~'f x State Pollution Control Commission 00/ e Northern Rivers Study NO. 4 Water Quality in the Richmond River I ~ I J eState P,ollution Control Commission ,~ Northern Rivers Study NO.4 Water Quality. in the Richmond River .' . Other ti tIes in the Northern Rivers Study are: Water Quality In the Tweed-Terranora Estuary Water Quality In the Brunswick River Water Quality In the Clarence River Water Quality In the Bellinger and Kalang Rivers Water Quality In the Macleay River Water Quality In the Hastings River Water Quality In the Manning River This report was prepared by Ross Williams, State Pollution Control Commission, Sydney. The Commission acknowledges the assistance provided by the following In carrying out this study: Commonwealth Government funds provided through the Wage Pause and Community Employment Schemes; and the NSW Water Resources Commission for flow data. ISBN 0 7305 0662 2 June 1987 CONTENTS Summary 1 Introduction 1 2 Richmond River Study 4 2.1 Objectives 4 2.2 Program 4 3 Catchment and River Characteristics 9 3.1 Catchment Description 9 3.2 Population Growth 10 3.3 Diffuse Source Pollution from Land Use Activities 12 3.4 Point Source, Discharges 12 3.5 Water Resources and River Flow 14 4 Water Quality in the Richmond Valley 21 4.1 Richmond River 21 4.2 Wilson River 29 4.3 Major Tributaries of the Richmond River 31 4.4 Quality of Effluent Discharged to the Richmond River 40 5 Factors Influencing Water Quality in the 42 Richmond River Basin 5.1 Point Source Discharges 42 5.2 Run-Off and its Contribution to River Water Quality 44 5.3 Impact of Flood Mitigation and Drainage Practices 45 5.4 Urban Run-Off 46 5.5 Impact of Pesticides 46 6 Comparison of Water Quality 48 With Other NSW Waterways 7 Conclusions 51 8 Recommendations 53 9 References 55 Appendixes A Station Locations 56 B Analytical Methods 60 C Land Use Activities Associated with Each 61 Sampling Station Figures 1 Northern Rivers Study Catchment Basins 2 2 Location of Sample Collection Sites 6 3 Rainfall Distribution in the Richmond Valley 15 4 Weekly Rainfall at Selected Locations in the 16 Richmond Valley 5 Flow in the Richmond River 18 6 Selected Salinity Values for Flow Characterisation 19 7 Temperature, Salinity, Dissolved Oxygen and pH: 22 Richmond River 8 Secchi, NFR, Turbidity and VSS: Richmond River 24 9 TP, TN, N:P Ratio and Chlorophyll a: Richmond River 27 10 Soluble Nutrients and Keldjahl Nitrogen: Richmond River 28 11 Temperature, Salinity, Dissolved Oxygen and pH: 30 Wilson River 12 Secchi, NFR, Turbidity and VSS: Wilson River 32 13 TP, TN, N:P Ratio and Chlorophyll a: Wilson River 33 14 Soluble Nutrients and Keldjahl Nitrogen: Wilson River 34 15 Temperature, Salinity, Dissolved Oxygen and pH: 36 Major Tributaries 16 Secchi, NFR, Turbidity and VSS: Major ,Tributaries 38 17 TP, TN, N:P Ratio and ChlorophyJl a: Major Tributaries 39 18 Soluble Nutrients and Keldjahl Nitrogen: 41 Major Tributaries Tables 1 Water Quality Sampling Stations Per River Catchment 5 2 Land Use and Discharges Near Sampling Stations: 5 Richmond River 3 Location of Mainstream Stations: Richmond River 7 4 Location of Stations on Richmond River Tributaries 7 5 Flood Plain Land Uses and Probable Impacts on 9 Water Quality 6 Population Forecasts: North Coast Statistical Division 10 7 Average Annual Population Growth Rates for Selected 11 North Coast LGAs 8 Discharge Information 13 9 Stream Flow Variability 17 10 Water Quality Subdivisions Based on River Flow 20 11 Average Nutrient Concentrations for the Richmond River 26 .12 Average Nutrient Concentrations for the Wilson River 35 13 Average Nutrient Concentrations for Richmond River 37 Tributaries 14 Approximate Median Concentrations and Loads of 40 Contaminants in Discharges to the Richmond River 15 High Flow Nutrient and NFR Loads: Richmond and Wilson 44 Rivers 16 Analyses of Sediment Samples for Selected Pesticides 47 17 Threshold Nutrient Concentrations at Which Nuisance 48 Plant Growth Has Occurred 18 Selected Water Quality Characteristics for Low Flows 49 of North Coast Rivers Summary The State Pollution Control Commission has conducted extensive water quality surveys of several rivers in the North Coast Region of New South Wales. The program was developed in response to increasing concern from the public and government organisations that point and diffuse sources of pollution were having detrimental impacts on aquatic environments and fisheries resources. The program involved investigations of all major rivers on the North Coast including the Tweed, Brunswick, Richmond, Clarence, Bellinger, Kalang, Macleay, Hastings and Manning. The investigations commenced in November 1983 and data were collected until April 1986. When compared with other northern rivers studied, water quality in the Richmond River