GUIDELINE FOR ENVIRONMENTAL MANAGEMENT RISK-BASED ASSESSMENT OF ECOSYSTEM PROTECTION IN AMBIENT WATERS GUIDELINE FOR ENVIRONMENTAL MANAGEMENT RISK-BASED ASSESSMENT OF ECOSYSTEM PROTECTION IN AMBIENT WATERS EPA Victoria 40 City Road, Southbank Victoria 3006 AUSTRALIA October 2004 Publication 961 ISBN 0 7306 7644 7 © EPA Victoria, 2004 The delivery of this guideline was assisted by funding from the joint Commonwealth and State partnership for the National Action Plan for Salinity and Water Quality and also the collaboration of North Central and Corangamite Catchment Management Authorities on the guideline case studies. Foreword State environment protection policies (SEPPs) aim to safeguard the environment. Policies express the community’s expectations, needs and priorities for using and protecting the environment. The SEPP (Waters of Victoria) (WoV) has provided significant steps forward in the management and protection of our aquatic ecosystems. A key part of this is the adoption of a risk-based approach to the policy environmental quality objectives. This is a relatively new approach reflecting current scientific knowledge and direction. The increasing adoption of risk-based methods by environmental agencies and resource managers has evolved from the need to develop transparent processes that better deal with the complexity and variability of aquatic ecosystems. This guideline has been produced to provide support to catchment management authorities, coastal boards, water authorities and other resource managers in the implementation of the SEPP (WoV) risk-based approach. It provides decision frameworks and information on how to undertake risk-based assessments, with practical case study examples of these. MICK BOURKE CHAIRMAN TABLE OF CONTENTS 1. INTRODUCTION..............................................................................................................................................1 1.1 PURPOSE .................................................................................................................................................1 1.2 CONTEXT ..................................................................................................................................................1 2. RISK-BASED ASSESSMENT........................................................................................................................ 2 3. ISSUES, INDICATORS AND OBJECTIVES FOR VICTORIA’S AQUATIC ECOSYSTEMS ..........................................3 4. FRAMEWORK FOR RISK-BASED ASSESSMENT IN AMBIENT WATERS USING SEPP (WOV) ENVIRONMENTAL QUALITY OBJECTIVES ........................................................................................................................................... 6 4.1 ASSESSMENT OF AMBIENT MONITORING DATA AGAINST SEPP (WOV) ENVIRONMENTAL QUALITY OBJECTIVES ................... 8 4.2 RISK-BASED INVESTIGATION ......................................................................................................................... 8 4.3 DECISION MAKING AND RISK MANAGEMENT .................................................................................................... 15 5. CASE STUDIES .........................................................................................................................................16 5.1 UPPER LODDON CATCHMENT .......................................................................................................................16 5.2 UPPER BARWON CATCHMENT.......................................................................................................................30 6. REFERENCES............................................................................................................................................ 41 7. GLOSSARY...............................................................................................................................................43 8. ACRONYMS .............................................................................................................................................44 APPENDIX 1. KEY ISSUES FOR VICTORIA’S WATERBODIES.....................................................................................45 APPENDIX 2. STATE ENVIRONMENT PROTECTION POLICY (WATERS OF VICTORIA) ENVIRONMENTAL QUALITY OBJECTIVES....................................................................................................................................................... 49 APPENDIX 3. THE AUSTRALIAN AND NEW ZEALAND GUIDELINES FOR FRESH AND MARINE WATER QUALITY (ANZECC AND ARMCANZ, 2000) ........................................................................................................................................58 APPENDIX 4. REVIEW OF COMMON ISSUES AND INCONSISTENCIES IN THE MEASUREMENT OF SUSPENDED PARTICULATE MATTER (SPM), TURBIDITY AND SEDIMENTATION (UPPER BARWON CATCHMENT CASE STUDY)........ 60 RISK-BASED ASSESSMENT OF ECOSYSTEM PROTECTION IN AMBIENT WATERS 1. INTRODUCTION applications were both practical and appropriate within a regional context. State environment protection policies help to This guideline is designed for use by experienced protect our environment by providing a ‘blueprint’ of people with an appropriate level of aquatic agreed environmental outcomes and strategic ecosystem knowledge. directions. They enable the community to set the uses and values of aquatic environments that are to 1.2 Context be protected, to set objectives or ‘goal-posts’ that indicate when they are protected, and to provide Environmental agencies and resource managers are clear guidance and tools on how to achieve this. increasingly adopting approaches that incorporate risk or risk-based assessments as the best way to The State Environment Protection Policy (Waters of protect aquatic ecosystems. Such assessments Victoria) (Gazette no. S 107) (SEPP (WoV)) introduces provide an explicit and transparent process for a risk-based approach to the management and coming to terms with the need to make management protection of our aquatic ecosystems. decisions for complex ecosystems that may not Clause 25(1)(a) of the SEPP (WoV) identifies that EPA always be fully understood. will provide guidance to stakeholders to assist in A risk-based approach was developed under the implementing the policy, in particular, develop National Water Quality Management Strategy – guidance on the application of an environmental Australian and New Zealand Guidelines for Fresh risk assessment framework. and Marine Water Quality (ANZECC and ARMCANZ, 2000). This approach has been adopted in the SEPP 1.1 Purpose (WoV) and was used as the basis for the This document provides guidance on how to development of the SEPP (WoV) environmental undertake risk-based assessments in ambient quality objectives. waters1. As such, these guidelines can be Under this approach, the SEPP (WoV) environmental considered a user manual to support catchment quality objectives are no longer a simple pass-fail management authorities, coastal boards, water number, which ignored spatial and temporal authorities and other resource managers. variability and, most importantly, the complexity of Case study examples are included in this guideline aquatic ecosystems. The environmental quality to provide practical applications of risk-based objectives now represent levels at which there is a assessments. They were conducted in partnership potential risk that adverse ecological effects may with water resource managers to ensure the occur. Where the environmental quality objectives are not met, a risk-based investigation needs to be conducted to ascertain if there is an adverse risk to 1 Ambient waters are defined in the ANZECC and ARMCANZ Guidelines (2000) as “all surrounding the ecosystem. The size and detail of the waters, generally of largely natural occurrence”. investigation required will vary, depending on prior These include fresh, estuarine and marine waters. Guidelines for Environmental Management 1 RISK-BASED ASSESSMENT OF ECOSYSTEM PROTECTION IN AMBIENT WATERS knowledge and/or investigations of the system, the While no strict definition has been used in the SEPP potential scale of the impact, the immediacy and (WoV), the interpretation of risk should encompass acceptability of the risk, and the degree to which a all the elements and intent of the above definitions. particular waterbody has been impacted by previous In simple terms, risk can be considered to be the activities. probability (likelihood) of an adverse outcome or event. 2. RISK-BASED ASSESSMENT Qualitative risk assessment can be an important tool in decision-making as it provides a good basis In general terms, a risk can be understood to be the for developing an understanding of the problem and likelihood of an undesirable effect occurring due to the desired outcomes. However, qualitative analysis a hazard (a situation, event or substance that can of risk is based on subjective assessments of the become harmful). Risk has been variously defined likelihood and consequences of the hazards. That as: is, perception of risk, cultural, personal and • “a statistical concept defined as the expected professional values, and past experiences all likelihood or probability of undesirable effects influence the risk assessment. As a consequence, it resulting from a specified exposure to known or should be recognised that these estimates of risk potential environmental concentrations of a represent views or opinions for which there are likely material. A material is considered safe if the to