Risk-Based Pipework Integrity Programme for the Victorian Desalination Plant

Overview

The Victorian Desalination Plant, operated by Watersure, is one of Australia's most significant water infrastructure assets. Located in Wonthaggi, the plant has a capacity of up to 150 gigalitres per year and plays a critical role in securing Melbourne's water supply. The facility features an extensive network of complex pipework systems spanning pretreatment, reverse osmosis, potabilisation, and brine concentration processes, constructed from diverse materials including super duplex stainless steel, GRP, and carbon steel.

Watersure engaged SAS Asset Management to develop a risk-based management framework for the plant's pipework assets. With the plant having been operational since practical completion in December 2012 and piping system failures already costing in the order of $9 million, the need for a structured, proactive approach to managing pipework integrity was clear.

The Challenge

Managing pipework across a large-scale desalination plant presents unique challenges. The Victorian Desalination Plant operates under a Public-Private Partnership (PPP) contract that includes specific residual design life requirements at contract close, representing one of the most significant financial risks to the operator. Without a robust understanding of asset condition and remaining life, Watersure could not effectively link condition data to replacement and refurbishment plans.

Key challenges included:

• Insufficient condition inspection activities to effectively manage the assets and understand their state of degradation.
• Pipework being treated as individual spools rather than integrated systems, preventing a holistic approach to management.
• Prioritisation failures that continued to block meaningful progress on a structured inspection programme.
• A need to align existing risk management frameworks with the requirements of AS3788 (Pressure Equipment - In Service Inspection) for risk-based inspection.
• Multiple piping material types, each with distinct failure modes and degradation mechanisms, requiring tailored assessment approaches.

Our Approach

Meta-Industry Review

SAS-AM commenced with an extensive review of Watersure's contractual requirements and broader industry practices to inform the recommended approach. This meta-industry study encompassed a literature review of pipework management standards, a review of risk management frameworks used across comparable industries (oil and gas, petrochemical, power generation), and an assessment of future risk-based management framework options suitable for the desalination context.

Our review confirmed clear alignment between Watersure's contractual requirements and their management system, while identifying that integrating an AS3788 Risk-Based Inspection Framework into existing processes would provide the robust, structured approach needed to understand asset condition and inform maintenance, replacement, and refurbishment decisions in line with global best practice.

Risk-Based Management Framework Development

Following the meta-industry review, SAS-AM developed a pilot Risk-Based Management Framework (RBMF) using the 1st pass reverse osmosis high-pressure super duplex pipework system as the test case. This system was universally agreed to be the ideal starting point given its criticality and known history of delivery defects.

The framework development followed a structured seven-step process:

• Definition of the management framework - Establishing the processes, procedures, and documentation required to manage pipework risk.
• Failure modes and detectability assessment - Identifying all potential failure modes for each pipe system and assessing the ability to detect them.
• Threat assessment - Evaluating the threats that could lead to pipe failure events, including corrosion, fatigue, and design-related issues.
• Impact assessment - Assessing the consequences of pipe failure across safety, environmental, operational, and financial dimensions.
• Modelling, simulation, and optimisation of controls - Determining the optimal mix of condition monitoring, preventative, and reactive controls.
• Management plan development and pilot programme - Creating actionable inspection and maintenance plans.
• Refinement and adoption - Post-pilot review to refine the process before rolling out across remaining systems.

Pipework Condition Assessment and Management Process

SAS-AM developed a comprehensive Pipework Condition Assessment and Management Process (CAMP) that shifted Watersure's approach from managing pipework as individual spools to managing integrated systems. This included developing a visual pipework system model of the entire plant, creating a functional system structure proposal for the Hexagon EAM system, and establishing a prioritised approach to systematically assessing all pipe systems.

EAM System Integration

A key deliverable was the design of an implementation plan for incorporating the risk-based inspection framework into Watersure's Hexagon enterprise asset management (EAM) system. This ensured that risk assessments, inspection programmes, and condition data would be captured and managed within the existing operational systems rather than sitting in standalone documents.

Results

Structured Risk-Based Framework

Watersure now has a robust, AS3788-aligned risk-based inspection framework that provides a systematic way of understanding asset condition across all pipework systems. The framework integrates with existing Watersure risk management processes while incorporating the specific requirements of pressure equipment inspection standards.

Improved Pipework System Understanding

The development of a whole-of-plant visual pipework system model and functional system structure has given Watersure a comprehensive view of their pipework assets. This enables both technical and non-technical stakeholders to understand the relationships between systems and prioritise management activities accordingly.

Proactive Risk Management

By linking condition inspection activities directly to replacement and refurbishment plans, Watersure can now optimise value for money while meeting the residual design life requirements of their PPP contract. The framework ensures that inspection effort is directed where risk is highest, rather than applying blanket inspection regimes across all assets.

Scalable Methodology

The pilot-first approach, starting with the RO 1st Pass super duplex system, demonstrated the methodology's effectiveness and allowed refinement before broader rollout. Post-pilot economies of scale mean that each subsequent system assessment requires progressively less effort to deliver, making the programme commercially sustainable across the full pipework portfolio.

Why This Engagement Matters

Australia's desalination infrastructure represents billions of dollars in public investment and plays a vital role in water security for millions of people. Managing these assets effectively requires more than routine maintenance - it demands a structured, risk-informed approach that considers the full spectrum of degradation mechanisms, operational contexts, and contractual obligations.

At SAS-AM, we bring deep experience in risk-based asset management across critical infrastructure sectors. This engagement demonstrates our ability to translate complex industry standards into practical, implementable frameworks that deliver real value for asset operators and, ultimately, for the communities that depend on the services these assets provide.