which it changes from one state to another. Water quality monitoring data is, however, an essential component of model development and recent field data is lacking. OEH developed and implemented an estuary- wide water quality monitoring program in the Hunter River estuary in order to address this need for recent water quality data to inform model development. The main findings of the OEH water quality monitoring program and stormwater water quality monitoring program were discussed in earlier sections of this review, with full results reported elsewhere (Swanson et al. 2017a,b,c,d). A long-term water quality monitoring program is needed in the Hunter estuary to provide data required for models being developed but also to track change in condition. The NSW MER program assesses the health of the upper Hunter River estuary every three years, however, more frequent monitoring of all regions of the estuary is recommended. Further monitoring of water quality in the estuary would build a long-term dataset which can be used by stakeholders to detect change in condition as a result of management and regulatory actions in the heavily modified catchment.

Catchment inflows OEH in collaboration with WRL deployed multi-probe loggers at key locations to monitor post flood recovery following the flooding event of 21–23 April 2015. Salinity, temperature, dissolved oxygen, turbidity and depth data were recorded providing much needed data on catchment inflows under flood conditions and can also be used calibrate and verify hydrodynamic models. This data has not been reported yet but will be in future.

68 Lower Hunter River Health Monitoring Program – Literature and data review

4 Conclusions and recommendations

The Hunter River estuary is a degraded ecosystem, particularly in the lower reaches of the harbour and at the Port of Newcastle. The rapid decline in condition of the Hunter River estuary throughout last century was the result of multiple pressures on the system. Saltmarsh cover declined dramatically over the last century as tidal movements were restricted in wetland areas to make way for grazing, urban and industrial areas. Pollutants from agricultural, urban and industrial land use in the catchment, and restriction of natural tidal flows for land reclamation and flood mitigation, have impacted ecological processes in the estuary. There have been no formal observations of seagrass in the Hunter River since European settlement although anecdotal stories of fish catch imply that seagrass was present in the estuary in the late 1800s. The loss of seagrass from the Hunter estuary probably occurred as a result of increased turbidity in response to extensive land and bank erosion in the catchment. Kooragang Wetlands and wetlands at Tomago and Hexham Swamp have been extensively rehabilitated over the past decade returning tidal flows, flora and fauna to these vital estuarine habitats. Riparian vegetation such as wetlands and saltmarsh act as a buffer between the estuary and the catchment, and improve water quality by filtering sediments and nutrients from stormwater runoff as it drains to the estuary. The numerous projects that have restored and rehabilitated wetlands in the Hunter River estuary are likely to have improved water quality in the estuary. Concentrations of inorganic nutrients (ammonium, nitrates and phosphates) throughout the estuary were high, often exceeding NSW trigger values for coastal riverine estuaries. Median concentrations of ammonium were highest in the South Arm suggesting that industry is the primary source of ammonium to the estuary, while median concentrations of nitrate and phosphate increased with distance upstream. Dissolved nutrient concentrations were considerably lower than in the past, however, wastewater and stormwater from industrial sites, and contaminated groundwater, are current sources of dissolved nutrients to the lower estuary. While the total loads of pollutants discharged from some industrial sites have been significantly reduced in recent years, there is potential for further reductions through pollution reduction programs. Despite the persistently high concentrations of inorganic nutrients in the water column, chlorophyll-a levels are not as high as one would expect and algal blooms are rarely seen in the Hunter River estuary. This observation may be the outcome of multiple stressors (turbidity, high nutrient concentration, dissolved metals) acting synergistically to reduce the growth of microalgae. Shorter residence times of waters in the lower estuary due to flushing with oceanic water may also help to reduce chlorophyll-a concentrations. Over 100 years of heavy industry on the shores of the Hunter River has led to the enrichment of riverbed sediments with industrial contaminants such as heavy metals, PAH and organochlorines. Continual dredging of port areas to maintain deepwater access to berths has reduced the contaminant load in the lower estuary by removing enriched sediments. The quality of industrial discharges has improved, however, low concentrations of industrial chemicals, metals in particular, still pollute the river on a daily basis. Newcastle’s industrial past has led to higher than usual background concentrations of metals in the Hunter River, which is unlikely to change with continued inputs from industrial sites (e.g. metal fabrication, chemical and fertiliser production and handling) and port operations (e.g. metal concentrates and coal loaders). Contaminated lands on current and former industrial sites continue to pose a threat to the health of the lower Hunter River estuary. While management of the remediation of these sites has improved, the remediation process is long as evidenced in the remediation of the former BHP Billiton Closure site at Mayfield. This commenced in 2001 and is still continuing in parts; it has involved up to 17 voluntary management proposals. The remediation of the sediments adjacent to the land-based site, and which comprised a component of the larger remediation project, involved removing 800,000 cubic tonnes of contaminated sediments in the Hunter River adjacent to the site.