above Woodburn and its tributaries Tomki Creek and North Canal was generally poor, the result of the discharge of treated indus trial and sewage effluent. The Richmond and its major tributary, the Wilson River, were well-mixed systems with salinity measured a maximum distance upstream of 40 kilometres at Woodburn. Dissolved oxygen concentrations were normal in the Richmond while elevated concentrations were observed in the Wilson River. Clarity was adequate in the lower estuary but deteriorated in the central catchment. This could be attributed to both urban and agricultural run-off during medium and high flow events respectively. Nutrient concentrations were high in both rivers adjacent to, and downstream of, major communities such as Lismore, Casino, Kyogle and Coraki. This resulted in assimilation zones downstream of these points and sometimes in nuisance algal growth during low flows. Noxious weed infestations were serious between Coraki and Woodburn. These assimilation zones can be attributed to current disposal strategies of both treated industrial and domestic wastewaters. It is recommended that the industries discharging wastewaters review current treatment practices and take concerted action to reduce organic and/or nutrient loads discharged into the river. The local councils and Public Works Department should also review current sewage treatment and effluent disposal strategies' impact on the water quality in the Richmond and Wilson Rivers. Prawn farming is "a small new industry in the Richmond, mainly located in the lower estuary. It should have minimal impact though proponents will need to satisfy the Commission that adequate dilution and/or flushing of wastewaters is available for receiving waters. The survey found that flood mitigation drains contained poor quality water but detected no significant influence on the main stream. These water bodies were also the source of significant noxious weed infestations. The river sediments showed no pesticides at the levels of detection, 0.05 mg/L for organochlorines and 0.1 mg/L diuron. However lindane and aldrin were detected In a flood mitigation drain at levels of 0.2 and 0.3 mg/L respectively. 1 INTRODUCTION The State Pollution Control Commission has conducted extensive water quality surveys of major rivers in the North Coast Region of New South Wales. The program was developed in response to increasing concern from the public and government organisations that point and diffuse sources of pollution were having detrimental impacts on aquatic environments and fisheries resources. The region offers an attractive lifestyle with ample aquatic recreational facili ties and in recen t times has experienced major popula tion grow tho Rapid expansion in the region has led, in some instances, to overloading of sewage facilities and increased industrial activity and urban run-off. The region also boasts a rapidly deVeloping tourist/holiday industry catering to a wide cross-section of the population. In addition to pressures from an expanding population, concern has been expressed about the impact of other land use activities such as: agricultural practices, in particular the use of pesticides and fertilisers; soil erosion, both from the land and river banks; loss of aqua tic habit a t through we tland reclama tion; and control and operation of drains and flood mitigation structures. It is the Government's and the Commission's desire to ensure water quality problems do not develop as a result of changing land use activities and where problems already exist, that communities, industries and relevant government organisations take appropriate action to' ameliorate them. The objective is to maintain acceptable standards of water quality, such as dissolved oxygen concentrations and clarity, and to reduce the risk of the development 'of eutrophic or stratified water column conditions which could affect the viability of wildlife, recreational and, fisheries resources. The study was partially funded by the Commission's resources and by the Commonwealth Government's Wage Pause and Community Employment (CEP) Programs. This is one of a series of reports summarising the investigations, carried out under the Northern Rivers Water Quality Study. The study program developed by the State Pollution Control Commission involved investigations of all major rivers in the North Coast Region including the Tweed, Brunswick, Richmond, Clarence, Bellinger, Kalang, MacIeay, Hastings and Manning. Figure l'details the range and extent of the catchment areas studied. The study commenced in November 1983 and data were collected until April 1986. Not all rivers were sampled over this period as the program has been flexible; as sufficient information was collected on a specific river, some surveys were