69 Lower Hunter River Health Monitoring Program – Literature and data review

High concentrations of dissolved nutrients nitrate and ammonia, and dissolved metals zinc and manganese, and high counts of faecal coliforms were recorded in the upper reaches of Throsby Creek after rain events. Population growth will lead to increased inputs of pollutants from urban sources, including nutrients, total suspended solids (TSS) and faecal coliforms, in urban runoff and WWTW discharges. Diffuse urban inputs of pollutants from the urban catchments in the lower reaches of the estuary are substantial, even though total loads of nutrients exported from the agricultural land use in the upper catchment far outweigh total loads exported to the estuary from the lower urbanised and industrialised catchments. Best practice and behaviour change may lead to reductions in diffuse pollution from agricultural and urban areas. This will require continued efforts by local councils and landcare groups in identifying and managing sources and educating the community. There have been great gains in the past five years in reducing the pollutant loads being discharged from licensed industrial premises, through the implementation of pollution reduction programs (PRP). Tighter regulation of industrial discharges, improved on-site practices through PRP and remediation of contaminated lands and sediments over the past 15 years have considerably improved the condition of the lower Hunter River estuary. Concentrations of nitrates and ammonium in the main channel of the lower South Arm are likely to be 5 to 10 times lower than before 2000 (Swanson et al. 2017a). Point source pollution from industrial sites, however, contributes large amounts of pollutants daily to the lower estuary in wastewater and stormwater discharges. Point source pollution differs from diffuse pollution as it is a constant source of pollutants to the estuary resulting from continuous discharges of wastewater. Point source pollution is also easier to manage and reduce than sources of diffuse pollution. The quality of stormwater discharged from licensed premises often requires monthly monitoring as a condition of the environment protection licence granted by the EPA, however, concentration limits rarely apply to stormwater discharges. In those cases where concentration limits are not applied to stormwater discharges, the licensee must comply with s.120 of the Protection of the Environment Operations Act, i.e. they are required by law to not pollute waters. Stormwater runoff from licensed premises is undoubtedly polluting waters, and has been shown to contain very high concentrations of pollutants. Large volumes of treated wastewater (kilolitres) are discharged daily from some licensed sites. Even though concentration limits may apply to these licensed discharges, nevertheless large loads (amounts) of pollutants are still entering estuary waters due to the sheer volume of wastewater being discharged. Setting concentration limits for pollutants in stormwater discharges from licensed premises, reducing the volumes of wastewater and stormwater discharges, and increasing the frequency of monitoring, are critical steps towards future tighter regulation of industrial pollution by the EPA. There is not a strong understanding among regulators and consultants regarding the assessment of nutrients and metals, the correct interpretation of monitoring data and the application of ANZECC guideline criteria. Future assessments of contaminated sites and EPLs may want to consider the potential for the impact of multiple stressors on estuary health. Increased communication and collaboration between OEH Science Division and the regulatory divisions of the EPA could lead to better outcomes in the management and regulation of pollution of the State’s waterways. The water quality data collected during this program forms a baseline dataset against which future developments in the lower catchment can be assessed. The NSW MER program assesses the health of the upper Hunter River estuary every three years, however, more frequent monitoring of all regions of the estuary is recommended to build a long-term dataset which can be used by stakeholders to detect change in condition as a result of management and regulatory actions in the heavily urbanised and industrialised catchment. Further investigations are needed to assess the condition of biological indicators in the estuary (e.g. fish and macroinvertebrate assemblages, sediment microbial function).

70 Lower Hunter River Health Monitoring Program – Literature and data review

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Streever B 1999, Bringing Back the Wetlands, Sainty & Associates Pty Ltd, NSW. SEWPAC 2012, Wetlands Australia: National Wetlands Update September 2012–Issue No. 21, Australian Government Department of Sustainability, Environment, Water, Population and Communities (SEWPAC), Canberra. Swaine DJ 1977, Trace elements in coal, in: Trace substances in environmental health – XI, pp.107–116, DD Hemphill (Ed), University of Missouri, Columbia, USA. Swanson RL, Potts JD & Scanes PR 2017a, Lower Hunter River Health Monitoring Program Water Quality Monitoring Program 2014–15 Report, Office of Environment and Heritage, Sydney. Swanson RL, Potts JD & Scanes PR, 2017b, Lower Hunter River Health Monitoring Program: Stormwater Quality Monitoring Program 2015 Report, Office of Environment and Heritage, Sydney. Swanson RL, Ferguson AJP & Scanes PR 2017c, Preliminary Ecological Assessment of the Lower to Mid Hunter River Estuary, Office of Environment and Heritage, Sydney. Swanson RL, Potts JD and Scanes PR 2017d, Lower Hunter River Health Monitoring Program: Project Summary Report, Office of Environment and Heritage, Sydney. Tenison-Woods Rev. JE 1882, Fish and fisheries of New South Wales, Thomas Richards Government Printer, Sydney. Cited in Pepperell JG (no date). The Ecology Lab 1998, Bioaccumulation in Aquatic Fauna from the Hunter River: Final report, The Ecology Lab Pty Ltd. USEPA 2001, PLOAD version 3.0: An ArcView GIS tool to calculate non-point sources of pollution in watershed and stormwater projects, User’s manual, Appendix IV: Event mean concentrations and export coefficients, United States Environmental Protection Agency. URS 2004, Human health and ecological risk assessment of sediments in the south arm of the Hunter River: Final Report, URS Australia Pty Ltd, Sydney. URS 2005, Sediment remediation, simulated bench scale trials: South Arm Hunter River: Final report, URS Australia Pty Ltd, Sydney. URS 2006a, Assessment of depth and extent of sediment contamination in the South Arm of the Hunter River: Final Report, URS Australia Pty Ltd, Sydney. URS 2006b, Kriging estimates of the volume of contaminated sediments in the South Arm of the Hunter River: Final Report, URS Australia Pty Ltd, Sydney. URS 2006c, Arsenic Groundwater Investigation and Review of Remedial Options: Final Report, URS Australia Pty Ltd, Sydney. URS 2007a, Final definition of sediment in the south arm of the Hunter River beyond the Primary Remediation Zone: Final Report, URS Australia Pty Ltd, Sydney. URS 2007b, Updated pilot trial sediment report remediation chemical fixation and solidification: South Arm Hunter River: Final report, URS Australia Pty Ltd, Sydney. URS 2009, Appendix 1: Hunter River Water Quality Monitoring Program: Stabilisation Optimisation Study, URS Australia Pty Ltd, Sydney. URS 2012a, Annual ammonium groundwater monitoring: December 2011: Orica Kooragang Island, URS Australia Pty Ltd, Sydney. URS 2012b, Appendix H: Environmental Impact Assessment for Proposed IPL Ammonium Nitrate Manufacturing Facility: Surface Water and Wastewater Management Report, report prepared for Incitec Pivot Ltd, URS Australia Pty Ltd, Sydney.

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URS 2012c, Water quality sampling in the Hunter River Estuary: November 16, 2012: Interim Report, prepared for Incitec Pivot Ltd, URS Australia Pty Ltd, Sydney. URS 2013, Investigation of arsenic levels in the Hunter River at Kooragang Berths 2 and 3, URS Australia Pty Ltd, Sydney. URS 2014a, Bi-annual arsenic groundwater monitoring results: Orica Kooragang Island, URS Australia Pty Ltd, Sydney. URS 2014b, IPL Kooragang Island Facility Stormwater Management Plan, URS Australia Pty Ltd, Sydney. Underwood AJ & Chapman MG 1995, Introduction to coastal habitats, in Coastal Marine Ecology of Temperate Australia, Underwood AJ & Chapman MG (editors), University of New South Wales Press Ltd, Sydney, pp. 1–15. Weijs L, Dirtu AC, Das K, Gheorghe A, Reijnders P & Neels H et al. 2009, Inter-species differences for PCBs and PBDEs in marine top predators from the Southern North Sea: Part 2: Biomagnification in harbour seals and harbour porpoises, Environmental Pollution 157: 445–71. Weijs L, Detlef T, Roach AC, Manning TM, Chapman JC & Edge K et al. 2013, Assessing levels of halogenated organic compounds in mass-stranded long-finned pilot whales (Globicephala melas) from Australia, Science of the Total Environment 461–462: 117–125. Woodward-Clyde 1999, Human Health and Environmental Risk Assessment: BHP Steelworks Site, Newcastle, NSW: Interim Report, Woodward-Clyde Consultants. WorleyParsons 2008, Kooragang Coal Export Terminal: Baseline and initial dredging period water quality and water level monitoring: September 2007–February 2008: Issue No.4, Worley Parsons Ltd. WorleyParsons 2011, Compilation of sediment quality in maintenance dredge area, Attachment 1 in NPC Port consent application, Worley Parsons Ltd. WorleyParsons 2013, Oyster bio-monitoring study: Burwood Beach WWTW: Report 301020- 03413–105, prepared for Hunter Water, Worley Parsons Ltd. Williams R, Watford F & Balashov V 2000, Kooragang Wetland Rehabilitation Project: History of Changes to Estuarine Wetlands of the Lower Hunter River, NSW Fisheries Final Report Series No. 22, NSW Department of Primary Industries, Sydney. Vreeland V 1974, Uptake of chlorobiphenyls by oysters, Environmental Pollution 6: 135–140.

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